4.9 ECOLOGY
The information in this section is a summary of a more detailed analysis of the ecological characteristics and the status of threatened and endangered species in Appendix F, and of wetlands in Appendix G. The scientific names of species mentioned in this section appear in Appendix F.
4.9.1 Vegetation
LLNL Livermore Site
The LLNL Livermore site covers 821 acres of which approximately 640 acres are developed. The vegetation at this site was initially altered in the 1800s when livestock grazing began on a large scale in the Central Valley and surrounding areas of California. The intensity of grazing that took place on lands at this site is not known; however, it is highly likely that the native perennial grasslands and riparian plant communities were adversely altered by grazing and other agricultural activities. Grazing is one of the principal reasons for the significant loss and degradation of wetland riparian plant communities in the Central Valley and surrounding areas (Warner, 1981).
The plant communities at the LLNL Livermore site were further degraded and destroyed when the U.S. Navy acquired the land in 1942 and covered the site with concrete runways, roads, and buildings. In addition, Arroyo Las Positas, which flowed through the site, was channelized and now traverses part of the eastern boundary and flows through the northern part of the site.
The developed areas at the LLNL Livermore site are planted with ornamental vegetation and lawns. There are also small areas of disturbed ground with early successional plant species. The undeveloped land in the security zone is the introduced grassland plant community dominated by non-native grasses such as slender oat and ripgut brome.
Another relatively undisturbed plant community at the LLNL Livermore site is a remnant of the native wooded riparian plant community along Arroyo Seco. This arroyo bisects SNL, Livermore and traverses the southwest corner of the LLNL Livermore site. At the LLNL Livermore site, Arroyo Seco is steep-sided, with the slopes covered with grass species such as slender oat and ripgut brome. Much of the arroyo has native tree species such as red willow and California walnut, and introduced species such as black locust and almond.
LLNL operations do not usually impact vegetation offsite. One current project that would affect vegetation offsite is the infrastructure modernization project. Part of this project is an 8000-ft-long 16-inch water supply pipeline from the Hetch Hetchy water supply Mocho Pumping Station to SNL, Livermore. The water supply pipeline is within an existing 10-ft right-of-way. Two thousand ft are below a currently paved area, while 6000 ft are in natural or landscaped areas. Construction of this pipeline would result in an estimated temporary clearing of 1.4 acres of existing plant communities (assuming a 10-ft-wide disturbance zone along the 6000-ft pipeline). The disturbed area would become vegetated with early succession grasses and forbs soon after completion of the project.
LLNL Site 300
LLNL Site 300 covers approximately 7000 acres of land in eastern Alameda County and western San Joaquin County. The northern portion is characterized by rolling hills while the southern part consists of steep, deep canyons. The site was acquired in 1953, and since then no grazing or farming has taken place. A relatively small part (approximately 5 percent) has been developed for LLNL activities; the remainder is undisturbed, except for controlled burning. Controlled burning takes place every year on approximately 2000 acres of land in the northern part of the site.
Four upland plant community types are located within LLNL Site 300: (1) introduced grassland, (2) native grassland, (3) coastal sage scrub, and (4) oak woodlands (Taylor and Davilla, 1986a). (See Figure F-3 in Appendix F, which is a plant community type map.) Introduced grasslands cover 5647 acres, and are dominated by slender oat and ripgut brome grass; native perennial grasslands cover approximately 723 acres, and are dominated by pine bluegrass. Coastal sage scrub plant community type is dominated by California sagebrush, California buckwheat, black sage, and snakeweed. This type typically occurs on southwest facing slopes in the southern portion of the site and covers 108 acres. Oak woodland, dominated by blue oak, occurs in scattered areas on steep slopes in the southern half of the site and covers approximately 150 acres. The understory is dominated by grassland species such as brome grass and slender oat (Taylor and Davilla, 1986a). Small areas of wetlands occur at the site and are discussed in section 4.9.4 below.
Ongoing practices at LLNL Site 300 that affect the site's vegetation include the exclusion of grazing and other agricultural uses; annual maintenance of fire roads and breaks; an annual controlled burn; weed control along roads, power poles, and security fences; planned minor construction in or adjacent to existing facilities; and road-widening projects. The maintenance of fire roads and breaks, and weed control measures, for example, have resulted in sparse vegetative cover dominated by early successional plant species and including introduced grass species. The area of land disturbed for fire roads, weed control, buildings, and other facilities, however, occupies less than 5 percent of LLNL Site 300 total area.
The exclusion of grazing and other agricultural activities has resulted in a greater diversity of plant community types at LLNL Site 300 than in nearby offsite lands that are grazed. In addition, steep onsite slopes show less instability and erosion than nearby grazed lands because of a more stable plant cover, including soil-building native plant species (Taylor and Davilla, 1986a).
Approximately 2000 acres are burned annually at LLNL Site 300 to control vegetation that could become an uncontrolled fire hazard. These burns have been conducted for the last 31 years. The development of stands of native grassland is strongly correlated with the burn area (see Figure F-4 in Appendix F) (Taylor and Davilla, 1986a). The exclusion of grazing and other agricultural practices in 1953 may also have contributed to the development of the over 700 acres of native perennial grasslands onsite.
