Disinfection and Cleaning of Water Wells & Spring Water Catchments

Wells and water catchments: risk of contamination

Both groundwater wells and spring water catchments can become contaminated through impurities in the water, posing a health risk. Wells and catchments are systems that draw water from the ground or from a spring.

Regular maintenance and monitoring are essential for both groundwater wells and water catchments to ensure they function properly and that the water quality meets hygiene standards. These systems must be protected from potential contamination from agricultural activities, waste disposal, human settlements, or industrial facilities.

If wells are not used regularly, waterborne germs and biofilms can quickly form in the pipes, pumps, and other water-carrying parts. In adverse situations, such contamination can spread retrogradely and affect the entire system.

Disinfection of a contaminated well / spring water intake: possible procedure

Disinfecting a well contaminated with microorganisms requires careful planning and execution to ensure all contaminated areas in the well are reached and treated. The necessary steps typically involved in disinfecting a contaminated well include:

• Water Sampling: Before disinfection, water samples must be taken from the well and analyzed in a laboratory to determine the extent of contamination and the types of microorganisms present.
• Preparation of the Disinfection Solution: The disinfection solution is prepared by mixing disinfectant with water. The concentration of the disinfectant depends on the type of contamination and the size of the well. Sanosil disinfectants with boosted hydrogen peroxide are particularly suitable for this purpose, as they offer several advantages over other products.
• Pumping the Disinfection Solution into the Well: The disinfection solution is dosed into the well sump, and the pumps are activated to circulate the contents. It is crucial to ensure that the solution reaches all parts of the well.
• Contact Time: The minimum contact time for disinfecting wells and water systems varies depending on the concentration of the disinfectant used. Generally, a shorter contact time is required at higher concentrations, while a longer contact time is needed at lower concentrations.
• Flushing the Well: After disinfection, the well is thoroughly flushed to remove any remaining disinfectant and detached biofilms.
• Resampling the Water: After disinfection, water samples are taken from the well again and analyzed in a laboratory to ensure the success of the disinfection. It is important to consider the possible VBNC (Viable But Non-Culturable) status of microorganisms, which can distort the results. (This step is not necessary with Sanosil disinfectants, as they do not induce VBNC status and reliably eliminate germs through complete disintegration of DNA.)

After successful disinfection, contamination is completely eradicated.

Disinfection of a well: concerns regarding the introduction of chemicals into groundwater-bearing layers

When disinfecting a well, it is crucial to exercise great caution, as disinfectants are introduced into the well shaft. There is a risk of chemically contaminating the groundwater. Non-oxidizing and long-lasting biocides, such as glutaraldehyde, are particularly critical and should be avoided.

Hydrogen peroxide-based biocides, such as Sanosil disinfectants, do not pose this risk because hydrogen peroxide decomposes into water and oxygen.

Practical experience has shown that with the use of Sanosil disinfectants, after a settling period and flushing the well (discarding the contents), no disinfectant residues can be detected.