The professor, Marc Edwards, said Tuesday that lead contamination levels continue to surpass acceptable federal standards and urged residents to keep using bottled or lead-filtered water for cooking or drinking.
Edwards said the system's comeback from its reliance on the contaminated Flint River has been slowed because of the reluctance of many to run their taps amid concerns about health issues and the cost of water bills.
"The system is definitely on its path to recovery," Edwards said. "But we need to get more water running through the system."
In a statement, Michigan Gov. Rick Snyder said many of the Virginia Tech findings and recommendations track with those of the state.
"The Governor has said that scientific data will drive our position on the water quality in Flint, not an arbitrary date, and having the work of Marc Edwards and his team to help the state and federal partners with additional studies has been tremendously helpful," Ari Adler, Snyder's spokesman, said in the statement.
Virginia Tech researchers said the federal Environmental Protection Agency and the state will likely recommend a flushing program for homes in the coming weeks to help with system recovery and pipe cleaning.
A switch that led to massive problems
Two years ago, the state decided to save money by switching Flint's water supply from Lake Huron (which it was paying the city of Detroit for) to the Flint River, a tributary that runs through town, notorious among locals for its filth.
Soon after the switch, the water started to look, smell and taste funny. Residents said it often looked dirty.
The Flint River is highly corrosive, 19 times more so than the Lake Huron supply, according to Edwards and other researchers from Virginia Tech.
Virginia Tech researchers found that 174 water samples taken from homes tested in 2015 showed a decrease in lead, researcher Kelsey Pieper said. But in some homes, the lead levels remain dangerously high, Pieper said.
Edwards said his the team plans another round of tests in August.
More water needs to flow through system
The EPA says anything over 15 parts per billion is unsafe. Samples collected last month showed
Flint with a lead level of 22.8 ppb -- compared with 28.5 ppb recorded in August, according to the researchers.
"In some of these homes, we haven't made much progress because not enough water has been flowing into the system," Edwards said.
Six months ago, the state of Michigan switched Flint's drinking water source back to Lake Huron, after the disastrous trial using the Flint River.
But when the state switched the city's water supply to the Flint River, it did not properly treat the water, and the water corroded the pipes, leaching lead and heavy metal into the drinking water supply.
Even though the water was switched back, the pipes are damaged, and lead-tainted water, which can stunt childhood development and affect nearly every part of the body, is still coming out of taps in some areas.
"The delivery of the cure, which is this clean water that needs to flow through the system, in some Flint homes is simply not happening," Edwards said.
The state of Michigan, which failed to properly treat the Flint River water, has pledged $58 million to Flint.
But none of that is for the replacement of lead service lines. The governor proposed $25 million for infrastructure in his budget proposal, but that money wouldn't likely be available until October.