South Carolina
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South Carolina water profile

Nitrate in South Carolina community water systems

South Carolina is a low-nitrate state whose few higher readings cluster where growth is fastest — York and Lexington counties on the Piedmont and Sumter on the Coastal Plain. See where the pattern concentrates and what each reporting system measured in the three years from August 9, 2023 to August 9, 2026.

Browse all 553 South Carolina systems →

Search by the utility or system name shown on a water bill. Example: City of Rock Hill. Private wells are not in this inventory.

98%
of the state’s 563 active community water systems have a current result here
553
systems with a current nitrate result
4,611,483
people served by those reporting systems
1.1%
of reporting systems at or above 5 mg/L
How to read these numbers Each system is placed into a band by its most recent reported result within a rolling three-year window. The bands describe how strongly human activity, read from nitrate, has marked a water source; they are not a safety verdict. Figures describe system reporting, not nitrate measured at an individual tap.

How South Carolina's systems fall across the five bands

Most systems report below 3 mg/L

Natural background
0.00–0.99 mg/L as N
423 systems · 3,992,071 served
Human impact likely
1.00–2.99 mg/L as N
112 systems · 584,846 served
Human impact clear
3.00–4.99 mg/L as N
12 systems · 11,726 served
Health-study range
5.00–9.99 mg/L as N
6 systems · 22,840 served
Above the federal limit
10.00 mg/L and above
0 systems · 0 served

Each system appears in one band only, placed by its most recent reported result in the current three-year window. Counts sit beside people served so a small number of larger systems cannot hide behind a row of tiny ones. Of the 6 systems reporting 5 mg/L or more, 1 stayed at or above 5 across the whole three-year range; the other 5 reached it only on a high sample and otherwise ran lower.

Most recent reading May 2026; the typical system was last tested around Dec 2025. 396 systems sampled their own water; 157 systems carry a supplier’s result.

The named systems

Every reading here belongs to a utility with a name

Highest recent readings
SystemMost recent resultBandBased onPeople served
Siesta Cove Rv Park Marina (Sc3270802)6.70 mg/LOct 2025Health-study range10 samples40
Breezy Hill W/D (Sc0220006)6.30 mg/LApr 2026a high point — runs lowerHealth-study range49 samples17,822
Sumter Co-Wedgefield-Stateburg Wd5.70 mg/LOct 2025Health-study range6 samples1,200
Wallace Water Company (Sc3420002)5.60 mg/LApr 2026a high point — runs lowerHealth-study range21 samples3,552
Chucks Mhp (Sc4660077)5.10 mg/LApr 2026a high point — runs lowerHealth-study range10 samples168
Pecan Grove Commons (Sc4660003)5.00 mg/LApr 2026Health-study range6 samples58
Hidden Oaks Mhp (Sc3260140)4.30 mg/LJan 2026Human impact clear8 samples40
Bgwc Silver Lakes-Windwood (Sc4650034)4.20 mg/LJan 2025a high point — runs lowerHuman impact clear6 samples191
Largest systems
SystemMost recent resultBandBased onPeople served
Greenville Water (2310001)0.04 mg/LApr 2026Natural background6 samples396,265
Charleston Water System (Sc1010001)0.03 mg/LMar 2026Natural background4 samples327,422
Columbia City Of (Sc4010001)0.03 mg/LMar 2026Natural background7 samples319,500
Gsw&Sa (Sc2620004)1.20 mg/LApr 2026Human impact likely17 samples252,840
Spartanburg Water System (4210001)0.03 mg/LMay 2026Natural background3 samples166,364

Each result shows its date and what it rests on, so a lone sample is never taken for a settled measurement. A single high sample is not a complete account of what a household drinks.

Where higher nitrate concentrates

A small signal in the growth counties

Human impact is clear on drinking water served in five of South Carolina’s 46 counties. Each is shaded by how many of its systems reported 3.00 mg/L as N or above. Shading counts systems, not severity — a county with many small utilities can outrank one holding a single larger system that reads higher. The table beside the map splits the two bands so that difference stays visible.

