R 299.2445 Groundwater monitoring system.

Rule 2445. (1) The supervisor of mineral wells may require a surface facility installed or substantially modified after the effective date of these rules to have 1 of the following monitoring systems to detect leakage from secondary containment areas: (a) A minimum of 1 groundwater monitoring well downgradient, which is in close proximity to all secondary containment areas and completed at depths as specified in the hydrogeological investigation, so as to intercept any discharge from the secondary containment area to groundwater contained in a usable aquifer. (b) Tertiary containment underlying the secondary containment which shall be constructed and sealed in a manner to capture any waste product, stored product or brine that may leak or seep through the secondary containment. A layer of permeable material and a monitoring tube shall be placed between the secondary and tertiary containment to allow monitoring to determine the presence of any leakage or seepage through the secondary containment. (2) A monitoring well installed under subrule (1)(a) of this rule shall be subject to the following provisions: (a) The drilling method shall be specified. (b) Monitoring wells completed in fine-textured earth materials shall have special construction, such as gravel packing around the screen, or other construction methods approved by the supervisor of mineral wells. (c) Monitoring wells shall have suitable equipment and methods for sampling groundwater, as specified in the hydrogeological investigation. (d) Casings shall be installed so as to prevent vertical leakage of fluids between the casing and the drill hole and shall be capped and provided with a cap locking device. Use of a vented cap is desirable, but care shall be taken to prevent introduction of contaminants through such vents. (e) The well casing shall be protected against accidental damage and shall be adequately marked so as to be clearly visible during winter and summer conditions. (f) When a monitoring well is to be permanently abandoned, approved plugging procedures shall be followed as provided in part 127 of 1978 PA 368, MCL 333.12701 et seq. (3) The monitoring system required by subrule (1) of this rule shall be kept in a functional condition. Water samples shall be collected and water level measurements taken once every twelfth month. The water samples shall be tested for the parameters specified in R 299.2443(1)(a). Results of analyses and water level measurements shall be submitted to the supervisor of mineral wells within 60 days of taking the sample or making the water level measurement.