2006 Community Water 

System Survey 

Volume II: 

Detailed Tables and 

Survey Methodology
Cover Photo: The Gaffney Board of Public Works Water Tower, Gaffney, South Carolina 

The Gaffney Board of Public Works Water Tower, or “Peachoid” as it is known, stands 135 feet tall and 

holds one million gallons of water. The tank was commissioned to be built in 1980. Contractors took 

five months to design and mold the steel. A seven-ton, 60-feet long leaf was applied to one side. Peter 

Freudenburg, an artist specializing in super-graphics and murals spent hours inspecting real peaches to 

use as a model to paint the tank. Fifty gallons of paint in twenty colors were required to complete the 

project. EPA wishes to thank the Board for participating in this survey, for allowing us to acknowledge 

this fact and for providing us with the cover photo. 

Photo by Kim Fortner of the Gaffney Board of Public Works 

Office of Water (4606M) 

EPA 815-R-09-002 

May 2009 

www.epa.gov/safewater 
2006 Community Water 

System Survey

Volume II: Detailed Tables and 

Survey Methodology

Contents 

Part 1: Detailed Survey Results ................................................................................................................... 1

Interpreting the Survey Results................................................................................................................. 3

Notes on Interpreting the Detailed Tables ................................................................................................ 5

 Detailed Tables ....................................................................................................................................... 9

Part 2: Methodology Report..................................................................................................................... 221

1. Introduction....................................................................................................................................... 223

1.1 Study Background ................................................................................................................... 223

1.2 Survey Overview ..................................................................................................................... 223

2. Sample Design and Weighting.......................................................................................................... 227

2.1 Sample Design and Selection .................................................................................................. 227

2.1.1 SDWIS Sampling Frame and Coverage ......................................................................... 227

2.1.2 Sample Design and Selection..........................................................................................228

2.1.3 Stratum Migration........................................................................................................... 230

2.2 Weighting and Estimation ....................................................................................................... 233

2.2.1 Derivation of Base Weight and Non-response Adjustment ............................................ 233

2.2.2 Variance Estimation........................................................................................................ 235

3. Survey Design and Response ............................................................................................................ 239

3.1 Questionnaire Design .............................................................................................................. 239

3.2 Data Verification ................................................................................................................. 239

3.3 The Pilot Test .......................................................................................................................... 240

3.4 Site Visit Operations................................................................................................................ 240

3.5 Self-administered Survey Administration ............................................................................... 241

3.6 Data Entry................................................................................................................................ 242

3.7 Survey Response ..................................................................................................................... 245

4. Quality Assurance and Peer Review ................................................................................................ 247

i 
4.1 Draft Questionnaire Pre-test and Survey Pilot Test................................................................. 247

4.1.1 Pre-test ............................................................................................................................ 247

4.1.2 Pilot Test ......................................................................................................................... 247

4.2 Sampling Quality Assurance ................................................................................................... 248

4.3 Data Collection Quality Assurance ......................................................................................... 248

4.4 Expert Review of Responses ................................................................................................... 250

4.5 Data Processing Quality Assurance......................................................................................... 248

4.5.1 Data Entry ....................................................................................................................... 248

4.5.2 Automated Data Validation Checks................................................................................ 249

4.5.3 Database Quality Assurance ........................................................................................... 249

4.5.4 Tabulation Quality Assurance......................................................................................... 250

4.6 Quality Assurance during Report Preparation ......................................................................... 251

4.7 Peer Review............................................................................................................................. 251

Appendix: Community Water System Survey Questionnaire ................................................................. 253

ii 
List of Tables 

(Tables are by primary source of water and system service population, unless otherwise noted.) 

Table Description 

Table 1 Crosswalk from SDWIS to CWS Survey 2006 Sample 

Table 2 Number and Percentages of Systems by Primary Water Source 

Table 3 Number and Percentages of Systems by SDWIS Water Source 

Table 4 Number of Systems by Type of Ownership 

Table 5 Number of Systems by Ownership and Water Source 

Table 6 Percentage of Systems with Access to Computers, Peripherals, and the Internet 

Table 7 Average Daily Flow for Public Systems by Primary Water Source 

Table 8 Average Daily Flow for Private Systems by Primary Water Source 

Table 9 Average Daily Flow For All Systems by Primary Water Source 

Table 10 Average Annual Flow for Public and Private Systems 

Table 11 Annual Water Deliveries and Unaccounted for Water by Ownership 

Table 12 Annual Deliveries per Customer Service Connection by Ownership 

Table 13 Average Number of Entry Points to the Distribution System 

Table 14 Number and Percentage of Systems Selling to Other Public Water Suppliers 

Table 15 Water Systems Not Providing Any Treatment

Table 16 Ground Water Entry Points Not Receiving Treatment 

Table 17 Treatment Plants per System 

Table 18 Number of Wells Treated per Treatment Plant 

Table 19 Treatment Plant Flow Characteristics 

Table 20 Ratio of Design Capacity to Average and Peak Daily Production 

Table 21 Treatment Objectives by Population 

Table 22 Treatment Objectives by Daily Flow 

Table 23 Treatment Schemes by Population 

Table 24 Treatment Schemes by Daily Flow 

Table 25 Treatment Practices for Surface Water Plants by Population 

Table 26 Treatment Practices for Surface Water Plants by Daily Flow 

Table 27 Treatment Practices for Ground Water Plants by Population 

Table 28 Treatment Practices for Ground Water Plants by Daily Flow 

Table 29 Disinfection Practices and Objectives by Population 

Table 30 Disinfection Practices and Objectives by Daily Flow 

Table 31 Surface Water Residual Management Processes by Treatment Scheme 

Table 32 Ground Water Residual Management Processes by Treatment Scheme 

Table 33 Mixed Water Residual Management Processes by and Treatment Scheme 

Table 34 All Water Plants Residual Management Processes by Treatment Scheme 

Table 35 Surface Water Residual Management Processes by Daily Flow and Treatment Scheme 

Table 36 Ground Water Residual Management Processes by Daily Flow and Treatment Scheme 

Table 37 Mixed Water Residual Management Processes by Daily Flow and Treatment Scheme 

Table 38 All Water Plants Residual Management Processes by Daily Flow and Treatment Scheme 

Table 39 Plants With Specific Discharge Options by Population and Treatment Scheme 

Table 40 Plants With Specific Discharge Options by Daily Flow and Treatment Scheme 

Table 41 Raw Water Concentration of Various Contaminants in Very Large Systems 

Table 42 Finished Water Concentration of Various Contaminants in Very Large Systems 

Table 43 Percentage of Systems Using Each Treatment Scheme 

iii 
Table Description 

Table 44 Treated-Water Storage Information 

Table 45 Storage Capacity past the First Residential Customer by Type of Vessel 

Table 46 Practices to Maintain Water Quality in Storage Vessels 

Table 47 Systems that Want Additional Information about Practices 

Table 48 Distribution System and Transmission Line Summary 

Table 49 Average Size of Pipe in Distribution and Transmission Systems by Ownership 

Table 50 Pressure Zones and Booster Disinfection Practices 

Table 51 Number of Pressure Losses 

Table 52 System Flushing Practices 

Table 53 Seasonal Disinfection Residuals for Entry Points and Distribution Systems 

Table 54 Water Security Awareness and Security Barriers by Ownership 

Table 55 Water Security Awareness and Security Barriers by Adjusted Population Categories 

Table 56 Service Connections Profile by Ownership 

Table 57 Population Served by Ownership 

Table 58 Total Water System Revenue and Revenue Per Thousand Gallons by Source 

Table 59 Total Water System Revenue by Ownership 

Table 60 Total Water System Revenue by Source, Excluding Zero Revenue 

Table 61 Total Water System Revenue by Ownership, Excluding Zero Revenue 

Table 62 Revenue if Reporting Positive Revenue and Expenses by Ownership 

Table 63 Systems with Each Type of Revenue Source by Ownership 

Table 64 Percentage Received From Each Type of Revenue Source by Ownership 

Table 65 Average Revenue of Systems Serving 10,000 or fewer 

Table 66 Percentage of Revenue from Each Customer Category by Ownership 

Table 67 Total Revenue in Dollars per Thousand Gallons Delivered by Ownership 

Table 68 Water Sales in Dollars per Thousand Gallons Delivered by Ownership 

Table 69 Water Sales in Dollars per Thousand Gallons by Ownership and Customer Class 

Table 70 Annual Residential Revenue per Connection by Ownership 

Table 71 Residential Rate Structure and Billing Profile by Ownership 

Table 72 Non-Residential Rate Structure and Billing Profile by Ownership 

Table 73 Programs for Lower Cost Drinking Water for Low-income Households by Ownership 

Table 74 Seasonal Populations by Ownership 

Table 75 Total Expenses by Source 

Table 76 Total Expenses in Dollars per 1000 Gallons Delivered by Source 

Table 77 Total Expenses by Ownership 

Table 78 Total Expenses in Dollars per 1000 Gallons Delivered by Ownership 

Table 79 Expenses if Reporting Positive Revenue and Expenses by Ownership 

Table 80 Expense Breakdown by Major Categories by Ownership 

Table 81 Ratio of Total Revenue to Total Expenses by Ownership 

Table 82 Ratio of Total Revenue to Total Expenses by Private Systems 

Table 83 Average System Revenue and Expenses by Type of Revenue and Expense 

Table 84 Number of Employees and Annual Labor Costs by Source 

Table 85 Number of Employees and Annual Labor Costs by Ownership 

Table 86 Percentage of Systems with Major Capital Investment in the Past 5 Years by Source 

Table 87 Percentage of Systems with Major Capital Investment in the Past 5 Years by Ownership 

Table 88 Amount of Major Capital Investment in the Past 5 Years by Source 

Table 89 Amount of Major Capital Investment in the Past 5 Years by Ownership 

Table 90 Percentage of Systems Making Major Capital Investments by Source and Type 

iv 
Table Description 

Table 91 Percentage of Systems Making Major Capital Investments by Ownership and Type 

Table 92 Average Amount of Major Capital Investment Allocated Years by Source and Type 

Table 93 Average Amount of Major Capital Investment Allocated Years by Ownership and Type 

Table 94 Allocation of Major Capital Investments of Average Systems by Source and Type 

Table 95 Allocation of Major Capital Investments of Average Systems by Ownership and Type 

Table 96 Allocation of Major Capital Investments Nationally by Source and Type 

Table 97 Allocation of Major Capital Investments Nationally by Ownership and Type 

Table 98 Percentage of Systems Making Major Capital Investments by Ownership and Purpose 

Table 99 Amount of Major Capital Investment Allocated by Ownership and Purpose 

Table 100 Allocation of Major Capital Investments of Average Systems by Ownership and Purpose 

Table 101 Allocation of Major Capital Investments Nationally by Ownership and Purpose 

Table 102 Percentage of Systems Acquiring Capital Funds from Each Source by Ownership 

Table 103 Amount of Capital Funds Acquired from Each Source in the Past 5 Years 

Table 104 Allocation of Sources of Funds for Major Capital Investments of the Average System 

Table 105 Allocation of Sources of Funds for Major Capital Investments Nationally 

Table 106 Average Interest Rates for Capital Funds 

Table 107 Asset Management Plans 

v 

Part 1: 

Detailed Survey Results 

1 

Interpreting the Survey Results 

This volume presents extensive and detailed tabulations of the wide variety of data collected by the 2006 

Community Water System (CWS) Survey. The tables in this volume summarize the survey results at 

very fine levels, breaking out the data by eight different population size categories of water systems, and 

then further breaking out each size category by other system characteristics, such as type of ownership or 

primary water source. 

The report consists of 107 summary tables, many of which include confidence intervals for each estimate 

presented. In these tables, each confidence interval appears immediately below the calculation to which it 

applies. Please familiarize yourself with the interpretive notes when you review the tables themselves. 

The tabulations presented in this report are based on data collected from a sample of U.S. water systems 

rather than a census of every water system in the United States. A confidence interval is one way to 

gauge how precisely an estimate based on a sample of systems represents all water systems in the country. 

Any result presented in a table must be viewed as the center of a range that would encompass the precise 

number that would be found if every U.S. water system could have been included in the tabulation, and 

not only those who were sampled and responded to the survey. The confidence interval expresses this 

range as a A"@ that is, as an amount to be added to and subtracted from the calculated data point actually 

presented in the table. The size of the confidence interval is designed to include the true value in the 

stated range 95 percent of the time; i.e., if we drew repeated samples and produced the confidence interval 

for each sample, the interval would include the true value 95 percent of the time. 

For example, Table 77 shows that the average annual expenses of publicly owned water systems serving 

more than 500,000 people are $187.6 million. The table also shows the confidence interval for this 

estimate to be "$41.2 million. Thus, based on the sample of water systems, we can be 95 percent certain 

that the average annual per capita expense of all publicly owned systems serving populations of over 

500,000 is between $146.4 million and $228.8 million. 

These tables always express the confidence interval in the same units as the calculation to which it 

applies. Thus, in Table 9 the confidence interval numbers for average daily water flow represent the same 

units as the base calculation, namely, millions of gallons per day. In the same table, the confidence 

interval numbers for the percentage of water derived from different sources are themselves expressed as 

percentages. In all cases, the confidence interval may be directly added to and subtracted from the 

corresponding calculation to determine the expected range. 

These tables serve as a starting point for detailed analyses of the data. As shown in Volume I, and as will 

be apparent in many of the tables in this volume, water systems are a diverse group. While the mean or 

medians as measures of central tendency may be appropriate statistics in some cases, in others further 

detail will be required. As described in the notes below, outliers were dropped from some of the analyses 

to produce meaningful estimates of Atypical@ systems. Additional adjustments may be necessary to 

support other analyses. Some analyses may require the use of percentiles or other measures of the full 

distribution of the data. Other analyses may need to exclude the tails of the distribution to characterize 

typical systems. EPA will continue to analyze the data and present results to support its various 

regulatory and policy development and implementation analyses. 

Finally, several of the tables report results for water systems’ treatment plants and facilities. For this 

report, a treatment plant or facility is any location where the water system takes steps to change the 

quality of the water. It includes standard facilities that are clearly recognized as treatment plants, such as 

conventional filtration plants. It also includes smaller facilities that may not be considered treatment 

plants in other contexts; for example, a chemical feed on a well that adds chlorine to the water is 

3 
considered a treatment facility in this report. There is one exception to the general rule that all points 

where the system makes changes to the water is a treatment facility. Systems that purchase water may 

boost disinfection or adjust pH within their distribution system; these sites are not counted as treatment 

facilities. 

4 
Detailed Survey Result Tables 

Notes on Interpreting the Detailed Tables 

1. Weighted data. The survey results presented in the following tables are all based on weighted 

data. As described in Chapter 2 of the methodology report, each water system contained in the 

final survey database was assigned a sample weight. These weights are necessary because the 

data are from a statistically representative sample of water systems, rather than from a census of 

every water system in the U.S. In effect, each sampled system represents some number of similar 

systems from the entire population of U.S. water systems; the number of systems so represented 

is equal to the sample weight. When added up, the weights of all systems in the final sample will 

equal the total number of U.S. CWSs that meet the eligibility definition used for the survey (e.g., 

Federal and state-owned systems were not included). Thus, for the tables to represent all eligible 

U.S. water systems, it is necessary to incorporate each system’s sample weight as an additional 

factor in each calculation involving a data item reported by that system. Another way of 

expressing this is to say that, when tabulating the data, each sampled system counts not just once 

as itself, but counts as many times as the numerical amount of its weight. See section 2.2 for a 

detailed discussion of the derivation of the sample weights. 

2. Interpretation of Table Results. Each result presented in the tables is the weighted average of 

the particular data item, for the group of water systems characterized by the row and column 

headings labeling the table cell where the results appears. The survey data are tabulated so as to 

facilitate analysis of water systems. In general, this means that the report tabulates all summary 

results by calculating a given item for each system, factoring into that result the system’s 

sampling weight, then presenting the mean of the weighted results for all the systems falling into 

the respective table categories (as defined by the table row and column headings). This has 

significant implications when the calculation of a specific item requires deriving the result from 

two or more survey variables, e.g., a ratio or a percentage breakdown of component amounts 

within a total amount. For example, in the case of a ratio, the reported result is the average 

(mean) of the ratios for each system, rather than the ratio of average values for each of the two 

variables across systems. This approach treats every system in the universe equally, implying 

that characteristics of the system are the primary unit of analysis. The alternate approach would 

treat the content of the component variables in each table as the unit of analysis. 

By way of example, consider two systems. One system produces 1,000,000 gallons per day, and 

400,000 of those come from ground sources; hence, 40% of the system’s water comes from 

ground sources. The other system produces 2,000,000 gallons per day and 1,600,000 of those 

come from ground sources; hence, 80% of the systems water comes from ground sources. The 

CWS Survey report would show a result that, on average, these two systems produce 60% of their 

water from ground sources: (40%+80%)/ 2. If the alternate approach where chosen, gallons 

would be the unit of analysis, and the calculation would show that 67% of the water in those 

systems comes from ground sources: (400,000+1,600,000)/(1,000,000+2,000,000). (To focus 

clearly on the point being illustrated, this example does not attempt to demonstrate the further 

effect that the system sample weights have on the actual calculations.) 

The report has adopted the former approach because this initial view of the data is intended 

primarily as an analysis of system-level characteristics. There are some exceptions to this 

approach. Table 17 presents data on both level of the system and a water treatment plant (many 

systems have more than one treatment plant, while some facilities have none). Tables 18 - 42 

5 
present data on the level of a treatment plant. Tables 96, 97, 101, and 105 present data on the 

share of capital funds in the nation, rather than system averages. 

3. Percentages summing to 100 percent. Some tables present absolute or percentage breakdowns 

of the whole into its components, e.g., breakdowns of total revenue into different customer 

categories, such as Table 66. Logically, in such breakdowns, the line item amounts should sum to 

the total amount, and line item percentages should sum to 100 percent. However, in some 

instances, the tabulated results may not sum exactly to the whole. To increase the precision of 

each individual result, each component line item was calculated separately using all the data 

available for the line item. Due to differential item non-response, some component variables may 

actually have more or fewer observations available than other components. While including all 

available data in the calculation of the component increases the precision of the tabulated result 

for the component, it can cause a small reduction in consistency across components, since slightly 

different systems may be represented in the different calculations. EPA and the CWS Survey 

analysts decided that the increased accuracy for each item outweighs the slight reduction in 

consistency. 

In a few tables, a series of percentages may validly sum to greater than 100%. This occurs when 

more than one item may apply to the same system. For example, treatment plants may have more 

than one treatment objective, so the percentage of plants with each objective will sum to more 

than 100 percent. This situation is always noted on the table. 

4. Confidence Intervals. The size of the confidence interval is designed to include the true value in 

the stated range 95 percent of the time. Each confidence interval presented in Part 2 is based on 

the assumption that the average value reported in a given table cell is normally distributed. 

Calculations based on small numbers of systems may violate this assumption. In such cases the 

reported confidence intervals will not be correct. Most of these can be identified by noticing 

when the plus/minus confidence interval width is larger than, or almost as large as, the calculated 

average itself. To compute correct confidence intervals for such situations requires examination 

of the empirical distributions for each variable in the tabulation and is beyond the scope of this 

report. 

The reader should take note of results where the lower end of the confidence interval is below 

zero, because negative numbers are not meaningful in any of the tabulations presented in this 

report. Similarly, for calculations of percentages, high ends of ranges above 100% are not 

meaningful. While the reader should be on the lookout for these conditions when any number is 

near zero or any percentage is near 100%, they can occur at other times, particularly when the 

confidence interval is large. As stated in note 3, a series of percentages may validly sum to 

greater than 100% in some tables, when more than one item may apply to the same system. This 

situation is not related to the issue of confidence intervals extending an individual percentage 

beyond 100%. 

5. Treatment of outliers. For several of the tables, one or two observations have values well above 

the mean or even the 90th percentile. These outliers would tend to distort the estimates presented 

in the table and would lead to a misrepresentation of the central tendency for the characteristics in 

question. In cases like this, the outliers are dropped from the analysis. A note is added at the 

bottom of the table when outliers are dropped. The note also will show how the exclusion of the 

outliers affects the estimate. 

6 
6. Interpretation of blank cells and cells with calculated results of zero. 

 Empty Cells: Throughout the tables, some individual cells or blocks of continuous cells have an 

asterisk, to denote the cell does not contain an estimate. Any empty cell or block of cells means 

that there were no observations with data for the cell(s) in question. Generally, this occurs for 

one of three reasons. 

7

• There are no systems in the cell. The most common illustration of this occurs in all tables 

that break out the data by ownership type. When data are reported for ancillary systems, the 

cells for the systems serving more than 3,300 people are always blank for ancillary systems, 

since there are no ancillary systems in these size categories. 

• The item does not apply to the group of systems belonging to that cell. For example, in Table 

106, the cell for Drinking Water State Revolving Fund (DWSRF) loans for private systems 

serving 100 or fewer people is empty. This is because no private systems of this size made 

use of DWSRF loans. 

• The item applies to the group of systems belonging to the cell, but no systems provided data 

for the item (sometimes referred to as “missing data” in terms of the analytical data file and 

as “item non-response” in terms of the data collection process that led to the final data file). 

For example, in Table 16, none of the ground water systems serving 3,301 to 10,000 

customers provided data on their number of wells per entry point, so these cells are empty on 

the table. 

It is not always possible to distinguish between the last two reasons from the information 

available in the table. Sometimes the reason is apparent for the table itself. Often, however, 

further analysis of the database would be needed to determine which particular reason is the basis 

for a blank cell. 

Zero Results: In discussing Table 106 above, it was noted that certain cells are blank for 

customer categories of private systems. However, other tables have cells which specifically 

report a zero result and are zero instead of blank. This illustrates an important distinction when 

interpreting the tables. Blank cells and cells reporting a zero result are not the same, and should 

not be interpreted as such. A reported result of zero means that data were available to produce a 

calculation, and the calculation resulted in a zero. 

It should also be noted that occasionally a report of a zero result is a function of the level of 

precision chosen as appropriate for presenting the data in a given table. In a few instances, items 

appearing as zero results are actually very small numbers that round to zero within the precision 

limits of the respective table. 

Observations. The term “observations” refers to the actual number of sampled water systems 

that provided data for a given tabulated item. Some tables present the number of observations on 

which the tabulated results are based. In these as in all the tables, the results are still based on the 

weighted data, not on the simple means of the un-weighted observations. The report of the 

number of observations can be used as a very approximate indication of the sampling precision of 

the tabulated result. Results based on a small number of observations may not be precise 

estimates of the universe of water systems represented by the sampling systems. They are 

7. 

included because they may be useful indicators of areas worth further investigation. 
8. Individual table notes. Additional specific notes and definitions appear on individual tables. 

8

The specific CWS Survey questionnaire item(s) on which each table is based are cited below the 

table. The citation refers to the corresponding question number(s) on the CWS Survey 

questionnaire, which can be found in this report as an Appendix to the Methodology Report. The 

citations are in the format “Q.#;” the question numbering is identical in both questionnaire 

versions. 

. Variables for row and column headings. In addition to the data sources for the specific 

tabulations, several data items are used repeatedly throughout the tables as the break-out variables 

for the table row and column headings. Their sources are not cited on the individual tables. 

These items and their data sources are 

• Population served, from question 21. If data were not reported in the survey, the population 

data from the Safe Drinking Water Information System (SDWIS) are used. 

• Water source, from question 6. 

• Ownership, from question 3. Note: for the sake of brevity in the table headings, privately 

owned community water systems are labeled as “Private Systems” and publicly owned 

community water systems are labeled as “Public Systems.” This use of the label “Public 

Systems” should not be confused with the CFR definitional term Public Water System, which 

is a broad class of water systems providing the public with piped drinking water for human 

consumption. A CWS means a public water system which serves at least 15 service 

connections used by year-round residents or regularly serves at least 25 year-round residents. 

(40 CFR 141.2) 

• Treatment facility flow, from question 7. 

For population served and water source, data from SDWIS are used if the system did not provide 

the data in the survey. Approximately 20 percent of the sample was assigned population data 

from SDWIS because of missing or incomplete responses to the population served questions. An 

additional 4 percent were assigned source data from SDWIS. 

0. Estimate of the number of systems in the nation. The report provides an estimate of the 

national number of community water systems, 49,133, excluding federally owned systems, tribal 

systems, and systems in the Trust Territories. This is a weighted estimate based on the sample 

and responses to the survey regarding water source and the number of people served. Table 1 of 

this Volume presents the count of systems by water source, system ownership, and population 

served. It also shows the change in these categories since the 2000 CWS Survey. (The estimate of 

the number of systems in 2000 is from Table 3 of Community Water System Survey 2000 Volume 

II: Detailed Tables and Survey Methodology.) 

1. Use of the terms expenses and expenditures. Systems use the terms expenses or expenditures 

to refer to their spending. Private systems generally use the term “expenses” in accounting as a 

term for the spending done by a system. Public systems refer to spending as “expenditures”; they 

reserve the term “expense” for when a cost is incurred, and use the term “expenditure” for when 

the spending takes place. Tables 62, 75-82, 91, 94, and 95 use the term expenses to report 

spending by both public and private systems. 

2. Major capital investments. Systems provided information about major capital investments. 

9

1

1

1

This includes spending on land, plant, and equipment that is not part of routine maintenance. 
Detailed Tables 

9
10
Table 1

Change in Estimated Number of Community Water Systems between 2000 and 2006

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 

Primarily Ground Water Systems

Public Systems

Systems in 2000 489 3,556 6,694 2,560 1,080 124 143 9 Systems in 2006 1,069 4,501 6,450 1,999 1,614 195 108 8 Percentage change 118.6 26.6 -3.6 -21.9 49.4 57.3 -24.5 -11.1 

Private Systems

Systems in 2000 11,267 9,590 2,276 511 259 12 17 1 Systems in 2006 9,246 7,857 2,269 630 115 23 8 5 Percentage change -17.9 -18.1 -0.3 23.3 -55.6 91.7 -52.9 400.0 

All Ground Water Systems

Systems in 2000 11,756 13,146 8,970 3,071 1,339 136 160 10 Systems in 2006 10,315 12,358 8,719 2,629 1,730 217 116 13 Percentage change -12.3 -6.0 -2.8 -14.4 29.2 59.6 -27.5 30.0 

Primarily Surface Water Systems

Public Systems

Systems in 2000 245 683 1,139 935 894 182 162 49 Systems in 2006 62 245 895 779 809 206 222 55 Percentage change -74.7 -64.1 -21.4 -16.7 -9.5 13.2 37.0 12.2 

Private Systems

Systems in 2000 588 453 73 73 95 28 16 4 Systems in 2006 277 365 173 86 117 25 44 8 Percentage change -52.9 -19.4 137.0 17.8 23.2 -10.7 175.0 100.0 

All Surface Water Systems

Systems in 2000 833 1,136 1,212 1,008 989 210 178 53 Systems in 2006 339 610 1,068 864 925 231 266 63 Percentage change -59.3 -46.3 -11.9 -14.3 -6.5 10.0 49.4 18.9 

(
Table 1 (Cont.)

Change in Estimated Number of Community Water Systems between 2000 and 2006

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 

Primarily Purchased Water Systems

Public Systems

Systems in 2000 * 1,513 3,449 819 568 109 89 19 Systems in 2006 373 1,102 2,430 839 634 137 91 24 Percentage change * -27.2 -29.5 2.4 11.6 25.7 2.2 26.3 

Private Systems

Systems in 2000 69 666 386 154 117 16 3 2 Systems in 2006 390 1,155 1,205 232 43 10 5 * Percentage change 465.2 73.4 212.2 50.6 -63.2 -37.5 66.7 * 

All Purchased Water Systems

Systems in 2000 69 2,179 3,835 973 685 125 92 21 Systems in 2006 764 2,257 3,634 1,071 677 148 96 24 Percentage change 1,007.2 3.6 -5.2 10.1 -1.2 18.4 4.3 14.3 

All Systems

Public Systems

Systems in 2000 734 5,752 11,282 4,314 2,542 415 394 77 Systems in 2006 1,505 5,848 9,775 3,617 3,057 538 421 86 Percentage change 105.0 1.7 -13.4 -16.2 20.3 29.6 6.9 11.7 

Private Systems

Systems in 2000 11,924 10,709 2,735 738 471 56 36 7 Systems in 2006 9,913 9,376 3,647 948 275 57 57 13 Percentage change -16.9 -12.4 33.3 28.5 -41.6 1.8 58.3 85.7 

All Systems

Systems in 2000 12,658 16,461 14,017 5,052 3,013 471 430 84 Systems in 2006 11,418 15,224 13,421 4,564 3,332 596 478 100 Percentage change -9.8 -7.5 -4.3 -9.7 10.6 26.5 11.2 19.0 

Data: 2000 Survey: Q.3, Q.7

2006 Survey: Q.3, Q.6* No purchased water systems of this size in sample.The counts of systems are weighted estimates based on the sample. Totals may not add drounding.
Primary Water Source 

Ground Water Systems 

100% Ground Water 

Number Percentage of systems with this source designation by service population 

Primarily Ground Water 

Number Percentage of systems with this source designation by service population 

Surface Water Systems 

100% Surface Water 

Number Percentage of systems with this source designation by service population 

Primarily Surface Water 

Number Percentage of systems with this source designation by service population 

Purchased Water Systems 

100% Purchased Water 

Number Percentage of systems with this source designation by service population 

Primarily Purchased Water 

Number Percentage of systems with this source designation by service population 

All 

Number Percentage of systems with this source designation by service population 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

10,308 12,155 8,409 2,072 1,384 164 70 

90 80 63 45 42 27 15 

7 203 310 558 346 54 47 0 1 2 12 10 9 10 

319 566 756 646 601 146 170 

3 4 6 14 18 25 35 

20 44 311 218 324 84 96 

0 0 2 5 10 14 20 

760 2,131 3,326 967 473 102 47 

7 14 25 21 14 17 10 3 126 308 103 204 46 49 0 1 2 2 6 8 10 

11,418 15,224 13,421 4,564 3,332 596 478 

100 100 100 100 100 100 100 

Data: Q.6 Notes: Systems included in one of the Primarily Ground Water, Primarily Surface Water, o

Purchased Water categories have their largest source in that category; however, thhave more than one type of source. 

Table 2 

Number and Percentage of Systems 

By Primary Water Source 
SDWIS Water Source Classification 

Surface Water Systems 

Number Percentage

Purchased Surface Water Systems 

Number Percentage

Ground Water Under the Direct Influence of Surface Water (GWUDI) Systems 

Number Percentage

Purchased GWUDI Systems 

Number Percentage

100% Ground Water Systems 

Number Percentage

Purchased Ground Water Systems 

Number Percentage

All Systems 

Number Percentage

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

or Less 500 3,300 10,000 50,000 100,000 500,000 500

139 379 908 985 1,118 251 299 

1 2 7 22 34 42 63 

643 1,776 2,639 1,426 681 143 89 

6 12 20 31 20 24 19 

200 231 221 48 55 5 6 

2 2 2 1 2 1 1 

* * * 2 * * 2 

* * * 0 * * 0 

10,308 12,358 8,719 2,103 1,447 192 78 

90 81 65 46 43 32 16 

128 481 934 * 31 5 4 

1 3 7 * 1 1 1 

11,418 15,224 13,421 4,564 3,332 596 478 

100 100 100 100 100 100 100 

Data: Q.6 Notes: Reflects SDWIS classification of water systems, i.e., the hierarchy starting with surface 

the system receives any of its water from a surface source, it is considered a surface wsystem. The SDWIS hierarchy is: surface water, purchased surface water, ground watdirect influence (GWUDI) of surface water, purchased GWUDI, ground water, and purcwater. 

Table 3 

Number and Percentage of Systems 

By SDWIS Source Classification 
Ownership Type 

Publicly Owned Systems 

Owned and operated by a government or public agency Owned by a government or public agency and operated by a private contractor 

All Public 

Privately Owned Systems 

Operated for profit primarily as a water business Not operated for profit Operated a necessary part of another business (i.e., ancillary systems) 

All Private 

All Systems 

All 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 

or Less 500 3,300 10,000 50,000 100,000 

1,505 5,344 9,514 3,474 2,950 519 

504 261 143 106 19 

1,505 5,848 9,775 3,617 3,057 538 1,019 2,161 1,661 299 168 34 3,529 3,365 1,647 649 107 24 5,365 3,851 338 * * * 

9,913 9,376 3,647 948 275 57 

11,418 15,224 13,421 4,564 3,332 596 

Data: Q.3 Notes: Publicly owned systems include municipal systems, systems run as public enterprise funds, state-run systems, and special districts. It exclud

federal systems. Examples of privately owned systems not operated for profit are homeowners' associations and non-profit cooperatives. Privowned systems that are a necessary part of another business are referred to as ancillary systems because the water business is not the primbusiness. The majority of ancillary systems are mobile home parks that provide water as one of a number of services for residents of the par

Table 4 

Number of Systems 

By Ownership 
Ownership Type 

Public Systems 

Primarily Ground Water Systems Primarily Surface Water Systems Primarily Purchased Water Systems 

All Public 

Private Systems 

Primarily Ground Water Systems Primarily Surface Water Systems Primarily Purchased Water Systems 

All Private 

All Systems 

Primarily Ground Water Systems Primarily Surface Water Systems Primarily Purchased Water Systems 

All 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

1,069 4,501 6,450 1,999 1,614

62 245 895 779 809

373 1,102 2,430 839 634

1,505 5,848 9,775 3,617 3,057

195 108 206 222 137 91 538 421 

9,246 7,857 2,269 630

277 365 173 86390 1,155 1,205 232

9,913 9,376 3,647 948 

115 23 8 

117 25 44 

43 10 5 

275 57 57 

10,315 12,358 8,719 2,629 1,730 

339 610 1,068 864 925 764 2,257 3,634 1,071 677 

11,418 15,224 13,421 4,564 3,332 

217 116 231 266 148 96 596 478 

Data: Q.3, Q.6 Notes: 

Table 5 

Number of Systems 

By Ownership and Primary Water Source 
Table 6 

Percentage of Systems with Access to Computers, Peripherals, and the Internet 

By Primary Water Source 

System Service Population Categor

100 101 - 501 - 3,301 - 10,001 - 50,001 - 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 

Ground Water Systems 

Percentage of systems with access to computers for sending and receiving information 74.2 79.3 91.8 90.4 93.7 100.0 Of the systems with computers, the percentage that have: 

Microsoft Excel 94.8 92.6 100.0 91.6 92.5 100.0 Microsoft Access 53.1 53.9 62.0 63.0 72.2 85.1 CD drive 98.3 96.3 98.5 87.5 92.5 100.0 DVD player 69.7 55.5 73.3 65.9 70.6 81.5 

Of the systems with a computer, the percentage with each type of internet access: 

High speed Internet (e.g., cable, DSL, wireless, T1) 89.1 78.4 86.0 89.8 96.0 100.0 Dial-up modem 10.9 20.4 14.0 9.7 4.0 0.0 No access 0.0 1.2 0.0 0.5 0.0 0.0 

Observations 88 105 111 42 56 32 

Surface Water Systems 

Percentage of systems with access to computers for sending and receiving information 49.2 85.2 95.8 87.2 98.4 100.0 Of the systems with computers, the percentage that have: 

Microsoft Excel 95.9 98.5 97.2 90.9 97.4 100.0 

Microsoft Access 47.4 44.2 70.1 53.1 68.1 83.7 CD drive 90.8 98.6 98.4 93.9 98.7 97.8 DVD player 57.2 76.9 65.7 62.1 77.9 72.5 

Of the systems with a computer, the percentage with each type of internet access: 

High speed Internet (e.g., cable, DSL, wireless, T1) 58.7 77.4 85.6 88.9 88.3 95.2 Dial-up modem 41.3 21.2 14.4 11.1 10.4 4.8 No access 0.0 1.4 0.0 0.0 1.3 0.0 

Observations 49 67 78 48 68 44 
By Primary Water So

100 

or Less 

Percentage of Systems with Access to Comput

urce 

System Se

101 - 501 - 3,301

500 3,300 10,000 

ers, Peripherals, and the 

rvic

 -

Inte

e Population Categ

10,001 - 50,001 -

rnet

or

50,000 100,000 

88.9 93.6 89.9 97.3 100.0 87.8 96.2 95.2 100.0 96.5 

68.4 54.1 52.5 85.8 83.4 

100.0 100.0 80.8 90.6 96.5 

66.4 64.2 66.9 76.4 76.4 75.7 82.6 79.9 100.0 100.0 24.3 9.4 20.1 0.0 0.0 

0.0 8.0 0.0 0.0 0.0 

 23 48 19 17 23 

Primary Water Source 

Purchased Water Systems 

Percentage of systems with access to computers for sending and receiving information 100.0 Of the systems with computers, the percentage that have: 

Microsoft Excel 100.0 Microsoft Access 49.3 CD drive 100.0 DVD player 84.6 

Of the systems with a computer, the percentage with each type of internet access: 

High speed Internet (e.g., cable, DSL, wireless, T1) 67.9 Dial-up modem 32.1 No access 0.0 

Observations 8

All Systems 

Percentage of systems with access to computers for sending and receiving information Of the systems with computers, the percentage that have: 

Microsoft Excel 75.2 80.9 92.6 89.7 95.6 100.0 

Microsoft Access 95.3 92.1 98.7 92.3 95.4 99.1 CD drive 52.7 55.8 60.5 58.8 73.9 84.1 DVD player 98.3 97.0 98.9 87.2 93.8 98.3 

Of the systems with a computer, the percentage with each type of internet access: 70.8 58.2 70.2 65.4 73.9 76.7 

High speed Internet (e.g., cable, DSL, wireless, T1) 86.6 77.9 85.0 87.4 94.6 98.1 Dial-up modem 13.4 21.0 12.8 12.3 5.0 1.9 No access 0.0 1.0 2.2 0.3 0.4 0.0 

Observations 145 195 237 109 141 99 

Data: Q.4 Notes: 

Table 6 (Cont.)
Table 7

Average Daily Flow (MGD) for Public Water Systems

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ov

500,0

Primarily Ground Water Systems100% Ground Water 

Average Daily Flow 0.049 0.037 0.170 0.684 2.663 8.316 17.384 201.3

Confidence interval +|- 0.050 +|- 0.009 +|- 0.039 +|- 0.158 +|- 0.722 +|- 2.411 +|- 3.789 +|- 73.82

Primarily Ground Water

Average Daily Flow * 0.029 0.292 1.349 5.664 9.106 39.614 165.9

Confidence interval * +|- 0.000 +|- 0.183 +|- 0.883 +|- 4.609 +|- 2.861 +|- 11.021 +|- 29.33

Percentage drawn from each source for Primarily Ground Systems:

% Ground Water * 99.5 69.0 81.7 77.4 85.9 68.9 99

Confidence Interval * +|- 0.0 +|- 4.9 +|- 10.3 +|- 9.1 +|- 7.7 +|- 3.9 +|- 0

% Surface Water * 0.0 8.3 5.0 16.2 3.6 11.1 0

Confidence Interval * +|- 0.0 +|- 13.5 +|- 5.3 +|- 11.5 +|- 4.0 +|- 4.1 +|- 0

% Purchased Water * 0.5 22.6 13.4 6.4 10.5 20.0 0

Confidence Interval * +|- 0.0 +|- 18.3 +|- 10.0 +|- 4.2 +|- 8.2 +|- 4.5 +|- 0

Observations 11 38 82 46 58 35 51 Primarily Surface Water Systems100% Surface Water

Average Daily Flow 0.018 0.064 0.215 1.024 3.003 9.116 25.883 178.0

Confidence interval +|- 0.012 +|- 0.041 +|- 0.048 +|- 0.185 +|- 0.498 +|- 1.195 +|- 3.829 +|- 48.94

Primarily Surface Water

Average Daily Flow 0.019 0.027 0.304 0.998 3.540 15.009 33.735 196.4

Confidence interval +|- 0.000 +|- 0.015 +|- 0.212 +|- 0.324 +|- 0.886 +|- 4.647 +|- 4.493 +|- 44.19

Percentage drawn from each source for Primarily Surface Systems:

% Ground Water 14.6 8.3 19.8 8.4 13.0 11.1 10.6 6

Confidence Interval +|- 0.0 +|- 7.1 +|- 6.3 +|- 7.6 +|- 5.8 +|- 6.4 +|- 2.6 +|- 3

% Surface Water 85.4 83.4 79.6 90.3 81.9 79.2 81.6 79

Confidence Interval +|- 0.0 +|- 7.2 +|- 6.0 +|- 7.5 +|- 6.5 +|- 8.3 +|- 4.1 +|- 5

% Purchased Water 0.0 8.3 0.7 1.4 5.1 9.8 7.8 13

Confidence Interval +|- 0.0 +|- 13.6 +|- 0.9 +|- 1.5 +|- 4.1 +|- 7.6 +|- 3.4 +|- 6

Observations 13 32 62 55 72 48 106 

(Continu
Table 7 (Cont.)

Average Daily Flow (MGD) for Public Water Systems

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ov

500,0

Primarily Purchased Water Systems100% Purchased Water

Average Daily Flow 0.018 0.032 0.272 0.575 2.968 13.652 24.374 110.0

Confidence interval +|- 0.020 +|- 0.013 +|- 0.317 +|- 0.195 +|- 1.198 +|- 7.681 +|- 4.047 +|- 55.79

Primarily Purchased Water

Average Daily Flow * * 0.208 0.539 4.952 13.380 37.885 142.8

Confidence interval * * +|- 0.220 +|- 0.362 +|- 2.127 +|- 4.254 +|- 6.358 +|- 41.5

Percentage drawn from each source for Primarily Purchased Systems:

% Ground Water * * 16.6 18.2 3.4 11.4 19.4 5

Confidence Interval * * +|- 23.2 +|- 22.9 +|- 3.6 +|- 6.5 +|- 4.7 +|- 3

% Surface Water * * 0.0 0.3 14.7 5.5 10.3 21

Confidence Interval * * +|- 0.0 +|- 0.7 +|- 15.2 +|- 5.3 +|- 4.6 +|- 12

% Purchased Water * * 83.4 81.5 81.9 83.1 70.3 73

Confidence Interval * * +|- 23.2 +|- 22.9 +|- 14.0 +|- 8.1 +|- 4.8 +|- 10

Observations 3 13 33 22 23 28 44 All SystemsAverage Daily Flow 0.040 0.037 0.203 0.786 3.315 10.831 28.672 168.1

Confidence Interval +|- 0.035 +|- 0.008 +|- 0.077 +|- 0.131 +|- 0.647 +|- 1.832 +|- 2.325 +|- 26.5

Percentage drawn from each source:

% Ground Water 14.6 79.5 36.0 51.5 37.8 32.2 28.2 14

Confidence Interval +|- 0.0 +|- 35.2 +|- 16.3 +|- 17.1 +|- 12.9 +|- 10.5 +|- 4.3 +|- 6

% Surface Water 85.4 18.3 36.7 25.9 37.4 37.5 42.4 59

Confidence Interval +|- 0.0 +|- 32.2 +|- 21.2 +|- 13.6 +|- 10.6 +|- 11.0 +|- 5.9 +|- 8

% Purchased Water 0.0 2.2 27.3 22.6 24.8 30.3 29.3 25

Confidence Interval +|- 0.0 +|- 4.2 +|- 21.5 +|- 14.9 +|- 12.6 +|- 10.6 +|- 4.8 +|- 8

Observations 27 83 177 123 153 111 201 Data: Q.6Notes: Flow is the amount of water drawn from each source. It includes water delivered to customers 

system losses.
Table 8

Average Daily Flow (MGD) for Private Water Systems

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ov

500,0

Primarily Ground Water Systems100% Ground Water 

Average Daily Flow 0.007 0.021 0.093 0.855 1.580 14.463 27.711 17.0

Confidence interval +|- 0.002 +|- 0.005 +|- 0.026 +|- 0.373 +|- 0.422 +|- 14.896 +|- 12.607 +|- 0.0

Primarily Ground Water

Average Daily Flow 0.011 * 0.147 0.641 3.146 5.648 37.250 

Confidence interval +|- 0.000 * +|- 0.000 +|- 0.224 +|- 1.588 +|- 5.444 +|- 9.999 

Percentage drawn from each source for Primarily Ground Systems:

% Ground Water 99.7 * 66.5 87.4 60.3 54.0 69.0 

Confidence Interval +|- 0.0 * +|- 0.0 +|- 6.0 +|- 2.4 +|- 0.5 +|- 2.6 

% Surface Water 0.3 * 0.0 0.5 24.5 12.8 30.6 

Confidence Interval +|- 0.0 * +|- 0.0 +|- 1.1 +|- 21.5 +|- 20.9 +|- 2.3 

% Purchased Water 0.0 * 33.5 12.1 15.2 33.2 0.3 

Confidence Interval +|- 0.0 * +|- 0.0 +|- 6.2 +|- 21.1 +|- 20.3 +|- 0.3 

Observations 68 61 27 12 7 4 4 Primarily Surface Water Systems100% Surface Water

Average Daily Flow 0.021 0.030 0.301 0.569 4.005 7.674 23.717 110.1

Confidence interval +|- 0.010 +|- 0.010 +|- 0.193 +|- 0.241 +|- 1.937 +|- 3.775 +|- 5.327 +|- 0.00

Primarily Surface Water

Average Daily Flow 0.003 3.424 * 1.115 3.538 7.687 18.200 93.3

Confidence interval +|- 0.002 +|- 4.164 * +|- 0.000 +|- 1.982 +|- 2.687 +|- 5.567 +|- 51.67

Percentage drawn from each source for Primarily Surface Systems:

% Ground Water 11.1 43.0 * 32.6 13.8 16.6 1.0 2

Confidence Interval +|- 18.2 +|- 10.4 * +|- 0.0 +|- 14.3 +|- 21.1 +|- 1.0 +|- 2

% Surface Water 83.8 57.0 * 67.4 84.2 79.9 93.4 91

Confidence Interval +|- 15.3 +|- 10.4 * +|- 0.0 +|- 13.7 +|- 16.7 +|- 4.8 +|- 9

% Purchased Water 5.0 0.0 * 0.0 2.0 3.5 5.6 5

Confidence Interval +|- 7.4 +|- 0.0 * +|- 0.0 +|- 2.6 +|- 4.8 +|- 5.3 +|- 6

Observations 31 29 11 6 11 6 15 

(Continu
Table 8 (Cont.)

Average Daily Flow (MGD) for Private Water Systems

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ov

500,0

Primarily Purchased Water Systems100% Purchased Water

Average Daily Flow 0.008 0.024 0.125 0.426 0.790 12.245 6.655 

Confidence interval +|- 0.008 +|- 0.017 +|- 0.044 +|- 0.130 +|- 0.000 +|- 0.330 +|- 0.000 

Primarily Purchased Water

Average Daily Flow 0.007 0.022 0.699 * 1.830 * * 

Confidence interval +|- 0.000 +|- 0.000 +|- 0.749 * +|- 0.000 **

Percentage drawn from each source for Primarily Purchased Systems:

% Ground Water 0.0 10.0 3.6 * 0.0 * * 

Confidence Interval +|- 0.0 +|- 0.0 +|- 1.0 * +|- 0.0 **

% Surface Water 17.9 0.0 0.0 * 47.2 * * 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 * +|- 0.0 **

% Purchased Water 82.1 90.0 96.4 * 52.8 * * 

Confidence Interval +|- 0.0 +|- 0.0 +|- 1.0 * +|- 0.0 **

Observations 5 9 14 4 2 2 1 All SystemsAverage Daily Flow 0.007 0.031 0.139 0.676 2.536 9.638 20.846 65.6

Confidence Interval +|- 0.002 +|- 0.018 +|- 0.054 +|- 0.183 +|- 0.749 +|- 3.708 +|- 4.667 +|- 42.00

Percentage drawn from each source:

% Ground Water 39.7 15.0 24.8 84.0 21.8 31.2 13.0 2

Confidence Interval +|- 46.0 +|- 10.3 +|- 34.5 +|- 8.6 +|- 16.1 +|- 19.2 +|- 11.6 +|- 2

% Surface Water 44.3 8.6 0.0 4.7 66.7 53.6 82.3 91

Confidence Interval +|- 38.7 +|- 17.5 +|- 0.0 +|- 8.2 +|- 17.3 +|- 32.1 +|- 10.3 +|- 9

% Purchased Water 15.9 76.5 75.2 11.3 11.5 15.1 4.7 5

Confidence Interval +|- 25.2 +|- 27.6 +|- 34.5 +|- 6.0 +|- 12.8 +|- 17.0 +|- 4.6 +|- 6

Observations 104 99 52 22 20 12 20 Data: Q.6Notes: Flow is the amount of water drawn from each source. It includes water delivered to customers 

system losses.
Primary Water Source 

Primarily Ground Water Systems 100% Ground Water 

Average Daily Flow 

Confidence interval 

Primarily Ground Water 

Average Daily Flow 

Confidence interval 

Percentage drawn from each source for Primarily Ground Systems: 

% Ground Water 

Confidence Interval 

% Surface Water 

Confidence Interval 

% Purchased Water 

Confidence Interval 

Observations Primarily Surface Water Systems 100% Surface Water 

Average Daily Flow 

Confidence interval 

Primarily Surface Water 

Average Daily Flow 

Confidence interval 

Percentage drawn from each source for Primarily Surface Systems: 

% Ground Water 

Confidence Interval 

% Surface Water 

Confidence Interval 

% Purchased Water 

Confidence Interval 

Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Ov

or Less 500 3,300 10,000 50,000 100,000 500,000 500,0

0.012 0.027 0.151 0.710 2.586 8.715 18.031 104.0

+|- 0.006 +|- 0.005 +|- 0.030 +|- 0.145 +|- 0.675 +|- 2.572 +|- 3.669 +|- 92.48

0.011 0.029 0.256 1.090 5.525 8.650 39.418 165.9

+|- 0.000 +|- 0.000 +|- 0.150 +|- 0.601 +|- 4.347 +|- 2.749 +|- 10.134 +|- 29.32

99.7 99.5 68.4 83.8 76.4 81.7 68.9 99

+|- 0.0 +|- 0.0 +|- 3.8 +|- 6.9 +|- 8.6 +|- 8.5 +|- 3.6 +|- 0

0.3 0.0 6.2 3.4 16.7 4.8 12.8 0

+|- 0.0 +|- 0.0 +|- 10.7 +|- 3.3 +|- 11.0 +|- 4.2 +|- 4.0 +|- 0

0.0 0.5 25.3 12.9 6.9 13.5 18.3 0

+|- 0.0 +|- 0.0 +|- 14.5 +|- 6.7 +|- 4.1 +|- 9.1 +|- 4.4 +|- 0

79 99 109 58 65 39 55 

0.021 0.044 0.232 0.980 3.101 8.982 25.721 174.5

+|- 0.009 +|- 0.021 +|- 0.054 +|- 0.169 +|- 0.491 +|- 1.134 +|- 3.548 +|- 46.47

0.009 1.741 0.304 1.007 3.539 14.051 30.431 174.7

+|- 0.008 +|- 2.614 +|- 0.212 +|- 0.299 +|- 0.803 +|- 4.161 +|- 4.081 +|- 38.05

12.4 25.8 19.8 10.2 13.2 11.8 8.7 5

+|- 11.7 +|- 16.8 +|- 6.3 +|- 7.8 +|- 5.4 +|- 6.2 +|- 2.3 +|- 2

84.4 70.1 79.6 88.5 82.4 79.3 83.9 82

+|- 9.8 +|- 13.5 +|- 6.0 +|- 7.6 +|- 5.8 +|- 7.5 +|- 3.4 +|- 4

3.2 4.1 0.7 1.3 4.5 8.9 7.4 11

+|- 5.4 +|- 7.6 +|- 0.9 +|- 1.4 +|- 3.3 +|- 6.7 +|- 2.9 +|- 4

44 61 73 61 83 54 121 

(Continu

Table 9 

Average Daily Flow (MGD) for Public and Private Water Systems 

By Primary Water Source 
Average Daily Flow (MGD) for Public and Private Water Systems 

Primary Water Source Primarily Purchased Water Systems 100% Purchased Water 

Average Daily Flow 

Confidence interval 

Primarily Purchased Water 

Average Daily Flow 

Confidence interval 

Percentage drawn from each source for Primarily Purchased Systems: 

% Ground Water 

Confidence Interval 

% Surface Water 

Confidence Interval 

% Purchased Water 

Confidence Interval 

Observations All Systems Average Daily Flow 

Confidence Interval 

Percentage drawn from each source: 

% Ground Water 

Confidence Interval 

% Surface Water 

Confidence Interval 

% Purchased Water 

Confidence Interval 

Observations 

By Primary Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Ov

or Less 500 3,300 10,000 50,000 100,000 500,000 500,0

0.013 0.028 0.225 0.545 2.823 13.509 22.430 110.0

+|- 0.012 +|- 0.011 +|- 0.214 +|- 0.159 +|- 1.141 +|- 6.896 +|- 4.746 +|- 55.78

0.007 0.022 0.452 0.539 4.772 13.380 37.885 142.8

+|- 0.000 +|- 0.000 +|- 0.451 +|- 0.362 +|- 2.047 +|- 4.248 +|- 6.356 +|- 41.52

0.0 10.0 10.2 18.2 3.2 11.4 19.4 5

+|- 0.0 +|- 0.0 +|- 13.3 +|- 22.9 +|- 3.4 +|- 6.5 +|- 4.7 +|- 3

17.9 0.0 0.0 0.3 16.6 5.5 10.3 21

+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.7 +|- 14.9 +|- 5.3 +|- 4.6 +|- 12

82.1 90.0 89.8 81.5 80.2 83.1 70.3 73

+|- 0.0 +|- 0.0 +|- 13.3 +|- 22.8 +|- 13.6 +|- 8.1 +|- 4.8 +|- 10

8 22 47 26 25 30 45 

0.012 0.033 0.186 0.767 3.250 10.725 27.907 154.2

+|- 0.006 +|- 0.011 +|- 0.058 +|- 0.113 +|- 0.598 +|- 1.694 +|- 2.168 +|- 26.07

34.3 40.9 33.2 59.9 36.2 32.1 26.4 12

+|- 38.3 +|- 47.6 +|- 15.3 +|- 13.4 +|- 11.8 +|- 9.6 +|- 4.2 +|- 5

53.2 12.5 27.4 20.4 40.5 39.1 47.1 64

+|- 35.4 +|- 17.0 +|- 16.9 +|- 10.2 +|- 10.1 +|- 10.3 +|- 5.7 +|- 7

12.5 46.6 39.5 19.7 23.4 28.8 26.5 22

+|- 20.2 +|- 52.2 +|- 20.8 +|- 11.4 +|- 11.4 +|- 9.7 +|- 4.3 +|- 7

131 182 229 145 173 123 221 

Data: Q.6 Notes: Flow is the amount of water drawn from each source. It includes water delivered to customers 

system losses. 

Table 9 (Cont.) 
Source 

Ground Water Sources 

Average Annual Flow 

Confidence Interval 

Percentage systems with ground water sources 

Surface Water Sources 

Average Annual Flow 

Confidence Interval 

Percentage systems with surface water sources 

GWUDI Sources 

Average Annual Flow 

Confidence Interval 

Percentage systems with GWUDI sources 

Unknown Surface Water Sources 

Average Annual Flow 

Confidence Interval 

Percentage systems with unknown surface water sources 

Purchased Finished Ground Water 

Average Annual Flow 

Confidence Interval 

Percentage systems with purchased finished ground water

Purchased Partial/Untreated Ground Water 

Average Annual Flow 

Confidence Interval 

Percentage systems with purchased partial/untreated ground water 

Purchased Finished Surface Water 

Average Annual Flow 

Confidence Interval 

Percentage systems with purchased finished surface water

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 

4.3 11.1 53.1 260.8 917.8 2,382.9 5,274.0 

+|- 2.2 +|- 2.9 +|- 10.1 +|- 59.8 +|- 232.5 +|- 507.5 +|- 893.5 +|

80.0 77.4 68.1 57.8 60.0 49.8 44.7 

7.2 20.5 85.4 316.3 1,097.7 3,290.2 8,467.9 

+|- 4.0 +|- 10.2 +|- 23.8 +|- 59.0 +|- 269.8 +|- 517.2 +|- 807.4 +|

1.1 2.2 6.3 18.7 31.9 41.3 58.4 7.0 67.6 78.6 159.6 511.2 1,026.8 5,667.9 

+|- 4.5 +|- 122.3 +|- 57.9 +|- 54.5 +|- 459.2 +|- 711.7 +|- 1,867.0 

1.8 1.5 1.9 1.3 2.4 4.0 4.8 

* * * * * 1,398.0 3,498.0 

* * * * * +|- 0.0 +|- 0.0 

0.0 0.0 0.0 0.0 0.0 0.9 0.4 2.1 3.6 40.9 44.3 242.5 796.8 2,158.4 

+|- 0.0 +|- 3.2 +|- 19.7 +|- 33.4 +|- 343.7 +|- 1,001.9 +|- 1,143.9 

1.1 3.7 9.9 1.0 3.9 5.9 5.5 

* * * * 365.0 5.0 3,657.3 

* * * * +|- 0.0 +|- 0.0 +|- 2,358.5 +|

0.0 0.0 0.0 0.0 0.2 0.4 2.2 

5.3 11.9 100.9 133.3 917.4 3,374.9 5,324.2 

+|- 5.1 +|- 4.4 +|- 98.6 +|- 46.6 +|- 330.1 +|- 1,533.6 +|- 863.0 +|

5.6 10.8 19.1 29.4 23.3 30.1 29.7 

(Co

Table 10 

Average Annual Flow for Public and Private Systems (Millions of Gallons per Year) 

From Each Source Type 
Average Annual Flow for Public and Private Syste

From Each Source T

S

100 101 - 501 -

Ownership Type or Less 500 3,300 

Purchased Partial/Untreated Surface Water 

Average Annual Flow 5.9 6.9 218.0 

Confidence Interval +|- 5.6 +|- 0.0 +|- 0.0 

Percentage systems with purchased partial/untreated surface water 0.1 0.1 0.1 

Purchased Finished GWUDI Water 

Average Annual Flow * * *

Confidence Interval * * * 

Percentage systems with purchased finished GUDI water 0.0 0.0 0.0 

Purchased Partial/Untreated GWUDI Water 

Average Annual Flow * * * 

Confidence Interval * * * 

Percentage systems with purchased partial/untreated GWUDI water 0.0 0.0 0.0 

Unknown Purchased Water 

Average Annual Flow * 4.1 * 

Confidence Interval * +|- 0.0 * +|- 77.7 +|- 1,180.8 +|- 0.0 +|- 312.4 +|

Percentage systems with unknown purchased water 0.0 0.0 0.0 2.1 3.2 0.8 0.8 

Observations 158 217 294 205 260 184 380 Data: Q.6 Notes: Flow is the amount of water drawn from each source. It includes water delivered to custom

system losses. 

ms (Millions of Gallons pe

ype

ystem Service Population 

3,301 - 10,001 - 50

10,000 50,000 10 

503.9 197.5 5,572.4 7,376.2 

+|- 200.4 +|- 268.6 +|- 1,101.1 +|- 2,395.9 +|- 

1.1 1.7 3.9 5.7 

60.3 * * 2.4 

+|- 66.7 * * +|- 0.0 

1.8 0.0 0.0 0.4 

* * * 200.0 

* * * +|- 0.0 

0.0 0.0 0.0 0.4 

88.8 843.2 1.7 384.5 

r Year)

Category 

,001 - 100,001- 

0,000 500,000 

Table 10 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001-

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 OvePublic Systems Sold to Other Water Suppliers 

Finished Water 0.0 5.1 6.6 44.9 77.8 500.6 1,669.3 

Confidence Interval +|- 0.0 +|- 0.8 +|- 6.3 +|- 27.9 +|- 30.2 +|- 198.9 +|- 393.5 +

Partially or Untreated Water 0.0 0.0 0.0 9.1 0.6 0.4 86.5 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 14.0 +|- 1.1 +|- 0.6 +|- 86.0 +

Residential Customers 7.0 11.1 54.6 148.1 647.4 2,034.4 4,980.0 

Confidence Interval +|- 5.4 +|- 1.9 +|- 20.0 +|- 23.9 +|- 131.7 +|- 323.1 +|- 499.1 +

Non-residential Customers 

Finished Water 1.0 1.5 20.7 76.0 378.8 976.0 2,969.2 

Confidence Interval +|- 1.3 +|- 1.2 +|- 12.5 +|- 23.4 +|- 136.9 +|- 292.3 +|- 341.0 +

Partially or Untreated Water 0.0 * 5.7 19.4 1.5 16.4 304.0 

Confidence Interval +|- 0.0 * +|- 11.1 +|- 23.1 +|- 2.2 +|- 17.5 +|- 166.2 

Unaccounted for Water 1.7 3.0 9.4 37.2 113.2 302.8 763.5 

Confidence Interval +|- 1.8 +|- 2.9 +|- 2.7 +|- 10.3 +|- 24.6 +|- 96.7 +|- 140.4 +

Unaccounted for Water as Percentage of Total 12.1 16.2 16.6 12.8 10.1 8.5 7.9 

Confidence Interval +|- 9.5 5 +|- 3.7 +|- 2.8 +|- 1.9 +|- 1.7 +|- 0.9 

Observations 24 79 173 77 117 81 161 Private Systems Sold to Other Water Suppliers 

Finished Water 0.0 0.0 1.8 16.4 160.9 1,646.6 1,006.3 

Confidence Interval +|- 0.0 +|- 0.0 +|- 2.9 +|- 26.6 +|- 120.7 +|- 1,307.4 +|- 804.0 +

Partially or Untreated Water 0.3 0.0 0.0 0.0 17.6 0.0 0.0 

Confidence Interval +|- 0.4 +|- 0.0 +|- 0.0 +|- 0.0 +|- 37.7 +|- 0.0 +|- 0.0 

Residential Customers 2.6 7.7 43.3 169.3 345.7 1,730.6 5,039.3 

Confidence Interval +|- 0.7 +|- 1.7 +|- 19.1 +|- 46.0 +|- 92.3 +|- 582.0 +|- 1,456.0 +

Non-residential Customers 

Finished Water 0.5 0.4 15.5 36.0 39.9 1,567.2 3,651.4 

Confidence Interval +|- 0.9 +|- 0.7 +|- 12.8 +|- 29.5 +|- 41.0 +|- 775.8 +|- 927.8 +

Partially or Untreated Water 1.3 0.0 0.0 0.0 0.0 0.0 0.0 

Confidence Interval +|- 2.6 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +

Unaccounted for Water 0.2 0.8 4.6 23.0 102.3 1,214.4 3,496.7 

Confidence Interval +|- 0.2 +|- 0.3 +|- 1.6 +|- 10.3 +|- 57.6 +|- 1,475.8 +|- 1,760.6 +

Unaccounted for Water as Percentage of Total 6.7 10.7 11.3 11.4 15.5 17.2 24.5 

Confidence Interval +|- 5.8 +|- 3.0 +|- 3.6 +|- 5.5 +|- 5.7 +|- 15.2 +|- 6.3 

Observations 95 96 52 16 11 8 16 

(Con

Table 11 

Annual Water Deliveries and Unaccounted for Water (Millions of Gallons per Year) 

By Ownership 
Annual Water Deliveries and Unaccounted for Water (Millions of Gallons per Year) 

By Ownership 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001-

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 Ove

All Systems 

Sold to Other Water Suppliers 

Finished Water 0.0 0.8 6.0 38.8 83.1 586.8 1,576.1 

Confidence Interval +|- 0.0 +|- 1.8 +|- 5.5 +|- 22.8 +|- 29.5 +|- 221.6 +|- 360.7 +

Partially or Untreated Water 0.2 0.0 0.0 7.2 1.3 0.3 81.5 

Confidence Interval +|- 0.4 +|- 0.0 +|- 0.0 +|- 11.2 +|- 1.8 +|- 0.6 +|- 81.5 +

Residential Customers 3.1 9.1 51.5 152.8 627.2 2,016.9 4,988.1 

Confidence Interval +|- 1.1 +|- 1.4 +|- 15.4 +|- 21.4 +|- 124.3 +|- 303.8 +|- 475.7 +

Non-residential Customers 

Finished Water 0.7 1.1 19.7 66.2 359.0 1,010.9 3,070.2 

Confidence Interval +|- 0.8 +|- 0.8 +|- 10.5 +|- 19.6 +|- 130.2 +|- 284.5 +|- 337.0 +

Partially or Untreated Water 1.0 0.0 4.7 13.5 1.5 14.8 285.3 

Confidence Interval +|- 2.0 +|- 0.0 +|- 9.1 +|- 15.8 +|- 2.1 +|- 15.9 +|- 156.1 

Unaccounted for Water 0.6 2.0 8.3 33.4 112.6 358.1 1,157.5 

Confidence Interval +|- 0.6 +|- 1.6 +|- 2.1 +|- 8.0 +|- 23.4 +|- 140.4 +|- 421.3 +

Unaccounted for Water as Percentage of Total 8.2 13.6 15.4 12.5 10.4 9.0 10.4 

Confidence interval +|- 5.0 +|- 3.2 +|- 3.0 +|- 2.5 +|- 1.9 +|- 2.0 +|- 2.1 

Observations 119 175 225 93 128 89 177 Data: Q.21.A Notes: Unaccounted for water includes system losses, water for fire suppression, and water used in the 

treatment process. Average deliveries only includes estimates for systems reporting each type. 

Table 11 (Cont.) 
Ownership Type 

Public Systems 

Mean Residential Deliveries 

Confidence Interval 

Median Residential Deliveries Non-Residential Deliveries

Mean Finished Water Deliveries

Confidence Interval 

Median Finished Water Deliveries Mean Partially or Untreated Water Deliveries 

Confidence Interval 

Median Partially or Untreated Water Deliveries 

Observations 

Private Systems 

Mean Residential Deliveries 

Confidence Interval 

Median Residential Deliveries Non-Residential Deliveries

Mean Finished Water Deliveries

Confidence Interval 

Median Finished Water Deliveries Mean Partially or Untreated Water Deliveries 

Confidence Interval 

Median Partially or Untreated Water Deliveries 

Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 

109 107 94 86 89 115 123 

+|- 61 +|- 22 +|- 11 +|- 11 +|- 8 +|- 17 +|- 8 

112 80 77 75 77 102 112 

1,499 156 325 694 639 727 869 

+|- 3,058 +|- 91 +|- 103 +|- 294 +|- 156 +|- 152 +|- 85 

142 98 185 329 444 657 645 

* * 317 14,131 9,867 15,261 324,478 

* * +|- 0 +|- 11,841 +|- 16,549 +|- 19,498 +|- 136,099 +|

* * 317 9,000 4,114 9,557 65,833 

27 84 157 64 98 65 136 96 86 104 91 83 78 71 

+|- 22 +|- 14 +|- 18 +|- 25 +|- 28 +|- 37 +|- 21 

67 70 87 81 67 62 57 

1,339 95 3,053 4,330 511 545 868 

+|- 426 +|- 100 +|- 4,595 +|- 7,352 +|- 119 +|- 220 +|- 426 

1,560 62 367 116 460 606 462 

429 * * * * * * 

+|- 0 * * * * * * 

429 * * * * * * 

81 111 56 27 20 13 21 

(Con

Table 12 

Annual Deliveries per Customer Service Connection 

By Ownership 

(Thousands of Gallons) 
Annual Deliveries per Customer Service Connection

By Ownership

Ownership Type All Systems 

Mean Residential Deliveries 

Confidence Interval 

Median Residential Deliveries Non-Residential Deliveries

Mean Finished Water Deliveries

Confidence Interval 

Median Finished Water Deliveries Mean Partially or Untreated Water Deliveries 

Confidence Interval 

Median Partially or Untreated Water Deliveries 

Observations 

(Thousands of Gallons) 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 

98 94 97 87 88 112 115 

+|- 23 +|- 12 +|- 9 +|- 10 +|- 8 +|- 16 +|- 9 

71 74 82 81 77 102 105 

1,410 145 825 1,588 636 712 869 

+|- 1,343 +|- 80 +|- 801 +|- 1,858 +|- 152 +|- 143 +|- 102 

183 84 197 311 444 620 631 429 317 14,131 9,867 15,261 324,478 79,103 

+|- 0 +|- 0 +|- 11,841 +|- 16,549 +|- 19,498 +|- 136,099 +|- 72,199 

429 * 317 9,000 4,114 9,557 65,833 108 195 213 91 118 78 157 

Data: Q.21A Notes: Average deliveries per connection are for systems that have deliveries and connections 

for that delivery type; it excludes systems that do not have positive deliveries per connectionAverage deliveries per connection exclude the upper and lower 5 percent of the observations

Table 12 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Primarily Ground Water Systems 

Entry Points from Ground Water Sources 1.1 1.2 1.7 2.1 3.4 9.7 11.6 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.4 +|- 0.7 +|- 8.7 +|- 3.0 +

Entry Points from Surface Water Sources 0.0 0.0 0.0 0.0 0.1 0.1 0.3 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.1 

Observations 83 99 110 57 60 38 54 

Primarily Surface Water Systems 

Entry Points from Ground Water Sources 0.1 0.1 0.2 0.1 0.3 0.3 0.8 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.3 

Entry Points from Surface Water Sources 1.0 1.1 1.0 1.0 1.1 1.4 1.4 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.1 

Observations 47 66 78 64 83 54 122 

Primarily Purchased Water Systems 

Entry Points from Ground Water Sources 0.0 2.0 1.0 0.9 2.6 2.3 2.8 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.2 +|- 1.1 +|- 1.1 +|- 0.8 +

Entry Points from Surface Water Sources 1.0 0.0 0.0 0.1 0.2 0.6 0.7 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.2 +|- 0.2 +|- 0.4 +|- 0.3 

Observations 1 1 4 4 7 9 23 

All Systems 

Entry Points from Ground Water Sources 1.1 1.2 1.5 1.6 2.3 4.5 3.9 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.4 +|- 4.4 +|- 0.9 

Entry Points from Surface Water Sources 0.0 0.1 0.1 0.3 0.4 0.7 1.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.1 

Observations 131 166 192 125 150 101 199 

Data: Q.6, Q. 7 Notes: For primarily purchased water systems, the estimate of ground water and surface w

points are for non-purchased water entry points only. The average number of entry points for ground water systems is driven up by one s200 entry points. The average is reduced to 14.5 entry points when this system is e

Table 13 

Number of Entry Points to the Distribution System 

Primary Water Source 
Primary Water Source 

Primarily Ground Water Systems 

Finished Water % of Systems Selling Finished Water Partially Treated or Untreated Water % of Systems Selling Treated or Untreated Water Observations 

Primarily Surface Water Systems 

Finished Water % of Systems Selling Finished Water Partially Treated or Untreated Water % of Systems Selling Treated or Untreated Water Observations 

Primarily Purchased Water Systems 

Finished Water % of Systems Selling Finished Water Partially Treated or Untreated Water % of Systems Selling Treated or Untreated Water Observations 

All Systems 

Finished Water % of Systems Selling Finished Water Partially Treated or Untreated Water % of Systems Selling Treated or Untreated Water Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 50

* 129 436 343 401 70 29 

0.0 1.0 5.0 13.0 23.2 32.3 25.0 

242 * * 48 31 5 4 

2.3 0.0 0.0 1.8 1.8 2.1 3.6 

88 105 111 62 66 40 56 

* * 181 195 308 140 176 

0.0 0.0 16.9 22.6 33.2 60.7 66.3 

* * * 12 20 5 25 

0.0 0.0 0.0 1.4 2.2 2.0 9.5 

49 67 78 65 85 54 124 

* * 12 174.2 111.2 35 35 

0.0 0.0 0.3 16.3 16.4 24.0 36.9 

* * * * * * 2 

0.0 0.0 0.0 0.0 0.0 0.0 2.0 

8 23 48 27 25 30 45 

* 129 628 713 820 246 241 

0.0 0.8 4.7 15.6 24.6 41.2 50.3 

242 * * 60 52 9 32 

2.1 0.0 0.0 1.3 1.6 1.5 6.6 

145 195 237 154 176 124 225 

Data: Q.21.A Notes: 

Table 14 

Number and Percentage of Systems Selling to Other Public Water Suppliers 

By Primary Water Source 
Table 15

Water Systems Not Providing Any Treatment 

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 All Sizes

Primarily Ground Water Systems

% of Systems 28.1 24.3 10.3 4.0 0.0 2.5 5.7 0.0 19.1

Confidence Interval +|- 10.4 +|- 10.2 +|- 8.3 +|- 5.4 +|- 0.0 +|- 4.4 +|- 4.5 +|- 0.0 +|- 5.1

# of Entry Points 1.1 1.3 2.0 3.5 * 1.0 7.3 * 0.2

Confidence Interval +|- 0.1 +|- 0.2 +|- 0.6 +|- 4.3 * +|- 0.0 +|- 7.4 * +|- 0.1

Observations 22 23 11 2 60 1 3 6 62

Primarily Surface Water Systems

% of Systems 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0

# of Entry Points * * * * * * * * *

Confidence Interval * * * * * * * * *

Observations 0 0 0 0 0 0 0 0 0

Primarily Purchased Water Systems

% of Systems 0.0 0.0 25.2 0.0 22.2 23.7 4.5 0.0 15.5

Confidence Interval +|- 0.0 +|- 0.0 +|- 43.0 +|- 0.0 +|- 36.9 +|- 25.8 +|- 6.3 +|- 0.0 +|- 19.6

# of Entry Points * * 1.0 * 4.0 3.1 7.0 * 0.2

Confidence Interval * * +|- 0.0 * +|- 0.0 +|- 1.3 +|- 0.0 * +|- 0.2

Observations 1 1 1 4 1 2 1 5 5

All Systems

% of Systems 27.5 22.8 9.6 2.8 1.2 3.1 2.0 0.0 17.0

Confidence Interval +|- 10.2 +|- 9.6 +|- 7.3 +|- 3.9 +|- 2.3 +|- 3.1 +|- 1.4 +|- 0.0 +|- 4.5

# of Entry Points 1.1 1.3 1.9 3.5 4.0 2.3 7.3 * 1.6

Confidence Interval +|- 0.1 +|- 0.2 +|- 0.6 +|- 4.3 +|- 0.0 +|- 1.9 +|- 5.5 * +|- 0.1

Observations 22 23 12 2 1 3 4 50 67

Data: Q.6

Notes: Number of entry points and observations are for systems that do not treat. 

Categories where all systems treat are denoted as zero.

Excludes systems that purchase 100% of their water.

