Department of Environmental Quality Director Curt Fransen told the Senate Resources and Environment Committee Wednesday the issue arose last year.
That's when the federal Environmental Protection Agency rejected Idaho's human health criteria for nearly 90 toxic pollutants present in surface waters because it determined that the state's fish consumption estimates were too low.
Under the Clean Water Act, there's a calculation for how much toxics can be discharged in Idaho waterways by industry, municipalities and others, based on human fish consumption.
Fearing the EPA will set water quality standards that burden the economy, Fransen now wants to hire social scientists to survey people across Idaho, to find out just how much fish they consume.
"The basic notion is, there are toxic materials in water, it ends up in fish, and if people eat those fish, it ends up in people, creating a health risk," he said.
A survey would include not only tribal subsistence fishers from Idaho's Indian tribes, as well as passionate recreational anglers in Idaho who use their pastime to fill their freezers.
The issue has a long history.
In 2006, the state adopted an estimate that its residents eat about a pound of fish from Idaho waters monthly. Six years later, however, the EPA decided that wasn't high enough, Fransen said.
"They believe the fish consumption rates may be higher than the default we used," he said.
For instance, Oregon recently adopted a standard for consumption that was 10 times higher than Idaho's.
Given the EPA decision, Fransen told the Senate panel that Idaho has two options.
"Do nothing, and allow EPA to promulgate its own toxics criteria. Our second choice is, do a fish consumption study, so we have actual numbers," he said.
He anticipates that the state will find that people's fish consumption will exceed the rejected standard, but will allow the state to set toxics guidelines that aren't as stringent as what the EPA might demand.
"Other studies from around the Northwest indicating that fish consumption rates could be higher," he said.
Lawmakers on the panel said the issue is very important to businesses whose activities have an impact on Idaho's waterways. Sen. John Tippets, R-Montpelier, pointed out he works for a phosphate mining and processing company, Agrium Conda, with activities in southeastern Idaho.
"This issue has the potential to impact anyone that has the potential to impact the quality of water," Tippets said.
Others on the panel cautioned against trying to adopt a standard for fish consumption that was too low, given that human health is potentially at stake.
"I just hope that we keep in mind, that we try to keep it to a higher level, just for health purposes," said Sen. Michelle Stennett, D-Ketchum.
Legislative budget writers are still considering whether to give the agency the money.