607 systems serving 2,696,783 people
  This drinking water quality report shows results of tests conducted by water utilities in Connecticut, provided to the Environmental Working Group (EWG) by the Connecticut Department of Public Health. It is part of EWG's national database that includes 47,667 drinking water utilities and 20 million test results from 45 states and the District of Columbia. Water utilities nationwide detected more than 300 pollutants between 2004 and 2009. More than half of these chemicals are unregulated, legal in any amount. Despite this widespread contamination, the federal government invests few resources in protecting rivers, reservoirs, and groundwater from pollution in the first place. The information below summarizes drinking water quality for this state.

Water Utilities
Population Served
Detected Chemicals
Exceed health guidelines*
Exceed Legal Limits*
Unregulated chemicals detected
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

  39 Contaminants Exceeding Health Based Limits

Contaminants detected in Connecticut drinking water above health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities

Number of Systems
At Any Level Above Health Limits At Any Level Above Health Limits
Lead (total) 2,650,234 2,650,234 462 462
Combined Radium (-226 & -228) 1,175,233 1,175,233 330 330
Combined Uranium (mg/L) 972,301 972,301 415 415
Alpha particle activity (excl radon and uranium) 705,543 705,543 300 300
Radium-228 670,115 670,115 268 268
Arsenic (total) 650,241 650,241 26 26
Copper 2,692,691 527,938 578 165
Total trihalomethanes (TTHMs) 431,300 431,300 2 2
Total haloacetic acids (HAAs) 431,300 431,300 2 2
Radium-226 309,877 309,877 185 185

  Sources of Connecticut Drinking Water Contaminants

The contaminants identified in Connecticut drinking water come from a wide variety of sources, including agriculture, industry, water treatment plants, and polluted storm runoff from urban areas.

67 Total Contaminants Detected (2004 - 2009)
22 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Arsenic (total), Cyanide, Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Endrin, Lindane, Methoxychlor, Toxaphene, Dalapon, Oxamyl (Vydate), Atrazine, Alachlor (Lasso), 2,4-D, 2,4,5-TP (Silvex), 1,2-Dibromo-3-chloropropane (DBCP), Ethylene dibromide (EDB), o-Dichlorobenzene, p-Dichlorobenzene, 1,2-Dichloropropane, Ethylbenzene

20 Sprawl and Urban Pollutants
(road runoff, lawn pesticides, human waste)

Arsenic (total), Cadmium (total), Copper, Cyanide, Lead (total), Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Antimony (total), Lindane, Dalapon, Di(2-Ethylhexyl) adipate, 2,4-D, 2,4,5-TP (Silvex), Benzo[a]pyrene, Dichloromethane (methylene chloride), p-Dichlorobenzene, Tetrachloroethylene, Benzene

46 Industrial Pollutants

Arsenic (total), Barium (total), Cadmium (total), Chromium (total), Cyanide, Lead (total), Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Antimony (total), Beryllium (total), Thallium (total), Asbestos, Lindane, Di(2-Ethylhexyl) adipate, Di(2-ethylhexyl) phthalate, Hexachlorocyclopentadiene, Hexachlorobenzene (HCB), 1,2,4-Trichlorobenzene, cis-1,2-Dichloroethylene, Ethylene dibromide (EDB), Dichloromethane (methylene chloride), p-Dichlorobenzene, Vinyl chloride, 1,1-Dichloroethylene, trans-1,2-Dichloroethylene, 1,2-Dichloroethane, 1,1,1-Trichloroethane, Carbon tetrachloride, 1,2-Dichloropropane, Trichloroethylene, 1,1,2-Trichloroethane, Tetrachloroethylene, Benzene, Toluene, Ethylbenzene, Alpha particle activity (excl radon and uranium), Combined Uranium (mg/L), Combined Radium (-226 & -228), Radium-226, Radium-228, Strontium-90, Combined Uranium (pCi/L), Gross beta particle activity (pCi/L)

13 Water Treatment and Distribution Byproducts
(pipes and fixtures, treatment chemicals and byproducts)

Total trihalomethanes (TTHMs), Total haloacetic acids (HAAs), Chloroform, Bromodichloromethane, Dibromochloromethane, Dichloroacetic acid, Trichloroacetic acid, Monochloroacetic acid, Di(2-ethylhexyl) phthalate, Cadmium (total), Vinyl chloride, Asbestos, Benzo[a]pyrene

18 Naturally Occurring
(naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

Nitrate, Copper, Nitrate & nitrite, Barium (total), Lead (total), Arsenic (total), Radium-228, Radium-226, Alpha particle activity (excl radon and uranium), Combined Radium (-226 & -228), Gross beta particle activity (pCi/L), Combined Uranium (pCi/L), Chromium (total), Combined Uranium (mg/L), Selenium (total), Nitrite, Mercury (total inorganic), Cyanide

2 Unregulated Contaminants
EPA has not established a maximum legal limit in tapwater for these contaminants

Lead (total), Strontium-90

  Testing Summary for Connecticut

The federal government has set standards for some of the pollutants found in tap water supplies.

Contaminants reported as tested by water suppliers in Connecticut 90
  Contaminants tested due to federal law: 88
  Contaminants tested in addition to those required by federal law: 2
  Violation Summary for Connecticut

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Connecticut since 2004.

Violation Type Number of Violations
Failure to monitor regularly 5,764
Failure to report information to the public or state agency in the Consumer Confidence Report 595
Inadequate reporting of information to the public 566
Failure to monitor, Routine Major (Coliform bacteria) 370
Monitoring and Reporting Disinfection Byproduct Rule 363
Over maximum contaminant level, Average 337
Maximum contaminant level, Monthly (Coliform bacteria) 310
Public Notification Violation for National Primary Drinking Water Regulations 228
Failure to monitor, Routine Minor (Coliform bacteria) 50
Other Non-National Primary Drinking Water Regulations Potential Health Risks 41
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) 41
Maximum contaminant level, Acute (Coliform bacteria) 34
Follow-up and Routine Tap Sampling 34
Failure to monitor, Repeat Major (Coliform bacteria) 28
Initial Water Quality Parameter Monitoring and Reporting 20
Public Education 18
Optimal Corrosion Control Treatment Study Recommendation 12
Initial, Follow-up, or Routine Source Water Treatment Monitoring and Reporting 5
Initial Tap Sampling for Lead and Copper 5
Over maximum contaminant level, Single Sample 4
Treatment Technique Precursor Removal 3
Failure to monitor, Repeat Minor (Coliform bacteria) 3
Filter Turbidity Reporting 3
Excess Turbidity at 0.3 NTU 1

Sources : EWG (Environmental Working Group)