The Power of Information

National Drinking Water Database


2,060 systems serving 10,834,741 people

This drinking water quality report shows results of tests conducted by water utilities in Pennsylvania, provided to the Environmental Working Group (EWG) by the Pennsylvania Department of Environmental Protection. 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.

32 Contaminants Exceeding Health Based Limits

Contaminants detected in Pennsylvania 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)10,449,39710,398,5231,2411,212
Total trihalomethanes (TTHMs)10,758,5119,889,3841,663779
Arsenic (total)3,736,5613,736,561336336
Dichloromethane (methylene chloride)2,659,3832,659,3835050
Alachlor (Lasso)1,600,0401,600,04022

Water Utilities in Pennsylvania Reporting Chemicals Exceeding Health Guidelines

Water utilities in Pennsylvania reporting chemicals exceeding health guidelines, according to an Environmental Working Group analysis of data obtained from state water authorities, include:

Chemicals tested
Chemicals found
Chemicals exceeding
health guidelines
Bonneaville Muni Water Auth2,347661813
Mcconnellsburg Boro Muni Auth2,00052249
Richland Township Sb3,95883169
Trumbauersville Mun Waterworks1,05730139
Oakwood Heights Mhp8529238
Gettysburg Muni Auth11,50059148
Philadelphia Water Department1,600,00050128
Audubon Water Company8,80069218
Schwenksville Borough Auth4,38039158
Richland Twp Water Auth Wbwc2,00944168
Warminster Municipal Authority40,00047148
Sellersville Boro Water Works4,90071168
Lake Meade Muni Auth3,1624187
Littlestown Boro4,00045117
Superior Water Company Main7,50044157
Horsham Water & Sewer Auth25,00056157
Warrington Twp Water&sew Dept15,12933147
Dover Twp Water Sys14,6403186
Aqua PA Links AT Gettysburg Sy2557156
New Oxford Manor Mhp3504076

Sources of Pennsylvania Drinking Water Contaminants

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

59Total Contaminants Detected (2004 - 2009)
19Agricultural Pollutants
(pesticides, fertilizer, factory farms)

Arsenic (total), Cyanide, Nitrate, Nitrite, Selenium (total), Lindane, Dalapon, Glyphosate, Simazine, Metolachlor, Atrazine, Alachlor (Lasso), 2,4-D, Foaming agents (surfactants), o-Dichlorobenzene, p-Dichlorobenzene, 1,2-Dichloropropane, Monochlorobenzene (Chlorobenzene), Ethylbenzene

18Sprawl and Urban Pollutants
(road runoff, lawn pesticides, human waste)

Arsenic (total), Cadmium (total), Cyanide, Mercury (total inorganic), Nitrate, Nitrite, Antimony (total), Lindane, Dalapon, Glyphosate, 2,4-D, Benzo[a]pyrene, Foaming agents (surfactants), Xylenes (total), Dichloromethane (methylene chloride), p-Dichlorobenzene, Tetrachloroethylene, Benzene

47Industrial Pollutants

Aluminum, Arsenic (total), Barium (total), Cadmium (total), Chromium (total), Cyanide, Manganese, Mercury (total inorganic), Nitrate, Nitrite, Selenium (total), Antimony (total), Beryllium (total), Thallium (total), Lindane, Di(2-ethylhexyl) phthalate, Hexachlorocyclopentadiene, Pentachlorophenol, 1,2,4-Trichlorobenzene, cis-1,2-Dichloroethylene, Foaming agents (surfactants), Xylenes (total), 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, Monochlorobenzene (Chlorobenzene), Benzene, Toluene, Ethylbenzene, Styrene, Alpha particle activity (excl radon and uranium), Alpha particle activity (incl. radon & uranium), Radium-226, Radium-228, Tritium, Strontium-90, Combined Uranium (pCi/L), Gross beta particle activity (pCi/L)

6Water Treatment and Distribution Byproducts
(pipes and fixtures, treatment chemicals and byproducts)

Cadmium (total), Di(2-ethylhexyl) phthalate, Benzo[a]pyrene, Total haloacetic acids (HAAs), Total trihalomethanes (TTHMs), Vinyl chloride

17Naturally Occurring
(naturally present but increased for lands denuded by sprawl, agriculture, or industrial development)

Aluminum, Arsenic (total), Barium (total), Chromium (total), Cyanide, Manganese, Mercury (total inorganic), Nitrate, Nitrite, Selenium (total), Alpha particle activity (excl radon and uranium), Alpha particle activity (incl. radon & uranium), Radon, Radium-226, Radium-228, Combined Uranium (pCi/L), Gross beta particle activity (pCi/L)

4Unregulated Contaminants
EPA has not established a maximum legal limit in tapwater for these contaminants

Metolachlor, Radon, Tritium, Strontium-90

Testing Summary for Pennsylvania

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

Contaminants reported as tested by water suppliers in Pennsylvania92
 Contaminants tested due to federal law: 73
 Contaminants tested in addition to those required by federal law: 19

Violation Summary for Pennsylvania

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

Violation TypeNumber of Violations
Failure to monitor regularly13,063
Monitoring and Reporting Disinfection Byproduct Rule8,126
Failure to monitor, Routine Major (Coliform bacteria)1,969
Failure to report information to the public or state agency in the Consumer Confidence Report1,881
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination)1,598
Public Notification Violation for National Primary Drinking Water Regulations1,146
Filter Turbidity Reporting661
Over maximum contaminant level, Average514
Failure to monitor or report, Routine/Repeat (Indicators of microbial or virus contamination)422
Inadequate reporting of information to the public410
Follow-up and Routine Tap Sampling309
Maximum contaminant level, Monthly (Coliform bacteria)276
Failure to monitor, Routine Minor (Coliform bacteria)154
Treatment Technique Precursor Removal126
Treatment Technique (Surface Water Treatment Rule)117
Failure to monitor, Repeat Minor (Coliform bacteria)98
Over maximum contaminant level, Single Sample66
Initial Tap Sampling for Lead and Copper63
Failure to monitor: Check/Repeat/Confirmation sampling52
Failure to monitor, Repeat Major (Coliform bacteria)37
Maximum contaminant level, Acute (Coliform bacteria)28
Optimal Corrosion Control Treatment Study Recommendation26
Monitoring & Reporting of Filter Profile/Comprehensive Performance Evaluations Failure22
Non-Acute maximum residual disinfectant level21
Excess Turbidity at 1 NTU21
Excess Turbidity at 0.3 NTU10
Water Quality Program Entry Point Non-Compliance4
Optimal Corrosion Control Treatment Installation/Demonstration3
Record Keeping Violation2
Initial Water Quality Parameter Monitoring and Reporting1