General Protection of Groundwater Quality and Resources

PURPOSE: This rule is for the overall protection of groundwater resources in Missouri. (1) Wells shall be constructed for their intended use in a manner that will protect groundwater resources and prevent contamination by surface and groundwater by ensuring the casing and wellhead completion are watertight and sealing off formations that are likely to pose a threat to groundwater. (2) A person may not leave a well incomplete or a borehole open and shall plug or complete the well as directed by the department. (3) A well previously used for storage or injection of gas, chemical, or any liquid shall not be converted to a well used for water supply. (4) A person who converts a water well to an oil or gas well shall notify the department pursuant to section 256.614.2, RSMo. (5) Maintenance and Repair of Wells. (A) Wells shall be maintained by the owner in a condition where it will protect groundwater and not be a source of, or channel for, contamination or pollution to groundwater. (B) All materials used in the construction, maintenance, or repair of any well shall meet the requirements in these rules. (C) Broken, punctured, or damaged casing, or any part of the wellhead that is damaged or missing shall be repaired, replaced, or plugged pursuant to 10 CSR 23-3.110. (D) Casing and/or drop pipe when being installed or replaced shall not come in direct contact with the ground surface. (E) Major reconstruction of operational wells in existence on September 28, 1985 (pre-law wells) shall conform to minimum standards pursuant to 10 CSR 23-3. Major reconstruction of wells does not include pulling or setting a pump or plumbing alterations. (6) Lubricants used during the drilling process shall not adversely affect the groundwater quality by entering the borehole. (7) Water used in the drilling process or well development shall be of potable quality. (8) Best management practices such as silt fences, straw bales, containment pits, or basins shall be used to contain drill cuttings, fluid, and foam resulting from drilling operations to minimize impact to land and prevent a discharge to waters of the state. If a discharge to a water of the state occurs, notify the department. (9) Cross connections between wells and other systems or equipment containing water, chemicals, or substances of unknown risk to groundwater are prohibited, except when equipped with a suitable protective device such as a break tank or backflow prevention device. The owner shall test, retain all records of such tests, and maintain the backflow prevention device to ensure proper operation and protection of groundwater pursuant to 10 CSR 23-3.050(1)(C). Petroleum, fertilizer, and pesticide tanks will be allowed at the well site while irrigating and chemigating and be removed from the well site or emptied when not in use. AUTHORITY: sections 256.606, 256.614, 256.615, and 256.626, RSMo 2016.* Original rule filed April 2, 1987, effective July 27, 1987. Emergency amendment filed Nov. 16, 1993, effective Dec. 11, 1993, expired April 9, 1994. Amended: Filed Aug. 17, 1993, effective March 10, 1994. Amended: Filed June 27, 2018, effective Feb. 28, 2019. *Original authority: 256.606, RSMo 1991; 256.614, RSMo 1985, amended 1991; 256.615, RSMo 1991; and 256.626, RSMo 1985, amended 1991.