Centre Wellington- Well FPH1 Treatment Strategy Review

The Township of Centre Wellington (Township) hired C3 Water Inc. (C3W) to assist with the review of treatment strategies for the Township’s Well FPH1 Facility. Concentrations of trichloroethylene (TCE) exceed the Provincial Maximum Acceptable Concentration (MAC) in the Township’s Well GPH1 raw water.

TCE treatment is currently carried out using an air fed stripping process, and treated water TCE levels are below the Provincial MAC. Although TCE is successfully removed from the water supply using the air stripping technique, it is suspected that dissolved carbon dioxide gas is also being removed through this process. This appears to be impacting pH and carbonate speciation in the treated water. As a result calcium and magnesium become insoluble. This causes increased deposition of calcium and magnesium salts to occur on the air stripping media and equipment, as well as equipment which forms part of the downstream water distribution system. This build-up, also commonly referred to as calcification, has been noted on the air stripping media and distribution equipment including process piping, valves, and customer services and faucets.

The Township hired C3W to investigate alternative treatment strategies which address the TCE issue and also reduce the level of calcification.

Phase 1 of this project included:

  1. Project initiation meeting, collection and review of background information.
  2. Full site investigations at the Township Well FPH1 to analyze existing site conditions.
  3. Development and analysis of alternative treatment strategies. The AWWA Rothberg Tamburini & Winsor (RTW) Model for Water Process & Corrosion Chemistry was used to measure the effectiveness of alternative solutions.
  4. Development of preliminary design for short-listed alternatives:
    • Preliminary upgrade descriptions and drawings.
    • Conceptual opinion of probable cost.
  5. Review workshop with Township Operations staff to determine the optimal treatment strategy.
  6. Final results and proposed upgrades reporting.

Implementation of a CO2 gas injection system was selected as the optimal treatment solution through Phase 1. Phase 2 of this project included pilot scale system demonstration for the CO2 gas injection system. Results indicated system success.

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