Each year in North Idaho, hundreds to thousands of acres of public waterways are treated with herbicides to kill aquatic weeds, at a rate of up to 200 pounds per acre.

Meanwhile, the number of mosquito abatement districts has increased around the Northwest to address the threat of West Nile virus.

When used judiciously and by the label, pesticides can benefit society and natural resources by controlling invasive species and reducing the threat of virus-carrying mosquitoes.

However, pesticides also have the potential of leaving a chemical residue, which can be harmful to aquatic life, to crops irrigated with the tainted water, and – in some cases – humans.

New common-sense federal rules designed to address that risk are under attack in Congress. Some politicians think proposed safeguards to help keep our water clean are unnecessary.

Here’s some background: When a city, a factory or a mine needs to dispose of wastewater, it must first get permission from the government to put contaminated water into a river or a lake.

The resulting discharge permit spells out exactly how much pollution can be discharged, and requires monitoring to track the amounts. It basically ensures that people “look before they leap” when it comes to clean water.

This has been the case since 1972, when President Richard Nixon signed the Clean Water Act into law.

As with most laws, there are exceptions.

One notable loophole is the use of pesticides and herbicides in public waterways, either for the purpose of killing aquatic weeds or mosquito larvae, or indirectly through the spraying of forests to kill pests in the forest canopy or alongside irrigation ditches.

Even though these practices can leave significant chemical residue in the water, they went essentially unregulated. The only guidance was the instructions on the product’s label.

In 2009, a federal appeals court ruled that the Clean Water Act applies to pesticide use in waterways. In response, the Environmental Protection Agency proposed a national general permit for pesticides.

Under the permit, anyone treating more than 20 acres of surface water, 20 miles of irrigation ditches, or a square mile of forest canopy with pesticides can get a permit if they do certain things, such as use the least amount of pesticides necessary, analyze safe alternatives to pesticide use, and provide minimal post-application monitoring.

None of these regulations bans pesticides. Rather, they just make sure there is a watchdog standing by, so they are used safely.

These are reasonable requirements to protect public streams, rivers and lakes that may support sensitive fisheries and serve as a drinking water source for people. Nonetheless, some pesticide users are complaining, calling the new regulations burdensome.

Congress has responded with the Reducing Regulatory Burdens Act (HR 872), which has already passed the U.S. House and is now making its way through the U.S. Senate. The act would prevent the EPA from protecting our waterways from pesticide discharges under the Clean Water Act.

Without the national permit, there’s little oversight to make sure pesticides are used safely. We all need clean water, but we have a limited supply on Earth. It’s far easier – and cheaper – to prevent pollution than to clean it up.

No one likes weeds or mosquitoes. Properly applied, pesticides and herbicides are valuable tools to improve our lives. At the same time, we must balance our war on pests with our fundamental need for clean, safe water. A national pesticide general permit is one small step toward protecting our water for today and for generations to come.

A permit is a small price to pay to protect something as priceless as clean water.