GRAND RAPIDS, Mich. – Michigan Gov. Rick Snyder said Friday that he hopes the water in Flint might be safe to drink again in three months, but it's impossible to predict because it's not a question of time, but of science.

"It's not based on time," Snyder said during a question-and-answer session following a luncheon speech.

"It's going to be based on tests and science and people believing, including outside experts, that it's safe to drink." He added: "We would all hope sooner rather than later; but it's not based on time, it's based on science, facts and caution."

Snyder said comments he made earlier Friday, in which he said he hoped the Flint water could be safe to drink in three months, may have been taken out of context.

State lawmakers joined Snyder at the luncheon to watch him sign a $28 million supplemental appropriation bill for Flint from the state's 2015-16 budget, which Snyder has described as only one step in addressing the public health and infrastructure catastrophe resulting from lead contamination of city drinking water.

Snyder was scheduled to be on a trade mission to Israel and the Middle East this week, but scrubbed the trip to focus on Flint.

Flint's water became contaminated with lead in April 2014 after the city, while under the control of a state-appointed emergency manager, temporarily switched its source from Lake Huron water treated by the Detroit Water and Sewerage Department to water from the Flint River, treated at the Flint water treatment plant.

Department of Environmental Quality Director Dan Wyant resigned in December after acknowledging the department failed to require the addition of needed corrosion-control chemicals to the corrosive Flint River water.

As a result, lead leached from pipes, joints and fixtures, contaminating the drinking water for Flint households. Lead causes permanent brain damage in children and other problems.

For months, state officials downplayed reports of lead in the water and a spike in the lead levels in the blood of Flint children before acknowledging a problem Oct. 1. Since then, Snyder has faced repeated questions about when he first knew there was too much lead in Flint's drinking water.

Snyder has said the buck stops with him on the Flint water issue, but said again Friday the disaster happened because of mistakes at the local, state and federal level and his focus is on fixing things, not assessing blame.

"Mistakes were made; problems happened," he said. "We're going to solve them; we're going to fix them."

Snyder said he hopes the Flint tragedy can be used as a wake-up call for Michigan to address other problems with underground infrastructure.

Some critics have linked the Flint problem with a lack of transparency in the Snyder administration, since Flint residents who were drinking the contaminated water were not aware of e-mails and reports that were being sent back and forth between state departments and the U.S. Environmental Protection Association on the issue.

Snyder made no commitments when asked if he favored extending the state Freedom of Information Act to cover records in the governor's office and the Legislature. "That is an active topic," Snyder said. "We're going to be working on how to enhance transparency."