SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Soil and Groundwater Investigation Report Mountain House Development Site#6 February 25,2010 In the context of a soil and groundwater investigation, RSLs, ESLs, and WQOs are screening levels used only to define the extent of affected soil and groundwater, and not to assess site- specific health or ecological risks or establish cleanup standards. If the concentration of a crude- oil constituent in soil or groundwater does not exceed its RSL, ESL, or WQO, the soil or groundwater is considered to be not affected. Further, the presence of a constituent at a concentration above a screening level does not necessarily indicate risk to human health or the environment. 1.1 SYNOPSIS SAIC advanced 15 soil borings at the site in November 2009. The extent of affected soil and groundwater at the site has been delineated, and no further site investigation is recommended. 2. BACKGROUND 2.1 LOCATION AND SITE DESCRIPTION The site is in an agricultural area northwest of the City of Tracy in San Joaquin County, California. The Mountain House study area is situated at elevations ranging from approximately 20 to 30 feet above mean sea level in relatively flat-laying areas. The site is located along a 1/2 mile stretch of West Byron Road,between Wicklund Road and West Bethany Road (Figure 1). 2.2 HISTORICAL AND EXISTING PIPELINE FACILITIES The site includes right of ways (ROWS) associated with the former OVP and TAOC pipelines. The OVP was installed between 1902 and 1904 as a"hot line" (i.e., the oil was heated to facilitate transmission), and carried San Joaquin Valley crude oil (SJV crude) north from the Kern River Oil Fields in and near Bakersfield to the Richmond Refinery. The pipeline and associated pump stations operated from 1903 until the early to mid-1930s. The OVP was again used during the early 1940s to primarily transmit Bunker C fuel oil from the Richmond Refinery to railroad hubs in Tracy. The former OVP alignment at the site runs along the south side of West Byron Road. The former TAOC alignment at the site lay within the Union Pacific Railroad(UPRR) ROW, located on the north side of West Byron Road. The TAOC pipeline system was constructed in 1907 and transmitted heavy crude oil from the southern San Joaquin Valley to the Bay Area. For a relatively short timespan the pipelines transmitted a cutter stock with the crude oil between Coalinga and the Bay Area; the cutter stock was used to reduce the viscosity of the oil. The TAOC system operated until the 1970s. Active pipelines in the UPRR ROW include the Kinder Morgan Energy Partners, L.P. (KM) pipeline and Chevron Pipeline Company's Bay Area Products Line (BAPL). The KM pipeline and BAPL reportedly transport gasoline, diesel, and jet fuel. The exact KM pipeline and BAPL locations have not been identified; therefore, they are not shown on Figure 2. 2.3 EXISTING AND PLANNED DEVELOPMENT West Byron Road is currently a two-lane thoroughfare serving southwest San Joaquin and eastern Contra Costa counties between Tracy and the Sacramento River Delta. The site is located among agricultural areas in and near the community of Mountain House, California. Properties located to the north of West Byron Road are in the Mountain House community, and 2 Fmin Science to Solutions