1,297 systems serving 10,103,190 people
  This drinking water quality report shows results of tests conducted by water utilities in Ohio, provided to the Environmental Working Group (EWG) by the Ohio Environmental Protection Agency- Division of Drinking and Ground Waters. 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.

  45 Contaminants Exceeding Health Based Limits

Contaminants detected in Ohio 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
Total haloacetic acids (HAAs) 9,972,773 9,972,173 1,084 1,083
Total trihalomethanes (TTHMs) 10,025,008 9,767,672 1,143 829
Bromodichloromethane 9,674,302 9,674,302 852 852
Dibromochloromethane 9,453,723 9,451,462 843 838
Dichloroacetic acid 9,307,690 9,307,690 686 686
Chloroform 9,709,701 8,630,789 860 497
Bromoform 8,088,690 8,088,690 611 611
Atrazine 4,459,090 2,905,651 80 71
Arsenic (total) 2,698,921 2,698,921 287 287
Radium-228 2,065,159 2,065,159 162 162

  Sources of Ohio Drinking Water Contaminants

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

80 Total Contaminants Detected (2004 - 2009)
19 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Arsenic (total), Cyanide, Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Phosphorus, Diquat, Simazine, Picloram, Metolachlor, Atrazine, Alachlor (Lasso), 2,4-D, Bromomethane, Metribuzin, p-Dichlorobenzene, 1,2-Dichloropropane, Ethylbenzene

24 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), Molybdenum, Phosphorus, 2,4-D, Acetone, MTBE, Benzo[a]pyrene, sec-Butylbenzene, Xylenes (total), p-Xylene, Dichloromethane (methylene chloride), p-Dichlorobenzene, Tetrachloroethylene, Benzene, o-Xylene

58 Industrial Pollutants

Aluminum, Arsenic (total), Chlorite, Barium (total), Cadmium (total), Chromium (total), Cyanide, Lead (total), Manganese, Mercury (total inorganic), Nitrate & nitrite, Nitrate, Nitrite, Selenium (total), Strontium, Antimony (total), Beryllium (total), Chromium (hexavalent), Molybdenum, Thallium (total), Phosphorus, Asbestos, Di(2-ethylhexyl) phthalate, Chloromethane, Acetone, MTBE, Pentachlorophenol, 1,2,4-Trichlorobenzene, cis-1,2-Dichloroethylene, Total polychlorinated biphenyls (PCBs), 1,2,3-Trichlorobenzene, sec-Butylbenzene, Bromochloromethane, Xylenes (total), p-Xylene, 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, Styrene, o-Xylene, Alpha particle activity (excl radon and uranium), Alpha particle activity (incl. radon & uranium), Combined Radium (-226 & -228), Radium-226, Radium-228, Gross beta particle activity (pCi/L)

19 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, Bromoform, Dibromoacetic acid, Monochloroacetic acid, Monobromoacetic acid, Chlorite, Di(2-ethylhexyl) phthalate, Cadmium (total), Chloromethane, Vinyl chloride, Asbestos, Bromochloromethane, Benzo[a]pyrene

22 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), Manganese, Radium-228, Radium-226, Alpha particle activity (excl radon and uranium), Combined Radium (-226 & -228), Gross beta particle activity (pCi/L), Chromium (total), Alpha particle activity (incl. radon & uranium), Aluminum, Selenium (total), Nitrite, Chromium (hexavalent), Mercury (total inorganic), Chloromethane, Cyanide, Phosphorus

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

Lead (total), Strontium, Molybdenum, Phosphorus, Metolachlor, Chloromethane, Bromomethane, Acetone, MTBE, 1,2,3-Trichlorobenzene, sec-Butylbenzene, Bromochloromethane, Metribuzin

  Testing Summary for Ohio

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

Contaminants reported as tested by water suppliers in Ohio 155
  Contaminants tested due to federal law: 98
  Contaminants tested in addition to those required by federal law: 57
  Violation Summary for Ohio

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

Violation Type Number of Violations
Failure to monitor regularly 2,497
Over maximum contaminant level, Average 664
Failure to monitor, Routine Major (Coliform bacteria) 524
Monitoring and Reporting Disinfection Byproduct Rule 364
Inadequate reporting of information to the public 217
Failure to report information to the public or state agency in the Consumer Confidence Report 182
Follow-up and Routine Tap Sampling 143
Treatment Technique (Surface Water Treatment Rule) 137
Maximum contaminant level, Monthly (Coliform bacteria) 125
Failure to monitor, Routine Minor (Coliform bacteria) 107
Maximum contaminant level, Acute (Coliform bacteria) 41
Failure to monitor, Repeat Major (Coliform bacteria) 37
Filter Turbidity Reporting 37
Excess Turbidity at 0.3 NTU 32
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) 28
Treatment Technique Precursor Removal 22
Excess Turbidity at 1 NTU 20
Public Education 10
Initial Tap Sampling for Lead and Copper 8
Failure to monitor, Repeat Minor (Coliform bacteria) 7
Initial Water Quality Parameter Monitoring and Reporting 6
Optimal Corrosion Control Treatment Study Recommendation 4
Failure to Filter (Surface Water Treatment Rule) 3
Over maximum contaminant level, Single Sample 2
Water Quality Program Entry Point Non-Compliance 1
Public Notification Violation for National Primary Drinking Water Regulations 1
Optimal Corrosion Control Treatment Installation/Demonstration 1

Sources : EWG (Environmental Working Group)