Laserfiche WebLink
0 <br /> California me ional Water Quality Co rol Board <br /> 9 Y <br /> Central Valley Region '= <br /> Katherine Hart, Chair <br /> Linda S.Adams 11020 Sun Center Drive#200, Rancho Cordova, California 95670-611 rind G. Browr <br /> Secrelcnyfor Phone(916)464-3291 - FAX(916)464-4645 O Jr. <br /> Environmental http://www.waterboards.ca.gov/centralvalley FEBGovernor <br /> Proleclion CD 2011 <br /> ENVIRONMENTAL HE4LTH <br /> 18 February 2011 PERMIT/SERVICES <br /> Mr. James Diel <br /> Manager, Site, Remediation <br /> Union Pacific Railroad Company <br /> 9451 Atkinson Street, Suite 100 <br /> Roseville CA 95747-5528 <br /> PHASE II FIELD INVESTIGATION AND LNAPL MOBILITY REPORT, UNION <br /> PACIFIC RAILROAD COMPANY FORMER TRACY MAINTENANCE FACILITY, <br /> 720 EAST 6r" STREET, TRACY, SAN JOAQUIN COUNTY <br /> The California Regional Water Quality Control Board, Central Valley Region (Central <br /> Valley Water Board) staff has received and reviewed the Phase II Field Investigation <br /> and LNAPL Report (Report), dated 29 November 2010, prepared by ARCADIS U.S., <br /> Inc. (ARCADIS) on behalf of Union Pacific Railroad Company (UP). <br /> The Report presents the results of the second phase of a two-phase investigation <br /> begun in 2008 to delineate the lateral and vertical extent of light non-aqueous phase <br /> liquid (LNAPL), principally diesel, as well as dissolved-phase Total Petroleum <br /> Hydrocarbons quantified as diesel (TPHd) in shallow (10-25 feet below ground surface) <br /> groundwater. A screening survey to characterize lateral extent of LNAPL and vertical <br /> extent of the smear zone was conducted in Phase I. Investigation activities included in- <br /> situ light-induced fluorescence to identify petroleum hydrocarbons in soil. A total of 55 <br /> direct-push borings were advanced, and 13 confirmation borings and temporary wells <br /> were installed. Phase II involved the installation of 31 additional soil borings, 26 <br /> hydropunch/cone penetrometer borings, and conversion of five borings to permanent <br /> monitoring wells in 2009. Locations of Phase II borings were based upon results from <br /> Phase I. Bail-down testing of LNAPL, soil core photography, LNAPL chemical analysis, <br /> soil physical properties analysis, and LNAPL recoverability analysis were also <br /> performed during Phase Il. <br /> Multiple lines of evidence were used to estimate the extent, mobility, and recoverability <br /> of LNAPL, including the following: <br /> • Observations in monitoring wells. <br /> • Aquifer characteristics (porosity, soil capillarity parameters, water and LNAPL <br /> saturations). <br /> • LNAPL and other fluid characteristics. <br /> • Pore velocity and pore-entry pressure calculations. <br /> California Environmental Protection Agency <br />