Under current operations, a major funded project that will affect vegetation is the LLNL Site 300 Revitalization Project. Vegetation would be removed by various aspects of this plan including road improvements (14.5 acres), construction of a central control port (0.6 acre), and water system improvements (1.4 acres onsite and 2.0 acres offsite). A total of 16.5 acres of introduced grassland habitat would be eliminated onsite. The offsite water supply improvements include a 1.7-mile 10-inch pipeline from San Francisco's Hetch Hetchy water supply system. Construction of this pipeline would result in the temporary disturbance of an estimated 2.0 acres of land (assuming a 10-ft width disturbance zone along the 1.7-mile-long pipeline). The plant community types along this pipeline have not been characterized; these 2.0 acres of land are likely to be in the introduced grassland plant community type. The loss of vegetation from this project is long term for the road widening and control tower construction (15.1 acres) and short term (1 year) for the remaining construction activities.
SNL, Livermore
SNL, Livermore covers 413 acres, of which approximately 213 acres are developed and 200 acres are undeveloped land. As with the LLNL Livermore site, the vegetation was initially altered in the 1800s due to livestock grazing. The developed areas have been landscaped and there are also small areas of disturbed ground with early successional plant species. The undeveloped land in the security zone is grassland, dominated by non-native grasses such as slender oat and ripgut brome.
Arroyo Seco has three distinct segments at SNL, Livermore based on vegetative characteristics (Environmental Science Associates, Inc., 1990). The eastern segment of this drainage supports a remnant riparian strip of vegetation consisting of several large sycamore, valley oak, and numerous red willow. The riparian understory includes patches of mule fat, seaside heliotrope, curly dock, and tree tobacco. Ripgut brome and slender oat grow along the channel-grassland interface in most areas. Patches of cattail and rush, and a high concentration of red willow occur at the existing flood control area near the eastern border of the site.
The central segment of Arroyo Seco at SNL, Livermore measures approximately 8 ft wide and supports less diverse vegetation because of the developed adjacent areas. A few valley oak, almond, and species characteristic of disturbed sites persist. Arroyo Seco exits the developed portion of the site by way of a 75-ft cement-lined flood control channel. Vegetation along this improved portion of the channel includes a canyon live oak, annual grasses, and several early successional species.
Vegetation within or adjacent to the western segment of the channel consists of a canopy of red willow, valley oak, and several eucalyptus with a sparse understory of seaside heliotrope, ripgut brome, slender oat, and other early successional species. This segment of the channel measures roughly 12 ft wide and 15 ft deep (Environmental Science Associates, Inc., 1990).
Operations at SNL, Livermore have resulted in the construction of projects in developed areas. Because these areas contain sparse vegetation that is not sensitive, the impacts of these activities on vegetation is minimal.
Tritium Levels in Vegetation and Commodities
In 1990, tritium was measured in Livermore Valley rainwater, vegetation, milk, wines, and honey (LLNL, 1991f). The dose received from consumption of all products is analyzed by the AIRDOS-PC model discussed in section 4.10. In 1990, the tritium content of the moisture in vegetation in the Livermore Valley ranged from 2.2×10-7 mCi/mL to 1.4×10-6 mCi/mL depending on the sampling location. The maximum potential dose resulting from the consumption of vegetation with the highest average tritium concentration is 6.6×10-5 rem/yr (0.066 mrem/yr) (LLNL, 1991f). In addition, two sampling locations at LLNL Site 300, one adjacent to a landfill and one adjacent to the Building 850 Firing Table, which is the source of the tritium, have, since 1971, frequently shown elevated tritium values in the moisture in vegetation. During 1990, the highest reported value was 4.2×10-5 mCi/mL and the average at that location was 1.3×10-5 mCi/mL. This vegetation is not consumed by humans nor is it used as a source of feed; however, if a hypothetical person's total diet was only this vegetation (grasses), the resulting annual dose would be 2.3×10-4 rem (0.23 mrem). This dose is well within the radiation dose limit of 0.01 rem (10 mrem) per year specified in NESHAP for radiation doses resulting from airborne releases of radionuclides and far below the average background dose of 0.3 rem (300 mrem) per year. The radiation dose to animals would be about the same as to humans and is well below the exposure levels needed to ensure protection of nonhuman populations (NCRP, 1991).
Retail wines produced in the Livermore Valley, California wines from outside the Livermore Valley, and wines from European vineyards are also analyzed for tritium. The average tritium concentration of Livermore Valley wines sampled between 1986 and 1989 was 3.35×10-7 µCi/mL. This is greater than the average tritium concentrations of wines produced in other regions of California (1.05×10-7 µCi/mL) and Europe (2.43×10-7 µCi/mL) purchased during this same period. There are no health or environmental standards for tritium in wine; however, the observed tritium levels are well below the regulatory limit for drinking water of 2×10-5 mCi/mL. The potential dose from drinking Livermore Valley wines was calculated for both a high and a realistic consumption rate. High consumption assumes a person drinks one bottle (0.75 liter) per day for a year. The more realistic scenario assumes a person drinks one bottle of wine per week for a year. Using the 3.35×10-7 µCi/mL average tritium concentration, the resulting effective dose equivalents are 6×10-6 rem/yr (0.006 mrem/yr) and 8×10-7 rem/yr (0.0008 mrem/yr), respectively. These doses are well within the radiation dose limit of 0.01 rem (10 mrem) per year specified in NESHAP for radiation doses at the edge of nuclear facilities resulting from airborne releases of radionuclides and far below the average background dose of 0.3 rem (300 mrem) per year.
