NWP 48: Commercial Shellfish Mariculture Activities

Structures or work in navigable waters of the United States and discharges of dredged or fill material into waters of the United States necessary for new and continuing commercial shellfish mariculture operations (i.e., the cultivation of bivalve molluscs such as oysters, mussels, clams, and scallops) in authorized project areas.

Acreage limit

The 2026 rule states no acreage limit for NWP 48. Eligibility turns on the activity description in the rule text and the general conditions that apply, not on a numeric cap.

Pre-construction notification: Conditional

PCN required if the activity directly affects more than 1/2-acre of submerged aquatic vegetation.

If a PCN is required, general condition 32 gives the district engineer 30 calendar days to determine whether it is complete, then up to 45 calendar days from receipt of the complete PCN to respond before the permittee may proceed. Those are two separate clocks, not one.

Source

Federal Register citation: 91 FR 768
Effective date: March 15, 2026
Cited text: 91 FR 768 - Reissuance and Modification of Nationwide Permits (final rule, 8 Jan 2026) Read the rule

What this page does not tell you

District regional conditions. Any of the 38 USACE districts can narrow NWP 48, add a notification requirement beyond general condition 32, or revoke the permit entirely inside its boundaries. PermitBird holds no compiled regional conditions yet. Check the district.
State Clean Water Act Section 401 certification. Each of the 54 states and territories must certify, condition, waive or deny use of this permit before it authorises a discharge there. PermitBird holds no compiled certification yet. Check the state.