Town of Milliken Regulation No. 38 Rulemaking Hearing June 8-10

Town of Milliken

June 8, 2015: Regulation #38 South Platte Basin RMH June 15, 2015: Completion of Alternate Supply evaluation report December 2018: Temporary Modification RMH December 2019: Temporary Modification RMH December 31, 2020: Proposed selenium Temporary Modification expires July 15, 2015: Completion of detailed study plan for fish survey 2016: Likely Milliken RO Discharge permit renewal 2015: Conduct initial phase of fish survey study Town of Milliken June 8, 2015: Regulation #38 South Platte Basin RMH June 15, 2015: Completion of Alternate Supply evaluation report December 2018: Temporary Modification RMH December 2019: Temporary Modification RMH July 15, 2015: Completion of detailed study plan for fish survey 2016: Likely Milliken RO Discharge permit renewal 2015: Conduct initial phase of fish survey study

Basis for Selenium Temporary Modification Demonstrated permit compliance problem Demonstrated permit compliance problem Significant uncertainty (Type A and B) Significant uncertainty (Type A and B) Ambient-based value = 12.3 µg/L Ambient-based value = 12.3 µg/L Town of Milliken

Summary of Proposal Revise the existing temporary modification for dissolved selenium from a numeric value of 13.1 µg/L to a numeric value of 12.3 µg/L. Revise the existing temporary modification for dissolved selenium from a numeric value of 13.1 µg/L to a numeric value of 12.3 µg/L. Extend the temporary modification from December 31, 2015 through December 31, 2020 Extend the temporary modification from December 31, 2015 through December 31, 2020 Town of Milliken