Nitrates in Iowa drinking water: What does it mean for you?
A study shows that nitrates in drinking water may be tied to 300 cases of cancer in Iowa each year. Olivia Sun, Des Moines Register
New research shows nitrate pollution in Iowa's drinking water may be responsible for up to 300 cases of cancer annually in the state.
Here are some takeaways from the Environmental Working Group's peer-reviewed research, which was released this month:
IOWA RANKS HIGH: Four states — Iowa, Delaware, Arizona and California — have "average levels of nitrate contamination that, at the high end … could cause more than 10 cases of cancer per 100,000 people a year," according to the nonprofit research and advocacy group, based in Washington, D.C.
THE CANCER RISKS: Environmental Working Group estimates four-fifths of the cases were occurrences of colorectal cancer, with ovarian, thyroid, kidney and bladder cancer making up the rest.
WHAT ARE NITRATES? Naturally occurring, nitrogen is essential for plant nourishment, along with phosphorus. Farming is a large source of the nutrients, which are applied to fields. An overabundance in water can lead to problems, including toxic algal blooms that befoul water supplies and are harmful to pets and people.
FEDERAL PROTECTIONS: The federal standard for nitrates in drinking water is 10 milligrams per liter, a level set in 1962 to prevent "blue baby syndrome," a potentially fatal condition that starves infants of oxygen if they ingest too much nitrate.
EVOLVING SCIENCE: This report and others drive home the need to "revisit the nitrate drinking water standard," said David Cwiertny, a University of Iowa environmental engineer. "We need to reevaluate whether the current standard is protective enough for human health."
DON'T LOSE FAITH: Despite concerns raised in the study, Cwiertny said Iowans shouldn't "lose faith in drinking water supplies. ... It should start a conversation."
It's taken six years to dredge, drain and clean Easter Lake on Des Moines' south side. It's now open for recreation like swimming and boating. Zachary Boyden-Holmes, DesMoines
PUBLIC WATER: Des Moines Water Works uses a large nitrate removal system to keep within the federal limits. The utility averages nitrate levels that are half the federal standard, an official said. All cities carefully monitor nitrate and other contaminants in their water to ensure they're meeting federal standards.
PRIVATE WELLS: Nearly 300,000 Iowans rely on private wells, and could be especially at risk of having higher nitrate levels in water. But unlike public drinking water systems in cities and towns, no state or federal law requires existing private wells to be tested for contaminants such as nitrates, bacteria and arsenic. And few Iowans test their wells.
WHAT YOU CAN DO: If you have a private well, the state provides about $30,000 annually to counties to test drinking water at no cost to homeowners.
The University of Iowa also just launched a site that provides information about nitrates and other contaminants by location.
People living in cities and towns can use their local consumer confidence report to better understand what's in their water. And if you're still concerned, reverse osmosis treatment systems can remove nitrates but can be costly.
WHAT'S IOWA DOING? Farm groups back a voluntary approach outlined in the 2013 Iowa Nutrient Reduction Strategy. It calls for reducing by 45% nitrogen and phosphorus levels that leave urban and rural areas and contribute to the Gulf of Mexico's dead zone.
Last year, lawmakers approved spending $270 million over 12 years to cut nutrients coming from cities and farms. Officials said private and public investment in nutrient reduction efforts last year reached $500 million, with increased research and conservation, among other efforts.