WORK PLANS - Laserfiche WebLink

Home Browse Search

CA ARNG Field Quality Assurance Project Plan 9.3 Decontamination Procedures 9.3.1 General Equipment The purpose of decontamination and cleaning procedures during drilling, well installation, and soil and water sampling is to prevent foreign contamination of the samples and cross -contamination between wells and between sampling sites. Before use, all drilling and groundwater and soil sampling equipment will be decontaminated by steam cleaning or alternatively by washing with a non -phosphate detergent such as Liquinox® or equivalent. A tap water rinse and a DI water rinse will follow the detergent washing. The following item -specific decontamination procedures will be observed: • Drill rig: Steam clean prior to drilling at each new site. • Auger flights and tools: Steam clean prior to drilling each borehole. • Downhole abandonment equipment (e.g., tremie pipe): Steam clean between each well. • Samplers: Steam clean or detergent wash between each use. • Soil gas sampling syringes and retractable probe tips: Bake in an oven at least eight hours at 120°C between each use. Well casing and screen: Steam clean before installing unless it is sealed in plastic and certified to be cleaned by the manufacturer. • Water level sounder: Rinse with DI water, detergent wash (i.e., Liquinox), tap water rinse, and DI water (in that order) between each use. • Bailer: Detergent wash and steam clean followed by a rinse with DI water (in that order) between each use, or if disposable, discard between uses. • Bailer cable: Steam clean or, if disposable, discard between uses. • Development rig: Steam clean between wells. • Pumps: Steam clean exterior of pump and hose and run detergent water and tap water through pump if there is no check ball installed on pump. • Aquifer test equipment: Steam clean between uses. • HydroPunch® sampling equipment: Steam clean prior to use at each new site. 9.3.2 Cone Penetrometer Testing Equipment 9.3.2.1 Downhole CPT equipment will be decontaminated by passing the sounding rods and probe tip through a rod -washing chamber at the bottom of the hydraulic ram assembly as they are retrieved. High- pressure steam cleans soil and groundwater from the exterior of the downhole equipment. Rubber seals at the top and bottom of the rod washing chamber prevent decontamination water from leaking to the ground surface and scrape soil from the downhole equipment. Decontamination water will be collected and stored for appropriate disposal. field QAPP.DOC 9-21 May 2000