Arsenic, Mercury, and Selenium in Fish Tissue from Idaho Lakes and Reservoirs: A Statewide Assessment

(DEQ Publication, Updated June 2008: pdf 1.3 mb, 80 pages)

In 2007, DEQ obtained fish tissue samples from 50 randomly selected lakes and reservoirs across Idaho.  These samples were analyzed for arsenic, mercury, and selenium concentrations.  These results, as well as results of other miscellaneous mercury sampling, are reported in this document.

> Link to Errata.  If you downloaded this report prior to June 23, 2008, please refer to this erratum or download the updated report.

2006 River Monitoring Mercury Report

(DEQ Publication, March 2008: pdf 3.9 mb, 41 pages)

In 2006 DEQ collected fish tissue samples from 10 randomly selected river across Idaho as part of a larger water quality investigation.  Mercury concentrations were determined from these fish samples. 

Brownlee Reservoir Mercury TMDL Water Column Study: Results and Field Summary

(DEQ Publication, March 2008: pdf 194 kb, 7 pages)

This study collected mercury samples at a number of random locations in the reservoir for seven months.  Those random samples were than aggregated into a mean mercury concentration for that sampling event. 

Salmon Falls Creek Subbasin Assessment and Total Maximum Daily Loads

(DEQ Publication, December 2007)

Mercury is one of the pollutants in this TMDL.  It details results of mercury sampling in water, fish, and wet deposition 2005 through 2007.  Mercury sources, needed reductions, targets, and loads are covered. 

Evaluation for Total Mercury in Brownlee Reservoir, Tributary Streams, Snake River Hells Canyon TMDL, Idaho and Oregon

(DEQ Publication, June 2007: pdf 485 kb, 21 pages)

This study looked at total mercury concentrations inflow and outflows to Hells Canyon to Brownlee Reservoir and a number of tributaries in Idaho and Oregon as well as tributaries to the Snake River below Hells Canyon in Idaho and Oregon.  DEQ was attempting to target future mercury source monitoring on those systems that showed higher relative mercury concentrations. 

Orofino Creek Mercury Monitoring Program Final Report

(DEQ Publication, February 2007: pdf 250 kb, 11 pages)

Due to some free mercury that was found by a dredge miner in Orofino Creek, DEQ elected to follow-up by collecting sediment, fish, and water samples for mercury analysis, both in Orofino Creek and the Clearwater River below Orofino Creek. 

Upper Portneuf River Fish Tissue and Water Column Mercury Sampling Results

(DEQ Publication, 2007: pdf 299 kb, 9 pages)

This was a follow-up to the 2006 USGS fish tissue data that showed elevated levels of mercury in the upper Portneuf River.  DEQ resampled the USGS section and an additional site up river from Lava Hot Springs. 

2006 Mercury Snowpack Report

(DEQ Publication, June 2007: pdf 2.9 mb, 57 pages)

Findings from the 2006 field investigation of mercury contamination in snow at two different locations. 

Brownlee Reservoir Mercury TMDL Fish Tissue Study: Results and Field Summary

(DEQ Publication, June 2006: pdf 220 kb, 9 pages)

DEQ along with the Idaho Department of Fish and Game collected fish from four different sites in Brownlee Reservoir for mercury fish tissue analysis. 

Analysis of Total Mercury Concentrations in Fish Samples from Jordan Creek and Non-Jordan Creek Sites

(DEQ Publication, 2006: pdf 523 kb, 14 pages)

This study looked at mercury fish tissue concentrations in Jordan Creek from Silver City to the Oregon state line and in tributaries to Jordan Creek with historic mining and other with no mining history. 

Lake Lowell Mercury Assessment Fish Tissue Study: Results and Field Summary

(DEQ Publication, 2006: pdf 293 kb, 9 pages)

In 2006 DEQ, in cooperation with the Idaho Department of Fish and Game, collected four different fish species in three different locations for mercury analysis in Lake Lowell. 

Evaluation of Trends of Mercury Deposition in Salmon Falls Creek Reservoir, Idaho, Using Reservoir Sediment Cores

(USGS Publication, May 2006: pdf 1.1 mb, 37 pages)

This was a contract with the USGS to investigate mercury concentrations in sediment cores from Salmon Falls Reservoir.  The report also details historical mercury flux rates over time. 

2005 Snowpack Sample Collection Event

(USGS Publication, August 2005: pdf 2.1 mb, 68 pages)

Findings from the 2005 field investigation of mercury contamination in snow at three different sites. 

Implementation Guidance for the Idaho Mercury Water Quality Criteria

(DEQ Publication, April 2005: pdf 1.7 mb, 212 pages); read background on the mercury fish tissue criterion.