Tank and Reservoir Wet Cleaning
Regular cleaning of potable water storage tanks and reservoirs is one of the easiest ways to maintain high water quality and recommended chlorine residual levels. Aquatic Inspections strictly follows AWWA policies and procedures when cleaning potable water storage facilities. As per AWWA Standard C652-02, sediment is not walked on or disturbed during the cleaning process. De-watering/filtration bags can be used in environmentally sensitive areas to capture sediment during a tank/reservoir cleaning. The wet cleaning is videotaped to document the sediment is not disturbed. All appurtenances will be videotaped before and after the cleaning.
Cleaning as part of your regular maintenance, including an inspection, is the best way to accurately document the condition of the floor. In many situations the condition of the coating on the floor of steel water storage facilities can not be accurately documented until the sediment is removed. Tie-wire/rebar corrosion and cracks in concrete tanks, as well as cracking liners in flexible membrane facilities can also be more accurately documented after the removal of sediment and debris. It is often during the cleaning process when leaks are detected. Leaks can be far more easily documented by divers than workers in a de-watered situation.
Through the years we’ve documented up to 4′ of sediment in some potable water storage facilities. In addition to sediment we’ve also documented the following in water storage facilities:
- animal remains
- drug paraphernalia
- beer and wine bottles
- rubber rafts
- Steel Drums of unknown contents
- Practice hand grenade (military base)
- Root intrusions
- Cell phones