Although five months have passed since Flint, Michigan, changed its water supply because of problems with lead contamination and discolored drinking water, about 9 percent of the city’s sites tested positive for more than permissible amount of lead in water, the governor’s office said Tuesday. Meanwhile, a date of March 17 has been set for a judge to hear arguments on a request that seeks to stop Flint’s administration from charging the residents for water during the crisis, the Associated Press reported.

Michigan Gov. Rick Snyder’s office said in a statement that 423 sites were tested, of which the lead concentration in 37 sites exceeded the limit of 15 parts per billion. Out of those, eight sites posted readings of over 100 parts per billion. The Flint administration's delayed response to the water contamination has triggered outrage in the region and led to calls of Snyder's resignation.

“There is still a lot of work to do and we will not be satisfied that the water is ready until we see the results of many tests that can ensure the water truly is safe to drink,” Snyder said in the statement.

“That’s why we are so appreciative of the residents who are willing to work with us to have their water regularly tested as part of this official scientific survey. By working together, we can help get people the water they need straight from their tap and help the city and its residents move forward,” he added.

The officials will visit houses that have an unacceptable lead level and will get state support for inspection of plumbing lines, bottled water, filters, blood testing and health information while regular testing continues at about 600 sites across the city, according to the statement.

In 2014, Flint changed the source of its tap water from Detroit's system to the Flint River. But the corrosive water from the river drained more lead content from the city pipes than Detroit’s water. Last October, Flint switched back to Detroit’s water after blood samples taken from children showed high levels of lead, a toxic agent that can damage the nervous system.

Experts believe that it could take some time for the anti-corrosive chemicals that are being added to the water to re-coat the lead pipes so that they do not leak lead into the city’s water, according to Reuters. State lawmakers have agreed to send $30 million to Flint, but the money will only cover a portion of the water bills, the AP reported. Residents in Flint have been using filters to safeguard themselves from lead contamination.

On Sunday, William H. "Billy" Murphy Jr., Baltimore attorney, brought a federal class-action suit against the state and local officials in Flint calling the state to refund the $150 million in water bills that were paid by those affected by the city’s contaminated water, the Baltimore Sun reported. The lawsuit also calls for an additional compensation for “all of the damages that are a consequence of having to be forced to use dangerous water” and that the total amount sought will be “significantly more, because it includes the cost of changing the interior plumbing in every house, and hot water heaters.”

The defendants mentioned in the lawsuit are Snyder, former mayor Dayne Walling, emergency managers Darnell Earley and Gerald Ambrose, the Michigan Department of Environmental Quality and the Michigan Department of Health and Human Services, the Baltimore Sun reported. The lawsuit says that the officials not only provided contaminated water, but they were also part of the "far more insidious" act of trying to cover up the problem.