Continuing its vanguard approach to environmental regulation, California is poised to incorporate Total Maximum Daily Load (TMDL)-specific requirements into its industrial storm water general permit (IGP). TMDLs are pollutant- and water body-specific and establish the maximum amount of a pollutant a water body can receive while meeting water quality standards. Once effective, these new requirements will provide additional avenues of attack for the already active Clean Water Act citizen suit docket. The State Water Resources Control Board (State Board) issued what appears to be its final TMDL-related revision to California’s IGP on September 26, 2018. Following an October 24, 2018, workshop, the State Board plans to consider adoption of the revised permit on November 6, 2018.

Our earlier post explained in detail the February 2018 proposed TMDL revisions to California’s IGP. Briefly, these involve incorporation of TMDL-related numeric action levels (TNALs), numeric effluent limits (NELs), and onsite and offsite compliance options that enable alternative compliance demonstration through the capture and retention of storm water runoff produced from the 85th percentile 24-hour storm event, provided capacity is restored within a 24-hour drain time. As we explained, the TMDL-related requirements only apply to “Responsible Dischargers,” i.e., those who (1) discharge storm water to an impaired water body with a TMDL assigned to industrial storm water point source discharges; and (2) engage in activities that are a potential source of a covered pollutant. However, any discharger regulated under the IGP can take advantage of the compliance options. While these options include detailed and potentially onerous construction and ongoing monitoring requirements, their benefits are substantial. Once a compliance option is implemented, a discharger is (1) in compliance with the IGP’s mandate to implement required best management practices (BMPs) to reduce pollutants in storm water runoff; (2) deemed in compliance with applicable TMDL-specific limitations (i.e., TNALs or NELs), the IGP’s Receiving Water Limitations, and the IGP’s prohibition against discharges that “cause or threaten to cause pollution, contamination, or nuisance”; and (3) exempt from a host of IGP requirements, including the obligation to implement exceedance action response programs for discharges beyond the 85th percentile 24-hour storm event that exceed applicable numeric action levels (NALs).

This post highlights the State Board’s changes or clarifications made in response to public comments on its February 2018 draft. While the State Board maintains its revisions are intended “to provide a clear TMDL compliance framework,” and “[s]ignificant effort was put in to ensure that the Amendment is as clear as possible,” dischargers implementing the permit may feel differently. The revised IGP is 81 pages, and the accompanying Fact Sheet explaining the permit has more than doubled, going from 76 to 176 pages.

Key changes pertaining to the revised permit are summarized below.

