NEWS RELEASE

August 14, 2007

OWASA said Tuesday that recent testing of drinking water in 21 new buildings found no violations of lead standards under the Federal Safe Drinking Water Act.

The federal limit for lead is 15 parts per billion (ppb). One part per billion corresponds to one penny in $10 million. OWASA serves the Chapel Hill-Carrboro community including the University of North Carolina at Chapel Hill.

In mid-May, OWASA began testing a random sample of homes, businesses and institutional buildings less than two years old. In 15 buildings, the results were below the detectable level of 3 parts per billion for lead.  Results in the other 6 locations were between 4.1 and 6.5 parts per billion.  An outside laboratory certified by the State analyzed the water samples for OWASA because lead testing involves special equipment.

The purpose of the testing was to determine whether there is a link between new plumbing systems and lead contamination. OWASA was concerned about the potential for lead contamination before a protective corrosion-inhibiting coating forms inside new plumbing systems. This coating develops because OWASA adds chemicals to drinking water during treatment to inhibit corrosion, thereby reducing the potential for release of lead from a customer’s water pipes and fixtures into the water.

Under plumbing codes in effect since 1986, the lead content of solder is limited to 0.2%, but brass water fixtures such as faucets may have up to 8% lead. Therefore, there was concern that lead may be released or “leached” from new fixtures into drinking water before the corrosion-inhibiting coating develops.

OWASA continues to offer free tests for lead in customers’ drinking water

Rachel Monschein, Laboratory Supervisor at OWASA’s Jones Ferry Road Water Treatment Plant in Carrboro, said that OWASA invites customers to have their OWASA tap water tested for lead at no charge.

Customers who wish to have their tap water tested are encouraged to contact OWASA’s Laboratory staff at 537-4227 or to send e-mail to rmonschein@owasa.org. Customers are asked to get a special bottle from OWASA for getting a sample of tap water for laboratory analysis.

Study of OWASA’s drinking water treatment process by Dr. Marc Edwards

In the spring, OWASA also engaged Dr. Marc Edwards, a nationally known water treatment researcher at Virginia Tech, to evaluate possible changes in OWASA’s treatment process could reduce the potential for release of lead from plumbing systems into drinking water.

“The current chemicals and dosages used in the OWASA water treatment process are working well for corrosion control and for limiting the potential for leaching lead and copper.  Based on the work by Dr. Edwards, we have slightly lowered the pH of our treated water [from 8.3 to 8.0-8.1] and increased the corrosion control inhibitor dosage to further minimize the potential for lead leaching,” said Kenneth Loflin, OWASA’s Water Treatment and Supply Manager.

Additional background information

Does OWASA test for lead contamination in water from older buildings?

Yes. Since 1992, OWASA has periodically checked for lead in water from homes built between 1982 and 1985 in accord with the Safe Drinking Water Act and related State rules. The most recent testing for lead occurred in the summer of 2005, and included testing of water in 30 older homes.  Such testing is required every three years. The 2005 test results in all 30 homes were below the detectable level of 3 parts per billion.

Of the 240 residential water samples analyzed for lead from 1992 through 2005, all samples except four were below the limit of 15 ppb and those four samples were retested and found to be below the action level.

In 2006 and to date in 2007, OWASA has tested for lead in water from 55 residences in response to customers’ requests.  The results were below the detectable level of 3 parts per billion in 54 or 98% of the tests. In the remaining 1 test, the result was 4 parts per billion.

OWASA also annually tests drinking water as it leaves the treatment plant. Results from these tests have been below 3 ppb for more than 10 years.

OWASA’s annual Water Quality Report Card

In the 2006 calendar year, OWASA provided about three billion gallons of water to the Carrboro-Chapel Hill community in accord with State and Federal standards for drinking water quality.

OWASA tested for more than 100 contaminants in drinking water, but only 13 were present at detectable levels. All were below the limits set by the U.S. Environmental Protection Agency under the Safe Drinking Water Act.

OWASA’s laboratory testing results in 2006 and related information on the community’s water sources and the drinking water treatment process are reported in the utility’s annual “Water Quality Report Card.” OWASA customers received the Water Quality Report Card in June and early July by mail, and the report is available in the water system section of the OWASA Website, www.owasa.org.

This year, the Water Quality Report includes expanded information on OWASA’s testing for lead in drinking water as well as information on the Chapel Hill-Carrboro community’s water sources, OWASA’s drinking water treatment process, and information on pH, the low mineral content or “softness” of OWASA water, and other characteristics. 

For more information

Sandra Bradshaw, Laboratory Manager
Telephone: 537-4206; E-mail: sbradshaw@owasa.org

Rachel Monschein, Laboratory Supervisor, Jones Ferry Road Water Treatment Plant
Telephone: 537-4227; E-mail: rmonschein@owasa.org

Kenneth Loflin, Water Supply and Treatment Manager
Telephone: 537-4232; E-mail: kloflin@owasa.org