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Non-Transient Non-Community Water System · PWS PR0518085

Upr Cayey

Cayey, Puerto Rico 00736 - drinking water served from groundwater sources to 2,613 people, tracked in EPA SDWIS and UCMR5.

2,613
People served
399
EPA violations
6
Health-based
4 PFAS
UCMR5 result

The verdict

EPA records 399 drinking-water violations at Upr Cayey, 2% of them health-based - above the Puerto Rico per-system average, and UCMR5 testing detected 4 PFAS compounds.

399
Total EPA violations on record
2%
Health-based (MCL / treatment failure)
2,613
People served by this system
4
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Upr Cayey

Upr Cayey is a private-owned non-transient non-community water system that delivers drinking water to 2,613 residents in Cayey, Puerto Rico (Cayey Municipio County) through 66 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 399 total violations for this system , of which 6 (2%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 390 monitoring and reporting violations are on file. The most recent violation on record dates to 2023.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 18 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 4 PFAS compounds were detected in samples collected from this system, with a maximum reported concentration of 16.4 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%).

Upr Cayey's 399 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

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

Population Served
2,613
Total Violations
399
Health-Based Violations
6
Water Source
Groundwater

System Details

System Type
Non-Transient Non-Community
Owner Type
Private
Connections
66
County
Cayey Municipio
School/Daycare
Yes
MCL Violations
6
Monitoring Violations
390
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 18 2015
Lead and Copper Rule MR 15 2018
Total Haloacetic Acids (HAA5) MR 13 2019
TTHM MR 13 2019
Picloram MR 13 2023
Nitrate MR 10 2021
Coliform (TCR) MCL 6 2011
Endrin MR 6 2021
Toxaphene MR 6 2021
Dalapon MR 6 2021
Endothall MR 6 2021
Glyphosate MR 6 2021
OXAMYL MR 6 2021
Heptachlor MR 6 2021
2,4,5-TP MR 6 2021
Pentachlorophenol MR 6 2021
ETHYLENE DIBROMIDE MR 6 2021
Chlordane MR 6 2021
BHC-GAMMA MR 6 2021
Dinoseb MR 6 2021
Hexachlorocyclopentadiene MR 6 2021
Carbofuran MR 6 2021
LASSO MR 6 2021
Heptachlor epoxide MR 6 2021
HEXACHLOROBENZENE MR 6 2021
Total Polychlorinated Biphenyls (PCB) MR 6 2021
1,2-DIBROMO-3-CHLOROPROPANE MR 6 2021
Methoxychlor MR 6 2021
Simazine MR 6 2021
Atrazine MR 6 2021

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 8 of 58 samples detected PFAS.

