Regular inspection and cleaning of water storage tanks are essential for maintaining high water quality in the distribution system and prolonging the tank’s lifespan. Routine inspections help detect minor issues before they escalate into significant problems that could pose health risks, require costly repairs, or result in premature tank failure. Without regular cleaning, tanks may become sources of contamination, leading to potential health hazards and aesthetic concerns.
There are two primary types of tank inspections:
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Wet Inspections – Typically conducted by certified divers or remotely operated vehicles (ROVs), wet inspections assess water quality and structural integrity without the need to drain the tank. In many cases, state regulations mandate wet water quality inspections.
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Dry Inspections – Often required when wet inspections reveal underlying issues, dry inspections focus on evaluating coatings for structural damage, measuring mil thickness, and checking the steel gauge thickness in metal tanks. Unlike wet inspections, dry inspections require the tank to be completely drained and taken out of service. Due to this, dry inspections tend to be three times more expensive than wet inspections.
How often Should a Water System Inspect and Clean Storage Tanks?
The frequency of water storage tank inspections and cleanings depends on the tank type and water quality. As a general guideline, tanks should be inspected at least every five years, or more often if mandated by state regulations. Cleaning and necessary repairs should be carried out based on the inspection results, with additional inspections recommended between scheduled maintenance intervals.
Most states do not have a certification process for tank inspectors. Before hiring an inspector, request a sample report that aligns with the specific tank type and verify that it meets the requirements of the state regulatory agency.
With the implementation of the 2017 water quality regulations, it is advisable to hire inspectors who can provide in-service temperature readings to detect stratification within the tank.
Circulation
Circulation is essential for preventing stratification of water within a tank. As an aside, freezing of potable storage tanks should be avoided with proper circulation and water turnover.
Water is typically added to and drawn from the bottom of the water container via inlet and outlet piping. The water level rises when the fill rate exceeds the draw rate. When the draw rate exceeds the fill rate, the water level falls. If the fill and draw rates remain constant, the system is drawing the water that was just added. As a result of the lack of circulation, the water at the top of the container becomes stratified and stagnant. Furthermore, the chlorine that remains in stagnant water can deplete, allowing microbial growth as well as the development of tastes and odors. Adding mixers to your tank to help with these issues is a common and cost-effective way to prevent this.
Testing for Contaminants
Bacteriological testing must be completed before the tank can be returned to service, regardless of the method used. The presence of coliform bacteria in sample testing after disinfection indicates the presence of potentially harmful contaminants in the water.
Water analysis can determine whether or not microbes and bacteria in a water sample pose a risk to public health. Other contaminants, on the other hand, are visible from within the tank. Dirt, mud, sand, rust, and other elements or particles can accumulate at the bottom of a tank, covering an otherwise pristine white tank bottom with inches of sediment. If too much sediment settles in the pipes, the outlet pipes can also become clogged.
To discuss any of the concepts described here in more detail, our friendly and experienced customer service team can help. We offer tried and tested services around Houston, Texas and Longbeach, California.
Call Raven American Tanks at +1 800 656 0167
Or email at info@amtanks.com
