Researchers have more than tripled their estimate of the number of water service lines that need to be replaced in Flint.
University of Michigan professors, who had believed the city had 8,000 lead or galvanized steel lines, now estimate the city has as many as 29,100 lines.
That’s more than half, 53 percent, of the service lines leading to 55,000 homes and businesses in Flint, Mayor Karen Weaver said in announcing the latest estimate Thursday.
The report makes it important that the city move beyond the use of filters and move toward wholesale replacement of water lines, she said.
“These findings make it even more imperative that the state and federal government step up to pay for replacing lead-tainted service lines,” she said.
Of the 29,100 parcels, 17,500 would need full replacement of service lines while 11,600 would require partial replacement, according to the researchers.
The latest number is based on inspections of service lines leading to 159 homes using a Hydrovac to flush dirt from around the pipes near the curb.
Because only a small number of lines have been inspected or replaced, researchers concede their estimate may be too high.
To get a more accurate reading, researchers would need to do a large-scale Hydrovac excavation project, said Ret. Brig. Gen. Michael McDaniel, who is coordinating the mayor’s lead line replacement initiative.
But McDaniel said he would rather err on the high side to ensure that every single home gets the help it needs.
“Given our unwillingness during a city public health emergency to disregard any potential residence that might need a lead-tainted service line replaced, we have assumed a conservative estimate,” he said.
The estimate was required by the U.S. Environmental Protection Agency to comply with the requirements of the federal Lead and Copper Rule.
Because the lead in the city’s water supply exceeded the federal action level of 15 parts per billion, the city must replace more than 2,000 service lines by June 2017.
City records noting the location of lead service lines in Flint have proven to be unreliable, and records for some parcels don’t exist at all, said city officials. That has left visual inspections as the only way to get an accurate assessment of where lead and galvanized steel service lines were installed.
Under Weaver’s initiative, crews continue to replace service lines in neighborhoods most likely to have lead service lines, and where a significant number of young children or seniors live.
Weaver’s goal is to have service lines replaced at 1,000 homes by the end of December, although the actual number may be fewer if bad weather occurs. More homes will receive new pipes next year, with the number depending on the funding received.
The state of Michigan has set aside $25 million to pay for pipe replacements through September 2017, enough to pay for replacing pipes to about 5,000 homes.
Congress is considering an aid package that would bring tens of millions of dollars to Flint that could be used to repair the city’s damaged water system. If the 29,100 figure proves accurate, replacing the other 28,100 service lines could cost at least $140 million.