proposed removal of lake bottom sediments from Lake 4
Prince William Forest Park.
Comment Period: 01/20/2006 - 02/18/2006
CHAPTER I – PURPOSE AND NEED FOR ACTION
The purpose of the proposed Federal action is to correct safety deficiencies at Camp 4 Dam. Camp 4 Dam was previously classified as having a downstream hazard classification of significant because failure of the dam would jeopardize the lives of people present in areas affected by floodwater. Camp 4 Dam has been overtopped by floodflows in the past resulting in the erosion of the downstream face of the dam. The dam can be expected to be overtopped during floods which occur at 10- to 12-year intervals, which could result in dam failure. Dam failure could also imperil park resources because of erosion which could occur in the stream channels and the downstream flood plain. Large amounts of sediment present in the reservoir could be transported and deposited downstream during and after a failure event. In addition to the correction of safety deficiencies, lake-bottom sediments will be dredged from Camp 4 Lake to restore the lake’s recreational capability.
An Environmental Assessment (EA) and subsequent Finding of No Significant Impact (NPS 2001) was previously prepared to assess the potential environmental effects of disturbance associated with construction activities at Camp 1, 4, and 5 dams, including the dredging and removal of lake-bottom sediments from Camp 1 and 5 lakes. The dam repairs and modifications were designed as a requirement of the National Park Service (NPS) Safety of Dams Program to ensure long-term satisfactory performance of the dams and reduce the potential risk for dam failure. The EA, as referenced, is hereby wholly incorporated in this Supplemental Environmental Assessment (SEA). Issues not discussed in this SEA were adequately addressed in the 2001 EA and remain valid for the proposed action.
This SEA has been prepared to assess the potential environmental effects of the disturbance associated with the dredging and removal of lake-bottom sediments in Camp 4 Lake.
Prince William Forest Park (PRWI) is located in the southeast corner of Prince William County, Virginia, 32 miles south of Washington D.C. Interstate 95, a major north-south travel route, is located east of the park boundary and provides access to the park from two major exits. PRWI is bordered by State Highway 234 on the north and State Highway 619 on the south and west. The Chopawamsic backcountry area is a detached portion south of the main park with access from State Highway 619 (Figure 1).
Lands adjacent to the park boundary are equally divided between public and private ownership. The Quantico Marine Corps Base and Quantico National Cemetery are located on the southern boundary, along with small private tracts located along State Highway 619. The lands along the northern boundary are predominately private ownership and are zoned either residential or commercial.
PRWI was originally designated as the Chopawamsic Recreation Demonstration Area in 1933, and transferred to the Department of the Interior (DOI) as a unit of the NPS in 1936. Continuing population growth and land development in northern Virginia have made the park an increasingly rare landscape along the east coast. It is the only component of the National Park System dedicated to preserving a representative example (15,000 acres) of the Piedmont physiographic province and the rare deciduous forest type that it supports. It protects a major portion of the Quantico Creek and Chopawamsic Creek watersheds and a Piedmont/Coastal Plain ecosystem that appears much as it did in pre-colonial times.
PRWI preserves and administers five actively used Civilian Conservation Corps (CCC)-era cabin camps, four of which are listed on the National Register of Historic Places as historic districts. The camps have seen significant use over the years, including housing and training World War II recruits for the Office of Strategic Services, the forerunner of the Central Intelligence Agency. These areas continue to be used for group camping activities and outdoor experiences.
The PRWI General Management Plan (NPS 1999) identified the Quantico Creek watershed as a prime resource requiring long-term protection and preservation. The natural flows of Quantico Creek have been altered by the construction of dams to create recreational lakes for cabin campers. The dams act as sediment traps for stormwater runoff, and the lakes must be periodically dredged. The lakes also represent one of the primary wetland resources for the park, and they continue to provide a historic scene tied to the cabin camps. Although the lakes are artificial, the NPS General Management Plan has recommended that the dams should be rehabilitated and maintained to preserve the wetland habitat and the associated wildlife that they support (NPS 1999). The Finding of No Significant Impact (FONSI) for the PRWI General Management Plan specifically states in the Summary of Environmental Consequences that “periodic dredging of these facilities will ensure that sediment from stormwater runoff does not impact the downstream freshwater habitats of Quantico and South Fork Quantico Creeks.” Dams 1 and 4 are also listed on the National Register of Historic Places as part of the Pleasant Historic District. Any proposed removal of the dams would constitute an adverse effect on the historic district.
Safety deficiencies were corrected and construction activities completed at Camp 1 and 5 dams, along with lake-bottom sediment removal in April of 2002. Due to a lack of funding, safety deficiencies were not corrected at Camp 4 Dam during the 2001/2002 construction period.
All Federal agencies are required to consult with each other and to employ systematic and interdisciplinary techniques in planning and decision making. The National Environmental Policy Act (NEPA) requires a full and honest disclosure of all environmental impacts associated with the proposed alternatives. This Draft SEA has been prepared in compliance with NEPA. The draft is being distributed for a 30-day public review. All comments and letters received will be reviewed and considered in the finalization of this document.
The Endangered Species Act (ESA) requires consultation with the U.S. Fish and Wildlife Service (USFWS) for federally listed threatened and endangered species identified to exist or potentially exist in the project area. Section 7 consultation with the USFWS was initiated in 2000 for the EA (NPS 2001) and again in 2005 for this SEA. USFWS consultation has identified three threatened species, one endangered species, and six species of concern. Based on the review of this document, the USFWS will decide whether concurrence with a no-effect determination is appropriate.
The Fish and Wildlife Coordination Act of 1958, as amended, requires that whenever the Federal Government authorizes, sponsors, or issues a permit to impound, modify, divert, or otherwise control the waters of any stream or body of water for any purpose by any entity, the entity must consult with the USFWS and the State fish and wildlife management agency.
The USFWS has been provided opportunity to comment on the project through consultation under the ESA, and by review of this draft SEA. Virginia Department of Game and Inland Fisheries has also been provided opportunity to comment on this draft SEA.