The highest tritium concentration measured in goat milk in the Livermore Valley in 1990 was reported to be 3.8×10-6 mCi/mL. Consumption of 310 L per year of goat milk at this concentration would result in an annual radiation dose of 4.6×10-6 rem (0.0046 mrem). (For an explanation of concentrations (mCi/mL) and doses (mrem) see section 4.16.) This dose is well within the radiation dose limit of 0.01 rem (10 mrem) per year specified in NESHAP for radiation doses resulting from airborne releases of radionuclides and far below the average background dose of 0.3 rem (300 mrem) per year. Tritium levels measured in Livermore area honey fluctuate significantly from year to year, and may be either higher or lower than in other California honey. Tritium is found in honey in about the same concentrations as those found in wine; in 1990, the concentration ranged from 1.3×10-7 to 7.9×10-7 mCi/mL and averaged 3.2±1.0×10-7 µC/mL. There are no health or environmental standards for tritium in honey; however, the observed tritium levels are below regulatory levels for drinking water of 2×10-5 mCi/mL (LLNL, 1991f).
It should be noted that the calculation of radiation doses for tritium releases into the atmosphere using AIRDOS-PC, and presented in section 4.10, assume that food ingested is in equilibrium with the tritiated water vapor in the air. Thus the doses presented above are a subset of the AIRDOS-PC calculations and are not additive.
4.9.2 Fish and Wildlife
There are no perennial streams or permanent bodies of water at LLNL or SNL, Livermore, other than the sewage lagoon at LLNL Site 300. Fish are not known to inhabit the sewage lagoon, although amphibians such as the red-legged frog do.
LLNL Livermore Site
A total of 3 species of amphibians and reptiles, 31 species of birds, and 10 species of mammals were observed at the LLNL Livermore site during the 1991 biological surveys (see Tables F-6 through F-8 in Appendix F for lists of species).
Wildlife includes species that live in the undeveloped grassland and species that live in the developed areas or along the arroyo. Representative species observed in the undeveloped grassland areas include the fence lizard, the black-tailed hare, the California ground squirrel, the red fox, and the western meadowlark. Nesting birds include the American crow, American robin, house finch, mockingbird, and house sparrow. These species nest in the planted trees onsite. A raven's nest was observed among some pipes on an LLNL Livermore site building. Bird species observed along Arroyo Seco include the mourning dove, acorn woodpecker, and turkey vulture.
Current operations and funded projects result in a minimal impact to wildlife resources since most of the activities occur in developed areas that do not contain important wildlife habitat. A small amount of wildlife habitat associated with the Mocho Pumping Station water supply pipeline, as described in section 4.9.1, would be affected. This effect would be minimal due to the small amount of land cleared and the rapid revegetation of disturbed ground.
LLNL Site 300
LLNL Site 300, with large areas of undisturbed vegetation, interspersion of various plant community types, and availability of water at springs, provides habitat for a diversity of wildlife.
A total of 20 amphibian and reptile species have been observed at LLNL Site 300 (see Table F-6 in Appendix F). The scarcity of permanent water limits the potential of LLNL Site 300 to support more than a few species of amphibians. Aquatic habitat is available at the sewage lagoon and some of the drainages contain aquatic vegetation supported by underground springs and seeps. Two species of salamanders were observed: the California slender salamander and the tiger salamander. The latter species was observed during 1986 biological surveys (Orloff, 1986), but not during 1991 surveys. Frog and toad species known to occur on the site are the western toad, Pacific treefrog, and red-legged frog.
Conditions are far more favorable for reptiles than for amphibians. Grassland provides ideal habitat for racers and gopher snakes. Rock sites provide suitable habitat for such species as the western fence lizard, western skink, common kingsnake, and the western rattlesnake. Seeps and springs provide excellent habitat for the northern alligator lizard. Side-blotched lizards and California horned lizards frequent areas with more open vegetation and sandy soils.
A total of 70 bird species have been observed at LLNL Site 300 (see Table F-7 in Appendix F). These species were recorded during springtime biological surveys in both 1986 (Orloff, 1986) and 1991. Although grasslands normally support a limited resident bird population, the LLNL Site 300 interspersion of several different plant community types and an abundance of seeds and insects provide good habitat for a variety of birds. The western meadowlark, horned lark, and savannah sparrow were the most common small birds seen throughout the open grassland areas. Vegetation at springs and seeps provides nesting habitat for the red-winged blackbird. These permanent water sources attract a greater number of birds than normally found in the adjacent grasslands. For example, mourning dove, cliff and barn swallow, and California quail all require daily water. Oak woodland and a few cottonwood provide nesting habitat for western kingbird, northern oriole, loggerhead shrike, and American goldfinch. Coastal sage scrub supports scrub jay, Anna's hummingbird, rufous-crowned sparrow, and white-crowned sparrow. Ecotones (boundary areas between two habitats) of sage scrub and grassland provide ideal habitat for mourning dove, California quail, lazuli bunting, and lark sparrow. Rocky outcrops and cliffs provide breeding sites for white-throated swift, cliff swallow, Say's phoebe, and rock wren.
LLNL Site 300 supports a population of nesting raptors. Several great horned owl and barn owl nests were found on rock ledges of steeper cliffs. The great horned owl nested onsite in 1986 and 1991, while the barn owl nested onsite only in 1986. These cliffs also provide potential nest sites for the golden eagle and prairie falcon, although these species are not known to nest onsite. Several pairs of red-tailed hawks nested in large trees and on a utility pole onsite. Areas with taller grasses may allow ground-nesting raptors such as the northern harrier and short-eared owl to successfully breed onsite; however, there is no indication that these species nested onsite in 1991.
