01The verdict: is Rayo Plata water safe?
Rayo Plata's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (89.5/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 3,855 residents using groundwater (wells).
3 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Top half in Puerto Rico
Rayo Plata ranks #2 of 101 graded Puerto Rico cities.
See the comparison ↓1 violation in the last five years
Recent compliance history is the best predictor of future problems — the year-by-year record is below.
See the record ↓Rayo Plata's drinking water received a grade of A- (89.5 out of 100), indicating good water quality. The city's 1 water system serves approximately 3,855 residents using groundwater.
Lead levels were measured at 6.0 ppb (90th percentile), which is within EPA limits but above recommended levels. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 27 violations on record, including 9 health-based violations. 3 remain unresolved.
Rayo Plata ranks #2 out of 101 cities in Puerto Rico for water quality, placing it one of the best in the state. Rayo Plata relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. While lead levels are within EPA limits, they are above the recommended 5 ppb threshold that health organizations consider ideal. A point-of-use filter adds an extra layer of protection.
02What's in Rayo Plata's water
Every contaminant flagged in Rayo Plata, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 6.0 | 15 | ppb | Inorganic | Safe |
03Rayo Plata's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 27 violations on record, including 9 health-based violations. 3 remain unresolved.
8 of the last ten years were clean. The numbered years had EPA violations — red when any were health-based, amber when they were paperwork or missed-testing issues.
▼ Down 2 ppb since 1993. Latest reading: 6 ppb (2023) — 40% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Rayo Plata's water comes from
Rayo Plata's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under local government ownership.
3,855 people
Residents served across Rayo Plata's service area.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 3,855 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| RAYO | PR0003573 | 3,855 | Groundwater |
Water bodies near Rayo Plata
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Rayo Plata's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Drought
Sabana Grande Municipio is in D2 (severe drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Rayo Plata compares
Scores for nearby Puerto Rico cities on one line, with the average marked.
dashed line = Puerto Rico average (39/100)
Rayo Plata scores 89.5/100 — above the Puerto Rico average of 39/100. It outscores 10 of 10 nearby cities.
38.5 / 100FToa Alta, PR
38.5 / 100FMayaguez, PR
42.1 / 100FPonce, PR
34.9 / 100FAguadilla, PR
38.3 / 100FRincon, PR
38.3 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Rayo Plata's water — not generic advice.
Filter drinking & cooking water
NSF-certified water filter. Lead detected at 6.0 ppb
Compare tested filters →Flush taps & check your service line
Lead leaches from pipes as water sits. Run cold water 30 seconds before drinking (especially mornings), and ask the utility whether your address still has a lead service line.
Lead risks explained →Watch for Rayo Plata alerts
We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.
All water alerts →Frequently asked questions
Is Rayo Plata, PR tap water safe to drink?
Rayo Plata's water quality earned a grade of A- (89.5/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #2 out of 101 cities tested in Puerto Rico.
What contaminants are in Rayo Plata's water?
Lead was measured at 6.0 ppb (90th percentile). 27 violations are on record.
How is Rayo Plata's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Rayo Plata?
While lead levels are within EPA limits, a filter adds extra protection. Based on current data, basic filtration should suffice for additional peace of mind.
Where does Rayo Plata's water come from?
Rayo Plata's water is sourced from Groundwater. The city has 1 water system serving approximately 3,855 residents.
What health violations has Rayo Plata's water system had?
Rayo Plata has 9 health-based violations on record. The most recent violation was recorded in July 2022. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
Is Rayo Plata's groundwater at risk of contamination?
Rayo Plata uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 27 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Rayo Plata's water compare to other cities?
Rayo Plata ranks #2 out of 101 cities in Puerto Rico (better than 98% of state cities) and #2759 out of 15382 cities nationally (82th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.