Section 404 of the Clean Water Act of 1972, as amended, is administered by the U.S. Army Corps of Engineers (COE) with oversight from the EPA. All activities involving the placement of dredged or fill materials into waters of the United States, including wetlands, are subject to the COE permitting process. Both nationwide and individual permits are issued under Section 404. Nationwide permits are issued on a State, regional, or nationwide basis for any category of activities where such activities are similar in nature and will cause only minimal adverse environmental effects both individually and cumulatively. Previous Safety of Dams work at Camp 1 and 5 dams was covered under the Corps Nationwide Permit 3. NPS will obtain the appropriate authorization from COE for operations in and around Quantico Creek.
This section of the Clean Water Act, although administered by the EPA, is the responsibility of the States and Eligible Indian Tribes to develop and enforce. Section 401 provides the States with authority to grant or deny certification for a federally permitted or licensed activity that may result in a discharge to the waters of the United States. States may also waive water quality certification. Compliance with Section 401 would be achieved by review of this document by the Virginia Division of Water Quality.
The State of Virginia has primacy in administering Section 402 of the Clean Water Act. Section 402 regulates the point source discharge of wastewater into the waters of the United States.
The Clean Air Act requires that any Federal entity engaged in an activity that may result in the discharge of air pollutants must comply with all applicable air pollution control laws and regulations (Federal, State, or local). The act requires the EPA to publish national primary standards to protect public health and more stringent national secondary standards to protect public welfare. States and local governments are responsible for the prevention and control of air pollution.
Measures will be incorporated into the contractor’s construction specifications to ensure that compliance with these laws and regulations is achieved.
The American Indian Religious Freedom Act of 1978 requires Federal agencies to consider the impacts of projects on the ability of American Indians to continue their traditional cultural and religious practices.
The Archaeological Resources Protection Act of 1979 requires permits to remove archaeological resources from Federal or Indian lands. Permits may be issued to educational or scientific institutions, only if the removal would increase knowledge about archaeological resources.
The Archaeological and Historic Preservation Act of 1974 authorizes Federal agencies to protect historical and archaeological data that might be lost as a result of construction of irrigation projects, a dam, or other Federal activity.
The Coastal Zone Management Act of 1972 directs State programs to provide for protection of natural resources in coastal zones including wetlands, flood plains, estuaries, beaches, dunes, fish and wildlife, and their habitat.
This document provides the Commonwealth of Virginia with Prince William Forest Park’s Consistency Determination under Coastal Zone Management Act section 307(c)(1) [or (2)] and 15 CFR Part 930, sub-part C. This information is provided pursuant to 15 CFR section 930.39.
The National Historic Preservation Act of 1966 (NHPA) establishes the Federal policy concerning the protection of historic properties. Federal agencies are required to carry out all activities under NHPA in cooperation with States, Tribes, and local governments. The act designates the State Historic Preservation Officer (SHPO) as the responsible entity in each State and Tribal Historic Preservation Officer (THPO) for tribes for administering programs under NHPA. The act also creates the Advisory Council of Historic Preservation (ACHP) to serve as the advisory body to the Executive Branch on historic preservation issues. Section 106 of the act requires Federal agencies to consider the effects of their undertakings on historic resources and to give the SHPO and/or THPO and the ACHP reasonable opportunity to comment on the effects of those undertakings. Finally, the 1992 amendments require the Federal agency to consider the impacts of undertakings on properties of traditional religious and cultural importance to American Indians and to involve American Indian Tribes to participate in the consultation process, should such resources be affected.
NPS has initiated consultation with the Virginia SHPO on this proposed project.
Native American Graves Protection and Repatriation Act
The Native American Graves Protection and Repatriation Act (NAGPRA) establishes Federal policy with respect to Native American burials and graves located on Federal or Indian lands. Federal agencies are required to consult with and to obtain the concurrence of the appropriate Tribes with respect to activities that may result in the disturbance and/or removal of such burials and graves on Federal or reservation lands.
No burials and graves have been identified in the project area. Since this area has been previously disturbed, it is doubtful that any would be encountered, but if burials or graves are discovered, NPS will comply with the provisions of NAGPRA.
Executive Order 11988 directs Federal agencies to take flood plain management into account when formulating or evaluating water or land use plans. Executive Orders represent administrative policy and do not have the force of law that comes with delegation of authority provided by Congress.
Potential impacts to the Quantico Creek flood plain were considered and evaluated in this SEA.
Executive Order 11990 directs each Federal agency to provide leadership and take action to minimize the destruction, loss or degradation of wetlands, and to preserve and enhance the natural and beneficial values of wetlands in carrying out agency duties and responsibilities. Executive Orders represent administrative policy and do not have the force of law that comes with delegation of authority provided by Congress. Best Management Practices would be implemented to reduce erosion and turbidity in the aquatic environment during the construction phase
Under the No Action Alternative, the work required to eliminate safety hazards at Camp 4 Dam would not occur. The dam would continue to deteriorate and the potential for failure would increase. Dam failure would include downstream impacts beyond the park boundary. Camp 4 Lake has been drained since June 2005 to accommodate the required sediment sampling program. Recreational use would continue to be limited due to the lake reaching the sediment storage capacity.
The Bureau of Reclamation (Reclamation) entered into an Interagency Agreement with NPS in 2005 for Reclamation to conduct investigations, design and construction management services for the repairs and modifications to Camp 4 Dam and Lake. Because of Reclamation’s expertise and oversight of the DOI Maintenance, Operations, and Safety of Dams work, NPS has regularly used Reclamation’s services and advice in maintaining NPS dams.
Reclamation is responsible for investigations, design, construction management, and contract administration for the modifications at Camp 4 Dam. Reclamation has also been performing lake-bottom sediment testing at Camp 4 Lake to determine if the material can be classified as non-hazardous waste, dredged, and transferred to a State certified solid waste disposal facility.
Camp 4 Dam is located in the northeast portion of PRWI on Quantico Creek (Figure 1). The dam has been overtopped by floodflows in the past, which have resulted in erosion on the crest and downstream face of the dam. The dam is a 13‑foot-high earthfill dam with a crest length of about 143 feet and a crest width of 21 feet. The reservoir storage, when the reservoir surface is at spillway crest, has been estimated to be around 8 acre-feet of water and 4 acre-feet of sediment. The slope of the downstream face is about 2.5 horizontal to 1.0 vertical at the head of the localized gullies. The upstream face has a 3 horizontal to 1 vertical slope. The spillway is located on the left abutment and has native bedrock for a foundation. The spillway has a width of about 50 feet, and the invert is about 4.7 feet below the crest of the dam. A 30-inch-diameter concrete outlet works pipe is located near the right abutment. A slide gate can be operated from a platform in the reservoir near the upstream face of the dam (Figure 2).
