Despite this winter being milder compared to others in Lennox, South Dakota, it's important to continue practicing cold weather water tower maintenance and operations. Even in the Midwest, where vehicles can safely drive on most bodies of water, some may wonder what prevents an elevated storage tank exposed to the elements from completely freezing solid.
Protecting the city's public water supply remains a top priority. From regular chlorine residual monitoring to monthly bacteria testing and even lateral line flushing, all aspects are part of the process. During the summer, when water usage tends to peak, water storage reaches nearly full capacity, utilizing both water towers to their maximum capacity of roughly one million gallons. However, warmer weather poses a concern to water quality, known as thermal stratification, which refers to horizontal differences in water temperature. Cooler water from the Lewis & Clark Regional Water System is delivered, as warmer water has had a chance to heat from sun exposure, creating two separate layers inside the storage tank. This poses a risk of losing residual disinfectant and growing disinfectant by-products. If water consumption is low, the warmer water can potentially "float" on top and never leave the water storage tank in the distribution system. Hence, having a proper fill schedule that matches usage is crucial, ideally being fed water to match demand, allowing for continuous blending.
Filling schedules also plays a crucial role in the winter. Normally, water storage levels are adjusted lower to about half capacity as water demand lessens. This allows water levels to fluctuate daily, prevent overflows and protect against damage caused by expansion, minimizing the risk of freezing. An additional level of protection that the City of Lennox employs is mixing pumps. Each tower has a mixing pump that continuously circulates water from the riser pipe to the bowl, preventing static conditions. Turnover also helps break up any surface ice that has formed. City of Lennox staff also have tools to monitor water tower conditions remotely 24/7, including water discharge pressure, water levels, vault temperatures, and leak detection. Additionally, each tower undergoes a full inspection annually by water tower professionals.
In summary, the City of Lennox takes proactive measures during the winter to ensure the proper functioning and integrity of its water towers. By adjusting water storage levels, utilizing mixing pumps, and remote monitoring tools, the city mitigates the risk of freezing and maintains the reliability of its water supply system. Along with annual inspections by water tower professionals, these efforts underline Lennox's dedication to providing safe and dependable water services to residents year-round.