Providing Safe Drinking Water 

in America: 2006 National 

Public Water Systems Compliance 

Report - Fact Sheet 

What is the scope of the report? The National Public Water System Compliance Report 

for 2006 describes how the Environmental Protection Agency (EPA) and its state and tribal 

partners are meeting the goal of ensuring that Americans receive safe drinking water from public 

water systems (PWSs). The report also discusses the data we use to measure our success and the 

progress we are making in our efforts to increase its reliability and completeness. Appendix B of 

the report summarizes, in table format, the annual reports that each State must prepare discussing 

drinking water violations at PWSs in their jurisdictions. 

Additionally, the report summarizes PWS compliance in Indian country, including violations on 

Indian country, EPA’s enforcement and compliance assistance activities with respect to tribal 

PWSs, and the financial assistance EPA has provided to facilitate the provision of safe drinking 

water to Tribes. 

Who are the potential users of the report? The target audience for the report is the 

public. 

PWS COMPLIANCE 

The report concludes that most Americans received drinking water from public water systems 

that recorded no significant violations in 2006. Ninety-three percent of America’s public water 

systems did not have any reported violations of health-based standards, and 73% of the 

population is served by public water systems which did not have any reported significant 

violations in 2006. The tribes did not report a health-based violation for 89% of their public 

water systems, and 53% of the populations served by public water systems in Indian country did 

not have any reported significant violations in 2006. 

This report uses information from the Federal Safe Drinking Water Information System 

(SDWIS/FED), the national database in which EPA records information the states are required to 

report on PWS compliance. For the national public water system compliance reports, EPA 

examines SDWIS/FED records of violations of primary drinking water regulations that specify: 

1) the maximum permissible level of a contaminant in water that is delivered to any user of a 

public water system (Maximum Contaminant Level or MCL); 2) techniques for treating water to 

make it safe; 3) monitoring and reporting requirements (how and when water must be tested and 

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the results reported); and 4) significant user notification violations.1 While SDWIS/FED collects 

information on monitoring and reporting violations, only “significant” monitoring and reporting 

violations are counted in this report. A “significant” monitoring and reporting violation occurs, 

with rare exceptions, when no samples are taken or no results are reported during a compliance 

period. 

National Findings 

National PWS Universe Summary 

Systems by Size Number of Systems Users served 

Large Systems 4,103 235,575,036 

Medium System 5,109 28,974,008 

Small System 147,060 39,611,079 

All Sizes 156,182 304,102,891 

•	 156,182 public water systems together served over 304 million users. The actual number 

of individuals served was smaller, because millions of Americans drank water from, and 

were counted as users by, more than one public water system during the course of the 

year. 

•	 Although most public water systems are small, the larger systems serve the majority of 

people. 

National PWS Compliance Summary 

Type of Violation Number of Systems with 

Violations 

Number of Violations Users Served 

All Violation Types 42,108 128,666 81,466,047 

Health-based 11,115 18,637 26,483,028 

Monitoring & reporting 29,660 91,077 49,152,615 

CCR 7,333 11,346 17,838,339 

Public Notification 7,606 7,606 7,266,860 

•	 93% of America’s 156,182 public water systems (serving 90% of the users) reported no 

violations of a health-based drinking water standard in 2006. 

•	 The states reported either a health-based violation, a significant monitoring & reporting 

violation, or a significant CCR violation at 42,108 public water systems in 2006. 

•	 73% of the population served by public water systems received drinking water from a 

system that reported no violations of a health-based standard, was not cited for a 

This report tabulates only “significant” monitoring and reporting and notification (e.g., CCR) violations. Table A–1 of the National Public 

Water System Compliance Report presents descriptions of significant monitoring violations for the different drinking water regulations. 

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significant violation of a monitoring and reporting requirement, and issued a consumer 

confidence report and public notification, if required. 

Users Served by PWS 

Without Reported Significant Violation 

73% 

27% 

Users Served by PWS without Reported Significant Violation 

Users Served by PWS with Reported Significant Violation 

• Of the 156,182 public water systems nationwide, EPA determined that 14,036 systems were in 

significant noncompliance for calendar year 2006. Over 90% of the public water systems 

determined to be in significant non-compliance are small systems serving 3,300 or fewer users. 

