Final Environmental Impact Statement for the Tank Waste Remediation System, Hanford Site,

L.5.0 ENVIRONMENTAL CONSEQUENCES

L.5.1 GEOLOGY

No comments were submitted for this section.

L.5.2 WATER RESOURCES

Comment Number 0089.23

Nez Perce Tribe ERWM

Comment Page 5-15, Paragraph 2

The use of 1979 sitewide groundwater level measurements may not be a conservative approach to risk assessment as the groundwater mound at B pond forms a hydraulic barrier which delays and deflects tank wastes in the groundwater from traveling directly towards the Columbia River.

Response Please refer to the response to Comment numbers 0012.16 and 0072.259.

Comment Number 0091.01

Dyson, Jessica

Comment This new data showing contamination dangerously close to our groundwater would not even been told to us at this point if it was left up to the Department of Energy. This is vital information for the public to have and it does have significant impacts on the public. Almost all of our agriculture in Washington comes from eastern Washington and most of the land surrounding the Columbia River is irrigated with the rivers water. Any radiation in the groundwater will make it to the river and possibly to our dinner tables. It is your responsibility to account for all the risks to the public and be as conservative in your assumptions as possible to protect our communities.

Response DOE and Ecology are equally concerned about protecting the groundwater resources. The Draft EIS, in Volume One, Section 4.2 and Volume Five, Appendix I, documented that contaminants were present in the vadose zone beneath the tank farms and that one source of the contamination was past tank leaks. In Volume One, Section 3.3 the Draft EIS stated that new data were emerging that indicated contamination at lower levels than previously estimated. The new and emerging data are, in many cases, preliminary in that they indicate the presence of contamination beneath the tanks but do not provide any explanation on how they were transported. Potential contaminant transport mechanisms including chemically enhanced mobility of contaminants, preferential pathways (natural and man-made), and the effect of large liquid loss (as compared to the predicted losses for the TWRS remediation) were evaluated as part of the uncertainty analysis in Volume Five, Appendix K. This emerging information as well as future information that are being collected will be addressed by NEPA analysis for tank closure to ensure that the groundwater and Columbia River are adequately protected. The alternatives presented represent a full range of potential actions. The EIS incorporates "bounding" assumptions designed to result in conservative calculations of impacts. DOE and Ecology remain committed to selecting an alternative that will protect the valuable resources, which include the Columbia River, the groundwater beneath the tank farms and food sources produced in Eastern Washington. The preferred alternative would be protective of the groundwater and limit future contaminants from TWRS sources to well below drinking water standards in the Columbia River. An evaluation of potential Columbia River impact due to release of all tank waste is provided in Volume One, Section 5.2 and indicates that even for a large release, drinking water standards would not be exceeded. The preferred alternatives would release only about 1/100th of the waste and the rate of release would be slowed due to the infiltration-limiting cap over the tanks. Please refer to the response to Comment number 0030.02.

L.5.3 AIR QUALITY

Comment Number 0072.28

CTUIR

Comment The emission estimates were not documented.

Response Emission estimates were provided in the Engineering Data Packages for the various alternatives, which are available for public review in DOE Reading Rooms and Information Repositories. Emission rates were calculated from these emission estimates using the construction and operating schedules presented in the packages. The resulting emission rates are presented in Volume Five, Appendix G. Emission calculations in tons emitted for each constituent are contained in the references shown in Volume Five, Appendix G. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.29

CTUIR

Comment No onsite receptors were evaluated and no risks were calculated.

Response Onsite receptors were evaluated and risks were calculated in Volume One, Section 5.11 and Volume Three, Sections D.4, D.5, and D.6 of the Draft EIS in Volume Three, Appendix D. A rectangular grid of 834 receptors, which encompasses the entire Hanford Site, was used to evaluate potential air impacts onsite. The risk associated with potential air impacts, along with those from other media evaluated (groundwater and soil), was calculated for each exposure scenario evaluated and presented in Volume Three, Appendix D. Risk contour maps are presented in Volume Three, Section D.5 of the Final EIS.

Comment Number 0072.30

CTUIR

Comment Only a small subset of released constituents were modeled.

Response The pollutants presented in Volume One, Section 5.13 represent a small subset of the pollutants modeled. The results presented were for the pollutants that contributed to impacts. The complete list of pollutants and the modeling results are located in Volume Five, Appendix G. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.31

CTUIR

Comment There was no recognition that tank farms are only part of the annual Hanford dose; some apportionment is needed.

Response In Volume One, Section 2.0, Purpose and Need for Action, it is stipulated that this EIS addresses Hanford Site tank waste and encapsulated cesium and strontium to reduce existing and potential future risk to the public, Site workers, and the environment. An assessment of the contamination at the entire Hanford facility (Sitewide assessment) would facilitate apportionment of the contribution of TWRS. The Sitewide assessment is not within the scope of this document; consequently, no apportionment is presented. However, Volume One, Section 5.13 does address potential cumulative impacts of TWRS alternative emissions with emissions from ongoing and reasonably foreseeable activities. Please refer to the response to Comment number 0072.243. Because the information requested in the comment was included in the Draft EIS to the extent appropriate for the TWRS analysis, no modification to the document is warranted.

Comment Number 0072.32

CTUIR

Comment Particulate deposition should be included, since this is part of the annual NESHAPs reporting requirement.

Response The inclusion of particulate deposition in air emission modeling would reduce airborne concentrations and thus minimize offsite impacts. Ignoring the effect of particulate deposition results in a conservative estimate of air emission impacts. Particulate deposition was accounted for in the determination of anticipated risks to the general public due to ingestion of vegetation, meat, and milk contaminated by airborne deposition, as discussed in Volume Three, Appendix D. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.239

CTUIR

Comment P G-2: Sect. G.2.1: It is not clear whether fugitive emissions are included in the Area Sources. The relation between Stack/Fugitive-Area and Normal/Unplanned releases (per NESHAPs) should be made clearer. Are the stack numbers the same as those reported in the annual NESHAPs report? Is there a 1:1 correspondence between all the sources in the EIS and the NESHAPs reports? Please clarify the regulatory framework. For each source, please add the anticipated duration of operation or emission for the various alternatives (also add columns to the tables after the emission rate columns).

Response This comment contains six sections, each with its separate explanations. For clarity, each explanation has been given a number.

When fugitive emissions are included in the Area Sources, the text of the EIS points this fact out. In the Draft EIS, Volume Five, Section G.2.1, the following area sources associated with fugitive emissions are specifically called out: Waste Retrieval Annexes Areas, page G-3; and Process Facilities and Tank Farm Construction, page G-5.
All emissions are considered under National Emissions Standards for Hazardous Pollutants (NESHAPs) regardless of their source. There is no relation between Stack/Fugitive-Area and Normal/Unplanned releases, because all contribute to the emissions from the Hanford Site.
Because the stack designations used in the EIS are for air modeling and environmental planning purposes and have therefore not been constructed, they will not be found in the annual NESHAPs report.
The sources in the EIS are of a conceptual nature. The exact sources that will be active during construction and operation would be determined during final design. Consequently, there is no correspondence between the sources in the EIS and the NESHAPs reports.
The regulatory framework of the EIS is explained in detail in Volume One, Section 6.0. In particular, the relevant environmental requirements are detailed in Volume One, Section 6.1.
The anticipated durations of the construction and operating phases for each alternative are shown by alternative in Volume Five, Section G.2.2, Model Scenarios.

Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.240

CTUIR

Comment P G-13: Sect. G.3.1.2: Please forward information regarding particle sizes, Ranges, densities, and deposition rates for this section. This information was not in the tables referenced. Additionally filter failure rates should also be included.

Response A study conducted on cooling towers (Wistrom and Ovard 1973) shows the size of particulate matter (PM) emitted from cooling towers to range from 20 µm to 2,400 µm. Particles larger than 450 µm settle out within 400 feet from the tower. Approximately 30 percent of tower emissions are less than 450 µm and may drift offsite. These particulates will decrease in size as the water drop evaporates.

Particulate matter nominally 10 micrometers (µm) or less (PM-10) emissions associated with construction mainly are due to engine exhaust and fugitive dust. AP-42 Table C.2-2 (Wistrom and Ovand 1973) shows that 95 percent of PM due to engine combustion is smaller than 10 µm and 90 percent is smaller than 2.5 µm. Fugitive dust emissions tend to be smaller than 30 µm with 20 to 40 percent less than 10 µm, depending on source.

Radiological PM emissions emitted from HEPA air filters will be much smaller than 10 µm. The term HEPA was designated by the U.S. Atomic Energy Commission for filters that are at least 99.97 percent efficient by volume on 0.3 µm particles (Austin and Timmermann 1965). A control efficiency of 99.95 percent per filter was assumed in the Engineering Design Packages, which are cited in the EIS and available for reviews in DOE Reading Rooms and Information Repositories. Particle size data, densities, and deposition rates from the various emission sources are currently not available.

Comment Number 0072.241

CTUIR

Comment P G-13: PP 3: What are the filter failure rates for the tank farms and the WESF?

Response WSRC-TR-93-262 gives a recommended value of 5.0E-07 per hour for failure from rupture under regular operating conditions (4.4E-03 per year). The HEPA filtration systems have monitoring and alarm systems. If the filter plugs or blow out, the differential pressure gives indication. HEPA filter failure accidents are not covered in Volume Five, Appendix G but in Volume Four, Appendix E, Accident Analysis.

Comment Number 0072.242

CTUIR

Comment P G-15: Sect. G.3.1.4: No onsite receptor locations were evaluated. Since parts of the Hanford Site will be accessible to the public well before the 100 year assumed duration of Site-wide institutional controls is up, some on-site receptors should be added. Public dose limits apply to Site visitors as well as to the offsite boundary receptor. The only points of compliance indicated in this section were the Site boundary and the nearest residence. Although this is conventional for NESHAPs reporting, it is unacceptable for this EIS.

Response Sitewide institutional controls are designed to protect the public and restrict public access to areas of the Site that may pose a risk. In deciding which areas may be open to the public, a detailed assessment of potential exposure must be made and compared to the public dose limits then in effect. A discussion of anticipated health effects both during and after remediation may be found in Volume One, Section 5.11. Contour maps of potential health effects from air released during remediation are presented in Volume Four, Appendix E and Volume One, Section 5.11. Please refer to the response Comment number 0072.29.

Comment Number 0072.243

CTUIR

Comment P G-18: PP 2: The NESHAPs citation (40 CFR 61, Subpart H0 applies to the entire Hanford Site as a single source, not to a single program, activity or Area. Therefore, the proper comparison of air modeling results is not to the upper limit of allowed dose, but to a fraction of that limit. NRC uses the term "apportionment" (see, for instance, the WIPP permit) to set limits for individual activities within a larger unit; in the case of WIPP, the storage facility is not allowed to exceed 25 percent of the overall source term. The federal total dose limit for offsite receptors is 100 mrem (all pathways) and 10 mrem (inhalation only). This limits applies to the entire Hanford Site, and the ROD must specify what portion of this limit can be "filled" by TWRS activities. The 1 mrem contour (Phase 2, for instance) occurs in locations where non-rad workers work, and that are outside the bounds of the 200 Area. There is a second impact zone offsite (Ringold area, on the other side of the Columbia River) that will be of concern during actual operations.

Response The 40 CFR 61 Subpart H exposure limit is applied to the Site as a whole. As part of the Hanford Site Air Operating Permit, the annual potential emission from each discharge point has been identified. NESHAPs compliance is based on exposure at the nearest actual residence. Inhalation pathway exposure for the nearest resident for the TWRS alternatives ranges from 0.019 to 2.4 mrem/yr as shown in Volume Four, Tables G.4.0.20 to G.4.0.30. For 1994, the nearest resident received 0.01 mrem by the inhalation pathway from all Hanford Site emissions (PNL 1995). Assuming the other Site facilities emissions continued at the 0.01-mrem/yr rate, the inhalation pathway exposures for the Site, including the TWRS alternatives, would range from 0.029 to 2.41 mrem/yr (0.019 plus 0.01 mrem/yr to 2.4 plus 0.01 mrem/yr). To be conservative, the TWRS EIS analysis also was performed for hypothetical residences at currently unoccupied locations along the Columbia River and Highway 240. All of these hypothetical residence locations were calculated to be below 1 mrem/yr (10 percent of the 10-mrem/yr NESHAPs) except for the In Situ Vitrification alternative, which was 18.8 mrem/yr at the maximum location. The potential for this exposure could be mitigated by including such measures as continued restriction on location of residences in the subject area.

However, because there are no residences at these hypothetical residence locations, the NESHAPs of 10-mrem/yr would not apply and there would be no exceedance. Volume One, Section 5.13 contains an analysis of the cumulative air quality impacts of the TWRS alternatives and other Site activities. Because the information contained in the Draft EIS is correct, no change to the text was made.

Comment Number 0072.244

CTUIR

Comment P G-36: Table G.3.1.2: No rationale is given for the selection of non-radiological constituents. Please do not refer us to endless other documents - the TWRS EIS is a stand-alone product that will be the sole basis of the ROD. It must provide complete information for evaluation. In particular, the document "Jacobs 1996" that is cited as the basis for the emission estimates is not publicly available, and may not have received any peer review at all. Presenting table after table of emission rates without any explanation is meaningless, and CTUIR cannot accept any results based on such unsupported data.

Response Incorporation of technical data and information by reference is used as a means to limit the volume of the EIS. Referenced supporting technical data, including Jacobs 1996, are publicly available in the Administrative Record and were provided to DOE Reading Rooms and Information Repositories during the Public Comment Period. An independent technical review of the Draft EIS was completed and a copy of this report is available in the TWRS EIS Administrative Record. This independent technical review found that data used in the analyses were derived from valid and fully documented sources that were traceable, and models used to predict impact analyses either were EPA-approved or accepted by experts as fundamentally sound.

Non-radiological constituents and emission rates for current operations (including the No Action alternative) at the tank farm were derived from the Hanford Site Air Operating Permit Application, which covers existing tank farms and evaporator operation. The selection of non-radiological constituents was based on measured emissions from monitoring instrumentation or tank vapor space sampling results. Constituents and emission rates for waste treatment operations addressed in other alternatives were derived from material balance calculations developed for each alternative.

Comment Number 0072.245

CTUIR

Comment P G-57: Table G.3.1.20: Only 5 radionuclides were used for some of the air modeling. 10 nuclides were used for other alternatives, without any explanation. Various sets of hazardous air pollutants were also used. Since the tank contents do not change between the various alternatives, this is illogical. This entire section must be improved.

Response The tables cited in Volume five, Appendix G provided radionuclide emission rates for the alternatives presented in the EIS. The tables showing five radionuclides were based on radionuclides presently reported by the tank farm operations groups. Because no additional information is available, these radionuclides form the basis for emission rates for alternatives where no activities are performed on the tank contents, (i.e., No Action, Long-Term Management, In Situ Fill and Cap). For the remaining alternatives, there is additional information on radionuclide emissions in the flowsheets contained in the engineering data packages. Where additional information is available, additional radionuclides are shown in the tables for a particular alternative, along with the source (e.g., process plant stack). The hazardous air pollutants referred to in the comment are shown in the preceding tables. The tables for No Action, Long-Term Management, and In Situ Fill and Cap alternatives show the emissions presently reported by the tank farm operations groups. The tables for the remaining alternatives show emissions during construction and operation, which are both taken from the engineering data packages. Construction emissions are those anticipated from use of heavy equipment on the Hanford Site. Operating emissions are those given in the flowsheets in the engineering data packages, which are available for review in DOE Reading Rooms and Information Repositories. Because the information contained in the Draft EIS is correct, no change to the text was made.

Comment Number 0072.246

CTUIR

Comment P G-21: Sect. G.5.3: No description of the presumed filter efficiency (and failure rates), particulate size range and deposition rates were given. Additionally, no consideration whatsoever of the long-term impacts of deposited material (either radiological or nonradiological) was given. If deposition rates had been evaluated, there would have been high impact areas identified (Gable Mountain and White Bluffs). Since federal NESHAPs reporting requires deposition and incorporation into agricultural products as part of the annual dose evaluation, corresponding calculation should be presented in the EIS. If they are not, it will be impossible to demonstrate that any of the alternatives will, in fact, be able to meet compliance limits.

Response Routine emissions are discussed in Volume One, Section G.3.1. HEPA filter efficiency was factored into the emission rates provided in the engineering data packages that support routine emissions. HEPA filter failure accidents are discussed in Volume Four, Appendix E, Accident Analysis. Please refer to the response to Comment number 0072.241.

Dose evaluations from routine emissions are not covered in Volume Five, Appendix G, but are discussed in Volume Three, Appendix D. The intent of Appendix G is to access whether or not the air emissions are in conformance with air quality standards. Please refer to the response to Comment numbers 0072.32, 0072.239, and 0072.240 for related information. Because the information contained in the Draft EIS is correct, no change to the text was made.

Comment Number 0072.247

CTUIR

Comment P G-33: Fig. G.4.0.12: Even without any deposition being included, it is apparent that there are high concentrations at the high elevations on Gable Mountain and Rattlesnake Ridge. This means that tribal members visiting those sites will receive a greater exposure than the general public. Further, more deposition will naturally occur at these higher elevations, thus placing these culturally important areas and the people who visit them at increased risk. This section must be revised and linked to socio-cultural impacts.

Response DOE and Ecology acknowledge the concern regarding potential concentrations of radionuclides on Gable Mountain and Rattlesnake Ridge. Further information on the short-term impacts of air emissions during operation of TWRS facilities is contained in Volume Five, Figures G.4.0.1 through G.4.0.12. At higher elevations, predicted concentrations and dose values could be somewhat greater than in the lower elevations, in the immediate area. For areas near Gable Mountain and Rattlesnake Ridge, predicted radionuclide doses are well below the Washington State Acceptable Source Impact Levels (ASILs) and radionuclide dose limits established by State and Federal standards. It would be reasonable to conclude that, even if the predicted doses are somewhat greater at higher elevations, these doses would not be expected to exceed State or Federal standards. The long-term impacts of remediation on Tribal members are addressed in a separate Native American scenario presented in Volume One, Section 5.11 and Volume Three, Appendix D. For information on this scenario, please refer to the response to Comment numbers 0072.198 and 0072.225 for post-remediation accident impacts.

Comment Number 0072.248

CTUIR

Comment P G-20: Sect. G.5.2.2: No description of the actual vitrification operations was given including temperatures, feed materials, emissions, air pollution control device efficiency, effects of startup, trial melts, upsets, and maximum rated capacity. The recent vitrification event at Savannah River should serve as an indication of anticipated variances in emissions.

Response A description of the vitrification operations is provided in Volume Two, Appendix B and was based on information in the referenced Engineering Data Package, which is available for review in the DOE Reading Rooms and Information Repositories. Please refer to the specific data package for vitrification to obtain the most detailed information available. Emissions are based on design rates for the equipment, which should represent peak emissions. Average operating rates (and emissions) are estimated to be approximately 40 percent of the design rates. The information requested in the comment is a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.249

CTUIR

Comment P G-83: Tables G.4.0.1-19: these Tables seem to have been prepared solely for reporting purposes and have no identifiable relation to dose and risk. Each individual contaminant is compared to a regulatory level, but no other information is presented. The concentrations vary from 1 hour to annual averages, again without explanation as to whether this assumes maximum continuous operation, or something else.

