# Volume II: Detailed Tables and Survey Methodology 

# Community Water System Survey 2000

# Office of Water (4607M)

E P A 815-R-02-005B

December 2002
www.epa.gov/safewater

Printed on Recycled Paper Photo by Brian Rourke 

# Cover Photo : Bangor, Maine Water District Thomas Hill Standpipe . Designed by Ashley B. Tower of Tower and Wallace of New York and Holyoke, MA, the standpipe was built during 1897 by Major James M. Davis on land once owned by the Thomas
brothers.

The standpipe is actually two structures: a 1.75 million gallon riveted steel tank enclosed by a 110-foot tall wooden jacket. The tank itself is 75 feet in diameter and 50 feet tall. It is topped by a “carousel,” a three-ton steel drum from which 24 iron trusses reach to the sides of the building.

The wooden jacket is 85 feet in diameter. It consists of twenty-four 1-foot x 1-foot x 48-foot hard pine main posts covered by 42,000 board-feet of hard pine and 220,000 cedar shingles. The jacket sits atop a stone foundation 9 feet high and 3 1/2 feet thick. A 100-step winding staircase leads to the 12-foot wide promenade deck overlooking the City of Bangor and surrounding communities.

The standpipe is topped by a 38-foot high flagpole and a railing consisting of 192 banisters that give it the look of a large wedding cake or crown when lit at night. The entire structure was built in just 6 months.

Listed on the National Register of Historic Places and designated as an American Water Works Landmark, the standpipe continues to store water and regulate water pressure for Bangor’s downtown.

# i Table of Contents

List of Tables

................................................................. ii

Part 1: Detailed Survey Results

..................................................... 1

Interpreting the Survey Results

............................................... 3

Notes on Interpreting the Detailed Tables

....................................... 5

Detailed Tables

......................................................... 11

Part 2: Methodology Report

..................................................... 115

1. Introduction

........................................................ 117

2. Sample Design and Weighting

........................................... 120

3. Survey Design and Response

............................................ 137

4. Quality Assurance and Peer Review

...................................... 148

Appendix A: Community Water System Survey Questionnaire

..................... 159

# 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 CWSS 2000 Sample

Table 2 Number and Percentages of Systems

Table 3 Number of Systems by Ownership and Primary Source of Water

Table 4 Average Daily Production

Table 5 Unaccounted for Water by Ownership

Table 6 Average Number of Wells

Table 7 Average Number of Entry Points to the Distribution System

Table 8 Number of Systems Selling to Other Public Water Suppliers

Table 9 Water Systems Not Providing Any Treatment

Table 10 Ground Water Entry Points Not Receiving Treatment

Table 11 Treatment Plants per System

Table 12 Number of Wells Treated per Treatment Plant

Table 13 Treatment Plant Flow Characteristics

Table 14 Ratio of Daily Treated Production to Design Capacity for Plants

Table 15 Treatment Plants and Operator Hours per Week by Population

Table 16 Treatment Plants and Operator Hours per Week by Daily Flow

Table 17 Plants Lacking 24/7 Operator that Have SCADA Systems by Population

Table 18 Systems Lacking 24/7 Operator that Have SCADA Systems by Daily Flow

Table 19 Treatment Objectives by Population

Table 20 Treatment Objectives by Daily Flow

Table 21 Treatment Schemes by Population

Table 22 Treatment Schemes by Daily Flow

Table 23 Treatment Practices for Surface Water Plants by Population

Table 24 Treatment Practices for Ground Water Plants by Population

Table 25 Treatment Practices for Surface Water Plants by Daily Flow

Table 26 Treatment Practices for Ground Water Plants by Daily Flow

Table 27 Contaminants in Very Large Ground Water and Surface Water Systems

Table 28 Contaminants in Very Large Water Systems

Table 29 Plants Using Residual Management Process Options by Population

# Table Description

iii

Table 30 Plants Using Residual Management Process Options by Daily Flow

Table 31 Plants With Specific Discharge Options by Population

Table 32 Plants With Specific Discharge Options by Daily Flow

Table 33 Treated-Water Storage Information

Table 34 Average Capacity Treated-Water Storage Information

Table 35 Pipe Distribution Summary by Ownership

Table 36 Average Size of Pipe in Distribution System by Ownership

Table 37 Percentage of Pipe in Each Age Category by Source

Table 38 Percentage of Pipe in Each Age Category by Ownership

Table 39 Service Connections Profile by Ownership

Table 40 Population Served by Ownership

Table 41 Annual Deliveries per Customer Service Connection by Ownership

Table 42 Cross Connection Control Programs by Ownership

Table 43 Cross Connection Control Program Information by Ownership

Table 44 Elements of Cross Connection Control Programs by Population

Table 45 Backflow Prevention Assemblies that Fail Annually by Ownership

Table 46 Total Revenue by Source

Table 47 Total Revenue by Ownership

Table 48 Total Revenues by Type of Private System

Table 49 Revenue if Reporting Positive Revenue and Expenses by Ownership

Table 50 Systems with Each Type of Revenue Source by Ownership

Table 51 Percentage Received From Each Type of Revenue Source by Ownership

Table 52 Percentage of Revenue from Each Customer Category by Ownership

Table 53 Total Revenue in Dollars per Thousand Gallons Sold by Ownership

Table 54 Water Sales Revenue by Ownership

Table 55 Customer Breakdown of Water Sales Revenue by Ownership

Table 56 Residential Revenue per Connection by Ownership

Table 57 Residential Revenue per Connection by Type of Private System

Table 58 Residential Rate Structure and Billing Profile by Ownership

Table 59 Total Expenses by Source

Table 60 Total Expenses by Ownership

Table 61 Expenses if Reporting Positive Revenue and Expenses by Ownership

# Table Description

iv

Table 62 Expense Breakdown by Major Categories by Ownership

Table 63 Total Expenses in Dollars per 1000 Gallons Produced by Source

Table 64 Total Expenses in Dollars per 1000 Gallons Produced by Ownership

Table 65 Ratio of Total Revenue to Total Expenses by Ownership

Table 66 Ratio of Total Revenue to Total Expenses by Private Systems

Table 67 Number of Employees and Annual Labor Costs by Source

Table 68 Number of Employees and Annual Labor Costs by Ownership

Table 69 Major Capital Improvements in the Past 5 Years by Source

Table 70 Major Capital Improvements in the Past 5 Years by Ownership

Table 71 Total Capital Investment in the Past 5 Years by Source

Table 72 Total Capital Investment in the Past 5 Years by Ownership

Table 73 Type of Capital Expense in the Past 5 Years

Table 74 Capital Expense in the Past 5 Years

Table 75 Allocation to Each Type of Capital Expenses in the Past 5 Years

Table 76 Systems Investing Capital Funds in Each Category by Ownership

Table 77 Capital Funds Invested in the Past 5 years by Ownership

Table 78 Amount Capital Funds Invested by Ownership

Table 79 Source of Capital Funds in the Past 5 Years by Ownership

Table 80 Source of Capital Funds in the Past 5 Years by Ownership and System

Table 81 Amount of Capital Funds Acquired From Each Source by Ownership

Table 82 Average Interest Rate for Capital Funds Lending Sources by Ownership

# 1 

# Part 1

Detailed Survey Results

# 2

# 3 INTERPRETING THE SURVEY RESULTS

This volume presents extensive and detailed tabulations of the wide variety of data collected by the 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 82 tables that summarize the data, many of which include confidence intervals for each calculation 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, not from a census of every water system in the United States. A confidence interval is one way to gauge how precisely a given tabulation of survey data can be generalized to the entirety of U.S. systems represented by the surveyed systems. 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 “plus/minus,” 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 60 shows as a survey result that the average publicly owned water system serving over 500,000 people has annual expenses of $131.5 million. The table also shows the confidence interval for this estimate to be ±$23.7 million. Thus, based on the sample of water systems, we can be 95 percent certain that the average annual per capita expenses of all publicly owned systems serving populations of over 500,000 is between $107.8 million and $155.2. million.

These tables always express the confidence interval in the same units as the calculation to which it applies. Thus, in Table 4 the confidence interval numbers for average daily water production 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 production derived from different water 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

# 4

some of the tables to produce meaningful estimates of “typical” 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 require excluding 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 reports 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 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.