33
Primary Water Source 

Primarily Ground Water Systems 

# of Ground Water Entry Points Untreated per System 

Confidence Interval 

# of Wells per Untreated Entry Point 

Confidence Interval 

% Ground Water Entry Points Untreated per System 

Confidence Interval 

% that are Seasonal/Emergency 

Confidence Interval 

Observations 

Primarily Surface Water Systems 

# of Ground Water Entry Points Untreated per System 

Confidence Interval 

# of Wells per Untreated Entry Point 

Confidence Interval 

% Ground Water Entry Points Untreated per System 

Confidence Interval 

% that are Seasonal/Emergency 

Confidence Interval 

Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 

0.3 0.3 0.2 0.2 0.1 2.9 1.2 

+|- 0.1 +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.2 +|- 4.7 +|- 0.9 

1.2 1.3 1.1 * 3.8 2.6 * 

+|- 0.2 +|- 0.3 +|- 0.3 * +|- 0.0 +|- 1.5 * 

28.8 24.3 10.7 5.1 3.4 9.9 10.1 

+|- 10.5 +|- 10.2 +|- 8.3 +|- 5.9 +|- 6.1 +|- 12.2 +|- 5.6 

3.7 3.8 0.0 * 100.0 47.9 * 

+|- 7.6 +|- 8.1 +|- 0.0 * +|- 0.0 +|- 36.5 * 

83 99 110 57 60 38 54 

0.0 0.0 0.0 0.1 0.0 0.0 0.1 

+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.0 +|- 0.1 

1.2 * * * 2.5 * * 

+|- 0.2 * * * +|- 1.8 * * 

0.0 0.0 2.0 17.0 4.6 0.0 9.1 

+|- 0.0 +|- 0.0 +|- 4.2 +|- 35.4 +|- 5.9 +|- 0.0 +|- 8.6 

6.4 * * * 1.6 * * 

+|- 8.8 * * * +|- 2.8 * * 

47 66 78 64 83 54 122 

(C

Table 16 

Ground Water Entry Points Not Receiving Treatment 

By Primary Water Source 
Primary Water Source 

Primarily Purchased Water Systems 

# of Ground Water Entry Points Untreated per System 

Confidence Interval 

# of Wells per Untreated Entry Point 

Confidence Interval 

% Ground Water Entry Points Untreated per System 

Confidence Interval 

% that are Seasonal/Emergency 

Confidence Interval 

Observations 

All Systems 

# of Ground Water Entry Points Untreated per System 

Confidence Interval 

# of Wells per Untreated Entry Point 

Confidence Interval 

% Ground Water Entry Points Untreated per System 

Confidence Interval 

% that are Seasonal/Emergency 

Confidence Interval 

Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 

0.0 1.0 0.3 0.0 0.9 0.7 0.8 

+|- 0.0 +|- 0.0 +|- 0.4 +|- 0.0 +|- 1.5 +|- 0.9 +|- 0.6 

1.0 1.0 1.0 20.0 3.7 * * 

+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 1.9 * * 

* 50.0 25.2 0.0 26.7 30.5 16.0 * +|- 0.0 +|- 43.1 +|- 0.0 +|- 43.4 +|- 32.0 +|- 11.0 

0.0 100.0 25.9 0.0 88.9 * * 

+|- 0.0 +|- 0.0 +|- 15.5 +|- 0.0 +|- 8.0 * * 

1 1 4 4 7 9 23 

0.3 0.3 0.2 0.1 0.1 1.3 0.4 

+|- 0.1 +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.1 +|- 2.2 +|- 0.3 

1.2 1.2 1.2 1.1 1.0 7.0 2.7 

+|- 0.2 +|- 0.2 +|- 0.3 +|- 0.3 +|- 0.0 +|- 8.1 +|- 1.3 

28.8 24.5 11.0 5.3 5.1 11.4 11.1 

+|- 10.4 +|- 10.2 +|- 8.0 +|- 5.6 +|- 6.2 +|- 10.3 +|- 4.4 

3.7 6.2 7.4 0.0 25.9 80.0 18.6 

+|- 7.6 +|- 8.5 +|- 11.8 +|- 0.0 +|- 15.5 +|- 49.8 +|- 12.9 

131 166 192 125 150 101 199 

Data: Q.6 Notes: Number of entry points that are not treated per system include both treated and un

points, i.e, systems that treat all of their entry points are included in the analysis a

Table 16 (Cont.) 

Ground Water Entry Points Not Receiving Treatment 

By Primary Water Source 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Ground Water Systems 

100% Ground Water Systems 

Number of Water Treatment Plants/System 1.1 1.2 1.7 2.1 3.4 7.6 9.3 

Confidence Interval +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.5 +|- 0.8 +|- 5.3 +|- 2.6 +

Number of Wells/Plant 1.6 1.8 1.8 2.4 2.3 1.8 8.8 

Confidence Interval +|- 0.4 +|- 0.3 +|- 0.4 +|- 0.9 +|- 0.6 +|- 2.4 +|- 6.1 

Observations 60 75 95 41 47 26 30 

Primarily Ground Water Systems 

Number of Water Treatment Plants/System 1.0 1.0 1.5 1.7 2.7 5.7 13.7 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.5 +|- 0.4 +|- 1.2 +|- 2.2 +|- 6.2 +

Number of Wells/Plant 4.0 1.0 2.8 5.7 2.1 1.9 3.1 

Confidence Interval +|- 0.0 +|- 0.0 +|- 2.0 +|- 4.1 +|- 0.9 +|- 0.9 +|- 1.3 

Percentage of Plants Treating Surface Water 100.0 0.0 16.7 11.7 14.7 4.2 5.1 

Confidence Interval +|- 0.0 +|- 0.0 +|- 25.8 +|- 11.1 +|- 14.0 +|- 3.4 +|- 2.7 

Observations 1 1 4 17 16 11 22 

Surface Water Systems 

100% Surface Water Systems 

Number of Water Treatment Plants/System 1.0 1.1 1.1 1.1 1.1 1.5 1.3 

Confidence Interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.3 +|- 0.1 

Observations 42 62 61 49 57 35 76 

Primarily Surface Water Systems 

Number of Water Treatment Plants/System 1.6 2.3 1.7 1.1 1.9 2.1 3.5 

Confidence Interval +|- 0.6 +|- 2.0 +|- 0.2 +|- 0.1 +|- 0.5 +|- 0.8 +|- 0.8 

Number of Wells/Plant 0.5 0.9 0.9 0.3 1.7 1.6 1.6 

Confidence Interval +|- 0.2 +|- 0.3 +|- 0.4 +|- 0.2 +|- 0.9 +|- 1.0 +|- 0.8 

Percentage of Plants Treating Surface Water 60.7 44.3 57.4 74.1 59.1 60.4 44.0 

Confidence Interval +|- 23.9 +|- 38.7 +|- 8.2 +|- 31.3 +|- 12.8 +|- 22.8 +|- 9.0 +

Observations 5 4 17 15 28 19 46 

(Co

Table 17 

Number of Water Treatment Plants per System 

By Primary Water Source 
Number of Water Treatment Plants per System

By Primary Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Purchased Water Systems 

100% Purchased Water Systems 

Number of Water Treatment Plants/System 1.0 1.4 1.4 1.0 1.0 2.4 1.3 

Confidence Interval +|- 0.0 +|- 0.5 +|- 0.2 +|- 0.0 +|- 0.0 +|- 0.9 +|- 0.4 

Observations 2 4 12 6 2 3 7 

Primarily Purchased Water Systems 

Number of Water Treatment Plants/System 1.0 1.0 1.3 1.3 2.2 2.9 3.1 

Confidence Interval 0.0 0.0 +|- 0.5 +|- 0.5 +|- 0.9 +|- 1.3 +|- 0.8 +

Number of Wells/Plant 0.0 3.0 7.7 0.9 0.8 1.2 4.4 

Confidence Interval 0.0 0.0 +|- 13.4 +|- 0.7 +|- 0.3 +|- 0.6 +|- 3.5 

Percentage of Plants Treating Surface Water 100.0 0.0 0.0 9.1 6.3 22.9 24.1 

Confidence Interval 0.0 0.0 +|- 0.0 +|- 18.7 +|- 9.6 +|- 18.0 +|- 11.6 

Observations 1.0 1.0 3 4 8 8 22 

All Systems 

Number of Water Treatment Plants/System 1.1 1.2 1.6 1.7 2.5 4.1 4.4 

Confidence Interval +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.4 +|- 2.1 +|- 0.9 

Number of Wells/Plant 1.6 1.6 1.7 2.5 2.0 1.5 4.2 

Confidence Interval +|- 0.3 +|- 0.2 +|- 0.5 +|- 1.0 +|- 0.4 +|- 1.1 +|- 2.0 

Percentage of Plants Treating Surface Water 3.0 5.5 7.4 16.5 17.2 18.8 23.1 

Confidence Interval 

Observations 

+|- 0.8 

111 

+|- 2.4 

147 

+|- 2.2 

192 

+|- 3.9 

132 

+|- 3.9 

158 

+|- 12.4 

102 

+|- 4.7 

203 

Data: Q.6, Q.7 Notes: Includes systems with at least one treatment plant only. 

See "Plant" definition in introduction. Number of Wells/Plant refers to the average number of ground water wells treated awater treatment plant. For primarily surface water systems, a treatment plant may owater, but the majority of the water in the system comes from a surface water sourc

Table 17 (Cont.)
Please note that the unit of analysis changes for the following tables. 

Tables 18 - 42 report data for treatment plants rather than water systems.
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Ground Water Plants 

Number of Wells/Plant 1.7 1.8 1.8 3.2 2.3 3.4 5.4 2.8 

Confidence Interval +|- 0.4 +|- 0.2 +|- 0.4 +|- 1.3 +|- 0.5 +|- 1.3 +|- 2.7 +|- 0.6 

Observations 65 93 170 104 210 133 604 439 

Mixed Plants 

Number of Wells/Plant 2.6 1.8 7.8 1.9 3.2 7.6 9.7 1.0 

Confidence Interval +|- 1.8 +|- 0.3 +|- 8.4 +|- 0.9 +|- 1.5 +|- 4.3 +|- 7.5 +|- 0.0 

Observations 3 7 9 7 11 4 12 1 

All Plants 

Number of Wells/Plant 1.7 1.8 1.9 3.1 2.3 3.6 5.5 2.8 

Confidence Interval +|- 0.4 +|- 0.2 +|- 0.6 +|- 1.3 +|- 0.5 +|- 1.2 +|- 2.6 +|- 0.6 

Observations 68 100 179 111 221 137 616 440 

Data: Q.6, Q.7 Notes: This table reports the number of wells treated per ground water plant. Plants with sources 

other than wells are excluded. Ground water plants are defined as treating wells only. For this analysis mixed plants treat at least one well and one non-ground water source. 

Table 18 

Number of Wells Treated per Treatment Plant 

By Water Source 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,

Ground Water Plants 

Average Daily Flow 19 23 89 397 862 2,686 2,502 3,Confidence Interval +|- 14 +|- 5 +|- 20 +|- 110 +|- 276 +|- 1,234 +|- 631 +|- 2,5Peak Daily Flow 36 48 196 770 1,728 4,367 4,793 5,Confidence Interval +|- 20 +|- 12 +|- 48 +|- 204 +|- 480 +|- 1,827 +|- 1,172 +|- 3,4Design Capacity 121 186 536 1,278 2,309 5,789 5,907 6,Confidence Interval +|- 55 +|- 54 +|- 151 +|- 407 +|- 674 +|- 2,465 +|- 1,467 +|- 3,

Surface Water Plants 

Average Daily Flow 9 52 226 819 2,763 7,105 16,297 62,Confidence Interval +|- 3 +|- 25 +|- 63 +|- 113 +|- 733 +|- 1,200 +|- 1,647 +|- 10,5Peak Daily Flow 23 122 476 1,364 4,955 11,739 27,271 96,Confidence Interval +|- 8 +|- 69 +|- 142 +|- 218 +|- 1,644 +|- 2,090 +|- 2,996 +|- 15,9Design Capacity 61 249 835 2,196 6,718 16,503 37,032 127,Confidence Interval +|- 28 +|- 130 +|- 231 +|- 355 +|- 2,074 +|- 3,007 +|- 4,141 +|- 22,5

Mixed Plants 

Average Daily Flow 30 29 208 2,086 2,961 5,141 20,651 47,Confidence Interval 40 +|- 2 +|- 46 +|- 1,582 +|- 1,108 +|- 3,464 +|- 5,458 +|- 36,9

Peak Daily Flow 37 335 332 3,967 4,151 7,598 34,470 58,Confidence Interval 36 +|- 115 +|- 88 +|- 3,346 +|- 1,586 +|- 5,400 +|- 10,080 +|- 42,5

Design Capacity 106 364 455 8,405 5,748 12,054 46,633 81,Confidence Interval 104 +|- 121 +|- 207 +|- 7,788 +|- 2,191 +|- 4,002 +|- 13,460 +|- 58,

(Continu

Table 19 

Treatment Plant Flow Characteristics 

By Water Source 

(Thousands of Gallons/Day) 
(Table 13 in the 2000 Report, Table 16 from draft 1

pulation Category 

001 - 50,001 - 100,001- O

,000 100,000 500,000 500,

)

acteristics

s/Day) 

tem Service Po

3,301 - 10,

10,000 50

523 1,290 3,979 6,892 19,

+|- 129 +|- 295 +|- 1,143 +|- 1,226 +|- 11,0

966 2,425 6,519 11,948 30,

+|- 237 +|- 545 +|- 1,780 +|- 2,046 +|- 16,6

1,647 3,265 8,997 15,805 40,

+|- 497 +|- 746 +|- 2,458 +|- 2,795 +|- 21,6

ed purchased water. 

ants in the sample. It includes only plants that report

duction, peak daily production, and design capacity. 

Treatment Plant Flow Char

By Water Source

(Thousands of Gallon

Sys

100 101 - 501 -

Water Source or Less 500 3,300 

All Plants 

Average Daily Flow 19 24 104 Confidence Interval +|- 14 +|- 5 +|- 20 Peak Daily Flow 35 56 223 Confidence Interval +|- 20 +|- 16 +|- 48 Design Capacity 119 191 559 

Confidence Interval +|- 53 +|- 52 +|- 138 

Data: Q.6, Q.7 Notes: Excludes plants that treat only treat

Table presents average flows for plcomplete data for average daily pro

Table 19 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 Ground Water Plants 

Ratio: Design Capacity to Average Daily Production 16.77 10.57 7.91 5.55 3.60 2.85 3.83 

Confidence interval +|- 9.49 +|- 3.05 +|- 1.90 +|- 2.08 +|- 0.69 +|- 0.38 +|- 0.80 

Ratio: Design Capacity to Peak Daily Production 7.49 5.05 3.79 1.81 1.48 2.09 1.28 

Confidence interval +|- 3.41 +|- 1.35 +|- 1.05 +|- 0.31 +|- 0.20 +|- 0.90 +|- 0.09 

Observations 43 72 137 84 175 169 430 

Surface Water Plants 

Ratio: Design Capacity to Average Daily Production 8.42 7.18 4.26 2.96 3.50 2.62 2.90 

Confidence interval +|- 3.56 +|- 4.01 +|- 0.54 +|- 0.47 +|- 1.69 +|- 0.53 +|- 0.56 

Ratio: Design Capacity to Peak Daily Production 3.60 2.58 2.19 1.75 1.93 1.47 1.40 

Confidence interval +|- 1.57 +|- 1.00 +|- 0.53 +|- 0.19 +|- 0.99 +|- 0.11 +|- 0.05 

Observations 34 46 65 70 88 79 191 

Mixed Plants 

Ratio: Design Capacity to Average Daily Production 4.71 12.55 2.10 3.40 1.99 4.20 2.40 

Confidence interval +|- 2.87 +|- 4.17 +|- 0.64 +|- 0.91 +|- 0.43 +|- 3.04 +|- 0.36 

Ratio: Design Capacity to Peak Daily Production 2.57 1.11 1.40 1.92 1.38 3.68 1.51 

Confidence interval +|- 1.00 +|- 0.07 +|- 0.54 +|- 0.31 +|- 0.22 +|- 3.30 +|- 0.26 

Observations +|- 3.00 5 10 6 9 4 15 

All Plants 

Ratio: Design Capacity to Average Daily Production 16.46 10.47 7.46 4.97 3.54 3.04 3.51 

Confidence interval +|- 9.16 +|- 2.87 +|- 1.70 +|- 1.62 +|- 0.63 +|- 0.46 +|- 0.56 

Ratio: Design Capacity to Peak Daily Production 7.34 4.88 3.60 1.82 1.56 1.95 1.32 

Confidence interval +|- 3.28 +|- 1.28 +|- 0.93 +|- 0.25 +|- 0.25 +|- 0.65 +|- 0.06 

Observations 80 123 212 160 272 252 636 

Data: Q.6, Q.7 Notes: Table presents average ratios for plants in the sample. It includes only plants that 

complete data for average daily production, peak daily production, and design capaExcludes plants that treat only purchased treated water. 

Table 20 

Ratio of Design Capacity to Average and Peak Daily Production 

By Water Source 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,0

Water Source or Less 500 3,300 10,000 50,000 100,000 500,0Ground Water Plants 

Algae control 0.0 0.0 2.4 0.0 0.3 1.4 Corrosion control 11.5 14.0 14.5 20.2 32.7 18.1 3Primary disinfection 86.6 90.6 90.8 91.1 91.4 97.2 8Secondary disinfection 12.9 13.6 14.3 5.1 5.6 7.1 Disinfectant byproduct control 0.0 0.0 1.0 12.2 7.1 7.1 Dechlorination 0.0 0.0 0.0 1.0 0.6 0.6 Oxidation 1.5 13.9 6.3 10.5 6.7 4.6 Iron removal 23.3 20.8 28.5 19.0 18.2 51.5 Manganese removal 6.5 13.9 10.3 14.9 14.0 51.7 Taste/odor control 3.0 3.4 7.7 12.3 14.7 8.1 TOC removal 0.0 0.0 0.6 2.0 1.0 1.4 Particulate/turbidity removal 10.2 3.6 4.8 8.9 3.7 7.7 Softening (hardness removal) 10.2 4.5 3.6 8.5 1.4 5.7 Recarbonation 0.0 0.0 0.6 2.0 0.0 1.0 Organic chemical contaminant removal (e.g., VOCs, pesticides) 0.0 0.0 0.4 2.0 5.8 4.9 Inorganic chemical contaminant removal (e.g., arsenic) 6.7 11.5 0.6 2.0 0.1 1.4 Radionuclides contaminant removal 1.7 0.0 0.6 0.0 4.1 1.4 Security 0.0 0.0 0.0 1.0 2.3 0.0 Mussel control 0.0 0.0 0.0 0.0 0.0 0.0 Fluoridation 1.7 8.0 14.5 30.7 11.3 29.3 2Other 1.7 1.1 0.0 6.1 1.0 0.3 Observations 62 89 161 108 230 197 6

Table 21 

Treatment Objectives 

Percentage of Plants Having Each Treatment Objective 

By Water Source 
Treatment Objectiv

Percentage of Plants Having Each T

By Water Source

100 101 -

Water Source or Less 500 Surface Water Plants 

Algae control 0.0 2.4 Corrosion control 11.2 14.3 

Primary disinfection 100.0 97.2 Secondary disinfection 15.5 37.4 Disinfectant byproduct control 0.0 1.2 Dechlorination 0.0 0.0 Oxidation 3.1 7.3 Iron removal 3.1 5.9 Manganese removal 0.0 3.9 Taste/odor control 3.1 7.6 TOC removal 8.7 11.0 Particulate/turbidity removal 77.5 65.4 Softening (hardness removal) 1.6 3.6 Recarbonation 0.0 0.0 Organic chemical contaminant removal (e.g., VOCs, pesticides) 0.0 1.7 Inorganic chemical contaminant removal (e.g., arsenic) 1.5 0.0 Radionuclides contaminant removal 0.0 0.0 Security 0.0 0.0 Mussel control 0.0 1.2 Fluoridation 0.0 2.4 Other 1.5 1.2 Observations 43 62 

e

r

501 - 3,30

3,300 10,0 

5.2 19.5 16.6 17.4 1

27.5 43.0 59.3 46.5 7

98.9 93.0 90.8 91.0 9

48.1 39.0 45.2 51.1 6

4.8 29.3 30.0 41.6 30.0 0.0 0.0 3.9 

7.5 23.7 21.8 33.9 3

11.1 22.3 25.6 42.4 2

2.6 25.1 38.1 42.4 3

8.5 26.5 45.2 45.5 48.6 36.2 35.2 43.8 4

97.1 91.8 88.4 86.2 9

3.7 9.8 8.1 3.9 0.0 2.8 2.3 2.6 0.0 9.8 10.7 7.9 10.0 8.4 6.1 3.9 0.0 0.0 1.3 0.0 0.0 0.0 1.2 0.0 1.1 4.2 3.6 6.6 

15.5 40.3 54.6 63.0 6

0.0 2.8 6.2 5.2 

70 68 89 80 1

egory 

1 - 10,001 - 50,001 - 100,0

00 50,000 100,000 500,0

ve

ervice Population Cat

s

eatment Objecti

System S

Table 21 (Cont.)
Treatment Objectiv

Percentage of Plants Having Each T

By Water Source

100 101 -

Water Source or Less 500 

Mixed Plants 

Algae control 0.0 0.0 

Corrosion control 0.0 8.4 25.7 51.6 42.7 48.4 4

Primary disinfection 100.0 100.0 100.0 100.0 85.8 100.0 7Secondary disinfection 0.0 0.0 35.8 36.6 71.5 24.2 8Disinfectant byproduct control 0.0 0.0 0.0 22.5 24.1 24.2 4Dechlorination 0.0 0.0 0.0 0.0 0.0 0.0 Oxidation 0.0 8.4 13.6 15.0 28.5 72.6 1Iron removal 0.0 12.6 5.5 7.5 17.0 48.4 2Manganese removal 0.0 8.4 5.5 7.5 17.0 48.4 2Taste/odor control 0.0 0.0 0.0 26.7 24.1 72.6 3TOC removal 23.5 0.0 5.5 36.6 21.4 72.6 3Particulate/turbidity removal 75.3 12.6 21.8 51.6 66.8 72.6 6Softening (hardness removal) 0.0 0.0 21.6 7.5 33.2 0.0 2Recarbonation 0.0 0.0 0.0 7.5 14.2 24.2 2Organic chemical contaminant removal (e.g., VOCs, pesticides) 0.0 0.0 0.0 0.0 7.1 100.0 Inorganic chemical contaminant removal (e.g., arsenic) 0.0 0.0 0.0 0.0 7.1 24.2 Radionuclides contaminant removal 0.0 0.0 0.0 0.0 0.0 0.0 Security 0.0 0 0.0 0.0 7.1 0.0 Mussel control 0.0 0.0 0.0 36.6 7.1 0.0 Fluoridation 0.0 0.0 13.6 51.6 28.5 48.4 6Other 0.0 0.0 0.0 0.0 0.0 24.2 1Observations 3 7 10 6 13 4 

0

jective

m Service Population Category 

3,301 - 10,001 - 50,001 - 100,0

10,000 50,000 100,000 500,

7.5 0.0 0.0 

es

reatment Ob

Syste

501 -

3,300 

4.1 

Table 21 (Cont.)
Treatment Objectiv

Percentage of Plants Having Each T

By Water Source

gory 

100 101 - - 100,0

Water Source or Less 500 00 500,0

All Plants 

Algae control 0.0 0.1 2.6 3.2 2.8 4.4 Corrosion control 11.5 13.9 15.7 24.6 37.1 23.7 4Primary disinfection 87.0 91.1 91.6 91.7 91.2 96.1 9Secondary disinfection 13.0 14.7 17.2 11.3 13.4 15.5 2Disinfectant byproduct control 0.0 0.1 1.2 15.2 11.1 13.7 1Dechlorination 0.0 0.0 0.0 0.8 0.5 1.2 Oxidation 1.6 13.4 6.5 12.7 9.6 10.8 1Iron removal 22.6 19.9 26.7 19.2 19.3 49.8 1Manganese removal 6.3 13.2 9.6 16.3 17.8 49.9 1Taste/odor control 3.0 3.6 7.6 14.9 19.7 15.7 1TOC removal 0.3 0.6 1.3 8.3 6.9 10.0 1Particulate/turbidity removal 12.2 7.1 12.0 22.9 18.6 23.0 2

Softening (hardness removal) 9.9 4.4 4.0 8.6 3.2 5.3 Recarbonation 0.0 0.0 0.5 2.3 0.7 1.5 Organic chemical contaminant removal (e.g., VOCs, pesticides) 0.0 0.1 0.3 3.2 6.6 6.4 1Inorganic chemical contaminant removal (e.g., arsenic) 6.5 10.7 0.5 3.0 1.2 2.1 Radionuclides contaminant removal 1.7 0.0 0.5 0.0 3.6 1.1 Security 0.0 0 0.0 0.8 2.3 0.0 Mussel control 0.0 0.1 0.1 1.7 0.7 1.2 Fluoridation 1.7 7.6 14.6 32.8 18.5 39.4 3Other 1.7 1.1 0.0 5.5 1.8 1.5 Observations 108 158 241 182 332 281 8

Data: Q.8 Notes: Excludes plants that treat purchased water. 

es

reatment Objective

System Service Population Cate

501 - 3,301 - 10,001 - 50,001

3,300 10,000 50,000 100,0

Table 21 (Cont.)
Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - 

Water Source 0.01 0.1 1.0 10.0 100.0 

Ground Water Plants 

Algae control 0.0 1.4 1.0 1.5 4.7 Corrosion control 12.4 11.9 26.2 31.4 26.6 Primary disinfection 89.1 90.8 91.1 93.1 94.5 Secondary disinfection 13.0 12.9 8.4 6.9 19.2 Disinfectant byproduct control 0.3 1.6 5.0 11.0 8.6 Dechlorination 0.0 0.0 0.7 0.3 0.0 Oxidation 7.1 8.9 7.4 8.9 16.7 Iron removal 26.7 21.4 26.3 15.9 62.1 Manganese removal 13.7 9.7 17.2 12.3 58.2 Taste/odor control 2.4 5.1 11.2 18.6 24.1 TOC removal 0.0 0.0 1.6 2.3 5.7 Particulate/turbidity removal 7.5 3.7 5.8 9.2 42.6 Softening (hardness removal) 7.4 3.0 5.2 3.7 24.0 Recarbonation 0.0 0.0 1.5 0.3 8.5 Organic chemical contaminant removal (e.g., VOCs, pesticides) 0.0 0.4 3.4 7.5 12.5 

Inorganic chemical contaminant removal (e.g., arsenic) 8.3 4.4 1.5 1.7 4.7 Radionuclides contaminant removal 1.3 0.0 1.7 3.6 3.9 Security 0.0 0.3 1.1 0.0 0.0 Mussel control 0.0 0.0 0.0 0.0 0.0 Fluoridation 0.4 13.8 19.4 21.3 47.6 Other 1.3 0.7 2.5 3.1 6.4 Observations 121 339 796 631 60 

(Con

Table 22 

Treatment Objectives 

Percentage of Plants Having Each Treatment Objective 

By Water Source and Plant Average Daily Production 
Percen

By W

D) 

0 - - 

Water Source 0.01 0 

Surface Water Plants 

Algae control 0.0 3.6 12.1 17.8 16.8 Corrosion control 22.1 26.7 32.4 56.6 67.6 Primary disinfection 100.0 98.0 96.7 89.9 97.5 Secondary disinfection 28.4 48.1 41.7 45.6 57.6 Disinfectant byproduct control 1.4 2.8 17.1 32.3 40.8 Dechlorination 0.0 0.0 0.0 1.0 0.0 Oxidation 1.3 5.9 15.6 28.2 35.5 Iron removal 5.8 16.4 10.3 31.4 20.5 Manganese removal 16.1 3.7 14.4 36.8 28.1 Taste/odor control 5.2 9.9 16.7 44.5 45.1 TOC removal 11.0 9.3 21.4 38.3 54.7 Particulate/turbidity removal 77.3 81.5 89.6 92.2 95.1 Softening (hardness removal) 1.3 4.5 4.1 9.7 9.0 Recarbonation 0.0 0.0 0.0 3.7 5.0 Organic chemical contaminant removal (e.g., VOCs, pesticides) 1.2 0.9 4.1 11.3 13.0 Inorganic chemical contaminant removal (e.g., arsenic) 1.2 0.0 3.3 6.7 4.7 

Radionuclides contaminant removal 0.0 0.0 0.0 1.7 1.9 Security 0.0 0.0 0.8 0.3 0.8 Mussel control 0.0 0.9 3.3 4.5 6.9 Fluoridation 1.4 1.1 30.8 58.7 64.4 Other 1.2 0.9 2.4 4.3 5.9 Observations 50 77 113 230 231 

(Con

e 

Plant Average Daily Production (MG

0.01 - 0.1 - 1.0 - 10.0 

0.1 1.0 10.0 100.

reatment Objectiv

e Daily Production

es

tage of Plants Having Each T

ater Source and Plant Averag

Treatment Objectiv

Table 22 (Cont.)
Treatment Objectiv

Percentage of Plants Having Each T

By Water Source and Plant Averag

Water Source Mixed Plants 

Algae control Corrosion control Primary disinfection Secondary disinfection Disinfectant byproduct control Dechlorination Oxidation Iron removal Manganese removal Taste/odor control TOC removal Particulate/turbidity removal Softening (hardness removal) Recarbonation Organic chemical contaminant removal (e.g., VOCs, pesticides) Inorganic chemical contaminant removal (e.g., arsenic) Radionuclides contaminant removal Security Mussel control Fluoridation Other Observations 

0 - 

0.01 

0.0 0.0 

100.0 100.0 97.2 93.3 79.1 

0.0 6.1 32.5 69.5 73.3 0.0 0.0 5.8 30.3 41.3 0.0 0.0 0.0 0.0 0.0 

0.0 7.4 15.4 27.3 36.7 0.0 11.1 6.7 18.0 27.3 

0.0 7.4 6.7 18.0 21.5 

0.0 0.0 7.5 30.6 44.8 0.0 0.0 7.5 47.3 43.6 0.0 20.9 19.0 89.7 78.5 0.0 0.0 25.5 11.4 21.5 0.0 0.0 2.9 13.6 21.5 0.0 0.0 0.0 12.6 22.1 0.0 0.0 0.0 5.7 22.1 0.0 0.0 0.0 0.0 5.8 0.0 0.0 0.0 5.7 0.0 0.0 0.0 0.0 34.7 7.0 

0.0 0.0 15.4 57.8 66.3 0.0 0.0 0.0 3.2 7.0 

2 9 15 21 13 

(Con

es

reatment Objective 

e Daily Production 

Plant Average Daily Production (MGD) 

0.01 - 0.1 - 1.0 - 10.0 - 

0.1 1.0 10.0 100.0 

0.0 5.8 0.0 7.6 7.4 23.8 67.2 58.1 

Table 22 (Cont.)
Treatment Objective

Percentage of Plants Having Each Tr

By Water Source and Plant Average

0 -

Water Source 0.01 

All Plants 

Algae control 0.0 1.5 2.3 6.6 12.6 

Corrosion control 12.6 12.5 26.8 40.8 54.2 Primary disinfection 89.4 91.3 91.9 92.1 95.9 Secondary disinfection 13.4 14.5 12.7 21.7 46.0 Disinfectant byproduct control 0.3 1.7 6.3 18.5 30.6 Dechlorination 0.0 0.0 0.6 0.5 0.0 Oxidation 6.9 8.7 8.5 15.8 29.6 Iron removal 26.1 21.1 23.9 20.9 33.9 Manganese removal 13.7 9.4 16.5 20.2 37.4 Taste/odor control 2.5 5.3 11.6 27.3 38.4 TOC removal 0.3 0.4 3.9 15.5 38.7 Particulate/turbidity removal 9.3 7.6 15.3 38.7 77.8 Softening (hardness removal) 7.2 3.1 5.7 5.9 14.2 Recarbonation 0.0 0.0 1.4 2.0 6.7 Organic chemical contaminant removal (e.g., VOCs, pesticides) 0.0 0.4 3.4 8.9 13.2 Inorganic chemical contaminant removal (e.g., arsenic) 8.1 4.1 1.7 3.4 5.4 

Radionuclides contaminant removal 1.2 0.0 1.5 2.9 2.7 Security 0.0 0.3 1.0 0.3 0.5 Mussel control 0.0 0.0 0.4 2.9 4.7 Fluoridation 0.5 13.0 20.5 34.7 60.8 Other 1.3 0.7 2.4 3.5 6.1 Observations 173 425 924 882 304 

Data: Q.8 Notes: Excludes plants that treat purchased water. 

s

eatment Objective 

 Daily Production 

Plant Average Daily Production (MGD) 

0.01 - 0.1 - 1.0 - 10.0 - 

0.1 1.0 10.0 100.0 

Table 22 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 Ground Water Plants 

Disinfection with no additional treatment 53.9 49.6 51.8 47.8 40.7 18.5 42.2 26.8 Other chemical addition 11.1 15.6 25.4 26.9 24.6 61.8 37.4 52.5 Ion exchange, activated alumina, aeration 16.6 9.5 7.6 7.3 16.6 4.8 4.3 8.5 Other filtration (not direct or conventional) 16.5 16.7 10.7 12.8 12.7 11.6 7.3 8.3 Direct filtration 0.0 0.0 0.6 1.0 2.5 0.8 0.8 0.0 Conventional filtration (with and without softening) 0.0 1.2 1.3 4.2 0.1 1.3 1.8 1.4 Membranes 0.0 1.2 0.6 0.0 0.1 0.3 0.6 0.2 Other 1.9 6.3 1.9 0.0 2.7 0.7 5.6 2.3 Observations 62 89 161 108 230 197 658 444 

Surface Water Plants 

Disinfection with no additional treatment 17.6 32.0 2.3 0.0 0.0 8.4 2.4 0.9 Other chemical addition 0.0 1.3 4.7 8.3 8.1 1.3 6.7 11.7 Ion exchange, activated alumina, aeration 0.0 0.0 0.0 1.4 1.2 0.0 0.4 0.0 

Other filtration (not direct or conventional) 61.6 26.0 33.8 9.9 5.8 1.3 3.8 0.0 Direct filtration 7.4 11.5 15.9 19.7 16.6 20.4 12.4 9.9 Conventional filtration (with and without softening) 11.7 22.4 33.6 56.4 68.4 62.6 73.9 74.8 Membranes 1.7 6.9 9.7 4.2 0.0 4.5 0.5 2.7 Other 0.0 0.0 0.0 0.0 0.0 1.5 0.0 0.0 Observations 43 62 70 68 89 80 197 111 

Mixed Plants 

Disinfection with no additional treatment 24.7 83.1 56.6 29.1 14.2 0.0 6.5 0.0 Ion exchange, activated alumina, aeration 0.0 0.0 5.5 0.0 26.1 0.0 34.3 0.0 Ion exchange, Activated Alumina, Aeration 0.0 0.0 16.1 19.2 0.0 27.4 0.0 0.0 Other filtration (not direct or conventional) 51.8 4.2 4.1 0.0 0.0 0.0 20.1 0.0 Direct filtration 0.0 4.2 0.0 0.0 21.4 24.2 0.0 0.0 Conventional filtration (with and without softening) 0.0 4.2 17.7 51.6 31.2 48.4 39.1 51.3 Membranes 23.5 0.0 0.0 0.0 7.1 0.0 0.0 48.7 Other 0.0 4.2 0.0 0.0 0.0 0.0 0.0 0.0 Observations 3 7 10 6 13 4 15 2 

All Plants 

Disinfection with no additional treatment 52.8 49.2 48.1 39.9 33.5 16.4 32.6 21.4 Other chemical addition 10.8 14.6 23.4 23.3 22.0 49.9 30.4 43.9 Ion exchange, activated alumina, aeration 16.1 8.8 7.2 6.7 13.7 4.2 3.4 6.7 Other filtration (not direct or conventional) 17.9 17.0 12.3 11.9 11.3 9.6 6.7 6.5 Direct filtration 0.2 0.7 1.8 3.9 5.2 4.7 3.4 2.0 Conventional filtration (with and without softening) 0.3 2.3 4.1 13.6 11.9 13.3 18.7 16.7 Membranes 0.1 1.5 1.3 0.7 0.3 1.1 0.5 0.9 Other 1.9 5.9 1.7 0.0 2.2 0.8 4.3 1.8 Observations 108 158 241 182 332 281 870 557 

Data: Q.8A Notes: Excludes plants that treat purchased water. See treatment scheme description in Volume I. 

Table 23 

Treatment Schemes 

Percentage of Plants Using Each Treatment Scheme 

By Water Source 
Water Source 

Ground Water Plants 

Disinfection with no additional treatment Other chemical addition Ion exchange, activated alumina, aeration Other filtration (not direct or conventional) Direct filtration Conventional filtration (with and without softening) Membranes Other Observations 

Surface Water Plants 

Disinfection with no additional treatment Other chemical addition Ion exchange, activated alumina, aeration Other filtration (not direct or conventional) Direct filtration Conventional filtration (with and without softening) Membranes Other Observations 

Mixed Plants 

Disinfection with no additional treatment Ion exchange, activated alumina, aeration Ion exchange, Activated Alumina, Aeration Other filtration (not direct or conventional) Direct filtration Conventional filtration (with and without softening) Membranes Other Observations 

All Plants 

Disinfection with no additional treatment Other chemical addition Ion exchange, activated alumina, aeration Other filtration (not direct or conventional) Direct filtration Conventional filtration (with and without softening) Membranes Other Observations 

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 Al

48.2 57.3 36.9 41.2 4.3 0.0 

14.0 19.9 35.4 23.2 6.5 0.0 

15.9 5.6 10.5 17.8 7.2 0.0 

18.1 12.1 10.9 10.7 62.0 0.0 

0.0 0.0 1.5 3.2 3.0 0.0 

0.0 1.2 2.3 0.9 11.4 100.0 

1.2 0.0 0.7 0.5 0.0 0.0 

2.6 3.9 1.9 2.5 5.5 0.0 

121 339 796 631 60 2 

22.7 18.5 2.0 1.9 0.9 5.3 

0.0 0.9 11.4 3.3 6.6 21.1 

0.0 0.0 0.8 0.9 0.0 0.0 

45.0 33.3 20.0 5.3 2.0 0.0 

19.0 10.6 17.5 17.8 10.1 15.8 

12.0 26.6 43.2 68.4 79.3 57.9 

1.3 10.0 4.9 2.4 1.1 0.0 

0.0 0.0 0.3 0.0 0.0 0.0 

50 77 113 230 231 19 

100.0 75.4 50.9 5.7 7.0 * 

0.0 0.0 11.3 7.8 21.5 * 

0.0 0.0 18.8 2.5 0.0 * 0.0 13.5 0.0 0.9 14.6 * 

0.0 3.7 0.0 19.4 0.0 * 

0.0 3.7 18.2 57.2 56.9 * 

0.0 0.0 0.8 6.5 0.0 * 

0.0 3.7 0.0 0.0 0.0 * 

2 9 15 21 13 * 

47.6 55.7 33.5 27.3 2.2 4.8 

13.6 18.8 32.0 16.3 7.1 19.1 

15.5 5.3 9.7 11.8 2.3 0.0 

18.8 13.2 11.6 8.6 21.5 0.0 

0.5 0.5 3.1 8.5 7.5 14.4 

0.3 2.4 7.2 24.5 56.9 61.7 

1.2 0.5 1.1 1.4 0.7 0.0 

2.5 3.7 1.7 1.6 1.7 0.0 

173 425 924 882 304 21 

Data: Q.8 Notes: Excludes plants that treat purchased water. See treatment scheme description in Volume I. 

Table 24 

Treatment Schemes 

Percentage of Plants Using Each Treatment Scheme 

By Water Source 
Table 25

Treatment Practices for Surface Water Plants

Percentage of Plants Performing Each Treatment

System Service Population Category

Surface Water Treatment Practice

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 A

Disinfection 

Chlorine 98.4 79.0 97.4 80.8 80.5 75.1 78.9 78.0 Chlorine dioxide 0.0 0.0 0.0 11.0 8.7 18.5 14.0 2.5 Chloramines only 0.0 1.2 2.2 13.7 14.8 17.1 32.4 35.6 Chloramines with a free chlorine

period (based on need in thedistribution system and notroutinely done) 0.0 0.0 1.1 1.4 5.8 3.9 9.3 1.7 

Chloramines with seasonal 

(routine) free chlorine use 0.0 0.0 0.0 8.2 1.2 9.2 0.9 4.2 

Ozone 0.0 1.4 1.5 1.4 1.2 11.8 15.8 14.4 Ultraviolet light 3.1 1.7 2.2 1.4 1.3 2.6 4.7 1.7 Mixed oxidant 0.0 19.4 1.5 4.1 2.3 0.6 0.0 0.0 

Filtration Processes

Coagulant addition/rapid mix 17.6 33.3 44.2 71.3 78.1 81.5 88.4 83.9 Polymer addition 16.8 22.4 31.1 54.9 46.4 35.8 56.7 56.8 Flocculation 7.3 20.8 36.4 60.3 68.7 70.4 75.8 74.6 Settling/sedimentation 20.8 24.5 33.3 61.7 70.7 64.5 77.2 73.8 Lime/soda ash softening 0.0 2.5 3.4 19.2 16.9 5.2 11.8 21.2 Recarbonation 0.0 0.0 0.0 2.7 3.5 2.6 4.2 6.8 

Filtration

Micro strainer 12.5 2.8 1.1 2.7 1.2 0.0 2.8 0.8 Slow sand filter 6.2 5.0 17.6 9.6 6.9 1.9 2.8 0.0 Bag or cartridge 33.8 6.0 0.0 0.0 0.0 0.0 0.0 0.8 Diatomaceous earth 1.6 0.6 6.7 0.0 2.3 1.3 0.5 0.0 Pressure filtration 19.5 18.2 12.5 2.7 1.2 1.3 0.0 0.0 Green sand 0.0 0.0 1.1 0.0 0.0 0.0 0.9 0.8 Rapid sand filter 3.1 7.3 12.3 24.6 30.7 22.1 15.5 6.8 

Deep bed mono-media 0.0 1.2 0.0 2.7 1.6 0.0 5.6 7.6 Dual/multi media 15.3 19.8 31.8 57.6 51.5 61.6 67.3 65.3 

(Continued)
Table 25 (Cont.)

Treatment Practices for Surface Water Plants

Percentage of Plants Performing Each Treatment

System Service Populatio

ctice

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

n Category

Surface Water Treatment Pra

50,001 - 

100,000

100,001-

500,000

Over 

500,000 A

Membranes

Reverse osmosis 1.5 1.7 0.0 1.4 1.2 0.0 0.9 0.0 Microfiltration 8.7 7.9 11.6 5.5 0.0 4.5 0.9 0.8 Ultrafiltration 5.3 1.2 0.0 0.0 1.2 0.0 2.8 1.7 Nanofiltration 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Other

Aeration 0.0 0.0 1.1 6.9 9.7 6.6 4.6 3.4 Potassium permanganate 1.6 9.2 7.8 24.7 32.9 26.8 26.3 21.2 

Corrosion control 8.1 11.8 26.0 34.2 46.6 42.0 63.6 62.7 Ion exchange 1.6 2.4 0.0 0.0 0.0 0.0 0.5 0.0 Activated alumina 0.0 0.0 0.0 0.0 0.0 0.0 0.9 0.8 Iron-based adsorptive media 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Sequestration 0.0 1.3 0.0 4.1 5.8 9.7 3.8 5.9 Fluoride addition 0.0 2.4 15.5 39.8 58.1 63.5 66.0 73.7 Dissolved air flotation 0.0 0.0 1.5 0.0 0.0 0.0 1.4 0.8 Granular activated carbon 7.2 3.1 3.0 11.0 14.2 14.4 15.2 17.8 Centrally managed POU/POE 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0 Clearwell and/or contact vessel 45.3 41.6 40.6 52.2 53.0 49.5 59.9 42.3  (e.g., basin, pipeline)Other 10.8 7.3 14.5 9.6 18.3 22.3 36.3 25.2 

Observations 43 62 70 68 89 80 197 111 Data: Q.8Notes: Represents treatment practices for plants treating water that comes entirely or partly from surf

sources. Percentages may not add to 100 percent because systems may perform more than one treatm
Table 26

Treatment Practices for Surface Water Plants

Percentage of Plants Performing Each Treatment

By Plant Average Daily Production

Plant Average Daily Production (MGD)

Surface Water Treatment Practice

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 All Size

Disinfection 

Chlorine 87.2 83.4 90.3 81.2 79.6 57.9 84.Chlorine dioxide 0.0 0.0 4.4 11.2 12.4 0.0 6.Chloramines only 11.6 2.3 8.6 15.1 30.5 36.8 12.Chloramines with a free chlorine

period (based on need in thedistribution system and notroutinely done) 0.0 0.0 1.6 5.4 5.3 0.0 2.

Chloramines with seasonal 

(routine) free chlorine use 0.0 0.0 3.3 4.6 1.7 5.3 2.

Ozone 0.0 1.9 1.1 3.2 17.0 31.6 3.Ultraviolet light 6.5 1.4 0.8 2.9 2.7 0.0 2.Mixed oxidant 0.0 13.9 3.6 1.5 0.4 0.0 4.

Filtration Processes

Coagulant addition/rapid mix 31.0 35.9 56.8 80.6 93.2 78.9 63.Polymer addition 18.7 24.1 42.2 46.8 58.8 63.2 40.Flocculation 19.9 26.3 49.2 68.7 80.2 73.7 53.Settling/sedimentation 20.1 29.1 47.3 69.7 82.3 63.2 53.Lime/soda ash softening 11.6 3.4 8.2 15.2 14.8 15.8 10.Recarbonation 0.0 0.0 0.0 4.5 5.7 10.5 2.

Filtration

Micro strainer 13.3 1.0 1.6 1.8 1.9 0.0 2.Slow sand filter 7.7 4.4 15.4 7.6 1.6 0.0 8.Bag or cartridge 26.4 4.2 0.0 0.1 0.0 0.0 2.Diatomaceous earth 1.3 3.5 4.1 1.1 0.0 0.0 2.Pressure filtration 15.9 26.3 2.5 1.1 0.0 0.0 6.Green sand 0.0 0.0 0.0 0.0 1.1 0.0 0.Rapid sand filter 18.2 4.4 21.8 24.6 15.0 10.5 18.Deep bed mono-media 0.0 0.9 1.0 2.1 6.0 10.5 1.Dual/multi media 5.6 28.0 40.9 59.2 71.8 52.6 45.

(Continued)
Table 26 (Cont.)

Treatment Practices for Surface Water Plants

Percentage of Plants Performing Each Treatment

By Plant Average Daily Production

Plant Average Daily Production (MGD)

Surface Water Treatment Practice

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 All Size

Membranes

Reverse osmosis 2.4 0.9 0.8 0.9 0.4 0.0 0.Microfiltration 7.1 11.0 6.5 2.6 0.3 0.0 5.Ultrafiltration 4.3 0.9 0.0 1.0 2.3 0.0 1.Nanofiltration 0.0 0.0 0.0 0.0 0.0 0.0 0.

Other

Aeration 0.0 0.2 4.9 8.5 3.1 5.3 4.Potassium permanganate 1.3 11.6 18.2 30.1 22.7 5.3 20.Corrosion control 8.0 24.7 28.0 46.9 59.2 68.4 36.Ion exchange 1.3 1.7 0.0 0.0 0.4 0.0 0.Activated alumina 0.0 0.0 0.0 0.1 0.4 5.3 0.Iron-based adsorptive media 0.0 0.0 0.0 0.0 0.0 0.0 0.Sequestration 0.0 0.9 1.7 6.1 5.3 5.3 3.Fluoride addition 1.4 1.1 31.6 60.4 65.9 89.5 37.Dissolved air flotation 0.0 1.9 0.0 0.3 0.7 0.0 0.Granular activated carbon 7.1 2.1 6.3 15.8 16.9 15.8 9.Centrally managed POU/POE 0.0 0.0 0.0 0.1 0.0 0.0 0.Clearwell and/or contact vessel 55.8 31.4 49.9 56.0 53.2 26.3 49. (e.g., basin, pipeline)Other 7.5 11.5 12.8 19.0 32.4 26.3 16.

Observations 50 77 113 230 231 19 72Data: Q.8Notes: Represents treatment practices for plants treating water that comes entirely or partly

from surface sources. Percentages may not add to 100 percent because systems may perform more than onetreatment. 
Table 27

Treatment Practices for Ground Water Plants

Percentage of Plants Performing Each Treatment

System Service Population Category

Ground Water Treatment Practice

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 A

Disinfection 

Chlorine 84.7 94.3 92.2 91.8 92.9 96.3 91.3 100.0 Chlorine dioxide 0.0 1.1 0.0 1.0 0.0 0.3 0.0 0.0 Chloramines only 0.0 0.0 1.2 2.3 0.4 2.1 5.9 0.4 Chloramines with a free chlorine

period (based on need in thedistribution system and notroutinely done) 0.0 0.0 0.0 1.7 0.8 0.0 1.4 0.0 

Chloramines with seasonal 

(routine) free chlorine use 0.0 0.0 0.0 0.0 0.0 2.0 1.5 1.2 

Ozone 0.0 0.0 0.0 0.0 0.6 0.7 0.3 0.0 Ultraviolet light 1.7 0.0 0.0 1.0 0.7 0.0 0.4 0.0 Mixed oxidant 0.0 0.0 1.1 0.0 2.4 0.0 0.0 0.0 

Filtration Processes

Coagulant addition/rapid mix 0.0 2.4 2.4 3.1 5.5 2.9 1.6 1.2 Polymer addition 0.0 0.1 0.0 3.0 2.4 2.9 1.0 1.0 Flocculation 0.0 1.1 1.2 4.1 0.7 2.3 1.9 1.4 Settling/sedimentation 0.0 2.3 1.8 7.2 0.7 2.3 2.1 1.7 Lime/soda ash softening 0.0 0.0 1.0 1.0 8.7 7.4 2.7 1.7 Recarbonation 0.0 0.0 0.6 1.0 0.0 0.6 1.7 0.7 

Filtration

Micro strainer 0.0 1.1 0.6 0.0 0.0 0.3 0.3 0.0 Slow sand filter 0.0 0.0 0.0 1.0 0.0 0.3 0.9 0.0 Bag or cartridge 8.6 0.0 0.6 1.0 0.1 1.0 1.2 0.2 Diatomaceous earth 0.0 0.0 0.6 0.0 0.0 0.0 0.0 0.0 Pressure filtration 1.7 4.5 1.2 4.0 7.0 1.7 2.9 0.2 Green sand 6.2 9.2 5.9 5.8 2.9 7.2 0.9 5.4 Rapid sand filter 0.0 2.3 1.2 1.0 3.7 1.3 0.9 1.1 

Deep bed mono-media 0.0 0.0 0.6 0.0 0.0 0.0 0.4 0.0 Dual/multi media 0.0 2.5 1.8 5.8 4.2 2.4 3.4 3.5 

(Continued)
Table 27 (Cont.)

Treatment Practices for Ground Water Plants

Percentage of Plants Performing Each Treatment

System Service Population Category

Ground Water Treatment Practice

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 A

Membranes

Reverse osmosis 1.7 2.3 1.2 1.0 0.2 0.3 1.8 0.4 Microfiltration 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Ultrafiltration 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.0 Nanofiltration 0.0 0.0 0.0 0.0 0.0 0.7 0.8 0.0 

Other

Aeration 4.7 4.7 12.6 15.4 22.3 15.1 8.4 10.8 Potassium permanganate 3.1 2.5 6.6 5.4 4.9 7.6 1.8 0.0 

Corrosion control 11.5 11.5 13.0 13.0 22.8 58.5 27.9 53.4 Ion exchange 18.6 7.9 3.6 3.1 1.8 0.3 2.0 0.7 Activated alumina 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Iron-based adsorptive media 3.4 1.2 0.6 0.0 0.0 0.0 1.7 1.7 Sequestration 8.6 3.6 13.7 6.2 8.3 5.4 5.3 12.2 Fluoride addition 1.7 8.0 14.5 32.4 14.6 61.7 29.9 12.9 Dissolved air flotation 0.0 0.0 0.0 0.0 0.2 0.0 0.1 0.0 Granular activated carbon 0.0 1.1 0.0 1.0 0.9 1.5 4.7 11.4 Centrally managed POU/POE 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0 Clearwell and/or contact vessel 31.4 24.6 17.6 9.1 2.1 3.5 5.2 3.9  (e.g., basin, pipeline)Other 3.3 7.1 2.4 8.5 6.1 1.6 11.7 1.1 

Observations 62 89 161 108 230 197 658 444 Data: Q.8Notes: Represents treatment practices for plants treating water that comes entirely or partly from grou

sources.

Percentages may not add to 100 percent because systems may perform more than one treatm
Table 28

Treatment Practices for Ground Water Plants

Percentage of Plants Performing Each Treatment

By Plant Average Daily Production

Plant Average Daily Production (MGD)

Ground Water Treatment Practice

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 All Size

Disinfection 

Chlorine 90.4 93.6 93.4 90.9 91.7 100.0 92.Chlorine dioxide 0.0 0.7 0.4 0.2 0.0 0.0 0.Chloramines only 0.0 0.5 1.7 3.0 3.5 0.0 0.Chloramines with a free chlorine

period (based on need in thedistribution system and notroutinely done) 0.0 0.0 0.7 1.8 0.0 0.0 0.

Chloramines with seasonal 

(routine) free chlorine use 0.0 0.0 0.0 0.9 10.0 100.0 0.

Ozone 0.0 0.0 0.0 1.4 0.0 0.0 0.Ultraviolet light 0.0 0.1 0.6 0.1 0.0 0.0 0.Mixed oxidant 0.0 0.5 0.5 2.0 0.0 0.0 0.

Filtration Processes

Coagulant addition/rapid mix 1.3 1.6 4.3 3.6 16.3 100.0 2.Polymer addition 0.0 0.1 1.7 2.8 11.9 0.0 0.Flocculation 0.0 1.6 1.7 2.2 13.6 100.0 1.Settling/sedimentation 0.0 2.3 3.1 3.7 15.4 100.0 2.Lime/soda ash softening 0.1 0.4 5.0 2.5 18.8 100.0 1.Recarbonation 0.0 0.0 1.1 0.3 7.3 100.0 0.

Filtration

Micro strainer 0.0 0.7 0.7 0.3 0.0 0.0 0.Slow sand filter 0.0 0.0 0.4 0.5 0.9 0.0 0.Bag or cartridge 5.1 0.5 0.4 0.6 7.9 0.0 1.Diatomaceous earth 0.0 0.5 0.0 0.0 0.0 0.0 0.Pressure filtration 2.6 2.8 4.2 3.3 0.0 0.0 3.Green sand 10.5 4.8 4.9 2.5 39.5 0.0 6.Rapid sand filter 0.0 2.3 1.0 3.5 8.2 100.0 1.Deep bed mono-media 0.0 0.5 0.0 0.0 0.0 0.0 0.Dual/multi media 0.0 2.4 3.8 5.6 20.9 100.0 2.

(Continued)
Table 28 (Cont.)

Treatment Practices for Ground Water Plants

Percentage of Plants Performing Each Treatment

By Plant Average Daily Production

Plant Average Daily Product

tice

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

ion (MGD)

Ground Water Treatment Prac

10.0 - 

100.0

Over 

100

A

Size

Membranes

Reverse osmosis 1.2 0.7 1.8 0.9 4.4 0.0 1.Microfiltration 0.0 0.0 0.0 0.0 0.0 0.0 0.Ultrafiltration 0.0 0.0 0.0 0.1 0.0 0.0 0.Nanofiltration 0.0 0.0 0.0 0.3 3.9 0.0 0.

Other

Aeration 3.8 8.4 17.6 19.6 68.5 0.0 11.Potassium permanganate 3.5 3.7 5.3 5.1 43.2 0.0 4.Corrosion control 11.0 10.5 24.1 24.0 60.0 50.0 15.Ion exchange 15.8 3.8 2.9 3.7 4.8 0.0 6.Activated alumina 0.0 0.0 0.0 0.0 0.0 0.0 0.Iron-based adsorptive media 2.6 1.2 0.2 0.4 0.0 0.0 1.Sequestration 8.7 6.6 10.9 8.0 7.4 0.0 8.Fluoride addition 0.5 13.9 25.0 22.9 68.3 50.0 14.Dissolved air flotation 0.0 0.0 0.0 0.4 0.0 0.0 0.Granular activated carbon 1.2 0.1 1.0 3.9 5.2 0.0 0.Centrally managed POU/POE 0.0 0.0 0.1 0.1 0.0 0.0 0.Clearwell and/or contact vessel 28.7 17.2 9.8 6.6 25.0 0.0 17. (e.g., basin, pipeline)Other 4.9 3.8 6.9 7.1 7.2 100.0 5.

Observations 121 339 796 631 60 2 1,94

Data: Q.8Notes: Represents treatment practices for plants treating water that comes entirely or partly

from ground sources. Percentages may not add to 100 percent because systems may perform more thanone treatment. 
Primary Secondary System Service Population Category 

disinfection disinfection 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over method method or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Ground Water Plants 

Chlorine Chlorine 11.2 10.2 10.1 2.0 3.4 3.6 1.2 1.9 

Chloramines * * * 1.0 * * 0.6 1.0 Other * 3.4 3.6 1.0 * * 1.3 2.2 

None 71.9 77.0 74.9 82.0 82.8 89.8 79.0 87.7 

Chlorine dioxide Chlorine * * * * * * * * 

Chloramines * * * * * * * * 

Other * * * * * * * * 

None * * * 1.0 * * * * 

Chloramines Chlorine * * * * * 0.3 0.2 * 

Chloramines * * 0.6 * * 0.7 * * Other * * * * * * * * 

None * * 0.6 2.7 0.4 2.0 6.8 * 

Ozone Chlorine * * * * * * 0.1 * 

Chloramines * * * * * * * * 

Other * * * * * * * * 

None * * * * * * * * 

Ultraviolet light Chlorine * * * * * * * * 

Chloramines * * * * * * * * 

Other * * * * * * * * 

None * * * * * * * * 

Mixed oxidant Chlorine 1.7 * * * 0.7 * * * 

Chloramines * * * * * * * * 

Other * * * * * * * * 

None * * 1.1 * 1.8 * * * 

Other Chlorine * * * * * * * * 

Chloramines * * * * * 0.3 0.3 * 

Other 1.7 * * * * 0.3 * * 

None * * * 1.3 2.4 * 0.4 0.4 

None Chlorine * * * * 2.2 1.8 2.8 6.1 

Chloramines * * * * * * 0.1 * 

Other * * * 1.0 * * * * 

None 13.4 9.4 9.2 7.9 6.4 1.0 7.1 0.7 

(Continued

Table 29 

Disinfection Practices and Objectives 

Percentage of Plants Performing Each Treatment 
Disinfection Practices and Objectives

Percentage of Plants Performing Each Treatment 

Primary Secondary System Service Population Category 

disinfection disinfection 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over method method or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Surface Water Plants 

Chlorine Chlorine 14.0 14.4 43.3 5.5 24.0 9.2 13.0 26.9 

Chloramines * * * 4.1 1.2 9.2 14.3 12.6 Other * * 1.1 12.4 5.9 2.6 5.2 5.0 None 82.9 60.4 47.0 42.3 40.9 37.1 30.9 16.8 

Chlorine dioxide Chlorine * * * 1.4 1.6 2.8 0.5 * 

Chloramines * * * 1.4 0.2 1.3 2.3 * Other * * * * * * 2.8 * 

None * * * 1.4 * 1.3 0.9 * 

Chloramines Chlorine * * * 1.4 * * * * 

Chloramines * * * * 4.2 2.6 2.5 * 

Other * * * * 1.2 * 2.8 1.7 

None * * * 5.4 5.8 6.6 2.8 10.1 

Ozone Chlorine * * 1.5 * * * 2.8 2.5 

Chloramines * * * * 1.2 2.6 4.2 5.9 

Other * * * * * 7.9 1.4 1.7 

None * * * * * * 0.5 * 

Ultraviolet light Chlorine * 1.2 2.2 * * 1.3 * * 

Chloramines * * * * * * * * 

Other * * * * * * * * 

None * * * * * * * * 

Mixed oxidant Chlorine 1.6 * * * * * * * 

Chloramines * * * * * * * * 

Other * 19.4 * 1.4 * * * * 

None * * 1.5 1.4 * * * * 

Other Chlorine 1.6 * * 1.4 1.2 * 0.5 * 

Chloramines * * * 2.7 1.2 * 2.8 2.5 Other * 1.2 * 4.1 * 3.9 1.9 0.8 None * 0.5 2.2 6.9 2.3 2.6 2.8 2.5 

None Chlorine * 1.2 * 4.1 2.3 5.1 0.9 3.4 

Chloramines * * * * 1.2 * 2.8 0.8 

Other * * * * * 2.6 0.9 * 

None * 1.6 1.1 2.7 5.8 1.3 0.4 6.7 

(Continued

Table 29 (Cont.)
Disinfection Practices and Objectives

Primary disinfection method Mixed Plants 

Chlorine 

Secondary 

disinfection method 

Chlorine 

Chloramines Other None 

Percentage of Plants Performing Each Treatment 

System Service Population Category 

100 

or Less 

101 -

500 

501 -

3,300 

3,301 -

10,000 

10,001 -

50,000 

50,001 -

100,000 

100,001-

500,000 

Over 

500,000 

* * 35.8 7.0 33.2 24.2 * * 

* * * * * * 34.3 * * * * 27.1 14.2 * 6.5 * 

100.0 100.0 64.2 58.9 21.4 75.8 6.5 48.7 

Chlorine dioxide Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * * * 

* * * * * * * * * * * * * * * * 

Chloramines Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * 6.5 * 

* * * * 7.1 * * * * * * * * * 6.5 * 

Ozone Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * 6.5 * 

* * * * * * 6.5 * * * * * * * * * 

Ultraviolet light Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 

Mixed oxidant Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * * * 

* * * * * * * * * * * * * * * * 

Other Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * * * 

* * * 7.0 2.7 * * * * * * * 7.1 * * 51.3 

None Chlorine 

Chloramines Other None 

* * * * 14.2 * 13.0 * * * * * * * 7.1 * 

* * * * * * * * * * * * * * 6.5 * 

(Continued

Table 29 (Cont.)
Disinfection Practices and Objectives

Percentage of Plants Performing Each Treatment 

Primary Secondary System Service Population Category 

disinfection disinfection 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over method method or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

All Plants 

Chlorine Chlorine 11.3 10.3 13.1 2.7 7.3 4.8 3.9 7.3 

Chloramines * * * 1.5 0.2 1.7 4.3 3.5 

Other * 3.1 3.3 3.6 1.3 0.5 2.2 2.8 None 72.3 76.5 72.6 75.1 74.7 79.9 66.8 72.2 

Chlorine dioxide Chlorine * * * 0.2 0.2 0.5 0.1 * 

Chloramines * * * 0.2 0.0 0.2 0.5 * 

Other * * * * * * 0.6 * 

None * * * 1.0 * 0.2 0.2 * 

Chloramines Chlorine * * * 0.2 * 0.3 0.1 * 

Chloramines * * 0.5 * 0.7 1.0 0.7 * 

Other * * * * 0.4 * 0.6 0.4 

None * * 0.5 3.1 1.2 2.9 5.9 2.2 

Ozone Chlorine * * 0.1 * * * 0.7 0.5 

Chloramines * * * * 0.2 0.5 1.1 1.3 

Other * * * * * 1.5 0.4 0.4 

None * * * * * * 0.1 * 

Ultraviolet light Chlorine * 0.1 0.2 * * 0.2 * * 

Chloramines * * * * * * * * 

Other * * * * * * * * None * * * * * * * * 

Mixed oxidant Chlorine 1.7 * * * 0.5 * * * 

Chloramines * * * * * * * * 

Other * 1.0 * 0.2 * * * * 

None * * 1.1 0.2 1.4 * * * 

Other Chlorine 0.0 * * 0.2 0.2 * 0.1 * 

Chloramines * * * 0.4 0.2 0.3 0.9 0.5 

Other 1.7 0.1 * 0.9 0.1 1.0 0.4 0.2 None * 0.0 0.2 2.1 2.5 0.5 1.0 1.1 

None Chlorine * 0.1 * 0.6 2.5 2.4 2.6 5.5 

Chloramines * * * * 0.2 * 0.9 0.2 Other * * * 0.8 * 0.5 0.2 * 

None 13.0 8.8 8.4 6.8 6.1 1.0 5.6 2.0 

Data: Q.8 Notes: Percentages may not add to 100 percent because systems may perform more than one treatment. 

Table 29 (Cont.)
Primary Secondary Plant Average Daily Production (MGD) 

disinfection disinfection 0 - 0.01 - 0.1 - 1.0 - 10.0 - Over method method 0.01 0.1 1.0 10.0 100.0 100 All Sizes Ground Water Plants 

Chlorine Chlorine 10.6 8.7 5.8 4.1 1.8 * 8.0 

Chloramines * * 0.4 0.2 3.0 * 0.1 Other 1.2 3.7 0.4 0.3 8.4 * 1.9 None 76.1 77.4 80.5 81.3 71.7 * 78.2 

Chlorine dioxide Chlorine * * * * * * * 

Chloramines * * * * * * * 

Other * * * * * * * 

None * * 0.4 * * * 0.1 

Chloramines Chlorine * * * 0.2 * * 0.0 

Chloramines * 0.5 * 0.3 * * 0.2 Other * * * * * * * 

None * 0.1 2.0 2.9 6.6 * 0.8 

Ozone Chlorine * * 0.0 * * * 0.0 

Chloramines * * * * * * * 

Other * * * * * * * 

None * * * * * * * 

Ultraviolet light Chlorine * * * * * * * 

Chloramines * * * * * * * 

Other * * * * * * * 

None * 0.1 0.2 * * * 0.1 

Mixed oxidant Chlorine * * * * * * * 

Chloramines * * * * * * * 

Other * * * * * * * 

None * 0.5 0.5 1.0 * * 0.4 

Other Chlorine * * * * * * * 

Chloramines * * * 0.2 0.9 * 0.0 Other 1.3 * * * 2.2 * 0.3 None * * 0.9 2.6 * 100.0 0.4 

None Chlorine * 0.1 1.3 1.5 3.0 * 0.5 

Chloramines * * * 0.1 * * 0.0 

Other * * 0.4 * * * 0.1 None 10.9 9.1 7.2 5.3 2.5 * 8.7 

(Continued)

Table 30 

Disinfection Practice and Objectives 

Percentage of Plants Performing Each Treatment 

By Plant Average Daily Production 
Percentage of Plants Performing Each Treatment

By Plant Average Daily Production 

Primary Secondary Plant Average Daily Production (MGD) disinfection disinfection 0 - 0.01 - 0.1 - 1.0 - 10.0 - Over method method 0.01 0.1 1.0 10.0 100.0 100 All Sizes Surface Water Plants 

Chlorine Chlorine 12.9 27.7 22.1 18.3 21.3 26.3 21.3 

Chloramines * * 2.0 5.4 10.5 5.3 3.5 Other * 1.4 5.8 7.0 4.1 * 4.8 None 69.1 49.2 49.0 40.6 27.5 15.8 45.0 

Chlorine dioxide Chlorine * * 0.8 1.4 1.5 * 0.9 

Chloramines * * 0.8 0.7 * * 0.5 Other * * * 0.1 2.0 * 0.3 None * * 0.8 0.1 1.3 * 0.4 

Chloramines Chlorine * * 0.8 * * * 0.3 

Chloramines 11.6 * * 1.7 1.2 * 1.4 Other * * * 1.3 1.1 5.3 0.6 None * 1.4 1.7 5.6 7.9 5.3 3.5 

Ozone Chlorine * 1.9 * 0.1 2.3 10.5 0.7 

Chloramines * * 0.8 0.3 5.9 15.8 1.1 

Other * * 0.3 1.5 1.9 * 0.8 None * * * * 0.4 * 0.0 

Ultraviolet light Chlorine 2.7 1.4 0.8 0.3 * * 0.8 

Chloramines * * * * * * * 

Other * * * * * * * 

None 1.3 * * * * * 0.1 

Mixed oxidant Chlorine * * * * * * * 

Chloramines * * * * * * * 

Other * 13.9 0.8 * * * 2.8 None * * 1.9 * * * 0.6 

Other Chlorine 1.3 * 0.8 0.9 * * 0.6 

Chloramines * * 1.7 0.8 3.4 * 1.1 Other * 0.9 1.7 1.0 1.2 5.3 1.2 None 1.2 * 4.1 2.8 4.0 * 2.7 

None Chlorine * 0.9 2.5 2.7 0.4 * 1.9 

Chloramines * * * 1.4 0.4 5.3 0.5 

Other * * * 0.7 0.4 * 0.3 None * 1.2 0.8 5.3 1.3 5.3 2.4 

(Continued)

Table 30 (Cont.)

Disinfection Practice and Objectives
Disinfection Practice and Objectives

Percentage of Plants Performing Each Treatment

Primary disinfection method 

Secondary 

disinfection method 

By Plant Average Daily Production 

Plant Average Daily Production (MGD) 

0 -

0.01 

0.01 -

0.1 

0.1 -

1.0 

1.0 -

10.0 

10.0 -

100.0 

Over 

100 All Sizes 

Mixed Plants 

Chlorine Chlorine 

Chloramines Other None 

* 6.1 28.9 17.4 16.3 * 20.3 

* * * 1.0 29.1 * 1.2 

* * * 35.5 * * 8.4 

100.0 93.9 65.6 24.8 7.0 * 60.9 

Chlorine dioxide Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * * * * * * * * * * * * * * * 

Chloramines Chlorine 

Chloramines Other None 

* * * * * * * 

* * * 0.9 * * 0.2 

* * * 5.7 * * 1.3 * * * * 7.0 * 0.2 

Ozone Chlorine 

Chloramines Other None 

* * * * * * * * * * * 7.0 * 0.2 

* * * * 7.0 * 0.2 

* * * * * * * 

Ultraviolet light Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * 

* * * * * * * * * * * * * * 

Mixed oxidant Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * 

* * * * * * * * * * * * * * 

Other Chlorine 

Chloramines Other None 

* * * * * * * * * * * * * * 

* * 2.8 2.2 * * 1.9 

* * * 5.7 5.8 * 1.5 

None Chlorine 

Chloramines Other None 

* * 2.7 5.7 13.9 * 3.1 * * * 1.0 * * 0.2 

* * * * * * * * * * * 7.0 * 0.2 

(Continued) 

Table 30 (Cont.)
Percentage of Plants Performing Each Treatment

Primary disinfection method 

Secondary 

disinfection method 

By Plant Average Daily Production 

Plant Average Daily Production (MGD) 

0 -

0.01 

0.01 -

0.1 

0.1 -

1.0 

1.0 -

10.0 

10.0 -

100.0 

Over 

100 All Sizes 

All Plants 

Chlorine Chlorine 

Chloramines Other None 

10.6 9.6 8.3 9.1 15.0 23.9 9.5 

* * 0.6 1.9 8.8 4.8 0.5 

1.1 3.5 1.0 3.9 5.3 * 2.3 

75.9 76.3 76.6 66.1 40.8 14.4 74.7 

Chlorine dioxide Chlorine 

Chloramines Other None 

* * 0.1 0.4 0.9 * 0.1 

* * 0.1 0.2 * * 0.0 

* * * 0.0 1.3 * 0.0 

* * 0.4 0.0 0.9 * 0.1 

Chloramines Chlorine 

Chloramines Other None 

* * 0.1 0.1 * * 0.0 

0.3 0.4 * 0.8 0.8 * 0.3 

* * * 0.6 0.7 4.8 0.1 

* 0.1 1.9 3.6 7.5 4.8 1.1 

Ozone Chlorine 

Chloramines Other None 

* 0.1 0.0 0.0 1.5 9.6 0.1 * * 0.1 0.1 4.1 14.4 0.1 

* * 0.0 0.5 1.5 * 0.1 * * * * 0.3 * 0.0 

Ultraviolet light Chlorine 

Chloramines Other None 

0.1 0.1 0.1 0.1 * * 0.1 

* * * * * * * 

* * * * * * * * * * * * * * 

Mixed oxidant Chlorine 

Chloramines Other None 

0.0 0.1 0.1 * * * 0.1 

* * * * * * * 

* 0.7 0.1 * * * 0.3 

* 0.4 0.7 0.6 * * 0.4 

Other Chlorine 

Chloramines Other None 

0.0 * 0.1 0.3 * * 0.1 

* * 0.2 0.4 2.5 * 0.1 

1.2 0.0 0.3 0.4 1.5 4.8 0.4 

0.0 * 1.2 2.8 2.8 9.1 0.7 

None Chlorine 

Chloramines Other None 

* 0.1 1.5 2.1 1.7 * 0.7 * * * 0.5 0.3 4.8 0.1 

* * 0.3 0.2 0.3 * 0.1 

10.6 8.6 6.3 5.0 1.9 4.8 7.9 

Data: Q.8 Notes: Percentages may not add to 100 percent because systems may perform more than one treatment. 

Table 30 (Cont.)