Reclamation has proposed to rehabilitate the existing access road from Camp 4 (Unit C) to the dam. The road is approximately 150 feet long, 8 feet wide, and will be widened to 15 feet to accommodate equipment access to the dam area. After the necessary tree and shrub removal, the access road will be stabilized with 4 inches of coarse gravel. A temporary access road across the spillway will be constructed by placing five 58 by 36 inch (height by width) by 44-foot (length) corrugated metal pipes on geotextile fabric and clean gravel.
The pipes and fabric will then be covered with 2 feet of gravel and sterile fill to form the road base.
All trees, shrubs, stumps, and vegetation will be removed from the dam crest, downstream embankment and within 10 feet of the toe of the dam. Fill material will be hauled in to fill all holes and gullies on the downstream portion of the dam and to raise the dam crest 3 feet. Approximately 610 cubic yards of material will be needed to restore the dam embankment and crest. Reclamation also plans to remove and replace the existing trash rack panels and slide gate. Existing metal work associated with the existing slide gate will be removed. The new cast iron slide gate will be manually operated. The access road across the spillway will be removed when all construction activities are completed. Impacts associated with construction operations and rehabilitation of Camp 4 Dam were addressed in the 2001 EA.
Reclamation has also proposed to remove approximately 25,000 cubic yards of sediment from the lake bottom. Reclamation has developed a sediment sampling and testing plan (Reclamation 2004) that will be implemented to ensure that the material meets the Virginia requirements for disposal in a State-approved landfill. When the lake is dredged, a dredging disturbance limit will be confined to the center area of the lake so that a 30-foot buffer zone is maintained between the shoreline/high water mark and the dredging area for all the area outside the designated swimming area (Figure 2). This buffer is designed to protect established wetland vegetation and wildlife habitat associated with the lake. Dredged sediments will be hauled across dam to the Camp 4 access road, then to State Highway 234.
Reclamation was previously involved in field sampling in July 2001 in preparation for the effort to dredge Camp 1 and Camp 5 lakebeds and to accomplish repairs and modifications to these dams. Analyses of these sediment samples from Camp 1 and 5 indicated that the lakebed sediments met the acceptance standards required for Category 1 material at the Prince William County Sanitary Landfill. Camp 4 Lake is situated just downstream of Camp 1, and there are no accounts of any hazardous material entering or being placed in Camp 1 Lake. The lakebed sediments are, therefore, also expected to meet acceptance standards required for Category 1 material. Sampling and testing of Camp 4 sediments will be performed in order to assure that these sediments are indeed within acceptance standards for disposal.
Sediment removal was initially proposed to only include the swimming area adjacent to Camp 4.
This SEA has been prepared to assess the potential environmental effects of the disturbance associated with the dredging and removal of lake-bottom sediments in Camp 4 Lake. This document fulfills the NEPA compliance and related laws. Table 1 compares the impacts associated with the proposed removal of sediment alternative and the No Action Alternative.
Due to the localized nature of the proposed project, no significant impacts to topography, soils, or land use are expected. These resources are briefly discussed to provide a complete description of the project area. There would be no negative impacts with regard to Environmental Justice or Indian Trust Assets (ITAs), which are also discussed below.
Approximately three-fourths of the park is in the Piedmont and one‑fourth in the Coastal Plain Region. The topography is undulating, with narrow ridge tops and relatively steep‑sided valleys. The park is underlain by late Precambrian to early Paleozoic rocks, which are overlain in the eastern part of the park by unconsolidated Cretaceous period deposits. The soils of the park are sandy, relatively infertile, and easily disturbed. The steep terrain and poor quality soils combine to create severe erosion problems.
Minor soil erosion could occur at the construction site. This would be controlled with appropriate erosion control devices such as silt fences and protective berms.
Sand dunes do not occur within Prince William Forest Park. The park is located primarily in the Piedmont province, and along the fall line.
Relief is moderately high, and the elevation ranges from about 10 feet to nearly 400 feet above sea level. Ridge tops are narrow to moderately wide and nearly level to gently sloping. Side slopes are moderately wide to narrow and sloping to very steep. In the Piedmont, the geology consists largely of granite gneiss, hornblende gneiss, and mica schist rock types. The ridges of the Piedmont are capped with thin mantels of coastal plain or other alluvial sediments in many places. Fairly broad flood plains have developed along the larger streams. The Coastal Plain is underlain by stratified marine sediments of sand, silt, clay, and gravel. The lowland soils are strongly acidic and of low natural fertility. The soils have low permeability, making them subject to at least seasonal wetness. The slopes and gently sloping ridges are occupied by more porous soils that are more easily eroded. They also are strongly acidic and of low fertility. Unconsolidated soil types are generally located in the Coastal Plain, Coastal Plain caps, flood plains, and flood plain and stream terraces. The erosion potential in these areas ranges from moderate to high.
The project is located in PRWI, a unit of the National Park System. In the immediate project area, the lakes are used for recreational purposes, such as boating, fishing, and swimming.
Executive Order 11898 requires that direct or indirect effects of the Preferred Alternative, including equitable distribution of benefits and risks on minority or low-income populations and communities, be identified and evaluated. The Preferred Alternative would not exclude either by intention or design, any minority or low-income populations within the project area from benefits associated with the action. Additionally, a decision to implement the Proposed Action would not subject any minority or low-income populations to a disproportionate share of project-related environmental or health risks or to an inequitable share of project costs.
ITAs are defined as legal interests in property held in trust by the United States for Indian Tribes or individuals. Examples of ITAs include lands, minerals, timber, hunting and fishing rights, water rights, and instream flows.
ITAs are those properties, interests, or assets of an Indian Tribe or individual Indian over which the Federal Government also has an interest, either through administration or direct control. The Federal Government acts in a fiduciary or trust capacity with respect to these properties, interests, or assets. No ITAs will be affected by the project.