# 5 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 reflect the fact that the data come 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. Community Water Systems that meet the eligibility definition used for the survey (e.g., Federal and state-owned systems were not included). Thus, for the tables to validly 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 2,000,0000 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

# 6

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 11 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 12-26 and 29-32 present data on the level of a treatment plant. Tables 27 and 28 present data for test points within systems. Tables 37 and 38 present data on the amount of pipe in the nation, rather than on the system level. Tables 75, 78, and 81 present data on the share of capital funds in the nation, rather than system averages.

3. Percentages summing to 100% . Some percentage tables may not present results that total to 100%, as would ordinarily be expected. Such tables would be among those that present absolute or percentage breakdowns of the whole into its components, e.g., breakdowns of total revenue into different customer categories, such as Table 51. 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. In general, this assumption is true. However, calculations based on small numbers of systems may violate this assumption. In such cases the reported confidence intervals will not

# 7

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.

Because of the foregoing issue, the reader should take note of results where the lower end of the confidence interval is below zero, as 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 90 th 

# 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. For example, 3 systems serving greater than 500,000 people in the sample have more than 100 entry points to the distribution system from ground water sources. Other systems of similar size, on average, have 14 entry points from ground water. If the three outliers are included, the average number of entry points is over 65.

In cases like this, the outliers are dropped from the analysis. It is noted at the bottom of the table when outliers are dropped. The note also will show how the exclusion of the outliers affect the estimate,

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.



# C 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.



# C The item does not apply to the group of systems belonging to that cell. For example, in table 82, the cell SRF loans for private systems serving 100 or fewer people is empty.

# 8 This is because no private systems of this size made use of SRF loans.



# C 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 13, none of the mixed-water treatment plants in systems serving 25-100 customers provided data on their flows, 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 82 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 thing, 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 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.

7. 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 unweighted 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 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. The specific CWS Survey questionnaire item(s) on which each tabulation is based are cited below the table. The citation refers to the corresponding question number(s) on the CWS Survey mail 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.

# 9 9. 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



# C Population served , from question 20. (If data were not reported in the survey, the population data from SDWIS are used.



# C Water source, from question 7.



# C Ownership, from questions 3 and 4. 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 Community Water System 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)



# C Treatment facility flow, from question 12.

For population served and water source, data from SDWIS are used if the system did not provide the data in the survey. Approximately 10 percent of the sample were assigned population data from SDWIS because of missing or incomplete responses to the population served questions. An additional 5 percent were assigned source data from
SDWIS.

10. Estimate of the number of systems in the nation . The report provides an estimate of the national number of community water systems, 52,186. This estimates is a weighted estimate based on sample, and is slightly different from the count of systems in the first quarter of 2002 SDWIS database. The total count is 166 lower than in SDWIS; the count of systems by source and population served is different as well. Table 1 of this Volume presents a detailed crosswalk from count of systems in the latest SDWIS database and the estimate based on the 2000 CWS Survey. The differences between the SDWIS counts and the CWSS estimate can be divided into 5 groups.

First the latest SDWIS draw is a snapshot of systems in 2002. The survey describes systems as they existed in 2000. The data used for the frame for the survey was drawn in 1998; this frame had approximately 3,700 fewer systems in it then the 2002 SDWIS. Second, to prepare for the survey (and the 1999 Drinking Water Infrastructure Needs Survey, DWINS, which used the same frame), the states conducted a thorough review of the database. As part of the states’ review the population of consecutive systems were adjusted to account for the total number of people served by each system. While SDWIS

# 10 includes only direct retail populations in its estimate of each systems’ population-served, the CWS Survey classifies systems by the total population they serve. Also, several major cities had multiple records in SDWIS; independent of the states’ review, the multiple records were removed from the data base and replaced with a single record. The net result of this step adds 4,800 systems to the database; it also moves several systems across population served categories.

The third step adjusts for inactive systems. As part of the data collection effort, several systems in the sample were not active water systems. In some cases, they merged with other systems; in other cases, they were no longer community water systems (e.g., they were no longer in business, or they served fewer than 25 people or 15 connections at least 6 months of the year). In these cases, steps were taken to confirm the status of the systems. For example, site visitors went to the system to confirm its status. Approximately 1,200 systems were dropped from the inventory for this reason.

The remaining two changes do not affect the total count of systems; rather, they affect the number of systems classified as ground, surface, or purchased, and they affect the number of systems in each population-served category. SDWIS uses a hierarchy to classify systems by source; basically, a system is classified as a surface water system if it uses any surface water. The survey classifies systems by its primary source of water; a system is classified as a surface water system if surface water is its largest source. It is a ground water system if its largest source is ground water. It is a purchased system otherwise. The systems’ responses to the survey are used to classify their source. The final adjustment changes the population-served based on the reported population in the

survey.

