In Fredonia, NY, Advanced Tank & Infrastructure Solutions (ATiS) was supporting a utility with a wider programme to manage elevated total trihalomethane levels within its distribution system.
The programme included installing a tank mixer to improve circulation and reduce the water-quality risks associated with excessive water age. ATiS also recognised that the condition of the tank’s internal surfaces could be contributing to avoidable disinfectant demand.
TTHMs form when disinfectant—usually chlorine—reacts with naturally occurring organic material in water. Temperature, pH, source-water characteristics, contact time, treatment practice and water age can all influence their formation.
Biofilm and accumulated deposits on storage-tank surfaces can add to this challenge. They may contribute organic material and exert a chlorine demand of their own, making disinfectant residuals less stable as water moves through the tank and distribution system.
Where residual falls, utilities may need to adjust chlorine dosing to maintain the required disinfectant level at the point of delivery. If additional chlorine reacts with organic precursors over sufficient time, the potential for further TTHM formation can increase.
Tank cleaning is therefore not a complete TTHM-control strategy in isolation. Mixing, turnover, source-water treatment, precursor removal and disinfection practice all remain important. However, removing biofilm and accumulated deposits can eliminate one avoidable source of chlorine demand and support more stable, predictable residual management.
At Fredonia, a previous contractor had spent four days attempting to pressure-wash the tank without successfully completing the clean. The centre image shows the limited progress achieved through that approach.
ATiS subsequently applied Pantonite using a low-pressure process, with a telescopic lance and non-atomising applicator. The clean was completed in under six hours.
The total period from taking the tank offline to beginning refill was approximately 24 hours.
The project demonstrates two distinct benefits: addressing the internal condition of a storage tank as part of a wider water-quality strategy, while also reducing cleaning time and operational disruption.
Understanding the underlying causes of infrastructure performance loss is the first step towards making better maintenance decisions.