Delaware Riverkeeper Network

Delaware Riverkeeper Network

Founded	1988
Type	Nonprofit organization
Purpose	Environmental protection; watershed advocacy; environmental rights
Headquarters	Bristol, Pennsylvania, U.S.
Region served	Delaware River watershed
Methods	Advocacy and community engagement; legal action; scientific monitoring; restoration
Key people	Maya K. van Rossum (Delaware Riverkeeper)
Website	www.delawareriverkeeper.org

Delaware Riverkeeper Network (DRN) is a nonprofit environmental organization focused on protecting and restoring the Delaware River watershed in the United States. The organization operates across Pennsylvania, New Jersey, Delaware, and New York through advocacy, community engagement, scientific monitoring, and legal action to address pollution, habitat degradation, and other threats to the river ecosystem. DRN is led by the Delaware Riverkeeper, a role currently held by environmental attorney Maya K. van Rossum.

The Delaware Riverkeeper Network was established in 1988 with the appointment of the first Delaware Riverkeeper.^[1] Its mission is to safeguard the Delaware River, its tributaries, and the communities that depend on them. DRN pursues this mission through legal and policy advocacy, scientific research, public education, and community-based initiatives aimed at improving watershed health.^[2] Throughout the 1990s and 2000s, DRN expanded its scientific monitoring programs, community partnerships, and policy advocacy efforts across the watershed.

In the early 2010s, the Delaware Riverkeeper Network played a central role in one of Pennsylvania’s most significant environmental legal battles. In 2012, DRN joined several municipalities in challenging Act 13, a state law that expanded natural gas development and restricted local zoning authority over drilling and fracking operations. The case, Robinson Township v. Commonwealth, reached the Pennsylvania Supreme Court, which in 2013 struck down key provisions of the law. Independent reporting has described the ruling as a landmark moment in Pennsylvania environmental law, noting that the decision revived the state’s long‑dormant Environmental Rights Amendment and reshaped the legal framework for environmental oversight in the Commonwealth.^[3]

DRN implements programs focused on water quality protection, habitat restoration, and community participation in watershed stewardship. Its work includes ecological monitoring, public outreach events, and campaigns addressing environmental justice, land use, and regional development impacts. The organization also assists local communities responding to pollution incidents and other environmental threats.^[4]

The Delaware Riverkeeper Network has engaged in extensive litigation across federal and state courts to challenge projects and regulatory decisions affecting the Delaware River watershed. One of the organization’s most significant early legal actions, the 2013 Pennsylvania Supreme Court decision in Robinson Township v. Commonwealth, is discussed in the History section of this article. The subsections below summarize additional major cases and regulatory challenges pursued by the organization in recent years. DRN’s litigation portfolio spans federal courts, state courts, and administrative tribunals, with cases involving the Clean Water Act, National Environmental Policy Act, Endangered Species Act, and state environmental permitting processes.

The Delaware Riverkeeper Network has pursued a multi‑year effort to secure stronger dissolved oxygen water quality standards for the Delaware River Estuary. In April 2022, DRN and partner organizations submitted a legal petition under the Clean Water Act requesting that the U.S. Environmental Protection Agency (EPA) initiate federal rulemaking to update the standards. EPA granted the petition in December 2022 and issued proposed revised standards on December 21, 2023.^[5]

Under Section 303(c)(4)(B) of the Clean Water Act, EPA was required to finalize the standards within 90 days. When the deadline passed without a final rule, DRN sent EPA a 60‑day Notice of Intent to Sue in mid‑2024. After the notice period expired without agency action, DRN filed a complaint in the U.S. District Court for the Eastern District of Pennsylvania on October 2, 2024, alleging that EPA’s delay violated the Clean Water Act.^[6]

On September 22, 2025, the U.S. Environmental Protection Agency (EPA) signed a rule revising outdated water quality standards for 38 miles of the Delaware River.^[7] This new rule, once published and implemented through permitting decisions, will require wastewater treatment plants in the Delaware Estuary to update their wastewater practices, specifically treating ammonia in their discharge.^[7] Improperly treated municipal and industrial wastewater discharges into the River have historically been a major cause of the Delaware Estuary’s poor water quality, which has included the presence of hypoxic and anoxic zones (low levels or absence of oxygen).^[8]

