CDPHE Site Application vs. Discharge Permit Application: The Two-Step Process Colorado Developers Often Confuse Into One

What does a CDPHE site application decide?

It decides whether this facility belongs at this site, serving this area. Regulation 22 (5 CCR 1002-22) covers domestic wastewater treatment works with a design capacity over 2,000 gallons per day: plants, lift stations and certain interceptors (§22.1(2)). The Water Quality Control Division reviews each site application and its engineering report against the factors in §22.5.

Those factors include:

• the legally responsible person and the legal description of the site;
• whether treating the waste in an existing or area-wide facility is feasible;
• nearby water supply intakes, floodplains and other natural hazards;
• public health and safety at the proposed location;
• whether the treatment process can meet the effluent limits or water quality planning targets;
• local comment and the regional water quality management plan, often called the 208 plan.

Approval is narrow. Under §22.4(7) it means only that the application meets Regulation 22, not that the site is the best one. Under §22.4(8) you still need every other federal, state and local approval.

What goes into the site application engineering report?

The report is the end of the planning process, not a design report. Section 22.6(1)(b) says a design report is not needed for site approval, then lists what the engineering report must cover at a minimum:

• the service area, existing and projected population, phasing, and flow and loading projections;
• the proposed site, alternative sites and treatment alternatives;
• water quality planning targets developed with the Division;
• opportunities to consolidate with other treatment works;
• floodplain and natural hazard evidence and preliminary geotechnical information;
• site control, institutional and financial arrangements, and an implementation schedule;
• the owner's ability to operate the plant, including an emergency operations plan.

For a phased project, size the report to the full build-out you can support. The flow projections and phasing are part of what the Division approves, and a later capacity change goes back through the local agencies (§22.4(14)).

Water quality planning targets carry the limits into the site step. Section 22.2(35) defines them as the Division's planning limits for the alternatives and the selected plant. They can come from preliminary effluent limitations (PELs), existing permits or water quality assessments, and they reflect capacity, discharge location, technology-based limits and the standards for the receiving water.

Who reviews the site application before CDPHE does?

Local agencies review it first, and they get 60 days. Under §22.6(2), the applicant sends the application and report to the management agency, the county if the site is unincorporated, any city or town within three miles, the local health authority and the 208 planning agency. After 60 days, the applicant may submit to the Division without a missing comment.

Two more timing rules matter:

• A sign must stand on the property for 15 continuous days before the application goes to the Division (§22.6(3)).
• The Division's goal is a final decision within 60 days of receiving the application and fee (§22.4(5)).

Approval does not last forever. If construction has not started by the date in the approval letter, 18 months unless the Division sets another date, the approval expires (§22.4(9)).

Where does design approval fit between the two?

Design approval comes after site approval and before any construction. For a treatment plant, §22.13 sets a two-step review: a process design report (PDR) for a Division decision, then final plans and specifications or a self-certification by the engineer. A professional engineer registered in Colorado must stamp both.

The final design must match the approved site application, the PDR approval letter and the Division's current design criteria, covered in our post on CDPHE domestic wastewater design criteria. Site clearing, dewatering and access roads can start after site approval, but not work that is part of the treatment works itself.

What does the discharge permit application decide?

It sets the terms the plant must meet once it runs. Regulation 61, the Colorado Discharge Permit System, covers the effluent limits, monitoring, reporting and other conditions. Under §61.4(1)(c), you apply for a new individual permit at least 180 days before the discharge begins.

The two steps connect. Section 61.4(1)(c) also says a domestic plant's permit application may be preceded by its site application. Under §61.8(7)(b), any condition in the site location approval can become a permit condition if the permit names it. Our post on the CDPHE discharge permit process covers the permit side in detail.

Can the discharge permit come before site approval?

In some cases, yes, since a 2020 rule change. In the rulemaking effective June 14, 2020, the Commission recast PELs as water quality planning targets and changed §61.4(1) so a new permittee can elect to get the permit first and site approval second. The permit then serves as the planning target for the site application.

The Commission's statement of basis limits that path. It does not fit where the site information is needed first to set the permit conditions, which the Division expects for some groundwater permits. Confirm the order with the Division early.

Where do outfall and land application choices belong?

Settle the disposal method during the site step. The discharge location drives the planning targets, the receiving stream review and the permit type. Moving an outfall sewer away from the approved site location needs the site application procedures again (§22.6(1)).

There is one narrow exception. Moving the discharge point within an approved site location and the same stream segment may not need new site approval, as the Division determines. Systems of 2,000 gallons per day or less fall outside Regulation 22 and are permitted locally as on-site systems under Regulation 43.

How do you sequence the two applications without rework?

Lock the site, flows and disposal method before either application is written. Use this check. If any answer is no, fix that first.

1. Is the design capacity over 2,000 gallons per day, so Regulation 22 applies?
2. Do you have water quality planning targets, or a request in with the Division?
3. Does the service area fit the regional water quality management plan?
4. Have you looked at consolidation with an existing plant?
5. Are build-out flows and phasing in the engineering report?
6. Is the outfall or land application approach settled?
7. Have the county, nearby town, health authority and 208 agency had their 60 days?
8. Does your schedule hold the 180-day permit lead time and the 18-month construction window?

Then ask your engineer three things: which order the Division expects for this site, what the planning targets assume, and what would force a site approval amendment later.

This article is general education on Colorado rules as read in October 2026, including Regulation 22 as effective June 14, 2020. Procedures and forms change, and the Division decides each application, so confirm current requirements for your project.

Frequently asked questions

Can the site application and discharge permit application be filed at the same time?

Regulation 61 says a domestic plant's permit application may be preceded by its site application, and since 2020 a new permittee may elect to get the permit first in some cases. The rules do not bar overlap, but each step still needs its own information. Confirm the order with the Division.

How long does a CDPHE site location approval last?

Until the construction start date in the approval letter, which is 18 months from approval unless the Division sets another date (§22.4(9)). If there are no significant changes, an extension can be requested by letter.

I'm a developer planning a phased mountain resort in Colorado with its own package plant. Do I need a new site application for every phase?

Not always. The engineering report must address staging, phasing and flow projections (§22.6(1)(b)(i)), so the application can cover build-out. A capacity increase beyond what the approval covers needs a new site application (§22.7), and a capacity change before design or construction is finished goes back to the local review agencies (§22.4(14)). Confirm with the Division what your approval letter covers.

I'm the civil engineer on a Front Range subdivision and the owner wants to start grading the plant site. What can happen before design approval?

After site location approval, the owner may do site clearing, dewatering and access roads with its own forces or under a contract with no treatment works elements (§22.13(1)). Excavation, pipe galleries and equipment purchase wait for PDR approval and acceptance of the final design.

Related resources

• Colorado's Wastewater Discharge Permit Rules: What Communities Need to Know
• Colorado Package Wastewater Treatment Plant Permitting: CDPHE Approval, Operations, and Compliance
• Colorado Water Quality Control Commission Basin Specific Standards: Why the Same Discharge Limit Does Not Apply Statewide
• Plan of Reuse vs. Direct Discharge: Strategic Wastewater Disposal Decisions in Colorado

Sequencing CDPHE site and discharge approvals for a Colorado plant?

We map the site location, design and permit steps for your project, then build the engineering report so each step has what it needs.

We specialize in:

• CDPHE site location applications and engineering reports
• Process design reports and final design
• Discharge permit applications
• Package wastewater treatment plant design
• Lift station and collection system design
• Construction administration

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