Response As is stipulated in Volume Five, Section G.5.3 (page G-21), these tables were used to screen the potential impacts associated with air contaminants at the Site versus applicable regulatory (State and Federal) levels. The tables compare the modeling results to the Federal and State standards. The maximum 1-hour average concentration that resulted from the modeling was converted to 3-, 8-, and 24-hour average concentrations to compare to applicable standards when appropriate. The 1-hour average concentration was multiplied by 0.9 to obtain the 3-hour average, 0.7 for the 8-hour average, and 0.4 for the 24-hour average (EPA 1992b).

Predicted maximum emissions for hazardous air pollutants and pollutants for which a Washington State ASIL exists are provided along with the applicable level in Tables G.4.0.1 through G.4.0.19. Some of the pollutants evaluated have Washington State ASIL of Federal Standards reported for 1-hour, 3-hour, 8-hour, or 24-hour concentrations. For instance, PM-10 has a Federal and State 1-, and 8-hour standard. Consequently, for carbon monoxide, the 1-hour model predicted concentration was adjusted by multiplying it by 0.7 to obtain an 8-hour concentration. Because the 1-hour concentration can be altered by multiplying it by the appropriate conversion factor; a conservative estimate of the contaminant concentration is available for comparison to the applicable standards. The modeling results for all alternatives show no exceedances of Federal or State air quality standards for criteria pollutants, hazardous air pollutants, or radionuclides. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.250

CTUIR

Comment P G-83: Tables G.4.0.19: Groundshine must be included in the evaluation, with and without an assumption of intervention, and with varying degrees of intervention success.

Response Table G.4.0.19 is not in Volume Five, Appendix G on page G-83 as indicated; it is on page G-105. It is assumed the commentor is to referring to Tables G.4.0.1 to G.4.0.19. Because the constituents presented in Tables G.4.0.1 to G.4.0.19 are not radioactive, these constituents would not contribute to a groundshine pathway. However, Tables G.4.0.20 to G.4.0.30 compare the maximum dose per year from radiological constituents with State air quality standards (the purpose of Volume Five, Appendix G is to measure air emissions against air quality standards). The radiological releases do not exceed the air quality standards so intervention would not be required. The groundshine pathway was included in the evaluation of remediation risk to onsite and offsite receptors. Results of the remediation risk evaluation are presented in Volume Three, Appendix D. These results indicate that the impacts from groundshine are orders of magnitude less than from inhalation. The additive impact from groundshine, therefore, would not change the maximum dose shown in Volume Five, Tables G.4.0.20 to G.4.0.30 and no change to the document is warranted.

Comment Number 0072.251

CTUIR

Comment P G-12 - P G-19: Sects. G.3.0 and G.5.1: This section provides insufficient detail about modeling methods. Exposure assumptions must be presented, as well as assumptions about the particulate size range and respirable fraction used in the dose estimation.

Response The model used for this investigation is the Industrial Source Complex Model (ISC2). The model is a Gaussian dispersion model, which can be used for estimating the concentration of pollutants at a receptor. The model is a guideline air quality model accepted by the EPA for regulatory applications. The assumptions in Gaussian dispersion modeling are as follows.

Pollutant emissions are continuous.
Mass of pollutants released remains in the atmosphere during transfer from the source to the receptor.
Meteorological conditions do not change.
Diffusion in the downwind direction is negligible in comparison to transfer by the wind. Thus diffusion occurs in only the vertical and crosswind directions.
Time averaged concentrations in the crosswind and vertical direction are assumed to be distributed normally.

ISC2 was run using the standard rural dispersion coefficients. Standard EPA procedures were followed and the regulatory default option was used. The options implemented included the following:

Final plume rise that accounts for the effective height of the source of emission;
Buoyancy-induced dispersion that allows for the plume size to increase at the stack exit point;
Default wind profile exponents;
Default potential temperature gradients; and
Upper bound values for building downwash.

The respirable fraction of particulates is assumed to be those with diameter less than or equal to 10 µm (PM-10). Respirable particulates that are greater than 5 µm typically are trapped by hair follicles in the trachea and never reach the lungs.

The risk calculations for each exposure scenario are calculated in Volume Three, Appendix D. For the residential farmer exposure scenario, the exposure parameters for inhalation are as follows:

Inhalation rate - 20	m³
	day

Exposure frequency - 365	day
	yr

Exposure duration =	6 yrs (child)
	24 yrs (adult)

Body weight =

16 kg (child)
70 kg (adult)

Averaging time = 365	day	* 30 yr
	yr

The exposure parameters for each scenario evaluated are presented in Volume Three, Appendix D. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0100.01

WDOH

Comment First, Washington's standard for radioactive air emissions is CAP-88. CAP-88 should be used for the modeling in the EIS.

Response There were several reasons why EPA's preferred radionuclide dose model was not used in this analysis. While portions of the dose calculation methodology of the Clean Air Assessment Package-1988 (CAP-88), as well as other site-specific models such as GENII, may have been incorporated in the risk assessment, the air dispersion algorithms of those models were not. The ISC2 was selected as the general air dispersion model for the following reasons:

ISC2 is a sophisticated model with capabilities comparable to CAP-88, such as the ability to account for a wide spatial separation of many varied source types;
ISC2 is an EPA guideline model, and was the choice for assessing traditional pollutants (e.g., dust and combustion products) and air toxic emissions;
Use of ISC2 for all air dispersion modeling provided for consistency in the EIS; and
A sitewide compliance demonstration with the radiological standards was not the goal of this EIS.

Volume Five, Appendix G contains a comparison of the ISC2 and CAP-88 modeling results and shows that these results compare closely.

Comment Number 0100.02

WDOH

Comment Second, the state standard for total radionuclides is misstated at 25 mrem/yr.

Response The text in Volume Five, Appendix G has been modified to state that the Ambient Air Quality Standard (WAC 173-480) for the maximum accumulated dose equivalent at any offsite receptor from a commercial nuclear facility is 25 mrem/yr. As a Federal facility, the Hanford Site could be expected to comply with the EPA regulation (40 CFR 61), which limits the maximum predicted dose at the nearest residence to 10 mrem/yr dose equivalent.

L.5.4 BIOLOGICAL AND ECOLOGICAL RESOURCES

Comment Number 0019.12

WDFW

Comment Page 5-64, third paragraph, third bullet. Should include "candidate" category as well.

Response The EIS text presents this key issue of the biological and ecological resources impact analysis in the following sentence: "... potential impacts on plant and animal species of concern (those listed or candidates for listing by the Federal government or Washington State as threatened, endangered and sensitive)."

Comment Number 0019.13

WDFW

Comment Page 5-65, section 5.4.1, first paragraph. WDFW believes it is more appropriate to discuss the percent loss of shrub-steppe within the waste management zone (WMA) to emphasize the impacts to shrub-steppe there. Currently, there is approximately 5,800 acres of undisturbed shrub-steppe within the WMA. Impacts to undisturbed shrub-steppe would range up to 6 percent in the WMA from the TWRS alternatives.

Response The EIS was modified in Volume One, Section 5.4 to add the percentage of undisturbed shrub-steppe that potentially would be affected by TWRS EIS alternatives within the waste management area.

Comment Number 0019.14

WDFW

Comment Page 5-67, Table 5.4.1, Phased Implementation (Total). Impacts do not match what is stated elsewhere in the text. 470 acres is stated here. 540 acres (pg. 5-230) and 690 acres (pg. 5-123) are mentioned elsewhere. Please clarify.

Response The EIS was modified to clarify and correct the potentially affected acreages for the Phased Implementation (Total alternative), based on revisions to the Phased Implementation alternative that occurred since publication of the Draft EIS. Volume One, Table 5.4.1 identifies the total amount of shrub-steppe that would be affected. Volume One, Section 5.4 identifies the total amount of land that would be affected, not only the amount of shrub-steppe. Table 5.14.1 has been revised to indicate that shrub-steppe impacts for the Phased Implementation (Total alternative) would be 94 hectares (240 acres) in the 200 Areas and 140 hectares (350 acres) at the potential borrow sites for a total impact of 240 hectares (590 acres). Volume One, Section 5.7 (page 5-123) indicates that approximately 320 hectares (790 acres) would be the total temporary construction-related land use, including both shrub-steppe and non shrub-steppe areas.

Comment Number 0019.15

WDFW

Comment Page 5-71, section 5.4.2, first paragraph. The nesting period should also include a discussion on passerines (sage sparrow, etc.) and that site clearing would avoid the breeding season for these species. These species also receive protection under the Migratory Bird Treaty Act.

Response The EIS has been modified in Volume One, Section 5.4 to include potential impacts on nesting passerine (songbird) species. Mitigation of potential impacts to these species would be described in the Mitigation Action Plan.

Comment Number 0019.16

WDFW

Comment Page 5-75, section 5.4.5, first paragraph. WDFW concurs with the importance of the McGee Ranch as a wildlife corridor for species migration, proliferation, and genetic diversity. Impacts to the McGee Ranch would have a significant adverse affect on wildlife.

Response DOE and Ecology acknowledge the position of the WDFW on McGee Ranch and addressed the wildlife corridor in the Affected Environment discussion in Volume One, Section 4.4 and Volume Five, Appendix I, and potential impacts to the wildlife corridor under each of the alternatives in Volume One, Section 5.4. It is important to note that the TWRS EIS will not support decisions associated with closure of the tanks and it is only under the hypothetical closure option analyzed in the EIS that adverse impacts to McGee Ranch would occur. Thus, no action taken as a result of this EIS would affect species migrations proliferation, or genetic diversity associated with the corridor. Please refer to the response to Comment numbers 0019.03 and 0072.08 for related information on how closure is addressed in the EIS and related impacts on potential borrow sites.

L.5.5 CULTURAL RESOURCES

Comment Number 0089.16

Nez Perce Tribe ERWM

Comment Page I-60, Paragraph 2

It needs to be emphasized that disturbed areas still have potential to contain cultural resources.

Response The EIS has been modified in Volume One, Section 5.5 to indicate that disturbed areas may contain cultural resources that were not identified during the cultural resources survey. This fact is acknowledged by DOE and Ecology and is the reason why the mitigation measures identified in

Volume One, Section 5.20 of the Draft and Final EIS include a commitment to conduct cultural resource surveys, consult with affected Tribal Nations, and mitigate through avoidance whenever feasible.

Comment Number 0101.03

Yakama Indian Nation

Comment In addition we consider that the actions should assure that cultural values of the Yakama Nation, not directly related to public health and safety or the ecological aspects of the environment, should be protected. These other cultural values stem from what could be termed religious beliefs and are associated with the sanctity of the land forms and other natural resources at Hanford.

To accomplish objective establishment of performance bases, i.e., a valid suite of scenarios to be used in the performance assessments, we consider experts knowledgeable in predicting future possible demographic conditions and societal land use patterns, including intruder scenarios, should be utilized. Delphi methods for polling expert opinions on such subjective topics should be employed. YIN representatives should be involved with this activity to assure the demographers, anthropologists, archaeologists, geologists and other experts having the knowledge to anticipate future conditions adequately incorporate scenarios involving Indian usage of the land, the water and the other natural resources, reflecting historical data as warranted. Without the valid determination of such conditions, including those which may occur and would be limiting with respect to the design confidence level, any of the actions described in the subject EIS may be unfounded and not protective of the public health and safety and the environment. In addition, actions justified as a result of the impact assessments may not meet requirements stemming from cultural values discussed above.

Response Please refer to the response to Comment number 0072.149 for a discussion of consultation with Tribal Nations on the TWRS EIS, and Comment numbers 0072.37, 0072.40, 0072.268, 0072.251, and 0072.53 for discussions of changes to the EIS based on Tribal comments on cultural values, cultural sites, and land uses. The discussion of Treaty rights and privileges has been modified in the Final EIS, based on consultation with the affected Tribal Nations, in Volume One, Section 4.4 and Volume Five, Appendix I. The EIS used reference cases, including the Native American subsistence scenario, for comparative purposes to predict unrestricted future land uses beyond the 100-year administrative control period to 10,000 years. These are incorporated into the Native American User Scenario, which is addressed in Volume One, Section 5.11 and Volume Three, Appendix D. For a complete discussion of this issue, refer to the response to Comment number 0072.149. For discussion of how the EIS addresses environmental justice analysis relative to the Tribal Nations, please refer to the response to Comment numbers 0072.271, and 0072.252.

In response to this and other comments by affected Tribal Nations, the risk assessment for the EIS was revised to include an evaluation of anticipated post-remediation risk to a Native American subsistence user of the Hanford Site. Inclusion of a Native American scenario in the Draft EIS was not feasible because a methodology for the assessment had not been developed sufficiently to be incorporated into the Draft EIS. The scenario used for the analysis was developed through consultation with representatives of the affected Tribes and included discussions regarding societal land use patterns, the intruder scenarios, and demographic conditions. Please refer to the response to Comment number 0072.198, which contains a complete discussion of the information included plus a document reference list regarding the addition of a Native American scenario. Please refer to the response to Comment number 0072.225 for a discussion of post-remediation accident impacts to Tribal Nation sacred sites and cultural values.

L.5.6 SOCIOECONOMICS

Comment Number 0072.33

CTUIR

Comment Counting the number of Native Americans living in the 3 nearest counties does not satisfy the Environmental Justice Executive Order or DOE policy.

Response As discussed in the response to Comment number 0072.53, the EIS environmental justice analysis provides demographic data in Volume One, Section 4.6 on Native Americans, as well as low-income and minority populations within an 80-km (50-mi) radius of the Hanford Site Central Plateau. This area includes portions of 10 counties in Washington and Oregon. Volume One, Section 5.19, Environmental Justice, presents a review of all TWRS alternatives' impacts on the natural and human environment that were addressed throughout Volume One, Section 5.0 to determine whether any potentially disproportionate and adverse impacts would occur to the identified minority or low-income populations, including Native American populations. Volume One, Section 5.20 identifies potential mitigation measures that DOE could adopt to address potential environmental justice impacts identified in Section 5.19. Please also refer to the response to Comment numbers 0072.252 and 0072.149.

Comment Number 0072.34

CTUIR

Comment Economic impacts of accidents were not included.

Response The model used to analyze economic impacts incorporates historical data on Tri-Cities socioeconomic conditions to test its results (e.g., the accuracy with which the model, using historical data yields output for past employment that agrees with known past employment levels). The model was then applied to future Hanford Site employment under each alternative to estimate area employment, housing prices, and taxable retail sales. Total area employment estimates were used to estimate impacts on public services. This analysis was presented in Volume One, Section 5.6.

DOE's Recommendations for the Preparation of Environmental Assessments and EISs (DOE 1993d) directs that impacts from low-probability events be analyzed with the amount of detail commensurate with their likelihood of concurrence and potential consequence. The likelihood of an accident under the TWRS alternatives that could affect the local economy is low. Further, there are no historical data for the Tri-Cities that could be used to provide a basis for analyzing potential economic impacts of accidents at the Hanford Site. Volume One, Section 5.6 and Volume Five, Appendix H have been modified to explicitly state that economic impacts of accidents have not been analyzed for post-remediation accident impacts. Please refer to the response to Comment number 0072.225 for a discussion of post-remediation accident impacts on Tribal Nation sacred sites and cultural resources and modifications to Volume Four, Appendix E regarding this issue.

Comment Number 0072.35

CTUIR

Comment No costs for storage, mitigation or disposal were included

Response An econometrics model was used for the economic impact analysis in the EIS to assess the impacts of TWRS alternatives. Hanford Site employment is used in the model as the key independent variable, and then equations based on historical data for the Tri-Cities area, are used to forecast the impacts of changes in future Site employment on socioeconomic conditions (e.g., total nonfarm employment, housing prices). Employment associated with TWRS activities such as waste storage and disposal is included in the analysis; thus, the costs of storage and disposal are included indirectly in the socioeconomic analysis. The direct costs of storage and disposal under each alternative are provided in Volume One, Section 3.0 and Volume Two, Appendix B. Please refer to the response Comment number 0072.225 for a discussion of the impact of mitigation of post-remediation accidents. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.36

CTUIR

Comment Jobs and housing as the only socioeconomic measures is unsatisfactory.

Response In addition to jobs and housing, the EIS socioeconomic impact analysis includes impacts on taxable retail sales, population, and a wide range of public facilities and services, including schools, police and fire services, medical services, solid and sanitary waste disposal systems and electricity and natural gas energy services in Volume One, Section 5.6 and Volume Five, Appendix H. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.252

CTUIR

Comment P H-1: Sect H.1.0: The topics covered in this section include the impact on local jobs, impact on the Tri-Party Agreement Milestone schedule, and impacts on demographics, housing prices and similar items. Therefore, we would expect to also see a full treatment of community and tribal quality of life, and intra- and intergenerational equity. This is, in fact, the intent of NEPA and is required under Executive Order 12898. We are aware that scoping discussions pertaining to this type of analysis were held with contractors and Headquarters personnel, yet it is entirely omitted from the Draft EIS.

Executive Order 12898 and DOE Environmental Justice Policy. The Executive Order states that the human health and environment of minority populations must be evaluated, including differential patterns of consumption, social and economic impacts, and whether there is a disproportionate burden of exposures and/or risks on these populations. DOEs Environmental Justice Strategy includes provisions for identifying high risk populations (including subsistence consumption patterns), and for identifying DOE activities that might have a disproportionately high human health or environmental effects on minority populations. This goes far beyond merely counting the number of Native Americans in the three Hanford counties. CTUIR expects DOE to consult with technical staff in order to ensure that adverse impacts on a traditional subsistence lifestyle and characterization of populations at highest risk are adequately evaluated for the baseline conditions and for each alternative for as long into the future as the contamination or post-remediation conditions persist.. The DOE Strategy also directs programs to "encourage ... participation [of American Indian Tribes] in the development of NEPA documents." Since a typical simple "scoping" briefing does not satisfy this directive, and since many of the deficiencies of this EIS could have been anticipated and corrected before publication of the Draft EIS, CTUIR further expects DOE to proceed with the revision of the EIS and negotiation of the Record of Decision to genuinely include CTUIR as an equal participant in the decision-negotiation process and in the development of mitigation action plans.

Response Volume One, Section 5.19 was devoted to a summary of the environmental justice analysis included in the EIS. Volume Five, Appendix H is intended describe the analysis of the socioeconomic impacts of the TWRS EIS alternatives. A summary of this impact analysis is presented in Volume One, Section 5.6. The impacts of the alternatives on other aspects of the human and natural environment are presented in Volume One, Section 5.0 (e.g., air, water, human health, and land use).

The environmental justice requirement states that the environmental justice analysis should be completed to the "extent practicable and appropriate" (EO 12898). In developing the data to support the analysis, the Executive Order instructs agencies to "collect, maintain, and analyze information on the race, national origin, income level, and other readily accessible and appropriate information for areas surrounding facilities or sites expected to have substantial environmental, human health, or economic effect on the surrounding populations." This information is to be used to determine if "programs, policies, and activities have disproportionately high and adverse human health or environmental effects on minority populations and low-income populations."

