Water Sampling

Coal and water samples collected by our customers are picked up on a daily basis or as required under special circumstances. Alternatively, MAS offers water collection and sampling services including stream sampling, NPDES, groundwater and well sampling.

Recently, the PADEP has focused on the contamination of groundwater samples with sediments containing metals mainly as a result of the disturbance of sediments located at the bottom of some wells. To address this,during the 1990's procedures and equipment for low-flow water sampling were being developed by the ASTM and this method of well sampling was gaining wide acceptance by regulatory agencies. As a result, in 2002, ASTM released their Designation D6771-02 Standard Practice for Low-Flow Purging and Sampling for Wells and Devices used for Ground-Water Quality Investigations. Using this ASTM practice as a base, Miltech Analytical Services, Inc. has developed its own equipment and procedures for low-flow purging and sampling of groundwater wells associated with solid waste and ash disposal sites. Miltech has been implementing this low-flow approach at coal mines and ash disposal sites since 2003.

During low flow sampling, an adjustable volume centrifugal pump is normally used for both purging and sampling. In cases where well in-flow is very low (less than about 0.1 L/min) diaphragm pumping is used. Generally, the procedure involves the following:
Step 1. Measure the standing water level in the well.

Step 2. Lower the pump into the well to a position at approximately the mid-point along the length of the well screen.

Step 3. Purge the well by extracting three well volumes.

Step 4. After purging adjust pump discharge to exactly match well inflow as indicated on the emscope probe that has been inserted into the well.

Step 5. Pump well for a fixed period of time while holding well level fixed. Measure volume, sample and field analyze temperature, pH and conductivity.

Step 6. Repeat Step 5 until ASTM stabilization parameters are met over each of three consecutive readings.

Step 7. After stabilization collect an amount of sample based on the analyses required as determined by the laboratory manager.