Colorado Department of Public Health and Environment (CDPHE) has implemented a program practice in which nearly all No Exposure Certifications (NECs) are set to expire on February 10, 2026, regardless of when they were issued. CDPHE Water Quality Control Commission (WQCC) Regulation Number 61 gives the Division discretionary authority to issue NEC stormwater permit exclusions for terms shorter than five years, even though federal rules require recertification every five years. Colorado facilities operating under an NEC should plan around this statewide synchronized renewal cycle.
Your NEC checklist submittal deadline may be sooner than expected and now is a good time to review your facility for stormwater program compliance. If your facility no longer meets “no exposure” criteria, Trinity is here to support stormwater permitting, including recommending best management practices (BMPs) to implement for permit compliance and preparing a compliant Stormwater Management Plan (SWMP).
What is NEC and Why it Matters
Facilities may apply for NEC if all industrial materials and activities are kept under storm-resistant cover such that they are prevented from exposure to rain, snow, snowmelt, or runoff. Most industrial facilities are required to obtain stormwater permit coverage if they do not fulfill all conditions of NEC exclusion. The COR900000 Industrial Stormwater General Permit for Non‑Extractive Industries (General Permit) covers stormwater discharges from various industry sectors, and includes requirements for inspections, monitoring, reporting, and the development of an SWMP.
To avoid increased compliance and monitoring requirements associated with the General Permit, Trinity recommends evaluating your facility’s NEC compliance status today. A proactive review of site practices, storage areas, containers, and housekeeping can help ensure your site continues to meet the “no exposure” definition.
Common Pitfalls that Jeopardize “No Exposure”
CDPHE can conduct unannounced inspections at NEC facilities, which are required to maintain conditions of no exposure at all times. As your site prepares for NEC renewal, take care to observe for the following common non-compliance findings.
Inadequate Storm-Resistant Sheltering
Simply placing materials under a roof or cover does not automatically satisfy no exposure requirements. Materials may still be considered exposed if precipitation or runoff can contact them indirectly, or if they can be mobilized by wind. For example, lightweight materials, dust, fines, or residues stored near open sides of structures or bay doors may be blown into contact with stormwater.
It is also important to remember that NEC eligibility is evaluated on a facility‑wide basis. If even one industrial activity or material is exposed to stormwater anywhere on site, the facility as a whole may be deemed ineligible for NEC.
Temporary covers, such as tarps or plastic sheeting, should be used with caution. While they may be appropriate during short‑term construction or renovation activities, reliance on temporary coverings for routine operations can create compliance risk, particularly if they are not consistently maintained or fail during wind, snow, or rain events.
Roof Areas
Roof areas are often overlooked during NEC evaluations but can be a significant source of exposure. Roofs may be considered exposed if they receive air emissions or particulate fallout that can be mobilized by precipitation and carried offsite in stormwater runoff.
In addition, roofs and associated surfaces constructed from galvanized materials or other reactive metals may contribute pollutants when stormwater washes over them. Downspouts and roof drainage paths should be evaluated to ensure they are not conveying pollutants associated with industrial activities. Facilities with air emissions, material dust, or rooftop equipment should pay particular attention to rooftop conditions during NEC renewal.
Secondary Containment Areas
Fuel transfer points, chemical transfer areas, and similar locations must be managed carefully to maintain no exposure. These areas should be located within clearly defined secondary containment and, where appropriate, protected by covers and drip pans sufficient to prevent spills, drips, or leaks from contacting stormwater.
Stormwater or precipitation that collects within secondary containment areas may not be discharged directly to the stormwater system unless authorized under another permit or properly managed through alternative legal means (such as off‑site disposal by a licensed vendor). In some cases, facilities may route precipitation from transfer areas to a separate collection system designed to prevent mixing with stormwater runoff. Improperly managed secondary containment is a common inspection finding during NEC reviews.
Staging Areas
Even short‑term outdoor staging of industrial materials can invalidate NEC eligibility if precipitation can contact those materials. There are no blanket allowances for “temporary” storage under the No Exposure exclusion.
Materials staged outdoors—such as pallets, raw materials, waste containers, or equipment—must be fully protected from rain, snow, snowmelt, and runoff at all times. This includes protection from wind‑driven precipitation. Staging areas near loading docks and yard entrances are frequent sources of unintended exposure.
Facilities should evaluate material flow and logistics practices when preparing for NEC renewal.
PFAS Residuals
Recent CDPHE guidance highlights the importance of addressing residual contamination, particularly related to per‑ and polyfluoroalkyl substances (PFAS). Areas where PFAS‑containing foams, chemicals, or equipment have been used, stored, or cleaned may retain residual contamination that poses exposure risk over time.
PFAS compounds degrade very slowly. If releases have occurred in the past, residual contamination may remain at concentrations with the potential for health or environmental impacts. For NEC eligibility, such residual materials must not remain exposed to stormwater.
Facilities that can confirm there is no potential for PFAS materials to be present outdoors—and that all other industrial materials meet no exposure criteria—may still be eligible to apply for NEC. A careful site‑specific evaluation is recommended.
No Exposure vs. No Discharge
“No exposure” does not mean “no discharge.” Facilities may lawfully discharge stormwater under NEC, provided that stormwater does not come into contact with industrial materials or activities. The regulatory standard focuses on preventing contact between stormwater and industrial pollutants, not on the presence or absence of discharge itself.
If the industrial activity requires stormwater discharge permit coverage but does not discharge stormwater or have the potential to discharge stormwater to surface waters of the State, the facility may claim they have no potential to discharge and opt out of permit coverage. This no discharge determination must be made by the owner / operator. Facilities claiming no discharge do not require NEC submittal, though Trinity recommends maintaining internal documentation regarding the no discharge determination. Note that any unpermitted discharge from a facility claiming no discharge could be subject to CDPHE enforcement.
Recommendations for Maintaining NEC
Thorough knowledge of pollutant sources is critical for maintaining NEC facility status. Frequent inspections are the most useful tool for maintaining conditions of no exposure, though they are not required by CDPHE. Trinity recommends reviewing the NEC checklist against site conditions on a frequent basis to identify and remedy any exposed industrial materials or activities. It can be especially helpful to conduct these voluntary inspections in various conditions, including rain, snowmelt, and wind events to observe for any evidence of potential stormwater contamination that may otherwise go unnoticed in the absence of these conditions.
What To Do if You No Longer Qualify for NEC
If conditions have changed at your facility, such as new outdoor activities, expanded yard storage, or the addition of waste streams, you may need coverage under the General Permit or other CDPHE permit. This could require the development of an SWMP, application of sector‑specific BMPs, and the potential need to conduct benchmark monitoring depending on your industrial sector. Trinity can assist you with assessing stormwater program applicability and complying with these requirements. For more information, please contact Libby Hyde with our Denver office, or call 720.638.7647.
