Guaraguao, PR
Lead detected, under the action levels
Latest 90th-percentile lead: 6 ppb (monitoring period 2026-2026). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
About Guaraguao
Guaraguao serves about 935 people through 350 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in Ponce Municipio County, PR. EPA system ID: PR0004114; phone on file: 787-620-2277. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Lead results over time
Against the period ending 2025 (5 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Guaraguao is 6 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 6 ppb |
| 2025 | 5 ppb |
| 2025 | 6 ppb |
| 2024 | 6 ppb |
| 2024 | 6 ppb |
| 2023 | 6 ppb |
| 2023 | 6 ppb |
Against other PR systems
Of the 111 PR systems with a lead result, the median latest reading is 5 ppb; 10 are over 15 ppb right now and 16 have gone over at some point. Guaraguao's 6 ppb sits at the 55th percentile in PR and the 93rd nationally (higher means more lead).
Other water systems in Ponce Municipio County
17 other systems share Ponce Municipio County; 0 of them have a higher latest lead result than Guaraguao. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Cotto Laurel | 12,979 | - |
| Cerrillos | 5,658 | 6 ppb |
| Real Anon | 2,814 | - |
| Anon Carmelita | 900 | - |
| Asoc. Civica Pastillo Tibes | 652 | - |
| Bo. Monte Llanos | 327 | - |
| Acued. Comunal Rio Chiquito | 320 | 3 ppb |
| Servicio De Agua | 300 | - |
| Estancias Del Madrigal | 258 | - |
| Acued. Comunal Sect. Santas Pascuas, Inc | 240 | - |
Your move
Test your own tap with a certified lab first-draw sample; Ponce, PR may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Guaraguao whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. What a 90th-percentile result does and does not tell you: how to read a lead result. Size matters more than most people expect: small vs large water systems.