Is Mountain Lakes Water Dep water safe to drink?

Mountain Lakes Water Dep (PWS ID: NJ1425001) has 340 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 2 PFAS compounds found. EPA SDWIS lists this system's service population as 4,012 people using Groundwater sources.

How many people does Mountain Lakes Water Dep serve?

EPA SDWIS reports that Mountain Lakes Water Dep serves 4,012 people (this public water system's service population, not the municipal population of Riverdale or any other city). It is a Local-owned system using Groundwater water sources with 1,501 service connections. The operator address is listed in Riverdale, New Jersey.

What type of violations does Mountain Lakes Water Dep have?

Mountain Lakes Water Dep has 340 total violations: 0 health-based violations (MCL exceedances or treatment failures), 323 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Mountain Lakes Water Dep water?

Yes. UCMR5 testing detected 2 PFAS compounds in Mountain Lakes Water Dep's water supply: PFOA, PFPeA. PFAS are persistent "forever chemicals" that do not break down in the environment.

What water source does Mountain Lakes Water Dep use?

Mountain Lakes Water Dep 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 Mountain Lakes Water Dep sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Mountain Lakes Water Dep ranks #8,835 of 29,740 by people served, and #239 of 689 in New Jersey. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Mountain Lakes Water Dep's violation count compare nationally?

Mountain Lakes Water Dep has 340 recorded EPA SDWIS violations, fewer than 8% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 92% of that cohort has fewer violations than Mountain Lakes Water Dep. 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 → New Jersey

Community Water System · PWS NJ1425001

Mountain Lakes Water Dep

Operator location Riverdale, New Jersey - 0% of 340 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 4,012 served per SDWIS.

Compiled by PlainWater · May 15, 2026

4,012
People served (this PWS) Larger third of systems: 340
EPA violations (this PWS) Upper third of systems: 0
Health-based (this PWS) Lower third by health-based share: 2 PFAS
UCMR5 (this PWS) Lower third of PFAS-detected systems

Follow published updates (RSS)

Mountain Lakes Water Dep standing, high SDWIS violation third

0% of 340 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%). UCMR5: lower-third PFAS panel (≤ 2 compounds). Population rank #8,835 of 29,740 among systems serving 500+.

The verdict

Mountain Lakes Water Dep sits in the upper third of the sitemap cohort by violation count (340), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (4,012; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is only 0% - almost all of this trail is monitoring or reporting. UCMR5 detected 2 PFAS compounds (lower-third PFAS panel (≤ 2 compounds)).

#8,835 of 29,740
Population · /systems: #239 of 689
Population · NJ: 340
Total EPA violations on record: 0%
Health-based (MCL / treatment failure)

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

PFAS Detected

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

Water Safety Score

48/100

Mountain Lakes Water Dep

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 A+

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

Monitoring & reporting violations F

340

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

PFAS contamination F

0.0133 µg/L

Highest PFAS compound level detected in UCMR5 testing

System Details

System Type: Community
Owner Type: Local
Connections: 1,501
County: Morris
School/Daycare: No
MCL Violations: 0
Monitoring Violations: 323
Treatment Tech Violations: 0

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Nitrate	MR	18	2007
Consumer Confidence Rule	Other	14	2024
Xylenes, Total	MR	14	2005
p-Dichlorobenzene	MR	14	2005
trans-1,2-Dichloroethylene	MR	14	2005
1,2-Dichloroethane	MR	14	2005
1,1,1-Trichloroethane	MR	14	2005
1,2-Dichloropropane	MR	14	2005
CHLOROBENZENE	MR	14	2005
Benzene	MR	14	2005
Toluene	MR	14	2005
Styrene	MR	14	2005
1,2,4-Trichlorobenzene	MR	14	2005
o-Dichlorobenzene	MR	14	2005
1,1-Dichloroethylene	MR	14	2005
Carbon tetrachloride	MR	14	2005
Trichloroethylene	MR	14	2005
1,1,2-Trichloroethane	MR	14	2005
Tetrachloroethylene	MR	14	2005
cis-1,2-Dichloroethylene	MR	14	2005
DICHLOROMETHANE	MR	14	2005
Vinyl chloride	MR	14	2005
Ethylbenzene	MR	14	2005
Coliform (TCR)	MR	6	2005
Chlorine	MR	5	2025

