Water Quality Study 2008


Keiser and Associates evaluated the water quality of Asylum Lake and Little Asylum Lake from 2006 to 2008. The purpose of the water quality assessment was to develop a better understanding of current lake conditions, identify factors influencing water quality, and recommend strategies for long-term management and improvement.

Efforts of the study included:

- Watershed delineation and assessment of runoff contributions

- Identification of stormwater pollutant sources and loading estimates

- Water quality monitoring (seasonal and wet weather)

- Stormwater inlet and lake outlet sampling

- Sediment sampling

- Aquatic plant surveying

- Development of a hydraulic mass balance

- Development of a phosphorous mass balance

- BMP recommendations and preliminary stormwater treatment concepts

The study found both lakes to be considered mesotrophic to eutrophic, meaning they are experiencing an overload of nutrients. Stormwater inputs are significant, and pollutants are mainly entering the lake from drains located near Drake Road and Stadium Drive. Large concentrations of phosphorous were found at the bottom of the lake and in the sediments. Heavy metals such as mercury were also found in bottom waters and in sediments, most likley from atmospheric and stormwater sources. Anoxic conditions were recorded indicating high sediment oxygen demand. Recommendations for improving the health of the lakes included invasive species management, stormwater control, and sediment/hypolimnetic treatments.

**A detailed description of the methods and results of the study can be found in the PDFs listed below. To see all of the data collected, click Read Entire PDF.


Keiser and Associates Water Quality Study 2008:

Read Entire PDF

Table of Contents

Introduction

Monitoring Methods and Analysis

Results

Discussion

Conclusion

Recommendations

References

Maps and Charts



WMU seal