New Mexico’s Conditional Certification of EPA’s Proposed Reissuance of the Multi Sector General Permit for Stormwater Discharges Associated with Industrial Activity Raises Significant Concerns


In mid-2020, the Environmental Protection Agency (EPA) proposed to reissue the Multi Sector General Permit (MSGP) for stormwater discharges associated with industrial activity (Permit NMR050000) under the Clean Water Act (CWA) Section 402 National Pollutant Discharge Elimination System (NPDES).  Section 401 of the CWA and associated federal regulations under the NPDES program administered by EPA establish a state certification process whereby state certifications may “include [c]onditions which are necessary to assure compliance with the applicable provisions of [the CWA] and with appropriate requirements of State law” including where “pollutants . . . may be discharged at a level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State water quality standard . . ..”  See 40 C.F.R. 124.53(e) and 122.44(d)(1)(i).

NMED’s Conditional Certification

On the basis of this certification authority, the New Mexico Environment Department (NMED) first certified the MSGP on June 22, 2020, but then revoked and reissued a new certification on August 17, 2020 (Reissued Certification).  The Reissued Certification—numbering 14 pages in length—offers five conditions summarized as follows:

  1. Monitoring and reporting requirements for 18 per- and poly-fluoroalkyl substances (PFAS) that would require sampling and analysis by an accredited lab using New Mexico’s combined PFAS and perflourooctane sulfonate (PFOS) screening level of 0.070 ug/L “to determine if more attention is warranted” such as “corrective action . . . to minimize, reduce and eliminate PFAS from the industrial activity through product substitution and/or additional best management practices and operations controls.” 
  1. Modification of benchmark values in monitoring for pollutants to require monitoring for those New Mexico surface water quality standards that are more stringent than EPA’s proposed MSGP benchmarks, as a means of upholding New Mexico’s antidegradation policy in NMAC. 
  1. Ineligibility for MSGP coverage where the stormwater discharges are to “outstanding national resource waters (ONRWs, sometimes referred to as “tier 3” waters addressed by New Mexico’s antidegradation policy at NMAC. 
  1. Requirements for sampling and testing to determine whether groundwater or spring water discharged from a facility is potentially contaminated in excess of New Mexico’s surface water quality standards, in which case the discharge must be conducted under an individual NPDES permit, and if the discharge is to the ground surface or an unlined pond, a Notice of Intent must be provided to NMED’s Ground Water Quality Bureau to allow assessment of any groundwater discharge permit requirements. 
  1. If stormwater discharges are to ponds or other impoundments, the water must drain or infiltrate within 96 hours or a permit to capture and store surface water must be filed with the Office of the State Engineer (OSE) either a water right must be transferred for the impoundment or a variance must be obtained from OSE, and if the discharge contains a “water contaminant” under NMAC, a Notice of Intent must be provided to NMED’s Ground Water Quality Bureau to allow assessment of any groundwater discharge permit requirements.

Significant Concerns Being Raised

To date, two New Mexico industry groups have lodged written objections to NMED’s Reissued Certification dated August 17, 2020.  Specifically, by letter to NMED’s Secretary dated September 16, 2020, which is copied to EPA’s Region 6, New Mexico’s Association of Commerce and Industry (ACI), joined in by a letter of the same date by the New Mexico Mining Association (NMMA), has raised both procedural and substantive issues with the conditions offered by NMED.  To date, neither NMED nor EPA have responded to the concerns raised by ACI and NMMA, nor has EPA taken any further action on NMED’s proposed conditions of certification.

  1. Procedural Concerns

ACI and NMMA have raised procedural concerns about flaws in purported notices issued by both EPA and NMED.  Although EPA published notice of EPA’s proposed issuance of the MSGP, the notice did not provide any indication of what conditions NMED might recommend to EPA.  Likewise, although NMED published notice that it would be conducting a Section 401 certification process on EPA’s proposed MSGP, because the notice did not identify the conditions it ultimately included in its Reissued Certification, potentially impacted parties statewide have been denied a meaningful opportunity to comment on NMED’s proposed 401 certification conditions submitted to EPA.  ACI and NMMA both request further public notice and opportunities for potentially impacted parties to comment on the proposed conditions.  It is not clear as of this writing whether this request will be heeded.

  1. Substantive Concerns

ACI and NMMA have also raised substantive concerns with four of the five conditions offered by NMED in its Reissued Certification.  The substantive concerns they have raised, in summary, are as follows:

  • Condition 1: NMED has not adopted PFAS standards in surface water, so monitoring of stormwater discharges for PFAS analytes is beyond NMED’s certification authority under CWA Section 401; and
  • NMED has no justification for proposing a PFAS screening level of 0.070 ug/L, nor authority to effectively create a PFAS screening level via a CWA Section 401certification without a rulemaking under New Mexico’s Water Quality Act.
  • Condition 2: NMED’s anti-degradation policy does not give NMED the ability to change federal benchmarks to track surface water quality in receiving waters in New Mexico; and
  • NMED’s request to modify federal benchmarks to reflect NM’s surface water standards exacerbates concerns of the National Academy of Science’s National Research Council with using low-flow, dry weather standards for the differing flow and load conditions resulting from stormwater events.
  • Condition 3: There is no justification for requiring all stormwater discharges to Outstanding Natural Resource Waters (ONRWs) to obtain individual NPDES permits, and the impacts on existing dischargers and EPA Region 6 would be substantial.
  • Condition 5: NMED’s attempt to incorporate OSE or water rights-related requirements are not grounded in CWA Section 401 provisions and therefore are improper under recent EPA guidance and 2020 rules limiting the scope of 401 certifications, and might inappropriately make compliance with such state-based requirements a matter of federal enforcement;
  • NMED’s proposed requirement for dischargers to submit to NMED a proposed discharge of stormwater containing a “water contaminant” that may reach groundwater is an inappropriate attempt to regulate discharges to groundwater under the auspices of CWA Section 401; and
  • NMED provides no basis for requiring discharges of impounded water to meet benchmark values, because that is a back door effort to establish effluent limits for stormwater discharges.


For more information please contact Stuart Butzier.