Edgefield County: regional 'paper' permit limits leave sewer capacity constrained, limiting new development

County staff reported to the Edgefield County Council that the region's wastewater system is limiting new development because the Horse Creek Wastewater Treatment Plant has reached its permitted capacity, even though the plant currently treats less than its physical rating.

John, the county staffer who briefed the council, said Edgefield operates two local treatment plants — the Brook Street plant (rated 750,000 gallons per day) and a Johnston plant (rated 900,000 gallons per day) — but that most flow from the county’s industrial customers and from Trenton South development travels on an 18-inch force main to the Horse Creek plant. He said Horse Creek’s physical rating is 20,000,000 gallons per day and it generally treats roughly 12–13 million gallons on an average day, rising toward 15 million during rain events, which leaves some physical capacity but no DHEC-authorized permit capacity.

“That’s kind of the capacity piece of the puzzle,” John told the council, explaining the difference between physical capacity (what the lines and plant can carry or treat) and permit (paper) capacity, the latter set by the state regulator DHEC and used to allocate future development’s sewage loads.

To free up permit capacity, utilities contributing to Horse Creek are conducting audits of permitted but unbuilt allocations and removing projects that were never built. Horse Creek also is designing and permitting a planned 6,000,000-gallon-per-day upgrade; county staff said Horse Creek may be allowed to allocate capacity against that planned expansion. Edgefield has submitted a request through North Augusta to Horse Creek for about 75,000 gallons per day to honor prior willingness-to-serve letters and early applicants.

Short-term relief options described to the council include: (1) auditing and striking unbuilt permitted allocations to free “paper” capacity; (2) asking North Augusta/Horse Creek to allocate a small amount of capacity (the county’s current request is about 75,000 gpd); and (3) negotiating to buy capacity from North Augusta when and if it is available. Staff cautioned that Edgefield’s own plant expansion options are financially constrained — the county is in the middle of roughly a $13 million water-plant upgrade with another $20–$30 million in possible projects on the horizon — and pumping sewage long distances to treat elsewhere is not economically sensible for lower-end parts of the county.

Looking farther ahead, staff said Edgefield has discussed building its own large-scale wastewater treatment plant to secure local control, but the county would face a major challenge finding an acceptable receiving stream for discharge; the Savannah River is used for drinking water withdrawal in multiple jurisdictions, and Edgefield has limited river frontage for discharge.

Council members asked whether a medium-sized industry or a 100–200-home subdivision could be permitted immediately; staff’s answer was no unless the developer holds a prior written willingness-to-serve letter or other preexisting allocation. A council member described the effect as an effective moratorium on new sewer-dependent development until permit capacity is resolved. Council also raised an unresolved question about a prior upgrade (referenced by a member as $40,000,000) and whether it produced additional permit capacity; staff said they had no definitive answer and that those questions remain under review.

Next steps: county staff said they are continuing daily negotiations with North Augusta representatives, awaiting Horse Creek’s response on the requested 75,000 gpd allocation and continuing the permit-audit process. Council was told staff hopes for resolution in the near term but could not give a firm timeline.