Disinfection Practice and Objectives
Surface Water Plant Treatment Schemes and Residual Management 

Practice 

Treatment Scheme: Disinfection with no additional treatment 

Dewatering

Mechanical dewatering

Non-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

0.0 0.0 0.0 * * 0.0 0.0 0.0 0.0 0.0 * * 0.0 0.0 0.0 0.0 0.0 * * 0.0 0.0 

0.0 0.0 0.0 * * 0.0 0.0 

0.0 0.0 0.0 * * 0.0 0.0 0.0 0.0 0.0 * * 0.0 0.0 0.0 0.0 0.0 * * 0.0 0.0 

0.0 7.7 0.0 * * 33.3 0.0 

0.0 0.0 0.0 * * 0.0 0.0 

0.0 0.0 0.0 * * 0.0 0.0 0.0 7.7 0.0 * * 0.0 0.0 

12 13 3 * * 6 5 

* 0.0 0.0 0.0 0.0 0.0 21.3 

* 0.0 25.0 33.9 0.0 100.0 35.5 

* 0.0 0.0 0.0 0.0 0.0 35.5 

* 0.0 50.0 0.0 0.0 100.0 14.2 

* 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 

* 0.0 25.0 0.0 0.0 100.0 20.0 

* 0.0 25.0 0.0 0.0 0.0 6.7 

* 0.0 0.0 0.0 0.0 0.0 0.0 

* 0.0 25.0 33.3 25.0 0.0 13.3 

* 100.0 25.0 0.0 0.0 100.0 40.0 

* 1 4 3 4 1 15 

* * * 0.0 100.0 * 0.0 

* * * 0.0 0.0 * 0.0 

* * * 

* * * 0.0 100.0 * 0.0 

* * * 0.0 100.0 * 0.0 

* * * 0.0 0.0 * 0.0 * * * 0.0 0.0 * 0.0 

* * * 0.0 0.0 * 0.0 

* * * 0.0 100.0 * 0.0 

* * * 0.0 0.0 * 0.0 

* * 0.0 0.0 * 0.0 

* * * 0.0 0.0 * 0.0 

* * * 1 1 * 1 

(Co

Table 31 

Residual Management Practices For Each Treatment Scheme 

Percentage of Surface Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source 
Surface Water Plant Treatment

Practice 

Treatment Scheme: Other filtra

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Direct filtration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

0.0 0.0 3.2 14.3 0.0 0.0 50.0 

25.1 34.4 34.2 42.9 40.0 0.0 50.0 

10.6 28.7 30.4 0.0 40.0 0.0 37.5 

19.9 38.0 37.4 42.9 20.0 0.0 12.5 

0.0 0.0 0.0 0.0 20.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.7 0.0 0.0 14.3 0.0 100.0 37.5 

3.7 27.3 22.2 57.1 40.0 0.0 50.0 

7.4 0.0 5.6 0.0 0.0 0.0 0.0 

7.4 0.0 27.8 14.3 20.0 100.0 25.0 0.0 0.0 5.6 57.1 20.0 0.0 62.5 

27 22 18 7 5 1 8 

0.0 0.0 0.0 7.2 0.0 0.0 23.0 0.0 36.6 39.0 49.9 85.9 77.1 61.7 

100.0 17.8 7.3 7.2 20.8 19.3 26.8 

0.0 57.8 53.7 57.3 55.5 25.7 38.3 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.8 0.0 0.0 15.4 28.6 30.8 37.5 38.5 

0.0 0.0 15.4 42.9 38.5 31.3 23.1 

0.0 22.2 0.0 14.3 7.7 0.0 0.0 

0.0 11.1 46.2 14.3 23.1 37.5 30.8 0.0 0.0 38.5 35.7 38.5 68.8 69.2 

3 9 13 14 13 16 26 

0.0 0.0 0.0 7.3 13.8 20.3 29.9 

14.5 70.9 61.1 48.9 64.0 56.1 59.9 

14.5 17.0 25.5 29.3 40.2 34.8 30.5 

14.5 45.5 67.8 56.2 43.0 45.2 31.3 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.7 0.0 7.9 4.3 2.1 

20.0 11.8 11.1 22.0 19.0 27.7 45.1 

0.0 23.5 25.9 36.6 38.1 38.3 23.9 

20.0 0.0 0.0 0.0 1.6 0.0 0.0 

20.0 35.3 33.3 14.6 22.2 23.4 23.9 20.0 0.0 29.6 39.0 30.2 46.8 57.0 

5 17 27 41 63 47 142 

(Co

 Schemes and Residual Management 

tion (not direct or conventional) 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001-

or Less 500 3,300 10,000 50,000 100,000 500,000 5

Residual Management Practices For Each Treatment Scheme

Percentage of Surface Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source 

Table 31 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of Surface Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source 

System Service Population Category 

Surface Water Plant Treatment Schemes and Residual Management 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Practice or Less 500 3,300 10,000 50,000 100,000 500,000 5

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 0.0 * 0.0 0.0 Non-mechanical dewatering 0.0 19.4 21.5 33.3 * 41.7 100.0 

Disposal 

Land application 0.0 0.0 0.0 0.0 * 41.7 100.0 On-site storage 0.0 37.8 46.4 0.0 * 41.7 0.0 Deep well injection 0.0 0.0 0.0 0.0 * 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 * 0.0 0.0 Non-hazardous waste landfill 0.0 0.0 11.1 0.0 * 0.0 0.0 Direct discharge to surface water 0.0 40.0 33.3 33.3 * 25.0 0.0 Septic system 0.0 0.0 11.1 0.0 * 0.0 0.0 Sanitary Sewer 0.0 0.0 66.7 66.7 * 0.0 0.0 Recycle filter backwash 0.0 20.0 0.0 66.7 * 50.0 100.0 

Observations 1 5 9 3 * 4 1 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering * * * * * 0.0 * 

Non-mechanical dewatering * * * * * 0.0 * 

Disposal 

Land application * * * * * 0.0 * 

On-site storage * * * * * 0.0 * 

Deep well injection * * * * * 0.0 * 

Hazardous waste landfill * * * * * 0.0 * 

Non-hazardous waste landfill * * * * * 0.0 * 

Direct discharge to surface water * * * * * 0.0 * 

Septic system * * * * * 0.0 * 

Sanitary Sewer * * * * * 0.0 * 

Recycle filter backwash * * * * * 0.0 * 

Observations * * * * * 1 * 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by Table 23 an

Table 31 (Cont.)
System Service Population Category 

Ground Water Plant Treatment Schemes and Residual Management 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Practice or Less 500 3,300 10,000 50,000 100,000 500,000 5

Treatment Scheme: Disinfection with no additional treatment 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 0.0 0.0 0.0 5.0 Non-mechanical dewatering 0.0 0.0 0.0 0.0 0.0 0.0 0.4 

Disposal 

Land application 0.0 0.0 0.0 0.0 0.0 0.0 0.8 On-site storage 0.0 0.0 0.7 24.5 5.3 0.0 1.2 Deep well injection 0.0 0.0 0.0 7.7 0.0 0.0 0.4 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Non-hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 0.4 Direct discharge to surface water 0.0 0.0 1.1 6.4 8.5 0.0 0.8 Septic system 0.0 4.4 0.0 0.0 0.0 0.0 1.2 Sanitary Sewer 0.0 0.0 0.0 8.5 6.4 0.0 0.8 Recycle filter backwash 0.0 0.0 0.0 0.0 0.0 0.0 0.4 

Observations 41 45 88 47 47 56 241 

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering 

Mechanical dewatering 0.0 7.5 0.0 0.0 0.4 0.0 0.4 Non-mechanical dewatering 0.0 0.0 0.0 0.0 0.4 0.0 0.4 

Disposal 

Land application 0.0 0.0 0.0 0.0 0.0 0.0 8.6 On-site storage 0.0 0.0 1.3 9.1 3.0 0.0 12.1 Deep well injection 0.0 0.0 1.3 4.6 0.0 0.6 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Non-hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 1.3 0.0 Direct discharge to surface water 0.0 0.0 0.0 0.0 1.6 0.0 8.1 Septic system 0.0 0.0 0.0 3.8 1.6 0.0 0.4 Sanitary Sewer 12.5 0.0 0.0 0.0 6.3 2.6 4.7 Recycle filter backwash 12.5 6.3 0.0 0.0 0.0 0.0 0.0 Observations 8 16 48 26 63 78 236 

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering 

Mechanical dewatering 10.4 12.3 0.0 0.0 0.0 0.0 0.0 Non-mechanical dewatering 0.0 0.0 18.2 0.0 0.0 0.0 0.0 

Disposal 

Land application 40.7 23.9 0.0 0.0 0.0 0.0 4.0 On-site storage 20.8 0.0 18.2 28.6 3.4 0.0 11.7 Deep well injection 0.0 0.0 0.0 0.0 10.2 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 3.8 Non-hazardous waste landfill 10.0 0.0 0.0 0.0 6.7 20.0 3.8 Direct discharge to surface water 0.0 0.0 0.0 0.0 0.0 0.0 30.8 Septic system 20.0 12.5 0.0 0.0 0.0 0.0 0.0 Sanitary Sewer 20.0 25.0 8.3 14.3 16.7 6.7 3.8 Recycle filter backwash 0.0 0.0 0.0 0.0 0.0 6.7 7.7 Observations 10 8 12 7 30 15 26 

(Co

Table 32 

Residual Management Practices For Each Treatment Scheme 

Percentage of Ground Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source 
Residual Management Practices For Each Treatment Scheme

Percentage of Ground Water Plants Using Each Residual Management Practice by Treatement Scheme

Ground Water Plant Treatment Schemes and Residual Management Practice 

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Direct filtration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

By Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

0.0 0.0 0.0 8.0 6.2 3.0 10.4 0.0 0.0 30.8 23.9 8.5 14.0 32.0 

10.5 7.1 13.0 8.0 1.6 11.6 21.6 

28.0 0.0 36.7 31.9 8.5 63.3 34.0 

0.0 0.0 0.0 8.0 0.7 6.0 13.2 0.0 0.0 0.0 0.0 0.0 4.3 4.3 

10.0 0.0 5.3 7.7 20.6 0.0 10.6 

0.0 6.3 15.8 30.8 14.7 21.7 21.3 

30.0 18.8 0.0 15.4 0.0 8.7 2.1 

20.0 50.0 52.6 30.8 67.6 34.8 42.6 

0.0 0.0 0.0 7.7 17.6 60.9 27.7 

10 16 19 13 34 23 47 

* * 0.0 100.0 0.0 42.1 36.7 

* * 0.0 100.0 66.7 57.9 46.4 

* * 0.0 0.0 18.2 57.9 36.7 

* * 100.0 100.0 9.1 84.1 64.8 

* * 0.0 0.0 0.0 0.0 0.0 * * 0.0 0.0 0.0 0.0 0.0 

* * 0.0 0.0 33.3 66.7 33.3 

* * 0.0 0.0 16.7 33.3 50.0 

* * 0.0 100.0 0.0 0.0 33.3 

* * 100.0 0.0 50.0 0.0 50.0 

* * 0.0 100.0 16.7 33.3 50.0 

* * 1 1 6 3 6 

* 0.0 0.0 0.0 100.0 48.5 35.2 

* 0.0 50.0 25.0 100.0 48.5 56.7 

* 0.0 50.0 0.0 100.0 48.5 51.4 

* 100.0 50.0 50.0 100.0 74.2 56.7 

* 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 

* 0.0 0.0 0.0 0.0 25.0 58.3 

* 0.0 50.0 0.0 0.0 25.0 16.7 

* 0.0 0.0 0.0 0.0 0.0 0.0 

* 100.0 0.0 75.0 0.0 0.0 0.0 

* 0.0 0.0 25.0 100.0 25.0 50.0 

* 1 2 4 1 4 12 

(Co

Table 32 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of Ground Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source 

System Service Population Category 

Ground Water Plant Treatment Schemes and Residual Management 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Practice or Less 500 3,300 10,000 50,000 100,000 500,000 5

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering * 0.0 0.0 * * 0.0 0.0 Non-mechanical dewatering * 0.0 100.0 * * 0.0 0.0 

Disposal 

Land application * 0.0 100.0 * * 0.0 0.0 On-site storage * 0.0 100.0 * * 0.0 24.5 Deep well injection * 0.0 0.0 * * 0.0 24.5 Hazardous waste landfill * 0.0 0.0 * * 0.0 0.0 Non-hazardous waste landfill * 0.0 0.0 * * 0.0 0.0 Direct discharge to surface water * 0.0 0.0 * * 100.0 50.0 Septic system * 100.0 0.0 * * 0.0 0.0 Sanitary Sewer * 0.0 0.0 * * 0.0 25.0 Recycle filter backwash * 0.0 0.0 * * 0.0 0.0 

Observations * 1 1 * * 1 4 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 * 50.0 100.0 3.8 Non-mechanical dewatering 0.0 0.0 0.0 * 50.0 0.0 0.0 

Disposal 

Land application 0.0 0.0 0.0 * 0.0 0.0 0.0 On-site storage 0.0 0.0 0.0 * 50.0 0.0 0.0 Deep well injection 0.0 0.0 0.0 * 0.0 0.0 3.5 Hazardous waste landfill 0.0 0.0 0.0 * 0.0 100.0 0.0 Non-hazardous waste landfill 0.0 0.0 0.0 * 0.0 0.0 25.9 Direct discharge to surface water 100.0 0.0 0.0 * 0.0 0.0 14.8 Septic system 0.0 0.0 0.0 * 0.0 0.0 0.0 Sanitary Sewer 0.0 20.0 0.0 * 50.0 0.0 25.9 Recycle filter backwash 0.0 0.0 0.0 * 50.0 0.0 3.7 Observations 1 5 3 * 2 2 27 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by Table 23 an

Table 32 (Cont.)
Mixed Water Plant Treatment Schemes and Residual Management 

Practice 

Treatment Scheme: Disinfection with no additional treatment 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 

0.0 0.0 0.0 0.0 0.0 * 0.0 

0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 

0.0 0.0 0.0 0.0 0.0 * 0.0 

0.0 0.0 0.0 0.0 0.0 * 0.0 

0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 

1 3 3 1 2 * 1 

* * 0.0 * 27.3 * 0.0 

* * 0.0 * 0.0 * 19.0 

* * 0.0 * 0.0 * 0.0 

* * 0.0 * 0.0 * 0.0 

* * 0.0 * 0.0 * 0.0 * * 0.0 * 0.0 * 0.0 

* * 0.0 * 50.0 * 20.0 

* * 0.0 * 50.0 * 20.0 

* * 0.0 * 0.0 * 0.0 

* * 0.0 * 0.0 * 20.0 

* * 0.0 * 50.0 * 0.0 

* * 1 * 2 * 5 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * * * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 0.0 0.0 * 0.0 * 

* * 1 1 * 1 * 

(Co

Table 33 

Residual Management Practices For Each Treatment Scheme 

Percentage of Mixed Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source 
Residual Management Practices For Each Treatment Scheme

Percentage of Mixed Water Plants Using Each Residual Management Practice by Treatement Scheme

Mixed Water Plant Treatment Schemes and Residual Management Practice 

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Direct filtration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

By Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

0.0 0.0 0.0 * * * 32.4 0.0 100.0 0.0 * * * 67.6 0.0 0.0 100.0 * * * 67.6 

0.0 100.0 100.0 * * * 64.7 

0.0 0.0 0.0 * * * 0.0 0.0 0.0 0.0 * * * 0.0 0.0 0.0 0.0 * * * 33.3 

0.0 100.0 0.0 * * * 0.0 

0.0 0.0 0.0 * * * 0.0 

0.0 0.0 0.0 * * * 33.3 0.0 0.0 0.0 * * * 66.7 

1 1 1 * * * 3 

* 0.0 * * 0.0 100.0 * 

* 100.0 * * 100.0 0.0 * 

* 0.0 * * 100.0 0.0 * 

* 0.0 * * 50.0 0.0 * 

* 0.0 * * 0.0 0.0 * * 0.0 * * 0.0 0.0 * 

* 0.0 * * 0.0 100.0 * 

* 100.0 * * 0.0 100.0 * 

* 0.0 * * 0.0 0.0 * 

* 0.0 * * 0.0 0.0 * 

* 0.0 * * 100.0 0.0 * 

* 1 * * 2 1 * 

* 0.0 0.0 0.0 22.8 50.0 16.7 

* 100.0 53.8 100.0 68.4 50.0 100.0 

* 0.0 30.8 29.0 68.4 50.0 33.3 

* 0.0 46.2 14.5 22.8 0.0 50.0 

* 0.0 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 50.0 0.0 

* 0.0 0.0 0.0 40.0 0.0 50.0 

* 0.0 50.0 75.0 20.0 0.0 0.0 

* 0.0 0.0 0.0 0.0 0.0 0.0 

* 100.0 25.0 25.0 40.0 50.0 16.7 

* 0.0 25.0 50.0 80.0 100.0 100.0 

* 1 4 4 5 2 6 

(Co

Table 33 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of Mixed Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source 

System Service Population Category 

Mixed Water Plant Treatment Schemes and Residual Management 100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Practice or Less 500 3,300 10,000 50,000 100,000 500,000 5

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering 0.0 * * * 0.0 * * Non-mechanical dewatering 0.0 * * * 100.0 * * 

Disposal 

Land application 0.0 * * * 100.0 * * On-site storage 0.0 * * * 100.0 * * Deep well injection 0.0 * * * 0.0 * * Hazardous waste landfill 0.0 * * * 0.0 * * Non-hazardous waste landfill 0.0 * * * 0.0 * * Direct discharge to surface water 0.0 * * * 0.0 * * Septic system 0.0 * * * 0.0 * * Sanitary Sewer 100.0 * * * 0.0 * * Recycle filter backwash 0.0 * * * 100.0 * * 

Observations 1 * * * 1 * * 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering * 0.0 * * * * * 

Non-mechanical dewatering * 0.0 * * * * * 

Disposal 

Land application * 0.0 * * * * * 

On-site storage * 0.0 * * * * * 

Deep well injection * 0.0 * * * * * 

Hazardous waste landfill * 0.0 * * * * * 

Non-hazardous waste landfill * 0.0 * * * * * 

Direct discharge to surface water * 0.0 * * * * * 

Septic system * 0.0 * * * * * 

Sanitary Sewer * 0.0 * * * * * 

Recycle filter backwash * 0.0 * * * * * 

Observations * 1 * * * * * 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by Table 23 an

Table 33 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

All Water Plant Treatment Schemes and Residual Management Practice or Less 500 3,300 10,000 50,000 100,000 500,000 5

Treatment Scheme: Disinfection with no additional treatment 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 0.0 0.0 0.0 4.8 Non-mechanical dewatering 0.0 0.0 0.0 0.0 0.0 0.0 0.4 

Disposal 

Land application 0.0 0.0 0.0 0.0 0.0 0.0 0.8 On-site storage 0.0 0.0 0.7 23.9 5.2 0.0 1.2 Deep well injection 0.0 0.0 0.0 7.5 0.0 0.0 0.4 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Non-hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 0.4 Direct discharge to surface water 0.0 1.6 1.1 6.3 8.2 3.2 0.8 Septic system 0.0 3.3 0.0 0.0 0.0 0.0 1.2 Sanitary Sewer 0.0 0.0 0.0 8.3 6.1 0.0 0.8 Recycle filter backwash 0.0 1.6 0.0 0.0 0.0 0.0 0.4 

Observations 54 61 94 48 49 62 247 

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering 

Mechanical dewatering 0.0 7.4 0.0 0.0 1.2 0.0 1.5 Non-mechanical dewatering 0.0 0.0 0.3 2.2 0.4 0.5 2.6 

Disposal 

Land application 0.0 0.0 0.0 0.0 0.0 0.0 9.9 On-site storage 0.0 0.0 1.9 8.5 2.7 0.5 12.0 Deep well injection 0.0 0.0 1.3 4.3 0.0 0.6 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Non-hazardous waste landfill 0.0 0.0 1.9 0.0 1.4 2.5 1.6 Direct discharge to surface water 0.0 0.0 1.9 0.0 2.9 0.0 8.2 Septic system 0.0 0.0 0.0 3.4 1.4 0.0 0.4 Sanitary Sewer 12.5 0.0 1.9 3.4 7.2 2.5 5.5 Recycle filter backwash 12.5 11.8 1.9 0.0 1.4 1.3 2.3 Observations 8 17 53 29 69 79 256 

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering 

Mechanical dewatering 10.4 12.3 0.0 0.0 1.3 0.0 0.0 Non-mechanical dewatering 0.0 0.0 17.3 0.0 0.0 0.0 0.0 

Disposal 

Land application 40.7 23.9 0.0 0.0 1.3 0.0 3.9 On-site storage 20.8 0.0 17.3 25.3 4.6 0.0 11.4 Deep well injection 0.0 0.0 0.0 0.0 10.1 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 3.7 Non-hazardous waste landfill 10.0 0.0 0.0 0.0 6.5 18.8 3.7 Direct discharge to surface water 0.0 0.0 0.0 0.0 3.2 0.0 29.6 Septic system 20.0 12.5 0.0 0.0 0.0 0.0 0.0 Sanitary Sewer 20.0 25.0 7.7 11.1 16.1 6.3 3.7 Recycle filter backwash 0.0 0.0 0.0 0.0 0.0 6.3 7.4 Observations 10 8 13 9 31 16 27 

(Co

Table 34 

Residual Management Practices For Each Treatment Scheme 

Percentage of All Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source 
Residual Management Practices For Each Treatment Scheme

Percentage of All Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

All Water Plant Treatment Schemes and Residual Management Practice or Less 500 3,300 10,000 50,000 100,000 500,000 5

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering 

Mechanical dewatering 0.0 0.0 0.7 8.8 5.7 2.9 16.8 Non-mechanical dewatering 2.4 3.0 31.3 26.3 10.9 13.7 36.2 

Disposal 

Land application 10.4 8.7 17.4 7.0 4.5 11.3 26.1 On-site storage 27.1 3.2 37.3 33.3 9.4 61.7 32.7 Deep well injection 0.0 0.0 0.0 7.0 2.1 5.8 10.7 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 4.2 3.4 Non-hazardous waste landfill 5.3 0.0 2.6 10.0 17.9 4.2 15.5 Direct discharge to surface water 2.6 20.5 18.4 40.0 17.9 20.8 24.1 Septic system 13.2 7.7 2.6 10.0 0.0 8.3 1.7 Sanitary Sewer 10.5 20.5 39.5 25.0 61.5 37.5 39.7 Recycle filter backwash 0.0 0.0 2.6 25.0 17.9 58.3 34.5 

Observations 38 39 38 20 39 24 58 

Treatment Scheme: Direct filtration 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 27.4 0.0 11.1 25.5 Non-mechanical dewatering 0.0 42.2 26.6 60.8 79.2 70.4 58.8 

Disposal 

Land application 100.0 16.2 5.0 5.6 25.5 23.7 28.7 On-site storage 0.0 52.6 68.5 66.6 36.5 32.5 43.2 Deep well injection 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 3.1 Non-hazardous waste landfill 0.0 0.0 14.3 26.7 28.6 45.0 37.5 Direct discharge to surface water 0.0 10.0 14.3 40.0 28.6 35.0 28.1 Septic system 0.0 20.0 0.0 20.0 4.8 0.0 6.3 Sanitary Sewer 0.0 10.0 50.0 13.3 28.6 30.0 34.4 Recycle filter backwash 0.0 0.0 35.7 40.0 38.1 60.0 65.6 Observations 3 10 14 15 21 20 32 

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 4.7 15.0 23.9 29.8 Non-mechanical dewatering 14.5 38.8 57.3 48.6 64.5 55.2 61.1 

Disposal 

Land application 14.5 8.6 32.8 22.1 42.6 36.6 32.1 On-site storage 14.5 69.5 60.8 50.1 41.9 45.9 33.8 Deep well injection 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Hazardous waste landfill 0.0 0.0 3.0 0.0 7.2 5.7 1.9 Non-hazardous waste landfill 20.0 10.5 9.1 18.4 20.3 26.4 46.3 Direct discharge to surface water 0.0 21.1 30.3 36.7 36.2 35.8 22.5 Septic system 20.0 0.0 0.0 0.0 1.4 0.0 0.0 Sanitary Sewer 20.0 42.1 30.3 20.4 23.2 22.6 21.9 Recycle filter backwash 20.0 0.0 27.3 38.8 34.8 47.2 58.1 Observations 5 19 33 49 69 53 160 

(Co

Table 34 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of All Water Plants Using Each Residual Management Practice by Treatement Scheme

All Water Plant Treatment Schemes and Residual Management Practice 

Treatment Scheme: Membranes 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Other Treatment 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

By Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.9 53.5 33.3 100.0 31.3 19.6 0.0 0.0 40.8 0.0 100.0 31.3 19.6 

0.0 9.5 68.2 0.0 100.0 31.3 19.6 

0.0 0.0 0.0 0.0 0.0 0.0 19.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 10.0 0.0 0.0 0.0 0.0 

0.0 33.3 30.0 33.3 0.0 40.0 40.0 

0.0 16.7 10.0 0.0 0.0 0.0 0.0 

50.0 0.0 60.0 66.7 0.0 0.0 20.0 

0.0 16.7 0.0 66.7 100.0 40.0 20.0 

2 6 10 3 1 5 5

0.0 0.0 0.0 * 50.0 66.7 3.8 0.0 0.0 0.0 * 50.0 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 

0.0 0.0 0.0 * 50.0 0.0 0.0 

0.0 0.0 0.0 * 0.0 0.0 3.5 0.0 0.0 0.0 * 0.0 66.7 0.0 0.0 0.0 0.0 * 0.0 0.0 25.9 

100.0 0.0 0.0 * 0.0 0.0 14.8 

0.0 0.0 0.0 * 0.0 0.0 0.0 

0.0 16.7 0.0 * 50.0 0.0 25.9 0.0 0.0 0.0 * 50.0 0.0 3.7 

1 6 3 * 2 3 27 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by Table 23 an

Table 34 (Cont.)
Surface Water Plant Treatment Schemes and Residual Management 

Practice 

Treatment Scheme: Disinfection with no additional treatment 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 A

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.0 0.0 0.0 0.0 0.0 0.0 0.0 

0.0 0.0 0.0 0.0 0.0 0.0 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

0.0 16.7 33.3 11.1 0.0 0.0 

0.0 0.0 0.0 0.0 0.0 0.0 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 16.7 0.0 0.0 0.0 0.0 

11 6 3 9 1 1 

* 0.0 0.0 0.0 29.5 0.0 

* 0.0 14.5 28.4 50.6 25.0 

* 0.0 0.0 3.9 41.0 0.0 

* 0.0 14.4 0.0 32.7 0.0 * 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 25.0 

* 0.0 12.5 9.1 18.8 25.0 

* 0.0 12.5 0.0 18.8 0.0 

* 0.0 0.0 0.0 0.0 0.0 

* 0.0 12.5 18.2 18.8 0.0 

* 100.0 12.5 9.1 43.8 0.0 

* 1 8 11 16 4 

* * 0.0 88.0 * * 

* * 0.0 0.0 * * 

* * 0.0 88.0 * * 

* * 0.0 88.0 * * 

* * 0.0 0.0 * * * * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 50.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 1 2 * * 

(Continued) 

Table 35 

Residual Management Practices For Each Treatment Scheme 

Percentage of Surface Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source and Plant Average Daily Production 
Residual Management Practices For Each Treatment Scheme

Percentage of Surface Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Surface Water Plant Treatment Schemes and Residual Management Practice 

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Direct filtration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 A

0.0 0.7 0.0 17.7 40.0 * 

17.3 59.0 20.6 34.3 40.0 * 

14.5 18.0 34.5 31.9 40.0 * 

14.5 64.0 12.4 32.4 0.0 * 

0.0 0.0 0.0 14.7 0.0 * 0.0 0.0 0.0 0.0 0.0 * 3.8 3.7 5.6 22.2 20.0 * 

11.5 18.5 33.3 33.3 60.0 * 

0.0 3.7 5.6 0.0 0.0 * 

7.7 7.4 22.2 22.2 20.0 * 0.0 3.7 22.2 33.3 60.0 * 

26 27 18 9 5 * 

0.0 0.0 0.0 5.9 22.4 0.0 

60.9 39.6 45.5 72.6 67.0 66.7 

6.4 27.7 9.4 19.5 23.1 0.0 

0.0 53.0 56.0 57.6 28.4 0.0 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.5 0.0 0.0 

25.0 0.0 13.6 37.5 36.0 66.7 

0.0 0.0 27.3 32.5 28.0 0.0 

50.0 0.0 9.1 2.5 0.0 0.0 

0.0 20.0 27.3 37.5 12.0 0.0 

25.0 10.0 36.4 55.0 72.0 100.0 

4 10 22 40 25 3 

0.0 0.0 5.9 13.0 34.8 36.4 

39.0 68.1 55.7 58.6 55.1 18.2 

16.6 29.1 31.0 35.1 25.4 0.0 

33.0 48.5 65.8 44.4 28.0 18.2 

0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.9 3.4 4.5 0.0 

12.5 16.7 21.2 26.9 42.5 36.4 

12.5 29.2 25.0 34.5 26.8 27.3 

12.5 0.0 0.0 0.7 0.0 0.0 

37.5 25.0 25.0 20.7 29.6 36.4 12.5 8.3 36.5 40.0 63.7 63.6 

8 24 52 145 179 11 

(Continued) 

Table 35 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of Surface Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Plant Average Daily Production (MGD) 

Surface Water Plant Treatment Schemes and Residual Management 0 - 0.01 - 0.1 - 1.0 - 10.0 - Over Practice 0.01 0.1 1.0 10.0 100.0 100 A

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 0.0 31.2 * Non-mechanical dewatering 0.0 9.1 50.2 17.6 68.8 * 

Disposal 

Land application 0.0 0.0 0.0 17.6 68.8 * On-site storage 0.0 50.9 33.3 17.6 0.0 * Deep well injection 0.0 0.0 0.0 0.0 0.0 * Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 * Non-hazardous waste landfill 0.0 12.5 0.0 0.0 0.0 * Direct discharge to surface water 0.0 12.5 57.1 16.7 0.0 * Septic system 0.0 12.5 0.0 0.0 0.0 * Sanitary Sewer 0.0 25.0 42.9 50.0 33.3 * Recycle filter backwash 0.0 12.5 14.3 50.0 100.0 * Observations 1 8 7 6 3 * 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering * * 0.0 * * * Non-mechanical dewatering * * 0.0 * * * 

Disposal 

Land application * * 0.0 * * * On-site storage * * 0.0 * * * Deep well injection * * 0.0 * * * Hazardous waste landfill * * 0.0 * * * Non-hazardous waste landfill * * 0.0 * * * Direct discharge to surface water * * 0.0 * * * Septic system * * 0.0 * * * Sanitary Sewer * * 0.0 * * * Recycle filter backwash * * 0.0 * * * Observations * * 1 * * * 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by 

Table 23 and Table 24. 

Table 35 (Cont.)
Ground Water Plant Treatment Schemes and Residual Management 

Practice 

Treatment Scheme: Disinfection with no additional treatment 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 A

0.0 0.0 0.0 2.8 0.0 * 0.0 0.0 0.0 0.0 22.5 * 0.0 0.0 0.1 0.0 0.0 * 

0.0 1.1 9.3 10.6 0.0 * 

0.0 0.5 2.7 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 20.0 * 

0.0 0.0 2.9 1.4 0.0 * 

3.9 0.0 0.4 0.9 0.0 * 

0.0 0.6 2.5 0.5 20.0 * 0.0 0.0 0.0 0.5 0.0 * 

51 158 239 216 5 * 

0.0 3.6 0.2 0.0 27.4 * 0.0 0.0 0.2 0.2 27.4 * 0.0 0.0 0.8 1.8 0.0 * 

0.0 0.0 2.5 13.2 0.0 * 

0.0 0.0 1.2 0.7 0.0 * 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.5 0.0 * 

0.0 0.0 4.0 3.1 0.0 * 

0.0 0.0 0.3 0.5 50.0 * 

3.1 0.0 3.7 2.1 0.0 * 3.1 0.9 0.0 0.0 0.0 * 

32 115 349 191 2 * 

15.3 0.0 0.0 0.0 0.0 * 

0.0 17.9 0.0 0.0 0.0 * 

37.5 0.0 0.0 0.4 0.0 * 

15.9 17.9 10.6 0.4 11.3 * 

0.0 0.0 0.0 17.2 0.0 * 0.0 0.0 0.0 1.6 0.0 * 7.7 0.0 2.3 7.9 0.0 * 

0.0 0.0 2.3 11.1 0.0 * 

23.1 0.0 0.0 0.0 0.0 * 

23.1 6.3 7.0 9.5 0.0 * 

0.0 0.0 0.0 3.2 16.7 * 

13 16 43 63 6 * 

(Continued) 

Table 36 

Residual Management Practices For Each Treatment Scheme 

Percentage of Ground Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source and Plant Average Daily Production 
Residual Management Practices For Each Treatment Scheme

Percentage of Ground Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Ground Water Plant Treatment Schemes and Residual Management Practice 

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Direct filtration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 A

0.0 0.0 3.8 13.8 9.1 * 0.0 12.1 28.8 16.9 8.1 * 7.0 10.7 10.0 11.5 7.0 * 

18.8 12.0 37.9 10.0 71.9 * 

0.0 0.0 3.9 5.0 6.3 * 0.0 0.0 1.6 1.7 3.7 * 6.3 3.6 9.5 8.6 7.4 * 

0.0 14.3 9.5 22.4 29.6 * 

37.5 0.0 3.2 1.7 7.4 * 

25.0 57.1 50.8 36.2 44.4 * 

6.3 0.0 15.9 24.1 63.0 * 

16 28 63 58 27 * 

* * 27.7 2.1 100.0 * 

* * 36.6 84.0 0.0 * 

* * 8.0 14.0 100.0 * 

* * 80.6 8.9 100.0 * 

* * 0.0 0.0 0.0 * * * 0.0 0.0 0.0 * 

* * 16.7 44.4 50.0 * 

* * 0.0 55.6 0.0 * 

* * 16.7 11.1 50.0 * 

* * 33.3 44.4 50.0 * 

* * 33.3 22.2 100.0 * 

* * 6 9 2 * 

* 0.0 0.0 66.6 15.5 0.0 

* 39.7 17.8 60.4 65.6 100.0 

* 39.7 0.0 80.2 34.4 0.0 

* 100.0 35.5 60.4 84.5 50.0 

* 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 

* 0.0 0.0 40.0 44.4 100.0 

* 0.0 20.0 0.0 44.4 0.0 

* 0.0 0.0 0.0 0.0 0.0 

* 50.0 60.0 0.0 0.0 50.0 

* 0.0 20.0 60.0 44.4 100.0 

* 2 5 10 9 2 

(Continued) 

Table 36 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of Ground Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Plant Average Daily Production (MGD) 

Ground Water Plant Treatment Schemes and Residual Management 0 - 0.01 - 0.1 - 1.0 - 10.0 - Over Practice 0.01 0.1 1.0 10.0 100.0 100 A

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering 0.0 * 0.0 0.0 * * Non-mechanical dewatering 0.0 * 97.3 0.0 * * 

Disposal 

Land application 0.0 * 97.3 0.0 * * On-site storage 0.0 * 97.3 17.7 * * Deep well injection 0.0 * 0.0 17.7 * * Hazardous waste landfill 0.0 * 0.0 0.0 * * Non-hazardous waste landfill 0.0 * 0.0 0.0 * * Direct discharge to surface water 0.0 * 0.0 75.0 * * Septic system 50.0 * 0.0 0.0 * * Sanitary Sewer 0.0 * 50.0 0.0 * * Recycle filter backwash 0.0 * 0.0 0.0 * * Observations 2 * 2 4 * * 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 20.4 39.3 100.0 Non-mechanical dewatering 0.0 0.0 0.0 8.4 0.0 0.0 

Disposal 

Land application 0.0 0.0 0.0 0.0 0.0 0.0 On-site storage 0.0 0.0 0.0 8.4 0.0 0.0 Deep well injection 0.0 0.0 0.0 3.2 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 3.6 20.0 100.0 Non-hazardous waste landfill 0.0 0.0 12.5 21.4 0.0 0.0 Direct discharge to surface water 33.3 0.0 0.0 7.1 40.0 0.0 Septic system 0.0 0.0 0.0 0.0 0.0 0.0 Sanitary Sewer 0.0 16.7 25.0 17.9 20.0 0.0 Recycle filter backwash 0.0 0.0 0.0 7.1 0.0 0.0 Observations 3 6 8 28 5 1 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by 

Table 23 and Table 24. 

Table 36 (Cont.)
Mixed Water Plant Treatment Schemes and Residual Management 

Practice 

Treatment Scheme: Disinfection with no additional treatment 

Dewatering

Mechanical dewatering

Non-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 A

0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 * 

0.0 0.0 0.0 0.0 0.0 * 

0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 * 

0.0 0.0 0.0 0.0 0.0 * 

0.0 0.0 0.0 0.0 0.0 * 

0.0 0.0 0.0 0.0 0.0 * 0.0 0.0 0.0 0.0 0.0 * 

2 3 4 1 1 * 

* * 0.0 73.6 0.0 * 

* * 0.0 0.0 32.4 * 

* * 0.0 0.0 0.0 * 

* * 0.0 0.0 0.0 * * * 0.0 0.0 0.0 * * * 0.0 0.0 0.0 * 

* * 0.0 33.3 33.3 * 

* * 50.0 0.0 33.3 * 

* * 0.0 0.0 0.0 * 

* * 0.0 33.3 0.0 * 

* * 0.0 33.3 0.0 * 

* * 2 3 3 * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * * * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 0.0 0.0 * * 

* * 2 1 * * 

(Continued) 

Table 37 

Residual Management Practices For Each Treatment Scheme 

Percentage of Mixed Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source and Plant Average Daily Production 
Residual Management Practices For Each Treatment Scheme

Percentage of Mixed Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Mixed Water Plant Treatment Schemes and Residual Management Practice 

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering

Mechanical dewatering

Non-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Direct filtration 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering

Mechanical dewateringNon-mechanical dewatering

Disposal

Land applicationOn-site storageDeep well injectionHazardous waste landfillNon-hazardous waste landfillDirect discharge to surface waterSeptic systemSanitary SewerRecycle filter backwashObservations

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

0.01 0.1 1.0 10.0 100.0 100 A

0.0 0.0 * 0.0 47.9 * 0.0 27.3 * 100.0 52.1 * 0.0 45.4 * 100.0 52.1 * 

0.0 72.7 * 100.0 47.9 * 

0.0 0.0 * 0.0 0.0 * 0.0 0.0 * 0.0 0.0 * 0.0 0.0 * 0.0 50.0 * 

0.0 33.3 * 0.0 0.0 * 

0.0 0.0 * 0.0 0.0 * 

0.0 0.0 * 0.0 50.0 * 0.0 0.0 * 100.0 50.0 * 

1 3 * 1 2 * 

* 0.0 * 16.1 * * 

* 100.0 * 83.9 * * 

* 0.0 * 83.9 * * 

* 0.0 * 41.9 * * 

* 0.0 * 0.0 * * * 0.0 * 0.0 * * 

* 0.0 * 33.3 * * 

* 100.0 * 33.3 * * 

* 0.0 * 0.0 * * 

* 0.0 * 0.0 * * 

* 0.0 * 66.7 * * 

* 1 * 3 * * 

* 0.0 0.0 10.0 40.9 * 

* 100.0 68.5 82.3 89.8 * 

* 0.0 36.9 40.3 53.1 * 

* 0.0 31.5 20.4 36.7 * 

* 0.0 0.0 0.0 0.0 * * 0.0 0.0 0.0 14.3 * 

* 0.0 0.0 33.3 28.6 * 

* 0.0 50.0 33.3 0.0 * 

* 0.0 0.0 0.0 0.0 * 

* 100.0 16.7 44.4 14.3 * 

* 0.0 33.3 77.8 100.0 * 

* 1 6 9 7 * 

(Continued) 

Table 37 (Cont.)
Residual Management Practices For Each Treatment Scheme

Percentage of Mixed Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Plant Average Daily Production (MGD) 

Mixed Water Plant Treatment Schemes and Residual Management 0 - 0.01 - 0.1 - 1.0 - 10.0 - Over Practice 0.01 0.1 1.0 10.0 100.0 100 A

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering * * 0.0 0.0 * * Non-mechanical dewatering * * 0.0 88.5 * * 

Disposal 

Land application * * 0.0 88.5 * * On-site storage * * 0.0 88.5 * * Deep well injection * * 0.0 0.0 * * Hazardous waste landfill * * 0.0 0.0 * * Non-hazardous waste landfill * * 0.0 0.0 * * Direct discharge to surface water * * 0.0 0.0 * * Septic system * * 0.0 0.0 * * Sanitary Sewer * * 100.0 50.0 * * Recycle filter backwash * * 0.0 50.0 * * Observations * * 1 2 * * 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering * 0.0 * * * * 

Non-mechanical dewatering * 0.0 * * * * 

Disposal 

Land application * 0.0 * * * * 

On-site storage * 0.0 * * * * 

Deep well injection * 0.0 * * * * Hazardous waste landfill * 0.0 * * * * Non-hazardous waste landfill * 0.0 * * * * 

Direct discharge to surface water * 0.0 * * * * 

Septic system * 0.0 * * * * 

Sanitary Sewer * 0.0 * * * * 

Recycle filter backwash * 0.0 * * * * Observations * 1 * * * * 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by 

Table 23 and Table 24. 

Table 37 (Cont.)
Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

All Water Plant Treatment Schemes and Residual Management Practice 0.01 0.1 1.0 10.0 100.0 100 A

Treatment Scheme: Disinfection with no additional treatment 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 2.7 0.0 0.0 Non-mechanical dewatering 0.0 0.0 0.0 0.0 12.8 100.0 

Disposal 

Land application 0.0 0.0 0.1 0.0 0.0 0.0 On-site storage 0.0 1.0 8.7 10.1 0.0 0.0 Deep well injection 0.0 0.5 2.6 0.0 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 0.0 Non-hazardous waste landfill 0.0 0.0 0.0 0.0 14.3 0.0 Direct discharge to surface water 0.0 0.6 3.3 1.8 0.0 0.0 Septic system 3.1 0.0 0.4 0.9 0.0 0.0 Sanitary Sewer 0.0 0.6 2.4 0.4 14.3 0.0 Recycle filter backwash 0.0 0.6 0.0 0.4 0.0 0.0 Observations 64 167 246 226 7 1 

Treatment Scheme: Disinfection, Other Chemical Addition 

Dewatering 

Mechanical dewatering 0.0 3.6 0.2 1.6 25.1 0.0 Non-mechanical dewatering 0.0 0.0 0.8 2.1 44.3 25.0 

Disposal 

Land application 0.0 0.0 0.7 1.9 28.8 0.0 On-site storage 0.0 0.0 3.0 12.1 22.9 0.0 Deep well injection 0.0 0.0 1.2 0.7 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 25.0 Non-hazardous waste landfill 0.0 0.0 0.3 1.5 19.0 25.0 Direct discharge to surface water 0.0 0.0 4.5 2.9 19.0 0.0 Septic system 0.0 0.0 0.3 0.5 4.8 0.0 Sanitary Sewer 3.1 0.0 3.9 3.4 14.3 0.0 Recycle filter backwash 3.1 1.7 0.3 1.0 33.3 0.0 Observations 32 116 359 205 21 4 

Treatment Scheme: Ion exchange, activated alumina, aeration 

Dewatering 

Mechanical dewatering 15.3 0.0 0.0 2.1 0.0 * Non-mechanical dewatering 0.0 17.9 0.0 0.0 0.0 * 

Disposal 

Land application 37.5 0.0 0.0 2.4 0.0 * On-site storage 15.9 17.9 9.8 2.4 11.3 * Deep well injection 0.0 0.0 0.0 16.6 0.0 * Hazardous waste landfill 0.0 0.0 0.0 1.5 0.0 * Non-hazardous waste landfill 7.7 0.0 2.2 7.6 0.0 * 

Direct discharge to surface water 0.0 0.0 2.2 12.1 0.0 * Septic system 23.1 0.0 0.0 0.0 0.0 * Sanitary Sewer 23.1 6.3 6.5 9.1 0.0 * Recycle filter backwash 0.0 0.0 0.0 3.0 16.7 * Observations 13 16 46 66 6 * 

(Continued) 

Table 38 

Residual Management Practices For Each Treatment Scheme 

Percentage of All Water Plants Using Each Residual Management Practice by Treatement Scheme 

By Water Source and Plant Average Daily Production 
Residual Management Practices For Each Treatment Scheme

Percentage of All Water Plants Using Each Residual Management Practice by Treatement Scheme

By Water Source and Plant Average Daily Production 

Plant Average Daily Production (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

All Water Plant Treatment Schemes and Residual Management Practice 0.01 0.1 1.0 10.0 100.0 100 A

Treatment Scheme: Other filtration (not direct or conventional) 

Dewatering 

Mechanical dewatering 0.0 0.1 3.1 14.5 11.9 * Non-mechanical dewatering 1.1 17.8 27.3 20.7 11.1 * 

Disposal 

Land application 7.5 12.0 14.6 15.9 10.1 * On-site storage 18.5 18.9 33.2 14.8 67.0 * Deep well injection 0.0 0.0 3.1 6.9 5.8 * Hazardous waste landfill 0.0 0.0 1.2 1.5 2.9 * Non-hazardous waste landfill 4.8 3.4 8.6 10.3 11.8 * Direct discharge to surface water 7.1 17.2 14.8 23.5 32.4 * Septic system 14.3 1.7 3.7 1.5 5.9 * Sanitary Sewer 14.3 31.0 44.4 33.8 41.2 * Recycle filter backwash 2.4 1.7 17.3 26.5 61.8 * Observations 42 58 81 68 34 * 

Treatment Scheme: Direct filtration 

Dewatering 

Mechanical dewatering 0.0 0.0 11.1 5.7 32.4 0.0 Non-mechanical dewatering 60.9 44.1 41.9 76.3 58.4 66.7 

Disposal 

Land application 6.4 25.6 8.8 22.6 33.0 0.0 On-site storage 0.0 49.1 65.8 44.4 37.6 0.0 Deep well injection 0.0 0.0 0.0 0.0 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 1.9 0.0 0.0 Non-hazardous waste landfill 25.0 0.0 14.3 38.5 37.0 66.7 Direct discharge to surface water 0.0 9.1 21.4 36.5 25.9 0.0 Septic system 50.0 0.0 10.7 3.8 3.7 0.0 Sanitary Sewer 0.0 18.2 28.6 36.5 14.8 0.0 Recycle filter backwash 25.0 9.1 35.7 50.0 74.1 100.0 Observations 4 11 28 52 27 3 

Treatment Scheme: Conventional filtration (with and without softening) 

Dewatering 

Mechanical dewatering 0.0 0.0 3.8 14.0 33.8 31.0 Non-mechanical dewatering 39.0 55.3 46.3 61.1 57.0 30.2 

Disposal 

Land application 16.6 33.6 22.9 36.7 27.0 0.0 On-site storage 33.0 71.8 54.7 42.4 31.9 22.9 Deep well injection 0.0 0.0 0.0 0.0 0.0 0.0 Hazardous waste landfill 0.0 0.0 1.6 3.0 4.6 0.0 Non-hazardous waste landfill 12.5 14.8 17.5 28.0 42.1 46.2 Direct discharge to surface water 12.5 25.9 27.0 32.3 26.7 23.1 Septic system 12.5 0.0 0.0 0.6 0.0 0.0 Sanitary Sewer 37.5 29.6 27.0 20.7 27.7 38.5 Recycle filter backwash 12.5 7.4 34.9 43.3 64.1 69.2 Observations 8 27 63 164 195 13 

(Continued) 

Table 38 (Cont.)
f All Water Plants Using Each Residual Management Practice by Treatement Sche

By Water Source and Plant Average Daily Production 

Plant Average Daily Product

Residual Management Practices For Each Treatment Scheme

Percentage o me

ion (MGD) 

0 - 0.01 - 0.1 - 1.0 - 10.0 - Over 

All Water Plant Treatment Schemes and Residual Management Practice 0.01 0.1 1.0 10.0 100.0 100 A

Treatment Scheme: Membranes 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 0.0 31.2 * Non-mechanical dewatering 0.0 9.1 73.3 29.9 68.8 * 

Disposal 

Land application 0.0 0.0 49.9 29.9 68.8 * On-site storage 0.0 50.9 65.4 33.0 0.0 * Deep well injection 0.0 0.0 0.0 3.2 0.0 * Hazardous waste landfill 0.0 0.0 0.0 0.0 0.0 * Non-hazardous waste landfill 0.0 12.5 0.0 0.0 0.0 * Direct discharge to surface water 0.0 12.5 40.0 33.3 0.0 * Septic system 33.3 12.5 0.0 0.0 0.0 * Sanitary Sewer 0.0 25.0 50.0 33.3 33.3 * Recycle filter backwash 0.0 12.5 10.0 33.3 100.0 * Observations 3 8 10 12 3 * 

Treatment Scheme: Other Treatment 

Dewatering 

Mechanical dewatering 0.0 0.0 0.0 20.4 39.3 100.0 Non-mechanical dewatering 0.0 0.0 0.0 8.4 0.0 0.0 

Disposal 

Land application 0.0 0.0 0.0 0.0 0.0 0.0 On-site storage 0.0 0.0 0.0 8.4 0.0 0.0 Deep well injection 0.0 0.0 0.0 3.2 0.0 0.0 Hazardous waste landfill 0.0 0.0 0.0 3.6 20.0 100.0 Non-hazardous waste landfill 0.0 0.0 11.1 21.4 0.0 0.0 Direct discharge to surface water 33.3 0.0 0.0 7.1 40.0 0.0 Septic system 0.0 0.0 0.0 0.0 0.0 0.0 Sanitary Sewer 0.0 14.3 22.2 17.9 20.0 0.0 Recycle filter backwash 0.0 0.0 0.0 7.1 0.0 0.0 Observations 3 7 9 28 5 1 

Data: Q.9 Notes: Treatment schemes listed are based on the categorization presented by 

Table 23 and Table 24. 

Table 38 (Cont.)
Table 39

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source and Treatment Scheme

System Service Population Category

Water Source and Treatment Scheme

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

5

Ground Water Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * * 0.7 1.0 1.0 0.0 0.7 Septic system * * 0.0 0.0 0.0 0.0 0.0 Sanitary sewer * * 0.0 0.0 0.3 0.0 0.0 Observations * * 3.0 3.0 4.0 2.0 3.0 

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * * * * 1.0 * 0.7 Septic system * * * * 0.0 * 0.0 Sanitary sewer * * * * 0.0 * 0.0 Observations * * * * 1.0 * 27.0 

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * * * 1.0 * 1.0 Septic system * * * * 0.0 * 0.0 Sanitary sewer * * * * 0.0 * 0.0 Observations * * * * 8.0 * 8.0 

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water * 1.0 1.0 0.7 1.0 0.2 0.9 Septic system * 0.0 0.0 0.3 0.0 0.0 0.0 Sanitary sewer * 0.0 0.0 0.0 0.0 0.0 0.2 Observations * 1.0 3.0 5.0 5.0 9.0 11.0 

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * * * * 0.7 0.7 1.0 Septic system * * * * 0.0 0.0 0.3 Sanitary sewer * * * * 0.0 0.0 0.7 Observations * * * * 2.0 2.0 3.0 

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water * * 1.0 * * 1.0 1.0 Septic system * * 0.0 * * 0.0 0.0 Sanitary sewer * * 0.0 * * 0.0 0.0 Observations * * 1.0 * * 1.0 2.0 

Treatment Scheme: Membranes

Direct Discharge to Surface Water * * * * * 1.0 0.6 Septic system * * * * * 0.0 0.0 Sanitary sewer * * * * * 0.0 0.4 Observations * * * * * 1.0 3.0 

Treatment Scheme: Other

Direct Discharge to Surface Water 1.0 * * * * 0.0 0.5 Septic system 0.0 * * * * 0.0 0.0 Sanitary sewer 0.0 * * * * 0.0 0.1 Observations 1 * * * * 2 8 

(Co
Table 39 (Cont.)

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source and Treatment Scheme

System Service Population Category

Water Source and Treatment Scheme

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

5

Surface Water Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * 1.0 * * * 1.0 * 

Septic system * 0.0 * * * 0.0 * Sanitary sewer * 0.0 * * * 0.0 * Observations * 1.0 * * * 2.0 * 

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * 0.0 1.0 * * * 0.5 Septic system * 0.0 0.0 * * * 0.0 Sanitary sewer * 0.0 0.0 * * * 0.5 Observations * 1.0 1.0 * * * 2.0 

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * * * 1.Septic system * * * * 0.Sanitary sewer * * * *0.

Observations * * * * 1.

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water 1.0 1.0 1.0 1.0 1.Septic system 0.0 0.0 0.0 0.0 0.Sanitary sewer 0.0 0.0 0.2 0.3 0.Observations 1.0 6.0 4.0 4.0 2.

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * * 1.0 0.9 1.Septic system * * 0.0 0.1 0.Sanitary sewer * * 0.0 0.0 0.Observations * * 2.0 7.0 5.

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water * 0.8 0.7 0.8 1.Septic system * 0.0 0.0 0.0 0.Sanitary sewer * 0.0 0.0 0.1 0.Observations * 5.0 10.0 20.0 25.

Treatment Scheme: Membranes

Direct Discharge to Surface Water * 1.0 1.0 1.0Septic system * 0.0 0.0 0.0Sanitary sewer * 0.0 0.7 0.0Observations * 2.0 3.0 1.0

Treatment Scheme: Other

Direct Discharge to Surface Water ****Septic system  Sanitary sewer ** **Observations ****

0 * * 0 * * 

0 * * 0 * * 

0 * 1.0 0 * 0.0 0 * 0.3 0 * 4.0 0 1.0 0.8 0 0.0 0.0 0 0.2 0.30 5.0 9.0

0 0.9 1.01 0.0 0.02 0.3 0.2

0 19.0 35.0

* 1.0 1.0* 0.0 0.0* 0.0 0.0* 1.0 1.0************

(C

o
Table 39 (Cont.)

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source and Treatment Scheme

System Service Population Category

Water Source and Treatment Scheme

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

5

Mixed Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water *******Septic system *******Sanitary sewer *******Observations *******

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * * * * 1.0 * 1.0 

Septic system * * * * 0.0 * 0.0 Sanitary sewer * * * * 0.0 * 0.0 Observations * * * * 1.0 * 1.0 

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water *******Septic system *******Sanitary sewer *******Observations *******

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water * 1.0 * * * * * Septic system * 0.0 * * * * * Sanitary sewer * 0.0 * * * * * Observations * 1.0 * * * * * 

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * 1.0 * * * 1.0 * Septic system * 0.0 * * * 0.0 * Sanitary sewer * 0.0 * * * 0.0 * Observations * 1.0 * * * 1.0 * 

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water * * 0.7 1.0 0.7 * * Septic system * * 0.0 0.0 0.0 * * Sanitary sewer * * 0.3 0.7 0.3 * * Observations * * 3.0 3.0 2.0 * * 

Treatment Scheme: Membranes

Direct Discharge to Surface Water *******Septic system *******Sanitary sewer *******Observations *******

Treatment Scheme: Other

Direct Discharge to Surface Water *******Septic system *******Sanitary sewer *******Observations *******

(Co
Table 39 (Cont.)

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source and Treatment Scheme

System Service Population Category

Water Source and Treatment Scheme

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

5

All Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * 1.0 0.7 1.0 1.0 0.7 0.7 Septic system * 0.0 0.0 0.0 0.0 0.0 0.0 Sanitary sewer * 0.0 0.0 0.0 0.3 0.0 0.0 Observations * 1.0 3.0 3.0 4.0 4.0 3.0 

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * 0.0 1.0 * 1.0 * 0.7 Septic system * 0.0 0.0 * 0.0 * 0.0 Sanitary sewer * 0.0 0.0 * 0.0 * 0.0 Observations * 1.0 1.0 * 2.0 * 32.0 

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * * * 1.0 * 1.0 Septic system * * * * 0.0 * 0.0 Sanitary sewer * * * * 0.0 * 0.0 Observations * * * * 1.0 * 8.0 

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water 1.0 1.0 1.0 0.8 1.0 0.2 0.9 Septic system 0.0 0.0 0.0 0.2 0.0 0.0 0.0 Sanitary sewer 0.0 0.0 0.0 0.1 0.0 0.0 0.2 Observations 1.0 8.0 7.0 9.0 7.0 9.0 15.0 

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * 1.0 1.0 0.9 0.9 0.9 0.8 Septic system * 0.0 0.0 0.1 0.0 0.0 0.1 Sanitary sewer * 0.0 0.0 0.0 0.0 0.1 0.4 Observations * 1.0 2.0 7.0 7.0 8.0 12.0 

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water * 0.8 0.8 0.8 1.0 0.9 1.0 Septic system * 0.0 0.0 0.0 0.0 0.0 0.0 Sanitary sewer * 0.0 0.1 0.2 0.2 0.3 0.2 Observations * 5.0 14.0 23.0 28.0 20.0 37.0 

Treatment Scheme: Membranes

Direct Discharge to Surface Water * 1.0 1.0 1.0 * 1.0 0.6 Septic system * 0.0 0.0 0.0 * 0.0 0.0 Sanitary sewer * 0.0 0.7 0.0 * 0.0 0.4 Observations * 2.0 3.0 1.0 * 2.0 3.0 

Treatment Scheme: Other

Direct Discharge to Surface Water 1.0 * * * * 0.0 0.5 Septic system 0.0 * * * * 0.0 0.0 Sanitary sewer 0.0 * * * * 0.0 0.1 Observations 1 * * * * 2 8 

Data: Q.9Notes: Treatment schemes listed are based on the categorization presented by Table 23 a

These are the systems with the option to discharge to surface water, septic systemsewers, and make use of these options.
Table 40

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source, Treatement Scheme, and Plant Average Daily Production

Plant Average Daily Production (MGD)

Water Source and Treatment Scheme

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 A

Ground Water Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * 0.00 0.88 0.66 0.00 * Septic system * 0.00 0.00 0.00 0.00 * Sanitary sewer * 0.00 0.14 0.00 0.00 * Observations * 5 24 34 1 * 

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * * 0.64 1.00 * * Septic system * * 0.00 0.00 * * Sanitary sewer * * 0.00 0.00 * * Observations * * 22 6 * * 

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * 1.00 1.00 * * Septic system * * 0.00 0.00 * * Sanitary sewer * * 0.00 0.00 * * Observations * *17 * *

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water * 1.00 0.80 0.97 0.15 * Septic system * 0.00 0.20 0.08 0.00 * Sanitary sewer * 0.00 0.00 0.06 0.04 * Observations * 4 7 14 12 * 

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * * 0.00 1.00 * * Septic system * * 0.00 0.05 * * Sanitary sewer * * 0.00 0.09 * * Observations * *25 * *

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water * * 1.00 * 1.00 * Septic system * * 0.00 * 0.00 * Sanitary sewer * * 0.00 * 0.00 * Observations * *1 *4 *

Treatment Scheme: Membranes

Direct Discharge to Surface Water * * 0.00 1.00 * * Septic system * * 0.00 0.00 * * Sanitary sewer * * 1.00 0.00 * * Observations * *13 * *

Treatment Scheme: Other

Direct Discharge to Surface Water 1.00 * 0.00 0.26 0.43 0.00 Septic system 0.00 * 0.00 0.00 0.00 0.00 Sanitary sewer 0.00 * 0.00 0.00 0.21 0.00 Observations 1 * 1 6 3 1 

(Continued)
Table 40 (Cont.)

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source, Treatement Scheme, and Plant Average Daily Production

Plant Average Daily Production (MGD)

Water Source and Treatment Scheme

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 A

Surface Water Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * 1.00 1.00 1.00 * * 

Septic system * 0.00 0.00 0.00 * * Sanitary sewer * 0.00 0.00 0.00 * * Observations *111 * *

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * 0.00 1.00 * 0.59 * Septic system * 0.00 0.00 * 0.00 * Sanitary sewer * 0.00 0.00 * 0.41 * Observations *11 *5 *

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * * 1.00 * * Septic system * * * 0.00 * * Sanitary sewer * * * 0.00 * * Observations * * *1 * *

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water 1.00 1.00 1.00 1.00 1.00 * Septic system 0.00 0.00 0.00 0.00 0.00 * Sanitary sewer 0.00 0.07 0.16 0.34 0.00 * Observations 3.0 5 6 3 3 * 

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * * 0.86 0.98 0.89 * Septic system * * 0.14 0.00 0.00 * Sanitary sewer * * 0.00 0.04 0.22Observations * * 7 14 8

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water 1.00 0.91 0.68 0.93 0.83Septic system 0.00 0.00 0.00 0.03 0.00Sanitary sewer 0.00 0.00 0.05 0.19 0.20Observations 1.0 8 19 52 57

Treatment Scheme: Membranes

Direct Discharge to Surface Water * 1.00 1.00 1.00 *Septic system * 0.00 0.00 0.00 *Sanitary sewer * 0.00 0.28 0.00 *Observations *141 *

Treatment Scheme: Other

Direct Discharge to Surface Water *****Septic system *****Sanitary sewer *****Observations *****

* 

* 

0.50 

0.00 0.17 

6 

* * * 

* * * * * 

(Continued)
Table 40 (Cont.)

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source, Treatement Scheme, and Plant Average Daily Production

Plant Average Daily Production (MGD)

Water Source and Treatment Scheme

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 A

Mixed Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * * * * * * Septic system * * * * * * Sanitary sewer ******

Observations * * * * * * 

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * * 1.00 * 1.00 * 

Septic system * * 0.00 * 0.00 * Sanitary sewer * * 0.00 * 0.00 * Observations * *1 *1 *

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * * * * * Septic system * * * * * * Sanitary sewer * * * * * * Observations * * * * * * 

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water * 1.00 **** 

Septic system * 0.00 **** 

Sanitary sewer * 0.00 **** 

Observations *1 * * * *

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * 1.00 * 1.00 * * 

Septic system * 0.00 * 0.00 * * Sanitary sewer * 0.00 * 0.00 * * Observations *1 *1 * *

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water * * 0.75 0.94 0.00 * 

Septic system * * 0.00 0.00 0.00 * Sanitary sewer * * 0.25 0.68 0.00 * Observations * *441 *

Treatment Scheme: Membranes

Direct Discharge to Surface Water * * * * * * 

Septic system * * * * * * Sanitary sewer * * * * * * Observations * * * * * * 

Treatment Scheme: Other

Direct Discharge to Surface Water * * * * * * 

Septic system * * * * * * Sanitary sewer * * * * * * Observations * * * * * * 

(Continued)
Table 40 (Cont.)

Percentage of Water Treatment Plants Allowed to Discharge to 

Surface Water, Septic Systems, or Sanitary Sewers that Use that Option

By Water Source, Treatement Scheme, and Plant Average Daily Production

Plant Average Daily Production (MGD)

Water Source and Treatment Scheme

0 - 

0.01

0.01 - 

0.1

0.1 - 

1.0

1.0 -

10.0

10.0 - 

100.0

Over 

100 A

All Plants

Treatment Scheme: Disinfection with no additional treatment

Direct Discharge to Surface Water * 0.26 0.88 0.67 0.00 * Septic system * 0.00 0.00 0.00 0.00 * Sanitary sewer * 0.00 0.14 0.00 0.00 * Observations * 6 25 35 1 * 

Treatment Scheme: Other chemical addition

Direct Discharge to Surface Water * 0.00 0.81 1.00 0.67 * Septic system * 0.00 0.00 0.00 0.00 * Sanitary sewer * 0.00 0.00 0.00 0.33 * Observations * 1 24 6 6 * 

Treatment Scheme: Ion exchange, activated alumina, aeration

Direct Discharge to Surface Water * * 1.00 1.00 * * Septic system * * 0.00 0.00 * * Sanitary sewer * * 0.00 0.00 * * Observations * *18 * *

Treatment Scheme: Other filtration (not direct or conventional)

Direct Discharge to Surface Water 1 1.00 0.85 0.98 0.19 * Septic system 0 0.00 0.15 0.05 0.00 * Sanitary sewer 0 0.01 0.04 0.16 0.04 * Observations 3 10 13 17 15 * 

Treatment Scheme: Direct filtration

Direct Discharge to Surface Water * 1.00 0.75 0.99 0.89 * Septic system * 0.00 0.12 0.01 0.00 * Sanitary sewer * 0.00 0.00 0.06 0.22 * Observations * 1 9 20 8 * 

Treatment Scheme: Conventional filtration (with and without softening)

Direct Discharge to Surface Water 1 0.91 0.76 0.94 0.84 0.50 Septic system 0 0.00 0.00 0.03 0.00 0.00 Sanitary sewer 0 0.00 0.07 0.27 0.18 0.17 Observations 1 8 24 57 62 6 

Treatment Scheme: Membranes

Direct Discharge to Surface Water * 1.00 0.95 1.00 * * Septic system * 0.00 0.00 0.00 * * Sanitary sewer * 0.00 0.31 0.00 * * Observations * 1 5 4 * * 

Treatment Scheme: Other

Direct Discharge to Surface Water 1.00 * 0.00 0.26 0.43 0.00 Septic system 0.00 * 0.00 0.00 0.00 0.00 Sanitary sewer 0.00 * 0.00 0.00 0.21 0.00 Observations 1 * 1 6 3 1 

Data: Q.9Notes: Treatment schemes listed are based on the categorization presented by

Table 23 and Table 24. These are the systems with the option to discharge to surface water, sepsystems, or sanitary sewers, and make use of these options.
Table 41

Raw Water Concentration of Various Contaminants in Very Large Ground Water and Surface Water Systems

(Concentration in Parts per Billion)

Contaminant

% Not 

Reporting/ 

Testing

% Reporting 

No Detect

Mean 

Concentration

Median 

Concentration

90th Percentile 

Concentration Observations

Sys

Rep

All Plants

1,1-Dichloroethane 98.2 0.0 0.066 0.066 0.066 1 

1,2-Dichloroethylene 98.2 0.0 0.066 0.066 0.066 1 

1,4 Dioxane 59.0 0.0 0.956 0.900 1.300 25 Alachlor ESA 89.7 0.0 0.937 0.280 4.190 6 Alachlor OA 98.2 0.0 1.850 1.850 1.850 1 Chlorodibromomethane 98.2 0.0 2.923 2.923 2.923 1 Chloroform 98.2 0.0 59.030 59.030 59.030 1 Cryptosporidium 98.2 0.0 0.000 0.000 0.000 1 DCPA diacid 65.1 0.0 18.205 13.950 43.400 22 

Dichlorobromomethane 98.2 0.0 16.051 16.051 16.051 1 MTBE 66.1 10.0 2.098 1.050 5.200 20 

Metalaxyl 93.0 0.0 0.810 0.845 1.310 4 Methylene Chloride 98.2 0.0 0.066 0.066 0.066 1 

Metolachlor 96.4 0.0 0.290 0.290 0.340 2 Metolachlor ESA 75.0 0.0 2.558 1.550 6.010 16 Metolachlor OA 76.2 0.0 1.918 1.080 5.140 15 Perchlorate 2.4 0.0 1.217 0.880 2.430 80 

THM's 98.2 0.0 78.009 78.009 78.009 1 Trichloroethylene 98.2 0.0 0.066 0.066 0.066 1 VOC's 98.2 0.0 0.379 0.379 0.379 1 Vinyl Chloride 98.2 0.0 0.0659 0.066 0.066 1 

Data: Q.10Notes: The data presented in this table were requested only of systems serving populations of more than 500,000. These

systems were asked to provide data on their unregulated contaminants. This is a listing of the most prevalent responses. Unweighted data. Data are for contaminant test points reported by systems in the survey. The percent not reporting ortesting includes all test points for systems reporting at least one raw water contaminant. The percent reporting no detect only includes points where the contaminant is tested. Mean, median, and 90th percentile are for test points with positive concentrations. The number of observations and systems reporting are for those with no detect or positive concentrations. 
% Not 

Reporting/ % Reporting Mean Median 90th Percentile 

Water Source and Contaminant Testing No Detect Concentration Concentration Concentration Observations 

All Plants 

1,1-Dichloroethane 99.2 100.0 * * * 1 

1,2,3-Trichloropropane 99.2 0.0 400.000 400.000 400.000 1 

1,2-Dichloroethylene 99.2 100.0 * * * 1 

1,4 Dioxane 81.1 32.0 0.953 0.800 1.400 25 

Acetaminophen 99.2 0.0 0.018 0.018 0.018 1 

Alachlor ESA 95.3 83.3 0.350 0.350 0.350 6 

Alachlor OA 99.2 100.0 * * * 1 

Aluminum 85.0 52.6 52.346 65.000 79.000 19 Bicarbonate 99.2 0.0 163000.000 163000.000 163000.000 1 

Boron 86.6 23.5 135.385 140.000 200.000 17 Bromide 95.3 66.7 59.500 59.500 110.000 6 Bromobenzene 99.2 100.0 * * * 1 

Bromochloroacetic acid 97.6 0.0 13.000 13.000 13.000 3 

Bromodichloromethane 88.2 6.7 8.492 4.450 21.000 15 

Bromoform 94.5 28.6 3.332 2.600 6.850 7 

Caffeine 99.2 0.0 0.017 0.017 0.017 1 

Calcium 77.2 0.0 40055.172 30000.000 95000.000 29 

Carbon Dioxide 98.4 0.0 58500.000 58500.000 112000.000 2 Chloral Hydrate 99.2 0.0 2.100 2.100 2.100 1 

Chlorate 97.6 33.3 42.500 42.500 51.000 3 Chloride 80.3 0.0 64227.199 49990.000 140000.000 25 

Chlorodibromomethane 97.6 0.0 2.240 1.800 4.400 3 

Chloroform 87.4 6.3 23.479 10.000 89.000 16 

Chromium 96.1 20.0 2.880 1.570 8.260 5 

Cobalt 99.2 100.0 * * * 1 

DCPA acid metabolites 99.2 0.0 9.500 9.500 9.500 1 

DCPA diacid 83.6 81.8 5.625 5.000 10.700 22 

Dibromoacetic acid 97.6 0.0 1.900 1.900 1.900 3 

Dibromochloromethane 91.3 27.3 6.409 6.400 14.000 11 

Dichloroacetic acid 96.1 0.0 37.360 50.000 50.000 5 

Dichlorobromomethane 99.2 0.0 1.364 1.364 1.364 1 

Foaming Agents 98.4 100.0 * * * 2 Ibuprofen 99.2 0.0 0.002 0.002 0.002 1 

Iodide 99.2 0.0 5.900 5.900 5.900 1 

Iron 88.2 80.0 70522.336 539.000 211000.000 15 Lithium 99.2 0.0 2.700 2.700 2.700 1 

MTBE 84.6 65.0 1.200 0.500 5.000 20 

Magnesium 76.4 0.0 11272.333 9950.000 24000.000 30 

Manganese 99.2 0.0 0.003 0.003 0.003 1 

Metalaxyl 96.9 100.0 * * * 4 

Methylene Chloride 99.2 100.0 * * * 1 

(

Table 42 

Finished Water Concentration of Various Contaminants in Very Large Ground Water and Surface Water Systems 

By Water Source 

(Concentration in Parts per Billion, Unless Otherwise Noted) 
Finished Water Concentration of Various Contaminants in Very Large Ground Water and Surface Water Systems

By Water Source

Water Source and Contaminant 

Metolachlor Metolachlor ESA Metolachlor OA Molybdenum Monobromoacetic acid Monochloroacetic acid NDMA Nickel Orthophosphates Perchlorate Phosphates Phosphorus Potassium Radon (pCi/L) Silica Silicon Silver Sodium Strontium Sulfamethoxazole Sulfate Surfactants THM's Total Dissolved Solids Total Organic Carbon Trichloroacetic acid Trichloroethylene VOC's Vanadium Vinyl Chloride Zinc p-Isopropyltoluene pH (pH) 

(Concentration in Parts per Billion, Unless Otherwise Noted) 

% Reporting % Reporting Mean Median 90th Percentile 

N/A No Detect Concentration Concentration Concentration Observations 

94.5 71.4 1.400 1.400 1.400 7 88.1 93.8 2.350 2.350 2.350 16 

88.8 93.3 1.770 1.770 1.770 15 

98.4 0.0 16.000 16.000 31.000 2 

97.6 0.0 2.400 2.400 2.400 3 97.6 0.0 4.300 4.300 4.300 3 

93.7 75.0 0.001 0.001 0.001 8 95.3 0.0 668.833 3.450 4000.000 6 

99.2 0.0 3.000 3.000 3.000 1 39.9 35.9 1.382 0.880 3.000 92 

99.2 0.0 700.000 700.000 700.000 1 99.2 0.0 380.000 380.000 380.000 1 

78.7 0.0 2505.185 2510.000 4100.000 27 97.6 33.3 350.335 350.335 407.670 3 92.1 0.0 9560.000 11150.000 12400.000 10 99.2 0.0 5280.000 5280.000 5280.000 1 

96.1 100.0 * * * 5 62.2 0.0 36281.043 19500.000 83000.000 48 99.2 0.0 330.000 330.000 330.000 1 

99.2 0.0 0.002 0.002 0.002 1 

88.2 0.0 105820.000 50000.000 255000.000 15 

99.2 0.0 100.000 100.000 100.000 1 

99.2 0.0 7.668 7.668 7.668 1 

78.0 0.0 378829.281 288000.000 770000.000 28 

83.5 19.0 2091.765 2200.000 3330.000 21 

96.1 0.0 13.800 16.000 16.000 5 99.2 100.0 * * * 1 

99.2 100.0 * * * 1 

96.1 20.0 2.363 2.225 4.100 5 

99.2 100.0 * * * 1 

99.2 0.0 254.000 254.000 254.000 1 

99.2 100.0 * * * 1 

78.7 0.0 8.187 8.200 9.100 27 

Data: Q10 and CCR Notes: The data presented in this table were requested only of systems serving populations of more than 500,000. These systems 

were asked to provide data on their unregulated contaminants. The data received by the CWS survey are supplemented with data from Consumer Confidence Reports (CCR) issued by the systems. Unweighted data. Data are for contaminant test points reported by systems in the survey. The percent not reporting or testing includes all test points for systems reporting at least one finished water contaminant. The percent reporting no detect 

only includes points where the contaminant is tested. Mean, median, and 90th percentile are for test points with positive 

Table 42 (Cont.)

(Table 28 in the 2000 Report, Table 33 from draft 1)
Please note that the unit of analysis changes for the following tables. 

The remaining tables report data for water systems except where noted. 
Table 43

Treatment Schemes

Percentage of Systems Using Each Treatment Scheme

By Water Source

System Service Population Category

Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 

100% Ground Water System

Disinfection with no additional treatment 52.2 52.9 47.8 49.2 36.7 6.9 33.4 31.5 Other chemical addition 12.0 12.9 27.6 28.1 29.9 53.9 29.8 0.0 Ion exchange, activated alumina, aeration 17.9 9.9 10.6 10.0 32.4 20.8 20.1 0.0 Other filtration (not direct or conventional) 17.8 16.9 15.3 20.9 28.2 41.0 43.2 15.7 Direct filtration 0.0 0.0 1.1 0.0 8.1 6.9 3.3 0.0 Conventional filtration (with and without softening) 0.0 1.4 2.1 5.5 0.4 6.9 10.0 68.5 Membranes 0.0 1.4 1.1 0.0 0.4 3.5 0.0 0.0 Other 2.1 5.9 1.1 0.0 3.1 0.0 10.0 0.0 

Observations 87 103 107 45 50 28 33 4 

Primarily Ground Water Systems

Disinfection with no additional treatment 0.0 100.0 25.0 32.1 25.4 32.6 32.4 0.0 Other chemical addition 0.0 0.0 50.0 16.7 55.0 57.1 27.3 50.0 Ion exchange, activated alumina, aeration 0.0 0.0 0.0 0.0 10.0 11.7 22.1 100.0 Other filtration (not direct or conventional) 100.0 0.0 50.0 40.3 20.0 23.4 44.7 50.0 

Direct filtration 0.0 0.0 0.0 13.8 7.5 16.1 9.1 0.0 Conventional filtration (with and without softening) 0.0 0.0 0.0 24.8 15.0 20.6 35.2 0.0 Membranes 0.0 0.0 0.0 0.0 0.0 0.0 4.4 50.0 Other 0.0 0.0 0.0 0.0 5.4 11.7 22.5 0.0 

Observations 1 2 4 17 16 12 23 2 

100% Surface Water System

Disinfection with no additional treatment 15.4 27.9 4.9 0.0 0.0 9.7 0.0 0.0 Ion exchange, activated alumina, aeration 0.0 1.4 6.6 9.8 2.0 0.0 2.3 15.8 Ion exchan Ion exchange,Activated Alumina Activated Alumina, Aeration Aeration 0.0 0.0 0.0 2.0 2.0 0.0 0.0 0.0 

0.0 0.0 0.0 2.0 2.0 0.0 0.0 0.0 

Other filtration (not direct or conventional) 62.0 27.8 27.9 12.0 6.0 0.0 3.5 0.0 Direct filtration 8.0 13.7 15.3 22.0 15.4 12.4 17.6 15.8 Conventional filtration (with and without softening) 10.9 24.2 39.9 52.1 76.5 84.1 85.9 84.2 Membranes 3.6 5.6 7.1 6.0 0.0 3.1 1.2 10.5 Other 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Observations 44 62 61 50 57 35 77 20 

Primarily Surface Water System

Disinfection with no additional treatment 100.0 54.3 60.9 6.3 11.3 5.4 19.3 15.8 Ion exchange, activated alumina, aeration 0.0 0.0 9.4 0.0 15.3 16.2 18.2 36.8 Ion exchange, Activated Alumina, Aeration 0.0 0.0 0.0 24.5 3.8 0.0 7.7 0.0 Other filtration (not direct or conventional) 36.0 31.4 30.7 6.3 19.0 5.4 12.5 15.8 Direct filtration 0.0 0.0 12.1 6.3 22.8 29.2 10.2 21.1 Conventional filtration (with and without softening) 0.0 22.9 35.6 62.8 65.7 65.4 85.4 78.9 Membranes 0.0 0.0 16.2 0.0 3.8 2.3 2.1 0.0 Other 0.0 22.9 0.0 0.0 0.0 0.0 2.1 5.3 

Observations 5 5 17 15 28 19 47 19 

(Continued)
Table 43 (Cont.)

Treatment Schemes

Percentage of Systems Using Each Treatment Scheme

By Water Source

System Service Population Category

Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 

Primarily Purchased Water System

Disinfection with no additional treatment 0.0 100.0 66.4 21.7 32.0 33.0 31.2 38.8 Other chemical addition 0.0 0.0 0.0 56.4 32.0 31.1 27.7 19.4 Ion exchange, activated alumina, aeration 0.0 0.0 0.0 0.0 0.0 16.5 18.6 19.4 Other filtration (not direct or conventional) 0.0 0.0 0.0 0.0 0.0 35.9 18.6 19.4 Direct filtration 0.0 0.0 0.0 0.0 24.0 0.0 13.4 20.4 Conventional filtration (with and without softening) 100.0 0.0 0.0 21.9 12.0 31.1 26.1 40.8 Membranes 0.0 0.0 0.0 0.0 0.0 0.0 9.1 19.4 Other 0.0 0.0 33.6 0.0 0.0 16.5 4.4 19.4 

Observations 1 1 4 4 9 10 24 5 

Data: Q.8ANotes: Excludes plants that only treat purchased water.

