Puerto Rico has 54 publicly owned wastewater treatment plants (POTWs) serving an estimated 2,239,581 residents. The map below plots every one of them, draws the sewershed (service-area boundary) around each, and links each plant to its EPA ECHO compliance record by NPDES permit number. The data is the EPA’s National Sewersheds dataset, version 1.2.
Use the search box on the map above to find a specific plant by name, city, or operator. Click any marker to open a card with the plant’s operator, address, population served, and a link to its EPA ECHO compliance file. The map starts pre-zoomed to Puerto Rico.
The 10 largest wastewater treatment plants in Puerto Rico
Ranked by residential population served (2022). Population is from the EPA’s Clean Watersheds Needs Survey, the four-yearly state reporting cycle that feeds this dataset.
| # | Plant | Operator | City | Pop. served |
|---|---|---|---|---|
| 1 | San Juan Puerto Nuevo WWTP | PRASA BAYAMON | San Juan | 340,412 |
| 2 | Bayamon Regional WWTP | PRASA | Catano | 238,964 |
| 3 | Carolina Regional WWTP | PRASA | San Juan | 208,812 |
| 4 | Caguas Regional WWTP | PRASA | Caguas | 180,254 |
| 5 | Ponce Regional WWTP | PRASA | Ponce | 123,674 |
| 6 | Arecibo WWTP | PRASA | Arecibo | 83,484 |
| 7 | Mayaguez Regional WWTP | PRASA | Mayaguez | 63,413 |
| 8 | Toa Alta WWTP | PRASA | Toa Alta | 61,687 |
| 9 | Cayey WWTP | PRASA | Cayey | 51,994 |
| 10 | Aguadilla Regional WWTP | PRASA | Aguadilla | 51,308 |
Top wastewater operators in Puerto Rico
Puerto Rico’s wastewater system is run almost entirely by PRASA — the Puerto Rico Aqueduct and Sewer Authority — which operates 49 of the 54 POTWs in the territory. PRASA is the only sole-territory wastewater operator in the United States and serves the largest plant fleet of any single operator in the country.
| # | Operator | Plants | Population served |
|---|---|---|---|
| 1 | PRASA | 49 | 1,816,727 |
| 2 | PRASA Bayamon | 1 | 340,412 |
| 3 | PRASA Vega Alta WWTP | 1 | 35,395 |
| 4 | Fajardo Regional WWTP | 1 | 30,149 |
| 5 | PRASA Lares STP | 1 | 16,863 |
Sewershed boundary data for Puerto Rico
Puerto Rico’s sewershed polygon boundaries are not currently published in the EPA National Sewersheds dataset — only the plant point locations and attribute data appear. The map shows each plant’s location and details, but service-area boundaries are not drawn for the territory. For the full national audit of sewer service-area mapping coverage, see our state-by-state sewer service-area maps audit.
How to find your wastewater treatment plant in Puerto Rico
- Type your municipio or town name into the search box on the map above.
- Click the marker nearest your address. The plant card shows the operator, full address, and the population the plant serves.
- Click “View EPA ECHO compliance record” in the plant card to open the plant’s enforcement and discharge-monitoring history at echo.epa.gov.
- If you fall outside any visible plant area, you are most likely on a private septic system — common in rural Puerto Rico, particularly in the central mountain region.
Related Puerto Rico infrastructure maps
Wastewater plants sit at the back end of the same water cycle that supplies drinking water and receives industrial discharge. For the full national context, see our interactive US wastewater treatment plants map, the 100 largest US wastewater treatment plants, and the 50 largest US wastewater operators. For the drinking-water side of the same cycle, see our US tap water quality map; for industrial inputs to municipal sewers, see the map of EPA-permitted industrial stormwater facilities; for PFAS and Superfund context, see our PFAS contamination map and Superfund sites map.
Frequently asked questions
How many wastewater treatment plants are in Puerto Rico?
The EPA’s National Sewersheds dataset lists 54 publicly owned wastewater treatment plants (POTWs) in Puerto Rico, serving an estimated 2,239,581 residents. Privately operated industrial wastewater plants are regulated separately and not included.
What is PRASA?
PRASA is the Puerto Rico Aqueduct and Sewer Authority — the public corporation that runs almost all of the territory’s drinking water and wastewater systems. PRASA operates 49 of the 54 wastewater treatment plants in Puerto Rico, making it the largest single-operator plant fleet in the United States.
What is a POTW?
POTW stands for Publicly Owned Treatment Works — any wastewater treatment plant owned by a state, municipality, sewer district, or other public entity. The Clean Water Act regulates POTWs through the National Pollutant Discharge Elimination System (NPDES).
