Pump Installation and Wellhead Completion

PURPOSE: This rule sets specific standards as to the proper procedures for the installation of pumps, plumbing, and completion of the wellhead. (1) Pumps and Pumping Equipment. (A) Pumps shall be surface mounted or submersible. Water may not be withdrawn from a well by using a bailer or well bucket. (B) Surface mounted pumps shall be constructed so that no unprotected openings into the well casing exist. A hand pump, hand pump head, stand or similar device shall have a closed spout directed downward and a pump rod that operates through a stuffing box. A power driven pump shall be attached to the casing or approved suction or discharge line by a watertight connection. (C) For inactive wells or new wells waiting on pump installation, the wellhead shall be fitted with a cap that is watertight and sufficiently installed to prohibit vandalism or other contamination from the surface. (D) Backflow Prevention. 1. A backflow prevention device shall be installed on all wells where agricultural chemical injection or other pressurized contaminant sources are used. 2. A double check-spring loaded backflow prevention device shall be installed between the point of chemical injection and the water well in accordance with the manufacturer’s instructions and shall have the following: A. A valve so that water can be drained from the system to prevent freezing; B. A vacuum relief valve to prevent back-siphoning of chemicals into the well; C. An automatic low pressure drain at least threequarters inch (3/4") in diameter that drains the check valve body of water when operation of the pump is discontinued; D. A watertight seal around the check valve; E. An inspection port at least four inches (4") in diameter to allow inspections of the inside of the check valve; and F. A check valve able to withstand a minimum hydraulic pressure of one hundred fifty (150) pounds per square inch (psi) without leaking and resistant to corrosion. 3. The well pump and the chemical injection pump shall be electrically or mechanically connected so that when the well pump stops, the chemical pump will shut off automatically. (E) Electrical. 1. A permitted pump installation contractor shall perform all electrical wiring that impacts the operation of the pump or pressure system to the point of entry. Any person may perform electrical wiring on high yield wells. 2. The electric wire shall not be installed through the pitless connection and shall be grounded. (F) Plumbing. A permitted pump installation contractor, except as exempted in section 256.607.2, RSMo, shall perform all plumbing that impacts the distribution of water from its source, through the pressure system to the point of entry. This includes but is not limited to pressure tanks, water treatment equipment and any other materials needed to complete the installation of the water system, inside and outside of the structure. (2) Water suction lines for surface pumps shall be constructed of galvanized iron, steel, plastic, or aluminum. Other materials may be used provided advanced written approval is obtained from the department. A well seal or equivalent shall be installed between the well casing and suction pipe that is watertight. (3) Frost proof yard hydrants shall not be installed directly on the wellhead and be securely anchored. (4) Pump Discharge Lines. (A) A discharge line from the well to the pressure tank shall not be under negative pressure during normal operation. (B) Pump discharge ports on high yield wells shall be covered when not in use. (5) Drop pipe shall be rigid, of sufficient strength to support the weight and torque of the pump, be able to withstand the operating water pressure, be impact and abrasion resistant, and not impart contaminants into the groundwater. (6) Wellhead Completion. (A) Above-ground connections shall— 1. Be a minimum of twelve inches (12") above ground surface or well house floor; 2. Have watertight piping and electrical connections that are mechanical or welded and sealed; 3. Have a protective well cap that seals tightly against the casing and has a screened vent or a casing seal that has a new rubber gasket. Cutting the rubber well seal for installation is not allowed; 4. When used, have surface driven pumps extending at least one inch (1") into the base of the motor; 5. Be provided with a minimum of one-half inch (1⁄2") diameter screened vent pointed downward; 6. Not use hubcap type well caps for permanent use; and 7. Use temporary caps until a permanent cap or well seal is installed. (B) Below-ground connections shall— 1. Use a pitless adaptor or pitless unit of sufficient strength to withstand normal operating stress; 2. Construct the hole cut in the casing for the installation RESOURCES of the pitless adaptor/unit to ensure a watertight seal with the pitless adaptor/unit in place; 3. Use a protective well cap that seals tightly against the casing and has a screened vent; and 4. Have native or grout material packed tightly around the casing and discharge pipe after installation. (7) Disinfection. (A) The permittee shall be responsible for disinfecting a new, repaired, or reconstructed well or pump installation or replacement. (B) The well, pressure tank, and pumping equipment shall be disinfected with chlorine to achieve a concentration of at least one hundred (100) parts per million (ppm) of chlorine. (C) The minimum contact period before pumping the well to waste and flushing the chlorine solution from the distribution system is two (2) hours. (D) When pulling a pump the electrical wire and drop pipe shall not touch the ground. If contamination occurs, disinfect all items prior to reinstallation. (E) A discharge of chlorinated water to waters of the state shall be reported to the department. AUTHORITY: sections 256.606 and 256.626, RSMo 2016.* Original rule filed April 2, 1987, effective July 27, 1987. Amended: Filed Aug. 17, 1993, effective March 10, 1994. Amended: Filed Nov. 1, 1995, effective June 30, 1996. Amended: Filed June 27, 2018, effective Feb. 28, 2019. Amended: Filed March 20, 2024, effective Nov. 30, 2024. *Original authority: 256.606, RSMo 1991, and 256.626, RSMo 1985, amended 1991.