FOR IMMEDIATE RELEASE
DATE: November 17 , 2005
UPDATE ON LEAD AND COPPER SAMPLING FOR 2005
Good News on Lead Levels
The most recent sampling round, once again, meets the Lead Action Level. Results from lead and copper samples collected in September 2005 show that 90.5% percent of the targeted high-risk homes had lead levels equal to or below the Lead Action Level (AL) of 15 parts per billion (ppb), meeting the requirement of at least 90 percent. In September, 2005, the 90th percent value was 13.8 ppb. MWRA, as a system, has met four straight rounds and 7 of the last 9 sampling rounds.
MWRA source waters contain no lead, but lead can leach from lead service pipes connecting homes to water mains and from lead solder and brass fixtures in homes. In 1991, EPA issued the Lead & Copper Rule which set action levels of 15 ppb for lead and 1,300 ppb for copper, and required that 90 percent or more of targeted high-risk homes be below that level. The samples must be first flush samples taken at homes and locations most likely to have high levels of lead after the water has sat stagnant overnight.
In 1996, MWRA began to add sodium carbonate and carbon dioxide to the water to make it less corrosive. Lead levels dropped significantly after this change in treatment, but still did not consistently meet the standard. Therefore, in 2002 and 2003, MWRA adjusted the corrosion control process by fine-tuning the pH and alkalinity levels. 7 of the last 9 rounds of lead sampling have now been below the 15 ppb Action Level, and MWRA continues to work so that the MWRA service area will consistently be below the 15-ppb Action Level.
The September 2005 data showed that 90.5% percent of the targeted high-risk homes had lead levels below the Action Level of 15 ppb, meeting the target of 90 percent. The figure below shows the over 80% reduction in lead levels since 1992.
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