The cancer-causing toxin chromium-6 is present in 140 Chicago-area water systems, according to a new study published this week by the Environmental Working Group.
Chromium-6 was made famous by the 2000 movie “Erin Brockovich,” in which Julia Roberts, playing the titular character, takes on a California power company accused of polluting a city’s water supply. The toxin can cause liver damage, reproductive problems and developmental harm.
The U.S. Environmental Protection’s maximum for chromium is 100 parts per billion, and none of the 162 systems tested in Cook, DuPage, Will, Kane, Lake, McHenry and Kendall counties reached that level, nor even came close.
But only 22 of the tested systems showed no trace of chromium-6.

California’s Office of Environmental Health Hazard Assessment, however, set 0.02 parts per billion as a public health goal. At that level, the Environmental Working Group maintains, just one out of a million people is likely to develop cancer after 70 years of drinking the water.
Of 47 Illinois counties tested, 37 exceed 0.02 parts per billion, according to the study published by the Environmental Working Group.
Here is the data for communities tested in Cook, DuPage, Kane, Kendall, Will, McHenry and Lake counties.

Cook County

• Alsip – Population Served: 19,298
• Arlington Heights – Population Served: 75,101
• Bartlett – Population Served: 41,500
• Bellwood – Population Served: 19,161
• Berwyn – Population Served: 55,000
• Blue Island – Population Served: 23,463
• Bridgeview – Population Served: 16,446
• Brookfield – Population Served: 19,085
• Buffalo Grove – Population Served: 44,949
• Calumet City – Population Served: 37,232
• Chicago – Population Served: 2,695,598
• Chicago Heights – Population Served: 30,392
• Chicago Ridge – Population Served: 14,305
• Cicero – Population Served: 85,600
• Country Club Hills – Population Served: 16,169
• Crestwood – Population Served: 10,950
• Des Plaines – Population Served: 58,918
• Des Plaines MHP – Population Served: 580
• Dolton – Population Served: 23,153
• Elk Grove Village – Population Served: 33,127
• Elmwood Park – Population Served: 25,405
• Evanston – Population Served: 74,486
• Evergreen Park – Population Served: 19,852
• Forest Park – Population Served: 14,167
• Franklin Park – Population Served: 18,333
• Glenview – Population Served: 48,892
• Glenwood – Population Served: 9,000
• Hanover Park – Population Served: 37,973
• Harvey – Population Served: 25,000
• Hazel Crest – Population Served: 14,162
• Hickory Hills – Population Served: 14,049
• Hoffman Estates – Population Served: 51,895
• Homewood – Population Served: 19,433
• IL American – Alpine Heights – Population Served: 711
• IL American Water Co. – Chicago – Population Served: 12,522
• IL American – Fernway – Population Served: 5,844
• Justice-Willow Springs Water Commission – Population Served: 18,450
• La Grange – Population Served: 15,608
• La Grange Park – Population Served: 13,579
• Lansing – Population Served: 28,663
• Lemont – Population Served: 16,000
• Leyden Township Water District – Population Served: 16,000
• Lincolnwood – Population Served: 12,590
• Lyons – Population Served: 10,729
• Markham – Population Served: 12,500
• Matteson – Population Served: 19,000
• Maywood – Population Served: 24,160
• Melrose Park – Population Served: 25,400
• Midlothian – Population Served: 14,400
• Morton Grove – Population Served: 23,270
• Mt. Prospect – Population Served: 41,492
• Niles – Population Served: 30,068
• Norridge – Population Served: 13,609
• North Lake – Population Served: 11,878
• North Maine Utilities – Population Served: 26,475
• Northbrook – Population Served: 33,435
• Oak Forest – Population Served: 27,962
• Oak Lawn – Population Served: 56,690
• Oak Park – Population Served: 51,878
• Orland Park – Population Served: 58,229
• Palatine – Population Served: 68,500
• Palos Heights – Population Served: 15,500
• Palos Hills – Population Served: 17,484
• Park Forest – Population Served: 22,056
• Park Ridge – Population Served: 37,775
• Richton Park – Population Served: 13,646
• River Forest – Population Served: 11,172
• River Grove – Population Served: 10,668
• Riverdale – Population Served: 13,549
• Rolling Meadows – Population Served: 24,099
• Sauk – Population Served: 11,000
• Schaumburg – Population Served: 74,227
• Schiller Park – Population Served: 11,793
• Skokie – Population Served: 64,784
• South Holland – Population Served: 25,000
• South Stickny SD – Population Served: 31,324
• Streamwood – Population Served: 39,900
• Summit – Population Served: 11,054
• Tinley Park – Population Served: 56,703
• Westchester – Population Served: 16,824
• Western Springs – Population Served: 13,105
• Wheeling – Population Served: 37,648
• Wilmette – Population Served: 27,087
• Winnetka – Population Served: 12,907
• Worth – Population Served: 11,300

