250 A.3d 346
Md. Ct. Spec. App.2021Background:
- MDE issued a Phase II NPDES general permit for small MS4s and designated Queen Anne’s County for coverage, although only a small portion of the county was within the Census-defined "urbanized area."
- The draft/tentative permit justified county-wide designation on the basis that the county was located within an urbanized area; the final determination relied instead on water-quality criteria (TMDL/WIP and Maryland Biological Stream Survey data) to designate MS4s outside the urbanized area.
- The permit also imposed a requirement to restore 20% of untreated impervious surface in the permittee’s urbanized area (baseline excludes already-treated acres) and included mapping, outfall screening, and pollution-prevention (good-housekeeping) requirements.
- Queen Anne’s County objected, arguing MDE lacked authority to designate areas outside the actual urbanized area, that the 20% restoration improperly assigned responsibility for nonpoint and third-party discharges, and that several permit conditions exceeded the CWA’s “maximum extent practicable” (MEP) standard.
- The circuit court affirmed MDE; the Court of Special Appeals vacated in part and remanded—requiring remand to MDE for new comment on the post-comment-period rationale for county-wide designation—but otherwise affirmed (upholding the 20% restoration and the mapping/outfall/good-housekeeping provisions).
Issues:
| Issue | County's Argument | MDE's Argument | Held |
|---|---|---|---|
| 1) Validity/procedure of designating MS4s outside the actual urbanized area | Designation exceeded authority and was procedurally defective because MDE changed its rationale after the comment period and the new criteria were not disclosed | MDE argued County had opportunity to comment and the agency reasonably relied on TMDL/WIP and MBSS data to designate areas outside the urbanized area | Remand required under EN §1-601(d): County’s objections to the post-comment-period justification were not reasonably ascertainable during comment; vacated as to area designation and remanded to MDE for further proceedings |
| 2) Whether 20% impervious-surface restoration makes County liable for nonpoint or third-party discharges | The restoration requirement improperly makes County responsible for runoff and discharges that do not enter its MS4 (nonpoint/third-party sources) | MDE: the restoration term is a water-quality-based effluent limitation tied to the Bay TMDL/WIP; it is a proxy for required pollutant reductions and does not assign legal liability for third-party discharges | Upheld: under Carroll County, the restoration term is an authorized water-quality-based effluent limit implementing wasteload allocations in the Bay TMDL; MDE did not exceed CWA authority |
| 3) Applicability of Carroll County to small MS4s (timing/assignment in TMDL) | Carroll County is distinguishable because that case addressed medium MS4s and pre-existing assignments in the TMDL; small MS4s were unregulated when the Bay TMDL issued | MDE: WIP (contemporaneous with Bay TMDL) anticipated impervious restoration across Phase I & II; permit terms must be consistent with TMDL assumptions and may be more stringent based on approved TMDL | Upheld: Carroll County applies; consistency requirement applies to later-issued permits and to small MS4s; 20% restoration remains authorized |
| 4) Whether mapping, outfall screening, and good-housekeeping provisions exceed MEP | These provisions are beyond MEP and more onerous than federal minimums | MDE: federal regs set minimums but allow additional elements and more stringent conditions where needed to protect water quality; record shows rational basis and substantial evidence (existing programs, practicability adjustments) | Upheld: MDE articulated rational basis/substantial evidence that these provisions are within discretion and not arbitrary or beyond MEP |
Key Cases Cited
- Maryland Dep’t of the Env’t v. County Commissioners of Carroll County, 465 Md. 169 (Court of Appeals of Md.) (upholding county-wide impervious restoration as a water-quality-based effluent limitation tied to the Bay TMDL)
- Maryland Dep’t of the Env’t v. Anacostia Riverkeeper, 447 Md. 88 (Court of Appeals of Md.) (discussing MS4 permitting framework and BMP/MEP principles)
- Potomac Riverkeeper, Inc. v. Maryland Dep’t of the Env’t, 238 Md. App. 174 (Court of Special Appeals of Md.) (explaining public-comment/remand principles and that final permit terms may differ from draft but parties must have adequate notice of foreseeable changes)