(This story has been updated to correct a date.)

FLINT, MI -- Seventy-one water systems in Michigan now have higher lead levels than the city of Flint, results of the most recent federally-required testing shows.

Water sampling in Flint from January through June showed the city's 90th percentile for lead was at 7 parts per billion, far better than the last six months of 2016, but still higher than 92.6 percent of the 1,333 water systems regulated by the state Department of Environmental Quality.

In the first six months of this year, 71 water systems had higher concentrations of lead than Flint. Just 24 systems had more lead than the city in the second half of 2016.

Only two private water systems in the state -- Island Lake Apartments in Livingston County and Knorrwood Knolls Subdivision in Oakland County -- had at least 10 percent of water samples from high-risk sites exceed 15 ppb in testing this year, the federal threshold for lead.

Although the new results show how far Flint has come in emerging from the city's water crisis, it is also a reminder of how much better other water systems are performing when lead is the measure.

"The water lead levels in Flint, continue to trend downwards from levels we measured in August 2015," said Marc Edwards, a professor from Virginia Tech University, whose research identified extreme corrosivity of improperly treated water from the Flint River and the resulting leeching of lead from transmission pipes and home plumbing here.

"Obviously, Flint benefits from a more rigorously vetted sampling pool than elsewhere in the state, so if anything, there are probably many, many more systems in Michigan that probably have worse water lead levels than Flint," Edwards said.

Dozens do have higher lead concentrations, according to the Lead and Copper Rule test results requested by MLive-The Flint Journal from the DEQ, including the cities of Monroe (15 ppb), Benton Harbor (12 ppb), Muskegon (11 ppb), Owosso (11 ppb) and Saginaw (10 ppb).

Not only cities and townships, but subdivisions, apartment complexes and mobile home parks have water systems required to comply with LRC testing rules.

Thirty-six of those water systems registered 10 percent of homes with 10 ppb of lead or more during the first six months of the year, meaning the systems would be above the lead limit proposed by Gov. Rick Snyder earlier this year.

MLive-The Journal could not reach representatives of the two water systems that are currently above 15 ppb of lead in 2017 testing.

Knorrwood Knolls, which had a 90th percentile of 22 ppb of lead, has increased phosphate treatment dosages and is conducting further investigation to determine why its levels are so high, according to the DEQ.

A notice posted online by Oakland County Water Resources Commissioner Jim Nash says treatment of water to make it less corrosive to pipes and home plumbing began in Knorrwood Knolls in October 2016.

"The source of the lead is being investigated through additional testing and the ... phosphate feed rate and/or phosphate blend" will be adjusted until lead concentrations are lowered, the county's posting says.

Island Lake Apartments in Livingston County, which registered the highest lead level of any water system in the state at 82 ppb, also had elevated lead in water (37 ppb) levels during testing in the last six months of 2016, according to state records.

The system serves a population of less than 50, according to the DEQ.

MLive-The Journal could not reach APA Investments LLC or Rama Cherukuri, the registered agent for the subdivision.

The U.S. Environmental Protection Agency first published the Lead and Copper Rule in 1991 and has used it since as a tool to control lead and copper in drinking water.

The rule requires water system sampling every six months with the number of samples based on the population the system serves.

In addition to Snyder, others have said the LRC is in need of revision.

In April, U.S. Rep. Dan Kildee, D-Flint Twp., introduced the National Opportunity for Lead Exposure Accountability and Deterrence Act of 2017 in the House of Representatives.

That measure would lower the federal lead action level from 15 to 10 ppb by 2020 and to 5 ppb in 2026.

Kildee and U.S. Sen. Tammy Duckworth (D-IL) have also sent a joint letter to EPA Administrator Scott Pruitt, detailing concerns about other proposed revisions to the LRC.

The current regulation requires that water systems target homes at high risk for lead contamination, such as those with lead service lines.

If lead concentrations exceed an action level of 15 ppb or copper concentrations exceed an action level of 1.3 ppm in more than 10 percent of customer taps sampled, the system must take action to control corrosion.

LRC testing in Flint before the city's water crisis was compromised because city officials have said they submitted false documents to state regulators, claiming sampling sites were qualified as high risk even though the city had no reliable inventory that told them the composition of service lines.

In the most recent six-month tests, Flint's levels were 7 ppb in the first six months of 2017, 12 ppb in the second half of 2016, 20 ppb in the first half of 2016.

Before the city's water source changed to the Flint River in April 2014, Flint's water registered 0 ppb of lead in testing dating back to 2008.

Rob Bincsik, Flint water distribution center supervisor, said in a statement to MLive-The Journal that lower lead levels are "the result of a lot of hard work from many people including city of Flint employees, consultants, as well as those assisting from DEQ and EPA.

"The results are directly related to a more optimized level of corrosion control and the continued removal of lead service lines," Bincsik said.

Flint Mayor Karen Weaver said in a written statement that while "results are promising, we also realize there is still a substantial amount of work that remains to be done."

"As work continues to replace lead tainted service lines, we must continue to complete improvement projects throughout the distribution system and fully optimize our corrosion control program, which should only improve our water quality more and more," Weaver said.