Story Published: Sep 6, 2008 at 3:59 PM PDT

Story Updated: Nov 21, 2008 at 1:48 AM PDT

SALEM, Ore. (AP) _ Seven pesticides have been identified in Oregon groundwater or streams that could pose a risk to human or environmental health.

State experts say that four already violate state water-quality standards or guidelines that protect aquatic life while the U.S. Environmental Protection Agency has linked three of the pesticides to cancer.

Wildlife advocates say almost all seven can hurt Pacific salmon.

But the exact threat is unclear because there are no standards for some of the pesticides.

"You can do all the monitoring in the world, but without benchmarks, it doesn't mean much," said Steve Riley, an Oregon Department of Agriculture water issues specialist.

Riley is part of a team of state experts trying to establish benchmarks that outline safe levels for each pesticide.

The guidelines will help agencies better understand and explain to the public and pesticide applicators when there's a problem.

"It's a wonderful step in the right direction," said Aimee Code with the Northwest Coalition for Alternatives to Pesticides.

For example, she said, 10 parts per billion might not mean anything on its own, but if there's a benchmark, we can say 10 parts per billion might lead to salmon decline or increase the risk of cancer.

Oregon is one of many states turning to its own experts to set benchmarks based on existing research rather than waiting for EPA standards, which haven't kept up with current pesticides.

A pesticide might be on the market for 20 or 30 years before the EPA's water division finishes reviewing its effect, said Kevin Masterson, toxics coordinator for the Oregon Department of Environmental Quality.

"The EPA and the states around the country don't have standards for the majority of current-use pesticides," Masterson said.

More standards exist for drinking water, but there still are more pesticides without standards than those with them, he said.

To bridge the gap, the EPA has encouraged states to develop benchmarks from a list of 57 pesticides of concern.

Unlike EPA standards, benchmarks don't have the enforcement power or require public review. But that also makes them less expensive and faster to implement, Masterson said.