Is This System Environmentally Necessary?
What are the indicators that septic systems are affecting water quality?
According to the Michigan State University Extension on Water Quality, septic discharge affects water quality by increasing levels of (1) E.coli bacteria, (2) phosphorous, and (3) nitrate.[i] E.coli is harmful to humans if ingested. Some levels of phosphorus and nitrogen are necessary to sustain aquatic life, but elevated levels of these materials contribute to algae blooms and decrease levels of dissolved oxygen necessary to sustain other aquatic life.[ii]
What are safe limits for E.coli, phosphorus, and nitrate in lakes?
With respect to E.coli, the State of Michigan deems water to be safe for human contact under 300 colonies/100 ml. Phosphorus occurs naturally in lakes at levels around .005 parts per million (ppm)[iii] and is considered optimal under .025 ppm.[iv] A lake with nitrate levels under 250 ppm is considered “enriched,” between 250 and 750 ppm is considered “slightly enriched,” between 750 and 1,250 ppm is considered “enriched,” and over 1,250 ppm is considered “highly enriched.”[v]
How is water quality in Bear Lake?
The Bear Lake Watershed Alliance reports, “Results of water testing place Bear Lake in the top 15% of similar sized lakes in Michigan. Water clarity, as measured by Secchi Disk is excellent.”[vi] In 2021, Bear Lake averaged .009 parts per million (ppm) phosphorous over multiple tests.[vii] Bear Lake’s most recent E.coli testing (August 2022) showed an average of 8.12 colonies/100 ml over seven locations tested.[viii] The state of Michigan deems water to be safe for swimming under 300 colonies/100 ml. Thus, Bear Lake’s E.coli levels, even with septic systems, are less than 3% of state safety limits.[ix]
How is water quality in Portage Lake?
According to the 2021 Portage Lake Watershed Lake Management Plan, “The majority of the sample sites in the Portage Lake watershed that have been monitored for E.coli have had consistently low concentrations meaning that in the context of E.coli, water quality is high and public health risk is low.”[x] In Portage Lake, “2021 monitoring found no elevated sampling in the July sampling, which tested numerous locations including Portage Point Inn, Swimming beaches, Camps, and inlet areas,” according to the Lake Management Plan.[xi] Testing also shows phosphorous levels declining and water clarity consistently remaining high over the last decade.[xii] July, 2021 testing showed phosphorus levels averaging .008 ppm over four locations.[xiii] Nitrate levels were only 230 ppm in the lake, not even rising to the level of “slightly enriched.”[xiv]
What about the November, 2022 Environmental Assessment?
The TLCSA released an environmental assessment on November 2, 2022.[xvii] However, the document focused on whether building the system would harm wetlands, historical sites, and endangered species, not on whether the proposed STEP system will reduce contamination.[xviii] The report included no test results or data on Bear Lake or Portage Lake water quality, nor did its authors conduct any actual assessment of septic tanks on the lakes.[xix]
[i] https://www.canr.msu.edu/news/nutrients-from-septic-systems-can-impact-well-and-surface-water
[ii] https://www.canr.msu.edu/news/nutrients-from-septic-systems-can-impact-well-and-surface-water
[iii] https://osse.ssec.wisc.edu/curriculum/earth/Minifact2_Phosphorus.pdf
[iv] https://ei.lehigh.edu/envirosci/watershed/wq/wqbackground/phosphatesbg.html#:~:text=in%20a%20watershed%3F-,1.,not%20exceed%200.025%20mg%2FL.
[v] Portage Lake Watershed Lake Management Plan 2021, Portage Lake Watershed Forever, p. 41
[vi] https://www.bearlakewatershed.com/water-testing
[vii] Cooperative Lakes Monitoring Program, 2021 Data Report for Bear Lake, Manistee County
[viii] Bear Lake Bulletin, Fall, 2022
[ix] Nitrate testing appears to be unavailable based on the author’s search.
[x] Portage Lake Watershed Lake Management Plan 2021, Portage Lake Watershed Forever
[xi] Portage Lake Watershed Lake Management Plan 2021, Portage Lake Watershed Forever
[xii] Portage Lake Watershed Lake Management Plan 2021, Portage Lake Watershed Forever
[xiii] Portage Lake Watershed Lake Management Plan 2021, Portage L
[xiv] Portage Lake Watershed Lake Management Plan 2021, Portage Lake Watershed Forever, p. 41
[xv] TLCSA, “Questions from the Public,” Nos. 221, 222
[xvi] TLCSA, “Questions from the Public,” Nos. 221, 222
[xvii] “Environmental Assessment, Two Lakes Collaborative Sewer Authority Project,” Michigan Rural Community Assistance Partnership, November 11, 2022
[xviii] “Environmental Assessment, Two Lakes Collaborative Sewer Authority Project,” Michigan Rural Community Assistance Partnership, November 11, 2022
[xix] “Environmental Assessment, Two Lakes Collaborative Sewer Authority Project,” Michigan Rural Community Assistance Partnership, November 11, 2022
Has the TLCSA studied environmental necessity or impact on the lakes?
The TLCSA stated that there are no studies showing that septic systems are adversely affecting water quality on Portage Lake or Bear Lake.[xv] Despite touting water quality improvement as a reason for the $58,968,000.00 project, the TLCSA also stated there are no projections showing a sewer system would reduce contamination, if it even exists.[xvi] The excerpts below are taken from the TLCSA’s “Questions from the Public” document.