The Executive Order mandate to collect data that are readily available on the area surrounding the site likely to be impacted by a proposed action and to analyze impacts that may have disproportionately high and adverse effects on minority and low-income populations is consistent with NEPA requirements. NEPA requires that a sliding scale be applied to analysis of potential impacts on the human and natural environment. "The sliding scale approach to NEPA analysis recognizes that agency proposals can be characterized as falling somewhere on a continuum with respect to environmental impacts. This approach embodies instruction that CEQ has provided (40 CFR 1502.1 and 1502.2, for example) with respect to preparation of EISs. The term 'scale' refers to the spectrum of significance of environmental impact. Do not attempt to quantify impacts on environmental resources when it is clear form the context that any impacts would be virtually absent" (DOE 1993d).

For the purposes of complying with the environmental justice and NEPA requirements, the TWRS EIS adopted the following approach to analysis of potential impacts to minority and low-income populations. The data presented in Volume One, Section 4.0 and Volume Five, Appendix I support the environmental justice analysis by describing the affected environment, including potentially affected populations. Consistent with Executive Order 12898 requirements, Section 4.6 and Appendix I identify minority and low-income populations that may be impacted by the proposed action. The second NEPA requirement is to determine the potential impacts of the EIS alternatives on the affected environment. The analysis of potential impacts to the affected environment is presented in Volume One, Section 5.0. This analysis considers the potential impacts on all populations and if an impact would adversely and disproportionately impact minority or low-income populations, the impact was identified.

Based on the analysis of potential impacts to the human and natural environment, the environmental justice initiative requires the agency to determine if any of the impacts would pose a disproportionately high and adverse impact on minority and low-income populations. This analysis is presented in Volume One, Section 5.19. For each area of potential impact (e.g., land use, human health, air quality, water quality) impacts presented in Volume One, Section 5.0 were reviewed to determine if there were any potential disproportionate and adverse impacts to the surrounding populations. If an adverse impact was identified, a determination was made as to whether minority or low-income populations would be disproportionately affected. In the Draft EIS, two potential impacts were identified that would present a concern based on the requirements of the environmental justice initiative. The analysis of the impacts for the Final EIS have been reviewed based on comments and consultation with Tribal Nations. The result of this review has been a modification to the text of Volume One, Section 5.19 to indicate that under all of the alternatives, except No Action and Long-Term Management, certain adverse impacts to sacred sites would occur.

The final requirement of the environmental justice initiative is to mitigate any disproportionate and adverse impacts. In the EIS, mitigation measures that address the environmental justice impacts are addressed in Volume One, Section 5.20. Based on the decision documented in the ROD, DOE will prepare a Mitigation Action Plan, which will document mitigation measures to be implemented

For the Draft EIS, the analysis of human health impacts determined that minority and low-income populations would not be disproportionately and adversely impacted by TWRS actions compared to non-minority and non-low-income populations. However, one area of potential differential impacts could not be fully analyzed in the Draft EIS. This area of potential impacts, long-term risks to human health under a Native American Subsistence scenario, could not be incorporated into the Draft EIS because a methodology for the analysis had not been developed to a level sufficient to support incorporation into the EIS. Subsequent to publication of the Draft EIS, a Native American subsistence scenario has been developed for use on the Hanford Site. Following consultation with affected Tribal Nations, this scenario has been incorporated into the Final EIS. This analysis is presented in Volume Three, Appendix D and summarized in Volume One, Section 5.11. For discussion of consultations with Tribal Nations, please refer to the response to Comment number 0072.149.

Throughout the NEPA process, DOE and Ecology have been proactive in consulting with the affected Tribal Nations regarding the content of the TWRS EIS. Many substantive portions of the Draft EIS were the result of consultation with affected tribes from scoping to the publication of the Draft EIS; just as many of the changes in the Final EIS reflect consultation that has occurred since the Draft EIS was issued for comment. Consultation is a valuable part of the NEPA process. As with any intergovernmental relationship, DOE and Ecology understand that the consultation process requires improvement and will continue to work with the affected Tribal Nations to that end. A proactive consultation process results in the meaningful exchange of technical information between both parties and a shared understanding of the challenges, issues, and concerns that the agencies and Tribal Nations face as they work to improve the environment of the Hanford Site. Please also refer to the response to Comment numbers 0072.53 and 0072.271 for related discussions. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.253

CTUIR

Comment P H-2: Sect H.1.1: This section deals solely with Hanford employment numbers. We would also expect to see baseline information about local services (for example, school attendance and student-teacher ratios; number of emergency and enforcement personnel per capita, and so on). Various economic impact analysis methods, such as economic base models, econometrics analysis, or input/output models, would require some of this data.

Response Baseline data about local services (e.g., schools, police, and fire services) are provided in Volume Five, Appendix I (Affected Environment), rather than Volume Five, Appendix H (Socioeconomic Impact Modeling). The model used in the EIS uses the historical statistical relationship between Hanford Site employment and other socioeconomic factors (i.e., total nonfarm employment, population, and housing prices) to predict the effects of the TWRS alternatives employment on total nonfarm employment, population, and housing prices. Changes in Hanford Site employment drive the changes in these other socioeconomic aspects of the Tri-Cities area. The model outputs, in terms of future population changes, then were used to assess the TWRS alternatives potential impacts on school enrollments, police and fire services, and other local services. The assessment of impacts on these services was performed by evaluating how the additional TWRS demands on the service systems would affect their ability to meet the total demand (non-TWRS related demands plus TWRS-related demands). This element of the assessment did not involve using the socioeconomic impact model. Please refer to the response to Comment number 0072.36.

Comment Number 0072.254

CTUIR

Comment P H-4: Sect. H.2.0: No documentation for the 2.4 multiplier (2.4. non-Hanford jobs created/lost for each Hanford job) is provided. Various estimates have been used by local civic planners.

Response The socioeconomic impact assessment model uses the historical statistical relationship between Hanford Site employment and total Tri-Cities nonfarm employment as the basis for predicting how changes in future Site employment would affect total area nonfarm employment. The analysis of historical data shows a relationship of approximately 2.4 non-Hanford jobs created/lost (for each Hanford job). This 2.4 multiplier is in reasonably close agreement with employment multipliers used in other Site NEPA analysis. For example, the Final SIS EIS used an employment multiplier of 2.2, based on socioeconomic input/output analysis performed by PNL in 1987 and 1991 (DOE 1995i). The socioeconomic model used for the TWRS EIS also was used for another recent Hanford NEPA document, the HRA EIS. The socioeconomic model used in the TWRS EIS is the most recent model specifically designed to analyze the Tri-Cities economy and incorporated the most recent data available at the time the Draft EIS was prepared.

Comment Number 0072.255

CTUIR

Comment P H-6: Sect. H.2.3: There needs to be identification of the age distribution was used, only total population seems to be here.

Response The socioeconomic impact assessment model utilizes and predicts total population only. The model does not utilize or predict age distribution of the local population. Age distribution modeling would have limited utility in analyzing the relative difference in impacts among the alternatives. For the purpose of this EIS, the only socioeconomic indicator reliant on age distribution in the population would be the impact to public schools in the Tri-Cities area. For this analysis, it was assumed that the age distribution in the future population under each alternative would be the same as the present age distribution (Volume One, Section 5.6). The information requested in the comment is a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.256

CTUIR

Comment P H-7: Sect H.2.4: This section needs to be edited to count for accident impacts.

Response The socioeconomic impact assessment model and methodology used for this EIS does not incorporate possible economic impacts of potential accidents. Language has been added to Volume One, Section 5.6 and Volume Five, Appendix H.2.4 to inform the reader that the economic impact analysis does not address potential impacts associated with accidents. The probability of an accident that would have major economic impacts is extremely low, as described in Volume One, Section 5.12 and Volume Four, Appendix E. Please refer to the response to Comment number 0072.225 for a discussion of post-remediation accident impact on Tribal Nation sacred sties and cultural resources. Please also refer to the response to Comment number 0072.34 for a discussion of economic impacts caused by accidents.

Comment Number 0072.257

CTUIR

Comment P H-7: Sect H.3.0: Same comment as above. (See Comment number 0072.256.)

Response Please refer to the response to Comment number 0072.256, 0072.34, and 0072.225.

L.5.7 LAND USE

Comment Number 0036.18

HEAL (Exhibit)

Comment EIS does not deal with most important aspect of permanent land-use commitments.

According to the EIS, there are no potential implications for future land use that need to be dealt with in this EIS. This is because the EIS does not include closure decisions, and Hanford's land use plan is not done. According to the EIS, "No exclusion or restricted use zones have been defined, but this type of land-use issue is expected to be addressed in the land use planning process for the Hanford Site that is currently underway" (p. 5-121). This is a cop-out. The decisions that will be made in this EIS have clear, far-reaching, and critical future land use implications.

The alternatives leave behind waste resulting in risks for future generations that are between significant and downright scary. Some of the alternatives result in risks that absolutely mandate land use restrictions. Potential land use restrictions are a real and important aspect of determining an alternative's impacts.

By limiting the land use commitments to essentially the amount of shrub-steppe that is torn up, the agencies ignore the important health and economic aspects of potential future land use restrictions. In dealing with deadly tank wastes, a few acres of shrub-steppe is nothing compared to keeping Hanford off-limits forever.

Response Volume One, Section 5.7 addresses three distinct land-use implications of the TWRS alternatives. These include permanent land use commitments in the 200 Areas associated with the remedial activities addressed in the EIS, permanent land use commitments in the 200 Areas associated with the potential closure scenario included in the EIS to support a comparative analysis of the alternatives, and land use commitment implications outside the 200 Areas associated with the remedial activities and potential closure scenario.

The impact analysis for commitments in the 200 Areas associated with remedial activities concluded "Temporary and permanent proposed land use commitments for remedial activities under all TWRS EIS alternatives would be consistent with past and existing land uses for the 200 Areas, as well as with proposed use of the area as an exclusive-use waste management area." These land use commitments would range from 0 to 99 acres according to which alternative was implemented and would largely consist of the tank farms and LAW disposal vaults.

For permanent land use commitments associated with the potential closure scenario presented in the EIS, the EIS concluded that land use commitments would include, "the areas that would be covered by the Hanford Barriers under all alternatives except No Action and Long-Term Management." These land use commitments would require approximately an additional 20 to 40 acres beyond those committed under that remedial phase of the implemented alternative.

For land use implications outside the 200 Areas, the EIS indicates that "Groundwater contamination has land use implications. While land uses might not be precluded because of underlying groundwater contamination, the value of land for potential future uses such as agriculture could be diminished or restricted because the underlying groundwater could not be used. Under all EIS alternatives, TWRS activities would contribute to future Site groundwater contamination."

The EIS also states that "No exclusion or restricted use zones have been defined, but this type of land use issue is expected to be addressed in the land use planning process for the Hanford Site that is currently underway." This land use planning process, the CLUP, would consider the implications of the impacts of the TWRS alternatives in the identification of land areas requiring exclusive and/or restricted use. Thus, the information provided in the EIS is a critical part of the land use planning process and provides an important basis for future decisions. When considering the impacts of land use options associated with the TWRS alternatives, land use planners will have available for consideration an extensive amount of information regarding risks to future generations under various land use scenarios. The EIS analyzes health risks associated with alternative land uses in Volume One, Section 5.11 and Volume Three, Appendix D, including residential farmer, industrial worker, and shoreline recreational user. Since the publication of the Draft EIS, a Native American subsistence user scenario has been added to the analysis. For more information on this scenario, please refer to the response to Comment number 0072.198. The EIS also provides information regarding the implications for the waste site intruder or residential farmer who uses waste site drilling spoils site. Finally, the EIS provides data regarding the extent of groundwater contamination that potentially could result from each alternative. All risks and impacts analyzed were extended to 10,000 years into the future.

The EIS does not limit the analysis of land use commitments to "essentially the amount of shrub-steppe that is torn up." None of the land use impacts identified are based on shrub-steppe disturbance as a criteria for determining land use impacts. Rather, for temporary land use commitments, the EIS does identify the amount of land that is not currently disturbed within the 200 Areas that would be needed to support "construction and operating the alternatives and construction activities associated with closure." This land would be unavailable for alternative uses during the period of construction or operations and then after construction or operations was completed. Permanent land use commits land used for waste disposal facilities to permanent waste disposal. These areas become unavailable for alternative uses. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

L.5.8 VISUAL RESOURCES

No comments were submitted for this topic.

L.5.9 NOISE

No comments were submitted for this topic.

L.5.10 TRANSPORTATION

No comments were submitted for this topic.

L.5.11 ANTICIPATED HEALTH EFFECTS

Comment Number 0005.16

Swanson, John L.

Comment I would like to see the cancer risk estimates presented in the context of comparison with the cancer risk to the involved population due to background radiation and to other "naturally" occurring cancers. I would also be interested in seeing estimated values of something like "dollars per cancer prevented" for the alternatives.

Response The context requested by the comment is presented in Volume One, Sections 4.11 and 5.11, which discuss the effects of radiation on humans, including the cancer risk from exposure to natural or background radiation sources. DOE and Ecology believe that presenting estimates such as dollars per cancer prevented would be inappropriate because such estimates could be construed as a value judgment. The purpose of the EIS is to provide decision makers and stakeholders with a balanced, unbiased assessment of the impacts associated with the alternatives.

Comment Number 0072.197

CTUIR

Comment P D-2: Table D.1.0.1: The first bullet in the post remediation risk is unacceptable because closure was addressed within earlier sections, and the leakage is tank waste leakage, not some other form or source of leakage.

Response The existing contaminants from past practice are not in the scope of this EIS. The impact of closure is not evaluated for this EIS. DOE will conduct an appropriate NEPA review in the future (59 FR 4052). For purposes of comparing the alternatives, a single and consistent method of closure, closure as a landfill, was assumed for all alternatives. This does not mean that closure as a landfill is proposed or necessarily would be selected in the future. Volume One, Section 3.3.1 discusses the closure issue in greater detail. The leakage of tank waste during the remediation is considered in the risk assessment in this EIS. Past tank waste leaks are considered in the analysis of cumulative impacts presented in Volume One, Section 5.13 and Volume Four, Appendix F. For additional information on the relationship between closure and this EIS, please refer to Comment numbers 0072.08 and 0101.06 for discussions of the closure issue and 0030.02, 0091.01, and 0012.15 for a discussion of vadose zone contamination. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.198

CTUIR

Comment P D-12: Sect. 2.1.3: Please insert a subsistence Native American scenario into this section. The subsistence Native American scenario represents a Native American living on the land subsisting from all the natural resources inherent on the Hanford site. This scenario involves complete acts or activities, is assumed to have access to ground water and is assumed to live anywhere on the site or anywhere along the Columbia River.

Response In consultation with the affected Tribes, a Native American scenario has been developed and used to evaluate the post-remediation risk to a Native American user of the Hanford Site. This scenario represents exposures received during a 70-year lifetime by a Native American living on the land and subsisting on its inherent natural resources. Subsistence activities included in this scenario include hunting, fishing, and gathering of plants and materials. Pathways include those defined for the residential farmer scenario in the Hanford Site Risk Assessment Methodology (HSRAM) (DOE 1995c), plus additional pathways, such as sweat bathing, which represent activities unique to the Native American subsistence lifestyle. The ingestion rates of native foods are based on a combination of EPA-suggested intake rates (EPA 1989b), intake rates used for the Native American scenarios in the Columbia River Comprehensive Impact Assessment (Napier et al. 1996), and data obtained through consultation with the affected Tribes. A complete description of the Native American exposure scenario and the method for its evaluation have been added to Volume Three (Appendix D, Section D.2.1). Results of the post-remediation risk calculations for the Native American scenario have been added to Volume Three (Appendix D, Section D.5.0). A summary of the scenario description and the risk results have also been added to Volume One (Section 5.11.2). For related information on post-remediation accident impacts to Tribal Nation sacred sites and cultural resources, please refer to the response to Comment number 0072.225.

Comment Number 0072.199

CTUIR

Comment P D-14: Please insert the subsistence Native American scenario here.

Response The risk assessment for the EIS was revised in Volume One, Section 5.11 and Volume Three, Appendix D to include an evaluation of anticipated post-remediation risk to a Native American user of the Hanford Site. Please refer to the response to Comment number 0072.198 for more information on the Native American scenario.

Comment Number 0072.200

CTUIR

Comment P D-16: Please insert table D2.1? Exposure pathways included in subsistence Native American Scenario: Subsistence Native American Exposure factors; Subsistence Native American Summary Intake factors.

Response Three new tables containing the data and assumptions used for evaluating post-remediation exposures for the Native American scenario were added to the post-remediation methodology discussion presented in Volume Three, Appendix D, Section D.2.1.3. Table D.2.1.2 presents the exposure pathways included in the Native American scenario, Table D.2.1.3 presents the Native American scenario exposure factors, and Table D.2.1.4 presents the Native American scenario summary intake factors. In addition, please refer to the response to Comment number 0072.198 for more information on the scenario.

Comment Number 0072.201

CTUIR

Comment P D-23: External-exposure route shielding is spelled incorrectly.

Response The spelling error has been corrected in Volume Three, Table D.2.1.6.

Comment Number 0072.202

CTUIR

Comment External-other factors 'shielding' is spelled incorrectly.

Response The spelling error has been corrected in Volume Three, Table D.2.1.6.

Comment Number 0072.203

CTUIR

Comment Same comment as above. (see comment number 0072.202)

Response The spelling error has been corrected in Volume Three, Table D.2.1.6.

Comment Number 0072.204

CTUIR

Comment P D-32: The Strenge-Chamberlain 1995 reference does not differentiate between roots and leafy matter.

Response The risk calculation for all receptors indicates that the contribution of roots and leafy vegetables to the overall risk is very small compared to drinking water. This is demonstrated in the uncertainty analysis developed for the Final EIS and presented in Volume Five, Appendix K.

Comment Number 0072.205

CTUIR

Comment P D-33: The fish ingestion pathway should be based upon the whole fish and not just on what is considered to be 'edible' portions. For further information contact CTUIR technical staff regarding this issue.

Response The concept of edibility varies from culture to culture and Native Americans might consume portions of fish and other animals not commonly consumed by other cultures. The Native American scenario added to the Final EIS, which was developed through consultation with the affected Tribal Nations, includes pathways for ingestion of fish organs, animal organs, and wild bird meat. Intake of fish organs was accounted for by increasing the total fish muscle tissue intake by 10 percent and assuming that contaminated concentrations in fish organs were 10 times the concentrations in fish muscle tissue. Intake of animal organs and wild bird meat was similarly accounted for by increasing the total meat ingestion rate. Please refer to the response to Comment number 0072.198.

Comment Number 0072.206

CTUIR

Comment P D-35: Please re-look at this paragraph, it is awkward and needs to be redone in relation to recent material regarding the Chernobyl accident. Additionally, there is new information regarding genetic affects as presented in NCRP no. 116.

