'What they put on the fields contaminates our water'
Iowa's pollution problem

Decades of adding fertilisers and manure to drive Iowa’s crop production has loaded the land with nutrients it can’t hold on to – and they’re ending up in the water supply

Brent Bierbaum climbs into the ditch running alongside one of his corn fields and dips a nitrate testing strip into the water. He checks the strip: the reading is somewhere between 10 and 20 parts per million. It confirms the water running off this field contains nitrates at levels that would be unsafe, and illegal, in drinking water.

Brent, whose family have been farming in this part of south-west Iowa for five generations, never used to worry about the runoff from his fields. On a hot day, cutting thistles in the corn fields, he’d go down to the creek and drink straight from the tile line – the water coming off the fields. “Cold, clean – it’s the best water around,” he says.

Things changed when his local town, Griswold, started having problems with their drinking water. Nitrates are a soluble form of nitrogen that is added to fields as synthetic fertiliser and animal manure; nitrates from Brent’s fields, and other neighbouring farms, were making their way into the town’s wells. Nitrate from farmland in Iowa is already a major contributor to the chemicals making their way to the Gulf of Mexico via the Mississippi river, suffocating marine life in the “dead zone”. Suddenly what had been a distant problem, more than a thousand miles away, was on the doorstep, threatening the health of friends and neighbours.

more...https://www.theguardian.com/environment/2019/sep/26/nitrate-problem-iowa-dont-use-the-tap-water-for-babies