10 CSR 23-3.050 Pump Installation PURPOSE: This rule sets specific standards as to the proper procedures for the installation of pumps for wells.

(1) Pumps and Pumping Equipment.

(A) A pump shall be constructed so that no unprotected openings into the interior of the pump or 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, including flange connections, hose clamptype connections or other flexible couplings.

(B) Priming Requirements. A pump shall be designed, installed and maintained so that priming is not required for ordinary use. Pumps installed for use only on a well water irrigation system are exempted but priming water shall be clear water, free of contamination and carrying a chlorine residual. An irrigation well equipped with a centrifugal pump may be primed without chlorination when the pump is filled with water taken directly from the well.

(C) Backflow Prevention for Chemical Injection Systems on Irrigation Wells. A chemical injection system may not be connected to a well used for human consumption.

1. Where a chemical injection system is connected directly to a well used for irrigation and which is not used as a potable water supply, a single check-spring loaded backflow prevention shall be installed between the point of chemical injection on the pump discharge piping and the water well in accordance with the manufacturer's instructions and shall have the following:

A. Valving 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 three-quarters inch (3/4") in diameter, positioned so that when draining occurs liquid will run away from the well. The automatic low pressure drain shall quickly drain the check valve body of water when operation of the irrigation 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. The check valve shall withstand a minimum hydraulic pressure of one hundred fifty (150) pounds per square inch (psi) without leaking. Valve shall be galvanized, epoxy coated or similar material that resists corrosion.

2. The irrigation 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.

(D) Temporary Pump Removal. If the pump is removed temporarily from the well for any reason, the well shall be capped with a watertight seal strong enough to prevent entry of contamination or foreign objects.

(E) Pump Bearing Lubrication. Lubrication of bearings of power driven pumps shall be with water or oil which will not adversely affect the groundwater.

1. Water lubrication. If a storage tank is required for lubrication water, it shall be designed to protect the water from contamination.

2. Oil lubrication. The reservoir shall be designed to protect the oil from contamination with a shutoff valve to stop oil flow when not pumping.

(F) Electrical Installation. All electrical installations shall be performed and maintained in accordance with the existing electric codes. A permitted well installation contractor or pump installation contractor must perform all electric wiring which impacts the operation of the pump or pumping system. This includes wiring from the pump to the control boxes to the main power supply such as the breaker box in a house. The electric wire must never be run through the pitless adapter.

(G) All plumbing or water supply distribution from the well to the point of entry hookup shall be installed and maintained in accordance with existing plumbing codes. A permitted well installation contractor or pump installation contractor must perform all plumbing which impacts the distribution of water from its source, through the pressure system to the point of entry inside or outside of the structure or building being served. This includes, but is not limited to, pressure tanks, water treatment equipment and any other materials needed to complete the initial installation of the water system, inside and outside of the structure, except as exempted in section 256.607, RSMo.

(2) Operational domestic and multifamily wells must have a pump, either surface mounted or submersible. Wells must have a watertight seal at the top of the well to prevent contamination from entering the well from the top. Water may not be withdrawn from a drilled well by use of a well bucket that is lowered down the well for the purpose of retrieving water for human consumption or for nonhuman uses.

(3) Water Suction Lines. A water suction line shall be constructed of galvanized iron or steel, cast iron or plastic pipe as approved by the division or other material given approval by the division. Aluminum pipe is acceptable for well water irrigation systems in addition to the previously mentioned materials. When connecting metallic pipes or casing of dissimilar types, care must be taken so that electrolysis does not occur. If the pump is located next to the well with the pump suction line emerging from the top of the well, a well seal or equivalent shall be installed between the well casing and suction pipe to provide a watertight closure.

(4) Pump Discharge Lines.

(A) A buried discharge line between the well casing and the pressure tank in any installation, including a deep well turbine or a submersible pump, shall not be under negative pressure at any time. If a check valve is installed in a buried water line between the well casing and the pressure tank, the water line between the well casing and the check valve shall meet the requirements for a suction line unless equipped with an air release valve.

(B) Pump discharge ports on irrigation wells shall be covered when not in use.

(5) Drop Pipe. The pipe used to hang the pump in a well must be composed of thermoplastic acrylonitrile-butadene-styrene (ABS) or polyvinyl chloride (PVC) materials that have Schedule 80 (SCH 80) or thicker walls or if metallic drop pipe is used, a wall thickness of at least Schedule 40 (SCH 40) is required.