Response Although some epidemiological data for the Chernobyl accident are available in the scientific literature, the studies are not yet complete and the ICRP has not yet issued revised recommendations for hereditary risk factors based on Chernobyl data. The international risk community is now evaluating the hereditary effects of the Chernobyl accident by tracking the incidence of hereditary effects in the progeny of the exposed population and statistically comparing this incidence to that of a nonexposed control population. Until these studies are complete and the ICRP publishes revised recommendations regarding hereditary risk, it would not be appropriate to use Chernobyl data as the basis for an evaluation of hereditary risk.

In response to this comment, the genetic effects information in National Council on Radiation Protection and Measurement (NCRP) No. 116 has been reviewed. This information suggests that the human and animal genetic studies mentioned in the EIS might underestimate the genetic effects of ionizing radiation. The text of the EIS in Volume Three, Section D.2.1.3.3 has been modified to indicate that genetic effects might be greater than indicated by previous human and animal studies, but that the data are not sufficiently validated to permit analysis at this time.

Comment Number 0085.04

Klein, Robin

Comment At the same time, we must act aggressively and do what we can now to prevent further calamity and contamination. Also, the Draft EIS considers these hypothetical users over the next 10,000 years. It is ludicrous to consider such bearing uses, or to consider controls or restrictions for use of soil, groundwater, whatever, so many years hence. Therefore we have a responsibility, an obligation to clean up the site to the fullest extent possible, and as aggressively as we can to reduce spread and impact of the contaminants.

Response DOE and Ecology acknowledge the preference expressed in the comment and will take this preference and other public comments into consideration when making a final decision on remediating the TWRS waste. Consideration of land uses over long periods of time extending into the future was carried out for purposes of comparing alternatives that would have impacts far into the future. The alternatives evaluated represent a reasonable range of alternatives for accomplishing the TWRS mission. Long-term impacts are calculated to support the decision-making process. The EIS also presents short-term impacts associated with implementation of the alternatives and within the 100-year administrative control period. Both long-term and short-term impacts are presented to provide the public and the decision makers with information on environmental and human health impacts that support the comparison of the impacts among the alternatives. Because both short- and long-term impacts are provided, no change to the document is warranted.

Comment Number 0085.05

Klein, Robin

Comment For the record, the anticipated numbers of cancers and fatalities in the Draft EIS that would result from various scenarios and alternatives are a subject of scientific and political controversy in and of themselves, and should not be taken as absolute in this Draft EIS, but rather as relative measures.

Response The risk calculations were performed to support the impact assessment and comparison of alternatives. These risks were not intended and should not be interpreted to represent absolute risks. The Final EIS in Volume One, Section 5.11 and Volume Three, Appendix D presents ranges of risk for each alternative, which provides a better estimate of the potential risks associated with each alternative. For the Final EIS, an expanded uncertainties analysis has been incorporated in Volume Five, Appendix K. This analysis addresses the nominal bounding risk estimate.

L.5.11.1 Remediation Risk

Comment Number 0005.56

Swanson, John L.

Comment One page 5-154 it is said that the cesium and strontium capsules contain no nonradiological chemicals. This is not true; they contain nonradioactive isotopes of cesium and strontium as well as stable isotopes produced on decay of the radioactive isotopes, and also the added chloride and fluoride. (On page 6-22 it is said that these capsules contain hazardous, characteristic, and/or listed wastes).

Response Wording to clarify that the capsules contain chloride, fluoride, and decay products (barium-137 and zirconium-90), in addition to the cesium and strontium, has been added to Volume One, Section 5.11. Risk from nonradiological chemicals during remediation was not evaluated because no nonradiological chemical emissions are associated with any of the capsule alternatives. Wording to clarify this point has also been added to Volume One, Section 5.11.

Comment Number 0028.01

DHHS

Comment The Draft EIS TWRS section dealing with potential adverse human health effects resulting from environmental releases of radioactive or hazardous materials, Volume Three and Appendix D, appears to be well developed and comprehensive:

Radiological and hazardous waste exposures to the public from treatment, storage, and disposal operations were estimated using information on waste loads (source terms) and potential at-risk years. Exposure modeling included meteorological data, hydro-geologic data, and potential release scenarios that included both facility and transportation accidents. Pathway modeling included use of GENII-S environmental modeling code. The function and source of each model type are well documented.
Risk estimate endpoints for the public included a) cancer incidence from radionuclide and chemical exposures, b) cancer fatalities from radionuclide exposure, c) adverse effects from transportation and/or transportation accidents.
Risk from radiological exposures were estimated using ICRP 60 risk factors. The uncertainties in the risk analysis procedure included model uncertainty, scenario uncertainty, and parameter uncertainty (sampling error, data sources).
The risk to public health from the transportation and storage of DOE waste materials, as expressed by the Draft EIS TWRS are reasonable.

Response DOE and Ecology acknowledge the comments concerning risk assessment. In response to public comments, the risk assessment has been enhanced by adding a Native American scenario to the evaluation of anticipated post-remediation risk and the analysis and presentation of risk ranges to request uncertainties. Please refer to the response to Comment number 0072.198 for a discussion of the Native American scenario and Comment number 0085.05 for a discussion of risk ranges.

Comment Number 0069.08

Pollet, Gerald

Comment Next, it is wrong to assume that the public in the near term, that is between now and the year 2028, will remain at the Site boundary in calculating risks. Even if you use the Site boundary, the risk calculations are out of date, and fail to consider risks from people using the river, and the new residences that are far closer than the previous north Richland case used.

Response The risk assessment in the Draft EIS addressed users of the Columbia River, the Fitzner Eberhardt Arid Lands Ecology Reserve, and areas of the Hanford Site north of the Columbia River. This information is presented in Volume One, Section 5.11 and Volume Three, Appendix D. The risk assessment in the Draft EIS does not use north Richland as the Site boundary. Rather, the assessment uses a modified boundary, which includes areas likely to be released by DOE in the near future. The maximally-exposed individual receptor is assumed to be located much closer to TWRS contamination sources than north Richland. The site boundary and receptor locations are discussed in Volume Three, Section D.2.2.3. Potential changes in onsite and offsite population and its effect on the risk calculation are addressed in the uncertainties discussion in Volume Five, Appendix K, which has been added to the EIS.

Comment Number 0069.09

Pollet, Gerald

Comment Third, the EIS must clearly show the risk from releases and explosions during the remediation period for each alternative. It's important that you show and use a conservative assumption as to the impact of delay. Throughout the EIS, in determining costs, you use a 40 percent cost contingency factor. In other words the costs are inflated just 40 percent as a contingency. Risk is a function of time, and what is amazing is that there is no contingency factor for time throughout this EIS in calculating risks. So we say that a plant will run 4 years, because that's the design basis for Phase 1 plant. Well if we have a 40 percent contingency for cost, one would also rationally say we might want to have a 40 percent contingency in terms of delay for that same plant. Therefore we have to re-calculate the risks.

Response Risks from releases during remediation were addressed in the Draft EIS in Volume One, Section 5.11 and Volume Two, Appendix D and remediation accidents, including explosions, were addressed in Volume One, Section 5.12 and Volume Four, Appendix E. The EIS analysis used bounding assumptions in analyzing health and accident impacts. A 60 percent efficiency factor was calculated into the remediation operations for each alternative. This assumption is presented in Volume One, Section 3.4.1. This is reflected in the length of operation time for each alternative in the TWRS EIS, and therefore, provides a contingency in the schedule. The probability of an accident (which would drive the risk) is based on the operation duration with the 60 percent efficiency factored in. Based on the assumed efficiency factor, the substance of the comment's suggestion that the EIS use a conservation estimate for facility operations has already been incorporated into the analysis, and therefore no change to the document is warranted. Please also refer to the response to Comment numbers 0072.225 and 0069.09 for discussions of accident risk during remediation and the 100-year administrative period.

Comment Number 0072.17

CTUIR

Comment For each scenario, the airborne release fraction (ARF) and respirable fraction (RF) should be presented separately, not as a single factor, because the nonrespirable fraction would be the fraction that deposits.

Response The airborne release fraction (ARF) and respirable fraction (RF) for planned atmospheric releases, such as would occur during routine TWRS remediation operations, would be the same. This is because planned releases would pass through a filtration system and all particulates that escape the filter would be in the respirable size range. Nevertheless, these particulates would eventually deposit, although they would stay suspended for long periods of time and be dispersed over large areas. The exposure calculation accounts for the contribution from these deposited particles. Please refer to the response to Comment numbers 0072.250, 0072.251, and 0072.17 for related information. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.207

CTUIR

Comment P D-87: Ground releases resulting in contaminant error concentrations would result in exposure to subsistence Native Americans.

Response The receptors evaluated for the remediation risk assessment (involved worker, noninvolved worker, and general public) were selected to represent a reasonable range of plausible onsite and offsite exposure scenarios that could arise during the construction and routine operational phases of the TWRS program. Because use restrictions and administrative controls would be in place at the Site throughout the remediation period, an onsite Native American scenario is not plausible. Plausible onsite exposures would be to the TWRS workers and noninvolved workers having access to the Site routinely during the remediation period.

Although an offsite Native American scenario is plausible during remediation, the exposures for such a scenario would not differ appreciably from the exposures presented in Volume Three, Section D.4.0 for the general public. This is because the inhalation pathway, which dominates all other pathways in the offsite remediation risk calculation, does not vary between the Native American scenario and the general public scenario. Because the remediation risk for the general public provides a reasonable approximation of the risk to the Native American, risk during remediation to the Native American has not been calculated separately and the EIS has not been changed. For a discussion of inhalation exposure for onsite receptors, please refer to the response to Comment number 0072.29, and for a discussion of inhalation impacts during remediation associated with sacred sites please refer to Comment number 0072.247.

The onsite Native American scenario, although not plausible during remediation, is considered plausible for the period following remediation. DOE and Ecology have developed a Native American scenario in consultation with the affected Tribes. This scenario has been added to the analysis of post-remediation risk presented in Volume Three, Appendix D and Volume One, Section 5.11.2 of the EIS. Please refer to the response to Comment number 0072.198.

Comment Number 0072.208

CTUIR

Comment P D-89: Sect. D 4.2.2: Please indicate what fraction of the Hanford site permit would be the allowable admission rates for the tank farms tank waste retrieval and evaporators.

Response At this time, it is not known what alternative will be implemented, and potential emissions associated with tank waste disposal actions are not covered by existing permits. Once the decision is made, the applicable permits would be obtained including possible revision or amendment of existing permits. Volume One, Section 6.0 discusses possible permitting necessary for implementation of the different alternatives. The chemical emissions for each of the alternatives are presented in Volume Five, Appendix G and are compared with the applicable Federal and State standards or permissible levels. Please refer to the response to Comment numbers 0072.243 and 0072.246 for related discussions. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.209

CTUIR

Comment P D-102: PP2: Please change dilution to dispersion.

Response Dilution has been changed to dispersion in the discussion of transport for this and all other alternatives in Volume Three, Section D.4.1 through D.4.9.

Comment Number 0072.210

CTUIR

Comment P D-105: What portion of each tank is expected to volatilize during gravel filling. As the tanks liquid is displaced by the gravels mass, raising the liquid level and disturbing the settled contents, a portion of the tanks contents can be assumed to exhale.

Response Tank emissions during gravel filling were calculated and included in the impact assessment. Emission data are provided in Volume Five, Section G.3. Additional technical data are provided in the Administrative Record for the TWRS EIS and are available for public review in the DOE Reading Rooms and Information Repositories locations listed in Volume One, Section 7.0. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.211

CTUIR

Comment P D-118: Sect. 4.1.1: Please indicate what portion of the overall source term is represented by the tanks contents.

Response One hundred percent of the source term is from the tank contents as presented in Volume Two, Appendix A. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.212

CTUIR

Comment P D-268: Sect. D.4.14: The mention of accumulation of contaminants in food products indicates that there may have been discussion of Native American food products. Please indicate when and where you have consulted with the affected Tribes regarding this topic.

Response The cited statement refers to a generic source of food products used for the remediation risk analysis. The remediation risk assessment in the Draft EIS addresses risk to the TWRS worker, the noninvolved worker, and the general public, but does not specifically address risk to a Native American receptor. Risk to a Native American receptor during the remediation period would be dominated by the inhalation pathway. For this reason, it would be similar to the risk presented in Volume Three, Appendix D, Section D.4.0 for the general public. The discussion of uncertainty in the risk assessment has been moved from Volume Three, Appendix D to a new Volume Five, Appendix K.

In response to Tribal Nations comments, DOE and Ecology have consulted with the affected Tribes and have developed a Native American scenario for inclusion in the post-remediation risk assessment for the Final EIS. The analysis of post-remediation risk to the Native American receptor has been added to Volume Three, Appendix D, Section D.5.0. Please refer to the response to Comment numbers 0072.149, 0072.55, 0072.198, 0072.207, and 0072.225 for more information on this topic.

Comment Number 0072.213

CTUIR

Comment P D-271: PP1: The consideration that age dependence is not expected to be as important as other factors is unacceptable to the people of the CTUIR whose very lives depend on the health and safety of their elders.

Response The statement regarding age dependency pertains to the internal dose calculation and its sensitivity to the overall dose and risk results. The statement "Age-dependent variations are considered to be less important because the generally higher internal dose factors (ICRP 1975) for the lower age groups are offset by lower breathing and food consumption rates" does not support or oppose the risk response for low or high age groups. For clarity, this sentence has been changed in Appendix D to read "Age-dependent variations are considered to be less sensitive..." In addition, the exposure duration for the Native American scenario added to the risk assessment assumes 70 years instead of the 30 years used for the other receptor scenarios. Please refer to the response to Comment number 0072.198 for related information. The information requested in the comment represents a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.214

CTUIR

Comment P D-272: PP 2: This paragraph is confusing, where was the total population evaluated?

Response The population for the onsite and offsite risk calculations is presented in Volume Three, Tables D.2.2.3 and D.2.2.4, respectively.

Comment Number 0090.05

Postcard

Comment Please listen to us say no:

I urge USDOE and the State of Washington to fully calculate the risks of explosions and leaks from any delay in vitrifying these wastes.

Response For a discussion of the relationship between closure, including past tank leaks, please refer to the response to Comment numbers 0012.15, 0072.08, 0101.05, and 0101.06. The risk of tank deflagrations and explosions has been further analyzed by DOE and Ecology for the Final EIS. The results of the new analysis have been incorporated into the Final EIS in Volume Four, Sections E.2.2, E.3.3, E.4.3, E.5.3, E.6.3, E.7.3, E.8.3, E.9.3, E.10.1, and E.10.2. A bounding risk from delay in vitrifying these wastes is presented in Volume Four, Section E.2.2 where the risk is shown from accidents that could result if vitrification is delayed indefinitely under the No Action alternative. Please refer to the response to Comment numbers 0069.10, 0069.12, and 0081.07 for more information regarding risk analysis relative to delays in remediation.

L.5.11.2 Post-Remediation Risk

Comment Number 0009.02

Broderick, John J.

Comment Potential health effects must be reasonable--not zero. There is not enough money to try to clean Hanford so completely that there will be no health impacts. For this reason, the remediation of the tank waste must permit leaving some waste in place with reasonable number of potential health effects.

Response DOE and Ecology acknowledge the preference expressed in the comment and will take this preference and other public comments into consideration when making a final decision on remediating the TWRS waste. Please refer to the response to Comment number 0040.01 for a discussion of factors influencing the evaluation of alternatives. The risk assessment is intended to provide an unbiased analysis of the anticipated health effects associated with the alternatives, and health effects are only one of many impacts analyzed in the EIS.

Comment Number 0012.17

ODOE

Comment Risk Assessment

The risk assessment in the EIS is sufficient to support the proposed action. We do not believe it is sufficient to support any decision which would leave waste in Hanford tanks.

The risk assessment shows long-term substantial environmental and public risks across most of the Hanford Site. The uncertainty in these estimates is so large, we believe the risk assessment should therefore not be relied upon or used as a decision making tool to micro-manage cleanup. It should only be used as a rough measure of the relative effectiveness of the various alternatives at reducing risks. The risks shown are large and justify complete removal and vitrification of all tank wastes.

The risk assessment shows great risk reduction from ISV. It does not however, include the large uncertainty in the technical feasibility of this alternative. ISV has only been demonstrated to a depth of 15 feet in soil. It has not been demonstrated for the depth and areas required for ISV of tank wastes. The risk assessment gives no indication a large uncertainty exists for this alternative. The uncertainty this creates in the ultimate risks is too large for this to be considered a viable alternative.

Response DOE and Ecology acknowledge the preference expressed in the comment and will take this preference and other public comments into consideration when making a final decision on remediating the TWRS waste. Please refer to the response to Comment number 0040.01 for a discussion of factors influencing the evaluation of alternatives.

The risk assessment was conducted to support a comparison of alternatives rather than to determine the absolute risk associated with a particular alternative. Health effects are but one of many impacts considered in selecting the preferred alternative.

DOE and Ecology understand the concern regarding uncertainty and have identified the need to provide additional information in the EIS to clarify the sources and magnitude of uncertainty in the risk calculations. Further uncertainty analysis has been completed and presented in the EIS in Volume Five, Appendix K. Issues concerning uncertainty in the implementability of the ISV alternative are discussed in Volume One, Section 3.4 and Volume Two, Appendix B. The ISV design is recognized as being conceptual in nature and having a high degree of associated uncertainty.

Comment Number 0036.12

HEAL (Exhibit)

Comment Risk from tank waste may be underestimated.

For the preferred alternative, the risk calculations assume that 99 percent of the waste will be retrieved. HEAL supports this assumption and the goal of total retrieval. However, it is unlikely that fully 99 percent will actually be retrieved given current and reasonably foreseeable technologies. Therefore, the risk may actually be much greater due to a larger amount of waste left in the tanks. This is not a request to change this assumption. Rather, it is a point stressing the importance of retrieving all the waste.

Response As is pointed out in Volume Four, Appendix F, Section F.2, the goal of the Tri-Party Agreement is to leave no more than 1 percent of the waste in the tanks after retrieval. Until waste from a sufficient number of tanks has been retrieved, it is not known whether the residual content will be greater or less than the goal of the Tri-Party Agreement. The amount and type of waste that would remain in the tanks after retrieval is also uncertain. The engineering data for the waste retrieval and transfer function common to all ex situ alternatives were developed using 99 percent retrieval as a goal. This information is presented in Volume One, Section 3.4 and Volume Two, Appendix B. The retrieval assumption also included a conservative assumption that the 1 percent residual would be as soluble as the 99 percent retrieved from the tank. This assumption provides a bounding case for impacts to groundwater and health risks under conditions where less that 99 percent of the waste is retrieval. Please refer to the response to Comment numbers 0005.18, 0089.07, 0072.59, and 0076.01 for related information. Because of the uncertainties associated with waste retrieval and the assumptions used in the EIS to bound the impact analysis, no change to the document is warranted.

Comment Number 0036.19

HEAL (Exhibit)

Comment Risk confirms importance of this program.

The high human health risks posed by all of the alternatives emphasize the importance of the Hanford tank waste disposal program. While the uncertainty involved with the EIS's risk calculations is high, the calculations still serve as a rough guide to future health risks.

