Iowa Department of Natural Resources water quality technician Elizabeth Heckman walks to the beach for weekly water sampling at Lake Macbride in Solon on Tuesday, June 2, 2020. (The Gazette) Credit: The Gazette

This story was co-published with The Gazette, an Iowa newspaper.

Backbone State Park stretches across 2,001 acres of northeast Iowa, featuring a lake ballooning from the Maquoketa River. There, visitors can swim, kayak or simply lie on the beach during warm Iowa summers.

The state park — Iowa’s first — was built in 1920 on land donated by E.M. Carr, the grandfather of 82-year-old Mike Carr who now lives in Manchester. Mike Carr said he can remember Backbone Lake in the 1950s when it was the site of Red Cross swimming lessons and the hot spot for swimmers of all skill levels.

“It was just packed,” he said. “All the little swimmers were learning to swim inside the 5-foot mark. Those who knew how to swim, we’d always swim out to the big raft.”

Now, Backbone Lake has led Iowa lakes in swim warnings for bacteria over the last 14 years.

Iowa ranks low for public land acreage, making its sparse public spaces — and their beaches — more attractive to residents. Iowa’s state parks have seen a 19% increase in visitation since 2000.

Yet, year after year, public officials must warn against swimming at many of these public beaches due to poor water quality — despite state attention to the issue. The Iowa Nutrient Reduction Strategy, for instance, was designed to reduce nitrogen and phosphorous loads in Iowa waters by 45%. A recent Iowa Environmental Council report found little progress has been made since the policy’s adoption due to its voluntary measures.

DNR water quality technician Elizabeth Heckman gathers a water sample at Lake Macbride Beach in Solon on Tuesday, June 2, 2020. In addition to gathering water samples, Heckman also noted the number of people on the beach and in the water, the water turbidity, dissolved oxygen, water temperature and pH level. (The Gazette) Credit: The Gazette

The Gazette and Investigate Midwest collaborated to analyze two decades of beach monitoring data from the Iowa Department of Natural Resources. Sampling at about 40 beaches typically stretches from Memorial Day to Labor Day, depending on the year.

We recorded how many times E. coli and microcystins — human health risks in Iowa’s waterways — surpassed safe standards in recorded water samples since the 2000s. We also discovered which state park beaches most often exceeded those standards. High test results can trigger beach advisories encouraging visitors to stay out of contaminated water.

After sharing our results with five water quality experts, we found, although individual locations may display some progress, Iowa’s beaches overall show little to no improvement in the past two decades. Some experts told us they were most worried about consistently high E. coli presence, while others found the unpredictable risk of microcystins more concerning.

Localized restoration attempts have earned small victories. But, to see widespread success, experts say Iowa farming practices, incentives and regulations need reform.

“If there’s anything that we can pull from this data or any trend that we can identify, it’s that we consistently have issues here in Iowa that are affecting our recreation opportunities and our quality of life,” said Alicia Vasto, the Iowa Environmental Council Water Program director. “We need to be doing more to address it in ways that are actually going to make a difference.”

E. coli consistency ‘most concerning’

Connor Nicholas, 22, gathers a sample from Prairie Rose Lake on July 30, 2015 as part of the Iowa DNR beach monitoring program. photo by Lauren Mills, IowaWatch Credit: Photo by Lauren Mills/IowaWatch

E. coli is a group of bacteria found in our intestines, food and ecosystems. It’s common in Iowa water bodies, originating from feces from wildlife, humans or manure runoff from farm fields. Bacteria levels are typically higher after heavy rains that sweep the organisms from the shores into the water.

Not all E. coli is harmful. But its presence indicates feces that can carry pathogens dangerous for swimmers who accidentally ingest it.

“As those numbers get higher, the risk of getting an illness from bacteria, viruses, parasites, and things like that goes up,” said Dan Kendall, the state’s lake and beach monitoring coordinator.

The Gazette’s and Investigate Midwest’s probe found E. coli has a constant and bountiful presence at Iowa beaches. A fifth of monitoring tests administered since 2002 have exceeded the state threshold, which is 126 units of bacteria per 100 milliliters of water.

This summer, samples topped that threshold 142 times, compared to last summer’s 126 exceedances.

“The E. coli results are probably most concerning,” said David Cwiertny, director of the University of Iowa’s Center for Health Effects of Environmental Contamination. “The data over time is pretty consistent and shows we aren’t making much progress over two decades toward improving water quality at our beaches.”

