Duncan sits between Spartanburg and Greer, centered on the crossing of SC 290 and SC 292, with town limits that reach north to US 29 and south to I-85. It began as a railroad stop in the 1870s and was chartered in 1889. It has grown quickly since 2010, from about 3,200 people to just over 4,000 in 2020, with industrial employers along the interstate and new subdivisions to match.
The utility map surprises people who move here from Spartanburg. Natural gas in Duncan comes from the Greer Commission of Public Works, not Piedmont. Water comes from the Startex-Jackson-Wellford-Duncan Water District, which treats it at its plant in Lyman and reports it as extremely soft. Sewer is the Town of Duncan's, billed through SJWD.
Duncan permits its own construction work. The town has a building official at Town Hall on West Main Street, and plumbing and gas permits and inspections inside town limits go through the town rather than the county.
Gas Guys answers 24 hours a day and is a short run down I-85 or US 29 from Spartanburg.
Duncan at a glance
- Natural gas
- Greer CPW. Duncan is in the Greer Commission of Public Works natural gas territory, not Piedmont's, so meter, service line and utility-side leak calls go to Greer CPW.
- Water
- SJWD Water District
- Sewer
- Town of Duncan (billed through SJWD)
- Permits
- Town of Duncan
- Housing
- Older homes around Main Street and the SC 290 crossroads, with newer subdivisions built as the town grew.
Plumbing and gas in Duncan: what to know
Tankless conversions
Many homes built in the last few decades came with a 40- or 50-gallon gas tank in the garage or attic. Switching to tankless is a common upgrade, but many tankless units draw several times the gas a tank does. The line from the Greer CPW meter often needs upsizing, and the venting changes too, so the job is planned from the meter, not from the old tank.
Very soft water
SJWD reports its water hardness at roughly 6 to 8 milligrams per liter, which is very soft. Scale buildup in water heaters and fixtures is minimal, so tankless descaling is rarely urgent. Soft water can wear through a tank heater's anode rod faster, though, which makes an anode check a good habit.
Water heaters in attics
An attic water heater saves floor space and puts a ceiling at risk. A drain pan piped to a safe place, a relief valve discharge line that runs where it should, and a look at the tank's age are the minimum. A leaking attic heater is the kind of call that should not wait until morning.
Older pipes near the old town
Homes near the old town center predate the growth and can have galvanized supply lines, cast iron drains, and gas piping extended piecemeal. They call for a different inspection than a 2015 house: pressure and flow at the fixtures, a leak check on the gas, and a camera in the main drain if backups repeat.
Grill and outdoor kitchen lines
Newer homes with patios often get a natural gas line for a grill, fire pit or outdoor kitchen. That line is usually buried plastic pipe with a tracer wire, rising through steel with a shutoff near the appliance, and many grills need a natural gas conversion kit. It is private piping, so SC811 will not mark it later; keep a sketch of where it runs.