DeKALB – DeKalb School District 428 officials were notified this week that the retesting of lead in three replaced district water sources came in under the recommended remediation or replacement level.
A drinking fountain at Huntley Middle School, a kitchen sink at Clinton Rosette Middle School and a health office sink at Brooks Elementary School were replaced after testing showed the lead present above the action level of
15 parts per billion.
Tammy Carson, District 428 director of facility operations, said maintenance staff also will be replacing four other drinking fountains over the next week: two at Founders Elementary School, one at Huntley Middle School and one at Littlejohn Elementary School.
“These four were over the notification level [of 5 ppb], so the decision was made by administration to replace those drinking fountains also,” Carson said.
A law signed by Gov. Bruce Rauner in January 2017 required Illinois public schools with students up to fifth grade and built before 1987 to test their water by the end of 2017. Those built in 1987 and after must do the testing by the end of this year.
Results showed some sinks in DeKalb tested four or five times higher than the district’s recommended action level. A sink at Jefferson Elementary School tested at about 1,500 ppb.
Lead is a poison that affects virtually every system in the body, according to the Centers for Disease Control and Prevention. It is particularly harmful to the developing brains and nervous systems of young children.
City water treatment
Bryan Faivre, superintendent of DeKalb’s utilities division, said the city’s groundwater supply does not contain lead. It is a localized problem, not just to individual residences and businesses, but to each faucet within a building.
“It makes it very difficult for a public water supply to combat that effectively,” Faivre said.
Faivre said since about 1990, the city has controlled lead, based on the Environmental Protection Agency’s Lead and Copper Rule. At the start, the city took 60 samples every six months as required by the EPA from high-risk homes, which usually still contained lead service lines or used lead solder for copper piping.
Because samples are obtained by homeowners, Faivre said a lot of variables affect testing, such as how long pipes are kept without the water running and whether the same faucets are used year over year. Water must not be run for eight to 10 hours before samples are taken, which gives time for metals to leech into the water and gives an almost worst-case scenario for the home.
“Samples are ideally taken from the same homes that are always used for sampling, which allows you to compare data to show effective corrosion control,” Faivre said.
According to lead and copper testing results from the city of DeKalb’s Water Division, the 90th percentile lead test has as high as 12 ppb since 1992. The highest recorded result from a home, however, registered at 200 ppb in 1996.
If municipalities can show their lead levels are kept in compliance, testing only needs to be done for 30 samples every three years, Faivre said.
Unlike other contaminants, which use a maximum contaminant level for water quality, lead testing uses an action level as its threshold. Lead tests more than the action level, which is set at 15 ppb for DeKalb, don’t necessarily signify an immediate health risk, but do they require municipalities to begin lead treatment.
If the 90th percentile of samples are above the action level, the city must start treatment to lower the numbers. Although Faivre said the city has not had to do this because of high lead levels, it did have to go back to six-month testing after a significant upgrade to its water treatment operations.
About 2000, DeKalb built five treatment plants for radium treatment with the anticipation it could have a significant change to the phosphate, pH levels and overall corrosiveness of the water. Because of the change in operation, testing went back to 60 samples every six months.
Faivre said there was not a considerable change in tests taken after the plants were finished, although there were elevations in copper corrosion. Since copper corrodes quicker than lead, Faivre said, copper levels are used to indicate if there might be a future lead problem.
One way to ensure lead levels will be under control is the use of phosphate, Faivre said. It was first added to water in the 1970s to keep iron content in suspension, but one of the unexpected benefits was that it provides a microscopic coating on piping that helps prevent metal from leaching into the water.
“We test for phosphate every day to ensure that our corrosion control is in check,” Faivre said. “By maintaining proper phosphate levels, it’s one way of ensuring that we wouldn’t have an issue.”
But regardless of how high or low the lead content might be, Faivre reminded residents that there is no safe level of lead.
“Whether it’s 15 [ppb], eight or three, the goal is to minimize lead exposure in drinking water,” Faivre said. “We minimize it to the best of our abilities knowing we will not completely eliminate it.”