State Water Resources Control Board adopts statewide Caltrans stormwater permit, approves time schedule order

The State Water Resources Control Board on June 22 voted unanimously to adopt a proposed statewide municipal stormwater National Pollutant Discharge Elimination System (NPDES) permit and an accompanying time schedule order for the California Department of Transportation (Caltrans).

Mary Boyd, project manager for the Division of Water Quality's municipal stormwater unit, told the board the permit package reflects four years of development, public workshops and responses to a 60‑day comment period on the 2021 draft. "We placed TMDL requirements in a time schedule order," Boyd said, and staff added statewide trash provisions, more sensitive laboratory requirements, and electronic reporting to the Stormwater Multiple Application and Reporting Tool (SMARTS).

The permit replaces the prior Caltrans permit and includes seven attachments covering definitions, stormwater management plan requirements, TMDL implementation, trash controls, monitoring, and reporting. Key changes include a requirement that Caltrans produce retrofit plans and asset inventories, a clarified cooperative‑agreement definition to avoid double counting, a 30‑day public comment period for TMDL compliance plans, stricter site inspection reporting (including dates, inspector names and photos, and 60‑day submittal), and revised trash milestones that require phased progress to full‑capture equivalency at 100% of acres identified as significant trash‑generating areas.

Public speakers praised portions of the package while flagging remaining concerns. Sean Bothwell, executive director of the California Coastkeeper Alliance, commended staff and Caltrans for changes including moving from a credit system to traditional effluent limits for some TMDLs and stronger site inspection reports, but urged permit language and incentives to avoid "sacrifice zones" where cooperative agreements might leave upstream impairments unaddressed. Bothwell also pressed for Caltrans to address salt management in settling ponds and for the board to study 6PPD‑quinone — a tire‑wear transformation product linked to rapid salmon mortality — and possible biofiltration solutions for salmon‑bearing streams.

Caltrans chief environmental engineer Shailah Choudhary said Caltrans will continue partnering with the State Water Board and regional boards, highlighted Caltrans' participation in the Governor's Clean California initiative and enhanced litter pickup efforts, and confirmed protocols to pick up trash before vegetation herbicide application in most cases. "We do not place any pesticide or herbicide directly into storm drain systems," Choudhary said, while confirming limited herbicide use for vegetation and safety needs.

Board discussion led to two specific directions captured in the record. First, the board agreed to add cooperative‑agreement language in the permit (attachment D, section D5.1) instructing regional and state boards, when evaluating cooperative agreements, to consider potential localized impacts between a Caltrans discharge location and cooperative agreement projects "with a goal of reducing areas of nonattainment and avoiding nonattainment in areas disproportionately impacted by pollutants." Second, the board directed staff, in coordination with regional boards, Caltrans, fishery agencies and environmental groups, to assess options for identifying and addressing 6PPD‑quinone discharges to coho salmon‑bearing streams and to schedule an informational item for the board at an appropriate future meeting.

On procedure and timing, staff told the board a permit effective date is anticipated prior to full implementation; staff said they will report back with initial information on 6PPD before the permit's effective date. The permit also contains a modified time schedule order milestone calculation that staff described as moving from a three‑year to a four‑year annual milestone formula for certain phased obligations.

The formal motion — to adopt the staff proposal with late revisions (change sheet 1) and the proposed time schedule order — was moved by Board Member Laurel Firestone and seconded by Board Member Nicole Morgan. Clerk Janine Townsend recorded the roll call: Firestone (aye), Morgan (aye), (recorded as) McGuire/Maguire (aye), Vice Chair Doreen D'Adamo (aye), and Chair Joaquin Esquivel (aye). The board adopted the permit and time schedule order by unanimous vote.

What the permit changes mean: municipalities, Caltrans and regional boards will now use clearer TMDL compliance plans with a 30‑day public comment window; Caltrans must inventory assets, prepare prioritized retrofit plans and report on progress annually; trash control milestones are explicitly phased to achieve full‑capture equivalency across identified significant trash acres; monitoring methods must rely on sufficiently sensitive methods and ELAP‑certified labs where required; and more reporting will be submitted electronically via SMARTS.

Next steps: staff will incorporate the late revisions into final permit documents, coordinate with regional boards on TMDL compliance plans, and carry out the board direction to study 6PPD‑quinone options and report back with an informational item at an appropriate future meeting. The board will reconvene on July 19; staff said they will aim to provide initial information on the 6PPD question prior to the permit's effective date.

Votes at a glance: Adopt staff proposal (permit and time schedule order) — motion passed, 5‑0 (Firestone, Morgan, McGuire/Maguire, D'Adamo, Esquivel).