Is Mt Greylock Regional School water safe to drink?

Mt Greylock Regional School (PWS ID: MA1341010) has 88 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. EPA SDWIS lists this system's service population as 930 people using Groundwater sources.

How many people does Mt Greylock Regional School serve?

EPA SDWIS reports that Mt Greylock Regional School serves 930 people (this public water system's service population, not the municipal population of Williamstown or any other city). It is a Local-owned system using Groundwater water sources with 1 service connections. The operator address is listed in Williamstown, Massachusetts.

What type of violations does Mt Greylock Regional School have?

Mt Greylock Regional School has 88 total violations: 0 health-based violations (MCL exceedances or treatment failures), 79 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Mt Greylock Regional School water?

No. Mt Greylock Regional School was tested for PFAS under the EPA's UCMR5 monitoring program and no PFAS contamination was detected.

What water source does Mt Greylock Regional School use?

Mt Greylock Regional School 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.

Where does Mt Greylock Regional School sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Mt Greylock Regional School ranks #20,627 of 29,740 by people served, and #342 of 418 in Massachusetts. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Mt Greylock Regional School's violation count compare nationally?

Mt Greylock Regional School has 88 recorded EPA SDWIS violations, fewer than 29% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 70% of that cohort has fewer violations than Mt Greylock Regional School. 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 → Massachusetts

Non-Transient Non-Community Water System · PWS MA1341010

Mt Greylock Regional School

Operator location Williamstown, Massachusetts - 0% of 88 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 930 served per SDWIS.

Compiled by PlainWater · May 15, 2026

930
People served (this PWS) Smaller third of systems: 88
EPA violations (this PWS) Upper third of systems: 0
Health-based (this PWS) Lower third by health-based share: No PFAS
UCMR5 (this PWS) Tested, none detected

Follow published updates (RSS)

Mt Greylock Regional School standing, high SDWIS violation third

0% of 88 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: UCMR5 tested, none detected. Population rank #20,627 of 29,740 among systems serving 500+.

The verdict

Mt Greylock Regional School sits in the upper third of the sitemap cohort by violation count (88), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (930; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is only 0% - almost all of this trail is monitoring or reporting. UCMR5 tested this system and reported no PFAS above the minimum reporting level.

#20,627 of 29,740
Population · /systems: #342 of 418
Population · MA: 88
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.

B-

Water Safety Score

65/100

Mt Greylock Regional School

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

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: Non-Transient Non-Community
Owner Type: Local
Connections: 1
County: Berkshire
School/Daycare: Yes
MCL Violations: 0
Monitoring Violations: 79
Treatment Tech Violations: 0

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
Lead and Copper Rule	MR	4	2011
Heptachlor epoxide	MR	2	2009
Pentachlorophenol	MR	2	2009
Toxaphene	MR	2	2009
2,4,5-TP	MR	2	2009
BHC-GAMMA	MR	2	2009
Benzo(a)pyrene	MR	2	2009
Di(2-ethylhexyl) adipate	MR	2	2009
Di(2-ethylhexyl) phthalate	MR	2	2009
Dinoseb	MR	2	2009
Glyphosate	MR	2	2009
OXAMYL	MR	2	2009
LASSO	MR	2	2009
2,3,7,8-TCDD	MR	2	2009
2,4-D	MR	2	2009
ETHYLENE DIBROMIDE	MR	2	2009
Endothall	MR	2	2009
Revised Total Coliform Rule	MON	2	2018
Hexachlorocyclopentadiene	MR	2	2009
Simazine	MR	2	2009
Diquat	MR	2	2009
Atrazine	MR	2	2009
Carbofuran	MR	2	2009
Total Polychlorinated Biphenyls (PCB)	MR	2	2009
1,2-DIBROMO-3-CHLOROPROPANE	MR	2	2009
Endrin	MR	2	2009
Dalapon	MR	2	2009
Heptachlor	MR	2	2009
Chlordane	MR	2	2009
Methoxychlor	MR	2	2009

Violation Count vs. the National Corpus

Mt Greylock Regional School has 88 recorded EPA violations, 70% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 29% carry more. 0% of this system's own violations are health-based (0 of 88), and it ranks #20,627 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)

88 Around the middle fewer violations than 29% 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

Mt Greylock Regional School 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 Mt Greylock Regional School. 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
Mt Greylock Regional School: 88 violations, 0% health-based (this system)

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 58 samples detected PFAS.

