Cove Hydroelectric Project Decommissioning, Idaho
Undercontract to PacifiCorp, a major northwestern power utility, Cirrus prepared an environmental report detailing all physical, biological, and socioeconomic effects of decommissioning this century-old hydroelectric project on the Bear River. Impacts on the federally listed Bonneville cutthroat trout were a central concern. The report provided the basis for FERC’s NEPA process prior to their approval of the decommissioning. The project began in 2004 and was completed in 2005. Once the environmental report was complete, Cirrus was contracted to assist PacifiCorp in acquiring the NPDES permit, Section 401 certification, stream alteration permit, and Section 404 permit necessary to complete the project.
Following project approval, Cirrus prepared and implemented a water quality monitoring plan for the demolition project. The plan, completed in 2006, was a requirement for Section 401 certification, and it provided for constant monitoring of water quality parameters of concern, provided thresholds and responsive actions, and documented the effects of dam removal.
Prior to demolition of the dam, Cirrus programmed and installed YSI 6920 Sondes above and below the project area to monitor water quality. Turbidity and dissolved oxygen were the major concerns. During the 3 months of the project, the Sondes were maintained, and data was monitored, formatted, and disseminated to relevant parties on a daily basis. When turbidity standards were exceeded, water samples were collected and delivered to a lab for testing. This required coordination with other contractors to determine when project activities would potentially lead to increased turbidity.
Cirrus also served as liaison with the Idaho Department of Environmental Quality during the project, keeping them updated on water quality measurements and project activities and consulting with them on water quality monitoring plan implementation.
The decommissioning of the dam began on August 15, 2006, and was completed October 31, 2006.
Upper Bear River TMDL, Utah
Under contract with the Utah Division of Water Quality, Cirrus completed a TMDL water quality study and remediation plan, in accordance with appropriate sections of the Clean Water Act and implementing regulations of the Environmental Protection Agency (EPA) and the State of Utah. The study and plan addressed non-point source pollutant loads and subsequent low dissolved oxygen (DO) contributing to impairment of the upper reach of the Bear River in Utah. Cirrus worked closely with representatives of the Natural Resource Conservation Service (NRCS) and local stakeholders to assess specific streambank and upslope conditions associated with livestock feeding operations and agricultural development.
A water budget for the Upper Bear River was defined for gauged and ungauged tributary streams and mainstem Bear River segments using available flow records and GIS coverage that provided spatially discrete precipitation data. The water budget provided a foundation to define loading processes in the project area. Pollutant loads to impaired segments of the Upper Bear River were defined using an assessment of existing water quality and flow data, and modeled response of DO concentration to reductions in pollutant loading.
Linkages between pollutant sources and DO concentrations in the Upper Bear River were determined with the QUAL2K river and stream water quality model. This model provided a means for determining the response of DO to changes in flow and water quality parameters as well as incorporating the influence of biological growth components (algae) and sediment-water interactions.
GIS was used to facilitate a landscape analysis identifying where the most severe pollution source-areas were located within the watershed, and which sub-basins had the greatest likelihood of contributing to impairment of water quality and biotic resources. Water quality data was integrated with various GIS data including hydrography and geomorphology, providing a means to evaluate current land use practices and future land management planning. A spatial assessment of land cover and land use management data was completed to determine pollutant loading under existing and future scenarios. Spatial data was also entered into a customized GIS application which linked flow and water quality database records to monitoring locations in the watershed. This linkage provided a means for interpreting data with respect to pollutant source locations. Finally, cartographic applications were implemented to create maps for public record, analysis reports and documentation as well as for the public website.
The final TMDL technical report included load allocations for all significant pollutant sources contributing to impaired water bodies in the project area. Load allocations accounted for future changes anticipated to occur in the project area as well as a margin of safety. A project implementation plan was included in the report and contained a prioritized list of site-specific measures, projected costs, and projected load reductions that would result following implementation of Best Management Practices (BMPs). Cirrus worked closely with the NRCS to ensure that recommended BMPs were in accordance with agency protocol to qualify for future Section 319 water quality funded projects in the Upper Bear River watershed.
The TMDL report was submitted to the Utah Division of Water Quality in March 2006. The TMDL report met all of that agency’s requirements and was submitted to the EPA in April 2006. Following internal review, the report was accepted and approved by the EPA on August 4, 2006, and is currently being implemented.