U.S. Environmental Protection Agency, Region 6, under subcontract to Weston Solutions, Inc.
- Surface water, groundwater, and sediment sample collection for total and dissolved metals
- Use of multi-parameter water quality instruments
- Multiple sampling areas and potential exposure areas
- Involvement with local, state, and federal emergency response agencies
The U.S. Environmental Protection Agency (EPA) was conducting an investigation of the Gold King Mine near Silverton, Colorado in August 2015 to assess the on-going water releases and treatment options for the inactive mine. During excavation conducted as part of the investigation on August 5, 2015, pressurized water began leaking above the mine tunnel. Approximately three million gallons of heavy metal-laden wastewater spilled into Cement Creek, a tributary to the Animas River. Colorado and New Mexico state officials declared a state of emergency and upheld restrictions on residential well water use and recreational river use. Farmers refrained from using irrigation ditches for livestock and agricultural sustainment.
On August 8th Avatar scientists mobilized to the disaster area as a subcontractor to WESTON under their Region 6 START (Superfund Technical Assessment and Response Team) contract. Once onsite, Avatar joined teams of technicians which collected surface water and sediment samples, assessed water quality, and went door-to-door to collect residential well water samples, all performed in accordance with Weston’s approved SOPs and in coordination with EPA Region 6.
River monitoring efforts included the daily collection and analysis of surface water and sediment samples at nine locations along the Animas and San Juan Rivers. These nine locations were strategically located upstream of water intakes which support the towns of Aztec, Farmington, the Lower Valley Water Users Association, Morning Star Water Supply System and the North Star Water Users Association. Surface water samples collected were analyzed for total dissolved and suspended solids, total metals, pH, alkalinity, and anions. In addition, in-situ measurements were recorded and include pH, ORB, conductivity, turbidity, and dissolved oxygen. Sample site photographs looking upstream and downstream were taken daily to document river conditions for each sample.
Residents within reasonable distances from the impacted Animas River also had their private wells sampled for dissolved and total metals, hardness, major anions and cations. Water quality data was collected at sample locations using multi-parameter meters. Data including temperature, pH, dissolved oxygen, oxidation/reduction potential, specific conductance and turbidity were recorded in field log books along with sample ID, location coordinates, and site conditions. After each well was sampled, a photo was taken of the field log and sent, via text message, back to the command post where a data manager loaded the information into the EPA Scribe database, an accelerated data integration software. At the end of every shift, Avatar processed samples for laboratory shipment and reported all findings back to EPA and Weston’s Incident Commander.