| Water Service System Provider | Average Population | Average Household Income | TTHM (ppb) |
| Hatillo-Camuy | 41,953 | $17,201 | 44 |
| Quebradillas Urbano | 25,919 | $16,630 | 48 |
| Morovis Urbano | 32,610 | $20,589 | 56 |
| Florida Urbano | 12,680 | $20,315 | 58 |
| Arecibo Urbano | 96,440 | $18,001 | 59 |
| Barceloneta Urbano | 24,816 | $16,889 | 59 |
| Utuado Urbano | 33,149 | $16,599 | 63 |
| Jayuya Urbano | 16,642 | $14,808 | 65 |
| Vega Baja Urbano | 59,662 | $19,096 | 71 |
| Mayaguez Urbano | 89,080 | $14,120 | 86 |
| Isabela Urbano | 45,631 | $16,748 | 88 |
| Sabana Grande Urbano | 25,265 | $16,846 | 95 |