1,506 systems serving 5,184,785 people
  This drinking water quality report shows results of tests conducted by water utilities in Missouri, provided to the Environmental Working Group (EWG) by the Missouri Department of Natural Resources- Public Drinking Water Program. 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 Missouri 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
Bromodichloromethane 3,771,400 3,771,400 652 652
Dichloroacetic acid 3,497,617 3,497,617 483 483
Total trihalomethanes (TTHMs) 4,583,573 3,457,231 670 437
Lead (total) 3,430,929 3,430,929 1,377 1,377
Chloroform 3,732,657 3,050,059 694 403
Total haloacetic acids (HAAs) 3,034,819 3,030,354 418 411
Alpha particle activity 2,795,668 2,795,668 890 890
Dibromochloromethane 2,398,069 2,258,628 620 555
Radium-228 1,832,132 1,832,132 307 307
Bromoform 1,622,785 1,622,785 415 415

  Sources of Missouri Drinking Water Contaminants

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

109 Total Contaminants Detected (2004 - 2009)
25 Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Nitrate, Nitrate & nitrite, Arsenic (total), Selenium (total), Atrazine, Ethylbenzene, Cyanide, Simazine, 1,2-Dichloropropane, Metolachlor, p-Dichlorobenzene, Bromomethane, Monochlorobenzene (Chlorobenzene), o-Dichlorobenzene, Oxamyl (Vydate), Methoxychlor, 3-Hydroxycarbofuran, Aldicarb sulfoxide, Methomyl, m-Dichlorobenzene, Aldicarb, Carbaryl, Metribuzin, Aldrin, Chlorneb

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

Nitrate, Copper, Nitrate & nitrite, Lead (total), Arsenic (total), Tetrachloroethylene, MTBE, Xylenes (total), Cadmium (total), Antimony (total), Mercury (total inorganic), m- & p- Xylene, Dichloromethane (methylene chloride), Cyanide, o-Xylene, Benzene, Silver (total), Trichlorofluoromethane, p-Dichlorobenzene, Di-n-butylphthalate, Naphthalene, n-Propylbenzene, Bromobenzene, Carbaryl, tert-Butylbenzene, sec-Butylbenzene, Chlorneb

78 Industrial Pollutants

Nitrate, Nitrate & nitrite, Barium (total), Lead (total), Arsenic (total), Manganese, Radium-228, Radium-226, Alpha particle activity, Alpha particle activity (excl radon and uranium), Combined Radium (-226 & -228), Gross beta particle activity (pCi/L), Combined Uranium (pCi/L), Tetrachloroethylene, Trichloroethylene, Chromium (total), Combined Uranium (mg/L), Aluminum, Selenium (total), MTBE, Xylenes (total), cis-1,2-Dichloroethylene, Chlorite, 1,1-Dichloroethylene, Di(2-ethylhexyl) phthalate, 1,2,3-Trichloropropane, Carbon tetrachloride, Ethylbenzene, Toluene, 1,1,1-Trichloroethane, Cadmium (total), Dichlorodifluoromethane, Antimony (total), Mercury (total inorganic), 1,1-Dichloroethane, m- & p- Xylene, Chloromethane, Dichloromethane (methylene chloride), Cyanide, o-Xylene, Thallium (total), 1,2-Dichloroethane, Benzene, 1,2-Dichloropropane, Silver (total), Trichlorofluoromethane, Vinyl chloride, p-Dichlorobenzene, Styrene, Di-n-butylphthalate, Naphthalene, Monochlorobenzene (Chlorobenzene), 1,2,4-Trimethylbenzene, Pentachlorophenol, Dibromomethane, Bromochloromethane, 1,1,2-Trichloroethane, Chloroethane, 1,2,4-Trichlorobenzene, Isopropylbenzene, 1,3,5-Trimethylbenzene, n-Propylbenzene, 1,2,3-Trichlorobenzene, o-Chlorotoluene, p-Isopropyltoluene, 1,1,1,2-Tetrachloroethane, Bromobenzene, n-Butylbenzene, m-Dichlorobenzene, tert-Butylbenzene, sec-Butylbenzene, 2,2-Dichloropropane, 1,1,2,2-Tetrachloroethane, p-Chlorotoluene, cis-1,3-Dichloropropene, 1,3-Dichloropropane, trans-1,3-Dichloropropene, 2,6-Dinitrotoluene

