Defending the Citizen Suit in 2026: New Threshold Defenses, Constitutional Challenges, and Pricing the Case

Andrew C. Silton, Principal and Co-Chair, Water Practice | Beveridge & Diamond PC

Andrew C. (Drew) Silton is a Principal in the Washington, DC office of Beveridge & Diamond PC and Co-Chair of the firm’s Water practice. He led the firm’s team in City & County of San Francisco v. EPA, 145 S. Ct. 704 (2025), in which the Supreme Court held that EPA and the states lack Clean Water Act authority to make permittees responsible for the overall condition of their receiving waters, and he has defended multiple citizen suits, including cases of first impression.His practice centers on high-stakes litigation, enforcement defense, and regulatory counseling on water pollution control and water quality problems.

• Education & Credentials

Drew earned his J.D., magna cum laude, from Georgetown University in 2011, where he was elected to the Order of the Coif, and his B.A. in Biology and History from the University of Virginia in 2008, where he was a Phi Beta Kappa member and an Echols Scholar. He is admitted to the bars of the District of Columbia, Pennsylvania, and Virginia, and to practice before the U.S. Supreme Court, the U.S. Court of Appeals for the Ninth Circuit, the U.S. District Court for the Eastern District of Pennsylvania, and the Virginia Supreme Court.

• Recognition & Leadership

Chambers and Partners USA named Drew “Up and Coming” in Environmental Law for 2026. Bloomberg Law listed him among “They’ve Got Next: The 40 Under 40” in Environmental Law and Appellate for 2025, Law360 named him a Rising Star in Environment for 2025, and The American Lawyer recognized him as Runner-Up Litigator of the Week in March 2025. He was also recognized by Best Lawyers “Ones To Watch” in Environmental Law from 2021 through 2023 and as a Super Lawyers Washington, DC Rising Star from 2020 through 2022. Within the firm, he co-chairs the Water practice.

• Professional Involvement

Drew is a frequent speaker on Clean Water Act litigation and permitting. In September 2026 he and Erika Spanton presented a National Association of Clean Water Agencies webinar on the implications of San Francisco v. EPA, and he has addressed that decision at the California Association of Sanitation Agencies Annual Meeting and the WEF/WEAT Collection Systems and Stormwater Conference. He speaks regularly at NACWA’s National Clean Water Law & Enforcement Seminar and Water Environment Federation conferences, has presented for the Association of Corporate Counsel on NPDES permitting, and co-authored a paper on biosolids land application in the Proceedings of the Water Environment Federation.

• Experience

Beyond the San Francisco matter, Drew helped bring that case to the Supreme Court’s merits docket and has mounted other appellate challenges to agency and local government actions. He defends large Clean Water Act enforcement actions, including for multiple large cities and public utilities facing DOJ, EPA, and state actions over wet weather discharges, and he negotiated one of the first federal consent decrees addressing stormwater violations during utility-scale solar facility construction.

Erika H. Spanton, Principal and Co-Lead, Water Practice | Beveridge & Diamond PC

Erika H. Spanton is a Principal in the Seattle office of Beveridge & Diamond PC, where she co-leads the firm’s Water Practice. Her mixed practice of litigation, regulatory, and white collar defense work focuses on water quality, Safe Drinking Water Act, and marine decarbonization matters. Her recent results include negotiating early, favorable resolutions of Clean Water Act citizen suits in California and Washington and defeating class certification in high-stakes California litigation.

• Education & Credentials

Erika earned her J.D. from Lewis & Clark in 2008 with a Certificate in Environmental & Natural Resources Law; she served as Lead Articles Editor of the Lewis & Clark Law Review and received the First Year Honors Appellate Brief and the Pro Bono Honors Award. She earned her B.A., magna cum laude, from Middlebury College in 2004 in Environmental Studies, with high honors, and Political Science. She is admitted to the Washington bar and to the U.S. District Courts for the Western and Eastern Districts of Washington.

• Recognition & Leadership

Erika was recognized in Best Lawyers: Ones To Watch for 2025 in Environmental Law and Environmental Litigation. In addition to co-leading the firm’s Water Practice, she co-founded and leads its Fisheries & Aquaculture industry group. She serves as Vice Chair of the Water Resources Committee Year in Review for the American Bar Association’s Section of Environment, Energy, and Resources and as Co-Chair of the National Association of Women Lawyers’ Energy and Environmental Law Affinity Group.

