Is Cocos water safe to drink?

Cocos (PWS ID: PR0004895) has 899 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. EPA SDWIS lists this system's service population as 9,956 people using Groundwater sources.

How many people does Cocos serve?

EPA SDWIS reports that Cocos serves 9,956 people (this public water system's service population, not the municipal population of Salinas or any other city). It is a Local-owned system using Groundwater water sources with 3,729 service connections. The operator address is listed in Salinas, Puerto Rico.

What type of violations does Cocos have?

Cocos has 899 total violations: 58 health-based violations (MCL exceedances or treatment failures), 821 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Cocos water?

No. Cocos was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.

What water source does Cocos use?

Cocos uses Groundwater 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.

Where does Cocos sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Cocos ranks #4,708 of 29,740 by people served, and #54 of 235 in Puerto Rico. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Cocos's violation count compare nationally?

Cocos has 899 recorded EPA SDWIS violations, fewer than 1% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 99% of that cohort has fewer violations than Cocos. A system can have zero recorded violations and still be actively monitored, and a high violation count often reflects a system that reports thoroughly, not necessarily one with worse water.

States → Puerto Rico

Community Water System · PWS PR0004895

Cocos

Operator location Salinas, Puerto Rico - larger served population (> 3,309) at 9,956 people served; 899 SDWIS violations on record from groundwater sources.

Compiled by PlainWater · May 15, 2026

9,956
People served (this PWS) Larger third of systems: 899
EPA violations (this PWS) Upper third of systems: 58
Health-based (this PWS) Middle third by health-based share: No PFAS
UCMR5 (this PWS) Tested, none detected

Follow published updates (RSS)

Cocos standing, high SDWIS violation third

9,956 people served (SDWIS) - larger served population (> 3,309). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 6% is middle-third health share (≤ 23%). UCMR5: UCMR5 tested, none detected. Population rank #4,708 of 29,740 among systems serving 500+.

The verdict

Cocos sits in the upper third of the sitemap cohort by violation count (899), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (9,956; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 6% (middle-third health share (≤ 23%)). UCMR5 tested this system and reported no PFAS above the minimum reporting level.

#4,708 of 29,740
Population · /systems: #54 of 235
Population · PR: 899
Total EPA violations on record: 6%
Health-based (MCL / treatment failure)

Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.

Water Safety Score

0/100

Cocos

Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.

Health-based violations F

EPA SDWIS health-based violations on record (MCL, MRDL, treatment technique)

Monitoring & reporting violations F

841

Non-health SDWIS violations (monitoring, reporting, and other compliance)

PFAS contamination N/A

Tested, none detected

Highest PFAS compound level detected in UCMR5 testing

System Details

System Type: Community
Owner Type: Local
Connections: 3,729
County: Salinas Municipio
School/Daycare: No
MCL Violations: 58
Monitoring Violations: 821
Treatment Tech Violations: 0

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Coliform (TCR)	MCL	47	2016
Total Polychlorinated Biphenyls (PCB)	MR	26	2020
Heptachlor epoxide	MR	20	2020
Chlordane	MR	20	2020
BHC-GAMMA	MR	20	2020
Heptachlor	MR	20	2020
HEXACHLOROBENZENE	MR	20	2020
Endothall	MR	20	2020
Endrin	MR	20	2020
Methoxychlor	MR	20	2020
Toxaphene	MR	18	2018
2,4,5-TP	MR	18	2020
Pentachlorophenol	MR	18	2020
Dalapon	MR	18	2020
Picloram	MR	18	2020
2,4-D	MR	18	2020
Dinoseb	MR	18	2020
1,2-DIBROMO-3-CHLOROPROPANE	MR	16	2018
ETHYLENE DIBROMIDE	MR	16	2018
1,2,4-Trichlorobenzene	MR	15	2018
cis-1,2-Dichloroethylene	MR	15	2018
Xylenes, Total	MR	15	2018
p-Dichlorobenzene	MR	15	2018
1,1-Dichloroethylene	MR	15	2018
trans-1,2-Dichloroethylene	MR	15	2018
1,2-Dichloroethane	MR	15	2018
1,1,1-Trichloroethane	MR	15	2018
Carbon tetrachloride	MR	15	2018
1,2-Dichloropropane	MR	15	2018
Trichloroethylene	MR	15	2018