11. 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 49, 59-66, and 73-78 use the term expenses to report spending by both public and private systems.Table 1Crosswalk from SDWIS to CWSS 2000 SampleUniverse of SystemsSDWIS CWSS Projected Universe CWSSClassification123456SampleYear data represents 2002 2000 2000 2000 2000 2000 2000Adjust for state review, and consecutive and grouped systemsNo No Yes Yes Yes Yes YesAdjust for inactive systemsNo No No Yes Yes Yes YesAdjust water source definitionNo No No No Yes Yes YesAdjust population servedNo No No No No Yes YesWater source System Service PopulationGround water 25 - 100 12,838 13,073 13,901 12,740 12,713 11,756 104101 - 500 13,238 12,329 13,960 12,894 12,845 13,145 93501 - 3,300 9,367 8,933 9,459 9,069 8,960 8,970 923,301 - 10,000 2,368 2,126 2,348 2,333 2,557 3,071 6710,001 - 50,000 1,211 1,019 1,221 1,274 1,296 1,340 5050,001 - 100,000 136 94 157 149 138 136 29100,001 - 500,000 55 42 68 72 68 161 44Over 500,000 6 6 12 18 12 10 7Surface water 25 - 100 417 386 396 827 823 833 46101 - 500 635 437 688 1,150 1,150 1,136 55501 - 3,300 1,450 1,245 1,479 1,355 1,351 1,212 693,301 - 10,000 998 834 970 1,040 964 1,008 7610,001 - 50,000 921 791 930 941 918 988 8350,001 - 100,000 191 150 209 202 190 210 58100,001 - 500,000 172 144 189 191 168 178 110Over 500,000 38 29 65 59 54 53 38Purchased water 25 - 100 1,028 867 776 679 710 69 6101 - 500 2,176 1,840 1,972 2,030 2,079 2,180 23501 - 3,300 3,059 2,678 2,815 3,441 3,553 3,834 503,301 - 10,000 1,049 886 925 894 746 973 2710,001 - 50,000 773 590 678 650 652 685 2850,001 - 100,000 121 76 101 119 142 125 30100,001 - 500,000 67 31 58 53 80 92 48Over 500,0005 2 5 6 17 21 13Total 52,319 48,608 53,382 52,186 52,186 52,186 1,246Notes: For a more detailed discussion, refer to Note 10 in the introduction to the tables.Each column represents the following:1: Current SDWIS universe2: Unadjusted SDWIS universe when CWSS sample was drawn.3: Adjusted SDWIS universe when CWSS sample was drawn.4-6: CWSS projected Universe.Classification 3 served as the sample frame. (The frame did not separate purchased systems.)The universe of systems for classifications 4-6 are estimates, based on the sample.(Continued)11Table 1(Cont.)Crosswalk from SDWIS to CWSS 2000 SampleClassification definitionsYear2002 Represents the count of systems in the fourth quarter of 20012000 Represents the number of systems in the inventory in 2000.State ReviewThe States reviewed the inventory for the 1999 Drinking Water Infrastructure Needs Survey.Consecutive systemsSDWIS counts the population served directly by the water system as the population served by the system. In consecutivesystems, only the retail population is counted -- customers served by systems who purchase the water from the wholesalerare not include in the wholesaler's population served. The adjustment counts the wholesale and retail population as part ofthe population served. This adjustment was made by the states as part of their review of their inventories.Amalgamated systemsSome systems contain more than one PWSID in SDWIS and are therefore counted as multiple systems. These systemsare counted as a single system for the survey.Inactive systemsSome systems in SDWIS are no longer active community water systems. Others have been combined withexisting systems. These inactive systems are dropped from the inventory.Water SourceSDWIS classifies water systems as surface water if they contain any surface water sources.CWSS classifies systems by the primary source of water -- i.e., the source that provides most of the system's water.Population servedThe population served in SDWIS is as reported, adjusted for consecutive systems. The population served is adjusted for thesystems' responses to the survey.12Table 2Number and Percentage of SystemsBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water Systems100% Ground WaterNumber10,358 12,521 8,687 2,576 971 80 108 7 35,308Percent82 76 62 51 32 17 25 8 68Mostly Ground WaterNumber1,398 624 283 495 368 56 53 3 3,280Percent11 4 2 10 12 12 12 4 6Primarily Surface Water Systems100% Surface WaterNumber790 897 1,015 835 769 140 113 36 4,595Percent6 5 7 17 26 30 26 43 9Mostly Surface WaterNumber43 239 197 173 220 70 65 17 1,024Percent0 1 1 3 7 15 15 20 2Primarily Purchased Water Systems100% Purchased WaterNumber69 2,050 3,412 773 476 94 46 13 6,933Percent1 12 24 15 16 20 11 15 13Mostly Purchased WaterNumber* 130 423 200 209 31 45 8 1,046Percent* 1 3 4 7 7 10 10 2AllNumber12,658 16,461 14,017 5,052 3,013 471 430 84 52,186Percent100 100 100 100 100 100 100 100 100Data:Q.7Notes:* No purchased water systems of this size in sample.13Table 3Number of SystemsBy Ownership and Primary Source of WaterSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublicPrimarily Ground Water Systems489 3,556 6,694 2,560 1,080 124 143 9 14,655Primarily Surface Water Systems245 683 1,139 935 894 182 162 49 4,289Primarily Purchased Water Systems* 1,513 3,449 819 568 109 89 19 6,566All Public734 5,752 11,282 4,314 2,542 415 394 77 25,510PrivatePrimarily Ground Water Systems11,267 9,590 2,276 511 259 12 17 1 23,933Primarily Surface Water Systems588 453 73 73 95 28 16 4 1,330Primarily Purchased Water Systems69 666 386 154 117 16 3 2 1,413All Private11,924 10,709 2,735 738 471 56 36 7 26,676AllPrimarily Ground Water Systems11,756 13,146 8,970 3,071 1,339 136 160 10 38,588Primarily Surface Water Systems833 1,136 1,212 1,008 989 210 178 53 5,619Primarily Purchased Water Systems69 2,179 3,835 973 685 125 92 21 7,979All12,658 16,461 14,017 5,052 3,013 471 430 84 52,186Data:Q.3, Q.7Notes:* No purchased water systems of this size in sample.14Table 4Average Daily Production (MGD)By Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water Systems100% Ground WaterAverage Daily Production0.011 0.034 0.158 1.053 2.628 11.892 17.631 125.642 0.313Confidence interval+|- 0.009 +|- 0.009 +|- 0.034 +|- 0.193 +|- 0.382 +|- 1.643 +|- 13.186 +|- 23.115 +|- 0.052Mostly Ground WaterAverage Daily Production0.003 0.019 0.524 0.872 3.718 11.225 29.778 144.963 3.587Confidence interval+|- 0.004 +|- 0.000 +|- 0.552 +|- 0.365 +|- 1.154 +|- 1.490 +|- 4.390 +|- 32.023 +|- 1.236% Ground Water66.7 83.3 58.1 78.0 84.5 74.1 73.0 83.5 78.6Confidence Interval+|- 0.0 +|- 0.0 +|- 4.9 +|- 11.1 +|- 9.3 +|- 3.6 +|- 5.5 +|- 14.8 +|- 5.9% Surface Water0.0 0.0 41.9 7.4 2.1 12.4 6.1 0.0 6.0Confidence Interval+|- 0.0 +|- 0.0 +|- 4.9 +|- 7.3 +|- 3.9 +|- 6.1 +|- 3.1 +|- 0.0 +|- 3.9% Purchased Water33.3 16.7 0.0 14.7 13.4 13.5 