Enhanced Methods in Potable Water Disinfection Erase Germs and Pathogens Resistant to Common Chlorination

Potable Water Disinfection


Pathogens such as pseudomonas are natural inhabitants in moist environments occurring naturally in soil and water. The main route of entry into a drinking water network is via contaminated materials during construction work on the pipeline, installation of water meters, as well as dirt ingress due to on-site storage of system components.

The industry has relied upon sodium hypochlorite to initially disinfect then maintain Free chlorine levels while insuring potability of our existing municipal drinking water systems.

Free chlorine levels are mandated to insure what has been deemed “microbiologically clean water”, however levels greater .02 mg/l have been recognized as having unpleasant taste or color. In new pipeline installations, Total concentrations of .05 mg/l or greater are introduced so that chlorine demand may be present to react with organics, metals and other compounds present in water prior to disinfection. Importantly, hypochlorite is ineffective at treating water for multi-resistant germs such as Pseudomonas Aeruginosa, and Legionella.

Chlorine has been widely used commercially, however, available compounds come with cautions due to their hazardous materials characterizations as a corrosive, an oxidizer and poisonous (if inhaled) in its gaseous phase. Solids, liquids and gaseous forms of these materials are subject to scrutiny during transport, storage, and usage.

When chlorine reacts with organic material its concentration is reduced Trihalomethanes (THMs) and disinfection byproducts (DHPs) are formed. These are a concern as they are known to be carcinogenic.

In everyday disinfection of new pipeline installations, pipeline renovations or recommissioning of dormant or inactive potable water systems there is also the issue of disinfection water removal after treatment. The residual hypochlorite concentrations may be significantly higher than that suitable for distribution and needs to be released into the environment while pipeline concentrations are diluted and normalized.

Enter the Lesstech Disinfection System. The natural biofilm in drinking water pipes must be free from harmful pathogens and germs. Treatment by L.E.S.S. (Light-Erasure-Spraying-System) will ensure a healthy, natural and stable biofilm within the potable water system.

UV-C technology has been well known and utilized for many decades, used in sterilization of water, air and surfaces of any material. UV-C light exhibiting an Ultraviolet spectral range of between 200-280 nm acts of the DNA of viruses, bacteria, and germs. This renders the reproduction of pathogens no longer possible. Comprehensive disinfection is guaranteed while producing no harmful byproducts or compounds.

The L.E.S.S. system provides three stages of full-scale disinfection:

  1. UV-C radiation causing the inactivation of all pathogens and germs
  2. Disinfectant Spray System includes a bactericidal effect in remote areas of the pipeline such as pipe connections
  3. Fumigation with carbon dioxide or nitrogen which stuns any incumbent microorganisms or invertebrates which may have been present in the pipeline prior to disinfection.

By passing the lesstec robot through the pipeline to be treated the following benefits may be immediately realized:

  • SAFETY achieved by avoiding transport handling or exposure to hypochlorite solids, liquid or chlorine gas.
  • COMPLETE DISINFECTION of the pipeline, including all pathogens such as legionella and pseudomonas aeruginosa.
  • TELEVISED INSPECTION of the watermain to verify all joints, connections and services.
  • NO CHLORINE DISCHARGE of residual overchlorinated water to discard into the sewer, storm water or necessary containments.

In summary, treatment with L.E.S.S. provides fast and sustainable disinfection. Removal of pathogens is long-lasting through inactivation, which precludes post-germination. There is no Environmental Impact caused by chlorine release, repeat chlorination, neutralization chemicals or hydrogen peroxide implementation. There are no harmful by-products.

The method is totally transparent, offering data logging along with a video record of each step, providing substantial time and cost savings.

Fred Tinberg is CTO of Class-Mueller Group, Inc. of Palm City, which developed Lesstech


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