Grand Strand Water & Sewer News
Public Notice - Conway WWTP Earthen Berm Project
January 24, 2022
Public Notice
The Federal Emergency Management Agency (FEMA) and South Carolina Emergency Management Division (SCEMD) have received Grand Strand Water and Sewer Authority’s application for Federal grant funding through the Building Resilient Infrastructure and Communities Program (BRIC).
As part of the application process and in accordance with Executive Order 11988 and 44 CFR §9.12, final public notice is hereby given for Grand Strand Water and Sewer Authority’s proposed project which contains actions in or affecting the floodplain and/or wetlands. The project will conform to applicable state and local floodplain protection standards
Funding for the proposed project will be conditional upon compliance with all applicable federal, tribal, state and local laws, regulations, floodplain standards, permit requirements and conditions.
Applicant: Grand Strand Water and Sewer Authority
Project Title: Conway WWTP Earthen Berm Project
Location of Proposed Work:
For acquisitions and elevations – The area affected by this project consists of one (1) existing site known as the Conway Wastewater Treatment Plant constructed in 2003 in Horry County, South Carolina being specifically located at 2915 New Road, Conway.
Planning Factors and Considerations:
Several significant factors were considered as part of this project, including, but not limited to:
- Consistency with local goals and initiatives to reduce contamination impacts from flooding events;
- The economic impact to the community associated with loss of sewer service.
Proposed Work and Purpose:
Water and wastewater services are provided to the City of Conway and surrounding areas by Grand Strand Water and Sewer Authority (GSWSA). This project consists of an earthen berm located around all structures (excluding oxidation ponds) and is being proposed to make much needed improvements to the wastewater treatment plant in the City of Conway in order to prevent flooding and associated damage and loss of sewer service to customers in the future. GSWSA is seeking Hazard Mitigation funding under DR-4492-SC and/or BRIC funding for the construction of the berm.
The Conway Wastewater Treatment Plant (WWTP) in the City of Conway is permitted to treat 4 MGD and currently operates at approximately 75%, serving 37,500 customers according to the NPDES permit application last submitted in 2017. The plant has been heavily impacted by flooding due to an increase in hurricanes and major rain events in recent years. The higher and more sustained flooding that has been experienced threatens the ability of the plant to treat and contain wastewater.
The plant has experienced two significant flooding events since 2015, both after a hurricane. When the plant floods, there is disruption in operations and customer sewer service is impacted. There is no place to divert the flood water flows. With the number and severity of hurricanes and major rain events increasing, it is unlikely that that flood events of recent years will be isolated incidents.
The proposed solution to the repeated flooding is to build a barrier that includes an earthen berm around the plant to prevent floodwater from flowing into the plant and to install a pump station in a low-lying area within the plant property to pump out any rain or floodwater that cannot flow out of the property once the gates are closed. The flood elevation from the FEMA FIRM panel is approximately 10 feet. The top of the proposed berm will be at an elevation of 16 feet, approximately two feet above the previous storm of 13.77 feet. The storm elevation was provided by USGS Flood Event Viewer. The barrier will consist of approximately 17,000 cubic feet of fill material. A pump station will be located in a low area of the site. The pump station will likely have a submersible pump with the ability to transfer water outside of the barrier wall for average rain events as well as assist in dewatering the site during catastrophic events. The pump size will be selected based on the 2, 10, and 25 year/ 24-hour rainfall frequencies (Available from NOAA) for the area (3.86 inches (2 year), 6.36 inches (10 year), and 7.84 inches (25 year), and the area of the site that will drain to the pump station. Project engineers will estimate volume of run-off by modeling the site in HydroCAD. Using the projected run-off, a pump selection will be made
Project Alternatives:
Since it is not economically feasible to relocate the WWTP itself to higher ground or elevate each onsite structure required for operation, no other alternatives were considered due to cost effectiveness.
Comment Period:
Comment period must be open for a minimum of 15 days; therefore, comments are due by close of business on February 8, 2022.
Comments are solicited from the public; local, state or federal agencies; and other interested parties in order to consider and evaluate the impacts of the proposed project. The comments can be made in writing and addressed to GSWSA, Attn: Nichole Boyd Clemons, PO Box 2368, Conway, SC 29528 or by email to [email protected].
Maps:
A map of the project area is available for public inspection at Grand Strand Water & Sewer Authority’s Administration Center located at 166 Jackson Bluff Road, Conway, SC 29526.
Point(s) of Contact:
For additional information, please contact:
Nichole Boyd Clemons
Engineering/Operations Supp. Supervisor
Phone: 843-443-8258
Email: [email protected]
