Michigan Governor Rick Snyder (R) has become embroiled in a water pollution crisis in Flint, as his administration becomes increasingly implicated in the state's slow response time.

In a letter to state employees on Monday, Snyder said that the crisis, and his administration's response to it, has had a caustic effect on the public's trust of government there.

"As you have heard from me and the media, our reputation and trust can be severely impacted when people do not make good decisions, or use good judgment in solving problems," the letter read.

"That principle is universal, but never more so than when public health is at stake," he continued in the letter. "What happened in Flint can never be allowed to happen again anywhere in our state."

But as the machinations of officials' lagging response have been revealed in emails and documents, public calls for his resignation have only gotten louder.

Here are three reasons people are calling for Snyder to resign or to be held legally accountable.

MLive.com

1. Snyder played an early role in facilitating a water-source transfer

Earlier in January, protesters lined up outside of Flint's city hall and the Genesee County Jail, calling for the arrest of the governor. He has been criticized for his role in appointing the town's emergency managers, under whose control the city of Flint transferred its water source from Detroit to the much more corrosive Flint River. Shortly after the switch, which was hailed as a short-term cost-cutting measure, questions began to surface relating to the safety of the water. Snyder has issued multiple apologies and has even claimed partial responsibility for the crisis.

Twitter/@RollingStone - twitter.com

2. He's ultimately responsible for the damage caused by polluted water

Snyder has called out other agencies for bureaucratic delays in fixing the issue. But many say he is ultimately responsible, since implicated agencies report to him. In January, the EPA admitted that it did not act fast enough to address the crisis, but said those delays were "impacted by failures and resistance at the state and local levels to work with us in a forthright, transparent, and proactive manner consistent with the seriousness of the risks to public health."

This week, the House Oversight Committee will hold a hearing seeking answers from federal and state officials involved in the crisis, but Snyder will not be in attendance, MSNBC reported. Committee members voiced disappointment that the governor would not be present.

"I am deeply disappointed at the Majority's lack of commitment to a thorough and meaningful hearing," Rep. Barbara Lawrence (D-MI) said over the weekend. "A sincere search for truth and justice requires a full review by the entire Committee of the decisions and policies of all those involved," she said, adding that Snyder "was at the top of my list of witnesses due to the central role that he played."

In a letter addressed to Snyder, Flint resident and filmmaker Michael Moore said the governor was responsible for the irreversible damage contaminated water did to local residents, especially children.

Michael Moore - michaelmoore.com

3. He may have known about the crisis early on, but did nothing

Emails that have been released show that in some cases, public officials were dismissive to Flint resident's complaints over the quality of their water. They also shed light on when officials knew about water contamination. In January of 2015, a full year before National Guardsmen began handing out water to Flint residents, officials with the state's Department of Technology, Management and Budget made sure state employees in Flint had bottled water after complaints surfaced about the safety of public water.

Snyder said he learned about the problem in October, and took "drastic action." He also maintains that he will not resign, saying that staying in office is the more responsible course of action given the magnitude of the problem.

"It is a failure of policy and personnel that has harmed citizens of Michigan and made the state an object of national and international astonishment," Richard Peterson, a political philosophy and ethics professor emeritus at Michigan State University wrote in the Lansing State Journal. "Should the governor resign? Of course he should!"