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4d. Groundwater Elevations Each monitoring well was opened and expandable caps were removed. • Each well was allowed to equilibrate to atmospheric pressure for a minimum• of 30 minutes. A water level meter was used to measure the depth-to-groundwater in each monitoring well. The depth,time, and visual observations regarding well access, condition, security,etc., were recorded on Water Level Data Sheets. 4e.Purging The volume of standing water in each monitoring well was calculated using the diameter of the well,the measured depth-to-water,and the depth-to-bottom. The volume was recorded on the Well Sampling Data Sheet for each well. Monitoring wells MW-5 and MW-6 were purged using an electronic submersible pump. Monitoring well MW-8 was purged using a new disposable polyethylene bailer. During the purging process,the indicator parameters of pH, conductivity, oxidation reduction potential, and temperature were measured. Visual observations of color and odor were also monitored in purged wells. The time,readings, and visual comments were recorded on Well Sampling Data Sheets. Each well was purged of three well volumes. Purge and decontamination water was transferred to 55-gallon drums labeled and stored on site. 4E Groundwater Sample Collection Groundwater samples were collected by lowering a previously unused,disposable, polyethylene,bottom-filling bailer into the well. When completely full,the bailer was carefully retracted from the well casing. The water was transferred from the bailer to the appropriate certified clean sampling containers. Each VOA was immediately capped. The vials were inverted and gently tapped to check for the presence of air bubbles. If any bubbles were visible,a new vial was filled and confirmed to be free of any air bubbles. The samples were labeled with the following information: Sample ID Date and Time Sample Collected Location Sampler's Initials Sample information was documented on a Chain-of-Custody form. The samples were placed in an ice chest chilled with ice. Upon completion of the sampling activities,each well was closed and secured by replacing the well cap and lid. 5. Equipment Used Disposable gloves Potable water Alconox soap Containers to hold rinsate water Scrub brushes Tools to open wells Keys to wells Water Level Data Form /Pencil Well Sampling Data Sheets SOP GW Sampling 2 of 3 August 2011