We found 13 public water systems that could serve the same population as Mary Island State Park (ordered by population size).
| Name | Areas served | Population served | Contaminant count | Violation count |
|---|---|---|---|---|
| Alexandria Village | Alexandria Bay | 1,900 | 0 | 0 |
| Grass Point State Park | Alexandria Bay | 1,200 | 0 | 1 |
| Tiba - Boldt Castle | Alexandria Bay | 1,000 | 0 | 0 |
| Wellesley Island State Park | Alexandria Bay | 1,000 | 0 | 0 |
| Cedar Point State Park | Alexandria Bay | 750 | 0 | 0 |
| Waterson Point State Park | Alexandria Bay | 200 | 0 | 0 |
| Canoe-picnic Point State Park | Alexandria Bay | 175 | 0 | 2 |
| Alexandria Town Wd #1 - Otter Street | Alexandria Bay | 60 | 0 | 0 |
| Bay Haven Mobile Home Park | Alexandria Bay | 40 | 0 | 0 |
| Thousand Islands Winery | Alexandria Bay | 25 | 0 | 0 |
| Jack & Bills Camps | Alexandria Bay | 25 | 0 | 0 |
| Alex Bay Retail Plaza | Alexandria Bay | 25 | 0 | 0 |
| Martins | Alexandria Bay | 25 | 0 | 0 |