Public Comment for C-43 West Basin Storage Reservoir Alum Treatment pursuant to Section 408

USACE announces public comment on proposed C-43 West Basin Reservoir Alum Treatment System pursuant to Section 408

Aerial location map for the C-43 West Basin Storage Reservoir

Aerial location map of the C-43 West Basin Storage Reservoir

C-43 West Basin Storage Reservoir S-470 pump station where the alum injection system is proposed to be installed

C-43 West Basin Storage Reservoir S-470 pump station where the alum injection system is proposed to be installed

The U.S. Army Corps of Engineers (USACE) Jacksonville District announces a 30-day public comment period for the Draft Environmental Assessment (EA) and Proposed Finding of No Significant Impact (FONSI) for the approval of construction of an aluminum sulfate (alum) treatment system during the construction of the authorized C-43 West Basin Storage Reservoir (WBSR) in Hendry County, Florida. The Corps is evaluating the request from the South Florida Water Management District (SFWMD) to modify the C-43 WBSR Federal Civil Works project pursuant to 33 U.S.C. 408.

Comments are due June 5, 2023.

Due to concerns stemming from increased harmful algal blooms resulting from operation of the C-43 Basin, Executive Order 19-12, issued on January 10, 2019, directed the Florida Department of Environmental Protection (FDEP) to “work with the South Florida Water Management District (SFWMD) to add a stormwater treatment component to the C-43 Reservoir to provide additional treatment and improve the quality of water leaving this important storage component” of the Comprehensive Everglades Restoration Plan (CERP). In response, a reservoir water quality treatment system at the S-470 pump station has been proposed.

In 2020, the SFWMD conducted the C-43 Water Quality Feasibility Study and identified alum treatment as the most cost-effective treatment technology for reducing phosphorous concentrations and improving water quality for water releases from the C-43 WBSR. It was determined that in-reservoir treatment using an inline injection of the alum had substantial water quality benefits and was compatible with the existing C-43 WBSR project compared to post-reservoir treatment of the reservoir outflow. Therefore, the proposed water quality treatment feature is an in-reservoir alum injection system that would be installed at the inflow of the C-43 WBSR. Though water quality improvement is not a project purpose, the potential exists for the reservoir to provide benefits from long-term nutrient (i.e., phosphorus and nitrogen) removal.

Inline injection of alum during reservoir filling is expected to be useful in suppressing potential nuisance algal growth within the reservoir while optimizing performance of the reservoir. A key advantage of the in-reservoir alum treatment system is its ability to be designed and constructed concurrently with construction of the C-43 WBSR. The in-reservoir alum treatment system proved to be the most cost-effective option that reduced nutrients and improved the quality of water leaving the C-43 WBSR to the Caloosahatchee River and its downstream estuary, while maintaining the current C-43 WBSR construction, design, schedule, and project purpose.

The Draft EA and Proposed FONSI evaluate the environmental effects of approving the construction of the proposed inline alum treatment system as part of the C-43 WBSR under the Corps Section 408 authority and are available for review at the links below (note: it may take a few minutes to download some of the documents due to the large file size):

Section 408 Review of the Caloosahatchee River (C-43) West Basin Storage Reservoir - Reservoir Alum Treatment Project

Draft Environmental Assessment and Proposed FONSI

Appendix A

Appendix B

Appendix C

Appendix D

Notice of Availability

Please submit comments on the Draft Environmental Assessment (EA) and Proposed FONSI via email to Jacob.S.Thompson@usace.army.mil (recommended subject: “Section 408 C-43 WBSR Alum EA Comments”) by June 5, 2023.

What is Section 408?

Section 408 is the process that allows alteration to a federally authorized project. The proposed project cannot pose a risk to the public interest and will not impair the usefulness of the federally authorized project. Examples of federally authorized projects include, but are not limited to levees, dams and the federal navigation channel.

This requirement was established in Section 14 of the Rivers and Harbors Act of 1899, codified at 33 United States Code (USC) 408 (Section 408).

Section 408

Through the Civil Works program, the US Army Corps of Engineers (USACE) serves the public by providing the Nation with quality and responsive management of the Nation’s water resources.  As a result, USACE, in partnership with stakeholders, has constructed many Civil Works projects across the Nation’s landscape.  Given the widespread locations of these projects, many embedded within communities, over time there may be a need for others outside of USACE to alter or occupy these projects and their associated lands.  Reasons for alterations could include improvements to the projects; relocation of part of the project; or installing utilities or other non-project features.

In order to ensure that these projects continue to provide their intended benefits to the public, Congress mandated that any use or alteration of a Civil Works project by another party is subject to the approval of USACE.  This requirement was established in Section 14 of the Rivers and Harbors Act of 1899, which has since been amended several times and is codified at 33 USC 408 (Section 408).

Section 408 provides that USACE may grant permission for another party to alter a Civil Works project upon a determination that the alteration proposed will not be injurious to the public interest and will not impair the usefulness of the Civil Works project.

Additional Information on Section 408

USACE’s procedures for reviewing requests for Section 408 permission is contained in Engineer Circular (EC) 1165-2-220.  The corresponding internal guidance related to designating a lead district as referenced in EC 1165-2-220 can be found at this link.

To view a fact sheet with additional information about Section 408 and the revised policy, click here.

USACE reviewed and considered public comment on the draft EC 1165-2-220 to inform the final policy and procedural guidance.  To view the summary of comments received, click here.