Affected Environment.—PRWI is a large natural preserve that is surrounded by an area that is highly developed for residential, industrial, and transportation uses. The portions of the park to be influenced by the project are primarily used by visitors at the cabin camps.
Environmental Consequences.—Consequences for the No Action Alternative and Preferred Alternative are as follows:
No Action Alternative.—There would be no impact to visual aesthetics under the No Action Alternative. However, if the dam failed the empty reservoir and disturbed area around the dam and downstream would be visually unappealing.
Preferred Alternative.—There would be a temporary negative impact to visual quality due to heavy construction equipment and disturbance around the dam and inundation zone under the Preferred Alternative. However, the construction zone’s location is away from the areas of highest visitation in the park. The primary visitors that could view the construction areas would be in the vicinity of cabin Camps 1 and 4. Camp 4 cabins will be closed to public use during the construction phase. Rehabilitation of the dam and lake will restore the area to an appearance more similar to the original intended condition. The visual impacts would be short term, minor and would occur in a small, localized area.
Affected Environment.—Currently there is no established air quality monitoring program in the park. The greatest threat to the park resources is industrialization in northern Virginia, auto emissions, and local traffic. Because of the park’s proximity to the Nation’s capital, Interstate 95 (a major north-south travel route), local highways, the Quantico Marine Corps Base, and local residential development, vehicle emissions have the major influence on the park’s air. The park is located in an EPA ozone non-attainment area and a Virginia DEQ area for volatile organic compounds (voc’s) and nitrogen oxide emissions.
Environmental Consequences.—Consequences for the No Action Alternative and Preferred Alternative are as follows:
No Action Alternative.—There would be no impacts or changes to current air quality conditions, if no action were taken.
Preferred Alternative.—Construction activities would cause short-term dust generation and equipment emissions. National Ambient Air Quality standards are not expected to be exceeded. Any impacts associated with dust generation would be mitigated with the use of water trucks. The air quality impacts would be short term, negligible, and minor. It is proposed that on days when the Air Quality Index is forecast for Red or Purple, the use of gasoline or diesel equipment would be limited. Equipment, such as haul trucks, used for conveying soils will employ coverings for their loads. Spilled or tracked dirt will be promptly removed from paved streets, and of dried sediments resulting from soil erosion. If dust abatement is necessary, the park will follow the guidelines established in 9 V AC 5-40‑90 et seq. in the Regulations for the Control and Abatement of Air Pollution.
Affected Environment.—The natural quiet of the park is a valuable resource because of its proximity to the Nation’s capital, Interstate 95 (a major north-south travel route), local highways (State Highway 234 and State Highway 619), and local residential development. One detraction to the quiet is frequent training practices occurring on the adjacent Quantico Marine Corps Base property. Military aircraft are regularly seen and heard flying over and adjacent to the park along with occasional detonations and explosions.
Environmental Consequences.—Consequences for the No Action Alternative and the Preferred Alternative are as follows:
No Action Alternative.—Noise and traffic levels would not be affected under the No Action Alternative. Public safety would still be a concern downstream of the park.
Preferred Alternative.—Modifications to Camp 4 Dam and the sediment removal operations would cause a temporary increase in noise and traffic associated with construction activities. Equipment used for construction would be expected to generate noise levels of 60 to 100 A‑weighted decibels for up to 180 days. Trucks hauling construction equipment and materials would contribute to traffic, and thus public safety concerns in the park. Trucks hauling dredged sediments from Camp 4 Lake would utilize the Camp 4 access road to Highway 234. The construction contractor would be required to provide traffic control devices such as barricades, flasher lights, flange, and danger signals during the construction period. No blasting will be permitted for any aspect of the project. The impact from construction operations would be short term and minor. The proposed project hours are from 8:00 a.m. to 6:00 p.m. Monday through Thursday. Work on weekends and Federal holidays is not permitted.
Affected Environment.—The Quantico and South Fork Quantico Creeks, which flow southeast and join near the eastern boundary of PRWI, are the major streams located in the park. Quantico Creek receives drainage from a basin that is essentially undeveloped and provides habitat for a number of native aquatic species. An intricate network of smaller streams drains the rest of the park. The Quantico Creek drainage basin is about 7 square miles with the South Fork drainage basin encompassing 11 square miles of woodlands. The water quality in the Quantico and South Fork Quantico Creeks and in other small tributaries in the park is generally good and supports numerous fish species and benthic organisms. The natural streamflow of both branches has been altered by the damming of the surface waters to create the recreation lakes for cabin campers. The dams act as sediment traps for stormwater runoff, and the lakes must be periodically dredged to retain their usefulness.
PRWI’s annual water quality monitoring program includes testing for e.coli, benthic macroinvertibrates, and water chemistry. E. coli is monitored as a requirement by the State Water Control Board for protecting public health at recreation lakes used for swimming. These data are used to create a baseline for identifying changes in water quality caused by weather patterns, development around the park, visitor use, and possible sewage system failure. Recent results from the annual testing indicate that the overall health of the park’s streams is good (NPS 1998).
Environmental Consequences.—Consequences for the No Action Alternative and the Preferred Alternative are as follows:
No Action Alternative.—No immediate changes to the water resources of PRWI would occur with this alternative. If Camp 4 Dam were to fail, large quantities of sediment could be transported downstream affecting the quality of water in the park and downstream to the Potomac River. Floodflows associated with failure of Camp 4 Dam could also cause severe scouring and erosion at the reclaimed Cabin Branch Pyrite Mine (Figure 1) which could re-expose mine tailings. Erosion of the tailings would reduce water quality downstream of the site.
Preferred Alternative.—Under this alternative, there would be a temporary change in the operations of Camp 4 Dam during the construction period of March through July. During this period, no water would be stored in the lake with all flows passing directly through the dam to maintain normal downstream flows. Erosion and sediment control Best Management Practices will be employed by the contractor to reduce potential impacts and to reduce and/or control non-point source pollution.
Point source pollution controls will be employed at all construction disturbance sites, including access roads, the construction operations area, and the dam. All solid wastes generated from this project will be reused, recycled, or disposed of in an approved landfill.
