Overview

When Aqua Pennsylvania (Aqua) acquired the Treasure Lake Water System in DuBois, Pennsylvania in 2013, they knew big challenges were ahead of them. The distribution system serving almost 2,000 homes was prone to leaks in the mains, and the lone storage tank in the system was a 500,000 gallon welded steel standpipe built in the 1970s, and was in desperate need of a rehabilitation. The tank needed repainting inside, where corrosion was eating away at the roof rafters and shell, as well as on the exterior, where the past overcoating had begun to peel away.

Every summer when the temperatures rose and crowds swarmed the community for weekends and vacation, the water operators held their breaths. They hoped water stored in the tank would be enough to feed the homes, in the event of a main break, until it could be repaired. Aqua was in a quandary. To repaint the tank, it needed to be drained. But it was impossible to run the water system without it.

We helped Aqua evaluate their options, and once selected, design a new standpipe, then rehabilitate the existing standpipe, creating much needed flexibility and redundancy.

One option was to use temporary storage during the two months the tank would be offline for rehabilitation. This was a costly option adding hundreds of thousands of dollars to the project, and would also be required each time future maintenance was needed. A better solution, albeit more costly, was to build a twin tank next to the existing tank. This option would provide redundancy in the system, doubling their storage to help during main breaks, and allowing them to easily take one tank offline as needed for repairs.

The first step was finding the right location for the new tank. Fortunately, Aqua owned the properties on either side of the existing tank. Entech prepared specifications and drawings, and over the course of a year, Caldwell Tank fabricated and built the new standpipe. Additional work included new water mains on site to improve water flow in a loop around the tank, active and passive mixing inside the tank, new electrical service and lighting on site, and fencing surrounding the property. Once the new tank was online, the existing tank could be drained without fear of affecting the distribution system, and the much needed rehabilitation began. Unfortunately, it was March. The painter, IK Stoltzfus, found 4 feet of ice in the base of the tank, thwarting their start on the interior. New mixers were definitely needed inside this tank too! They were able to start on the exterior, fully blasting and painting the tank within containment tarping, as well as performing metal repairs on the accessories to bring them into compliance with current AWWA, OSHA, and PADEP requirements. Once the ice melted, the interior surfaces were closely inspected for deep pits and corroded areas in need of welding repairs, then the interior was blasted and painted.

With both tanks online, the system operators finally have peace of mind and can sleep well at night, knowing there is plenty of storage backing them up during the summer.