DOVER — Eight sites in Delaware have been recorded as having lead in water in quantities greater than the allowable federal limit over the past three years.
A law that went into effect in 1991 mandates drinking water systems contain no more than .015 milligrams of lead per liter, or 15 parts per billion.
The tens of thousands of water systems around the country are tested regularly, and if lead is recorded in quantities greater than the action level in 10 percent of samples, changes must be made at that site.
According to the Environmental Protection Agency, about 1,400 water systems nationwide had lead in quantities greater than 15 ppb at some point over the past three years. In Delaware, seven of the eight contaminated sites are in Sussex County.
The good news is that five of the locations have been clear for at least two years, several appear to be isolated incidents and the populations served by the water systems are small.
Those locations include two mobile home communities, a campground, a housing development, a school, a government building, a nonprofit outreach center and a business airpark.
Tall Pines Resort Community, a Lewes campground, is the most frequent offender, with six tests over the limit since 1993 and two since 2013.
It is also the biggest water system that tested positive; the population it serves is 1,538, according to the EPA.
Currently, the system appears safe — the last result showing more than 15 ppb was in 2013, and the most recent sample reported just 3.6 ppb.
Three sites showed more lead than the allowable limit in their most recent tests.
One is the Edward W. Pyle State Service Center in Frankford. The center, which offers assistance mostly related to health care and family services, had 15.9 ppb in its last test.
Four samples from the center have surpassed 15 ppb since 1993.
The other two active sites are Country Club Village housing development in Milford and Smyrna Christian School & Church.
Among the eight places that have tested positive recently, Smyrna Christian School & Church and Slaughter Neck Community Action Agency are the only ones that serve a school or day care.
Slaughter Neck Community Action Agency’s water system is also the lone site that is not privately owned — it’s run by the state instead.
At the federal level, the Environmental Protection Agency sets standards and oversees water. Locally, the Delaware Office of Drinking Water is responsible for supervising the approximately 500 public water systems in the state.
Those systems include cities, schools and businesses.
Of the 500, about 200 are community water systems, which encompass municipalities, housing developments and manufactured housing neighborhoods.
Another 100 include schools and businesses that operate their own wells, and the remaining 200 are “transient non-community” locations with their own wells, such as convenience stores and recreational camps.
The transient facilities are not required to test for lead, since few people, if any, regularly drink water at those sites, Office of Drinking Water Director Ed Hallock explained.
“It’s a cost-benefit analysis,” Mr. Hallock said.
Water systems generally are tested every three years. However, those that miss a test or report lead in quantities greater than 15 ppb must then conduct a test every six months for the next year.
If both of those are clear, the schedule is shifted to annually for a year or two and then reverts to the three-year cycle.
Housing developments and municipalities collect samples from about “five or 10” residents when required, test the lead levels and then send them into the state, Mr. Hallock said.
To ensure results are accurate, samples must be taken early in the day. Faucets that have seen frequent use for hours or are left running for several minutes before a test can show lower lead levels, giving the false impression the water is safe.
Some places, such as Flint, Michigan, the site of controversy over lead-contaminated water, reportedly have manipulated numbers by not using certain samples or letting water run before collecting some to test.
Mr. Hallock said is not aware of any systems in Delaware that have fudged the numbers.
While technically any amount of lead can be dangerous, the maximum has been set at 15 ppb.
For systems that surpass that in 10 percent of test sites, the Office of Drinking Water conducts further tests and works with the system owners to make changes and keep people safe.
Customers must be informed of the exceedance and provided tips on ways to make water safer.
Before taking a sip or filling a glass, for instance, someone can let the faucet run for a minute. People also can avoid using hot water, which dissolves lead quicker than cold water.
Raising the pH levels or adding a corrosion inhibitor can help prevent lead leaching into the water from older pipes, Mr. Hallock said.
Administrators that fail to take the necessary steps can be fined, although Mr. Hallock said the state has never had to issue penalties to coerce system operators.
Many positive lead tests result not from the operator’s system or the water itself but from pipes in the Delawarean’s residence.
Older homes are more likely to have pipes that use since-banned lead components.
“There’s a much better standard so we’re improving as we go along,” Mr. Hallock said.
The fact seven of the eight sites that recently tested positive are in Sussex County is no coincidence, he said. Water in lower Delaware typically has lower pH levels, making it more corrosive.
Large water systems, such as Wilmington, were required to study corrosiveness in the early 1990s when lead-control mandates were handed down by the EPA, and some cities and providers added corrosion inhibitors as a precaution.
Smaller communities have often avoided doing so because of the cost and complexity, Mr. Hallock said
A few months ago, Sen. Gregory Lavelle, R-Sharpley, requested information on the quality of the state’s drinking water.
The information provided to him showed Delaware’s water is generally in good shape in regard to possible lead contamination, but it is a “dynamic” situation, Sen. Lavelle said.
Mr. Hallock said while it is difficult to compare states in water quality, he believes Delaware is doing well.
In the wake of the Flint scandal, the EPA is expected to hand down some new guidelines within the next two years, he said.
“I’m sure they’ll look and see if additional changes are needed,” he said.