Weapons of Mass Destruction (WMD)

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CHAPTER 3. AFFECTED ENVIRONMENT


This chapter describes the existing environmental and socioeconomic characteristics of the Savannah River Site (SRS) and nearby region that could be affected by the proposed action or its alternatives. The data presented in this chapter are required to assess the consequences of the proposed action and its alternatives.


3.1 Introduction


SRS is located in southwestern South Carolina adjacent to the Savannah River, which forms the boundary between South Carolina and Georgia. It encompasses approximately 800 square kilometers (300 square miles) within the Atlantic Coastal Plain physiographic province. SRS is approximately 40 kilometers (25 miles) southeast of Augusta, Georgia, and 32 kilometers (20 miles) south of Aiken, South Carolina. Figure 3-1 shows the location of SRS within the South Carolina-Georgia region.

SRS is a controlled area with limited public access. Through traffic is allowed only on SC Highway 125, U.S. Highway 278, SRS Road 1, and CSX railroad corridors (Figure 3-1). Figure 3-2 shows SRS areas and facilities, which include five nuclear production reactors (C-, K-, L-, P-, and R-Reactors); a nuclear target and fuel fabrication facility (M-Area), which assembled the targets and fuel that went into the reactors; two chemical separations areas (F- and H-Areas), which processed irradiated targets and fuel assemblies to separate and recover various isotopes and which contain the liquid high-level radioactive waste tank farms; a waste vitrification facility (S-Area), which vitrifies liquid high-level radioactive waste; a saltstone facility (Z- Area), which solidifies low-level radioactive sludge into a cement-like matrix; N-Area, where some wastes are stored; E-Area, which includes waste treatment, storage, and disposal facilities; and various administrative, support, and research facilities. These facilities have generated a variety of liquid high-level radioactive, low- level radioactive, hazardous, mixed (hazardous and radioactive), and transuranic wastes. Section 3.13 provides photographs and descriptions of specific waste management facilities. Section 4.4.15 and Appendix B also describe facilities at SRS.

Figure 3-1. Savannah River Site.

Figure 3-2. SRS areas and facilities.


3.2 Geologic Resources



3.2.1 SOILS AND TOPOGRAPHY


SRS is located on the Aiken Plateau of the Upper Atlantic Coastal Plain physiographic province about 40 kilometers (25 miles) southeast of the Fall Line that separates the Atlantic Coastal Plain from the Piedmont physiographic province (Figure 3-3). The Aiken Plateau is highly dissected and consists of broad, flat areas between streams and narrow, steep-sided valleys. It slopes from an elevation of approximately 200 meters (650 feet) at the Fall Line to an elevation of about 75 meters (250 feet) on the southeast edge of the plateau. Because of SRS's proximity to the Piedmont province, it is somewhat more hilly than the near-coastal areas, with onsite elevations ranging from 27 to 128 meters (90 to 420 feet) above sea level. Relief on the Aiken Plateau is as much as 90 meters (300 feet) locally. The plateau is generally well drained, although small poorly drained depressions do occur. The Final Environmental Impact Statement, Continued Operation of K-, L-, and P-Reactors, Savannah River Site, Aiken, South Carolina (DOE 1990) contains a complete description of the geologic setting and the stratigraphic sequences at SRS.

Previously disturbed soils are mostly well drained and were taken from excavated areas, borrow pits, and other areas where major land-shaping or grading activities have occurred. These soils are found beside and under streets, sidewalks, buildings, parking lots, and other structures. Much of the soil in the existing waste management areas has been moved, so soil properties can vary within a few meters. Slopes of soils generally range from 0 to 10 percent and have a moderate erosion hazard. These disturbed soils range from a consistency of sand to clay, depending on the source of the soil material (USDA 1990).

Undisturbed soils at SRS generally consist of sandy surface layers above a subsoil containing a mixture of sand, silt, and clay. These soils are gently sloping to moderately steep (0 to 10 percent grade) and have a slight erosion hazard (USDA 1990). Some soils on uplands are nearly level, and those on bottomlands along the major streams are level. Soils in small, narrow drainage valleys are steep. Most of the upland soils are well drained to excessively drained. The well-drained soils have a thick, sandy surface layer that extends to a depth of 2 meters (7 feet) or more in some areas. The soils on bottomlands range from well drained to very poorly drained. Some soils on the abrupt slope breaks have a dense, brittle subsoil.

Figure 3-3. General location of the SRS and its relationship to physiographic provinces of the southeastern United States.


3.2.2 Geologic Structures


Several fault systems occur offsite, northwest of the Fall Line. DOE (1990) contains a detailed discussion of these offsite geologic features. A recent study (Stephenson and Stieve 1992) identified six faults under SRS: Pen Branch, Steel Creek, Advanced Tactical Training Area (ATTA), Crackerneck, Ellenton, and Upper Three Runs Faults. Identification of faults is important because earthquakes can occur along these faults. The location of faults must be considered when siting hazardous waste management facilities. South Carolina Department of Health and Environmental Control (SCDHEC) regulations specify a setback distance of at least 61 meters (200 feet) from a fault where displacement during the Holocene Epoch (approximately 35,000 years ago to the present) has occurred. None of the waste management areas occur within 61 meters (200 feet) of any faults, nor is there evidence that any of the identified faults have moved in the last 35,000 years. Based on information developed to date, none of the faults discussed in this section are considered "capable," as defined by the Nuclear Regulatory Commission in 10 CFR 100, Appendix A. The capability of a fault is determined by several criteria, one of which is whether the fault has moved at or near the ground surface within the past 35,000 years.

Several subsurface investigations conducted on SRS waste management areas encountered soft sediments classified as calcareous sands. These sands contain calcium carbonate (calcite), which can be dissolved by water. The calcareous sands were encountered in borings in S-, H-, and Z-Areas between 33 and 45 meters (110 to 150 feet) below ground surface. Preliminary information indicates that these calcareous zones are not continuous over large areas, nor are they very thick. If the calcareous material dissolved, possible underground subsidence could result in settling at the ground surface. No such settling has been reported at any of the waste management facilities; however, the U.S. Department of Energy (DOE) is currently investigating potential impacts of subsidence.