In March 2023, a chemical release from the Trinseo Altuglas facility in Bristol, Pennsylvania discharged thousands of gallons of latex emulsion into Otter Creek, a tributary of the Delaware River. The Delaware River spill prompted drinking water concerns in the Philadelphia region and led to temporary shutdowns of intake operations by local water utilities.^[9]

The Delaware Riverkeeper Network issued public statements following the incident and conducted on‑the‑ground assessments of affected waterways. The organization criticized delays in public notification and called for stronger oversight of industrial facilities along the river.^[10] DRN staff documented visible pollution in impacted tributaries and urged state and federal agencies to conduct comprehensive investigations into the cause, extent, and environmental consequences of the spill.^[11]

In 2024, the Delaware Riverkeeper Network joined with other environmental organizations in notifying three states (PA, NJ, DE) of their intent to sue under the federal Endangered Species Act, alleging that state actions and inaction were contributing to the unlawful killing of Atlantic sturgeon, a federally protected species native to the Delaware River.^[12] The groups later filed suit seeking to compel stronger protections and compliance with the Act.^[13]

In 2024, the DRN and Citizens for Pennsylvania's Future secured a procedural victory when the United States Court of Appeals for the Third Circuit ruled that their legal challenge to state‑issued permits for the Transcontinental Gas Pipeline Company’s (Transco) expansion project could proceed before the Pennsylvania Environmental Hearing Board (EHB). The court rejected arguments from Transco and the Pennsylvania Department of Environmental Protection that such challenges must be brought exclusively in federal court, affirming that the EHB retains authority to review state environmental permits. The decision preserved the ability of affected communities and environmental groups to contest pipeline‑related impacts on waterways, wetlands, and exceptional value streams in Bucks County and other regions of Pennsylvania. ^[14]

In 2024, the Delaware Riverkeeper Network joined a coalition of environmental organizations, an affected landowner, and several state Attorneys General in challenging the Federal Energy Regulatory Commission’s (FERC) approval of the Regional Energy Access Expansion (REAE) pipeline. The petitioners argued that FERC’s review under the National Environmental Policy Act (NEPA) did not adequately assess climate impacts or demonstrate a public need for the project.^[15]

In a unanimous decision, the United States Court of Appeals vacated FERC’s orders authorizing the project and remanded the matter to the agency for further review.^[15]

In 2025, the Delaware Riverkeeper Network responded to renewed political efforts to weaken or overturn the Delaware River Basin Commission’s (DRBC) permanent ban on hydraulic fracturing within the watershed. Reports indicated that pro‑fracking Pennsylvania legislators had met with the federal Environmental Protection Agency administrator, raising concerns that federal officials might seek to challenge the DRBC’s authority to maintain the ban.^[16] Environmental organizations, including DRN, publicly reaffirmed their support for the DRBC’s fracking prohibition and launched initiatives to defend the watershed from potential federal intervention.^[17] Coalition partners emphasized that previous attempts by industry groups, landowners, and state legislators to overturn the ban had been dismissed by the courts, and advocacy groups launched a coordinated campaign to defend the DRBC’s authority. The ban on fracking was established by the DRBC after 11 years of advocacy and broad and diverse public engagement led by Delaware Riverkeeper Network. The organization and coalition organizations publicly reaffirmed their commitment to defending the ban and supporting the DRBC’s decision. ^[18]

In 2025, the Delaware Riverkeeper Network filed a lawsuit in the United States District Court for the District of New Jersey challenging the Delaware River Basin Commission’s (DRBC) decision to grant a second extension for the proposed Gibbstown Liquefied Natural Gas (LNG) Export Terminal project in Gloucester County, New Jersey. The organization argued that the extension violated the DRBC’s Rules of Practice and Procedure, which allow only one extension of a Section 3.8 approval and require that a project remain materially unchanged and be actively pursued by the applicant.^[19]