See treatment scheme description in Volume I.
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 Primarily Ground Water Systems 

Fully or partially buried 24.7 22.7 7.1 24.8 14.7 26.7 30.1 18.7 

Confidence Interval +|- 29.4 +|- 19.8 +|- 5.8 +|- 12.0 +|- 10.4 +|- 15.0 +|- 9.5 +|- 27.7 

Ground level 40.1 26.4 30.2 30.0 36.6 54.8 73.8 81.3 

Confidence Interval +|- 31.1 +|- 19.3 +|- 12.4 +|- 12.6 +|- 13.5 +|- 22.0 +|- 9.3 +|- 27.7 

Elevated 32.1 25.3 58.4 64.8 76.2 68.9 45.8 100.0 

Confidence Interval +|- 27.9 +|- 16.6 +|- 13.2 +|- 13.3 +|- 12.0 +|- 16.4 +|- 10.5 +|- 0.0 

Hydropneumatic 26.9 13.2 7.1 0.0 5.8 16.7 13.1 18.7 

Confidence Interval +|- 27.3 +|- 13.6 +|- 6.3 +|- 0.0 +|- 6.0 +|- 12.1 +|- 7.1 +|- 27.7 

Standpipes 25.6 12.4 15.1 22.4 32.1 7.5 10.7 100.0 

Confidence Interval +|- 26.2 +|- 13.1 +|- 8.1 +|- 11.5 +|- 13.1 +|- 7.1 +|- 6.4 +|- 0.0 

Standpipes operated as surge tanks 0.0 0.0 0.0 4.1 2.1 2.8 2.0 0.0 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 5.6 +|- 4.1 +|- 5.0 +|- 2.7 +|- 0.0 

Other 0.0 0.0 0.0 0.0 2.1 0.0 2.2 0.0 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 4.1 +|- 0.0 +|- 3.1 +|- 0.0 

Primarily Surface Water Systems 

Fully or partially buried 19.3 12.7 11.0 17.6 25.9 28.9 37.7 61.1 

Confidence Interval +|- 17.9 +|- 12.6 +|- 7.4 +|- 12.0 +|- 9.4 +|- 11.5 +|- 8.9 +|- 10.0 

Ground level 80.7 81.2 70.7 34.0 46.1 54.2 66.0 86.1 

Confidence Interval +|- 17.9 +|- 14.4 +|- 13.3 +|- 11.8 +|- 10.7 +|- 12.6 +|- 10.2 +|- 7.1 

Elevated 7.0 7.7 21.9 70.6 58.6 78.8 71.5 66.7 

Confidence Interval +|- 13.9 +|- 9.2 +|- 9.4 +|- 11.2 +|- 10.6 +|- 10.2 +|- 6.7 +|- 9.6 

Hydropneumatic 35.2 18.8 8.6 4.4 2.6 6.5 7.2 19.4 

Confidence Interval +|- 32.2 +|- 16.8 +|- 8.9 +|- 4.8 +|- 3.5 +|- 6.3 +|- 3.3 +|- 8.1 

Standpipes 7.0 0.0 23.0 29.3 24.8 40.0 26.2 36.1 

Confidence Interval +|- 13.9 +|- 0.0 +|- 13.9 +|- 12.8 +|- 9.2 +|- 12.5 +|- 6.4 +|- 9.8 

Standpipes operated as surge tanks 0.0 0.0 1.6 0.0 2.7 0.0 3.2 5.6 

Confidence Interval +|- 0.0 +|- 0.0 +|- 3.1 +|- 0.0 +|- 3.5 +|- 0.0 +|- 2.2 +|- 4.7 

Other 0.0 0.0 0.0 0.0 2.6 0.0 1.6 0.0 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 3.5 +|- 0.0 +|- 1.6 +|- 0.0 

(Continued

Table 44 

Treated-Water Storage Information 

Percentage of Systems That Have Each Type of Treated-Water Storage 

By Primary Water Source 
Treated-Water Storage Information 

Percentage of Systems That Have Each Type of Treate

By Primary Water Source 

100 101 -

System Servi

501 - 3,301 -

Primary Water Source or Less 500 3,300 10,000

Primarily Purchased Water Systems 

Fully or partially buried 0.0 39.0 3.9 10.5 

Confidence Interval +|- 0.0 +|- 42.6 +|- 7.7 +|- 12.4 

Ground level 51.4 59.8 43.0 28.3 

Confidence Interval +|- 68.4 +|- 42.6 +|- 24.2 +|- 19.3 

Elevated 0.0 19.8 51.6 70.3 

Confidence Interval +|- 0.0 +|- 33.8 +|- 21.0 +|- 19.8 

Hydropneumatic 0.0 40.6 3.9 1.2 

Confidence Interval +|- 0.0 +|- 42.6 +|- 7.7 +|- 2.3 

Standpipes 48.6 18.6 16.5 26.3 

Confidence Interval +|- 68.4 +|- 33.7 +|- 15.2 +|- 18.4 

Standpipes operated as surge tanks 0.0 0.0 0.0 4.7 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 8.9 

Other 0.0 0.0 0.0 0.0 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 

All Systems 

Fully or partially buried 20.9 24.8 6.7 19.9 17.8 32.9 40.3 50.7 

Confidence Interval +|- 24.5 +|- 16.9 +|- 4.4 +|- 7.8 +|- 6.7 +|- 8.9 +|- 6.1 +|- 10.7 

Ground level 43.7 35.6 37.1 30.4 38.0 55.4 68.9 83.4 

Confidence Interval +|- 26.9 +|- 17.5 +|- 10.4 +|- 8.7 +|- 8.6 +|- 10.7 +|- 6.8 +|- 6.4 

Elevated 26.3 23.2 53.3 67.3 62.2 68.0 63.7 66.4 

Confidence Interval +|- 23.1 +|- 14.0 +|- 10.2 +|- 9.1 +|- 8.7 +|- 8.8 +|- 5.4 +|- 9.1 

Hydropneumatic 23.5 18.2 6.5 1.2 3.8 11.9 12.0 18.6 

Confidence Interval +|- 22.6 +|- 13.5 +|- 4.7 +|- 1.1 +|- 3.3 +|- 5.8 +|- 3.3 +|- 6.9 

Standpipes 28.0 12.7 16.2 24.7 29.7 23.4 20.6 37.8 

Confidence Interval +|- 23.3 +|- 11.6 +|- 6.9 +|- 8.2 +|- 8.2 +|- 7.3 +|- 4.1 +|- 10.9 

Standpipes operated as surge tanks 0.0 0.0 0.1 3.4 2.3 1.0 2.3 3.8 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.3 +|- 3.8 +|- 2.5 +|- 1.8 +|- 1.4 +|- 3.2 

Other 0.0 0.0 0.0 0.0 1.9 0.0 1.9 0.0 

Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 2.4 +|- 0.0 +|- 1.3 +|- 0.0 

Data: Q.11B Notes: Column totals do not equal 100. 

Systems that use any surface water includes systems that use ground water under the direinfluence of surface water and systems that purchase surface water. 100% ground water systems includes systems that purchase ground water. 

d-Water Storage

ce Population Category 

10,001 - 50,001 - 100,001- Over 

 50,000 100,000 500,000 500,000 

12.4 53.1 60.3 32.7 

+|- 15.9 +|- 19.9 +|- 12.5 +|- 21.7 

27.9 59.0 71.8 75.8 

+|- 22.7 +|- 19.7 +|- 10.5 +|- 18.0 

28.1 43.2 61.8 51.2 

+|- 21.1 +|- 19.7 +|- 11.6 +|- 27.4 

0.0 14.6 25.2 16.1 

+|- 0.0 +|- 13.6 +|- 10.0 +|- 14.4 

31.7 17.4 15.4 16.1 

+|- 21.5 +|- 14.6 +|- 8.3 +|- 14.4 

2.3 0.0 0.0 0.0 

+|- 4.4 +|- 0.0 +|- 0.0 +|- 0.0 

0.0 0.0 2.4 0.0 

+|- 0.0 +|- 0.0 +|- 3.2 +|- 0.0 

Table 44 (Cont.)
System Service Population Categ

100 101 - 501 - 3,301 - 10,001 - 50,001 Ove

Primary Water Source or Less 500 3,300 10,000 50,000 100,00 0,000 

Primarily Ground Water Systems 

Average storage capacity 0.2 0.2 0.6 1.2 4.4 9.2 24.1 22.3 

Confidence Interval +|- 0.2 +|- 0.3 +|- 0.6 +|- 0.3 +|- 1.6 +|- 2.9 +|- 5.8 +|- 14.2 

Average Number of Vessels 

Fully or partially buried 1.0 0.3 0.2 1.0 0.3 1.0 1.9 0.4 Ground level 0.8 0.6 0.6 0.7 1.3 3.0 4.2 4.2 Elevated 0.3 0.3 0.7 1.1 2.0 3.5 2.1 11.1 Hydropneumatic 0.5 0.1 0.1 0.0 0.1 0.3 1.5 7.5 Standpipes 0.3 0.2 0.2 0.4 0.8 0.2 0.6 5.8 Standpipes operated as surge tanks 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Other 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 

Observations 76 94 107 56 62 36 49 4 

Primarily Surface Water Systems 

Average storage capacity 0.1 0.4 0.6 1.5 3.9 10.8 26.5 179.0 

Confidence Interval +|- 0.1 +|- 0.5 +|- 0.1 +|- 0.3 +|- 0.7 +|- 2.6 +|- 5.4 +|- 43.6 

Average Number of Vessels 

Fully or partially buried 0.2 0.1 0.1 0.2 0.6 0.6 1.5 3.7 Ground level 1.1 1.9 1.1 0.9 2.2 3.1 4.1 19.0 Elevated 0.1 0.0 0.4 1.4 1.7 3.0 3.3 5.5 Hydropneumatic 0.4 0.3 0.1 0.1 0.1 0.1 0.8 1.6 Standpipes 0.1 0.0 0.3 0.6 0.8 1.1 2.1 3.3 Standpipes operated as surge tanks 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.2 Other 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 

Observations 47 62 75 64 84 49 114 38 

(Continue

ory 

- 100,001-

0 500,000 50

Table 45 

Storage Capacity past the First Residential Customer by Type of Vessel

By Primary Water Source 

(In Millions of Gallons) 
Storage Capacity past the First Residentia

By Primary Water 

(In Millions of Ga

Sys

100 101 - 501 -

Primary Water Source or Less 500 3,300 

Primarily Purchased Water Systems 

Average storage capacity 1.4 0.8 1.2 

Confidence Interval +|- 1.9 +|- 1.2 +|- 1.5 

Average Number of Vessels 

Fully or partially buried 0.0 0.3 0.3 Ground level 2.6 0.8 1.1 Elevated 0.0 0.0 0.6 Hydropneumatic 0.0 0.8 0.0 Standpipes 0.5 0.2 0.4 Standpipes operated as surge tanks 0.0 0.0 0.0 Other 0.0 0.0 0.0 

Observations 7 22 44

All Systems 

Average storage capacity 0.4 0.3 0.8 

Confidence Interval +|- 0.4 +|- 0.3 +|- 0.5 

Average Number of Vessels 

Fully or partially buried 0.8 0.3 0.2 Ground level 1.1 0.7 0.7 Elevated 0.3 0.2 0.6 Hydropneumatic 0.4 0.2 0.1 Standpipes 0.3 0.2 0.3 Standpipes operated as surge tanks 0.0 0.0 0.0 0.1 0.0 0.0 0.1 0.1 Other 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Observations 130 178 226 147 169 110 204 52 

Data: Q.11 A and B. Notes: Average number of vessels is the average for systems that report a count for that storage 

The calculation includes zeros reported in the denominator, i.e., if a system reported a stocapacity, every record was used for the average number of vessels calculation, including z

l Customer by Type of Vessel 

Sou

llon

tem

3

1

+

0.1 0.7 1.8 3.3 3.7 0.6 0.8 3.7 8.4 8.2 1.1 0.8 2.0 3.5 1.9 0.0 0.0 0.2 0.7 0.5 0.9 0.9 1.1 0.5 0.5 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

 27 23 25 41 10 

1.2 4.2 11.9 28.7 148.8 

+|- 0.2 +|- 0.9 +|- 2.6 +|- 4.0 +|- 40.1 

0.6 0.5 1.0 1.9 3.4 0.7 1.5 3.2 5.0 15.2 1.1 1.7 3.0 3.0 5.3 0.0 0.1 0.2 0.9 1.9 0.5 0.8 0.8 1.4 2.9 

rce

s) 

 Service Population Category 

,301 - 10,001 - 50,001 - 100,001- Ove

0,000 50,000 100,000 500,000 500,000 

0.8 3.7 19.3 40.7 111.4 

|- 0.2 +|- 2.0 +|- 9.2 +|- 9.9 +|- 90.4 

Table 45 (Cont.)
Table 46

Practices to Maintain Water Quality in Storage Vessels

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

500

Primarily Ground Water Systems

Percentage of systems that: 

Modeling or other detention time evaluations 0.0 0.0 2.3 12.7 29.6 23.1 45.6 Confidence Interval +|- 0.0 +|- 0.0 +|- 3.3 +|- 8.9 +|- 12.9 +|- 14.1 +|- 10.5 +|- 

Longer fill/draw cycles to increase mixing 17.2 21.1 29.3 48.5 53.5 36.8 56.3 Confidence Interval +|- 22.9 +|- 16.4 +|- 12.8 +|- 13.8 +|- 14.2 +|- 17.9 +|- 10.4 +|- Inlet/outlet modifications 0.0 0.0 10.2 14.4 11.3 13.6 29.9 Confidence Interval +|- 0.0 +|- 0.0 +|- 8.0 +|- 9.8 +|- 8.2 +|- 10.9 +|- 9.4 +|Mechanical mixing 0.0 4.1 2.8 6.2 3.4 0.0 12.6 Confidence Interval +|- 0.0 +|- 8.2 +|- 4.0 +|- 6.7 +|- 4.4 +|- 0.0 +|- 6.6 +|Increase or switch disinfectant residual 17.4 0.0 2.3 22.9 20.3 22.3 36.7 Confidence Interval +|- 22.9 +|- 0.0 +|- 3.2 +|- 11.5 +|- 11.3 +|- 14.0 +|- 10.1 +|- Operational modifications to maintain disinfectant residual 0.2 8.3 8.6 37.8 48.4 26.3 60.5 Confidence Interval +|- 0.2 +|- 11.4 +|- 6.3 +|- 13.3 +|- 14.2 +|- 15.0 +|- 10.3 +|- Other 9.0 22.4 3.7 5.5 8.9 2.8 6.6 Confidence Interval +|- 16.2 +|- 18.3 +|- 4.3 +|- 6.1 +|- 8.0 +|- 5.0 +|- 5.3 +|

Average number of years between cleaning 9.5 5.9 6.5 5.8 7.4 5.6 5.2 Confidence Interval +|- 4.4 +|- 2.4 +|- 1.2 +|- 1.1 +|- 1.5 +|- 1.1 +|- 0.6 +|

(Cont
Table 46 (Cont.)

Practices to Maintain Water Quality in Storage Vessels

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

500

Primarily Surface Water Systems

Percentage of systems that: 

Modeling or other detention time evaluations 4.2 7.7 9.4 35.4 41.2 48.6 54.6 Confidence Interval +|- 8.5 +|- 10.6 +|- 7.7 +|- 12.0 +|- 10.5 +|- 12.6 +|- 9.4 +|

Longer fill/draw cycles to increase mixing 7.0 20.5 24.6 47.2 56.9 71.1 62.8 Confidence Interval +|- 13.9 +|- 15.8 +|- 11.8 +|- 13.1 +|- 10.6 +|- 11.5 +|- 9.0 +|Inlet/outlet modifications 0.0 1.4 9.9 20.7 24.8 25.8 28.7 Confidence Interval +|- 0.0 +|- 2.7 +|- 8.9 +|- 9.7 +|- 9.2 +|- 11.0 +|- 6.7 +|Mechanical mixing 0.0 1.5 0.0 5.9 8.1 4.6 10.5 Confidence Interval +|- 0.0 +|- 2.9 +|- 0.0 +|- 5.4 +|- 5.9 +|- 5.6 +|- 8.7 +|Increase or switch disinfectant residual 7.0 0.0 2.2 39.7 38.5 26.8 32.3 Confidence Interval +|- 13.9 +|- 0.0 +|- 3.3 +|- 13.3 +|- 10.4 +|- 11.2 +|- 7.3 +|- Operational modifications to maintain disinfectant residual 21.1 17.3 14.1 38.3 53.4 55.7 53.7 Confidence Interval +|- 27.7 +|- 17.7 +|- 8.8 +|- 12.3 +|- 10.7 +|- 12.6 +|- 9.0 +|Other 40.2 13.9 8.6 3.0 5.3 8.6 8.1 Confidence Interval +|- 32.6 +|- 16.9 +|- 8.8 +|- 3.9 +|- 4.9 +|- 7.2 +|- 8.7 +|

Average number of years between cleaning 5.9 8.1 5.9 7.1 6.5 6.6 6.4 Confidence Interval +|- 4.0 +|- 2.4 +|- 1.6 +|- 1.5 +|- 1.1 +|- 1.6 +|- 0.8 +|

(Cont
Table 46 (Cont.)

Practices to Maintain Water Quality in Storage Vessels

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

500

Primarily Purchased Water Systems

Percentage of systems that: 

Modeling or other detention time evaluations 0.0 0.0 0.0 1.2 34.1 64.9 48.1 Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 2.3 +|- 23.6 +|- 18.9 +|- 12.2 +|- 

Longer fill/draw cycles to increase mixing 51.4 38.4 35.3 78.8 63.4 64.9 74.2 Confidence Interval +|- 68.4 +|- 41.9 +|- 21.6 +|- 16.7 +|- 22.6 +|- 18.9 +|- 10.2 +|- Inlet/outlet modifications 0.0 1.2 13.8 22.7 21.9 43.2 51.9 Confidence Interval +|- 0.0 +|- 2.4 +|- 17.9 +|- 18.8 +|- 19.2 +|- 19.7 +|- 12.2 +|- Mechanical mixing 0.0 0.0 0.0 4.7 2.3 4.7 20.6 Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 8.9 +|- 4.4 +|- 7.9 +|- 9.4 +|- Increase or switch disinfectant residual 0.0 18.6 2.4 14.8 17.0 32.0 42.5 Confidence Interval +|- 0.0 +|- 33.7 +|- 4.7 +|- 13.7 +|- 16.8 +|- 18.0 +|- 11.8 +|- Operational modifications to maintain disinfectant residual 51.4 0.0 6.3 37.3 73.6 77.3 74.4 Confidence Interval +|- 68.4 +|- 0.0 +|- 9.0 +|- 20.1 +|- 21.6 +|- 16.4 +|- 10.2 +|- Other 1.3 0.0 0.0 7.7 6.2 10.6 2.4 Confidence Interval +|- 3.2 +|- 0.0 +|- 0.0 +|- 10.5 +|- 11.6 +|- 12.5 +|- 3.2 +|- 

Average number of years between cleaning 3.6 8.1 7.3 5.6 6.8 4.2 4.5 Confidence Interval +|- 2.1 +|- 2.0 +|- 3.4 +|- 1.5 +|- 2.0 +|- 0.8 +|- 0.7 +|

(Cont
Table 46 (Cont.)

Practices to Maintain Water Quality in Storage Vessels

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

500

All Systems

Percentage of systems that: 

Modeling or other detention time evaluations 0.2 0.5 2.4 14.4 34.0 42.3 51.3 Confidence Interval +|- 0.4 +|- 0.7 +|- 2.3 +|- 5.5 +|- 8.5 +|- 9.8 +|- 6.2 +|- 

Longer fill/draw cycles to increase mixing 21.6 24.0 30.3 55.7 56.3 57.0 63.5 Confidence Interval +|- 22.1 +|- 14.7 +|- 10.3 +|- 9.6 +|- 9.0 +|- 10.7 +|- 6.1 +|Inlet/outlet modifications 0.0 0.3 11.1 17.7 17.4 24.7 33.4 Confidence Interval +|- 0.0 +|- 0.4 +|- 6.9 +|- 7.5 +|- 6.2 +|- 7.9 +|- 5.3 +|- Mechanical mixing 0.0 3.3 1.9 5.7 4.7 2.9 12.9 Confidence Interval +|- 0.0 +|- 6.3 +|- 2.6 +|- 4.5 +|- 3.0 +|- 2.9 +|- 5.5 +|Increase or switch disinfectant residual 14.4 3.2 2.3 24.3 25.4 26.1 35.3 Confidence Interval +|- 18.7 +|- 6.3 +|- 2.4 +|- 7.8 +|- 7.3 +|- 8.1 +|- 5.4 +|- Operational modifications to maintain disinfectant residual 8.5 7.5 8.6 37.8 54.4 49.0 59.3 Confidence Interval +|- 14.6 +|- 8.9 +|- 4.8 +|- 9.2 +|- 9.0 +|- 10.3 +|- 6.2 +|- Other 9.4 18.0 3.3 5.5 7.3 6.8 6.6 Confidence Interval +|- 13.3 +|- 14.2 +|- 3.0 +|- 4.3 +|- 4.8 +|- 4.5 +|- 5.3 +|

Average number of years between cleaning 7.6 6.5 6.6 6.0 7.0 5.8 5.7 Confidence Interval +|- 3.6 +|- 1.8 +|- 1.1 +|- 0.8 +|- 0.9 +|- 0.8 +|- 0.5 +|

Data: Q.11DNotes:
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 A

Primarily Ground Water Systems 

Modeling or other detention time evaluations 0.0 0.0 13.9 6.7 7.1 22.0 6.3 18.7 Confidence Interval +|- 0.0 +|- 0.0 +|- 8.0 +|- 6.8 +|- 7.0 +|- 13.9 +|- 4.9 +|- 27.7 Longer fill/draw cycles to increase mixing 0.0 0.0 14.1 8.2 9.7 10.5 6.3 18.7 Confidence Interval +|- 0.0 +|- 0.0 +|- 9.2 +|- 7.7 +|- 8.1 +|- 9.3 +|- 4.9 +|- 27.7 Inlet/outlet modifications 0.0 9.1 11.0 5.5 10.2 12.0 8.5 18.7 Confidence Interval +|- 0.0 +|- 17.0 +|- 9.0 +|- 6.1 +|- 8.1 +|- 9.9 +|- 5.7 +|- 27.7 Mechanical mixing 0.0 0.0 9.6 3.4 5.6 13.6 4.2 18.7 Confidence Interval +|- 0.0 +|- 0.0 +|- 8.6 +|- 4.7 +|- 6.0 +|- 10.9 +|- 4.1 +|- 27.7 Increase or switch disinfectant residual 0.0 0.0 7.9 4.6 6.7 5.3 6.3 18.7 Confidence Interval +|- 0.0 +|- 0.0 +|- 6.7 +|- 5.6 +|- 7.0 +|- 6.6 +|- 4.9 +|- 27.7 Operational modifications to maintain disinfectant residual 0.0 0.0 9.6 6.7 10.5 16.4 8.5 18.7 Confidence Interval +|- 0.0 +|- 0.0 +|- 8.6 +|- 6.8 +|- 8.2 +|- 11.9 +|- 5.7 +|- 27.7 

Other 0.0 0.0 3.4 0.0 0.0 2.8 2.2 0.0 Confidence Interval +|- 0.0 +|- 0.0 +|- 4.6 +|- 0.0 +|- 0.0 +|- 5.0 +|- 3.1 +|- 0.0 

Primarily Surface Water Systems 

Modeling or other detention time evaluations 4.2 15.2 18.3 13.2 22.2 9.5 13.1 19.4 Confidence Interval +|- 8.5 +|- 12.8 +|- 10.8 +|- 8.0 +|- 8.9 +|- 6.8 +|- 5.1 +|- 8.1 Longer fill/draw cycles to increase mixing 4.2 15.7 14.6 7.4 16.4 6.4 9.7 5.6 Confidence Interval +|- 8.5 +|- 11.9 +|- 9.9 +|- 6.1 +|- 8.0 +|- 5.8 +|- 3.9 +|- 4.7 Inlet/outlet modifications 4.2 19.9 15.1 11.8 15.1 16.3 15.5 19.4 Confidence Interval +|- 8.5 +|- 13.5 +|- 10.3 +|- 7.6 +|- 7.7 +|- 9.4 +|- 5.4 +|- 8.1 Mechanical mixing 4.2 9.1 14.6 10.3 13.7 14.1 13.1 19.4 Confidence Interval +|- 8.5 +|- 10.0 +|- 10.0 +|- 7.1 +|- 7.4 +|- 8.8 +|- 5.1 +|- 8.1 Increase or switch disinfectant residual 4.2 9.1 16.7 11.8 11.6 7.7 4.8 5.6 Confidence Interval +|- 8.5 +|- 10.0 +|- 10.6 +|- 7.6 +|- 6.8 +|- 6.7 +|- 2.7 +|- 4.7 Operational modifications to maintain disinfectant residual 4.2 16.5 16.7 8.9 20.4 5.5 8.1 13.9 Confidence Interval +|- 8.5 +|- 13.8 +|- 10.7 +|- 6.6 +|- 8.7 +|- 5.7 +|- 3.5 +|- 7.1 Other 4.2 6.1 8.4 0.0 0.0 2.4 0.0 2.8 Confidence Interval +|- 8.5 +|- 8.2 +|- 8.4 +|- 0.0 +|- 0.0 +|- 4.2 +|- 0.0 +|- 3.4 

(Continued) 

Table 47 

Percentage of Systems that Want Additional Information about Practices to Maintain Water Quality in Storage Vessels 

By Primary Water Source 
Percentage of Systems that Want Additional Information about Practices to Maintain Water Quality in Storage Vessels

By Primary Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 A

Primarily Purchased Water Systems 

Modeling or other detention time evaluations 0.0 37.2 11.8 14.0 18.5 19.9 10.2 0.0 Confidence Interval +|- 0.0 +|- 41.8 +|- 13.2 +|- 14.6 +|- 18.7 +|- 15.7 +|- 6.9 +|- 0.0 Longer fill/draw cycles to increase mixing 0.0 18.6 7.9 9.3 18.5 9.9 7.6 0.0 Confidence Interval +|- 0.0 +|- 33.7 +|- 10.8 +|- 12.3 +|- 18.7 +|- 11.8 +|- 6.0 +|- 0.0 Inlet/outlet modifications 0.0 0.0 3.9 4.7 12.4 14.6 10.0 0.0 Confidence Interval +|- 0.0 +|- 0.0 +|- 7.7 +|- 8.9 +|- 15.9 +|- 13.6 +|- 6.7 +|- 0.0 Mechanical mixing 0.0 0.0 4.7 4.7 2.3 15.2 5.0 0.0 Confidence Interval +|- 0.0 +|- 0.0 +|- 7.9 +|- 8.9 +|- 4.4 +|- 14.3 +|- 4.9 +|- 0.0 Increase or switch disinfectant residual 0.0 0.0 3.9 5.8 8.5 15.2 5.0 0.0 Confidence Interval +|- 0.0 +|- 0.0 +|- 7.7 +|- 9.2 +|- 12.4 +|- 14.3 +|- 4.9 +|- 0.0 Operational modifications to maintain disinfectant residual 0.0 0.0 3.9 10.5 14.7 12.1 16.5 0.0 Confidence Interval +|- 0.0 +|- 0.0 +|- 7.7 +|- 12.5 +|- 16.4 +|- 12.1 +|- 11.6 +|- 0.0 

Other 0.0 0.0 0.0 0.0 6.2 9.9 0.0 0.0 Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 11.6 +|- 11.8 +|- 0.0 +|- 0.0 

All Systems 

Modeling or other detention time evaluations 0.2 7.3 13.8 9.8 13.8 16.2 11.0 15.0 

Confidence Interval +|- 0.4 +|- 8.8 +|- 6.6 +|- 5.5 +|- 5.7 +|- 6.6 +|- 3.4 +|- 6.3 Longer fill/draw cycles to increase mixing 0.2 4.2 12.7 8.3 13.3 8.7 8.5 5.6 Confidence Interval +|- 0.4 +|- 6.4 +|- 7.1 +|- 5.4 +|- 5.9 +|- 4.9 +|- 2.7 +|- 3.9 Inlet/outlet modifications 0.2 8.2 9.7 6.5 12.1 14.3 12.9 15.0 Confidence Interval +|- 0.4 +|- 13.2 +|- 6.4 +|- 4.3 +|- 5.6 +|- 6.2 +|- 3.6 +|- 6.3 Mechanical mixing 0.2 0.6 8.9 5.1 7.5 14.2 9.5 15.0 Confidence Interval +|- 0.4 +|- 0.6 +|- 6.2 +|- 3.7 +|- 3.9 +|- 6.3 +|- 3.2 +|- 6.3 Increase or switch disinfectant residual 0.2 0.6 7.8 6.4 8.6 8.3 5.2 5.6 Confidence Interval +|- 0.4 +|- 0.6 +|- 5.0 +|- 4.1 +|- 4.7 +|- 4.8 +|- 2.1 +|- 3.9 Operational modifications to maintain disinfectant residual 0.2 1.1 8.9 8.0 14.3 10.9 9.8 11.3 

Confidence Interval +|- 0.4 +|- 0.9 +|- 6.2 +|- 5.0 +|- 5.8 +|- 5.5 +|- 3.4 +|- 5.5 Other 0.2 0.4 3.0 0.0 1.1 4.1 0.5 1.9 Confidence Interval +|- 0.4 +|- 0.5 +|- 3.2 +|- 0.0 +|- 2.1 +|- 3.5 +|- 0.7 +|- 2.3 

Data: Q.11D Notes: 

Table 47 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,00Public Systems 

Distribution Mains 

Miles of Pipe in Place 4 4 20 46 152 415 682 

Confidence interval +|- 3 +|- 1 +|- 8 +|- 13 +|- 42 +|- 130 +|- 65 

Service Connections per Mile 31 43 50 83 79 68 99 

Confidence interval +|- 12 +|- 10 +|- 10 +|- 39 +|- 21 +|- 22 +|- 38 

Average Pipe Replaced Annually in the Past 5 Years (miles) 0 0 0 1 1 2 2 

Confidence interval +|- 0 +|- 0 +|- 0 +|- 2 +|- 0 +|- 1 +|- 0 

Average New Pipe Installed Annually in the Past 5 Years (miles) 0 0 0 1 3 6 8 

Confidence interval +|- 0 +|- 0 +|- 0 +|- 1 +|- 2 +|- 2 +|- 1 

Observations 27 80 172 120 141 99 193 

Transmission Lines 

Miles of Pipe in Place 1 0 1 16 24 38 89 

Confidence interval +|- 1 +|- 0 +|- 1 +|- 14 +|- 17 +|- 20 +|- 22 

Average Pipe Replaced Annually in the Past 5 Years (miles) 0 0 0 0 0 0 0 

Confidence interval +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 

Average New Pipe Installed Annually in the Past 5 Years (miles) 0 0 0 0 0 1 

Confidence interval +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 1 +|- 0 

Observations 27 81 172 121 144 101 194 

Table 48 

Distribution System and Transmission Line Summary 

By Ownership 
Distribution System and Transmission L

By Ownership 

S

100 101 - 501

Ownership Type or Less 500 3,30

Private Systems 

Distribution Mains 

Miles of Pipe in Place 4 3 2

Confidence interval +|- 6 +|- 2 +|- 12

Service Connections per Mile 263 81 6

Confidence interval +|- 347 +|- 21 +|- 33

Average Pipe Replaced Annually in the Past 5 Years (miles) 0 0

Confidence interval +|- 0 +|- 0 +|- 0

Average New Pipe Installed Annually in the Past 5 Years (miles) 0 0

Confidence interval +|- 0 +|- 0 +|- 0

Observations 115 107 54 

Transmission Lines 

Miles of Pipe in Place 0 0 1 

Confidence interval +|- 0 +|- 0 +|- 0 +|-

Average Pipe Replaced Annually in the Past 5 Years (miles) 0 0 0 0 0 0 0 

Confidence interval +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 

Average New Pipe Installed Annually in the Past 5 Years (miles) 0 0 0 0 0 0 3 

Confidence interval +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 +|- 4 

Observations 117 109 55 24 19 10 17 

ine Sum

ystem S

 - 3,3

0 10

4 

 +|-

7 

 +|-

 0

 +

 0

 +

mary

ervice Population Category 

01 - 10,001 - 50,001 - 100,001

,000 50,000 100,000 500,00

80 242 344 70

 39 +|- 167 +|- 151 +|- 391 

49 80 246 1,136 

 23 +|- 95 +|- 287 +|- 1,441 

 1 0 1 

|- 0 +|- 0 +|- 1 +|- 1 

 0 1 2 10 

|- 0 +|- 1 +|- 1 +|- 6 

22 19 10 17 

14 70 54 94 

 13 +|- 49 +|- 74 +|- 88 

Table 48 (Cont.)
Distribution System and Transmission Line

By Ownership 

Sy

100 101 - 501 -

Ownership Type or Less 500 3,300 All Systems 

Distribution Mains 

Miles of Pipe in Place 4 4 21 

Confidence interval +|- 5 +|- 1 +|- 7 

Service Connections per Mile 229 66 55 

Confidence interval +|- 296 +|- 15 +|- 12 

Average Pipe Replaced Annually in the Past 5 Years (miles) 0 0 0 

Confidence interval +|- 0 +|- 0 +|- 0 

Average New Pipe Installed Annually in the Past 5 Years (miles) 0 0 0

Confidence interval +|- 0 +|- 0 +|- 0 

Observations 142 187 226 

Transmission Lines 

Miles of Pipe in Place 0 0 1 

Confidence interval +|- 0 +|- 0 +|- 0 

Average Pipe Replaced Annually in the Past 5 Years (miles) 0 0 0 

Confidence interval +|- 0 +|- 0 +|- 0 

Average New Pipe Installed Annually in the Past 5 Years (miles) 0 0 0 

Confidence interval +|- 0 +|- 0 +|- 0 

Observations 144 190 227 

Data: Q.12A Notes: Includes systems reporting zero mi

Service connections include reside

s

 Summary

tem Service Population Category 

3,301 - 10,001 - 50,001 - 100,001

10,000 50,000 100,000 500,00

53 159 411 684 

+|- 14 +|- 42 +|- 123 +|- 75 

75 79 78 23

+|- 31 +|- 21 +|- 29 +|- 245 

1 1 2 2 

+|- 1 +|- 0 +|- 1 +|- 0 

 1 3 6 8 

+|- 1 +|- 2 +|- 2 +|- 1 

142 160 109 210 

15 28 40 89 

+|- 11 +|- 16 +|- 19 +|- 22 

0 0 0 0 

+|- 0 +|- 0 +|- 0 +|- 0 

0 0 1 

+|- 0 +|- 0 +|- 1 +|- 1 

145 163 111 21

les of pipe. 

ntial customers only. 

Table 48 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 50

Public Systems 

Distribution Mains Less Than 6" 

Percentage of systems with this size pipe 91.1 80.2 84.3 72.6 76.2 76.4 82.5 Average length of pipe 3.6 2.3 12.4 70.6 51.2 42.3 103.1 3

Confidence interval +|- 3.6 +|- 0.8 +|- 9.5 +|- 77.7 +|- 31.8 +|- 10.7 +|- 16.2 +|- 1

Distribution Mains 6" to 10" 

Percentage of systems with this size pipe 32.6 82.0 93.1 81.7 92.6 87.7 87.1 Average length of pipe 1.9 3.1 9.3 53.2 96.7 256.5 436.7 1,8

Confidence interval +|- 1.6 +|- 1.2 +|- 2.1 +|- 23.3 +|- 16.3 +|- 95.0 +|- 40.1 +|- 3

Distribution Mains Greater Than 10" and Less Than 24" 

Percentage of systems with this size pipe 0.4 4.3 33.9 57.1 82.5 86.7 88.8 Average length of pipe 19.9 2.7 2.6 5.8 23.9 64.0 126.3 5

Confidence interval +|- 24.9 +|- 0.3 +|- 0.7 +|- 1.4 +|- 5.7 +|- 8.9 +|- 11.5 +|- 1

Distribution Mains Greater Than 24" 

Percentage of systems with this size pipe 0.1 0.1 2.9 1.1 26.4 65.5 74.4 Average length of pipe 9.7 0.2 0.9 0.9 6.4 13.4 34.7 1

Confidence interval +|- 0.0 +|- 0.0 +|- 1.2 +|- 0.9 +|- 4.1 +|- 3.4 +|- 4.0 +|- 

Observations 27 80 172 118 142 100 189 

Private Systems 

Distribution Mains Less Than 6" 

Percentage of systems with this size pipe 90.8 85.1 85.1 84.9 82.3 73.3 95.4 1Average length of pipe 3.4 3.2 63.8 106.5 93.1 51.5 100.8 1

Confidence interval +|- 5.4 +|- 1.7 +|- 89.3 +|- 130.2 +|- 97.8 +|- 33.6 +|- 53.6 +|- 

Distribution Mains 6" to 10" 

Percentage of systems with this size pipe 19.2 28.0 86.7 91.6 87.1 84.5 95.4 1Average length of pipe 1.2 2.4 10.1 56.3 137.9 197.1 446.6 1,4

Confidence interval +|- 1.2 +|- 1.3 +|- 3.1 +|- 20.6 +|- 27.5 +|- 78.9 +|- 241.8 +|- 1,0

Distribution Mains Greater Than 10" and Less Than 24" 

Percentage of systems with this size pipe 0.0 2.3 17.3 37.0 86.9 73.3 95.4 1Average length of pipe * 3.3 2.1 16.8 38.6 47.8 121.3 3

Confidence interval * +|- 2.9 +|- 1.3 +|- 16.2 +|- 12.7 +|- 23.0 +|- 67.5 +|- 1

Distribution Mains Greater Than 24" 

Percentage of systems with this size pipe 0.0 0.0 0.0 12.9 35.5 52.2 60.6 1Average length of pipe * * * 2.5 4.1 10.9 28.5 

Confidence interval * * * +|- 1.7 +|- 4.2 +|- 3.4 +|- 10.5 +|- 

Observations 115 108 55 22 19 10 17 

(Contin

Table 49 

Average Size of Distribution Systems 

By Diameter of Pipe and Ownership 

(Length of Pipe in Miles) 
Average Size of Distribution S

By Diameter of Pipe and Own

(Length of Pipe in Miles

100 101 - 50

Ownership Type or Less 500 3,

All Systems 

Distribution Mains Less Than 6" 

Percentage of systems with this size pipe 90.9 83.2 8Average length of pipe 3.4 2.8 2

Confidence interval +|- 4.8 +|- 1.1 +|- 2

Distribution Mains 6" to 10" 

Percentage of systems with this size pipe 21.0 48.7 9Average length of pipe 1.4 2.8 

Confidence interval +|- 1.0 +|- 0.9 +|- 

Distribution Mains Greater Than 10" and Less Than 24" 

Percentage of systems with this size pipe 0.0 3.1 2Average length of pipe 19.9 3.0 

Confidence interval +|- 24.9 +|- 1.3 +|- 

Distribution Mains Greater Than 24" 

Percentage of systems with this size pipe 0.0 0.0 2.1Average length of pipe 9.7 0.2 0.9

Confidence interval +|- 0.0 +|- 0.0 +|- 1.2 

Observations 142 188 227

Data: Q.12A Notes: Includes systems reporting zero miles of pipe. 

ys

ers

) 

S

1 -

300

4.56.6

6.3 

1.4

9.5

1.8 

9.3

2.5

0.6 

tems

hip

ystem Service Population Category 

3,301 - 10,001 - 50,001 - 100,001- 

 10,000 50,000 100,000 500,000 50

 74.7 76.7 76.1 83.9  77.8 54.8 43.0 102.9 3

+|- 67.4 +|- 30.5 +|- 10.2 +|- 15.7 +|- 

 83.5 92.2 87.5 88.0 

 53.8 99.8 251.6 437.8 1,7

+|- 19.2 +|- 15.3 +|- 87.9 +|- 44.7 +|- 3

 53.5 82.9 85.5 89.5 

 7.2 25.1 62.8 125.7 5

+|- 2.3 +|- 5.3 +|- 8.5 +|- 12.8 +|- 1

 3.2 27.1 64.4 72.9 

 2.1 6.1 13.2 34.2 1

+|- 1.3 +|- 3.7 +|- 3.2 +|- 3.7 +|- 

 140 161 110 206 

Table 49 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Primarily Ground Water Systems 

Average number of pressure zones in the distribution system 1.4 1.2 1.5 2.5 3.6 5.1 6.5 Confidence interval +|- 0.3 +|- 0.1 +|- 0.4 +|- 1.2 +|- 2.6 +|- 2.9 +|- 2.3 +Average number of pressure zones with booster disinfection stations 0.0 0.0 0.0 0.6 0.3 0.5 0.5 Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.2 +|- 0.3 +|- 0.2 Average number of booster disinfection stations in the distribution system 0.0 0.0 0.1 0.5 0.2 1.2 0.8 Confidence interval +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.3 +|- 0.1 +|- 0.9 +|- 0.3 

Primarily Surface Water Systems 

Average number of pressure zones in the distribution system 1.6 1.6 1.8 2.3 3.7 4.2 8.4 Confidence interval +|- 0.4 +|- 0.5 +|- 0.3 +|- 0.5 +|- 1.0 +|- 1.2 +|- 2.4 Average number of pressure zones with booster disinfection stations 0.0 0.1 0.1 0.3 0.3 0.6 0.9 Confidence interval +|- 0.0 +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.4 +|- 0.3 Average number of booster disinfection stations in the distribution system 0.0 0.1 0.1 0.3 0.5 0.6 1.5 Confidence interval +|- 0.0 +|- 0.2 +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.3 +|- 0.4 

(Co

Table 50 

Pressure Zones and Booster Disinfection Practices 

By Primary Water Source 
Pressure Zones and Booster Disinfection Practices

By Primary Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Primarily Purchased Water Systems 

Average number of pressure zones in the distribution system 1.3 2.7 1.8 4.0 2.7 6.2 8.7 Confidence interval +|- 0.4 +|- 2.0 +|- 0.8 +|- 3.1 +|- 1.0 +|- 2.0 +|- 2.0 

Average number of pressure zones with booster disinfection stations 0.3 0.2 0.3 0.6 0.4 0.5 2.3 

Confidence interval +|- 0.4 +|- 0.3 +|- 0.3 +|- 0.5 +|- 0.5 +|- 0.3 +|- 1.0 

Average number of booster disinfection stations in the distribution system 0.3 0.2 0.4 0.8 0.4 0.6 5.5 

Confidence interval +|- 0.4 +|- 0.3 +|- 0.3 +|- 0.5 +|- 0.4 +|- 0.3 +|- 4.2 

All Systems 

Average number of pressure zones in the distribution system 1.4 1.5 1.6 2.8 3.4 5.0 8.1 Confidence interval +|- 0.2 +|- 0.3 +|- 0.3 +|- 1.0 +|- 1.3 +|- 1.2 +|- 1.5 

Average number of pressure zones with booster disinfection stations 0.0 0.0 0.1 0.5 0.3 0.5 1.1 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.3 

Average number of booster disinfection stations in the 

distribution system Confidence interval 

0.0 

+|- 0.0 

0.0 

+|- 0.0 

0.1 

+|- 0.1 

0.5 

+|- 0.2 

0.3 

+|- 0.1 

0.8 

+|- 0.3 

2.2 

+|- 0.9 

Data: Q.13.A Notes: 

Table 50 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Primarily Ground Water Systems 

Pressure losses due to power outage 0.3 0.2 0.1 0.9 0.0 0.0 0.1 Confidence interval +|- 0.2 +|- 0.2 +|- 0.1 +|- 1.3 +|- 0.1 +|- 0.0 +|- 0.1 Pressure losses due to fire 0.0 0.0 0.0 0.3 0.0 0.0 0.2 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.0 +|- 0.0 +|- 0.2 Pressure losses due to main pipeline burst 0.3 0.9 1.4 1.3 1.9 10.6 17.2 

Confidence interval +|- 0.2 +|- 1.1 +|- 1.4 +|- 1.0 +|- 1.6 +|- 7.9 +|- 10.8 Pressure losses due to other reasons 0.1 0.0 0.0 1.5 0.1 6.2 16.2 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.0 +|- 2.2 +|- 0.2 +|- 7.3 +|- 15.3 

Primarily Surface Water Systems 

Pressure losses due to power outage 0.6 0.3 0.0 0.2 0.3 0.0 0.3 Confidence interval +|- 0.9 +|- 0.4 +|- 0.1 +|- 0.3 +|- 0.4 +|- 0.0 +|- 0.3 Pressure losses due to fire 0.0 0.0 0.0 0.3 0.0 0.0 0.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.1 +|- 0.0 +|- 0.0 Pressure losses due to main pipeline burst 0.3 1.1 1.0 2.0 7.3 10.3 11.5 

Confidence interval +|- 0.4 +|- 1.6 +|- 1.1 +|- 1.5 +|- 7.3 +|- 6.8 +|- 8.8 Pressure losses due to other reasons 0.4 0.0 0.0 1.2 2.3 0.6 6.5 

Confidence interval +|- 0.5 +|- 0.1 +|- 0.0 +|- 1.8 +|- 3.8 +|- 1.1 +|- 8.8 

(Co

Table 51 

Number of Annual Pressure Losses below 20 PSI 

By Primary Water Source 
Number of Annual Pressure Losses below 20 PSI

By Primary Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 5Primarily Purchased Water Systems 

Pressure losses due to power outage 0.0 0.0 0.0 0.0 0.3 0.2 0.0 Confidence interval +|- 0.1 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.2 +|- 0.0 Pressure losses due to fire 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 

Pressure losses due to main pipeline burst 0.0 4.6 2.1 1.6 1.1 1.4 8.7 

Confidence interval +|- 0.0 +|- 8.2 +|- 3.4 +|- 1.6 +|- 1.5 +|- 1.6 +|- 6.8 

Pressure losses due to other reasons 0.0 0.0 0.1 0.0 0.2 2.9 12.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.3 +|- 4.1 +|- 15.5 

All Systems 

Pressure losses due to power outage 0.3 0.2 0.0 0.6 0.2 0.1 0.2 Confidence interval +|- 0.2 +|- 0.2 +|- 0.0 +|- 0.9 +|- 0.2 +|- 0.1 +|- 0.2 

Pressure losses due to fire 0.0 0.0 0.0 0.3 0.0 0.0 0.1 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.3 +|- 0.0 +|- 0.0 +|- 0.1 

Pressure losses due to main pipeline burst 0.3 1.5 1.5 1.5 3.3 8.1 12.5 

Confidence interval +|- 0.2 +|- 1.5 +|- 1.2 +|- 0.7 +|- 2.3 +|- 4.1 +|- 5.8 

Pressure losses due to other reasons 0.1 0.0 0.0 1.2 0.8 3.4 10.1 

Confidence interval +|- 0.1 +|- 0.0 +|- 0.0 +|- 1.4 +|- 1.1 +|- 3.1 +|- 7.0 

Data: Q.13.B Notes: 

Table 51 (Cont.)
Primary Water Source 

Primarily Ground Water Systems 

Percentage of systems that flush their distribution system on a regular basis Of the systems that flush on a regular basis: 

Average percentage of systems flushed each year

Percentage of systems that use each type of the following 

approaches:

Uni-directionalConventional or random

Dead endOther

Of systems that do not flush on a regular basis: 

Percentage that flushed their system once Percentage that flushed their system more than one time Average number of years between last two system flushes 

Primarily Surface Water Systems 

Percentage of systems that flush their distribution system on a regular basis Of systems that flush on a regular basis: 

Average percentage of system flushed each year

Percentage of systems that use each type of the following 

approaches:

Uni-directionalConventional or random

Dead endOther

Of systems that do not flush on a regular basis: 

Percentage that flushed their system once Percentage that flushed their system more than one time Average number of years between last two system flushes 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001

or Less 500 3,300 10,000 50,000 100,000 500,000 

31.8 70.4 87.5 88.0 91.5 85.4 75.3 

98.9 98.5 94.2 77.9 75.9 44.1 52.3 

7.0 12.4 21.5 26.4 41.3 47.5 46.5 

40.0 60.6 60.2 71.5 68.1 64.8 67.3 63.4 52.2 43.7 85.3 72.2 89.2 89.2 

0.0 1.4 2.0 1.8 5.3 3.2 13.6 

5.1 17.3 14.1 13.4 28.0 0.0 16.9 3.5 16.1 32.8 61.0 0.0 18.6 16.2 1.0 2.2 1.2 4.3 * 1.0 1.5 

32.4 53.9 82.7 76.1 87.0 80.9 69.2 

89.7 92.8 87.3 82.5 78.3 70.3 63.4 

25.5 13.4 23.2 22.0 30.1 21.2 40.0 27.2 77.8 59.9 73.1 71.4 85.7 75.0 39.2 40.4 48.0 78.0 78.0 80.0 82.2 

14.2 1.0 0.0 4.9 4.0 8.6 13.2 

3.0 5.6 56.2 23.1 12.2 0.0 11.3 0.0 2.6 13.1 30.9 61.2 5.2 26.3 

* 1.0 1.0 3.3 2.2 1.0 1.6 

Table 52 

System Flushing Practices 

By Primary Water Source 
System Flushing Practices

Primary Water Source Primarily Purchased Water Systems 

Percentage of systems that flush their distribution system on a regular basis Of systems that flush on a regular basis: 

Average percentage of system flushed each year

Percentage of systems that use each type of the following 

approaches:

Uni-directionalConventional or random

Dead endOther

Of systems that do not flush on a regular basis: 

Percentage that flushed their system once Percentage that flushed their system more than one time Average number of years between last two system flushes 

All Systems 

Percentage of systems that flush their distribution system on a regular basis Of systems that flush on a regular basis: 

Average percentage of system flushed each year

Percentage of systems that use each type of the following 

approaches:

Uni-directionalConventional or randomDead endOther

Of systems that do not flush on a regular basis: 

Percentage that flushed their system once Percentage that flushed their system more than one time Average number of years between last two system flushes 

By Primary Water Source 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001

or Less 500 3,300 10,000 50,000 100,000 500,000 

49.3 78.8 86.1 86.2 76.4 71.0 85.1 

100.0 91.5 97.3 69.4 44.3 58.1 59.0 

67.9 6.6 28.6 33.0 11.3 53.1 59.8 66.1 65.4 46.3 41.5 72.2 62.6 70.2 33.9 53.3 44.5 98.4 80.4 82.2 85.2 

0.0 0.0 0.0 10.6 8.2 11.2 15.0 

0.0 0.0 15.3 39.8 0.0 14.5 16.0 

66.1 24.6 30.7 50.0 36.7 14.5 52.1 

1.0 1.0 4.5 1.0 1.0 1.0 1.0 

32.9 71.0 86.7 85.3 87.6 80.2 73.9 

98.7 97.2 94.5 76.5 71.4 57.4 59.6 

13.6 11.5 23.5 27.3 33.6 38.5 46.3 42.3 61.9 56.4 64.2 69.6 72.5 71.9 59.7 52.0 44.2 87.4 75.0 84.1 84.7 

0.4 1.1 1.3 4.6 5.4 7.0 13.7 

4.8 14.7 18.8 22.6 14.0 5.1 13.2 6.5 16.2 30.2 49.2 29.6 12.2 26.9 1.0 2.0 2.2 3.3 1.7 1.0 1.5 

Data: Q.14, Q.15, Q.16, Q.17 Notes: The questionnaire did not define "regular basis." 

Table 52 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Season or Less 500 3,300 10,000 50,000 100,000 500,000 

Summer (June through September) 

Average entry point disinfectant residual for the treatment plant with the highest average daily flow (mg/L as Cl2) 

Ground water treatment plants 

Total Cl2 1.65 1.10 1.48 1.52 1.47 2.05 2.37 

Free Cl2 1.02 1.09 1.15 0.99 3.39 0.93 0.68 

Surface water treatment plants (including mixed plants) 

Total Cl2 1.93 1.71 1.85 1.96 2.15 2.41 2.45 

Free Cl2 0.94 1.18 1.44 1.37 1.37 1.38 1.03 

Average distribution system residual (mg/L as Cl2) 

Ground water treatment plants 

Total Cl2 1.04 0.78 1.01 1.11 1.13 1.86 1.66 

Free Cl2 0.77 0.81 0.62 0.77 2.66 0.63 0.54 

Surface water treatment plants (including mixed plants) 

Total Cl2 0.83 1.38 1.26 1.41 1.68 1.58 1.64 

Free Cl2 0.65 0.63 0.70 0.77 0.94 0.87 0.66 

Average percentage of systems samples <0.2 mg/L (including non-detects), total Cl2 7.6 5.6 4.9 3.7 7.5 5.3 2.7 

Table 53 

Seasonal Disinfection Residuals for Entry Points and Distribution Systems 
Seasonal Disinfection Residuals for Entry Points and Distribution Systems 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Season or Less 500 3,300 10,000 50,000 100,000 500,000 

Winter (December, January, and February) 

Average entry point disinfectant residual for the treatment plant with the highest average daily flow (mg/L as Cl2) 

Ground water treatment plants 

Total Cl2 1.65 1.06 1.36 1.43 1.49 2.19 2.43 

Free Cl2 0.96 1.10 1.11 1.07 3.10 0.91 0.73 

Surface water treatment plants (including mixed plants) 

Total Cl2 1.70 3.50 1.91 2.02 2.07 2.45 2.31 

Free Cl2 0.91 1.19 1.43 1.33 1.30 1.35 1.01 

Average distribution system residual (mg/L as Cl2) 

Ground water treatment plants 

Total Cl2 0.96 0.78 0.91 0.97 1.14 1.75 1.83 

Free Cl2 0.75 0.85 0.64 0.80 2.92 0.64 0.58 

Surface water treatment plants (including mixed plants) 

Total Cl2 1.24 1.35 1.34 1.49 1.76 1.77 1.74 

Free Cl2 0.69 0.66 0.75 0.85 1.05 0.97 0.75 

Average percentage of systems samples <0.2 mg/L (including non-detects), total Cl2 5.5 5.6 5.7 2.9 6.5 4.5 2.2 

Data: Q.18 Notes: If system has more than one treatment plant, the residuals reported are for the p

highest average daily flow. The estimate of distribution system residuals distinguishes between ground and plants. The distribution system is characterized as ground water if the largest treground water. If the largest treatment plant treats surface water or surface and gdistribution system is characterized as surface water. 

Table 53 (Cont.) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500

Public Systems 

Attended EPA-sponsored water security training 48.4 33.0 27.5 54.7 55.8 60.2 Used EPA Web-based water security technology product guides 0.0 12.7 10.0 21.4 30.0 37.3 Heard of EPA's Response Protocol Toolbox 23.1 22.3 18.7 39.7 38.9 47.8 Heard of the 14 features of an "active and effective" water security program 9.2 15.1 16.9 24.1 23.0 27.4 Heard of mutual aid and assistance agreements/compacts 56.8 60.6 68.5 56.5 58.5 68.5 Interested in joining such an agreement or compact 68.9 60.3 56.0 73.3 65.7 80.9 Barriers to enhancing security 

Lack of interest at the system, public, or rate board level 31.0 54.7 46.4 54.0 57.5 64.4 Competing priorities (regulatory compliance, aging infrastructure, etc.) 74.1 63.9 70.6 64.9 64.8 64.7 Lack of funding 33.9 25.1 27.0 12.7 12.5 13.0 Lack of knowledge / guidance / training materials 9.4 8.9 18.5 24.4 9.5 9.6 Other 17.2 25.9 21.6 22.6 34.0 31.4 

Preferred sources of water security information and products 

Department of Homeland Security 0.0 4.3 3.4 12.9 5.2 14.4 

EPA 25.7 8.4 5.4 11.6 10.0 9.5 Water Associations 48.1 38.1 35.9 35.1 36.7 28.4 No preference 17.8 42.5 44.5 31.8 38.4 40.7 Other 7.8 0.3 9.9 5.0 5.3 2.6 

Private Systems 

Attended EPA-sponsored water security training 17.4 19.9 30.9 71.4 35.5 58.4 Used EPA Web-based water security technology product guides 3.9 7.7 5.7 22.6 7.7 21.3 Heard of EPA's Response Protocol Toolbox 6.6 10.7 17.0 41.0 33.6 55.0 Heard of the 14 features of an "active and effective" water security program 2.7 14.4 28.8 41.7 6.9 26.9 Heard of mutual aid and assistance agreements/compacts 19.4 28.3 55.2 55.1 13.6 46.1 Interested in joining such an agreement or compact 39.6 38.5 48.5 59.6 37.1 61.1 Systems reporting the following barriers to enhancing security 

Lack of interest at the system, public, or rate board level 22.3 32.1 40.2 56.2 54.6 65.2 Competing priorities (regulatory compliance, aging infrastructure, etc.) 47.0 44.2 58.6 53.8 13.7 47.1 Lack of funding 37.9 39.5 36.1 16.5 4.3 16.9 Lack of knowledge / guidance / training materials 22.9 22.2 10.6 10.9 12.9 25.8 Other 44.1 37.6 41.7 41.2 62.1 37.1 

Preferred sources of water security information and products 

Department of Homeland Security 1.2 0.0 2.5 8.3 8.6 16.9 EPA 2.7 10.8 6.1 15.9 17.1 7.9 Water Associations 21.8 20.9 41.6 31.0 12.9 21.3 No preference 46.6 52.8 32.1 31.5 38.6 53.9 Other 12.8 10.8 13.5 8.2 0.0 0.0 

Table 54 

Water Security Awareness and Security Barriers 

By Ownership

(Percentage of Systems) 
Water Security Awareness and Security Barriers

By Ownership

(Percentage of Systems) 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500

All Systems 

Attended EPA-sponsored water security training 21.5 25.0 28.4 58.2 54.1 60.0 Used EPA Web-based water security technology product guides 3.3 9.6 8.8 21.7 28.2 35.8 Heard of EPA's Response Protocol Toolbox 8.8 15.1 18.2 40.0 38.5 48.5 Heard of the 14 features of an "active and effective" water security program 3.5 14.7 20.1 27.8 21.7 27.4 Heard of mutual aid and assistance agreements/compacts 24.3 40.7 64.9 56.2 54.8 66.3 Interested in joining such an agreement or compact 48.6 50.9 54.2 70.5 65.1 79.6 Systems reporting the following barriers to enhancing security 

Lack of interest at the system, public, or rate board level 23.4 40.7 44.7 54.5 57.3 64.5 Competing priorities (regulatory compliance, aging infrastructure, etc.) 50.5 51.8 67.4 62.6 60.6 63.0 Lack of funding 37.4 34.0 29.5 13.5 11.8 13.4 Lack of knowledge / guidance / training materials 21.1 17.1 16.4 21.6 9.8 11.1 Other 40.6 33.1 27.0 26.5 36.3 32.0 

Preferred sources of water security information and products 

Department of Homeland Security 1.0 1.7 3.2 12.0 5.4 14.6 EPA 5.8 9.9 5.5 12.5 10.6 9.3 Water Associations 25.3 27.5 37.5 34.2 34.7 27.7 No preference 42.8 48.9 41.1 31.7 38.4 41.9 Other 12.1 6.8 10.9 5.7 4.8 2.4 

Data: Q.20 Notes: 

Table 54 (Cont.)
Ownership Type 

Public Systems 

Attended EPA-sponsored water security trainingUsed EPA Web-based water security technology product guidesHeard of EPA's Response Protocol ToolboxHeard of the 14 features of an "active and effective" water security programHeard of mutual aid and assistance agreements/compactsInterested in joining such an agreement or compactBarriers to enhancing security

Lack of interest at the system, public, or rate board levelCompeting priorities (regulatory compliance, aging infrastructure, etc.)Lack of fundingLack of knowledge / guidance / training materialsOther

Preferred sources of water security information and products

Department of Homeland SecurityEPAWater AssociationsNo preferenceOther

Private Systems 

Attended EPA-sponsored water security trainingUsed EPA Web-based water security technology product guidesHeard of EPA's Response Protocol ToolboxHeard of the 14 features of an "active and effective" water security programHeard of mutual aid and assistance agreements/compactsInterested in joining such an agreement or compactSystems reporting the following barriers to enhancing security

Lack of interest at the system, public, or rate board levelCompeting priorities (regulatory compliance, aging infrastructure, etc.)Lack of fundingLack of knowledge / guidance / training materialsOther

Preferred sources of water security information and products

Department of Homeland SecurityEPAWater AssociationsNo preferenceOther

System Service Population Category 

3,301 - 50,000 - Over 

25 - 3,300 49,999 99,999 100,000 All S

31.2 55.2 60.2 80.8 

10.1 25.3 37.3 53.8 

20.3 39.4 47.8 77.2 15.6 23.6 27.4 46.5 

64.7 57.4 68.5 84.2 58.3 69.8 80.9 71.6 

47.9 55.6 64.4 71.2 

68.6 64.9 64.7 56.2 

27.0 12.6 13.0 8.3 

14.4 17.6 9.6 5.8 

22.7 27.8 31.4 33.6 

3.4 9.4 14.4 10.7 

8.2 10.9 9.5 20.2 

37.7 35.8 28.4 23.2 41.5 34.8 40.7 37.8 

6.4 5.1 2.6 5.3 

20.6 63.3 58.4 83.2 

5.7 19.3 21.3 18.6 

9.9 39.4 55.0 45.0 

11.6 33.9 26.9 32.1 

28.7 45.8 46.1 48.0 41.8 58.1 61.1 42.0 

29.1 55.8 65.2 43.2 

47.7 44.8 47.1 33.8 

38.3 13.8 16.9 8.5 

20.6 11.3 25.8 0.0 

41.1 45.9 37.1 69.2 

0.9 8.4 16.9 29.8 

6.6 16.2 7.9 22.9 

24.6 26.9 21.3 5.5 46.8 33.1 53.9 18.8 

12.1 6.3 0.0 20.1 

Table 55 

Water Security Awareness and Security Barriers 

By Ownership

(Percentage of Systems) 
Water Security Awareness and Security Barriers

By Ownership

(Percentage of Systems) 

System Service Population Category 

3,301 - 50,000 - Over 

Ownership Type 25 - 3,300 49,999 99,999 100,000 All SAll Systems 

Attended EPA-sponsored water security training 25.1 56.5 60.0 81.1 Used EPA Web-based water security technology product guides 7.6 24.4 35.8 49.5 Heard of EPA's Response Protocol Toolbox 14.4 39.4 48.5 73.3 Heard of the 14 features of an "active and effective" water security program 13.3 25.2 27.4 44.7 Heard of mutual aid and assistance agreements/compacts 44.1 55.6 66.3 79.8 Interested in joining such an agreement or compact 52.2 68.3 79.6 69.4 Systems reporting the following barriers to enhancing security 

Lack of interest at the system, public, or rate board level 37.2 55.7 64.5 67.8 Competing priorities (regulatory compliance, aging infrastructure, etc.) 56.6 61.7 63.0 53.4 Lack of funding 33.5 12.8 13.4 8.3 Lack of knowledge / guidance / training materials 18.0 16.6 11.1 5.1 Other 33.2 30.6 32.0 37.9 

Preferred sources of water security information and products 

Department of Homeland Security 2.0 9.2 14.6 13.0 EPA 7.3 11.7 9.3 20.6 Water Associations 30.2 34.4 27.7 21.0 No preference 44.5 34.5 41.9 35.5 Other 9.7 5.3 2.4 7.1 

Data: Q.20 Notes: 

Table 55 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 Public Systems 

Mean Residential Connections 50 115 512 2,724 6,831 18,279 39,311 

Confidence Interval +|- 2 +|- 25 +|- 67 +|- 1,587 +|- 977 +|- 1,335 +|- 3,834 +

Median Residential Connections 36 105 355 1,701 5,500 17,176 34,345 Mean Non-Residential Connections 7 14 51 366 561 1,536 3,816 

Confidence Interval +|- 5 +|- 8 +|- 11 +|- 313 +|- 103 +|- 410 +|- 362 

Median Non-Residential Connections 3 5 35 160 450 1,395 3,296 Observations 25 84 181 127 156 111 204 

Private Systems 

Mean Residential Connections 24 88 602 1,686 5,378 65,938 92,001 

Confidence Interval +|- 11 +|- 31 +|- 495 +|- 528 +|- 1,262 +|- 76,266 +|- 32,527 +|

Median Residential Connections 23 65 310 1,855 4,628 17,331 64,279 Mean Non-Residential Connections 17 24 29 55 95 8,917 8,113 

Confidence Interval +|- 14 +|- 40 +|- 20 +|- 34 +|- 97 +|- 10,378 +|- 3,158 +

Median Non-Residential Connections 4 1 10 10 10 2,643 6,543 Observations 117 111 56 27 20 12 21 

All Systems 

Mean Residential Connections 30 110 527 2,422 6,770 21,243 47,035 

Confidence Interval +|- 11 +|- 21 +|- 100 +|- 1,150 +|- 937 +|- 5,447 +|- 8,357 +

Median Residential Connections 24 77 347 1,768 5,400 17,331 39,302 Mean Non-Residential Connections 15 16 48 276 542 1,995 4,446 

Confidence Interval +|- 11 +|- 11 +|- 10 +|- 228 +|- 100 +|- 856 +|- 737 

Median Non-Residential Connections 4 5 33 116 435 1,395 3,475 Observations 142 195 237 154 176 123 225 

Data: Q.21A Notes 

Table 56 

Service Connections Profile 

By Ownership 

(Number of Connections) 
Ownership Type 

Public Systems 

Mean Population Served Directly by System 

Confidence Interval 

Mean Population Served per Residential Connection 

Confidence Interval 

Mean Population Served through Sales to Other Systems 

Confidence Interval 

Mean Total Population Served 

Confidence Interval 

Observations 

Private Systems 

Mean Population Served Directly by System 

Confidence Interval 

Mean Population Served per Residential Connection 

Confidence Interval 

Mean Population Served through Sales to Other Systems 

Confidence Interval 

Mean Total Population Served 

Confidence Interval 

Observations 

All Systems 

Mean Population Served Directly by System 

Confidence Interval 

Mean Population Served per Residential Connection 

Confidence Interval 

Mean Population Served through Sales to Other Systems 

Confidence Interval 

Mean Total Population Served 

Confidence Interval 

Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001

or Less 500 3,300 10,000 50,000 100,000 500,000 

65 259 1,241 4,989 18,845 53,621 136,788 

+|- 14 +|- 31 +|- 127 +|- 420 +|- 2,039 +|- 3,867 +|- 10,146 

2.0 3.8 2.9 2.9 3.0 3.2 3.7 

+|- 1 +|- 2 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 

0 1 20 504 2,574 15,350 63,005 

+|- 0 +|- 1 +|- 19 +|- 195 +|- 729 +|- 3,856 +|- 10,802 

65 259 1,260 5,493 21,420 68,971 199,793 

+|- 14 +|- 31 +|- 128 +|- 395 +|- 1,908 +|- 3,117 +|- 9,037 

27 84 181 127 156 111 204 59 237 1,191 5,818 20,223 42,684 217,830 

+|- 5 +|- 25 +|- 196 +|- 953 +|- 5,458 +|- 14,959 +|- 63,920 

4.2 3.3 3.4 3.0 2.9 2.9 3.0 

+|- 2 +|- 0 +|- 1 +|- 1 +|- 0 +|- 2 +|- 0 

0 0 1 273 3,926 26,657 41,707 

+|- 0 +|- 0 +|- 2 +|- 250 +|- 3,064 +|- 13,910 +|- 24,732 

59 238 1,192 6,090 24,148 69,341 259,536 

+|- 5 +|- 25 +|- 196 +|- 877 +|- 5,459 +|- 6,088 +|- 52,344 

118 111 56 27 20 13 21 

60 246 1,227 5,165 18,960 52,540 146,908 

+|- 4 +|- 19 +|- 106 +|- 392 +|- 1,930 +|- 3,830 +|- 14,605 

3.9 3.5 3.0 2.9 3.0 3.2 3.6 

+|- 2 +|- 1 +|- 0 +|- 0 +|- 0 +|- 0 +|- 0 

0 0 15 455 2,686 16,468 60,345 

+|- 0 +|- 1 +|- 14 +|- 163 +|- 715 +|- 3,844 +|- 10,240 

60 246 1,242 5,620 21,646 69,008 207,254 

+|- 4 +|- 19 +|- 107 +|- 365 +|- 1,807 +|- 2,875 +|- 11,898 

145 195 237 154 176 124 225 

Data: Q.21A Notes: 

Table 57 

Population Served 

By Ownership 
Table 58

Total Water System Revenue and Revenue Per Thousand Gallons Delivered

By Primary Water Source

System Service Population Category

Primary Water Source

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

O

500,

Primarily Ground Water Systems

Mean Revenue in Thousands of Dollars 8 23 183 447 2,122 6,275 14,810 125,

Confidence Interval +|- 4 +|- 6 +|- 60 +|- 140 +|- 649 +|- 1,844 +|- 3,986 +|- 42,3

Median Revenue in Thousands of Dollars 0 17 125 199 1,399 6,575 8,597 168,Mean Revenue Per Thousand Gallons of Water Produced in Dollars 2.60 2.97 4.29 3.62 2.91 3.49 4.39 2

Confidence Interval +|- 1.42 +|- 0.77 +|- 1.45 +|- 1.21 +|- 0.54 +|- 0.65 +|- 2.57 +|- 0

Observations 88 105 111 62 66 40 56 

Primarily Surface Water Systems

Mean Revenue in Thousands of Dollars 24 66 354 726 2,639 17,543 27,851 148,0

Confidence Interval +|- 13 +|- 34 +|- 98 +|- 201 +|- 592 +|- 13,702 +|- 7,123 +|- 29,0

Median Revenue in Thousands of Dollars 23 17 240 607 2,110 7,206 16,860 95,2Mean Revenue Per Thousand Gallons of Water Produced in Dollars 6.00 5.18 5.75 3.62 3.91 5.10 2.88 2

Confidence Interval +|- 4.49 +|- 3.05 +|- 1.32 +|- 0.58 +|- 0.73 +|- 2.42 +|- 0.32 +|- 0

Observations 49 67 78 65 85 54 124 

Primarily Purchased Water Systems

Mean Revenue in Thousands of Dollars 20 56 1,001 632 3,234 9,606 29,676 94,9

Confidence Interval +|- 16 +|- 38 +|- 1,163 +|- 196 +|- 1,276 +|- 2,801 +|- 5,027 +|- 42,5

Median Revenue in Thousands of Dollars 10 28 138 608 1,916 7,923 23,757 86,0Mean Revenue Per Thousand Gallons of Water Produced in Dollars 4.94 5.77 5.68 4.53 3.60 3.64 4.97 2

Confidence Interval +|- 1.01 +|- 2.79 +|- 1.64 +|- 1.14 +|- 0.61 +|- 1.64 +|- 1.62 +|- 1

Observations 8 23 48 26 25 30 45 

All Systems

Mean Revenue in Thousands of Dollars 9 29 418 543 2,492 11,463 25,042 132,4

Confidence Interval +|- 4 +|- 8 +|- 326 +|- 99 +|- 462 +|- 5,418 +|- 4,302 +|- 23,2

Median Revenue in Thousands of Dollars 0 17 130 390 1,634 7,008 17,092 95,2Mean Revenue Per Thousand Gallons of Water Produced in Dollars 2.91 3.44 4.78 3.89 3.32 4.20 3.63 2

Confidence Interval +|- 1.28 +|- 0.78 +|- 1.06 +|- 0.72 +|- 0.37 +|- 1.11 +|- 0.67 +|- 0

Observations 145 195 237 153 176 124 225 

Data: Q.21Notes: Total water system revenue includes revenue from water sales to residential and non-residen

customers and to other systems; fees; transfers from the government including municipalgovernment transfers from the general fund; and other sources including penalties and fines. 
Table 59

Total Water System Revenue

By Ownership

(Thousands of Dollars)

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

O

500,

Public Systems

Mean 37 49 477 523 2,569 7,732 21,999 136,

Confidence Interval +|- 23 +|- 17 +|- 440 +|- 104 +|- 494 +|- 1,210 +|- 2,509 +|- 26,1

Median 17 31 144 411 1,696 7,008 16,286 94,9Number of Systems Reporting Zero Revenue 4 12 8 46 37 25 42 

Observations 27 84 181 127 156 111 204 

Private Systems

Ancillary Systems

Mean 1 5 50 N/A N/A N/A N/A 

Confidence Interval +|- 1 +|- 4 +|- 66 N/A N/A N/A N/A 

Median 0 0 0 N/A N/A N/A N/A 

Number of Systems Reporting Zero Revenue 53 32 5 N/A N/A N/A N/A 

Observations 61 43 7 N/A N/A N/A N/A 

Other Private Systems

Mean 9 25 281 618 1,633 46,432 47,430 108,2

Confidence Interval +|- 4 +|- 8 +|- 218 +|- 270 +|- 980 +|- 52,013 +|- 22,189 +|- 48,1

Median 5 18 111 390 1,330 6,783 35,898 168,

Number of Systems Reporting Zero Revenue 17 17 11 10 9 5 6 

Observations 57 68 49 26 20 13 21 

All Private Systems

Mean 5 17 259 618 1,633 46,432 47,430 108,2

Confidence Interval +|- 2 +|- 6 +|- 203 +|- 275 +|- 1,023 +|- 52,350 +|- 22,162 +|- 47,8

Median 0 3 103 390 1,330 6,783 35,898 168,

Number of Systems Reporting Zero Revenue 70 49 16 10 9 5 6 

Observations 118 111 56 26 20 13 21 

Data: Q.21Notes: Total water system revenue includes revenue from water sales to residential and non-residen

customers and to other systems; fees; transfers from the government including municipalgovernment transfers from the general fund; and other sources including penalties and fines. 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,

Primarily Ground Water Systems 

Mean Revenue in Thousands of Dollars 19 35 207 853 2,840 9,730 24,556 142,2

Confidence Interval +|- 8 +|- 7 +|- 66 +|- 197 +|- 767 +|- 2,416 +|- 5,484 +|- 34,9

Median Revenue in Thousands of Dollars 11 27 133 758 1,696 7,314 18,870 168,Mean Revenue Per Thousand Gallons of Water Produced in Dollars 5.19 4.49 4.75 3.86 3.20 3.64 5.39 2

Confidence Interval +|- 2.59 +|- 0.94 +|- 1.56 +|- 1.24 +|- 0.51 +|- 0.59 +|- 3.09 +|- 0

Observations 37 68 97 38 50 25 34 

Primarily Surface Water Systems 

Mean Revenue in Thousands of Dollars 34 110 377 1,224 3,873 22,387 32,360 156,0

Confidence Interval +|- 18 +|- 34 +|- 104 +|- 195 +|- 670 +|- 17,269 +|- 7,895 +|- 29,8

Median Revenue in Thousands of Dollars 26 63 244 1,057 2,972 7,706 20,297 99,0Mean Revenue Per Thousand Gallons of Water Produced in Dollars 8.09 8.78 6.07 3.83 4.07 5.24 2.93 2

Confidence Interval +|- 7.37 +|- 3.28 +|- 1.37 +|- 0.54 +|- 0.73 +|- 2.47 +|- 0.32 +|- 0

Observations 27 49 73 42 60 43 105 

Primarily Purchased Water Systems 

Mean Revenue in Thousands of Dollars 20 74 1,135 879 3,916 11,109 35,027 109,3

Confidence Interval +|- 16 +|- 47 +|- 1,311 +|- 179 +|- 1,401 +|- 2,914 +|- 5,060 +|- 51,6

Median Revenue in Thousands of Dollars 10 44 195 835 2,241 9,044 26,043 94,9Mean Revenue Per Thousand Gallons of Water Produced in Dollars 4.96 6.95 6.33 4.53 3.60 3.64 5.11 2

Confidence Interval +|- 1.01 +|- 2.98 +|- 1.74 +|- 1.14 +|- 0.61 +|- 1.65 +|- 1.64 +|- 1

Observations 7 18 43 20 20 26 38 

All Systems 

Mean Revenue in Thousands of Dollars 20 45 471 927 3,345 15,221 31,489 143,8

Confidence Interval +|- 8 +|- 11 +|- 366 +|- 124 +|- 545 +|- 7,137 +|- 5,016 +|- 24,7

Median Revenue in Thousands of Dollars 11 29 142 835 2,383 7,923 21,573 102,Mean Revenue Per Thousand Gallons of Water Produced in Dollars 5.29 5.06 5.28 4.06 3.52 4.30 3.84 2

Confidence Interval +|- 2.10 +|- 0.94 +|- 1.14 +|- 0.73 +|- 0.36 +|- 1.13 +|- 0.69 +|- 0

Observations 71 135 213 100 130 94 177 

Data: Q.21 Notes: Excludes systems that do not report positive revenue. 

