Task 1. Semi Annual Field Parameter Measurements Measure groundwater field parameters (temperature, ground water elevation, specific conductance, pH, and turbidity). In order to assess the groundwater gradient at the time of sampling, water level measurements will be made in the three (3) wells (MW-1, MW-2 and MW-3) at the beginning of each sampling round prior to purging and sampling the wells. The depth-to-water will be measured in each well according to the protocol described in the M&RP. The depth-to-water measurements will then be converted to relative groundwater elevations with respect to mean sea level by subtracting them from the surveyed casing elevations. The resulting ground water elevations will be assessed to interpret the groundwater gradient at the time of sampling. Task 2. Semi Annual Monitoring Parameters Purge wells and collect samples as described in the M&RP. The sampling will be conducted concurrent with the field parameter measurements. One groundwater sample from each of the four (4) wells (MW-4, MW-5, MW-6 and MW-7) will be submitted under chain-of-custody control to a laboratory certified by the State of California Toxic Substances Control (DTSC) for the requested analysis. Samples will be analyzed on a regular laboratory turnaround that may require up to two (2) to three (3) weeks for receipt of analytical data. The four (4) samples will be analyzed for: ▪ Total Dissolved Solids (TDS) by EPA Methods ▪ Total Organic Carbon (TOC) ▪ Chemical Oxygen Demand (COD) ▪ Iron (Fe) by EPA Methods ▪ Chloride (CI) by EPA Methods ▪ Sodium (Na) by EPA Methods ▪ Sulfate (SO4) by EPA Methods ▪ Volatile Organic Compounds (VOCs) by EPA Method 8260 Task 3. Semi Annual Monitoring for Constituents of Concern Purge wells and collect samples as described in the M&RP. The sampling shall be conducted concurrent with the field parameter measurements. One (1) groundwater sample from each of the four (4) wells (MW-4, MW-5, MW-6 and MW-7) will be submitted under chain-of-custody control to a laboratory certified by the State of California Toxic Substances Control (DTSC) for the requested analysis. Samples will be analyzed on a regular laboratory turnaround that may require up to two (2) to three (3) weeks for receipt of analytical data. The four (4) samples will be analyzed for: ▪ Alkalinity by EPA Methods ▪ Bicarbonate ▪ Calcium (Ca) ▪ Carbonate (CO3) ▪ Magnesium (Mg) ▪ Manganese (Mn) ▪ Nitrate (as N) by EPA Methods ▪ Potassium (K) ▪ Zinc (Zn)
