276 A.3d 573
Md.2022Background
- Maryland Department of the Environment (MDE) issued a 2018 general NPDES permit covering 35 small municipal separate storm sewer systems (MS4s), including Queen Anne’s County; the permit requires restoration of 20% of untreated impervious surface in the county’s urbanized area by 2025 and implements EPA minimum control measures.
- Queen Anne’s County challenged the permit, arguing (1) permit terms and the minimum control measures unlawfully exceed the Clean Water Act’s “maximum extent practicable” (MEP) standard, and (2) the impervious‑surface and “good housekeeping” provisions unlawfully assign responsibility for third‑party/nonpoint discharges or reach beyond the MS4 service area.
- Circuit Court and Court of Special Appeals upheld the MDE’s final determination; the Court of Appeals granted certiorari to decide whether Carroll County should be reconsidered and whether the small MS4 general permit is lawful.
- This Court had previously decided two controlling MS4 cases: Anacostia Riverkeeper (large MS4s) upheld a 20% restoration condition as satisfying MEP, and Carroll County (medium MS4s) held permits may include conditions beyond MEP to meet water‑quality standards and may reference areas beyond the MS4.
- The MDE’s final permit allowed restoration credit for measures taken anywhere within the jurisdiction (not limited to the MS4 watershed) and retained an option for individual permits; Queen Anne’s County had participated in the administrative comment process before seeking judicial review.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Whether permit conditions (including minimum control measures) unlawfully exceed the Clean Water Act’s MEP standard | County: MEP is a statutory ceiling; permit exceeds that ceiling by imposing requirements beyond MEP | MDE: EPA regulations and prior Maryland precedent allow water‑quality based conditions beyond MEP; minimum controls are MEP or serve water quality | Court: Carroll County governs under stare decisis; permit conditions are lawful—MEP is a baseline and may be exceeded to protect water quality; minimum controls do not unlawfully exceed MEP |
| Whether impervious‑surface restoration and “good housekeeping” provisions unlawfully assign responsibility for third‑party/nonpoint discharges or exceed the MS4’s geographic scope | County: Using county/urbanized‑area baselines and crediting jurisdiction‑wide measures makes County liable for other parties’ discharges and regulates beyond MS4 service area | MDE: Conditions are water‑quality based proxies for effluent limits, permit does not require work outside MS4 watershed and allows flexibility/credit anywhere in jurisdiction; legal responsibility for third parties remains with those parties | Court: Consistent with Carroll County, assigning nonpoint reductions to point‑source permits to achieve water quality is permitted; permit does not unlawfully make County liable for third‑party point sources and may reference areas beyond MS4 as a baseline; County retains discretion to satisfy requirements within MS4 area |
Key Cases Cited
- Maryland Dep’t of the Env’t v. Anacostia Riverkeeper, 447 Md. 88 (2016) (upheld 20% impervious‑surface restoration as satisfying MEP for large MS4 permits)
- Maryland Dep’t of the Env’t v. County Comm’rs of Carroll Cty., 465 Md. 169 (2019) (held MS4 permits may include water‑quality based conditions beyond MEP and may reference areas beyond MS4 boundaries)
- EPA v. California ex rel. State Water Res. Control Bd., 426 U.S. 200 (1976) (water‑quality standards can justify more stringent effluent limitations for point sources)
- Defenders of Wildlife v. Browner, 191 F.3d 1159 (9th Cir. 1999) (addressed whether MS4 permits must meet water‑quality standards vs. be limited to MEP)
- County of Maui v. Hawaii Wildlife Fund, 140 S. Ct. 1462 (2020) (federalism and limits on Clean Water Act reach regarding discharges and state regulatory roles)
- Am. Farm Bureau Fed’n v. EPA, 792 F.3d 281 (3d Cir. 2015) (discusses interplay of nonpoint pollution and NPDES permit stringency)