A total of 26 mammal species have been observed onsite (see Table F-8 in Appendix F). Mammals were recorded during threatened and endangered species surveys that included ground surveys over the entire site, night spotlighting, and establishment of scent stations in 1986 and 1991, and small-mammal trapping in 1986 (Orloff, 1986).
Productive and diverse grasslands on LLNL Site 300 support an abundance of rodents and lagomorphs (rabbits and hares). Conditions are ideal for California ground squirrels in the northern portion of LLNL Site 300 where the terrain is less rugged. Other common rodents include the house mouse, deer mouse, kangaroo rat, pocket gopher, and, in the higher grass cover, the California vole and western harvest mouse. Lagomorphs such as black-tailed hares and desert cottontails are also widespread and abundant, with the latter tending to occupy areas with more cover.
Rocky areas with associated coastal sage scrub support the California pocket mouse and desert woodrat. The woodrat occurs primarily in rocky areas in this northern extreme of its range.
Many mammalian predators are supported by this rich prey base. Grassland predators include long-tailed weasel, spotted skunk, striped skunk, coyote, American badger, and bobcat. Only the American badger is restricted to open grasslands. Red foxes, which have been reported from nearby areas to the east and north of the site (California Department of Fish and Game, 1983; Bio-Tech, 1983), have greatly expanded their range in the Central Valley in recent years. They show a preference for more disturbed areas, often denning in roadside culverts. Sage scrub, wooded, and riparian habitats attract other mammalian predators not normally found in grasslands, including gray fox, raccoon, and mountain lion. Although these habitats are preferred, they are relatively limited on LLNL Site 300; consequently, grassland areas are used as well. Only minor areas of riparian vegetation are associated with the seeps and springs that occur along the canyon bottoms. Black-tailed deer prefer these habitats but are frequently seen in the open grasslands.
The maintenance of fire roads, fire breaks, and weed control are current operations that adversely affect wildlife through the elimination of vegetation; however, these areas typically become revegetated each year and provide some wildlife habitat. The controlled burn and the exclusion of grazing and other agricultural practices promote a diversity of wildlife habitat at LLNL Site 300. Burns are usually uneven, with vegetation burned to the ground in some places, partially burned in others, and some patches unburned. This patchiness is beneficial to wildlife. Although the controlled burn may be detrimental to small grassland-nesting birds and other small species of wildlife, together with the exclusion of livestock grazing and other agricultural practices the burn has created a positive effect by creating diverse habitat that supports a variety of wildlife species.
The clearing of 18.5 acres of land for the LLNL Site 300 Revitalization Plan, as described in section 4.9.1, would displace wildlife typical of the grassland plant community. Much of this area (15.1 acres) represents a long-term loss of wildlife habitat. However, this habitat has marginal value to wildlife because it is in highly disturbed land along roads.
SNL, Livermore
Wildlife use at SNL, Livermore is similar to that described above for the LLNL Livermore site.
4.9.3 Threatened and Endangered Species
Detailed studies for threatened, endangered, and other species of concern (referred to as sensitive species in this section) were conducted at the LLNL Livermore site, LLNL Site 300, and SNL, Livermore. Other species of concern refers to federal candidate species and California species of special concern. The details regarding these studies appear in the biological assessment in Appendix F, section F.2; the results are summarized in this section.
Informal consultation was initiated on February 6, 1991, when the U.S. Fish and Wildlife Service was requested to provide a list of potential sensitive species that may occur at the sites. Such a list was provided on March 5, 1991 (The Fish and Wildlife Service letter is Attachment 1 of Appendix F). A meeting to discuss proposed studies of sensitive species was held with the Fish and Wildlife Service on April 9, 1991. During this time and later, informal consultations were held with the California Department of Fish and Game to review proposed studies and to receive input regarding potential sensitive species to be addressed. This consultation process, along with knowledge of additional sensitive species that may occur near the site, resulted in the identification of 40 plant and animal sensitive species that may occur at the sites (Table 4.9-1).
The methods used to evaluate the status of the species listed in Table 4.9-1 are presented in section F.2.4 of Appendix F. The methods were consistent with federal and/or state guidelines where such guidelines exist. Where such guidelines do not exist, survey methods consistent with accepted biological techniques were used. Surveys were conducted by botanists and zoologists with training and experience in conducting surveys for the species in question.
LLNL Livermore Site
There were no sensitive plants, invertebrates, amphibians, reptiles, birds, or mammals observed during surveys at the LLNL Livermore site.
LLNL Site 300
The location of sensitive habitats at LLNL Site 300 is shown in Figures 4.9-1, 4.9-1A, 4.9-1B, and 4.9-1C. (Figure 4.9-1 is an index map for these figures). The only sensitive plant species known to occur at LLNL Site 300 is the federal and state endangered large-flowered fiddleneck. This species is known to exist naturally in only three locations; two are at LLNL Site 300 (Figure 4.9-1B), and one is on a nearby ranch. The largest population onsite (Drop Tower population) was discovered in the 1960s and during recent years has fluctuated between 23 and 355 individual plants. The second onsite population was discovered near the bottom of a deep canyon in 1988 and is approximately 2 miles west of the Drop Tower population. The large-flowered fiddleneck is considered one of the most endangered plant species in California and perhaps the nation (Pavlik, 1990). Surveys in 1986 (Taylor and Davilla, 1986b) and surveys of nine canyons and several side canyons in 1991 failed to identify any additional populations of the large-flowered fiddleneck at LLNL Site 300. The recovery plan for this species that was prepared by the U.S. Fish and Wildlife Service called for the establishment of four additional populations of this species within its historic range to reduce the possibility of extinction. A population of this species was successfully introduced near Antioch in 1990 (Pavlik, 1990) and three additional sites were established during the fall of 1991 (Pavlik, 1991). (See Appendix F for further details regarding protection of this species.)
