Studies have linked nitrate exposure below 10 ppm to increased risk of colorectal cancer, bladder cancer, thyroid disease and other health problems. The EPA cited new science on cancer and birth defects in the 2010 drinking water standards review as well as in its 2017 scoping review. Whether it’s drinking water standards or water quality standards, most of that is done at the federal level,” Stoner said. Lab technician Bill Blubaugh collected water samples from the Raccoon River for testing by Central Iowa Water Works in Des Moines, Iowa. The Iowa Water Quality Information System did not see proposed funding from the state pass this legislative session, leading the program to rely on county and city funds.