NWP 6Effective 2026-03-15

Survey Activities

Requirements at a Glance

  • No Pre-Construction Notification (PCN) required
  • Maximum impact area: 0.1 acres
  • Authorized under Section 10 and Section 404
  • Discharge for temporary pads cannot exceed 1/10-acre
  • Exploratory trenches must be restored to pre-construction elevations
  • Trenches cannot be constructed or backfilled in a way that drains waters of the U.S.
  • Top 6 to 12 inches of a trench in wetlands must be backfilled with native topsoil
  • Does not authorize drilling or discharge from oil and gas test wells
  • Permanent structures and road fills are not authorized

Purpose & Scope

Nationwide Permit 6 authorizes various survey activities in waters of the United States. These activities include core sampling, seismic exploratory operations, and the plugging of seismic shot holes or other exploratory-type bore holes. It also covers exploratory trenching, which is defined as mechanical land clearing of the upper soil profile to expose bedrock or substrate for mapping or sampling. The permit allows for the construction of temporary pads, provided the discharge of dredged or fill material does not exceed 1/10-acre. However, it explicitly does not authorize drilling or discharges from test wells for oil and gas exploration, nor does it cover fills for roads or permanent structures. Any areas disturbed by exploratory trenching must be restored to their pre-construction elevations and cannot be used to drain waters of the United States.

What Changed in 2026

The 2026 reissuance of NWP 6 contains no substantive changes to its terms and conditions compared to the 2021 version. The Corps reevaluated the permit's quantitative and qualitative limits and determined they remain effective in ensuring that authorized survey activities result in no more than minimal individual and cumulative adverse environmental effects. While the permit text itself was not modified, the Corps updated the supporting environmental documentation. This update incorporates the most recent national-scale ecological data, such as the 2022 National Lakes Assessment and the 2021 National Wetland Condition Assessment, to ensure the environmental baseline used for the permit's re-evaluation is current.

Who Needs This Permit?

Environmental consultants, geologists, archaeologists, and utility companies typically use this permit to conduct preliminary site investigations. It is essential for professionals performing soil surveys, wetland delineations, and historic resource surveys that require core sampling or exploratory trenching in jurisdictional waters.

Common Project Types

  • Core sampling for soil and substrate mapping
  • Seismic exploratory operations for energy resource identification
  • Exploratory trenching to expose bedrock for sampling
  • Installation of temporary pads for survey equipment
  • Wetland delineation transects and sample plots
  • Plugging of seismic shot holes and bore holes

Environmental Review

The Corps determined that reissuing NWP 6 results in 'no effect' on federally-listed endangered or threatened species or their critical habitat. This finding is based on General Condition 18, which requires project-specific ESA Section 7 consultation if an activity 'might affect' these resources; no activity is authorized until that process is complete. Similarly, compliance with Section 106 of the National Historic Preservation Act is managed through General Condition 20. Non-federal permittees must submit a Pre-Construction Notification (PCN) if an activity has the potential to affect historic properties. This case-by-case review ensures that survey activities, even those that do not typically require a PCN under the permit's specific terms, are properly evaluated for cultural resource impacts.

Frequently Asked Questions

Do I need a PCN for survey activities under NWP 6?

What is the acreage limit for temporary pads under NWP 6?

Can I use NWP 6 to drill an exploratory oil well?

Does this permit allow for the recovery of historic artifacts?

How must I backfill an exploratory trench in a wetland?

Stay current on NWP 6 updates

Get notified when regulations change — no spam, just updates that matter.


Related Permits