Friday, October 27, 2000
Lead levels in three school taps require action
In a recent round of water testing at the Carlisle School, lead levels above the Environmental Protection Agency's (EPA) action level were found in three of the 20 taps that were tested. Supervisor of buildings and grounds David Flannery told the school committee at their October 17 meeting that the problem is with the plumbing as the well water at the source has no detectable lead. He said that it would take some time to track down the cause of the contamination, but he was confident he could solve the problem.
The school's water system is considered a public water supply, and as such it is subject to regulations and testing. As the licensed public water system operator, Flannery is responsible for monitoring and maintaining water quality. He explained that the lead-monitoring program was implemented in accordance with EPA and state Department of Environmental Protection (DEP) requirements in 1993. As part of the plan, 20 taps at the school were identified as representative of the system and water from these taps was tested in the fall of 1993 and again in the spring of 1994. In both of those tests, the water from all 20 taps did not exceed the EPA action level of 0.015 milligrams per liter (mg/l) for lead. Because the lead levels were below the action level in those two rounds of testing, further testing for lead was not required until this year.
Three problem taps
In March 2000, when these same 20 taps were sampled, two taps exceeded the lead limit. One was in a malfunctioning water fountain in the Spalding Building. Flannery said that the stream regulator in the water fountain was only allowing a trickle of water to come out. When the regulator was replaced and the fountain flushed, the water was retested and measured only 0.001 mg/l of lead. Therefore, the fountain is in compliance and requires no further action.
The other faucet was in a boy's bathroom in the Highland Building, now leased to the Emerson Umbrella for artists' studios. After flushing and retesting, the sink's tap still showed a lead level of 0.023 mg/l. It was shut off while the investigation continued.
In September 2000, the same 20 taps were tested and two more taps showed lead exceeding the limit. In the old brick building, which houses a single art classroom, the boys' bathroom sink had 0.020 mg/l of lead and in the Grant Building, the boys' bathroom sink had 0.025 mg/l of lead. As a result, both of these taps were also shut off.
Source and solution
The source of the problem is a mystery and some detective work will be necessary, Flannery explained. Lead in drinking water usually appears when water sitting in pipes causes corrosion. Although lead has not been used for pipes since the 1930s and lead solder has not been used in plumbing since 1986, lead can still be a contaminant in the other metals that are used. The pH of the school water measures 7.4, which is very close to neutral (7), so it should not be corrosive. In addition, the other taps show no lead or very low lead levels. Furthermore, the taps that indicate a presence of lead now, did not show it in earlier tests.
Flannery has met with representatives from the DEP to develop a compliance order that includes a timetable for steps that must be taken. These include notification of parents and students and the board of health, a corrosion control study done by a registered engineer, implementation of corrosion control measures to adjust the pH of the water to neutral, and two more rounds of testing in 2001. Flannery estimated the total cost to correct the problem would be about $5,000. Also, testing will be required twice a year until lead levels are consistently below the limits.
School committee member Harry Crowther asked whether all of the drinking fountains had been tested. Flannery responded that about half of them had been included in the 20 tested taps. Crowther suggested that the rest of them be tested as well. The testing was done later in the week and the results made available on October 24 showed no detectable lead in water from the remaining seven drinking fountains.
Officials made it clear that water in the Corey kitchen met drinking water standards.
© 2000 The Carlisle Mosquito