The EIS shows that the human health risks are directly related to the amount of tank waste left behind. Assuming only 1 percent of the waste is left behind still leaves the farmer at 10,000 years with a 3 in 10,000 chance of cancer. The risk resulting from tank waste being left behind is demonstrated by the Ex Situ/In Situ Combination alternative in which 90 percent of the contaminants are removed by retrieving 50 percent of the waste volume. The risks resulting from this alternative for the farmer at 10,000 years are 3 in 1,000 -- an increase of an order of magnitude over the ex situ alternatives.

The reduction in risk gained in removing 99 percent of the contaminants as opposed to 90 percent shows the importance of the tank waste treatment and disposal program.

Response DOE and Ecology acknowledge the preference expressed in the comment and will take this preference and other public comments into consideration when making a final decision on remediating the TWRS waste. Please refer to the response to Comment number 0040.01 for a discussion of factors influencing the evaluation of alternatives.

Comment Number 0038.04

Reeves, Merilyn

Comment It has also been assumed that the Hanford tank wastes pose a great risk to future generations. And this EIS confirms that assumption.

The EIS shows that the future risk is directly correlated to the amount of waste left behind in the tanks.

The impact of leaving only a small amount of contamination behind is evidenced by the difference in long-term risk for the preferred alternative, where one percent of the waste is left in the ex situ, in situ alternatives, where there is 10 percent left behind, and by leaving nine percent more waste the risk for the residential farmer in 5,000 years increases the factor by 10. These clearly show that the only responsible solution is to retrieve all the waste.

Response DOE and Ecology acknowledge the preference expressed in the comment and will take this preference and other public comments into consideration when making a final decision on remediating the TWRS waste. Please refer to the response to Comment number 0040.01 for a discussion of factors influencing the evaluation of alternatives.

Comment Number 0040.03

Rogers, Gordon J.

Comment I reject dangers to hypothetical intruders as not a realistic concern (for the In Situ Fill and Cap alternative); which is also connected to the administrative control assumption.

Response It is common for purposes of NEPA assessment to assume that government agency administrative controls will end after a period of 100 years. In the absence of administrative controls, there is a probability of inadvertent human intrusion into the waste remaining onsite. To assist in differentiating between the alternatives, and to provide a more complete picture of the health risks posed by leaving waste onsite, the risk assessment included a hypothetical intrusion scenario. The scenario analyzed, well drilling, was considered the most likely intruder scenario. The probability of occurrence of this scenario is evaluated in the uncertainty analysis presented in Volume Five, Appendix K. Please refer to response to Comment number 0101.01 for a related discussion.

Comment Number 0041.02

Berry, Bill

Comment On Appendix D, the long-term analysis of risks, which unavoidably involves uncertainty to the point of being meaningless, assumes that a large industrial facility of 2,200 workers might exist on the Site in the future. The analysis then assumes that the facility would have a land use area of 785 sq. km., yielding a population density of 2.81 individuals/sq. km. Although this analysis may produce a type of average risk assuming the facility could be randomly located anywhere within the 785 sq. km. area (the facility clearly would not require anything near the entire area), a better approach would be siting the facility within the area of highest risk. This approach would provide a bounding estimate of risks to workers in the vent that the future industrial facility was located at the worst possible location.

Response The uncertainties regarding the risk assessment are presented in Volume Five, Appendix K, which has been added for the Final EIS. The industrial worker scenario is not land-area dependent; therefore, in calculating the total risk to the industrial worker, the population density of 2.81 and land use area of 785 km² were not used. As discussed in the response to Comment number 0041.03, population density and land use area were needed only for the residential farmer calculation. Volume Three, Table D.5.14.1 has been modified to show that population density and area of land use are not applicable to the industrial scenario. Please refer to the response to Comment number 0012.17.

The comment suggestion regarding the assumed siting of the industrial facility was considered. In response to this comment, the risk to the industrial worker has been recalculated assuming the facility is located in the area of highest risk. The text in Volume Three, Section D.5.14, has been modified to reflect the revised assumption.

Comment Number 0041.03

Berry, Bill

Comment In Table D.5.14.1 the population density for the recreational scenario appears incorrect (1950/104=18.75). I did not check the calculated incidence and fatalities to determine the population density that was used in the calculation. Those numbers should be checked or an explanation of why the lower population density was used should be provided as a footnote with the table.

Response The population density value given in Volume Three, Table D.5.14.1 for the recreational scenario was in error and has been changed. However, the cancer incidence and cancer fatality calculations are correct. To perform these calculations, a value for receptor population was required for each scenario. For the residential farmer scenario, a population estimate was not available; therefore, the population was calculated by multiplying an assumed population density by the Hanford Site area. Population estimates were available for the other scenarios; therefore, a population density was not needed. Population densities are shown in the table for all scenarios for the sake of consistency. The text in Volume Three, Section D.5.14 has been modified to clarify how population density was used in the calculations.

Comment Number 0055.07

Martin, Todd

Comment Moving off of costs, the risks that we see in the EIS are profoundly troublesome to me and I think they under estimate the actual risk. This is not something that I think should be changed, but I think it should be noted. 99 percent retrieval is probably a dubious assumption. It is the correct assumption and it is where we should be going but we are probably not going to get there. In addition, if sluicing does result in more leaked waste we can expect to see much higher risks when you are seeing a residential scenario 10,000 debt years down of three in 10,000 cancer rate with only 1 percent of the waste left behind. Imagine what it is for 2 percent, 3 percent, or maybe 10 percent.

Response As discussed in Volume One, Sections 3.3.1 and 3.4.1, there are many technical uncertainties associated with the alternatives for remediating tank waste. Although the design information for these alternatives is an early planning stage, the technologies represented are considered sufficient to bound the range of viable technologies that are applicable to tank remediation. For purposes of analysis, 99 percent retrieval efficiency was considered a reasonable assumption for the ex situ alternatives. Please refer to the response to Comment number 0036.12 regarding tank waste retrieval assumptions and Comment numbers 0005.18, 0089.07, 0072.59, and 0076.01 for additional discussions regarding the 99 percent retrieval assumption.

Because of uncertainties regarding the amount and type of residual waste that would remain in the tanks, it was assumed for the ex situ alternatives that the residual waste would contain 1 percent of all constituents in the original tank inventory, including the water-soluble constituents. In actuality, the residuals would contain less of the water-soluble constituents because they would be preferentially retrieved through sluicing. The assumption that 1 percent of the water-soluble waste remains in the tanks thus provides an upper bound on the impacts associated with the ex situ alternatives. The In Situ Fill and Cap and Ex Situ/In Situ Combination 1 and 2 alternatives leave more waste in the tanks and provide an upper bound on the impacts associated with the amount and type of waste disposed of onsite. Additional discussion of the uncertainties surrounding retrieval are presented in Volume Five, Appendix K.

Regarding leaks during sluicing, the predicted groundwater contaminant concentrations used for the risk analysis in the Draft EIS were calculated assuming that SSTs leaked a volume of 15,000 liters (4,000 gallons) per tank during retrieval. Detailed discussion of the tank release assumptions used for the groundwater modeling effort is presented in Volume Four, Appendix F, Section F.2.2. For additional discussion regarding this assumption, please refer to the response to Comment numbers 0029.01, 0030.03, and 0072.75.

Comment Number 0069.03

Pollet, Gerald

Comment This is a long-term risk scenario where the risks to people in this area here from groundwater contamination are essentially 1 person dies out of every 100 exposed. And that is without taking into account the type of assumption that should be made for leaks today. That means, the risks are far greater if we leave any tank waste in-place. Call it in situ capping, it's gravel, folks. It's cemented gravel on top of it. It will reach groundwater.

Response For the No Action, Long-Term Management, and In Situ Fill and Cap alternatives, the maximum anticipated post-remediation risk (incremental lifetime cancer risk) reaches levels as high as 1 in 100. However, as shown in Volume One, Table 5.11.4, the post-remediation risk for the other alternatives is anticipated to be less (i.e., no risk or risk less than 1.0E-06).

Impacts associated with past leaks from the tanks, based on data that became available following publication of the Draft EIS, are addressed in Volume Four, Appendix F and in the cumulative impacts discussion in Volume One, Section 5.13. For more information related to this issue please refer to the response to Comment numbers 0012.05, 0030.02, and 0091.01.

Comment Number 0069.06

Pollet, Gerald

Comment Now I come to the issue of risks. The, I'm going to turn this off, Environmental Impact Statement makes a number of assumptions about risks that are clearly erroneous, and out of date as well. First, it apparently uses a recreational exposure scenario for calculating risk, which we have criticized repeatedly recently, of the public using the Columbia River just 56 hours a year. It is ludicrous. In fact, we believe that a rational scenario for recreational exposure is 1,040 hours a year. The risks shown for recreational exposure, and I want to remind everyone that and for the record remind everyone that risk is a function of time, therefore the risks presented for these scenario's are 18 times too low.

Response The exposure scenarios used in the risk assessment were based on the recommendations published in the HSRAM (DOE 1995c). These recommendations have been approved by the signatories to the Tri-Party Agreement for use in Hanford Site risk assessments. In the case of the recreational shoreline user scenario, the HSRAM scenario was modified to increase the exposure duration from one week to two weeks for 30 years. This provided a more bounding estimation of risk than would have resulted from using the HSRAM scenario and is considered by DOE and Ecology to be appropriate. Because the information contained in the Draft EIS is correct, no change to the text was made.

Comment Number 0069.07

Pollet, Gerald

Comment Second point as to this exposure scenarios along the Columbia River, folks where is the Native American Treaty Right usage? It is not presented here. That is a usage, guaranteed by the Treaty of 1855, which one can rationally assume will be asserted during this timeframe, and which allows Native American treaty right tribes to live along this area of the Columbia River, and to gather foods and fish in the usual accustomed places while living along the river for extended periods of time.

Response Please refer to response to Comment numbers 0072.37, 0072.198, 0072.252, and 0072.225 for discussions of the analysis of impacts in response to Comments submitted by Tribal Nations regarding treaty rights, cultural resources, and future land use.

Comment Number 0072.18

CTUIR

Comment No Native American exposure scenario is included. During the revision of the EIS, if such a scenario is added, it must be preceded by consultation with CTUIR.

Response The risk assessment for the EIS has been revised to include an evaluation of anticipated post-remediation risk to a Native American user of the Hanford Site. The scenario used for the analysis was developed through consultation with representatives of the affected Tribes. Please refer to the response to Comment number 0072.198 for more information on the Native American scenario. For impacts associated with post-remediation accidents, refer to the response to Comment number 0072.225.

Comment Number 0072.19

CTUIR

Comment Deposition of particulates was not included.

Response The size of the particulates released during remediation would be very fine. These particulates would stay suspended in the atmosphere for long periods of time and would be transported over very large distances. A typical deposition velocity for particulates dispersed in the atmosphere is 1.0E-03 m/s. The post-remediation risk from deposition of particulates released to the atmosphere during remediation is very small. This risk is 3 to 4 orders of magnitude smaller than the inhalation risk during remediation. Anticipated health risk during and after remediation is contained in Volume One, Section 5.11, and Volume Three, Appendix D. Air quality issues are discussed in Volume One, Section 5.3. Please refer to the response to Comment numbers 0072.32 and 0072.240. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.20

CTUIR

Comment Genetic effects must be included, both for individual generations and for multiple generations.

Response The health effects endpoints used for the risk assessment (cancer incidence and cancer fatalities) were selected for consistency with other EISs prepared by DOE and with the endpoints used for the accident analysis presented in Volume Four, Appendix E. Cancer incidence and cancer fatalities are the endpoints commonly used for NEPA reviews, where the purpose of the assessment is to compare impacts among alternatives rather than to calculate absolute risks. A calculation of hereditary effects would not affect the ability of the decision makers and stakeholders to discriminate among the alternatives, because the results of the calculations would provide data that would support the same understanding of the relative difference among alternatives as does the existing calculation of cancer occurrences and cancer fatalities. For this reason, the decision to omit consideration of genetic risk from the EIS is considered appropriate, and the EIS has not been changed. The anticipated hereditary effects associated with the alternatives may be calculated by multiplying the radiological doses (rem) presented in Volume Three, Appendix D by the dose-to-risk conversion factor of 1.3E-04 (genetic risk per rem) published by the ICRP in 1991. Please refer to the response to Comment number 0072.206.

Comment Number 0072.21

CTUIR

Comment Existing soil and groundwater contamination was not included in the source term.

Response Existing soil and groundwater contamination are not included in the scope of the TWRS program and were specifically excluded from consideration in this EIS. However, existing soil contamination is addressed, in terms of its cumulative impacts with the TWRS alternatives in Volume One, Section 5.13 and Volume Four, Appendix F. Please refer to the response to Comment numbers 0030.02, 0072.08, 0012.15, 0091.01. Because the analysis requested in the comment is not within the scope of the EIS, no modification to the document is warranted.

Comment Number 0072.22

CTUIR

Comment No evaluation of socio-cultural quality of life was included.

Response Volume Three, Appendix D is the technical support document for analyzing remediation and post-remediation health risks to human health and ecological and biological resources. This appendix does not and was not intended to provide an assessment of quality-of-life issues. The human health analysis presented in Volume Three, Appendix D is summarized in Volume One, Section 5.11. Impacts to ecological and biological resources are summarized in Volume One, Section 5.4.

To the extent that impacts to human health and biological and ecological resources are an indicator of the socio-cultural quality of life, the relative differences in impacts reported in Volume One, Sections 5.11 and 5.4 provide the public and decision makers with information on which a comparison among the alternatives may be formed. This same statement would apply to all areas of impact assessment summarized in Volume One, Section 5.0. In addition to human health and ecological and biological impacts, Section 5.0 documents potential impacts by alternative to geology, air quality, water quality, land use, biological and ecological resources, the economy, public services, and visual effects, among others. In total, the analysis presented in Section 5.0 represents the potential impacts of the alternatives on the human and natural environment and hence on the socio-cultural quality of life.

The broad range of data regarding potential impacts are presented in the EIS so that the public, agencies, Tribal Nations, and decision makers can be aware of potential impacts during the decision making process. It is the role of each of these participants in the decision making process to compare the impacts and apply their values when determining which among the factors that will influence the selection of the alternative to be implemented should be considered in comparison to other factors. The role of the EIS is to objectively present alternatives, provide a comparison of impacts among alternatives, and provide an opportunity for public, agency, and Tribal Nation participation in the NEPA process. Please refer to the response to Comment numbers 0072.37, 0072.53, 0072.271, and 0072.252. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.23

CTUIR

Comment For ecological evaluation, instantaneous dilution in the River is unacceptable.

Response The ecological impact analysis presented in Volume One, Section 5.4 and Volume Three, Appendix D does not assume instantaneous dilution of groundwater reaching the Columbia River. Potential hazards were estimated for direct exposure to the groundwater before dilution, with organisms using no other water source. Please refer to the response to Comment number 0072.217 for a discussion of dilution factors used in the analysis. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.24

CTUIR

Comment The ecological dose limits need to be revised (terrestrial is more protective than aquatic), and the ecological Hazard Indexes (HI) that were developed for the EIS need to add a safety factor for sensitive life stages.

Response The ecological radiation dose limits used for terrestrial and aquatic receptors are consistent with those recommended by the International Atomic Energy Agency (IAEA) (IAEA 1992) and NCRP (NCRP 1991), respectively. IAEA states that "It would appear that chronic does of 1 mGyd^-1 or less to even the more radiosensitive species in terrestrial ecosystems are unlikely to cause measurable detrimental effects in populations and that up to this level adequate protection would therefore be provided....In the aquatic environment it would appear that limiting chronic dose rates to 10 mGyd^-1 or less to the maximally-exposed individuals in a population would provide adequate protection for the population" (1mGyd^-1 equals 0.1 rad d^-1, and 10 mGy d^-1 equals 1.0 rad d^-1, the units used as benchmarks in the text) (IAEA 1992). NCRP (NCRP 1991) addresses aquatic organisms only and concurs with the 1.0 rad d^-1 value used as a benchmark in the EIS.

It is unclear what safety factor would be appropriate to protect sensitive life stages. The ecological hazard indexes (HIs) used in the EIS to estimate potential hazards from nonradioactive chemicals are conservative in that they are based on high exposure parameter exposures. For example, the No Action alternative analysis assumes direct contact with stored wastes, which is highly unlikely. Adding a safety factor to the HI in this scenario would not alter the conclusion in the EIS that such exposure would be lethal. The information requested in the comment is a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.54

CTUIR

Comment Hypothetical Future Land Users should include specific Native American usage scenarios - these are not "hypothetical" but inevitable.

Response The risk assessment for the EIS has been revised to include an evaluation of anticipated post-remediation risk to a Native American user of the Hanford Site. The land use scenarios analyzed in the risk assessment are referred to as hypothetical in the sense that they would not occur until TWRS activities and other remediation activities outside the scope of this EIS are completed. Please refer to the response to Comment number 0072.198 for information on the Native American scenario.

Comment Number 0072.215

CTUIR

Comment P D-274: Sect. D.5.0: It is noted that there is no Native American scenario. Please insert a Native American scenario after consultation with affected Tribes.

Response The risk assessment for the EIS was revised to include an evaluation of anticipated post-remediation risk to a Native American user of the Hanford Site. The scenario used for the analysis was developed through consultation with representatives of the affected Tribes and the results of the analysis are presented in Volume One, Section 5.11 and Volume Three, Appendix D. Please refer to the response to Comment number 0072.198 for more information on the Native American scenario.

Comment Number 0072.216

CTUIR

Comment P D-275: Sect. D.5.1: Please insert MUSTs after DSTs.

Response The text of Volume Three, Section D.5.1 has been changed as requested in the comment.

Comment Number 0072.217

CTUIR

Comment P D-276: PP4: What exactly is the dilution factor used here? In addition, all contaminates in the ground water must be evaluated in the surface water.

Response As stated in the referenced paragraph (Volume Three, Section D.5.1.2), the dilution factor used is 1.21E-04. This factor indicates that a groundwater plume intersecting the river with a concentration of 1.0 Ci/L will produce a surface water concentration of 1.21E-04 for the entire Columbia River (from Hanford to the Pacific Ocean). Not all contaminants were addressed because some contaminants are not mobile in groundwater. The analysis addresses those groundwater contaminants that are the most mobile and contribute appreciably to risk. The transport of contaminants from tanks to groundwater and surface water is discussed in Volume Four, Appendix F. The information requested in the comment is a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.218

CTUIR

Comment P D-277: Sect. D.5.14: PP4: There are no risk free areas, please indicate exactly what this means.

Response This paragraph was included to explain why "holes" appear in the risk distributions on certain risk contour plots. These "holes" appear as white areas that have risk values less than the minimum contour interval (i.e., less than 1.0E-06). They are not risk free but have less risk than lowest value contoured. The text in Volume Three, Appendix D has been modified to clarify this point.

Comment Number 0072.219

CTUIR

Comment P D-279: PP 1: The surface water exposures should have been calculated for all constituents, not just five using an unknown dilution factor.