DuPage County

• Addison – Population Served: 36,942
• Bensenville – Population Served: 18,352
• Bloomingdale – Population Served: 22,018
• Burr Ridge – Population Served: 10,559
• Carol Stream – Population Served: 39,711
• Darien – Population Served: 22,086
• Downers Grove – Population Served: 47,833
• Elmhurst – Population Served: 44,000
• Glen Ellyn – Population Served: 27,450
• Glendale Heights – Population Served: 34,208
• Hinsdale – Population Served: 17,940
• Lisle – Population Served: 22,390
• Lombard – Population Served: 43,395
• Naperville – Population Served: 142,179
• Oak Brook – Population Served: 15,773
• Roselle – Population Served: 22,763
• Villa Park – Population Served: 22,517
• Warrenville – Population Served: 12,310
• West Chicago – Population Served: 27,273
• Westmont – Population Served: 24,898
• Wheaton – Population Served: 52,894
• Wood Dale – Population Served: 13,770
• Woodridge – Population Served: 35,278

Will County

• Crest Hill – Population Served: 20,837
• Frankfort – Population Served: 24,648
• IL American Water Co. – Homer Township – Population Served: 22,038
• IL American Water Co. – West Suburban – Population Served: 63,330
• Joliet – Population Served: 148,402
• Lockport – Population Served: 24,839
• Mokena – Population Served: 19,500
• New Lenox – Population Served: 24,394
• Peotone – Population Served: 4,142
• Plainfield – Population Served: 39,581
• Romeoville – Population Served: 52,000
• Shorewood – Population Served: 15,615

Kane County

• Aurora – Population Served: 199,000
• Batavia – Population Served: 26,000
• Carpentersville – Population Served: 38,196
• Elgin – Population Served: 108,188
• Geneva – Population Served: 21,495
• IL Youth Center – St. Charles – Population Served: 300
• Montgomery – Population Served: 27,122
• North Aurora – Population Served: 17,000
• Sleepy Hollow – Population Served: 3,100
• South Elgin – Population Served: 21,985
• St. Charles – Population Served: 32,974

Lake County

• Antioch – Population Served: 14,430
• Barrington – Population Served: 10,500
• Deerfield – Population Served: 18,225
• Fox Lake Plant 2 – Population Served: 3,100
• Grayslake – Population Served: 20,973
• Great Lakes Naval Training Station – Population Served: 28,150
• Gurnee – Population Served: 31,295
• Highland Park – Population Served: 29,763
• Lake Forest – Population Served: 21,600
• Lake Zurich – Population Served: 19,984
• Libertyville – Population Served: 20,315
• Lindenhurst – Population Served: 14,462
• Mundelein – Population Served: 31,064
• North Chicago – Population Served: 19,877
• Rockland MHP – Population Served: 165
• Round Lake – Population Served: 18,289
• Round Lake Beach – Population Served: 28,845
• Lake Co. PW – Vernon Hills – Population Served: 23,748
• Wauconda – Population Served: 13,603
• Waukegan – Population Served: 89,078
• Lake Co. PW – Wildwood Subdivision – Population Served: 13,737
• Zion – Population Served: 24,413

McHenry County

• Algonquin – Population Served: 30,046
• Cary – Population Served: 18,271
• Crystal Lake – Population Served: 40,743
• Huntley – Population Served: 24,291
• Lake in the Hills – Population Served: 28,965
• McHenry – Population Served: 22,020
• Nunda Utilities Company – Population Served: 570
• UTL, Inc. – Killarney Water Company – Population Served: 1,047
• Woodstock – Population Served: 24,770

Kendall County

• Oswego – Population Served: 31,400
• Plano – Population Served: 10,693
• Yorkville – Population Served: 18,000