1. (a) A monitoring well shall be cased as follows:

   1. (1) The casing must maintain the integrity of the monitoring well borehole and be constructed of material that will not react with the groundwater being monitored.
   2. (2) The minimum casing diameter must be 4 inches unless otherwise approved by the Department in writing.

   3. (3) The well must be constructed with a screen that meets the following requirements:

      1. (i) The screen must be factory-made.
      2. (ii) The screen may not react with the groundwater being monitored.
      3. (iii) The screen must maximize open area to minimize entrance velocities and allow rapid sample recovery.
   4. (4) The well must be filter-packed with chemically inert clean quartz sand, silica or glass beads, unless otherwise approved by the Department. The material must be well-rounded and dimensionally stable.
   5. (5) The casing must extend at least 1 foot aboveground, unless the Department has approved flush mount wells.
   6. (6) The annular space above the sampling depth must be sealed to prevent contamination of samples and the groundwater.
   7. (7) The casing must be designed and constructed to prevent cross contamination between surface water and groundwater.
   8. (8) Alternative casing designs for wells in stable formations may be approved by the Department.

2. (b) Monitoring well casings must be enclosed in a protective casing that must:

   1. (1) Be of sufficient strength to protect the well from damage by heavy equipment and vandalism.
   2. (2) Be installed for at least the upper 10 feet of the monitoring well, as measured from the well cap, with a maximum stick up of 3 feet, unless otherwise approved by the Department in writing.
   3. (3) Be grouted and placed with a concrete collar at least 3 feet deep to hold it firmly in position.
   4. (4) Be numbered for identification with a label capable of withstanding field conditions.
   5. (5) Protrude above the monitoring well casing.
   6. (6) Have a locked cap.
   7. (7) Be made of steel or other material of equivalent strength.

Cross References

This section cited in 25 Pa. Code § 290.304 (relating to assessment plan); and 25 Pa. Code § 290.307 (relating to interim water quality monitoring requirements).