NMPDES Transition: New Mexico is transferring NPDES stormwater permitting from EPA to NMED. The WQCC rulemaking hearing is scheduled for June 8–18, 2026. Read the detailed NMPDES guide →
NMEPA-AdministeredSWPPP Requirements in New Mexico
New Mexico is one of a handful of states where the EPA directly administers the NPDES stormwater program rather than delegating it to a state agency. This means construction operators in New Mexico must obtain coverage under the EPA's Construction General Permit (CGP) rather than a state-issued permit. The New Mexico Environment Department (NMED) still plays a role through Section 401 water quality certifications and state-level surface water quality standards. New Mexico's arid climate creates unique stormwater challenges — disturbed desert soils are highly susceptible to wind and water erosion, and infrequent but intense monsoon storms can cause significant sediment discharge events.
New Mexico SWPPP Key Facts
- ✓EPA directly administers the NPDES stormwater program in New Mexico — not the state
- ✓NOI filing is done through EPA's NeT (NPDES eReporting Tool) system
- ✓No state-level NOI or annual permit fees
- ✓Section 401 water quality certification through NMED may be required
- ✓Monsoon season (June–September) creates high-risk inspection periods
- ✓Projects near the Rio Grande and tribal lands may have additional requirements
- ✓New Mexico has over 20 tribal nations, some with their own environmental regulations
- ✓Wind erosion controls are as critical as water erosion controls in arid regions
New Mexico County Map
4 MS4 jurisdictions · 33 countiesMS4 Jurisdictions
Standard Counties
Administering Agency
- Agency
- U.S. Environmental Protection Agency Region 6 (EPA Region 6)
- Phone
- 1-866-EPA-WEST
Permit Details
- Permit Name
- NPDES Construction General Permit (CGP)
- Permit Number
- NMR120000
- Effective Date
- 2023-02-16
- Expiration Date
- 2028-02-15
- Permit Document
- View Current Permit
SWPPP Thresholds & Triggers
- Acreage Threshold
- 1 acre
New Mexico is one of a few states where the EPA directly administers the NPDES stormwater program rather than the state. Projects disturbing 1+ acres or part of a common plan of development must obtain CGP coverage. The New Mexico Environment Department (NMED) handles state water quality certifications under Section 401.
Inspection Requirements
- Inspection Frequency
- Every 7 calendar days, or every 14 days with an allowable rain event inspection schedule
- Rain Event Threshold
- 0.25 inches within 24 hours
- Certified Inspector
- Not required by state
New Mexico does not mandate specific certifications. The EPA CGP requires inspectors to be 'qualified' — knowledgeable in erosion and sediment control principles. Professional credentials such as CPESC or CESSWI can help demonstrate this standard but are not required. Inspections must cover all BMPs, discharge points, and material storage areas.
Penalties & Enforcement
- Max Civil Penalty (Per Day)
- $64,618
- Criminal Penalties
- Negligent violations: $2,500–$25,000/day and/or up to 1 year imprisonment. Knowing violations: $5,000–$50,000/day and/or up to 3 years. Knowing endangerment: up to $250,000 and/or up to 15 years.
EPA Region 6 has been active in enforcement actions in New Mexico, particularly around construction projects near sensitive waterways like the Rio Grande and its tributaries. The arid climate makes sediment control critical — disturbed desert soils are highly erodible.
Permit Fees
- NOI Filing Fee
- $0 (EPA-administered, no state NOI fee)
- Annual Fee
- None (covered under EPA CGP)
- NOT Filing Fee
- $0
- Other Fees
- Section 401 water quality certification fees may apply for projects near sensitive waters — contact NMED for current schedule.
How New Mexico Differs from Federal Requirements
- ⚠No state-administered permit — EPA CGP applies directly
- ⚠No state NOI or annual permit fees
- ⚠Section 401 water quality certification through NMED is a separate requirement
- ⚠Projects on tribal lands may require additional sovereign nation permits
- ⚠State-level surface water quality standards (NMAC 20.6.4) may impose additional monitoring near impaired waters
SWPPP Tips for New Mexico
- ➤File your NOI through EPA's NeT system at least 14 days before breaking ground
- ➤Plan for monsoon season — install robust BMPs before June and inspect after every storm event
- ➤Wind erosion BMPs (tackifiers, windbreak fences, watering) are essential in NM's arid climate
- ➤Check if your project is near tribal lands — additional sovereign nation permits may apply
- ➤NMED's Section 401 certification can add weeks to your timeline — start early
- ➤Keep extra stabilization materials on-site during monsoon season for emergency repairs
- ➤Document all no-discharge events during dry periods — this supports your compliance record
New Mexico SWPPP FAQs
Why doesn't New Mexico have its own stormwater permit?+
New Mexico has not applied for or received EPA authorization to administer its own NPDES program. This means the EPA directly issues and enforces stormwater permits in the state through its Region 6 office in Dallas, TX. The New Mexico Environment Department handles state water quality standards and Section 401 certifications but does not issue NPDES permits.