The valley elderberry longhorn beetle is the only sensitive insect (federal threatened) of those listed on Table 4.9-1 that has the potential to occur at LLNL Site 300. This species occurs almost exclusively on elderberry bushes, so elderberry that grow within the range of this species are considered potential habitat. A fairly large stand of elderberry occurs in a series of canyons just north of Elk Ravine, while a lesser stand occurs in the wooded riparian zone along Elk Ravine. Elderberry is known to occur in small clumps in three other locations on LLNL Site 300 (see Figure 4.9-1A and Figure 4.9-1B). No valley elderberry longhorn beetles were observed during the 1991 survey; however, this species is secretive and often difficult to find.
Four species of fairy shrimp (federal candidate species) have the potential to occur at LLNL Site 300. Sampling of water and soil in appropriate habitat did not result in the observation of these species.
The California tiger salamander and red-legged frog (both federal candidate and state species of special concern) were observed at LLNL Site 300 during 1986 surveys (Orloff, 1986). These species were not observed onsite during 1991 surveys except for red-legged frog tadpoles in the LLNL Site 300 sewage lagoon.
The Alameda whipsnake (federal candidate and state threatened species) was observed onsite in 1986 (Orloff, 1986). This species was not observed at LLNL Site 300 in 1991, although the closely related California whipsnake was recorded in two locations in 1991. Potential habitat for the whipsnake subspecies is chaparral brush, broken by grassy patches and rocky gullies, or stream courses with scattered trees and shrubs (Orloff, 1986). This type of habitat was mapped at LLNL Site 300 (mostly the coastal sage scrub plant community type) and is designated as potential habitat for this state threatened and federal candidate species (Figure 4.9-1B).
The California horned lizard (state species of special concern) was observed during the 1991 field surveys. This species was observed in the more open grasslands with sandy or gravelly areas at the northern portion of the site.
Of the bird species listed in Table 4.9-1, only the golden eagle and burrowing owl (both state species of special concern) were observed during the 1991 surveys. Immature and adult golden eagles were observed frequently at LLNL Site 300 soaring and feeding, mostly in the rolling terrain in the northern segment of the site. All cliffs and other appropriate areas were searched for nests and none were observed for the golden eagle.
In 1986, the burrowing owl was a relatively common nesting species at LLNL Site 300, especially in the more gently rolling terrain in the north (Orloff, 1986). Surveys in 1991 confirmed that this species is still nesting, but at reduced levels, at LLNL Site 300.
The tricolored blackbird (federal candidate species) was observed nesting in cattail at two locations at LLNL Site 300 in 1986 (Orloff, 1986). This species was not observed nesting at LLNL Site 300 in 1991.
Of the mammals listed on Table 4.9-1, the San Joaquin pocket mouse (formerly a federal candidate species) and the American badger (state species of special concern) were the only species observed onsite. Detailed surveys for the San Joaquin kit fox (federal endangered, state threatened) were conducted at LLNL Site 300 in 1980 (Rhoads et al., 1981), 1986 (Orloff, 1986), and 1991. Neither the kit fox nor active dens were observed at LLNL Site 300 during these surveys; however, three possible kit fox scats and one possible track were observed onsite in 1991. At present the kit fox is not considered a resident species at LLNL Site 300, although this area is potential habitat.
The San Joaquin pocket mouse was observed during the 1986 (Orloff, 1986) and 1991 surveys and is considered a resident species at LLNL Site 300. Potential habitat for this species at LLNL Site 300 is extensive since this species inhabits grassland with fine soils and scattered shrubs. This species was recently removed from the list of federal candidate species (56 Fed. Reg. 53,804-58,836, 1991).
The American badger was observed at LLNL Site 300, occurring in the more rolling terrain at the northern segment of the site.
A summary of potential impacts of current LLNL Site 300 operations on sensitive species that occur or have the potential to occur onsite appears on Table 4.9-2. A more detailed discussion of these impacts is included in Appendix F. As indicated in the table, while the impacts of the annual controlled burn are generally beneficial or inconsequential for most species, the practice has the potential to injure the young of ground-nesting raptors (short-eared owl and northern harrier) and negatively affect fairy shrimp habitat. However, the two raptor species referred to did not nest onsite in 1991, and sampling for fairy shrimp indicates that these species do not occur at LLNL Site 300. The impact of the exclusion of grazing has had a beneficial effect or no effect on sensitive species. Taken together, the controlled burn and lack of livestock grazing have promoted a high degree of habitat and species diversity that occurs in few grassland ecosystems in California. These practices have had an overall positive impact on sensitive wildlife species at LLNL Site 300.
As indicated on Table 4.9-2, the impact of ground squirrel poisoning (conducted as needed for rodent control) has the potential to be slightly adverse to most sensitive species. This poisoning occurs principally at the two high explosives wastewater surface impoundments. These impoundments are fenced, preventing access to most species of wildlife, and are in an area of relatively high human activity. Sensitive species were not observed at or near these impoundments during the 1991 surveys. Potential kit fox dens were not observed at or near these impoundments during the sitewide sensitive species surveys in 1986 (Orloff, 1986) or during the 1991 surveys. In addition, burrows and dens of the burrowing owl and American badger; raptor nests; and potential habitat of the valley elderberry longhorn beetle, tiger salamander, red-legged frog, and Alameda whipsnake do not occur in the area of these impoundments. Further, there have been no reported occurrences of sensitive species mortality in the impoundments. Therefore, the ground squirrel poisoning at the surface impoundments does not appear to affect sensitive species.