Response All the constituents are used in the analysis, but only five constituents (i.e., carbon-14, technetium-99, iodine-129, neptunium-237, and uranium) with high mobility (low K_d) will contribute appreciably to risk within the 10,000-year time period. Because the information contained in the Draft EIS is correct, no change to the text was made.

Comment Number 0072.220

CTUIR

Comment P D-284: Sect. D.5.6.1: Other sources that should be evaluated here should include tank leakage, because the one percent if left in the tanks will add to the current leakage inventory and continue to migrate just as current leakage inventory does.

Response The effects of contamination from past activities are not within the scope of the EIS but will be addressed in a future NEPA analysis on tank farm closure. Please refer to the response to Comment number 0072.08. The potential cumulative impacts of past tank leaks, TWRS alternatives, and other Site actions are addressed in Volume One, Section 5.13 and Volume Four, Appendix F. Because the analysis requested in the comment is not within the scope of the EIS, no modification to the document is warranted.

Comment Number 0072.221

CTUIR

Comment P D-432: Sect. D.6.2.2: Ecological effects that should be documented here include loss of habitat, disintegration of habitat, loss of diversity.

Response Loss of habitat, disintegration of habitat, and loss of diversity are examples of the "variety of potential indirect effects on other ecological variables" mentioned in the text of Volume Three, Section D.6.2.2. These items have been added to the text of the methods and results sections for clarification. The following sentences have been added to Volume Three, Section D.6.

"Examples of potential indirect effects include decreased biodiversity, habitat loss or alteration, and impacts on productivity and nutrient turnover. Any direct effects on individual organisms exposed to stored wastes could lead to a variety of indirect effects on the ecosystem, including decreased biodiversity, habitat loss or alteration, and impacts on productivity and nutrient turnover. Since the direct impacts of air and groundwater exposure are estimated to be small, any associated indirect impacts on the ecosystem would be correspondingly minor. Thus, potential direct impacts on organisms and any associated indirect impacts on the ecosystem would be expected to be relatively small. Corresponding indirect impacts on the ecosystem would be similarly unlikely."

The direct impacts of loss of habitat, fragmentation of habitat, and loss of diversity for ecological and biological resources are provided in Volume One, Section 5.4.

Comment Number 0072.222

CTUIR

Comment P D-433: Sect. D.6.2.4: The conceptual model for terrestrial organisms needs to take into account impacts that result in the loss of diversity and associated potential ecosystem imbalances.

Response The conceptual model is intended to illustrate potential pathways by which ecological receptors may be exposed to contaminants. Loss of diversity and other alterations in the ecosystem, though important, are potential indirect effects of organism exposures to contaminants, and were not used as assessment or measurement end points in the analysis. Potential indirect effects have been added to the text of Volume Three, Section D.6.2.2 and to Volume One, Section 5.4. Please refer to the response to Comment number 0072.221.

Comment Number 0072.223

CTUIR

Comment P D-434: There should be an arrow from waste to plants and animals and an arrow from plants to all of the animals. It is well known that hawks and shrikes use vegetation for nesting, soil for dusting. Coyotes have been known to eat plants and are in constant contact with the soil.

Response The conceptual model figure shows those pathways that were evaluated in the analysis. The scenario examining direct exposure to stored wastes assumed the "soil" contaminant concentrations were identical to those in the waste, effectively connecting "waste" compartment directly to the "plant" compartment, as suggested. Adding additional exposure pathways with a very small contribution to total risk would not alter the conclusion in the text that direct exposure to stored wastes would be lethal. The information requested in the comment represents a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.224

CTUIR

Comment P D-435: The CRITRII model uses simple food chain and bioaccumulation factors to estimate doses to a very few select species in a very complex set of ecosystems. This model extrapolates from grain values and leafy vegetable values eaten by standard wild animals (the pocket mouse and the male deer) assuming that the biochemistry is similar to the typical lab rat. There is no differentiation for embryos, fetuses, pregnant females, developing young, or very old animals. Additionally there are assumptions for biological steady states which negates underlying health problems an animal could have. It would seem then that because of the large amount of unknowns associated with the biochemical uptake and transfer mechanisms, the resulting uptake factors, the impacts to different age groups and sexes of the assessment group, the lack of information of underlying health, the small receptor group size, the lack of true representativeness, the role of each species in stabilizing the biodiversity, that the uncertainty analysis would have explained the results noting these factors.

Simply leaving the reader to assume that the only secondary sources of uncertainty are those which are the most easily quantified is very unfortunate. Please address the uncertainties listed above.

Response The conceptual model used to estimate hazards to terrestrial organisms and the CRITRII model used for estimating maximum radiation doses to aquatic organism exposed to groundwater entering the Columbia River make a series of simplifying assumptions, including the use of representative species. These models do not distinguish among species subpopulations, such as differing age groups, and they assume steady-states for such factors as the transfer of contaminants through the food chain.

Volume Three, Appendix D does not address sensitive subpopulations, but transfer factors used to estimate uptake by plants and assimilation in the mouse are mentioned as uncertainty sources, as are the No Observed Adverse Effect Levels used to estimate HIs. In addition, the analysis used bounding assumptions such that risk is more likely to be overstated than understated. For example, the No Action alternative analysis assumes direct contact with stored wastes and consumption of contaminated groundwater with no dilution of the water in the Columbia River, both of which are highly unlikely. It is unlikely that detailed uncertainty analysis would alter the conclusion that direct exposure to stored wastes would be lethal. The uncertainty discussion in Volume Three, Section D.6.5 has been modified to address the issue raised in the comment by adding the following sentences.

"The CRITRII model was used only for estimating maximum radiation doses to aquatic organism exposed to groundwater entering the Columbia River at 300 and 500 years. These estimates were all lower than one millionth of a rad per day, the benchmark recommended by NCRP (1991) as protective of aquatic organisms. It is unlikely that detailed uncertainty analysis would alter the conclusion that groundwater risks to aquatic organisms are very low."

Comment Number 0081.09

Pollet, Gerald

Comment I have two minor points that I wish to say. One is, I think that in this EIS something unique was done that is very valuable, and we'd like to thank Ecology and U.S. DOE for including these visualizations of the risks. In these risk isopleth maps for the first time. It allows the public to see that if in fact you take a look at leaving waste behind, along the Columbia River, the risk of fatal cancer at a glance you can see there are areas that have extremely high risks of fatal cancer. I think this is, it's an innovation to not just present data in tables, but to present this as a map where you can visualize what the risks are for different locations.

Response DOE and Ecology acknowledge the comment regarding the contour plot method used in the EIS to illustrate the areal risk distributions resulting from the risk calculations. DOE and Ecology continually strive to present these complex issues in an understandable form and believe the areal distribution of risk is one of the best innovations in presenting the results of risk assessments.

Comment Number 0089.12

Nez Perce Tribe ERWM

Comment Page D-15

The Hanford Site use scenarios including, Residential Farmer, Industrial, Recreational Shoreline User and Recreational Land User are not adequate to describe a Native American use scenario. The recreational scenarios only assumes usage for 14 days per year for 30 years. Information is now being compiled on the Hanford Site for Native American use scenarios. This information is currently being prepared through the Columbia River Comprehensive Impact Assessment effort. Please contact Joe Fitch of the Nez Perce Tribe ERWM for specific information regarding Nez Perce Tribal use and Native American use scenarios.

Response The risk assessment for the EIS has been revised to include an evaluation of anticipated post-remediation risk to a Native American user of the Hanford Site. The scenario used for the analysis was developed through consultation with representatives of the affected Tribes. Under this scenario, an individual engaged in a subsistence Native American lifestyle is assumed to spend 365 days per year on the Site over a 70-year lifetime. Please refer to the response to Comment number 0072.198 for information on this scenario. For information on the recreational use scenario, please refer to the response to Comment numbers 0041.03 and 0069.06.

Comment Number 0101.02

Yakama Indian Nation

Comment In order to base performance assessments on assumptions that are consistent with providing reasonable assurance of protecting public health and safety and the environment far into the future, a design confidence level for the entire Hanford Sites performance must be established. Then, the suite of scenarios developed to define conditions to be evaluated over the time frame protection is intended must be objectively established, consistent with providing the design confidence level intended. The legal term frequently used to define the necessary confidence level is reasonable assurance. This is generally recognized to be a very high level of confidence, consistent with the intent of various environmental laws and the Atomic Energy Act to protect public health and safety and to protect the environment.

Response DOE and Ecology recognize the potential for diversity of criteria across the projects at Hanford and concur with the consistent Hanford Sitewide environmental performance design criteria. The level of confidence in the TWRS EIS risk assessment provides reasonable assurance that impacts will not be higher than the level assessed in the EIS. In the TWRS EIS, the long-term scenarios are based on 95 percent confidence that they are bounding risks.

In accordance with CEQ requirements, the EIS is prepared early in project planning well in advance of detail design criteria, which would be needed for rigorous probabilistic risk assessment. As more information becomes available relative to the tank waste, the level of uncertainty will be reduced and more precise estimates of impacts will be possible. Please refer to the response Comment number 0101.03 for a related discussion and 0072.225 for a discussion of the NEPA requirement to analyze impacts commensurant with their likelihood and potential consequences.

L.5.12 ACCIDENTS

Comment Number 0012.21

ODOE

Comment Table E.15.0.2 on page E-248 of Volume Four considers loading of waste glass with 40 weight percent of waste oxide. It reports a population dose of 7,900 person-rem for the Ex Situ Intermediate Separations alternative. This is beyond the limit by weight that waste oxide can be put in glass. Loadings of over 30 weight percent waste oxide are no longer glass. They are sodium silicates. As a consequence, the population dose is wrong. Errors such as this greatly increase the uncertainty in the potential real risk to the population, as compared to the modeled risk in the EIS.

Response The 40 percent waste oxide loading used for this sensitivity analysis also included a 1.5 blending factor. Use of the 1.5 blending factor would result in a net waste oxide loading of 27 percent. Published literature supports waste oxide loadings in excess of 30 weight percent. Therefore, the populations dose of 7,900 person-rem for the Ex Situ Intermediate Separations alternative is appropriate for analysis and no change to the document is warranted.

Comment Number 0072.225

CTUIR

Comment P E-3: PP 4: bullets 3-4: Page E-3: These bullets state that "unmitigated consequences" would be the basis of comparison, while page E-27 states that ingestion and groundshine were not evaluated as accident consequences because mitigation measures were assumed to occur. This is inconsistent. In addition, mitigation is never 100 percent successful, and the potential impact areas, food interdiction requirements, evacuation and relocation costs, and many other factors are all clearly consequences of the more severe accidents. Assuming that intervention is only partially effective (as is really the case), also means that, depending of the half lives of the materials released, there would be long-term and multigeneration impacts from some of the accidents. Intervention itself can be extremely destructive, as an example of event consequences that must be included. Regardless of the habitual methods for performing Safety Analyses, a full accident evaluation must include all potential consequences. CTUIR technical staff can also provide recommendations for translating environmental concentrations into human, environmental and socio-cultural risks.

Response The bullets are in reference to unmitigated consequences being compared to the Hanford Site risk acceptance guidelines for developing safety controls for the TWRS Accelerated Safety Analysis. DOE and Ecology have further analyzed the risk from the unstabalized tanks collapsing after the 100-year institutional control period. Because this is a likely event and there would be no institutional controls, evacuation and interdiction of food consumption would not be a mitigative barrier. The resulting analysis includes the added risk from groundshine, ingestion, and deposition. The new analysis is presented in Volume Four, Sections E.2.3 and E.3.4. Text also has been added to the methodology in Volume Four, Section E.1.1 to reflect this change.

All other remediation accident scenarios either have very small offsite consequences or the probability of the event is extremely unlikely. The Final EIS provides an analysis of the environmental and socio-cultural impacts from these accidents with the amount of detail commensurate with their likelihood and potential consequences as directed in Recommendations for the Preparation of Environmental Assessments and EISs, Office of NEPA Oversight, DOE, Washington, D.C., May 1993 (DOE 1993d). The text has been modified in the methodology in Volume Four, Appendix E to provide a qualitative assessment of the potential environmental and socio-cultural impacts and mitigative measures that would be taken. Please refer to the response to Comment numbers 0072.226 and 0072.26.

Comment Number 0072.226

CTUIR

Comment P E-13: Sect. E.1.1: Accident risk evaluation in general has a long history, yet methods are still archaic. As we have described elsewhere, the evaluation of risk from normal operations and from accidents needs to span the full range of potential impacts, including not only human dose, but also environmental and socio-cultural impacts. Methods are available for deriving guidelines for accident risks that include risk acceptance criteria for different accident frequency classes for each risk measure. For any revision of such risk acceptance guidelines, CTUIR expects to see risk acceptance criteria for each type of impact that could occur from accidents, and can offer technical and regulatory guidance in selecting appropriate risk levels.

Response The direction from Recommendation for the Preparation of Environmental Assessments and EISs, Office of NEPA Oversight, DOE, Washington D.C., May 1993 (DOE 1993d) is to calculate the potential risk from accidents (e.g., the number of LCFs from exposure to radiological constituents). The risk is not to be measured against risk acceptance guidelines, but against potential risks calculated in the other proposed alternatives. Risk is measured against risk acceptance guidelines in safety analysis reports for operation and facility design. Risk assessment guidelines help provide guidance in establishing administrative and mechanical barriers to mitigate or prevent unacceptable accidents from occurring. No change to the document is warranted.

Comment Number 0072.227

CTUIR

Comment P E-27: PP 4: Groundshine and ingestion pathways must be included.

Response DOE and Ecology have further analyzed the risk from the unstabalized tanks collapsing after the 100-year institutional control period. Because this is a likely event and there would be no institutional controls, evacuation and interdiction of food would not be a mitigative barrier. The resulting analysis includes the added risk from groundshine, ingestion, and deposition. The new analysis is presented in Volume Four, Sections E.2.3 and E.3.4. Text also has been added to the methodology in Volume Four, Section E.1.1 to reflect this change. Please refer to the response to Comment number 0072.225 for a discussion of impacts of remediation accidents.

Comment Number 0072.228

CTUIR

Comment P E-29: PP 3: Maximally-Exposed Individual General Public: Since the conventional offsite boundary dose was omitted from the evaluation, the MEI noninvolved worker dose (at 100m) must be considered the MEI offsite dose as well. Although not clearly stated, we presumed that the general population dose was estimated either by 160 annular sector analysis or by assuming that at each distance the entire population resides at plume centerline. In either case, the single point estimate result represents an average, with half the population being at higher risk. For this reason, we assume for the rest of this evaluation that the population dose is an average and the MEI worker dose is the same as the public MEI dose.

Response The conventional offsite boundary dose for the maximally-exposed individual (MEI) was not omitted from the evaluation (e.g., Volume Four, Table E.2.2.2 shows the MEI general public dose from a spray release due to a mispositioned jumper).

The population dose is not an average. Onsite and offsite population dose calculations were based on population-weighted Chi/Q values generated from onsite and offsite population distributions (i.e., estimates of the distribution of the population relative to the facility where the accident is postulated to occur). Both the Site and offsite areas were broken up into 16 sectors. The sector with the bounding population-weighted Chi/Q was assumed in the scenario. In addition, bounding 99.5 percent maximum sector Chi/Q values were used in the dose calculations.

The MEI worker dose is not the same as the public MEI dose. Dose is dependent on Chi/Q, which is dependent on distance. These values are reflected in the Chi/Q values (time integrated atmospheric dispersion coefficient) used for each receptor in the analysis. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.229

CTUIR

Comment P E-38: Table E.2.2.1: The column labeled "risk" either needs to be explained or omitted. The column labeled "severity" also needs some explanation - what does "No" mean with respect to severity, and how was this determined? Does this entire table apply to each tank individually? If so, then all of the anticipated accidents summed over all the tanks suggests that there would be several reportable incidents per year. Since the consequence analysis did not include any risk measure except dose, the consequences of these events (and especially programmatic impacts) are probably greatly underestimated.

Response Table E.2.2.1 in Volume Four is a screening table that is similar to those used elsewhere in the document. The table and purpose of the table were defined in Volume Four, Section E.1.1.2, which contains the explanations of "risk," "severity," and "no" and how the data were determined. The table does not apply to each tank individually but to the tank farms collectively. The intent of the analysis was to measure only health effects resulting from accidents; therefore, no change to the EIS is warranted. Please refer to the response to Comment numbers 0069.06, 0072.225, and 0072.226.

Comment Number 0072.230

CTUIR

Comment P E-40: Sect. E.2.2.1.1: It would be helpful if the discussion of the particular accident scenarios included the numerical reference from table E.2.2.1.

Response The accident scenario described can be traced to Volume Four, Table E.2.2.1 by using the name of the accident; therefore, no change to the document is warranted.

Comment Number 0072.231

CTUIR

Comment P E-40: Table E.2.2.2: Please note that in these tables there is information presented for the MEI public, although the prior discussion did not indicate that this would be the case. If this is also done consistently in the later tables, the discussion at the beginning of the section should include description of the MEI public offsite individuals location.

Response The location of the general public MEI is defined in Volume Four, Section E.1.1.5, Receptor Location. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0072.232

CTUIR

Comment P E-42,43,44,45,46: Tables E.2.2.4-E.2.2.5: The totals from Tables E.2.2.4 and E.2.2.5 should be added, because exposure to toxics and corrosive would be simultaneous and the effects are not necessarily independent. For the mispositioned jumper accident, the MEI worker would experience both effects at the same time, though the same portal of entry (the lungs), and therefore the effects are at least additive if not supra-additive.

Response Toxic and corrosive effects are independent and for that reason these efforts are not additive. Corrosive chemicals cause localized destructive physical damage to the exposed cells and underlying tissue with which there is direct contact (e.g., skin, eyes, and lining of the lungs). Toxic chemicals are absorbed through the cell membrane wall into the blood stream or lymphatic system where target organs are affected. Because the information contained in the Draft EIS is correct, no change to the text was made.

Comment Number 0072.233

CTUIR

Comment P E-57: PP1: What is the reason for using the 50 percent inventory rather than the 100 percent inventory? Is there an official Record of Assumption to track when and by whom this decision was made? This section indicates an onsite residential population of 183 people, but this is not described earlier under receptor locations. Please clarify. Given the current controversy around the possibility of any dome collapse (for example, with overload and filtration of releases upward through gravel, and so on), it might be useful to discuss all dome collapse and dome failure scenarios in a little more detail.

Response A discussion of the 100 percent inventory is found in Volume Four, Appendix E, Section E.1.1. As defined in Section E.1.1, the highest radioactivity concentration for each radionuclide was combined to define a hypothetical highest concentration tank inventory or "super tank" used to bound accidents. For single tank accidents or spray releases, this methodology is reasonable. However, for multiple tank accidents it would be unreasonable to represent all the tanks as the super tank; therefore, the nominal tank inventory would be more reasonable when an accident involves multiple tanks.

The decision to use a nominal inventory for accidents involving multiple tanks was made during the consequence analysis of the post-remediation accident scenario. The population living on the Hanford Site after the institutional control period was assumed to be 10 percent of the current Hanford Site population work force or 1,090, as discussed in Volume Four, Appendix E, Section E.2.3. The dome collapse and dome failure scenarios have been addressed in detail in Volume Four, Appendix E, Section E.2.3 and this analysis has been modified in the Final EIS to address information unavailable for inclusion in the Draft EIS analysis.