3.2.3 SeisMICITY


Two major earthquakes have occurred within 300 kilometers (186 miles) of SRS. The first was the Charleston, South Carolina, earthquake of 1886, which had an estimated Richter scale magnitude of 6.8 and occurred approximately 145 kilometers (90 miles) from SRS. The SRS area experienced an estimated peak horizontal acceleration of 10 percent of gravity (0.10g) during this earthquake (URS/Blume 1982). The second major earthquake was the Union County, South Carolina, earthquake of 1913, which had an estimated Richter scale magnitude of 6.0 and occurred about 160 kilometers (99 miles) from SRS (Bollinger 1973). Because these earthquakes have not been conclusively associated with a specific fault, researchers cannot determine the amount of displacement resulting from them.

Two earthquakes occurred during recent years inside the SRS boundary. On June 8, 1985, an earthquake with a local Richter scale magnitude of 2.6 and a focal depth of 0.96 kilometer (0.59 mile) occurred at SRS. The epicenter was west of C- and K-Areas (Figure 3-4). The acceleration produced by the earthquake did not activate seismic monitoring instruments in the reactor areas (which have detection limits of 0.002g). On August 5, 1988, an earthquake with a local Richter scale magnitude of 2.0 and a focal depth of 2.68 kilometers (1.66 miles) occurred at SRS. Its epicenter was northeast of K-Area (Figure 3-4). The seismic alarms in SRS facilities were not triggered. Existing information does not conclusively correlate the two earthquakes with any of the known faults on the site.

A report on the August 1988 earthquake (Stephenson 1988) reviewed the latest earthquake history. The report predicts a recurrence rate of 1 earthquake per year at a Richter scale magnitude of 2.0 in the southeast Coastal Plain. However, the report also notes that historic data that can be used to accurately calculate recurrence rates are sparse.

A Richter scale magnitude 3.2 earthquake occurred on August 8, 1993, approximately 16 kilometers (10 miles) east of the city of Aiken near Couchton, South Carolina. Residents reported feeling this earthquake in Aiken, New Ellenton (immediately north of SRS), and North Augusta, South Carolina [approximately 40 kilometers (25 miles) northwest of SRS]. Although detected by SRS instruments, no seismic alarms were triggered.

The current design basis earthquake that nuclear safety-related facilities are engineered to withstand is one that would produce a horizontal peak ground acceleration of 20 percent of gravity (0.2g). Based on current estimates, an earthquake of this magnitude or greater can be expected to occur about once every 5,000 years.


3.3 Groundwater


This section updates the detailed water resources information provided in the Final Environmental Impact Statement, Waste Management Activities for Groundwater Protection, Savannah River Plant, Aiken, South Carolina (DOE 1987) and in DOE (1990), and incorporates the latest aquifer terminology used at SRS.


3.3.1 Aquifer Units


The most important hydrologic system underlying SRS occurs above the Piedmont hydrogeologic province in the Coastal Plain sediments, in which groundwater flows through porous sands and clays.

Figure 3-4. Geologic fault of SRS.

Figure 3-5 names the geologic formations based on the physical character of the rocks (lithostratigraphy) and the corresponding names used to identify their water-bearing properties (hydrostratigraphy); this figure also identifies the shallow, intermediate, and deep aquifers. This eis uses depth-based identification to simplify discussions of groundwater resources and consequences. More detailed discussions of SRS groundwater features are available in DOE (1987) and DOE (1990).


3.3.2 GROUNDWATER FLOW


Groundwater beneath SRS flows at rates ranging from a few centimeters (inches) per year to several hundred meters (feet) per year toward streams and swamps on the site and into the Savannah River.

At SRS, groundwater movement is controlled by the depths of the incisions of creeks and streams where water discharges to the surface. The valleys of the smaller perennial streams collect discharge from the shallow aquifers. Groundwater in the intermediate aquifer flows to Upper Three Runs or to the Savannah River. Water in the deep aquifer beneath SRS flows toward the Savannah River or southeast toward the coast. Beneath some of SRS, groundwater flow is predominantly downward from the upper to the lower parts of the shallow aquifer. This downward flow occurs under A-, M-, L-, and P-Areas. In other areas, groundwater flow is upward, from the lower to the upper parts of the shallow aquifer and from the deep aquifer to the lower part of the shallow aquifer. This upward flow occurs, for example, in the separations (F and H) areas and around C-Area. The upward flow increases near Upper Three Runs.

This section and Section 3.3.3 present groundwater flow and quality, respectively, associated with waste units with known or potential releases to the subsurface. Waste units discussed in these sections are listed in the SRS Federal Facility Agreement (EPA 1993a); Appendix G.1 of this eis (Resource Conservation and Recovery Act (RCRA)/Comprehensive Environmental Response, Compensation and Liability Act Units List) - sites with known releases; Appendix G.2 of this eis (RCRA Regulated Units) or Appendix G.3 of this eis (Site Evaluation List) - sites with potential releases to be investigated. Table 3-1 lists these waste units by area and the known contaminants for each area (or group of waste units). Refer to Figure 3-6 for the location of these units.

Some SRS facilities that will be investigated in the future for potential groundwater remediation (and the horizontal flow directions of the groundwater beneath them) include the M-Area Metallurgical Laboratory (horizontal flow to the west-northwest in the shallow aquifer and to the south toward Upper Three Runs in the intermediate aquifer); K-Area seepage basin (flow to the southwest toward Indian Grave Branch); L-Area seepage basin (flow toward Pen Branch and L-Lake); and the P-Area seepage basin (flow toward Steel Creek). F- and H-Areas and vicinity are on a surface and groundwater divide; shallow groundwater flows toward either Upper Three Runs or Fourmile Branch.

For further technical discussions of groundwater flow beneath waste units of interest for this eis, as well as beneath SRS in general, for the relationships of groundwater flow between the three main aquifers, and for values for aquifer properties that are useful in analysis of groundwater flow and consequences, see DOE (1987, 1990).

Figure 3-5. Comparison of lithostratigraphy, 1982 hydrostratigraphic nomenclature, and current hydrostratigraphy for the SRS region.


Table 3-1. Waste units associated with known or potential releases to the groundwater at SRS.a

Area Waste Units Contaminants
A- and M-Areas
  • M-Area Hazardous Waste Management Facility
  • Metallurgical Laboratory Seepage Basin
  • Savannah River Technology Center (SRTC) Seepage Basins
Volatile organic compounds (VOCs), radionuclides, metals, nitrates
Reactor Areas
  • Reactor Seepage Basins
  • Acid/Caustic Basins
  • K-Area Retention Basin
  • L-Area Oil/Chemical Basin
C-, K-, L-, and P-Areas: tritium, other radionuclides, metals, VOCs
R-Area: radionuclides, cadmium
E-Area, Separations (F and H) Areas
  • Burial Ground Complex
  • Mixed Waste Storage
  • F/H Seepage Basins
  • F/H Tank Farms
  • H-Area Retention Basin
Tritium, other radionuclides, metals, nitrate, sulfate, VOCs
G-Area
  • Sanitary Landfill
Tritium, lead, VOCs
TNX
  • Seepage Basins
  • Burying Ground
Radionuclides, VOCs, nitrate
D-Area
  • Oil Disposal Basin
Metals, radionuclides, VOCs, sulfate

a. Source: Modified from Arnett, Karapatakis, and Mamatey (1993).