The disking of fire roads and fire breaks to prevent the spread of fire onto ranches bordering LLNL Site 300 has the potential to have an adverse effect on some species and to be beneficial to others (see Table 4.9-2). This activity has the potential to trap species such as the San Joaquin pocket mouse, American badger, burrowing owl, and San Joaquin kit fox in their dens and burrows. Vehicle traffic has no impact or only a slightly adverse impact depending on the type of sensitive species (see Table 4.9-2). One San Joaquin pocket mouse (formerly listed as a candidate species) was found dead along a road in 1986 (Orloff, 1986) and 1991. No records exist of other sensitive species mortality related to vehicle traffic. The potential for sensitive species mortality remains low because of LLNL's policy regarding speed limits and limited vehicle traffic on the fire trails. The potential for sensitive species to be killed or injured by traffic on the road is negligible. There is also judged to be no impact from onsite fencing because there are sufficient openings (except the fencing around the surface impoundment) for the passage of large and small mammals. Explosives testing has no impacts or only slightly adverse impacts depending on the type of sensitive species (see Table 4.9-2). The use of warning sounds before explosives testing reduces any potential impact to raptors soaring overhead. The surface impoundments could have an adverse impact on two sensitive bat species if they were to forage for food over the impoundments; however, these species are not known to occur at LLNL Site 300. In addition, as indicated above for ground squirrel poisoning, sensitive species or potential habitat for sensitive species do not occur in the area of the surface impoundments. Also, these impoundments are fenced to exclude most wildlife and are in an area with a relatively high degree of human activity. Therefore, the surface impoundments do not have a negative impact on sensitive species. The sewage lagoon is judged to have a beneficial impact or no impact on sensitive species.
The site revitalization project at LLNL Site 300 will result in the clearing of 18.5 acres in the introduced grassland plant community (as described in section 4.9.1); this area is potential sensitive species habitat. The California horned lizard, burrowing owl, San Joaquin pocket mouse, and American badger are sensitive species that have the potential to occur in this grassland habitat. In addition, this area represents potential San Joaquin kit fox habitat even though this species was not observed during sitewide sensitive species surveys in 1986 (Orloff, 1986) or 1991, or at any other time. LLNL performs preconstruction surveys for the burrowing owl, American badger, and San Joaquin kit fox so these species can be protected from potential harm. The potential also exists for some incidental effects to the California horned lizard and the San Joaquin pocket mouse (formerly listed as a candidate species) from construction projects associated with site revitalization projects.
Because sensitive habitats are protected, operations at the site do not affect other sensitive species, including the large-flowered fiddleneck, valley elderberry longhorn beetle habitat, Alameda whipsnake, California tiger salamander, and California red-legged frog, or birds of prey. The large-flowered fiddleneck populations onsite are currently protected from human disturbance. A plan to protect the valley elderberry longhorn beetle habitat from any disturbance would be implemented through the establishment of a 300-foot protected zone around the clumps of elderberry bushes (see mitigation measure 7.2.6B in section 5.1.7.3). The whipsnake habitat that occurs in the coastal sage scrub plant community in the southern part of the site has been designated sensitive habitat. The two amphibians may occupy springs at LLNL Site 300. These areas also have been designated as sensitive habitat (see Figure 4.9-1).
SNL, Livermore
No sensitive plants, invertebrates, amphibians, reptiles, birds, or mammals were observed during surveys at SNL, Livermore.
Table 4.9-1 Sensitive Species That May Occur at the LLNL Livermore Site, LLNL Site 300, and SNL, Livermore
| Site | Status | |||
| Species | LLNL Livermore Site SNL, Livermore | LLNL Site 300 | Federal | State |
| Plants | ||||
| Palmate bird's beak | X | Endangered | Endangered | |
| Large-flowered fiddleneck | X | Endangered | Endangered | |
| Valley spearscale | X | Candidate | --- | |
| Hispid bird's-beak | X | Candidate | Rare | |
| Contra Costa buckwheat | X | Candidate | --- | |
| Diamond-petaled poppy | X | Candidate | --- | |
| Hairless allocarya | X | Candidate | --- | |
| Showy Indian clover | X | Candidate | --- | |
| Caper-fruited tropidocarpum | X | Candidate | --- | |
| Invertebrates | ||||
| Valley elderberry longhorned beetle | X | Threatened | --- | |
| Ricksecker's water scavenger beetle | X | Candidate | --- | |
| Curved-foot hygrotus diving beetle | X | Candidate | --- | |
| Molestan blister beetle | X | Candidate | --- | |
| Callippe silverspot butterfly | X | Candidate | --- | |
| Vernal pool fairy shrimp | X | X | Candidate | --- |
| California linderiella | X | X | Candidate | --- |
| Conservancy fairy shrimp | X | X | Candidate | --- |
| Longhorned fairy shrimp | X | X | Candidate | --- |
| Amphibians | ||||
| California tiger salamander | X | X | Candidate | Species of special concern |
| California red-legged frog | X | X | Candidate | Species of special concern |
| Reptiles | ||||
| Alameda whipsnake | X | X | Candidate | Threatened |
| California horned lizard | X | X | --- | Species of special concern |
| Birds | ||||
| Golden eagle | X | --- | Species of special concern | |
| Bald eagle | X | X | Endangered | Endangered |
| Black-shouldered kite | X | --- | California protected | |
| Cooper's hawk | X | --- | Species of special concern | |
| Northern harrier | X | --- | Species of special concern | |
| Peregrine falcon | X | Endangered | Endangered | |
| Prairie falcon | X | --- | Species of special concern | |
| Swainson's hawk | X | --- | Threatened | |
| Sharp-shinned hawk | X | --- | Species of special concern | |
| Short-eared owl | X | --- | Species of special concern | |
| Burrowing owl | X | --- | Species of special concern | |
| Tricolored blackbird | X | Candidate | --- | |
| Mammals | ||||
| Pacific western big-eared bat | X | X | Candidate | Species of special concern |
| Great western mastiff bat | X | X | Candidate | Species of special concern |
| San Joaquin kit fox | X | X | Endangered | Threatened |
| San Joaquin pocket mouse | X | Candidate* | --- | |
| Riparian woodrat | X | Candidate | Species of special concern | |
| American badger | X | X | --- | Species of special concern |
* No longer a federally listed candidate species (Fed. Reg., November 21, 1991).
