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January 18, 2006

Lead Levels at Home Taps Decreasing

Test results from an independent laboratory indicate that lead levels are coming down at GUC customers’ taps. "In previous samples taken a year ago, 22% were above the EPA Action Level, and in our most recent samples, taken in November 2005, 16% are above the Action Level," said Ron Elks, GUC’s General Manager/CEO. "We are encouraged that changes made to our corrosion control program appear to be producing positive results."

It’s important to note that water supplied to GUC customers has no detectable levels of lead present when it leaves the Water Treatment Plant, and none of the 565 miles of GUC-owned water lines that carry water to your homes are made of lead. They are made mostly of plastic and iron and do not add lead to your water.

If drinking water contains any lead, the most likely source is the home’s plumbing system. The most common cause is corrosion, a reaction between the water and lead pipes or solder. Since the early 1970s, GUC has maintained a continuous program to minimize the amount of lead present. GUC’s corrosion control program involves adding a protective coating inside customer-owned pipes. Even with the most effective corrosion control program, detectable levels of lead may still be present in your tap water.

Since 1992, Greenville Utilities has conducted a testing program for lead in home water samples, in accordance with federal drinking water regulations implemented by the U.S. Environmental Protection Agency (EPA). The regulations are unique in that they require water systems to collect samples at the customer’s tap to determine compliance. The samples are taken by volunteer homeowners, collected by GUC staff and analyzed by an independent certified laboratory.

These samples are designed to be worst-case samples. They are taken at homes where lead pipe or lead solder is present, and after the water has remained in the pipes for at least six hours, when it is more likely to contain lead.

Regulations require that no more than 10% of the tap samples collected can exceed the EPA "Action Level" of 15 parts per billion (ppb) for lead. To put that amount into perspective 15 parts per billion equals 15 seconds in 32 years or 15 cents in $10 million dollars.

If more than 10% of the homes sampled have lead levels greater than 15 ppb, then the Action Level has been exceeded and we must take certain steps to ensure our treatment process has been optimized. (An Action Level is not a violation of water quality standards; rather it is a "trigger" to take further action.)

From the time GUC began testing in 1992 until 2004, only 2% of the homes GUC sampled for lead content have exceeded the Action Level. That is well within the 10% allowed by EPA.

In 2004, of 107 homes sampled, 24 (22%) exceeded the Action Level of 15 ppb. As a result, GUC increased its public information efforts, conducted a corrosion study, increased our testing frequency, and offered free lead testing to all water customers.

While no specific cause for the increase in lead has been identified to date, in 2002, the treatment process at the Water Plant was upgraded in order to comply with new EPA regulations. These required changes may have had an impact on the effectiveness of GUC’s corrosion control program. GUC switched to orthophosphate as a corrosion control inhibitor in August 2004, immediately after exceeding the EPA Action Level. Since that time, GUC has conducted a comprehensive corrosion control study. The five-month study, which was completed in March 2005, concluded that orthophosphate did, in fact, yield the best results in providing a protective coating or lining in household pipes. GUC has consulted with the leading experts in the field and is conducting ongoing research to determine if further improvements can be made to the corrosion control program

"While we are pleased that our latest testing results represent an improvement, we will continue our increased public education efforts until our compliance samples are below the 10% Action Level required by EPA," said Elks. "This month, all GUC water customers will be receiving a brochure in the mail, with background information about lead and advice on minimizing your exposure to lead in drinking water."

For further information, contact GUC at 551-1551 or click here.

For free lead testing, call 551-1551.