Overview

Chloromethane is an industrial solvent, aerosol propellant and a refrigerant. It also forms as a byproduct of water disinfection. The EPA classifies chloromethane as possibly carcinogenic to humans.

State, National, and Health Guidelines for Drinking Water

EWG Health Guideline: 2.69 ppb

The EWG Health Guideline of 2.69 ppb for chloromethane was defined by the Environmental Protection Agency as a benchmark for testing under the Unregulated Contaminant Monitoring Rule program. This health guideline protects against cancer.

ppb = parts per billion

National Standard Exists

Health Concerns:

Cancer

Want to remove
Chloromethane from your water?

Try these filter technologies:

Activated Carbon,

Reverse Osmosis,

understand filter technology

Chloromethane around the Country

	UTILITIES REPORTING ABOVE HEALTH GUIDELINES		UTILITIES WITH CONTAMINATION
State	Utilities	People Served	Utilities	People Served
California		0	0		65	4,260,924
Maryland		20	15,997		117	2,074,177
Florida		0	0		25	1,442,915
New York		0	0		125	840,276
Massachusetts		0	0		38	818,293
Illinois		0	0		29	555,036
Alabama		0	0		17	462,093
Wisconsin		0	0		58	363,336
Texas		4	7,682		98	346,821
New Jersey		2	41,860		20	244,978
Washington		1	182		53	211,419
North Carolina		0	0		14	167,532
Connecticut		0	0		6	154,789
Louisiana		0	0		12	152,410
Mississippi		0	0		11	141,698
Georgia		0	0		15	114,896
Tennessee		0	0		3	88,633
Delaware		0	0		17	85,789
South Carolina		0	0		5	76,907
Indiana		0	0		11	76,731
Kentucky		0	0		3	42,281
Arkansas		0	0		29	35,926
Utah		0	0		3	33,265
Nebraska		1	809		17	26,392
Oregon		0	0		5	25,623
Ohio		0	0		1	24,747
Minnesota		0	0		9	24,591
Pennsylvania		0	0		3	22,913
Wyoming		2	1,571		18	9,271
Vermont		0	0		5	8,179
Iowa		0	0		9	7,573
Nevada		0	0		3	5,882
Michigan		0	0		3	1,859
Montana		1	750		3	1,330
Rhode Island		0	0		2	345
New Hampshire		0	0		1	50
Missouri		1	40		1	40

