Grease Trap Regulations in South Carolina

Overview

If you run a restaurant in South Carolina, you must follow FOG rules. FOG stands for fats, oils, and grease. Two groups set the rules. The South Carolina Department of Environmental Services (DES) handles state oversight. Local water and sewer utilities handle most day-to-day enforcement.

The state does not have one law that requires used cooking oil recycling. Instead, cities and counties write their own rules. Some require recycling. Most require grease trap installs, regular cleaning, and clear records. The state's restaurant industry keeps growing. So local agencies push harder on FOG rules to protect aging sewer pipes from clogs and overflows.

Governing Authorities

The South Carolina Department of Environmental Services (DES), formerly DHEC, regulates grease traps under SC Code of Regulations 61-56, Section 201.2. This applies most often to food service sites on septic systems (SC DES regulations). If your site connects to a city sewer, the local utility takes the lead.

Key local enforcement bodies include:

• Columbia Water runs a Commercial FOG Program. It enforces standards under the City Code of Ordinances, Sewer Use Ordinance Section 23-117 (Columbia City Code).
• Charleston Water System (CWS). Its Wastewater Collection team reviews and approves grease trap plans. It also inspects traps after install and checks back regularly.
• Renewable Water Resources (ReWa) serves Greenville County and parts of Anderson, Laurens, Pickens, and Spartanburg Counties. ReWa permits and inspects sites and requires flow calculations under SC DES regulation 61-67.
• Dorchester County Water & Sewer requires grease interceptors at all commercial food sites. That includes restaurants, motels, hotels, cafeterias, bakeries, and schools.
• Rock Hill Utilities runs a Grease Discharge Permit program for FOG-generating businesses.
• Spartanburg Sanitary Sewer District (SSSD) runs a grease control program to stop FOG blockages and overflows.

Key Requirements

Grease Interceptor Sizing and Installation:

• For septic systems, no grease trap may hold less than 1,000 gallons of liquid. You also cannot use an interior trap in place of a properly sized exterior grease trap (SC Reg. 61-56).
• City sewer systems also usually require interceptors of at least 1,000 gallons.
• State law requires grease traps to hold wastewater for at least 30 minutes.
• All grease traps must be reachable from the surface. Each must have an extended outlet sanitary tee. The tee must end six to twelve inches above the tank bottom.

Cleaning Frequency:

• Charleston Water System requires grease traps and interceptors to be fully pumped and cleaned at least four times a year. The CWS Inspector can require more.
• Columbia rules require cleaning when FOG and solids reach 25% of the trap's capacity. Or every 90 days. Whichever comes first.
• Grease interceptors should be cleaned at least every six months. Real-world schedules range from weekly to twice a year. Your volume drives the pace.
• Some cities require cleaning as often as needed, even daily. The gap between cleanings cannot exceed 90 days.

Record-Keeping and Permits:

• Columbia requires you to keep maintenance logs on-site for 2 years.
• Many rules require cleaning and maintenance records for at least 3 years. You must show them to city inspectors on request.
• Dorchester County requires records for 3 years.
• All food service sites must use a DHEC-licensed waste hauler or pumper. The hauler must remove all contents.
• ReWa runs a permit and Grease Interceptor certification system. All food service customers fall under a general permit. The permit lists conditions for sewer connection.

Discharge Limits:

• Charleston Water System sets a FOG discharge limit of 100 mg/l.
• Dorchester County bans wastewater with animal or vegetable fats, oils, or grease above 100 mg/liter unless the county approves it first.

Fines and Enforcement

South Carolina cities use inspections, warnings, and rising penalties to drive compliance:

• Fines can reach $10,000 per violation per day under the SC Pollution Control Act. Health departments can issue warnings or order a business closed. You can also be billed for sewer cleanup costs (SC Code §48-1-330).
• In Columbia, fines can run from $500 to $2,000 per day. The city can revoke your permit. Severe or repeat cases can lead to closure.
• Charleston Water System warns that going over the discharge limit can trigger costly enforcement to bring your trap back into compliance.

Enforcement uses both scheduled and surprise inspections. Cities check trap maintenance during these visits. Dorchester County inspects grease traps every quarter. The county confirms cleaning schedules are being followed.

