Is Guayanilla, PR Tap Water Safe to Drink?
Graded B+, with 7 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
81.6/100
waterverge.com Guayanilla, PR — Water Quality Report
Guayanilla's drinking water received a grade of B+ (81.6 out of 100), indicating good water quality. The city's 1 water system serves approximately 801 residents using surface water.
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 103 violations on record, including 19 health-based violations. 7 remain unresolved.
What to know about Guayanilla's water
Guayanilla ranks #7 out of 101 cities in Puerto Rico for water quality, placing it one of the best in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
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.
As a small community water system, Guayanilla may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
Water quality score
See methodology →Is Guayanilla, PR water safe to drink?
Guayanilla's drinking water has significant quality concerns based on EPA testing data. With a grade of B+ (81.6/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 801 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Guayanilla
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Guayanilla's water quality assessment. Grade: B+ (81.6/100).
Contaminants: Consumer Confidence Rule.
Contaminants: Consumer Confidence Rule.
Contaminants: Consumer Confidence Rule.
Key contaminant findings
Based on the most recent EPA sampling data for Guayanilla's water supply.
Within EPA limits but above the American Academy of Pediatrics recommended level of 1 ppb. An NSF 53-certified filter provides additional protection.
Violation history
Guayanilla's water system has 103 total violations on record, including 19 health-based violations. 7 remain unresolved. 1 violation was issued in the last 5 years.
Where does Guayanilla's water come from?
Guayanilla's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 1 water system serving approximately 801 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Lago Garzas Nr Adjuntas (lake), Rio Portugues Nr Tibes (river), Rio Guayanilla (river), Lago Lucchetti (lake), Rio Yauco (river).
What Guayanilla residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Guayanilla's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Violation summary
Violations & advisories
Recommended water filters
Based on contaminants detected in Guayanilla's water supply, we recommend the following filter types.
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 |
Lead level trend (90th percentile)
See how Guayanilla compares by contaminant
Explore where Guayanilla ranks among all Puerto Rico cities for specific contaminants.
Water source & infrastructure
Where Guayanilla's water comes from
Guayanilla's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 801 people through 1 water system.
Water bodies near Guayanilla
Guayanilla is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Guayanilla
| System Name | PWSID | Population | Source |
|---|---|---|---|
| JAGUA PASTO | PR0004244 | 801 | SW |
How Guayanilla compares
Full Puerto Rico rankings →Guayanilla's score of 81.6/100 is above the average of 38/100 among major Puerto Rico cities. It outscores 10 of 10 nearby cities.
Nearby cities
View Puerto Rico rankings →About Guayanilla, PR
Learn more about your water
Guides and resources related to Guayanilla's water quality findings.
Explore water quality across Guayanilla Municipio
Frequently asked questions
Is Guayanilla, PR tap water safe to drink?
Guayanilla's water quality earned a grade of B+ (81.6/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #7 out of 101 cities tested in Puerto Rico.
What contaminants are in Guayanilla's water?
Lead was measured at 6.0 ppb (90th percentile). 103 violations are on record.
How is Guayanilla'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 Guayanilla?
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 Guayanilla's water come from?
Guayanilla's water is sourced from Surface water. The city has 1 water system serving approximately 801 residents.
What health violations has Guayanilla's water system had?
Guayanilla has 19 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. 7 violations remain unresolved.
How does Guayanilla's water compare to other cities?
Guayanilla ranks #7 out of 101 cities in Puerto Rico (better than 93% of state cities) and #7413 out of 15744 cities nationally (53th percentile). The grade of B+ reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Guayanilla's small water system affect quality?
Guayanilla's system serves approximately 801 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 103 violations on record.