• In 2006, states and EPA addressed non-compliance at 6,035 public water systems. Additionally 

the states and EPA addressed 4,157 of the systems with new SNC outside of the 2006 calendar 

year, leaving 3,844 systems (over 2% of the systems nationally) with unaddressed SNCs. 

National Findings 

PWS Universe Summary in Indian Country 

Number of Systems Users served 

Large Systems 14 291,628 

Medium System 45 249,982 

Small System 758 388,628 

All Sizes 817 930,238 

•	 817 public water systems in Indian country served 930,238 users. Most are small 

systems, which serve 3,300 or fewer people. 

PWS Compliance Summary in Indian Country 

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Type of Violation Number of Systems with 

Violations 

Number of Violations Users Served 

Any Type of Violation 496 1,936 495,248 

Health-based 92 165 111,031 

Monitoring & reporting 321 1,076 259,970 

CCR 292 691 272,287 

Public Notification 4 4 8,171 

•	 725 (89%) of the 817 public water systems, serving 83% of the users, in Indian country 

reported no violations of a health-based drinking water standard in 2006. 

•	 496 (61%) of the 817 public water systems reported health-based or significant reporting 

violations. 

Systems with Reported Significant Violations 

61% 

39% 

Reported Significant Violations 

No Reported Significant Violations 

• Of the 817 public water systems in Indian country, EPA determined that 292 systems were in 

significant noncompliance with one or more drinking water standards in calendar year 2006. 

Over 90% of these systems are small systems serving 3,300 or fewer users. 

• In 2006, states and EPA addressed non-compliance at 100 public water systems. Additionally 

the states and EPA addressed 68 of the systems with SNC outside of the 2006 calendar year, 

leaving 124 systems (over 15% of the systems in Indian country) with unaddressed SNCs. 

Data Quality Summary 

The data used in this report came from EPA’s national SDWIS/FED database. SDWIS/FED is 

composed of data that primacy states are required to submit to SDWIS/FED each quarter. EPA 

periodically conducts data verifications (independent, on-site audits) of primacy state and tribal 

drinking water programs to ensure that the primacy state is determining compliance in 

accordance with Federal regulations. EPA’s review showed that the quality of the information 

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the states reported to SDWIS/FED is improving, but the data are incomplete. This finding 

principally reflects differences between state and EPA regulatory interpretation rather than a 

preponderance of data management issues. 

EPA’s analysis of the data verifications found: 

•	 87% of all inventory data in SDWIS/FED were consistently reported. 

•	 Most of the discrepancies between apparent and reported violations are because 

violations were not reported by the states into the data system. 

•	 29% of monitoring and reporting violations had been reported to SDWIS/FED. 

•	 62% of the MCL/treatment technique violations had been reported to SDWIS/FED. 

Conclusions/Recommendations 

Most Americans received water from systems for which the states reported no violations of 

health-based standards, and for which the states reported no significant violations of monitoring 

and reporting requirements. 

States and EPA should continue working together to address significant violations of drinking 

water requirements. In addition, EPA should continue to work with its state partners to identify 

and resolve any problems that may have produced data discrepancies and to ensure that complete 

and accurate documentation is available. Working closely with the Association of State 

Drinking Water Administrators (ASDWA), EPA will continue to implement its updated 2006 

Data Reliability Analysis and Action Plan (DRAAP). One of the goals is to achieve 90% 

complete and accurate data for health-based violations, as well as improving the quality of 

monitoring and reporting violations and inventory data. EPA should continue efforts to 

modernize the SDWIS database to reduce data quality problems from data entry to transmission 

in the future. 

Where is the report available? 

Electronic: An electronic version of the report is available on EPA’s website containing
 

compliance data and other information about Local Government Services and Operations: 

http://cfpub.epa.gov/compliance/resources/reports/accomplishment/sdwa/. 

Fact Sheet	 March 2009