Regulations
Mesa County SWPPP Checklist: Concrete Washout & The 5-2-1 Drainage Authority
Mesa County
Jurisdiction: Mesa County (Including City of Grand Junction, Fruita, Palisade, and the Grand
Permit / authority: Governing Authority: 5-2-1 Drainage Authority / Mesa County Stormwater Management
Junction Drainage District) Manual (SWMM) Stormwater management in the Grand Valley is unique due to the consolidation of several municipalities. Mesa County, Grand Junction, Fruita, Palisade, and the Grand Junction Drainage District contracted through intergovernmental agreements to form the 5-2-1 Drainage Authority. If you are pouring concrete anywhere in these jurisdictions, you must follow the unified guidelines set forth in the Mesa County SWMM.
1. The 5-2-1 Unified SWMM Mandate
The Rule: All proposed development must provide for on-site runoff collection and conveyance in accordance with the Stormwater Management Manual and applicable federal and state laws. The Mesa County Nuance: Because these five entities operate under the 5-2-1 Drainage Authority, compliance is standardized across borders. Chapter 7.7 of the Mesa County Land Development Code dictates that a concrete washout violation in the Town of Palisade or the City of Fruita is governed by the exact same SWMM manual—and carries the same weight—as a violation in downtown Grand Junction.
2. Strict MS4 Discharge Ban & Ordinance 3824
The Rule: Concrete washout water shall not be discharged to the MS4. The Mesa County Nuance: The City of Grand Junction strictly enforces this via stormwater pollution prevention Ordinance Number 3824 (Chapter 13.28 GJMC). This ordinance explicitly requires the control of illegal discharges. Allowing highly alkaline concrete washout to leak into the street, curb, or any channel (defined as a natural or artificial low-lying area with a definite bed and banks) is a direct violation of this code.
3. CDOT Subsection 208.05 Containment Requirement
The Rule: Construction sites must utilize Best Management Practices (BMPs), which include schedules of activities, prohibitions of practices, and structural controls to prevent the pollution of state waters. The Mesa County Nuance: Local municipalities heavily rely on Colorado Department of Transportation (CDOT) specifications for right-of-way and roadway improvements. Engineering specifications dictate that concrete washout water or waste from field laboratories and paving equipment must be strictly contained in accordance with CDOT subsection 208.05. Containment must physically prevent any seepage or breach into the surrounding soil.
4. Dewatering & "CDW Permit" Triggers
The Rule: To discharge pollutants to waters of the state, a site must have a CDPS permit authorizing the release. The Mesa County Nuance: Mesa County standard construction specifications explicitly list "concrete washout" as a primary pollutant source alongside disturbed soil. If a designated washout area floods or requires construction dewatering, and that water has come into contact with concrete washout, the contractor cannot simply pump it out. The site must obtain a separate CDW permit specifically for the discharge of this contaminated water to State waters.
