Ground Water Sampling
Groundwater samples will be collected according to the EPD Manual for Groundwater Monitoring, revised September, 1991.
Below is a listing of pump types and tubing materials used by AEM.
|Peristaltic||4||Field filtration, purging||Metals||4|
- Submersible pump housing, internal surfaces, and upper fitting for tubing are stainless steel. A 4′ to 8′ length of Teflon tubing is attached to the stainless steel fitting. The remainder of the discharge tubing is garden hose. The suspension cable is 3′ to 4′ of stainless steel or Teflon-coated stainless steel, attached to a nylon rope. A check valve at the upper stainless steel/Teflon junction prevents backflow of purge water into the well.
- The bladder pump housing is Lexan plastic and the tubing is polyethylene. This pump is used for purging only in the case of 2″ diameter deep wells. After bladder pump purging, one well volume is purged with an appropriate bailer prior to sampling.
- Centrifugal surface pumps utilize 4′ joinable sections of PVC pipe with a 3′ to 4′ Teflon tail piece. Only the Teflon portion contacts the formation water. A foot valve prevents backflow of purge water into the well.
- Peristaltic pumps are routinely used only for in-line field filtration of metals samples. Tubing may be medical grade silicon, Tygon, or polypropylene flexible tubing. On rare occasions, a small diameter shallow well may be purged using this pump. In this case, a Teflon tailpipe arrangement would be used, with only the Teflon contacting the formation water. To prevent backflow of purge water, the tubing is withdrawn from the well while the pump is running.
Below is a listing of bailer materials available for groundwater sampling:
|Bailer Material||Permissible Parameters||Non-permissible Parameters|
|PVC||Metals; non-metallic inorganics: nutrients, demands; biological||Organics, volatile or extractable|
|Stainless Steel||All parameters||None|
|Clear PVC or acrylic||Free product thickness|