CW1 documents

[Case Study]LONGBOAT KEY, FL - Automated Disinfectant Residual Control Technology Saves Millions of Gallons of Water While Maintaining Consistent Chloramine Residual Levels

Written by Pete Kyrkos | Nov 6, 2024 10:05:46 PM

Located along the central west coast of Florida, the beautiful town of Longboat Key occupies a barrier island with over 7,000 residents. As is common with a number of Florida’s barrier island communities, water supply is from the mainland. 
In this case, Longboat Key receives chloraminated potable water from their water wholesaler.

The chloraminated water helps prevent pathogen growth and has generally good longevity in systems. However, a number of issues can create difficulties in maintaining an effective concentration of monochloramine. Warm temperatures, climate seasonality, distance travelled by the water and many dead-ends (increased water age) can exacerbate the degradation of disinfectant levels in the water Longboat Key receives from the water wholesaler. In general, warmer temperatures encourage the disassociation of the monochlormaine molecule resulting in the release of ammonia. Ammonia can become food source for various types of nitrifying bacteria – further accelerating water quality decay.

With only one full-time operator covering water treatment and aiding water distribution and sewer 
collections as needed, maintaining disinfectant residual levels became a desperate game of 
“whack-a-mole” as a cycle of testing followed by manual dosing with sodium hypochlorite became the 
norm during periods of potential nitrification (nitrite and nitrate accumulation). Often having to 
make corrections in the middle of the night and rely on high volume flushing (up to tens of 
millions of gallons per year), Rich Walters, Water Treatment Operator, felt that there had to be a better way.