L.5.12.1 Nonradiological Occupational and Transportation Accidents

Comment Number 0072.25

CTUIR

Comment The accident scenarios need to be better described in the EIS, without referring the reader constantly to other documents, especially since there is such controversy about how frequently the accidents might happen, or even if they could happen at all.

Response The information requested is contained in the referenced documents in DOE Reading Rooms and Information Repositories for public review. The use of references in the EIS is consistent with CEQ guidance that EISs be as concise as feasible and that where appropriate supporting data and technical analysis be incorporated by reference (40 CFR 1502.21). The document is very lengthy and DOE and Ecology believe they have struck an appropriate balance between presentation of analysis in the EIS and incorporating by reference supporting materials. The information requested in the comment is a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0072.26

CTUIR

Comment The SAR approach to accident risks is inadequate for an EIS type of analysis: the full range of types of risk (including environmental and socio-cultural) need to be included since all of these would be affected by accidents.

Response DOE and Ecology have further analyzed the risk from the unstabalized tanks collapsing after the 100-year institutional control period. Because this is a likely event and there would be no institutional controls, no recovery action is accounted for. The resulting analysis includes the added risk from deposition to the environment and cultural resources. Therefore, the airborne release rate (ARR) and RF are presented separately in the EIS. The analysis is presented in Volume Four, Sections E.2.3 and E.3.4 of the Final EIS. Text also has been added to the methodology in Section E.1.1 to reflect this change.

All other scenarios occur within the 100-year institutional control period and have either very small offsite consequences or the probability of the event is extremely unlikely. DOE and Ecology have determined to evaluate the environmental and socio-cultural impacts from these accidents with the amount of detail commensurate with their likelihood and potential consequences as directed in Recommendations for the Preparation of Environmental Assessments and EISs, Office of NEPA Oversight, DOE, Washington, D.C., May 1993 (DOE 1993d) and following consultation with the commentor. The evaluation added to each alternative does not include a rigorous quantitative analysis but provides a qualitative assessment of the potential environmental and socio-cultural impacts resulting from deposition and mitigative measures that would be taken to offset these impacts. Please refer to the response to Comment number 0072.225.

Comment Number 0072.234

CTUIR

Comment P E-100: Sect. E.6.0: Where is the discussion of the environmental Impact due to the removal of the sand, gravel and silt? Additionally, where are the discussions regarding the impacts to known cultural sites associated with the proposed borrow sites?

Response Environmental and cultural site impacts associated with removal of sand, gravel, and silt are analyzed in Volume One, Sections 5.1, 5.5, and 5.7, and summarized in Section 5.14.

Comment Number 0072.235

CTUIR

Comment This table indicates that under the intermediation separation alternative (the preferred alternative), the closure caps (the Hanford Barriers) will require approximately over 85,000 trips to bring silt from McGee Ranch, 97,000 trips from Borrow Pit 30 for tank fill material, 122,000 trips to bring riprap from Vernita Quarry, and 100,000 trips to bring sand from Borrow Pit 30. What total volume of each material does this represent? This table indicates that all of this material is needed for the barriers, and no alternative sites are presented. Since the selection of a preferred alternative includes a de facto decision about closure, this EIS must include a discussion of the environmental and cultural harm that will be caused by this huge amount of clean fill, and the mitigation that will be performed should this closure plan be pursued. Closure is an inseparable part of the preferred alternative, so an excuse that closure is not in the scope of this EIS will be unacceptable.

Response The total volume of material removed from the potential borrow sites for hypothetical closure scenario is as follows:

Silt from McGee Ranch = 853,000 yd³
Tank fill from Borrow Pit 30 = 986,000 yd³
Riprap from Vernita Quarry = 1,220,000 yd³
Sand from Borrow Pit 30 = 1,000,000 yd³

The environmental and cultural impacts to the borrow sites listed are discussed in Volume One, Sections 5.1, 5.4, 5.5, and 5.7, and summarized in Section 5.14.

A hypothetical closure scenario was addressed to show the relationship between closure and remediation of the tank waste. For discussion of the closure scenario, please refer to the response to Comment numbers 0072.08 and 0101.06 and for more information regarding borrow site impacts, refer to the response to Comment number 0019.03. Because the analysis requested in the comment is not within the scope of the EIS, no modification to the document is warranted.

Comment Number 0081.07

Pollet, Gerald

Comment There is one other area of risks that we would like to spend another piece of paper on, and that has to do with explosion risks. We believe that the assumptions used are erroneous, and the Department of Energy had more than ample time to incorporate additional data about the risk of explosions in far more tanks than that are on the watch list today. The Wyden Safety Watch List Law requires the listing of tanks that have the potential for uncontrolled release of fission products, i.e., an explosion. We know that the Department has been sitting for months and months on a recommendation that 25, in other words twice as many tanks, have the potential to explode. That greatly changes the risk assumptions used and the presentation of data in the EIS.

Response In December 1995, Westinghouse Hanford Company (WHC) recommended to the DOE that 25 additional tanks be added to the Flammable Gas Watchlist. DOE-RL submitted the same recommendation to the U.S. Department of Energy, Headquarters (DOE-HQ), the organization responsible for formally making the decision. DOE-HQ requested that the Chemical Reactions Sub-Panel review and comment on the basis for the recommendation. DOE-HQ, on the basis of the sub-panel review, recommended to DOE-RL that the recommendation to add the tanks to the Watchlist to be withdrawn. DOE-RL withdrew the recommendation about the same time that WHC withdrew its original recommendation to DOE-RL.

The risk of tank deflagrations and explosions has been analyzed further by DOE and Ecology. The results of the new analysis that shows the event to be more credible (a higher annual frequency) have been incorporated into the Final EIS Volume Four, Appendix E, Sections E.2.2, E.3.3, E.4.3, E.5.3, E.6.3, E.7.3, E.8.3, E.9.3, E.10.1, and E.10.2.

L.5.12.2 Radiological Accidents

Comment Number 0069.10

Pollet, Gerald

Comment Fifth, we know that there are five times as many tanks with the potential for a hydrogen gas explosion as this EIS assumes. This assumption, found in the documents provided which are Westinghouse documents, the assumption is six flammable gas tanks. There are 25 awaiting to be added to the Watchlist. Which is the Wyden Watchlist. They've been awaiting being put on that Watchlist, which is a legal requirement for tanks of the potential to explode, since long before this EIS was issued. The department has known that tanks, additional tanks have the potential for hydrogen buildup above the flammability limit for a year now. It is not shown in the EIS at all. You should be clearly showing the annual risk of delay in terms of tank leaks, pressure vents, and explosions. Clearly show the risks per year of each alternative, and reveal which wastes would be retrieved, and which delayed in each alternative.

Response The annual frequency of a hydrogen deflagration as analyzed in the Draft EIS was based on 25 flammable tanks (Volume Four, Appendix E, Section E.2.2). Please refer to the response to Comment number 0081.07.

A bounding risk from the delay in remediating these wastes is presented in Volume Four, Section E.2.2, where the risk is shown from accidents that could result if remediation is delayed indefinitely under the No Action alternative. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

Comment Number 0069.11

Pollet, Gerald

Comment The ultimate question is which alternative gets on with retrieval of wastes, with what risks on the fastest timeline... beyond the design basis accident, i.e., greater than 10 to the -6th one million events. It's also incredible that the same one million chance, or greater, is given to red oil exothermic reactions. Based on the Westinghouse report which say's that the exothermic reaction will only occur by the 135 centigrade. Yet, in 1994, when the Department of Energy agreed not to restart the Plutonium Finishing Plant, it had placed administrative controls on the calciner, which are equivalent to the evaporators in many respects, had place administrative controls because it's own studies, including those done at Los Alamos and at Hanford, showed that the exothermic reactions could occur at temperatures far less than 135. This data was available, but ignored. It basically means that the risks presented here are entirely underestimated. Especially for tank explosions and pressure events, and other releases.

Response The Hanford solvent extractions separations plants (e.g., Plutonium Finishing Plant) operate with nitric acid systems where tributyl phosphates could react to form red oil. The exothermic events relating to red oil have occurred in mixtures of fuming nitric acid and normal paraffinic hydrocarbons (which are commonly called red oil). The explosion occurs when the mixtures are overheated and low molecular weight gaseous decomposition products are generated. Safeguards have been put in place at these facilities to limit the chance for a runaway thermal reaction, which would produce large quantities of flammable hydrogen gas. Unlike the Plutonium Finishing Plant, the waste in the Hanford Site tanks has been neutralized before transfer to the tanks and the waste is being maintained at an alkaline and not at an acidic pH. The material used for construction of the Hanford Site tanks is not suitable to store acidic wastes; therefore, alkalinity was and is measured and controlled before waste is placed or transferred into the tanks.

Red oil, a reaction product of tributyl phosphate, nitric acid, and heavy metal nitrates, cannot be formed on the alkaline wastes stored in the tanks. In the unlikely event that red oil is routed to the waste complex due to a process upset in an operating plant (i.e., material is not neutralized with sodium hydroxide [caustic]), contact with the large volume of diluted caustic in the storage tanks would neutralize the waste. Because the Hanford Site tank waste is in an alkaline and not an acidic state, a red oil exothermic reaction was determined to fall in the incredible range (less than 1.0E-06/yr) and the potential risks have not been underestimated in the EIS. The information relative to this issue was included in the Draft EIS in Volume Four, Appendix E; therefore, modification to the document is warranted.

Comment Number 0069.12

Pollet, Gerald

Comment One must wonder is the Department of Energy delaying placing additional tanks on the legal Watchlist until this comment period is closed? Why aren't we showing the risks from hydrogen events and from exothermic reactions, as the Department's own studies have shown them to be?

Response These decisions regarding placement of tanks on the Watchlist were made independent of the EIS schedule and do not reflect an intent to not address these issues in the EIS. Please refer to the response to Comment numbers 0069.10 and 0081.07.

Comment Number 0069.13

Pollet, Gerald

Comment As Todd Martin said earlier this evening, all that we know about some of these events is that they have a far greater probability than 1 the million. We cannot put a definitive figure on them. I would agree with that. We can't put a definitive figure on them. But we do know, for instance for the exothermic reaction, we know that the Department of Energy has had 3 explosions, at Hanford and Savannah River, involving this same material, same exothermic reaction. Yet this EIS is based on a Westinghouse study that assumes the possibility of one event is greater than one in a million. We have had three events, therefore, in the last 50 years and that does not equal a rate of occurrence of one in a million.

Response Please refer to the response to Comment numbers 0081.07 and 0069.11, which address similarly worded comments.

Comment Number 0072.27

CTUIR

Comment Deposition needs to be included, and therefore the ARF and RF need to be presented separately.

Response Please refer to the response to Comment numbers 0072.17, 0072.26, and 0072.251, which address similarly worded comments.

Comment Number 0089.19

Nez Perce Tribe ERWM

Comment The risks from tank wastes to the environment and the public appear to be understated and inconsistent with those on the Risk Data Sheets for the Hanford Site.

Response The risks to the environment and the public from tank waste as stated in the TWRS EIS are based on more current data and analyses than those used in the RDSs. Also, they serve different purposes. RDSs are used to obtain funding for Hanford operations and evaluate the cost of

environmental, socio-economic, and health impacts. The TWRS EIS only evaluates the health risks in terms of health effects, not cost; therefore, no change to the document is warranted.

Comment Number 0090.03

Postcard

Comment Please listen to us say no:

to ignoring the risk of tank explosions.

Response Please refer to the response to Comment numbers 0081.07 and 0069.11, which address this issue.

Comment Number 0098.05

Pollet, Gerald

Comment Explosion risks in this EIS. This EIS is based on a 1995 Westinghouse document that assumes a plutonium or uranium nitrate and tributyl phosphate or other solvent exothermic reaction, i.e., a red oil explosion, will only initiate at a 135 degrees centigrade and bases a lot of the risk estimates in terms of things like evaporator risks and explosion risks on that assumption. That assumption was disproven by Los Alamos National Laboratory study a year before this Westinghouse report which is the basis of the EIS. I would like to know why we are paying contractors to ignore official findings of the Department of Energy including there at Hanford which said, We had to put administrative controls on Plutonium Finishing Plant because of an acknowledgement that this reaction could occur temperatures far below 135 degrees centigrade. I think that Westinghouse should be penalized for producing a document that ignored the rest of the data at Hanford and from Los Alamos National Lab about the risk of a red oil explosion. The state needs to take a look at that and take a look at how those explosion risks are calculated because frankly, they did the same thing that the state fought in terms of the Plutonium Finishing Plant and they continue to try to get away with saying that this exothermic reaction only occurs at 135 degrees. Secondly, the data ignores the fact that the evidence shows that these reactions release hydrogen at flammable ... above the flammable limits at far lower temperatures and you're likely first to get a hydrogen explosion before you get the explosion from the red oil.

Response Red oil explosions are considered an incredible event and not discussed in the risk evaluations in the EIS; however, data pertaining to red oil explosions in the Hanford waste tanks are presented in Volume Four, Appendix E. Please refer to the response to Comment number 0069.11, which provides a more extensive discussion of the issue in response to a similarly worded comment.

L.5.12.3 Potential Toxicological Accidents

No comments were submitted for this topic.

L.5.13 CUMULATIVE IMPACTS

Comment Number 0019.17

WDFW

Comment Page 5-210, section 5.13.3.1, second paragraph. The EIS states that "closure of the SSTs and DSTs is beyond the scope of this EIS." If closure is beyond the scope, WDFW believes it is inappropriate to mention potential borrow sites for post-remediation activities since a thorough analysis has not being performed.

Response Although closure is not included in the TWRS EIS scope, as discussed in Volume One, Section 3.3.1, a generic closure method was included in all the alternatives (except No Action and Long-Term Management) to allow meaningful comparison of the in situ and ex situ alternatives on a relatively equal basis. It is necessary to address potential impacts at borrow sites in order to identify all impacts that may occur. The borrow sites shown in the Draft EIS were used only for calculational purposes. The EIS was modified in the Summary and Volume One, Sections 1.0, 3.3.1, and 5.0 to clarify that the borrow sites addressed are only identified for calculational purposes. A decision on which sites would be used will be made in the future when NEPA analysis is prepared for closure purposes. Please refer to the response to Comment numbers 0078.08 and 0019.03 for more information on this topic. Because the information contained in the Draft EIS is correct, no change to the text was made at the location specified in the comment.

Comment Number 0053.02

Carpenter, Tom

Comment I think that we have got waste that have leaked into the ground under the tanks. The figure varies. I have heard 950,000 gallons is the official figure of what has leaked from the single-shell tanks into the ground; however, a number of engineers out there have told me that, for instance tank 105A which had a serious steam event back in the mid-60's resulted in a great deal of contamination going down to the ground underneath the tank and the 500,000 gallon tank ended up needing over a million gallons of cooling water. So cooling water or evaporating water that was not counted as leaks to the ground. So that 950,000 gallon figure is not accounted into there.

Response Approximately 600,000 to 900,000 gallons of liquid are known or assumed to have been released to the soil beneath leaking tanks and this information is presented in the EIS in Volume One, Section 1.0 and 4.2. Cooling water that may have leaked from SSTs would be included in that volume. Cooling water that has evaporated would not be included in the leak volume. It is because of the insufficient information available regarding contamination of soil and groundwater that closure is not within the scope of the TWRS EIS. For more information on this issue, please refer to the response to Comment numbers 0091.01, 0030.02, 0072.63, and 0072.08. The Final EIS analysis of cumulative impacts, including soil contamination from past leaks has been modified and is presented in Volume One, Section 5.13 and Volume Four, Appendix F.

Comment Number 0101.05

Yakama Indian Nation

Comment Need to Consider Cumulative Impacts--Consideration of key actions and their resulting impacts having already occurred or potentially occurring in the future should be assessed by the subject EIS, consistent with NEPA guidance regarding consideration of cumulative impacts. Particular attention should be paid to impacts from other waste disposal sites, partially remediated sites or contaminated ground water posing an additional hazard from either simple additive effects and/or more complicated synergistic effects.

We consider it is inappropriate to base actions on a partial evaluation of impacts affecting the public health and safety and the environment, particularly when it is known or expected that other impacts from known or expected actions are cumulative.

Response Cumulative impacts of past, present, and future Hanford operations, together with the potential impacts of the TWRS alternatives, are included in the cumulative impacts section (Volume One, Section 5.13) of the EIS. No potentially synergistic effects were identified.

L.5.14 UNAVOIDABLE ADVERSE IMPACTS

Comment Number 0019.18

WDFW

Comment Page 5-230, Table 5.14.1, Phased Implementation alternative, Row on Biological Resources. There is a discrepancy between the figures on shrub-steppe habitat loss here (540 acres total) and that mentioned on 5-123 which states 690 acres. This is the second comment regarding clarification on upper impact level for the Phased Implementation alternative. What is the correct figure?

Response Please refer to the response to Comment number 0019.14 for the corrected information on the potentially affected acreages.

L.5.15 RELATIONSHIP BETWEEN SHORT-TERM USES OF THE ENVIRONMENT AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY

No comments were submitted for this topic.

L.5.16 IRREVERSIBLE AND IRRETRIEVABLE COMMITMENT OF RESOURCES

No comments were submitted for this topic.

L.5.17 CONFLICTS BETWEEN THE PROPOSED ACTION AND THE OBJECTIVES OF FEDERAL, REGIONAL, STATE, LOCAL, AND TRIBAL LAND-USE PLANS, POLICIES, OR CONTROLS

No comments were submitted for this topic.

L.5.18 POLLUTION PREVENTION

No comments were submitted for this topic.

L.5.19 ENVIRONMENTAL JUSTICE

Comment Number 0072.53

CTUIR

Comment Despite initial scoping agreements to include environmental justice as a separate section (per Executive Order 12898), no such section was prepared. The mere counting of the number of Native Americans residing in the three closest counties is not adequate.

Response DOE agrees that re-compiling existing demographic information would not satisfy the intent of Executive Order 12898. The environmental justice initiative has a technical component that involves analyzing whether there is a disproportionately elevated and adverse health or environmental impact on any minority community or low-income community and, if such impacts are identified, mitigating those impacts. In response to the environmental justice requirement, the TWRS EIS project included the following tasks.

Identify potentially affected low-income populations and minority populations within an 80-km (50-mi) radius of the Hanford Site central plateau.
Conduct technical analyses to establish if disproportionately high and adverse impacts to low-income and minority populations are associated with any EIS alternative.
Identify mitigation measures, if appropriate.

The basic EIS consists of a description of the affected environment and environmental consequences in Volume One, Sections 4.0 (supported by a more detailed analysis in Volume Five, Appendix I) and Section 5.0 (supported by detailed analysis in Volumes Two through Five), respectively. Volume One, Section 4.0 contains a description of the potentially affected minority, Native American, and low-income populations (Section 4.6). Section 4.0 also contains, where appropriate, other information pertinent to those populations within the affected environment including relationship of Native Americans to the Hanford Site in Section 4.4 (biological and ecological), Section 4.5 (cultural resources), Section 4.7 (land use), and Section 4.8 (visual resources). A more detailed description of each is provided in the associated section of Volume Five, Appendix I.