A Storm Water Pollution Prevention Plan (SWPPP), as described in Section 402 of the Clean Water Act, would be prepared by the contractor prior to construction. The SWPPP will: (1) identify pollutant sources that may affect the quality of stormwater discharges, and (2) identify practices to reduce pollutants in stormwater discharge during and after construction. Reclamation will review and approve the plan, then NPS will submit it to the State in order to obtain coverage under a general permit for controlling stormwater from the construction site.
The contractor will also be required to submit a water control plan that will describe the proposed method for diversion and care of the streams during construction/dredging and measures that will be required to meet water quality standards. Construction activities will not be permitted in the stream channel below the dam. A temporary increase in turbidity would be expected in the immediate area of the dredging operations and construction of the access across the spillway of Camp 4 Dam, but these would be short term and minor.
Section 404 of the Clean Water Act identifies conditions under which a regulatory permit is required for projects that result in the placement of dredged or fill materials into waters of the United States. NPS has applied for a permit from the COE for all operations associated with the project.
Shoreline Sanitation – This project does not involve septic tanks.
Coastal Lands Management - There are no anticipated Chesapeake Bay Preservation Act issues raised by this project.
Affected Environment.—Fisheries resources that could potentially be affected by the proposed project are those established in Quantico Creek. The natural streamflow of the stream has been altered by historical damming and lake maintenance/ dredging. The park streams generally have good water quality due to the isolation from development and include both free flowing pool and riffle habitat and lake habitat. Species present in the local streams are representative of the park’s diverse habitat and include: American eel, common shiner, golden shiner, white sucker, creek chubsucker, northern hogsucker, brown bullhead, chain pickerel, various species of sunfish, yellow perch, smallmouth bass, rainbow trout, brown trout, and channel catfish. All fish populations are naturally reproducing or remnants from previous stocking. There are currently no fish stocking programs conducted by Virginia Department of Game and Inland Fisheries or PRWI.
Environmental Consequences.—Consequences for the No Action Alternative and the Preferred Alternative are as follows:
No Action Alternative.—Fisheries resources currently existing in PRWI would not be affected under this alternative. However, sedimentation from failure of Camp 4 Dam could impact the fish populations in the park and downstream to the Potomac River. Habitat could be degraded by the increase in sediments in pools, riffles, and the meandering backwater where Quantico Creek enters the Potomac.
Preferred Alternative.—The Preferred Alternative could cause a temporary increase in turbidity to the localized area of Quantico Creek from dredging and construction operations. Aquatic organisms that serve as a fisheries food source that are associated with both deepwater and shallow habitat in Camp 4 Lake would be temporarily lost. Camp 4 Lake was drained in June 2005 to implement the lake-bottom sediment sampling plan. The contractor will be required to implement a Water Pollution Control Plan and Storm Water Pollution Prevention Plan to protect surface water runoff and the receiving stream. Fish populations in Camp 4 Lake have been temporarily impacted during the drawdown and construction period, but additional open water/pool habitat will be restored when Camp 4 Lake is restored to the original storage capacities. The Fisheries Management program is administered by the Virginia Marine Resources Commission. The impacts to fishery resources will be short term and minor under the preferred alternative.
This regulatory program also includes the State Tributylin Regulatory Program. This project does not involve the use of tributylin.
Affected Environment.—The majority of PRWI lies within the Piedmont physiographic province, consisting of lowland plateaus with rolling hills and stream cut valleys. Elevations in the park range from about 10 feet to about 400 feet above sea level. Approximately one-fourth of the park lies in the Coastal Plain physiographic province which is a flatter coastal environment. Because of the park’s proximity to the Potomac River, it was part of the first areas to be cleared and settled in the 1600s. From the first settlement until the early 20th century, lands in and around the park were intensively farmed and eventually abandoned. It is evident that the stream valleys of Quantico Creek were the least farmed or first abandoned because the oldest mature forests are generally found along these streams.
· Upland.—The dominant forest species at PRWI are white oak, red oak, hickory, tulip-poplar, American beech, maple, elm, and Virginia pine. Some uncommon species present include: butternut, bigtooth aspen, black walnut, sweet bay magnolia, black walnut, eastern hemlock, and American sycamore. Several of these species are at their distributional limits. Common understory species include: dogwood, redbud, Hercules club, mountain laurel, American holly, ironwood, sassafras, and hophornbeam. Some invasive exotic plant species such as wisteria, honeysuckle, Ailanthus, Japanese knotweed, and a variety of grasses pose a threat to the natural and historical landscapes (NPS 1995).
· Wetlands.—Periodic dredging of the park lakes has historically occurred to remove accumulated sediments and to maintain adequate water depths to support recreational usage by campers. The past dredging operations have reduced the successional development of hydrophytic vegetation on accumulated sediments and maintained more open water areas typical of impoundments surrounded by steep topography. Current digital National Wetland Inventory (NWI) maps use the Cowardin classification system (Cowardin et. al 1979) to describe Camp 4 Lake as palustrine, unconsolidated bottom, permanently flooded, and diked/impounded (PUBHh - Figure 3). The NWI maps do not include any other wetlands in the project area or along the creeks, however emergent wetlands do exist downstream of the dam and in the shallow embayments in the lake. The more common hydrophytic species occurring in the project area include wool grass, water purslane, false nettle, eastern bur-reed, beaked spike-rush, rice cutgrass, common elderberry, and alder.
· Subaqueous Lands Management.—This project does not involve any encroachments in, on, or over State-owned subaqueous lands.
· Wetlands Management.—This project is not expected to affect wetland species. A buffer of 30 feet has been proposed to protect all shoreline and aqueous vegetation during the proposed sediment removal. Every effort to prevent adverse and temporary impacts to wetlands will occur throughout this project. In the case of unavoidable impacts, the park will not be operating any machinery or vehicles within identified wetlands; erosion and sediment controls will be installed in accordance with the Virginia Erosion and Sediment Control Handbook.