20.9 16.5 15.4Confidence Interval+|- 0.0 +|- 0.0 +|- 0.0 +|- 9.6 +|- 8.8 +|- 6.4 +|- 5.8 +|- 14.8 +|- 5.3Observations86 88 88 53 35 20 20 5 395Primarily Surface Water Systems100% Surface WaterAverage Daily Production0.010 0.071 0.279 0.935 4.766 11.041 31.875 271.287 4.280Confidence interval+|- 0.007 +|- 0.031 +|- 0.059 +|- 0.153 +|- 1.430 +|- 2.681 +|- 2.733 +|- 79.561 +|- 0.995Mostly Surface WaterAverage Daily Production0.014 0.013 0.269 0.779 4.253 11.537 42.431 219.892 8.636Confidence interval+|- 0.012 +|- 0.010 +|- 0.141 +|- 0.318 +|- 1.325 +|- 1.682 +|- 5.065 +|- 96.067 +|- 4.026% Ground Water35.2 24.0 13.5 18.9 14.3 10.4 14.0 8.9 15.6Confidence Interval+|- 19.6 +|- 6.5 +|- 10.3 +|- 10.6 +|- 6.5 +|- 4.7 +|- 2.9 +|- 4.1 +|- 4.1% Surface Water64.8 76.0 69.4 76.7 81.5 85.4 82.8 86.4 77.7Confidence Interval+|- 19.6 +|- 6.5 +|- 8.0 +|- 8.5 +|- 5.8 +|- 5.0 +|- 3.0 +|- 4.1 +|- 3.6% Purchased Water0.0 0.0 17.0 4.4 4.1 4.3 3.3 4.7 6.6Confidence Interval+|- 0.0 +|- 0.0 +|- 13.0 +|- 4.4 +|- 4.3 +|- 3.4 +|- 1.6 +|- 2.3 +|- 3.7Observations41 49 56 63 64 35 70 26 404(Continued)15Table 4 (Cont.)Average Daily Production (MGD)By Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Purchased Water Systems100% Purchased WaterAverage Daily Production0.008 0.017 0.150 0.886 2.302 9.595 23.975 129.602 0.866Confidence interval+|- 0.008 +|- 0.004 +|- 0.046 +|- 0.445 +|- 0.918 +|- 1.417 +|- 3.277 +|- 69.896 +|- 0.309Mostly Purchased WaterAverage Daily Production* 0.016 0.103 1.407 5.595 16.498 32.220 280.185 5.538Confidence interval* +|- 0.000 +|- 0.093 +|- 0.490 +|- 1.969 +|- 8.407 +|- 4.606 +|- 68.668 +|- 3.383% Ground Water* 33.3 42.8 28.4 12.8 22.4 19.5 11.2 31.0Confidence Interval* +|- 0.0 +|- 4.6 +|- 10.9 +|- 7.3 +|- 10.8 +|- 4.4 +|- 5.8 +|- 7.3% Surface Water* 0.0 0.0 3.9 6.9 8.1 8.3 13.1 2.8Confidence Interval* +|- 0.0 +|- 0.0 +|- 6.1 +|- 8.0 +|- 9.2 +|- 3.6 +|- 6.0 +|- 2.5% Purchased Water* 66.7 57.2 67.7 80.3 69.5 72.2 75.7 66.2Confidence Interval* +|- 0.0 +|- 4.6 +|- 9.7 +|- 10.3 +|- 7.2 +|- 4.7 +|- 8.2 +|- 6.1Observations6 22 47 19 17 22 23 7 163All SystemsAverage Daily Production0.011 0.033 0.166 0.995 3.589 11.305 28.811 222.672 1.103Confidence Interval+|- 0.008 +|- 0.007 +|- 0.024 +|- 0.131 +|- 0.518 +|- 1.093 +|- 5.427 +|- 41.741 +|- 0.124Observations138 166 208 170 159 116 201 58 1,216Data:Q.7Notes:* No purchased water systems of this size in sample.Definitions:Production is the amount of water drawn from each source. It includes water delivered to customers and system losses.16Table 5Unaccounted for Water (MGD)By OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,300 3,301 - 10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsAverage Unaccounted for Water0.003 0.001 0.017 0.113 0.296 1.166 2.152 18.272 0.188Confidence Interval+|- 0.006 +|- 0.000 +|- 0.006 +|- 0.032 +|- 0.074 +|- 0.268 +|- 0.567 +|- 4.405 +|- 0.032% of Total Water Produced1.140 5.990 9.935 11.562 8.528 9.693 6.306 7.959 8.949Confidence Interval+|- 1.419 +|- 7.067 +|- 3.763 +|- 3.161 +|- 1.861 +|- 2.044 +|- 1.556 +|- 1.027 +|- 2.211Private SystemsAverage Unaccounted for Water0.000 0.001 0.012 0.100 0.287 1.055 3.050 7.347 0.019Confidence Interval+|- 0.000 +|- 0.000 +|- 0.009 +|- 0.061 +|- 0.110 +|- 0.395 +|- 0.835 +|- 2.972 +|- 0.006% of Total Water Produced0.187 2.188 6.237 10.686 12.330 11.093 10.636 7.744 2.323Confidence Interval+|- 0.269 +|- 2.660 +|- 3.940 +|- 4.252 +|- 4.511 +|- 4.317 +|- 2.582 +|- 4.017 +|- 1.237All SystemsAverage Unaccounted for Water0.000 0.001 0.016 0.111 0.294 1.152 2.227 17.258 0.098Confidence Interval+|- 0.000 +|- 0.000 +|- 0.006 +|- 0.028 +|- 0.064 +|- 0.238 +|- 0.536 +|- 4.031 +|- 0.012% of Total Water Produced0.258 3.355 9.136 11.435 9.135 9.867 6.670 7.939 5.561Confidence interval+|- 0.269+|- 2.859+|- 3.218+|- 2.724+|- 1.747+|- 1.864+|- 1.508+|- 1.001 +|- 1.305Data:Q.5DDefinitions:Unaccounted for water includes system losses, water for fire suppression, and water used in the treatment process.17Table 6Average Number of WellsBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsWellsMean1.4 1.9 2.6 4.1 7.8 18.1 20.5 132.2 2.5Confidence interval+|- 0.1 +|- 0.2 +|- 0.4 +|- 0.7 +|- 1.5 +|- 3.6 +|- 10.1 +|- 36.9 +|- 0.2Median1 2 2 4 7 18 19 179 2Observations101 93 90 67 49 28 43 6 477Primarily Surface Water SystemsWellsMean1.5 1.3 1.3 3.5 6.9 11.1 20.9 29.3 5.4Confidence interval+|- 0.8 +|- 0.6 +|- 0.4 +|- 1.7 +|- 3.5 +|- 5.5 +|- 7.3 +|- 11.4 +|- 2.5Median1 1 1 5 6 7 7 27 2Observations2 5 6 9 11 16 33 8 90Primarily Purchased Water SystemsWellsMean* 1.0 1.5 3.7 5.2 15.9 16.6 83.9 3.9Confidence interval* +|- 0.0 +|- 0.6 +|- 1.7 +|- 2.7 +|- 10.5 +|- 3.3 +|- 26.0 +|- 1.6Median* 1 2 3 4 9 15 66 2Observations*1 3 6 11 6 22 3 52All SystemsWellsMean1.4 1.9 2.5 4.1 7.4 16.2 19.9 76.9 2.5Confidence interval+|- 0.1 +|- 0.2 +|- 0.4 +|- 0.6 +|- 1.3 +|- 3.2 +|- 6.4 +|- 18.0 +|- 0.2Median1 2 2 4 6 12 15 69 2Observations103 99 99 82 71 50 98 17 619Data:Q.10Notes:* No purchased water systems of this size in sample.Excludes systems with zero wells.One surface water system serving 3,301-10,000 with 64 wells was dropped from the estimate. If included, themean number of wells are 18.8 for this category.Drops 2 outliers from the over 500,000 population category, each with over 200 wells. If outliers were included,the average number of wells for ground water systems are 185 and surface water 49 for this size category18Table 7Average Number of Entry Points to the Distribution SystemBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsEntry Points from Ground Water Sources1.2 1.4 1.8 2.8 4.2 6.3 7.2 13.9 1.7Confidence interval+|- 0.1 +|- 0.2 +|- 0.3 +|- 0.4 +|- 1.1 +|- 2.1 +|- 4.0 +|- 7.6 +|- 0.1Entry Points from Surface Water Sources0.1 0.1 0.0 0.1 0.1 0.9 0.1 0.0 0.1Confidence interval+|- 0.1 +|- 0.1 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.8 +|- 0.1 +|- 0.0 +|- 0.0Observations104 93 92 67 50 29 43 5 483Primarily Surface Water SystemsEntry Points from Ground Water Sources0.1 0.3 0.2 0.4 0.8 1.2 1.4 1.9 0.4Confidence interval+|- 0.1 +|- 0.3 +|- 0.1 +|- 0.4 +|- 0.7 +|- 1.3 +|- 0.5 +|- 1.8 +|- 0.2Entry Points from Surface Water Sources1.3 1.2 1.1 1.2 1.3 1.6 1.6 2.7 1.2Confidence interval+|- 0.4 +|- 0.3 +|- 0.1 +|- 0.2 +|- 0.1 +|- 0.2 +|- 0.1 +|- 0.3 +|- 0.1Observations46 55 69 76 83 58 109 37 533Primarily Purchased Water SystemsEntry Points from Ground Water Sources0.0 0.1 0.2 0.3 1.1 2.6 4.5 6.9 0.3Confidence interval+|- 0.0 +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.7 +|- 2.5 +|- 2.1 +|- 5.5 +|- 