Think Tank
A new water tank enhances fire protection in Wareham, Mass.
By Chief Robert McDuffy & Timothy M. Stinson, P.E.

After a rash of devastating fires during the early part of the 20th century, including one that swept through the center of town, residents of Wareham, Mass., began demanding better fire protection. It came in the form of the Wareham Fire District (WFD), which was established in 1907 by prominent Main Street business owners.

Naturally, today’s Wareham residents expect the same dependable fire protection. To address that need, the WFD recently enhanced its fire protection by installing a 209,000-gallon, composite elevated storage tank adjacent to an existing fire station. The storage tank is constructed of factory-coated-glass-fused-to-steel panels and carries water through a 12" inlet-outlet pipe. Besides supplying the town’s White Island Shores district with drinking water, the $1.4 million storage tank will provide water for firefighting operations.

The storage tank’s unique design helps increase fire protection by improving the hydraulic gradeline, providing better fire flow to the area and providing increased water volume (120,000 additional gallons).

Increase in Fire Flow Protection
The storage tank’s overflow elevation matches the overflow elevations of tanks in the nearby sections of Bourne Hill and West Wareham. This elevation was determined to provide a minimum working static pressure of 35 psi to the highest elevation in the White Island Shores area. Typical normal working pressure in the area will be approximately 60 psi. Because we matched the three storage tank overflow elevations, we don’t expect an increase in static pressure.

But the real proof of the benefit to the community came in a series of fire flow tests that we conducted to determine how capably it would reduce pressure fluctuations in the White Island Shores area. We selected two sites for the tests—one represented a location near the storage tank, and the other was at the extreme end of the White Island Shores distribution system.

The tests were conducted in a two-step fashion. The first tests were performed with the new storage tank offline, with water being supplied solely by the Bourne Hill and West Wareham storage tanks. After the completion of those tests, the valves at the new storage tank site were re-opened and the area was only supplied by the new storage tank. The 16" valve in Glen Charlie Road was closed to eliminate flow into White Island Shores from the Bourne Hill and West Wareham storage tanks.

The test results were quite encouraging: They showed an increase in fire flow protection ranging from 23 to 41 percent in the White Island Shores area. What’s more, the tests were performed when the storage tank levels were approximately 14 feet below maximum. If the storage tank water level was closer to overflow, pressures (both static and residual) would have increased by approximately 6 psi, which would’ve also increased available fire flow by an additional 250 to 300 gpm.

The results of the fire flow test are as shown in the following table:

Other Features
The tank also features a couple of components that further enhance fire protection. The storage tank’s hydraulic redundancy prevents water flow disruption in the instance of a main break or if one of the WFD’s other two tanks needs to be taken offline for maintenance.

Another interesting design component: the tank’s altitude valve, which prevents overflowing by monitoring the height of the water inside the tank and closing it when it is full. The altitude valve remains closed until the water level falls to a pre-set elevation, at which point the filling process starts over.

Attractive Design Elements
This type of storage tank has become attractive to other communities looking to improve fire protection tools. Design elements that made this tank a good option for our community include:
· A glass-fused-to-steel design that allows us to forego costly painting efforts, which typically are necessary every 10 to 15 years.
· Prefabricated steel plate panels that were shipped directly to the site, where they were hoisted into place and bolted together. Because of these panels, the structure and supporting concrete pedestal required only 5 months to construct at a cost of $1.4 million.
· The storage tank sits on a 24-foot-diameter concrete pedestal, which is hollow and can be used for storage or parking or can be built out for an office area.

More Sophisticated Tools
The WFD has come a long way since its founding, when large fires were more commonplace and bucket brigades were often the weapon of choice in fighting them. Today’s fire protection tools are far more sophisticated. By fully utilizing such tools, the district is helping fire personnel be better prepared for emergencies and properly ensuring the safety of Wareham residents.

Chief Robert M. McDuffy, who holds a degree in fire science, is the fire chief representing the Wareham (Mass.) Fire District (WFD). Chief McDuffy has been a member of the WFD since 1981. Starting on the call force, he was promoted to a lieutenant assigned to fire prevention/fire alarm/fire investigation and continued to rise up the ranks. He has now served as fire chief for more than a decade.

Timothy M. Stinson, P.E., is a principal engineer with Kleinfelder/S E A. He has more than 30 years of experience with water resource projects, including design layout, specification preparation, project engineering and project management for water mains, pumping stations, treatment facilities, storage tanks and chemical treatment projects located in various communities throughout New England. Stinson is an Air Force Vietnam War veteran. He can be reached at tim.stinson@seacon.com.


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