Several factors may be causing the discolored water. There have been a few water main breaks over the past two weeks, in the areas of Oak Ridge Turnpike and Rutgers Avenue, Robertsville Road and LaSalle Road, and Delaware Avenue.
There is also discoloration in the water due to naturally occurring iron and manganese, originating from the raw water and making it through the filters at the plant and precipitating out in the distribution system.
“The concentration of iron and manganese is higher than typically found in the lake's raw water and we are not the only community that pulls water from Melton Lake that is experiencing discolored water complaints,” explained Public Works Director Shira McWaters. “The cause of the increased levels of iron and manganese is believed to be the unusually hot and dry weather we had a few weeks back. It is not uncommon for lakes to experience different layers of temperature resulting in a turnover of the water, when the balance is tipped. We believe this is what has happen resulting in disturbance of these elements in the lake.”
There have been several areas that have experienced discolored water from their faucets as a result of this. Oak Ridge Public Works crews have responded to each and have flushed mains. Some of the areas include around the hospital, Briarcliff area, Gable Valley, Emory Valley and Woodland.
“The concentration of iron and manganese is higher than normal in these areas and is precipitating out in the mains. In addition, we have lowered the chlorine residual from the Water Treatment Plant to help reduce the oxidation of manganese from the finished water, so it doesn't precipitate out in the water,” McWaters said. Although iron and manganese concentrations are elevated, they do not pose a health risk.
Crews are also monitoring the raw water lake concentrations and are investigating using a drinking water-approved chemical that is commonly used to precipitate out iron and manganese before treatment.
When Public Works receives a call about discolored water, crews flush the water mains. Customers should also flush the faucets in their homes or offices to help remove it from the interior plumbing of the building.
“We encourage people to call us if they are having any issues with their water,” McWaters said.
For more information, call the City of Oak Ridge Public Works Department at (865) 425-1875.