0.2Entry Points from Surface Water Sources0.0 0.0 0.0 0.0 0.1 0.2 0.3 0.5 0.0Confidence interval+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.3 +|- 0.0Observations6 23 50 27 28 30 48 12 224All SystemsEntry Points from Ground Water Sources1.1 1.1 1.2 1.8 2.4 3.1 4.2 4.3 1.3Confidence interval+|- 0.1 +|- 0.2 +|- 0.0 +|- 0.0 +|- 0.6 +|- 1.1 +|- 1.2 +|- 2.0 +|- 0.1Entry Points from Surface Water Sources0.2 0.1 0.1 0.3 0.5 1.0 0.8 1.9 0.2Confidence interval+|- 0.1 +|- 0.1 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.0Observations156 171 211 170 161 117 200 54 1,240Data:Q.10Notes:Drops 3 outliers from the over 500,000 population category, each with over 100 ground water entry points.The number of entry points are 68 for ground water systems and 5 for surface water systems if includedin the estimate.19Table 8Number of Systems Selling to Other Public Water SuppliersBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsTreated Water0 334 655 465 325 44 67 11 1,901Untreated Water0 0 63 0 0 4 6 1 75Observations104 91 87 66 47 28 44 7 474Primarily Surface Water SystemsTreated Water25 17 172 426 521 150 148 47 1,507Untreated Water19 0 0 11 39 3 12 8 93Observations44 53 68 73 80 56 105 36 515Primarily Purchased Water SystemsTreated Water0 0 463 208 255 49 39 16 1,029Untreated Water0 0 0 0 16 0 7 3 26Observations5 23 50 26 27 30 47 12 220All SystemsTreated Water25 351 1,290 1,099 1,101 243 255 73 4,438Untreated Water19 0 63 11 55 7 26 13 194Observations153 167 205 165 154 114 196 55 1,209Data:Q.5a20Table 9Water Systems Not Providing Any TreatmentBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsPercent of Systems35.2 22.1 14.8 13.9 2.0 3.0 2.6 0.0 22.9Confidence Interval+|- 13.1 +|- 11.2 +|- 9.3 +|- 10.1 +|- 3.9 +|- 5.2 +|- 4.3 +|- 0.0 +|- 6.1Number of Entry Points1.2 1.4 2.6 3.3 2.0 20.0 3.0 0 1.6Confidence Interval+|- 0.1 +|- 0.3 +|- 1.1 +|- 1.3 +|- 0.0 +|- 0.0 +|- 0.00+|- 0.2Observations104 93 92 67 50 29 44 7 486Primarily Surface Water SystemsPercent of Systems0.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1Confidence Interval+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0Number of Entry Points1.0 0 0.0 0.0 0.0 0.0 0.0 0.0 1.0Confidence Interval+|- 0.00+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0Observations46 55 69 76 83 58 110 38 535Primarily Purchased Water SystemsPercent of Systems0.0 100.0 0.0 0.0 0.0 26.7 8.0 0.0 13.5Confidence Interval+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 27.4 +|- 8.7 +|- 0.0 +|- 22.3Number of Entry Points0.0 1.0 0.0 0.0 0.0 10.5 5.0 0.0 1.7Confidence Interval0.0+|- 0.00.0 0.0 0.0+|- 7.9 +|- 4.60.0+|- 1.4Observations1 3 8 10 8 25 6 61All SystemsPercent of Systems33.0 21.1 12.5 9.9 1.1 3.3 2.0 0.0 19.9Confidence Interval+|- 12.3 +|- 10.3 +|- 7.8 +|- 7.3 +|- 2.1 +|- 3.2 +|- 2.1 +|- 0.0 +|- 5.3Number of Entry Points1.2 1.4 2.6 3.3 2.0 13.7 3.9 0 1.6Confidence Interval+|- 0.1 +|- 0.3 +|- 1.1 +|- 1.3 +|- 0.0 +|- 6.9 +|- 2.40+|- 0.2Observations150 149 164 151 143 95 179 51 1,082Data:Q.10, Q.11Notes:*No data for these cells.Estimate of number of entry points for systems that do not treat. Categories where all systems treat are denotedas zero.Excludes systems that purchase 100% of their water.21Table 10Ground Water Entry Points Not Receiving TreatmentBy System Service PopulationSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water Systems# of Ground Water Entry Points Untreated per System 0.4 0.3 0.5 0.6 0.2 2.2 2.6 1.8 0.4Confidence Interval +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.4 +|- 0.2 +|- 1.4 +|- 2.3 +|- 1.8 +|- 0.1% of Ground Water Entry Points Untreated per System 35.3 24.7 17.7 16.6 7.2 36.2 12.3 25.7 25.2Confidence Interval +|- 13.1 +|- 11.2 +|- 9.9 +|- 11.3 +|- 6.3 +|- 25.3 +|- 9.1 +|- 20.7 +|- 6.3Observations104 93 92 60 44 26 42 6 467Primarily Surface Water Systems# of Ground Water Entry Points Untreated per System 0.1 0.0 0.1 0.1 0.6 1.1 1.1 1.8 0.2Confidence Interval +|- 0.1 +|- 0.0 +|- 0.1 +|- 0.1 +|- 0.7 +|- 1.3 +|- 0.5 +|- 1.8 +|- 0.1% of Ground Water Entry Points Untreated per System 82.4 11.3 77.5 24.0 54.3 64.4 49.2 37.5 42.2Confidence Interval +|- 34.5 +|- 20.8 +|- 26.7 +|- 20.6 +|- 24.6 +|- 19.5 +|- 10.0 +|- 18.7 +|- 18.3Observations46 55 69 76 83 58 109 37 533Primarily Purchased Water Systems# of Ground Water Entry Points Untreated per System 0.0 0.1 0.0 0.0 0.5 0.7 1.2 2.8 0.1Confidence Interval +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.0 +|- 0.5 +|- 1.0 +|- 0.8 +|- 2.9 +|- 0.1% of Ground Water Entry Points Untreated per System 0.0 100.0 0.0 0.0 45.6 44.5 28.4 56.9 26.0Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 33.2 +|- 39.3 +|- 15.2 +|- 33.0 +|- 26.1Observations6 23 50 25 26 29 45 13 217All Systems# of Ground Water Entry Points Untreated per System 0.4 0.3 0.3 0.3 0.4 1.3 1.7 2.1 0.3Confidence Interval +|- 0.1 +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.8 +|- 0.8 +|- 1.4 +|- 0.1% of Ground Water Entry Points Untreated per System 35.5 25.1 18.0 16.4 17.9 44.5 23.5 36.6 25.6Confidence Interval +|- 13.0 +|- 11.0 +|- 9.5 +|- 10.2 +|- 7.6 +|- 15.6 +|- 9.4 +|- 13.1 +|- 6.0Observations156 171 211 161 153 113 196 56 1,217Data: Q.10, Q.11, Q.12Notes: * No observations.Number of entry points that are not treating for all systems include treated and untreated entry points.Drops 2 outliers from the over 500,000 population category, each with over 100 ground water entry points. If included,ground water entry points not receiving treatment are 27.5 and surface water entry points not receiving treatment are 4.4 forthis size category .22Please note that the unit of analysis changes for the following tables.Tables 11-32 report data for treatment plants rather than water systems.23Table 11Treatment Plants per SystemBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water Systems100% Ground Water Systems# Water Treatment Plants/System 1.1 1.4 1.5 2.3 2.4 6.3 5.2 17.3 1.5Confidence Interval +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.5 +|- 0.7 +|- 3.3 +|- 4.0 +|- 11.6 +|- 0.1# Wells /Plant 1.2 1.4 1.5 2.0 3.0 2.6 2.8 4.3 1.6Confidence Interval +|- 0.1 +|- 0.2 +|- 0.3 +|- 0.6 +|- 1.1 +|- 1.4 +|- 1.5 +|- 4.8 +|- 0.1Observations62 66 75 39 31 18 20 3 314Mostly Ground Water Systems# Water Treatment Plants/System 1.3 1.4 2.1 2.0 4.7 1.4 3.5 2.0 2.0Confidence Interval +|- 0.4 +|- 0.5 +|- 0.5 +|- 0.6 +|- 2.0 +|- 0.5 +|- 1.2 +|- 0.0 +|- 0.5# Wells /Plant 1.0 1.0 1.0 1.8 1.6 4.1 6.1 41.3 1.6Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.6 +|- 0.6 +|- 2.8 +|- 