3.3.3 GROUNDWATER QUALITY


Groundwater of excellent quality is abundant in this region of South Carolina from many local aquifers. The water in Coastal Plain sediments is generally of good quality and suitable for municipal and industrial use with minimum treatment. The water is generally soft, slightly acidic (pH of 4.9 to 7.7), and low in dissolved and suspended solids. High dissolved iron concentrations occur in some aquifers. Groundwater is the only source of domestic water at SRS and where necessary, it is treated to raise the pH and remove the iron.

Figure 3-6.

Industrial solvents, metals, tritium, and other constituents used or generated at SRS have contaminated the shallow aquifers beneath 5 to 10 percent of SRS (Arnett, Karapatakis, Mamatey 1993). Localized contamination of groundwater in the deep aquifer was found in the early 1980s beneath M-Area. Low concentrations of trichloroethylene (11.7 milligrams per liter) have been detected in water from a production well in M-Area. Similarly, low trichloroethylene values have been detected in a few other wells used for process water (du Pont 1983). Groundwater contamination has not been detected outside SRS boundaries. Figure 3-6 shows (1) the locations of facilities where SRS monitors groundwater, (2) areas with constituents that exceeded drinking water standards (40 CFR Part 141) in 1992, and (3) waste units associated with known or potential releases that may require groundwater remediation. Most contaminated groundwater at SRS occurs beneath a few facilities; contaminants reflect the operations and chemical processes performed at those facilities. For example, contaminants in the groundwater beneath A- and M-Areas include chlorinated volatile organic compounds, radionuclides, metals, and nitrate. At F- and H-Areas, contaminants in the groundwater include tritium and other radionuclides, metals, nitrate, chlorinated volatile organic compounds, and sulfate. At the reactors (C-, K-, L-, and P-Areas), tritium, other radionuclides, and lead are present in the groundwater. At D-Area, contaminants in the groundwater include volatile organic compounds, chromium, nickel, lead, zinc, iron, sulfate, and tritium. A recent SRS annual environmental report (Arnett, Karapatakis, and Mamatey 1993) presents specific groundwater data from more than 1,600 monitoring wells at SRS, including approximately 120 wells in A- and M-Areas, 218 plume-definition wells in these areas, 8 wells in the areas of the reactors of interest, and more than 350 wells in F- and H-Areas.

After the discovery in 1981 that groundwater beneath A- and M-Areas was contaminated with volatile organic compounds, SRS established an assessment program to define the extent and migration rate of the contamination. A groundwater extraction system was installed in 1983 and modified in 1985. It consists of 11 wells which pump more than 1,890 liters (500 gallons) per minute from the lower section of the shallow aquifer and an air stripper process which removes the volatile organic compounds. The treated waste is discharged to Tims Branch and Upper Three Runs through permitted outfalls.


3.3.4 GROUNDWATER USE


Groundwater is a domestic, municipal, and industrial water source throughout the Upper Coastal Plain. Most municipal and industrial water supplies in Aiken County are from the deep aquifers. Domestic water supplies are primarily from the intermediate and shallow aquifers. In Barnwell and Allendale Counties, the intermediate zone and overlying units that thicken to the southeast supply some municipal users. At SRS, most groundwater production is from the deep aquifer, with a few lower-capacity wells pumping from the intermediate zone. Every major operating area at SRS has groundwater-producing wells. Total groundwater production at SRS is from 34,000 to 45,000 cubic meters (9 to 12 million gallons) per day, similar to the volume pumped for industrial and municipal production within 16 kilometers (10 miles) of SRS.

DOE has identified 56 major municipal, industrial, and agricultural groundwater users within 32 kilometers (20 miles) of the center of SRS (DOE 1987). The total amount pumped by these users, excluding SRS, is about 135,000 cubic meters (36 million gallons) per day.


3.4 Surface Water



3.4.1 SAVANNAH RIVER


The Savannah River is the southwestern border of SRS for about 32 kilometers (20 miles). SRS is approximately 260 river kilometers (160 river miles) from the Atlantic Ocean. At SRS, river flow averages about 283 cubic meters (10,000 cubic feet) per second. Three large upstream reservoirs, Hartwell, Richard B. Russell, and Strom Thurmond/Clarks Hill, moderate the effects of droughts and the impacts of low flows on downstream water quality and fish and wildlife resources in the river.

The Savannah River, which forms the boundary between Georgia and South Carolina, supplies potable water to several municipal users. Immediately upstream of SRS, the river supplies domestic and industrial water to Augusta, Georgia, and North Augusta, South Carolina. The river also receives sewage treatment plant effluents from Augusta, Georgia; North Augusta, Aiken, and Horse Creek Valley, South Carolina; and from a variety of SRS operations through permitted stream discharges. Approximately 203 river kilometers (126 river miles) downstream of SRS, the river supplies domestic and industrial water for the Port Wentworth (Savannah, Georgia) water treatment plant at river kilometer 47 (river mile 29) and for Beaufort and Jasper Counties in South Carolina at river kilometer 63 (river mile 39.2). In addition, Georgia Power's Vogtle Electric Generating Plant withdraws an average of 1.3 cubic meters (46 cubic feet) per second for cooling and returns an average of 0.35 cubic meters (12 cubic feet) per second. Also, the South Carolina Electric and Gas Company's Urquhart Steam Generating Station at Beech Island, South Carolina, withdraws approximately 7.4 cubic meters (261 cubic feet) per second of once-through cooling water.

In 1992, SCDHEC changed the classification of the Savannah River and the SRS streams from "Class B waters" to "Freshwaters." The definitions of Class B waters and Freshwaters are the same, but the Freshwaters classification imposes a more stringent set of water quality standards. Table 3-2 provides data on water quality in the Savannah River upstream and downstream of SRS during 1992. Comparison of the upstream and downstream concentrations shows little impact from SRS discharges on the water quality of the Savannah River, except for an increase in the tritium concentration. Constituents of SRS discharges are within the guidelines for drinking water established by the U.S. Environmental Protection Agency (EPA), SCDHEC, and DOE.


