Below is a summary of the test results we received from Trace Analytical Laboratories in Muskegon, Michigan. They are the laboratory we selected to analyze our collected samples.
It is interesting to note that Total Phosphorus concentrations for samples from Dennis Creek and Freeman Creek were 50 ug/L (micrograms per liter) and 200 ug/L respectively. While their measured flows were significantly less than that of the Big Sable River, these concentrations are alarmingly high. Normally, we like to see total phosphorus values, for water coming into the lake, at concentrations below 20 ug/L. This is the concentration above which we start to see excessive aquatic vascular plant growth. Values below 10 ug/L are even better when trying to keep plant growth to a minimum. As an example: Most people view Northern Michigan’s Torch Lake as one of our State’s more pristine freshwater lakes. Total Phosphorus concentration of this lake have been measured at only 2 ug/L. Phosphorus is the major nutrient contributing to aquatic plant growth.
Total Suspended Solids are a measure of particulate material (sediments) coming into the lake. While I am not aware of a generally accepted standard for suspended solids, lower levels are better than higher levels. These particulates drop out of suspension when water flows decrease in the calmer lake water environment. This contributes to gradual filling-in of the lake.