July 1, 2001
Waterworks struggle to cope
The Des Moines Register, Des Moines, IA
Here are some examples of municipal water systems around Iowa that are trying to cope with high nitrate levels.
Cedar Rapids -- Nitrates in drinking water don't violate federal standards in Cedar Rapids, but would have for most of this spring and early summer if the Cedar Rapids Water Department had to rely on only the Cedar River, said John North, water utility director.
Des Moines -- Nitrates in the Raccoon River hit a record 17.5 milligrams per liter in late May. The maximum considered safe to drink is 10. When the waterworks' nitrate filtration system is running, the cost averages $3,000 a day. It has operated 41 days in 2001, following no days in 2000.
Winterset -- Scott Wesselmann, water superintendent, said the town is closing in on 2.5 months of exceeding the drinking water standard, record stretch. The utility draws its water from Cedar Lake. It regularly notifies customers to take precautions, such as using other water sources for infants under 6 months old.
Nitrate madness: Why do Iowans tolerate waterways laden with far above normal nitrates?
Editorial of The Des Moines Register, Des Moines, IA, July 1, 2001
Iowans have gotten used to hearing about nitrates in our water.
So used to it that the Des Moines Water Works being forced to buy the world's largest nitrate-filtration system seems only logical.
So used to it that reports of nitrates inundating Iowa rivers and lakes are met with little more than a public shrug.
So used to it that even a study linking nitrates in drinking water to a high risk of bladder cancer in Iowa women didn't throw us for a loop.
We're used to it. Iowa is a border-to-border farm state. Producers have to fertilize. Nitrate runoff is unavoidable. That's been our excuse. It's still our excuse, as if, really, nothing can be done.
Which is far from true.
A lot can be done. Some things are being done. But more must be done on a broader basis, beginning with Iowans insisting that this degradation of our waterways is an absolute outrage that will no longer be tolerated.
Cleanup is critical. One reason is concern about health hazards nitrates could pose, among them blue-baby syndrome, miscarriages, non-Hodgkin's lymphoma. Another reason is the ecological damage that stretches all the way from small streams in Iowa to oxygen-starved fishing grounds in the Gulf of Mexico.
Agriculture gets too much of the blame, much of it deserved. Nitrogen fertilizer is applied -- sometimes overapplied -- to virtually every cornfield in the state every year. Nitrogen can convert to nitrates. Rains flush nitrates into waterways.
But nitrogen fertilizer application is not the only practice that contributes nitrates. It's livestock manure application. It's soil in corn-soybean rotation. It's whether that soil is tilled or not, among many other factors.
In all those ways, the agricultural enterprise contributes probably 90 percent of the nitrates in Iowa waterways, said Jerry Hatfield, laboratory director of the National Soil Tilth Laboratory at the U.S. Department of Agriculture Research Service in Ames.
Other sources of nitrates include untreated human sewage, lawn fertilizer and non-farm plant decay. Some nitrate presence is naturally occurring. Too much of a presence becomes the problem.
It's estimated that perhaps one or two milligrams per liter of nitrates in streams are naturally occurring. The federal safe drinking water standard for nitrates is a maximum 10 milligrams per liter. That's a standard that 41 public water systems in Iowa violated in 1999. The report for 2000 is due soon.
In 2001, nitrate counts in some public water systems are running high -- a record high was set in Des Moines -- partly because of heavy rains this spring.
An Iowa Department of Natural Resources survey of 60 sites on rivers in April and May found nitrate levels on average about 1.5 milligrams per liter above the usual.
Had many producers not joined a campaign last fall to delay nitrogen fertilizer application until cool weather arrived, the numbers might be even higher.
Iowans should not have to be accustomed to nitrates polluting our waters. A variety of means are available to reduce nitrates, but they eed to be universally practiced to be effective.
Clean water and agriculture can co-exist -- if Iowans insist on it.
top | Home