3.4.2 SRS STReaMS


This section describes the pertinent physical and hydrological properties of the six SRS tributaries that drain to the Savannah River.

The five tributaries which discharge directly to the river from SRS are Upper Three Runs, Beaver Dam Creek, Fourmile Branch, Steel Creek, and Lower Three Runs (Figure 3-7). A sixth stream, Pen Branch, does not flow directly into the Savannah River but joins Steel Creek in the Savannah River floodplain swamp. These tributaries drain all of SRS with the exception of a small area on the northeast side. No development occurs in this area of SRS, which drains to an unnamed tributary of Rosemary Branch, a tributary of the Salkehatchie River. Each of these six streams originates on the Aiken Plateau in the Coastal Plain and descends 15 to 60 meters (50 to 200 feet) before discharging into the river. The streams, which historically have received varying amounts of effluent from SRS operations, are not commercial sources of water. The natural flow of SRS streams ranges from 0.3 cubic meter (11 cubic feet) per second in smaller streams such as Indian Grave Branch, a tributary to Pen Branch, to 6.8 cubic meters (240 cubic feet) per second in Upper Three Runs (Wike et al. 1994).

Upper Three Runs is a large, cool [annual maximum temperature of 26.1C (79F)] blackwater stream that discharges to the Savannah River in the northern part of SRS. It drains an area approximately 545 square kilometers (210 square miles), and during water year 1991 (a water year is October through September) had a mean discharge of 6.8 cubic meters (239 cubic feet) per second at the mouth of the creek (Wike et al. 1994). The 7-day, 10-year low flow (the lowest flow expected in any consecutive 7 days in any 10 years) is 2.8 cubic meters (100 cubic feet) per second. Upper Three Runs is approximately 40 kilometers (25 miles) long, with its lower 28 kilometers (17 miles) within the boundaries of the SRS. This creek receives more water from underground sources than other SRS streams and, therefore, has lower dissolved solids, hardness, and pH values. Upper Three Runs is the only major tributary on SRS that has not received thermal discharges. It receives surface water runoff and water from permitted discharges in A-, E-, F-, H-, M-, S-, and Z-Areas. Table 3-3 presents maximum and minimum values for water quality parameters for Upper Three Runs for 1993. Water quality parameters for other onsite streams are presented in Appendix E.

Figure 3-7. Major stream systems and facilities at the Savannah River Site.

Beaver Dam Creek is approximately 5 kilometers (3.1 miles) long and drains approximately 2.2 square kilometers (approximately 1 square mile). Beaver Dam Creek originates at the effluent canal of D-Area and flows south, parallel to Fourmile Branch. Some of the discharges of Fourmile Branch and Beaver Dam Creek mix in the Savannah River floodplain swamp before entering the Savannah River. Prior to SRS operations, Beaver Dam Creek had only intermittent or low flow. It has received thermal effluents since 1952 as a result of the cooling water operations from the heavy water production facility (shut down in 1982) and a coal-fired power plant in D-Area. Currently, Beaver Dam Creek receives condenser cooling water from the coal-fired power plant, neutralization wastewater, sanitary wastewater treatment effluent, ash basin effluent waters, and various laboratory wastewaters. In water year 1991, the mean flow rate for Beaver Dam Creek taken approximately 1 kilometer (0.6 miles) south of D-Area was 2.6 cubic meters (93 cubic feet) per second. The mean temperature found during the comprehensive cooling water study (conducted between 1983 and 1985) (Gladden et al. 1985) was 25C (77F), with a maximum temperature of 34C (93F) (Wike et al. 1994). As required by a Record of Decision (DOE 1988), water from the Savannah River is added to the D-Area powerhouse condenser discharges during the summer months to maintain the temperature of the stream below 32.2C (90F) (DOE 1987).

Fourmile Branch is a blackwater stream that previous SRS operations have affected. It originates near the center of SRS and follows a southwesterly route for approximately 24 kilometers (15 miles). It drains an area of about 57 square kilometers (21 square miles), receiving effluents from F- and H-Areas. It received C- Reactor effluent until C-Reactor was placed on shutdown status in 1987; however, thermal discharges ceased in 1985. When C-Reactor was operating, its discharge resulted in water temperatures in excess of 60C (140F). Since the shutdown of C-Reactor, the maximum recorded water temperature has been 31C (89F), with a mean temperature of 18.5C (65F). With C-Reactor discharge, the flow in Fourmile Branch measured about 11.3 cubic meters (400 cubic feet) per second. The average flow at SRS Road A-12.2 (southwest of SC Highway 125) in water year 1991 was 1.8 cubic meters (63 cubic feet) per second (Wike et al. 1994). In its lower reaches, Fourmile Branch broadens and flows via braided channels through a delta formed by the deposition of sediments eroded from upstream during high flows. Downstream of the delta, the channels rejoin into one main channel. Most of the flow discharges into the Savannah River at river kilometer 245 (river mile 152.1), while a small portion of the creek flows west and enters Beaver Dam Creek. When the Savannah River floods, water from Fourmile Branch flows along the northern boundary of the floodplain swamp and joins with Pen Branch and Steel Creek, exiting the swamp via Steel Creek instead of flowing directly into the river.

Pen Branch and Indian Grave Branch drain an area of about 55 square kilometers (21 square miles). Pen Branch is approximately 24 kilometers (15 miles) long and follows a southwesterly path from its headwaters about 3.2 kilometers (2 miles) east of K-Area to the Savannah River Swamp. At the swamp, it flows parallel to the Savannah River for about 8 kilometers (5 miles) before it enters and mixes with the waters of Steel Creek. In its headwaters, Pen Branch is a largely undisturbed blackwater stream. Until K-Reactor shut down in 1988, Indian Grave Branch, a tributary of Pen Branch, received the thermal effluent from the reactor. When K-Reactor operated, Indian Grave Branch's average natural flow of 0.3 cubic meters (10 cubic feet) per second increased to about 11.3 cubic meters (400 cubic feet) per second. As required by a Record of Decision (DOE 1988), a recirculating cooling tower was completed in 1992 to cool water for K-Reactor. This system has not operated because K-Reactor was placed in cold standby in 1992. However, if it were to operate, the flow in Indian Grave Branch would be reduced to 1.6 cubic meters (55 cubic feet) per second with 1.3 cubic meters (45 cubic feet) per second coming from cooling tower blowdown (DOE 1987). This change would alter the water quality and temperature and flow regimes in Pen Branch. Currently, the Pen Branch system receives non-thermal effluents (e.g., non-process cooling water, ash basin effluent waters, powerhouse wastewater, and sanitary wastewater) from K-Area and sanitary effluent from the Central Shops (N-) Area. In water year 1991, the mean flow of Pen Branch at SRS Road A (SC 125) was 4.1 cubic meters (145 cubic feet) per second. During reactor operation, the mean water temperatures of Pen Branch ranged from 33.5 to 48C (92 to 119F). Since the shutdown of K-Reactor, the mean temperature of Pen Branch has been 22C (72F) (Wike et al. 1994).

