EPA Construction General Permit (CGP) — NMR100000 Guide for New Mexico
The EPA Construction General Permit (CGP) is the federal authorization for construction stormwater discharges. In New Mexico, this permit is NMR100000 — effective February 17, 2022, expiring February 16, 2027. Filing a Notice of Intent (NOI) before ground disturbance is a legal prerequisite, not a formality.
CGP 2022 Key Requirements
The 2022 CGP (effective February 2022) introduced tighter requirements compared to the prior 2017 permit. Key changes relevant to New Mexico operators include:
SWPPP Requirements
- Site description including drainage area map
- Identification of potential pollutant sources
- BMP selection documentation with rationale
- Inspection schedule and responsible personnel
- Spill prevention and response procedures
- Post-construction permanent stabilization measures
Inspection Documentation
- Inspection date, time, and inspector name
- Weather conditions and 24-hr rainfall data
- BMP condition assessment for all installed controls
- Description of any corrective actions required
- Follow-up verification within 7 days
- Signature of Qualified Inspector
Records Retention
- SWPPP available on site during construction
- Inspection records retained 3 years post-NOT
- NOI acknowledgment on file
- All SWPPP amendments retained with dates
- Corrective action documentation retained
- NOT filing confirmation retained
NMR100000 Specific Provisions for New Mexico
While the CGP 2022 is a national permit, NMR100000 contains New Mexico–specific provisions negotiated with EPA Region 6. Key New Mexico provisions:
NOI Filing Requirements
The Notice of Intent (NOI) is the formal mechanism for obtaining coverage under NMR100000. It must be filed and acknowledged before any ground disturbance begins.
Current — EPA NeT System
- File at https://npdes.epa.gov/net/
- Acknowledgment typically within 7 days
- eNOI PDF confirmation serves as permit coverage
- Site-specific information: acreage, latitude/longitude, receiving waters, operator information
Transition — NMPDES eDMR (2026)
- •File via NMPDES eDMR portal after transition
- •WQCC hearing June 8–18, 2026 sets transition date
- •Dual-permit compliance window during transition
- •New permit number format (state-issued)
Inspection Schedule — 7-Day, 14-Day, and Post-Storm
NMR100000 Part IV establishes two inspection schedules operators may choose from, plus mandatory post-storm inspections:
| Schedule | Frequency | Post-Storm Trigger | Best For |
|---|---|---|---|
| Schedule 1 (Standard) | Every 14 calendar days | Within 24 hrs of ≥ 0.25" | Most NM projects |
| Schedule 2 (Reduced) | Every 7 calendar days | Within 24 hrs of ≥ 0.25" | High-risk sites / sensitive waters |
| Inactive Sites | Monthly (winter laydown) | Within 24 hrs of ≥ 0.25" | Sites with no active earthwork |
Note: Arizona AZPDES AZG2022-001 uses a 0.50-inch post-storm trigger rather than 0.25 inches. If you operate sites in both states, Inspections Plus manages the differing thresholds in your inspection scheduling system.
NMPDES Transition Timeline
CGP vs. MSGP — Know the Difference
The CGP covers construction-related soil disturbance. The MSGP covers industrial activities with stormwater exposure — an entirely different regulatory framework. Many facilities — particularly those undertaking construction on active industrial sites — require both permits simultaneously.
Full CGP vs. MSGP comparison — 10-dimension tableReady to get started?
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