Identifying potentially affected minority populations, Native American, and low-income populations in the 80-km (50-mi) area surrounding the Hanford Site central plateau involved analyzing census data (Section 4.6). Identifying this area for analysis conforms to the geographic maximum extent of potential environmental impacts as described in the other sections of the EIS. This area included Benton County, Washington, and portions of nine other counties in Washington and Oregon, as well as portions of the Yakama Indian Reservation. The 1990 census was used as the source of the population data. Data were produced and analyzed for all census blocks located completely or partially within the 80-km (50-mi) area surrounding the Site. The results are summarized in Volume One, Section 4.6 and provided in greater detail in Volume Five, Appendix I. This section also included an acknowledgement that Tribal Nations located outside of this area "have historical and treaty interest in the Hanford Site area."

Socioeconomic data presented in Volume One, Section 4.6 were limited to Benton and Franklin Counties, Washington. The more limited area was identified because the socioeconomic impacts (e.g., jobs, tax revenue, retail sales, housing, and public facilities and services) of the Hanford Site on areas beyond the two-county area historically have been slight. Considering a smaller area does not diminish the impact of the Hanford Site on the Tribal Nations who have treaty rights and privileges to the Site. Other links to the Site are described in the relevant sections of the description of the affected environment.

The second portion of the environmental justice analysis was a description of the analysis of the potential environmental consequences of each of the TWRS alternatives presented in Volume One, Section 5.0, and in the other related appendices. Generally, these sections (i.e., Section 5.1 through 5.12) address impacts to air and water, ecological and biological resources, and human health and safety. Sections 5.13 through 5.20 contain analysis issues such as the impact of the alternatives on commitment of resources and land uses as well as environmental justice and mitigation measures.

For the environmental justice analysis, based on the minority, Native American, and low-income populations within the 80-km (50-mi) area, as well as Tribal Nations outside the 80-km (50-mi) area with treaty interests in the Hanford Site, each of the areas of technical analysis presented in the EIS was reviewed to determine if any "potentially disproportionate and adverse impacts" would occur. If "an adverse impact" was identified, a determination was made as to whether the impacts on minority, Native American, or low-income populations would be "disproportionately affected."

Volume One, Section 5.19 of the Draft EIS identified two areas of potentially adverse and disproportionate impact relative to Tribal Nations -- continued access restrictions to portions of the 200 Areas that would continue under long-term land use restrictions and potential disproportional post-remediation health impacts under in situ disposal alternatives. Subsequent to the publication of the Draft EIS, consultation with Tribal Nation identified other areas of concerns regarding potential adverse impacts to cultural resources. This section has been modified to identify those areas of concern. As required by the environmental justice initiative, Section 5.20 identifies potential mitigation measures that DOE could adopt to address the potential environmental justice impacts identified in Section 5.19.

Please refer to the response to Comment numbers 0072.149 and 0072.252 for information regarding consultation with Tribal Nations.

Comment Number 0101.08

Yakama Indian Nation

Comment Requirements-Based Alternative Designs Needed -- The TWRS design alternatives in the EIS that are considered fail to reflect a requirement-based approach in the conceptual design process. This effectively forecloses consideration of Yakama Nation cultural values and associated requirements. Hence, impacts within the realm of socio-economic impacts related to these values and requirements are not addressed in the EIS. For example, the potential economic burden on future generations or the impact of alternative closure designs for waste sites or interim storage facilities on the Indian use of nearby religious sites are not assessed in the subject EIS, although the values affected by these impacts are of prime importance to the Yakama Nation.

Response The TWRS alternatives considered in the EIS reflect a requirement-based approach to the conceptual design, but because of the large number of potential alternatives, a broader range of requirements was taken to develop the full range of reasonable alternatives. As indicated in the Draft EIS Volume One, Section 3.3.1, the alternatives were developed using the following requirements:

That a No Action alternative be addressed in the analysis (NEPA);
That the EIS developed representative alternatives for detailed analysis that bound the full range of reasonable alternatives when a wide range of alternatives were available for analysis (NEPA);
That 99 percent of the waste from the tanks will be retrieved for the ex situ alternatives (except for the ex situ/in situ combination alternatives); and
That management and disposal practices of radioactive waste, as well as the degree of separations required to facilitate near surface disposal of LAW and offsite disposal of HLW, will be consistent with DOE and Atomic Energy Act regulations.

This process allowed the analysis and consideration of cultural values and other associated issues in the EIS. For each of the alternatives, impacts to the human and natural environment, including impacts to Tribal Nation cultural values, were analyzed in the EIS. A description of the existing environment was provided in Volume One, Section 4.0 and Volume Five, Appendix I and impacts to the environment were provided in Volume One, Section 5.0 and associated appendices. Based on comments submitted by Tribal Nations and consultation with affected Tribal Nations during and following the comment period, the text of the EIS has been modified to reflect comments regarding the affected environment and potential impacts to Tribal Nation cultural values. Please refer to the response to Comment numbers 0037.01, 0072.271, 0072.53, 0072.154, 0072.252, and 0072.268 and 0072.149 for discussions of changes to the EIS based on consultation with Tribal Nations.

Regarding potential burdens to future generations, the EIS addresses potential health impacts to future generations, out to 10,000 years into the future, for a variety of potential future Site users. The Final EIS was modified to include a Native American Subsistence scenario based on consultation with affected Tribal Nations. Please refer to the response to Comment number 0072.198 for a discussion of this scenario. Other potential burdens to future generations are addressed to the extent the impact analysis indicates that a natural resource would be adversely impacted. Other impacts, such as impacts associated with accident risk, are not addressed in detail in the EIS because their small likelihood and potential consequences. Please refer to the response to Comment numbers 0072.26 and 0072.225 for discussions regarding accident impacts.

Impacts associated with alternative closure designs for waste sites were addressed within the context of the scope of the TWRS EIS. Closure is not within the scope of the EIS, hence, the EIS addressed a single closure scenario to provide the public, Tribal Nations, and decision makers with information needed to compare the relative impacts of each alternative. Please refer to the response to Comment number 0072.08 and 0019.03 for a discussion of closure and its relationship to the EIS.

L.5.20 MITIGATION MEASURES

Comment Number 0019.06

WDFW

Comment The Final Environmental Impact Statement Safe Interim Storage (SIS) of Hanford Tank Wastes made a firm commitment to develop a stand alone Mitigation Action Plan. The SIS project should be commended for being consistent with USDOEs Land and Facility Use Plan. The SIS project is part of the TWRS program. However, the TWRS EIS does not make the same explicit commitments as the SIS EIS did for mitigation of Priority Shrub-Steppe Habitat. There appears to be inconsistency within the TWRS program in interpreting and implementing the Land and Facility Use Policy.

The TWRS project will impact from 540 to 690 acres of shrub-steppe habitat. WDFW has several specific comments asking for clarification on acreage (refer to specific comments). WDFW strongly recommends compensatory mitigation for this project. The project should develop a stand alone Mitigation Action Plan, since the Biological Resource Mitigation Strategy has not been completed or reviewed by the natural resource agencies. At this point in time, the Biological Resource Mitigation Strategy may not meet mitigation requirements defined by WDFWs and USFWs mitigation policies. Besides biological arguments, this recommendation is based on USDOEs Land and Facility Use Policy which states "it will sustain the natural resources for which it is steward." By performing compensatory mitigation for this project, USDOE-RL is consistent with its Land and Facility Use Policy.

Response There is no inconsistency within the TWRS program. The EIS explicitly states that a Mitigation Action Plan will be performed as required by NEPA. Like the SIS project, the TWRS EIS program will make commitments for mitigation will be made in the TWRS EIS, the specific requirements will be contained in the Mitigation Action Plan. Under the regulations that implement NEPA (40 CFR 1500-1508), the EIS is not the place to document the specific mitigation measures that will be performed. The mitigation measures for the TWRS EIS may be far more complex than the measures identified by the SIS EIS so it is not feasible to document these in the Final EIS.

The 540 to 690 acres of shrub-steppe habitat mentioned in the comment refer to disturbances during tank farm closure activities, which is outside of the scope of this EIS and will be addressed in a future NEPA analysis. Please refer to the response to Comment number 0019.14 for more information on the potentially affected acreages. The information requested in the comment represents a level of detail that DOE and Ecology believe is not necessary for meaningful discrimination among the alternatives.

Comment Number 0019.19

WDFW

Comment Page 5-260, section 5.20.2. Request the word "Potential" be removed from section title. The section includes discussion of mitigation for shrub-steppe habitat, but vague language is used throughout without any firm commitment to doing mitigation. Again, WDFW strongly recommends mitigation for impacts to shrub-steppe.

Response General commitments for mitigation are contained in the TWRS EIS. The Mitigation Action Plan (MAP) will contain the specific requirements for mitigation. The term potential mitigation measures is the correct term because, as explained in Volume One, Section 5.20, page 5-260 of the Draft EIS, the mitigation measures included in this section are not included in the alternatives. One or more of these mitigation measures identified in Volume One, Section 5.20.2 could be included in the alternative selected for implementation. One likely mitigation measure is to mitigate impacts to the shrub-steppe habitat, as DOE has done for numerous other projects at Hanford. Following publication of the Final EIS, a Mitigation Action Plan will be prepared identifying additional mitigation measures DOE intends to implement.

Comment Number 0019.20

WDFW

Comment Page 5-262, section 5.20.2, third paragraph containing bullets. WDFW strongly recommends this idea be developed under its own section and that an explicit commitment be made for development and implementation of mitigation for the loss of shrub-steppe habitat. This would be consistent with Secretary Hazel O'Leary's Land and Facility Use Policy which states "USDOE will sustain the natural resources for which is steward", and would also be consistent with an earlier TWRS program EIS action.

Response Please refer to the response to Comment numbers 0019.06 and 0019.09 for discussions that respond to this issue.

Comment Number 0072.06

CTUIR

Comment Regardless of the proposed final Hanford tank waste retrieval and closure plans developed under the TWRS-EIS process, and prior to permitting of a treatment/disposal facility by the state under RCRA, a CTUIR aboriginal-lands human health and environmental sampling and analysis network must be established in order to help the CTUIR identify and mitigate potential future contamination impacts in a variety of environmental media. Existing environmental networks, albeit fragmentary, in both northeastern Oregon and southwestern Washington long have measurably demonstrated the regional environmental distribution of Hanford-source radionuclide and hazardous contaminants in air, water, soil, vegetation, and wildlife.

Response Cultural and archeological surveys of the areas that might be impacted by the project were performed and are summarized in Volume One, Section 5.5. Future environmental impacts on all environmental media were fully assessed and are presented in Volume One, Section 5.0 and associated appendices. A Native American exposure scenario is included in the Final EIS in Volume One, Section 5.11 and Volume Three, Appendix D. DOE annually samples and reports the regional contaminant levels in all environmental media on and near the Hanford Site in the Annual Hanford Site Environmental Report (PNL 1996), which is made available to the public and is summarized in Volume One, Section 4.0 and Volume Five, Appendix I of the EIS. Because the information requested in the comment was included in the Draft EIS, no modification to the document is warranted.

L.5.21 MISCELLANEOUS

Comment Number 0034.01

Belsey, Richard

Comment Health and safety, the Hanford tanks are the greatest threat to public health and worker safety and the environment in the whole Hanford Site.

Response DOE and Ecology acknowledge the preference expressed in the comment and will take this preference and other public comments into consideration when making a final decision on remediating the TWRS waste. Please refer to the response to Comment number 0040.01 for a discussion of factors influencing the evaluation of alternatives.

Comment Number 0046.02

DiGirolamo, Linda Raye

Comment Scientist and technicians got the DOE into a horrible, life threatening, INDUSTRY in Washington State and they are dancing around the gravity of the "CRUD" this industry creates. This nuclear "CRUD" is not only not biodegradable it is also EXPANDING in its lethal abilities...making it a true, toxic hazard which will not only never degrade but will most probably lead to the cause of the destruction of our whole planet. How? a) Nuclear winters (already experiencing), b) climate changes, c) Atmospheric interruptions d) river poisonings e) well water poisonings f) human and animal mutations...etc. (too many impacts to list on this page).

Comment Number 0061.02

Longmeyer, Richard

Comment If there are any planned activities which will disturb or destroy these monuments, NGS requires not less than 90 days' notification in advance of such activities in order to plan for their relocation. NGS recommends that funding for this project include the cost of any relocation(s) required.

Response DOE and Ecology acknowledge the comment and the notification requirements. DOE and Ecology intend to comply with all requirements. No change to the text was appropriate based on this comment.

Comment Number 0072.164

CTUIR

Comment P 5-3: PP 2: Please indicate the process of determining which environmental component has uncertainties to be discussed. This is a VALUE laden statement which needs definition and consultation with the CTUIR.

Response The process for determining which environmental component has uncertainties associated with the environmental impacts analysis involved determining whether the methodology used in the impacts analysis involved using data regarding waste characteristics, technologies, or processes that were uncertain due to the level of confidence in the quality of the data or the maturity of performance data regarding the technology or process. In cases where data are incomplete or unavailable, NEPA requires DOE to "make clear that such information is lacking" (40 CFR 1502.22). If the incomplete information is relevant to reasonably foreseeable significant adverse impacts, the agency must: 1) include information in the EIS that informs the decision maker of the status of the information; 2) summarize the existing credible scientific evidence relevant to evaluating the potential impacts; and 3) evaluate the potential impacts "based on theoretical approaches or research methods generally accepted in the scientific community."

For the TWRS Draft EIS, this process was accomplished by including in the analysis of each environmental component a discussion of the assumptions used in the impact analysis, information on the implications of the assumptions used, and information on the uncertainties associated with the data, assumptions, and/or methodologies used in the analysis. Based on this and other comments received on the Draft EIS, a new appendix (Volume Five, Appendix K) has been included in the Final EIS to provide a single-source of information regarding the uncertainties associated with the analysis of the proposed action.

The referenced statement, as well as the entire Draft EIS, has been subject to consultation with the CTUIR, other affected Tribal Nations, and other interested parties. Please refer to the response to Comment number 0072.149. The changes to the EIS mentioned previously were a result of the consultation process, as well as other comments received on this and other related issues. Other comments and consultation input from Tribal Nations resulted in changes to specific assumptions and uncertainties analysis. These changes are documented throughout in this appendix. Please refer to the response to Comment number 0101.08 for a related discussion.

Comment Number 0098.04

Pollet, Gerald

Comment Groundwater data. I find it incredible and I am going to address this, make this personal - Mike Thompson from the Department of Energy - for you to stand in front of the audience and talk about the borehole probably being contaminated when the Department of Energy's own occurrence report conclusively states that, Borehole contamination is not the cause of the contamination found in ... underneath the SX Tank Farm. That the correlation between boreholes, this proves the claim that an individual borehole was contaminated and that would be the source of this cesium finding. Now if that is the official position of the Department of Energy in its occurrence report, I think it is not permissible for you to stand up and without even acknowledging the official position, try to destroy the credibility of the data presented from your contractor.

Response The position stated by Mr. Thompson at the Seattle TWRS EIS Meeting, and in previous meetings with the Hanford Advisory Board was, "although the conceptual model describing cesium-137 in an aerially extensive plume as deep as 125 feet may eventually prove to be correct, there are other conceptual models (involving preferential contaminant flow down the drywells) that can explain the observed data. There is insufficient evidence in hand to conclusively discriminate between the two primary potential conceptual models for cesium-137."

At the time of the TWRS EIS meetings, the SX Tank Farm Report was not written. Only the data reports were available for review. The interpretation, displayed in graphical form, showing a plume of cesium-137 to a depth of 125 feet (and possibly beyond) was not substantiated by published analysis of the full suite of data. It was unknown if there had been adequate consideration of all pertinent data required to discriminate between multiple viable conceptual models that could result in the observed data. The release and distribution of graphical representation of one of several potential conceptual models prior to release and distribution of the data analysis report has prompted considerable debate in the technical community. The debate focuses on the interpretation of the distribution of cesium-137 in the soil. Debate over the potential transport of mobile contaminants (technetium-99, tritium, and chromium) is considerably less polarized. Please refer to the response to Comment number 0012.15.

Cesium-137 has been found in the lower regions of some of the drywells in the SX Tank Farm. The occurrence of gamma-emitting radionuclides (presumably cesium-137) in these drywells has been known for years, and has previously been interpreted to be borehole contamination. The new interpretation that there is an aerially extensive plume of cesium-137 in the soil is not consistent with what is known about cesium-137 transport through the soil as demonstrated by laboratory studies and field observation. Cesium-137 is an alkali element, univalent cation, with properties similar to other alkali elements (lithium, sodium, potassium, and rubidium). Adsorption preference on mineral surfaces behaves according to Coulomb's Law, in the Lyotropic Series (adsorption to mineral surfaces for cesium is greater than rubidium, potassium, sodium, and lithium); cesium-137 adsorbs with higher affinity than other alkali metals. In laboratory studies and in Hanford soil washing tests, it also has been demonstrated that cesium-137 ions absorb into the structure of molecules, specifically to "wedge sites" of micas, where they can substitute for potassium ions, and are hard to displace. Cesium-137 does not complex (interact with common inorganic anions such as ferrocyanide) and has little interaction with most organic chemicals. Ammonium ions may displace cesium-137. Cesium-137 exhibits high adsorption coefficients K_ds (>1,000) in dilute solutions. K_ds decrease with solution strength, but even at a K_das low as 4.5, the contaminant should move as little as approximately 20 feet through the soil column.

The SX Tank Farm drywells have been drilled through contamination from tank leaks. The drywells are not sealed to prevent the flow of contamination down the annular space between the casing and the soil. A drive shoe is attached to the bottom of the casing, which is larger in diameter than the casing, thus providing for a potential annular space for vertical contaminant transport. When these wells were deepened, the existing (potentially contaminated) casing was driven deeper as new pipe was welded to the top of the casing string and driven downward. Flooding of drywells has been known to occur in other tank farms, providing another transport mechanism for contaminants. There are data showing the two deep drywells are contaminated on the inside of the casing. The data indicate that contamination has entered the boreholes.

The DOE commissioned an expert panel to review the SX Tank Farm drywell logging data and the interpretations to determine which conceptual model for cesium-137 transport is correct: 1) an aerially extensive cesium-137 plume to at least 125 feet or 2) a more shallow soil plume and deeper, localized contamination due to preferential flow down the unsealed drywells. The panel has requested additional field data to make that determination.

There are a number of potential mechanisms that may have caused the contamination recently measured. Until additional data are collected, the mechanism or mechanisms responsible cannot be reliably determined. Volume Five, Appendix K contains a discussion of the levels of contamination measured, potential mechanisms that could have caused the contamination, and how each mechanisms might affect the results presented in the EIS.

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Weapons of Mass Destruction (WMD)

L.5.0 ENVIRONMENTAL CONSEQUENCES