Major City FOG Programs

Columbia

The City of Columbia runs a FOG program under Sewer Use Ordinance Section 23-117. The ordinance sets limits on what businesses may send into the city's sewers. The city expanded routine inspections into the Commercial FOG Program in 2009. It also hired the first full-time FOG inspector that spring.

Columbia rules require grease trap cleaning when FOG and solids hit 25% of capacity. Or every 90 days. Whichever comes first. Larger interceptors need cleaning at least every six months. Frequency can range from weekly to every six months.

Food service sites must submit FOG applications. They must also keep detailed maintenance logs. The program works. Columbia logged only three sanitary sewer overflows tied to grease clogs in FY17-18.

Charleston

Charleston Water System (CWS) requires food service sites on its sewer system to install and maintain grease traps. The Wastewater Collection team reviews and approves plans, inspects traps after install, and checks back regularly.

Grease traps and interceptors must be fully pumped and cleaned at least four times a year. The CWS Inspector can require more. CWS uses sizing methods that often call for larger interceptors. Sizing depends on factors like location. Sites in dense food service areas can stack up more risk to the system.

Charleston enforces strictly. Sites must keep maintenance logs. They must also submit detailed application forms with plans and diagrams.

Greenville County (ReWa Service Area)

Renewable Water Resources (ReWa) runs nine water recovery facilities. It manages over 380 miles of pipe. It serves Greenville County and parts of Anderson, Laurens, Pickens, and Spartanburg Counties.

As the local wastewater provider, ReWa regulates all discharges into the sewer system. That includes oversight of food service sites through its FOG Control Program and Grease Control Regulation.

Grease interceptor submittals require flow calculations based on SC Department of Environmental Services regulation 61-67.

ReWa offers a free FOG Register system to help sites stay compliant with its Sewer Use Regulations. You must take part to stay in compliance. The program charges permit fees. It also requires higher security standards on grease control devices.

Dorchester County

Dorchester County Water & Sewer requires a grease interceptor at every commercial food site that sends prep wastewater into the sewer. That includes restaurants, motels, hotels, cafeterias, bakeries, and schools. The trap must be in place before the site opens.

All food service sites must use a DHEC-licensed waste hauler or pumper. The hauler must remove every part of the trap contents. That covers floating material, wastewater, and bottom sludge in both chambers. Cleanings must include scraping solids from walls, floors, baffles, and pipe.

Dorchester County also offers free access to an online FOG BMP compliance portal. The portal gives regulators, food service sites, and haulers shared tools to track FOG control work.

Frequently Asked Questions

How often do I need to clean my grease trap in South Carolina?

It depends on your city and trap type. Charleston requires cleaning at least four times per year (quarterly). Columbia requires cleaning when FOG and solids reach 25% capacity or every 90 days minimum. Larger grease interceptors usually need cleaning at least every six months. High-volume sites may need weekly service. Your local utility inspector can require more frequent cleaning based on your site's conditions.

What size grease interceptor does my restaurant need?

For food service sites on septic systems, South Carolina requires a minimum 1,000-gallon capacity. City sewer systems usually require 1,000 gallons minimum too. Actual sizing depends on fixture units, flow rates, type of food prep, and local rules. Charleston Water System, Columbia Water, and other utilities use their own sizing math. They must approve all interceptor installs first. Contact your local water and sewer authority before install to confirm size and approval.

Who can pump my grease trap and how do I keep records?

South Carolina requires that grease traps be serviced only by DHEC-licensed waste haulers or pumpers. Most cities require a maintenance log. The log should show the date, time, and volume of FOG removed during each cleaning. Keep records on-site for 2-3 years depending on your jurisdiction. Show them to inspectors on request. Columbia requires 2-year retention. Dorchester County and other areas require 3-year retention. Some utilities like Dorchester County and ReWa offer online compliance portals where service providers can upload cleaning records directly.

Find Grease Trap Service in South Carolina

Our directory lists 44 licensed grease trap service providers across South Carolina. These licensed haulers help you stay compliant with state and local FOG rules. They handle routine cleaning, maintenance, and the paperwork inspectors expect. Whether you run a restaurant in Charleston, Columbia, Greenville, or anywhere else in the state, you can find pros who know South Carolina's grease trap rules. Visit our South Carolina grease trap service directory to connect with licensed providers in your area.