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ProposedAntidegradation Rule

Stormwater Program Videoconference

April 23, 2013

Bill Cole,Water Quality Standards Unit

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Clean Water Act“…restore and maintain the chemical, physical, and biological integrity of the nation’s waters.”

Water quality standards• Designated beneficial uses• Criteria to support designated

beneficial uses• Antidegradation provisions

Why antidegradation?

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How does antidegradation work?

Outstanding resources(Tier 3)

High water quality(Tier 2)

Existing uses(Tier 1)

Levels of protection

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Tier 2 protection: Prohibits degrading high water quality unless necessary for important social or economic development

Assimilati ve capacity

Variability

Long-term average

Water quality standard

Conditions

Degraded

Pristine

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Tier 2 Review

Antidegradation Assessment:1. Alternative analysis2. Social/economic justification

Agency review &preliminary

determination

Public participation

Agency finaldetermination

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Why revise the rule?

Current rules outdated

Reduce potential for litigation and

permit delays

Improve consistency with Fed

rules/guidance

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Implications for stormwater program

Review trigger

Separate implementation

procedures

Scope of implementation

Activities that impact waters of the state

CWA regulatory authority exists

8(Size ≠ scale of activities)

Current scope of antidegradation implementation

Scope of implementation

Activities that impact waters of the state

CWA regulatory authority exists

Proposed rule increases scope of

implementation

9(Size ≠ scale of activities)

Scope of implementation

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Proposed rule:• Net increase in loading or other causes of

degradation• Baseline = date of most recently issued permit

Current rule, significant discharges:• Daily flow rate or• Toxic pollutant loading, with• Baseline = Jan 1, 1988

Review trigger

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Separate implementation

procedures

Widened scope of implementation requires separate procedures for:

• Individual NPDES wastewater permits; • General NPDES permits and individual

stormwater permits;• 401 certifications of individual federal

permits; and• 401 certifications of general federal permits.

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Separate implementation

procedures

Stormwater Implementation Procedures

• Agency does review during permit development • Review includes of parameters of concern

identification, an alternatives analysis, social/ economic justification, protection of ORVWs

• Individual activities covered under the permit are not subject to additional review when permit conditions are met

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Rulemaking next steps

2007 Start

Initial stakeholder meetings

Response to comments/ questions

Water quality forum direction

Proposed changes Initial

draft

More internal/ external input

Revise rule

SONAR development

“Administrative” process

Adopt

EPA approval

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ProposedAntidegradation Rule

Updates:MPCA’s Nondegradation Rulemaking Webpage

Questions/comments:Bill Cole, william.cole@state.mn.us