318 AUTHORIZATION

AGENCY: Montana Department of Environmental Quality

WHAT IS A 318 AUTHORIZATION?

A 318 Authorization allows a temporary increase in turbidity, or cloudiness in the water caused by suspended particles, during certain stream-related construction or enhancement projects in Montana surface waters.

It is intended for short-term impacts that may occur while work is being completed in or near the water.

  • WHO IS THIS AUTHORIZATION FOR?

    A 318 Authorization may apply to landowners, agencies, businesses or contractors completing work that may temporarily increase sediment or turbidity in surface water.

    This may include work associated with a 310 Permit, SPA 124 Permit or other stream-related project.

  • DO I NEED A 318 AUTHORIZATION?

    You may need a 318 Authorization if your project is expected to temporarily increase turbidity during construction.

    This may include:

    • Streambank stabilization

    • Stream restoration or enhancement

    • Culvert or crossing work

    • In-stream construction

    • Excavation or grading near a stream

    • Other work that may temporarily disturb the streambed or banks

    In some cases, the 318 requirement may be addressed during the 310 Permit or SPA 124 Permit review process rather than through a separate application to DEQ.s.

HOW TO APPLY

  • 1. COMPLETE JOINT APPLICATION IN GILLY

    1. Create an account or log in

    2. Start a new application

    3. Select 318 Authorization if it applies to your project

    4. Complete the required application information

    5. Save your progress and return as needed

  • 2. DOWNLOAD FROM GILLY

    • Download your completed Joint Application

    • Gather any additional plans, drawings or supporting materials required by the Army Corps

  • 3. SUBMIT TO MONTANA DEPARTMENT OF ENVIRONMENTAL QUALITY (DEQ)

    After you complete it in Gilly, download the Joint Application and submit it directly to the Montana Department of Environmental Quality.

    318 Authorization applications are not submitted through Gilly.

    If the 318 requirement is being handled through your 310 or SPA 124 review, follow the instructions provided by the reviewing agency.

    https://deq.mt.gov/Water/assistance

OTHER DETAILS

  • FEE:

    $250 application fee

    The fee applies to individual 318 applications submitted directly to Montana DEQ.

  • REVIEW TIME:

    Typically 30–60 days

    Individual applications submitted to DEQ are normally processed within 30 to 60 days. If the authorization is addressed through a 310 or SPA 124 permit review, the timeline generally follows that permit process.

  • ADDITIONAL PERMITS NEEDED:

    Project dependent

    A 310 Permit, SPA 124 Permit, Section 404 / 10 Permit or other authorization may also be required depending on the project.

318 AUTHORIZATION PROJECT EXAMPLES MAY INCLUDE:

  • Stream and Bank Projects

    Bank Stabilization: Installing riprap, bioengineering or other stabilization that temporarily disturbs the stream or increases sediment.

    Stream Restoration: Reshaping channels, restoring habitat or completing other stream enhancement work.

  • Crossings & Infrastructure

    Culvert Work: Installing, replacing or repairing culverts where construction may temporarily increase turbidity.

    Stream Crossings: Building or repairing crossings that require work within the stream channel.

  • In-Stream Construction

    Excavation & Grading: Moving soil or sediment in or near the streambed.

    Construction Activities: Other short-term work in or near surface water that may temporarily increase sediment or cloudiness.