Sourced from the Darlington County Water and Sewer Authority, the City of Darlington, Darlington County Codes Enforcement, SC Rural Water Association listings, and R.61-56 — last checked August 2026.
Who Issues Darlington County Septic Permits
This surprises people moving to South Carolina from almost anywhere else: Darlington County does not issue septic permits, and neither does any other South Carolina county. Onsite wastewater permitting is a state function.
The agency is the South Carolina Department of Environmental Services (SCDES), created on July 1, 2024 when Act 60 of 2023 split the old DHEC into SCDES for environmental programs and SC DPH for public health.
Where the application goes: ATTN: OSWW, SCDES, 2600 Bull Street, Columbia, SC 29201
Statewide phone: 1-855-731-2504
Online: epermitting.des.sc.gov · Form: D-1740, rev. 07/2026
The Fee Is $150 in Every County
Because permitting is centralized, there is one fee statewide. R.61-56 § 102.2: the Department “shall charge a fee of one hundred and fifty dollars ($150.00) to evaluate the site of a proposed onsite wastewater system,” amended effective May 27, 2022. There is a $150 re-application fee if the instructions are not followed.
You may instead hire a Professional Soil Classifier privately, capped at “no more than three (3) times SCDES’s fee” — so up to $450. People use it to skip the queue, and the queue is real: a 700-permit backlog in April 2023, and coastal counties running six to fourteen weeks behind.
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The Ratio Is the Story
That single comparison is more useful than any percentage, and it is worth being precise about what it does and does not mean. It is a utility customer ratio, not a household septic percentage — municipal systems in Darlington city, Hartsville and Lamar serve properties the county authority does not count, and some rural properties have neither. Do not let anyone convert this into “97 percent of Darlington County is on septic.” The source is also undated, so the vintage of both figures is unknown — confirm with the authority before quoting them.
What it does establish is direction: outside the towns, an onsite system is the norm here, and the state’s § 300 bar on permits where sewer is “accessible” rarely comes into play.
One Number You Might Find That Will Send You Wrong
This is a recurring hazard across South Carolina, and Darlington is not the worst case. In Florence County, the office actually called “Environmental Services” is animal services. County websites were built before the 2024 agency reorganization and have not caught up.
The Rule That Costs the Most Money: Six Inches
South Carolina requires a minimum vertical separation of six inches between the deepest point of effluent application and the zone of saturation — the level groundwater reaches — for systems under 1,500 gallons per day (R.61-56 § 200.3).
- South Carolina — 6 inches
- North Carolina — 18 inches on the coast, 12 inches inland
- Georgia — 24 inches
- Alabama — 24 inches
South Carolina permits systems on ground its neighbors would refuse. Darlington is Pee Dee country — flat, with a water table that responds quickly to rain.
The Repair Area Nobody Tells You About
Under R.61-56 § 200.7, a new system must reserve “a usable repair or replacement area equivalent to at least fifty (50) percent of the size of the original system” — 100 percent for community systems.
Read that as a land requirement, because that is what it is. Your lot has to hold the tank, the drainfield, and half a drainfield again in reserve, while meeting every setback. On a tight lot the reserve area is what fails, not the drainfield. On the larger rural parcels here that is usually manageable; in the older village lots around Hartsville and Lamar it is worth checking before you buy.
Setbacks and Sizing
- 75 feet from a private well · 100 feet from a public well
- 75 feet from the mean high water line of a stream, canal or retention pond, and from a delineated critical area line
- 25 feet from a drainage ditch · 25 feet upslope of a basement
- 5 feet from a property line · 5 feet from a building
- Rock or a restrictive horizon must sit more than 12 inches below the deepest point of effluent application
There is no state minimum lot size for a septic lot. R.61-56 requires only that the lot be large enough to hold the system, the reserve area and the setbacks. We could not read Darlington County’s ordinances, so whether the county sets a minimum lot size or any rule stricter than the state is unverified. A gap in our research, not a finding of no rule.
When Sewer Blocks a Septic Permit
R.61-56 § 300 is blunt: “Permits for new onsite wastewater systems shall not be issued where a wastewater treatment facility is accessible for connection,” and the same bar applies to repairing or replacing a failing system.
But the state sets no distance. “Accessible” is defined only negatively — “where annexation or easements to cross adjacent property are required to connect… the wastewater treatment facility shall not be considered accessible.” So if connecting would require you to be annexed, or to cross a neighbor’s land, sewer is not accessible and your septic permit stands. Every mandatory-connection distance in South Carolina is local.
The Darlington County Water & Sewer Authority is at 131 Industrial Way, Darlington, SC 29532 — (843) 393-8131, open 8:30 to 5:00, with an after-hours line at (843) 678-3816. It serves Darlington County plus portions of Florence and Lee counties. The City of Darlington runs its own system from 400 Pearl Street, (843) 398-4040, Monday to Friday 8:30–5:00, with more than 3,200 water accounts. Hartsville and Lamar are also designated wastewater management agencies.
What the authority has been building tells its own story. Two Clean Water revolving fund projects were initiated in September 2021: upgrades at the Ashland Water Treatment Plant (ground storage tank, two booster pumps, emergency generator), and standby generators at ten sewer pump stations — Primus Park, Middle School, US 52, Indian Branch, Summerville, Hyman Paper, Highgate, Bethea, Chesterfield and Matown — explicitly to “provide emergency power should electrical power fail” and prevent sewage spills. No dollar figures are published for either. Notably, no septic-to-sewer conversion project is listed at all.
What We Could Not Confirm
The vintage of the 18,508 / 726 figures. The source publishes no date. This is the most important caveat on the page.
Any Darlington County ordinance provision on septic, minimum lot size or sewer connection. The county code was not retrievable.
Dollar figures for the two 2021 revolving fund projects, whether the 843-661-4825 line reaches septic permitting, and any count or percentage of homes on septic — none exists at any vintage.
Where Darlington County Sits
Darlington sits in the Pee Dee between Florence and the North Carolina line, with Darlington, Hartsville and Lamar as its towns and a great deal of farmland between them. A county whose water utility reaches everywhere and whose sewer utility reaches almost nowhere.
Nearby counties we cover: Marion County · Dillon County · Clarendon County. All of them run through the same state permit and the same $150 fee — what differs is the local ordinance layer, compared on our South Carolina septic permits by county page.
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