24 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, Bromochloroacetic acid, Monobromoacetic acid, Chlorite, Di(2-ethylhexyl) phthalate, Bromodichloroacetic acid, Cadmium (total), Chloromethane, Vinyl chloride, Dibromomethane, Bromochloromethane, Chloroethane, Chlorodibromoacetic acid, m-Dichlorobenzene, Tribromoacetic acid

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, 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), Aluminum, Selenium (total), Mercury (total inorganic), Chloromethane, Cyanide, Silver (total)

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

Lead (total), Carbaryl, Methomyl, p-Isopropyltoluene, Aldicarb sulfoxide, Metolachlor, Aldicarb, 3-Hydroxycarbofuran, Chloromethane, Dichlorodifluoromethane, Bromomethane, Chloroethane, Trichlorofluoromethane, trans-1,3-Dichloropropene, cis-1,3-Dichloropropene, Naphthalene, MTBE, 2,6-Dinitrotoluene, Di-n-butylphthalate, Aldrin, Dibromomethane, 1,3-Dichloropropane, 1,2,3-Trichloropropane, 2,2-Dichloropropane, 1,2,4-Trimethylbenzene, 1,2,3-Trichlorobenzene, n-Butylbenzene, 1,3,5-Trimethylbenzene, tert-Butylbenzene, sec-Butylbenzene, Bromochloromethane, Bromochloroacetic acid, Metribuzin, o-Chlorotoluene, p-Chlorotoluene, m-Dichlorobenzene, 1,1-Dichloroethane, 1,1,1,2-Tetrachloroethane, 1,1,2,2-Tetrachloroethane, Bromobenzene, Isopropylbenzene, n-Propylbenzene, Bromodichloroacetic acid, Chlorodibromoacetic acid, Tribromoacetic acid, Chlorneb

  Testing Summary for Missouri

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

Contaminants reported as tested by water suppliers in Missouri 287
  Contaminants tested due to federal law: 110
  Contaminants tested in addition to those required by federal law: 177
  Violation Summary for Missouri

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

Violation Type Number of Violations
Failure to monitor regularly 1,413
Failure to monitor, Routine Major (Coliform bacteria) 1,045
Maximum contaminant level, Monthly (Coliform bacteria) 1,016
Over maximum contaminant level, Average 899
Failure to report information to the public or state agency in the Consumer Confidence Report 432
Failure to monitor, Routine Minor (Coliform bacteria) 398
Public Notification Violation for National Primary Drinking Water Regulations 327
Follow-up and Routine Tap Sampling 117
Inadequate reporting of information to the public 86
Failure to monitor, Repeat Major (Coliform bacteria) 58
Treatment Technique Precursor Removal 57
Maximum contaminant level, Acute (Coliform bacteria) 51
Excess Turbidity at 0.3 NTU 48
Initial Tap Sampling for Lead and Copper 41
Failure to monitor, Repeat Minor (Coliform bacteria) 34
Monitoring and Reporting Disinfection Byproduct Rule 28
Filter Turbidity Reporting 20
Improper Treatment Techniques 16
Excess Turbidity at 1 NTU 8
Acute maximum residual disinfectant level 4
Treatment Technique (Surface Water Treatment Rule) 2
Failure to notify public of violation 2
Failure to notify state agency 1
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination) 1
Other Non-National Primary Drinking Water Regulations Potential Health Risks 1

Sources : EWG (Environmental Working Group)