Table 4.9-2 Summary of Impacts Matrix for Sensitive Species That Occur or Have the Potential to Occur at LLNL Site 300a
| Species | Annual Controlled Burning | Lack of Livestock Grazing | Ground Squirrel Poisoning | Disking Fire Roads and Fire Breaks | Vehicle Traffic | Fencing Facilities | Explosive Testing | Surface Impoundments | Sewage Lagoon |
| Large-flowered fiddleneckb | none | beneficial | none | none | none | none | none | none | none |
| San Joaquin kit foxc | beneficial | mixed | slightly adverse | adverse | slightly adverse | none | slightly adverse | none | none |
| San Joaquin pocket mousee | beneficial | beneficial | slightly adverse | adverse | slightly adverse | none | none | none | none |
| American badgerb | beneficial | beneficial | slightly adverse | adverse | slightly adverse | none | slightly adverse | none | none |
| Pacific western big-eared batd | none | none | none | none | none | none | none | adverse | beneficial |
| Great western mastiff batd | none | none | none | none | none | none | none | adverse | beneficial |
| Golden eagleb | beneficial | mixed | slightly adverse | beneficial | none | none | slightly adverse | none | none |
| Prairied falcon | beneficial | beneficial | slightly adverse | beneficial | none | none | slightly adverse | none | none |
| Burrowing owlb | beneficial | mixed | slightly adverse | slightly adverse | none | none | slightly adverse | none | none |
| Short-eared owld | mixed | beneficial | slightly adverse | slightly adverse | none | none | slightly adverse | none | none |
| Black-shouldered kited | beneficial | none | slightly adverse | beneficial | none | none | slightly adverse | none | none |
| Northern harrierd | mixed | beneficial | slightly adverse | beneficial | none | none | slightly adverse | none | none |
| Tricolored blackbirdd | none | beneficial | none | none | none | none | none | none | beneficial |
| Alameda whipsnakeb | none | none | none | none | none | none | none | none | none |
| California tiger salamanderd | none | beneficial | slightly adverse | none | slightly adverse | none | none | slightly adverse | beneficial |
| Red-legged frogb | none | beneficial | none | none | slightly adverse | none | none | slightly adverse | beneficial |
| Fairy shrimpd | slightly adverse | beneficial | none | slightly adverse | slightly adverse | none | none | none | none |
| Valley elderberry longhorn beetle potential habitatb | none | beneficial | none | none | none | none | none | none | none |
| California horned lizardb | none | none | slightly adverse | slightly adverse | slightly adverse | none | none | none | none |
aThis matrix represents the types of
impacts that may be expected to occur as a result of current operations.
However, except for limited vehicle-traffic–related mortality for such
species as the San Joaquin pocket mouse, there is no evidence that these types
of impacts have occurred onsite.
bSpecies observed during 1991 surveys.
cPotential habitat observed in 1991.
dSpecies not observed during 1991
surveys.
eNo longer a federally listed
candidate species (Fed. Reg., November 21, 1991).
4.9.4 Wetlands
Wetlands were mapped at LLNL and SNL, Livermore using the unified federal method (Federal Interagency Committee for Wetland Delineation, 1989). Although revisions to that document have been proposed, the 1989 version remains in effect until the revisions become final (56 Fed. Reg. 40,446–40,480, 1990). A detailed analysis of wetlands appears in Appendix G; the following is a summary of that appendix. The location of the natural wetlands at LLNL Site 300, including the vernal pool, are shown on Figures 4.9-1A, 4.9-1B, and 4.9-1C. Figures G-9 through G-23 in Appendix G are detailed maps of the LLNL Site 300 wetlands.
LLNL Livermore Site
Wetlands, though very limited at the LLNL Livermore site, do occur along Arroyo Las Positas at the northern perimeter of the site. These wetlands occur in three distinct areas and are associated with culverts that channel runoff from the surrounding area into this arroyo. Two areas totaling 0.3 acre were dominated by salt grass with a species of Carex also common. Willow, curly dock, primrose, and alkali ryegrass also occur here. The third wetland occurs along the arroyo near Building 194, and is a small area (0.06 acre) dominated by cattail.
Operations at the LLNL Livermore site do not affect the approximately 0.36 acre of wetlands along Arroyo Las Positas at the site other than to contribute to the amount of water discharged into the arroyo. Over time, wetland vegetation may increase along this arroyo from flow out of the onsite retention basin, which may fill with water from the ground water remediation program (this program is part of current operations). There is also the potential for wetlands to develop around the edge of the retention basin.
