CDPHE Issues New General Permit for Stormwater Discharges Associated with Construction Activities & Launches Web-Based Permitting Portal

November 8, 2018

On November 1, 2018, the Colorado Department of Public Health and Environment (CDPHE) issued a new General Permit for Stormwater Discharges Associated with Construction Activities—COR400000 (2018 General Construction Permit).  The 2018 General Construction Permit will take effect on April 1, 2019, replacing the current general permit that has been in place since 2007.   

This Legal Alert briefly summarizes some of the key aspects of the 2018 General Construction Permit, including its applicability and coverage, notable revisions, and important timing considerations.  This Alert also discusses the Colorado Environmental Online Services (CEOS) platform, which was launched by CDPHE on November 1, 2018.

Legal Alert Key Takeaways

  • CDPHE issued a new General Permit for Stormwater Discharges Associated with Construction Activities (COR400000) on November 1, 2018, which becomes effective on April 1, 2019.
  • The new permit introduces several significant changes to the requirements of the existing 2007 permit, including issues current and new permittees need to be aware of and comply with beginning April 1, 2019.
  • CDPHE also launched the Colorado Environmental Online Services (CEOS) web-based permitting platform; and starting April 1, 2019, all CDPHE permit applicants and existing permittees—not just those applying for coverage under the 2018 General Construction Permit—must use CEOS for permit actions.

2018 General Construction Permit Basics

The 2018 General Construction Permit is issued pursuant to Colorado’s Discharge Permit System (CDPS), which implements Section 402 of the Federal Clean Water Act.  Coverage is generally required for the discharge of stormwater from construction activity—including construction associated with oil and gas and mining activities, in addition to most other industries—that will disturb at least one acre of land or that is part of a common plan of development or sale that will disturb at least one acre.  Most construction projects in Colorado will be covered by the new permit, which provides a common set of terms and requirements applicable to stormwater management at covered projects.  Under certain circumstances, a project will need an individual CDPS permit, with terms tailored to the specifics of the project. 

The 2018 General Construction Permit, like the prior version, authorizes stormwater (and certain related non-stormwater) discharges associated with construction activities to waters of the State.  The chief requirements of the permit include implementation of “control measures” (formerly called “best management practices”) to minimize pollutant discharges from construction sites, development and implementation of a Stormwater Management Plan (SWMP), and regular site inspection and reporting to ensure compliance with permit terms.

Significant Changes in the 2018 General Construction Permit

The 2018 General Construction Permit introduces several significant (as well as a variety of less significant) changes to the existing requirements of the 2007 permit, including:

