Public Notice and Citizen Petition in Colorado Water Quality Permitting: Preparing for Opposition

How does public notice work for a Colorado discharge permit?

The applicant sees a preliminary draft first, then the public gets the draft. CDPHE's draft permit actions page describes a 14-day applicant review of preliminary drafts for new and renewed individual Colorado Discharge Permit System (CDPS) permits. The public can view those drafts, but the comment period opens later.

When the draft goes on public notice, the same page says commenters usually have 30 days, and tells them to check the exact deadline for each permit. Comments go to the permit writer listed for that permit, on the Division's comment form.

Use your 14 days well. It is the last quiet chance to fix a wrong flow, a wrong receiving water or a limit derived from bad data before anyone else reads it.

Who can challenge a final permit, and how?

The applicant or an affected or aggrieved person can request an adjudicatory hearing. According to CDPHE's permit adjudications page, hearings can challenge the terms of an issued permit, the terms of a permit modification, or the denial of an application.

The path runs in four steps:

1. A party files a hearing request with the Division under Regulation 61.7 and Regulation 21.
2. The Division decides whether to grant it.
3. If granted, the department refers the case to a hearing officer or the Office of Administrative Courts.
4. The administrative law judge issues an interim decision, which can be appealed to the CDPHE executive director, whose decision is final agency action under the Water Quality Control Act.

Regulation 61.7 sets a 30-day window after the Division's final permit decision, and the request generally has to show each issue was raised during public comment, or why it could not have been. Read the current rule text before you rely on any deadline.

Is the citizen petition a Water Quality Control Commission hearing?

No, not for an individual permit. The permit hearing runs through the Division and the Office of Administrative Courts, with the executive director deciding any appeal. The Water Quality Control Commission writes the regulations and standards those permits apply.

That matters for preparation. The person challenging your permit is arguing that the Division misapplied the rules to your facts, so your defense is the technical record behind the permit.

Can other people join a hearing?

Yes. CDPHE's adjudications page says any person or group who may be affected or aggrieved can request party status and take part as an intervenor. A request explains the person's interest, the issues they see and the general nature of their evidence.

Before the case goes to a hearing officer, intervention requests go to the Division's permits section. After that, the hearing officer or the Office of Administrative Courts sets deadlines in a case management order. CDPHE notes that intervention does not necessarily require an attorney, so expect neighbors and local groups as well as organized opponents.

When is a hearing not available?

When there was no public notice and comment, and for several kinds of action. The adjudications page lists certifications of coverage under general permits, denials of modification or termination requests, and minor permit modifications.

The page also says the Division has denied a number of requests because they lacked what Regulations 21 and 61.7 require. A hearing request is a legal filing with set content, not a letter of objection.

Where does opposition usually come from?

From whoever relies on the receiving water. In practice that means a few groups, each with its own questions:

• Downstream water users ask about the quality at their diversion and the effect on flows they rely on.
• Watershed and conservation groups often know the stream's data and history well, and they read the antidegradation analysis closely.
• Neighbors and local governments raise concerns about the site, odor, recreation or precedent for growth.

Antidegradation is a common target. CDPHE's antidegradation and permits page says every antidegradation alternative limit is subject to public comment, and the alternatives analysis under Regulation 31, Section 31.8(3)(d)(iii) asks whether a reasonable option would cause less or no degradation. If a reuse option was practical and the application did not take it seriously, someone will say so.

How do you build an application that holds up under opposition?

Make every number in it one you can defend in front of a judge. Opponents look for the assumption that helped the applicant.

1. Base flow and loading projections on real growth figures, not the low case.
2. Show your low-flow and dilution assumptions, with their data sources.
3. Evaluate alternatives honestly, including reuse and connecting to an existing system.
4. Keep the engineering report, the site application and the permit application consistent.
5. Talk to downstream users and the local government before the draft is noticed.
6. Answer each substantive comment on the record during the comment period.

Early engagement does not prevent opposition. It does mean concerns arrive while the design can still change, rather than in a hearing request. For the steps around the permit itself, see our guide to the CDPHE discharge permit process.

A note on limits: this is general education on Colorado procedures as of October 2026, not legal advice. Hearing rules, deadlines and forms change, so read the current Regulations 21 and 61 and confirm the path with CDPHE and a Colorado attorney.

Frequently asked questions

How long is the public comment period on a Colorado discharge permit?

CDPHE says commenters usually have 30 days, and each notice gives its exact deadline. Check the draft permit actions page for the date on your permit.

Can the applicant request a hearing too?

Yes. The applicant can request an adjudicatory hearing on the terms of its issued permit or on a denial, under the same rules as any other party.

We're a Colorado municipality renewing our discharge permit with tighter limits. Can a downstream group still take it to a hearing?

Yes, if it qualifies as affected or aggrieved and files a complete, timely request. Renewed individual permits go through preliminary draft review and public notice like new ones, so prepare the renewal record with the same care.

I'm developing a mountain subdivision with a new plant discharging to a small creek. Would a general permit avoid the hearing risk?

CDPHE says hearings are not available for certifications of coverage under general permits. Whether your discharge can qualify for a general permit at all is a separate question, so ask the Division early rather than designing around an assumption.

Related resources

• Antidegradation Policy in Colorado Water Permits: What It Means for New Discharge Permits
• Colorado's Wastewater Discharge Permit Rules: What Communities Need to Know
• Plan of Reuse vs. Direct Discharge: Strategic Wastewater Disposal Decisions in Colorado
• CDPHE Site Application vs. Discharge Permit Application: The Two-Step Process Colorado Developers Often Confuse Into One

Expecting opposition to your Colorado discharge permit?

We build the technical record behind the application, so the draft permit rests on numbers you can defend in comments and in a hearing. Talk with an engineer about your permit.

We specialize in:

• CDPS discharge permit applications
• Receiving water and antidegradation analysis
• Wastewater alternatives and reuse evaluations
• Public comment technical responses
• Wastewater treatment plant design
• Site civil engineering for land development

Modern Engineering Solutions, McKinney, Texas. Contact: (214) 833-6748 or mod-eng.com