Abandoned Well Identification and Plugging
This domain tests whether a well is abandoned and how it must be sealed so it cannot act as a direct path for contamination. Expect questions on notification, approved fill material, casing removal, and flowing wells.
What counts as abandoned
A well is abandoned when it is no longer used for its intended purpose and is not maintained for future use. An unused well with a broken cap, settling around the casing, or an open borehole is a high-risk pathway. Iowa rules require abandoned wells to be plugged by a certified water well contractor, with notification and a plugging record submitted to the DNR.
Plugging method
The pump, drop pipe, and obstructions are removed. The well is filled with approved material, typically neat cement or bentonite grout, placed so the seal is continuous. Gravel, sand, or drill cuttings are not acceptable substitutes because they do not seal. Where casing is removed, the resulting hole must still be sealed. Flowing artesian wells need a plug designed to hold pressure.
Worked example
A 200-foot well has casing to 60 feet and an open rock hole below. The crew proposes filling the bottom 140 feet with gravel and capping the top. That is wrong: gravel transmits water. The well should be sealed with approved grout from the bottom to the top, with the casing condition assessed and the plugging recorded.
Traps
Treating a well as abandoned only when the pump is gone; filling with gravel; failing to notify the DNR; and ignoring a flowing well's pressure.