Water utility to expand nitrate removal measures

Des Moines, Iowa—Des Moines Water Works (DMWW), the water utility that last year filed a lawsuit against three neighboring counties for polluting the Raccoon and Des Moines Rivers with high levels of nitrates from farm runoff (GM Jan. 19, 2015), announced that it will begin later this summer to route the waste water from its nitrate removal system to the city’s sanitary sewer system for further treatment instead of pumping it back into the Raccoon River downstream of Des Moines. The $1.3 million project, which involves construction of an underground pipeline beneath the Raccoon River to the sewer treatment facility, will end DMWW’s procedure of dumping nitrate-laden water back into the river, a disposal method the utility was criticized for but has used for at least 20 years under a permit approved by the Iowa Department of Natural Resources. The board overseeing DMWW also recently approved a five-year capital improvements plan that designates $241 million in system maintenance and expansion, roughly $70 million of which is designated for nitrate removal measures. The funds will reportedly be used to expand DMWW’s current denitrification facility instead of spending $176 million to build a new one. DMWW’s lawsuit against the boards of supervisors for Sac, Buena Vista, and Calhoun counties is ongoing, and charges that the elevated nitrate levels in the rivers are caused by the “extensive system of drainage infrastructure,” or field tiles, used on fertilized farmland in these districts, which “quickly transport nitrate by groundwater to the nearest waterway, bypassing natural absorption and de-nitrification processes that would otherwise protect the watersheds.” The suit has been criticized by opponents as an attack on agriculture, and represents a pivotal test for the Clean Water Act’s provision that exempts agriculture as a non-point source polluter. Both state and national organizations have weighed in on the case (GM March 16, 2015), including the Agribusiness Association of Iowa, numerous state crop and livestock associations, and The Fertilizer Institute (TFI).