SHOW LESS

Utilities with the highest amounts of chloromethane, 2013-2023

ALL UTILITIES

LARGE UTILITIES

Utility	Location	Tests	Average level	People served
Barrelville	Mt. Savage, MD	1 of 1	30.3 ppb	130
Minatare, City of	Minatare, NE	11 of 11	23.3 ppb	809
Mercer County Correctional Center	Trenton, NJ	1 of 2	21.6 ppb	860
Route 66 Homes	Cuba, MO	1 of 4	20.5 ppb	40
Tri-lakes Outdoors	Lufkin, TX	6 of 6	11.1 ppb	48
Bradford Estates	Frederick, MD	2 of 2	10.5 ppb	178
Town of Deer Park	Mountain Lake Park, MD	1 of 1	9.55 ppb	272
Town of Sharpsburg	Williamsport, MD	2 of 2	8.92 ppb	1,360
Town of Luke / Newpage Luke Mill	Luke, MD	2 of 2	8.88 ppb	68
Libertytown East	Frederick, MD	2 of 2	8.22 ppb	140
Knolls of Windsor	Frederick, MD	2 of 2	7.91 ppb	1,553
White Rock	Frederick, MD	4 of 4	7.90 ppb	256
Libertytown Apartments	Frederick, MD	2 of 2	7.86 ppb	97
White Oak Mobile Home Park	Swanton, MD	1 of 1	7.84 ppb	32
Backbone Mountain Boys Camp	Swanton, MD	1 of 1	7.66 ppb	60
Town of Kitzmiller	Mountain Lake Park, MD	1 of 1	7.51 ppb	370
Mount Aetna	Hagerstown, MD	1 of 1	7.26 ppb	688
Westwood Villa Apartments	College Station, TX	12 of 12	7.00 ppb	180
City of Giddings*	Giddings, TX	12 of 12	7.00 ppb	7,428
North Brunswick W Department*	Somerset, NJ	1 of 6	6.93 ppb	41,000
Town of Oakland	Oakland, MD	8 of 8	6.78 ppb	1,850
Susan Circle Community Ws	Vidor, TX	5 of 6	6.68 ppb	26
Ten Mile and Pleasant Valley Wua	Helena, MT	3 of 8	6.68 ppb	750
Long Point Water Company Inc.	Coupeville, WA	2 of 3	6.63 ppb	182
Cook Road Water District	Gillette, WY	3 of 3	6.43 ppb	291
Town of Woodsboro	Woodsboro, MD	6 of 6	6.33 ppb	846
Bloomington	Mountain Lake Park, MD	3 of 3	6.32 ppb	350
Antelope Valley I&s District (avisd)	Gillette, WY	1 of 1	6.10 ppb	1,280
Midland-lonaconing	Lonaconing, MD	9 of 18	5.89 ppb	5,000
Town of Westernport*	Westernport, MD	3 of 3	5.85 ppb	2,200
Brophytown Distribution System	Cumberland, MD	3 of 3	5.85 ppb	47
Swan Harbour Dell Mobile Home Park	Havre De Grace, MD	2 of 2	5.39 ppb	500
Town of Hampstead	Hampstead, MD	1 of 1	5.26 ppb	6,600
Town of Friendsville	Mountain Lake Park, MD	3 of 3	5.09 ppb	622
Cameron Parish Water and Water Works District 1	Cameron, LA	10 of 10	4.98 ppb	1,891
Elba Water Works*	Elba, AL	2 of 17	4.96 ppb	5,361
Woodland Trailer Park	Martinsburg, MD	4 of 4	4.72 ppb	65
City of Grandview	Grandview, WA	6 of 15	4.71 ppb	11,010
Thayerville Water District	Mountain Lake Park, MD	1 of 1	4.62 ppb	50
Williams Water Supply	Williams, IA	17 of 17	4.58 ppb	315
Town of Poolesville	Brunswick, MD	2 of 2	4.40 ppb	5,400
Deer Lake Haven Inc.	Freeland, WA	1 of 2	4.05 ppb	90
Deer Lodge Mobile Home Park	Frederick, MD	5 of 5	4.04 ppb	87
Galveston County Water Control and Improvement District 19	Houston, TX	2 of 5	3.96 ppb	660
Alpine Manor Home For Adults	Lima, NY	7 of 7	3.93 ppb	36
Maple Hill Mobile Estates	Port Deposit, MD	1 of 1	3.88 ppb	180
Greenleaf Waterworks	Greenleaf, WI	4 of 4	3.70 ppb	650
Town of Myersville	Myersville, MD	3 of 3	3.65 ppb	1,516
Highfield	Smithsburg, MD	5 of 5	3.61 ppb	1,141
Sandy Hook	Sharpsburg, MD	1 of 1	3.60 ppb	220

* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Chloromethane, but it likely has the contaminant in its water supply.

