There is no mechanism to officially extend the public comment period. However, with a public hearing to be held that extends the deadline on the application to March 20, 2018. Comments can be submitted up until 10 days after the public hearing. The hearing has not been scheduled yet, so there is still time to provide comments. It may not be possible to submit comments online through MiWaters now that the public notice period is over. But, folks can e-mail comments to me to be added into the file.
Also, please realize that DEQ authority on the proposed project is limited to that as provided under Part 301 Inland Lakes and Streams. Comments should be tied to criteria in Part 301. There are other issues surrounding the proposed project that are outside of DEQ authority. Part 301 can be found at http://www.michigan.gov/deq/0,4561,7-135-3313_3681_28734---,00.html
Department of Environmental Quality