The Environmental Protection Agency (EPA) added seven Iowa water segments to its impaired US waters list, saying they are all polluted with nitrate, possibly stemming from nitrogen fertilizer runoff.
The EPA added these seven water segments to the list of impaired waters on 12 November, determining each was laden with nitrate pollution. The EPA invoked water restoration plans in partnership with the Iowa Department of Natural Resources (DNR).
This is in addition to the 712 water segments in Iowa that are already on the state's list of water segments that need a restoration plan under the Clean Water Act, according to the EPA.
The largest contributor to nitrate pollution is manure and commercial fertilizer that runs off farm fields, according Pam Taylor, director of the Iowa Sierra Club Chapter. Nearly 85pc of land in Iowa is farmland, using nearly 149 lbs of nitrogen fertilizer per acre annually,the US Department of Agriculture said.
The Iowa DNR initially submitted a list of water segments that need restoration attention on 9 May, which was only partially approved by the EPA. This triggered the agency to place these additional water segments on public notice until 12 December. Once that date has passed, the EPA can implement a restoration plan in partnership with the Iowa DNR.
The Iowa Chapter of the Sierra Club is in support of the EPA's decision. It alleged that the DNR purposefully used an incorrect method to determine nitrate pollution, which may have enabled the DNR to excuse certain water segments from the list of impaired bodies.
Separately, a letter was also sent to the EPA on 16 April by several Iowa agencies requesting the EPA apply its emergency powers to address nitrate groundwater contamination in northeastern Iowa.