Total water system revenue includes revenue from water sales to residential and non-residencustomers and to other systems; fees; transfers from the government including municipal government transfers from the general fund; and other sources including penalties and fines. 

Table 60 

Total Water System Revenue and Revenue Per Thousand Gallons Delivered, Excluding Systems With Zero Revenue 

By Primary Water Source 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,

Public Systems 

Mean Revenue in Thousands of Dollars 46 57 504 890 3,366 10,011 27,639 143,9

Confidence Interval +|- 25 +|- 19 +|- 465 +|- 134 +|- 574 +|- 1,360 +|- 3,011 +|- 27,5

Median Revenue in Thousands of Dollars 18 38 150 758 2,344 7,676 20,293 97,7Mean Revenue Per Thousand Gallons of Water Delivered in Dollars 9.17 4.56 4.24 3.63 3.39 4.01 3.63 2

Confidence Interval +|- 7.88 +|- 1.24 +|- 0.56 +|- 0.56 +|- 0.36 +|- 1.10 +|- 0.72 +|- 0

Observations 23 72 173 84 119 86 162 

Private Systems 

Mean Revenue in Thousands of Dollars 12 32 357 1,089 3,009 80,994 60,014 143,2

Confidence Interval +|- 4 +|- 8 +|- 262 +|- 293 +|- 1,313 +|- 83,489 +|- 21,902 +|- 28,1

Median Revenue in Thousands of Dollars 10 23 133 976 2,725 15,107 42,571 168,Mean Revenue Per Thousand Gallons of Water Delivered in Dollars 4.19 5.21 6.61 5.61 5.17 3.20 4.03 2

Confidence Interval +|- 1.19 +|- 1.16 +|- 1.91 +|- 2.51 +|- 1.28 +|- 0.78 +|- 0.78 +|- 0

Observations 48 63 40 16 11 8 15 

Data: Q.21 Notes: Excludes systems that do not report positive revenue. 

Total water system revenue includes revenue from water sales to residential and non-residencustomers and to other systems; fees; transfers from the government including municipal government transfers from the general fund; and other sources including penalties and fines. 

Table 61 

Total Water System Revenue and Revenue Per Thousand Gallons Delivered, Excluding Systems With Zero Revenue 

By Ownership 
Table 62

Total Water System Revenue for Systems Reporting Positive Revenue and Expenses

By Ownership

(Thousands of Dollars)

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Public Systems

Mean 49 58 268 889 3,146 10,255 27,951 144,74

Confidence interval +|- 27 +|- 20 +|- 97 +|- 141 +|- 510 +|- 1,451 +|- 3,173 +|- 28,17

Median 18 38 146 758 2,173 7,847 20,179 95,20Observations 22 69 167 78 115 80 153 4

Private Systems

Ancillary Systems

Mean 6 18 189 N/A N/A N/A N/A N/

Confidence Interval +|- 1 +|- 6 +|- 81 N/A N/A N/A N/A N/

Median 6 16 155 N/A N/A N/A N/A N/Observations 8 9 2 N/A N/A N/A N/A N/

Other Private Systems

Mean 14 36 378 1,081 3,009 11,742 57,039 90,98

Confidence Interval +|- 6 +|- 10 +|- 298 +|- 343 +|- 1,314 +|- 2,762 +|- 24,648 +|- 21,45

Median 11 27 114 976 2,725 13,776 42,571 90,98Observations 33 46 35 13 11 6 13 

All Private Systems

Mean 12 33 370 1,081 3,009 11,742 57,039 90,98

Confidence Interval +|- 5 +|- 8 +|- 296 +|- 357 +|- 1,484 +|- 2,445 +|- 24,717 +|- 30,16

Median 10 23 133 976 2,725 13,776 42,571 90,98Observations 41 55 37 13 11 6 13 

All Systems

Mean 21 46 290 921 3,138 10,342 31,303 142,66

Confidence Interval +|- 9 +|- 11 +|- 99 +|- 132 +|- 484 +|- 1,386 +|- 5,255 +|- 27,05

Median 11 28 138 835 2,187 7,923 20,941 95,20Observations 63 124 204 91 126 86 166 5

Data: Q.21Notes: Excludes systems that did not report positive revenue or expenses.
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Public Systems 

Water Sales 74.4 85.1 94.4 56.4 74.9 74.0 78.1 92.8 

Confidence Interval +|- 29.9 +|- 9.7 +|- 4.6 +|- 10.2 +|- 7.6 +|- 7.7 +|- 4.1 +|- 4.1 

Water-Related Operations 26.6 45.6 70.0 55.2 67.3 64.6 73.0 83.0 

Confidence Interval +|- 24.9 +|- 14.3 +|- 9.2 +|- 10.2 +|- 8.3 +|- 8.7 +|- 4.5 +|- 10.1 

General Fund 7.8 9.4 9.6 4.5 6.3 20.8 15.0 22.8 

Confidence Interval +|- 14.5 +|- 8.5 +|- 5.1 +|- 3.1 +|- 3.6 +|- 7.1 +|- 3.5 +|- 10.1 

Other Revenue Sources 1.1 6.0 10.1 18.9 29.9 42.8 48.1 55.3 

Confidence Interval +|- 1.6 +|- 6.8 +|- 5.7 +|- 7.8 +|- 8.2 +|- 10.0 +|- 5.4 +|- 9.8 

Percentage of Systems Reporting No Revenue 17.4 12.9 5.3 39.6 23.7 22.8 20.4 5.4 

Confidence Interval +|- 29.0 +|- 9.1 +|- 4.6 +|- 10.1 +|- 7.4 +|- 7.4 +|- 4.0 +|- 3.6 

Observations 27 84 181 127 156 111 204 52 

Private Systems 

Water Sales 39.2 52.2 72.6 56.0 54.3 57.3 79.0 75.6 

Confidence Interval +|- 12.1 +|- 11.5 +|- 15.8 +|- 20.8 +|- 25.5 +|- 25.0 +|- 13.8 +|- 23.9 

Water-Related Operations 12.3 13.4 46.1 47.7 54.3 32.6 44.1 24.4 

Confidence Interval +|- 8.8 +|- 8.0 +|- 16.0 +|- 21.0 +|- 25.5 +|- 22.9 +|- 23.4 +|- 23.9 

Other Revenue Sources 36.8 41.6 12.4 35.7 24.1 9.0 47.5 63.4 

Confidence Interval +|- 10.5 +|- 11.3 +|- 10.7 +|- 19.2 +|- 22.1 +|- 15.0 +|- 24.2 +|- 30.9 

Percentage of Systems Reporting No Revenue 29.1 12.8 19.2 41.5 45.7 42.7 21.0 24.4 

Confidence Interval +|- 11.5 +|- 7.2 +|- 12.0 +|- 20.8 +|- 25.5 +|- 25.0 +|- 13.8 +|- 23.9 

Observations 118 111 56 27 20 13 21 6 

(Continued) 

Table 63 

Percentage of Systems with Each Type of Revenue Source 

By Ownership 
Percentage of Systems with Each Type of Revenu

By Ownership 

System Service Pop

100 101 - 501 - 3,301 - 10,0

Ownership Type or Less 500 3,300 10,000 50

All Systems 

Water Sales 43.8 64.8 88.5 56.3 73.2 72.4 78.2 90.5 

Confidence Interval +|- 11.4 +|- 9.1 +|- 6.0 +|- 9.1 +|- 7.3 +|- 7.5 +|- 4.0 +|- 4.5 

Water-Related Operations 14.1 25.7 63.5 53.6 66.2 61.5 69.5 75.2 

Confidence Interval +|- 8.2 +|- 8.3 +|- 8.1 +|- 9.2 +|- 7.9 +|- 8.5 +|- 5.4 +|- 11.0 

General Fund 1.0 3.6 7.0 3.6 5.8 18.8 13.2 19.8 

Confidence Interval +|- 2.0 +|- 3.4 +|- 3.7 +|- 2.5 +|- 3.3 +|- 6.4 +|- 3.1 +|- 9.2 

Other Revenue Sources 32.1 28.0 10.8 22.4 29.4 39.5 48.0 56.4 

Confidence Interval +|- 9.4 +|- 8.8 +|- 5.3 +|- 7.4 +|- 7.8 +|- 9.5 +|- 5.6 +|- 9.7 

Percentage of Systems Reporting No Revenue 27.5 12.8 9.1 40.0 25.5 24.7 20.5 7.9 

Confidence Interval +|- 10.8 +|- 5.6 +|- 5.2 +|- 9.0 +|- 7.1 +|- 7.2 +|- 3.9 +|- 4.2 

Observations 145 195 237 154 176 124 225 58 

Data: Q.21 Notes: Systems have more than one type of revenue, therefore column totals do not equal 100. 

Water Sales includes revenue from the sale of water to residential and non-residential custoWater Related Operations includes revenue from connection and development fees, transfethe general fund of municipal governments, and other related fees (fines and penalties, forexample.)General Fund includes transfers from municipal government general funds to publicly owne

systems.Other is all other sources of water-related revenue, including fines, penalties, and other fees

e Source

ulation Category 

01 - 50,001 - 100,001- Over 

,000 100,000 500,000 500,000 

Table 63 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Public Systems 

Water Sales 86.3 86.1 86.7 82.3 82.6 77.7 78.4 79.8 

Confidence Interval +|- 17.3 +|- 7.9 +|- 3.6 +|- 6.9 +|- 3.8 +|- 4.5 +|- 2.5 +|- 3.6 

Water-Related Operations 3.5 6.0 7.9 12.4 13.9 11.3 15.0 12.5 

Confidence Interval +|- 4.5 +|- 3.9 +|- 2.4 +|- 5.6 +|- 3.4 +|- 2.9 +|- 2.0 +|- 2.9 

General Fund 9.4 5.2 2.6 3.2 1.2 5.7 1.2 1.8 

Confidence Interval +|- 17.3 +|- 5.4 +|- 1.6 +|- 4.3 +|- 0.8 +|- 3.3 +|- 0.5 +|- 1.0 

Other Revenue Sources 0.9 2.7 2.8 2.2 2.4 5.4 5.4 5.9 

Confidence Interval +|- 1.6 +|- 4.6 +|- 2.3 +|- 1.3 +|- 1.2 +|- 2.0 +|- 1.5 +|- 2.1 

Observations 24 73 173 81 119 86 162 49 

Private Systems 

Water Sales 45.2 52.7 84.9 84.5 85.7 94.9 97.3 98.7 

Confidence Interval +|- 12.2 +|- 12.2 +|- 11.4 +|- 9.8 +|- 8.8 +|- 5.0 +|- 2.2 +|- 1.5 

Water-Related Operations 3.7 1.0 4.5 4.5 11.0 5.1 1.8 0.2 

Confidence Interval +|- 3.6 +|- 0.6 +|- 2.5 +|- 2.7 +|- 8.1 +|- 5.0 +|- 1.6 +|- 0.3 

Other Revenue Sources 51.2 46.3 10.6 11.0 3.3 0.0 0.9 1.0 

Confidence Interval +|- 13.3 +|- 12.4 +|- 11.8 +|- 9.8 +|- 4.5 +|- 0.0 +|- 0.6 +|- 1.2 

Observations 86 96 44 18 11 8 15 4 

(Continued) 

Table 64 

Percentage of System Revenue Received from Each Revenue Source For Systems Reporting Positive Revenue 

By Ownership 
Percentage of System Revenue Received from Each Revenue Source For Systems Repo

By Ownership 

System Service Population Cate

100 101 - 501 - 3,301 - 10,001 - 50,00

Ownership Type or Less 500 3,300 10,000 50,000 100,0All Systems 

Water Sales 51.3 65.5 86.2 82.7 82.8 78

Confidence Interval +|- 11.2 +|- 9.2 +|- 4.0 +|- 5.9 +|- 3.6 +|- 4

Water-Related Operations 3.6 2.9 7.1 10.8 13.7 10

Confidence Interval +|- 3.2 +|- 1.6 +|- 2.1 +|- 4.6 +|- 3.3 +|- 2.7 +|- 2.0 +|- 2.8 

General Fund 1.4 2.0 2.0 2.5 1.1 5.2 1.0 1.6 

Confidence Interval +|- 2.7 +|- 2.2 +|- 1.3 +|- 3.5 +|- 0.7 +|- 3.0 +|- 0.5 +|- 0.9 

Other Revenue Sources 43.6 29.6 4.7 4.0 2.4 5.0 4.8 5.4 

Confidence Interval +|- 11.9 +|- 9.5 +|- 3.6 +|- 2.2 +|- 1.1 +|- 1.9 +|- 1.3 +|- 2.0 

Observations 110 169 217 99 130 94 177 53 

Data: Q.21 Notes: Systems have more than one type of revenue, therefore column totals do not equal 100. 

Water Sales includes revenue from the sale of water to residential and non-residential custoWater Related Operations includes revenue from connection and development fees, transfethe general fund of municipal governments, and other related fees (fines and penalties, forexample.)General Fund includes transfers from municipal government general funds to publicly owne

systems.Other is all other sources of water-related revenue, including fines, penalties, and other fees

rting Positive Revenue

gory 

1 - 100,001- Over 

00 500,000 500,000 

.9 80.7 81.9 

.3 +|- 2.6 +|- 3.7 

.9 13.4 11.2 

Table 64 (Cont.)
Water Revenue Municip

Non-wat

Water Related Revenue 

Syst

Other Water Total Water Revenue (Net 

Water Sales General Fund Related Related Total Water Non-water Transfers 

Population Served Revenue Transfers Revenue Revenue Revenue Revenue Water Syste

Public Systems 

Mean Revenue 

25-100 101-500 

Subtotal, 25-500 

501-3,300 3,301-10,000 

Subtotal, 25-10,000 

26,962 42,398 39,575 

233,998 783,150 230,244 

63,702 84,995 81,246 89,416 

179,361 

94,611 

1,916 9,966 8,917 

39,305 

133,986 

47,346 

15,964 27,437 25,577 

50,779 

144,298 

59,943 

31,180 57,132 51,997 

271,632 

890,168 

276,020 

25,495 44,046 43,249 

137,623 

64,975 

96,268 

385,9213,6240,4

993,2

5,349,7

1,571,3

Observations 

25-100 101-500 

Subtotal, 25-500 

501-3,300 3,301-10,000 

Subtotal, 25-10,000 

20 

72 

92 

171 

77 

340 

2 

7 

9 

20 11 40 

11 

45 

56 

132 

74 

262 

13 

46 

59 

135 

76 

270 

21 

72 

93 

172 

84 

349 

2 

3 

5 

20 26 51 

12

Table 65 

Average Revenue of Community Water Systems Serving 10,000 or Fewer Reporting Positive Revenue 

By Ownership and Type of Revenue Source 
Average Revenue of Community Water Systems Serving 10,000 or Fewer Reporting

nue Source

 Total Water N

 Revenue 

11,719 32,455 23,393 

357,235 

1,088,984 

580,569 402,364 

3,685,785 

6,014,066 

 Positive Revenue

Municip

Non-wat

Syst

Revenue (Net 

on-water Transfers 

Revenue Water Syste

211,715 

ership and Type of Reve

Revenue 

ted Revenue 

er Water Total Water

Related Related

Revenue Revenue

Private Systems 

Mean Revenue 

3,536 4,366 3,958 

28,753 74,548 20,514 

3,5364,3663,958

30,07980,60221,023 143,447 773,652 

Observations 

13 

21 34 25 17 76 

13 

21 34 24 14 72 

48 

63 

111 

40 16 

167 

43 

41 84 

5 

12 

101 

By Own

Water 

Water Rela

Oth

Water Sales General Fund 

Population Served Revenue Transfers 

25-100 101-500 

Subtotal, 25-500 

501-3,300 3,301-10,000 

Subtotal, 25-10,000 

10,613 31,743 22,385 

338,117 

1,020,381 

136,609 

25-100 101-500 

Subtotal, 25-500 

501-3,300 3,301-10,000 

Subtotal, 25-10,000 

48 

62 

110 

40 16 

166 

Table 65 (Cont.)
Average Revenue of Community Water Systems Serving 10,000 or F

By Ownership and Type of Revenue So

Water Revenue 

Water Related Revenue 

Syst

Other Water Total Water Revenue (Net 

Water Sales General Fund Related Related Total Water Non-water Transfers 

Population Served Revenue Transfers Revenue Revenue Revenue Revenue Water Syste

All Systems 

Mean Revenue 

25-100 101-500 

Subtotal, 25-500 

501-3,300 3,301-10,000 

Subtotal, 25-10,000 

14,254 37,117 29,427 

257,359 832,171 191,953 

63,702 84,995 81,246 89,416 

179,361 

94,611 

3,136 8,174 6,704 

37,146 

122,293 

39,729 

7,245 

20,067 16,141 

46,745 

132,816 

49,275 

16,390 44,755 35,147 

290,787 

927,074 

222,291 

210,909 536,067 385,638 

1,113,768 

1,986,360 

639,251 

385,9213,6240,4

993,2

5,349,7

1,571,3

Observations 

25-100 101-500 

Subtotal, 25-500 

501-3,300 3,301-10,000 

Subtotal, 25-10,000 

68 

134 202 211 

93 

506 

2 

7 9 

20 11 40 

24 

66 90 

157 

91 

338 

26 

67 93 

159 

90 

342 

69 

135 204 212 100 516 

45 

44 89 25 38 

152 

12

Data: Q. 21 

Note: Total revenue is not derived from the simple addition of all the subcategories of revenue. Rather, it is the weighted av

of the revenue with the weights dependent on the likelihood that the average system will have access to a particular revenue subcategory. 

ewer Reporting Positive Revenue

urce

Municip

Non-wat

Table 65 (Cont.)
System Service Populati

100 101 - 501 - 3,301 - 10,001 - Ove

Ownership Type or Less 500 3,300 10,000 50,000 000 Public Systems 

Residential 93.8 93.3 86.1 69.9 73.3 48.2 

Confidence Interva

on Category 

50,001 - 100,001-

100,000 500,000 500,

69.5 58.3 

l +|- 8.8 +|- 5.1 +|- 4.7 +|- 9.0 +|- 4.6 +|- 5.0 +|- 2.9 +|- 6.1 

Non-Residential 6.2 6.4 12.8 19.3 20.7 18.7 27.0 23.4 

Confidence Interval +|- 8.8 +|- 5.1 +|- 4.7 +|- 6.5 +|- 3.7 +|- 3.0 +|- 2.0 +|- 3.3 

Wholesale 0.0 0.3 1.0 10.8 6.1 11.8 14.7 28.4 

Confidence Interval +|- 0.0 +|- 0.5 +|- 0.9 +|- 7.7 +|- 3.0 +|- 4.9 +|- 2.9 +|- 7.0 

Observations 27 84 181 127 156 111 204 52 

Private Systems 

Residential 96.6 99.5 93.5 87.6 79.0 56.9 65.0 61.6 

Confidence Interval +|- 5.8 +|- 0.6 +|- 7.0 +|- 8.9 +|- 15.3 +|- 21.3 +|- 4.8 +|- 2.9 

Non-Residential 0.5 0.3 6.4 7.3 2.7 18.2 30.8 34.8 

Confidence Interval +|- 0.6 +|- 0.3 +|- 6.9 +|- 5.4 +|- 2.2 +|- 12.8 +|- 3.1 +|- 3.3 

Wholesale 2.9 0.3 0.2 5.0 18.3 24.9 4.2 3.6 

Confidence Interval +|- 5.8 +|- 0.5 +|- 0.3 +|- 7.3 +|- 14.1 +|- 25.1 +|- 3.0 +|- 0.5 

Observations 118 111 56 27 20 13 21 6 

All Systems 

Residential 96.0 96.4 87.8 73.5 73.6 68.6 59.1 49.7 

Confidence Interval +|- 5.0 +|- 2.6 +|- 4.0 +|- 7.7 +|- 4.4 +|- 5.0 +|- 2.7 +|- 5.5 

Non-Residential 1.8 3.4 11.4 16.9 19.6 18.6 27.5 24.7 

Confidence Interval +|- 2.1 +|- 2.6 +|- 4.0 +|- 5.5 +|- 3.6 +|- 2.9 +|- 1.8 +|- 3.1 

Wholesale 2.3 0.3 0.8 9.6 6.8 12.8 13.4 25.7 

Confidence Interval +|- 4.5 +|- 0.4 +|- 0.7 +|- 6.3 +|- 2.9 +|- 4.9 +|- 2.7 +|- 6.6 

Observations 145 195 237 154 176 124 225 58 

Data: Q.21 Notes: Column totals may not equal 100 due to rounding. 

Table 66

Average Water Sales Revenue Profile:

Percentage of Revenue from Each Customer Category

By Ownership 
Ownership Type 

Public Systems 

Mean 

Confidence Interval 

MedianObservations

Private Systems 

Mean 

Confidence Interval 

MedianObservations

All Systems 

Mean 

Confidence Interval 

Median Observations 

Data: Notes: 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Ove

or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

9.04 4.04 4.04 3.46 3.18 3.91 3.41 2.39 

+|- 7.71 +|- 1.18 +|- 0.55 +|- 0.57 +|- 0.37 +|- 1.08 +|- 0.69 +|- 0.35 

4.62 3.42 3.08 3.37 2.93 2.97 2.47 2.24 

24 78 168 74 111 77 158 47 

2.05 2.81 5.13 5.48 5.17 3.20 3.64 2.41 

+|- 0.77 +|- 0.92 +|- 1.82 +|- 2.46 +|- 1.28 +|- 0.78 +|- 0.94 +|- 0.45 

0.00 1.19 4.69 4.70 5.60 3.48 3.69 2.07 

95 95 52 15 11 7 15 4 

2.91 3.30 4.34 3.89 3.31 3.86 3.44 2.39 

+|- 1.28 +|- 0.74 +|- 0.63 +|- 0.72 +|- 0.38 +|- 1.00 +|- 0.62 +|- 0.32 

0.99 2.50 3.58 3.43 3.10 3.00 2.58 2.19 

119 173 220 89 122 84 173 51 

Q.21 Includes wholesale deliveries and unaccounted for water. 

Table 67 

Water System Revenue from All Sources per Thousand Gallons Delivered 

By Ownership 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Ove

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Public Systems 

Mean 4.31 3.19 3.40 2.81 2.61 3.26 2.62 2.03 

Confidence Interval +|- 1.65 +|- 0.66 +|- 0.44 +|- 0.50 +|- 0.31 +|- 0.97 +|- 0.54 +|- 0.25 

Median 3.74 2.97 2.91 2.63 2.59 2.51 2.01 1.99 Observations 24 78 168 74 111 77 158 47 

Private Systems 

Mean 1.85 2.70 4.91 5.10 4.43 3.03 3.54 2.41 

Confidence Interval +|- 0.69 +|- 0.91 +|- 1.82 +|- 2.33 +|- 1.16 +|- 0.77 +|- 0.97 +|- 0.45 

Median 0.00 1.19 4.63 4.24 4.38 3.11 3.59 2.07 Observations 95 95 52 15 11 7 15 4 

All Systems 

Mean 2.15 2.90 3.81 3.29 2.73 3.24 2.73 2.07 

Confidence Interval +|- 0.66 +|- 0.60 +|- 0.59 +|- 0.68 +|- 0.32 +|- 0.90 +|- 0.51 +|- 0.23 

Median 0.84 2.36 3.14 3.04 2.69 2.52 2.22 2.02 Observations 119 173 220 89 122 84 173 51 

Data: Q.21 Notes: 

Table 68 

Water System Revenue from Water Sales per Thousand Gallons Delivered 

By Ownership 
Ownership Type 

Public Systems 

Residential

Mean

Confidence Interval 

MedianObservations

Non-Residential

Mean

Confidence Interval 

MedianObservations

Wholesale

Mean

Confidence Interval 

MedianObservations

Private Systems 

Residential

Mean

Confidence Interval 

MedianObservations

Non-Residential

Mean

Confidence Interval 

MedianObservations

Wholesale

Mean

Confidence Interval 

MedianObservations

System Service Population Category

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 A

4.90 3.63 4.04 3.64 3.35 4.15 2.78 2.68 

+|- 2.10 +|- 0.72 +|- 0.58 +|- 0.77 +|- 0.39 +|- 1.13 +|- 0.17 +|- 0.37 

4.30 3.27 3.26 3.11 3.18 3.04 2.66 2.53 

24 78 168 68 105 70 138 38 

2.95 4.40 4.42 3.12 2.90 3.02 2.67 2.76 

+|- 1.58 +|- 1.27 +|- 1.74 +|- 0.73 +|- 0.44 +|- 0.74 +|- 0.28 +|- 0.54 

2.18 4.49 3.34 2.73 2.52 2.69 2.11 2.53 

6 21 73 57 86 61 126 36 

* 0.00 2.01 1.62 2.09 2.40 1.66 1.99 

* +|- 0.00 +|- 0.93 +|- 0.65 +|- 0.58 +|- 0.93 +|- 0.15 +|- 0.26 

* 0.00 1.75 1.44 2.08 1.87 1.53 1.71 * 1 13 26 43 43 104 41 

1.95 2.92 5.41 6.22 5.67 6.23 6.00 3.00 

+|- 0.72 +|- 0.97 +|- 2.01 +|- 3.03 +|- 1.50 +|- 1.75 +|- 1.87 +|- 0.49 

0.00 1.33 5.12 4.83 5.63 6.25 5.30 2.65 

91 95 51 14 11 5 15 4 

1.15 7.88 3.22 4.86 3.60 3.20 4.34 2.87 

+|- 2.48 +|- 8.98 +|- 2.06 +|- 2.83 +|- 1.33 +|- 1.71 +|- 1.24 +|- 0.86 

0.00 2.00 5.38 2.91 3.91 4.02 4.66 2.20 

6 8 15 11 8 5 15 4 

0.50 * 3.71 4.11 3.35 2.11 2.67 1.68 

+|- 0.74 * +|- 4.46 +|- 0.42 +|- 1.80 +|- 0.88 +|- 0.80 +|- 0.22 

0.00 * 6.49 3.84 3.01 2.77 2.91 1.55 

2 * 2 3 8 4 12 4 

(Continued) 

Table 69 

Water System Revenue from Water Sales per Thousand Gallons Delivered 

By Ownership and Customer Class 
Water System Revenue from Water Sales per Thousand Gallons Delivered

By Ownership and Customer Class 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 A

All Systems 

Residential 

Mean 2.33 3.20 4.42 4.22 3.51 4.27 3.19 2.72 

Confidence Interval +|- 0.72 +|- 0.65 +|- 0.70 +|- 0.96 +|- 0.41 +|- 1.07 +|- 0.46 +|- 0.33 

Median 0.99 2.48 3.51 3.59 3.22 3.10 2.89 2.65 Observations 115 173 219 82 116 75 153 42 

Non-Residential 

Mean 1.68 5.05 4.21 3.46 2.93 3.03 2.90 2.78 

Confidence Interval +|- 2.09 +|- 2.01 +|- 1.48 +|- 0.86 +|- 0.42 +|- 0.69 +|- 0.36 +|- 0.48 

Median 0.00 4.49 3.44 2.82 2.64 2.69 2.22 2.53 Observations 12 29 88 68 94 66 141 40 

Wholesale 

Mean 0.50 0.00 2.09 1.86 2.22 2.38 1.80 1.95 

Confidence Interval +|- 0.74 +|- 0.00 +|- 0.90 +|- 0.67 +|- 0.56 +|- 0.87 +|- 0.23 +|- 0.23 

Median 0.00 0.00 1.75 1.53 2.08 1.93 1.74 1.55 

Observations 2 1 15 29 51 47 116 45 

 Q 26 Q.21 Notes: 

Table 69 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Mean Residential Revenues per Connection 470 314 445 320 290 352 343 3

Confidence interval +|- 287 +|- 60 +|- 244 +|- 54 +|- 28 +|- 40 +|- 20 +|- 

Median Residential Revenues per Connection 309 274 283 264 259 308 302 3Observations 22 72 169 63 98 66 137 

Private Systems 

Ancillary Systems Mean Residential Revenues per Connection 196 352 727 N/A N/A N/A N/A N

Confidence interval +|- 48 +|- 164 +|- 65 N/A N/A N/A N/A N

Median Residential Revenues per Connection 180 313 700 N/A N/A N/A N/A NObservations 6 11 2 N/A N/A N/A N/A N

 Other Private Systems 

Mean Residential Revenues per Connection 408 429 592 480 390 483 401 2

Confidence interval +|- 105 +|- 119 +|- 245 +|- 127 +|- 112 +|- 141 +|- 53 +|- 

Median Residential Revenues per Connection 415 313 397 423 366 469 432 2

Observations 38 49 38 13 11 6 15 All Private Systems Mean Residential Revenues per Connection 361 413 596 480 390 483 401 2

Confidence interval +|- 91 +|- 102 +|- 242 +|- 124 +|- 116 +|- 138 +|- 53 +|- 

Median Residential Revenues per Connection 312 313 397 423 366 469 432 2Observations 44 60 40 13 11 6 15 

All Systems 

Mean Residential Revenues per Connection 388 363 479 358 297 362 351 3

Confidence interval +|- 126 +|- 59 +|- 197 +|- 56 +|- 29 +|- 39 +|- 20 +|- 

Median Residential Revenues per Connection 312 291 304 340 269 330 328 3Observations 66 132 209 76 109 72 152 

Data: Q.21 Notes: Excludes systems that did not report positive revenue. 

Table 70 

Annual Residential Revenue per Connection 

By Ownership 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems

 Metered Charges 

Uniform Rate 41.2 46.3 54.5 35.6 38.7 30.9 27.3 3Declining Block Rate 7.8 9.7 20.6 16.1 16.2 6.1 17.8 1Increasing Block Rate 16.0 14.7 13.6 10.9 25.7 34.5 31.1 2Seasonal Rate 0.0 2.0 0.0 0.0 0.0 3.0 4.8 

 Unmetered Charges 

Separate Flat Fee for Water 8.9 26.7 18.8 19.7 19.5 10.0 21.7 1Annual Connection Fee 0.0 0.0 0.0 3.9 6.7 3.6 2.8 Combined Flat Fee for Water and Other Services 17.0 2.3 0.0 3.0 5.1 2.6 2.4 

 Other billing methods 0.7 6.2 6.5 2.3 2.6 1.8 8.9 1 Observations 27 84 181 127 155 111 204 

Private Systems

 Metered Charges 

Uniform Rate 15.1 27.3 48.0 50.7 55.2 29.2 33.1 5Declining Block Rate 0.0 5.0 15.6 2.6 18.5 7.9 56.5 6

Increasing Block Rate 8.7 9.6 14.0 24.9 2.1 7.9 0.0 1Seasonal Rate 0.0 0.0 0.0 0.0 0.0 0.0 3.4 

 Unmetered Charges 

Separate Flat Fee for Water 12.9 18.1 12.0 7.9 19.4 25.8 3.4 2Annual Connection Fee 0.0 1.3 0.0 5.0 4.8 0.0 0.0 Combined Flat Fee for Water and Other Services 34.8 37.3 1.8 0.0 0.0 0.0 0.0 

 Other billing methods 15.2 1.6 11.1 0.0 12.9 0.0 0.0  Observations 118 111 56 27 19 13 21 

(Contin

Table 71 

Percentage of Systems with Each Residential Rate Structure and Billing Profile 

By Ownership 
Percentage of Systems with Each Residential Rate Structure and Billing Profile

By Ownership 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0All Systems

 Metered Charges 

Uniform Rate 18.5 34.6 52.7 38.7 40.0 30.8 28.0 3Declining Block Rate 1.0 6.8 19.2 13.3 16.4 6.2 22.4 2Increasing Block Rate 9.7 11.6 13.7 13.8 23.9 31.9 27.3 2Seasonal Rate 0.0 0.8 0.0 0.0 0.0 2.7 4.7 

 Unmetered Charges 

Separate Flat Fee for Water 12.4 21.4 17.0 17.2 19.5 11.5 19.5 1Annual Connection Fee 0.0 0.8 0.0 4.2 6.6 3.3 2.5 Combined Flat Fee for Water and Other Services 32.5 23.9 0.5 2.4 4.7 2.4 2.1 

 Other billing methods 13.3 3.4 7.7 1.8 3.3 1.6 7.8 1 Observations 145 195 237 154 174 124 225 

Data: Q.22 Notes: These rate structures only apply to residential customers. 

Column totals may be greater than or less than 100. 

Table 71 (Cont.)
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems

 Metered Charges 

Uniform Rate 24.0 29.3 45.3 30.0 37.7 41.6 33.4 4Declining Block Rate 7.8 6.4 17.2 15.9 18.0 7.3 20.6 2Increasing Block Rate 8.0 8.3 9.9 8.3 20.0 25.7 24.8 1Seasonal Rate 0.0 2.0 0.0 0.0 0.0 3.0 5.3 1

 Unmetered Charges 

Separate Flat Fee for Water 16.6 17.5 14.3 15.1 21.9 9.0 19.0 1Annual Connection Fee 0.0 0.0 0.0 4.3 6.7 2.6 5.1 1Combined Flat Fee for Water and Other Services 0.0 2.2 0.0 4.0 6.1 1.7 2.4 

 Other billing methods 0.0 4.3 5.2 2.0 4.0 1.9 4.8  Observations 27 84 181 127 155 111 204 

Private Systems

 Metered Charges 

Uniform Rate 1.4 5.1 29.8 40.6 27.8 30.3 17.3 6Declining Block Rate 0.0 2.5 2.8 5.9 20.2 15.8 72.2 6

Increasing Block Rate 0.1 1.4 7.3 16.5 2.1 11.3 0.0 Seasonal Rate 0.0 0.0 0.0 0.0 0.0 0.0 3.4 

 Unmetered Charges 

Separate Flat Fee for Water 3.9 5.5 4.9 12.9 7.0 17.9 6.8 2Annual Connection Fee 0.0 0.0 0.0 2.6 4.8 0.0 0.0 Combined Flat Fee for Water and Other Services 2.5 5.1 0.0 0.0 0.0 0.0 0.0 

 Other billing methods 3.9 0.1 4.7 0.0 0.0 0.0 3.4  Observations 118 111 56 27 19 13 21 

(Contin

Table 72 

Percentage of Systems with Each Non-residential Rate Structure and Billing Profile 

By Ownership 
Percentage of Systems with Each Non-residential Rate Structure and Billing Profile

By Ownership 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0All Systems

 Metered Charges 

Uniform Rate 4.4 14.4 41.1 32.2 37.0 40.5 31.4 4Declining Block Rate 1.0 4.0 13.3 13.9 18.1 8.1 26.8 2Increasing Block Rate 1.1 4.1 9.2 10.0 18.7 24.3 21.8 1Seasonal Rate 0.0 0.8 0.0 0.0 0.0 2.7 5.1 

 Unmetered Charges 

Separate Flat Fee for Water 5.6 10.1 11.7 14.6 20.8 9.9 17.6 1Annual Connection Fee 0.0 0.0 0.0 3.9 6.6 2.4 4.5 Combined Flat Fee for Water and Other Services 2.2 4.0 0.0 3.2 5.7 1.5 2.1 

 Other billing methods 3.4 1.8 5.1 1.6 3.7 1.7 4.6  Observations 145 195 237 154 174 124 225 

Data: Q.22 Notes: These rate structures only apply to non-residential customers. 

Column totals may be greater than or less than 100. 

Table 72 (Cont.)
Ownership Type 

Public Systems 

Percentage of systems with a program Average number of households that qualify Of the systems with a program, the percentage that use the following eligibility requirements 

Income Age, Disability, and/or Income Other 

Observations 

Private Systems 

Percentage of systems with a program Average number of households that qualify Of the systems with a program, the percentage that use the following eligibility requirements 

Income Age, Disability, and/or Income Other 

Observations 

All Systems 

Percentage of systems with a program Average number of households that qualify Of the systems with a program, the percentage that use the following eligibility requirements 

Income Age, Disability, and/or Income Other 

Observations 

System Service Population Category

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

or Less 500 3,300 10,000 50,000 100,000 500,000 500,0

17.0 0.4 1.3 5.8 8.6 15.8 18.9 1

24 7 12 71 261 422 370 4,1

100.0 0.0 9.6 26.8 42.5 34.0 37.6 5

0.0 58.9 90.4 73.2 57.5 46.0 55.7 50.0 41.1 0.0 0.0 0.0 20.0 6.7 

27 84 181 117 151 107 196 

5.2 0.0 2.5 0.0 12.9 9.8 42.0 2

2 * 20 * 0 100 1,024 

33.0 * 0.0 * * 100.0 100.0 1033.0 * 0.0 * * 0.0 0.0 33.9 * 100.0 * * 0.0 0.0 

118 111 56 26 19 12 21 

6.8 0.1 1.6 4.5 8.9 15.2 21.8 1

11 7 14 71 231 402 495 3,8

59.7 0.0 5.9 26.8 42.5 40.7 63.4 619.9 58.9 55.9 73.2 57.5 41.3 32.7 320.4 41.1 38.1 0.0 0.0 18.0 4.0 

145 195 237 143 170 119 217 

Data: Q.23 Notes: 

Table 73 

Percentage of Systems with Programs to Lower the Cost of Drinking Water for Low-income Households 

By Ownership
Ownership Type 

Public Systems 

Percentage of systems that serve a residential population that changes on a seasonal basisAverage daily flow during the peak season (millions of gallons per day)Year-Round Average daily flow (millions of gallons per day) Average duration of peak season (days) Observations 

Private Systems 

Percentage of systems that serve a residential population that changes on a seasonal basisAverage daily flow during the peak season (millions of gallons per day)Year-Round Average daily flow (millions of gallons per day) Average duration of peak season (days) Observations 

All Systems 

Percentage of systems that serve a residential population that changes on a seasonal basisAverage daily flow during the peak season (millions of gallons per day)Year-Round Average daily flow (millions of gallons per day) Average duration of peak season (days) Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - All 

or Less 500 3,300 10,000 50,000 100,000 <10

0.0 0.0 0.0 8.6 10.5 7.8 

* * * 1.3 3.6 12.2 * * * 0.8 2.9 9.5 * * * 87.5 90.9 96.8 

0 1 10 139 212 120 

* 0.0 0.0 26.0 2.2 0.0 * * * 1.0 7.0 19.3 * * * 0.4 5.6 17.0 * * * 121.6 60.0 90.0 

0.0 1 1 47 18 10 0.0 0.0 0.0 12.3 9.9 7.1 

* * * 1.1 3.6 12.2 * * * 0.6 3.0 9.5 * * * 102.9 90.4 96.8 

0 2 11 186 230 130 

Data: Q.24 Notes: 

Table 74 

Characteristics of Water Systems Serving Less than 100,000 with a Seasonal Population 

By Ownership 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,

Primarily Ground Water Systems 

Mean 10 43 168 598 2,674 7,379 23,182 99,

Confidence interval +|- 4 +|- 23 +|- 43 +|- 215 +|- 812 +|- 2,121 +|- 7,199 +|- 78,3

Median 3 18 104 321 1,273 7,304 10,669 Observations 88 105 111 62 65 40 56 

Primarily Surface Water Systems 

Mean 167 238 469 1,353 3,125 9,225 33,857 184,

Confidence interval +|- 252 +|- 191 +|- 154 +|- 460 +|- 689 +|- 2,118 +|- 8,695 +|- 46,7

Median 43 85 246 766 2,547 7,597 20,371 120,Observations 49 67 78 65 82 54 124 

Primarily Purchased Water Systems 

Mean 16 43 330 755 3,380 9,779 39,788 153,

Confidence interval +|- 17 +|- 20 +|- 165 +|- 182 +|- 1,265 +|- 2,252 +|- 7,147 +|- 76,6

Median 7 32 166 798 2,074 9,261 27,702 81,Observations 8 23 48 27 25 30 45 

All Systems 

Mean 15 50 236 778 2,944 8,689 32,447 165,

Confidence interval +|- 8 +|- 21 +|- 54 +|- 156 +|- 531 +|- 1,259 +|- 5,398 +|- 38,4

Median 4 20 132 522 1,636 8,029 20,371 108,Observations 145 195 237 154 172 124 225 

Data: Q.26 Notes: Systems reporting zero expenses are included in this analysis. 

Table 75 

Total Expenses 

By Primary Water Source 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Primarily Ground Water Systems 

Mean 4.52 3.44 3.81 2.92 3.39 3.72 3.06 1

Confidence interval +|- 1.81 +|- 0.79 +|- 0.95 +|- 0.89 +|- 0.92 +|- 1.17 +|- 0.88 +|- 1

Median 2.25 2.62 2.55 2.97 2.65 4.17 2.52 0Observations 69 93 103 32 46 23 37 

Primarily Surface Water Systems 

Mean 8.98 7.16 6.26 5.59 4.08 4.39 3.69 3

Confidence interval +|- 2.87 +|- 1.70 +|- 1.31 +|- 1.41 +|- 0.81 +|- 1.73 +|- 0.45 +|- 0

Median 7.35 5.45 4.39 4.13 3.11 2.74 3.16 2Observations 38 55 71 37 58 41 100 

Primarily Purchased Water Systems 

Mean 3.80 4.86 5.59 4.64 3.70 3.30 4.23 3

Confidence interval +|- 1.71 +|- 1.48 +|- 1.12 +|- 1.42 +|- 1.26 +|- 1.28 +|- 0.56 +|- 1

Median 3.85 5.15 4.67 4.02 3.24 2.66 3.54 3Observations 8 19 45 18 19 22 35 

All Systems 

Mean 4.61 3.76 4.48 3.94 3.64 3.89 3.66 3

Confidence interval +|- 1.61 +|- 0.70 +|- 0.69 +|- 0.71 +|- 0.59 +|- 0.88 +|- 0.34 +|- 0

Median 2.55 2.76 3.15 3.36 2.75 2.77 3.12 2Observations 115 167 219 87 123 86 172 

Data: Q.26, Q.21 Notes: 

Table 76 

Total Expenses per Thousand Gallons Delivered 

By Primary Water Source 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500

Public Systems 

Mean 64 74 262 799 2,997 9,134 30,612 187,

Confidence interval +|- 62 +|- 41 +|- 73 +|- 177 +|- 558 +|- 1,330 +|- 3,656 +|- 41,

Median 15 35 144 571 1,659 8,029 19,727 120,Observations 27 84 181 127 153 111 204 

Private Systems 

Mean 7 36 165 696 2,283 4,518 16,738 24,

Confidence interval +|- 3 +|- 23 +|- 65 +|- 340 +|- 1,580 +|- 3,191 +|- 5,218 +|- 24,

Median 3 10 85 474 1,395 0 20,548 Observations 118 111 56 27 19 13 18 

Data: Q.26 Notes: Systems reporting zero expenses are included in this analysis. 

Table 77 

Total Expenses 

By Ownership 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Mean 8.31 4.78 4.89 4.05 3.62 4.07 3.63 3

Confidence interval +|- 7.75 +|- 1.34 +|- 0.95 +|- 0.83 +|- 0.61 +|- 0.94 +|- 0.33 +|- 0

Median 3.85 3.19 3.28 3.36 2.75 2.90 3.05 2Observations 22 77 168 74 114 78 158 

Private Systems 

Mean 4.08 3.04 3.40 3.47 4.05 1.81 3.92 1

Confidence interval +|- 1.40 +|- 0.65 +|- 0.80 +|- 1.23 +|- 1.68 +|- 0.79 +|- 1.55 +|- 1

Median 2.40 2.62 2.93 3.95 4.82 2.62 3.80 0Observations 93 90 51 13 9 8 14 

Data: Q.26, Q.21 Notes: 

Table 78 

Total Expenses per Thousand Gallons Delivered 

By Ownership 
Table 79

Total Expenses for Systems Reporting Positive Revenues and Expenses

By Ownership

(Thousands of Dollars)

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,000 

Public Systems

Mean 82 88 287 1,098 3,753 11,468 38,390 202,343 

Confidence interval +|- 82 +|- 49 +|- 82 +|- 244 +|- 676 +|- 1,485 +|- 4,635 +|- 44,087 

Median 17 40 156 718 2,547 9,499 26,646 168,087 Observations 22 69 167 78 115 80 153 48 

Private Systems

Mean 15 45 228 1,153 3,611 10,879 63,599 100,581 

Confidence interval +|- 7 +|- 28 +|- 89 +|- 442 +|- 2,045 +|- 3,353 +|- 34,496 +|- 19,094 

Median 10 23 116 822 2,793 11,596 32,170 100,581 Observations 41 55 37 13 11 6 13 2 

All Systems

Mean 32 67 274 1,108 3,744 11,434 41,295 198,399 

Confidence interval +|- 21 +|- 29 +|- 66 +|- 217 +|- 647 +|- 1,412 +|- 6,650 +|- 42,304 

Median 11 28 151 781 2,715 10,115 27,702 160,798 Observations 63 124 204 91 126 86 166 50 

Data: Q.26Notes: Excludes systems that did not report positive revenues or expenses.
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 All Si

Public Systems 

Purchased water 10.2 7.4 10.6 12.2 11.5 15.9 11.3 14.2 1

Confidence interval +|- 10.5 +|- 6.5 +|- 4.8 +|- 6.3 +|- 4.4 +|- 4.7 +|- 2.0 +|- 6.5 +|- 2

Security 0.0 0.0 0.1 2.6 0.2 1.3 1.0 0.4 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.1 +|- 3.6 +|- 0.1 +|- 1.8 +|- 0.9 +|- 0.1 +|- 

Depreciation 4.6 5.5 5.9 10.4 10.3 11.9 11.0 10.7 

Confidence interval +|- 7.2 +|- 4.7 +|- 1.8 +|- 2.4 +|- 1.7 +|- 2.2 +|- 1.0 +|- 1.6 +|- 

Payments to General Fund 0.0 0.8 2.3 4.2 3.5 3.9 4.0 1.9 

Confidence interval +|- 0.0 +|- 1.1 +|- 1.6 +|- 3.5 +|- 1.5 +|- 1.4 +|- 0.9 +|- 0.5 +|- 

Other Routine Operating Expenses 77.3 64.5 58.6 48.8 45.4 35.8 36.4 32.9 5

Confidence interval +|- 19.6 +|- 8.9 +|- 5.7 +|- 7.2 +|- 5.0 +|- 3.9 +|- 2.6 +|- 4.2 +|- 

Debt Service Expenses 0.8 10.8 14.9 12.5 11.9 14.1 15.6 17.9 1

Confidence interval +|- 0.9 +|- 5.0 +|- 3.3 +|- 3.7 +|- 2.9 +|- 3.2 +|- 1.2 +|- 2.7 +|- 2

Capital Improvements 4.0 6.8 5.9 8.2 14.0 16.1 18.3 20.4 

Confidence interval +|- 6.2 +|- 5.3 +|- 3.2 +|- 3.3 +|- 3.8 +|- 3.0 +|- 2.0 +|- 3.3 +|- 2

Payments to Reserve funds 3.2 4.3 1.8 1.1 3.2 1.1 2.3 1.6 

Confidence interval +|- 6.0 +|- 3.9 +|- 1.3 +|- 0.7 +|- 1.7 +|- 0.7 +|- 0.7 +|- 0.7 +|- 

Private Systems 

Purchased water 3.5 7.3 13.9 16.0 6.9 37.6 6.8 0.4 

Confidence interval +|- 6.2 +|- 5.2 +|- 8.2 +|- 12.2 +|- 9.0 +|- 26.9 +|- 10.9 +|- 0.4 +|- 

Security 0.3 0.2 0.1 8.4 0.0 0.0 0.5 1.9 

Confidence interval +|- 0.5 +|- 0.2 +|- 0.1 +|- 15.5 +|- 0.0 +|- 0.0 +|- 0.2 +|- 1.6 +|- 

Depreciation 1.8 0.9 6.8 14.9 15.6 9.2 14.1 14.5 

Confidence interval +|- 1.6 +|- 0.8 +|- 3.5 +|- 6.5 +|- 7.5 +|- 3.8 +|- 5.4 +|- 0.8 +|- 

Income Taxes 0.9 0.0 2.9 3.0 1.2 5.0 5.3 4.7 

Confidence interval +|- 0.8 +|- 0.0 +|- 3.8 +|- 3.0 +|- 2.2 +|- 3.6 +|- 4.7 +|- 4.1 +|- 

Other Routine Operating Expenses 79.8 78.6 63.0 42.0 38.3 26.3 46.4 39.3 7

Confidence interval +|- 8.6 +|- 9.1 +|- 10.0 +|- 14.0 +|- 12.2 +|- 15.0 +|- 7.5 +|- 7.8 +|- 

Debt Service Expenses: 3.7 1.5 9.8 8.6 17.8 7.1 8.2 21.0 

Confidence interval +|- 4.4 +|- 1.9 +|- 4.2 +|- 5.0 +|- 9.4 +|- 8.0 +|- 3.7 +|- 7.1 +|- 2

Capital Improvements 7.3 8.1 1.9 6.9 19.7 14.8 18.5 18.2 

Confidence interval +|- 4.8 +|- 5.9 +|- 1.4 +|- 5.3 +|- 16.4 +|- 10.4 +|- 7.3 +|- 11.2 +|- 

Payments to Reserve funds 2.7 3.5 1.8 0.2 0.4 0.0 0.1 0.0 

Confidence interval +|- 2.7 +|- 2.8 +|- 2.2 +|- 0.3 +|- 0.5 +|- 0.0 +|- 0.2 +|- 0.0 +|- 

(Continued) 

Table 80 

Percentage Breakdown of Expenses By Major Categories 

By Ownership 
Percentage Breakdown of Expenses By Major Categories

By Ownership 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 All Si

All Systems 

Purchased water 4.5 7.3 11.4 12.8 11.2 17.0 10.8 13.7 

Confidence interval +|- 5.5 +|- 4.6 +|- 4.1 +|- 5.6 +|- 4.2 +|- 4.7 +|- 2.1 +|- 6.3 +|- 2

Security 0.2 0.1 0.1 3.6 0.2 1.3 0.9 0.4 

Confidence interval +|- 0.4 +|- 0.1 +|- 0.1 +|- 4.1 +|- 0.1 +|- 1.7 +|- 0.8 +|- 0.1 +|- 

Depreciation 2.2 2.8 6.1 11.2 10.6 11.7 11.3 10.8 

Confidence interval +|- 1.8 +|- 2.1 +|- 1.6 +|- 2.3 +|- 1.7 +|- 2.1 +|- 1.0 +|- 1.5 +|- 

Income Taxes 0.0 0.3 1.7 3.5 3.3 3.7 3.6 1.8 

Confidence interval +|- 0.0 +|- 0.5 +|- 1.3 +|- 2.9 +|- 1.4 +|- 1.3 +|- 0.9 +|- 0.5 +|- 

Payments to General Fund 0.8 0.0 0.7 0.5 0.1 0.3 0.6 0.2 

Confidence interval +|- 0.7 +|- 0.0 +|- 0.9 +|- 0.6 +|- 0.1 +|- 0.3 +|- 0.6 +|- 0.2 +|- 

Other Routine Operating Expenses 79.4 72.7 59.6 47.6 45.0 35.3 37.5 33.1 6

Confidence interval +|- 7.9 +|- 7.0 +|- 4.9 +|- 6.5 +|- 4.8 +|- 3.8 +|- 2.6 +|- 4.1 +|- 

Debt Service Expenses 3.3 5.4 13.7 11.8 12.3 13.7 14.8 18.0 

Confidence interval +|- 3.7 +|- 2.6 +|- 2.8 +|- 3.2 +|- 2.8 +|- 3.1 +|- 1.2 +|- 2.6 +|- 

Capital Improvements 6.8 7.5 4.9 8.0 14.3 16.0 18.3 20.4 

Confidence interval +|- 4.2 +|- 4.1 +|- 2.5 +|- 2.9 +|- 3.7 +|- 2.9 +|- 1.9 +|- 3.2 +|- 

Payments to Reserve funds 2.8 3.8 1.8 0.9 3.1 1.1 2.1 1.5 

Confidence interval +|- 2.4 +|- 2.3 +|- 1.1 +|- 0.6 +|- 1.6 +|- 0.7 +|- 0.6 +|- 0.7 +|- 

Data: Q.26 Notes: Column totals may not equal 100 due to rounding. 

Excludes systems that did not report positive expenses. Debt service includes principal and interest. The general fund includes payments in lieu of taxes. 

Table 80 (Cont.)
Table 81

Ratio of Revenue to Expenses for Systems Reporting Positive Revenue and Expenses

By Ownership

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Over 

500,000 

Public Systems

Average Ratio 1.4 1.5 1.4 1.6 1.4 1.5 1.4 1.3 

Confidence interval +|- 0.4 +|- 0.3 +|- 0.1 +|- 0.7 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.1 

10th Percentile 0.7 0.7 0.7 0.6 0.8 0.8 0.8 0.8 25th Percentile 1.0 1.0 1.0 0.9 1.0 1.0 1.0 1.0 50th Percentile 1.5 1.3 1.2 1.1 1.2 1.2 1.1 1.2 75th Percentile 1.6 1.8 1.5 1.5 1.7 1.6 1.4 1.4 90th Percentile 2.1 3.0 2.4 2.0 2.2 2.3 2.1 1.6 Observations 22 69 167 78 115 80 153 48 

Private Systems

Average Ratio 1.6 1.5 1.8 1.2 1.7 1.4 1.3 1.2 

Confidence interval +|- 0.8 +|- 0.3 +|- 0.6 +|- 0.2 +|- 0.8 +|- 0.3 +|- 0.2 +|- 0.1 

10th Percentile 0.4 0.9 0.9 0.8 0.9 1.2 1.0 1.1 25th Percentile 0.8 1.0 1.1 0.9 0.9 1.2 1.0 1.1 50th Percentile 1.1 1.2 1.2 1.2 1.0 1.2 1.2 1.2 75th Percentile 1.6 1.4 1.7 1.3 1.7 1.5 1.3 1.3 90th Percentile 2.3 2.6 2.9 1.6 2.2 2.1 2.1 1.3 Observations 41 55 37 13 11 6 13 2 

All Systems

Average Ratio 1.5 1.5 1.5 1.5 1.4 1.5 1.4 1.3 

Confidence interval +|- 0.6 +|- 0.2 +|- 0.2 +|- 0.6 +|- 0.2 +|- 0.2 +|- 0.1 +|- 0.1 

10th Percentile 0.4 0.8 0.8 0.6 0.8 0.8 0.8 0.8 25th Percentile 0.9 1.0 1.0 0.9 1.0 1.0 1.0 1.0 50th Percentile 1.2 1.2 1.2 1.1 1.2 1.2 1.1 1.2 75th Percentile 1.6 1.6 1.5 1.4 1.7 1.6 1.4 1.4 90th Percentile 2.1 2.8 2.4 1.9 2.2 2.2 2.1 1.6 Observations 63 124 204 91 126 86 166 50 

Data: Q.21, Q.26CNotes: Refer to next table for additional detail on private systems.

Revenues include water sales and other water-related fees. Expenses include operating expenses, depreciation, and intexcludes principal payments and payments to capital and reserve funds. Only systems that report positive revenue andexpenses are included. This table includes the same systems as tables 62 and 79, but the average ratio is not the ratio oaverage revenue from table 62 and expenses from table 79. The ratio is calculated for each system and this table reportaverage of that ratio, as well as the 10th, 25th, 50th, 75th, and 90th percentiles. (The average of the ratios is not equal to ratio of the averages.) 
Table 82

Ratio of Revenue to Expenses for Systems Reporting 

Positive Revenue for Small Privately Owned Systems, By Type

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301-

10,000 All Sizes

Ancillary Systems

Average Ratio 1.2 1.7 1.4 N/A 1.4

Confidence interval +|- 0.6 +|- 0.5 +|- 0.4 N/A +|- 0.4

10th Percentile 0.4 1.0 1.2 N/A 0.525th Percentile 0.6 1.1 1.2 N/A 0.950th Percentile 0.9 1.4 1.2 N/A 1.275th Percentile 1.7 2.6 1.2 N/A 1.890th Percentile 2.5 3.0 2.5 N/A 2.6Observations 8 9 2 N/A 19

Other Private Systems

Average Ratio 1.7 1.4 1.8 1.2 1.6

Confidence interval +|- 1.1 +|- 0.3 +|- 0.6 +|- 0.2 +|- 0.4

10th Percentile 0.4 0.8 0.9 0.8 0.825th Percentile 1.0 1.0 1.1 0.9 1.050th Percentile 1.2 1.2 1.2 1.2 1.275th Percentile 1.6 1.3 1.7 1.3 1.590th Percentile 2.3 2.4 2.9 1.6 2.3Observations 33 46 35 13 127

All Private Systems

Average Ratio 1.6 1.5 1.8 1.2 1.6

Confidence interval +|- 0.8 +|- 0.3 +|- 0.6 +|- 0.2 +|- 0.3

10th Percentile 0.4 0.9 0.9 0.8 0.825th Percentile 0.8 1.0 1.1 0.9 1.050th Percentile 1.1 1.2 1.2 1.2 1.275th Percentile 1.6 1.4 1.7 1.3 1.690th Percentile 2.3 2.6 2.9 1.6 2.4Observations 41 55 37 13 146

Data: Q.21, Q.26CNotes:
Table 83

Average System Revenue and Expenses for Systems That Reported Positive Revenue and Expenses

By Type of Revenue and Expense

(Thousands of Dollars)

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

5

Public Systems

Revenue

Water Sales 42,061 42,533 229,714 758,567 2,537,418 8,197,502 21,890,502 118,3Connection, Development Fees, and Other Water Related 646 5,496 29,288 116,580 554,302 1,263,232 5,783,524 23,5Revenue from the Government 6,692 9,676 9,422 13,588 54,508 794,605 277,081 2,8Total Revenue 49,399 57,705 268,423 888,735 3,146,229 10,255,338 27,951,108 144,7

Expenses

General Operations 35,812 36,284 179,173 546,258 1,861,957 5,499,756 16,118,521 82,9Depreciation 3,932 8,671 20,707 135,087 374,269 1,571,869 4,332,834 23,6Interest 48 4,585 21,622 74,226 198,061 638,812 2,681,573 24,7Income Taxes 0 1,233 4,498 46,644 128,462 393,756 1,500,383 2,94Total Expenses 39,791 50,773 226,001 802,215 2,562,749 8,104,194 24,633,310 134,3

Net Income

Sales Only 2,270 -8,240 3,713 -43,648 -25,331 93,308 -2,742,808 -15,9Sales and Fees 2,915 -2,744 33,001 72,932 528,972 1,356,540 3,040,717 7,6Sales, Fees, and Government 9,608 6,931 42,422 86,519 583,480 2,151,145 3,317,798 10,44

Observations 22 69 167 78 115 80 153 

(Contin
Table 83 (Cont.)

Average System Revenue and Expenses for Systems That Reported Positive Revenue and Expenses

By Type of Revenue and Expense

System Service Population Category

Ownership Type

100 

or Less

101 - 

500

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

5

Private Systems

Revenue

Water Sales 10,421 31,416 349,383 998,870 2,397,964 11,281,324 56,591,902 90,1Connection, Development Fees, and Other 1,272 1,218 17,591 63,164 587,218 460,209 444,726 8Revenue from the Government 0 0 3,494 18,746 23,416 0 2,161 

Total Revenue 11,693 32,633 370,469 1,080,780 3,008,598 11,741,533 57,038,788 90,9

Expenses

General Operations 9,452 24,784 161,902 623,466 1,233,603 7,083,655 33,465,764 44,1Depreciation 521 943 15,343 235,611 511,678 935,865 7,869,484 14,3Interest 999 580 12,892 83,915 305,736 319,861 6,821,033 17,2Income Taxes 191 98 3,614 35,443 44,893 689,946 2,121,944 3,6Total Expenses 11,163 26,404 193,751 978,435 2,095,910 9,029,327 50,278,224 79,4

Net Income

Sales Only -742 5,011 155,632 20,435 302,054 2,251,997 6,313,679 10,7Sales and Fees 530 6,229 173,223 83,600 889,272 2,712,206 6,758,404 11,5Sales, Fees, and Government 530 6,229 176,717 102,345 912,688 2,712,206 6,760,565 11,5

Observations 41 55 37 13 11 6 13 

Q.21, Q.26Excludes systems that did not report positive revenue or expenses. 
Table 84

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Ground Water Systems

Managers

Full-time Employees

Mean Number of Employees 0.5 0.4 0.5 0.6 1.4 2.0 3.4 6.8 33.9 

Confidence interval +|- 0.3 +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.7 +|- 0.5 +|- 0.7 +|- 1.8 +|- 33.7 Observations 12 9 21 29 39 54 37 41 5 

Average Hourly Salary or Wage (Dollars) 30.0 21.0 26.0 20.3 28.1 29.9 34.9 38.4 39.6 

Confidence interval +|- 13.0 +|- 7.5 +|- 7.6 +|- 3.6 +|- 2.5 +|- 2.2 +|- 3.4 +|- 2.3 +|- 5.9 Observations 12 8 20 28 35 53 37 38 5 

Benefits as Percentage of Salary or Wage 23.7 18.0 21.2 25.4 33.8 31.0 31.2 41.4 42.6 

Confidence interval +|- 19.7 +|- 10.6 +|- 12.0 +|- 8.9 +|- 9.1 +|- 4.2 +|- 6.1 +|- 3.5 +|- 3.8 Observations 11 7 18 23 28 49 36 37 5 

Part-time Employees

Mean Number of Employees 0.9 1.1 1.0 1.0 1.0 2.0 2.0 2.0 

Confidence interval +|- 0.2 +|- 0.3 +|- 0.2 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 12 13 25 20 1 1 1 1 

Average Hourly Salary or Wage (Dollars) 19.4 11.5 16.5 21.3 34.5 119.2 27.5 45.8 

Confidence interval +|- 6.2 +|- 7.1 +|- 5.0 +|- 3.9 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 10 6 16 18 1 1 1 1 

Benefits as Percentage of Salary or Wage 7.6 3.0 5.4 25.2 35.0 25.0 25.0 0.0 

Confidence interval +|- 9.2 +|- 6.1 +|- 5.6 +|- 15.7 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 12 12 24 17 1 1 1 1 

Average Hours Per Employee Per Week 3.3 7.7 5.5 9.5 20.0 10.0 40.0 42.0 

Confidence interval +|- 1.4 +|- 3.7 +|- 2.0 +|- 3.5 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 11 12 23 20 1 1 1 1 

Contract Employees

Mean Number of Employees 2.0 1.0 1.0 1.0 1.0 1.9 1.0 * 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.0 +|- 0.3 +|- 0.0 * Observations 1 2 3 4 3 2 1 * 

Average Hourly Labor Cost (Dollars) 10.0 28.1 27.9 18.6 31.0 36.5 27.0 * 

Confidence interval +|- 0.0 +|- 6.5 +|- 6.5 +|- 6.8 +|- 16.8 +|- 3.7 +|- 0.0 * Observations 1 2 3 4 2 2 1 * 

Average Hours Per Employee Per Week 0.5 5.8 5.7 16.9 30.0 65.8 20.0 * 

Confidence interval +|- 0.0 +|- 8.5 +|- 8.4 +|- 11.2 +|- 18.3 +|- 10.3 +|- 0.0 * Observations 1 2 3 4 2 2 1 * 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Ground Water Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees 0.4 0.4 0.4 0.8 2.4 3.7 8.0 20.3 32.

Confidence interval +|- 0.3 +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.7 +|- 1.1 +|- 2.1 +|- 7.9 +|- 23.6 Observations 16 27 43 43 34 45 36 44 4 

Average Hourly Salary or Wage (Dollars) 19.4 16.8 17.6 15.4 17.6 19.1 19.1 23.3 21.9 

Confidence interval +|- 7.6 +|- 3.3 +|- 3.3 +|- 1.9 +|- 1.6 +|- 1.5 +|- 2.6 +|- 1.2 +|- 2.7 Observations 10 20 30 39 31 44 35 42 4 

Benefits as Percentage of Salary or Wage 16.7 18.0 17.5 22.1 37.1 33.7 31.4 44.9 41.9 

Confidence interval +|- 13.1 +|- 7.2 +|- 6.8 +|- 6.9 +|- 9.9 +|- 5.4 +|- 5.6 +|- 3.9 +|- 4.2 Observations 10 15 25 34 23 42 33 40 4 

Part-time Employees

Mean Number of Employees 1.1 1.0 1.1 1.2 1.6 1.2 2.5 1.0 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.9 +|- 0.4 +|- 2.7 +|- 0.0 Observations 24 32 56 38 4 5 2 2 

Average Hourly Salary or Wage (Dollars) 15.7 14.1 14.6 15.0 15.2 16.0 15.3 15.9 

Confidence interval +|- 4.7 +|- 2.1 +|- 2.0 +|- 2.5 +|- 5.3 +|- 12.6 +|- 4.0 +|- 5.1 Observations 12 24 36 37 4 4 2 2 

Benefits as Percentage of Salary or Wage 4.8 10.2 7.7 18.6 12.3 6.7 35.0 0.0 

Confidence interval +|- 5.5 +|- 6.4 +|- 4.4 +|- 10.0 +|- 14.4 +|- 6.9 +|- 0.0 +|- 0.0 Observations 20 25 45 33 3 3 1 1 

Average Hours Per Employee Per Week 5.5 9.7 7.9 10.0 16.3 22.8 40.0 25.0 

Confidence interval +|- 2.3 +|- 2.4 +|- 1.9 +|- 2.5 +|- 8.0 +|- 12.7 +|- 0.0 +|- 0.0 Observations 23 31 54 38 4 4 2 1 

Contract Employees

Mean Number of Employees 0.8 0.9 0.9 1.0 1.0 1.0 4.0 * 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.3 +|- 0.0 +|- 0.0 +|- 0.0 * Observations 14 27 41 12 4 1 1 * 

Average Hourly Labor Cost (Dollars) 34.3 39.6 37.6 35.7 27.4 13.4 * * 

Confidence interval +|- 13.0 +|- 12.6 +|- 9.2 +|- 14.9 +|- 7.7 +|- 0.0 * * Observations 16 25 41 11 3 1 * * 

Average Hours Per Employee Per Week 2.8 2.9 2.9 12.4 15.8 25.0 40.0 * 

Confidence interval +|- 1.4 +|- 1.4 +|- 1.0 +|- 8.4 +|- 14.1 +|- 0.0 +|- 0.0 * Observations 19 27 46 12 4 1 1 * 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Ground Water Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees 0.6 0.5 0.5 0.9 3.4 5.7 13.3 25.8 191.7 

Confidence interval +|- 0.2 +|- 0.3 +|- 0.2 +|- 0.3 +|- 0.9 +|- 1.0 +|- 3.2 +|- 4.3 +|- 38.7 Observations 17 25 42 47 43 52 33 37 3 

Average Hourly Salary or Wage (Dollars) 18.3 15.8 16.6 15.0 16.7 18.2 17.6 20.6 22.7 

Confidence interval +|- 6.5 +|- 2.9 +|- 2.8 +|- 1.8 +|- 1.4 +|- 1.5 +|- 2.8 +|- 1.3 +|- 3.6 Observations 12 21 33 43 40 52 33 36 3 

Benefits as Percentage of Salary or Wage 20.9 17.8 19.1 31.5 33.6 34.9 33.9 44.4 49.7 

Confidence interval +|- 17.7 +|- 6.5 +|- 8.1 +|- 8.8 +|- 8.1 +|- 4.7 +|- 5.7 +|- 4.0 +|- 3.7 Observations 13 17 30 37 33 49 33 34 3 

Part-time Employees

Mean Number of Employees 1.2 1.2 1.2 1.4 1.2 2.6 3.3 2.7 2.0 

Confidence interval +|- 0.4 +|- 0.4 +|- 0.3 +|- 0.2 +|- 0.3 +|- 1.2 +|- 2.3 +|- 1.5 +|- 0.0 Observations 9 27 36 25 4 8 7 3 

Average Hourly Salary or Wage (Dollars) 15.1 14.3 14.5 12.1 11.9 12.2 14.5 15.8 13.0 

Confidence interval +|- 2.9 +|- 2.8 +|- 2.3 +|- 1.8 +|- 4.1 +|- 4.6 +|- 2.4 +|- 5.2 +|- 0.0 Observations 6 22 28 23 4 8 7 3 

Benefits as Percentage of Salary or Wage 0.0 7.4 4.8 13.7 22.0 13.5 15.7 24.1 0.0 

Confidence interval +|- 0.0 +|- 6.6 +|- 4.5 +|- 11.5 +|- 5.8 +|- 12.2 +|- 17.2 +|- 22.9 +|- 0.0 Observations 14 27 41 23 3 6 5 3 

Average Hours Per Employee Per Week 1.5 8.0 6.2 7.9 25.6 31.4 33.9 22.0 40.0 

Confidence interval +|- 0.9 +|- 2.8 +|- 2.1 +|- 2.4 +|- 5.8 +|- 6.5 +|- 5.5 +|- 5.2 +|- 0.0 Observations 9 27 36 25 4 8 7 3 

Contract Employees

Mean Number of Employees 0.8 0.8 0.8 0.7 2.0 17.0 4.4 1.0 10.0 

Confidence interval +|- 0.2 +|- 0.2 +|- 0.1 +|- 0.3 +|- 0.0 +|- 0.0 +|- 1.3 +|- 0.0 +|- 0.0 Observations 12 12 24 5 ` 1 3 1 

Average Hourly Labor Cost (Dollars) 34.5 36.5 35.6 30.3 21.0 18.0 27.0 48.9 16.0 

Confidence interval +|- 14.3 +|- 20.7 +|- 13.2 +|- 29.1 +|- 1.6 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 9 12 21 4 2 1 1 1 

Average Hours Per Employee Per Week 2.1 5.1 3.5 6.3 30.0 60.0 40.0 17.0 8.0 

Confidence interval +|- 1.8 +|- 4.0 +|- 2.1 +|- 3.9 +|- 16.3 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 12 12 24 4 2 1 2 1 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Ground Water Systems

Administrative Staff

Full-time Employees

Mean Number of Employees 0.4 0.4 0.4 0.8 1.9 2.9 5.3 13.2 55.3 

Confidence interval +|- 0.4 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.5 +|- 0.8 +|- 1.9 +|- 5.5 +|- 43.3 Observations 7 15 22 31 35 48 35 41 5 

Average Hourly Salary or Wage (Dollars) 16.0 16.6 16.4 15.9 14.7 21.6 18.3 21.8 23.6 

Confidence interval +|- 3.3 +|- 10.9 +|- 7.2 +|- 4.9 +|- 1.5 +|- 4.6 +|- 2.8 +|- 1.8 +|- 3.7 Observations 7 12 19 28 32 48 35 38 5 

Benefits as Percentage of Salary or Wage 12.5 18.4 16.8 21.0 35.7 32.3 32.8 44.3 42.6 

Confidence interval +|- 12.0 +|- 8.8 +|- 7.4 +|- 8.1 +|- 9.3 +|- 4.7 +|- 6.0 +|- 3.8 +|- 3.9 Observations 5 12 17 23 27 44 33 37 5 

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.1 1.2 2.4 1.3 2.0 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.4 +|- 1.4 +|- 0.5 +|- 0.6 Observations 8 27 35 41 5 4 4 8 

Average Hourly Salary or Wage (Dollars) 13.3 11.5 11.8 14.5 10.3 30.4 14.8 12.6 

Confidence interval +|- 6.7 +|- 2.7 +|- 2.7 +|- 2.8 +|- 2.3 +|- 27.1 +|- 3.2 +|- 1.7 Observations 5 19 24 39 4 4 4 8 

Benefits as Percentage of Salary or Wage 1.8 6.0 4.6 18.4 7.0 16.1 21.4 10.7 

Confidence interval +|- 3.7 +|- 5.5 +|- 3.9 +|- 9.4 +|- 9.5 +|- 15.6 +|- 15.7 +|- 12.0 Observations 12 24 36 32 4 3 3 7 

Average Hours Per Employee Per Week 5.4 7.6 7.2 12.6 20.3 14.4 30.6 23.4 

Confidence interval +|- 3.9 +|- 2.5 +|- 2.1 +|- 3.1 +|- 9.4 +|- 4.3 +|- 7.7 +|- 4.0 Observations 8 27 35 40 5 4 4 7 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.0 2.0 2.0 1.0 6.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 1 4 5 5 1 1 1 3 

Average Hourly Labor Cost (Dollars) 10.0 14.2 13.3 27.8 20.0 12.0 27.0 35.2 16.0 

Confidence interval +|- 0.0 +|- 10.0 +|- 8.1 +|- 23.6 +|- 0.0 +|- 0.0 +|- 0.0 +|- 14.8 +|- 0.0 Observations 1 4 5 5 1 1 1 2 

Average Hours Per Employee Per Week 0.1 7.2 5.7 8.0 40.0 60.0 20.0 17.4 8.0 

Confidence interval +|- 0.0 +|- 6.6 +|- 5.8 +|- 6.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 13.1 +|- 0.0 Observations 1 4 5 5 1 1 1 3 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Surface Water Systems

Managers

Full-time Employees

Mean Number of Employees 0.3 0.6 0.6 0.6 1.2 1.9 4.4 10.2 30.9 

Confidence interval +|- 0.4 +|- 0.3 +|- 0.3 +|- 0.1 +|- 0.1 +|- 0.3 +|- 1.8 +|- 2.9 +|- 11.6 Observations 4 10 14 27 50 63 46 112 32 

Average Hourly Salary or Wage (Dollars) 27.3 24.4 24.8 23.3 25.9 29.4 32.5 36.3 38.6 

Confidence interval +|- 8.3 +|- 4.7 +|- 4.3 +|- 2.1 +|- 3.1 +|- 2.4 +|- 1.8 +|- 1.1 +|- 2.0 Observations 3 9 12 26 45 61 44 112 32 

Benefits as Percentage of Salary or Wage 27.7 32.8 32.1 30.0 32.1 32.2 35.7 41.4 37.5 

Confidence interval +|- 2.4 +|- 6.5 +|- 5.6 +|- 6.8 +|- 4.7 +|- 3.2 +|- 3.9 +|- 3.0 +|- 3.0 Observations 3 8 11 22 41 58 41 109 3

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.3 1.9 2.0 1.3 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.0 +|- 0.4 +|- 1.7 +|- 0.0 +|- 0.4 Observations 4 6 10 9 4 4 1 3 

Average Hourly Salary or Wage (Dollars) 57.9 18.2 26.0 20.7 32.7 25.8 35.0 63.6 

Confidence interval +|- 45.0 +|- 7.1 +|- 8.6 +|- 4.4 +|- 10.7 +|- 6.1 +|- 0.0 +|- 26.0 Observations 2 5 7 6 4 4 1 3 

Benefits as Percentage of Salary or Wage 0.0 12.5 10.0 24.7 36.3 33.5 28.0 24.5 

Confidence interval +|- 0.0 +|- 12.7 +|- 11.1 +|- 14.6 +|- 33.1 +|- 13.7 +|- 0.0 +|- 29.7 Observations 1 3 4 6 4 4 1 2 

Average Hours Per Employee Per Week 2.3 7.3 6.0 10.7 3.8 17.4 20.0 24.0 

Confidence interval +|- 1.1 +|- 4.6 +|- 3.4 +|- 4.9 +|- 0.6 +|- 3.9 +|- 0.0 +|- 4.0 Observations 4 6 10 9 3 3 1 3 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 * 1.0 * * 1.3 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 * +|- 0.0 * * +|- 0.3 Observations 1 2 3 * 1 * * 7 

Average Hourly Labor Cost (Dollars) 8.3 30.0 26.0 **** 35.3 

Confidence interval +|- 0.0 +|- 21.8 +|- 19.1 **** +|- 33.1 

Observations 1 2 3 * * * *2 

Average Hours Per Employee Per Week 8.0 7.5 7.6 * 40.0 * * 36.5 

Confidence interval +|- 0.0 +|- 5.3 +|- 4.3 * +|- 0.0 * * +|- 5.2 Observations 1 2 3 * 1 * * 5 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Surface Water Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees 0.9 0.7 0.7 1.4 2.7 5.6 15.6 22.8 93.8 

Confidence interval +|- 0.6 +|- 0.4 +|- 0.3 +|- 0.3 +|- 0.4 +|- 0.8 +|- 9.1 +|- 4.3 +|- 21.8 Observations 9 27 36 57 58 72 47 107 32 

Average Hourly Salary or Wage (Dollars) 24.9 13.2 14.4 16.3 17.7 19.0 19.1 22.5 23.7 

Confidence interval +|- 3.7 +|- 3.7 +|- 4.2 +|- 1.2 +|- 1.4 +|- 1.1 +|- 1.1 +|- 0.8 +|- 1.5 Observations 8 24 32 56 55 70 45 108 32 

Benefits as Percentage of Salary or Wage 32.9 28.3 29.1 29.7 35.7 34.4 36.4 42.2 42.

