The Latest on the city of Flint's water emergency (all times local):

12:30 p.m.

A research team led by a University of Michigan-Flint professor estimates the city has more than 8,000 lead service lines.

Dr. Marty Kaufman announced the findings at a news conference Monday at City Hall. Kaufman's team analyzed Flint's handwritten records, paper maps, and scanned images to create a digital database of lead pipes.

Kaufman stresses that while the project is a full compilation of available data, the records — compiled from a 1984 survey — don't always indicate the types of pipes used.

The numbers and locations of lead service lines in Flint is significant, because Mayor Karen Weaver, who appeared with Kaufman, wants them removed as quickly as possible.

Flint switched its drinking water source from Detroit to the Flint River in 2014.

Flint didn't treat the water with anti-corrosion chemicals, allowing the river water to scrape too much lead from aging pipes and into some residents' homes.

___

11:40 a.m.

Michigan Gov. Rick Snyder says 89 percent of water samples collected from key locations in Flint measured below the "action level" of 15 parts per billion for lead in an initial round of testing, but concerns remain.

Samples from the "sentinel" sites will help determine when it is safe to drink unfiltered water again. Snyder says the results are a "start" but "it's not time to draw conclusions."

Snyder told reporters Monday that 11 percent of 175 samples exceeded the action levels, including five homes above 100 parts per billion of lead.

The data is being collected over the next seven weeks.

Utilities are required to show water from customers' taps does not exceed the action level in at least 90 percent of homes sampled.