The headwaters of Steel Creek originate near P-Reactor. The creek flows southwesterly about 3 kilometers (approximately 2 miles) before it enters the headwaters of L-Lake. The lake is 6.5 kilometers (4 miles) long and relatively narrow, with an area of about 4.2 square kilometers (1,034 acres). Flow from the outfall of L- Lake travels about 5 kilometers (3 miles) before entering the Savannah River swamp and then another 3 kilometers (approximately 2 miles) before entering the Savannah River. Meyers Branch, the main tributary of Steel Creek, flows approximately 10 kilometers (6.2 miles) before entering Steel Creek downstream of the L-Lake dam and upstream of SRS Road A. The total area drained by the Steel Creek-Meyers Branch system is about 91 square kilometers (35 square miles). In 1954 (before the construction of L-Lake or Par Pond), Steel Creek started to receive effluents from L- and P-Reactors. By 1961, a total of 24 cubic meters (850 cubic feet) per second of thermal effluents was being released to Steel Creek. From 1961 to 1964 P-Reactor partially used the Par Pond recirculating system. In 1964, all P-Reactor effluent was diverted to Par Pond, and in 1968 L-Reactor was put on standby. In 1981, DOE initiated activities to restart L-Reactor. L-Lake was constructed in 1985 along the upper reaches of Steel Creek to cool the heated effluent from L-Reactor, and it received these effluents for several years until L-Reactor was shut down in 1988. In addition to receiving the cooling water from L-Reactor, Steel Creek also received ash basins runoff, nonprocess cooling water, powerhouse wastewater, reactor process effluents, sanitary treatment plant effluents, and vehicle wash waters. From October 1990 to September 1991, the mean flow rate of Steel Creek at SRS Road A was 4.7 cubic meters (185 cubic feet) per second, with an average temperature of 19C (66F) (Wike et al. 1994).

Lower Three Runs is a large blackwater creek draining about 460 square kilometers (286 square miles), with a 10-square kilometer (2,500-acre) impoundment, Par Pond, on its upper reaches. From the Par Pond dam, Lower Three Runs flows about 39 kilometers (24 miles) before entering the Savannah River. The SRS property includes Lower Three Runs and its floodplain from Par Pond to the river. The mean flow rate of Lower Three Runs in water year 1991 at Patterson Mill [8 kilometers (5 miles) below Par Pond] was 1.8 cubic meters (65 cubic feet) per second. The mean temperature at the Patterson Mill location during the period 1987 to 1991 was 18C (64F) (Wike et al. 1994).

Tables E.1-3 through E.1-7 present maximum and minimum values for water quality parameters for each of the remaining five major SRS tributaries that discharge to the Savannah River for 1993 (1992 for Beaver Dam Creek). The analytical results indicate that the water quality of SRS streams is generally acceptable, with the exception of the tritium concentrations. SCDHEC regulates the physical properties and concentrations of chemicals and metals in SRS effluents under the National Pollutant Discharge Elimination System program. SCDHEC also regulates chemical and biological water quality standards for SRS waters.


Table 3-2. Water quality in the Savannah River upstream and downstream from SRS (calendar year 1993).a,b

Upstream Downstream
Parameter Unit of measurec MCLd,e or DCGf Minimumg Maximumg Minimum Maximum
Aluminum mg/L 0.05-0.2h 0.174 0.946 0.182 0.838
Ammonia mg/L NAi,j 0.04 0.13 0.02 0.11
Cadmium mg/L 0.005d NDk ND ND ND
Calcium mg/L NA 3.1 4.24 3.25 5.09
Chemical oxygen demand mg/L NA ND ND ND ND
Chloride mg/L 250h 4 13 4 12
Chromium mg/L 0.1d ND ND ND ND
Copper mg/L 1.3l ND ND ND ND
Dissolved oxygen mg/L >5.0m 8.0 11.5 6.2 10.5
Fecal coliform Colonies per 100 ml 1,000m 13 1,960 5 854
Gross alpha radioactivity pCi/L 15d <DLn 0.586 <DL 0.325
Iron mg/L 0.3h 0.41 1.39 0.516 1.15
Lead mg/L 0.015l ND 0.002 ND 0.003
Magnesium mg/L NA 1.08 1.38 1.11 1.34
Manganese mg/L 0.05h 0.067 0.088 0.04 0.064
Mercury mg/L 0.002d,e ND ND ND ND
Nickel mg/L 0.1d ND ND ND ND
Nitrite/Nitrate (as nitrogen) mg/L 10d 0.17 0.31 0.18 0.31
Nonvolatile (dissolved) beta radioactivity pCi/L 50d 0.393 3.17 0.959 3.12
pH pH units 6.5-8.5h 6.0 6.8 6.0 6.7
Phosphate mg/L NA ND ND ND ND
Plutonium-238 pCi/L 1.6f <DL 0.00086 <DL 0.00174
Plutonium-239 pCi/L 1.2f <DL 0.000985 <DL 0.0012
Sodium mg/L NA 4.87 11.6 5.28 12.7
Strontium-90 pCi/L 8f <DL 0.174 0.009 0.22
Sulfate mg/L 250h 4.0 8.0 4.0 9.0
Suspended solids mg/L NA 5 17 5 16
Temperature C 32.2o 9.0 24.8 9.1 25.7
Total dissolved solids mg/L 500h 48 75 49 90
Tritium pCi/L 20,000d,e <DL 726 66 1,920
Zinc mg/L 5h ND ND ND 0.012

