NEWS RELEASE
Wednesday, October 26, 2005
OWASA testing confirms continued compliance
with national drinking water standards for lead
Testing of water from 30 homes in Chapel Hill and Carrboro shows that the utility's tap water continues to be better than the drinking water standards for lead.
In each of the 30 water samples gathered from July through late September, lead testing results were below the detectable level of 3 parts per billion. One part per billion corresponds to 1 penny in $10 million. (OWASA had publicized the test results for the first 28 of the home water samples in September and committed to releasing the results from the final two tests when they were received from an outside laboratory.)
“We want our customers to know that we have home tap water tested for lead every three years in accord with Federal Safe Drinking Water Act standards, and that all of the test results for 2005 were below the detectable level,” said Rachel Monschein, Laboratory Supervisor at OWASA's Jones Ferry Road Water Treatment Plant.
An independent, outside laboratory approved by the State analyzed the water samples for lead.
Background information
Water quality standards and testing
The U.S. Environmental Protection Agency (EPA) sets standards for lead and about 100 other contaminants under the Federal Safe Drinking Water Act. The EPA limits lead in drinking water to 15 parts per billion.
In addition to testing tap water from homes as indicated above, OWASA also regularly monitors drinking water as it leaves the Jones Ferry Road Water Treatment Plant. The average lead level in those tests has also been less than 3 parts per billion for the last 10 years.
Old water and plumbing systems
In some communities with old water systems, lead contamination in water has resulted from lead being released from lead fittings or pipes in the public water distribution system. In the OWASA water system, however, all known lead fittings and pipes have been abandoned or removed.
Lead can also be released or “leached” into tap water in the private plumbing systems of older homes because installation of lead pipes, solder and fixtures was allowed until 1986.
Water quality factors in the OWASA system
OWASA officials said that the high quality of OWASA drinking water reflects:
The quality of water in University Lake and the Cane Creek Reservoir, which are protected by local governments' stringent limits on development. The watersheds have rural and low intensity residential land uses, very few businesses, and no industry or wastewater treatment plants. Since 1997, OWASA has also acquired ownership or conservation easements on 1,004 acres in the Cane Creek watershed to help protect water quality.
Treatment, operation and management processes at the Jones Ferry Road Water Treatment Plant. OWASA's treatment plant and staff received a national award from the Partnership for Safe Drinking Water in June, 2005.
Careful monitoring and testing of water by Laboratory staff, which works closely with treatment plant operators. OWASA does more than 50,000 water quality tests each year. (Some tests are done by an outside laboratory company approved by the State.)
OWASA's addition of a corrosion inhibitor (phosphate) to treated drinking water to help keep lead from leaching into tap water from private plumbing system components. The phosphate creates a microscopic film on the inside of pipes and thus helps limit the release of lead from solder, pipes and fixtures into water.
Disinfection with chloramines and OWASA's water quality
Since 2002, OWASA has normally disinfected the drinking water with a compound of chlorine and ammonia called “chloramines.” Before 2002, and annually in the month of March since 2002, OWASA has used chlorine alone to disinfect drinking water.
Chloramine disinfection improves water quality by reducing contaminants called trihalomethanes and haloacetic acids, which are byproducts of the chlorine disinfection. High levels of those contaminants can increase the risk of cancer.
OWASA has not observed any change in lead levels since the utility began using chloramines for disinfection in 2002.
Annual Water Quality Report Cards
Each spring, OWASA publishes a Water Quality Report Card regarding water testing, treatment, quality and characteristics, the reservoirs that supply water for the Chapel Hill-Carrboro community and related matters.
The Water Quality Report Card for 2004 was mailed to OWASA customers in June, 2005 and it is available on the OWASA Website in English at htttp://www.owasa.org/pages/wqreport04/2004wqreport.html . A Spanish version is posted at http://www.owasa.org/pages/wqreport04/sp2004wqreport.html . OWASA continues to exceed the various EPA standards for drinking water as indicated in the Report Cards.
OWASA customers who wish to get information about having the water in their homes tested for lead are invited to call the OWASA Laboratory staff at 537-4227 or send an e-mail to rmonschein@owasa.org .
OWASA is the public, nonprofit water and sewer agency
serving the Carrboro-Chapel Hill community.