3.8 +|- 23.3 +|- 0.3% of Plants Treating Surface Water 0.4 26.1 10.0 17.4 2.9 57.9 11.4 25.0 11.0Confidence Interval +|- 1.0 +|- 29.4 +|- 17.5 +|- 11.0 +|- 4.2 +|- 33.5 +|- 7.0 +|- 22.8 +|- 8.5Observations9 4 3 13 12 8 21 2 72Primarily Surface Water Systems100% Surface Water Systems# Water Treatment Plants/System 1.0 1.0 1.0 1.1 1.0 1.2 1.3 2.6 1.1Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.2 +|- 0.1 +|- 0.3 +|- 0.0Observations40 48 56 61 64 35 68 25 397Mostly Surface Water Systems# Water Treatment Plants/System 1.0 1.8 1.2 1.6 1.5 1.5 2.2 2.8 1.6Confidence Interval +|- 0.0 +|- 0.3 +|- 0.4 +|- 0.6 +|- 0.5 +|- 0.3 +|- 0.2 +|- 0.5 +|- 0.2# Wells /Plant 2.0 1.1 1.3 2.6 2.9 3.6 17.0 19.3 3.0Confidence Interval +|- 0.0 +|- 0.3 +|- 0.5 +|- 1.3 +|- 1.6 +|- 1.8 +|- 7.2 +|- 8.0 +|- 1.8% of Plants Treating Surface Water 76.9 54.7 88.5 62.0 74.8 84.4 75.0 88.3 70.4Confidence Interval +|- 40.0 +|- 9.1 +|- 12.8 +|- 22.2 +|- 25.6 +|- 10.4 +|- 7.8 +|- 5.9 +|- 11.7Observations5 6 13 13 19 23 40 12 131(Continued)24Table 11 (Cont.)Treatment Plants per SystemBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Purchased Water Systems100% Purchased Water Systems# Water Treatment Plants/System 1.0 1.0 1.0 1.0 1.2 1.6 1.4 2.2 1.1Confidence Interval +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.3 +|- 0.6 +|- 0.4 +|- 0.6 +|- 0.1Observations4 6 6 3 6 6 9 3 43Mostly Purchased Water Systems# Water Treatment Plants/System * * 1.5 1.6 2.6 11.5 3.7 2.8 2.1Confidence Interval* *+|- 0.6 +|- 0.4 +|- 0.9 +|- 14.1 +|- 2.4 +|- 0.6 +|- 0.6# Wells /Plant * * 1.0 3.2 1.3 1.2 3.4 18.0 1.6Confidence Interval* *+|- 0.0 +|- 2.8 +|- 0.4 +|- 0.3 +|- 2.6 +|- 18.6 +|- 0.5% of Plants Treating Surface Water * * 0.0 9.4 10.7 3.9 21.6 81.8 7.3Confidence Interval* *+|- 0.0 +|- 14.9 +|- 15.4 +|- 6.9 +|- 16.6 +|- 14.2 +|- 6.0Observations* * 3 6 8 5 20 6 48All Systems# Water Treatment Plants/System 1.1 1.4 1.5 1.9 2.1 2.8 3.0 3.6 1.5Confidence Interval +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.3 +|- 0.4 +|- 1.0 +|- 0.9 +|- 1.0 +|- 0.1# Wells /Plant 1.2 1.3 1.5 2.0 2.4 2.3 4.3 7.4 1.6Confidence Interval +|- 0.1 +|- 0.2 +|- 0.2 +|- 0.5 +|- 0.6 +|- 1.0 +|- 1.5 +|- 6.3 +|- 0.1% of Plants Treating Surface Water 8.9 8.6 9.5 17.8 22.7 30.3 27.3 61.9 12.5Confidence Interval +|- 5.4 +|- 4.3 +|- 3.3 +|- 3.9 +|- 4.6 +|- 11.4 +|- 7.1 +|- 17.9 +|- 2.1Observations120 130 156 135 140 95 178 51 1,005Data: Q.10, Q.12Notes: *No data available for these cells.Includes systems with at least one treatment plant only.Some systems have surface water with ground water feeding into it which then run through surface water plants.There are only 5 systems serving over 500,000 people with 100% ground water. Two of these systems have over 190treatment plants and are excluded from the estimate. If included, the average number of treatment plants persystem are 92 for this stratum.Definitions: See "Plant" definition in introduction.25Table 12Number of Wells Treated per Treatment PlantBy Treatment Plant's Water SourceSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water Plants# Wells /Plant1.2 1.3 1.5 2.4 2.3 2.3 3.8 7.4 1.6Confidence Interval+|- 0.1 +|- 0.2 +|- 0.2 +|- 1.0 +|- 0.6 +|- 1.0 +|- 1.4 +|- 6.3 +|- 0.2Observations83 98 127 125 168 186 394 62 1,243Mixed Plants# Wells /Plant2.0 1.2 2.0 4.5 3.7 3.4 15.4 4.0 3.6Confidence Interval+|- 0.0 +|- 0.5 +|- 0.0 +|- 1.9 +|- 2.1 +|- 1.6 +|- 8.1 +|- 0.0 +|- 2.1Observations1 3 1 8 10 4 21 1 49All Plants# Wells /Plant1.2 1.3 1.5 2.4 2.4 2.3 4.3 7.4 1.6Confidence Interval+|- 0.1 +|- 0.1 +|- 0.2 +|- 1.0 +|- 0.6 +|- 1.0 +|- 1.5 +|- 6.2 +|- 0.2Observations84 101 128 133 178 190 415 63 1,292Data: Q.10, Q.12Notes: This table reports number of wells treated per ground water plant (ie: plants with zero wells are excluded).Two systems serving over 500,000 people have over 190 wells, each with its own treatment. They are excludedfrom this estimate; if included the number of wells per ground water plant for systems serving over 500,000are 1.9.26Table 13Treatment Plant Flow CharacteristicsByType of Water Source(Thousands of Gallons/Day)System Service Population Category100or Less101 -500501 -3,300 3,301 - 10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water PlantsAverage Daily Flow 6 30 106 461 1,148 3,142 4,251 15,649 312Confidence Interval +|- 1 +|- 9 +|- 24 +|- 103 +|- 267 +|- 1,199 +|- 1,724 +|- 2,827 +|- 60Peak Daily Flow 18 71 241 821 1,949 5,231 6,810 32,000 558Confidence Interval +|- 8 +|- 27 +|- 41 +|- 187 +|- 430 +|- 1,624 +|- 2,809 +|- 5,967 +|- 99Design Capacity 66 206 406 1,239 2,751 6,584 8,909 28,541 824Confidence Interval +|- 26 +|- 80 +|- 95 +|- 229 +|- 747 +|- 2,376 +|- 3,174 +|- 5,806 +|- 130Surface Water PlantsAverage Daily Flow 15 67 272 867 3,661 7,869 21,137 84,020 4,474Confidence Interval +|- 9 +|- 32 +|- 54 +|- 138 +|- 769 +|- 1,266 +|- 1,671 +|- 10,820 +|- 704Peak Daily Flow 24 130 498 1,420 5,936 13,184 34,104 138,713 7,351Confidence Interval +|- 8 +|- 73 +|- 117 +|- 218 +|- 1,041 +|- 2,184 +|- 2,620 +|- 19,450 +|- 1,165Design Capacity 39 227 888 2,146 8,404 17,129 42,530 173,283 9,544Confidence Interval +|- 16 +|- 145 +|- 260 +|- 414 +|- 1,617 +|- 2,739 +|- 3,322 +|- 25,220 +|- 1,507Mixed PlantsAverage Daily Flow * 11 120 522 4,017 6,272 22,112 54,700 4,023Confidence Interval*+|- 8 +|- 0 +|- 240 +|- 2,445 +|- 2,369 +|- 3,463 +|- 7,708 +|- 3,177Peak Daily Flow * 28 135 1,041 8,260 8,383 38,680 75,750 6,942Confidence Interval*+|- 31 +|- 0 +|- 562 +|- 7,580 +|- 3,015 +|- 6,423 +|- 8,792 +|- 5,606Design Capacity * 46 154 1,717 11,986 13,492 60,581 85,833 10,156Confidence Interval*+|- 29 +|- 0 +|- 796 +|- 10,098 +|- 6,623 +|- 10,534 +|- 11,955 +|- 8,129(Continued)Water Source27Table 13 (Cont.)Treatment Plant Flow CharacteristicsByType of Water Source(Thousands of Gallons/Day)System Service Population Category100or Less101 -500501 -3,300 3,301 - 10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesAll PlantsAverage Daily Flow 8 32 126 544 2,017 5,686 10,847 72,523 1,025Confidence Interval +|- 2 +|- 9 +|- 25 +|- 92 +|- 369 +|- 1,158 +|- 2,076 +|- 10,637 +|- 148Peak Daily Flow 19 75 272 945 3,383 9,471 17,645 119,940 1,727Confidence Interval +|- 7 +|- 25 +|- 39 +|- 166 +|- 597 +|- 1,785 +|- 3,303 +|- 18,076 +|- 242Design Capacity 61 204 464 1,431 4,794 12,257 22,978 147,722 2,342Confidence Interval+|- 22+|- 73+|- 96+|- 215+|- 922+|- 2,457+|- 4,368+|- 24,301 +|- 311Data: Q.7, Q.10, Q.12Notes:*No data available for these cells.Excludes plants that treat only purchased treated water.Table