Seasonal water testing to start
Local lakes
to be monitored
By ELISA SAND
As lake water thaws, local volunteers spring into action with water testing. Volunteers are currently testing water on Lake Madison, Lake Herman, Brant Lake, Round Lake and Long Lake.
They are testing for the presence of bacteria through Dakota Water Watch, a program sponsored by East Dakota Water Development District.
Additionally, Dakota State University Professor Dale Droge is monitoring the phosphorus levels in the local watershed.
“Our primary issues are still the same,” Droge said. “Much of the water has high phosphorus levels.”
High levels of phosphorus in the water feed the algae that is predominant in the area lakes each summer.
“We monitor and check the nutrient loads in the tributaries,” Droge said, adding that current levels are about double where they should be.
As snow started melting, Droge and a student started taking water samples. One of the goals is to catch runoff to determine its impact on the water.
“When you get water and soil moving, you get more phosphorus,” he said.
Last September when flooding was taking place, Droge said, phosphorus levels were pretty high. The phosphorus levels decrease as water makes its way from Lake Herman to Brant Lake.
“Lake Herman stays pretty consistent,” he said, indicating that tributaries to the north have higher levels of phosphorus in the spring, while the outlet varies.
“It (water) tends to pick up once it leaves the lake (Herman),” Droge said. “By the time it hits Lake Brant, the phosphorus levels drop off but are still high.”
Droge is a member of Lake County’s Water Quality Advisory Board.
“Ultimately, the goal is to try and figure out management processes to slow the release of phosphorus,” he said.
Some ways to decrease phosphorus levels include installation of filter strips, using zero phosphorus fertilizer and implementing erosion control methods to reduce the amount of sediment that gets carried along with the runoff.
One project under consideration is installation of oxygen circulators in The Harbor area on Lake Madison. The idea is to draw down the algae to the bottom of the lake and bring the oxygen-starved water to the surface.
Droge said he’s uncertain if circulators will make a difference since the oxygen levels in the water stay pretty consistent regardless of the depth of the water, but he plans to be involved in assessing the impact if they are installed.
Meanwhile, additional testing on local lakes looks at bacteria levels. Jay Gilbertson, manager of the East Dakota Water Development District, said water testing through the Dakota Water Watch program has been taking place for three years.
Dave Phalen conducts local testing at Brant Lake.
“The Brant Lake Development Association took this on as a project,” Phalen said. “We’re the most heavily sampled lake. Of all the lakes that have been tested, we are the third clearest.”
Phalen said what they’ve discovered is that water coming into Brant from Round Lake is better than the water going into Round Lake.
Tests take place twice a month. For each sample obtained, Phalen said, he documents the time, location, wind speed and direction, air temperature, water temperature and water depth. He also measures water clarity with a secchi disc.
The water tests look for the presence of coliform bacteria like e-coli. Phalen said each water sample is transferred to three sample bottles, and samples from each of those bottles are smeared onto petri dishes. The petri dishes are then set into an incubator and about 24 hours later he sits and counts the spots that appear.
“Sometimes they’re clear and sometimes they’re speckled,” he said.
Phalen said he currently collects samples from 17 locations, but he’s thinking about cutting back the number of sites to six.
Gilbertson said at the end of the year, the data collected is compiled into a book that details results from the past year. He said having local volunteers take samples, place them in local incubators and do the testing is much more cost efficient than running them through the state lab.
The purpose for water testing, he said, is to provide the state with baseline information about the local lakes for annual reports. Those state reports determine if lakes are meeting state standards for their designated uses.
“Most of what we’re finding is things are pretty much OK,” Gilbertson said.