Lagoon systems: wastewater treatment plants in North Carolina
29 plants · 35% of the state · 78 MGD reported by 13 plants
Klarifi identifies 29 publicly owned wastewater treatment plants with lagoon systems in North Carolina, 35% of the 83 plants in the state (78 MGD reported by 13 plants). The largest is Neuse River Resource Recovery Facility in Raleigh at 47.05 MGD.
Lagoon systems treat wastewater in large earthen ponds over weeks of retention time, with or without mechanical aeration. They serve thousands of small towns because they are cheap to run, but they struggle with ammonia and nutrient limits, fill with sludge over decades and are the plants most often converted or upgraded when a permit is renewed.
The largest lagoons in North Carolina
| # | Facility | City | Avg flow (MGD) | NPDES permit | Expires | Violations (3y) |
|---|---|---|---|---|---|---|
| 1 | Neuse River Resource Recovery Facility | Raleigh | 47.05 | NC0029033 | Feb 2025 | 1 |
| 2 | Goldsboro WRF | Goldsboro | 6.55 | NC0023949 | Jan 2029 | 4 |
| 3 | Town Of Cary - North Cary WWTP | Cary | 6.11 | NC0048879 | Feb 2028 | 0 |
| 4 | Town Of Cary - South Cary WWTP | Apex | 5.96 | NC0065102 | Apr 2028 | 0 |
| 5 | Triangle WWTP | Durham | 4.53 | NC0026051 | Apr 2027 | 3 |
| 6 | City Of High Point | Thomasville | 2.5 | NC0024228 | Feb 2031 | 0 |
| 7 | Contentnea Metropolitan Sewerage District | Grifton | 1.52 | NC0032077 | Nov 2030 | 0 |
| 8 | Tarboro WWTP | Tarboro | 1.46 | NC0020605 | Sep 2029 | 0 |
| 9 | Oxford WWTP | Oxford | 0.9 | NC0025054 | Sep 2030 | 2 |
| 10 | Yadkin River Water Treatment Plant | Unionville | 0.63 | NC0089893 | Jun 2025 | 0 |
Contacts and project signals for every plant on this list
Klarifi adds verified decision-maker contacts, permit limits, discharge monitoring data and the capital projects planned in each city, filterable by technology, size and compliance record.
Other technologies in North Carolina
Lagoon systems in other states
Lagoon systems in North Carolina: 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.
Wastewater terms: WWTP · POTW · Biosolids · Tertiary treatment · Significant industrial user · all terms