a. Source: Arnett (1994).
b. Parameters are those DOE routinely measures as a regulatory requirement or as part of ongoing monitoring programs.
c. mg/L = milligrams per liter; a measure of concentration equivalent to the weight/volume ratio.
pCi/L = picocuries per liter; a picocurie is a unit of radioactivity; one trillionth of a curie.
d. Maximum Contaminant Level (MCL), EPA National Primary Drinking Water Standards (40 CFR Part 141). See glossary.
e. Maximum Contaminant Level (MCL): SCDHEC (1976a). See glossary.
f. DOE Derived Concentration Guides (DCGs) for water (DOE Order 5400.5, "Radiation Protection for the Public and the Environment"). DCG values are based on committed effective dose of 100 millirem per year for consistency with drinking water MCL of 4 millirem per year. See glossary.
g. Minimum concentrations of samples. The maximum listed concentration is the highest single result found during one sampling event.
h.Secondary Maximum Contaminant Level (SMCL). EPA National Secondary Drinking Water Regulations (40 CFR Part 143).
i.NA = none applicable.
j.Dependent upon pH and temperature.
k.ND = none detected.
l.Action level for lead and copper.
m.WQS = water quality standard. See glossary.
n.Less than (<) indicates concentration below analyses detection limit (DL).
o.Shall not exceed weekly average of 32.2C (90F) after mixing nor rise more than 2.8C (5F) in 1 week unless appropriate temperature criterion mixing zone has been established.



Table 3-3. Water quality in Upper Three Runs downstream from SRS discharges (calendar year 1993).a,b

Parameter Unit of measurec MCLd,e or DCGf Minimumg Maximumg
Aluminum mg/L 0.05-0.2h 0.018 0.261
Ammonia mg/L NAi,j NDk 0.04
Cadmium mg/L 0.005d ND ND
Calcium mg/L NA ND ND
Chemical oxygen demand mg/L NA ND ND
Chloride mg/L 250h 2 3
Chromium mg/L 0.1d ND ND
Copper mg/L 1.3l ND ND
Dissolved oxygen mg/L >5m 5.0 12.5
Fecal coliform Colonies per 100 ml 1,000m 52 1,495
Gross alpha radioactivity pCi/L 15d <DLn 3.57
Iron mg/L 0.3h 0.363 0.709
Lead mg/L 0.015l ND 0.002
Magnesium mg/L NA 0.034 0.356
Manganese mg/L 0.05h 0.012 0.034
Mercury mg/L 0.002d,e ND ND
Nickel mg/L 0.1d ND ND
Nitrite/Nitrate (as nitrogen) mg/L 10d 0.10 0.19
Nonvolatile (dissolved) beta radioactivity pCi/L 50d 0.205 3.94
pH pH units 6.5-8.5h 5.2 8.0
Phosphate mg/L NA ND ND
Sodium mg/L NA 1.44 2.01
Strontium-89/90 pCi/L - <DL 0.783
Sulfate mg/L 250h 1 3
Suspended solids mg/L NA 1 20
Temperature C 32.2o 9.7 24.4
Total dissolved solids mg/L 500h 19 47
Tritium pCi/L 20,000d,e <DL 17,900
Zinc mg/L 5h ND ND

a. Source: Arnett (1994).
b.Parameters are those DOE routinely measures as a regulatory requirement or as a part of ongoing monitoring programs.
c.mg/L = milligrams per liter; a measure of concentration equivalent to the weight/volume ratio.
pCi/L = picocuries per liter; a picocurie is a unit of radioactivity; a trillionth of a curie.
d.Maximum Contaminant Level (MCL), EPA National Primary Drinking Water Standards (40 CFR Part 141). See glossary.
e.Maximum Contaminant Level; SCDHEC (1976a). See glossary.
f.DOE Derived Concentration Guides (DCGs) for water (DOE Order 5400.5). DCG values are based on committed effective doses of 4 millirem per year for consistency with drinking water MCL of 4 millirem per year. See glossary.
g.Minimum concentrations of samples taken at the downstream monitoring station. The maximum listed concentration is the highest single result during one sampling event.
h.Secondary Maximum Contaminant Level (SMCL), EPA National Secondary Drinking Water Regulations (40 CFR Part 143).
i.NA = none applicable.
j.Depends on pH and temperature.
k.ND = none detected.
l.Action level for lead and copper.
m.WQS = water quality standard. See glossary.
n.Less than (<) indicates concentration below analysis detection limit (DL).
o.Shall not exceed weekly average of 32.2C (90F) after mixing nor rise more than 2.8C (5F) in 1 week unless appropriate temperature criterion mixing zone has been established.



3.5 Air Resources



3.5.1 CLIMATE AND METEOROLOGY


The climate at SRS is temperate, with short, mild winters and long, humid summers. Throughout the year, the weather is affected by warm, moist maritime air masses (DOE 1991).

Summer weather usually lasts from May through September, when the area is strongly influenced by the western extension of the semi-permanent Atlantic subtropical "Bermuda" high pressure system. Winds are relatively light, and migratory low pressure systems and fronts usually remain well to the north of the area. The Bermuda high is a relatively persistent feature, resulting in few breaks in the summer heat. Climatological records for the Augusta, Georgia, area indicate that during the summer months, high temperatures were greater than 32.2C (90F) on more than half of all days. The relatively hot and humid conditions often result in scattered afternoon and evening thunderstorms (Hunter 1990).

The influence of the Bermuda high begins to diminish during the fall, resulting in relatively dry weather and moderate temperatures. Fall days are frequently characterized by cool, clear mornings and warm, sunny afternoons (Hunter 1990).

During the winter, low pressure systems and associated fronts frequently affect the weather of the SRS area. Conditions often alternate between warm, moist subtropical air from the Gulf of Mexico region and cool, dry polar air. The Appalachian Mountains to the north and northwest of SRS moderate the extremely cold temperatures associated with occasional outbreaks of arctic air. Consequently, less than one-third of all winter days have minimum temperatures below freezing, and temperatures below -7C (20F) occur infrequently. Snow and sleet occur on average less than once per year (Hunter 1990).

Outbreaks of severe thunderstorms and tornadoes occur more frequently during the spring than during the other seasons. Although spring weather is variable and relatively windy, temperatures are usually mild (Hunter 1990).

Data on severe weather conditions are important considerations in the selection of design criteria for buildings and structures at SRS. Information on the frequency and severity of past incidents provides a basis for predicting the probabilities and consequences of releases of airborne pollutants.


