FLINT, MI -- The city estimates 14,000 damaged lead and galvanized water service lines remain buried, about 15 percent more than past projections.
Director of Public Works Robert Bincsik provided the update in a May 16 letter to the U.S. Environmental Protection Agency, basing the projection on what crews have uncovered so far in work for the Flint Action and Sustainability Team (FAST) Start project.
City spokeswoman Kristin Moore said she doesn't believe the new estimate will require work to continue beyond next year and said crews are running ahead of schedule with work so far in 2018.
"During the first four phases of FAST Start, the city has conducted excavations at approximately 8,843 homes," Bincsik's letter says. "Of those ... 6,256 lead or galvanized steel service lines were identified or replaced ... approximately 30 percent of the lines were identified as already being copper from the water main to the house."
Experts have said lead and galvanized lines became damaged by corrosive Flint River water used by the city from April 2014 until October 2015. Those lines essentially absorbed -- and have the potential to release -- lead particles.
The city has about 30,000 water accounts, 28,400 of which are residential.
Bencsik's letter says if the percentage of copper service lines still in the ground continues as it has so far, Flint still has about 14,000 lines to replace.
The city's past shoddy record-keeping has slowed the replacement of galvanized and lead lines, forcing the use of hydro-excavation contractors to determine which lines need replacement and which can remain.
City officials have said previously that information about the composition of the service lines was often stored on blueprints or index cards, and in some cases, no information on the lines was maintained by the city.
In February, the EPA asked the city to update its efforts to rebuild its service line inventory, prompting Bincsik's letter.