The recent discovery of elevated levels of mercury in the Rogue River's resident pikeminnow could, at least temporarily, regulate suction-dredge miners off 216 miles of the Rogue River and other Oregon streams beginning in 2015.

The recent discovery of elevated levels of mercury in the Rogue River's resident pikeminnow could, at least temporarily, regulate suction-dredge miners off 216 miles of the Rogue River and other Oregon streams beginning in 2015.

The Oregon Department of Environmental Quality is proposing a five-year renewal of a general water-quality permit needed by miners to suction-dredge in Oregon streams.

But the renewal specifically does not cover dredging in certain "water quality-limited" streams, a status now pending for the Rogue River after it was found to have mercury levels as much as 10 times higher than state standards for toxic pollutants.

The water quality-limited designation for the Rogue was expected to become official this summer. If so, the Rogue would not qualify for suction dredging under the general statewide water-quality permit as currently proposed for 2015, said Beth Moore, the DEQ's general permit coordinator in Portland.

Suction dredgers, however, could return to the Rogue under the proposed general permit if the DEQ's designated total limit loads for mercury specifically account for the effects of dredging, Moore said.

Dredgers who would no longer have their operations covered under the general statewide water-quality permit could pay $300 and apply for an individual permit that would be site-specific, Moore said.

A public hearing to gather comment on the permit proposal will be held at 5 p.m. Monday at the Medford library, 205 S. Central Ave. Other hearings were scheduled next week for Portland and Baker City.

The current permit expires at the end of 2014.

The permit proposal specifically regulates how much turbidity dredges can legally create as they suck up stream gravels in their search for precious metals such as gold.

Suction-dredge mining employs a floating vacuum to suck gravel from a stream bottom. Materials from the river bottom then go through a sluice to allow miners to strain out gold and other heavy metals and discharges sand, silt and other fine materials into the water.

Under the permit proposal, dredgers would be able to operate during daylight hours and in approved areas as long as their turbidity plume did not travel more than 100 yards downstream or cause a plume that covered the entire stream.

Wild salmon advocates say the process damages spawning grounds and rearing habitat. Miners have argued that current laws already protect salmon and their habitat and that the rule changes harm their industry.

The dredging season differs between rivers and follows the legal in-water work period to protect wild salmon eggs and young fry in the gravels.

Dredgers have flocked by the hundreds to Oregon after states such as California enacted moratoriums on dredging and the price of gold skyrocketed. A new state law temporarily rolls back dredging permits for 2014-15 at 850 — the level they were in 2009 before they rose to about 2,400 permits last year.

The two-year dredging cap was to allow lawmakers, state agency representatives and stakeholders to work out a comprehensive new mining law to go into effect in 2016.

Independent of the cap debate is the extension of the general water-quality permit.

If the DEQ simply rolled over the language from the current permit, the Rogue may qualify as suction-dredging territory in 2015, Moore said.

Current rules allow for an exemption if the stream segment was properly mined under the permit before the stream was listed as water-quality impaired, Moore said. The Rogue fit that criteria in 2013.

The proposed water-quality permit also would cover suction dredges powered by motors 16 horsepower and under and with nozzle diameters no bigger than 4 inches in essential salmon habitat. In areas not designated as essential salmon habitat, miners would be banned from using dredges with motors larger than 30 horsepower and suction hoses with diameters larger than 6 inches.

The water-quality limited exemption from the current proposal is for those streams not meeting standards for sediment, turbidity and toxics. Mercury fits under the toxic designation.

The proposed permit also does not cover any mining outside the wet perimeter of a stream in essential salmon habitat, designated state scenic waterways or tribal lands.

Dredgers can operate in the Kalmiopsis Wilderness Area and several other federally designated wilderness areas in 2015 under the proposed permit, provided they cause no measurable increase in turbidity.

Dredgers also would have to pay $150 a year to be covered under the water-quality permit, according to the draft language.

Reach reporter Mark Freeman at 541-776-4470, or email at