Changes Underway: The Army Corps Modifies NWP 48 and Retires NWP 56

In 1972, Congress passed the Clean Water Act (CWA) which granted the United States Army Corps of Engineers (Corps) the power to issue permits regulating certain activities over navigable waters. In 1977, Congress expanded the scope of this authority by permitting the Corps the power to issue nationwide permits (NWP) with the condition that said permits adhere to certain requirements, in particular that they “will cause only minimal adverse environmental effects . . . and will have only minimal cumulative adverse effects on the environment.”¹ In adherence to the CWA these permits may be in effect for no longer than a five year period, but can be reissued.²

In June 2025, the Corps published a proposal to reissue certain existing NWPs, modify others, and not reissue a few. Most notably the Corps is choosing to modify NWP 48 and not reissue NWP 56.³

1. Modifications to Nationwide Permit 48: Commercial Shellfish Mariculture Activities

In 2007, NWP 48 was created to regulate and authorize ongoing shellfish activities throughout the United States. These activities include the active discharging of dredged or fill material into all “Waters of the United States” (WOTUS) and ongoing work or structures in navigable waters such as nets, cages, and buoys for shellfish related purposes.⁴ NWP 48 was reissued in 2017 with a modification prohibiting activities that directly affected more than one half acre of submerged aquatic vegetation beds—specifically in areas that had not been used for commercial shellfish activities in the past 100 years.⁵

Environmental groups challenged this change and argued that the Corps did not appropriately consider its full impact. In Coalition to Protect Puget Sound Habitat v. U.S. Army Corps of Engineers (Protect Puget Sound), environmental groups claimed that NWP 48 violated the CWA, the National Environmental Policy Act (NEPA), and the Endangered Species Act (ESA), by issuing a NWP for activities that have more than minimal environmental impact.⁶ By authorizing all shellfish aquaculture activities in the United States through one NWP, the groups argued that it is extraordinarily difficult to appropriately assess those impacts. Ultimately, the district court in Protect Puget Sound concluded that the Corps’ conclusions were at odds with the scientific record and that they failed to “adequately consider the impacts of commercial shellfish aquaculture activities authorized by NWP 48.”⁷ Despite the court’s conclusion it did not implement a nationwide block on the permit, but rather only blocked it from being applied to the state of Washington’s waters.⁸ Following this suit, the Corps abandoned the seemingly rigid half acre limitation and replaced it with a pre-construction notification (PCN) requirement.⁹ This meant that any project affecting more than a half-acre would be considered on a case-by-case basis. In its June 2025 proposal, the Corps formalized the Court's ruling by explicitly stating that NWP 48 does not apply to the state of Washington.

2. The Corps Declines to Reissue Nationwide Permit 56: Finfish Mariculture Activities

In 2021, NWP 56 was created to promote and streamline licensing for commercial finfish mariculture activities. These activities include building structures such as nets or cages in marine and estuarine waters for the purpose of cultivating finfish. Since its inception NWP 56 has drawn significant attention and criticism from environmental protection groups.

In Don’t Cage Our Oceans v. U.S. Army Corps of Engineers, the environmentalists argued that NWP 56 was unlawful because it authorized an activity which had more than a minimal adverse effect.¹⁰ Additionally, they argued that the Corps failed to do the proper analysis required by Section 10 of the Rivers and Harbors Act of 1899 (RHA) and NEPA.¹¹ The district court agreed and held that the permit violated both statutes and that the Corps had failed to conduct the proper analyses required.¹²

In its remedy the court issued a prospective vacatur of NWP 56, meaning that the Corps could not issue new permits under NWP 56, but previously issued permits would remain in place.¹³ As a result of this litigation the Corps has decided to not reissue NWP 56 in favor of issuing individual permits on a case-by-case basis. Some environmentalists may view this decision as a major victory in protecting marine ecosystems. However, others may argue that this decision is a setback or unnecessary regulatory burden on the U.S. seafood industry which in recent years has struggled to compete internationally.

For more information on the Don’t Cage Our Oceans litigation, see:

Don’t Cage Our Oceans: Challenging the Army Corps’ Nationwide Permit for Commercial Finfish Aquaculture and

Don’t Cage Our Oceans: The Army Corps’ Nationwide Permit for Commercial Finfish Aquaculture Found to be Unlawful

¹ 33 U.S.C. § 1344.
² Id.
³ Proposal to Reissue and Modify Nationwide Permits, 90 Fed. Reg. 26,100–26,167 (June 18, 2025).
⁴ Reissuance of Nationwide Permits, 72 Fed. Reg. 11,092–11,198 (Mar. 27, 2007).
⁵ Issuance and Reissuance of Nationwide Permits, 82 Fed. Reg. 1,860–2,008 (Jan. 6, 2017).
⁶ 417 F. Supp. 3d 1354, 1357 (W.D. Wash. 2019).
⁷ Id. at 1367.
⁸ Id. at 1369.
⁹ Reissuance and Modification of Nationwide Permits, 86 Fed. Reg. 2,744–2,877 (Jan. 13, 2021).
¹⁰ 2024 U.S. Dist. LEXIS 177843, 2024 WL 4349548, at 8 (W.D. Wash. Sept. 30, 2024).
¹¹ Id. at 7.
¹² Id. at 10.
¹³ Don’t Cage Our Oceans v. U.S. Army Corps of Eng’rs, 2025 U.S. Dist. LEXIS 48209, 2025 WL 835058, at 2 (W.D. Wash. Mar. 17, 2025).