Confidence interval +|- 11.7 +|- 9.7 +|- 8.3 +|- 5.9 +|- 4.9 +|- 3.6 +|- 3.8 +|- 3.0 +|- 3.8 Observations 8 21 29 50 49 65 42 106 32 

Part-time Employees

Mean Number of Employees 1.0 1.2 1.1 1.7 1.6 1.4 1.0 1.8 2.0 

Confidence interval +|- 0.1 +|- 0.2 +|- 0.1 +|- 0.5 +|- 0.4 +|- 0.4 +|- 0.0 +|- 0.7 +|- 0.0 Observations 23 27 50 15 7 8 2 9 

Average Hourly Salary or Wage (Dollars) 11.4 15.0 13.2 19.0 13.3 15.2 16.0 12.7 13.7 

Confidence interval +|- 5.8 +|- 3.8 +|- 4.5 +|- 4.4 +|- 3.5 +|- 3.7 +|- 8.6 +|- 1.8 +|- 0.0 Observations 15 25 40 15 7 7 2 8 

Benefits as Percentage of Salary or Wage 5.0 10.2 7.6 20.8 20.6 14.5 28.0 3.7 0.0 

Confidence interval +|- 8.6 +|- 9.5 +|- 7.4 +|- 13.9 +|- 15.1 +|- 13.8 +|- 0.0 +|- 4.3 +|- 0.0 Observations 12 24 36 16 6 7 1 7 

Average Hours Per Employee Per Week 9.3 8.4 8.9 11.9 14.0 22.4 16.0 21.8 20.0 

Confidence interval +|- 1.9 +|- 2.6 +|- 1.6 +|- 3.3 +|- 4.7 +|- 7.8 +|- 5.7 +|- 3.3 +|- 0.0 Observations 22 26 48 16 7 8 2 8 

Contract Employees

Mean Number of Employees 0.9 1.1 1.0 1.0 1.0 1.0 5.5 6.1 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.0 +|- 0.0 +|- 0.0 +|- 7.9 +|- 2.1 Observations 19 26 45 6 1 1 2 9 

Average Hourly Labor Cost (Dollars) 68.6 23.2 39.0 27.0 27.0 42.5 19.8 28.1 

Confidence interval +|- 49.7 +|- 5.6 +|- 18.9 +|- 10.0 +|- 0.0 +|- 0.0 +|- 9.2 +|- 10.4 Observations 19 24 43 6 1 1 2 8 

Average Hours Per Employee Per Week 3.6 10.0 8.4 15.1 9.0 40.0 40.0 38.6 

Confidence interval +|- 2.1 +|- 2.4 +|- 2.2 +|- 11.7 +|- 0.0 +|- 0.0 +|- 0.0 +|- 3.8 Observations 19 26 45 7 1 1 2 9 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Surface Water Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees 0.2 0.6 0.5 1.2 3.6 7.9 16.0 39.0 169.8 

Confidence interval +|- 0.3 +|- 0.3 +|- 0.3 +|- 0.2 +|- 0.6 +|- 1.4 +|- 3.0 +|- 9.4 +|- 44.7 Observations 2 18 20 40 52 65 39 96 3

Average Hourly Salary or Wage (Dollars) 20.6 15.1 15.4 15.7 16.2 16.9 17.3 20.6 22.

Confidence interval +|- 10.8 +|- 1.8 +|- 1.9 +|- 1.1 +|- 1.5 +|- 1.1 +|- 0.9 +|- 0.7 +|- 1.3 Observations 2 15 17 39 48 63 39 98 3

Benefits as Percentage of Salary or Wage 28.5 23.7 24.0 29.2 37.4 34.2 35.7 41.4 39.4 

Confidence interval +|- 2.6 +|- 7.1 +|- 6.7 +|- 5.4 +|- 5.3 +|- 3.6 +|- 4.7 +|- 3.3 +|- 3.9 Observations 2 16 18 36 45 59 38 96 30 

Part-time Employees

Mean Number of Employees 1.1 1.1 1.1 1.8 1.5 1.8 3.0 3.5 10.0 

Confidence interval +|- 0.3 +|- 0.4 +|- 0.3 +|- 0.6 +|- 0.5 +|- 1.5 +|- 0.7 +|- 1.3 +|- 0.0 Observations 7 11 18 13 4 5 4 9 

Average Hourly Salary or Wage (Dollars) 19.5 11.8 13.1 16.2 13.3 14.8 10.1 10.8 6.6 

Confidence interval +|- 6.0 +|- 3.3 +|- 3.3 +|- 3.7 +|- 5.0 +|- 5.7 +|- 0.2 +|- 1.3 +|- 0.0 Observations 4 10 14 14 4 5 4 9 

Benefits as Percentage of Salary or Wage 8.1 5.0 5.4 20.1 16.7 8.8 1.8 6.4 15.0 

Confidence interval +|- 14.8 +|- 6.4 +|- 5.8 +|- 11.8 +|- 31.6 +|- 15.7 +|- 3.1 +|- 4.1 +|- 0.0 Observations 3 9 12 13 3 4 4 9 

Average Hours Per Employee Per Week 6.2 6.3 6.3 11.9 21.8 20.0 30.5 26.7 14.0 

Confidence interval +|- 6.5 +|- 3.9 +|- 3.4 +|- 3.8 +|- 12.6 +|- 0.0 +|- 7.2 +|- 5.1 +|- 0.0 Observations 7 11 18 14 4 5 4 9 

Contract Employees

Mean Number of Employees 0.5 1.2 1.1 1.0 * * * 4.7 

Confidence interval +|- 0.0 +|- 0.4 +|- 0.3 +|- 0.0 * * * +|- 2.5 Observations 3 6 9 2 * * * 3 

Average Hourly Labor Cost (Dollars) 19.3 18.1 18.4 28.3 * * * 11.3 

Confidence interval +|- 0.0 +|- 9.9 +|- 7.8 +|- 31.7 * * * +|- 2.6 Observations 3 6 9 2 * * * 3 

Average Hours Per Employee Per Week 1.8 5.2 4.5 3.4 * * * 40.0 

Confidence interval +|- 0.0 +|- 3.4 +|- 2.9 +|- 1.0 * * * +|- 0.0 Observations 3 6 9 2 * * * 3 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Surface Water Systems

Administrative Staff

Full-time Employees

Mean Number of Employees 0.2 0.8 0.7 1.0 2.1 3.0 7.0 17.7 101.4 

Confidence interval +|- 0.4 +|- 0.5 +|- 0.4 +|- 0.3 +|- 0.4 +|- 0.6 +|- 2.9 +|- 4.7 +|- 45.2 Observations 3 11 14 19 41 60 42 110 3

Average Hourly Salary or Wage (Dollars) 33.7 15.5 17.8 16.3 16.0 19.0 18.4 22.5 21.6 

Confidence interval +|- 13.1 +|- 2.2 +|- 5.0 +|- 1.9 +|- 1.8 +|- 2.3 +|- 1.8 +|- 1.0 +|- 1.5 Observations 2 11 13 20 37 56 40 110 3

Benefits as Percentage of Salary or Wage 35.0 32.6 33.0 34.5 34.7 33.7 36.4 41.0 39.4 

Confidence interval +|- 20.5 +|- 14.0 +|- 12.2 +|- 7.8 +|- 5.7 +|- 3.7 +|- 3.7 +|- 3.1 +|- 3.8 Observations 3 10 13 19 33 53 36 108 30 

Part-time Employees

Mean Number of Employees 1.0 0.9 1.0 1.3 1.4 1.3 1.2 2.2 4.0 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.3 +|- 0.3 +|- 0.5 +|- 0.3 +|- 1.1 +|- 1.4 Observations 6 14 20 25 8 7 5 12 4 

Average Hourly Salary or Wage (Dollars) 12.6 13.9 13.8 14.0 14.7 22.5 15.4 15.4 23.

Confidence interval +|- 4.5 +|- 5.2 +|- 4.6 +|- 2.7 +|- 3.2 +|- 9.2 +|- 4.5 +|- 2.6 +|- 7.3 Observations 4 12 16 23 8 6 5 12 5 

Benefits as Percentage of Salary or Wage 9.3 1.9 2.8 17.4 35.6 21.2 19.5 12.6 31.2 

Confidence interval +|- 10.5 +|- 3.9 +|- 3.7 +|- 6.2 +|- 26.7 +|- 14.3 +|- 9.3 +|- 10.6 +|- 11.6 Observations 4 13 17 22 7 6 4 10 5 

Average Hours Per Employee Per Week 6.3 12.1 11.0 14.7 13.9 19.1 16.2 23.3 23.3 

Confidence interval +|- 3.4 +|- 4.5 +|- 3.8 +|- 4.1 +|- 4.7 +|- 2.1 +|- 7.3 +|- 5.1 +|- 1.9 Observations 6 12 18 26 8 7 5 11 3 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 * * 1.0 1.0 3.3 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 * * +|- 0.0 +|- 0.0 +|- 1.5 Observations 2 4 6 * * 1 1 4 

Average Hourly Labor Cost (Dollars) 34.5 19.6 22.3 * * 20.0 * 22.9 

Confidence interval +|- 21.6 +|- 4.4 +|- 5.3 * * +|- 0.0 * +|- 12.0 Observations 2 4 6 * * 1 * 3 

Average Hours Per Employee Per Week 1.5 14.6 12.3 * * 8.0 13.2 18.2 

Confidence interval +|- 1.0 +|- 16.1 +|- 13.3 * * +|- 0.0 +|- 0.0 +|- 5.1 Observations 2 4 6 * * 1 1 3 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Purchased Water Systems

Managers

Full-time Employees

Mean Number of Employees 0.3 0.1 0.1 0.7 1.1 1.4 3.1 7.5 15.8 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.3 +|- 0.2 +|- 0.3 +|- 0.5 +|- 2.1 +|- 11.2 Observations 1 3 4 12 22 22 24 41 12 

Average Hourly Salary or Wage (Dollars) * 20.1 20.1 22.8 27.5 33.9 42.4 43.3 45.5 

Confidence interval * +|- 4.6 +|- 4.6 +|- 5.6 +|- 4.8 +|- 3.2 +|- 3.8 +|- 3.0 +|- 5.6 Observations * 3 3 12 22 20 24 40 12 

Benefits as Percentage of Salary or Wage * 29.1 29.1 35.6 21.2 32.4 43.3 41.7 52.

Confidence interval * +|- 4.2 +|- 4.2 +|- 17.0 +|- 6.3 +|- 7.0 +|- 7.4 +|- 3.6 +|- 20.3 Observations * 3 3 10 20 20 24 39 12 

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.0 1.0 2.0 1.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 1 1 2 3 1 3 1 1 

Average Hourly Salary or Wage (Dollars) 20.0 40.0 29.6 14.3 20.0 31.4 40.0 25.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 14.2 +|- 5.9 +|- 0.0 +|- 8.9 +|- 0.0 +|- 0.0 Observations 1 1 2 3 1 3 1 1 

Benefits as Percentage of Salary or Wage 0.0 10.0 4.8 0.0 * 39.6 30.0 0.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 7.1 +|- 0.0 * +|- 20.3 +|- 0.0 +|- 0.0 Observations 1121 *311 

Average Hours Per Employee Per Week 2.0 7.5 4.6 14.0 10.0 31.5 5.0 20.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 3.9 +|- 10.9 +|- 0.0 +|- 33.4 +|- 0.0 +|- 0.0 Observations 1 1 2 3 1 3 1 1 

Contract Employees

Mean Number of Employees * * * 1.0 1.0 2.0 1.0 1.0 1.0 

Confidence interval * * * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations * * * 11112

Average Hourly Labor Cost (Dollars) * * * 15.0 21.2 28.0 50.0 53.0 43.0 

Confidence interval * * * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 13.7 +|- 0.0 Observations * * * 11112

Average Hours Per Employee Per Week * * * 13.0 40.0 40.0 5.0 27.5 40.0 

Confidence interval * * * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 19.3 +|- 0.0 Observations * * * 11112

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Purchased Water Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees * 0.2 0.2 1.5 1.5 3.8 6.2 15.1 59.5 

Confidence interval * +|- 0.1 +|- 0.1 +|- 0.9 +|- 0.7 +|- 0.8 +|- 2.1 +|- 2.8 +|- 35.6 Observations * 3 3 7 8 5 10 25 7 

Average Hourly Salary or Wage (Dollars) * 16.8 16.8 25.2 24.0 19.9 27.1 26.8 28.9 

Confidence interval * +|- 0.3 +|- 0.3 +|- 13.1 +|- 4.4 +|- 3.7 +|- 2.6 +|- 2.3 +|- 4.4 Observations * 2 2 6 8 4 10 25 7 

Benefits as Percentage of Salary or Wage * 33.0 33.0 24.5 25.0 11.1 42.8 39.2 42.6 

Confidence interval * +|- 0.0 +|- 0.0 +|- 6.8 +|- 6.3 +|- 2.2 +|- 8.2 +|- 4.5 +|- 2.4 Observations * 1 1 5 8 4 10 24 7 

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.5 1.8 1.5 1.0 3.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.5 +|- 0.4 +|- 0.7 +|- 0.0 +|- 0.0 Observations 4 2 6 12 3 2 1 1 

Average Hourly Salary or Wage (Dollars) 13.9 28.8 18.8 17.4 16.9 10.8 16.9 19.2 

Confidence interval +|- 0.1 +|- 3.0 +|- 7.9 +|- 4.8 +|- 9.8 +|- 3.9 +|- 0.0 +|- 0.0 Observations 4 2 6 12 3 2 1 1 

Benefits as Percentage of Salary or Wage 17.0 0.0 11.5 19.8 0.0 0.0 0.0 10.0 

Confidence interval +|- 24.5 +|- 0.0 +|- 18.7 +|- 14.3 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 Observations 4 2 6 10 2 2 1 1 

Average Hours Per Employee Per Week 1.3 5.3 2.6 7.2 12.4 16.0 32.0 15.0 

Confidence interval +|- 0.5 +|- 3.2 +|- 1.9 +|- 3.6 +|- 4.8 +|- 0.0 +|- 0.0 +|- 0.0 Observations 4 2 6 12 3 1 1 1 

Contract Employees

Mean Number of Employees * 0.5 0.5 1.0 * 4.5 * 21.0 11.0 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.0 * +|- 5.8 * +|- 0.0 +|- 12.2 Observations * 1 1 3 * 2 * 1 2 

Average Hourly Labor Cost (Dollars) * 62.5 62.5 39.3 * 27.0 * 43.0 45.

Confidence interval * +|- 0.0 +|- 0.0 +|- 26.1 * +|- 0.0 * +|- 0.0 +|- 2.6 Observations * 1 1 3 * 1 * 1 2 

Average Hours Per Employee Per Week * 3.0 3.0 0.9 * 40.0 * 40.0 36.4 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.2 * +|- 0.0 * +|- 0.0 +|- 4.5 Observations * 1 1 3 * 1 * 1 2 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Purchased Water Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees * 0.7 0.7 1.3 2.6 8.1 17.4 31.0 51.9 

Confidence interval * +|- 1.1 +|- 1.1 +|- 0.5 +|- 0.8 +|- 2.3 +|- 2.6 +|- 5.4 +|- 23.3 Observations * 5 5 19 25 22 24 38 9 

Average Hourly Salary or Wage (Dollars) * 14.7 14.7 16.7 18.3 21.4 24.0 23.2 25.3 

Confidence interval * +|- 1.4 +|- 1.4 +|- 2.1 +|- 2.1 +|- 1.9 +|- 1.7 +|- 1.6 +|- 4.5 Observations * 4 4 18 25 20 24 37 9 

Benefits as Percentage of Salary or Wage * 27.3 27.3 34.7 19.9 34.9 46.9 44.1 60.3 

Confidence interval * +|- 11.5 +|- 11.5 +|- 10.6 +|- 5.1 +|- 7.1 +|- 7.1 +|- 3.8 +|- 21.0 Observations * 3 3 17 24 20 23 36 9 

Part-time Employees

Mean Number of Employees 1.3 1.1 1.2 1.3 1.4 2.9 2.3 2.8 4.0 

Confidence interval +|- 0.6 +|- 0.2 +|- 0.2 +|- 0.4 +|- 0.6 +|- 2.2 +|- 1.3 +|- 0.6 +|- 0.0 Observations 3 11 14 16 3 6 3 4 

Average Hourly Salary or Wage (Dollars) 12.1 16.8 15.6 18.7 10.5 12.9 16.6 13.4 11.2 

Confidence interval +|- 1.0 +|- 5.8 +|- 4.5 +|- 3.6 +|- 2.6 +|- 3.9 +|- 8.0 +|- 2.3 +|- 0.0 Observations 3 11 14 16 2 6 3 4 

Benefits as Percentage of Salary or Wage 0.0 2.8 1.9 17.6 0.0 13.7 13.3 27.0 0.0 

Confidence interval +|- 0.0 +|- 5.2 +|- 3.7 +|- 12.0 +|- 0.0 +|- 20.7 +|- 20.5 +|- 29.5 +|- 0.0 Observations 3 8 11 10 1 5 3 3 

Average Hours Per Employee Per Week 4.5 4.6 4.6 10.4 19.7 23.4 26.7 41.4 29.0 

Confidence interval +|- 4.2 +|- 4.2 +|- 3.3 +|- 3.1 +|- 12.5 +|- 14.3 +|- 13.5 +|- 17.7 +|- 0.0 Observations 3 11 14 16 3 5 3 4 

Contract Employees

Mean Number of Employees * 0.5 0.5 1.7 2.0 12.0 2.0 1.0 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.7 +|- 1.6 +|- 0.0 +|- 0.0 +|- 0.0 Observations * 1 1 5 2 1 1 2 

Average Hourly Labor Cost (Dollars) * 62.5 62.5 18.1 59.5 26.0 25.0 35.0 

Confidence interval * +|- 0.0 +|- 0.0 +|- 8.7 +|- 67.3 +|- 0.0 +|- 0.0 +|- 24.4 Observations * 1 1 5 2 1 1 2 

Average Hours Per Employee Per Week * 3.0 3.0 16.6 30.0 40.0 12.0 29.1 

Confidence interval * +|- 0.0 +|- 0.0 +|- 11.1 +|- 16.3 +|- 0.0 +|- 0.0 +|- 8.9 Observations * 1 1 5 2 1 1 2 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Primarily Purchased Water Systems

Administrative Staff

Full-time Employees

Mean Number of Employees * 1.0 1.0 0.7 1.6 2.5 5.4 15.8 93.8 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.3 +|- 0.6 +|- 1.6 +|- 4.8 +|- 83.4 Observations * 1 1 13 19 20 24 37 1

Average Hourly Salary or Wage (Dollars) * 15.0 15.0 16.3 15.5 21.3 23.8 24.7 22.8 

Confidence interval * +|- 0.0 +|- 0.0 +|- 2.2 +|- 1.9 +|- 3.4 +|- 2.6 +|- 2.6 +|- 1.7 Observations * 1 1 12 19 19 24 36 1

Benefits as Percentage of Salary or Wage * 33.0 33.0 29.1 20.5 36.4 45.4 43.2 54.6 

Confidence interval * +|- 0.0 +|- 0.0 +|- 8.6 +|- 4.4 +|- 7.8 +|- 6.2 +|- 3.8 +|- 20.7 Observations * 1 1 13 18 19 24 36 1

Part-time Employees

Mean Number of Employees 1.0 1.1 1.1 1.3 1.0 1.4 1.5 4.9 63.6 

Confidence interval +|- 0.0 +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.0 +|- 0.4 +|- 0.7 +|- 2.1 +|- 76.2 Observations 1 11 12 16 3 6 2 9 3 

Average Hourly Salary or Wage (Dollars) 11.0 15.5 14.9 12.0 18.9 18.0 9.7 20.4 19.5 

Confidence interval +|- 0.0 +|- 6.1 +|- 5.4 +|- 2.3 +|- 9.1 +|- 4.5 +|- 1.6 +|- 6.0 +|- 4.8 Observations 1 10 11 15 3 6 2 9 3 

Benefits as Percentage of Salary or Wage 0.0 3.9 2.7 7.8 40.0 20.6 0.0 31.3 15.0 

Confidence interval +|- 0.0 +|- 7.0 +|- 5.1 +|- 10.8 +|- 0.0 +|- 17.9 +|- 0.0 +|- 12.5 +|- 17.5 Observations 2 7 9 11 1 6 1 9 2 

Average Hours Per Employee Per Week 2.0 6.7 6.2 12.1 6.9 20.6 22.0 27.1 26.2 

Confidence interval +|- 0.0 +|- 4.1 +|- 3.7 +|- 4.1 +|- 4.8 +|- 10.5 +|- 2.7 +|- 9.8 +|- 2.6 Observations 1 11 12 16 3 6 2 9 3 

Contract Employees

Mean Number of Employees * 1.0 1.0 1.0 2.0 4.0 1.0 3.5 57.7 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 1.1 +|- 63.7 Observations * 1 1 1 1 1 1 6 3 

Average Hourly Labor Cost (Dollars) * 50.0 50.0 35.0 16.6 25.0 35.0 38.1 35.7 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 16.7 +|- 7.7 Observations * 1 1 1 1 1 1 6 3 

Average Hours Per Employee Per Week * 1.5 1.5 10.0 35.0 35.0 5.0 29.8 40.0 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 6.1 +|- 0.0 Observations * 1 1 1 1 1 1 6 3 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Managers

Full-time Employees

Mean Number of Employees 0.5 0.4 0.5 0.6 1.3 1.8 3.7 8.9 27.4 

Confidence interval +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.1 +|- 0.4 +|- 0.3 +|- 0.7 +|- 1.9 +|- 9.0 Observations 17 22 39 68 111 139 107 194 49 

Average Hourly Salary or Wage (Dollars) 30.0 21.0 25.4 21.3 27.5 30.7 35.8 38.2 40.5 

Confidence interval +|- 12.9 +|- 5.8 +|- 6.5 +|- 2.6 +|- 2.0 +|- 1.5 +|- 1.9 +|- 1.1 +|- 1.9 Observations 15 20 35 66 102 134 105 190 49 

Benefits as Percentage of Salary or Wage 23.8 21.2 22.4 28.3 29.6 31.6 35.7 41.4 42.

Confidence interval +|- 19.5 +|- 7.9 +|- 10.3 +|- 7.3 +|- 5.2 +|- 2.8 +|- 3.7 +|- 2.1 +|- 6.6 Observations 14 18 32 55 89 127 101 185 48 

Part-time Employees

Mean Number of Employees 0.9 1.1 1.0 1.0 1.1 1.5 2.0 1.4 

Confidence interval +|- 0.2 +|- 0.3 +|- 0.2 +|- 0.0 +|- 0.2 +|- 0.5 +|- 0.0 +|- 0.3 Observations 17 20 37 32 6 8 3 5 

Average Hourly Salary or Wage (Dollars) 19.7 15.7 18.1 20.4 27.2 56.1 34.1 52.2 

Confidence interval +|- 5.6 +|- 10.2 +|- 5.3 +|- 3.5 +|- 7.2 +|- 37.9 +|- 6.8 +|- 18.8 Observations 13 12 25 27 6 8 3 5 

Benefits as Percentage of Salary or Wage 7.0 3.6 5.4 23.9 36.1 33.5 27.7 12.0 

Confidence interval +|- 8.6 +|- 5.7 +|- 5.2 +|- 14.4 +|- 28.9 +|- 10.7 +|- 2.7 +|- 17.4 Observations 14 16 30 24 5 8 3 4 

Average Hours Per Employee Per Week 3.1 7.7 5.5 10.1 8.0 21.5 21.7 27.1 

Confidence interval +|- 1.3 +|- 3.3 +|- 1.8 +|- 3.3 +|- 3.9 +|- 17.1 +|- 18.9 +|- 5.3 Observations 16 19 35 32 5 7 3 5 

Contract Employees

Mean Number of Employees 1.5 1.0 1.0 1.0 1.0 1.9 1.0 1.2 1.0 

Confidence interval +|- 1.0 +|- 0.0 +|- 0.0 +|- 0.3 +|- 0.0 +|- 0.2 +|- 0.0 +|- 0.2 +|- 0.0 Observations 2 4 6 5 5 3 2 9 

Average Hourly Labor Cost (Dollars) 9.2 28.2 27.8 17.8 27.7 34.4 43.3 44.5 43.0 

Confidence interval +|- 1.8 +|- 6.3 +|- 6.2 +|- 5.7 +|- 13.2 +|- 4.1 +|- 11.9 +|- 17.7 +|- 0.0 Observations 2 4 6 5 3 3 2 4 

Average Hours Per Employee Per Week 4.2 5.9 5.9 16.0 33.9 59.5 12.5 33.8 40.0 

Confidence interval +|- 8.0 +|- 8.0 +|- 7.8 +|- 8.9 +|- 13.0 +|- 17.7 +|- 12.4 +|- 6.9 +|- 0.0 Observations 2 4 6 5 4 3 2 7 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees 0.4 0.4 0.4 1.0 2.4 4.4 11.2 21.1 80.3 

Confidence interval +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.4 +|- 0.7 +|- 4.3 +|- 3.3 +|- 18.9 Observations 25 57 82 107 100 122 93 176 43 

Average Hourly Salary or Wage (Dollars) 19.6 16.4 17.3 16.3 18.1 19.1 19.9 23.3 24.2 

Confidence interval +|- 7.4 +|- 2.9 +|- 2.9 +|- 1.9 +|- 1.2 +|- 1.0 +|- 1.5 +|- 0.6 +|- 1.4 Observations 18 46 64 101 94 118 90 175 43 

Benefits as Percentage of Salary or Wage 17.2 19.0 18.3 23.8 35.4 33.4 34.9 42.4 42.

Confidence interval +|- 12.8 +|- 6.5 +|- 6.4 +|- 5.3 +|- 5.8 +|- 3.5 +|- 3.5 +|- 2.2 +|- 2.8 Observations 18 37 55 89 80 111 85 170 43 

Part-time Employees

Mean Number of Employees 1.1 1.0 1.1 1.3 1.6 1.3 1.6 1.8 2.0 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.5 +|- 0.3 +|- 1.2 +|- 0.6 +|- 0.0 Observations 51 61 112 65 14 15 5 12 

Average Hourly Salary or Wage (Dollars) 15.0 14.7 14.8 15.7 15.2 15.2 15.8 13.5 13.7 

Confidence interval +|- 3.7 +|- 2.3 +|- 1.9 +|- 2.1 +|- 3.6 +|- 7.2 +|- 3.7 +|- 2.1 +|- 0.0 Observations 31 51 82 64 14 13 5 11 

Benefits as Percentage of Salary or Wage 5.9 9.8 8.0 19.0 13.5 8.9 21.6 3.8 0.0 

Confidence interval +|- 5.5 +|- 6.0 +|- 4.2 +|- 7.9 +|- 10.2 +|- 6.7 +|- 16.6 +|- 3.8 +|- 0.0 Observations 36 51 87 59 11 12 3 9 

Average Hours Per Employee Per Week 5.4 9.5 7.6 9.5 14.7 22.3 29.4 21.5 20.0 

Confidence interval +|- 2.0 +|- 2.3 +|- 1.7 +|- 2.1 +|- 4.7 +|- 7.7 +|- 6.1 +|- 2.9 +|- 0.0 Observations 49 59 108 66 14 13 5 10 

Contract Employees

Mean Number of Employees 0.8 0.9 0.9 1.0 1.0 2.2 5.0 7.7 11.0 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.0 +|- 2.6 +|- 5.1 +|- 2.8 +|- 12.2 Observations 33 54 87 21 5 4 3 10 2 

Average Hourly Labor Cost (Dollars) 36.1 39.5 38.2 36.0 27.3 22.5 19.8 29.9 45.

Confidence interval +|- 12.7 +|- 11.6 +|- 8.7 +|- 12.2 +|- 7.1 +|- 12.0 +|- 9.2 +|- 9.4 +|- 2.6 Observations 35 50 85 20 4 3 2 9 2 

Average Hours Per Employee Per Week 2.8 3.5 3.3 9.9 15.4 31.4 40.0 38.8 36.4 

Confidence interval +|- 1.3 +|- 1.4 +|- 1.0 +|- 6.9 +|- 13.1 +|- 7.2 +|- 0.0 +|- 3.4 +|- 4.5 Observations 38 54 92 22 5 3 3 10 2 

(Continued
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees 0.6 0.5 0.5 1.0 3.2 6.9 15.3 34.5 142.6 

Confidence interval +|- 0.2 +|- 0.3 +|- 0.2 +|- 0.3 +|- 0.5 +|- 0.8 +|- 1.9 +|- 5.7 +|- 35.4 Observations 19 48 67 106 120 139 96 171 43 

Average Hourly Salary or Wage (Dollars) 18.3 15.6 16.4 15.5 17.1 18.6 19.1 21.2 23.0 

Confidence interval +|- 6.4 +|- 2.3 +|- 2.4 +|- 1.3 +|- 1.0 +|- 1.0 +|- 1.4 +|- 0.6 +|- 1.4 Observations 14 40 54 100 113 135 96 171 43 

Benefits as Percentage of Salary or Wage 21.0 19.5 20.0 32.0 30.0 34.7 37.7 42.6 45.2 

Confidence interval +|- 17.6 +|- 5.7 +|- 7.2 +|- 6.3 +|- 4.6 +|- 3.1 +|- 3.7 +|- 2.2 +|- 7.6 Observations 15 36 51 90 102 128 94 166 42 

Part-time Employees

Mean Number of Employees 1.2 1.2 1.2 1.4 1.3 2.6 3.0 3.2 3.9 

Confidence interval +|- 0.3 +|- 0.3 +|- 0.3 +|- 0.2 +|- 0.3 +|- 1.1 +|- 1.2 +|- 0.8 +|- 2.6 Observations 19 49 68 54 11 19 14 16 3 

Average Hourly Salary or Wage (Dollars) 14.1 15.0 14.8 14.9 11.6 12.8 13.8 12.4 11.4 

Confidence interval +|- 2.3 +|- 2.6 +|- 2.1 +|- 2.2 +|- 2.6 +|- 2.8 +|- 2.2 +|- 1.5 +|- 2.1 Observations 13 43 56 53 10 19 14 16 3 

Benefits as Percentage of Salary or Wage 0.0 6.4 4.2 15.1 16.9 12.9 10.8 14.4 2.9 

Confidence interval +|- 0.1 +|- 5.2 +|- 3.6 +|- 8.2 +|- 11.4 +|- 10.4 +|- 9.2 +|- 8.2 +|- 4.4 Observations 20 44 64 46 7 15 12 15 3 

Average Hours Per Employee Per Week 2.3 7.1 5.8 9.0 22.8 27.0 31.3 29.6 32.9 

Confidence interval +|- 1.4 +|- 2.6 +|- 1.9 +|- 1.7 +|- 6.2 +|- 6.4 +|- 4.8 +|- 5.9 +|- 9.0 Observations 19 49 68 55 11 18 14 16 3 

Contract Employees

Mean Number of Employees 0.8 0.8 0.8 1.2 2.0 15.6 3.7 2.8 10.0 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.6 +|- 0.8 +|- 2.7 +|- 1.6 +|- 1.5 +|- 0.0 Observations 15 19 34 12 4 2 4 6 

Average Hourly Labor Cost (Dollars) 34.4 38.0 36.5 23.4 40.2 20.2 25.6 25.9 16.0 

Confidence interval +|- 14.2 +|- 19.0 +|- 12.6 +|- 13.8 +|- 40.3 +|- 4.4 +|- 1.0 +|- 13.9 +|- 0.0 Observations 12 19 31 11 4 2 2 6 

Average Hours Per Employee Per Week 2.1 5.0 3.5 11.9 30.0 54.5 28.4 32.3 8.0 

Confidence interval +|- 1.8 +|- 3.6 +|- 2.0 +|- 7.9 +|- 11.5 +|- 11.0 +|- 21.2 +|- 6.6 +|- 0.0 Observations 15 19 34 11 4 2 3 6 

(Con
Table 84 (Cont.)

Number of Employees and Annual Labor Costs

By Primary Water Source

System Service Population Category

Primary Water Source/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Administrative Staff

Full-time Employees

Mean Number of Employees 0.4 0.4 0.4 0.8 1.9 2.9 6.0 16.3 93.

Confidence interval +|- 0.4 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.5 +|- 1.3 +|- 3.1 +|- 35.8 Observations 10 27 37 63 95 128 101 188 47 

Average Hourly Salary or Wage (Dollars) 16.3 16.6 16.5 16.0 15.2 20.9 19.7 22.8 22.2 

Confidence interval +|- 3.3 +|- 10.2 +|- 6.8 +|- 3.4 +|- 1.0 +|- 2.6 +|- 1.6 +|- 0.9 +|- 1.1 Observations 9 24 33 60 88 123 99 184 47 

Benefits as Percentage of Salary or Wage 13.3 19.3 17.7 24.4 31.3 33.7 37.2 42.1 43.8 

Confidence interval +|- 11.9 +|- 8.2 +|- 7.0 +|- 6.0 +|- 5.5 +|- 3.2 +|- 3.6 +|- 2.1 +|- 6.9 Observations 8 23 31 55 78 116 93 181 46 

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.2 1.2 1.7 1.3 2.9 29.0 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.6 +|- 0.3 +|- 1.0 +|- 30.1 Observations 15 52 67 82 16 17 11 29 7 

Average Hourly Salary or Wage (Dollars) 12.9 12.6 12.7 13.9 13.8 23.2 14.0 16.1 21.8 

Confidence interval +|- 5.6 +|- 2.6 +|- 2.5 +|- 2.1 +|- 4.5 +|- 10.8 +|- 2.8 +|- 2.3 +|- 4.8 Observations 10 41 51 77 15 16 11 29 8 

Benefits as Percentage of Salary or Wage 1.6 5.5 4.2 15.8 16.0 19.4 17.6 17.7 26.7 

Confidence interval +|- 3.1 +|- 4.5 +|- 3.3 +|- 7.1 +|- 8.5 +|- 10.6 +|- 9.7 +|- 8.4 +|- 9.7 Observations 18 44 62 65 12 15 8 26 7 

Average Hours Per Employee Per Week 5.0 7.5 7.0 12.6 14.9 18.2 22.3 24.4 24.8 

Confidence interval +|- 3.4 +|- 2.1 +|- 1.8 +|- 2.5 +|- 7.3 +|- 5.3 +|- 4.9 +|- 3.7 +|- 1.2 Observations 15 50 65 82 16 17 11 27 6 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.5 2.2 1.3 2.8 45.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 1.0 +|- 1.3 +|- 0.7 +|- 0.8 +|- 51.7 Observations 3 9 12 6 2 3 3 13 4 

Average Hourly Labor Cost (Dollars) 11.3 21.5 19.7 29.0 18.3 16.5 32.7 33.6 30.8 

Confidence interval +|- 2.7 +|- 16.3 +|- 13.9 +|- 19.6 +|- 3.5 +|- 5.6 +|- 3.9 +|- 10.1 +|- 8.0 Observations 3 9 12 6 2 3 2 11 4 

Average Hours Per Employee Per Week 0.2 6.4 5.4 8.3 37.5 43.5 12.7 23.9 32.

Confidence interval +|- 0.1 +|- 5.6 +|- 4.9 +|- 5.2 +|- 5.1 +|- 22.2 +|- 9.6 +|- 5.7 +|- 9.9 Observations 3 9 12 6 2 3 3 12 4 

Data: Q.25Notes: Labor costs includes wages, salaries, and fringe benefits.
Table 85

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Public Systems

Managers

Full-time Employees

Mean Number of Employees 0.3 0.4 0.4 0.6 1.3 1.9 3.4 7.5 30.0 

Confidence interval +|- 0.4 +|- 0.3 +|- 0.3 +|- 0.1 +|- 0.5 +|- 0.3 +|- 0.6 +|- 1.0 +|- 10.1 Observations 6 14 20 55 93 128 99 178 44 

Average Hourly Salary or Wage (Dollars) 34.4 23.0 26.0 20.8 27.5 31.0 35.3 38.3 41.2 

Confidence interval +|- 12.0 +|- 7.3 +|- 6.9 +|- 3.0 +|- 2.0 +|- 1.6 +|- 1.9 +|- 1.1 +|- 2.0 Observations 6 14 20 53 88 123 97 174 44 

Benefits as Percentage of Salary or Wage 28.7 27.4 27.7 29.3 31.6 32.1 35.7 40.2 41.4 

Confidence interval +|- 21.3 +|- 5.9 +|- 7.5 +|- 8.9 +|- 5.4 +|- 3.0 +|- 3.8 +|- 1.5 +|- 7.7 Observations 6 13 19 46 78 116 93 169 43 

Part-time Employees

Mean Number of Employees 1.0 1.3 1.1 1.0 1.1 1.5 2.0 1.4 

Confidence interval +|- 0.0 +|- 0.6 +|- 0.3 +|- 0.0 +|- 0.2 +|- 0.6 +|- 0.0 +|- 0.3 Observations 7 9 16 23 4 7 2 5 

Average Hourly Salary or Wage (Dollars) 18.4 20.8 19.3 19.2 23.4 58.3 31.0 52.2 

Confidence interval +|- 4.5 +|- 13.3 +|- 6.0 +|- 2.2 +|- 4.1 +|- 38.4 +|- 4.7 +|- 18.8 Observations 7 6 13 21 4 7 2 5 

Benefits as Percentage of Salary or Wage 7.9 9.3 8.5 24.0 19.5 33.5 26.4 12.0 

Confidence interval +|- 16.0 +|- 13.0 +|- 10.7 +|- 15.8 +|- 14.4 +|- 11.3 +|- 1.9 +|- 17.4 Observations 7 6 13 20 3 7 2 4 

Average Hours Per Employee Per Week 3.7 7.6 5.6 8.8 8.3 22.2 30.6 27.1 

Confidence interval +|- 2.3 +|- 5.5 +|- 3.1 +|- 2.7 +|- 4.1 +|- 18.3 +|- 12.5 +|- 5.3 Observations 7 8 15 23 4 6 2 5 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.0 1.9 1.0 1.2 1.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.4 +|- 0.0 +|- 0.2 +|- 0.0 +|- 0.2 +|- 0.0 Observations 1 1 2 4 4 3 2 8 

Average Hourly Labor Cost (Dollars) 8.3 40.0 30.1 17.2 21.6 34.4 43.3 44.5 43.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 21.0 +|- 6.4 +|- 0.7 +|- 4.1 +|- 11.9 +|- 17.7 +|- 0.0 Observations 1 1 2 4 2 3 2 4 

Average Hours Per Employee Per Week 8.0 5.0 5.9 19.2 31.1 59.5 12.5 32.8 40.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 1.9 +|- 10.8 +|- 16.3 +|- 17.7 +|- 12.4 +|- 8.0 +|- 0.0 Observations 1 1 2 4 3 3 2 6 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Public Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees 0.7 0.4 0.5 1.0 2.5 4.4 9.1 17.4 89.9 

Confidence interval +|- 0.8 +|- 0.1 +|- 0.3 +|- 0.2 +|- 0.5 +|- 0.7 +|- 1.3 +|- 1.8 +|- 19.7 Observations 10 28 38 87 87 112 86 160 38 

Average Hourly Salary or Wage (Dollars) 22.6 15.6 17.5 16.0 17.8 19.3 19.8 23.3 24.5 

Confidence interval +|- 13.3 +|- 3.6 +|- 4.7 +|- 2.3 +|- 1.3 +|- 1.0 +|- 1.5 +|- 0.7 +|- 1.6 Observations 10 27 37 84 82 109 83 159 38 

Benefits as Percentage of Salary or Wage 29.0 21.2 23.6 24.1 34.4 33.7 34.6 40.9 41.9 

Confidence interval +|- 20.1 +|- 9.1 +|- 8.9 +|- 5.6 +|- 6.1 +|- 3.6 +|- 3.6 +|- 1.7 +|- 3.1 Observations 9 23 32 77 71 102 78 154 38 

Part-time Employees

Mean Number of Employees 1.3 1.0 1.1 1.3 1.5 1.2 1.6 1.8 2.0 

Confidence interval +|- 0.6 +|- 0.1 +|- 0.3 +|- 0.3 +|- 0.4 +|- 0.2 +|- 1.2 +|- 0.6 +|- 0.0 Observations 11 26 37 50 12 13 5 12 

Average Hourly Salary or Wage (Dollars) 14.3 14.9 14.7 15.3 14.3 16.6 15.8 13.5 13.7 

Confidence interval +|- 2.8 +|- 2.3 +|- 1.8 +|- 2.1 +|- 3.2 +|- 8.1 +|- 3.7 +|- 2.1 +|- 0.0 Observations 11 24 35 49 12 11 5 11 

Benefits as Percentage of Salary or Wage 17.1 17.5 17.3 23.6 14.1 9.0 21.6 3.8 0.0 

Confidence interval +|- 18.8 +|- 9.2 +|- 9.5 +|- 8.8 +|- 10.8 +|- 8.1 +|- 16.6 +|- 3.8 +|- 0.0 Observations 9 22 31 48 10 10 3 9 

Average Hours Per Employee Per Week 4.9 10.0 8.0 9.8 15.1 23.8 29.4 21.5 20.0 

Confidence interval +|- 3.5 +|- 3.2 +|- 2.7 +|- 2.5 +|- 4.8 +|- 9.1 +|- 6.1 +|- 2.9 +|- 0.0 Observations 11 24 35 51 12 11 5 10 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 1.2 1.0 2.2 5.0 8.0 11.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.3 +|- 0.0 +|- 2.6 +|- 5.1 +|- 3.3 +|- 12.2 Observations 1 10 11 12 4 4 3 8 2 

Average Hourly Labor Cost (Dollars) 10.0 31.4 31.2 33.5 31.1 22.5 19.8 32.4 45.

Confidence interval +|- 0.0 +|- 20.8 +|- 20.6 +|- 11.2 +|- 7.8 +|- 12.0 +|- 9.2 +|- 11.7 +|- 2.6 Observations 1 10 11 12 3 3 2 7 2 

Average Hours Per Employee Per Week 7.0 3.5 3.5 15.0 8.5 31.4 40.0 39.4 36.4 

Confidence interval +|- 0.0 +|- 2.2 +|- 2.1 +|- 10.2 +|- 8.7 +|- 7.2 +|- 0.0 +|- 4.1 +|- 4.5 Observations 1 10 11 14 4 3 3 8 2 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Public Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees 0.3 0.5 0.5 1.2 3.3 6.8 15.3 30.0 145.6 

Confidence interval +|- 0.3 +|- 0.3 +|- 0.3 +|- 0.3 +|- 0.6 +|- 0.9 +|- 2.0 +|- 3.2 +|- 37.0 Observations 6 28 34 87 101 129 92 158 4

Average Hourly Salary or Wage (Dollars) 27.0 15.6 17.1 15.5 16.9 18.8 19.0 21.1 23.0 

Confidence interval +|- 15.6 +|- 3.2 +|- 3.8 +|- 1.5 +|- 1.1 +|- 1.0 +|- 1.5 +|- 0.7 +|- 1.4 Observations 6 27 33 84 95 126 91 157 4

Benefits as Percentage of Salary or Wage 28.7 22.8 23.8 33.3 30.9 34.8 37.4 41.2 45.8 

Confidence interval +|- 21.3 +|- 6.3 +|- 6.4 +|- 6.9 +|- 4.9 +|- 3.2 +|- 3.8 +|- 1.7 +|- 7.8 Observations 6 23 29 76 87 119 89 152 40 

Part-time Employees

Mean Number of Employees 1.6 1.0 1.2 1.5 1.3 2.7 3.0 3.2 7.

Confidence interval +|- 0.5 +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.3 +|- 1.1 +|- 1.4 +|- 0.8 +|- 2.5 Observations 8 24 32 37 11 17 12 16 2 

Average Hourly Salary or Wage (Dollars) 15.0 16.7 16.2 15.3 11.6 12.6 12.2 12.4 8.8 

Confidence interval +|- 2.2 +|- 3.5 +|- 2.7 +|- 3.0 +|- 2.6 +|- 3.0 +|- 1.3 +|- 1.5 +|- 1.9 Observations 8 23 31 36 10 17 12 16 2 

Benefits as Percentage of Salary or Wage 0.1 6.1 4.4 18.3 16.9 13.0 5.9 14.4 7.7 

Confidence interval +|- 0.3 +|- 6.3 +|- 4.8 +|- 10.9 +|- 11.4 +|- 10.5 +|- 9.1 +|- 8.2 +|- 6.3 Observations 7 20 27 32 7 14 10 15 2 

Average Hours Per Employee Per Week 4.4 6.8 6.2 9.3 22.8 28.7 33.8 29.6 21.3 

Confidence interval +|- 2.8 +|- 2.2 +|- 1.9 +|- 2.5 +|- 6.2 +|- 5.7 +|- 3.9 +|- 5.9 +|- 6.3 Observations 8 24 32 38 11 16 12 16 2 

Contract Employees

Mean Number of Employees * 1.0 1.0 1.6 2.0 15.6 3.7 3.1 10.0 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.6 +|- 1.1 +|- 2.7 +|- 1.6 +|- 1.6 +|- 0.0 Observations * 7 7 5 3 2 4 5 

Average Hourly Labor Cost (Dollars) * 14.0 14.0 15.8 47.0 20.2 25.6 28.4 16.0 

Confidence interval * +|- 6.7 +|- 6.7 +|- 7.2 +|- 50.6 +|- 4.4 +|- 1.0 +|- 16.1 +|- 0.0 Observations * 7 7 5 3 2 2 5 

Average Hours Per Employee Per Week * 8.8 8.8 20.3 26.7 54.5 28.4 30.8 8.0 

Confidence interval * +|- 7.5 +|- 7.5 +|- 8.0 +|- 12.5 +|- 11.0 +|- 21.2 +|- 7.6 +|- 0.0 Observations * 7 7 5 3 2 3 5 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Public Systems

Administrative Staff

Full-time Employees

Mean Number of Employees 0.5 0.5 0.5 0.8 1.9 2.8 5.6 16.6 101.5 

Confidence interval +|- 0.7 +|- 0.3 +|- 0.3 +|- 0.2 +|- 0.3 +|- 0.5 +|- 1.3 +|- 3.5 +|- 40.2 Observations 5 15 20 53 80 117 94 173 43 

Average Hourly Salary or Wage (Dollars) 13.9 20.5 19.0 16.0 14.9 21.0 19.9 23.1 22.3 

Confidence interval +|- 6.5 +|- 16.6 +|- 13.0 +|- 4.2 +|- 1.2 +|- 2.7 +|- 1.7 +|- 0.9 +|- 1.1 Observations 5 15 20 51 76 113 92 169 43 

Benefits as Percentage of Salary or Wage 31.4 26.6 27.2 25.7 31.3 34.1 37.2 40.7 44.6 

Confidence interval +|- 3.7 +|- 6.8 +|- 5.9 +|- 6.6 +|- 6.1 +|- 3.4 +|- 3.7 +|- 1.6 +|- 7.7 Observations 4 15 19 47 69 106 86 166 42 

Part-time Employees

Mean Number of Employees 1.0 1.1 1.1 1.1 1.1 1.7 1.3 2.9 29.0 

Confidence interval +|- 0.0 +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.6 +|- 0.3 +|- 1.0 +|- 30.1 Observations 3 31 34 64 14 17 11 28 7 

Average Hourly Salary or Wage (Dollars) 12.0 12.5 12.4 13.2 13.5 23.2 14.0 16.0 21.8 

Confidence interval +|- 7.2 +|- 3.3 +|- 3.0 +|- 2.3 +|- 4.8 +|- 10.8 +|- 2.8 +|- 2.4 +|- 4.8 Observations 3 28 31 60 13 16 11 28 8 

Benefits as Percentage of Salary or Wage 0.2 10.0 8.2 18.5 10.2 19.4 17.6 17.5 26.7 

Confidence interval +|- 0.4 +|- 8.3 +|- 7.0 +|- 8.2 +|- 7.3 +|- 10.6 +|- 9.7 +|- 8.6 +|- 9.7 Observations 4 24 28 52 10 15 8 25 7 

Average Hours Per Employee Per Week 5.8 7.7 7.5 13.5 15.4 18.2 22.3 24.6 24.8 

Confidence interval +|- 5.5 +|- 2.1 +|- 2.0 +|- 2.8 +|- 7.6 +|- 5.3 +|- 4.9 +|- 3.8 +|- 1.2 Observations 3 29 32 64 14 17 11 26 6 

Contract Employees

Mean Number of Employees * 1.0 1.0 1.0 2.0 2.2 1.5 3.4 45.0 

Confidence interval * +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 1.3 +|- 0.9 +|- 0.9 +|- 51.7 Observations * 4 4 3 1 3 2 10 4 

Average Hourly Labor Cost (Dollars) * 20.8 20.8 37.0 16.6 16.5 32.7 34.9 30.8 

Confidence interval * +|- 27.5 +|- 27.5 +|- 25.2 +|- 0.0 +|- 5.6 +|- 3.9 +|- 11.1 +|- 8.0 Observations * 4 4 3 1 3 2 10 4 

Average Hours Per Employee Per Week * 9.4 9.4 8.0 35.0 43.5 12.5 24.6 32.

Confidence interval * +|- 7.5 +|- 7.5 +|- 6.8 +|- 0.0 +|- 22.2 +|- 13.8 +|- 6.6 +|- 9.9 Observations * 4 4 3 1 3 2 9 4 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Private Systems

Managers

Full-time Employees

Mean Number of Employees 0.6 0.3 0.5 0.7 1.1 1.5 7.7 19.5 10.6 

Confidence interval +|- 0.3 +|- 0.4 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.4 +|- 7.5 +|- 10.2 +|- 4.5 Observations 11 8 19 13 18 11 8 16 5 

Average Hourly Salary or Wage (Dollars) 28.4 16.5 24.8 22.7 27.5 25.5 42.0 37.4 36.4 

Confidence interval +|- 16.3 +|- 5.5 +|- 11.3 +|- 5.6 +|- 6.0 +|- 3.4 +|- 7.0 +|- 4.0 +|- 4.1 Observations 9 6 15 13 14 11 8 16 5 

Benefits as Percentage of Salary or Wage 21.7 8.2 17.2 24.3 21.3 25.3 35.1 50.7 46.2 

Confidence interval +|- 26.2 +|- 7.8 +|- 18.7 +|- 8.8 +|- 13.2 +|- 5.8 +|- 16.2 +|- 9.1 +|- 6.9 Observations 8 5 13 9 11 11 8 16 5 

Part-time Employees

Mean Number of Employees 0.9 1.0 0.9 1.0 1.5 2.0 2.0 * 

Confidence interval +|- 0.3 +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.8 +|- 0.0 +|- 0.0 * Observations 10 11 21 9 2 1 1 * 

Average Hourly Salary or Wage (Dollars) 21.3 9.1 16.6 23.8 50.0 16.4 40.0 * 

Confidence interval +|- 11.4 +|- 6.7 +|- 9.2 +|- 11.3 +|- 0.0 +|- 0.0 +|- 0.0 * Observations 6 6 12 6 2 1 1 * 

Benefits as Percentage of Salary or Wage 6.2 0.3 3.1 23.8 85.0 34.0 30.0 * 

Confidence interval +|- 7.9 +|- 0.5 +|- 4.0 +|- 35.0 +|- 0.0 +|- 0.0 +|- 0.0 * Observations 7 10 17 4 2 1 1 * 

Average Hours Per Employee Per Week 2.5 7.7 5.3 12.8 4.0 10.0 5.0 * 

Confidence interval +|- 1.2 +|- 4.1 +|- 2.5 +|- 8.1 +|- 0.0 +|- 0.0 +|- 0.0 * Observations 9 11 20 9 1 1 1 * 

Contract Employees

Mean Number of Employees 2.0 1.0 1.0 1.0 1.0 * * 1.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 * * +|- 0.0 Observations 13411 * *1 

Average Hourly Labor Cost (Dollars) 10.0 27.9 27.7 20.0 40.0 ***

Confidence interval +|- 0.0 +|- 6.4 +|- 6.3 +|- 0.0 +|- 0.0 ***Observations 13411 * * * 

Average Hours Per Employee Per Week 0.5 5.9 5.9 5.0 40.0 * * 40.0 

Confidence interval +|- 0.0 +|- 8.3 +|- 8.2 +|- 0.0 +|- 0.0 * * +|- 0.0 Observations 13411 * *1 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Private Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees 0.4 0.5 0.4 0.8 1.9 4.6 41.8 46.7 30.3 

Confidence interval +|- 0.3 +|- 0.4 +|- 0.3 +|- 0.4 +|- 0.7 +|- 1.9 +|- 59.5 +|- 18.2 +|- 17.8 Observations 15 29 44 20 13 10 7 16 5 

Average Hourly Salary or Wage (Dollars) 17.3 17.0 17.1 17.7 19.7 16.9 22.1 23.1 22.9 

Confidence interval +|- 7.6 +|- 4.1 +|- 3.7 +|- 1.9 +|- 2.6 +|- 2.2 +|- 3.9 +|- 0.6 +|- 2.9 Observations 8 19 27 17 12 9 7 16 5 

Benefits as Percentage of Salary or Wage 11.9 17.2 14.9 21.9 42.3 28.5 38.1 52.4 43.6 

Confidence interval +|- 12.1 +|- 8.8 +|- 7.5 +|- 18.7 +|- 17.1 +|- 10.3 +|- 13.6 +|- 8.2 +|- 7.0 Observations 9 14 23 12 9 9 7 16 5 

Part-time Employees

Mean Number of Employees 1.1 1.0 1.0 1.2 3.5 2.0 * * 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.3 +|- 3.3 +|- 0.0 * * Observations 40 35 75 15 2 2 * * 

Average Hourly Salary or Wage (Dollars) 15.5 14.6 14.9 17.0 28.5 9.2 * * 

Confidence interval +|- 5.9 +|- 3.2 +|- 2.8 +|- 4.8 +|- 23.0 +|- 3.2 * * Observations 20 27 47 15 2 2 * * 

Benefits as Percentage of Salary or Wage 2.7 6.6 4.7 2.8 0.0 8.7 * * 

Confidence interval +|- 3.2 +|- 6.1 +|- 3.5 +|- 4.7 +|- 0.0 +|- 6.5 * * Observations 27 29 56 11 1 2 * * 

Average Hours Per Employee Per Week 5.5 9.3 7.5 8.4 9.1 16.0 * * 

Confidence interval +|- 2.4 +|- 3.0 +|- 2.1 +|- 4.4 +|- 6.7 +|- 0.0 * * Observations 38 35 73 15 2 2 * * 

Contract Employees

Mean Number of Employees 0.8 0.9 0.9 0.8 1.0 * * 6.5 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.0 * * +|- 4.7 Observations 32 44 76 9 1 * * 2 

Average Hourly Labor Cost (Dollars) 36.1 40.9 38.9 38.6 20.0 * * 21.0 

Confidence interval +|- 12.7 +|- 13.1 +|- 9.3 +|- 21.8 +|- 0.0 * * +|- 1.0 Observations 34 40 74 8 1 * * 2 

Average Hours Per Employee Per Week 2.8 3.6 3.2 4.0 40.0 * * 36.0 

Confidence interval +|- 1.3 +|- 1.5 +|- 1.0 +|- 2.6 +|- 0.0 * * +|- 4.1 Observations 37 44 81 8 1 * * 2 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Private Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees 0.6 0.6 0.6 0.5 3.1 7.3 15.3 69.9 79.0 

Confidence interval +|- 0.2 +|- 0.5 +|- 0.3 +|- 0.2 +|- 1.3 +|- 2.8 +|- 5.4 +|- 26.0 +|- 35.6 Observations 13 20 33 19 19 10 4 13 2 

Average Hourly Salary or Wage (Dollars) 15.1 15.7 15.4 15.2 17.9 15.4 21.1 21.5 22.2 

Confidence interval +|- 3.7 +|- 2.5 +|- 2.2 +|- 0.9 +|- 1.8 +|- 2.6 +|- 4.4 +|- 0.9 +|- 4.2 Observations 8 13 21 16 18 9 5 14 2 

Benefits as Percentage of Salary or Wage 18.5 13.3 16.1 24.6 26.1 33.5 42.7 53.2 34.0 

Confidence interval +|- 21.9 +|- 8.4 +|- 12.5 +|- 13.6 +|- 12.0 +|- 13.7 +|- 14.8 +|- 8.7 +|- 14.8 Observations 9 13 22 14 15 9 5 14 2 

Part-time Employees

Mean Number of Employees 0.9 1.4 1.2 1.1 * 1.0 3.0 * 2.0 

Confidence interval +|- 0.1 +|- 0.6 +|- 0.4 +|- 0.2 * +|- 0.0 +|- 1.3 * +|- 0.0 Observations 11 25 36 17 * 2 2 * 

Average Hourly Salary or Wage (Dollars) 13.1 13.4 13.3 14.1 * 14.8 22.7 * 13.0 

Confidence interval +|- 3.9 +|- 3.7 +|- 3.0 +|- 3.1 * +|- 0.5 +|- 5.6 * +|- 0.0 Observations 5 20 25 17 * 2 2 * 

Benefits as Percentage of Salary or Wage 0.0 6.6 4.1 9.1 * 0.0 34.2 * 0.0 

Confidence interval +|- 0.0 +|- 7.6 +|- 5.0 +|- 8.2 * +|- 0.0 +|- 7.8 * +|- 0.0 Observations 13 24 37 14 * 1 2 * 

Average Hours Per Employee Per Week 0.8 7.3 5.5 8.5 * 6.3 17.5 * 40.0 

Confidence interval +|- 0.2 +|- 4.3 +|- 3.3 +|- 3.2 * +|- 2.9 +|- 9.9 * +|- 0.0 Observations 11 25 36 17 * 2 2 * 

Contract Employees

Mean Number of Employees 0.8 0.6 0.8 1.1 2.0 * * 1.0 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.7 +|- 0.0 * * +|- 0.0 Observations 15 12 27 7 1 * * 1 

Average Hourly Labor Cost (Dollars) 34.4 50.6 42.1 27.3 20.0 * * 13.0 

Confidence interval +|- 14.2 +|- 23.8 +|- 13.9 +|- 19.0 +|- 0.0 * * +|- 0.0 Observations 12 12 24 6 1 * * 1 

Average Hours Per Employee Per Week 2.1 3.0 2.4 7.6 40.0 * * 40.0 

Confidence interval +|- 1.8 +|- 2.7 +|- 1.5 +|- 6.4 +|- 0.0 * * +|- 0.0 Observations 15 12 27 6 1 * * 1 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

Private Systems

Administrative staff

Full-time Employees

Mean Number of Employees 0.4 0.3 0.4 0.8 1.9 3.5 11.9 13.9 33.

Confidence interval +|- 0.4 +|- 0.3 +|- 0.2 +|- 0.5 +|- 0.6 +|- 1.1 +|- 8.0 +|- 4.0 +|- 10.2 Observations 5 12 17 10 15 11 7 15 4 

Average Hourly Salary or Wage (Dollars) 17.5 11.0 13.9 16.3 16.3 18.0 16.4 20.3 20.9 

Confidence interval +|- 1.6 +|- 1.6 +|- 2.5 +|- 2.1 +|- 1.8 +|- 7.6 +|- 2.3 +|- 1.7 +|- 1.8 Observations 4 9 13 9 12 10 7 15 4 

Benefits as Percentage of Salary or Wage 7.1 6.6 6.8 17.7 31.5 27.7 37.5 52.3 38.0 

Confidence interval +|- 5.9 +|- 7.9 +|- 5.2 +|- 10.8 +|- 13.5 +|- 6.9 +|- 14.1 +|- 8.6 +|- 5.3 Observations 4 8 12 8 9 10 7 15 4 

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.2 2.0 * * 2.0 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.3 +|- 0.0 * * +|- 0.0 Observations 12 21 33 18 2 * * 1 

Average Hourly Salary or Wage (Dollars) 13.3 12.8 12.9 15.9 20.0 * * 18.1 

Confidence interval +|- 8.1 +|- 4.2 +|- 4.1 +|- 3.8 +|- 0.0 * * +|- 0.0 Observations 7 13 20 17 2 * * 1 

Benefits as Percentage of Salary or Wage 2.0 1.4 1.7 8.1 85.0 * * 22.0 

Confidence interval +|- 4.0 +|- 2.6 +|- 2.3 +|- 11.4 +|- 0.0 * * +|- 0.0 Observations 14 20 34 13 2 * * 1 

Average Hours Per Employee Per Week 4.8 7.4 6.7 9.9 7.0 * * 20.0 

Confidence interval +|- 4.1 +|- 3.7 +|- 2.8 +|- 4.0 +|- 1.4 * * +|- 0.0 Observations 12 21 33 18 2 * * 1 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.0 * 1.0 1.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 * +|- 0.0 +|- 0.0 Observations 3 5 8 3 1 * 1 3 

Average Hourly Labor Cost (Dollars) 11.3 22.5 18.7 20.0 20.0 * * 20.3 

Confidence interval +|- 2.7 +|- 3.7 +|- 7.0 +|- 14.3 +|- 0.0 * * +|- 0.0 Observations 3 5 8 3 1 * * 1 

Average Hours Per Employee Per Week 0.2 2.2 1.5 8.6 40.0 * 13.2 21.9 

Confidence interval +|- 0.1 +|- 0.7 +|- 1.0 +|- 7.7 +|- 0.0 * +|- 0.0 +|- 11.1 Observations 3 5 8 3 1 * 1 3 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Managers

Full-time Employees

Mean Number of Employees 0.5 0.4 0.5 0.6 1.3 1.8 3.7 8.9 27.4 

Confidence interval +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.1 +|- 0.4 +|- 0.3 +|- 0.7 +|- 1.9 +|- 9.0 Observations 17 22 39 68 111 139 107 194 49 

Average Hourly Salary or Wage (Dollars) 30.0 21.0 25.4 21.3 27.5 30.7 35.8 38.2 40.5 

Confidence interval +|- 12.9 +|- 5.8 +|- 6.5 +|- 2.6 +|- 2.0 +|- 1.5 +|- 1.9 +|- 1.1 +|- 1.9 Observations 15 20 35 66 102 134 105 190 49 

Benefits as Percentage of Salary or Wage 23.8 21.2 22.4 28.3 29.6 31.6 35.7 41.4 42.

Confidence interval +|- 19.5 +|- 7.9 +|- 10.3 +|- 7.3 +|- 5.2 +|- 2.8 +|- 3.7 +|- 2.1 +|- 6.6 Observations 14 18 32 55 89 127 101 185 48 

Part-time Employees

Mean Number of Employees 0.9 1.1 1.0 1.0 1.1 1.5 2.0 1.4 

Confidence interval +|- 0.2 +|- 0.3 +|- 0.2 +|- 0.0 +|- 0.2 +|- 0.5 +|- 0.0 +|- 0.3 Observations 17 20 37 32 6 8 3 5 

Average Hourly Salary or Wage (Dollars) 19.7 15.7 18.1 20.4 27.2 56.1 34.1 52.2 

Confidence interval +|- 5.6 +|- 10.2 +|- 5.3 +|- 3.5 +|- 7.2 +|- 37.9 +|- 6.8 +|- 18.8 Observations 13 12 25 27 6 8 3 5 

Benefits as Percentage of Salary or Wage 7.0 3.6 5.4 23.9 36.1 33.5 27.7 12.0 

Confidence interval +|- 8.6 +|- 5.7 +|- 5.2 +|- 14.4 +|- 28.9 +|- 10.7 +|- 2.7 +|- 17.4 Observations 14 16 30 24 5 8 3 4 

Average Hours Per Employee Per Week 3.1 7.7 5.5 10.1 8.0 21.5 21.7 27.1 

Confidence interval +|- 1.3 +|- 3.3 +|- 1.8 +|- 3.3 +|- 3.9 +|- 17.1 +|- 18.9 +|- 5.3 Observations 16 19 35 32 5 7 3 5 

Contract Employees

Mean Number of Employees 1.5 1.0 1.0 1.0 1.0 1.9 1.0 1.2 1.0 

Confidence interval +|- 1.0 +|- 0.0 +|- 0.0 +|- 0.3 +|- 0.0 +|- 0.2 +|- 0.0 +|- 0.2 +|- 0.0 Observations 2 4 6 5 5 3 2 9 

Average Hourly Labor Cost (Dollars) 9.2 28.2 27.8 17.8 27.7 34.4 43.3 44.5 43.0 

Confidence interval +|- 1.8 +|- 6.3 +|- 6.2 +|- 5.7 +|- 13.2 +|- 4.1 +|- 11.9 +|- 17.7 +|- 0.0 Observations 2 4 6 5 3 3 2 4 

Average Hours Per Employee Per Week 4.2 5.9 5.9 16.0 33.9 59.5 12.5 33.8 40.0 

Confidence interval +|- 8.0 +|- 8.0 +|- 7.8 +|- 8.9 +|- 13.0 +|- 17.7 +|- 12.4 +|- 6.9 +|- 0.0 Observations 2 4 6 5 4 3 2 7 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Treatment Plant Operators

Full-time Employees

Mean Number of Employees 0.4 0.4 0.4 1.0 2.4 4.4 11.2 21.1 80.3 

Confidence interval +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.4 +|- 0.7 +|- 4.3 +|- 3.3 +|- 18.9 Observations 25 57 82 107 100 122 93 176 43 

Average Hourly Salary or Wage (Dollars) 19.6 16.4 17.3 16.3 18.1 19.1 19.9 23.3 24.2 

Confidence interval +|- 7.4 +|- 2.9 +|- 2.9 +|- 1.9 +|- 1.2 +|- 1.0 +|- 1.5 +|- 0.6 +|- 1.4 Observations 18 46 64 101 94 118 90 175 43 

Benefits as Percentage of Salary or Wage 17.2 19.0 18.3 23.8 35.4 33.4 34.9 42.4 42.

Confidence interval +|- 12.8 +|- 6.5 +|- 6.4 +|- 5.3 +|- 5.8 +|- 3.5 +|- 3.5 +|- 2.2 +|- 2.8 Observations 18 37 55 89 80 111 85 170 43 

Part-time Employees

Mean Number of Employees 1.1 1.0 1.1 1.3 1.6 1.3 1.6 1.8 2.0 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.5 +|- 0.3 +|- 1.2 +|- 0.6 +|- 0.0 Observations 51 61 112 65 14 15 5 12 

Average Hourly Salary or Wage (Dollars) 15.0 14.7 14.8 15.7 15.2 15.2 15.8 13.5 13.7 

Confidence interval +|- 3.7 +|- 2.3 +|- 1.9 +|- 2.1 +|- 3.6 +|- 7.2 +|- 3.7 +|- 2.1 +|- 0.0 Observations 31 51 82 64 14 13 5 11 

Benefits as Percentage of Salary or Wage 5.9 9.8 8.0 19.0 13.5 8.9 21.6 3.8 0.0 

Confidence interval +|- 5.5 +|- 6.0 +|- 4.2 +|- 7.9 +|- 10.2 +|- 6.7 +|- 16.6 +|- 3.8 +|- 0.0 Observations 36 51 87 59 11 12 3 9 

Average Hours Per Employee Per Week 5.4 9.5 7.6 9.5 14.7 22.3 29.4 21.5 20.0 

Confidence interval +|- 2.0 +|- 2.3 +|- 1.7 +|- 2.1 +|- 4.7 +|- 7.7 +|- 6.1 +|- 2.9 +|- 0.0 Observations 49 59 108 66 14 13 5 10 

Contract Employees

Mean Number of Employees 0.8 0.9 0.9 1.0 1.0 2.2 5.0 7.7 11.0 

Confidence interval +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.0 +|- 2.6 +|- 5.1 +|- 2.8 +|- 12.2 Observations 33 54 87 21 5 4 3 10 2 

Average Hourly Labor Cost (Dollars) 36.1 39.5 38.2 36.0 27.3 22.5 19.8 29.9 45.

Confidence interval +|- 12.7 +|- 11.6 +|- 8.7 +|- 12.2 +|- 7.1 +|- 12.0 +|- 9.2 +|- 9.4 +|- 2.6 Observations 35 50 85 20 4 3 2 9 2 

Average Hours Per Employee Per Week 2.8 3.5 3.3 9.9 15.4 31.4 40.0 38.8 36.4 

Confidence interval +|- 1.3 +|- 1.4 +|- 1.0 +|- 6.9 +|- 13.1 +|- 7.2 +|- 0.0 +|- 3.4 +|- 4.5 Observations 38 54 92 22 5 3 3 10 2 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Distribution System Operators

Full-time Employees

Mean Number of Employees 0.6 0.5 0.5 1.0 3.2 6.9 15.3 34.5 142.6 

Confidence interval +|- 0.2 +|- 0.3 +|- 0.2 +|- 0.3 +|- 0.5 +|- 0.8 +|- 1.9 +|- 5.7 +|- 35.4 Observations 19 48 67 106 120 139 96 171 43 

Average Hourly Salary or Wage (Dollars) 18.3 15.6 16.4 15.5 17.1 18.6 19.1 21.2 23.0 

Confidence interval +|- 6.4 +|- 2.3 +|- 2.4 +|- 1.3 +|- 1.0 +|- 1.0 +|- 1.4 +|- 0.6 +|- 1.4 Observations 14 40 54 100 113 135 96 171 43 

Benefits as Percentage of Salary or Wage 21.0 19.5 20.0 32.0 30.0 34.7 37.7 42.6 45.2 

Confidence interval +|- 17.6 +|- 5.7 +|- 7.2 +|- 6.3 +|- 4.6 +|- 3.1 +|- 3.7 +|- 2.2 +|- 7.6 Observations 15 36 51 90 102 128 94 166 42 

Part-time Employees

Mean Number of Employees 1.2 1.2 1.2 1.4 1.3 2.6 3.0 3.2 3.9 

Confidence interval +|- 0.3 +|- 0.3 +|- 0.3 +|- 0.2 +|- 0.3 +|- 1.1 +|- 1.2 +|- 0.8 +|- 2.6 Observations 19 49 68 54 11 19 14 16 3 

Average Hourly Salary or Wage (Dollars) 14.1 15.0 14.8 14.9 11.6 12.8 13.8 12.4 11.4 

Confidence interval +|- 2.3 +|- 2.6 +|- 2.1 +|- 2.2 +|- 2.6 +|- 2.8 +|- 2.2 +|- 1.5 +|- 2.1 Observations 13 43 56 53 10 19 14 16 3 

Benefits as Percentage of Salary or Wage 0.0 6.4 4.2 15.1 16.9 12.9 10.8 14.4 2.9 

Confidence interval +|- 0.1 +|- 5.2 +|- 3.6 +|- 8.2 +|- 11.4 +|- 10.4 +|- 9.2 +|- 8.2 +|- 4.4 Observations 20 44 64 46 7 15 12 15 3 

Average Hours Per Employee Per Week 2.3 7.1 5.8 9.0 22.8 27.0 31.3 29.6 32.9 

Confidence interval +|- 1.4 +|- 2.6 +|- 1.9 +|- 1.7 +|- 6.2 +|- 6.4 +|- 4.8 +|- 5.9 +|- 9.0 Observations 19 49 68 55 11 18 14 16 3 

Contract Employees

Mean Number of Employees 0.8 0.8 0.8 1.2 2.0 15.6 3.7 2.8 10.0 

Confidence interval +|- 0.2 +|- 0.1 +|- 0.1 +|- 0.6 +|- 0.8 +|- 2.7 +|- 1.6 +|- 1.5 +|- 0.0 Observations 15 19 34 12 4 2 4 6 

Average Hourly Labor Cost (Dollars) 34.4 38.0 36.5 23.4 40.2 20.2 25.6 25.9 16.0 

Confidence interval +|- 14.2 +|- 19.0 +|- 12.6 +|- 13.8 +|- 40.3 +|- 4.4 +|- 1.0 +|- 13.9 +|- 0.0 Observations 12 19 31 11 4 2 2 6 

Average Hours Per Employee Per Week 2.1 5.0 3.5 11.9 30.0 54.5 28.4 32.3 8.0 

Confidence interval +|- 1.8 +|- 3.6 +|- 2.0 +|- 7.9 +|- 11.5 +|- 11.0 +|- 21.2 +|- 6.6 +|- 0.0 Observations 15 19 34 11 4 2 3 6 

(Continued
Table 85 (Cont.)

Number of Employees and Annual Labor Costs

By Ownership

System Service Population Category

System Ownership/Employee Category

100 

or Less

101 - 

500

Sub, 500 

or less

501 - 

3,300

3,301 - 

10,000

10,001 - 

50,000

50,001 - 

100,000

100,001-

500,000

Ove

500,00

All Systems

Administrative Staff

Full-time Employees

Mean Number of Employees 0.4 0.4 0.4 0.8 1.9 2.9 6.0 16.3 93.