How do I file an NOI in New Mexico?+
Since EPA administers the program, you file your NOI electronically through EPA's NPDES eReporting Tool (NeT) at https://cdx.epa.gov/ You must file at least 14 days before commencing construction activity. There is no fee for NOI filing under the EPA CGP.
What BMP challenges are unique to New Mexico?+
New Mexico's arid climate with intense monsoon rains creates a dual challenge: sites can go weeks without precipitation, then receive heavy rainfall in short bursts. Wind erosion is also a major concern on exposed desert soils. Effective SWPPPs in NM typically include tackifiers, wind fences, and heavy-duty sediment basins sized for monsoon events.
Do I need a SWPPP for projects on tribal land in New Mexico?+
Yes, and you may need additional permits. Projects on tribal lands are subject to EPA's CGP plus any tribal environmental requirements. Contact both EPA Region 6 and the relevant tribal environmental department. Some pueblos and nations have their own construction and environmental permitting processes.
What happens during a monsoon season inspection?+
During monsoon season (typically June–September), you must inspect within 24 hours of any rain event producing 0.25 inches or more. Given the frequency of afternoon thunderstorms, this can mean multiple inspections per week. Document BMP conditions, any discharges, sediment accumulation, and corrective actions taken.
Are certifications required for SWPPP inspectors in New Mexico?+
No. New Mexico does not mandate specific certifications for SWPPP inspectors. The EPA CGP requires inspectors to be 'qualified' — meaning knowledgeable in erosion and sediment control principles — but does not specify particular credentials. Professional certifications such as CPESC, CESSWI, or CPSWQ can help demonstrate this standard and may be useful in the event of an enforcement action, but they are not a regulatory requirement.
New Mexico County SWPPP Jurisdictions
Use the county map at the top of this page to jump to a specific jurisdiction. Counties marked MS4 require an additional local construction stormwater permit on top of the state CGP.
MS4 Counties — Local Permit Overlay Required
Sandoval County
MS4 ActiveLocal MS4 Authority
City of Rio Rancho Stormwater
A local MS4 stormwater construction permit is required in addition to the state CGP for sites within this jurisdiction.
Rio Rancho (Phase II MS4) requires a local stormwater construction permit in addition to the EPA CGP. Rapid residential growth makes stormwater enforcement active. Pueblo of Santa Ana and Pueblo of Zia have sovereign jurisdiction on their respective lands.
Santa Fe County
MS4 ActiveLocal MS4 Authority
City of Santa Fe Water Division
A local MS4 stormwater construction permit is required in addition to the state CGP for sites within this jurisdiction.
City of Santa Fe has a Phase II MS4 permit — local stormwater construction ordinance applies within city limits. Santa Fe River watershed. High construction activity in the metro area.
Bernalillo County
MS4 ActiveLocal MS4 Authority
City of Albuquerque Stormwater
A local MS4 stormwater construction permit is required in addition to the state CGP for sites within this jurisdiction.
Albuquerque has a Phase I MS4 permit — the most active local stormwater enforcement in New Mexico. All construction sites within city limits must comply with both EPA CGP and City of Albuquerque stormwater ordinance. The City conducts regular construction site inspections. Rio Grande floodplain adds USACE Section 404 considerations.
Doña Ana County
MS4 ActiveLocal MS4 Authority
City of Las Cruces Utilities / Stormwater
A local MS4 stormwater construction permit is required in addition to the state CGP for sites within this jurisdiction.
Las Cruces is the second-largest city in NM and has a Phase II MS4 permit. Local stormwater construction ordinance applies within city limits. NMSU campus has its own environmental compliance program. Rio Grande and Mesilla Valley — USACE floodplain coordination required near the river.
All Other New Mexico Counties — State CGP Only
San Juan County
Four Corners region. Projects near the San Juan River require heightened sediment controls. Navajo Nation lands adjacent — verify tribal environmental jurisdiction.
No local MS4 overlay — state CGP applies directly.
Rio Arriba County
Rio Chama and upper Rio Grande tributaries. Oil and gas activity in the Chama basin may require additional stormwater controls beyond the CGP.
No local MS4 overlay — state CGP applies directly.
Taos County
Taos Pueblo (a sovereign nation) has its own environmental regulations for projects within pueblo boundaries. High-altitude construction requires extended vegetation stabilization timelines.
No local MS4 overlay — state CGP applies directly.
Colfax County
Cimarron River drainage. Coal mining history in parts of the county. Standard CGP applies — no local MS4 overlay.
No local MS4 overlay — state CGP applies directly.
Union County
High plains, wind erosion is the primary BMP challenge. Flat terrain means sheet flow and sediment tracking are key concerns. Standard CGP.
No local MS4 overlay — state CGP applies directly.
McKinley County
Gallup area. Navajo Nation surrounds much of this county — tribal environmental permits may be required for projects on or adjacent to Navajo lands. Coal mining adjacency.
No local MS4 overlay — state CGP applies directly.
