Residents can help to improve lake and stream water quality through responsible environmental stewardship. It starts with proper care and maintenance of onsite waste water septic treatment systems, picking up pet waste, eliminate lawn fertilization near lake shores and discourage feeding or attracting waterfowl to your lawn. A lawn herbicide for controlling weeds and crabgrass that does not contain fertilizers is Spectracide Weed Stop at about $12.75/bag that covers 5000sq. ft. It is sold at both Home Depot and Meijers.
Click on this link for more information: http://www.freep.com/story/news/local/michigan/2017/01/16/aging-septic-systems-fouling-michigan-waters/96639750/
In 2016 the Lake Manitou Association began in-lake and stream water E. coli testing as it is a bacterial product of animals and humans that in high enough concentrations can be a public health hazard. So far, Manitou in-lake shoreline water results of 8 E. coli tests are below Michigan Department Of Environmental Quality (MDEQ) standards for closing beaches or partial or full body contact. The daily maximum is 300 colony forming units (cfu). The In-lake test average to-date is 31.0 cfu. Shoreline water testing will continue.
Water test results from the Hardy Jennings Drain that enters Lake Manitou is carrying excessive amounts of E. coli, phosphorus and soil sediment. During the Spring, times of high water volume from rain storms or rapid snow melt, E. coli exceeds state standards for body contact. DNA analysis of the Hardy Jennings Drain water indicates high levels of animal waste. The next highest is human waste. During times of high water volume the Association recommends no body contact with the water in the channel from Waugh road to the mouth of the channel for at least three days. This includes pets. Before having body contact with that water consider the water’s odor, color of the water column and surface scum. The pollutants are quickly diluted upon entering the main body of water. The Shiawassee County Environmental Health Department and Michigan Department of Environmental Quality have been informed of our findings. You can find more information on E. coli at the Michigan Department Of Environmental Quality webpage: https://www.michigan.gov/deq/0,4561,7-135-3313_3681_3686_3728-383659–,00.html
Excessive amounts of phosphorus entering Lake Manitou from the Hardy Jennings Drain is a primary catalyst to the lake algae growth. Blue green algae can produce a bacteria called microcystin that, in high enough concentrations can be harmful to humans and pets.