Plum Island WWTP
539 Harbor View Cir, Charleston, SC 29412 · Charleston County · Publicly Owned Treatment Works
- Average flow
- 21.36 MGD
- Design flow
- 36 MGD
- NPDES permit
- SC0021229
- Administratively continued
- Permit expires
- July 2024
- Population served
- 232,756
- CWNS 2022
Plum Island WWTP is a publicly owned wastewater treatment works in Charleston, Charleston County, South Carolina treating an average of 21.36 million gallons per day against a permitted design capacity of 36 MGD, serving about 232,756 residents. It discharges under NPDES permit SC0021229 (administratively continued), which expires in July 2024, with 3 recorded violations in the last three years. EPA has recorded 1 formal enforcement action naming the plant, the latest in August 2022.
Treatment technology
2 treatment structures and unit processes identified at Plum Island WWTP.
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See the full treatment train at Plum Island WWTP: structures, unit processes and planned upgrades, with exact unit counts.
Compliance snapshot (last 3 years)
- Total violations
- 3
- Effluent violations
- 3
Based on NPDES Discharge Monitoring Reports. Full violation history, parameters and discharge data available in the Klarifi platform.
EPA enforcement history
Federal civil enforcement cases, compliance inspections and informal actions recorded for Plum Island WWTP in EPA's ICIS system.
- Formal actions
- 1
- 1 since FY2020
- Penalties assessed
- $2,594
- all cases
- Compliance actions
- $3,500
- required by EPA orders
- EPA inspections
- 1
- latest Sep 2020
Latest case · Aug 2022
CHARLESTON WATER SYSTEM - PLUM WWTP
Administrative order · CWA, SPCC and/or Federal Response Plan Violations · Final Order With Penalty · Penalty $2,594 · Compliance actions $3,500
EPA's description of the case:
“JULY 27, 2022 - SPCC Expedited Settlement Agreement: On September 9, 2020, an authorized representative of the United States Environmental Protection Agency (EPA) conducted an inspection of the…”
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Source: EPA ECHO, civil enforcement case 04-2022-0405.
Full case history with a free Klarifi account
Every action against Plum Island WWTP with dates, milestones, violation types and EPA's complete case summaries, plus inspections and informal actions.
Key contacts
2 verified contacts for Plum Island WWTP, with validated emails and direct phone numbers.
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Names, validated emails and direct phone numbers for decision-makers at Plum Island WWTP, plus the full compliance history and discharge data.
Nearby wastewater treatment plants in South Carolina
North Charleston · 5 mi away
14.5 MGD
Charleston · 6 mi away
—
Sullivans Island · 6 mi away
0.28 MGD
Mount Pleasant · 8 mi away
6.96 MGD
Isle Of Palms · 10 mi away
0.08 MGD
Goose Creek · 14 mi away
8.77 MGD
Dorchester · 14 mi away
6.84 MGD
Summerville · 22 mi away
4.75 MGD
Plum Island WWTP: frequently asked questions
Sources and methodology
Flow, permit and violation figures come from the EPA's ICIS-NPDES discharge monitoring records. Population served comes from the Clean Watersheds Needs Survey 2022. Treatment structures are identified by Klarifi's review of aerial imagery, and capital improvement projects are extracted from published municipal budget documents. Violations are counted over the last three years of monitoring reports.
Data refreshed October 26, 2026; facility record last updated August 3, 2026.
Wastewater terms: POTW · MGD · NPDES permit · Inflow and infiltration · Ozonation · Activated sludge · all terms