3.5.1.1 Occurrence of Violent Weather

The SRS area experiences an average of 55 thunderstorms per year, half of which occur during the summer months of June, July, and August (Shedrow 1993). On average, lightning flashes will strike six times per year on a square kilometer (0.39 square mile) of ground (Hunter 1990). Thunderstorms can generate wind speeds as high as 64 kilometers (40 miles) per hour and even stronger gusts. The highest 1-minute wind speed recorded at Bush Field in Augusta, Georgia, between 1950 and 1990 was 100 kilometers (62 miles) per hour (NOAA 1990).

Since SRS operations began, nine confirmed tornadoes have occurred on or close to SRS. Eight caused light to moderate damage. The tornado of October 1, 1989, caused considerable damage to timber resources on about 4.4 square kilometers (1,097 acres) and lighter damage on about 6 square kilometers (1,497 acres) over southern and eastern areas of the site. Winds produced by this tornado were estimated to have been as high as 240 kilometers per hour (150 miles per hour) (Parker and Kurzeja 1990). No tornado-related damage has occurred to SRS production facilities.

Based on tornado statistics for the SRS area, the average frequency of a tornado striking any given location in South Carolina was estimated to be 7.11x10-5 per year. This means that a tornado could strike any given location about once every 14,000 years (Bauer et al. 1989).

The nuclear materials processing facilities at SRS were built to withstand a maximum tornado wind speed of 451 kilometers per hour (280 miles per hour) (Bauer et al. 1989). The estimated probability of any location on SRS experiencing wind speeds equal to or greater than this is 1.2x10-7 per year. Such a tornado would occur about once every 10 million years (Bauer et al. 1989).

A total of 36 hurricanes have caused damage in South Carolina between 1700 and 1989. The average frequency of occurrence of a hurricane in the state is once every 8 years; however, the observed interval between hurricanes has ranged from as short as 2 months to as long as 27 years. Eighty percent of hurricanes have occurred in August and September.

Winds produced by Hurricane Gracie, which passed to the north of SRS on September 29, 1959, were as high as 121 kilometers (75 miles) per hour in F-Area. No other hurricane-force wind has been measured on SRS. Heavy rainfall and tornadoes, which frequently accompany tropical weather systems, usually have the greatest hurricane-related impact on SRS operations (Bauer et al. 1989).


3.5.1.2 Wind Speed and Direction

A joint frequency summary (wind rose) of hourly averaged wind speeds and directions collected from the H- Area meteorological tower at a height of 61 meters (200 feet) during the 5-year period 1987 through 1991 is shown in Figure 3-8. This figure indicates that the prevailing wind directions are from the south, southwest, west, and northeast. Winds from the south, southwest, and west directions occurred during about 35 percent of the monitoring period (Shedrow 1993).

The average wind speed for the 5-year period was 13.7 kilometers (8.5 miles) per hour. Hourly averaged wind speeds less than 7.2 kilometers (4.5 miles) per hour occurred about 10 percent of the time. Seasonally averaged wind speeds were highest during the winter [14.8 kilometers (9.2 miles) per hour] and lowest during the summer [12.2 kilometers (7.6 miles) per hour] (Shedrow 1993).


3.5.1.3 Atmospheric Stability

Air dispersion models that predict downwind ground-level concentrations of an air pollutant released from a source are based on specific parameters such as stack height, wind speed, pollutant emission rate, and air dispersion coefficients. The air dispersion coefficients used in modeling are determined by atmospheric stability.

Figure 3-8. Wind rose for SRS, 1987 through 1991.

The ability of the atmosphere to disperse air pollutants is frequently expressed in terms of the seven Pasquill-Gifford atmospheric turbulence (stability) classes A through G. Occurrence frequencies for each of the stability classes at SRS have been determined using turbulence data collected from the SRS meteorological towers during the 5-year period 1987 through 1991. Relatively turbulent atmospheric conditions that increase atmospheric dispersion, represented by the unstable classes A, B, and C, occurred approximately 56 percent of the time. Stability class D, which represents conditions that are moderately favorable for atmospheric dispersion, occurred approximately 23 percent of the time. Relatively stable conditions that minimize atmospheric dispersion, represented by classes E, F, and G, occurred about 21 percent of the time (Shedrow 1993).

In the southeastern United States, high air pollution levels typically occur when the air is stagnant and there is little dispersion of pollutants. Stagnant episodes generally occur when atmospheric pressure is high (i.e., the area is under a high-pressure system). Under a stagnating high-pressure system, the maximum height of air mixing is less than 1,524 meters (5,000 feet), and the average wind speed is less than 4.0 meters per second (9 miles per hour). According to upper air data, episodes of poor dispersion in the vicinity of SRS lasted for at least 2 days on 12 occasions over a 5-year period (1960 through 1964). Episodes lasting at least 5 days occurred on two occasions. A stagnation episode is defined as limited dispersion lasting 4 or more days. Two stagnation episodes have occurred in the SRS area each year over the 40-year period from 1936 through 1975. The total number of stagnant days averaged about 10 per year (Bauer et al. 1989).


3.5.2 EXISTING RADIOLOGICAL CONDITIONS



3.5.2.1 Background and Baseline Radiological Conditions

Ambient air concentrations of radionuclides at SRS include nuclides of natural origins, such as radon from uranium in soils; man-made radionuclides, such as fallout from testing of nuclear weapons; and emissions from coal- fired and nuclear power plants. SRS operates a 35-station atmospheric surveillance program. Stations are located inside the SRS perimeter, on the SRS perimeter, and at distances up to 161 kilometers (100 miles) from SRS (Arnett, Karapatakis, and Mamatey 1994).

Routine SRS operations release quantities of alpha- and beta-gamma-emitting radioactive materials in the form of gases and particulates. Gross alpha and nonvolatile beta measurements are used as a screening method for determining the concentration of all radionuclides in the air.

The average 1990 to 1993 gross alpha radioactivity and nonvolatile beta radioactivity measured at SRS and at distances of 40 kilometers (25 miles) to 161 kilometers (100 miles) from SRS are shown in Table 3-4. The maximum levels of onsite gross alpha and gross beta radioactivity were found near production/processing areas. For each year, average onsite gross alpha and nonvolatile beta radioactivity concentrations were similar to the average concentrations measured in offsite air (Arnett, Karapatakis, and Mamatey 1994). Nonvolatile beta concentrations do not include tritium (which accounts for more than 99 percent of the airborne radioactivity released from SRS) or carbon-14.

Tritium levels in 1993 are not directly comparable to those observed in previous years because the sampling protocol for atmospheric tritium oxide was changed in 1993. For 1993, the highest annual average concentration of tritium in air over SRS was 1.06x10-9 microcuries per milliliter. The maximum offsite tritium concentration was slightly higher than the 1992 level of 5.3x10-11 microcuries per milliliter (Arnett, Karapatakis, and Mamatey 1994).


