The levels of lead and copper in tap water, analyzed every three years by Dublin San Ramon Services District in homes considered to be at risk, are well within state and federal water quality standards, reports show.
The U.S. Environmental Protection Agency’s Lead and Copper Rule requires that 90 percent of samples be below the “action level” of 1.3 parts per million for copper and 15 parts per billion for lead.
The District’s results were much better, with all 66 samples below the copper action level and all but one below the lead action level.
“We expect to see good results like these because our water supplier, Zone 7, controls the pH of our drinking water to make it less corrosive to metal pipes," said Field Operations Supervisor Jim Dryden.
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Only one home’s lead level slightly exceeded the standard by three parts per billion. We’ve talked to the homeowner about ways to reduce the family’s lead exposure and offered to test the water again if they decide to replace the faucet used in the test,” he said.
Corrosion of plumbing materials is the primary source of lead and copper in drinking water. Many homes have copper pipes, and lead-based solder was allowed in homes built between 1982 and 1986.
The district analyzes samples of indoor tap water from at least 60 homes of this age every three years, a schedule determined by the EPA.
In July, the District asked 87 homeowners to participate in the testing; 66 did.
Lead-based solder was banned nationwide in 1986, and since 2010, California law has required that only lead-free pipes, plumbing fittings, and fixtures be used in drinking water systems.
Elevated levels of lead in drinking water, though rarely the sole cause of lead poisoning, can cause damage to the brain, red blood cells, and kidneys, especially in pregnant women and young children.
Short term exposure to elevated levels of copper can cause gastrointestinal distress and long-term exposure may lead to liver or kidney damage.
On August 19th, the University of Rochester (NY) announced results of a study, published in the journal Proceedings of the National Academy of Sciences, which suggests copper may be an environmental trigger for the onset and progression of Alzheimer’s disease.
The EPA was already beginning a stakeholder process this fall to review its Lead and Copper Rule, which was established in 1991 and updated in 2000 and 2007. The new research and other studies may be considered in that process.
How to reduce exposure to lead and copper in tap water
The EPA recommends these steps to reduce exposure if elevated levels of lead or copper are present in tap water:
- Flush the pipe for 15-30 seconds when a faucet has gone unused for several hours.
- Do not drink or cook with water from the hot water tap because hot water corrodes metal more quickly than cold. Instead, draw cold water and heat it.
- Replace corroded brass faucets, which contain copper and may contain lead.
- Have home plumbing checked to ensure it does not have lead-based solder.
Homeowners who wish to have their tap water tested for lead or copper should use a laboratory certified by the California Department of Public Health. A list of certified laboratories is available here.
If consumers choose to purchase a home water treatment system to remove copper or lead, the equipment should be certified for that purpose through an independent organization such as NSF International.
The EPA website http://water.epa.gov/drink/contaminants/basicinformation has additional information about copper and lead in drinking water.