The most notorious repeat offender, by far, is Backbone Beach. In two decades of data, we found its annual geometric mean of E.coli levels exceeded the state threshold in 14 of the 20 years. The geometric mean is a type of average used to dampen the effect of very high or low test values.

One of the suspected reasons the lake has poor water quality is because 86,000 acres of farmland drain into a 50-acre lake. But, unlike many impaired water bodies, Backbone has never had a total maximum daily load study, which is a water quality improvement plan designed by the DNR. That’s because of its unique ecosystem along a river, Kendall said, which leaves it difficult to tell exactly what and where the E. coli sources are.

All the while, Backbone’s beach monitoring results have grown distressingly predictable.

A man swims past several women kayaking at Lake MacBride in Solon, Iowa on Monday, September 5, 2022. (Savannah Blake/The Gazette) Credit: Savannah Blake/The Gazette

“Every year, we know Backbone is going to have an advisory within a couple of weeks at the beginning of the season, and it’ll likely stay on for the rest of the season,” Kendall said. “It’s a different beast.”

Beeds Lake State Park and McIntosh Woods State Park — both in north-central Iowa near Mason City — also rank high in their levels of E. coli in beach waters. Unlike Backbone, each lake has a dedicated DNR improvement plan revealing the sources of the bacteria.

The dominant E. coli source at McIntosh’s beach on Clear Lake is geese. The lake’s improvement plan said “waterfowl loafing on the beach” allows the bacteria to regenerate in the sand. Wildlife also contributes to bacteria numbers in Beeds Lake, according to its improvement plan. Septic discharges, nearby livestock operations and a local wastewater treatment plant add to the load as well.

Mary Skopec, executive director of the Iowa Lakeside Laboratory and previous lead of the state’s beach monitoring program, said lakes with poorer water quality may have more favorable conditions for E. coli.

“Water clarity is essential in providing the ability for sunlight to penetrate the water and kill bacteria — cloudy water impedes that process,” she said.

Unpredictable microcystin risks

If you’ve ever seen a lake that looks like pea soup, that’s most likely an algal bloom.

Microcystins are toxins produced from certain types of harmful algae blooms. These blooms depend on warm, stagnant waters and nutrients like nitrogen and phosphorous. Unlike E. coli, algae blooms are observed more during times of drought and grow better in clearer waters.

Since algae blooms are heavily influenced by climactic factors, they are often unpredictable. That irregularity was mirrored in our data analysis, where we found microcystin exceedances in Iowa lakes have risen and fallen since 2006.

In 2012, for instance, microcystin levels surpassed the state threshold — 8 micrograms per liter of water — 50 times. That peak coincided with Iowa’s most intense period of drought since 1988.

This summer, microcystins topped safe levels only 11 times. But as climate change continues to threaten more frequent droughts — to the point where state officials expressed interest in creating a drought plan this summer — experts are concerned about the growing threats microcystins may pose.

“As temperatures increase and nutrient levels continue at high concentrations, the conditions for blue-green algae to thrive and produce toxins will also continue,” said Marty St. Clair, a chemistry professor at Coe College, in Cedar Rapids, and director of the Coe Water Quality Laboratory.

People and pets can be exposed to microcystins if they swallow water, have direct contact or breathe airborne droplets containing the toxins. Symptoms of microcystin poisoning include rashes, hives, vomiting, asthmalike symptoms and fever. Severe exposure can cause liver damage.

Since 2011, 30 suspected microcystin poisoning cases have been reported to the Iowa Department of Public Health. Four of those cases were from exposure at a triathlon — an indication of how poor water quality can affect recreation.

“In my view, microcystin is more of a risk than E. coli,” said Chris Jones, a University of Iowa research engineer who studies water quality. “People should not swim in green water, especially opaquely green water, whether or not the latest microcystin result is acceptable.”

Water samples from Green Valley Beach, southwest of Des Moines, have exceeded the state threshold for microcystins 71 times since 2006 — almost double the amount of the next-highest beach. That’s because it sits in a watershed dominated by agriculture, and phosphorous gets repeatedly cycled within the system, Kendall said.

“(Attendance) has been dropping over time, and that would probably coincide more with the water quality decreasing,” he said, adding that other factors may impact visitation as well.

When algae blooms die, the decomposition sucks up dissolved oxygen needed by aquatic life. Since 1988, seven fish kills have been recorded in Iowa due to cyanobacteria blooms, according to the state.

