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Standards and Hearings Update For Permits Webinar

October 16, 2020

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Cadmium Rulemaking Hearing

Regulation Nos. 31 -38

December 9, 2019

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Cadmium Rulemaking Hearing

Regulation Nos. 31 -38

First rulemaking for a 10-Year Water Quality Roadmap parameter - statewide approach
Outreach through the roadmap workgroup
Technical Advisory Committee worked through technical topics
Replaced Colorado’s existing criteria (adopted in 2005)

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Duration	Equation*	Standard (µg/L) at Hardness (mg/L)
Duration	Equation*	25	400
Acute	cf_a*e^{(0.9151[ln(hardness)]-3.1485)}	0.82	9.15
Acute(trout)	cf_a*e^{(0.9151[ln(hardness)]-3.6236)}	0.51	5.69
Chronic	cf_c*e^{(0.7998[ln(hardness)]-4.4451)}	0.15	1.20

*Cf_a = 1.136672-[(ln(hardness))*(0.041838)]

Cf_c = 1.101672-[(ln(hardness))*(0.041838)]

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Adapting EPA’s Criteria to CO

EPA’s 2016 cadmium criteria are protective of freshwater aquatic life nationwide
On a statewide basis, it is possible to refine the standards to be protective of specific types of communities

E.g., with or without trout, warm or cold, etc.
Acute standard lowered to protect trout is more stringent than necessary to protect Colorado’s warm water aquatic life
EPA’s recommended chronic criterion is protective of all aquatic life, with no Colorado-specific adjustments needed

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Summary: Division Proposal

*at hardness >45 mg/L

Comparison of Colorado’s current standards and the division’s proposed standards, calculated at a range of hardness values.
Duration	Equation*	Standard (µg/L) at Hardness (mg/L)
Duration	Equation*	25	100	200	400
Current Colorado Cadmium Standards
Acute	cf_a*e^{(0.9151[ln(hardness)]-3.1485)}	0.82	2.74	5.01	9.15
Acute(trout)	cf_a*e^{(0.9151[ln(hardness)]-3.6236)}	0.51	1.70	3.11	5.69
Chronic	cf_c*e^{(0.7998[ln(hardness)]-4.4451)}	0.15	0.42	0.72	1.20
Proposed Colorado Cadmium Standards
Acute(warm)	cf_a*e^{(0.9789[ln(hardness)]-3.443)}	0.75	2.74	5.23	9.98
Acute(cold)	cf_a*e^{(0.9789[ln(hardness)]-3.866)}	0.49	1.79	3.43	6.54
Chronic	cf_c*e^{(0.7977[ln(hardness)]-3.909)}	0.25	0.72	1.21	2.03

*Cf_a = 1.136672-[(ln(hardness))*(0.041838)]

Cf_c = 1.101672-[(ln(hardness))*(0.041838)]

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Summary: Division Proposal

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Summary: Division Proposal

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Thank you to the TAC members!

Jessica DiToro Leonard Rice Engineers, Inc.

Dan Guth GEI Consultants, Inc.

Mindi May Colorado Parks and Wildlife

Dave Moon U.S. Environmental Protection Agency

Suzanne Pargee GEI Consultants, Inc.

Kyla Reiner Colorado Parks and Wildlife

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Triennial Review Rulemaking Hearing

Regulation No. 38

June 8-9, 2020

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Routine Review Cycle

Reg No. 31

34/35

32/36

38

33/37

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Triennial Review Elements

Review new information related to:

Use classifications
Standards to protect the uses
304(a) or other criteria (Exhibit C)
Site-specific standards
Temporary modifications
Discharger specific variances (DSVs)
Antidegradation designations
Updates to Reg. 31 in 2016

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WQCD Proposal Summary

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Cells highlighted in orange indicate outstanding issues

Welcome to the June 2020 Regulation No. 38 rulemaking hearing.
The division would like to thank everyone involved for your incredible work throughout this rulemaking hearing process. This includes division staff, parties, and of course the commission - who had to read all of the documents produced!
This has been a very unique time in which to participate in a rulemaking hearing, and we know that it has required a great deal of perseverance and adaptation.
The division sincerely appreciates the efforts of the parties for their timely sharing of data and information, and for their communication to clarify concerns and discuss potential resolution of issues. As you can see from the issues index, numerous outsanding issues have been resolved. I would also like to thank the staff from across that division - including permits, engineering, watershed, and enforcement - that provided critical information and feedback regarding the thoughtful, thorough, and appropriate proposals presented for consideration by the commisison today.
These efforts ensure that the commission has the best possible information upon which to base its actions in this rulemaking hearing.
We have a lot of issues to get through in the next two days, so let’s get right to work!

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Administrative & Informational Hearing

Regulation Nos. 31 & 85

Policy 17-1

October 12, 2020

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WQCD Recommendations - Reg 85 and 31 (and 32-38)

Propose RMH for November 2022 to consider:

adoption of lakes nutrient criteria in Reg 31 and statewide adoption of standards for certain lakes/reservoirs, as well as chlorophyll a standards for all waters
changes to Reg 85 as it relates to source investigation

Do not propose changes to the voluntary NPS provisions in Reg 85 in 2022
Consider additional outreach and education mechanisms for nutrient reductions

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WQCD Recommendations - VIP

Extend the expiration date for Policy 17-1 to December 2022
Do not propose major changes to Reg. 85 and Policy 17-1 as it relates to the VIP in 2022
Minor clarifications will be identified and suggested for changes in November 2022
Discussions regarding minor changes and update on data analysis - May or Aug WQ Roadmap Meetings 2021

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Basic Standards

Regulation Nos. 31 -38

June 14, 2021

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Review and Reconsider Methodologies

Discharger Specific Variance provisions

Conform with 2015 EPA rule revisions

Dissolved oxygen

“Adequate refuge” concept related to temperature standards in lakes and reservoirs

Site-specific standards

Longevity planning

Temporary modifications

Predicted (vs demonstrated) compliance problems
Consideration of other tools for regulatory relief
More specific elements of plan to resolve uncertainty and reporting
Consideration of bi-annual review frequency

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Next Steps

Work through the issues with the Roadmap Work Group, TACs, and all interested stakeholders
At November 2020 Reg. No. 31 Issues Formulation Hearing, present complete list of issues to be addressed in June 2021

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Questions?