DES MOINES, Iowa (AP) — Most of the Iowa water treatment departments that work to remove nitrates from drinking water dump the chemical back into the water supply where other cities will have to remove it.
The law sets a safe level for nitrates in drinking water, but it doesn't say what must be done with nitrates after they are removed.
Des Moines Water Works officials say they dumped an estimated 13,500 pounds of nitrates back into the river last year. At the same time, they urged farmers to limit how much nitrate-rich fertilizer ran off into waterways.
Sixteen municipal water utilities in Iowa have nitrate removal systems and they spend millions of dollars each year to comply with federal drinking water standards.