Red River Aquatic Biological Monitoring and Regulatory Support

GEI provides detailed ecological support for legal and regulatory issues. Services included environmental litigation, TMDL evaluations, CERCLA/Superfund studies, RIs, NRDAs, biological monitoring, and laboratory services.

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Key Challenges

Citizen lawsuit claiming damage to Red River: GEI scientists reviewed historic biological data on the river, conducted field sampling of fish, benthic invertebrates, and habitat. GEI discovered natural sources upstream of the mine had severely “damaged” the river and the impaired biology pattern predated significant mine activities. In two months, GEI developed a technical report summarizing observed current and historic trends, as related to the mine, and the lawsuit was dismissed before trial.

Stream is listed by the state as “impaired” on the 303(d) list for acute and chronic aluminum exceedances: GEI prepared detailed review of draft TMDL documents and proposed NMED studies; provided sampling biological data; and coordinated instream toxicity testing for water column and sediment toxicity. GEI subsequently prepared a technical report commenting on the draft TMDL documents and prepared a draft testimony for the Water Quality Commission, state commission hearing. This resulted in the withdrawal of the draft TMDLs for lack of scientific rigor.

Administration Order on Consent (AOC) signed between mine and EPA/NMED CERCLA/Superfund-type studies: GEI helped the mine owner negotiate the RI study plan with the EPA and NMED; conducted joint biological sampling for fish, benthic invertebrates, algae; tissue-metal concentrations for fish, benthic invertebrates, and aquatic plants; ambient toxicity testing of water and sediment; storm event toxicity testing; habitat/sediment characterization; source delineation; in-situ toxicity testing with native insects; report preparation and meetings with the EPA and NMED. GEI focused efforts by making sure CERCLA studies, NRDA, and ecorisk were based on comparisons to naturally impaired upstream conditions, minimizing cost to the client.

Ecological risk assessment: GEI provided support for ecorisk review of site conceptual models; conducted analysis of proposed Toxicity Reference Values (TRVs); developed site-specific TRVs for aluminum, copper, cadmium, zinc, and manganese used by EPA contractors; and provided technical review of EPA documents. GEI scientists produced technical memoranda for water quality criteria updates of aluminum, copper, cadmium, and zinc. GEI developed new water criteria for molybdenum, a metal without EPA criteria.

NRDAs and mitigation development: GEI provided primary aquatic ecological support for negotiations with Trustees on development of NRDA assessment methods, metrics, stream reaches, data usage, and final numbers for damage “debits.” GEI assisted with development of mitigation alternatives, mitigation “credits,” and final NRDAs.

Conduct aquatic biota long-term monitoring in support of mine operation: GEI developed and implemented a long-term monitoring program of fish, benthic invertebrates, and habitat in the Red River. The program provides a database for issues as they arise, including use in the TMDL, RI, NRDA, and NPDES discharge permitting, mine operation permits, and groundwater permit applications.

Laboratory Services: GEI has provided plant and soil toxicity testing to determine the feasibility of using rock pile soil for reclamation, despite the high molybdenum concentrations. Plant and soil tests utilized six plant species, each evaluated in the various soil types utilizing various planting methodologies. Additional services have included semi-annual whole effluent toxicity (WET) testing and analysis of benthic macroinvertebrate samples collected as a result of the ongoing biomonitoring.

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