• Professional Involvement

Erika is active in the National Association of Clean Water Agencies, the Pacific Northwest Clean Water Association’s Government Affairs Committee, the Washington State Bar Association’s Environmental & Land Use Law Section, and the King County Bar Association’s Environmental & Land Use Section. She also serves on the Environmental Law Institute’s Emerging Leaders Initiative Steering Committee and its Women in Environmental Law & Leadership Steering Committee, the Education Committee of Women in Environment, and participates in the D.C. Environment & Energy Associations.

• Experience

Erika has significant federal and state trial and appellate experience, including first-chairing numerous arbitrations and trials. On the regulatory side, she works across federal and state stormwater, wastewater, spill prevention and countermeasure (SPCC), and Safe Drinking Water Act requirements, including audits, compliance assessments, internal investigations, and penalty reduction negotiations, and she helps clients through challenging NPDES permit applications and modifications.

Garrett Jansma, Senior Counsel | Allen Matkins

Garrett Jansma is Senior Counsel in the Orange County office of Allen Matkins, where his practice centers on environmental litigation and regulatory compliance with substantial experience in Clean Water Act counseling and defense. He advises data center and other industrial and commercial clients on responding to citizen suits and government enforcement actions, and he represents clients in federal and state courts and before environmental agencies in matters involving CWA citizen suits, hazardous waste and regulated substances, California Air Resources Board enforcement, and Proposition 65 claims.

• Education & Credentials

Garrett earned his J.D. from the UCLA School of Law and his B.A. from Claremont McKenna College. He is admitted to practice in California.

• Recognition & Leadership

Garrett writes the California Stormwater Defense Blog and has published a series of recent analyses on citizen-suit defense, including “The 60-Day Notice: What It Is, What It Means, and What to Do When You Get One,” “Citizen Suits at a Constitutional Crossroads,” “Did CCSF Actually Change Anything?,” “‘A Cottage Industry’: The Economics of CWA Citizen Suit Enforcement,” and “The Environmental Plaintiffs: A Guide to the Organizations Filing Stormwater Citizen Suits in California.”

• Professional Involvement

Garrett presented at Water Solutions 11, hosted by UCI Beall Applied Innovation in Irvine, California, and his commentary on the citizen-suit campaign targeting California wineries appeared in Wine Business.

• Experience

With nearly 20 years of experience, Garrett counsels clients on environmental permitting, including NPDES and stormwater permits, and helps them build environmental compliance programs, drawing on his own in-house experience. Before joining Allen Matkins, he served as in-house environmental counsel and environmental compliance team manager for one of the world’s largest data center companies.

SESSION 1 – Barring or Narrowing the Citizen Suit in 2026: Constitutional Challenges, Diligent Prosecution, CCSF, and Mootness | Garrett Jansma | 12:00pm – 1:00pm

This session examines the threshold defenses now available to end or narrow a citizen suit before reaching the merits. It begins with emerging constitutional and executive-branch challenges, including PLF’s Article II and private nondelegation arguments in West Virginia Rivers Coalition v. Amsted Graphite and Tennessee Riverkeeper v. City of Springfield, DOJ’s position in NAACP v. xAI Corp. that its right to intervene includes the right to dismiss, and EPA’s “compliance first” policy as a potential avenue for resolving disputes with the agency during the 60-day notice period.

The session then addresses Suncor, focusing on the diligent prosecution bar, claim-by-claim matching, and waiver risks. It next examines how CCSF has fared in the Ninth Circuit, including Judge Davila’s Sunnyvale rulings and Puget Soundkeeper v. Port of Tacoma, which have so far preserved the enforceability of receiving-water terms “in the interim.” Finally, the session considers Naples and how obtaining permit coverage after a suit is filed may moot a no-permit claim, including the evidentiary record a defendant must establish to support that defense.

BREAK | 1:00pm – 1:10pm

SESSION 2 – Beating the Preliminary Injunction and Modeling Penalty Exposure in Citizen Suit Defense | Erika H. Spanton & Andrew C. Silton | 1:10pm – 2:10pm

This session equips defense counsel with the analytical tools to defeat or narrow a preliminary injunction in an environmental citizen suit and to model, contest, and mitigate civil penalty exposure through trial. Drawing on the Fourth Circuit’s June 2026 Chemours ruling and the Middle District of Pennsylvania’s July 2026 Modern Landfill penalty opinion, attendees will learn how to attack irreparable harm findings, cross-examine plaintiff experts on injury pathways, and construct a competing economic benefit calculation using EPA’s BEN model. Attorneys will leave with a framework for conducting penalty-phase discovery, retaining engineering experts, and presenting gravity-factor evidence that drives the ultimate penalty number down.