presents average flows for plants in the sample. It includes only plants that reported complete data for average dailyproduction, peak daily production, and design capacity.One ground water system serving 25-100 people with four plants all having an average daily flow greater than 4 MGD, a peakdaily flow greater than 8 MGD, and a design capacity greater than 11 MGD was dropped. If included, average daily flow is16,000 gallons of water per day, peak daily flow is 37,000 gallons of water per day, and design capacity is 94,000 gallons ofwater per day.One surface water plant with a capacity of 1.5 MGD in a system serving 25-100 people was excluded from this estimate. Ifincluded, average daily flow is 17,000 gallons of water per day, peak daily flow is 27,000 gallons of water per day, & designcapacity of 90,000 gallons of water per day.One ground water plant with a capacity of more than 400 MGD in a system serving greater than 500,000 people wasexcluded from this estimate. If included, average daily flow is 25 MGD, peak daily flow is 54 MGD, and design capacity is50 MGD.Water Source28Table 14Comparison of Average Daily Treated Production to Treatment Design Capacity for PlantsBy Primary Source of WaterSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water PlantsRatio: Average Daily Production to Design Capacity0.20 0.26 0.34 0.42 0.47 0.47 0.51 0.54 0.32Confidence interval+|- 0.09 +|- 0.10 +|- 0.07 +|- 0.11 +|- 0.07 +|- 0.06 +|- 0.08 +|- 0.11 +|- 0.04Ratio: Peak Daily Production to Design Capacity0.43 0.52 0.71 0.69 0.78 0.89 0.91 1.10 0.62Confidence interval+|- 0.19 +|- 0.14 +|- 0.09 +|- 0.12 +|- 0.06 +|- 0.06 +|- 0.13 +|- 0.23 +|- 0.06Observations31 64 90 93 85 68 205 17 653Surface Water PlantsRatio: Average Daily Production to Design Capacity0.53 0.42 0.36 0.45 0.45 0.46 0.53 0.50 0.44Confidence interval+|- 0.35 +|- 0.10 +|- 0.05 +|- 0.04 +|- 0.04 +|- 0.04 +|- 0.02 +|- 0.02 +|- 0.06Ratio: Peak Daily Production to Design Capacity0.78 0.72 0.63 0.74 0.73 0.76 0.83 0.83 0.72Confidence interval+|- 0.26 +|- 0.07 +|- 0.08 +|- 0.06 +|- 0.05 +|- 0.05 +|- 0.03 +|- 0.03 +|- 0.04Observations36 48 71 81 81 79 157 98 651Mixed PlantsRatio: Average Daily Production to Design Capacity* 0.24 0.78 0.30 0.44 0.51 0.41 0.65 0.34Confidence interval* +|- 0.04 +|- 0.00 +|- 0.02 +|- 0.15 +|- 0.10 +|- 0.05 +|- 0.07 +|- 0.09Ratio: Peak Daily Production to Design Capacity* 0.52 0.88 0.61 0.65 0.70 0.70 0.91 0.60Confidence interval* +|- 0.13 +|- 0.00 +|- 0.15 +|- 0.18 +|- 0.18 +|- 0.07 +|- 0.03 +|- 0.12Observations*3 1 7 9 4 27 6 57All PlantsRatio: Average Daily Production to Design Capacity0.25 0.28 0.34 0.43 0.46 0.46 0.51 0.52 0.34Confidence interval+|- 0.12 +|- 0.09 +|- 0.06 +|- 0.08 +|- 0.05 +|- 0.03 +|- 0.05 +|- 0.03 +|- 0.04Ratio: Peak Daily Production to Design Capacity0.49 0.54 0.70 0.70 0.76 0.82 0.87 0.87 0.64Confidence interval+|- 0.06 +|- 0.08 +|- 0.05 +|- 0.03 +|- 0.05 +|- 0.03 +|- 0.04 +|- 0.17 +|- 0.05Observations67 115 162 181 175 151 389 121 1,361Data:Q.10, Q.12Notes:* No data available for these cells.Table presents average ratios for plants in the sample. It includes only plants that reported complete data foraverage daily production, peak daily production, and design capacity.Excludes plants that treat only purchased treated water.One ground water system serving 25-100 people with four plants was dropped. This system has little impact onthe ratios.One surface water plant with a capacity of 1.5 MGD in a system serving 25-100 people was excluded from thisestimate. This system has little impact on the ratios.One ground water plant with a capacity of more than 400 MGD in a system serving greater than 500,000 people wasexcluded from this estimate. This system has little impact on the ratios.29Table 15Treatment Plants and Operator Hours per WeekBy Primary Source of Water and System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water Plants% of Plants with 24/7 Operator0.8 1.6 0.5 0.9 4.2 15.3 20.9 14.6 1.7Avg. hours/week for systems without a 24/7 Operator4.0 5.2 12.4 18.5 21.2 9.1 18.3 9.7 10.0Observations68 88 109 116 112 85 294 19 891Surface Water Plants% of Plants with 24/7 Operator0.0 0.0 0.9 15.8 51.4 65.6 84.1 96.5 22.1Avg. hours/week for systems without a 24/7 Operator8.4 21.0 45.1 60.4 102.3 65.6 32.8 36.3 43.5Observations46 55 74 80 84 78 165 111 693Mixed Plants% of Plants with 24/7 Operator0.0 0.0 0.0 8.9 53.1 71.5 68.7 100.0 22.4Avg. hours/week for systems without a 24/7 Operator3.0 3.4 43.0 54.8 59.4 48.0 40.9 * 27.4Observations1 3 1 8 10 4 27 6 60All Plants% of Plants with 24/7 Operator0.7 1.5 0.5 3.6 17.5 39.7 41.1 84.6 4.6Avg. hours/week for systems without a 24/7 Operator4.4 6.3 16.2 25.4 34.2 24.5 20.0 15.2 13.8Observations115 146 184 204 206 167 486 136 1,644Data:Q.17Notes:*No plants without a 24/7 operator in mixed plants serving greater than 500,000 people.Excludes plants treating only purchased treated water.Some plants are not run 24 hours a day, 7 days a week and therefore do not require an operator 24 hoursa day, 7 days a week.Definitions:"24/7" means that an Operator is on site 24 hours per day, 7 days per week.30Table 16Treatment Plants and Operator Hours per WeekBy Primary Source of Water and Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesGround Water Plants% of Plants with 24/7 Operator2.5 0.2 0.7 12.7 52.0 0.0 1.7Avg. hours/week for systems without a 24/7 Operator3.3 6.6 18.3 28.4 20.6 8.0 10.0Observations106 157 303 275 49 1 891Surface Water Plants% of Plants with 24/7 Operator0.3 0.0 4.2 48.4 92.8 100.0 22.1Avg. hours/week for systems without a 24/7 Operator5.8 18.3 49.6 91.5 50.6 * 43.5Observations28 79 138 178 245 25 693Mixed Plants% of Plants with 24/7 Operator5.8 0.0 0.0 50.2 83.2 * 22.4Avg. hours/week for systems without a 24/7 Operator2.0 17.6 49.0 68.2 42.8 * 27.4Observations3 3 8 16 30 * 60All Plants% of Plants with 24/7 Operator2.5 0.1 1.2 28.7 84.3 95.7 4.6Avg. hours/week for systems without a 24/7 Operator3.4 7.6 23.6 48.9 33.0 8.0 13.8Observations137 239 449 469 324 26 1,644Data:Q.17Notes:*No observations.Excludes plants treating only purchased treated water.Some plants are not run 24 hours a day, 7 days a week and therefore do notrequire an operator 24 hours a day, 7 days a week.Definitions:"24/7" means that an Operator is on site 24 hours per day, 7 days per week.31Table 17Plants Lacking 24/7 Operator that Have SCADA SystemsBy Primary Source of Water and System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring4.4 1.4 14.0 58.7 64.4 81.3 85.6 