Utility	Location	Tests	Average level	People served
North Brunswick W Department*	Somerset, NJ	1 of 6	6.93 ppb	41,000
City of Grandview	Grandview, WA	6 of 15	4.71 ppb	11,010
City of Cumberland*	, MD	3 of 7	2.17 ppb	27,039
Whitman Water System	Whitman, MA	1 of 14	2.13 ppb	14,574
Brockton Water Commission*	Brockton, MA	1 of 14	2.13 ppb	93,810
New Design - Frederick County*	Frederick, MD	6 of 12	1.86 ppb	49,200
City of Hagerstown*	Hagerstown, MD	2 of 6	1.81 ppb	92,200
Tewksbury Water Department	Tewksbury, MA	2 of 43	1.71 ppb	30,435
Midvale City Water System	Eagle Mountain, UT	2 of 62	1.44 ppb	33,000
Olivehurst Public UD	Olivehurst, CA	1 of 3	1.33 ppb	16,595
City of Frostburg*	, MD	4 of 8	1.24 ppb	11,000
City of Newberg*	Newberg, OR	1 of 2	1.10 ppb	25,138
South Elgin	South Elgin, IL	3 of 12	1.04 ppb	22,549
Golden State Water Company (GSWC) - Southwest	Hawthorne, CA	6 of 24	0.978 ppb	275,369
Methuen Water Department*	Methuen, MA	2 of 15	0.767 ppb	50,259
Milford Water Company*	Milford, MA	1 of 31	0.706 ppb	27,999
Water Works District #1 of Vermilion	Maurice, LA	2 of 2	0.690 ppb	23,490
Linda County Water District	Marysville, CA	2 of 3	0.680 ppb	21,654
North Attleboro Water Department*	North Attleborough, MA	3 of 36	0.611 ppb	28,712
Lawrence Water Works	Lawrence, MA	1 of 27	0.574 ppb	76,377
Billerica Water Works	Billerica, MA	2 of 27	0.522 ppb	40,243
City of Greenville	Greenville, MS	15 of 18	0.464 ppb	29,602
Saratoga Springs City*	Saratoga Springs, NY	4 of 15	0.435 ppb	35,900
City of Baltimore*	Baltimore, MD	6 of 13	0.408 ppb	1,600,000
City of Frederick*	Frederick, MD	4 of 20	0.361 ppb	54,000
City of Plant City Utility*	Plant City, FL	6 of 8	0.333 ppb	42,536
Lomita Water Department	Lomita, CA	2 of 6	0.332 ppb	20,256
Needham Water Department (MWRA)	Needham, MA	2 of 29	0.324 ppb	32,485
Crystal Lake*	Crystal Lake, IL	2 of 8	0.318 ppb	40,635
City of San Jacinto	San Jacinto, CA	1 of 18	0.294 ppb	18,950
Aqua Illinois - Kankakee*	Kankakee, IL	1 of 4	0.275 ppb	80,275
Elgin*	Elgin, IL	2 of 4	0.275 ppb	113,911
West Monroe Water System	West Monroe, LA	2 of 6	0.268 ppb	16,005
Sulphur Water System	Sulphur, LA	3 of 4	0.253 ppb	20,632
City of Santa Rosa*	Santa Rosa, CA	1 of 4	0.250 ppb	175,775
Crowley Water System (LAWCO)	Baton Rouge, LA	1 of 2	0.235 ppb	17,754
Orange County Utilities Department (OCUD) - West*	Orlando, FL	4 of 8	0.235 ppb	206,742
City of Alvin*	Alvin, TX	6 of 25	0.224 ppb	26,780
The Consolidated Water Supply Corporation Rockhill Road System	Crockett, TX	6 of 61	0.223 ppb	10,689
North Peninsula*	Poulsbo, WA	3 of 18	0.200 ppb	16,449
City of Gautier	Gautier, MS	5 of 14	0.200 ppb	19,776
Central	Winter Haven, FL	2 of 9	0.188 ppb	13,595
City of Rockville	Rockville, MD	1 of 5	0.186 ppb	52,000
Cary	Cary, IL	4 of 16	0.185 ppb	18,271
Queensbury Water District*	Queensbury, NY	6 of 25	0.185 ppb	39,799
Northwest Utilities*	Tampa, FL	3 of 12	0.183 ppb	206,485
City of Lemoore	Lemoore, CA	5 of 23	0.178 ppb	27,038
City of Pleasanton	Pleasanton, TX	1 of 46	0.176 ppb	11,142
Carolina Beach Water System	Carolina Beach, NC	5 of 16	0.175 ppb	12,294
Huntsville Utilities*	Huntsville, AL	1 of 82	0.171 ppb	262,155

EWG’s Tap
Water Database

Nitrate in
Tap Water

CONTAMINANT

Chloromethane

STATES DETECTED

37

serves

13 million

utilities detected

854

states detected

8

serves

68,891

utilities detected

32

Overview

State, National, and Health Guidelines for Drinking Water

National Standard Exists

Health Concerns:

Want to remove
Chloromethane from your water?

Chloromethane around the Country

Utilities with the highest amounts of chloromethane, 2013-2023

Know the Standards

Take Action

Need help finding a filter?

We’re in this together

Protect your water

EWG’s TapWater Database

CONTAMINANT

Chloromethane

STATES DETECTED

37

serves

13 million

utilities detected

854

states detected

8

serves

68,891

utilities detected

32

Overview

State, National, and Health Guidelines for Drinking Water

National Standard Exists

Health Concerns:

Want to removeChloromethane from your water?

Chloromethane around the Country

Utilities with the highest amounts of chloromethane, 2013-2023

Know the Standards

Take Action

Need help finding a filter?

We’re in this together

Protect your water

EWG’s Tap
Water Database

Want to remove
Chloromethane from your water?