Construction stormwater permit for Enbridge Line 3

Construction on the proposed Enbridge Line 3 pipeline cannot occur without the Minnesota Pollution Control Agency issuing water quality and air permits, as well as permits from the MN DNR and the U.S. Army Corp of Engineers. The MPCA is expected to make a final decision on the required Line 3 permits before November 14, 2020.

A Construction Stormwater general permit is a general permit that the agency has up to 30 days to review and approve. The submittal and consideration of the construction stormwater applications are allowed because the environmental review process is complete.

Current status

Line 3 Replacement Project

Enbridge Energy, Limited Partnership applied for coverage under the Construction Stormwater general permit for the Line 3 Replacement project on October 19th, 2020. The application is currently under review. You can find the application here:

Storage and laydown yards

Precision Pipeline Limited and Michels Corporation applied for coverage under the Construction Stormwater general permit for 24 storage and laydown yards associated with the Line 3 replacement project. All 24 applications have been reviewed and the permits have been issued. You can find the applications here:

Construction on the proposed Enbridge Line 3 pipeline cannot occur without required permits and certifications by state agencies and the U.S. Army Corps of Engineers. The approved applications for storage and laydown yards do not authorize any construction on the Line 3 replacement project.

Storage yard usage

The storage and laydown yards range from 5 to 116 acres in size and will be used to support construction activities on the main Line 3 project if required permits are approved. The yards will be utilized as an interim location for storing timber mats, weighted saddle bags, preparing and storing concrete coated pipe, and to support general storage, laydown and construction activities for the proposed pipeline construction. Activities and equipment at the storage yards may include:

  • Offloading of timber mats from semi-trucks, storing equipment and supplies, and conducting daily safety and task meetings.
  • Several semi-truck trailers joined together for storage of smaller items.
  • Construction trailers for field office locations for project personnel to park, assemble and dispatch.

Stormwater Pollution Prevention Plans (SWPPP)

To obtain a Construction Stormwater general permit, Enbridge or its contractors must develop a Stormwater Pollution Prevention Plan (SWPPP), specific to the project, which details how the requirements of the permit will be met. The SWPPP identifies the practices that will be implemented at the project to protect the environment and meet the requirements of the general permit. The SWPPP becomes an enforceable part of the permit. To ensure that the activities at proposed storage yards will not negatively impact water quality, the applicant must submit a detailed SWPPP.

  • SWPPPs reflect the project at the time of application and are considered living documents.
  • SWPPPs are required to be amended if site conditions change in order to meet permit requirements throughout the life of the project and control stormwater discharges from the site.
  • Common best management practices on these types of sites are perimeter controls including silt fence or sediment logs, temporary and permanent stabilization with seed and mulch. These practices are required to keep sediment on site and prevent sediment laden discharges to waters of the state.

Construction Stormwater general permit

When a project includes land-disturbing activities totaling an acre or more, a Construction Stormwater general permit must be obtained from the Minnesota Pollution Control Agency. Land-disturbing activities are regulated by this permit because they have the potential to allow stormwater—runoff caused by rain and snowmelt—to carry dirt and pollutants into our lakes, rivers and streams. The Construction Stormwater general permit requires the installation and maintenance of management practices to reduce potential pollution.

The current Construction Stormwater general permit was issued and became effective in August 2018. Prior to its issuance the permit went through a public-notice and comment process. When an applicant seeks coverage under this permit, there is no additional public comment period. When an applicant has submitted a complete and accurate application in accordance with the requirements of the permit, they can be authorized to discharge stormwater associated with construction activity under the permit.

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