Project Type

Chlorine Disinfection Regulatory Approval, Control Logic, and Operational Support


Western Municipal Water District


Riverside, CA

Current Status

Ongoing since 2017

Key Features

  • Wastewater disinfection
  • Chlorine contact basin tracery study
  • Control logic development
  • Operational support

Project Overview

The Western Riverside County Regional Wastewater Authority (WRCRWA) owns the Western Riverside County Regional Water Treatment Plant (WRCRWTP), which is operated by Western Municipal Water District (WMWD). The WRCRWTP recently expanded, which included the conversion of the disinfection process to chlorine-based disinfection. In 2017, Trussell conducted a tracer study to demonstrate the modal contact time of the chlorine contact basins for the WRCRWA plant expansion project. As part of the study, Trussell developed a test plan, obtained test plan approval from California’s Division of Drinking Water, conducted tracer tests, analyzed results, prepared a final report, and obtained approval from DDW.

In 2019, WRCRWA retained Trussell to optimize the WRCRWTP’s disinfection process by updating the chlorine narrative and providing operational support. Trussell incorporated online ammonia analyzers into the sodium hypochlorite dosing controls to ensure reliable CT levels for disinfection. Trussell also routinely analyzes process data and provides operational support to the district with the goal of reducing chemical use and improving treatment efficiency. Trussell Tech continues to support operations staff and to help implement additional improvements to the nitrification, chlorination, and dichlorination processes at WRCRWTP.

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