No Action Alternative.—There would be no impact to upland or wetland vegetation if the current conditions continued to exist. However, if the dam was to fail or overtop, hydrophytic vegetation and associated habitat in the immediate vicinity of the toe of the dam and in areas along the existing stream channels could be destroyed from severe flooding and scouring. With the loss of any dam, emergent vegetation associated with shallow littoral zones of the lake could dry out and convert to a more mesophytic community.
Preferred Alternative.—No wetlands will be disturbed by construction operations associated with upgrading the existing access roads, development of the construction operations zone, or repair work on Camp 4 Dam.
Reclamation will be performing lake-bottom sediment testing at Camp 4 Lake to determine if the dredged material can be transferred to a State-certified solid waste disposal facility. If sediment is dredged, an undisturbed 30-foot buffer zone will be maintained around the shoreline, outside of the swimming area, to preserve the existing hydrophytic vegetation communities that currently exist in shallow water areas and embayments. The areas that could potentially be dredged are classified as palustrine, unconsolidated bottom wetlands, and will continue to function as such after the lakes are refilled. Camp 4 Lake has been drained through a portion of the growing season to facilitate the sampling program, which could effect the species composition of the existing hydrophyte communities. However, after construction when the lake is back to normal water level, the existing seed source and rootstock should be adequate for re-establishment of a similar vegetative community. The potential effect to wetlands from all project activities would be short term and minor.
Affected Environment.—The dense forests and varied topography of the park provide diverse habitats for wildlife. Healthy breeding populations of white‑tailed deer, wild turkey, ruffed grouse, gray fox, and beaver are supported. Small mammals like raccoons, gray squirrels, and opossums are abundant, as are various reptiles and amphibians. The park is also home to numerous bird species including: great horned owls, woodcocks, pileated woodpeckers, numerous hawks, warblers, and songbirds. Bald eagles occasionally pass through the area, although they are not known to nest in the park. Many of the park's wildlife species, especially the larger predators, are relatively sensitive to human disturbances. As a result, their numbers are decreasing in other areas of the Piedmont, and their continued survival within the park is increasingly critical. As development continues in northern Virginia, PRWI will become an extremely valuable sanctuary for wildlife resources (NPS 1999)
No Action Alternative.—With the No Action Alternative, wildlife habitat and the associated species would remain at the same conditions that presently exist. However, with no water being impounded at Camp 4 Dam there has been a reduction of potential habitat for waterfowl, water birds, amphibians, and other species that rely on a slow moving, shallow water environment. If the dam were to fail there would be a reduction in the quality of downstream habitat due to increased sedimentation.
Preferred Alternative.—Construction/dredging operations would temporarily reduce the quantity and quality of the habitat currently available in the project area. Displaced individuals would likely relocate to similar habitat in adjacent areas and return following the project completion. Species that are less mobile could face direct mortality by construction activities or by loss of habitat. The direct loss of wildlife is not considered to be significant due to the limited acreage that will be physically disturbed by the construction operations. The total impacts to wildlife would be short term and minor.
Mitigation for the loss of habitat would be achieved through reseeding of grasses on disturbed areas, creation of more deepwater habitat in Camp 4 Lake, and the reestablishment of a stable water system in the lake.
This section of the SEA is intended to address the potential impacts to species listed under the ESA of 1973, as amended, and to fulfill the regulatory requirements of Section 7C. USFWS and NPS have identified the following species as potentially occurring in the vicinity of the project (Table 2). All the species listed below except for the small whorled pogonia (Isotria medeoloides) and Harperella (Ptilimnium nodosum) were adequately address in the 2001 EA and will not be discussed in any further detail because no new impacts were identified or no potential habitat exists in the project area.
The small whorled pogonia and the potential effects of the project are described below.
Affected Environment.—The small whorled pogonia is a member of the orchid family that flowers from mid-May in the south to mid-June in the northern portion of its range. It occurs both in fairly young forests and in maturing stands of mixed deciduous or mixed deciduous/coniferous forests. The majority of the sites where the orchid is found share several common characteristics. These may include sparse to moderate ground cover, a relatively open overstory canopy, and proximity to logging roads, streams, or other features that create persistent breaks in the canopy. Potential habitat includes dry, rocky, wooded slopes to moist slopes or slope bases crossed by vernal streams (58 FR 53904).
The small whorled pogonia is widely distributed with a primary range extending from southern Maine throughout the Atlantic seaboard states to northern Georgia and southeastern Tennessee. One of the three major population centers is concentrated in the Coastal Plain and Piedmont provinces of Virginia (Townsend 2005), with outliers in Delaware and New Jersey. The VA Department of Conservation and Recreation, Division of Natural Heritage is currently surveying suitable habitat within the park boundary and identifying the location of the existing populations. Both habitat and watershed conservation boundaries have been established for the protection of the populations and the adjacent suitable habitat (Pollio 2000). Floristic surveys were conducted in PRWI in 2003 and 2004 by George Mason University. No small whorled pogonia plants were documented during the surveys (Bradley et. al 2005).
Environmental Consequences.—Consequences for the No Action Alternative and Preferred Alternative are discussed below.
No Action Alternative.—There would be no immediate change to the existing habitat within the established conservation boundaries under the No Action Alternative. In the event that Camp 4 Dam failed, none of the known locations or conservation areas would be affected.
Preferred Alternative.—All construction areas, access roads, and sediment removal areas at Camp 4 Dam are located outside of the area of known locations and conservation area boundaries, therefore the small whorled pogonia would not be affected by the project.
Harperella and the potential effects of the project are described below.
Affected Environment.—Harperella, an annual plant that is a member of the carrot family, occurs in Alabama, Georgia, North and South Carolina, West Virginia, Maryland, and Virginia. Flowering begins in May in pond habitat populations and in late June or July in riverine populations and continues until the first frost. The plant tolerates a very specific water regime which includes moderately intensive spring floods that scour gravel bars and rock crevices where competing vegetation can occur. After floodwaters recede, seeds germinate in shallow rocky crevices where they complete their life cycle with their root system submerged or saturated. Potential habitat consists of rocky or gravelly shoals of clear flowing streams. In Coastal Plain areas, it also grows at the edges of pineland ponds, damp meadows, and saturated areas around springs (53 FR 37978).