Confidence interval +|- 0.4 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.5 +|- 1.3 +|- 3.1 +|- 35.8 Observations 10 27 37 63 95 128 101 188 47 

Average Hourly Salary or Wage (Dollars) 16.3 16.6 16.5 16.0 15.2 20.9 19.7 22.8 22.2 

Confidence interval +|- 3.3 +|- 10.2 +|- 6.8 +|- 3.4 +|- 1.0 +|- 2.6 +|- 1.6 +|- 0.9 +|- 1.1 Observations 9 24 33 60 88 123 99 184 47 

Benefits as Percentage of Salary or Wage 13.3 19.3 17.7 24.4 31.3 33.7 37.2 42.1 43.8 

Confidence interval +|- 11.9 +|- 8.2 +|- 7.0 +|- 6.0 +|- 5.5 +|- 3.2 +|- 3.6 +|- 2.1 +|- 6.9 Observations 8 23 31 55 78 116 93 181 46 

Part-time Employees

Mean Number of Employees 1.0 1.0 1.0 1.2 1.2 1.7 1.3 2.9 29.0 

Confidence interval +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.6 +|- 0.3 +|- 1.0 +|- 30.1 Observations 15 52 67 82 16 17 11 29 7 

Average Hourly Salary or Wage (Dollars) 12.9 12.6 12.7 13.9 13.8 23.2 14.0 16.1 21.8 

Confidence interval +|- 5.6 +|- 2.6 +|- 2.5 +|- 2.1 +|- 4.5 +|- 10.8 +|- 2.8 +|- 2.3 +|- 4.8 Observations 10 41 51 77 15 16 11 29 8 

Benefits as Percentage of Salary or Wage 1.6 5.5 4.2 15.8 16.0 19.4 17.6 17.7 26.7 

Confidence interval +|- 3.1 +|- 4.5 +|- 3.3 +|- 7.1 +|- 8.5 +|- 10.6 +|- 9.7 +|- 8.4 +|- 9.7 Observations 18 44 62 65 12 15 8 26 7 

Average Hours Per Employee Per Week 5.0 7.5 7.0 12.6 14.9 18.2 22.3 24.4 24.8 

Confidence interval +|- 3.4 +|- 2.1 +|- 1.8 +|- 2.5 +|- 7.3 +|- 5.3 +|- 4.9 +|- 3.7 +|- 1.2 Observations 15 50 65 82 16 17 11 27 6 

Contract Employees

Mean Number of Employees 1.0 1.0 1.0 1.0 1.5 2.2 1.3 2.8 45.0 

Confidence interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 1.0 +|- 1.3 +|- 0.7 +|- 0.8 +|- 51.7 Observations 3 9 12 6 2 3 3 13 4 

Average Hourly Labor Cost (Dollars) 11.3 21.5 19.7 29.0 18.3 16.5 32.7 33.6 30.8 

Confidence interval +|- 2.7 +|- 16.3 +|- 13.9 +|- 19.6 +|- 3.5 +|- 5.6 +|- 3.9 +|- 10.1 +|- 8.0 Observations 3 9 12 6 2 3 2 11 4 

Average Hours Per Employee Per Week 0.2 6.4 5.4 8.3 37.5 43.5 12.7 23.9 32.

Confidence interval +|- 0.1 +|- 5.6 +|- 4.9 +|- 5.2 +|- 5.1 +|- 22.2 +|- 9.6 +|- 5.7 +|- 9.9 Observations 3 9 12 6 2 3 3 12 4 

Data: Q.25Notes: Labor costs includes wages, salaries, and fringe benefits.
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Primarily Ground Water Systems 

Percentage of Systems 35.6 35.0 56.8 43.1 58.8 55.6 64.1 35.9 

Confidence interval +|- 11.2 +|- 9.6 +|- 10.0 +|- 12.8 +|- 12.7 +|- 17.5 +|- 9.1 +|- 30.5 

 Observations 88 105 111 62 66 40 56 6 

Primarily Surface Water Systems 

Percentage of Systems 36.4 45.0 64.7 50.9 57.0 70.5 77.1 87.2 

Confidence interval +|- 27.2 +|- 20.2 +|- 10.4 +|- 12.9 +|- 10.5 +|- 11.1 +|- 6.0 +|- 6.6 

 Observations 49 67 78 65 84 54 124 39 

Primarily Purchased Water Systems 

Percentage of Systems 0.4 32.9 44.5 51.9 72.2 76.0 77.3 80.3 

Confidence interval +|- 0.9 +|- 21.6 +|- 13.1 +|- 21.1 +|- 18.6 +|- 14.0 +|- 10.8 +|- 14.1 

 Observations 8 23 48 26 25 30 45 13 

All Systems 

Percentage of Systems 33.3 35.1 54.1 46.6 61.0 66.4 74.0 78.9 

Confidence interval +|- 10.3 +|- 8.5 +|- 7.8 +|- 9.2 +|- 8.2 +|- 8.1 +|- 4.6 +|- 9.3 

 Observations 145 195 237 153 175 124 225 58 

Data: Q.27 Notes: 

Table 86 

Percentage of Systems Making Major Capital Investments in the Past 5 Years 

By Primary Water Source 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Ove

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 Public Systems 

Mean 40.9 45.4 54.1 48.5 62.0 69.1 77.0 87.3 

Confidence interval +|- 24.0 +|- 13.8 +|- 8.5 +|- 10.3 +|- 8.6 +|- 8.3 +|- 4.2 +|- 5.4 

Observations 27 84 181 127 155 111 204 52 

Private Systems 

Mean 32.1 28.6 54.2 39.3 50.5 41.5 51.9 24.4 

Confidence interval +|- 11.2 +|- 9.7 +|- 13.5 +|- 21.0 +|- 25.9 +|- 24.4 +|- 24.3 +|- 23.9 

Observations 118 111 56 26 20 13 21 6 

Data: Q.27 Notes: 

Table 87 

Percentage of Systems Making Major Capital Investments in the Past 5 Years 

By Ownership 
Primary Water Source 

Primarily Ground Water Systems 

Mean Invested in the Past 5 Years 

Confidence interval 

Median Observations 

Primarily Surface Water Systems 

Mean Invested in the Past 5 Years 

Confidence interval 

Median Observations 

Primarily Purchased Water Systems 

Mean Invested in the Past 5 Years 

Confidence interval 

Median Observations 

All Systems 

Mean Invested in the Past 5 Years 

Confidence interval 

Median Observations 

System Service Population Category 

100 

or Less 

101 -

500 

501 -

3,300 

3,301 -

10,000 

10,001 -

50,000 

50,001 -

100,000 

100,001-

500,000 

500

75 180 598 982 3,382 14,420 45,405 134

+|- 67 +|- 193 +|- 305 +|- 595 +|- 1,307 +|- 3,471 +|- 23,488 +|- 117

6 23 113 400 2,385 17,500 11,800 134

16 23 54 20 35 15 26 24 455 756 2,358 5,244 17,576 54,344 392

+|- 20 +|- 307 +|- 313 +|- 1,128 +|- 1,543 +|- 5,306 +|- 10,723 +|- 92

9 240 210 971 3,500 13,050 43,635 273

11 22 46 23 42 33 86 

* 1,008 593 997 6,520 7,243 40,921 154

* +|- 774 +|- 366 +|- 575 +|- 9,106 +|- 2,316 +|- 11,726 +|- 105

* 681 181 922 645 4,401 26,609 61

* 9 20 11 15 20 31 

74 375 612 1,221 4,609 13,616 50,003 322

+|- 65 +|- 260 +|- 210 +|- 414 +|- 2,346 +|- 2,624 +|- 8,197 +|- 80

6 46 161 542 2,382 12,500 32,327 171

27 54 120 54 92 68 143 

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years. 

Excludes systems that did not report positive revenue or expenses. 

Table 88 

Amount of Major Capital Investment in the Past 5 Years 

By Primary Water Source 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500Public Systems 

Mean Invested in the Past 5 Years 217 545 722 1,193 4,703 13,680 47,126 331

Confidence interval +|- 159 +|- 375 +|- 282 +|- 458 +|- 2,473 +|- 2,756 +|- 7,815 +|- 84,

Median 99 92 189 486 2,382 12,908 31,926 171Observations 8 34 96 46 85 62 133 

Private Systems 

Mean Invested in the Past 5 Years 33 49 284 1,344 2,983 12,803 76,798 137

Confidence interval +|- 49 +|- 26 +|- 241 +|- 925 +|- 2,736 +|- 8,612 +|- 22,085 +|- 36,

Median 5 15 31 922 2,581 3,171 102,373 137Observations 19 20 24 8 7 6 10 

Data: Q.27 Notes: Excludes systems that have not made major capital improvements in the past five years

Excludes systems that did not report positive revenue or expenses. 

Table 89 

Amount of Major Capital Investment in the Past 5 Years 

By Ownership 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 All 

Primarily Ground Water Systems 

Land 0.1 2.7 8.1 1.1 25.3 48.0 41.4 66.7 Water Source 59.8 50.5 50.8 45.7 58.3 71.1 57.9 100.0 Transmission and Distribution System 30.5 49.0 54.7 88.8 84.1 87.7 83.0 100.0 Treatment 30.8 25.5 24.7 33.2 50.8 81.2 68.8 100.0 Storage 29.5 24.7 35.2 33.3 55.7 77.5 69.0 33.3 Security 14.0 3.0 4.7 40.0 42.1 63.1 44.9 66.7 Other 3.6 5.7 11.5 17.9 45.0 67.8 49.4 66.7 Observations 35 38 62 26 40 21 36 3 

Primarily Surface Water Systems 

Land 0.0 0.0 3.5 16.7 26.7 17.9 50.6 52.9 Water Source 24.9 34.8 20.3 25.0 26.2 34.7 59.3 67.6 Transmission and Distribution System 40.1 52.7 61.7 80.6 90.1 93.2 95.3 97.1 Treatment 72.3 51.8 39.6 69.4 60.9 81.7 90.5 97.1 Storage 27.5 17.0 34.4 50.0 37.6 65.3 68.4 73.5 Security 0.0 5.3 5.8 50.0 26.2 30.3 34.1 23.5 Other 5.5 7.9 9.8 25.0 46.2 45.4 64.6 91.2 Observations 28 36 49 36 49 39 94 34 

Primarily Purchased Water Systems 

Land 0.0 0.0 9.6 17.0 29.2 9.2 35.7 49.0 Water Source 0.0 31.7 9.5 2.2 16.2 5.9 50.0 24.5 Transmission and Distribution System 0.0 98.7 90.5 100.0 84.7 95.4 97.4 100.0 Treatment 0.0 17.2 5.8 10.7 16.1 27.2 54.8 49.0 Storage 100.0 33.2 19.2 39.3 45.3 26.4 71.9 49.0 Security 0.0 0.0 0.0 17.0 44.5 41.5 47.1 40.5 Other 0.0 1.0 4.8 17.0 22.6 36.9 61.2 41.0 Observations 1 9 21 13 19 23 36 10 

All Systems 

Land 0.1 2.2 8.0 8.5 26.6 24.6 45.5 52.8 Water Source 58.6 47.1 38.7 30.0 39.9 37.6 57.0 59.0 Transmission and Distribution System 30.8 56.1 63.4 90.1 85.8 92.2 93.1 97.9 Treatment 32.1 25.7 21.9 34.7 45.0 66.1 78.5 85.5 Storage 29.5 25.5 31.6 38.3 48.5 58.0 69.3 65.2 Security 13.5 2.7 3.8 36.0 38.6 43.5 39.1 30.2 Other 3.7 5.2 9.9 19.1 39.9 49.9 60.7 77.5 Observations 64 83 132 75 108 83 166 47 

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years. 

Table reports the percentage of systems that funded each investment type. It is not the percentage of funds invested in each category. Table 94 reports the percentage of funds invested in each category for the average system. Table 96 reports the percentage of funds invested in each category nationally. 

Table 90 

Percentage of Systems Making Major Capital Investments in the Past 5 Years 

By Type of Investment and Primary Water Source 

(Percentage of Systems Funding Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Land 0.6 0.0 8.1 10.3 23.8 25.7 42.3 5Water Source 62.0 46.9 35.1 29.5 38.9 38.1 54.9 5Transmission and Distribution System 22.8 56.2 63.1 89.7 84.7 93.0 92.5 9Treatment 23.9 26.5 16.8 37.4 42.9 66.7 77.1 8Storage 15.8 31.8 33.5 41.5 47.5 56.7 67.1 6Security 0.3 0.3 3.7 39.7 40.7 46.3 37.2 3Other 0.9 5.1 7.7 21.9 40.2 51.2 62.6 7Observations 13 43 103 64 99 77 156 

Private Systems 

Land 0.0 4.4 7.9 0.0 63.7 8.1 80.4 5Water Source 57.9 47.3 48.5 32.3 53.7 29.7 80.4 10Transmission and Distribution System 32.3 56.0 64.1 91.7 100.0 78.4 100.0 10Treatment 33.7 24.9 35.7 22.2 74.4 56.9 93.5 10

Storage 32.1 19.3 26.5 23.7 62.2 78.4 93.5 5Security 16.1 5.1 3.9 19.0 10.0 0.0 60.8 Other 4.2 5.2 15.7 6.4 36.3 29.7 39.2 10Observations 51 40 29 11 9 6 10 

Data: Q.27A 

Notes: Excludes systems that have not made major capital improvements in the past five years

Table reports the percentage of systems that funded each investment type. It is not the percentage of funds invested in each category. Table 95 reports the percentage of funds invested in each category for the average sysTable 97 reports the percentage of funds invested in each category nationally. 

Table 91 

Percentage of Systems Making Major Capital Investments in the Past 5 Years 

By Type of Investment and Ownership 

(Percentage of Systems Funding Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Primarily Ground Water Systems 

Land 0 0 5 3 22 441 555 500 Water Source 17 50 151 91 356 2,556 2,379 16,213 Transmission and Distribution System 20 75 219 423 2,033 3,569 12,499 37,767 Treatment 13 23 54 310 437 3,204 15,268 11,142 Storage 15 13 140 62 656 1,249 2,115 3,717 Security 1 0 0 11 10 65 60 767 Other 0 1 3 52 173 1,902 5,163 32,284 Observations 35 38 62 26 40 21 36 3 

Primarily Surface Water Systems 

Land 0 0 1 6 53 201 1,203 4,537 

Water Source 31 40 34 88 270 895 3,460 35,060 Transmission and Distribution System 183 97 378 982 1,776 8,219 23,526 156,023 Treatment 240 235 239 1,585 2,455 4,522 15,058 108,680 

Storage 6 34 129 433 587 1,839 2,828 12,660 Security 0 0 1 11 10 80 560 1,317 Other 0 1 8 25 287 1,494 7,694 54,836 Observations 28 36 49 36 49 39 94 34 

Primarily Purchased Water Systems 

Land 0 0 12 2 19 44 622 2,700 Water Source 0 8 32 8 290 59 5,036 2,802 Transmission and Distribution System 0 908 455 983 4,409 4,110 23,794 96,312 Treatment 0 1 12 2 618 284 8,833 12,702 Storage 15 83 57 175 512 1,290 4,822 37,024 Security 0 0 0 30 35 65 235 1,055 Other 0 7 18 15 355 716 4,928 12,645 Observations 1 9 21 13 19 23 36 10 

All Systems 

Land 0 0 6 3 29 229 944 3,854 

Water Source 18 44 113 69 318 1,165 3,562 26,112 Transmission and Distribution System 25 192 287 685 2,540 5,633 21,256 134,579 Treatment 20 31 62 492 999 2,917 13,799 79,628 Storage 15 24 120 168 604 1,503 3,095 18,062 Security 1 0 0 16 16 71 386 1,221 Other 0 2 7 37 246 1,398 6,581 43,255 Observations 64 83 132 75 108 83 166 47 

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years. 

Table 92 

Average Amount of Major Capital Investment Allocated in the Past 5 Years 

By Type of Investment and Primary Water Source 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Land 0 0 8 4 30 240 990 3,9

Water Source 89 68 129 48 331 1,043 3,729 26,4Transmission and Distribution System 57 351 339 637 2,600 5,494 18,582 138,3Treatment 86 53 72 479 1,049 3,072 13,748 81,5Storage 11 40 154 183 592 1,555 3,072 18,8Security 1 0 0 15 17 76 137 1,2Other 0 3 8 43 251 1,443 6,873 43,5Observations 13 43 103 64 99 77 156 

Private Systems 

Land 0 0 2 0 19 61 446 6

Water Source 4 20 70 165 130 3,063 1,739 18,4Transmission and Distribution System 19 36 147 908 1,731 7,797 50,410 47,3Treatment 8 9 35 555 324 501 14,349 33,8

Storage 15 8 30 102 762 688 3,347 6Security 0 0 1 20 1 0 3,108 Other 0 0 4 10 177 693 3,400 36,2Observations 51 40 29 11 9 6 10 

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years

Table 93 

Average Amount of Major Capital Investment Allocated in the Past 5 Years 

By Type of Investment and Ownership 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 All Siz

Primarily Ground Water Systems 

Land 0.0 0.0 2.0 0.1 1.8 2.6 1.5 0.6 Water Source 43.2 36.1 31.1 14.3 16.4 16.5 9.8 9.2 3Transmission and Distribution System 14.5 34.7 35.4 52.2 43.8 27.9 41.0 38.2 32Treatment 17.3 13.8 11.0 13.7 10.0 22.1 23.5 26.0 1Storage 15.7 12.2 15.6 8.4 12.4 12.7 10.4 1.4 1Security 9.0 0.3 0.5 5.0 6.7 4.9 3.4 0.5 Other 0.4 2.9 4.4 6.4 8.9 13.3 10.4 24.1 Observations 35 38 62 26 40 21 36 3 2

Primarily Surface Water Systems 

Land 0.0 0.0 0.1 1.2 2.4 0.7 2.1 1.1 Water Source 12.5 16.6 14.1 7.7 3.4 3.0 7.2 6.4 Transmission and Distribution System 26.9 35.9 41.4 36.9 48.9 49.7 42.3 43.6 4Treatment 53.0 33.9 25.6 34.0 26.1 25.2 29.6 29.2 2

Storage 4.8 8.8 14.8 17.7 9.4 11.4 5.5 3.6 1Security 0.0 0.0 2.4 0.9 2.5 0.8 0.9 0.4 Other 2.8 4.8 1.7 1.7 7.2 9.2 12.4 15.7 4Observations 28 36 49 36 49 39 94 34 3

Primarily Purchased Water Systems 

Land 0.0 0.0 0.4 0.1 14.1 0.2 1.1 1.2 Water Source 0.0 4.4 5.5 1.2 0.5 1.4 10.2 1.0 Transmission and Distribution System 0.0 80.1 83.2 80.2 56.8 71.5 56.6 68.8 7Treatment 0.0 1.5 0.6 0.2 8.0 3.5 11.9 12.7 Storage 100.0 13.3 9.5 13.6 15.2 14.5 7.8 11.5 1Security 0.0 0.0 0.0 2.3 1.4 0.6 0.9 0.7 Other 0.0 0.7 0.8 2.5 4.0 8.3 11.4 4.1 Observations 1 9 21 13 19 23 36 10 1

All Systems 

Land 0.0 0.0 1.4 0.3 5.0 1.1 1.8 1.1 Water Source 42.2 30.7 23.8 9.5 9.2 6.6 8.4 5.3 2Transmission and Distribution System 14.9 41.1 46.6 56.4 48.2 49.2 45.0 49.4 4Treatment 18.4 13.1 10.0 14.3 13.7 18.1 24.6 25.0 1Storage 15.4 12.2 14.2 11.7 12.3 12.7 7.0 5.4 1Security 8.7 0.2 0.6 3.4 4.3 2.0 1.4 0.5 Other 0.4 2.7 3.3 4.4 7.3 10.2 11.8 13.3 Observations 64 83 132 75 108 83 166 47 7

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years. 

Table reports the percentage of funds invested in each category for the average system. It is not the percentage of funds invested in each category nationally or the percentage of systems that funded each investment category. Table 90 reports the percentage of systems that funded each investment category.Table 96 reports the percentage of funds invested in each category nationally.

Table 94 

Allocation of Major Capital Investments of Average Systems in the Past 5 Years 

By Type of Investment and Primary Water Source 

(Percentage of Funds Allocated to Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Land 0.0 0.0 0.7 0.4 5.1 1.2 1.9 Water Source 58.2 32.3 23.5 8.3 9.6 6.7 8.9 Transmission and Distribution System 4.0 38.4 45.8 54.7 48.0 48.7 43.4 4Treatment 22.6 14.5 9.9 14.7 13.7 18.7 25.2 2Storage 15.0 14.3 15.6 12.9 11.6 11.9 7.2 Security 0.0 0.0 0.8 4.0 4.7 2.1 1.3 Other 0.2 0.5 3.7 5.0 7.4 10.7 12.2 1Observations 13 43 103 64 99 77 156 

Private Systems 

Land 0.0 0.0 3.4 0.0 3.3 0.1 0.5 Water Source 39.0 29.1 24.5 14.9 4.3 6.6 2.6 1Transmission and Distribution System 17.0 43.8 48.9 64.3 51.0 57.5 62.7 3Treatment 17.6 11.7 10.3 12.7 13.3 8.3 18.4 2

Storage 15.5 10.1 10.3 6.2 21.5 24.9 5.1 Security 10.4 0.4 0.1 0.6 0.1 0.0 3.1 Other 0.5 4.9 2.5 1.4 6.4 2.6 7.5 2Observations 51 40 29 11 9 6 10 

All Systems 

Land 0.0 0.0 1.4 0.3 5.0 1.1 1.8 Water Source 42.2 30.7 23.8 9.5 9.2 6.6 8.4 Transmission and Distribution System 14.9 41.1 46.6 56.4 48.2 49.2 45.0 4Treatment 18.4 13.1 10.0 14.3 13.7 18.1 24.6 2Storage 15.4 12.2 14.2 11.7 12.3 12.7 7.0 Security 8.7 0.2 0.6 3.4 4.3 2.0 1.4 Other 0.4 2.7 3.3 4.4 7.3 10.2 11.8 1Observations 64 83 132 75 108 83 166 

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years

Table 95 

Allocation of Major Capital Investments of Average Systems in the Past 5 Years 

By Type of Investment and Ownership 

(Percentage of Funds Allocated to Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Primary Water Source or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 All Siz

Primarily Ground Water Systems 

Land 0.0 0.0 0.9 0.3 0.6 3.4 1.5 0.5 Water Source 26.2 30.8 26.4 9.6 9.6 19.7 6.3 15.8 1Transmission and Distribution System 29.9 46.2 38.2 44.4 55.2 27.5 32.9 36.9 4Treatment 20.0 14.3 9.4 32.6 11.9 24.7 40.1 10.9 2Storage 22.8 8.0 24.4 6.5 17.8 9.6 5.6 3.6 1Security 0.9 0.2 0.1 1.1 0.3 0.5 0.2 0.7 Other 0.1 0.5 0.5 5.5 4.7 14.6 13.6 31.5 Observations 35 38 62 26 40 21 36 3 2

Primarily Surface Water Systems 

Land 0.0 0.0 0.1 0.2 1.0 1.2 2.2 1.2 Water Source 6.7 9.8 4.3 2.8 5.0 5.2 6.4 9.4 Transmission and Distribution System 39.8 23.8 47.9 31.4 32.7 47.6 43.3 41.8 4Treatment 52.2 57.7 30.3 50.6 45.1 26.2 27.7 29.1 3

Storage 1.3 8.4 16.3 13.8 10.8 10.7 5.2 3.4 Security 0.0 0.0 0.1 0.4 0.2 0.5 1.0 0.4 Other 0.0 0.3 1.0 0.8 5.3 8.7 14.2 14.7 1Observations 28 36 49 36 49 39 94 34 3

Primarily Purchased Water Systems 

Land 0.0 0.0 2.1 0.2 0.3 0.7 1.3 1.6 Water Source 0.0 0.8 5.4 0.7 4.6 0.9 10.4 1.7 4Transmission and Distribution System 0.0 90.1 77.6 80.8 70.7 62.6 49.3 58.3 6Treatment 0.0 0.1 2.1 0.2 9.9 4.3 18.3 7.7 Storage 100.0 8.2 9.7 14.4 8.2 19.6 10.0 22.4 1Security 0.0 0.0 0.0 2.5 0.6 1.0 0.5 0.6 Other 0.0 0.7 3.1 1.3 5.7 10.9 10.2 7.7 Observations 1 9 21 13 19 23 36 10 1

All Systems 

Land 0.0 0.0 1.1 0.2 0.6 1.8 1.9 1.3 Water Source 22.5 14.9 19.0 4.7 6.7 9.0 7.2 8.5 Transmission and Distribution System 31.8 65.6 48.1 46.6 53.5 43.6 42.8 43.9 4Treatment 26.1 10.6 10.5 33.5 21.0 22.6 27.8 26.0 24Storage 18.7 8.2 20.2 11.5 12.7 11.6 6.2 5.9 Security 0.8 0.1 0.1 1.1 0.3 0.6 0.8 0.4 Other 0.1 0.6 1.2 2.5 5.2 10.8 13.3 14.1 1Observations 64 83 132 75 108 83 166 47 7

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years. 

Table reports the percentage of funds invested in each category nationally. It is not the percentage of funds invested in each category for the average system or the percentage of systems that funded each investment category. Table 90 reports the percentage of systems that funded each investment category.Table 94 reports the percentage of funds invested in each category for the average system.

Table 96 

Allocation of Major Capital Investments Nationally in the Past 5 Years 

By Type of Investment and Primary Water Source 

(Percentage of Funds Allocated to Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Land 0.0 0.0 1.1 0.3 0.6 1.9 2.1 Water Source 36.3 13.2 18.2 3.4 6.8 8.1 7.9 Transmission and Distribution System 23.2 68.1 47.6 45.2 53.4 42.5 39.4 4Treatment 35.1 10.4 10.2 34.0 21.5 23.8 29.2 2Storage 4.6 7.7 21.7 13.0 12.2 12.0 6.5 Security 0.5 0.0 0.0 1.1 0.3 0.6 0.3 Other 0.2 0.6 1.1 3.0 5.2 11.2 14.6 1Observations 13 43 103 64 99 77 156 

Private Systems 

Land 0.0 0.1 0.7 0.0 0.6 0.5 0.6 Water Source 8.2 26.7 24.4 9.4 4.1 23.9 2.3 1Transmission and Distribution System 40.6 48.5 50.9 51.6 55.1 60.9 65.6 3Treatment 16.9 12.4 12.2 31.5 10.3 3.9 18.7 2

Storage 33.2 11.4 10.3 5.8 24.2 5.4 4.4 Security 1.1 0.6 0.2 1.1 0.0 0.0 4.0 Other 0.0 0.2 1.3 0.6 5.6 5.4 4.4 2Observations 51 40 29 11 9 6 10 

All Systems 

Land 0.0 0.0 1.1 0.2 0.6 1.8 1.9 Water Source 22.5 14.9 19.0 4.7 6.7 9.0 7.2 Transmission and Distribution System 31.8 65.6 48.1 46.6 53.5 43.6 42.8 4Treatment 26.1 10.6 10.5 33.5 21.0 22.6 27.8 2Storage 18.7 8.2 20.2 11.5 12.7 11.6 6.2 Security 0.8 0.1 0.1 1.1 0.3 0.6 0.8 Other 0.1 0.6 1.2 2.5 5.2 10.8 13.3 1Observations 64 83 132 75 108 83 166 

Data: Q.27A Notes: Excludes systems that have not made major capital improvements in the past five years

Table reports the percentage of funds invested in each category nationally. It is not the percentage of funds invested in each category for the average system or the of systems that funded each investment category. Table 91 reports the percentage of systems that funded each investment category.

Table 95 reports the percentage of funds invested in each category for the average sys

Table 97 

Allocation of Major Capital Investments Nationally in the Past 5 Years 

By Type of Investment and Ownership 

(Percentage of Funds Allocated to Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Compliance with Regulations 62.4 8.9 22.8 36.9 51.5 49.7 49.3 6Replacement or Major Repair 57.3 77.0 64.9 78.6 83.7 82.0 87.3 9System Expansion 1.6 36.8 44.5 76.3 77.4 78.1 83.8 8Observations 12 44 102 66 91 64 97 

Private Systems 

Compliance with Regulations 27.5 44.4 14.8 50.9 23.9 0.0 50.0 Replacement or Major Repair 76.9 56.3 74.3 51.3 21.9 70.4 100.0 System Expansion 11.1 24.6 43.1 64.9 100.0 100.0 50.0 Observations 51 39 30 11 8 4 2 

All Systems 

Compliance with Regulations 32.9 26.0 20.7 39.3 49.9 47.1 49.3 6Replacement or Major Repair 74.0 67.1 67.4 74.1 80.1 81.4 87.6 9System Expansion 9.7 30.9 44.1 74.4 78.7 79.3 83.2 8Observations 63 83 132 77 99 68 99 

Data: Q.27B Notes: Excludes systems that have not made major capital improvements in the past five years

Table reports the percentage of systems that funded each investment category. It is not the percentage of funds invested in each category. Table 100 reports the percentage of funds invested in each category for the average syTable 101 reports the percentage of funds invested in each category nationally. 

Table 98 

Percentage of Systems Making Major Capital Investments in the Past 5 Years 

By Investment Purpose and Ownership 

(Percentage of Systems Funding Each Investment Category) 
Ownership Type 

Public Systems 

Compliance with Regulations Replacement or Major Repair System Expansion Observations 

Private Systems 

Compliance with Regulations Replacement or Major Repair System Expansion Observations 

All Systems 

Compliance with Regulations Replacement or Major Repair System Expansion Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

or Less 500 3,300 10,000 50,000 100,000 500,000 500,0

46 10 91 175 451 2,481 4,439 20,8

96 178 190 371 1,661 4,910 15,812 136,7

76 327 436 750 3,060 5,055 25,376 134,912 43 100 61 89 63 95 

4 37 21 743 38 0 9,536 

16 23 134 168 218 6,229 10,527 

26 23 120 862 3,052 8,118 4,059 49 37 28 10 8 4 2 

11 23 72 275 426 2,348 4,535 20,8

29 105 176 335 1,574 4,981 15,713 136,7

34 185 352 770 3,059 5,220 24,976 134,961 80 128 71 97 67 97 

Data: Q.27 Notes: Excludes systems that have not made major capital improvements in the past five years

Table 99 

Amount of Major Capital Investment Allocated in the Past 5 Years 

By Investment Purpose and Ownership 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,0Public Systems 

Compliance with Regulations 1.4 28.5 38.1 50.5 48.1 41.9 44.4 4Replacement or Major Repair 56.3 70.3 51.3 41.6 42.5 44.3 43.6 4System Expansion 42.3 1.2 10.7 8.0 9.4 13.8 12.0 1Observations 12 43 100 61 89 63 95 

Private Systems 

Compliance with Regulations 7.8 17.8 34.8 41.0 89.5 50.9 25.5 Replacement or Major Repair 72.2 52.1 57.7 25.9 9.2 49.1 45.0 System Expansion 19.9 30.2 7.5 33.1 1.3 0.0 29.5 Observations 49 37 28 10 8 4 2 

All Systems 

Compliance with Regulations 6.8 23.5 37.2 48.8 50.6 42.4 44.1 4Replacement or Major Repair 69.6 61.8 53.0 38.8 40.5 44.6 43.6 4System Expansion 23.6 14.8 9.8 12.4 8.9 13.1 12.4 1Observations 61 80 128 71 97 67 97 

Data: Q.27B Notes: Excludes systems that have not made major capital improvements in the past five years

Table reports the percentage of funds invested in each category for the average systemIt is not the percentage of funds invested in each category nationally or the percentage that funded each investment category. Table 98 reports the percentage of systems that funded each investment category.

Table 101 reports the percentage of funds invested in each category nationally.

Table 100 

Allocation of Major Capital Investments of Average Systems in the Past 5 Years 

By Investment Purpose and Ownership 

(Percentage of Funds Allocated to Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Public Systems 

Compliance with Regulations 21.2 1.9 12.6 13.5 8.7 19.9 9.7 7.1 Replacement or Major Repair 44.1 34.6 26.5 28.6 32.1 39.5 34.7 46.7 System Expansion 34.7 63.5 60.8 57.9 59.2 40.6 55.6 46.1 Observations 12 43 100 61 89 63 95 29 

Private Systems 

Compliance with Regulations 8.4 44.8 7.7 41.9 1.2 0.0 39.5 * Replacement or Major Repair 34.9 27.2 48.7 9.5 6.6 43.4 43.6 * System Expansion 56.7 28.0 43.6 48.6 92.3 56.6 16.8 * Observations 49 37 28 10 8 4 2 * 

All Systems 

Compliance with Regulations 14.5 7.2 12.0 19.9 8.4 18.7 10.0 7.1 Replacement or Major Repair 39.3 33.7 29.2 24.3 31.1 39.7 34.7 46.7 System Expansion 46.2 59.1 58.7 55.8 60.5 41.6 55.2 46.1 

Observations 61 80 128 71 97 67 97 29 

Data: Q.27B Notes: Excludes systems that have not made major capital improvements in the past five years. 

Table reports the percentage of funds invested in each category nationally. It is not the percentage of funds invested in each category for the average system or the percentage of systems that funded each investment category. Table 98 reports the percentage of systems that funded each investment category.

Table 100 reports the percentage of funds invested in each category for the average system

Table 101 

Allocation of Major Capital Investments Nationally in the Past 5 Years 

By Investment Purpose and Ownership 

(Percentage of Funds Allocated to Each Investment Category) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Ov

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,00

Public Systems 

Current Revenues 58.5 64.9 48.3 74.5 77.1 75.1 63.6 55Equity or other funds from private investors 0.5 0.3 3.4 8.8 2.5 3.8 3.1 0Borrowing from private sector sources 0.3 15.0 12.0 23.9 22.2 28.6 41.4 35Department of Homeland Security grants 0.0 0.0 1.5 2.8 5.4 5.9 5.1 8Other government grants 39.9 34.8 29.9 28.5 15.2 23.7 15.0 21DWSRF principal repayment forgiveness 0.0 0.3 3.9 0.0 0.0 0.0 0.0 0DWSRF Loans 0.6 20.0 24.6 19.2 9.5 15.5 12.9 19Other borrowing from public sector sources 19.1 9.1 7.2 7.5 8.6 18.0 11.6 8Other 0.0 5.5 4.1 10.7 5.2 14.9 8.6 4Observations 13 43 103 64 99 77 156 4

Private Systems 

Current Revenues 59.7 83.8 73.1 72.8 53.3 51.3 13.1 0Equity or other funds from private investors 11.5 13.4 23.7 3.2 0.0 21.6 13.1 50Borrowing from private sector sources 3.6 1.4 21.7 29.1 10.0 21.6 13.1 50Department of Homeland Security grants 0.0 0.0 0.0 0.0 0.0 0.0 6.5 0Other government grants 4.1 9.3 3.9 0.0 24.1 0.0 0.0 0DWSRF principal repayment forgiveness 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0DWSRF Loans 0.0 0.0 0.8 39.5 10.0 8.1 60.8 0Other borrowing from public sector sources 0.1 4.4 7.9 12.5 22.6 8.1 0.0 0Other 16.7 6.4 8.6 0.0 0.0 21.6 54.3 0Observations 51 40 29 11 9 6 10 

All Systems 

Current Revenues 59.5 74.4 55.0 74.2 75.4 73.7 59.3 53Equity or other funds from private investors 9.7 6.9 9.0 7.8 2.4 4.9 3.9 2Borrowing from private sector sources 3.1 8.1 14.6 24.9 21.4 28.1 39.1 36Department of Homeland Security grants 0.0 0.0 1.1 2.3 5.1 5.6 5.2 8Other government grants 9.9 22.0 22.8 23.5 15.8 22.2 13.8 20DWSRF principal repayment forgiveness 0.0 0.1 2.8 0.0 0.0 0.0 0.0 0DWSRF Loans 0.1 10.0 18.1 22.8 9.6 15.1 16.9 18Other borrowing from public sector sources 3.2 6.8 7.4 8.4 9.6 17.5 10.6 8Other 14.0 6.0 5.3 8.8 4.8 15.3 12.4 4Observations 64 83 132 75 108 83 166 4

Data: Q.27C Notes: Excludes systems that have not made major capital improvements in the past five years. Systems can fund by more than one source

therefore column totals may be greater than or less than 100. A small number of privately owned systems serving populations of 3,301-10,000 and 100,001-500,000 relied heavily on the DWSRF. have a large impact on the results; therefore, they are not included in the analysis in volume I. 

Table 102 

Percentage of Systems Acquiring Capital Funds from Each Source in the Past 5 Years 

By Source of Funds and Ownership 

(Percentage of Systems Using Each Source of Funds) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- O

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,Public Systems 

Current Revenues 93 44 45 372 3,009 5,001 20,300 62,Equity or other funds from private investors 76 0 121 13 12 190 110 Borrowing from private sector sources 20 109 48 225 764 2,479 15,962 172,Department of Homeland Security grants 0 0 1 1 17 72 22 Other government grants 19 201 124 380 339 1,775 844 4,DWSRF principal repayment forgiveness 0 2 21 0 0 0 0 DWSRF Loans 0 114 214 296 533 884 2,033 25,Other borrowing from public sector sources 37 40 136 94 300 1,101 3,168 35,Other 0 5 23 69 25 1,035 3,024 Observations 13 43 97 61 86 63 108 

Private Systems 

Current Revenues 4 17 74 336 1,567 2,603 3,022 Equity or other funds from private investors 29 5 71 14 0 845 2,823 55,Borrowing from private sector sources 1 3 33 540 261 1,763 2,233 40,Department of Homeland Security grants 0 0 0 0 0 0 1 Other government grants 11 36 42 0 161 0 0 DWSRF principal repayment forgiveness 0 0 0 0 0 0 0 DWSRF Loans 0 0 0 797 169 1,524 37,700 Other borrowing from public sector sources 0 6 64 87 1,150 3,919 0 Other 5 6 5 0 0 2,330 41,358 Observations 48 39 29 10 8 5 6 

All Systems 

Current Revenues 19 30 53 366 2,922 4,860 18,792 60,Equity or other funds from private investors 37 3 107 13 12 229 347 1,Borrowing from private sector sources 4 56 43 283 734 2,436 14,764 168,Department of Homeland Security grants 0 0 0 1 16 68 20 Other government grants 12 118 101 310 328 1,670 770 4,DWSRF principal repayment forgiveness 0 1 15 0 0 0 0 DWSRF Loans 0 57 154 388 511 922 5,145 24,Other borrowing from public sector sources 6 23 116 93 351 1,268 2,892 34,Other 4 5 18 56 23 1,112 6,369 Observations 61 82 126 71 94 68 114 

Data: Q.27C Notes: Excludes systems that have not made major capital improvements in the past five years. 

A small number of privately owned systems serving populations of 3,301-10,000 and 100,001-500,000 relied heavily on the DWSRhave a large impact on the results; therefore, they are not included in the analysis in volume I. 

Table 103 

Amount of Capital Funds Acquired from Each Source in the Past 5 Years 

By Source of Funds and Ownership 

(Thousands of Dollars) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Public Systems 

Current Revenues 42.5 50.7 36.9 54.5 67.4 49.3 54.1 43.6 Equity or other funds from private investors 0.5 0.2 3.0 1.0 0.3 1.9 0.6 0.0 Borrowing from private sector sources 0.3 11.8 11.3 13.2 16.2 20.3 27.8 38.7 Department of Homeland Security grants 0.0 0.0 0.5 0.0 0.2 0.5 1.0 0.1 Other government grants 39.9 22.4 18.6 13.5 4.3 11.4 1.7 6.4 DWSRF principal repayment forgiveness 0.0 0.1 0.7 0.0 0.0 0.0 0.0 0.0 DWSRF Loans 0.6 11.5 19.6 7.8 7.3 6.8 5.3 6.1 Other borrowing from public sector sources 16.3 1.8 7.2 3.6 3.8 6.1 5.3 4.8 Other 0.0 1.4 2.2 6.2 0.4 3.6 4.1 0.2 Observations 13 43 97 61 86 63 108 29 

Private Systems 

Current Revenues 64.8 71.6 50.4 37.3 52.1 46.0 5.4 0.0 Equity or other funds from private investors 10.5 13.3 17.6 1.0 0.0 26.6 8.7 57.7 Borrowing from private sector sources 2.0 1.3 17.5 23.1 8.4 7.5 6.9 42.3 Department of Homeland Security grants 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Other government grants 4.5 7.3 1.6 0.0 3.6 0.0 0.0 0.0 DWSRF principal repayment forgiveness 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 DWSRF Loans 0.0 0.0 0.2 32.1 10.2 2.8 38.5 0.0 Other borrowing from public sector sources 0.1 0.7 5.3 6.5 25.7 7.2 0.0 0.0 Other 18.1 5.9 7.4 0.0 0.0 9.9 40.4 0.0 Observations 48 39 29 10 8 5 6 1 

All Systems 

Current Revenues 60.9 61.2 40.7 51.4 66.4 49.1 49.9 42.2 Equity or other funds from private investors 8.8 6.8 7.1 1.0 0.3 3.3 1.3 1.8 Borrowing from private sector sources 1.7 6.5 13.0 15.0 15.8 19.6 26.0 38.9 Department of Homeland Security grants 0.0 0.0 0.4 0.0 0.2 0.5 1.0 0.1 Other government grants 10.6 14.8 13.8 11.0 4.3 10.7 1.6 6.2 DWSRF principal repayment forgiveness 0.0 0.1 0.5 0.0 0.0 0.0 0.0 0.0 DWSRF Loans 0.1 5.7 14.1 12.3 7.5 6.5 8.2 6.0 Other borrowing from public sector sources 2.9 1.3 6.6 4.1 5.2 6.2 4.8 4.6 Other 15.0 3.7 3.7 5.0 0.4 4.0 7.2 0.2 Observations 61 82 126 71 94 68 114 30 

Data: Q.27C Notes: Excludes systems that have not made major capital improvements in the past five years. Table reports the percentage of funds acquir

from each source on average by each system. It is not the percentage of funds acquired from each category for the nation and the aggregate. That number is reported in Table 105. A small number of privately owned systems serving populations of 3,301-10,000 and 100,001-500,000 relied heavily on the DWSRF. have a large impact on the results; therefore, they are not included in the analysis in volume I. 

Table 104 

Allocation of Sources of Funds for Major Capital Investments of the Average System in the Past 5 Years 

By Source of Funds and Ownership 

(Percentage of Funds from Each Source) 
System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- Over 

Ownership Type or Less 500 3,300 10,000 50,000 100,000 500,000 500,000 

Public Systems 

Current Revenues 38.0 8.6 6.1 25.6 60.2 39.9 44.7 20.8 Equity or other funds from private investors 30.9 0.1 16.6 0.9 0.2 1.5 0.2 0.0 Borrowing from private sector sources 8.2 21.2 6.5 15.5 15.3 19.8 35.1 57.2 Department of Homeland Security grants 0.0 0.0 0.1 0.1 0.3 0.6 0.0 0.1 Other government grants 7.9 38.9 17.0 26.2 6.8 14.2 1.9 1.5 DWSRF principal repayment forgiveness 0.0 0.4 2.9 0.0 0.0 0.0 0.0 0.0 DWSRF Loans 0.0 22.1 29.3 20.4 10.7 7.1 4.5 8.3 Other borrowing from public sector sources 15.0 7.7 18.5 6.5 6.0 8.8 7.0 11.9 Other 0.0 1.0 3.1 4.8 0.5 8.3 6.7 0.1 Observations 13 43 97 61 86 63 108 29 

Private Systems 

Current Revenues 7.3 22.9 25.4 19.0 47.4 20.0 3.5 0.0 Equity or other funds from private investors 58.6 7.4 24.4 0.8 0.0 6.5 3.2 57.7 Borrowing from private sector sources 1.2 4.5 11.3 30.4 7.9 13.6 2.6 42.3 Department of Homeland Security grants 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Other government grants 22.6 49.1 14.7 0.0 4.9 0.0 0.0 0.0 DWSRF principal repayment forgiveness 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 DWSRF Loans 0.0 0.0 0.1 44.9 5.1 11.7 43.3 0.0 Other borrowing from public sector sources 0.0 7.8 22.2 4.9 34.8 30.2 0.0 0.0 Other 10.3 8.3 1.8 0.0 0.0 17.9 47.5 0.0 Observations 48 39 29 10 8 5 6 1 

All Systems 

Current Revenues 23.0 10.4 8.7 24.2 59.7 38.7 38.3 20.6 Equity or other funds from private investors 44.4 1.0 17.6 0.9 0.2 1.8 0.7 0.6 Borrowing from private sector sources 4.8 19.1 7.1 18.7 15.0 19.4 30.1 57.1 Department of Homeland Security grants 0.0 0.0 0.1 0.1 0.3 0.5 0.0 0.1 Other government grants 15.1 40.2 16.6 20.6 6.7 13.3 1.6 1.5 DWSRF principal repayment forgiveness 0.0 0.4 2.5 0.0 0.0 0.0 0.0 0.0 DWSRF Loans 0.0 19.3 25.4 25.7 10.4 7.3 10.5 8.2 Other borrowing from public sector sources 7.7 7.7 19.0 6.2 7.2 10.1 5.9 11.8 Other 5.0 1.9 2.9 3.7 0.5 8.8 13.0 0.1 Observations 61 82 126 71 94 68 114 30 

Data: Q.27 Notes: Excludes systems that have not made major capital improvements in the past five years. Table reports the percentage of funds acquir

from each source for the nation and the aggregate. It is not the percentage of funds acquired from each category on average by each system. That number is reported in Table 104. A small number of privately owned systems serving populations of 3,301-10,000 and 100,001-500,000 relied heavily on the DWSRF. have a large impact on the results; therefore, they are not included in the analysis in volume I. 

Table 105 

Allocation of Sources of Funds for Major Capital Investments Nationally in the Past 5 Years 

By Source of Funds and Ownership 

(Percentage of Funds from Each Source) 
Ownership Type 

Public Systems 

DWSRF Other Public Sector Private Sector Other Observations 

Private Systems 

DWSRF Other Public Sector Private Sector Other Observations 

All Systems 

DWSRF Other Public Sector Private Sector Other Observations 

System Service Population Category 

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 50

1.0 2.4 1.8 3.3 3.5 2.9 3.2 0.5 4.4 3.8 3.1 3.9 4.3 3.3 5.0 4.2 4.7 4.9 4.5 4.4 4.3 

* * 0.0 4.5 4.8 4.9 1.4 

4 12 37 25 39 31 61 

* * 1.5 6.0 6.4 0.8 6.2 

3.1 4.5 5.5 4.6 5.3 4.8 4.6 

* 7.7 6.7 6.0 4.3 7.5 5.8 

6.0 10.0 * * * 0.0 0.0 

3 6 8 8 3 2 6 

1.0 2.4 1.8 4.3 3.5 2.8 4.2 1.9 4.4 4.5 3.6 3.9 4.4 3.3 5.0 4.8 5.5 5.3 4.5 4.6 4.3 6.0 10.0 0.0 4.5 4.8 2.3 1.4 

7 18 45 33 42 33 67 

Data: Q.27 Notes: 

Table 106 

Average Interest Rates for Capital Funds 

By Ownership and Lender 
Ownership Type 

Public Systems 

Percentage of Systems 

Confidence Interval 

Observations 

Private Systems 

Percentage of Systems 

Confidence Interval 

Observations 

All Systems 

Percentage of Systems 

Confidence Interval 

Observations 

System Service Population Category

100 101 - 501 - 3,301 - 10,001 - 50,001 - 100,001- 

or Less 500 3,300 10,000 50,000 100,000 500,000 5

24.6 38.5 31.1 24.0 33.2 39.1 32.0 

+|- 23.6 +|- 13.5 +|- 9.2 +|- 8.4 +|- 8.6 +|- 10.3 +|- 4.9 

27 84 181 127 156 111 204 

9.8 17.2 13.6 26.5 14.8 17.9 10.5 

+|- 6.9 +|- 8.6 +|- 12.6 +|- 17.9 +|- 20.3 +|- 20.0 +|- 9.1 +

118 111 56 27 20 13 21 

11.7 25.4 26.3 24.6 31.7 37.1 29.4 

+|- 6.6 +|- 7.7 +|- 8.0 +|- 7.6 +|- 8.1 +|- 9.6 +|- 4.7 

145 195 237 154 176 124 225 

Data: Q.28 Notes: 

Table 107 

Percentage of Systems with Asset Management Plans or other Formal Written Strategy for Infrastructure Rehabilitation and R

By Ownership
Part 2: 

Methodology Report 

221 

1. Introduction 

1.1 Study Background 

In compliance with Executive Order 12866, the Regulatory Flexibility Act, and the Safe Drinking Water 

Act (SDWA), the U.S. Environmental Protection Agency’s Office of Ground Water and Drinking Water 

(OGWDW), Standards and Risk Management Division (SRMD) conducts periodic surveys of the 

financial and operating characteristics of community water systems. These Community Water System 

(CWS) Surveys supply information that is essential to support economic analyses of the costs and benefits 

of new regulations and changes to existing regulations on consumers, the water supply industry, and the 

nation. The information also will be used to measure the financial burden of EPA’s regulations on 

consumers and the industry. Furthermore, data from the survey will help EPA evaluate program and 

policy initiatives and develop guidance on Best Management Practices used in water treatment and 

distribution systems. Previous CWS Surveys captured information for the years 1976, 1982, 1986, 1995, 

and 2000. This survey gathered information for the year 2006. 

1.2 Survey Overview 

This section is intended to provide the reader with an overview of the design and conduct of the CWS 

Survey. The topics presented in this section will then be discussed at greater length in the following 

chapters. 

According to the latest inventory data, nearly 156,000 public water systems provide water to over 300 

million persons throughout the United States. (Factoids: Drinking Water and Ground Water Statistics for 

2007, EPA 816-K-07-004.) Public water systems are both community and non-community water systems. 

Community water systems are public water systems that supply water to the same population year-round. 

They serve approximately 280 million persons. The CWS Survey was designed to collect operating and 

financial information from a representative sample of community water systems. 

In order to reduce the burden of the survey on small systems, the data were collected from systems 

serving 3,300 or fewer people through site visits by water system professionals. Systems serving over 

3,300 people received a letter informing them of their selection in the survey and instructions on how to 

obtain the questionnaire form either electronically or through the mail. Water system professionals were 

assigned to the systems that received the mailed questionnaire to help them respond to the survey’s 

questions. A toll-free telephone number and an e-mail address also were sent to the systems to provide 

technical support. 

The CWS Survey was based on a nationally representative sample of CWSs. The sample was drawn from 

a list of approximately 50,000 systems in the 50 states and the District of Columbia in the federal version 

of the Safe Drinking Water Information System (SDWIS/FED). The survey used a stratified random 

sample design to ensure the sample is representative. The sample was stratified by several characteristics 

of water systems to increase the efficiency of estimates based on the sample. To limit the travel costs 

involved in visiting each small system in the sample, they were selected in geographic clusters in a twostage design. A sample of 2,210 systems was selected, including a census of all systems serving 

populations of 100,000 or more. 

A separate version of the questionnaire was developed for three categories of systems: systems serving 25 

to 100,000 people, those serving more than 100,000 and up to 500,000 people, and those serving more 

than 500,000 people. Some targeted questions were asked of systems in each size categories. E.g., 

additional questions were asked of very large systems serving more than 500,000 people regarding 

223
concentrations of several contaminants in raw and finished water. Similarly, questions that would not 

apply to very large systems were excluded from their version of the questionnaire. 

Water system professionals contacted the small systems in the sample to schedule appointments for the 

site visits. Upon mail out, each medium and large system was notified by telephone that they would 

receive a letter with information about the survey in the mail. The letter described the survey goals and a 

number of methods to complete the survey. All medium and large systems were given the option to 

complete a paper version or an electronic version of the questionnaire. With the toll-free number, a 

system could request a paper version or an Excel spreadsheet version of the questionnaire to be mailed 

directly to them with return instructions and a postage paid envelope. An alternative to obtain the survey 

was through the CWS Survey Web site where a system could download the spreadsheet or hardcopy 

version of the questionnaire. Or, if desired, the water system could complete the survey through a Webbased version of the questionnaire. The electronic formats of the survey were new to the survey in 2006. 

The spreadsheet questionnaire matched the layout of the hardcopy questionnaire identically, but most 

water systems preferred this method because of the ease of completing a survey in Excel and its near 

universal availability at a water system. Respondents could send the questionnaire to numerous 

departments for verification via email quickly and easily. The Web-based version maintained a similar 

layout, but structured as an online form. Phone calls were made throughout the data collection period to 

encourage non-respondents to participate and to provide technical support when needed. Requests to 

send completion instructions or the questionnaire were received through the toll-free support line and 

during the phone calls to the system; the information was sent as the requests were received. 

As completed questionnaires were returned, they were logged into a receipt control system using an online data tracking system. The completed questionnaires went through an extensive data quality review. 

The electronic versions of the questionnaire included automated validation checks. Water system analysts 

reviewed each questionnaire and contacted the systems to clarify answers, correct anomalous items, or 

collect missing responses. The questionnaires were then reviewed by senior staff. The senior staff also 

reviewed the site visits reports for each small system. Paper versions of the questionnaires were then keyentered using independent double-key entry. Finally, the electronic form of the data was run through 

automated cleaning and editing programs. 

A series of sample weights, non-response adjustments, and other statistical techniques were created and 

applied to the final set of sampled respondents. These weights allow for extrapolation from the sampled 

systems to the universe of CWSs in the nation. The sample design and weights also allow for the 

calculation of confidence intervals for each estimate. 

Planning and design of the survey began in February of 2006. A pre-test of the questionnaire was 

conducted in May of 2006. The pilot test was conducted in February 2007, and the final design was 

developed in March 2007. Data collection took place from March through December, 2007. Data 

processing and analysis continued through April 2008. 

EPA determined the information to be gathered and the scope of the survey. While providing overall 

management of this effort, EPA secured the services of several contractors who performed a variety of 

tasks in support of the survey design, survey administration, data processing, and analysis. The Cadmus 

Group, Inc., was the prime contractor. The site visits were conducted through subcontracts with several 

experienced water system professionals. Cadmus’ primary responsibilities were for overall project 

management; design of the questionnaire; sample design; selection of the sample; design, administration, 

and management of the data collection; development and maintenance of the on-line data tracking system, 

technical support to water systems in the sample; editing and preparation of the data for data entry; 

calculation of sample weights; expert quality assurance review of the survey data; data tabulations; and 

report preparation. 

224
EPA also requested comments on the survey from several independent reviewers. Barry Nussbaum of 

EPA's Office of Environmental Information, A. Richard Bolstein of George Mason University, and John 

Gaughan of Temple University reviewed the sampling plan. Bimal Sinha from the University of 

Maryland also provided comments. Barry L. Liner, PE and David Binning, PE Scott J. Rubin, JD, and 

Janice Beecher, Ph.D. reviewed the final report. 

225

2. Sample Design and Weighting 

2.1 Sample Design and Selection 

This section describes the sample design for the 2006 CWS Survey. It includes a description of the 

sampling frame, target sample size, stratification variables, and sampling methods. 

The survey relied on a probability sample of CWSs. For small systems (those serving populations of 

3,300 or less), a two-stage cluster sample was used. A stratified random sample was used for systems 

serving populations of between 3,301 and 100,000. Systems serving populations of over 100,000 were 

selected with certainty. The strata were defined by the combinations of the size of the residential 

population served by the water systems and the source of water (ground or surface). 

2.1.1 SDWIS Sampling Frame and Coverage 

The sampling frame was developed from the federal Safe Drinking Water Information System 

(SDWIS/FED. The system has been revised and is now known as SDWIS/ODS). SDWIS is a centralized 

database of information on public water systems, including their compliance with monitoring 

requirements, maximum contaminant levels (MCLs), and other requirements of the Safe Drinking Water 

Act (SDWA) Amendments of 1996. The following information was extracted from SDWIS for the 

statistical survey: 

C Name of system

C Address of system

C Populatio n served 

C Primary source (surface water or ground water) 

C Public water system identification number (PWSID) 

C Ownership type 

C Consecutive systems (i.e., does system purchase or sell water) 

From these data, EPA developed a sample list from which it (1) calculated summary statistics for use in 

calculating sample size, and (2) randomly chose systems within the design strata which will take part in 

the survey. 

SDWIS/FED was the appropriate sampling frame because: 

C It fully covered the target population. 

C It contains no duplication. 

C It contains no foreign elements (i.e., elements that are not members of the population). 

C It contains information for identifying and contacting the units selected in the sample. 

C It contains other information that will improve the efficiency of the sample design. 

SDWIS/FED was the best choice for a sample frame because of its inclusive coverage of all units of 

observation for this survey. In addition, SDWIS/FED has two other advantages: it contains information 

that will facilitate contacting the respondents, and it contains other information that is useful in stratifying 

the sample, thereby improving the efficiency of the sample design. However, SDWIS/FED was not 

designed to be such a sample frame; many properties of SDWIS/FED, and some lingering problems of 

227 
system classification in SDWIS/FED, can result in many inaccuracies for such sample frame applications 

and sample selection. 

The extracted data outlined above was sent to each state for review and verification. States verified the 

information for their systems so that the census and sample were drawn from a valid universe of systems. 

EPA updated the list based on the revisions provided by the states. A typical revision may consist of 

adjusting population served to include the population served by all consecutive connections. This revised 

list serves as the frame for the survey. The frame included 50,465 community water systems in the 50 

states and the District of Columbia. 

2.1.2 Sample Design and Selection 

Sample Eligibility 

To be eligible for the CWS Survey, a water system must meet several criteria. First, it must meet the 

CFR definition of a community water system; principally, a water system providing drinking water to 25 

or more permanent residents or to 15 permanent connections. (See 40 CFR 141.2 for the complete 

definition.) In addition, the CWS Survey excluded federal- and state-owned or operated systems because 

these are not affected by regulatory and economic forces in the same way as other systems. The survey 

also excluded systems in Puerto Rico, Virgin Islands, and the Pacific Islands. To the extent possible, all 

ineligible systems were identified in SDWIS/FED and removed from the frame; however, many ineligible 

systems could not be identified and were therefore left in the frame. If systems were clearly identified as 

ineligible during data collection (e.g., they are no longer an active water system, they no longer meet the 

CFR definition of a Community Water System, or they are owned by the federal or a state government), 

the data were excluded from analyses based on the sample. 

Sample Design 

The CWS Survey analytical plan specified precision level targets for subpopulations of systems, which 

required minimum sample sizes be achieved for each subpopulation. The precision targets for each 

subpopulation were 95 percent confidence intervals of " 10 percentage points for estimated proportions. 

The 2006 CWS Survey used site visitors to collect data from systems serving 3,300 or fewer people. The 

2006 CWS Survey was fielded at the same time as the 2007 Drinking Water Infrastructure Needs Survey 

and Assessment (DWINSA), which also relied on site visitors to collect its data. To minimize costs and 

to reduce the burden on systems serving 3,300 or fewer people, the two surveys combined their site visits 

of small systems. The DWINSA data quality objective for systems serving 3,300 of fewer people is to 

estimate a 95 percent confidence interval of the need for each stratum with a margin of error plus or 

minus 30 percent of the need of systems in each stratum. The sample sizes required for each stratum for 

the CWS Survey was compared to that of the DWINSA. The larger of the two samples was used in each 

stratum to ensure the data quality objectives of both surveys were met. 

The domains of the population of interest for EPA are based on two characteristics of the systems: 

1. The source of water. Using the SDWIS source classifications, systems that rely on any 

surface water were distinguished from systems that rely completely on ground water. 

2. The size of the population served by the system. Eight size categories were used: systems 

that serve less than 100 people; systems that serve 101 to 500 people; systems that serve from 

501 to 3,300 people; systems that serve from 3,301 to 10,000 people, systems that serve from 

10,001 to 50,000 people; systems that serve 50,001 to 100,000 people; systems that serve 

from 100,001 to 500,000 people; and systems serving more than 500,000 people. 

228
The two water sources and the eight system sizes produce sixteen strata. 

A system is classified as a surface water system in SDWIS if any of its water is surface water. Ground 

water under the direct influence of surface water is classified as surface water. Systems that rely on 

purchased water are included in the ground water strata because we assume the characteristics of the 

water and the treatment requirements will be more similar to ground water than to surface water. (While 

some untreated surface water is purchased, the majority is treated and therefore more similar to ground 

water than surface water.) 

The sample is stratified to achieve two goals. First, stratifying the data allows us to draw inferences about 

specific population domains. For example, EPA may wish to draw conclusions about systems serving 

populations 10,000 or less. We can ensure that estimates of the sub-populations will meet the required 

levels of precision by drawing the necessary number of observations for each stratum. 

The second goal achieved by stratifying the data is that we can increase the efficiency of our estimates by 

grouping systems into relatively homogeneous strata. The strata were chosen to minimize the differences 

among systems within strata, and to maximize the differences among strata. The results of previous 

surveys indicate there are important differences in the way systems are operated and in their finances 

across the strata selected. The operating characteristics and treatment requirements of ground water 

systems tend to be different from surface water systems. The operating and financial characteristics of 

large systems tend to be more complex than small systems. System management, and the resources 

available to it, also may vary by system size. The regulatory impact models require reasonably precise 

parameter estimates from each of these domains. The sample size in each domain should be large enough 

to provide a sufficient number of completed questionnaires to obtain estimates with reasonable precision. 

Table 2-1 shows the number of systems in the sample frame and the minimum sample size required to 

obtain an estimate for a proportion of 50 percent with an error not exceeding " 10 percentage points 

(except for a 1 in 20 chance) in each domain. (A 50 percent statistic was used because the standard error 

is largest when the population percentage is 50 percent. The error will be smaller for other population 

percentages.) Systems with populations served of over 100,000 were selected with certainty. 

Sample Selection 

For CWSs serving 3,300 or fewer people (small CWSs), a two-stage sampling design was used to reduce 

field data collection costs. Field data collectors were sent to the clusters of five systems at a time to 

collect data. The primary sampling unit (PSU) was a county or a group of counties. (Each county with 

fewer than five small systems was combined with geographically adjacent counties to form the primary 

sampling units.) At the first stage of sampling, a sample of 120 PSUs was selected with probabilities 

proportional to size. The measure of size was the number of small systems in the PSU. States were 

provided with a list of small CWSs in the counties selected, and EPA asked sates to verify that the 

systems on the list are active and serve populations of 3,300 or fewer. 

To select the second stage sample of small systems, the overall selection rate for each small system 

stratum was calculated as the target initial sample size in the stratum divided by number of systems in the 

stratum. The expected frequency of selection was calculated for each PSU in the first stage sample. For 

each PSU selected, the second stage selection rate for a stratum equaled the overall selection rate for the 

stratum divided by the first-stage expected frequency of selection. That second stage selection rate for a 

stratum was applied to the count of systems in that county to determine the fractional sample size. The 

fractional sample sizes was converted to integer sample sizes using stochastic rounding and with the 

constraint that the total integer sample size for a county hit equals six systems. To measure composite 

sample size in selecting counties or PSUs, an overall stratum selection rate was multiplied by the number 

229 
Table 2-1. Frame and Sample Sizes by Strata 

Source of Water Population Served Frame Size Required 

Sample 

Ground 100 or less 12,487 96 

101-500 14,800 103 

501 - 3,300 12,049 158 

3,301 - 10,000 3,665 94 

10,001-50,000 2,325 93 

50,001 - 100,000 350 76 

100,001 - 500,000 184 184 

More than 500,000 23 23 

Surface 100 or less 256 70 

101-500 525 82 

501 - 3,300 1,146 89 

3,301 - 10,000 954 88 

10,001-50,000 1,038 88 

50,001 - 100,000 295 73 

100,001 - 500,000 297 297 

More than 500,000 71 71 

All 50,465 1,685 

of systems in the stratum in that PSU, and summed over all strata in each primary sampling unit (county 

or group of counties). 

For systems serving populations of 3,301 to 100,000, the sample was obtained by drawing a random 

sample of systems from the cleaned frame, within each sampling stratum serving populations of this size. 

Systems in these strata were over-sampled to account for non-response. The over-sampling rate was 

based on EPA’s experience with the 1995 and 2000 CWS Surveys. Systems serving populations of more 

than 100,000 were selected with certainty. The resulting increase in sample size is warranted for the 

following reasons: 

C Each of the larger systems has a more significant impact on the total costs and benefits of 

regulations. 

C Because of the small numbers of systems in many of the larger strata, precision can be 

increased at comparatively lower cost than it can be for smaller systems. Other things being 

equal, doubling precision will quadruple sample size in strata with 5,000 systems or more. 

Many of the larger strata, however, have only hundreds of systems. In a stratum of 750 

systems, one could double precision by only tripling sample size. In a stratum of 200 

systems, one could double precision by doubling sample size. 

A total of 2,210 systems were selected. This is a larger number of systems than required (and shown in 

table 2-1) because of the need for over-sampling discussed above. The sample size by strata and the 

sampling rate are shown in table 2-2. The 2006 sample also is larger than the 2000 sample despite the 

reduction in the number of systems in the country. While the overall number of community water 

systems declined, the number of systems serving more than 100,000 people increased. Because these 

systems are selected with certainty, the total sample size increased in 2006. 

230 
Table 2-2. Sample Size and Sampling Rate by Strata 

Source of 

Water Population Served Sample Size 

Sampling 

Rate (%) 

Ground 100 or less 101 0.8 

101-500 124 0.8 

501 - 3,300 154 1.3 

3,301 - 10,000 206 5.6 

10,001-50,000 211 9.0 

50,001 - 100,000 151 43.0 

100,001 - 500,000 184 100.0 

More than 500,000 23 100.0 

Surface 100 or less 62 21.5 

101-500 75 12.7 

501 - 3,300 84 7.0 

3,301 - 10,000 183 18.7 

10,001-50,000 165 15.3 

50,001 - 100,000 119 39.0 

100,001 - 500,000 297 100.0 

More than 500,000 71 100.0 

All 2,210 4.3 

2.1.3 Stratum Migration 

Errors in the frame classification of the water systems by population served and water source introduces 

inefficiency in the sample design through a loss of sample size and/or by introducing unequal sampling 

rates. Among the respondents, 91 percent reported the same population served category as indicated by 

the frame. Over 95 percent reported the same source as the frame. 

Population Served by the System 

Table 2-3 compares the classification of systems by their population served using the population data 

from the frame and from the systems’ responses to the survey. In all size categories, 91 percent of 

systems confirmed their original size category. Within each size category, over 96 percent of systems 

were either in their original size category or in the adjacent class. 

Source of Water 

Table 2-4 shows the cross-tabulation of the frame-based and response-based water source classifications. 

Approximately 94 percent of the systems classified as ground water systems in the frame confirmed that 

status in the sample. Ninety-four percent of surface water systems in the frame were also classified as 

surface water systems in the sample. 

231 
Table 2-3. Survey Respondents by the Frame-Based and Sample-Based Size 

Categories 

Sample-Based Population 

Served Categories 

Frame-Based Population Served Category 

25-

100 

101-

500 

501-

3,300 

3,301-

10,000 

10,001-

50,000 

50,001-

100,000 

100,001-

500,000 

Over 

500,000 

25-100 Count 

Percent 

133 

87 

20 

13 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

101-500 Count 

Percent 

9 

5 

168 

90 

9 

5 

0 

0 

1 

1 

0 

0 

0 

0 

0 

0 

501-3,300 Count 

Percent 

2 

1 

6 

3 

219 

95 

4 

2 

0 

0 

0 

0 

0 

0 

0 

0 

3,301-10,000 Count 

Percent 

0 

0 

1 

1 

7 

5 

137 

89 

8 

5 

0 

0 

1 

1 

0 

0 

10,001-50,000 Count 

Percent 

0 

0 

0 

0 

1 

1 

11 

7 

147 

91 

1 

1 

1 

1 

0 

0 

50,001-100,000 Count 

Percent 

0 

0 

0 

0 

1 

1 

1 

1 

12 

9 

112 

86 

3 

2 

1 

1 

100,001-500,000 Count 

Percent 

1 

0 

0 

0 

0 

0 

1 

0 

8 

3 

11 

5 

218 

91 

1 

0 

Over 500,000 Count 

Percent 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

2 

3 

56 

97 

Table 2-4. Survey Respondents by the Frame-Based and the Sample-Based 

Source Categories 

Sample-Based 

Water Source 

Frame-Based Water Source 

Small Medium Large All 

Ground Surface Ground Surface Ground Surface Ground Surface 

Ground Count 364 19 209 15 89 8 662 42 

Percent 95 5 93 7 92 8 94 6 

Surface Count 4 189 12 217 5 183 21 589

 Percent 2 98 5 95 3 97 6 94 

Impact of Strata Migration on the Accuracy of Domain Estimates 

The sample was designed to estimate a 50 percent statistic with a 95 percent confidence interval of "10 

percentage points. One measure of the impact of the strata migration on the efficiency estimates is to 

calculate the size of the confidence interval given the number of observations in each stratum for the 

sample collected. Table 2-5 shows the minimum sample required to estimate a 50 percent statistic with a 

95 percent confidence interval of "10 percentage points under two scenarios.1

 First, it shows the sample 

size needed given the inaccuracies in the frame. In other words, it accounts for the migration across strata 

1. The sample of systems serving 3,301 or fewer persons was designed to estimate a 50 percent statistic with a 

confidence interval of "10 percent. It also was designed to estimate the national future investment need of these 

systems with a margin of error of "10 percent of their need. Therefore, the planned sample produces a confidence 

interval for a proportion that is smaller than "10 percent. See section 2.1.2 for the description of the sampling plan. 

232 
that occurred. Second, it shows the sample selected. (It is the same as the sample shown in table 2.1.) 

The table also shows the half-width of the 95 percent confidence interval that results from the actual 

sample selected, given the sample’s estimate of the number of systems in each sub domain. The impact of 

strata migration on the confidence interval for small ground water systems was negligible. Strata 

migration resulted in a slight increase in the size of the confidence interval for small surface water 

systems. Because the sample was designed to collect data on all systems with populations of more than 

100,000, the width of the confidence interval for these systems would have been zero. Strata migration 

substantially increased the width of the confidence interval for ground water systems serving more than 

500,000 persons and slightly for surface water systems serving greater than 100,001 to 500,000 persons 

because the number of systems in these strata is larger than expected. 

Table 2.5. Sample Sizes and the Impact on Precision of Estimates 

of Strata Migration 

Source Population Served 

Sample 

Needed 

Given 

Strata 

Migration 

Sample 

Selected 

Half width of 95% 

Confidence 

Interval 

Ground 100 or less 

101 – 500 

501 - 3,300 

3,301 - 10,000 

10,001 - 50,000 

 50,001 -100,000 

 100,00 1-500,000 

 Over 500,000 

96 

103 

158 

94 

92 

75 

173 

32 

96 

103 

158 

94 

93 

76 

184 

23 

0.100 

0.096 

0.077 

0.100 

0.099

0.099

0.000

0.109 

Surface 100 or less 

101 - 500 

501 - 3,300 

3,301 - 10,000 

10,001 - 50,000 

 50,001 -100,000 

 100,00 1-500,000 

 Over 500,000 

75 

83 

89 

88 

89 

70 

305 

68 

70 

82 

89 

88 

88 

73 

297 

71 

0.105 

0.101 

0.100 

0.100 

0.101

0.097

0.009

0.000 

2.2 Weighting and Estimation 

A sampling weight is attached to each responding water system record to (1) account for differential 

selection probabilities, and (2) reduce the potential bias resulting from non-response. The sampling 

weights are necessary for estimation of the population characteristics of interest. The sample variance is 

then used to calculate 95 percent confidence intervals for the estimates. 

2.2.1 Derivation of Base Weight and Non-response Adjustment 

The calculation of the sample weight reflects the complex nature of the sampling design. The community 

water system sample consists of a stratified element sample of medium and large water systems. Systems 

were stratified by water source and their population served. For small water systems a two-stage cluster 

sample design was used. 

233 
1. At the first stage geographic clusters (counties or county groupings) were sampled using 

probability proportional to size sampling. The measure of size was a function of the 

number of small systems in the cluster. 

2. Within clusters a stratified element sample of small systems was drawn. 

The response rate for systems serving 3,301 to 100,000 was below the target after an initial round of data 

collection. An additional 162 systems were selected in a second round of sampling to increase the sample 

size in these strata. 

Sixteen sampling strata were defined based on systems’ population served and source of water; all weight 

calculations use this sample stratum variable. 

Base weights 

The first step was the calculation of a base sampling weight for each sample system. The medium and 

large system samples are simple random samples within each stratum. The two-stage small system sample 

is designed to be self-weighting within each stratum. Therefore, for all systems the base sampling weight 

equals the number of systems in the stratum divided by the number sampled from that stratum. In other 

words the base weight for the hth stratum, Bh, is: 

(1) 

N Bh = h

nh

where Nh represents the number of systems in the stratum in SDWIS, and nh represents the number of 

systems sampled from the stratum. 

Non-response adjustment 

The second step in the weighting methodology was to make a unit non-response adjustment to the base 

sampling weights. For each medium and large system stratum, the non-response adjustment factor is 

equal to the ratio of the number of systems that completed the survey plus the number of non-respondents 

to the number of systems that completed the survey (i.e., the reciprocal of the stratum response rate). 

Ineligible systems are not incorporated into the unit non-response adjustment. The adjustment factor for 

the hth stratum is given by δh: 

(2) 

n + r δ h

h = h

nh

where rh is the number of refusals and other non-respondents in the hth stratum. 

For the small system sample the unit non-response adjustment was not implemented within each cluster 

because the sample sizes were too small. Rather the adjustment was carried out within each small system 

stratum at the total sample (i.e., national) level. 

Final weights 

The non-response adjustment factor δh was multiplied by the base sampling weight, Bh, to obtain the nonresponse adjusted base sampling weight. The non-response adjusted base sampling weight for the 

234 
medium and large systems that completed the survey is the final weight for use in analysis. The nonresponse adjusted weights can be written as: 

(3) W f

h = Bhδ h 

for medium and large systems, and 

(4) Wmh = Bmhδ h 

for small systems. 

The final step in the weight calculations for small systems was a ratio adjustment to the frame count of 

small systems in each small stratum at the national level. This step was carried out because the two-stage 

sample of small systems, drawn from 120 sample clusters, may not have the same stratum distribution as 

the entire frame of small systems. For each small system stratum, the sum of the non-response adjusted 

base sampling weights for systems with a completed survey was added to the sum of the base sampling 

weights for the ineligible systems. The count of small systems in the frame was then divided by this sum. 

This yielded a ratio adjustment factor for each small system stratum, ρh: 

(5) 

N

ρ h = h 

∑Wmhj + ∑Bmhj 

j∈Rh j∈Ih 

where: Rh is the set of systems that responded to the survey, and 

Ih is the set of systems sampled that were ineligible. 

j designates the jth sample system. 

For the small systems with a completed survey their non-response adjusted base sampling weight was 

multiplied by the ratio adjustment factor to yield a final weight for use in analysis: 

(6) W f

mh = Wmhρ h 

2.2.2 Variance Estimation 

The estimate of the variance must account for the sampling design. Weights are used to produce 

estimates for the population as a whole—or example, the proportion of treatment facilities that use a 

particular treatment practice, or the mean water-sales revenue of a system. Weights also affect the 

standard error of the estimates, and therefore the confidence intervals. 

The 2006 CWS Survey sampling design was relatively complex; medium and large systems were selected 

by strata; small systems were selected in clusters of counties (or, in some cases, groups of counties) using 

a probability proportional to size sampling. This sampling design also affects the estimate of the standard 

error. The stratification of the systems by water source and population served will tend to reduce the 

overall sample variance, as systems within a stratum tend to be similar to each other and different from 

systems in other strata. The clustering will likely increase the sampling variance, as systems within a 

cluster may be similar to each other. This effect of clustering may not be large; while systems within a 

county share some characteristics, the often are a diverse group in terms of population served and water 

source, as well as revenue, expenses, and operating characteristics. But ignoring the clustering may lead 

to an underestimate of the sampling variance, so it must be taken into account. 

235 
The treatment facilities in the sample were not selected independently; rather, they were selected in 

clusters in a two-stage process. For medium and large systems, the stratified random sample of systems 

was selected in the first stage; every treatment facility in each system was selected in the second stage. 

Facilities in small systems were selected in a three-stage process: counties (or groups of counties) were 

selected in the first stage; a sample of systems within each county was selected in the second stage; every 

facility within each system was selected in the third stage. The calculation of the sample variance of 

estimates regarding treatment facilities also must take into account this sampling design. 

