Tip of the Mitt

“Tip of the Mitt Interim Report

By Jennifer McKay — Policy Director Tip of the Mitt Watershed Council 

In 2022, Tip of the Mitt Watershed Council was contracted by the Higgins Lake Land Conservancy to conduct a literature review of studies pertinent to the proposed Higgins Lake Sewer System and provide recommendations for the management of nutrient loading of Higgins Lake. The Watershed Council acknowledges that “completion of the literature review has been significantly delayed due to substantial internal staffing changes and transitions within our organization. We greatly appreciate the patience of the Higgins Lake Land Conservancy in recognizing our organizational challenges, as well as the desire to ensure the product is scientifically accurate and thoroughly evaluated.” 

Based on our current research and evaluation, the Watershed Council is offering the following preliminary results from our literature review. Higgins Lake has long been noted for its high water quality and promoted as one of the cleanest lakes in Michigan. Despite this, concerns regarding water quality and pollution have existed by property owners and lake association members for more than 40 years. 

Since the early 1970s until the current date, Higgins Lake has been the subject of numerous studies regarding the overall health and management of the lake, in addition to analyses concerning nutrient loading and more specifically phosphorus loading from septic systems. The overall preliminary conclusion based on the literature review is that Higgins Lake is still an oligotrophic lake of high water quality. At the same time, as every lake in Northern Michigan, it has been impacted by the increase in human activity. 

While a considerable number of studies have been conducted and reports developed for Higgins Lake, unfortunately, the information provided by the literature review indicates it has not been consistent, coordinated, or replicated to confirm trends in nutrient pollution. Even if preliminary data is acknowledged, there is no evidence to find causation that the primary source of nutrient pollution in Higgins Lake is due to septic systems.

The studies reviewed encompassed almost 50 years. Those studies included different methodologies for sampling, including depth, location, and time of year. In addition, some of the reports did not conduct sampling but rather relied upon literature reviews and theoretical calculations or modeling. As a result, nutrient and phosphorus loading estimates attributed to septic systems varied greatly, from 17% – 99.6% (The 99.6% was a result of a conversion error in the report). At the same time, many studies identified several other sources contributing greater nutrient inputs to Higgins Lake, such as stormwater runoff. It is also important to acknowledge that many of the initial studies occurred before the introduction of zebra and quagga mussels, which have undoubtedly altered the lake ecosystem of Higgins Lake. 

Based upon the preliminary review, the potential recommended actions for Higgins Lake to reduce nutrient pollution will include: 

• Gerrish and Lyon Township pursue septic regulation ordinances. Even as a sewer project moves forward, it takes years to obtain funding and permits, develop best management practices, and finally construct the sewer system. A septic regulation ordinance can address nutrient pollution now, while conversations are still occurring regarding the potential of a sewer system.

• Pursue a septic monitoring program for Lake Higgins. While a multitude of studies have been conducted on Higgins Lake, it is recommended that a consistent, multi-year monitoring program be instituted to be able to determine if a trend exists. Also, new technology exists that can be used to identify human fecal waste. Such testing would be more conclusive than previous studies conducted. 

• More information and recommendations will come in the final report.