Is it time to inspect your water storage tank or reservoir, or would another time of year work better for your system? Each owner has his own answer, and in many cases, there is a unique answer for each tank or reservoir.
Numerous factors will dictate when you can most easily take your tank out of service. Style, construction and location of the tank, required flow rates, peak demand, the ability to isolate the reservoir from the system, and the possibility of ice in the tank are all considerations which affect the final decision.
The type of water storage tank you have will certainly make a difference. Below grade and enclosed tanks, such as clearwells, underground (buried and partially buried) reservoirs, and GAC and filter tanks, are able to be evaluated in the winter months, as are many concrete reservoirs. Steel and elevated storage tanks are best inspected during the warmer weather between late spring and early fall. If your tank is susceptible to the formation of ice, inspection is not an option until the ice is completely out of the tank.
Perhaps the major concerns of owners are the peak and daily required flow rates. Seasonal water demand, particularly considering industrial uses, can place other limitations on the ability to take the tank out of service.
As each owner must decide on the best time to inspect their tank based on the characteristics of their water system, careful consideration must be given to these factors. Many of you know, there may not be an ideal time to take the tank out of service; you may need to choose the “least bad” time. We would urge you to consider this case in another way – as an opportunity to evaluate the extent to which your staff knows the water system and can handle issues involved with operating the system in non-standard conditions. Often the capabilities of the system are not used, and abilities can be degraded if not used, so seeing this as a challenge to shift the focus of the system’s operation, and isolating parts can be a rehearsal for times when problems may occur.
Of course, there are methods of inspection that can occur without taking your tank out of service, the easiest and best method in our opinion is the remote operated vehicle, or ROV inspection. You can find out more about this ROV inspection here.