Violation Count vs. the National Corpus

Mountain Lakes Water Dep has 340 recorded EPA violations, 92% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 8% carry more. 0% of this system's own violations are health-based (0 of 340), and it ranks #8,835 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)

340 Higher than most more violations than 92% 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

Mountain Lakes Water Dep 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 Mountain Lakes Water Dep. 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
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
Mountain Lakes Water Dep: 340 violations, 0% health-based (this system)

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 8 of 203 samples detected PFAS.

Contaminant	Date	Result	MRL	Status
PFTA	8/26/2025	<8.00 ppt	8.00 ppt	Not Detected
PFTrDA	8/26/2025	<7.00 ppt	7.00 ppt	Not Detected
NEtFOSAA	8/26/2025	<5.00 ppt	5.00 ppt	Not Detected
NMeFOSAA	8/26/2025	<6.00 ppt	6.00 ppt	Not Detected
6:2 FTS	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
PFTrDA	7/15/2025	<7.00 ppt	7.00 ppt	Not Detected
PFHpA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFBS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHpS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFPeS	7/15/2025	<4.00 ppt	4.00 ppt	Not Detected
NFDHA	7/15/2025	<20.00 ppt	20.00 ppt	Not Detected
PFEESA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFMBA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFPeA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFMPA	7/15/2025	<4.00 ppt	4.00 ppt	Not Detected
PFOS	7/15/2025	<4.00 ppt	4.00 ppt	Not Detected
4:2 FTS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFNA	7/15/2025	<4.00 ppt	4.00 ppt	Not Detected
PFBA	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
HFPO-DA	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
ADONA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
9Cl-PF3ONS	7/15/2025	<2.00 ppt	2.00 ppt	Not Detected
11Cl-PF3OUdS	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
PFUnA	7/15/2025	<2.00 ppt	2.00 ppt	Not Detected
PFHxA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFDoA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFDA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFOA	7/15/2025	6.30 ppt	4.00 ppt	Detected
PFTA	7/15/2025	<8.00 ppt	8.00 ppt	Not Detected
8:2 FTS	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
PFHxS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
NEtFOSAA	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
NMeFOSAA	7/15/2025	<6.00 ppt	6.00 ppt	Not Detected
9Cl-PF3ONS	7/15/2025	<2.00 ppt	2.00 ppt	Not Detected
PFUnA	7/15/2025	<2.00 ppt	2.00 ppt	Not Detected
PFOA	7/15/2025	9.50 ppt	4.00 ppt	Detected
PFBS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHpA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHxS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFNA	7/15/2025	<4.00 ppt	4.00 ppt	Not Detected
PFOS	7/15/2025	<4.00 ppt	4.00 ppt	Not Detected
PFDA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
HFPO-DA	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
PFHxA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFHpS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
11Cl-PF3OUdS	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
ADONA	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected
PFBA	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
6:2 FTS	7/15/2025	<5.00 ppt	5.00 ppt	Not Detected
4:2 FTS	7/15/2025	<3.00 ppt	3.00 ppt	Not Detected

Health-based violations on Mountain Lakes Water Dep

0 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for NJ1425001.

EPA SDWIS · PWS NJ1425001 NJ primacy agency

Sources: EPA SDWIS · NJ DEP, Bureau of Safe Drinking Water

Nationwide peers

340 violations · 4,012 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 Mountain Lakes Water Dep

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

See how every tracked system in New Jersey compares on the same EPA violation measures. New Jersey 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.