Table 3-4. Average concentrations of gross alpha and nonvolatile beta radioactivity measured in air (1991 to 1993) (microcuries per milliliter of air).a

Location Number of Locations Average gross alpha radioactivity Average nonvolatile beta radioactivity
1991 1992 1993 1991 1992 1993
Onsite 5 2.5x10-15 1.8x10-15 1.9x10-15 1.8x10-14 1.9x10-14 1.8x10-14
SRS perimeter 14 2.6x10-15 1.8x10-15 1.8x10-15 1.8x10-14 1.9x10-14 1.9x10-14
40-kmb radius 12 2.5x10-15 1.7x10-15 1.8x10-15 1.8x10-14 1.8x10-14 1.8x10-14
161-km radius 4 2.6x10-15 1.7x10-15 2.0x10-15 1.8x10-14 1.7x10-14 2.0x10-14

a. Source: Arnett, Karapatakis, and Mamatey (1994).
b.Kilometer; to convert to miles, multiply by 0.621.



3.5.2.2 Sources of Radiological Emissions

The major SRS production facilities and the types and quantities of radionuclides released during 1993 are presented in Table 3-5. The dose to a member of the public from these releases, calculated by the MAXIGASP computer model, was 0.11 millirem. This dose is 1.1 percent of the 10-millirem-per-year EPA limit (see 40 CFR 52.21). Tritium (H-3), in both elemental and oxide forms, constitutes more than 99 percent of the radioactivity released to the atmosphere from SRS operations (Arnett, Karapatakis, and Mamatey 1994).


Table 3-5. Atmospheric releases by source facility in 1993.a

Curiesc
Radionuclideb Half-life Reactors Separations Reactor materials Heavy water SRTCd Diffuse and fugitivee Total
Gases and Vapors
H-3 (oxide) 12.3 yrs 3.85x104 9.39x104 NRf 448 NR 43.1 1.33x105
H-3 (elem.) 12.3 yrs NR 5.82x104 NR NR NR NR 5.82x104
H-3 Total 12.3 yrs 3.85x104 1.52x105 NR 448 NR 43.1 1.91x105
Carbon-14 5.7x103 yrs NR 0.0169 NR NR NR 4.00x10-6 0.0169
Iodine-129 1.6x107 yrs NR 0.00496 NR NR NR 6.88x10-7 0.00496
Iodine-131 8 days NR 8.89x10-5 NR NR 5.92x10-5 NR 1.48x10-4
Iodine-133 20.8 hrs NR NR NR NR 0.00196 NR 0.00196
Xenon-135 9.1 hrs NR NR NR NR 0.0319 NR 0.0319
Particulates
S-35 87.2 days NR NR NR NR NR 2.00x10-6 2.00x10-6
Cobalt-60 5.3 yrs NR 5.89x10-9 NR NR NR 3.34x10-17 5.89x10-9
Ni-63 100 yrs NR NR NR NR NR 2.00x10-7 2.00x10-7
Sr-89,90g 29.1 yrs 1.81x10-4 0.00188 8.32x10-5 7.19x10-5 1.19x10-5 1.11x10-4 0.00227
Zr-95 (Nb-95) 64 days NR NR NR NR NR 2.39x10-14 2.39x10-14
Ru-106 1.0 yrs 3.99x10-6 5.76x10-9 NR NR NR 4.96x10-12 4.00x10-6
Sb-125 2.8 yrs NR NR NR NR NR 7.27x10-15 7.27x10-15
Cesium-134 2.1 yrs NR 1.49x10-6 NR NR NR 1.40x10-17 1.49x10-6
Cesium-137 30.2 yrs 1.04x10-4 5.28x10-4 NR NR 1.51x10-6 4.33x10-11 6.34x10-4
Cesium-144 285 days NR NR NR NR NR 1.13x10-13 1.13x10-13
Eu-154 8.6 yrs NR NR NR NR NR 3.44x10-13 3.44x10-13
Eu-155 4.7 yrs NR NR NR NR NR 1.63x10-13 1.63x10-13
U-235,238 4.5x109 yrs NR 0.00186 1.55x10-5 NR 2.89x10-8 4.74x10-5 0.00192
Pu-238 87.7 yrs NR 0.00121 NR NR 1.00x10-8 4.63x10-12 0.00121
Pu-239h 2.4x104 yrs 4.11x10-6 0.00106 3.50x10-6 8.42x10-7 9.41x10-6 4.70x10-7 0.00108
Am-241,243 7.4x103 yrs NR 1.42x10-4 NR NR 1.34x10-6 8.86x10-13 1.43x10-4
Cm-242,244 18.1 yrs NR 4.96x10-5 NR NR 6.83x10-6 7.33x10-12 5.64x10-5

a. Source: Arnett, Karapatakis, and Mamatey (1994).

b. H-3= tritium Sb = antimony
S = sulfur Eu = europium
Ni= nickel U = uranium
Sr= strontium Pu = plutonium
Zr= zirconium Am = americium
Nb= niobium Cm = curium
Ru= rubidium

c.One curie equals 3.7x1010 becquerels.
d.Savannah River Technology Center.
e.Estimated releases from minor unmonitored diffuse and fugitive sources (i.e., sources other than stacks or vents such as windows and doors).
f.NR = not reported.
g.Includes unidentified beta-gamma emissions.
h.Includes unidentified alpha emissions.



3.5.3 NONRADIOLOGICAL CONDITIONS



3.5.3.1 Background Air Quality

SRS is in an area that is designated an attainment area because it complies with National Ambient Air Quality Standards for criteria pollutants, including sulfur dioxide, nitrogen oxides (reported as nitrogen dioxide), particulate matter (less than or equal to 10 microns in diameter), carbon monoxide, ozone, and lead (see 40 CFR 81). The closest nonattainment area (an area that does not meet National Ambient Air Quality Standards) to SRS is the Atlanta, Georgia, air quality region, which is 233 kilometers (145 miles) to the west.

Sources in attainment areas must comply with Prevention of Significant Deterioration regulations. The regulations apply to new and modified sources of air pollution if the net increase in emissions from the new or modified source is determined to exceed the Prevention of Significant Deterioration annual threshold limit (see 40 CFR 52.21). Development at SRS has not triggered Prevention of Significant Deterioration permitting requirements, nor is it expected to trigger such requirements in the future.