As the existing WHWD Birch Street facility tank reached the end of its useful life, the Board of Commissioners and Superintendent knew that the new design had to be carefully developed, continuing to be a symbol of the West Hempstead community. In conjunction with the District, H2M evaluated multiple tank designs, determining a composite elevated tank would best fit the needs of the District and their residents and set the trend as the first one constructed on Long Island.
A composite tank combines concrete, steel, and welding, allowing a new alternative for engineers and tank construction. The composite tank utilizes concrete, in lieu of steel, as the tank pedestal which provides several benefits. First, the concrete is a more sustainable material for construction on Lon Island, especially in terms of corrosion-resilience to exposure from salt-laden wind coming off of the Atlantic Ocean. Second, concrete reduces the amount of surface area of steel requiring rehabilitation and coatings throughout the life of the tank.
H2M had to specify and review certain protocols to ensure that the concrete would look uniform to provide an aesthetically pleasing landmark for the District. This included continuous reviews against mock-up walls and confirmation that the sand used in the concrete was uniform and sole-sourced. The contractor utilized jump forms to build the pedestal efficiently and quickly. The jump forms allowed the contractor to place concrete, allow curing, then utilize the same form by humping it to the next concrete pedestal ring. This compressed the construction schedule, decreased labor costs, increased the aesthetic consistency of the concrete, and reduced the overall cost of the placement of the concrete pedestal.
H2M used their knowledge of coatings systems and evaluated interior and exterior coating systems available on the market. They examined which coatings would stand the test of time coupled with the long-term life expectancy of the concrete base. Ultimately, the final interior coating system would provide the longest and most cost effective, as well as VOC compliant system available in the Country.
The new tank, now capable of storing 1 million gallons will serve the community well into the next century, all while providing lower maintenance costs and paving the way for other purveyors to follow