Contaminant	Date	Result	MRL	Status
PFTA	7/5/2023	<8.00 ppt	8.00 ppt	Not Detected
NEtFOSAA	7/5/2023	<5.00 ppt	5.00 ppt	Not Detected
PFTrDA	7/5/2023	<7.00 ppt	7.00 ppt	Not Detected
NMeFOSAA	7/5/2023	<6.00 ppt	6.00 ppt	Not Detected
PFPeS	4/4/2023	<4.00 ppt	4.00 ppt	Not Detected
ADONA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFBS	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFHpA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFHxS	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFNA	4/4/2023	<4.00 ppt	4.00 ppt	Not Detected
PFOS	4/4/2023	<4.00 ppt	4.00 ppt	Not Detected
PFOA	4/4/2023	<4.00 ppt	4.00 ppt	Not Detected
PFDA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFDoA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFHxA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFUnA	4/4/2023	<2.00 ppt	2.00 ppt	Not Detected
9Cl-PF3ONS	4/4/2023	<2.00 ppt	2.00 ppt	Not Detected
PFPeA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFHpS	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
NFDHA	4/4/2023	<20.00 ppt	20.00 ppt	Not Detected
11Cl-PF3OUdS	4/4/2023	<5.00 ppt	5.00 ppt	Not Detected
PFMBA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFMPA	4/4/2023	<4.00 ppt	4.00 ppt	Not Detected
8:2 FTS	4/4/2023	<5.00 ppt	5.00 ppt	Not Detected
4:2 FTS	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
6:2 FTS	4/4/2023	<5.00 ppt	5.00 ppt	Not Detected
PFBA	4/4/2023	<5.00 ppt	5.00 ppt	Not Detected
HFPO-DA	4/4/2023	<5.00 ppt	5.00 ppt	Not Detected
PFEESA	4/4/2023	<3.00 ppt	3.00 ppt	Not Detected
PFUnA	10/3/2023	<2.00 ppt	2.00 ppt	Not Detected
PFPeS	10/3/2023	<4.00 ppt	4.00 ppt	Not Detected
PFEESA	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
PFTrDA	10/3/2023	<7.00 ppt	7.00 ppt	Not Detected
PFPeA	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
PFMPA	10/3/2023	<4.00 ppt	4.00 ppt	Not Detected
8:2 FTS	10/3/2023	<5.00 ppt	5.00 ppt	Not Detected
4:2 FTS	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
6:2 FTS	10/3/2023	<5.00 ppt	5.00 ppt	Not Detected
PFBA	10/3/2023	<5.00 ppt	5.00 ppt	Not Detected
HFPO-DA	10/3/2023	<5.00 ppt	5.00 ppt	Not Detected
ADONA	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
PFHpS	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
11Cl-PF3OUdS	10/3/2023	<5.00 ppt	5.00 ppt	Not Detected
NFDHA	10/3/2023	<20.00 ppt	20.00 ppt	Not Detected
PFHxA	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
PFDoA	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
PFDA	10/3/2023	<3.00 ppt	3.00 ppt	Not Detected
PFOA	10/3/2023	<4.00 ppt	4.00 ppt	Not Detected
PFOS	10/3/2023	<4.00 ppt	4.00 ppt	Not Detected
PFNA	10/3/2023	<4.00 ppt	4.00 ppt	Not Detected

Health-based violations on Mt Greylock Regional School

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 MA1341010.

EPA SDWIS · PWS MA1341010 MA primacy agency

Sources: EPA SDWIS · MassDEP, Drinking Water Program

Nationwide peers

88 violations · 930 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 smaller service footprints

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

4 peers

What to do with Mt Greylock Regional School

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

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