12VAC5-630-450. Well abandonment.
A. Well abandonment is governed jointly by the Department of Environmental Quality and the Department of Health pursuant to § 62.1-44.92(6) of the Ground Water Act of 1973 (Repealed). In addition, the abandonment of any private well governed by this chapter, or any private well abandoned as a condition of a permit issued under this chapter, shall be administered by the Department of Health in conformance with this section.
B. A temporarily abandoned well shall be sealed with a water-tight cap or well head seal. Such a well shall be maintained so that it will not be a source or channel for contamination to ground water during temporary abandonment.
C. Permanent abandonment. The object of proper permanent abandonment is to prevent contamination from reaching ground water resources via the well. A permanently abandoned well shall be abandoned in the following manner:
1. All casing material may be salvaged.
2. Before the well is plugged, it shall be checked from land surface to the entire depth of the well to ascertain freedom from obstructions that may interfere with plugging (sealing) operations.
3. The well shall be thoroughly chlorinated prior to plugging (sealing).
4. Bored wells and uncased wells shall be backfilled with clean fill to the water level. A two-foot-thick bentonite plug shall be placed immediately above the water level. Clean fill shall be placed on top of the bentonite plug and brought up to at least five feet from the ground surface. The top five feet of the well casing, if present, shall be removed from the bore hole. In an open annular space is present around the well casing, the annular space shall be filled with grout to the maximum depth possible, but less than or equal to 20 feet. A one-foot-thick cement or bentonite grout plug that completely fills the bore void space shall be placed a minimum of five feet from the ground surface. The remaining space shall be filled with clean fill which is mounded a minimum of one foot above the surrounding ground surface. Bored wells or uncased wells abandoned in this manner shall be treated as wells with respect to determining the minimum separation distance to sources of contamination listed in Table 3.1. The location of these wells shall be permanently marked for future location.
5. Wells constructed in collapsing material shall be completely filled with grout or clay slurry by introduction through a pipe initially extending to the bottom of the well. Such pipe shall be raised, but remain submerged in grout, as the well is filled.
6. Wells constructed in consolidated rock formations or which penetrate zones of consolidated rock may be filled with sand or gravel opposite the zones of consolidated rock. The top of the sand or gravel fill shall be at least five feet below the top of the consolidated rock and at least 20 feet below land surface. The remainder of the well shall be filled with grout or clay slurry.
7. Other abandonment procedures may be approved by the division on a case by case basis.
8. Test and exploration wells shall be abandoned in such a manner to prevent the well from being a channel for the vertical movement of water or a source of contamination to ground water.
9. When bored wells are bored and a water source is not found, and the casing has not been placed in the bore hole, the bore hole may be abandoned by backfilling with the bore spoils to at least five feet below the ground surface. A two-feet-thick bentonite grout plug shall be placed at a minimum of five feet from the ground surface. The remainder of the bore hole shall be filled with the bore spoils.
Derived from VR355-34-100 § 3.11, eff. April 1, 1992.