Corrections made to fix astronomical levels of lead in the drinking water of Tensas Parish schools appear to have worked, the state health agency reported Thursday.

In the weeks prior to the opening of the two public schools in the impoverished northeast Louisiana parish, the Virginia Tech University lab found one of the fountains was delivering drinking water with lead levels of 402.6 parts per billion – about 27 times the legal limit of 15 ppb.

Scientists from the Louisiana Department Health came a couple of weeks later and found twice the acceptable amount of lead in the drinking water.

Lead impairs abstract thought, attention and memory.

Local officials were pressed to change out suspect fixtures and flush the lines with water that included chemicals aimed at coating the inside of the pipes to prevent lead from leeching into the drinking water. The hope was the fixes would lower the amount of lead, thus avoid more drastic – and expensive – repairs.

It apparently worked.

The findings released Thursday showed marginal lead readings, well within acceptable levels, in some locations and none in others.

“I’m cautiously optimistic,” Janie Jones, director of St. Joseph Disaster Relief & Research Task Force, said Thursday. “The school has done a great job with the temporary fixes.”

“This has been really worrying,” said Dr. Jimmy Guidry, the state’s health officer.

Both schools are in St. Joseph. He had just finished a two-year odyssey of shutting down, then replacing the entire 90-year-old drinking water system for the town of about a thousand residents.

He worried that installing a new system – St. Joe’s cost Louisiana taxpayers about $10 million – might not solve all the drinking water problems, particularly in state with widespread infrastructure problems.

St. Joseph's new system started delivering fresh drinking water in March. But consumers drink the water in buildings that sometimes have ancient and ill-maintained plumbing.

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In the next few weeks, Guidry’s office will start sampling drinking water from a dozen schools around the state.

“I’m pretty sure we’ll find some lead,” Guidry said. “We’ll expand that net if we find some problems in those 12 schools.”

Health officials are looking for the oldest school houses, determining when classes began, and talking with superintendents about what is needed.

“It was pleasant news to receive,” Paul Nelson, superintendent of the Tensas Parish School District, said Thursday about the state’s latest lead readings.

Nelson said the high numbers had come as a surprise.

State health officials and engineers told him that they suspected the readings were so high because the school’s water system was shut down for three months over the summer, allowing stagnant water to collect around water fountains and taps that had lead fixtures.

The 500 students were ordered not to drink the water as they returned to school last week. But that wasn’t much of a hardship, Nelson said.

Having been brought up in a place where they haven’t been able to drink the water in their homes, the students haven’t drunk from school water fountains in years, he said.

“Those fountains have just been basically hanging on the wall,” Nelson said.

The schools had long ago placed coolers that served Kentwood Spring water around the buildings and used bottled water for cooking in the cafeterias.

The district replaced all the fountains in both schools. The water comes out clean and clear for the first time in years.

But Nelson says he doesn’t expect the students to change their habits and start drinking from the fountains.

“We’re going to keep the Kentwood water coolers around for a while longer,” Nelson said.

Follow Mark Ballard on Twitter, @MarkBallardCnb.