DeLamar Project Area Mine Biological Monitoring

The DeLamar project area has been mined since the 1860’s. The watershed is grazed on an annual basis and has been mined since the 1860’s.  The most common mining operations were either milling operations or placer mines, and placer mining has occurred as recently as the middle 1980’s.  DeLarmar mine proper which has been in closure since 2003 with continuous reclamation, closure, and monitoring activities ongoing. As a result of historic mining activities, metal contaminants (primarily mercury) have become a concern in Jordan Creek.  Several abandoned mine sites located within the watershed contribute low pH water to Jordan Creek tributaries. Seasonal flows from these tributaries may influence water quality in Jordan Creek. The state of Idaho has indicated that the beneficial use designations for Jordan Creek should include the ability to support cold-water biota, as well as salmonid spawning and rearing.

EcoAnalysts has supported reclamation and closure, water-management activities, monitoring, and reporting since 1994. EcoAnalysts performs benthic macroinvertebrate bioassessments at monitoring stations on Jordan Creek. Jordan Creek flows through Silver City and DeLamar, Idaho, then flows into Oregon where it enters the Snake River.  Basic geology of the watershed consists of granites in the headwater regions, shifting to basalt and rhyolite in the lower reaches.  EcoAnalysts provides annual study design, field sampling, laboratory analysis of benthic macroinvertebrate community data, metric calculation, and interpretation of the metrics guided by the hypothesized response of metrics to disturbance.  The community metrics, along with physical habitat characteristics, are used to determine the overall health of the benthic macroinvertebrate community over time.