Water quality officials with the Iowa Department of Natural Resources (DNR), frustrated with the negative portrayal of the impaired waters listing, vowed last week to find ways to help Iowans understand that list is not a good indicator of the state’s water quality.
The slightly higher number of impaired water bodies in the 2016 list, up 1.9 percent, reflects additional monitoring and the broad categories that the DNR uses to comply with federal Environmental Protection Agency guidelines, said Roger Bruner, supervisor of the DNR’s Water Monitoring and Assessment Division, who spoke last week during a meeting of the Iowa Environmental Protection Commission (EPC). It does not, he stressed, indicate that Iowa water quality is getting worse.
The number of impaired water bodies in Iowa has also risen over the years because the agency has added uses, such as recreation, that the water bodies are expected to support, the officials said.
The agency identifies impaired waters as those that do not fully meet all applicable state water quality standards for their intended use.
Activists hone in on list
With several other indicators pointing to improvements in Iowa’s overall water quality, anti-livestock activists and opponents of the state’s Clear Water Initiative have honed in on the impaired water bodies list. They say the impaired water bodies list shows the need for additional regulations for farmers raising crops and livestock.
However, the DNR water officials countered those accusations and emphasized that the list of impairments does not indicate deteriorating water quality in Iowa. "The level of impaired waters in Iowa is generally pretty slight," Bruner told the EPC commissioners. In addition, categories have shifted over the years, making it difficult to make apples-to-apples comparisons, the DNR officials said.
They also said that there is a wide range of reasons for the impairments, including natural and human activity.
Every two years, the federal government requires the DNR to compile a list of water bodies that are not fully supporting one of several water use categories, such as a home for aquatic life, drinking water or recreation (water contact). In the report, the water bodies are judged on the wide range of factors, including bacteria, biological impacts and low-dissolved oxygen.
In addition, the DNR gathers data from other sources, such as the U.S. Geological Survey, the U.S. Army Corps of Engineers, municipal utilities, as well as a number of watershed monitoring projects around the state, such as the Watershed Management Authorities. There’s been more data from these outside sources in this report cycle, Bruner said.
The agency then establishes a degree of impairment from slight to severe, depending on how each water segment is meeting its designated uses.
Because of the increased monitoring and wide standards, the DNR says several high-quality waters in the state landed on the list, said Jon Tack, chief of the DNR’s water quality bureau. He noted that high-quality waters, such as Deer Creek in Mitchell County, the Volga River in Fayette County and West Okoboji Lake in Dickinson County, are on the impaired list because of the broad categories.
The DNR also said it plans to remove dozens of water bodies from the from the 2014 list, once approved by the EPA.
The DNR, Tack said, will continue its efforts to help the public understand the impaired waters list and what it does and does not show.
"We believe that it makes sense to continue to work to get our voice heard every two years when the report comes out," said Tack. "We think it’s the best way to get people to understand what the impaired list really means."
Chad Ingels, an EPC commissioner from Fayette County, agreed that the DNR needs to continue its education effort on impaired waters. "People tend to hear only one number and don’t really understand what’s behind it, so it is a concern for us," he said.
In time, Tack said, the DNR would like to develop a scoring metric that would be easier for the public to understand. "We don’t really like the fact that we are required to put out an impaired waters list every two years and then have to tell people it doesn’t mean what they think."
The DNR, Tack said, has set up a special website to help citizens get information on the monitored water segments. It is called ABD net and can be found at http://bit.ly/2oM7334.
Despite the snapshot impaired waters report, a number of longer-term trends in Iowa surface water quality show steady-to-declining levels of nitrate and phosphorus in most of Iowa’s monitored rivers and streams during the decade ending in 2012, according to a new U.S. Geological Survey summary.
In an new interactive mapping system, the USGS reports that nitrate levels were rated as trending steady to lower in 18 of 22 Iowa sites tested; phosphorus levels were rated as trending steady to lower in 23 of 25 sites tested; and five Iowa sites showed up as "somewhat likely up" or "likely up" in the surveys for either nitrates or phosphorus.
Also, a recent summary of annual monitoring results by the Iowa DNR showed that 75 percent of untreated water in Iowa streams at or below the Environmental Protection Agency’s 10-parts-per-million nitrate safety standard for finished drinking water.
After testing more than 14,000 river water samples the last 16 years, the DNR report shows that only about 10 percent of the untreated stream water exceeded the EPA drinking water standard, and that median nitrate concentrations ranged from 2.8 to 7.3 parts per million.
The trends stayed low, despite temporary, weather-induced spikes that can often occur during heavy rainfall events.
In addition, a recent Iowa State University survey found that farmers have invested $2.2 billion in conservation in the last 10 years. The same survey shows moderate-to-major increases by farmers in adopting precision fertilization programs, building conservation structures and fine-tuning nutrient management practices.
Another report from Iowa Learning Farms found that farmers planted nearly 630,000 acres of cover crops in 2016, up from only 10,000 acres in 2009.