  • Key Change in Terminology: The new permit replaces the well-known term “Best Management Practices” (BMPs) with “Control Measures” (CMs).  CMs are defined as “[a]ny [BMPs] or other method used to prevent or reduce the discharge of pollutants to state waters,” and may include BMPs and “other methods such as the installation, operation, and maintenance of structural controls and treatment devices.”  In general, CMs must follow “good engineering, hydrologic and pollution control practices,” and be designed to control all potential pollutant sources and to prevent pollution or degradation of state waters.   According to CDPHE, CMs encompass a broader category of pollutant reduction practices that a permittee may implement to comply with the new permit.
  • Co-Permittees Approach: Owners and operators are now required to be co-permittees, whereas only one was required to obtain coverage under the 2007 permit.  CDPHE anticipates this approach will increase commitment by both owners and operators to comply with the requirements to obtain a permit and meet permit requirements.  
  • CM Requirements:  The 2018 General Construction Permit adds several requirements for specific structural and non-structural CMs.  Most significantly, these include requirements to (1) maintain pre-existing vegetation within 50 feet of receiving State waters; (2) implement temporary stabilization measures (e.g., tracking, terracing, ripping/grooving, mulching) on portions of the site where land disturbing activities have ceased for at least 14 days; and (3) perform corrective actions (beyond mere maintenance) where CMs are inadequate, which was not an express requirement under the 2007 permit.
  • SWMP Requirements: Additional SWMP requirements under the new permit include the requirement to (1) list on the SWMP the qualified stormwater manager responsible for the site; (2) provide additional details in the SWMP’s Site Description and Site Map; and (3) revise the SWMP within 72 hours of certain changes at the site.  The 2018 General Construction Permit also incorporates flexibility into the SWMP submission requirement, allowing for its completion and submission at any time prior to commencement of construction (rather than prior to applying for permit coverage, as required under the 2007 permit).
  • Site-Inspections: The initial site inspection now must occur within seven days of construction commencement.  For subsequent inspections, in most cases, permittees can choose between (1) at least one inspection every seven days; or (2) at least one inspection every 14 days, if post storm-event inspections are conducted within 24 hours after the end of any precipitation/snowmelt event that causes surface erosion.  All inspections must be performed by the qualified stormwater manager.
  • Construction Dewatering: Discharges of uncontaminated groundwater to land (i.e., construction dewatering), which were expressly allowed under the 2007 permit, are no longer covered in the 2018 General Construction Permit.  According to CDPHE, such discharges were removed because generally they will be covered by and authorized under the agency’s “Low Risk Discharge Guidance Policy, Water Quality Policy 27 – Uncontaminated Groundwater to Land” and/or a separate general permit, and therefore do not need be covered under the 2018 General Construction Permit.

The above-described and other changes to the permit are discussed in detail in the COR400000 Fact Sheet issued by CDPHE with the 2018 General Construction Permit. 


  • Current Permittees: Projects with an existing permit certification under the 2007 permit do not need to apply for coverage under the 2018 General Construction Permit, as permit coverage will be automatically transferred as of March 31, 2019 to the new permit.  However, it is important for current permittees to understand the terms of the 2018 General Construction Permit, and begin making any necessary changes now, as the new terms will control project operations on April 1, 2019, with no additional grace period for compliance.  
  • New Permittees: Between now and March 31, 2019, new permittees are required to submit applications for coverage under the 2007 permit, and any such projects will be automatically transferred to the 2018 General Construction Permit as of March 31, 2019.  It is important to keep in mind, however, that the deadline for compliance with the new permit is less than five months away.  Any new projects starting between now and the April 1 effective date should consider structuring the project’s stormwater program to also meet the terms of the new permit.   After March 31, 2019, all projects must apply for coverage under the 2018 General Construction Permit using the CEOS electronic platform discussed below.  


CEOS, which was launched by CDPHE on November 1, 2018, is a web-based platform that allows permittees to interact with CDPHE’s environmental programs via a single, secure web portal.  Users can apply and pay for required permits and upload permit-related documents like site plans and inspection reports via CEOS.  Likewise, CDPHE can use the portal to process permit-related requests and otherwise communicate with applicants and permittees.  Starting April 1, 2019, all CDPHE permit applicants and existing permittees, not just those applying for coverage under the 2018 General Construction Permit, must use CEOS for permit actions.  With respect to the 2018 General Construction Permit, this will include applying for coverage under the new permit, modifying site maps, changing site contacts, and providing notice of permit violations.  


We have seen an increase in stormwater enforcement actions in the last year in Colorado and throughout the U.S.  In some cases, the U.S. Environmental Protection Agency (EPA) has stepped in to enforce stormwater compliance in the absence of state action.  The issuance of the 2018 General Construction Permit, and its upcoming effective date, may further increase scrutiny on construction stormwater management practices for Colorado projects, particularly during the next summer construction season when the new permit is in full effect.  As such, existing projects should start preparing for compliance with the 2018 Construction General Permit now, and new projects should design their stormwater management programs with an eye towards the new permit, even if the planned start date precedes April 1, 2019.  

If you have any questions regarding the 2018 General Construction Permit—or stormwater regulation and permitting in general—please do not hesitate to contact the authors of this Legal Alert or other members of the DGS Environmental Practice Group.

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