(6) Vents. All wells shall be vented with watertight caps terminating at least two feet (2') above the regional flood level (see 10 CSR 23-3.010(1)(A)6. for exception) or one foot (1') above the finished grade surface or the floor of a pump room, well room, whichever is higher. The casing vent shall be a minimum one-half inch (1/2") in diameter, screened and point downward. Vents may be offset provided they meet the provisions of this section. Any submersible pump shall be installed with a vented cap on the top of the well casing to prevent drawing near surface contamination into the well. When a well with a submersible pump kicks on and pumps water from the well, the drawdown of the water in the well creates a vacuum pulling air into the well. If the well is not vented properly, air will be pulled from around the drop pipe, through the electric wire hole, from around the well seal, and the like. If a well is not vented properly, it could be contaminating itself every time the pump kicks on by pulling near surface contaminants into the well.

(7) Disinfection.

(A) A new, repaired or reconditioned well or pump installation shall be thoroughly pumped to waste until the water is as clear as is reasonably possible, dependent upon groundwater conditions in the area. After that the well and pumping equipment shall be disinfected with chlorine so applied that a concentration of at least one hundred (100) parts per million (ppm) of chlorine shall be obtained in all parts of the well and plumbing system. The chlorine solution shall be introduced into the well in a manner to flush the well surfaces above the static water level with chlorine solution. A minimum contact period of two (2) hours (overnight is better) shall be provided before pumping the well to waste and flushing the chlorine solution from the distribution system. The well owner shall be instructed by the permittee concerning these procedures and can be responsible for pumping and flushing of the well following disinfection. A permittee shall be responsible for disinfecting the work performed on the well, pump or pumping equipment. Disinfection in a well repair operation may be accomplished at the beginning of the operation with chlorine applied to obtain a concentration of two hundred (200) ppm for the period of the well repair operation. The water shall be pumped to waste prior to the taking of water samples or use being made of the water. Caution: The chlorinated water must not leave the owner's property. If it does, the owner must report to the Water Pollution Control Program, Division of Environmental Quality.

(B) Special care must be exercised when replacing a pump because bacteria can easily contaminate what is pulled from the well (pump, drop pipe, electric wire) and it is difficult to disinfect the portions of the electric wire and drop pipe that are above water level. When pulling a pump, the electric wire should not be allowed to touch the ground. This may be accomplished by laying plastic on the ground or utilizing a mechanical system that winds up the electric wire as it is withdrawn from the well or other appropriate means. The drop pipe should be placed on pipe racks or other precautions should be taken to keep it from contacting the ground. If contamination does occur, special care must be taken to disinfect the contaminated areas.

(C) The following table will help in determining how much chlorine to add during disinfection of the well. First you will need to determine height of the water column in the well.

1. Formula to find height of water column: (total depth of well) minus (static water level) equals (height of water column). Example: (216 ft. well depth) - (37 ft. water level) = (179 ft. of water column). Then using the table find the casing size of the well, read across to the corresponding chlorine product column and use these amounts in the following formula:

2. Formula to find amount of chlorine product needed to disinfect well: (height of water column) times (amount of product from table) equals (amount of product needed to disinfect well) Example: For a six inch (6") casing using 5.25% Clorox product: (179 ft.) × (0.381) = 68 oz. or about one-half (1/2) gallon.

Click link to view: Table 1 - Disinfection Table

(D) When placing the chlorine into the well it must be thoroughly mixed with the existing water to disperse the chlorine throughout the water column. This is best done by batch dumping large volumes of chlorinated water into the well or by placing chlorine tablets in a porous bag and lowering it and raising it within the entire water column until the chlorine is dissolved.

(E) A practical alternative is to divide the amount of needed chlorine product calculated using the Disinfection Table into liquid and tablet form. Then-

1. Pour the tablets into the well which will dissolve near the bottom of the well;
2. Pour liquid chlorine product into the well being sure to wash down all surfaces that are above the static water level;
3. Circulate water into the house by running cold water until chlorine smell is detected, turning off cold, then running hot until chlorine smell is detected, in each faucet in the house. Proper ventilation must be maintained during this step and step 5 (see paragraph (7)(E)5.) to avoid overpowering potentially toxic chlorine fumes;
4. Stop circulating water and let set at least two (2) hours (preferably overnight); and
5. Flush system by running water until no chlorine odor is detected.

AUTHORITY: sections 256.606 and 256.626, RSMo 1994.* 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.
*Original authority: 256.606, RSMo 1991 and 256.626, RSMo 1985, amended 1991.

MO Dept. of Natural Resources: CODE OF STATE REGULATIONS - Matt Blunt (11/30/01) Secretary of State

Information on this page provided courtesy of Tom Schroeder Rotary Drilling and Pump Company - http://www.SchroederWaterWells.com