Variance Estimator 

The variance is estimated using a first-order Taylor expansion. The variance is calculated in Stata. The 

variance estimator is given by: 

( ) { ) ( ( ( 1 (7) V ˆ R ˆ = ) V ˆ Y ˆ − 2R ˆ Coˆ v Y ˆ, X ˆ + R ˆ 2

V ˆ X ˆ

X 2 

L mh ngu 

where Rˆ = Yˆ , the ratio of estimates of two population totals. Yˆ is equal to ∑∑∑w

Xˆ hij y hij , and

h=1 i=1 j=1 

L m n

Xˆ ∑∑∑h gu is equal to whij xhij . L is the number of strata, mh is the number of primary sampling units in 

h=1 i=1 j =1 

strata h, and nhi is the number of elements in the ith primary sampling unit in the hth strata. 

Most of the estimates produced in this volume are either means or proportions. A mean is simply a ratio 

in which xhij is equal 1. A proportion is simply a mean in which yhij is equal to a 0/1 variable.2 

) )}

Finite Population Correction 

A finite population correction factor was derived for medium and large systems in the sample. The factor 

is the ratio of systems in the sample to the number of systems in each stratum. Because the primary 

sampling units for small systems were selected with replacement, the finite population correction factor is 

set equal to zero for small systems. 

To estimate the variance, we first define the following ratio residual: 

1 d ˆ hij = Xˆ (y hij − R xhij (8) )

We then define the weighted total of the ratio residual as 

nhij

zdhi = ∑whijdhij

j=1

(9) 

and the weighted average of the residual as: 

2

See Cochran, W.G. 1977, Sampling Techniques, New York: John Wiley & Sons for amore 

information about variance estimates. 

236 
1 (10) ∑

mh

zdh z

m

dhi

h i=1

We can then define the variance estimate as: 

(11) V ( ) L m n

ˆ ˆ h

R = ∑(1 − f h 

h ) ∑(zdhizdh )

2 

h=1 mh −1 i=1 

where fh is the finite population correction. 

The estimate of the variance is used to estimate 95 percent confidence intervals in the detailed tables of 

this report. An implicit assumption is that the average values presented in each table are normally 

distributed. When the estimate is based on a large number of systems, this will generally be true; in cases 

where the estimate is based on a small number of systems, the assumption may not hold. The confidence 

interval in these cases may be larger than the mean itself. The confidence interval is not adjusted in these 

cases; to compute the correct confidence interval requires examination of the empirical distributions for 

each variable in the calculation and is beyond the scope of this study. 

237 

3. Survey Design and Response 

The survey was administered through site visits to small systems (those serving populations of 3,300 or 

less), and through a mail survey to medium and large systems (those serving more than 3,300 people). 

This chapter discusses the survey instrument, the processes for conducting the site visits and distributing 

the questionnaires, as well as the process to assure sufficient response rates and the handling of returned 

questionnaires. 

3.1 Questionnaire Design 

EPA staff responsible for regulatory development developed the questionnaire with the assistance of the 

Cadmus Group, Inc. The process began with a meeting of EPA staff to discuss their data needs, 

distinguishing core needs required for regulatory development from other data needs. Based on these 

discussions, some of the questions that were in the 2000 CWS Survey were eliminated from the 2006 

questionnaire. Other questions—especially those focusing on treatment—were further developed. A 

slightly modified version of the questionnaire was developed for systems that serve populations of over 

500,000; this version of the questionnaire included additional questions on source and finished water 

contaminant concentrations, and excluded questions that only would apply to small systems. The 

questionnaire in the Appendix is a composite of the three questionnaires used; the questions that are asked 

of systems serving up to 100,000 people, more than 100,000 and up to 500,000 people, and over 500,000 

people are noted. 

EPA worked with Cadmus on the wording and organization of the questionnaire. Cadmus was 

responsible for the design and layout of the questionnaire form, and for documenting and incorporating all 

revisions to the several design and test versions of the questionnaire. Throughout the design process, the 

EPA project officer consulted with the full range of EPA regulatory and analytical staff, representing 

expert advisors and future users of the data, to identify and correctly present the broad survey topics and 

specific survey questions to be included in the survey instrument. These covered such areas as water 

production, storage, distribution, treatment, and treatment system security, as well as financial 

information regarding water sales revenue, customer data, operating expenses, and capital investment. 

EPA went to great lengths to attempt to reduce the burden to respondents while collecting complete, 

accurate, detailed data. EPA decided to conduct site visits to small systems because of the difficulties 

they faced in responding to past Community Water System Surveys prior to 2000. Data for the 2007 

Drinking Water Infrastructure Needs Survey and Assessment were collected at the same site visit, 

minimizing the impact of the two surveys on small systems. EPA also coordinated its data collection 

efforts with that of the Water Treatment Plant Questionnaire, another survey conducted by the Agency. 

Both surveys required systems to report basic financial information; systems that responded to the Water 

Treatment Plant Questionnaire did not need to respond to the financial section of the CWS Survey. EPA 

also established a process to provide extensive technical assistance and guidance to medium and large 

systems. As discussed in chapter 4, EPA conducted a pre-test of the questionnaire to identify questions 

that posed potential problems for respondents. EPA also conducted a pilot test of the data collection 

methods. In response to both tests, EPA made several changes to the questionnaire, reducing the scope of 

several questions. For example, as a result of the pre-test, the number of age and diameter categories was 

reduced in the question regarding the length of the distribution system. 

3.2 Data Verification 

EPA forwarded the list of water systems selected in the sample to the states. The states were asked to 

verify that the systems were active systems, as well as the address, telephone, and the contact information. 

239 
3.3 The Pilot Test 

Approximately 50 systems were selected from the sample for a pilot test. Two clusters of small systems 

were selected for site visits by senior Cadmus water system professionals. Ten small systems participated 

in the pilot test. Approximately 40 systems serving more than 3,300 people received the questionnaire by 

mail. The pilot tested the site visit and mail-out process, and the technical support system. The pilot 

systems were included in the full sample. 

3.4 Site Visit Operations. 

Contractors with extensive water system experience conducted the site visits. In addition to Cadmus, the 

contractors were: 

C Southwest Environmental Engineering, and 

C McNenny Environmental Engineering and Consulting. 

C Abel 

C CH2M Hill 

C Schott Engineering 

C South Hills Consulting 

C Suarez Engineering 

C Sunrise 

C TCB, Inc. 

Cadmus trained the site visit staff. The training covered the survey, the information required from the 

systems, and the data collection protocol. The training included on-site inspections with Cadmus staff of 

a cluster of systems in the sample, as well as detailed instructions on the conduct of the visit. 

The states were contacted ahead of time to confirm the systems in the sample and to review information 

on the system contacts. Site visitors were told to let state contacts know they were in their area and what 

they were doing, as a courtesy. The surveyor extended the opportunity to the states to attend the survey. 

Otherwise, the surveyors were told to not burden the states with requests for assistance. 

As part of the training, site visitors were instructed as follows: 

C The survey is voluntary and not to be misrepresented as mandatory. It is an opportunity to 

provide information to be used by EPA to make sound, informed decisions and regulations. 

C Obtain the operating and financial information for the same time period of time, if at all 

possible 

C If information is not available for the separate classes of system (for example, water 

deliveries by customer class), then collect the totals (e.g., total deliveries). 

C Indicate the system has a treatment objective only if the facility was Adesigned@ for that 

purpose. For example, if the facility was designed for particulate removal and removed 

arsenic in the process, the surveyors were to only check particulate removal. 

C Complete the sequence of treatment after a walk-through of the treatment plant. If available, 

collect a schematic. 

240
C Related questions should be checked for consistency. For example, questions on water 

produced should be consistent with deliveries and unaccounted for water. Water delivered 

should be consistent with the number of customers and connections. 

C The importance of the financial data was emphasized. Again, if the information was not 

available in a manner that it could be broken down into components, get totals. 

C Collect financial reports if they are available and if the system will not break down the costs 

as requested. 

C Collect data on municipal tax and other non-water system revenue of publicly owned 

municipal water systems. 

Several issues arose during the site visits that required consistent responses. They included: 

C If the system indicated that it merged with another system, the site survey was conducted. 

C If a system decreased in size so it was no longer a community water system, the site visit was 

conducted to confirm the status. 

C If the system grew so it was no longer a small system, the site visit was conducted and data 

collected. 

Each site visitor was given a list of systems to visit. The site visitors contacted the systems to schedule 

the on-site interviews; the site visitors were required at times to contact the state to confirm contact 

information. Once on-site or in some cases prior to the site visit, the systems were provided with a letter 

introducing the site visitor and explaining the survey. The site visitor toured the system, interviewed the 

staff, photographed the system (from source to delivery), and filled out the questionnaire. The completed 

questionnaire, inclusive of the pictures, site map, and collected information and reports, was then 

submitted to Cadmus. Senior staff at Cadmus reviewed all surveys submitted by the site visitors to ensure 

the site visitors were filling out the questionnaire correctly and to ensure consistent responses from the 

site surveyors. The questionnaires were then logged into the tracking system as received and completed. 

During the site visits, Cadmus senior staff communicated with the site visitors via telephone and e-mail to 

ensure consistent and complete results. Group email was used to provide answers and clarification to the 

site visitors’ questions. All site visitors received the same information. 

3.5 Self-administered Survey Administration 

In an effort to minimize respondent burden and maximize the response rate, systems had three options for 

responding to the survey. A system could complete an electronic spreadsheet version, a Web-based 

version, or a paper version of the questionnaire. Each was available through a secured Web site. Also, 

systems could request that copies of the spreadsheet or paper questionnaire be sent to them directly. 

Cadmus sent each system a packet that included a letter from the EPA WAM and flier that explained how 

to respond to the survey. The flier included instructions on how to access the Web site and a toll-free 

telephone number the system could use if it had any questions. The fliers included unique log-in 

identifiers and passwords for each system. Information for the mailing label was extracted from the 

sample frame and attached to the envelope for mailing. 

The packets were mailed to approximately 1,400 community water systems over a 2 day period. Each 

system then received a telephone call from the analyst at Cadmus responsible for that system. The call 

241 
informed the system of the survey, told them they would receive the packet (if they had not already done 

so), and gave the systems a name and telephone number to call with any questions. If a system did not 

receive the packet, the analyst responsible for that system sent them another copy via FedEx or by e-mail. 

The analyst continued to follow-up with each system until the system either responded to the survey or 

refused to participate. The analysts provided technical assistance as necessary, and in some cases filledout the questionnaire through a telephone interview. 

As systems uploaded questionnaires, the tracking system automatically logged them in as received. As 

questionnaires were received from the water systems by mail or e-mail, Cadmus logged them into the online tracking system. The analyst responsible for the questionnaire reviewed it for data quality and to 

identify potential problems. Questionnaires submitted electronically were printed for the analysts to 

review. When necessary, senior engineering or financial staff was consulted regarding potential 

problems. If a problem or question could not be resolved by Cadmus staff, the analyst contacted the 

water system itself. When this initial review was completed, the questionnaire was forwarded to senior 

staff for additional review. All changes to the questionnaires were recorded in a permanent log. After the 

senior review was completed, revisions to the electronic data were made by the analysts. For paper 

questionnaires, the completed questionnaire was entered into an electronic spreadsheet version by two 

Cadmus analysts. A process was developed to ensure every response field was entered identically. Once 

the results were confirmed, the questionnaire was uploaded to the Web site. 

3.6 Data Entry 

Upon review by the senior staff, all questionnaires were logged as completed. If systems filled-out paper 

questionnaires, the questionnaires were key-entered using 100 percent verified double-key entry. After 

entry, the data were run through automated cleaning and editing programs that checked each variable for 

proper values and ranges. Items failing these checks were examined and either confirmed or corrected. 

Questionnaires that reached this stage were considered to be entered and cleaned. (The data were subject 

to further intensive checks as part of the quality assurance process, discussed in chapter 4.) 

Status reports were sent to the EPA project manager every two weeks during the data collection effort. 

The report showed the number of questionnaires with each of the following status codes: 

C Site visit appointments scheduled or questionnaires mailed 

C Questionnaires re-mailed 

C Inactive systems 

C Questionnaires undeliverable 

C Refusals 

C Site visits completed/questionnaire returned 

C Questionnaires reviewed and ready to enter into database 

C Completed questionnaires entered into database 

Table 3-1 presents an example of the information provided to EPA. 

242 
Exhibit 2: 2006 Community Water System Survey Status by Sampling Stratum 

Status 

Small Systems Medium and Large Systems 

25 – 101 – 501 - Sub- 3,301 - 10,001 - 50,001 - 100,001 - Over 

100 500 3,300 total 10,000 50,000 100,000 500,000 500,000 

Ground Water Systems 

Mail out 101 124 154 380 206 211 151 184 23 Sample Needed to Meet  Precision Targets 96 103 158 357 94 93 76 184 23 

Initial contact 101 124 154 380 170 167 133 174 20 Inactive 3 2 1 6 1 2 1 1 

Undeliverable Refusal 3 1 2 6 28 33 11 24 1 

Received from System 95 121 151 368 60 61 54 82 12 

Completed Analyst Review 77 102 119 299 50 48 48 70 11 

Completed Senior QA 52 59 63 174 21 12 17 32 4 Sent for Data Entry 42 51 59 152 14 15 11 13 

Received from Data Entry 42 51 59 152 12 15 11 12 

Completed Questionnaire 42 51 59 152 6 4 4 17 1 

Surface Water Systems 

Mail out 62 75 84 221 183 165 119 297 71 

Sample Needed to Meet  Precision Targets 70 82 89 241 88 88 73 297 71 Initial contact 62 75 84 221 162 157 113 283 69 

Inactive 1 1 2 1 1 1 

Undeliverable Refusal 2 7 3 12 19 17 13 27 10 

Received from System 59 67 81 207 67 81 58 144 42 Completed Analyst Review 44 59 66 169 54 63 48 122 36 Completed Senior QA 20 22 31 73 30 22 18 50 10 Sent for Data Entry 14 20 25 59 12 19 11 16 4 Received from Data Entry 14 20 25 59 10 18 11 15 3 

Completed Questionnaire 14 20 25 59 16 12 7 18 8 
Exhibit 2: 2006 Community Water System Survey Status by Sampling Stratum 

Status 

Small Systems Medium and Large Systems 

25 – 101 – 501 - Sub- 3,301 - 10,001 - 50,001 - 100,001 - Over 

100 500 3,300 total 10,000 50,000 100,000 500,000 500,000 

Surface and Ground Water Systems 

Mail out 163 199 238 600 389 376 370 481 94 

Sample Needed to Meet  Precision Targets 166 185 247 598 182 181 149 481 94 

Initial contact 163 200 238 601 332 324 245 457 89 

Inactive 4 3 1 8 1 3 2 1 1 

Undeliverable Refusal 5 8 5 18 47 50 24 51 11 

Received from System 154 189 232 575 127 142 111 226 54 Completed Analyst Review 121 162 185 468 104 111 95 192 47 Completed Senior QA 72 81 94 247 51 34 35 82 14 Sent for Data Entry 56 71 84 211 26 34 22 29 4 

Received from Data Entry 56 71 84 211 22 33 22 27 3 

Completed Questionnaire 56 71 84 211 22 16 11 35 9 
3.7 Survey Response 

The data collection effort was closed out December 31, 2007. Of the 2,210 systems sampled, 1,314 

responded to the survey. The overall response rate was 59.5 percent. Table 3.2 shows the response rate 

by strata. 

Table 3-2. CWS Survey Responses and Response 

Rate by Strata 

Source of 

Water Population Served 

Completed 

Questionnaires 

Response 

Rate (%) 

Ground 100 or less 94 93.1 

101-500 120 96.8 

501 - 3,300 150 97.4 

3,301 - 10,000 77 37.4 

10,001-50,000 74 35.1 

50,001 - 100,000 67 44.4 

100,001 - 500,000 87 47.3 

More than 500,000 14 60.9 

Surface 100 or less 59 95.2 

101-500 67 89.3 

501 - 3,300 81 96.4 

3,301 - 10,000 77 42.1 

10,001-50,000 87 52.7 

50,001 - 100,000 64 53.8 

100,001 - 500,000 152 51.2 

More than 500,000 44 62.0 

All 1,314 59.5 

Non-response may introduce a source of bias into estimates based on the survey. Non-respondents may be 

different than respondents; in some cases, these differences may be the reason for their refusal to 

participate in the survey. Non-response may have an impact on the survey’s estimates. Two areas of 

potential concern are systems’ estimates of system finance and systems’ treatment practices. 

The potential impact on system finances of non-response bias can be positive or negative. On the one 

hand, systems that are not doing well financially may not want to report their finances to the survey. On 

the other hand, systems reporting significant profits may not want to report their revenue and expenses. 

Therefore, both the sign (whether the bias is positive or negative) and relative magnitude of non-response 

bias on net revenue, for example, is uncertain. 

However, there is reason to believe that such bias as might exist is minimal. For one reason, the finances 

of many water systems are already public information. Most systems are publicly owned. In fact, the 

overwhelming majority of systems serving over 3,300 people are publicly owned, and it is these larger 

systems where the response rate has been problematic in the current survey. Public ownership means that 

their revenue and expenses are matters of public record. In addition, many privately owned systems are 

regulated by state public utility commissions, and their finances also are matters of public record. Most 

systems cannot hide unusual profits or losses simply by refusing to respond to the survey; therefore, the 

potential impact of non-response on the estimates of system finance likely is small. 

245 
Another reason to suspect that the impact of the non-response bias on the financial estimates is relatively 

small has to do with previous response rates among small systems. In 1995, EPA assumed that many 

small systems were having financial difficulty. The response rate among these systems was relatively low, 

below 40 percent in some categories. If non-respondents had poorer financial performances than 

respondents, the 1995 survey would overstate the financial well being of small systems. In part due to this 

concern, EPA conducted site visits to small systems in 2000 and response rates increased dramatically, 

exceeding 90 percent. The overall financial performance of these systems did not change between the two 

surveys. In fact, the success of the site visitors indicated that the low response rate of small systems was 

due to the difficulty they faced in filling out the questionnaire, not an attempt to hide possible financial 

problems. 

The survey also collects detailed information about systems treatment practices. Systems that are out of 

compliance with primary drinking water regulations may be reluctant to report their treatment practices. 

The magnitude of bias is uncertain. Further analysis could indicate the potential impact of the bias. For 

example, we could assume that some or all non-respondents do not treat their water to determine the 

potential impact of non-response bias. (Some of the non-respondents are large systems that almost 

certainly provide treatment. These systems could be excluded from this analysis.) This analysis could be 

used to estimate the upper bound of the impact of non-response bias and its impact on the 95 percent 

confidence interval. Further analysis may be warranted. 

246 
4. Quality Assurance and Peer Review 

All work under this contract was conducted in accordance with an approved Quality Assurance Project 

Plan. In addition, a Supplemental Quality Assurance Project Plan was developed specifically for this 

survey and was approved prior to the start of data collection. The supplemental plan for the CWS Survey 

encompassed specific measures to check and ensure the validity of the survey data from data collection 

through data processing and analysis, as well as measures to assure the quality of other survey 

components. The report results and statistical methods also were peer reviewed by subject matter experts. 

Section 4.1 discusses the questionnaire pre-test and the survey pilot test. Section 4.2 presents the 

measures taken to assure the quality of the statistical sample. Section 4.3 discusses the quality assurance 

procedures used during the data collection effort. Section 4.4 describes the expert review of questionnaire 

responses. Section 4.5 describes data processing quality assurance procedures. Section 4.6 describes the 

quality assurance steps taken during the preparation of this report. Section 4.7 describes the peer review 

process. 

4.1 Draft Questionnaire Pre-test and Survey Pilot Test 

A significant component of the survey quality assurance plan was to thoroughly test the questionnaire 

design, the survey design, and data collection procedures prior to implementing the full study. Efforts to 

confirm the validity and effectiveness of these designs and revising them when the tests reveal problems, 

errors, or difficulties, led to design and process improvements in such areas as data reliability, data 

completeness, accuracy of the sample frame, and response rates. 

4.1.1 Pre-test 

When the initial data collection objectives had been identified and the questionnaire shaped into a 

working draft instrument, EPA conducted a pre-test of this draft with seven water systems in New 

England of various sizes, including ground and surface water systems. The pre-test participants were 

recruited with the assistance of Ray Raposa of the New England Water Works Association. The main 

objective of the pre-test was to gauge the respondents’ reactions to the questionnaire itself. The test did 

not address any of the actual survey operations and response rate issues that would later be tested in the 

full-scale pilot test. 

The recruited systems received the questionnaire in June, 2006. EPA then convened a focus group 

meeting of the seven water systems, facilitated by survey research staff from Cadmus. The focus group 

explored questions regarding comprehensibility, use of clear and appropriate terminology, provision of 

suitable response categories, and questionnaire layout. The focus group also discussed respondents’ ease 

or difficulty in providing answers, their immediate knowledge of or access to information requested by 

the questionnaire, and their overall reaction to the survey. 

Overall, the focus group felt the questionnaire was clear and relatively easy to follow. As a result of the 

pre-test, some questions were re-worded, and others were shortened. Otherwise, the pre-test found no 

systematic problems in the respondents’ ability to provide answers to the questions. 

4.1.2 Pilot Test 

A full scale pilot test was conducted in February and March 2007. The pilot tested the questionnaire and 

the major operational components of the survey design. The results of the pilot, along with the final 

version of the questionnaires were delivered to EPA in March 2007. The full on-line tracking system was 

developed during the pilot, and the mail-out and receipt logging procedures were finalized. 

247 
Ten small systems and 40 medium and large systems were selected from the full sample for use in the 

pilot. All of the small systems and 15 of the medium and large systems responded by the end of March. 

As a result of the pilot, modest changes were made to the mail-out process and the instructions for 

systems. The pilot also resulted in changes to several questions in the questionnaires. Questions 12 

(length of distribution mains) and 27 (capital improvements) were simplified. Modest changes were made 

to several other questions to clarify the question. The pilot also finalized the site visit protocols, and 

identified issues that needed to be addressed when training the site visitors. 

4.2 Sampling Quality Assurance 

Quality assurance of the sampling process for the CWS Survey involved three principal areas: 

C Development of the sample frame 

C Sampling specifications, and 

C Use of software designed to draw complex samples. 

Development of the Sample Frame. EPA conducted an extensive review of the data used for the sample 

frame. By starting with the data used for the 2007 DWINSA frame, the 2006 CWS Survey was able to 

take advantage of the extensive data verification effort undertaken for the 2007 DWINSA. The 2007 

DWINSA frame was developed with SDWIS data from the third quarter of 2005. State representatives 

working on the DWINSA were sent their respective lists of systems from the data freeze and asked to 

make changes to population and source categories. The sample frame was then built using the data from 

the states. The development of the frame is discussed in detail in section 2.1. 

Sampling Specifications. In order to carry out the sampling processes, the survey statisticians prepared 

detailed specifications that served as directions for performing the sampling and as a permanent 

documentation of the process. The sampling plan was documented in both the supporting materials for 

the Information Collection Request submitted to the Office of Management and Budget, and in the 

Quality Assurance Project Plan. The specifications ensured the sample was drawn in conformity with the 

sample design and in a statistically valid manner. Barry Nussbaum of EPA's Office of Environmental 

Information, A. Richard Bolstein of George Mason University, and John Gaughan of Temple University 

reviewed the sampling plan. Bimal Sinha from the University of Maryland also provided comments on 

the sampling plan. 

Sampling Software. The CWS Survey sample of systems serving up to 3,300 people was drawn using a 

SAS program designed to draw two-stage cluster samples of this type. The sample of systems serving 

populations of 3,301 to 100,000 was a stratified random sample and was drawn using a Stata-based 

program to select random samples. 

4.3 Data Collection Quality Assurance 

Each component of the CWS Survey was implemented with precision and quality assurance. 

Questionnaire Design 

C The various drafts of the questionnaires were the product of close review and comments by 

EPA, Cadmus, and outside reviewers. Improvements also were made as a result of the pretest and pilot test. 

248 
C Questionnaire version control was maintained through the various drafts by allowing for one 

master copy and strictly enforcing version-control procedures. After changes were made to 

each version of the questionnaire, a new electronic folder with the date of the changes made 

was created. The most recent dated folder was used to add create any future changes. One 

Cadmus employee was responsible for making all changes and could track back previous 

versions of the questionnaire. 

C The questionnaire form was designed to clarify and simplify for respondents the provision of 

the highly detailed and complex data required for the survey. Graphic devices were used to 

make the form clearer and simpler to use. The devices included type fonts and sizes, borders, 

and text boxes. 

C Because of the difficulties many small systems have with filling out complex questionnaires 

like the CWS Survey, site visitors were sent to small systems to ensure the questionnaires 

were filled out correctly. 

Mail Data Collection 

C Analysts preparing the material for mailing were provided with specifications for the job and 

were supervised by a senior staff involved in a number of previous mailings. 

C Analysts worked to produce the letter and envelope to be mailed to each respondent. All 

labels were printed with verified SDWIS address information. All letters were tailored to 

each water system with their identification information using the mail merge function in 

Microsoft Word and a database of address information as well login information to the Web 

site. Consistency checks between the information printed on the letter and the label were 

constantly ongoing throughout the mail out. 

C Each recipient of the mailed questionnaire was assigned an analyst who maintained contact 

with the water system throughout the survey. The analysts provided reminder calls and 

technical support to the systems. They also reviewed the data as it was received, following 

up with the system if there were any questions. 

C Senior survey managers reviewed all surveys to ensure analysts were using consistent 

procedures for each survey. 

C The online tracking system ensured proper tracking and control of all questionnaires from the 

point of sampling until the data were entered and cleaned. In addition to supporting overall 

management of the project, the periodic status reports identified response rate problem areas 

which enabled Cadmus to take appropriate follow-up measures. 

Site Visits 

C Extensive training was provided to the site visitors, including a two day training session in 

Boulder, Colorado that included example site visits. 

C Detailed instructions were provided to each site visitor regarding the conduct of the on-site 

surveys. 

249 
C Regular contact was maintained with all site visitors. Site visitor questions and Cadmus 

responses were sent to all site visitors to ensure each site visitor received complete and 

consistent information. 

C Each completed survey was reviewed by Cadmus staff as it was received. Follow-up 

instructions were provided as needed. 

4.4 Expert Review of Responses 

As was done with responses to the 2000 CWS Survey, each questionnaire was subjected to a multi-level, 

detailed review by Cadmus staff as it was returned by the systems. Cadmus reviewed the questionnaire 

for completeness and internal consistency. Systems were called if key questions were not answered or if 

answers were inconsistent or unclear. 

Upon receipt of the completed questionnaire, the Cadmus analyst responsible for the system reviewed the 

survey. They identified missing information and questions or potential problems with responses. The 

analysts were provided training on how to evaluate a completed questionnaire, as well as written guidance 

for reviewing the responses. The written guidance included rules-of-thumb for internal consistency 

checks; these guidelines helped the analyst compare questions and identify inconsistent answers. For 

example, guidelines were provided on average annual water consumption per household, which were used 

to compare annual water production with the number of connections reported. 

Guidelines were provided regarding follow-up questions for the system. If essential data on system 

finance, treatment, and production were missing, or if inconsistencies could not be resolved, analysts 

contacted the system. If detailed information was not available (e.g., revenue by customer class), analysts 

attempted to collect more aggregate-level data (e.g., total water sales revenue.) Analysts worked with the 

systems to resolve inconsistencies. Senior staff contacted systems when difficult issues arose. Changes to 

the questionnaire were documented and logged. 

The analysts’ review of the surveys was itself reviewed by senior survey staff. Senior staff evaluated the 

reviews and provided feedback to the analysts. Senior staff and water system experts provided 

information and answered questions throughout the data collection period. 

Upon the completion of an analyst’s review of a questionnaire, the completed questionnaire was then 

reviewed by Cadmus water system experts. Each question in the survey was subject to review. The 

expert review focused on the validity of the responses to each question (e.g., checking that the treatment 

sequence is logical), consistency across questions (e.g., the treatment practice is consistent with the 

treatment objectives), and that questions were answered and reviewed consistently across by water 

systems. Any further changes were documented and logged. 

4.5 Data Processing Quality Assurance 

The completed surveys were edited and entered into an electronic database. The electronic data were then 

imported into a hierarchical database for distribution, and a statistical package for detailed analysis. 

Procedures were in place at every step to maintain the integrity and quality of the data. 

4.5.1 Data Entry 

Most water systems chose to fill out the questionnaire using the Excel spreadsheet. After completing the 

survey, the water system then uploaded it directly into the database. Throughout the entire process, 

validations checks were established to assure the highest quality responses. Automatic checks were in 

250 
built into the spreadsheet to make sure water systems input valid information. For example, water 

systems were asked to input percentages as a whole number, 25 percent was entered as 25, not .25. If a 

water system entered in the number .25, a message would appear asking the water system to verify the 

accuracy of the inputted number. In this manner the responses were controlled as the water system 

entered data. 

When a completed questionnaire was uploaded into the database by the water system, the data were 

subjected to a second set of automated checks. A report was created for the water system about any data 

issues. They were then given the option to change data before submitting the questionnaire. 

A paper copy of the completed questionnaire was printed out after the data were uploaded by the water 

system. The paper copy was reviewed by an analyst and changes were tracked directly on the paper. 

After senior staff approved the changes through an additional round of quality assurance, then the changes 

were made to the online database. This process allows for the database to maintain the most recent 

dataset and all responses can be tracked back to the original survey response. 

4.5.2 Automated Data Validation Checks 

In preparing the final database, EPA and Cadmus designed, produced, and analyzed a series of computer 

validation checks. These checks were run on the full survey database after the data were entered and 

passed the standard computer edits for values and ranges on a variable-by-variable basis. The checks 

included the following: 

C Distribution frequencies for all categorical variables; 

C Distribution frequencies for all continuous numerical variables formatted into four categories 

(non-zero responses, zero responses, legitimately skipped, and missing); 

C Univariates for each continuous variable; 

C Item-specific cross-tabulations of categorical variables; 

C Item-specific cross-univariates of continuous data; and 

C Item-specific advanced logic edits. 

4.5.3 Database Quality Assurance 

The final, clean survey database represented the product of the various review, editing, data entry, and 

data validation steps described above. Once the database was prepared, there were a number of 

subsequent data processing steps required to create a variety of files suitable for analyses and tabulations 

for the final delivery of a permanent database to EPA. The principal steps included: 

C Appending needed variables from external files, including sample and contact information 

from SDWIS. 

C Analyzing the hard copy questionnaires and the frequency distributions of continuous and 

categorical variables to devise rules for handling missing data. 

C Zero-filling blank responses. A detailed series of rules was developed for assessing blank 

responses and determining whether to regard these as zeros or missing values. In general, 

251 
blank quantity fields were treated as zero, except when there was external evidence in a 

logically related item that the response should not be zero. A detailed set of programming 

specifications was designed to implement these rules. 

C Creating new derived variables from the survey data to categorize systems into strata 

comparable to the original sampling strata but based on the final survey responses rather than 

the SDWIS data. 

C Attaching the sample weights to the analytical file. 

C For the final delivery of the database to EPA, deriving and attaching the numerous composite 

variables created for the production of the analytical tables in this report. 

Each step was planned in advance. Detailed specifications were written to guide the programming and 

data processing needed to perform each step. These documents are crucial quality assurance tools to help 

ensure that systems analysts have a clear and common understanding of the entire process of data 

management, that the processing stages fit together in a logical order and accomplish the intended 

objectives, and that there is an unambiguous audit trail of the condition of the data at each stage. 

Version control was maintained for all computer programs, and interim stages of all data files were 

permanently archived. This meant that when changes were made to a program or process, it was clear 

which the current version was and the sequential changes that had been made from one version to the next 

were apparent. It was always possible to restore any earlier version in full or to merge selected data from 

the old version to the new version. 

The combination of the processing specifications, version control, and data archiving ensured that no 

process was irreversible, that it was always possible to recover from any deliberate or inadvertent changes 

to the data, and that the characteristics of the survey data were fully known at each processing stage. 

4.5.4 Tabulation Quality Assurance 

The tabulations of the results presented in the tables in this report are varied and complex. Rather than 

being a simple presentation of individual survey variables, each table usually presents the results of 

multiple calculations involving several survey variables. Many tables present several such results in a 

single table. There often were several different ways of defining or calculating an item of interest, and 

sometimes there were different direct or derived sources of data for the calculation available on the survey 

database. Hence, the following steps were taken to help assure that each table accurately summarized and 

presented the data contained in the final survey database. 

C Identify important, relevant, and useful information that could be developed from analyses of 

the survey data; 

C Design each table to effectively present the results or to juxtapose related results in the same 

table; 

C Clearly describe the contents of each table; 

C Define in detail the variables, values, formulas, and derivations that went into each 

calculation; 

252 
C Prepare clear and detailed data processing specifications for carrying out the tabulations 

according to the calculation definitions; 

C Develop computer programs to process the data pursuant to the tabulation specifications; 

C Review the initial tabular output for: 

B Consistency with the design of the table of contents; 

B Conformity with the definitional and programming specifications; and 

B Reasonable agreement with expected values-based on external measures and expert 

knowledge of water system operations and finance; 

C Review definitions, specifications, programs, and underlying data for tabulations exhibiting 

data anomalies or outliers; 

C Review any definitions, specifications, or programs if the review process identifies errors or 

the need for modifications to previous decisions; and 

C Repeat previous tabulation quality assurance steps and re-run tabulations until no further 

unacceptable data anomalies are found. 

The tabulation process was fully automated, from the underlying source data through all processing stages 

to the final formatted tables. There were no intermediate stages requiring manual transfer or entry of data 

from one stage to the next. This eliminated human transcription error. Of equal importance, it also 

expedited the process of successive iterations of the tabulations during the quality review process, as each 

time a table was produced the output data automatically were transferred into the same final table form as 

on the previous iteration. This ensured that any new anomalies identified in later iterations did not result 

from transcription errors, and allowed the review staff to focus their investigations on the table data, 

specifications, and programs. 

4.6 Quality Assurance during Report Preparation 

The Survey’s quality assurance plan was followed throughout report preparation. Estimates in the report 

were produced in the statistical package Stata using a series of programs (called “do files”). The 

programs were reviewed by at least two analysts and all changes were tracked and documented. 

Estimates were internally reviewed and revisions were tracked. Decisions to exclude outliers or other 

data from analyses were documented. The reports were reviewed internally by Cadmus and by EPA. 

They also were reviewed by external experts, as discussed in the next section. 

4.7 Peer Review 

The sampling plan was reviewed by two independent external reviewers, A. Richard Bolstein of George 

Mason University and John Gaughan of the Temple University School of Medicine. Barry Nussbaum of 

EPA’s Office for Environmental Information also reviewed the sampling plan. Bimal Sinha from the 

University of Maryland also provided comments. The peer reviewers were asked to assess the September 

7, 2006 draft of the Sampling Plan for the 2006 Community Water System Survey. The peer reviewers 

were also provided with a copy of the survey instrument as background. The reviewers made 

recommended some minor changes to the sampling plan for small systems. The plan’s approach for 

dealing with primary sampling units whose composite measure of size exceed five was modified based on 

253 
reviewers’ comments. The reviewers also recommended revisions to the sampling plan description to 

clarify the survey’s approach. The final report was reviewed by the following: Barry L. Liner, PE and 

David Binning, PE of AEM Corporation, Scott J. Rubin, JD, and Janice Beecher, Ph.D., Michigan State 

University. 

254 
Appendix: 

Community Water System Survey Questionnaire 

255 

CWSS Questionnaire 

United States 

Environmental Protection Agency 

SURVEY OF COMMUNITY WATER SYSTEMS 

Exp
CWSS Questionnaire 

When you complete the survey, please upload it to our Web site at: 

www.CWSSurvey.com 

Follow the instructions to upload your completed questionnaire. Please have your login ID available. 

from the Cadmus Group, Inc. 

CWSSurvey@cadmusgroup.com 

You also may print a copy of the completed questionnaire and send it to us in the pre-paid Federal Express envelope provi

(Please call the toll free number sent with your introductory letter if you need a Federal Express envelope.) 

Or you may mail your printed copy of the completed questionnaire to: 

EPA Community Water System Survey 

c/o The Cadmus Group, Inc. 

57 Water Street 

Watertown, MA 02472 

Participation in the survey is voluntary. 

in prior surveys. 5 hours per respondent annually. provide information to or for a Federal agency. 

g 

number. The OMB control numbers for EPA's regulations are listed in 40 CFR Part 9 and 48 CFR Chapter 15. 2040-0273 and the expiration date is 1/31/2010. accordance with 5 CFR 1320.5 (b). Office of Management and Budget, 725 17th Street, NW, Washington, DC 20503, Attention: Desk Officer for EPA. correspondence. Do not send the completed survey to this address 

OM

This information was sent with you

If you are missing your introductory letter and need your login ID or prefer to return this questionnaire by e-mail as an attachmen

However, as a matter of policy, EPA will not disclose the identity of any respondent to this questionnaire, 

identity of any participating water system. While no respondent has ever claimed that the information asked for in this survey contains confidentiainformation (CBI), EPA will offer you the opportunity of claiming CBI in the event that we receive a Freedom of Information Act request for any would identify you or your system. It should be noted, however, that EPA has never received a Freedom of Information Act request for such informThe public reporting and record-keeping burden for this collection of information is estimated to average 3.58 hours per response, or from 1 hour t

Burden means the total time, effort, or financial resources expended by persons to generate, maintain, retain, or d

This includes the time needed to review instructions; develop, acquire, install, and utilize technolo

systems for the purposes of collecting, validating, and verifying information, processing and maintaining information, and disclosing and providininformation; adjust the existing ways to comply with any previously applicable instructions and requirements; train personnel to be able to respond collection of information; search data sources; complete and review the collection of information; and transmit or otherwise disclose the informatioagency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB 

The OMB Control Number for the 

The agency is required to display the OMB Control Number and inform respondents of its legal s

If you wish, you may send comments on the Agency's need for this information, the accuracy of the provided burden estimates, and any suggested for minimizing respondent burden, including through the use of automated collection techniques to the Director, Collection Strategies Division, U.Environmental Protection Agency (2822), 1200 Pennsylvania Ave., NW, Washington, D.C. 20460; and to the Office of Information and Regulator

Include the control number in 

Expiratio

i
CWSS Questionnaire 

Dear Owners and Operators of Community Water Systems: The United States Environmental Protection Agency (EPA) is conducting a national survey of drinking water systems, and yours is one of abhave been randomly selected to participate. According to your state's database, you have been identified as the most appropriate person to pryour water system. Participation in the survey is voluntary. What sort of information are we seeking? Information on a range of operating and financial characteristics, from the current treatment processystem, to your annual revenue and expenses. There are even a few questions that address security considerations. Conducted about every five years, this survey represents the first time we’ve been able to offer a variety of ways to participate. A hard copy be available, as always. But you will also be able to download a spreadsheet version of the questionnaire, or complete the questionnaire at a site. You will be contacted soon to determine which approach suits you best. If you would like to get started before you are contacted, detaquestionnaire are included from the Cadmus Group, Inc., the contractor administering the survey for EPA. This survey will accomplish a number of important objectives. It will give EPA current data to let us better consider the costs and benefits to develop new national drinking water regulations. It also will allow us to measure the impact of drinking water regulations put in place since turn, will help us determine more affordable approaches to drinking water treatment. Furthermore, the answers you provide will help us deve

programs to safeguard our nation's drinking water, provide guidance to the states, and measure the effectiveness of existing federal programsWater State Revolving Fund. This survey is part of a larger data collection effort by EPA. You also may be asked to provide information abneeds through the Drinking Water Infrastructure Needs Survey and Assessment. You will be contacted separately regarding the Needs SurveAs we have done in the past, EPA will only make use of the information you provide when it has been aggregated with the responses of many the same size category as yours. We will never disclose your name or the name of your water system in any public documents. The question

how your privacy will be protected. The agency is required to display the Office of Management and Budget (OMB) Control Number and inlegal significance in accordance with 5 CFR 1320.5 (b). The OMB Control Number for the survey is 2040-0273. The expiration date for Co

31, 2010. Answers to this questionnaire will help EPA understand your circumstances better than any other tool we have. If you have ever wanted to h

development of national rules that could directly affect you and your water system, providing answers to this questionnaire is an important conly 2,000 of you are being asked to speak for over 50,000 other systems, your voice is that much more important and will carry that much mever felt that federal regulators don't understand your situation, then please take this opportunity to tell us, in detail, just what your situation isdifference. 

Sincerely, Brian C. Rourke Program Analyst 

Standards and Risk Management Division Office of Water, US Environmental Protection Agency 

ii 
CWSS Questionnaire 

GENERAL INSTRUCTIONS 

This questionnaire asks about your system's operational and financial characteristics. Questions 1 through 4 ask for general information about your system.Questions 5 through 20 ask about your system's operational characteristics, including its water sources, treatment practices, storage and Questions 20 through 28 ask about your system's financial characteristics, including number of connections, revenue, expenses, and capiIf you received and completed EPA's Water Treatment Plant Questionnaire AND and you are willing to give EPA access that infosurvey, you do not need to complete questions 21 to 24, and questions 26 to 28. You will be contacted to confirm that you are williPlease complete the questionnaire. Save your file early and often!Additional copies of the questionnaire are available at www.CWSSurvey.com. To access the Web site, you will need to have your login ID available. The login ID and password were mailed to separately in an introductory letter from the Cadmus Group, Inc. This letter also conhelp-line for you to call if you needed any assistance. If you do not have this information, please contact The Cadmus Group, Inc. through CWSSurvey@cadmusgroup.com. You may upload the completed questionnaire to our Web site at www.CWSSurvey.com or send it to us via e-mail at CWSSurvey@cadmuYou also may print a copy and send it to us by FedEx or U.S. mail. We recommend uploading it to the Web site because you will be able your responses. See below for upload instructions.You are also encouraged to send schematics, diagrams, financial reports, or other information that will help provide a complete picture of If you have electronic copies of the documents, you may upload them to www.CWSSurvey.com. Please have your login ID available to uIf you only have paper copies, you may request a pre-paid FedEx envelope by e-mailing us at CWSSurvey@cadmusgroup.com, or by the number on your introductory letter from the Cadmus Group, Inc.To upload the survey to the Web site after completion: Please save your file often! And before uploading the questionnaire, please save the file one additional time. The upload process will uplrecently saved file. If you make changes before saving and attempting the upload, the new information will not be uploaded. After using 

password to access your water system's account at www.CWSSurvey.com, you will seen an option to upload your survey to the Web site. instructions once you have logged in to upload the file from your computer. After the upload you will have an opportunity to review any inconsistencies found in the questionnaire during the upload process. A reporthat explains these inconsistencies. You may print out the report, correct any issues you agree with in the file on your computer, save the 

corrected questionnaire. If you make any changes, be sure to save this report before you upload the questionnaire again! Once you agree  responses, you can finalize your responses by clicking the "Submit" button. The upload process will automatically fill out the online questionnaire at the website. The report that highlights inconsistencies in the resp

iii 
CWSS Questionnaire 

GENERAL INSTRUCTIONS 

will have hyperlinks to where this response appears in the online form. layout of the online form is different than that of the spreadsheet.) To e-mail your survey as an attachment: You may e-mail the questionnaire as an attachment to CWSSurvey@cadmusgroup.com. Your e-mail program will attach only the most recently saved version of the file. 

incorrect information will be submitted. Please save early and often! 

You may also e-mail copies of any your documents to the same e-mail address. Note on printing and mailing the questionnaire: Only the first page of every sheet is currently set to print. settings. Please ensure that you print out all information. the Cadmus Group, Inc.. Someone will assist you in changing the print ranges. Other versions of the questionnaire: If you prefer to have your work stored online, you may complete the questionnaire through the online form at www.CWSSurvey.com. There is a paper version of the questionnaire available. 

Questions? Comments? Concerns? 

Cadmus or e-mail Cadmus at CWSSurvey@cadmusgroup.com 

You will have the option to change your responses online. (Please 

If you choose this method, please save your file 

If you make any changes but do not save the file before 

Any information you add outside of this print range will not print unless you ad

If you need any help, please call the toll free number sent with your introductory 

If you decide to print out the questionnaire before starting 

please call toll-free and we will send you a paper version of the questionnaire via FedEx to ensure that all questions are returned in the pos

It can be sent to you via FedEx, along with a postage-paid envelope for easy return

If you have any questions, please call The Cadmus Group, Inc., toll-free using the number on you

iii
CWSS Questionnaire 

1 Please provide the name, title, and telephone number of the most knowledgeable person to contact for 

information. 

A. Part I – Operating Characteristics B. Part II – Financial Characteristics 

(Write “SAME” if same as A) 

Name: Title: Tel. No. Fax No. E-mail: 

2 This survey will ask you to provide operating and financial information for your public water system for 

the most recent 12-month period for which data are available. Please specify below the end dates for which 

data are provided. For part B, you may use data from the most recently completed fiscal year or the most recent year for which audited financial reoprts are available. A Operating information (end date):

mm dd yy

B Financial information (end date):

mm dd yy

1 
CWSS Questionnaire 

3A Please classify your water system using the following criteria. (Please check only one) 

Owned and operated by a government or public agency (not including government-owned systems that hire a private company to operate the system) Owned by a government or public agency and operated by a private contractor Owned privately and operated for profit primarily as a water business (e.g., American Water Company) Owned privately and not operated for profit (e.g., a homeowners association or a non-profit cooperative) Owned privately and operated as a necessary part of another business (e.g., a mobile home park) Please specify your primary business in part B. 

B If the system is owned privately and operated as a necessary part of another business, please specify the 

type of business:

4A Do you have regular access to a computer for sending and receiving information? 

Yes No (Skip to question 5) 

B Do any of your computers have the following software or peripherals? (Please check all that apply) 

Microsoft Excel Microsoft Access CD drive DVD player 

C What access do you have to the Internet? (Please check only one ) 

High-speed Internet access (e.g., cable, DSL, wireless, or T1) Dial-up modem access No access 

2 
Figure 1: Sample diagram of intakes, treatment 

CWSS Questionnaire 

The following definitions of water system components are used in this survey. Figure 1 is an example of a schematic of a water system shoplants, transmission lines, and the distribution system. Please refer to these definitions and the schematic for an explanation of the terms used in questions 6 through 11. Please submit diagrams as a guide. Please note that the identifier numbers used in the questions do not refer to specific items in figure 1. For example, use ‘S1' to refer to yoregardless of whether it is a flowing stream, as depicted in the schematic, or another surface water source. 

Term 

Example Code Definition 

Surface water intake 

S1, S2 Surface water intake refers to the structure at the surface 

water source (flowing stream, lake, reservoir, or ground water under the direct influence of surface water [GWUDI]) that permits the withdrawal of the water from that source. 

Ground water source 

G1, G2, G3, G4 

Ground water source refers to the connection of untreated water from one or more wells to a water treatment plant or directly into the distribution system. Where the water from multiple wells flows through a common pipe prior to entry to the treatment plant or distribution system, the combined flow is considered one ground water source. Do not include 

GWUDI. 

Purchased water connection 

P1, P2 A purchased water connection refers to the transmission of 

water from the seller's water system to a water treatment plant or directly to the distribution system of the purchaser's water system. 

Water treatment plant 

WTP 1, WTP 2 

A water treatment plant is any facility where water is filtered, disinfected, or otherwise treated prior to its transmi(or its conveyance to another purchasing water system). For the purposes of this survey, simple disinfection only entry into the distribution system are considered to constitute a water treatment plant. Other examples include larchemical feed on wells for disinfection. It does not include facilities within the distribution system that boost disi

Buyer B1, B2, B3 A buyer refers to any public water system to which water is sold. 

Entry point E1, E2, E3, 

E4 

An entry point is where treated or untreated potable water enters the water system's distribution system. 

3 
CWSS Questionnaire 

5 Please provide a copy of the schematic of your system. (Remember: you may send an existing schematic if available) 

Figure 1 is an example of the type of schematic requested. This information can be transmitted two ways. 1. If your files are stored on your computer:

A. Upload the schematic at the Web site www.CWSSurvey.com or, 

B. E-mail the schematic as an attachment to CWSSurvey@cadmusgroup.com 

To access the Web site you need to have your login ID and password available. The login ID and password were mailed to you separately. If you do not have your login information, please e-mail: CWSSurvey@cadmusg

2. If you prefer to send a hard copy through the mail, please call the toll-free number from your introductory letter from 

the Cadmus Group, Inc to request a pre-paid FedEx envelope to return this information.

Figure 1 is an example of the type of schematic requested. Please note that this can be e-mailed or uploaded at the same time as the financial information requested later in the surv

4 
CWSS Questionnaire 

Provide the following information for the ground water sources, surface water intakes, or purchased water connections for this water system. MG is millions of gallons of water. MGD is millions of gallons per day. If the source is used on a seasonal or emergency basis, the average daily amount is for the days the source is used.6A Ground water sources. (Click here to go to the definition on tab Fig 1.) 1 How many ground water sources (i.e., treatment plants or groups of wells tied directly to the distribution system) are in your water system? 

Number of sources: 

2 Please list each well or group of wells feeding into a single ground water entry point separately by line. 

Notes for the table: 1. Treatment includes any process that alone or in combination with other processes has an objective of producing or maintaining potable wa2. If you do not know the limit of your source, please leave this column blank. Limits on the availability of water include source capacity, water quality requirements, state and local water resource plans, local econom projections, contractual obligations, permits, water rights, and legal constraints. Limits also include current equipment constraints impose

pumps, and water treatment plant capacity. 

Ground water 

sources 

How many 

individual wells 

supply this ground 

water source? 

Is this a 

seasonal 

source? 

(Yes or No) 

Is this an 

emergency 

source? 

(Yes or No) 

If this is a seasonal 

or emergency 

source, how many 

months was it used 

in the 12-month 

period reported in 

question 2A? 

Is the water from 

this source treated 

by your system?1 

(Yes or No) 

What is the total 

amount of water 

drawn from this 

source in the 12-

month period 

reported in question 

2A? 

(MG) 

On av

much 

draw

source 

day w

used 

report

que

(

G1 G2 G3 G4 G5 G6 G7 G8 G9 

G10 

5 
CWSS Questionnaire 

6B Surface water intake identifiers. (Click here to go to the definition on tab Fig 1.) 

1 How many surface water intakes are in your water system? 

Number of intakes: 

2 Please list each surface water intake separately by line. 

Notes for the table: 1. GWUDI is ground water under the direct influence of surface water. 2. Treatment includes any process that alone or in combination with other processes has an objective of producing or maintaining potable w3. If you do not know the limit of your source, please leave this column blank. Limits on the availability of water include source capacity, water quality requirements, state and local water resource plans, local econo

 and growth projections, contractual obligations, permits, water rights, and legal constraints. Limits also include constraints imposed by 

components, pumps, and water treatment plant capacity. 

Surface water 

intake identifiers 

What is the source for 

this surface water 

intake? 

(Please select one) 

1) Flowing stream, 2) Reservoir or lake, 3) GWUDI1 

Is this a 

seasonal 

source? 

(Yes or No) 

Is this an 

emergency 

source? 

(Yes or No) 

If this is a seasonal 

or emergency 

source, how many 

months was it used 

in the 12-month 

period reported in 

question 2A? 

Is the water from 

this intake treated 

by your system?2 

(Yes or No) 

What is the total 

amount of water 

drawn from this 

source in the 12-

month period 

reported in 

question 2A? 

(MG) 

On av

much 

draw

source 

day w

used 

reporti

que

(

S1 S2 S3 S4 S5 S6 S7 S8 S9 

S10 

6 
CWSS Questionnaire 

6C Purchased water connections. (Click here to go to the definition on tab Fig 1.) 

1 How many purchased water connections are in your water system? 

Number of connections: 

2 If your system purchases water from one source but has multiple connections or turnouts, please list each connection or turnout separately by lin

Notes for the table: 1. Treatment includes any process that alone or in combination with other processes has an objective of producing or maintaining potable water2. GWUDI is ground water under the direct influence of surface water. 3. If you do not know the limit of your source, please leave this column blank. Limits on the availability of water include source capacity, water quality issues, state and local water resource plans, local economic develop projections, contractual obligations, permits, water rights, and legal constraints. Limits also include constraints imposed by system compone

capacity, and water treatment plant capacity. 

Purchased 

water connections 

Provide the 

PWSIDs or name 

of the sellers for 

each connection. 

A seller can appear 

more than once. 

Is this a 

seasonal 

source? 

(Yes or No) 

Is this an 

emergency 

source? 

(Yes or No) 

If this is a 

seasonal or 

emergency 

source, how 

many months 

was it used in 

the 12-month 

period 

reported in 

question 2A? 

When you 

purchase this 

water, is it one of 

the following? 

(Please select 

one) 

1) Finished, 2) Partially 

treated1 , 

3) Untreated, 4) Unknown 

What is the 

source of the 

purchased 

water? 

(Please select 

one) 

1) Ground, 2) Surface, 3) GWUDI,2 

4) Unknown 

Do you 

boost 

disinfection 

of water 

from this 

source after 

it enters the 

distribution 

system? 

(Yes or No) 

Do you 

provide any 

other 

treatment1 to 

this water 

besides 

booster disinfection? 

(Yes or No )

What 

total a

of w

drawn 

this sou

the 12-

per

report

questio

(M

P1 P2 P3 P4 P5 P6 P7 P8 P9 

P10 

7 
CWSS Questionnaire 

7 Provide the following information for each water treatment plant in this water system. A water treatment plant is any facility that treats 

the quality of the water prior to its entry to the distribution system. Large-scale filtration plants, chemical feeds on wells for disinfectionadjust pH prior to entry to the distribution system are included. Facilities within the distribution system that boost disinfection are not in

A How many water treatment plants are in your water system? 

Number of plants: 

B Please provide the following information for each water treatment plant in this water system. 

Notes for the table: 

Average daily production is the total amount of water produced by the plant divided by the number of days the plant was in use du

period in question 2A. Mathematically, it is the sum of all the daily flows divided by the number of daily flows. Design capacity ramount of water the plant can produce in a single 24-hour period with all treatment trains operating at capacity. Peak daily produc

amount produced in a single day over the 12-month reporting period in question 2A. 

Water 

treatment 

plant 

identifier 

List all of the surface, ground, and purchased 

water sources from question 6 that feed into each 

water treatment plant. 

What was the average daily 

production of each water 

treatment plant for the 12-month 

period reported in question 2A? 

(MGD) 

What was the design capacity for 

each water treatment plant? 

(MGD) 

WTP1 WTP2 WTP3 WTP4 WTP5 WTP6 WTP7 WTP8 WTP9 WTP10 

8 
CWSS Questionnaire 

Use the treatment process codes in table 1 and the objective codes in table 2 to describe the treatment processes used by each plant in question 

Table 1: Treatment Processes Codes 

Treatment CodeDisinfection

Chlorine T1 

Chlorine dioxide T2 Chloramines only Chloramine with a free chlorine 

T3 

T4 

period (based on need in the distribution system and not routinely done) 

Chloramine with seasonal T5 

(routine) free chlorine use 

Ozone T6 

Ultraviolet light Mixed oxidant 

T7 

T8 

Filtration Processes 

Coagulant addition/rapid mix Polymer addition Flocculation 

T9 

T10 T11 

Settling/sedimentation Lime/soda ash softening Recarbonation 

T12 

T13 T14 

Filtration 

Micro strainer T15 Slow sand filter T16 Bag or cartridge Diatomaceous earth 

T17 T18 

Pressure filtration T19 Green sand T20 

Treatment Code Filtration (continued)

Rapid sand filter Deep bed mono-media Dual/multi media 

T21 T22 

T23 

Membranes 

Reverse osmosis T24 

Microfiltration T25 

Ultrafiltration T26 

Nanofiltration T27 

Other 

Aeration T28 

Potassium permanganate Corrosion control 

T29 

T30 

Ion exchange 

Activated alumina 

T31 T32 

Iron-based adsorptive media 

Sequestration 

Fluoride addition 

T33 

T34 

T35 

Dissolved air flotation T36 

Granular activated carbon T37 Centrally managed POU/POE 

Clearwell and/or contact vessel 

(e.g., basin, pipeline) 

Other (1) see question 8 Other (2) see question 8 Other (3) see question 8 

T38 

T39 

T40 T41 T42 

Table 2: Treatment Ob

Treatment 

Algae control Corrosion control Primary disinfection Secondary disinfection Disinfectant byproduct control Dechlorination Oxidation Iron removal Manganese removal Taste/odor control TOC removal Particulate/turbidity removal Softening (hardness removal) Recarbonation Organic chemical contaminant removal (e.gInorganic chemical contaminant removal (eRadionuclides contaminant removal Security Mussel control Fluoridation Other (1) see question 8 Other (2) see question 8 Other (3) see question 8 

9 
CWSS Questionnaire 

8A Using the water treatment plant identifiers from question 7, characterize the treatment practices used in each of your system's treatment plants. 

- Please enter the treatment process and objective for each step of the treatment practice. Use the codes from tables 1 and 2 above. - You may enter up to 30 steps. Each step may have up to three processes and six objectives. - Do not include disinfection booster stations that are within the distribution system. 

Two examples are provided. The first example is conventional filtration. The second is iron/manganese removal. 

Roll your mouse here in order to see a list of processes and their codes Roll your mouse here in order to see a list of objectives and their codes 

WTP Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 Step 8 Step 9 Step 10 Step 11 S

Ex. 1 

Process T10 T11 T12 T23 T1 T39 

Objective O12 O12 O12 O12 O3 O3 

Ex. 2 

Process T29 T20 T1 

Objective O7 O8 O9 O8 O9 O3 

WTP1 

Process 

Objective 

WTP2 

Process 

Objective 

WTP3 

Process 

Objective 

WTP4 

Process 

Objective 

WTP5 

Process 

Objective 

WTP6 

Process 

Objective 

WTP7 

Process 

Objective 

WTP8 

Process 

Objective 

WTP9 

Process 

Objective 

WTP10 

Process 

Objective 

10 
CWSS Questionnaire 

8B Specify the other treatment practices from the water treatment plant identifiers from question 7. If, in the last table, you have other unspecified treatment processes or objectives (i.e., you used treatment codes T40, T41O22, O23), please write them in here. These treatment codes (T40, T41, and T42) are for any treatment process you use that is not listed in Table 1 on page 9. Please specify what each process is: 

T40: Other (1) T41: Other (2) T42: Other (3) 

These treatment codes (O21, O22, and O23) are for any objective you are trying to achieve that is not listed in Table 2 on page 9. Please specify what each objective is: 

O21: Other (1) O22: Other (2) O23: Other (3) 

11 
CWSS Questionnaire 

9 Using the water treatment plant identifiers from question 7, indicate if the specified residuals management practices are used and provide t

requested information regarding potential discharge. (Yes or No for each category) 

Notes for the table: 

1. Systems that are allowed to discharge to a waterway, septic system, or sanitary sewer do not face any legal or permitting restrictions on such discha

Do you use the following residual management process in the following water treatment plants? 

Water 

treatment 

plant 

identifier 

(Use the water treatment plant numbers from Question 7) 

Dewatering Disposal 

Mechanical 

dewatering 

(e.g., belt 

presses, 

centrifuges, 

pressure 

filters, and 

vacuum 

filters) 

Nonmechanical 

dewatering 

(e.g., 

lagoons, 

drying beds, 

and freeze 

assisted 

drying beds) 

Land application 

(e.g., 

beneficial 

use) 

On-Site 

Storage 

Deep 

well 

injection 

Waste landfill Waterway Septic system Sanit

Hazardous 

waste 

landfill 

Nonhazardous 

waste 

landfill 

Are you 

allowed to 

discharge 

to a waterway 

(surface 

water)?1 

If yes, 

do you 

discharge 

to a 

waterway? 

Are you 

allowed to 

discharge 

to a septic 

system?1 

If yes, do 

you 

discharge 

to a 

septic 

system? 

Are you 

allowed 

discharg

to a 

sanitary sewer?

WTP1 WTP2 WTP3 WTP4 WTP5 WTP6 WTP7 WTP8 WTP9 

WTP10 

12 
QUESTION 10 IS NOT ASKED FOR SYSTEMS IN YOUR SIZE CATEGORY, THEREFORE, THE QUESTION IS GRAYED 

ON YOUR QUESTIONNAIRE. PLEASE CONTINUE TO QUESTION 11.

CWSS Questionnaire 

10 A Is your system currently treating (directly or indirectly) for any contaminants not regulated by the federal government? 

(Directly means that the treatment in place is due to the presence of the unregulated contaminant. Indirectly means that the unregulated contaminant is being addressed because of current treatment practices for a regulated contam

YesNo (Skip to question 11) 

B Please provide the following information about unregulated contaminants addressed by your treatment plants. 

. 

Raw water Finished Water 

What are the unregulated contaminants that are being addressed by your treatment plants? Concentration Units Concentration Units 

13 

If known, please provide the concentration of the unregulated

contaminant in the raw and finished water as it leaves the plant

Enter N/A if unknown. Enter ND if the contaminant was not 

detected. Please also provide the units as well (e.g., mg/L). 

What wa

treatment plan

for the unreg

contaminant

plant ident

from questi
CWSS Questionnaire 

11 A What is the total capacity of storage located past 

the first residential customer? (in millions of gallons) 

B Please indicate the number of each type of storage facility you 

have in your utility that is located past the first residential customer. 

1 Fully or partially buried 2 Ground level 3 Elevated 4 Hydropneumatic 5 a. Standpipes 

b. How many standpipes are operated 

 as surge tanks? 

6 Other 

C Indicate the typical number of years between 

cleaning an individual storage vessel: 

14 

D Please provide the following information about the practic

quality in storage vessels. Also indicate additional inform

regardless of whether you use a practice. 

Do 

of t

p

ma

sto

in y

(Ple

th

a Modeling or other detention time evaluationsb Longer fill/draw cycles to increase mixingc Inlet/outlet modifications d Mechanical mixing 

e Increase or switch disinfectant residual 

f Operational modifications to maintain 

disinfectant residual 

g Other (please specify) 
CWSS Questionnaire 

12 Estimate the length of the transmission lines and distribution mains in your system, and length of pipe replaced in the last 5 years. 

A transmission line is defined as a pipeline that transports raw or partially treated water to a water treatment plant or that transports findistribution mains.A distribution main is defined as part of the pipeline network that distributes water to consumers.Replaced pipe is pipe that has either been physically removed from the ground or has been subject to major rehabilitation efforts.New pipe installed is new transmission lines or distribution mains that do not replace existing pipe. 

Source 

Pipe Type and Diameter 

Existing (or current) Length of pipe replaced 

length of pipe the past 5 years1 

(In Miles) (In Miles) 

Transmission lines 

Mains 

Less than 6" 6-10" Greater than 10" and Less than 24" 24" or greater 

Transmission Line Water Treatment 

Plant 

Transmission Line

D

1. Ending on the date shown in your answer to question 2A 

15 
CWSS Questionnaire 

13 A Please provide the following information about each pressure zone in your distribution system. 

1 How many pressure zones do you have in your distribution system? 2 How many pressure zones have booster disinfection stations? 3 How many booster disinfection stations do you have throughout your distribution system? 

B If your system has experienced a loss of pressure below 20 psi during the past operating year, 

please tell us the number of pressure losses that occurred for each of the following reasons: 

1 Power outage 2 Fire 3 Main pipeline burst 4 Other (such as maintenance, flushing) Please specify 

14 Do you flush your distribution system on a regular basis? 

Yes No (Skip to question 17) 

15 What percentage of the distribution system is flushed each year on a regular basis? 

(Please enter a whole number for the percentage, e.g., 50% is entered as 50, not .50) 

16 What approach is used when you flush your system on a regular basis? (Please check all that apply) 

A (Uni-) Directional (Restricting water flow to one direction using closed valves to maximize velocity, 

generally from source/plant to the lowest elevation in the system) 

B Conventional, random, or non-directional (Opening hydrants on lines without closing valves or 

restricting the direction of water flow)

C Dead end (opening a hydrant or flush valve on the dead-end line)D Other (Please specify)

17 A If you do not flush your system on a regular basis, have you ever flushed your system? 

Yes No (Skip to question 18) 

B 1 What was the last year in which you flushed your system? 

2 In what year did you flush the system before that? 

(Enter "NA" if you only flushed the system once.) 

16 
CWSS Questionnaire 

18 A Do you use chemical disinfection at any of your water treatment plants? 

Yes No (Skip to question 19) 

B Please provide the following data on disinfection residuals for one summer month (June, July, August, or September) and 

winter month (December, January, or February) for the treatment plant in the system with the highest average daily flow. (For the last part of the question asking for a percent, please enter the percent as a whole number instead of a decimal, e.g., 50% is entered as 50, not .5) 

Treatment Plant Distribution system 

Average entry point disinfectant residual for the 

treatment plant with the highest average daily Average distribution system Perce

flow disinfectant residual system 

Season Month 

(mg/L as Cl 2 ) (mg/L as Cl 2 ) incl

Total Cl2 Free Cl2 Water Source Total Cl2 Free Cl2 

Summer 

Winter 

17 
QUESTION 19 IS NOT ASKED FOR SYSTEMS IN YOUR SIZE CATEGORY, THEREFORE, THE QUESTION IS GR

ON YOUR QUESTIONNAIRE. PLEASE CONTINUE TO QUESTION 20.

The percentage of your residential customers adds to 0 percent. Please make sure it adds to 100 percent.

CWSS Questionnaire 

19 Please list the 5-digit ZIP codes in your service area. Please estimate the percentage of your residential customers that 

are in each ZIP code. This information will be used to identify the unique demographic characteristics of your service area so that EPA can better assess the financial and operating characteristics of the system. (Please enter the percent as a whole number instead of a decimal, e.g., 50% is entered as 50, not .5) 

Approximate Percentage of the 

Water System's Residential 

ZIP Code Customers in this ZIP Code 

Approximate Percenta

Water System's Res

ZIP Code Customers in this ZI

1 % 11 

2 % 12 

3 % 13 

4 % 14 

5 % 15 

6 % 16 

7 % 17 

8 % 18 

9 % 19 

10 % 20 

18 
1

2345

CWSS Questionnaire

20 Please answer the following questions about water security. Pleas

A 1 Has your water system attended any EPA-sponsored water security training? 

2 Have you used EPA's Web-based water security technology product guides? 3 Have you heard of EPA's Response Protocol Toolbox? 4 Have you heard of the 14 features of an “active and effective” water security program? 5 What, if any, information do you need that would help you protect your system against security threats? (Please write a br

B 1 Have you heard of mutual aid and assistance agreements or compacts? (If No, skip to section C) 

2 Would you be interested in joining such an agreement or contract? 3 If not, please explain why not : 

C What are the two greatest barriers to enhancing security at your system? (Please select up to 2 from the menus )

1 2 

Choices are: Lack of interest at the system, public, or rate board Competing priorities (regulatory compliance, aging Lack of funding Lack of knowledge / guidance / training materials Other (Please specify) If you selected "Other", please specify on the line below: 

D Who do you prefer to get Water Security Information/Products from? (Please select only one ) 

Department of Homeland Security EPA Water Associations No preference Other (Please specify) 

19 
If you received and completed EPA's Water Treatment Plant Questionnaire AND and you are willing to give EPA access to that in

for purposes of this survey, you do not need to complete questions 21 to 24, and questions 26 to 28. 

Are you willing to give EPA permission to use data from the Water Treatment Plant Questionnaire to complete the financial sections of the Community Water System Survey?

 Yes (Skip to Question 25) No (Continue to Question 21) 
CWSS Questionnaire 

21 A Please complete the table below for the most recently completed fiscal year (the 

12-month period indicated in question 2B). Financial information is needed to assess the financial condition of your water system, to assess possible future expenditures, and to see how costs are distributed among customers. No financial information provided will affect any EPA or other federal financial assistance program. Column A: What was the amount of water produced and delivered to each of the following customer categories? Report the amount in millions of gallons per year (MGY). Unaccounted for water includes system losses and uncompensated uses (e.g., fire flow). Columns B and C: How many connections and people did your drinking water system serve year-round? Please indicate the number of connections and number of 

people served by your water system for all customer types that apply. If you do not 

know the connections or people served, please provide your best estimate. Column D: What were your drinking water system's revenues from water sales for each of the following customer categories? (Enter “0” if you do not have revenue from a source.) 

Column A Column B Column C Column D 

Water Number of Number of Water 

Quantity Connections People Sales 

Delivered Served Served Revenue 

1 Sold to other water suppliers 

a Finished water 

b Partially treated 

or untreated water 

MGY MGY 

2 Residential MGY 

$ $ $ 

3 Non-residential (Commercial,

Industrial, Agricultural) a Finished water 

b Partially treated or 

untreated water 

MGY $ MGY $ 

4 Unaccounted for water and 

uncompensated usage MGY 

21 

B Please indicate your water sys

year from other water-related 

1 Connection and developm

2 Revenue from the Gover

General fund of Municip

3 Other water-related reven

above (e.g., fines, penalt

Please specify 

C Provide the PWSID or name o

included in the response to pa

1 Finished water 

2 Partially treated or untrea

D Please indicate the revenue yo

non-drinking-water-related buincluded above, including rensale of other goods and servic

E If you did not report any reven

how did you pay for your syst
QUESTION 24 IS NOT ASKED FOR SYSTEMS 

THEREFORE, THE QUESTION IS GRAYED OQUESTION 25.

CWSS Questionnaire 

22 Please identify your drinking water system's billing structure. 

(Please check all that apply) Nonresidential 

Customers 

Residential 

A Metered charges Customers 

1 Uniform rate 

2 Declining block rate 3 Increasing block rate 4 Peak period rate (e.g., seasonal)

B Unmetered charges 

5 Separate flat fee for water6 Annual connection fee7 Combined flat fee for water 

and other services (e.g., rental fees, 

association fees, pad fees)

C Other billing methods Please specify

23 A Does your system have a program that lowers the cost of drinking water 

for low- or fixed-income households? 

Yes No (Skip to question 24) 

B What are the eligibility requirements for this program? C How many households qualify 

for the program? 

22 

24 A Does your system serve a residential populat

seasonal basis? The seasonal population is c

that fluctuates within a system based on the population of a water system serving a winte

an influx during certain periods of the year.

Yes

No (Skip to question 25) 

B Please indicate the average daily flow during 

peak season (MGD) :

C Please indicate the approximate number of d

in the peak season (e.g. 30, 60, or 90 days): 
CWSS Questionnaire 

25 Please enter the following information about operators, mangers, and administrative staff that work at the water 

Enter the wage for hourly employees. Exclude overtime pay from the hourly wage. For salaried employees, en

hourly equivalent. For example, for full-time salaried employees, enter their salary divided by 2,080 hours. Benefits include statutory benefits such as FICA and unemployment insurance, as well as pension and other reticontributions, health insurance contributions, vacation, and sick leave. It also includes supplemental pay, includovertime pay for wage employees and holiday pay. (If you do not know the exact information, please provide your best estimate) A Full-time Employees 

Enter the number of full-time employees, their average hourly wage rate or salary equivalent, and their benepercentage of their salary or wages. 

Staff 

1 Operators 

a Treatment Plant 

b Distribution System 

2 Managers 3 Administrative staff 

Number of 

full-time 

employees 

Average 

hourly 

salary 

or wage 

($xx.xx) 

Benefits as a 

percentage 

of salary or 

wages 

$ % 

$ % 

$ % 

$ % 

23 
CWSS Questionnaire 

B Part-time Employees 

Enter the number of part-time employees, the average hours worked per week by part-time employees, their hourly wage rate or salary equivalent, and their benefits as a percentage of their salary or wage rate. 

($xx.xx) 

$ % $ % $ % $ % 

($xx.xx) 

$ $ $ $ 

24 

Staff 

1 Operators 

a Treatment Plant 

b Distribution System 

2 Managers 3 Administrative staff 

Number of 

part-time or 

employees 

Average 

number of 

hours 

per 

employee 

per 

week 

Average 

hourly 

wage 

Benefits as a 

percentage 

of salary or 

wages 

C Contract Employees 

For contract employees that operate the system, provide the number of employees, the number of hours worand the average hourly cost to the system (including wages, salaries, benefits, and fees). 

Staff 

1 Operators 

a Treatment Plant 

b Distribution System 

2 Managers 3 Administrative staff 

Number of 

contract 

employees 

Average 

number of 

hours 

per 

employee 

per 

week 

Average 

hourly labor 

cost 
The percentage of your total ca

percent. Please make sure it ad

CWSS Questionnaire 

26 This question is intended to account for all of your drinking water expenses 

related to the revenues referred to in questions 21 A and B. Please provide finanical data for the latest 12-month period for which they are available. Pleasedo not compile new data specifically for the survey if data already exists. The 

categories below are intended to be mutually exclusive. For example, expenses for purchased water in part B should include the cost of the water only (an 

operating expense), not the capital required to bring it to the system. A Please e-mail or upload available summaries of financial statements, 

including a balance sheet, income statement, and statement of cash flows. 

Please attach a depreciation schedule, if one is available (i.e., a program defining your process for depreciating the value of capital improvements). 

Please follow the upload or e-mail process listed in question 5. 

B Please enter the following routine operating expenses in the past year: 

1 Expenses for purchased water: 

2 Security-related expenses (spending for 

security only, e.g., gates, locks, or guards): 

3 Other routine operating expenses (including 

expenses for labor, chemicals, power, materials and supplies, and contractor services): 

4 Depreciation expenses: 

5 Income taxes: 6 Other payments to the general fund, e.g., 

payment in lieu of taxes: 

$ $ 

$ 

$ 

$ 

$ 

C Please enter the amount of debt service expenditures in the past year: 

7 Interest payments: 8 Principal payments: 

$ 

$ 

D Other Expenses 

9 Capital improvements: $ 

10 Payments to reserve funds: $ 

25 

27 A If you have paid for major capital improve

expansions in the 5 years ending on the da

question 2B, please indicate the total amo

expenditures. 

1 a Land: 

b How much land was purchased (ac

2 Water source: 

3 Transmission and distribution system

4 Treatment: 

5 Storage: 

6 Security (include security-related 

spending not included in other capitaexpenditures): 

7 All other not included above: 

B What percentage of the total capital exp

used for the following? (must total 100 pe

(Please enter the percent as a whole number inis entered as 50, not .5) 

1 System expansion, regardless of whether 

expenditure includes replacement and rep

of equipment or compliance with regulatio

2 Replacement and repair of equipment, reg

of whether it includes compliance with reg

but excluding spending for system expans

3 Compliance with regulations, excluding e

tures for system expansion and replaceme

and repair of equipment: 
The percentage of your cap

expenses adds to 0 percent. make sure it adds to 100 pe

CWSS Questionnaire 

C How were the major capital improvements, repairs, and expansions of the past 5 years from question 27A funded? 

(Please enter the percent as a whole number instead of a decimal, e.g., 50% is entered as 50, not .5) 

Percentage of 

capital expenses 

funded from each 

source (should sum 

to 100 percent) 

For borrowed funds, please pro

Average interest 

rate 

Aver

loan p

1 Current revenue (including payments 

from reserve funds): 

2 Equity or other funds from private investors:3 Department of Homeland Security Grant: 4 Other government grants: 5 Drinking Water State Revolving Fund 

a Principal Repayment Forgiveness: b Loans: 

6 Other borrowing from public sector 

sources (e.g., state or regional authorities): 

7 Borrowing from private sector sources 

(e.g., banks or the bond market): 

8 Other (Please specify) : 

% % % % % % % % % % % % % 

28 Do you have an asset management plan or other formal written strategy addressing 

your long-term (e.g., 20 years or more) needs for infrastructure rehabilitation and replacement? 

Yes No 

26