Contaminant Date Result MRL Status
PFOA 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
6:2 FTS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
4:2 FTS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
8:2 FTS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFMPA 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFPeA 6/20/2023 5.20 ppt 3.00 ppt Detected
PFOS 6/20/2023 13.20 ppt 4.00 ppt Detected
PFHxA 6/20/2023 3.00 ppt 3.00 ppt Detected
PFDoA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFTA 6/20/2023 <8.00 ppt 8.00 ppt Not Detected
HFPO-DA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFBS 6/20/2023 5.20 ppt 3.00 ppt Detected
ADONA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFBA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFNA 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
PFHxS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFHpS 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFPeS 6/20/2023 <4.00 ppt 4.00 ppt Not Detected
NFDHA 6/20/2023 <20.00 ppt 20.00 ppt Not Detected
PFEESA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFMBA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
11Cl-PF3OUdS 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
PFTrDA 6/20/2023 <7.00 ppt 7.00 ppt Not Detected
NEtFOSAA 6/20/2023 <5.00 ppt 5.00 ppt Not Detected
NMeFOSAA 6/20/2023 <6.00 ppt 6.00 ppt Not Detected
9Cl-PF3ONS 6/20/2023 <2.00 ppt 2.00 ppt Not Detected
PFDA 6/20/2023 <3.00 ppt 3.00 ppt Not Detected
PFUnA 6/20/2023 <2.00 ppt 2.00 ppt Not Detected
PFNA 1/9/2024 <4.00 ppt 4.00 ppt Not Detected
PFMBA 1/9/2024 <3.00 ppt 3.00 ppt Not Detected
PFPeA 1/9/2024 4.80 ppt 3.00 ppt Detected
PFMPA 1/9/2024 <4.00 ppt 4.00 ppt Not Detected
PFDoA 1/9/2024 <3.00 ppt 3.00 ppt Not Detected
PFDA 1/9/2024 <3.00 ppt 3.00 ppt Not Detected
PFTA 1/9/2024 <8.00 ppt 8.00 ppt Not Detected
PFOS 1/9/2024 16.40 ppt 4.00 ppt Detected
PFPeS 1/9/2024 <4.00 ppt 4.00 ppt Not Detected
PFHpA 1/9/2024 <3.00 ppt 3.00 ppt Not Detected
PFBS 1/9/2024 5.70 ppt 3.00 ppt Detected
PFOA 1/9/2024 <4.00 ppt 4.00 ppt Not Detected
NFDHA 1/9/2024 <20.00 ppt 20.00 ppt Not Detected
PFTrDA 1/9/2024 <7.00 ppt 7.00 ppt Not Detected
PFHpS 1/9/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxS 1/9/2024 <3.00 ppt 3.00 ppt Not Detected
PFHxA 1/9/2024 3.00 ppt 3.00 ppt Detected
PFUnA 1/9/2024 <2.00 ppt 2.00 ppt Not Detected
11Cl-PF3OUdS 1/9/2024 <5.00 ppt 5.00 ppt Not Detected
9Cl-PF3ONS 1/9/2024 <2.00 ppt 2.00 ppt Not Detected
ADONA 1/9/2024 <3.00 ppt 3.00 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 Upr Cayey.

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 PR0518085 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
2023 Picloram MR 13 SDWIS / PR0518085 / 2040
2021 Nitrate MR 10 SDWIS / PR0518085 / 1040
2021 Endrin MR 6 SDWIS / PR0518085 / 2005
2021 Toxaphene MR 6 SDWIS / PR0518085 / 2020
2021 Dalapon MR 6 SDWIS / PR0518085 / 2031
2021 Endothall MR 6 SDWIS / PR0518085 / 2033
2021 Glyphosate MR 6 SDWIS / PR0518085 / 2034
2021 OXAMYL MR 6 SDWIS / PR0518085 / 2036
2021 Heptachlor MR 6 SDWIS / PR0518085 / 2065
2021 2,4,5-TP MR 6 SDWIS / PR0518085 / 2110
2021 Pentachlorophenol MR 6 SDWIS / PR0518085 / 2326
2021 ETHYLENE DIBROMIDE MR 6 SDWIS / PR0518085 / 2946
2021 Chlordane MR 6 SDWIS / PR0518085 / 2959
2021 BHC-GAMMA MR 6 SDWIS / PR0518085 / 2010
2021 Dinoseb MR 6 SDWIS / PR0518085 / 2041

How Upr Cayey Compares

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

Metric Upr Cayey Puerto Rico avg Federal benchmark
Total violations 399 358.4 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 6 75.7 Indicates a contaminant exceeded a federal MCL
PFAS detection 4 compounds 40.4% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 2,613 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 Upr Cayey water safe to drink?
Upr Cayey (PWS ID: PR0518085) has 399 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 4 PFAS compounds found. This system serves 2,613 people using Groundwater sources.
How many people does Upr Cayey serve?
Upr Cayey serves 2,613 people in Cayey, Puerto Rico. It is a Private-owned system using Groundwater water sources with 66 service connections.
What type of violations does Upr Cayey have?
Upr Cayey has 399 total violations: 6 health-based violations (MCL exceedances or treatment failures), 390 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Upr Cayey water?
Yes. UCMR5 testing detected 4 PFAS compounds in Upr Cayey's water supply: PFPeA, PFOS, PFHxA, PFBS. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Upr Cayey use?
Upr Cayey uses Groundwater as its primary water source. It is classified as a Non-Transient Non-Community Water System, serving the same people for at least 6 months per year.
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.
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.