LLNL Site 300
LLNL Site 300 has 6.76 acres of wetlands. These wetlands are small and are in areas associated with the springs, runoff from some of the buildings, and one vernal pool (Figures 4.9-1A, 4.9-1B, and 4.9-1C). Many of the wetlands occur at springs in the bottom of deep canyons in the southern half of the site. These springs occur where water-bearing sandstone units outcrop in the canyon or valley bottoms. The wetlands that have developed at these springs are confined by the steep-sided canyon wall; they range in width from 5 to 30 ft and most are 10 to 20 ft wide. Most are relatively short, 100 to 600 ft; the longest in Oasis Canyon is approximately 2800 ft long. The plant species observed in these wetlands grew in relatively homogenous stands. Cattail was dominant in areas of flowing or totally saturated soil, forming dense stands, typically at the spring and downstream. Species such as rush, seep-spring monkey flower, and, in some places, white watercress were frequently observed in areas of flowing water. In some limited areas, rush was dominant in standing water or saturated soil. In drier areas, the alkali ryegrass forms dense stands and then intergrades into the upland plant communities. Large, isolated cottonwood were often present in the deep canyon spring-fed wetlands.
Of the 6.76 acres of wetlands, 1.88 acres are formed from runoff from four building complexes onsite. The dominant plant species are cattail, alkali ryegrass, and rush, as in the natural wetlands. These wetlands tend to occur in drainage ditches along roads or on steep banks near the buildings.
The only non–spring-fed natural wetland observed onsite is a 0.3 acre vernal pool in the northwest section of LLNL Site 300 (Figure 4.9-1A). This pool was oval shaped and had concentric rings of plant species such as annual hairgrass, cupped downingia, and smooth spike-primrose that are considered typical of vernal pools (Holland and Jain, 1977; Taylor and Davilla, 1986a). The surface was dry (May 1991), but moist soil was encountered a few inches below the surface, with clay hardpan at a depth of 12 to 15 inches.
Operations at LLNL Site 300 do not affect any natural wetlands, including the vernal pool. The major component of the current operations that has the potential to affect wetlands is the site revitalization plan. Diagnostic upgrades at Bunker 851 involve internal improvements, and, therefore, would not affect the artificial wetland near this site. The remaining revitalization activities (road upgrades, water supply pipeline and tanks, and construction of a central control post) would not affect wetlands. Part of the road upgrade along Linac Road will be near artificial wetlands created by runoff from Building 865; however, this section of road would be widened only 3 ft on either side and would not affect these wetlands.
Contaminated ground water plumes at LLNL Site 300 have the potential to contaminate some of the spring-fed wetlands onsite; however, detailed analysis of contaminated ground water plumes from Buildings 833, 834, and 850, the high explosives process area, landfill Pit 6 area, and the General Services Area have shown that these plumes have not contaminated any of the natural wetlands onsite (Bryn, Landgraf, and Booth, 1990; Crow and Lamarre, 1990; Ferry, Lamarre, and Landgraf, 1990; Taffet et al., 1991; Taffet and Oberdorfer, 1991; Webster-Scholten et al., 1991). Although a ground water plume from the General Services Area has contaminated the alluvial/shallow bedrock aquifer under a segment of Corral Hollow Creek offsite (Ferry, Lamarre, and Landgraf, 1990), there is no indication that springs along Corral Hollow Creek have been contaminated by this plume.
As part of its responsibilities under CERCLA, LLNL Site 300 is extracting and treating contaminated ground water at the eastern General Services Area and then discharging this treated water into Corral Hollow Creek. Treated ground water from this operation was released into Corral Hollow Creek starting in June 1991. Corral Hollow Creek, in the General Services Area, is bordered by wooded riparian vegetation with cottonwood the dominant canopy tree species. Mulefat and willow occur in the understory. One spring dominated by rush (Juncus sp.) occurs approximately 700 ft downstream from the eastern General Services Area (Ferry, Lamarre, and Landgraf, 1990). The wooded riparian vegetation is well developed in some areas and sparse in others.
Ground water restoration is an ongoing project at LLNL Site 300 and treated water from other ground water remediation projects at LLNL Site 300 would be discharged from a number of release points into Corral Hollow Creek. These flows would likely result in an increase in wetland vegetation with such species as cattail, rush, and alkali ryegrass becoming established. Also, an increase in cottonwood and willow can be expected. This increase in riparian wetland vegetation would benefit wildlife. One possible negative impact could be the development of an extensive area of perennial flow, which could promote fish migration up the creek and result in a reduction of sensitive amphibian species such as the tiger salamander and red-legged frog. However, the low flows at the discharge points (60 to 100 gal per minute at each point), the high porosity of the Corral Hollow Creek bed, and low rainfall–high evapotranspiration all make this outcome unlikely.
SNL, Livermore
The wetlands at SNL, Livermore consist of 1.44 acres at the east end of Arroyo Seco within the security zone. Most of this wetland is a 1.32-acre remnant wooded riparian area with valley oak and sycamore the dominant trees. Other common species are red willow, cattail, and rush. The remainder (0.12 acre) is an alkali marsh dominated by alkali ryegrass and salt grass (Environmental Science Associates, Inc., 1990).
Current operations at SNL, Livermore would not affect the 1.44 acres of wetlands at SNL, Livermore because current site activities, including projects now under construction, would not fill in, alter the drainage of, or cause indirect effects to the wetlands.
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