28 MRWA TODAY w Summer 2012

The Inspector Found WHAT?

By Erika Henderson, Director of Research, Pittsburg Tank & Tower

Shock and disbelief is probably the first two things that wentthrough the city officials minds when twenty-four dead rats werepulled from their water tank in Maryland, and during a roboticinspection in Georgia a fish swam past the camera. Althoughinsects and birds are the most common intruders found in watertanks, they are not the only intruders. Human remains used to befound in water reservoirs regularly, the number has dramaticallydecreased thanks to newer and stricter regulations. However, thereare still some cases of human carcasses being found in watertanks.

Fish, mussels, snakes, and turtles, and a significant amount ofmud and aquatic life have been discovered in water tanks thatreceive their water from lakes. These tanks should be cleanedmore frequently than others. In NY more than 50,000 gallons ofmud and aquatic life were cleaned out of a 2-million gallon tank,and 68,000 gallons of mud was cleaned out of a Kentucky tank.

These are examples of why it is crucial to have each tank inspect-ed and cleaned out regularly. America Water Works Association(AWWA) states that, “Tanks should be washed out and inspected

at least once every 3 years, and where water supplies have sedi-ment problems, annual washouts are recommended”(AWWAM42-88).

If part of the water tank is used for fire protection, then it mustalso follow National Fire Protection Association (NFPA) regula-tions. The NFPA25 states that, “The interior of steel tanks withoutcorrosion protection shall be inspected every 3 years, and the inte-rior of all other types of tanks shall be inspected every 5 years”(NFPA25-31). If vents, manways, overflow, and inlet/outlet pipeare checked regularly, these types of intruders can be avoided.Safety ladder cages and locks should also be inspected regularlyto avoid unauthorized access on or in the water tank.

When water problems occur, the water tank which stores thatwater is the best place to start an investigation. Cloudy or dirtylooking water may indicate an excess amount of sludge. The out-let pipe may need to be extended farther up the tank to allow waterto be taken from the middle of the tank instead of the bottomwhere sediment settles, or an over-the-top fill or mixing systemmay need to be installed to help prevent stagnation.

Shock and disbelief is probablythe first two things that wentthrough the city officials mindswhen twenty-four dead rats werepulled from their water tank.

Photo of dead squirrel found in tank above.

Photo of dead rat found in tank above.

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Summer 2012 w MRWA TODAY 29

The solution could be as simple ashaving it inspected and cleaned.Until just a few years ago, toinspect a water tank it had to betaken out-of-service. Time con-straints and the expense of waterloss due to draining and filling thetank proved problematic; as aresult, may delay water tankinspections until problems occur.

Today, however, this is not so. Now, by using a ROV (RemoteOperated Vehicle) a complete tank inspection can be done with noproblem. The tank can now be completely inspected and cleanedwithout draining the tank. A written inspection report is furnishedwhich includes a detailed evaluation, photographs, recommenda-tions of needed repairs, code updates, and a detailed cost estimatefor each item. After an inspection has been performed and thecondition of the tank has been determined, address the issues.

Structural repairs are priority and should be repaired on an emer-gency basis. A tank with structural repairs could collapse undercertain conditions and lives could be at risk. Specialattention should be given to the floor and roof onground storage tanks, and the bowl, riser, andwindage rods on elevated tanks. AWWA, NFPA,and OSHA regulations should be properlyaddressed and manways need to be the appropriatesize. The inspection report alone is not enough toinsure a safe and healthy environment to store water,but it does provide crucial information needed to do so.

PITTSBURGTANK & TOWER

MAINTENANCE CO., INC.

SAVE!We have a crew in

YOUR AREA! Inspections Repair New & Used Tanks

Wet In Service Cleaning Relocation ElevatedDry Paint Erectors UndergroundROV Insulation Dismantles Ground Storage

(Robotic) API Mixing System

ROV inspections can be viewed on

TV console during inspection & DVD

provided. All inspections include

bound reports, recommendations and

cost estimates.

Hugh McGee270-826-9000 Ext. 330

www.watertank.com

Photo of dead birds found insludge in tank above.

Toll Free 866.428.2242 | Metro 763.428.2242Bemidji 218.243.2440 | VeitUSA.com

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