Iowa is home to two rivers, the Cedar and Iowa rivers, voted as some of America’s most endangered rivers by the American Rivers organization. Over 180,000 people in the Cedar Rapids and Iowa City area depend upon the Cedar and Iowa rivers for drinking water, according to the organization’s Most Endangered Rivers publication. Both rivers are victims of the loss of wetlands to filter pollutants and farming practices that alter the landscape. The organization warns that the future may bring increased water treatment costs and the loss of already threatened species, such as freshwater mussels and rare plants. Polluted water can also present dangers for human health.
Agricultural tile drains, which lower the water table in Iowa fields and turn marsh into cropland, have erased around 90 percent of the state’s natural wetlands. One solution to the current runoff problem is reconstructing them.
For Aaron Gwinnup, a water resources engineer at HR Green, his pipe dream for the Iowa tiling system is to “have a small constructed or natural wetlands every place where tiles drain out.” This would not only keep the nutrients out of the rivers, but also let farmers keep their investments, Gwinnup said. Nutrients that flow into a wetland turn into plants and create a healthy wetland habitat.
Gwinnup said the nitrogen flowing off farm fields could be measured by “looking at the pocketbook of the average farmer. In one year, about $60 million in nitrogen fertilizer floats past sensors in Des Moines,” he said. “That’s a direct loss for farmers.”
Programs such as the Conservation Reserve Enhancement Program in the Iowa Department of Agriculture and Land Stewardship already work to help farmers create wetlands. The conservation reserve program provides incentives for farmers, including funding to help build wetlands and up to 15 years of rental payments from the U.S. Department of Agriculture for land that is taken out of farming and turned into wetlands.
According to researchers at Iowa State University, these wetlands can remove between 40 and 90 percent of the nitrogen from the water.
A new project, the Iowa Wetland Landscape Systems Initiative, is also in the works. The Initiative would take the same wetland concept and expand it to larger areas. These pilot projects restore wetlands, which receive tile drainage water from fields and filter out the nitrate.
Pilots Start Afresh in Wetlands
Unlike the Iowa Conservation Reserve Enhancement Program, known as CREP, the pilot projects do not “retrofit” wetlands into an existing tile system but rather start afresh with a new tile layout, explained Shawn Richmond, the program’s coordinator for the state’s department of agriculture.
The pilot projects include one completed site in Pocahontas County and six other sites that are in the hearing process.
The first completed project cost roughly $3 million, with $1.6 million supplied by the landowners. Richmond said the pilot projects will have a price tag of about $18 million for all seven sites.
Although water monitoring at the Pocahontas site has been limited so far, the five-year monitoring process is slated to begin this year, Richmond said.
Funding for monitoring plans has become complicated, because anticipated funding from the EPA and other agencies fell through. However, monitoring on the sites will continue as planned, Richmond said. The department will divert some resources from CREP sites to the pilots, he said, emphasizing that funding would not impede the planned monitoring.
Although the department does not have enough money for five years of monitoring, Richmond said he hoped the first round of testing would “lead to a pathway for future funds.”
Construction needs to begin soon for the next six sites due to the expiration date on $4 million supplied by the I-JOBS program, which ends June 30, 2013.
Pilot Success Could Spread
If the seven initial sites decrease nutrients that escape into Iowa waters, Richmond hopes to see more of these systems across the state, spreading the word to as many farmers a possible.
“You’re not going to have a farmer in Polk County see results in Pocahontas County and put much faith in those results,” Richmond said, driving out of Des Moines on a cold, grey afternoon last March to demonstrate a CREP wetland. “We need some broadening out so producers can see benefits in their own backyard.”
The limiting factor for CREP wetlands is public funds. When Iowa built the original tile system, farmers spent more than the U.S. spent to build the Panama Canal, according to Dean Lemke, the former state Water Resources Bureau chief in the agriculture department.
In total, the pilot project has an estimated budget of $15 million, which is split between private and public funds, Lemke said. He added that restoring 3,000 CREP wetlands in Iowa would be needed for the state to meet the 2015 goal set by the Mississippi River/Gulf of Mexico Watershed Nutrient. The goal aims to reduce nitrogen exports to the Gulf by 45 percent, which would run up a bill of approximately $1.8 billion.
“It would be wonderful in public policy if big boats of public funds would just pull into the harbor,” Lemke said.
At the current rate, Richmond estimated Iowa would need “a few hundred years” to meet the 2015 reduction goal.
However, he said he was hopeful that through private money and a focus on market-based initiatives, the program will be able to expand.
“I have a hard time thinking landowners won’t invest in maintaining at least the status quo of their drainage systems,” Richmond said, adding that farmers seemed “cautiously optimistic. They recognize as well as anyone the implications of inadequate drainage.”
The pilot program was one of six projects considered by the task force to be “success stories.” However, the program is not without its critics.
