Water loss is an impact to the quantity of water of either a private or public water supply. A water supply is a well, spring, or pond, that serves a residential, agricultural, commercial, or public water use. Underground mining and subsequent subsidence can affect the yield of a water supply. A water loss complaint can range from a decrease in water supply yield to a total loss of water. The cause of the water loss typically is a result of mine dewatering activities reducing the available water supply feeding a well or spring or from subsidence sealing off the fractures that were supplying groundwater to the well or spring. The mine operator is required to restore or replace water supplies contaminated, diminished or interrupted by underground mining. The operator is required to survey and document the conditions of water supplies that may be affected prior to mining to determine pre-mining conditions including flow/yield.
If the water user or owner believes their water has been affected by mining, they must contact the mine operator. The operator will then report this to the Department within 24 hours. A distinction is made regarding the location of the water supply relative to active mining. At any time, there is a zone on the surface, relative to the underground mining area, where it is probable that a water supply may be directly affected by mining activity - the rebuttable presumption zone (RPZ).
If the water supply is in this zone, the operator must supply the affected owner with a temporary water source until the issue is resolved. The operator is responsible to investigate the claim and provide the Department with a decision on whether the mine is responsible for the water contamination or not. If the operator believes they are not at fault, they must submit a report identifying the reason the mine is not at fault. After reviewing the operator’s report, the Department will make a final decision on the liability of the mining company for the supply. The Department will inform the parties. A further course of action may be an appeal to the Environmental Hearing Board.
In the cases where the water supply is located outside of the RPZ, the Department will initiate an investigation to determine if mining activity is the source of the well complaint. This investigation includes assessment of groundwater elevation data from piezometers that were installed and monitored as part of the permit, operating and post-mining requirements, review of construction details of the well or spring, review evidence of subsidence events in the area, and a general review of climatic conditions (example: drought conditions). The Department will make a decision on the liability of the mining company for the supply and inform the parties. A further course of action may be an appeal to the Environmental Hearing Board.
The Department expediently addresses water supply incidents. These cases are frequently resolved immediately, but a small group may remain “unresolved” for several months or years.
Water supply issues may remain unresolved for various reasons. Both the operator and the water supply owner may wish to hold off installing a replacement supply if mining will continue in the area. The operator and water user may wish to continue monitoring the supply through a wet or dry season to determine if there are additional affects or if the supply returns to pre-mining conditions. It may be difficult to immediately fix a supply – a new supply may need to be located which may mean installing a connection to a public supply.
The operator is required to pay for the difference in cost from the former supply to operate and maintain the new supply. This requires collection of records on the old and new supply to formulate the difference and agree to a settlement of compensation. The Department has no control over the speed at which a private agreement is negotiated and finalized between the water supply owner and mine operator. Attorneys may be involved in the compensation process. This often results in extended time to close the incident.