Municipal Freshwater Scarcity: Survey of Technology Adoption by Municipal Water Utilities (GAO-16-588SP, April 29, 2016), an E-supplement to GAO-16-474

Read the Full Report: Municipal Freshwater Scarcity: Using technology to improve distribution system efficiency and tap nontraditional water sources (GAO-16-474).


This e-supplement presents the results of GAO s web-based survey of 1,303 U.S. municipal water utilities. The survey asked questions about: (1) the technologies utilities use to improve water distribution efficiency; (2) the technologies they use to treat nontraditional water sources; (3) the challenges they face in using such technologies; and (4) the basic characteristics of their infrastructure, operations, and service area.

We selected a stratified random sample of 1,303 medium, large, and very large municipal water utilities located in water stressed and non-water stressed areas of the 48 contiguous states. We limited our study population to residential and municipal utilities that the U.S. Environmental Protection Agency (EPA) classified as active and utilities reported to serve more than 3,300 people, which is EPA s threshold for medium-sized utilities. Our study population serves nearly 225 million people, or about 75 percent of those served by community water systems. We obtained an unweighted response rate of 63.9 percent and a weighted response rate of 64.6 percent. A more detailed discussion of our objectives, scope, and methodology is contained in our report entitled Municipal Freshwater Scarcity: Using technology to improve distribution system efficiency and tap nontraditional water sources, GAO-16-474 (Washington, D.C.: April 29, 2016).

We conducted our work from July 2014 to April 2016 in accordance with all sections of GAO s quality assurance framework that are relevant to technology assessments. The framework requires that we plan and perform the engagement to obtain sufficient and appropriate evidence to meet our stated objectives and to discuss any limitations to our work. We believe that the information and data obtained, and the analysis conducted, provide a reasonable basis for the findings and conclusions in this product.

Survey results in this e-supplement are presented in aggregate form. To view the questionnaire, click on the "Questionnaire" links. To view the response to each question from within the questionnaire, click on the "view results" link. After viewing the responses to each question, click on the "view question" link to return to the questionnaire. To generate survey estimates presented here, we cleaned and recoded data to comply with logic and skip patterns and to remove infrequent outliers. For example, a respondent who failed to respond to question 11 on whether they had a treatment facility but reported a treatment facility count in question 18 would be coded as having a facility for the purposes of questions in section 2 of our survey. Similarly, the two respondents who reported 500 or more treatment facilities in question 18 were excluded from estimates for that question.

We omit estimates for several questions below to due lack of valid responses and reliability concerns. In some cases, the estimates were highly imprecise, in that they had extremely wide confidence intervals. In other cases, we found inconsistent reporting or other data problems that led us to question the reliability of responses to certain questions. For example, for question 19A, a subset of respondents appeared to answer the question in different magnitudes of order (for example, gallons or thousands of gallons rather than millions of gallons). In other cases, we determined that it was unlikely respondents could reliably respond to a specific question, such as the millions of gallons processed by nearby facilities in questions 22A and 23A. Where we felt data were likely reliable but insufficient to provide generalizable estimates, such as in challenges faced by individual utilities in question 13b, we report unweighted respondent counts rather than estimates.


Page Name Questionnaire Results
Introduction View View
Section 1 - Technologies for Water Distribution Efficiency View View
Section 2 - Use of Non-Traditional Water Sources View View
Section 3 - System Characteristics View View


Timothy M. Persons, Ph.D., Chief Scientist, at or (202) 512-6412



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