Report on Water Quality Sampling 2023

Water quality samples were taken on August 2, 2023 in all of the bays around the lake and in one “background” site – a place far from shore where the water should be cleanest. The results are in the attached table where this year’s results are listed, along with results dating back to 2013.

The levels of E. coli are excellent indicating that the water is excellent for all recreational activities.

This year’s results for TP are listed on the table but also on the attached map of the sampling sites. On the map, every sampling site is numbered and where red circles a sampling site, that indicates that the TP levels in the samples were higher than 0.015 mg/l and where yellow circles a sampling site, the levels found were either 0.013 or 0.014 mg/l so almost too high.

It is important to remember that phosphorous is naturally occurring in soil and is an important part of human and animal waste (septic systems are not designed to take out phosphorous so septic weeping or leaching beds can be a source of phosphorous even when they meet all the standards). There are no phosphates in laundry or dishwasher detergents or in other soaps. There are however, phosphorous in fertilizer that is added to gardens and lawns. If fertilizer is used on lawns or gardens within 100 feet of the water, it is likely that it will leach into the lake, especially with the heavy rains we have had this summer.

Possible reasons for higher TP levels in your areas may be the following:

  1. Runoff into the lake from the unusually heavy rainfall events in June and July this year may have carried more phosphorous and other nutrients into the lake than normal.
  2. Shoreline development where the shoreline has been denuded or even where most vegetation has been cut would have allowed more phosphorous than usual to leach into the lake especially during rainfall events.
  3. This year’s rainfall, runoff from the surrounding land and the naturally occurring underwater springs have kept lake water levels at an adequate height so far. However, the blocked inlet for the lake has resulted in less lake water turnover than usual which may be leading to more phosphorous loads in the lake.
  4. Geese may be a factor since their feces add phosphorous to the lake ecosystem.

To address any high TP levels, everyone can help by maintaining or adding as much vegetation as possible along their shoreline, by refraining from using fertilizers and by being lazy, not cutting their lawns and letting them grow into meadows.