Among them are Linda Kinman, the public policy analyst for the Des Moines Water Works, and Chris Jones, who formerly worked as lab supervisor for the water works.
Will Pilots Cause Problems?
Kinman and Jones expressed concerns about the monitoring process for the pilot projects.
“Monitoring, we believe, needs to happen to ensure the wetlands are performing nutrient removal to the degree expected and to monitor for any unintended consequences that might result from the size of the drainage area, increased size of the tile, the impacts of algae blooms and the amount of water going through the system,” Kinman said in an email.
The Des Moines Water Works is home to the world’s largest nitrate removal facility, proof of the large amount of nitrate that flows into Iowa rivers and complicates efforts to make the water drinkable.
In September 2010, the Des Moines Water Works expressed its concerns in a letter to the Gulf of Mexico Water Nutrient Task Force and said the project could further damage Iowa’s waters instead of cleaning them up.
“One of our concerns is construction of wetlands which would be receiving high levels of nitrogen,” Jones said. “They could become reservoirs for cyanobacteria and other harmful algal blooms and could be washed into the Raccoon River, which would have severe consequences for treatment and quality of drinking water.”
The water works is the source for drinking water for roughly 500,000 people. The letter argues that due to the potential impact on approximately one-sixth of the state’s population, the water works’ concerns deserve careful attention.
Kinman added she was mainly concerned about the size of the pilot systems.
“With CREP wetlands, one field may drain into the wetland,” she said. “Those have been fairly successful. But these [pilot programs] which would be installed at the base of a drainage district will receive more water and nutrient loads than conventional CREP wetlands.”
Kinman said that because the pilot projects are based on research from the smaller conservation reserve wetlands, she fears they do not have enough data to predict how these pilots will affect the environment.
“They are not going to be natural systems,” Jones said. “No one really knows how these systems function.”
The water works met with the department of agriculture on March 14 to talk about the pilots, but Kinman said they “didn’t really learn anything new. It appears one and maybe two projects are moving forward, but the lack of adequate funding and the lack of interest by producers in giving up the land necessary for the size of the wetland needed, is slowing the process.”
However, Jones said he would support a “true” pilot project — one that involved more monitoring and a stricter scientific methodology. He criticized the pilot project as a “sort of a diversion, if you will, for the true purpose, which is to reconstruct drainage.”
“These are engineered systems that had consequences that we didn’t know about before they went in,” Kinman said, referring to the construction of the drainage system over a century ago. “We need to know the consequences of a change before it goes in across the state.”
Richmond acknowledged these concerns, but said most were based on misinformation. Other scientists involved in the project agreed.
“They raise some good points,” said Matt Helmers, an associate professor and extension agricultural engineer at Iowa State University. “There is a need for data. The only way to gather data is through these pilot programs.”
William Crumpton, an associate professor and chair of the Environmental Science Program at Iowa State University, said the 10,000-acre pilot projects wouldn’t cause any further damage to the water supply.
“Ten-thousand acres of crop land total, out of about 30 million acres. That’s 1/3000 of the watershed area,” Crumpton said. “How could that possibly have an effect on water coming into Des Moines? They’re just too small.”
Helmers said he hoped to see a reduction in nitrogen flowing downstream over the next 50 years as more pilots are built. “But that’s talking about years and years to rebuild drainage systems.”
Helmers and Crumpton said the window of opportunity for incorporating wetlands with tile drains is quickly closing. Crumpton said he expected to see a spike in the number of landowners replacing their tile system during the next 10 to 20 years.
“This [current tile system] is clay tile put in the ground almost a century ago,” he said. “The tile will be replaced anyway.”
The point of the pilot program, Crumpton continued, was to gather data and research to help shape policy before people begin replacing their systems on a large scale.
“Any judgment made today is opinion,” he said. “We just don’t have the research. This pilot helps decide what should be the long-term policy to replace tiles in the state.”
Crumpton, Helmers and Richmond all emphasized that the pilot program, even if it should prove successful, is just one of many changes that will need to take place to improve the quality of the water flowing through Iowa and down to the Gulf.
“The wetlands are just one tool in the kit, as far as achieving the hypoxia reduction goals,” Richmond said. “[But] it is a heavy lifter.”
Iowa’s waters and human health
Because much of the nitrogen in Iowa waterways enters from runoff, it is hard to measure.
“We’re trying to get a handle on the trends,” said Steve Kalkhoff, a hydrologist at the Iowa Water Science Center who works for the National Water Quality Assessment Program. “The trend from the 80s to 2000 is increasing amounts of nitrogen, but it’s not uniform at all sites.”
The center is working on figuring out when, where and why nitrogen pollution is increasing, Kalkhoff added.
The water quality program, started in 1991 by the U. S. Geological Survey, provides an opportunity for long-term and consistent data. It was the program’s data that first raised concerns about nitrogen in Iowa, Kalkhoff said.
