Commercial divers to repair pipes in water storage tank in Newton

Divers have been hired by the city to repair suction pipes in a water storage tank owned by Newton Water Works. According to city documents, WaterWorks has been unable to provide water from a high service pump in the 1,000,000-gallon storage tank when the water level is below 11 feet at the Central Pump Station.

Fin Folk LLC, a specialized commercial diving company, investigated what failed inside the water storage tank. It was discovered the suction pipe had broken and became dislodged from the inner wall of the tank. The city also said the suction pipe on another high service pump had a major crack in it.

If left unrepaired, it is only a matter of time before it will also become dislodged. City documents state these pipes are large diameter ductile iron pipes with 90-degree elbows that hang from the ceiling of the tank and extend to near the floor of the tank. The pipes weigh several hundred pounds each.

The water storage tank is about 18 feet deep. Although the city has another storage tank that can store 2,000,000 gallons of water, staff said draining either one of the tanks to make repairs would likely be extremely difficult to keep up with the water demand. Which is why divers are recommended for the job.

Instead of one lump sum to pay for the repairs, Fin Folk LLC has devised a time and material quote to repair the suction pipes at a price not to exceed $43,000.

The project consists of building and installing platforms to hold the weight of the suction pipes, installing new pipe hanger assembles to the ceiling of the tank, drilling into the exterior of the tank and epoxying in anchor bolts and installing ductile lugs to secure the existing suction pipe to the interior of the tank wall.

Toward the end of the project contractors will seal the suction pipe with epoxy and repair the broken concrete wall with epoxy or underwater concrete patch. It is estimated Fin Folk LLC will complete the needed repairs in six to eight days, with a few extra days added on in case they run into unexpected problems.

Jody Rhone, utilities director for the City of Newton, told council members the diving company was previously hired last year to clean the water tower and all three reservoirs. When asked what caused the damage, Rhone said a check valve failed and pressure from the water tower reversed flow through the pump.

“Which caused some damage to the pump and also kicked that off of the wall inside because of the 90-degree elbow,” Rhone said during the April 15 city council meeting. “We’ve repaired the check valve. We’ve repaired the pump. And now we have to repair this suction pipe.”

Currently, Newton WaterWorks can only use the pump when the water in the tank is above 11 feet. When water goes below that threshold, the pump starts to suck in air and causing the pump to cavitate. The damage from cavitation could ruin the very expensive pump, Rhone said.