Harperella has been documented in Stafford County (south of PRWI) by the Virginia Division of Natural Heritage (Davis pers. com. 2005). Floristic surveys were conducted in PRWI in 2003 and 2004 by George Mason University, but no harperella plants were documented (Bradley et. al 2005).
Environmental Consequences.—Consequences for the No Action Alternative and Preferred Alternative are discussed below.
No Action Alternative.—With the No Action Alternative, any potential habitat that exists for harperella would remain in the same condition that presently exists. However, if the dam were to fail there could be a reduction in potential habitat downstream due to increased sedimentation.
Preferred Alternative.—There are no known locations of harperella in the vicinity of the construction area, access roads, or sediment removal areas at Camp 4 Dam. The sediment removal area is confined to the inundation zone of the lake and is well outside of any potential habitat, therefore the species would not be affected by the project.
Affected Environment.—PRWI was originally established as the Chopawamsic Recreation Demonstration Development Area in 1933. Studies of national recreation needs at that time revealed an urgent need for natural areas close to population centers with group campsites, hiking trails, and swimming and picnic facilities. PRWI is the largest natural or conservation park in the Washington metropolitan area and still offers the recreational opportunities originally identified for the park. This large natural preserve is significant when viewed from a national perspective. More than 80 percent of the United States population lives in the East, which contains only 12 percent of the wilderness in the lower 48 states. The varied recreational activities offered at PRWI are consistent with resource protection and appropriate for a unit of the National Park System. Recreational opportunities include: hiking, fishing, camping, picnicking, bicycling, and nature study supported by 37 miles of trails, 25 miles of streams, 5 ponds and lakes, one 80‑site family campground, one group campground, 1 RV campground (concessionaire operated), a designated backcountry camping area, 3 picnic areas, and 5 cabin camps (capacity 686 persons). The group campground, the family campground, one picnic area, a portion of cabin Camp 5, and a portion of the concession‑operated RV campground are operated during the winter. The most popular activities at the park are hiking, driving the Scenic Drive, and camping in the developed campgrounds.
During the past several years the park's annual visitation has remained relatively stable at around 250,000 visitors per year. Monthly visitation patterns indicate that visitation is seasonal; more than 75 percent of the visits occur from April through October. The largest monthly total typically occurs in May; July records the heaviest use of campsites and cabin camps. Most of the cabin camps are closed during the winter, affecting the visitation statistics for that season.
The use of campgrounds and cabin camps parallels the overall use of the park. Recent trends indicate a relatively stable demand for both cabin camps and campgrounds. Overnight use has remained fairly constant on certain days, particularly on weekends, when the demand for available campsites and cabin camps has sometimes exceeded the supply. The monthly patterns of use at the campgrounds and cabin camps also reflect overall visitation patterns at the park. Overnight use accelerates about April and continues until the end of October. The demand for individual rental cabins has also been constant (NPS 1999).
The park’s five cabin camps are composed of small historical wooden structures built in the 1930s by the CCC. The capacities of the camps are as follows: Camp 1 - 134, Camp 2 - 110, Camp 3 - 60, Camp 4 - 182, and Camp 5 – 200 (Figure 4).
Environmental Consequences.—The consequences of the No Action Alternative and the Preferred Action are described below.
No Action Alternative.—Due to the increased amount of sediment stored in Camp 4 Lake, the use of the swimming area has been severely limited. Recreational opportunities for boating and fishing have also been temporarily limited by the lake being drained for sediment sampling.
If Camp 4 Dam were to fail, the recreational resources of the impacted lake and the area immediately below the failed dam could temporarily be lost. Dam failure could also jeopardize the lives of hikers on downstream trails that would be inundated from floodflows.
Preferred Alternative.—Construction access to Camp 4 Dam will be from the park access road (Pleasant Road) south of State Highway 234, through Unit C of cabin Camp 4 to the existing dam access road (Figure 4). Recreational activities in the construction area around the dam and at Unit C would experience a short-term negative impact because Unit C would be temporarily closed from approximately May 2 through August 31, and/or for the duration of the project. By closing Unit C, the maximum daily capacity of campers at the group camp would be reduced from 182 to 152. Trails in the construction zone and recreational use of lake will also be closed to recreation during the construction period. All impacts to recreation activities will be short term and minor. When the dam is properly repaired and the accumulated sediments are removed, full recreation potential (fishing, boating, and swimming) will be restored to the lake.
Affected Environment.—Base camps of extended families of hunters and gatherers and a few activity sites are the prehistoric site types that are likely to exist in PRWI. Research in adjacent areas has revealed evidence of occupation back to 4500 B.C. and possibly to 8800 B.C. By 1100 B.C., there was an increase in the population of the Potomac Valley, and it is probable that the park area was more heavily used. By A.D. 700 to 900, villages had begun to be established. village site along one or more of the inlets to the Potomac River, very possibly the creeks in the vicinity of the park. It is probable that one or more of the groups that settled along the Potomac claimed the Quantico/Chopawamsic area as their land. By A.D. 1100, slash‑and‑burn agriculture, with a major reliance on corn, was prevalent in the region. It is doubtful that villages were sited within the park area because the soils were not well‑suited for maize agriculture, and the terrain discouraged major concentrated settlement. The more abundant site types are likely to have been hunting base camps along Quantico Creek. English contact, disease, and group warfare gradually affected Native Americans' use and occupation of the area. By 1660, Native Americans were gone from the park area (NPS 1995).
