Assessment of Risks to Public Health & Environment August 8, 2018

Topics Collaboration Public health – assessment of sediment recreational screening levels Environment – assessment of water quality standards Current and future monitoring activities Cement Creek

Gold King Mine Spill Gold King Mine wastewater spill occurred August 5, 2015 CDPHE staff responded from Grand Junction and Denver offices CDPHE collected 57 water, 38 sediment and 30 drinking water well samples between Aug 7-19, 2015 Cement Creek

Collaboration Partnership between CDPHE, San Juan Basin Public Health and San Juan County Public Health began in early 2016 Co-reviewed & commented on EPA’s Conceptual Monitoring Plan Address health and environmental contamination concerns Funding from EPA ($460,000) EPA 319 monies funded surface and drinking water, sediment, and verification sampling EPA 106 monies funded sondes at 3 USGS gages Formed basis for “Upper Animas Long-Term Monitoring Plan” or “LTMP” (April 4, 2016)

USGS Gages – Real-Time Data YSI* multi-parameter sondes installed in early Apr 2016 Temperature Specific conductance pH Turbidity Included O&M Initial Locations Cement Creek at Silverton (USGS 09358550) Animas River below Silverton (USGS 09359020) Animas River at Durango (USGS 09359500) USGS 09358550 @ Cement Creek * YSI Incorporated / Xylem Inc.

Training Day CDPHE staff visited Durango and Silverton on May 3, 2016 to train SJBPH and SJCPH staff Sampling equipment, coolers, and supplies delivered Training on sampling methods and multi-parameter sondes Samples collected at: CEM49 – Cement Creek at mouth Site 82 – Animas River near Silverton Site 81 – Animas River at Bakers Bridge Site 9423A – Animas River at 9th St Bridge

Alert Notifications Communicate water quality risks to the public Alert notification thresholds 1350 μs/cm spec. conductance @ Cement Cr 5.5 pH @ Animas below Silverton Subscribed to USGS WaterAlerts® to receive alerts Verification sampling Led by local health partners Verify elevated measurement & collect a water/sediment sample

Adding Superfund EPA officially added Bonita Peak Mining District to the Nat’l Priority List on Sep 9, 2016 EPA made $293,000 available for add’l water quality monitoring Revised LTMP Added “real-time” monitoring to 2 more UGSG gages plus more O&M Animas River at Silverton (USGS 09358000) Mineral Creek at Silverton (USGS 09359010) Added 2 more sampling sites Extended term of LTMP to Feb ‘18

By the Numbers… Sampling covered 2 spring runoffs (2016, 2017) and 2 low-flow periods (2016-17, 2017-18) Volume: 172 water samples 176 sediment samples 10 samples at public beaches 104 drinking water samples 0 verification samples This data now resides here: https://www.waterqualitydata.us/portal/ Bakers Bridge (Feb ‘17)

Data Usage… Develop initial and amended alert notification thresholds at 2 gages EPA technical reports ‘Analysis of Fate and Transport in the Animas and San Juan Rivers’ (EPA Webinar 2016) CDPHE sediment and water quality assessments

Sediment Assessment Assessments run by Environmental Epidemiology, Occupational Health, and Toxicology Section Evaluated the health risks related to recreational exposure at 11 sites Considerations: Potentially sensitive people, such as young children Assumed exposures could occur appx every weekend day from mid-April to mid-October Evaluated risk from exposure to 8 contaminants of concern Aluminum, Arsenic, Cobalt, Iron, Lead, Manganese, Uranium and Zinc

Sediment Assessment Recreational screening values derived for 52-day per year exposure to sediment Reasonable maximum exposure for users in Durango area Conclusion: no apparent public health risk from recreational exposure to sediments 6 monitoring locations in LTMP 5 popular swim “beaches” or launches at: Oxbow Park and Preserve 33rd St. boat launch Paradise Beach Santa Rita Park Dallabetta Park

Water Quality Assessment Water quality assessments conducted by segment Segment COSJAF03a Mainstem of the Animas River, including wetlands, from a point immediately below the confluence with Minnie Gulch to immediately above the confluence with Cement Creek Designations: Agriculture, Aquatic Life (Cold 1), Recreation E Data source(s) CDPHE site 9488 – Animas River at Silverton Finding: No exceedances of standards Silverton

Water Quality Assessment Segment COSJAF07 Mainstem of Cement Creek, including all tributaries, and wetlands, from the source to the confluence with the Animas River Designations: Agriculture, Recreation E Data Source(s) CDPHE site CEM49, EPA site CC48, RiverWatch site 323 Finding: Acute exceedances of pH (min) of 3.7 Silverton

Water Quality Assessment Segment COSJAF09 Mainstem of Mineral Creek, including wetlands, from immediately above the confluence with South Mineral Creek to the confluence with the Animas River Designations: Agriculture, Aquatic Life (Cold 2), Recreation E, Water Supply Data Source(s) CDPHE site 9447 – Mineral Creek at Silverton Finding: No exceedances of standards Silverton

Water Quality Assessment Segment COSJAF04a Mainstem of the Animas River, including wetlands, from a point immediately above the confluence with Mineral Creek to a point immediately above the confluence with Deer Park Creek Designations: Agriculture, Aquatic Life (Cold 2), Recreation E Data Source(s) CDPHE site 82, EPA site A72, RiverWatch site 3611 Finding: No exceedances of standards Silverton

Water Quality Assessment Segment COSJAF05a Mainstem of the Animas River, including wetlands, from Bakers Bridge (37.458620, -107.799194) to the Southern Ute Indian Reservation boundary Designations: Agriculture, Aquatic Life (Cold 1), Recreation E, Water Supply Data Source(s) CDPHE sites 81 and 9423A, EPA sites “Bakers Bridge”, GKM05, and “Rotary Park”, and MSI site “ROTARY” Finding: No exceedances of standards – there was a 1-in-3 year exception for Total Lead (acute) Silverton

Current Monitoring Activities EPA made $4,000,000 available to states and tribes from the Water Infrastructure for Improvement to the Nation (WIIN) Act (FFY17) ~$1,400,000 will be used for basin-wide monitoring (Sep 2018-Aug 2019) by EPA-contractor CDPHE requested $227,800 Extend sonde O&M to August 2020 (at 5 gages) Add’l well monitoring (contractual w/ SJBPH) Communication liaison

Future Monitoring Activities More WIIN Act monies (FFY18) available soon… Continuation of basin-wide monitoring by EPA contractor Extension of Communication Liaison position for 1-year Pending projects CDPHE presently active in both Monitoring and Communications workgroups Mineral Creek

Communications - Web San Juan Watershed @ EPA Highlights current activities Fact sheet https://www.epa.gov/san-juan-watershed

Colorado Department of Public Health and Environment Animas River South of Durango Animas River near Silverton Chris Theel Colorado Department of Public Health and Environment Water Quality Control Division - Environmental Data Unit christopher.theel@state.co.us 303.692.3558