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Community Water System · PWS PR0002672

Isabela

Santurce, Puerto Rico 00916 - drinking water served from surface water sources to 49,419 people, tracked in EPA SDWIS and UCMR5.

49,419
People served
522
EPA violations
326
Health-based
1 PFAS
UCMR5 result

The verdict

EPA records 522 drinking-water violations at Isabela, 62% of them health-based - above the Puerto Rico per-system average, and UCMR5 testing detected 1 PFAS compound.

522
Total EPA violations on record
62%
Health-based (MCL / treatment failure)
49,419
People served by this system
1
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Isabela

Isabela is a local-owned community water system that delivers drinking water to 49,419 residents in Santurce, Puerto Rico (Isabela Municipio County) through 18,509 service connections. Its water is drawn from surface water sources. EPA's Safe Drinking Water Information System records 522 total violations for this system , of which 326 (62%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 174 monitoring and reporting violations are on file. The most recent violation on record dates to 2020.

The most frequently cited contaminant at this system is Surface Water Treatment Rule, recorded in 164 violations (TT, health-based). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 7.2 ppt (parts per trillion). PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across Puerto Rico, EPA tracks 458 public water systems serving 3,328,141 people, with 164,144 cumulative violations and 34,657 health-based violations on record. About 100% of systems in the state carry at least one violation, and state-wide the average per system is 358.4 violations. Statewide, 40 of 99 UCMR5-tested systems have reported PFAS detections (40.4%).

Isabela's 522 violations sit above the Puerto Rico average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
49,419
Total Violations
522
Health-Based Violations
326
Water Source
Surface Water

System Details

System Type
Community
Owner Type
Local
Connections
18,509
County
Isabela Municipio
School/Daycare
No
MCL Violations
34
Monitoring Violations
174
Treatment Tech Violations
292

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Surface Water Treatment Rule TT 164 2001
Interim Enhanced Surface Water Treatment Rule TT 73 2010
CARBON, TOTAL TT 55 2007
Surface Water Treatment Rule MR 46 2018
TTHM MCL 19 2018
Turbidity MR 14 2017
Cryptosporidium MR 14 2017
E. COLI MR 14 2017
TTHM MR 11 2016
Total Haloacetic Acids (HAA5) MR 10 2016
Total Haloacetic Acids (HAA5) MCL 9 2018
Lead and Copper Rule MR 5 2016
Coliform (TCR) MCL 4 2013
Consumer Confidence Rule Other 4 2020
CHLOROBENZENE MR 3 2007
Revised Total Coliform Rule MON 3 2019
Xylenes, Total MR 2 2005
DICHLOROMETHANE MR 2 2005
o-Dichlorobenzene MR 2 2005
p-Dichlorobenzene MR 2 2005
Vinyl chloride MR 2 2005
1,1-Dichloroethylene MR 2 2005
Carbon tetrachloride MR 2 2005
1,1,2-Trichloroethane MR 2 2005
Tetrachloroethylene MR 2 2005
Benzene MR 2 2005
Ethylbenzene MR 2 2005
Styrene MR 2 2005
Coliform (TCR) MR 2 2009
Nitrate MR 2 2001

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 116 samples detected PFAS.

