A Homeowner’s Guide to Well Chlorination
Sources of Contamination:
The most common causes of bacterial contamination are small animals that climb into the well past loose-fitting well caps, or surface water that infiltrates buried wells that have poor sanitary seals. Sealed and vented, state-approved well caps are readily available. But buried wells should be brought above surface level and outfitted with a sealed cap.
Overviews of Chlorination and De-Chlorination:
Note: The following assumes you have above-ground access to the well.
Chlorination introduces chlorine into the well to be circulated throughout the entire water system. In our opinion, a combination of granular and pelletized chlorine is superior to liquid chlorine because the liquid sinks. It also can become trapped in the upper portion of the well if there is a strong vein of incoming water below it.
In wells with high counts of iron and manganese, the chlorine will oxidize the minerals and cause potentially severe staining and clogging of any treatment equipment, other water fixtures, or plumbing. There isn’t much choice. But the potential problems can be minimized. This is explained below. Chlorine also causes built up “films” to be sloughed off the inside of pipes. This, too, is a potential cause plumbing and fixture issues.
De-chlorination involves running the water from the bottom of the water storage tank or an outside hose spigot until it’s clear. To determine it’s clarity, fill a five-gallon bucket or a one-gallon, translucent milk jug. The color always needs to be seen in volume, not just from the hose.
Note: The formulas below provide a 50 parts per million (ppm) residual, which is more than enough chlorine to do the job (city water has about 0.5 ppm).
Use tables #1 and #2 (below) to calculate the following:
Example: 300 foot, 6” well:
The Chlorination Procedure:
The De-Chlorination Procedure:
Run a hose outside (not back into the well) where strongly chlorinated water will do the least amount of damage or harm until the water is clear and chlorine-odor free.
Important note: This can take several hours. It’s critical that you monitor the water flow to make certain you don’t run out of water. If you do, shut off the well pump at the circuit breaker and allow the well to recover.
As always, please call if you have any questions. We provide well chlorination services if you’d prefer to have us do the job.