The proposed terminal, originally approved in 2019 and upheld by the DRBC in 2020 following an administrative appeal brought by DRN, has not been constructed. The site remains subject to seasonal restrictions on in‑water work to protect endangered Atlantic sturgeon, and portions of the surrounding area are undergoing long‑term remediation for historic industrial contamination.^[20]

In September 2025, the U.S. Environmental Protection Agency finalized updated water quality standards for a 38‑mile stretch of the Delaware River between Philadelphia, Camden, and Wilmington. The rule raises dissolved oxygen requirements in this section of the river and is intended to improve aquatic habitat conditions, particularly for oxygen‑sensitive species such as the endangered Atlantic sturgeon. The EPA issued the new standards following litigation brought under the Clean Water Act by the Delaware Riverkeeper Network and other environmental groups, which argued that existing criteria did not adequately protect fish populations. Once implemented through permitting decisions, the standards will require wastewater treatment facilities discharging into the river to meet higher oxygen thresholds, including through reductions in ammonia levels. Federal and academic analyses cited in the rulemaking process noted that improved oxygen conditions could support long‑term recovery of fish species in the estuary.^[21]

Per‑ and polyfluoroalkyl substances (PFAS) are synthetic chemicals known for their persistence in the environment and potential health impacts. In 2005, DRN discovered the presence of PFAS in the Delaware River watershed by collecting tap water samples in Deepwater, New Jersey, near a DuPont manufacturing facility. This began a series of actions by the NJ Department of Environmental Protection (NJDEP), water companies, and municipalities that eventually led to New Jersey becoming the first state in the nation to adopt safe drinking water standards for a PFAS compound. Since then, other regulations controlling PFAS have been adopted. In 2025, through a court case (New Jersey v. Dupont), New Jersey reached a $2B settlement for damages by Dupont and related companies.^[22]

DRN also pursued PFAS regulation in Pennsylvania and Delaware. In 2017, DRN submitted a legal petition for rulemaking with the Environmental Quality Board (EQB) for a safe drinking water standard to be established for PFOA. The EQB accepted the petition but took no action until DRN filed a lawsuit against the State of Pennsylvania for its inaction in 2019. After litigation and public complaints, the Pennsylvania Department of Environmental Protection finally adopted maximum contaminant levels (MCLs) for PFOA and PFOS in 2023. In 2024, the EPA adopted federal safe drinking water standards for PFOA and PFOS and four other commonly found PFAS compounds. These will apply nationwide.^[23][24]

Delaware enacted legislation in 2025 requiring PFAS monitoring and public reporting for public water systems, with enforcement of federal standards beginning in 2029. DRN continues to advocate for the cessation of all PFAS use, protective environmental regulations, the accurate identification and elimination of PFAS pathways into the environment, rigorous and thorough clean-up, and for those responsible for the pollution to be made fully accountable.^[25]

The Delaware Riverkeeper Network collaborates with community groups, environmental organizations, academic institutions, and government agencies on initiatives related to watershed protection and environmental justice.^[26] The organization participates in regional and national coalitions, supports grassroots campaigns,^[27] and provides resources to communities responding to environmental threats. DRN also engages in public education efforts, including workshops, outreach events, and advocacy campaigns focused on river health and sustainable land use.^[28]

The Delaware Riverkeeper Network is led by the Delaware Riverkeeper, a position currently held by environmental attorney Maya K. van Rossum.^[29] The Delaware Riverkeeper serves as the organization’s chief advocate, representing the river and its communities in regulatory proceedings, public forums, and legal actions. The organization includes a multidisciplinary staff of approximately 20 members, including scientists, attorneys, technical experts, community organizers, and environmental advocates who support its programs and initiatives.^[30] DRN’s leadership structure emphasizes legal advocacy, scientific research, and community engagement, with senior roles such as a Deputy Director, Senior Attorneys, a Chief Innovation Officer, and program directors overseeing areas including habitat restoration, watershed monitoring, and community outreach.^[31]

• Delaware River Basin Commission
• Environmental justice