The types of water quality parameters we evaluate are biological, physical, and chemical. We look at the ground and surface water for contamination risks such as agricultural, industrial, and domestic activities. 

Monitoring the water quality of Lake Koronis is a priority of the KLA board. We, along with the North Fork Crow River Watershed District, are always on the watch for new ways to improve water quality. Read on below to find out more about some of the things we look out for.


Total Suspended Solids (TSS)

Total Suspended Solids (TSS) is how much sediment is in the water during sampling. The central standard is about 30 mg/L. Lake Koronis was measured to be at about 10 mg/L, so we are at a good level!


Total Kjeldahl Nitrogen (TKN)

Total Kjeldahl Nitrogen (TKN) is the total concentration of organic nitrogen and ammonia. Nitrogen levels have been consistent throughout the last few years.


Total Phosphorus (TP)

Total Phosphorus (TP) is a measure of all phosphorous, dissolved and solid, in a sample. It's commonly used to find the health of the water. The Central Regional Standard for phosphorus is around 0.100 mg/L.

There is an internal load of phosphorous. The committee works with the shore owners to do a preliminary assessment, contact the appropriate agency, discuss the situation, and work with the agency to work through a plan, permit, and grant if it is approved. 


Escherichia coli (E. coli)

E. coli is an indication of sewage or animal waste contamination in water. The Central Region Standard for E. coli is 126orgs/100mL. Some areas of Lake Koronis were well above the standard, so the Watershed and KLA are working on ways to address it. 


Trophic State Index (TSI)

Carlson’s Trophic Status (TSI) is a benchmark for lake water quality, by the Secchi disk, Chlorophyll 'a”, and total phosphorus. 

When the TSI is from 51-70, the water is in a Eutrophic state. The water has decreased transparency and lower levels of oxygen in the summer. There are evident weed problems. When the TSI is from 51-50, the water is in a Mesotrophic state. The water will be moderately clear with some probability of no oxygen in the lowest levels during the summer. Through July, we see some clearer water in a mesotrophic state, but as we get into August and September, the lake enters a eutrophic state.

On the South side of Lake Koronis, the mean TSI is decreasing. We are 99.9% confident that this shows that water quality is improving. 

On the North side of Lake Koronis, the mean TSI is also decreasing. We are 95% confident that this shows that water quality is improving.