FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

a Clayton } ENVIRONMENTAL s CONSULTANTS xi Mr. William Rieger I Page 2 Fortifiber Corporation Clayton Proposal No. 93-B-110 rl April 6, 1993 } l _ f SCOPE OF 3s' Clayton will install one monitoring well down gradient from the area of the tank -� excavation-. 'Information-gleaned from nearby sites indicates•that the water table•is- - -. between 10 and 15 feet bgs and the direction of flow is toithe north. However, the actual depth to water at the specific site will have to be ascertained in the field. The monitoring well will be installed outside the excavated ares downgradient from the tank locations. We will collect soil samples starting at 5 feet bgs. We estimate that we will collect two soil samples No soil samples will be collected below the water saturated zone. To aid in locating ' an contamination and selecting soil samples for analysis, Clayton will screen the soil Y g P Y � , Yt cutting during drilling using a photoionization detector (PID) and visually examine the , I soil to detect petroleum compounds � i� During drilling of the monitoring well, the characteristics will be logged in the field soil by a Clayton geologist, using the Unified Soil Classification System. Distinguishing Yt features such as color, odor, and relative soil moisture content will be noted. Drilling and sampling activities will be conducted in accordance with the RWQCB and Tri- Regional guidelines and with Clayton's drilling, well construction, and sampling protocols for borehole/monitoring well installation (Attachment 1). The drilling will be supervised by a civil engineer or a geologist registered in the State of California. The soil samples will be collected in precleaned brass tubes for the purpose of lithologic logging. The brass tubes selected for analysis will be sealed with aluminum foil, plastic caps, and tape, and immediately placed in a chilled cooler for shipment to Clayton's state-certified laboratory in Pleasanton, California, for analysis. Legal chain- of-custody procedures will be followed for handling of soil.samples. Clayton estimates that two soil samples will be collected. j The monitoring well will be constructed of 2-inch diameter PVC casing. Screened casing will be used extending above the water table. Solid!casing will then be installed E to the surface. The sand pack will extend to two feet above the screen. A 1-foot thick bentonite seal will be placed on top of the sand pack, and the well will be sealed to the surface using cement grout. A locking cap will secure the well in a Christie box raised above the surface grade by approximately 2 inches.j The well seal in newly developed wells must set for 48 to 72 hours prior to = development. Development of the well can volatilize contaminants present, therefore, the well niust settle for at least 48 to 72 hours between development and the first incident. The first site visit will involve well development, and the purging/sampling ,:, actual sam lin of the well will occur during the second site visit. sampling 8 � The well will be developed using disposable bailers until water turbidityand specific conductance stabilize. Water samples from the well will be collected using clean S disposable teflon bailers.,,Water will be collected in clean.laboratory-supplied I'a containers and placed.:immediately into an iced cooler for transport to Clayton's laboratory for analysis. One:trip blank will be furnished in.accordance with Clayton's" quality assurance/ytrality control (QA/QC) program.