A hazardous gasoline additive detected a year ago in two wells that supply drinking water to a Harford County elementary has reached alarming levels, prompting school officials to step up measures to safeguard pupils who returned this week.
Forest Hill Elementary, housed in a 7-year-old building a few miles north of Bel Air, began using bottled water last spring when the wells showed traces of methyl tertiary butyl ether, or MTBE.
Test results from samples taken earlier this month and last week confirmed spikes in those levels to 66 parts per billion in one well and 101 parts per billion in the other.
The same wells tested at 13.6 parts per billion last spring and at 4.6 parts per billion a year ago.
"Levels have increased significantly since spring, and this has caught our attention," said Jay May, chief of administration for Harford schools. "This latest reading really surprised us, but we can be comfortable knowing that the children have been on bottled water since last spring. The only thing we are using well water for now is to flush toilets and wash floors."
MTBE, which spreads readily through groundwater, has caused cancer in laboratory animals. The state will phase out its use by the end of next year, officials said.
Soil tests and other inspections have determined that the leak is not coming from the school property, May said.
Pressure testing also showed no leaks from a heating oil tank on the school site.
"In our minds, we don't see any potential sources of contamination on our site," May said. "We are looking for trends and what changed on our property from spring to summer. Nothing has changed. It seems like there is some other source."
The Maryland Department of the Environment is investigating the incident, as it does any contamination greater than 20 parts per billion, the threshold set by the federal Environmental Protection Agency.
Harford County routinely tests wells throughout the school system for potentially hazardous compounds and reports the findings to MDE.
"We are still investigating a gamut of possible causes," said MDE spokesman Robert D. Ballenger. "We are also sampling water throughout the area to make sure this is an isolated incident. We are looking at all sources and have not ruled out any."
In addition to using bottled water, the county set up 27 portable hand-washing stations for pupils and staff at Forest Hill for the start of school this week.
Food is cooked and, in the case of fresh vegetables and fruits, washed at Bel Air High before it is transported daily to Forest Hill.
While the increasing MTBE levels are a concern, short-term exposure to such low doses is not considered harmful, said Dr. Andrew Bernstein, Harford's health officer.
"This area of science is vague, with no absolute numbers or guarantees," Bernstein said. "But even at 101 [parts per billion], you are talking about a relatively minuscule amount. Short-term exposure at these low levels would not cause any immediate or long-term health effects. And these children are not being exposed."
Health department inspectors have been to the school four times in the past week, he said.
"The school has gone to great lengths to protect students and staff, and we are satisfied with the school's response to this situation," Bernstein said.
About 600 pupils started class at Forest Hill on Monday, and each received a letter informing parents of the situation, school officials said.
"Everybody is cooperating," said Principal Belinda A. Cole. "The community is trusting that we are doing the safe, right thing for the students. We are being open and honest as we have been from the beginning. We are frustrated about where this is coming from, but we are dealing with it."
Filtration equipment, which could effectively treat the water, may be installed in the school as a temporary measure.
In the long term, connection to the public water system might be a more viable option, May said.
"We want a resolution as soon as possible, and that would be an adequate treatment system to filter the water," Bernstein said.