Issues to Be Decided:

1. Issues to Be Decided: Appropriate Mo Standards to Protect Domestic Water Supply, Irrigated Agriculture, and Livestock Watering in Segments 13, 14, and 15 of Blue River, and Segment 8 of Upper Colorado River

3. Ray LazukClimax Mine Environmental Manager • Climax water treatment goal for decades has been to protect TenmileCreek. • Investments in water treatment include $23MM plant in 2007 and new $200MM facility. • No previous stakeholder concerns that permitted effluent wasn’t protecting water supply uses. • Climax has no intention of increasing levels of molybdenum in its discharge. • Water supply classification on Segment 13 and adoption of molybdenum standards without considering recent science are unjustified - puts Climax in a position of regulatory noncompliance.

4. F. J. Murray, Ph.D.Water Supply Mo Standard • Current water supply standard of 210 ug/L based on 1990 FungweStudy. • Proposed water supply standard of approximately 4000 ug/L based on 2013 90-Day Dietary Study. • Used same uncertainty factors as were used to develop 210 ug/L standard. • The new study reduces uncertainty.  It does not increase it.

5. Carolyn L. Fordham, Ph.D.Cattle Mo Standard • The Division’s proposed Mo Std of 160 ug/L contained an error. • Equation produces a range of values depending on parameters used. • The EPA range is between 236 and 572 ug/L. • No consensus on what DIR and WIR should be for Colorado cattle. • 300 ug/L is conservative and is at the low end of the safe range. • Recommend Commission adopt a Basin-Specific standard of 300 ug/L for Regulation 33 and 37.

6. Values of Mo WQS

7. Steve Maly, P.E. • No alluvial wells or direct surface diversions in Segment 13 for domestic water supply. • There are no diversions by Climax in Segment 13 for domestic use. • No domestic water supply use of Clinton Reservoir. • No domestic water supply use associated with Eagle Park Reservoir. • Tenmile Creek Pipeline – no domestic use in decree. De minimus return flow into Segment 14.

8. Bryce RomigSegment 13 Tenmile Creek I-70 Copper Mountain Highway 91 Climax Parshall Flume Segment 13 • Water decreed for water supply does not constitute water supply use on a segment • The permit program implements protection of downstream uses • No domestic water supply use • Therefore no Water Supply use classification • No water supply molybdenum standard • No irrigated agriculture or livestock watering • Therefore no agriculture molybdenum standard • Footnote 16, Table III, Regulation 31

9. Segment 14 Tenmile Creek • Used and classified for Water Supply • Compliance issue with molybdenum standard of 210 µg/L • Temporary Modification – "current conditions"Underlying Standard = 210 µg/L, Expiration 12/31/16 • No irrigated agriculture or livestock watering • Therefore no agriculture molybdenum standard • Per Footnote 16, Table III, Regulation 31 • Revisit scientific basis for human health based molybdenum standard in the 2016 Basic Standards rulemaking Town of Frisco Segment 14 Vail Pass Segment 14 West Tenmile Creek Copper Mountain

10. Segment 15 Clinton Creek • No water supply use • No water supply molybdenum standard • No irrigated agriculture or livestock watering • Therefore no agriculture molybdenum standard • Per Footnote 16, Table III, Regulation 31 Climax Mine Segment 15 Clinton Creek Clinton Gulch Reservoir Highway 91