Case Study: Drinking Water Well Disinfection

Disinfection of a Reactivated Drinking Water Well

A well shaft that has been inactive for a prolonged period is to be reactivated for drinking water extraction.

• What will be treated?  Well shaft containing 30m³ of water
• With which product?  Sanosil Super 25
• Method of application: Shock disinfection – flushing

Scenario Description

A drinking water well that has been inactive for an extended period is slated for reactivation. During its idle period, the water became contaminated with germs.

Issues / Special Considerations

Thick biofilms have formed in the riser pipe due to contamination. For various reasons, the client opts not to use chlorine solution for disinfection. Instead, they choose Sanosil Super 25, primarily for its effectiveness against biofilms and VBNC (Viable But Non-Culturable) germs.

Application

The heavily biofilm-covered riser pipe is mechanically cleaned using brush pigs. After reinstalling the separately cleaned pump, the dislodged biofilm is suctioned/pumped out.

1-2 liters of Sanosil Super 25 per cubic meter of water are added to the well content, and the well water is circulated using the pumping system, with the discharged water pumped back into the well shaft.

For logistical reasons, the disinfection solution is left in the well for several days. During this time, the disinfectant decomposes into water and oxygen. Subsequently, the entire contents of the well are pumped out, and the water is disposed of through the wastewater system. Flushing continues until no disinfectant residues can be measured. Multiple water samples are then taken.

Result

Contamination is completely eradicated. The water meets drinking water standards and can be utilized as such again. The drinking water well is cleared for operation.