Contaminant Date Result MRL Status
11Cl-PF3OUdS 9/27/2024 <5.00 ppt 5.00 ppt Not Detected
PFPeS 9/27/2024 <4.00 ppt 4.00 ppt Not Detected
NFDHA 9/27/2024 <20.00 ppt 20.00 ppt Not Detected
PFEESA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFMBA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFPeA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFMPA 9/27/2024 <4.00 ppt 4.00 ppt Not Detected
8:2 FTS 9/27/2024 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
6:2 FTS 9/27/2024 <5.00 ppt 5.00 ppt Not Detected
PFBA 9/27/2024 7.20 ppt 5.00 ppt Detected
HFPO-DA 9/27/2024 <5.00 ppt 5.00 ppt Not Detected
PFTA 9/27/2024 <8.00 ppt 8.00 ppt Not Detected
9Cl-PF3ONS 9/27/2024 <2.00 ppt 2.00 ppt Not Detected
PFUnA 9/27/2024 <2.00 ppt 2.00 ppt Not Detected
PFHxA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFDoA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFDA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFOA 9/27/2024 <4.00 ppt 4.00 ppt Not Detected
PFOS 9/27/2024 <4.00 ppt 4.00 ppt Not Detected
PFNA 9/27/2024 <4.00 ppt 4.00 ppt Not Detected
PFHxS 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFBS 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
NMeFOSAA 9/27/2024 <6.00 ppt 6.00 ppt Not Detected
NEtFOSAA 9/27/2024 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 9/27/2024 <7.00 ppt 7.00 ppt Not Detected
ADONA 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpS 9/27/2024 <3.00 ppt 3.00 ppt Not Detected
PFBA 6/13/2024 <5.00 ppt 5.00 ppt Not Detected
6:2 FTS 6/13/2024 <5.00 ppt 5.00 ppt Not Detected
PFBS 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFHpA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxS 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFNA 6/13/2024 <4.00 ppt 4.00 ppt Not Detected
PFOS 6/13/2024 <4.00 ppt 4.00 ppt Not Detected
PFOA 6/13/2024 <4.00 ppt 4.00 ppt Not Detected
PFDA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFDoA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFUnA 6/13/2024 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 6/13/2024 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
HFPO-DA 6/13/2024 <5.00 ppt 5.00 ppt Not Detected
8:2 FTS 6/13/2024 <5.00 ppt 5.00 ppt Not Detected
PFMPA 6/13/2024 <4.00 ppt 4.00 ppt Not Detected
PFPeA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFMBA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
PFEESA 6/13/2024 <3.00 ppt 3.00 ppt Not Detected
NFDHA 6/13/2024 <20.00 ppt 20.00 ppt Not Detected

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Isabela.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID PR0002672 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Puerto Rico Drinking Water Authority

Puerto Rico's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find PR regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2020 Consumer Confidence Rule Other 4 SDWIS / PR0002672 / 7000
2019 Revised Total Coliform Rule MON 3 SDWIS / PR0002672 / 8000
2018 Surface Water Treatment Rule MR 46 SDWIS / PR0002672 / 0200
2018 TTHM MCL 19 SDWIS / PR0002672 / 2950
2018 Total Haloacetic Acids (HAA5) MCL 9 SDWIS / PR0002672 / 2456
2018 Revised Total Coliform Rule MCL 2 SDWIS / PR0002672 / 8000
2017 Turbidity MR 14 SDWIS / PR0002672 / 0100
2017 Cryptosporidium MR 14 SDWIS / PR0002672 / 3015
2017 E. COLI MR 14 SDWIS / PR0002672 / 3014
2016 TTHM MR 11 SDWIS / PR0002672 / 2950
2016 Total Haloacetic Acids (HAA5) MR 10 SDWIS / PR0002672 / 2456
2016 Lead and Copper Rule MR 5 SDWIS / PR0002672 / 5000
2013 Coliform (TCR) MCL 4 SDWIS / PR0002672 / 3100
2010 Interim Enhanced Surface Water Treatment Rule TT 73 SDWIS / PR0002672 / 0300
2009 Coliform (TCR) MR 2 SDWIS / PR0002672 / 3100

How Isabela Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Isabela Puerto Rico avg Federal benchmark
Total violations 522 358.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 326 75.7 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 40.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 49,419 7,267 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 458 regulated public water systems in Puerto Rico.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Isabela water safe to drink? ▼
Isabela (PWS ID: PR0002672) has 522 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 49,419 people using Surface Water sources.
How many people does Isabela serve? ▼
Isabela serves 49,419 people in Santurce, Puerto Rico. It is a Local-owned system using Surface Water water sources with 18,509 service connections.
What type of violations does Isabela have? ▼
Isabela has 522 total violations: 326 health-based violations (MCL exceedances or treatment failures), 174 monitoring/reporting violations, and 292 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Isabela water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in Isabela's water supply: PFBA. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Isabela use? ▼
Isabela uses Surface Water as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.