Farmer’s friend also enemy to Clinton Lake
Each year during fall and winter months, on his land 25 miles southwest of Clinton, Carbondale farmer David Badger injects 100 pounds of nitrogen and 50 pounds of phosphorus into the ground to fertilize his fields.
“If you don’t control the weeds, you can’t grow a good crop. Using chemicals are the most economical way,” Badger said.
But the same fertilizers used to grow crops on the Badger farm also are feeding plants in Clinton Lake, one of Lawrence’s main sources of drinking water. That’s a problem.
The water both in the Wakarusa River watershed and in Clinton Lake routinely exceeds Environmental Protection Agency levels for nutrients, according to U.S. Army Corps of Engineers data.
Taste and odor issues
Nutrients that start upstream as a good thing -fertilizers on croplands and lawns in form of nitrogen and phosphorus – become a bad thing once they travel through the watershed. They encourage the growth of algae, tiny single-celled organisms that live in the water. That creates a situation that stinks, literally.
Nutrients are the biggest problem we have with the water in Clinton Lake, said Don Huggins, director for the Central Plains Center for Bioassessment.
“Nutrients in the stream stimulate the growth of algae and too much algae growth can create taste and odor issues in the water,” he said.
The problems begin as the nitrogen and phosphorus flow downstream into the lake. They feed algae, causing it to grow. The more nutrients that are in the water, the more abundant the algae become. Then, when algae starts to die and decompose, it creates byproducts, geosmin and methylisoborneol (MIB), the compounds that give the water taste and odor problems.
The muddy, earthy taste geosmin creates, along with the fishy taste MIB produces are flavors both the Kaw Valley Water Treatment Facility and Clinton Water Treatment Facility try to avoid.
Keith Whealy, Clinton Water Treatment Facility manager, said he had been shut down only once for taste and odor problems. That was in December 1998, when the levels of geosmin reached a high of about 60 nanograms per liter. At the time, that level was one of the highest episodes of geosmin ever reported in the nation.
“We were feeding the maximum amounts of carbon into the water, but we could only bring the levels down from 60 parts per trillion to 10 or 11,” Whealy said.
He said most humans could detect the taste of geosmin and MIB at about 7 parts per trillion. Even though the levels in the lake weren’t violating any health standards, the Clinton Water Treatment Facility shut down for seven weeks. Until the geosmin levels in the reservoir came back down, the Kaw Water Treatment Facility ran all of the water for the city.
Distaste for water
Jeanne Johnson, born and raised in Lawrence, said she grew up thinking she disliked drinking any kind of water. But, she came to find that it was just the city water she couldn’t take.
“I thought I hated water. It wasn’t until I was in college visiting a friend who had filtered water when I realized it was the water I was drinking,” Johnson said.
Even though people like Johnson are able to detect compounds at very low levels in the water, Whealy said Lawrence tap water is not dangerous.
“Taste and odor issues we deal with have nothing to do with the quality of water,” he said. “It’s an aesthetic quality.”
However, Kansas Biological Survey Assistant Director Paul Liechti pointed out there is a risk that Clinton Lake could get a toxic algae bloom that would shut down the whole system.
The more nutrients in the water, the more likely a toxic bloom of blue green algae, cyanobacteria, could appear, Liechti said.
The chances of a dangerous algae bloom are reduced if the amount of nutrient enrichment is kept low, he said.
Liechti said even if there weren’t farming going on in the watershed, the lake would still eventually go “eutrophic” (the scientific term for a nutrient-filled lake). “We’re just trying to keep it from getting too old too fast, by managing what’s going on,” he said.
Once a month, April through September, the U.S. Army Corps of Engineers collects samples to monitor a suite of variables including levels of nitrogen, phosphorous and chlorophyll in Clinton Lake.
From the four sample locations on the lake, along with some inflow and outflow locations, they are able to indirectly judge the algae content by looking at the amount of chlorophyll in the lake.
The EPA’s proposed levels for the amount of nutrients are routinely exceeded in Clinton Lake, with levels of nitrogen and phosphorous normally more than doubling the proposed amount of .36 milligrams per liter for nitrogen and .02 milligrams per liter for phosphorous. Measured from water samples at Clinton Lake, median total nitrogen concentrations range from 0.7 to 1.0 mg/L and median total phosphorus concentrations range from 0.06 to 0.13 mg/L.
Liechti says the balance of the two nutrients is what is most important and a reasonable level is a ratio between 10 to 16 parts nitrogen for every one part phosphorous.
“You can’t just reduce only one and not pay attention to the other,” Liechti said. “If you’re reducing the amount of nitrogen, you should also be reducing the amount of phosphorus.”
Liechti says farmers are taking steps to control the levels of pollutants that runoff into the water. By implementing best management practices, runoff of fertilizers can be reduced 50 percent or more depending on the situation.
Rather than spraying the chemicals on the top of the field or spreading them on top and then working them into the first couple inches of soil, David Badger said he deeply injects his fertilizer into the ground so that runoff is reduced.
“Once you inject it 6 to 8 inches into the ground then it’s there to stay,” Badger said.
The Watershed Restoration and Protection Strategy, started by the Kaw Valley Heritage Alliance, works at protecting the health of the lake and has created a number of goals for farmers and others to create better management practices.
The Kaw Valley Heritage Alliance, K-State Research and Extension and Wakarusa Watershed Joint District No. 35 have organized a series of meetings and workshops to get watershed residents, landowners, land managers, water users and policymakers involved with the continued health of Clinton Lake and the Upper Wakarusa Watershed.
“Everything that goes into the Clinton watershed makes everyone a steward to the lake or a contributor to the problem,” Huggins said.
Regulations and good farming practices are much easier and more accepted if people understand the situation and are willing to make a change to make the environment better, Liechti said.
“I think working together is the only way we are going to solve this, it’s just getting that general understanding,” he said.