You’ve packed a cooler, donned swim gear and slathered on sunscreen in preparation to hit an Iowa beach on a beautiful summer day.
But wait. What’s this?
It’s a notice saying swimming isn’t recommended because of high levels of disease-causing toxins produced by blue-green algae, whose blooms can be fed by fertilizer washing into lakes from nearby farms.
Iowa had a record 37 such advisories last summer at state park beaches, with some beaches, such as the one at Green Valley State Park in southwest Iowa, spending nearly as many weeks under a swim warning as weeks without.
Iowa water quality has been a hot topic in recent years as nitrates from Midwest agricultural fields contribute to a Gulf of Mexico “dead zone” where aquatic life — shrimps, oysters, etc. — can’t survive because of a lack of oxygen. Although Iowa has a nutrient reduction strategy, the plan doesn’t have deadlines and funding for clean-up initiatives is uncertain.
The U.S. Geological Survey defines water quality as a way to measure the suitability of water for a specific use, such as drinking, swimming or wildlife habitat. Scientists measure water characteristics including temperature, dissolved oxygen, bacteria levels, sediment and nitrate levels, and compare them with numeric standards for each use.
Beyond water coming from the tap, Iowans are most likely to consider the quality of water when they go out to swim in it, said Dan Kendall, coordinator of beach and lake monitoring programs for the Iowa Department of Natural Resources.
“Whenever someone goes to the beach and all of a sudden there’s a sign that says, ‘Don’t go in the water,’ it definitely makes them think about water quality,” he said.
Swimming season approaching
With about a month until Memorial Day, when Iowa’s 39 state park beaches open for the summer, the DNR is hiring new employees to prepare for beach monitoring. The program, which cost $62,300 in 2016, involves tests for E. coli bacteria and microcystin toxins that come from blue-green algae blooms.
If counties or cities want to test local beaches, the DNR provides a protocol for collecting samples and pays for water testing.
Advisories are updated once a week, usually on a Thursday, from Memorial Day through Labor Day. A color-coded map on the DNR’s beach monitoring website — http://urltrim.co/lsQ2Vz — shows which state and local beaches are safe for swimming each week.
The DNR started testing for E. coli in 2000 because the bacteria is an indicator for fecal material, which can carry parasites or other pathogens that can sicken swimmers. Fecal contamination can be caused by manure spills, septic tank leaks, storm runoff from fields treated with manure or direct contamination from animals, such as geese leaving droppings on the beach.
“For bacteria,” Kendall said, “there appears to be a slight trend upward.”
In the first eight years of bacteria monitoring, there were only two years in which more than 10 percent of Iowa’s state park beaches had bacteria levels above U.S. Environmental Protection Agency guidelines for one-time samples of 235 colony forming units per 100 milliliters of water.
During the most recent nine summers, all but one year had more than 10 percent of beaches with too much bacteria, with nearly one-third of Iowa state park beaches crossing that threshold in 2010, DNR data show.
The beach at Backbone State Park in northeast Iowa had no-swimming advisories 11 of 15 weeks in 2016, and Prairie Rose State Park beach in western Iowa was under advisory eight weeks of the summer, DNR data show.
Record advisory numbers
Blue-green algae is another growing problem.
The algae blooms, caused by a combination of nitrogen or phosphorus pollution and increased temperatures, can be harmful to humans and animals. Exposure to the microcystin toxins produced by some blue-green algae can cause gastroenteritis, skin irritation and allergic responses, as well as potentially life-threatening liver damage, according to the U.S. Centers for Disease Control and Prevention.
Since 2006, the DNR has issued 185 beach advisories for high levels of microcystin exceeding 20 micrograms per liter, the level deemed unsafe by the World Health Organization. Nearly 40 percent of those warnings came in 2015 and 2016 alone. The U.S. Environmental Protection Agency has draft recommendations that would set the recommended “safe” level of microcystins for swimming to under four micrograms per liter, Kendall said.
“Last year we had 37 beach advisories,” he said. “If it goes to four, we would have had 78.”
Two people last year reported symptoms consistent with blue-green algae poisoning after swimming in Iowa’s state park lakes, according to the Iowa Department of Public Health. One person reported vomiting, headache and diarrhea after swimming at Green Valley Lake, which has had 34 advisories since 2006 for elevated levels of microcystin toxins.
Iowa had eight suspected cases of microcystin poisoning in 2015.
Iowa’s Great Lakes
Blue-green algae has thrived in Iowa lakes in recent years because of an increase in statewide nitrate levels, warmer weather and extreme rain events, said Mary Skopec, who supervised DNR water monitoring for many years before becoming beach monitoring coordinator for 2014 through 2016.
“Whenever someone goes to the beach and all of a sudden there’s a sign that says, ‘Don’t go in the water,’ it definitely makes them think about water quality."
- Dan Kendall
Iowa Department of Natural Resources
Skopec is now director of the Iowa Lakeside Laboratory, a 147-acre state-owned campus on the banks of West Lake Okoboji, a glacier-formed lake in northwest Iowa regarded as one of Iowa’s cleanest water bodies. Even there, blue-green algae is a fear, she said.
“Zebra mussels showed up in West Lake about three years ago,” Skopec said. “They need to attach to something and Okoboji, the lakes have rocky bottoms.”
The mussels compete with native species for food and are linked to increases in blue-green algae, Skopec said. The murky green color and foul smell of algae-filled waters haven’t been a widespread problem in Okoboji-area lakes, which is important to a region that saw $276 million in tourism-generated expenditures in 2015, according to the tourism bureau.
“If you go to the Great Lakes region of Iowa, people are keenly aware of water quality,” Skopec said. “Folks are very interested in ensuring that value, including the economic value, is protected.”
The region even has its own festival focused on clean water. The Okoboji Blue Water Festival, launched in 2016 with a one-day event culminating in a concert with Boz Skaggs, will be Aug. 11 through 12 this year with exhibitors, a speakers’ panel and children’s activities, all focused on water quality education.
So what is being done to clean up Iowa’s public swimming beaches?
F.W. Kent Park, a 1,000-acre county park near Tiffin, is in the first phase of a $3.3 million to $3.7 million restoration project expected to improve water quality in the 27-acre lake used for fishing and swimming.
Kent Park staff posted advisories for high levels of E. coli or microcystin toxins from blue-green algae more than 20 times in the past three summers, barring swimmers once in 2015 and twice in 2016, Johnson County reported.
Upstream catchment basins intended to filter out pollutants had become full of sediment and invasive plants that weren’t helping purify the water, said Brad Freidhof, Johnson County conservation program manager.
“People think Mother Nature takes care of herself,” Freidhof said. “We’re going to try to control the nutrient levels in the lake. Where we have water come in, we’re going to have native plants to act as our filtration system.”
Once the catchment basins are cleared and new ones built, the county will drain the lake to see what changes might be needed on the floor surface, Freidhof said. The project will take two years and the cost will be split between the state and county.
Other solutions for improving water quality at beaches are changing the fish population or removing goose waste and garbage to discourage bacteria growth, Kendall said.
Some northeast Iowa counties, including Allamakee and Winneshiek, are looking for more control over the number of concentrated animal feeding operations, or CAFOs, allowed in their watersheds, said Susan Heathcote, water program director for the Iowa Environmental Council. However, Iowa Republicans, in the majority at the Statehouse, have said they’re not interested in tightening restrictions on ag operations at this time.
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This story appears in the second edition of the Iowa Ideas magazine. Order a free copy here.