5.0 Greenbelt Alternative Chapter 5 describes existing conditions of Figure 5- 1: Greenbelt Conceptual Site Plan the affected environment and identifies the environmental consequences associated with the Greenbelt Alternative. A detailed description of the WMATA methodologies employed to evaluate impacts for each MAINTENANCE resource and the relevant regulatory framework is YARD given in chapter 3, Methodology. The Greenbelt site consists of approximately 61 acres immediately adjacent to the Greenbelt Metro Station ¨¦§495 ¨¦§95 on Greenbelt Metro Drive in the City of Greenbelt, HOLLYWOOD Prince George’s County, Maryland, as shown in figure 5-1. It is bound on the north by Greenbelt Metro Drive and on the east by Cherrywood Lane. The southern and eastern boundaries are based on an option agreement signed with the Washington Metropolitan Area Transit Authority (WMATA) and the A.H. Smith VISITOR CENTER MAIN GATE Development Company (AKA: Renard Development NORTH EMPLOYEE VEHICULAR GATE Company, LLC) in 2014. Greenbelt Road (MD 193) is NARRAGANSET PKWY VISITOR PARKING PARKING (EXIT ONLY) located less than 1 mile to the south, while the Capital EMPLOYEE GREENBELT METRO DR PARKING Beltway is near the northeast site boundary. The LACKAWANNA ST M Greenbelt Metro Station is located approximately 0.1 GREENBELT SUBSTATION METRO STANDBY mile from the western site boundary. Approximately STATION HQ BUILDING GENERATORS DEVELOPABLE half of the site is currently used by WMATA as a AREA CHERRYWOOD LN parking lot for the adjacent Greenbelt Metro Station. TRUCK PERIMETER SCREENING & FENCE The remainder of the site is an undeveloped riparian REMOTE DELIVERY forest associated with Indian Creek, which crosses the HOLLYWOOD FACILITY CENTRAL UTILITY site from northeast to southwest. Several residential PLANT communities are near the site, including the South SECONDARY Core Greenbelt Station development to the south, VEHICULAR Franklin Park multifamily housing to the east, and GATE the Hollywood subdivision to the west. Land use in the vicinity of the site is primarily residential and open space. Other development in proximity to the site includes suburban office parks, a WMATA rail CHERRYWOOD LANE yard, and a Federal courthouse. Concentrations of GREENBELT STATION PKWY WETLANDS commercial uses occur approximately 1 mile west of SPRINGHILL DR the site along U.S. Route 1, while agricultural land associated with the Beltsville Agricultural Research Center (BARC) characterizes much of the landscape north of the site. BARC is the largest agricultural FRANKLIN PARK research complex in the world covering 6,600-acres of which several thousand acres is preserved as farmland. The research center house approximately 1,300 people in four buildings with more than 365,000 SF of space. U.S. General Services Administration 219 FBI Headquarters Consolidation Draft Environmental Impact Statement Figure 5- 2: Physiographic Provinces of the National The analysis of environmental impacts for the 5.1 Affected Environment GREENBELT EARTH RESOURCES Capital Region Greenbelt Alternative is based on the conceptual site AFFECTED ENVIRONMENT plan shown in Figure 5-1. This site plan is informed by The following sections describe the affected OVERVIEW both site planning principles and design requirements environment for the Greenbelt site and associated ¨§95 based on FBI program needs. These site plans • Parcel topography is generally flat, ¦¨§270 ¦ study areas for each resource topic evaluated in are conceptual in nature and represent a program- this Environmental Impact Statement (EIS). particularly in the area of the existing M A R Y L A parking lot and Indian Creek riparian V N compliant layout that would yield the most conservative I R G I N D forest with a slight slope between these I A Greenbelt Site estimate of the environmental impacts associated with two areas. ^ each alternative. Ultimately, the layout and design 5.1.1 Earth Resources of the proposed FBI HQ could potentially be altered WASHINGTON ¤£50 Earth resources encompass geology, topography, • Surface physiography of the Crownsville ¦¨§495 during the final design process with the selected D.C. and soils. Upland District, where the Greenbelt ¤£50 exchange partner. GSA would perform supplemental site is located, is characterized by flat to 66 NEPA analysis, as necessary, if there is substantial ¦¨§ ¦¨§495 gently southeast-dipping sedimentary 395 295 variance from what is considered in this EIS. 5.1.1.1 Geology and Topography ¦¨§ ¦¨§ 95 beds of Quaternary lluvium and Tertiary ¦¨§ ¤£301 terraces consisting mainly of quartzitic The Greenbelt site is situated within the western shore uplands region Atlantic Coastal Plain physiographic sands, gravels, silts, and clays. ¤£1 province, as shown in figure 5-2 (NPS 2008) (Reger • Five different soils were found on the and Cleaves 2008). The Coastal Plain physiographic ¦¨§95 site, which is composed of part asphalt province is bordered by the Atlantic Ocean to the and part forest, including Udorthents, east and the Piedmont physiographic province to the Highway