“A lot of water quality information has been pretty short term,” Kalkhoff said. Funding was difficult to maintain, and “sometimes the thought was ‘we’ve got three years of data, that’s enough.’”
To measure the nitrogen in Iowa waters, the program has surface-water sites in Cedar Rapids and along the Raccoon River.
“It isn’t much to look at, just a cylinder,” Kalkhoff said of a testing site. “It shoots beams of light through the water and measure how much light goes through, which is dependent on the level of nitrogen.”
But the program’s efforts to gather information have run into a few challenges, including the size of the rivers. The bigger the river the more difficult it is to gather samples.
“You can’t just go out and dunk a bucket in the Mississippi River,” he said. “It takes time and money, but you get a better idea of what is in the water.”
Although the human eye may not see the nitrogen in the water, the effects are visible.
“If you see a pond full of algae and duckweed and green, gross water, that is the work of too much fertilizer,” Gwinnup said.
Nitrogen, Gwinnup said, is a problem “from the second it leaves the fields. In the ponds and lakes and rivers all the way to the Gulf.”
Although the nitrogen in Iowa’s waters doesn’t create hypoxia and dead zones like it does in the gulf, it does create other health and wildlife hazards.
Some types of algae that flare up during summer months are toxic. For example, the blue-green algae, or cyanobacteria, produces the toxin microcystin, which is dangerous to animals and humans.
The Iowa Department of Public Health and the Iowa Department of Natural Resources have joined up to monitor bacteria levels in some Iowa waters. When the Department of Natural Resources finds high levels of bacteria during their beach monitoring program, the department of public health gets the word out to local health officials.
Last year, there were 14 reports of suspected cases of human exposure. Five were cases of skin irritation and rashes and nine involved gastro-intestinal issues, said Stuart Schmitz, an environmental toxicologist with the Iowa Department of Public Health.
Animals are often the most severely impacted, Schmitz said, noting that humans generally tend to avoid the blooms. Along with the waterfowl and animals that drink from the river, Schmitz said they see a couple of dogs affected every year.
“Microcystin is a liver toxin,” Schmitz said. “If you consume large amounts, and that’s what happens to dogs, you get very sick, followed by liver failure.”
Nitrogen is a naturally occurring nutrient and vitally important for life and growth, but when too much nitrate, a compound of nitrogen and oxygen, accumulates in the environment or in the body, it can cause problems, said Peter Weyer, the associate director for the Center for Health Effects of Environmental Contamination at the University of Iowa.
In the 1960s, the federal government limited the amount of nitrate to 10 milligrams per liter of water. This limit was originally intended to prevent a sort of hypoxia in infants known as blue-baby syndrome, which occurs when nitrate / nitrite impacts hemoglobin in the blood. When this happens, the baby’s blood can’t carry enough oxygen to tissues and body cells.
“Some people are saying we should raise the drinking water standard for nitrate to 15 to 20 milligrams per liter because cases of blue-baby syndrome are so rare,” Weyer said.
However, recent research suggests policy makers may want to hold off on any increase to the standard, not due to the risk of blue-baby syndrome but rather the potential increased risk for cancer.
When nitrate enters the body, Weyer explained, it converts to nitrite, which can then be converted into compounds that are carcinogenic. He was concerned about data that suggested greater risks for bladder, colon, stomach and thyroid cancers but stressed that the results are not conclusive.
One such study, in which Weyer was involved as a researcher, included over 20,000 Iowa women who drank from either private wells or municipal water supplies. The results, published in the journal Epidemiology, suggested that women drinking water with over 2.46 milligram per liter of nitrate for over 10 years are at an increased risk for bladder cancer.
Other studies conducted across the globe have shown similar cause for concern. One study in Slovakia published in the journal Environmental Research showed an increased incidence of non-Hodgkin lymphoma and colon cancer among people whose water supply contained nitrate levels between 4.5 and 11.3 milligrams per liter.
Another study from Spain published in the European Journal of Epidemiology showed higher mortality rates for prostate cancer among people exposed to nitrate in the water supply.
These findings are cause for concern since the legal limit, 10 milligrams per liter, is much higher than the levels noted in the studies.
If future studies support these findings the government would need to look at creating more stringent nitrate limits. However, Weyer stressed that the results are not definitive.
“We are confident only to the point where we think we need to do more studies,” he said.
But even if the current legal limit is deemed safe, the use of well water in Iowa is still cause for concern.
In municipal plants, the water is tested frequently and the unwanted contaminants are reduced or removed through a variety of treatment processes. But wells do not follow the same testing process.
“The nitrate that comes up in well water is pretty much what you drink,” Weyer said, adding that there is not a lot of data on private wells.
“We did a study on 475 wells in Iowa. Twelve to fifteen percent of the wells had high nitrate content, which means there are a fair number of people being exposed.”
Reposted with permission from IowaWatch.org