Algae blooms tend to come later in the summer — sometimes into September, when people are still swimming but lakes aren’t being tested, Skopec said. “I think we’ve created a public health gap by not sampling later in the season,” she said.

Lasting success requires change

Kevin Gull, a 65-year-old farmer from Guttenberg, grew up going to public beaches. Now, he avoids touching even a drop of water when visiting — because three years ago, Iowa waterways brought him to the brink of death.

He had sat in a lawn chair at the edge of the Mississippi River, feet in the flow. The next day, he saw red start to spread up his leg and he got a fever, signaling an infection. He fought for his life at a hospital for 10 days. Tests couldn’t determine the organism causing the infection.

“They were afraid they were going to lose me … I could’ve lost my leg or I could have lost my life,” he said. He now chooses to avoid touching Iowa waters entirely due to ongoing health risks from the encounter.

Some Iowa lakes have had successful restoration projects. The campground beach at Black Hawk State Park in northwestern Iowa, for instance, has surpassed the threshold for microcystin levels 37 times since 2006 — the second most of any analyzed beach.

How can we improve water quality?

Not all water quality researchers agree on solutions for improving water quality in Iowa’s lakes and rivers, but below are some ideas that have been proposed by experts:

  • Follow through with DNR lake improvement plans.
  • Target conservation practices on farmland that drains to recreational lakes.
  • Prohibit spreading manure on snow-covered ground.
  • Don’t allow farming in 2-year flood plain.
  • Regulate agricultural inputs such as fertilizer and manure applications.

Those problems are now dwindling thanks to a watershed improvement project started in 2012, said Ben Wallace, a fisheries biologist who is actively involved in the project. A decade into their plan — which includes more terracing, wetland restoration and tillage conservation practices — they’re already about halfway to their goal of 80% phosphorous reduction.

“We have about four or five bass tournaments a year here. We never had bass tournaments prior to (the water quality project),” he said. “We’re pretty happy with the successes that we’ve had, but we also know we’ve still got a lot more work to do.”

Other projects haven’t been as successful. Green Valley Lake has been dredged and studied, yet researchers aren’t sure why it still has such a high nutrient load. At Lake Darling State Park, near large hog populations in Washington County, the state completed a $16 million lake restoration project in 2016 and replaced the park’s sewer system in 2018. But E. coli and microcystin problems have continued.

To make lasting change, experts agree we need to reduce nutrients and sediments flowing into the lakes. This means better identifying, regulating and controlling root causes of the contamination. Others say best management practices for farming should be required instead of voluntary.

“It’s important for people to understand and recognize that the opportunities to get outside, recreate and enjoy natural places here in Iowa are really limited,” Vasto of the Iowa Environmental Council said. “I just encourage everybody to be a voice for these places, for our natural areas and for our public beaches.”

How we did the analysis

The Gazette and Investigate Midwest used water quality monitoring data from the Iowa Department of Natural Resources to conduct this analysis. We only included tests that were performed to detect the presence of E. coli bacteria and microcystin toxins.

County and special program beaches that were included in the database in 2006 and 2019 were removed after consultation with the Iowa Department of Natural Resources about the number of beaches that are typically monitored annually.

Routine water quality monitoring at Iowa state parks is usually performed in the summer. Still, we found tests conducted outside that time period in different years. We used the period May through August to standardize the analysis period among the different beaches and years.

We have also taken into account only the first control test administered at each beach each week, after consulting with experts to give the data consistency.

We adopted the threshold used by the Iowa Department of Natural Resources to identify high levels of E. coli — 126 or more bacterial units per 100 milliliters of water — and microcystins — 8 or more micrograms per liter of water

The analysis included 12,509 monitoring results for E. coli collected from 2002 to 2022, and 8,800 monitoring results for microcystins, which have only been collected since 2006.

Brittney J. Miller is an environmental reporter for The Gazette and a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues. Comments: (319) 398-8370;

Mónica Cordero is an investigative and data journalist for the Investigate Midwest and a corps member with Report for America.

Erin Jordan is an investigative reporter for The Gazette. Comments: (319) 339-3157;

Top image: Iowa Department of Natural Resources water quality technician Elizabeth Heckman walks to the beach for weekly water sampling at Lake Macbride in Solon on Tuesday, June 2, 2020. (The Gazette)

Type of work:

Mónica Cordero is a Report for America corps member and part of the Mississippi River Basin Ag & Water Desk team. Her expertise includes data analysis with Python and SQL, and reporting under the...

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