SC counties shaded by number of community water systems reporting nitrate at or above 3.00 mg/L as NCounties are shaded by how many community water systems reported nitrate at or above 3.00 mg/L as N in the three years from August 9, 2023 to August 9, 2026. The same counts appear in the table below this map.York County — 5 systems at 3.00–4.99 mg/L as N; 2 systems at 5.00 mg/L as N or aboveSumter County — 3 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveAiken County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveLexington County — 2 systems at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or aboveMarlboro County — 1 system at 3.00–4.99 mg/L as N; 1 system at 5.00 mg/L as N or above
none1–23–56–1112–2526+Number of drinking water systems reporting ≥3.00 mg/L NO₃–N per county as of August 9, 2026

York leads this layer with 2 reporting systems, followed by Aiken, Lexington, Marlboro. A small signal in the growth counties. Coverage note: the map places 95% of South Carolina’s reporting systems. Of the rest, 8 carry a supplier’s result measured elsewhere and belong off this map; 21 sampled their own water and are missing a county in the records, so the map reads as a floor by at least that much.

Counties with the most systems at or above 3 mg/L as N
County3–4.99≥5Total ≥3
York527
Sumter314
Lexington213
Aiken112
Marlboro112

Counts use each system's most recent reported result in the current three-year window. A system appears in only one of the two bands. Coverage note: the map places 95% of South Carolina’s reporting systems. Of the rest, 8 carry a supplier’s result measured elsewhere and belong off this map; 21 sampled their own water and are missing a county in the records, so the map reads as a floor by at least that much.

Find a specific South Carolina system

What the statewide pattern says

Sprawl on fractured rock and sandy plain

South Carolina's modest nitrate signal sits in its fastest-growing counties, on Piedmont fractured rock and sandy Coastal Plain — settings whose mechanics are documented just across the state line.

South Carolina's deep public supplies are well protected: USGS sampling of the Southeastern Coastal Plain aquifer system, which underlies the state's lower half, found nutrients absent at high or moderate concentrations at public-supply depth (Barlow, 2016 — USGS Fact Sheet 2016-3076).

The counties that do light up — York, Lexington, Sumter — are growth counties on the two shallow settings the region knows well. York and Lexington sit on Piedmont fractured crystalline rock under Charlotte and Columbia sprawl, the same province where North Carolina's geochemistry work documents nitrate moving through shallow fractures with denitrification only at depth (USGS SIR 2009-5149). Sumter and Marlboro lie on the sandy Coastal Plain, the province where Delmarva-to-Georgia studies repeatedly find shallow unconfined nitrate.

That is the honest South Carolina reading: the mechanism is documented at province scale, but South Carolina itself has no county-level nitrate study this page can cite, so the map marks the signal and the regional literature supplies the plausible pathway — nothing more.

The supported source reading is mixed suburban and agricultural nitrogen on shallow fractured rock and sandy plain — not a certified source at any individual system (Nolan and Hitt, 2006).

The general science — how nitrate moves, why some ground is vulnerable, and why the legacy lingers — is laid out with its sources on Where nitrate comes from.

Questions this page answers

What the South Carolina pattern does—and does not—say

Where does nitrate concentrate in South Carolina community water systems?

York leads this layer with 2 reporting systems, followed by Aiken, Lexington, Marlboro. A small signal in the growth counties.

If South Carolina runs low, why map it at all?

Because the few higher readings are not random: they sit in the fastest-growing counties on the two aquifer settings — Piedmont fractured rock and sandy Coastal Plain — whose nitrate behavior is well documented in neighboring states. The map shows where the state's private wells deserve a second look.

Is South Carolina's Coastal Plain groundwater safe from nitrate?

At public-supply depth, largely yes — USGS found nutrients absent at high or moderate levels in the deep aquifers. Shallow and surficial wells are the different story the regional literature warns about, and those are mostly private.

Does a high public-system result mean a nearby private well is high?

No. It is a local sentinel, not a well-specific result. It shows that nitrogen and a transport pathway have reached groundwater in the area; a certified-lab test is still the only way to know a specific private well.

Sources and provenance

What this page rests on

  1. NitrateSmart inventory: 553 South Carolina community water systems with a current nitrate result in the three years from August 9, 2023 to August 9, 2026. Figures count people served by reporting systems, not measured tap exposure.
  2. Nolan BT, Hitt KJ (2006). Vulnerability of Shallow Groundwater and Drinking-Water Wells to Nitrate in the United States. Environmental Science & Technology 40(24):7834–7840.
  3. Dubrovsky NM, and others (2010). Nutrients in the Nation's Streams and Groundwater, 1992–2004. USGS Circular 1350.
  4. Barlow JRB (2016). Groundwater Quality in the Southeastern Coastal Plain Aquifer System. USGS Fact Sheet 2016-3076 — includes South Carolina; nutrients low at public-supply depth.
  5. USGS (2009). Groundwater geochemistry of the Piedmont and Mountains provinces of North Carolina. SIR 2009-5149 — province-scale fractured-rock nitrate mechanism applied to South Carolina’s Piedmont counties.