From about 1650 to 1680 most of the land in the park vicinity was patented and settled by the English, who established large tobacco plantations that flourished until the late 1700s. Prince William County (named after William, Duke of Cumberland, youngest son of King George II) was formed in 1731, and the town of Dumfries gradually grew into a major colonial shipping and processing area for the tobacco growers. Because of its proximity to Dumfries, the park area became important tobacco‑growing land. However, with a single exception, there is no evidence that the planter‑elite actually settled in the park; rather, it was farmed by indentured servants, tenant farmers, and slaves directed by representatives of the large landowners. Tobacco remained by far the most important product shipped out of Dumfries from the park area until 1800. However, monocropping took its toll on the lands, and tobacco yields declined steadily throughout the latter part of the 18th century. Erosion of the uplands, exaggerated by heavy rains and flooding, caused the mouth of Quantico Creek to fill in and Dumfries was cut off from direct access to the Potomac. Despite efforts to build canals to the river, by the 1790s Dumfries' role as a port town had ended, and the economic and social system based on plantation agriculture gradually ceased to exist (NPS 1995). During late 1861 and early 1862, approximately 6,700 Confederate troops camped next to Quantico Creek near Dumfries. Dumfries was a major supply center, and several actions were directed toward its protection before the spring of 1862 when its warehouses and the fortifications at the mouth of the creek and on Grayson's Hill (just outside the eastern park boundary) were abandoned. A Confederate raid on Union forces in Dumfries was mounted, at least in part, from the southeastern section of what is now the park. A map from the 1860s shows a "line of rifle pits" at the northeastern boundary behind Grayson's Hills, and both Confederate and Union soldiers are said to be buried in several cemeteries within the present park boundary. The pyrite mine was established in 1899. At its production peak, it employed 250 workers, many of whom resided in the area that is now the park. When the mine finally closed in 1921, many of the employees found work at the newly established Quantico Marine Corps Base (NPS 1999).
In accordance with Section 110 of the NHPA of 1966, as amended, in 1986 the NPS prepared an archeological and historical overview and assessment of the park titled “The Hinterland: An Overview of the Prehistory and History of Prince William Forest Park, Virginia.” This study provides the historic and prehistoric context for the park's cultural resources. After that report was completed, the park nominated four of its five CCC cabin camps to the National Register of Historic Places. In 1989 cabin Camps 1, 2, 3, and 4 were approved and officially listed as part of the historic districts. In addition, a comprehensive archeological study was conducted for the park from 2000-2004. The final document has been used as a reference for this project.
Environmental Consequences.—Environmental consequences for cultural resources are described below.
No Action Alternative.—There would be no immediate change to the existing condition of the cultural resources in the project area under the No Action Alternative. However, Camp 4 Lake and the associated dam are included in the Camp 4, Pleasant Historic District (PHD). If Camp 4 Dam were to fail, a portion of the PHD would be lost and would be considered an adverse effect to the district. If Camp 4 Dam were to fail, the sudden release of water and the associated erosion and downstream scouring could impact other historic properties in the park.
Preferred Alternative.—Cabin Camp 4 was approved and officially listed as part of the park’s four historic districts in 1989. The Goodwill Historic District includes several buildings at Camp 1, a playing field, a water tower, and the access road to Camp 4. None of this Historic District will be impacted by project operations other than increased construction traffic on the existing access road. There are no improvements planned for this section of road.
The Camp 4 PHD includes all the cabins and associated structures, the access roads to the cabins, and access road to Camp 4 Dam. Unit C of Camp 4 and recreational use of the lake will be closed to the public during the construction period. All work to Camp 4 Dam is intended to restore the integrity and original characteristics of the feature and to reduce safety hazards to campers utilizing the recreation facilities.
PRWI has initiated consultation with the Virginia SHPO to determine if this project will affect the historic properties of the park.
No Action Alternative.—Under this alternative, the cumulative effects of not addressing structural deficiencies of Camp 4 Dam could ultimately result in dam failure. The cumulative impacts of a dam failure could be realized on a local, regional, and State level.
Preferred Alternative.—Potential impacts from this project to all associated resources would be avoided or mitigated. Dam operation and maintenance activities, not directly related to this project, would continue to be conducted according to NPS scheduling. No long-term cumulative effects would be expected as a result of implementing the preferred alternative.
The following list constitutes the environmental commitments associated with the construction and mitigation of the proposed preferred alternative:
· Prior to removal/dredging of lake-bottom sediments, Reclamation will complete sediment testing at Camp 4 Lake to determine if the material can be classified as non-hazardous waste, and transferred to a State certified solid waste disposal facility.
· Following construction, if necessary, all disturbed areas will be reseeded with a seed mixture acceptable to NPS.
· All waste materials and excess or unneeded fill associated with the project construction or operation will be disposed of properly and not in wetlands or identified flood plain areas.
· Discharges of fill material in wetlands or waters of the United States will be carried out in compliance with provisions of Section 404 of the Clean Water Act and the nationwide and/or project-specific permit requirements of the COE and any associated permits/ permitting agencies.
· Control measures, such as silt fences and protective berms, will be employed where necessary to reduce wind and water erosion and to prevent sedimentation to the stream.
· Construction areas will be watered during dry conditions to control dust.
· Noxious weeds will be controlled within any reseeded area only after consultation with and approval by NPS staff certified through the Commonwealth of Virginia in pesticide application. The accidental introduction of noxious/invasive plants from equipment will be prevented through an inspection of said equipment prior to offloading for use in the park.
· Tree removal will be kept to an absolute minimum.
· Contamination of water will be controlled at all construction sites from fuel spillage, lubricants, and chemicals, by following safe storage and handling procedures.
· Equipment exhaust systems will be maintained to factory or superior specifications to minimize noise.
· National ambient air quality standards will not be exceeded.
· Should any buildings, structures, sites, objects, or districts or properties of traditional religious and cultural importance be discovered that could potentially qualify as historic properties, NPS will consult with the SHPO to determine whether any qualify as historic properties and to determine the effects of construction activities on the properties per 36 CFR part 800.4 and 800.5. Any avoidance or mitigation measures would be instituted before construction begins.
· If unanticipated cultural resources, such as artifacts, foundations or other historic items are encountered during construction, all ground disturbing activities in the immediate area of the resource will be stopped until NPS can consult with the SHPO and evaluate the resource per 36 CFR Part 800.13.
· If any unanticipated threatened or endangered species are encountered during construction, all ground disturbing activities in the immediate area will be stopped until NPS can consult with the USFWS to determine the appropriate steps to avoid impacting the species.
· If any wildlife, including reptiles, mammals, or birds, are found within the construction site, work in the immediate area will be stopped and the NPS notified. At no time will wildlife be taken, fed, harassed, trapped, or disturbed. NPS staff will be immediately notified if wildlife that presents a health and/or safety concern is observed within the construction site.
· In order to reduce the potential impact to cultural/archeological resources in the area, the access road to the dam will be widened a maximum of 2 feet on each side of the centerline.