March 28, 2020
DIRECTIONS FOR DISINFECTING A DRILLED WELL WITH 100 PPM CHLORINE
Well Diameter Capacity
(gallons per ft.)
1. Determine the amount of water in your well by multiplying the gallons per foot by the number of feet in the well. (Considering the well full of water will be satisfactory in most cases, as a slight overdose does no harm). For example, using the above table, a 6-inch diameter well that is 300 feet deep contains 450 gallons of water (300 ft. X 1.5 gallons/ft. = 450 gallons).
2. Each 100 gallons of water in the well requires three cups of laundry bleach. Using the same example, a well containing 450 gallons of water requires 13.5 cups (450 gallons/100 gallons X 3 cups = 13.5 cups) or 3 ½ quarts of liquid laundry bleach. Mix this total amount in about 10 gallons of water.
3. Pour this solution into the top of the well between the casing and the drop pipe before the well seal is installed.
4. Connect one or more hoses from faucets on the discharge side of the pressure tank to the top of the well casing and start the pump, recirculating the water back into the well for at least 15 minutes. Then open each faucet in the system until a chlorine smell is noticeable. Close all faucets. Seal the top of the casing with a sanitary well seal.
5. Let stand for several hours, preferably overnight.
6. After standing, operate the pump, discharging water from all outlets until all chlorine odor disappears.
7. After several days use, submit a sample of the water to a laboratory for analysis.