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The sampler will inspect the well for the presence of lock, cap, surface seal integrity, obstructions, evidence of tampering, debris, or surface water collecting in the flush mount. 1.4 Well Purging and Sampling The wells will be sampled starting at the wells that have historically had the lowest concentrations of chemicals of concern and ending at the wells that historically have had the highest concentrations of the chemicals of concern. Sampling will be performed using the following procedure: 1. Set-up; 2. Purging and measurement of field parameters; 3. Sampling; and 4. Clean-up and decontamination. Detailed procedures for performing each of these steps are provided in the following subsections. 1.4.1 Set-up All necessary equipment for purging, sampling and storage will be brought to the well before the well is opened. Equipment will be placed on a clean HDPE plastic sheet near the well. General parameters describing the well and field condition(e.g.,well ID, depth, weather, date and time)will be documented on a field data sheet. Sampling will begin by opening the well and measuring the depth to the water surface and total well depth. The pump, tubing, field probe, and drums for purged water will then be set up. 1.4.2 Purging (Low Flow Protocol) The wells will be purged using the low flow/minimum drawdown protocol as described below. The general procedural requirements for purging are as follows. • The pump will be lowered slowly down the well positioning the well intake at the middle of the well screen. • The well will be purged at a low-flow pumping rate. Pumping will begin for the third well volume at a steady rate of approximately 100 mUmin and the depth to water will be measured frequently(e.g., every minute for the first few minutes)to ensure that less than 0.1 foot of drawdown occurs. The pumping rate may be