Violation Count vs. the National Corpus

Cocos has 899 recorded EPA violations, 99% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 1% carry more. 6% of this system's own violations are health-based (58 of 899), and it ranks #4,708 of 29,740 by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

899 Higher than most more violations than 99% of 29,740 water systems

the national water-system corpus, bucketed by value

Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source EPA SDWIS · 2026-05-15

How many violations vs. how serious, among peer systems

Cocos plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.

30 public water systems (500+ people served), EPA SDWIS current release.

How to read this

Each dot is one public water system; the highlighted dot is Cocos. A system to the right has more recorded violations; a system higher up has a larger share of those violations classified health-based rather than monitoring or reporting.

Rare but serious: few violations, but most of them are health-based.
Frequent, mostly paperwork: many violations, but mostly monitoring or reporting, not health-based.
Clean record: below-median on both counts, the tinted corner.

View all 30 systems as a list

City of Ballinger: 372 violations, 85% health-based
Nooksack Valley Water Association: 16 violations, 31% health-based
Montgomery Co RWD 12: 7 violations, 29% health-based
Irvin Water District #6: 11 violations, 27% health-based
Ticonderoga WD: 47 violations, 26% health-based
Pine Valley Plantation: 37 violations, 24% health-based
McLouth, City Of: 29 violations, 17% health-based
Kipling Oaks 1: 25 violations, 16% health-based
South Deerfield Water Supply District: 96 violations, 16% health-based
Sunset Ridge Water District: 82 violations, 15% health-based
Orange Water Dept: 136 violations, 14% health-based
Mount Pleasant Water Sys #1: 167 violations, 11% health-based
Cocos: 899 violations, 6% health-based (this system)
Lake Gibson Estates: 42 violations, 2% health-based
Benson Culinary Improvement District: 212 violations, 1% health-based
Conemaugh Twp Muni Auth: 567 violations, 1% health-based
Miccosukee Service Plaza: 0 violations, 0% health-based
Brazoria - Fort Bend Counties MUD 3: 0 violations, 0% health-based
Tanglewilde Thompson Place 600: 2 violations, 0% health-based
Center Water Co: 5 violations, 0% health-based
Spring Mills Elem School/Hvs: 9 violations, 0% health-based
Great Bend Industrial Park: 14 violations, 0% health-based
Glen Park Village: 19 violations, 0% health-based
Camp Is-Sho-Da: 22 violations, 0% health-based
Hamilton: 33 violations, 0% health-based
Town of Welaka: 54 violations, 0% health-based
Township of Blairstown Dpw: 61 violations, 0% health-based
McIntosh Water & Fire Pro Authority: 71 violations, 0% health-based
Clarkdale Municipal Water System: 114 violations, 0% health-based
Eureka Water Association: 273 violations, 0% health-based

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 348 samples detected PFAS.

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

Population served record for Cocos

EPA SDWIS lists 9,956 people served and 3,729 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.

EPA SDWIS · PWS PR0004895

Sources: EPA SDWIS

Nationwide peers

899 violations · 9,956 served: nearest cross-state SDWIS matches.

Cross-state systems with comparable violation load

Nearest cross-state community systems (500+ served) by total SDWIS violations on record.

4 peers

Cross-state systems with similar served population

Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).

4 peers

What to do with Cocos

Use this system's EPA-reported record as a starting filter, not a final verdict.

See how every tracked system in Puerto Rico compares on the same EPA violation measures. Puerto Rico systems
Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
Find and compare another public water system by name or PWSID. Search systems

EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.

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

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

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