August 18, 2016
With corrosion, heavy metal from pipes and plumbing fixtures can contaminate water at the tap even though source is lead-free
New Jersey’s untreated groundwater shows high potential for being corrosive, increasing the risk that water coming out of the taps of homeowners with private wells may be tainted with lead, according to a new study.
When water is corrosive, it can leach lead from pipes, fixtures, or lead solder used in plumbing fixtures, possibly contaminating supplies even though no problems exist in the well.
The nationwide study of more than 20,000 wells by the U.S. Geological Survey found that the Northeast, Southeast, and Northwest with the largest percentage of wells with potentially corrosive groundwater.
Lead, a serious public health hazard, can cause lifelong physical and mental problems, especially in children. While most people are commonly exposed to the contaminant via peeling lead-based paint, unsafe levels of lead have been found in numerous drinking water supplies, including schools in New Jersey, presumably from the same source — lead plumbing fixtures.
Approximately 400,000 homeowners depend on private wells for their drinking water, said Larry Hajna, a spokesman for the state Department of Environmental Protection. The state is aware of the study, which he said will help build on the existing knowledge of lead in water supplies.
In New Jersey, the areas where the likelihood of potentially corrosive well water was highest were in the eastern and southern coastal plains, according to Robert Reiser, section chief in the New Jersey Water Science Center for the U.S. Geological Survey. Three-quarters of the wells sampled in the state were found to have high potential for corrosive water based on one of two indicators the survey used, Reiser said.
New Jersey does require testing for a range of contaminants, including lead, when a home relying on private wells for drinking water is sold or leased. Public water systems routinely test for the contaminant.
But New Jersey’s testing program does not require periodic testing of private wells, and the analysis is of the well water, not what is coming out of the tap, noted Daniel Van Abs, an associate professor at Rutgers University. (Van Abs is a regular contributor to NJ Spotlight.)
The U.S. Geological Survey study did not sample water from the faucets or wells for lead, but some states have. Between 2012 and 2014, Virginia found 19 percent of private wells sampled exceeded the recommended action level for lead by the U.S. Environmental Protection Agency.
“We also observed that ‘lead-free’ plumbing components released lead when exposed to more corrosive groundwater supplies,’’ said Dr. Kelsey Pieper, a post-doctoral fellow at Virginia Tech University.
In Pennsylvania, lead levels exceeded the EPA action threshold in 12 percent of 251 drinking water systems monitored there by Penn State University Extension. In that state, corrosive water was usually associated with certain types of bedrock geology, but could be found across the entire state, according to Bryan Swistock, a water resources specialist with the extension.
The corrosive nature of some untreated groundwater is one of several factors that may affect the quality of household drinking water at the tap, according to Don Cline, USGS associate director for water. “[I]t is an essential factor that should be carefully considered in testing for water quality in both public and private water supplies,’’ he said.
About 44 million Americans get their drinking water from private wells, yet surveys indicate many homeowners are unaware of basic testing that should be done to help ensure safe drinking water in the home, according to officials.
Signs of corrosive water causing leaching of metals may include bluish-green stains in sinks, metallic taste to water, and small leaks in plumbing fixtures.
Many public water systems add anti-corrosive agents to their supplies to prevent leaching of lead. There also are steps homeowners can take to remove lead from private well water.
Point-of-use devices can remove lead at the tap, and point-of entry devices can reduce corrosiveness where water enters a home, according to a fact sheet prepared by the state Department of Health.