Coastside County Water District, California Drives System Reliability And Sustainability With Microclor® On‐Site Hypochlorite Generation, Encore® Metering Pumps And PolyBlend® Polymer Activation

Located in northern California, the Coastside County Water District (CCWD) provides treated water to the scenic town of Half Moon Bay and several unincorporated communities in the area. The system is served by two treatment plants, the Nunes Water Treatment Plant (4.5 MGD) and Denniston Creek Water Treatment Plant (1.0 MGD) and water is distributed through about 100 miles of transmission and distribution pipe. Consistent with an ethic of longer term thinking regarding infrastructure as well as promoting system reliability and sustainability, CCWD embarked on a plan to modernize and upgrade water treatment capabilities in the 2006‐2007 timeframe.

A key part of the upgrade effort was focused on the elimination of one‐ton chlorine gas cylinders at Nunes and 150‐lb pressurized gas cylinders at Denniston. Aside from the obvious improvements in operator and community safety (liquid containment of 0.8% sodium hypochlorite leak is far easier to manage than a chlorine gas leak), the cost savings related to the risk management plan and emergency scrubber maintenance made sense. CCWD undertook an effort to interview and analyze the on‐site hypochlorite generation (OSHG) offerings from the four largest suppliers in North America. Weighing heavily in the analysis were the related issues of dependability and reliability. As Sean Donovan, Treatment Plant Supervisor put it, “We are the vanguard of public health. We don’t get a day off, so we have to have reliable equipment”. CCWD ultimately chose the Process Solutions, Inc. Microclor® OSHG system for both plants with Denniston installing a 40 pound‐per‐day (pounds of equivalent chlorine gas) first and Nunes utilizing a 100 pound‐per‐day system about a year later.

After over seven years of operation, the Microclor® system has proven itself in terms of reliability and safety. The clear, vertically oriented cells and the system’s open architecture allows for easy inspection and simplifies any minor maintenance required. Furthermore, operators appreciate the fact that no special hazardous materials training or equipment is required (other than safety glasses and gloves) to work around the Microclor® system.