By Rep. Linda Runbeck
Letters I receive from constituents are always interesting, especially correspondence from local youth. A senior from Centennial High School, an avid fisherman, wrote urging action to protect Golden Lake so people can enjoy it today and into the future.
This led to questions of what residents might want to know about lakes in our area. What is the water quality of our lakes? Is there measurable quality data available? What are the trends?
Conversations with officials from the Minnesota Pollution Control Agency, Anoka County Parks, and Rice Creek Watershed provided some answers to these questions.
Lakes all around the state are subject to layers of monitoring by state agencies to check for levels of mercury in fish (DNR) and nutrients in the water (MPCA). Regarding mercury, the DNR's study results in a fish consumption guide per lake which can be accessed at www.dnr.state.mn.us/lakefind. If a lake exceeds state standards for mercury, the DNR advises on the frequency of eating fish, e.g., no more than once per week or once per month. While no advisories have been issued, Golden Lake slightly exceeds state standards for mercury while Centerville Lake, another popular fishing lake, does not.
As for nutrient levels, officials are mainly looking for levels of phosphorus and chlorophyll, along with a check for clarity. Samples are taken from each lake a total of 12 times over two years once each decade.
The result of MPCA's study is a list of lakes that are "impaired," i.e., having nutrient concentrations higher than state standards. The agency offers no gradations of impairment (such as from mild to severe). The lake is either on the list or not. High concentrations of phosphorous, they told me, do relate to increased "algal abundance" which affects the lake's appeal for swimming and other recreational uses. (Note: this algae is not the toxic or hazardous type of algae bloom.) So, is "impairment" as far as swimming or fishing somewhat in the eye of the beholder?
An interesting side note on phosphorous: Minnesota banned phosphorus from fertilizers in 2007. How much will the use of non-phosphorous fertilizers improve lake quality? We'll begin to know as the next 10-year cycle of results begins coming in. Certainly, each lake has its own set of circumstances affecting phosphorous levels. Some are spring-fed; others receive inflow from ditches. Others may be surrounded by roadways which produce run-off.
The Metropolitan Council is also studying lake quality. In conjunction with metro counties, they study 162 lakes with the help of 118 citizen volunteers who are trained in collecting and submitting water samples and field data. The Met Council's results come in the form of an A-F grade for lake quality. The majority of Anoka County lakes were rated A, B or C for phosphorous and chlorophyll as well as clarity readings. A helpful website is: www.metrocouncil.org/Wastewater-Water/Publications-And-Resources/Water-Quality-Monitor-Assess/Lake-Water-Quality-Summary-2013.aspx.
With four agencies studying the water quality of metro lakes, citizens can be assured that the subject is being fully addressed. Remediation to meet state standards will be the next area of discussion at state, county and city levels. Resources are critical when there are public safety aspects, such as with blue-green algae that produces algal toxins causing illness or in rare cases, death. Questions of cost/benefit should be raised in the cases of phosphorous overloads which cause less desirability for recreational purposes. And revenue raised from such sources as the 3/8-cent sales tax for the Clean Water Legacy should be made available for locally impaired lakes.
It will be valuable to learn what MPCA's lake quality studies at the ten-year interval will reveal. In the meantime, citizens are encouraged to continue practicing sound resource management while enjoying local lakes such as Golden, Centerville, Peltier, and Oneka.