complex; Udorthents, Loamy west, and ranges from the southern portion of Florida complex; Zekiah and Issue soils Coastal Plain 0 7.5 15 to southern Massachusetts. The division between complex; Russet-Christiana-Urban Piedmont Province I Miles the Coastal Plain and Piedmont provinces is also land complex and Elkton–Urban Land 1 in = 13.5 miles referred to as the fall line (Froelich and Hack 1975). complex. Sources: The Coastal Plain is characterized by gently rolling ESRI (2013), GSA (2013), DC GIS (2013) hills and valleys and is underlain by a southeastwardly thickening sequence of sediments consisting of sand and gravel aquifers interlayered with silt and clay and confining units. The sediments of the Coast Plain dip eastward at a low angle, generally less than one PHYSIOGRAPHIC PROVIDENCE degree, and range in age from Triassic (250 to 200 A geographic region with a characteristic Mya) to Quaternary (2.6 million years ago [Mya] to geomorphology and often specific present). Mineral resources of the coastal plain are subsurface rock type or structural elements. chiefly sand and gravel that are used as aggregate materials by the construction industry (MGS 2014). FALL LINE The geomorrphologic break between an upland region of relatively hard, crystalline basement rock and a coastal plain of softer sedimentary rock. U.S. General Services Administration 220 FBI Headquarters Consolidation Draft Environmental Impact Statement Within the Atlantic Coastal Plain and the western Figure 5- 3: Greenbelt Topography Figure 5- 4: Greenbelt Geology Overview shore upland region, the Greenbelt site lies within the Greenbelt Metro Dr AMSL Crownsville Upland District, which is characterized by 495 95 Capital Above mean sea level (AMSL) is the average level flat to gently southeast-dipping sedimentary beds of Beltway for the surface of one or more of Earth’s oceans Quaternary alluvium and Tertiary terraces consisting from which heights such as elevations may be mainly of quartzitic sands, gravels, silts, and clays. The measured. Greenbelt site lies within a shallow valley formed by Indian Creek. Overall, the site is flat; however, there is a slight to moderate slope between the existing parking lot and Indian Creek riparian forest. The overall elevation ranges from approximately 70 to 80 feet Ln d above mean sea level (AMSL) as shown in figure 5-3. oo w y rr e The geology of the Greenbelt site is heavily influenced h by Indian Creek. According to the geologic map C of Prince George’s County, Maryland, geologic deposits along the banks of Indian Creek consist of Springhill Dr Pleistocene- and Holocene-aged interbedded sand, Alluvium silt-clay, and gravel alluvium with an average thickness Qal of approximately 15 feet, and a maximum of 40 feet Qt Terrace Deposits (Glaser 2003). Surrounding the alluvium deposits 2 ft contours 0 375 750 are 20 to 25 feet thick early Quaternary-aged terrace 102 ft AMSL Feet Qt Sand-gravel facies deposits of interbedded sand, gravel, and silt-clay. The 1 in = 750 feet majority of the site is underlain by Cretaceous-aged Sources: Adapted from Geologic Map of Prince George’s County sand and gravel of interbedded quartz sand, pebbly 56 ft AMSL ESRI (2013), GSA (2013), DC GIS (2013), USGS (2008) sand, gravel, and silt-clays with a maximum thickness of 1,000 feet. Superficial geologic features have been previously disturbed by the operation of a sand and gravel mining operation, and the subsequent introduction of fill from the construction of Lake Artemesia for the construction of the Greenbelt Metro Station surface parking lot (Prince George’s County Planning Department 2012). Figure 5-4 illustrates the geology of the Greenbelt site and its environs. U.S. General Services Administration 221 FBI Headquarters Consolidation Draft Environmental Impact Statement Figure 5- 5: Greenbelt Soils 5.1.1.2 Soils Udorthents Associations The majority of the site northwest of Indian Creek is There are two Udorthent associations located 495 Greenbelt Metro Dr paved asphalt, while the southeastern half of the site on the Greenbelt site. The Udorthent, highway 95 is forested. Fill material from the construction of Lake association soils, are located mainly along the Hollywood Artemesia has been placed at the site for development western and northeastern site boundary and Park of the surface parking lot. The United States comprise approximately 14 percent of the site, while Department of Agriculture (USDA) Natural Resource Udorthent, loamy association soils, are located Conservation Service (NRCS) has identified five major primarily throughout the center of the site and along soil associations within the Greenbelt site, as shown the southwestern and northern boundaries and in figure 5-5 and table 5-1. None of the soils identified comprise approximately 57 percent of the site. It is at the site are considered highly erodible soils, nor important to note that the buildable area for this site Capita are any of the soils considered to be prime farmland alternative is located exclusively within these two (Prince George’s Soils Conservation District 2013).