Establishing baseline water quality and control parameters in new mining areas

1. Before mining a new area in a production zone, the operator shall submit a baseline ground water quality sampling plan that includes an adequate number of wells and samples to adequately characterize baseline water quality in production and nonproduction zones in and adjacent to the new mining area, including all aquifers potentially affected by the proposed mining operation. Water samples may not be taken until the specific conductivity, temperature, and pH have stabilized. These parameters are considered stabilized when there is less than 0.2 pH unit change and ten percent change in conductivity and temperature for at least three consecutive well volumes. These samples must be analyzed for the following parameters: ammonia, antimony, arsenic, barium, beryllium, bicarbonate, boron, cadmium, calcium, carbonate, chloride, chromium, conductivity, copper, dissolved oxygen, fluoride, gross alpha, gross beta, iron, lead, magnesium, manganese, mercury, molybdenum, nitrate, nitrate + nitrite, pH, potassium, selenium, sodium, sulfate, radium-226 and 228, thallium, total dissolved solids, uranium, vanadium, and zinc, and any other parameter specified by the department. 2. All baseline wells must be sampled at least once every month for a minimum of twelve months before any mining activities may occur. If a well shows results indicating a statistically significant variance for a parameter, whether due to laboratory error or natural fluctuation, the department may require additional samples. Sample results for each well must be submitted to the department. 3. The department shall consider the baseline water quality to determine the control parameter and the upper limit value of a control parameter that, if exceeded, indicates that an injected fluid may be present.