DES MOINES, Iowa (AP) — A Des Moines area water utility says construction and testing are complete on a $2.5 million system that will enable it to treat nitrate removed during it purification process rather than dump the material back into the Raccoon River. Des Moines Water Works announced Monday it had finished work on a pump station and pipe that will carry nitrate from a facility to the Des Moines wastewater center, where it will be treated and turned into a material that can be applied to farms.

For more than 25 years, Des Moines Water Works has removed nitrates from the Raccoon and Des Moines rivers as it purifies drinking water, but then dumped the chemical back into the Raccoon. The nitrate comes mainly from animal waste and chemical fertilizers that drain into the rivers from farmland. Des Moines Water Works provides drinking water for about 500,000 people.