If your private well develops a rotten-egg odor, tests positive for bacteria, or has recently undergone repairs, shock chlorination can help sanitize the well and connected plumbing system.
The Well Safe® Well Sanitizer Kit provides a convenient two-part calcium hypochlorite treatment designed specifically for private wells, storage tanks, and cisterns. Each kit includes fast-dissolving granules, sinking chlorinating pellets, and complete dosage and treatment instructions.
What Is Well Shock Chlorination?
Shock chlorination is the process of introducing a concentrated chlorine treatment into a well and circulating the treated water throughout the well and household plumbing system.
The chlorinated water must remain in contact with the well and plumbing for the period specified in the product instructions. After this contact period, the chlorine is completely flushed from the system.
Shock chlorination is a temporary sanitizing treatment. It is different from continuous chlorination, which introduces a controlled amount of chlorine every time the well operates.
When Should You Shock Chlorinate a Well?
Well sanitization is commonly performed as part of periodic well maintenance. Treatment may also be appropriate:
-
After pump service or replacement
-
After a well has been opened for inspection or repair
-
After plumbing or water-system equipment has been installed
-
After flooding or storm-related contamination
-
After a loss of water pressure
-
Following certain positive bacteria or coliform tests
-
When iron bacteria buildup is present
-
When sulfur bacteria contribute to a rotten-egg odor
Shock chlorination kills bacteria present in the well and water system during treatment. However, recurring bacteria can indicate an underlying problem such as a damaged well cap, cracked casing, surface-water intrusion, persistent biofilm, or another source of contamination.
When treating a positive bacteria test, follow the recommendations of the testing laboratory, well professional, or local health authority concerning treatment and follow-up testing.
What Is Included in the Well Safe® Kit?
Each Well Safe kit contains:
-
8 oz. of calcium hypochlorite granules
-
8 oz. of sinking chlorinating pellets
-
Complete dosage and treatment instructions
The granules dissolve for circulation throughout the well and household plumbing system. The pellets sink to help deliver treatment deeper into the well.
This two-part approach helps distribute chlorine through the water column rather than concentrating treatment near the top of the well.
How Much Well Safe Should You Use?
The proper dosage depends primarily on two measurements:
-
The diameter of the well
-
The depth of the standing water column
The standing water column is calculated by subtracting the depth to the static water level from the total well depth.
For example, a 300-foot well with a static water level 50 feet below the surface contains a 250-foot standing water column. The well diameter and water-column depth are then used with the dosage chart included in the Well Safe kit.
Do not calculate dosage using the total drilled depth alone. If the well measurements are unknown or the system has an unusual construction, consult a qualified well professional.
How to Use the Well Safe® Well Sanitizer Kit
Always follow the product label and the complete instructions included with the kit.
Find additional answers on the Well Safe® Frequently Asked Questions page.
The general treatment process is:
1. Determine the proper dosage
Use the included chart to calculate the amount of granules and pellets required for the well.
2. Prepare the water system
Follow the instructions concerning filters, water-treatment equipment, electrical components, and access to the well. Check the manufacturer’s recommendations before exposing water softeners, reverse-osmosis membranes, carbon filters, or other treatment equipment to a concentrated chlorine solution.
3. Add the granules and pellets
Add the calcium hypochlorite granules and sinking pellets according to the included instructions. The pellets help carry treatment deeper into the well while the dissolved granules are circulated through the system.
4. Circulate the chlorinated water
Circulate treated water back into the well as directed. Then run water through the connected plumbing outlets until chlorine is detected throughout the system.
5. Allow sufficient contact time
Allow the treatment to remain in the well and plumbing for 8–24 hours, following the included instructions. Do not use the water during the treatment period.
6. Flush the system
Flush the chlorinated water from the well and plumbing according to the instructions. Direct heavily chlorinated discharge away from plants, streams, ponds, septic systems, and other areas that could be affected.
Do not return the water system to normal use until treatment is complete and the chlorine has been flushed as directed.
How Is Well Safe Different from Household Bleach?
Well Safe uses calcium hypochlorite rather than the sodium hypochlorite found in household bleach.
Each Well Safe kit provides a documented concentration, well-specific dosage instructions, and two physical forms of treatment: fast-dissolving granules and sinking pellets. Its calcium hypochlorite components are certified to NSF/ANSI Standard 60 for drinking-water applications.
Household bleach can vary in strength and may contain fragrances, thickeners, splash-control ingredients, or other additives. When household bleach is used for well treatment, guidance generally specifies plain, unscented bleach of a known concentration.
Well Safe eliminates the need to select and measure a general household product by providing a purpose-designed well-sanitizing treatment with a dosage chart and complete instructions.
Can Well Safe Help Eliminate Rotten-Egg Odor?
A rotten-egg smell in well water is commonly associated with hydrogen sulfide gas. Sulfur-reducing bacteria in the well or plumbing system can contribute to its production.
Well Safe kills bacteria associated with sulfur odor and can eliminate rotten-egg smell when bacteria in the well or water system are the source.
However, hydrogen sulfide can also originate from groundwater conditions, plumbing, or a water heater. If the odor occurs only in hot water or returns soon after treatment, the source may require further investigation or a different treatment method.
Does Well Safe Kill Iron Bacteria?
Yes. Well Safe’s calcium hypochlorite treatment kills iron bacteria and helps control associated slime, staining, taste, and odor problems.
Iron bacteria can form persistent deposits and biofilm inside a well and plumbing system. Severe or recurring cases may require repeated treatment, professional cleaning, or correction of underlying well conditions.
How Often Should You Sanitize Your Well?
Well Safe is commonly used twice a year as part of routine well maintenance. Treatment is also recommended after well or pump service, repairs, flooding, loss of pressure, or other events that may introduce contamination into the system.
The appropriate schedule can vary according to well construction, water conditions, prior testing, and the reason for treatment. Always follow the product label and included instructions.
Should You Test the Water After Shock Chlorination?
When shock chlorination follows a positive bacteria or coliform result, follow-up laboratory testing is important. Testing immediately after treatment can reflect the temporary effect of chlorine rather than the well’s normal untreated condition.
A qualified water-testing laboratory or local health authority can recommend when to collect the follow-up sample and whether additional testing is appropriate.
Recurring positive results should not be treated as a routine maintenance problem. The well may need to be inspected for a structural defect or continuing source of contamination.
A Complete Two-Part Well-Sanitizing Treatment
The Well Safe® Well Sanitizer Kit combines calcium hypochlorite granules and sinking pellets to help sanitize the well and connected plumbing system from top to bottom.
Each kit includes the two-part treatment, well-dosage chart, and complete application instructions.
View the Well Safe® Well Sanitizer Kit
The information above is provided as general guidance. Well construction, water conditions, and treatment results can vary. For site-specific recommendations, especially following a positive bacteria test, consult a qualified well professional, water-testing laboratory, or local health or water authority.