Colorado Construction Storm Water Permit (6-CO-b)
Construction Storm Water Permit Process
6-CO-b.1 — Schedule Pre-application Conference and Site Inspection
The Water Quality Control Division (WQCD ) encourages the developer to schedule a pre-application conference and site inspection with the WQCD, where the WQCD evaluates the proposed discharges and identifies needed background information required for a complete application. 5 CCR 1002-61.5(1)(b).
6-CO-b.2 — Will the Construction Activity Disturb Less Than 5 Acres of Land?
The WCQD may waive the General Permit requirement for construction activities that disturb more than one acre, but less than 5 acres of land, if the developer meets certain conditions at the site pursuant to 5 CCR 1002-61.3(2)(f)(ii)(B).
6-CO-b.3 to 6-CO-b.4 — Does the Local Municipality Have a Qualifying Local Program?
The WCQD may designate a local municipality’s storm water quality control program as a Qualifying Local Program. The WCQD will only designate a local municipal program with requirements that are at least as strict as the General Permit. In cases where the local municipality has a Qualifying Program, the local municipality is responsible for notifying the developer that coverage under the CPDS General Permit is not required. 5 CCR 1002-61.8(12).
6-CO-b.5 to 6-CO-b.7 – Does the Construction Activity Have an R-Factor of Less Than 5 During the Construction Period?
An R-Factor Waiver allows a site owner or operator to apply for a waiver from the General Permit, if the R-Factor (a method for calculating erosion potential based on the length of the project and time of year) is less than five (5) during the period of construction. Developers should consult the CDPHE Construction Storm Water Forms R-Factor Waiver Application for instructions on using the Colorado-approved method to calculate R-Factor Waiver and applying for the waiver. Generally, only projects that will stabilize within a month or two after the start of construction will qualify for an R-Factor Waiver. 5 CCR 1002-61.3(2)(f)(ii)(B).
6-CO-b.8 — Develop Storm Water Management Plan (SWMP)
The General Permit requires dischargers to control and eliminate the sources of pollutants in storm water through the development of a Storm Water Management Plan (SWMP). SWMPs help identify possible pollutant sources that may contribute to storm water pollution and identify Best Management Practices (BMPs) that will reduce or eliminate water quality impacts. The WQCD has developed a SWMP Preparation Guidance document to assist developers in preparing the SWMP. The SWMP must:
- Identify all potential sources of pollution, which may reasonably be expected to affect storm water quality associated with construction activities from the facility;
- Describe the BMPs the project will use to reduce the pollutants in the storm water discharge associated with the construction activities and ensure the BMPs are selected and described in accordance with good engineering practices; and
- Be properly prepared, and updated in accordance with Part I.D.5.c of the Application for General Permit for Storm Water Discharges Associated with Construction Activity to ensure compliance with the terms and conditions of the General Permit. Specifically, the SWMP must include a site description, site map, storm water management controls, final stabilization and long-term storm water management, and inspection and maintenance procedures that comply with Part I.C of the General Permit.SWMP Preparation Guidance, at p. 4
Unless otherwise approved by the WQCD, an owner or operator must retain a copy of the SWMP on site. SWMP Preparation Guidance, at p. 4.
6-CO-b.9 — Application for Construction Storm Water Permit and Associated Documents
The owner, operator, developer, contractor, or other designated agent of the facility subject to the CDPS General Permit must submit an Application for General Permit for Storm Water Discharges Associated with Construction Activity to the WQCD. The developer must also submit, along with the application, a signed certification that the owner or operator has completed the SWMP at least 10 days prior to the anticipated construction start date. General Permit, at p.4. The applicant (developer) does not have to submit the SWMP, unless the WQCD requests a copy of the plan. 5 CCR 1002-61.4(3).
6-CO-b.10 to 6-CO-b.11 — Review Application Materials for Completeness
The WQCD reviews the application for completeness. The WQCD will notify the applicant (developer) after receipt of the application whether the application is complete. If the application is incomplete, the WQCD may request additional information. The WQCD will not begin to process the application until they receive all of the required information. The WQCD has up to ten calendar days after receipt of the application materials to request data and/or deny the authorization for any particular discharge. Upon receipt of addition information, the WQCD has an additional ten calendar days to issue or deny authorization for the particular discharge.
6-CO-b.12 — Does the WQCD Require an Individual Permit for the Discharge?
If after the WQCD evaluates the application, the WQCD determines that the applicant requires a CDPHE Industrial Individual Wastewater Discharge Permit Application, the WQCD will notify the applicant of the decision to deny certification for a General Permit and require the applicant to apply and receive an Individual Permit.5 CCR 1002-61.9(2)(b)(iii). At the WQCD's discretion, the applicant (developer) may receive temporary coverage under the General Permit, while the WQCD processes the Individual Permit application. General Permit, at p.5. When considering whether the project requires an Individual Permit instead of a General Permit, the WQCD evaluates:
- The quality of the receiving waters (i.e., presence of downstream drinking water intakes or high quality fishery, or for preservation of high quality water);
- The size of the construction site;
- Evidence of noncompliance under a previous permit for operation;
- The use of chemicals within the storm water system; or
- Discharges of pollutants of concern to waters for which there is an established Total Maximum Daily Load (TMDL).
Additionally, the WQCD may require a CDPHE Industrial Individual Wastewater Discharge Permit Application when storm water discharge may contribute to a violation of a water quality standard. 5 CCR 1002-61.9(2)(b)(iii)(A).
6-CO-b.13— Individual Construction Storm Water Permit
The WQCD develops an Individual Construction Storm Water Permit for the storm water discharge and issues it to the developer.
6-CO-b.14 — General Construction Storm Water Permit
The WQCD develops a General Construction Storm Water Permit for the storm water discharge and issues it to the developer. The WQCD will generally issue a General Discharge Permit for a period no longer than ten (10) years. 5 CCR 1002-61.1(4). General Permits must comply with the Discharge Permit System Regulations and the terms and conditions of the issued permit.
6-CO-b.15 — Appeal Decision (If Applicable)
Any party directly affected by a final order or determination of the WQCD may apply for a hearing with respect to such order or determination. Colorado – 25-8-403, Administrative Considerations. An “application affected or aggrieved by the WQCD’s final determination may demand an adjudicatory hearing within thirty (30) days of the issuance of the final permit determination.” 5 CCR 1002-61.7(a).
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Colorado Department of Public Health and Environment
Construction Storm Water Discharge Permitting Contact
Colorado Department of Public Health and Environment
Construction Permits Contact and Stormwater Construction Specialist