By Hailey Murphy, S.C. Sea Grant Consortium.
Co-Investigator Guinn Wallover (lower far right of frame) of Mount Pleasant Waterworks, and Cailyn Spedding, Piper Monk, and Cam Kwiatkowski, graduate and undergraduate research assistants at the College of Charleston, collect groundwater samples. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
Researchers at the College of Charleston, Clemson University, and Mount Pleasant Waterworks are investigating solutions to improve the longevity of waste treatment systems in the Town of Mount Pleasant.
Identified by resilience researchers as a topic of major concern, South Carolina’s coastal on-site wastewater treatment systems (OWTS), better known as septic systems, are facing compounding challenges: shallow water table conditions, projected sea level rise, increased frequency and intensity of rain and storm events, and a rapidly expanding population.
As coastal populations expand, OWTS installation and use are growing as well. Current permit design standards and regulations in South Carolina are unable to compensate for site conditions in the Lowcountry, thus, nearby water bodies may be vulnerable to wastewater discharge into shallow groundwater.
Diagram illustrating a cross section of conventional septic-system engineering for wastewater control, with arrows identifying the movement of materials through the system and soil layers before entering the groundwater. Graphic credit: Hailey Murphy/S.C. Sea Grant Consortium based on the original from Pipeline by National Small Flows Clearinghouse, Summer 1995.
One of the Consortium’s current funded research projects, “SOS (Solutions on Septic): Identifying Resilient Solutions for Septic Management in Coastal South Carolina,” led by Principal Investigator Timothy J. Callahan, Ph.D., of the College of Charleston, aims to understand and address the current OWTS and groundwater conditions. By producing data-based solutions for improved policy, regulation, and outreach, the team hopes to inform residents, decision-makers, and water management teams on the best path to support clean groundwater and healthy ecosystems in their community.
Co-Investigator Guinn Wallover of Mount Pleasant Waterworks and Piper Monk, graduate research assistant at the College of Charleston, analyzing total dissolved solids, and measuring pH and temperature. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
Co-Investigators include:
- Guinn Wallover, Mount Pleasant Waterworks.
- Amy E. Scaroni, Ph.D., Clemson University.
- Jestine Deepe, Mount Pleasant Waterworks.
This project is supported by partnerships with the College of Charleston’s EVSS program and Lowcountry Hazards Center; Clemson University’s Baruch Institute of Coastal Ecology and Forest Science; University of South Carolina’s North Inlet-Winyah Bay National Estuarine Research Reserve; Charleston Waterkeeper; Mount Pleasant Waterworks; and Charleston County.
Throughout the two-year project timeline (2024-2026), researchers will assess OWTS vulnerability in coastal communities in South Carolina and provide recommendations for a community-level septic system management strategy.
Maggie Garrigan, undergraduate research assistant at the College of Charleston, equipped with a peristaltic pump and tubing, collecting groundwater samples near the Wando River. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
The project team is compiling a database of multi-year groundwater elevation data for coastal South Carolina; developing a tool focused on sea level rise and groundwater elevation change to aid in identifying future scenarios in coastal communities; and assessing a catalog of OWTS management to evaluate current regulatory and incentive programs and manager feedback.
The team is currently conducting water sample testing on groundwater at four sites around the Mount Pleasant community to identify water elevation and quality, indicators of septic performance. Next, the team will be conducting surveys and interviews and holding focus group meetings with OWTS owners and stakeholders to assess septic owners’ current maintenance practices and identify solutions to assist communities in preventing septic failure. Meetings will be held in summer 2025 in select communities in Mount Pleasant.
Spedding conducts analysis in the lab at Mount Pleasant Waterworks. Photo credit: Hailey Murphy/S.C. Sea Grant Consortium.
By fall of 2026, the team aims to compile water data from the study into a dataset for water and septic managers; create a publicly accessible model for evaluating OWTS failure in current and future sea level rise scenarios; incorporate community input from OWTS owners; and share a septic management solutions plan for coastal decision-makers.
For more information, contact Timothy J. Callahan, Ph.D., Interim Associate Dean of Natural and Environmental Sciences and Professor of Geology and Environmental Geosciences at the College of Charleston.
Learn more about Consortium projects related to the Effects of Groundwater on Septic Systems in South Carolina.
The Sea Grant College Program relies on federal funding that is currently threatened. This funding is critical in providing research into vital coastal issues, such as water quality and disaster preparedness. The Consortium urges South Carolina residents and businesses to express support for the Sea Grant College Program to their elected officials. With your support, we can positively convey to elected leaders in Washington how important the South Carolina Sea Grant Consortium and the other 33 Sea Grant programs are to our coastal communities and businesses. Please contact info@scseagrant.org for more information on how to help.