Colorado Construction Stormwater Requirements | ComplianceGO

Colorado Construction Stormwater Requirements

Download the Colorado Construction Stormwater Inspection Form.

The Colorado CGP is dated 1 April 2019 and is administered by the Colorado Department of Public Health & Environment (CDPHE).

Permit Requirements:

  • Construction NOI (Notice of Intent) Permits can be filed online through the Colorado Environmental Online System (CEOS)
  • An NOI Permit is required for most construction sites:
    • All Construction sites that will disturb one acre or more
    • Construction sites that are part of a common plan of development
    • Stormwater discharges as designated by the CDPHE
  • Exceptions:
    • The jurisdictions of Durango, Golden, and Lakewood have qualifying local programs, meaning that small construction sites (under 5 acres), must obtain coverage locally instead of from the CDPHE Water Quality Control Division.
  • The CDPHE website references fees for construction stormwater permits, but does not provide information on the exact amounts.

Plan Requirements:

  • A Stormwater Management Plan (SWMP) is required on all construction projects that require a permit. 
  • The CDPHE does not have a specific SWMP template, but they do provide a SWMP content checklist to ensure everything you need is in the plan.
  • The SWMP must identify a Qualified Stormwater Manager for the project.

Inspector Requirements:

  • Inspections must be performed by a Qualified Stormwater Manager.
  • A Qualified Stormwater Manager doesn’t need any specific qualifications, but must be “knowledgeable in the principles and practices of erosion and sediment control and pollution prevention, and with the skills to assess conditions at construction sites that could impact stormwater quality and to assess the effectiveness of stormwater controls implemented to meet the requirements of this permit”.

Inspection Requirements:

  • Site Inspection Frequency:
    • Once every 7 days OR
    • Once every 14 days AND within 24 hours after the end of any precipitation or snowmelt that causes surface erosion.
      • Post-storm inspections can be used to fulfil the 14-day requirement
  • If site conditions make it impractical to inspect on the normal schedule, you can submit an alternate schedule to CDPHE for approval.
  • For sites that discharge to Outstanding Waters – you must inspect once every 7 days.
  • Reduced Inspection Frequencies:
    • If you are using the 14 day schedule, you may delay post-weather event inspections up to within 72 hours if there will be no construction activities after the weather event.
    • Completed portions of the site that are awaiting vegetation establishment may be inspected once every 30 days instead, as long as no construction activities will occur in those areas.
    • When snow cover exists over the site and there is no risk of melting and erosion, inspections may be temporarily halted until melting conditions begin.

Signature Requirements:

  • Colorado signatory requirements follow the EPA guidelines. 
  • Permits and plans must be certified and signed by:
    • In the case of a corporation, by a principal executive officer of at least the level of vice president, or a manager assigned or delegated in accordance with corporate procedures, with such delegation submitted in writing if required by the Department, who is responsible for manufacturing, production, or operating facilities and is authorized to make management decisions which govern the operation of the regulated facility;
    • In the case of a partnership, by a general partner;
    • In the case of a sole proprietorship, by the proprietor;
    • In the case of a municipal, state, federal, or other public entity by either a principal executive officer, or ranking elected official;
    • or by a duly authorized (in writing submitted to ADEM) representative of that person.
  • Inspections and other documents not submitted to CDPHE do not have a requirement for who can sign.
  • Documents submitted to CDPHE (such as permits and plans) must be certified using the following certification statement:
    • “I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.”
  • Documents NOT submitted to the CDPHE (such as inspections) must be certified using the following certification statement:
    • “I verify that, to the best of my knowledge and belief, all corrective action and maintenance items identified during the inspection are complete, and the site is currently in compliance with the permit.”

24 Hour Reporting Requirements:

  • Colorado requires oral reporting of the following circumstances with 24 hours of you becoming aware of the problem, and the submission of a written report within 5 days:
    • Anything which may endanger health or the environment
    • Any unanticipated bypass which exceeds effluent limitations
    • Any upset which causes the exceedance of effluent limitations
    • Daily maximum violations, including toxic pollutants, hazardous substances, or pollutants identified to control toxic and hazardous substances

Stabilization and Termination Requirements:

  • Temporary stabilization must be implemented on any portion of the site that has temporarily ceased operations for more than 14 calendar days.
    • The 14 day rule may be exceeded if the “function of the specific area of the site requires it to remain disturbed”, or if the terrain or climate prevent stabilization.
  • Final stabilization is required for all construction sites and is reached when the entire area is uniformly vegetated with a plant density of at least 70 percent of pre-disturbance levels or other equivalent stabilization methods are implemented.
  • All temporary BMPs must be removed once the site has been stabilized.
  • The Notice of Termination (NOT) can only be submitted under the following conditions:
    • Final stabilization has been achieved on all portions of the site;
    • Another operator has assumed control over the entire site and they have an NOI;
    • Coverage under an individual permit or alternative permit is obtained (very unusual).

This is a quick summary of the Construction Stormwater requirements in Colorado. To be sure you are meeting ALL the requirements and to lower your risk of audits, fines, stop-work orders, or jail time, you should thoroughly familiarize yourself with the Colorado Construction General Permit.

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