Los Alamos County
LANL (Los Alamos National Laboratory) has its own environmental compliance program. Projects on or adjacent to LANL property require additional DOE/NNSA coordination. Pajarito Plateau steep terrain — erosion risk is high.
No local MS4 overlay — state CGP applies directly.
Mora County
Mora River drainage into the Canadian River basin. Standard EPA CGP applies. Low construction volume — no MS4 overlay.
No local MS4 overlay — state CGP applies directly.
Harding County
Least populous county in NM. Very low construction activity. Standard EPA CGP applies with no local overlays.
No local MS4 overlay — state CGP applies directly.
Cibola County
Acoma Pueblo sovereign lands — tribal environmental permits required for projects on pueblo lands. Rio San Jose drainage. El Malpais volcanic terrain creates unusual stormwater pathways.
No local MS4 overlay — state CGP applies directly.
Valencia County
Rio Grande valley south of Albuquerque. Los Lunas and Belen are growing construction markets. No local MS4 overlay — EPA CGP applies directly. Rio Grande bosque areas may require USACE coordination.
No local MS4 overlay — state CGP applies directly.
San Miguel County
Pecos River watershed. Las Vegas, NM is the county seat. Montezuma area springs and wetlands — check WOTUS status before construction. Standard EPA CGP.
No local MS4 overlay — state CGP applies directly.
Guadalupe County
Pecos River valley. Standard EPA CGP applies. Low construction activity. Santa Rosa area — Pecos River proximity requires sediment controls.
No local MS4 overlay — state CGP applies directly.
Quay County
High plains east of the Pecos. Tucumcari area. Wind erosion dominant BMP concern. Standard EPA CGP, no local overlays.
No local MS4 overlay — state CGP applies directly.
Catron County
Largest county in NM by area, least accessible. Gila River headwaters — high-sensitivity watershed. Gila National Forest dominates — most construction requires USFS coordination in addition to EPA CGP.
No local MS4 overlay — state CGP applies directly.
Socorro County
Rio Grande flows through — USACE floodplain and Section 404 considerations apply near the river. Bosque del Apache NWR adjacency for southern projects. Standard EPA CGP.
No local MS4 overlay — state CGP applies directly.
Torrance County
Estancia Basin (closed drainage basin — no surface outlet). Estancia Valley has unique stormwater retention dynamics. Standard EPA CGP applies.
No local MS4 overlay — state CGP applies directly.
De Baca County
Pecos River valley. Fort Sumner area. Low construction volume. Standard EPA CGP, no local overlays.
No local MS4 overlay — state CGP applies directly.
Curry County
Clovis metro area growing construction market. Cannon AFB military lands have separate environmental compliance requirements. Wind erosion on flat eastern plains.
No local MS4 overlay — state CGP applies directly.
Grant County
Silver City area. Active copper mining in the Santa Rita area (Chino Mine) — mining stormwater regulated under MSGP, not construction CGP. Gila River headwaters — sensitive watershed.
No local MS4 overlay — state CGP applies directly.
Sierra County
Truth or Consequences / Elephant Butte Reservoir area. Rio Grande dams create unique hydrological conditions. Standard EPA CGP. Low construction volume.
No local MS4 overlay — state CGP applies directly.
Lincoln County
Ruidoso resort area has active construction. Bonito Lake watershed. Sacramento Mountains — steep terrain and high-intensity summer thunderstorms increase erosion risk significantly.
No local MS4 overlay — state CGP applies directly.
Chaves County
Roswell area — oil and gas in the Permian Basin extends here. Pecos River valley. Construction growth from energy sector. Standard EPA CGP.
No local MS4 overlay — state CGP applies directly.
Roosevelt County
Portales area. Eastern NM high plains. Wind erosion primary BMP concern. Standard EPA CGP, no MS4 overlay.
No local MS4 overlay — state CGP applies directly.
Hidalgo County
Southwestern-most NM county. Lordsburg area. Port of Entry at Columbus-adjacent border. Mining activity (copper). Standard EPA CGP.
No local MS4 overlay — state CGP applies directly.
Luna County
Deming area. Mimbres River (occasionally flowing). Very arid — wind erosion dominant. Standard EPA CGP. Low construction volume.
No local MS4 overlay — state CGP applies directly.
Otero County
Alamogordo and Holloman AFB. Military installation environmental compliance for on-base projects. White Sands National Park adjacent — high-visibility sensitive area. Sacramento Mountains stormwater.
No local MS4 overlay — state CGP applies directly.
Eddy County
Carlsbad — most active Permian Basin oil and gas county in NM. Very high construction volume from energy sector. Pecos River. Multi-well pad construction requires CGP coverage. High enforcement activity from EPA Region 6 in this area.
No local MS4 overlay — state CGP applies directly.
Lea County
Hobbs and Lovington — core Permian Basin oil and gas. Highest construction volume in eastern NM. Flat terrain, wind erosion dominant. CGP required for all construction sites 1+ acre.
No local MS4 overlay — state CGP applies directly.
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