  • Impaired Waterbody/Watershed: In an effort to clarify water body boundaries applicable to the TMDL, Table E-2 was added to Attachment E of the IGP. Table E-2 identifies the pollutant as well as the water segment(s), waterbody or watershed to which the TMDL applies. Where specific water segments are not identified, the TMDL applies to the entire water body. If the watershed is identified as the regulated area, the TMDL applies to the entire watershed. The State Board intends to make a map tool publicly available to assist dischargers with determining the applicability of TMDL requirements. The State Board also narrowed the applicability of the TMDL requirements by eliminating the inclusion of discharges to upstream reaches or tributaries of impaired waterbodies.
  • TMDLs Generally: Responding to concerns regarding the feasibility of complying with some of the stringent TMDL limits, the State Board explained that (1) it was implementing already approved TMDLs, not reviewing the TMDL development process; (2) TMDLs are designed to be translated into water quality-based effluent limitations (WQBELs); and (3) WQBELs are not based on technological achievability and/or feasibility. Defending its use of instantaneous maximum measurements for the incorporated TMDLs, the State Board explained that TMDLs protect impaired waterbodies, and, by evaluating compliance based on an instantaneous maximum value exceedance, TMDLs address “acute” pollutant sources associated with storm water discharges (versus annual average NALs that address chronic pollutant loading from storm water discharges).
  • TNALs: TNALs were adopted where receiving waters (as opposed to the point of discharge) were evaluated for pollutant loading capacity in the TMDL development process. Explaining that TNALs are BMP-based WQBELs, the State Board explained that a TNAL exceedance is not a per se violation of the IGP. Rather, similar to NALs under the current IGP, Responsible Dischargers that pursue the IGP’s existing Exceedance Response Action (ERA) process remain in compliance with the IGP. BMP stringency increases as dischargers move from Baseline status (i.e., general IGP compliance) through Level 1 and, as appropriate, Level 2 ERA processes. Under the proposed amendment, Responsible Dischargers in Baseline, Level 1 or Level 2 for a NAL start at the same TNAL level for a TNAL addressing the same pollutant. The State Board also eliminated TNALs for TMDLs where the industrial storm water allocation was based on dry-weight sediment discharge requirements (such as Ballona Creek), requiring instead compliance with the IGP’s general requirements.
  • NELs: NELs are based on more stringent TMDLs that measure compliance at the point of discharge and do not allow Responsible Dischargers to pursue ERA off-ramps through demonstration of natural background or non-industrial pollutant sources. Responsible Dischargers that exceed a NEL are in violation of the IGP. The State Board’s offered relief is a Regional Board Time Scheduled Order approved prior to the NEL exceedance. Such an order does not, however, protect against citizen suits. Because of the onerous ramifications of a NEL exceedance, the State Board added language to the Fact Sheet to address the applicability of mandatory minimum penalties ($3,000 per violation) to NEL exceedances.
  • Compliance Options: Addressing the concern that it may not be possible to drawdown the storm water runoff associated with an 85th percentile 24-hour storm within a 24-hour period (particularly in the event of back-to-back storms), the State Board added an option to offset a longer drawdown time under both the onsite and offsite compliance options by allowing for additional storage beyond the compliance storm standard. Citing concerns over protection of groundwater quality, the State Board also added requirements applicable to storm water infiltration beyond requiring infiltrated water to meet specified maximum contaminant levels or MCLs (identified in Table A to Attachment I). These include testing for a new list of contaminants (identified in Table B to Attachment I), preventing the migration of existing soil contamination to groundwater and interference with any groundwater remedial activities, and ensuring soil through which infiltration occurs has the appropriate characteristics to support infiltration rates.
    • Onsite Compliance Option: When utilizing the onsite option, the State Board clarified that a facility may use one or a combination of capture and reuse, diversion (to a publicly owned treatment works (POTW) or regional reclaimed water distribution system), infiltration, and/or evapotranspiration BMP(s), and that all options need to comply with any applicable local requirements. Responding to POTW comments that they cannot necessarily accept flow held by a facility utilizing the onsite option, the State Board added language explaining that many POTWs do not have capacity to accept storm water during and after wet-weather events or may be unable to accept the additional pollutants present in industrial storm water and still meet their effluent limitations. They also noted that sewer use or pretreatment permits will likely be required before a POTW would authorize such diversions.
    • Offsite Compliance Option: The State Board revised the offsite compliance option to allow for agreements between private entities (provided there is Regional Board approval) as well as other local jurisdiction(s) rather than just limiting agreements to local municipality(ies). Adding more clarity to the offsite agreements, the State Board explained it expects the agreements to include “an agreement date, location of the offsite BMPs, monitoring and implementation agreements, funding, and a process for agreement termination.”
  • Air Particulate Emissions: While maintaining that “air particulate emissions” should have been part of a facility’s pollutant source assessment process required under the existing IGP, the proposed amendment explicitly mandates it. Additionally, the SWPPP needs to identify “any industrial activities and areas that are associated with other regulations or regulated by other permits (including, but not limited to, air quality permits) with the potential to expose pollutants to storm water.”
  • Effective Date: Recognizing the amendment’s complexity, the State Board did not include an effective date. Rather, it left the decision on a delayed effective date for the November 6, 2018, adoption meeting. When discussing the revisions in public forums, State Board staff have indicated a possible June 2019 effective date. Note that if an approved TMDL incorporated into Attachment E has a compliance date beyond the amendment’s effective date, the latter date will apply for compliance with that TMDL.

Before the TMDL IGP amendment becomes effective, a discharger that discharges storm water to any of the waterbodies with TMDLs identified in Attachment E should (1) take the opportunity to ensure its pollutant source assessment is current and accurate; (2) determine if it will be subject to any of the TNALs or NELs; and (3) if subject to NELs, take steps now, so it has a plan in place to ensure compliance with applicable NEL requirements before they become effective.