WORK PLANS - Laserfiche WebLink

Home Browse Search

• DDJC-Sharpe Permaneniezometer Installation W 3rk Plan Addendum GMS Boundary Condition Vex fication 1.0 INTRODUCTION part of the DDJC-Well Monitoring Program); and 1.1 The Defense Distribution Depot San Joaquin California Sharpe Site(DDJC-Sharpe) • Perform a survey to determine the tol,of is currently implementing various investigation, casing elevation and ground surface leva- design,and remediation activities for contami- tion and northing/easting coordinates at nated soils and groundwater.These efforts are in each piezometer location. support of the Installation Restoration Program (IRP),Resource Conservation and Recovery Act 1.4 The upper 300 feet of the subsurface (RCRA),Comprehensive Environmental beneath DDJC-Sharpe consists of interbe ded Response,Compensation,and Liability Act sand, silt,and clay layers;groundwater is (CERCLA), Superfund Amendments and encountered at approximately 20 feet below Reauthorization Act(SARA), and other regula- ground surface(bgs). Groundwater flow beneath tory driven environmental programs and the installation is generally to the northwest; activities. however,pumping from extraction wells lias altered the hydraulic gradient in some are s. 1.2 The purpose of this work plan addendum is Groundwater occurs in stratigraphic zone that to describe specific field activities to be con- are hydraulically interconnected. These a uifer ducted under Task Order(TO) 38(U.S. Army zones have been designated as the A,B, Q and Corps of Engineers,Huntsville [CEHNC], D zones.Where they are present,conftnin Contract Number DACA87-95-D-0001).This layers of these zones consist of laterally scon- work plan is an addendum to the Groundwater tinuous clay, silty clay,and sandy clay lay rs. Modeling System(GMS)Boundary Condition Verification Work Plan(Radian International, 1.5 Results from this field effort will be 1998), under which temporary piezometers were documented in an engineering technical installed in August and September 1998.Field memorandum(ETM). activities to be performed under this work plan addendum are intended to collect information 2.0 PLANNED ACTIVITIES that can be used to verify the groundwater boundary conditions at DDJC-Sharpe.The 2.1 Permanent groundwater piezometers will be boundary condition information will be used in installed at 22 off-depot locations using Clyr modeling the groundwater at DDJC-Sharpe. The equipment.The piezometers will be locate groundwater modeling is being performed by within a 1/2-to 1-mile radius from the ins Ila- U.S. Army Corps of Engineers (USACE) tion boundary to provide data for groundwater Waterways Experiment Station(WES)to modeling at DDJC-Sharpe. The CPT borings simulate the flow and transport of contaminants will be located within the public right-of-v Fay of present in the groundwater at DDJC-Sharpe. existing roads, as shown on Figure 2-1.CIT dissipation tests will be performed to estimate 1.3 The specific field activities to be performed the elevation of the top of the A Zone (i.e., the to verify the boundary conditions at DDJC- first occurrence of groundwater). The resu Its of Sharpe include the following: the CPT dissipation tests will be used to deter- mine piezometer screen locations.Permanent • Install 22 permanent off-depot piezometers 1-inch piezometers will be installed at the CPT (within a 1/2-to 1-mile radius of the DDJC- locations to provide a more accurate groan - Sharpe installation), and collect ground- water elevation reading. Top of casing elei ation water elevation data using cone penetrome- and ground surface elevation data will be ter testing(CPT)procedures(water levels obtained from these piezometer locations by will be monitored and reported quarterly as surveying. Information on specific field KA02238\Sharpe Piez WP\CPT addendum Sharpe.doc 1 Ma h 2002