82.8 19.4% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control5.4 3.8 15.5 20.1 53.2 57.6 42.4 82.8 14.1Observations63 82 106 113 108 71 234 16 793Surface Water Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring6.3 21.6 43.7 50.6 74.5 96.0 96.4 100.0 39.1% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control3.0 18.5 31.9 26.4 61.0 93.0 67.5 75.0 28.0Observations46 55 73 65 38 20 25 4 326Mixed Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring0.0 0.0 0.0 39.1 46.0 100.0 100.0 * 20.7% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control0.0 89.8 0.0 29.3 0.0 0.0 85.7 * 57.6Observations1 3 1 7 5 1 8 * 26All Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring4.6 2.8 17.2 57.1 65.6 85.4 86.7 86.0 21.5% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control5.1 6.2 17.3 21.2 53.6 66.7 45.3 81.4 16.0Observations110 140 180 185 151 92 267 20 1,145Data:Q.17Notes:*No observations.Definitions:"24/7" means that an Operator is on site 24 hours per day, 7 days per week.32Table 18Systems Lacking 24/7 Operator that Have SCADA SystemsBy Primary Source of Water and Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.0 10.0 - 100.0Over100 All SizesGround Water Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring4.2 8.1 39.8 81.7 79.6 100.0 19.4% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control7.0 8.8 21.8 53.9 61.7 100.0 14.1Observations101 153 298 209 31 1 793Surface Water Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring5.5 20.5 45.7 69.8 100.0 * 39.1% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control2.4 14.7 31.9 53.2 69.7 * 28.0Observations27 79 127 75 18 * 326Mixed Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring0.0 6.7 26.8 71.8 100.0 * 20.7% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control97.9 6.7 26.8 5.5 77.4 * 57.6Observations2 3 8 8 5 * 26All Plants% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Monitoring4.2 9.1 40.6 77.9 88.1 100.0 21.5% of Plants without a 24/7 Operator that HaveSCADA Systems for Process Control8.5 9.2 23.4 52.6 65.6 100.0 16.0Observations130 235 433 292 54 1 1,145Data:Q.7, Q.17Notes:*No observations.Definitions:"24/7" means that an Operator is on site 24 hours per day, 7 days per week.33Table 19Treatment ObjectivesPercentage of Plants Having Each Treatment ObjectiveBy Primary Source of Water and System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water PlantsAlgae control 0.0 0.0 0.0 4.3 0.0 2.3 5.5 0.2 0.9Corrosion control 4.9 14.7 38.1 31.9 43.2 24.5 23.5 49.5 26.3Disinfection 98.2 95.7 100.0 99.2 92.3 97.0 97.6 100.0 97.6Dechlorination 0.0 0.0 0.0 0.0 2.3 1.2 3.2 0.0 0.4Oxidation 2.3 8.0 17.0 12.1 16.9 2.7 15.7 2.3 10.9Iron Removal/Sequestration 31.9 55.5 57.6 35.0 22.6 26.9 21.8 4.0 43.4Manganese Removal/ Sequestration0.0 17.3 24.4 23.8 17.5 26.9 19.0 2.1 17.4Fluoridation 0.0 4.0 19.3 37.9 20.0 30.5 24.5 5.1 14.6Taste/odor control 0.0 8.1 12.8 9.9 9.9 2.8 13.4 2.3 8.3TOC removal 0.0 0.0 0.2 3.8 0.8 3.1 9.1 0.0 1.1Particulate/ Turbidity Removal16.4 3.5 6.8 15.2 6.6 6.3 13.0 2.5 9.0Softening15.8 7.6 21.5 11.7 13.1 6.5 11.0 0.4 13.3Recarbonation0.0 0.0 0.0 3.5 2.3 1.8 7.5 0.2 1.1Organic contaminant removal1.7 0.0 2.2 4.4 3.3 6.0 8.5 1.1 2.3Inorganic contaminant removal0.0 6.0 0.9 6.8 5.1 2.7 3.4 0.4 3.7Radionuclides contaminant removal0.0 2.2 2.2 3.2 2.0 3.2 1.4 0.0 1.9Other0.0 0.0 0.0 1.1 7.0 3.9 0.4 0.0 1.2Observations83 98 125 124 166 191 394 469 1,650Surface Water PlantsAlgae control 0.0 3.5 19.9 52.8 57.2 55.1 57.7 55.2 33.6Corrosion control 3.7 22.3 67.5 70.7 84.2 80.8 77.7 86.8 57.6Disinfection 97.6 99.3 100.0 99.0 100.0 100.0 100.0 100.0 99.4Dechlorination 0.0 0.0 1.4 3.7 3.7 6.2 3.5 7.0 2.4Oxidation 0.0 2.7 7.2 30.3 34.8 40.5 46.4 39.7 20.6Iron Removal/Sequestration 0.0 27.0 35.5 35.5 37.3 42.3 26.2 17.8 29.4Manganese Removal/ Sequestration0.0 27.0 27.1 34.7 39.6 47.0 29.2 28.9 29.1Fluoridation 0.0 6.0 52.1 56.7 73.4 67.9 65.0 82.9 45.4Taste/odor control 6.3 9.4 46.6 71.2 74.0 73.7 67.4 79.7 49.2TOC removal 0.8 0.0 6.9 44.1 63.8 54.3 64.1 51.0 31.2Particulate/ Turbidity Removal47.5 73.5 95.6 97.9 98.7 98.0 92.7 87.1 85.9Softening16.8 0.0 14.5 25.2 19.8 12.4 5.3 9.6 14.6Recarbonation0.0 0.0 7.3 12.0 6.9 8.3 5.8 5.8 5.8Organic contaminant removal0.0 0.0 4.8 34.4 34.4 42.0 19.3 19.6 18.8Inorganic contaminant removal1.2 20.7 2.7 22.7 25.2 29.1 15.6 12.7 16.6Radionuclides contaminant removal0.0 0.0 1.3 8.3 9.8 17.1 3.4 4.7 5.2Other0.0 0.0 0.0 1.2 5.8 1.4 1.2 9.3 1.9Observations50 58 76 82 85 81 167 106 705(Continued)34Table 19(Cont.)Treatment ObjectivesPercentage of Plants Having Each Treatment ObjectiveBy Primary Source of Water and System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesMixed PlantsAlgae control * 0.0 * 30.2 31.8 60.1 41.6 66.7 19.9Corrosion control * 0.0 * 50.4 68.2 60.1 74.2 83.3 35.9Disinfection 100.0 100.0 100.0 100.0 97.3 100.0 100.0 100.0 99.4Dechlorination * 0.0 * 0.0 0.0 0.0 3.3 20.0 0.6Oxidation * 0.0 * 40.3 54.5 39.9 41.6 40.0 26.3Iron Removal/Sequestration * 3.4 * 40.3 42.7 0.0 24.1 0.0 22.2Manganese Removal/ Sequestration* 0.0 * 40.3 53.6 0.0 26.8 0.0 23.3Fluoridation * 0.0 * 60.5 64.5 100.0 57.4 0.0 34.9Taste/odor control * 6.8 * 50.4 65.4 60.1 63.1 100.0 37.4TOC removal * 0.0 * 10.1 75.4 100.0 44.7 100.0 27.1Particulate/ Turbidity Removal100.0 10.2 * 65.1 86.3 100.0 82.6 100.0 50.4Softening* 0.0 * 10.1 43.6 20.2 30.6 0.0 15.2Recarbonation* 0.0 * 10.1 32.7 20.2 23.5 0.0 12.1Organic contaminant removal* 0.0 * 10.1 20.9 20.2 29.0 16.7 10.3Inorganic contaminant removal* 0.0 * 10.1 20.9 0.0 16.3 16.7 8.8Radionuclides contaminant removal* 0.0 * 20.2 10.0 0.0 6.3 16.7 7.6Other* 0.0 * 10.1 0.0 0.0 0.0 0.0 2.2Observations1 3 1 9 11 4 29 6 64All PlantsAlgae control 0.0 0.4 2.7 13.6 13.9 21.8 19.4 10.1 6.5Corrosion control 4.8 15.2 41.8 39.0 53.2 45.0 38.6 56.1 31.3Disinfection 98.2 96.0 100.0 99.2 94.1 98.1 98.3 100.0 97.8Dechlorination 0.0 0.0 0.2 0.7 2.6 2.7 3.2 1.3 0.7Oxidation 2.0 7.2 15.9 16.0 21.8 14.3 24.0 8.9 12.7Iron Removal/Sequestration 28.8 52.2 55.2 35.2 26.4 31.3 22.9 7.6 41.3Manganese Removal/ Sequestration0.0 17.9 24.7 26.2 23.2 32.6 21.8 6.6 19.3Fluoridation 0.0 4.1 23.5 41.7 33.2 42.1 35.5 25.0 19.4Taste/odor control 0.9 8.2 17.7 22.7 26.2 24.7 28.4 16.4 15.5TOC removal 0.1 0.0 1.0 11.3 17.2 19.4 23.6 9.4 6.3Particulate/ Turbidity Removal20.9 12.8 23.1 32.7 29.8 35.1 35.2 17.8 23.3Softening15.9 6.6 20.7 14.1 15.3 8.4 10.5 1.9 13.5Recarbonation0.0 0.0 0.9 5.1 4.1 3.9 7.8 1.1 2.0Organic contaminant removal1.5 0.0 2.6 10.4 10.8 16.8 11.9 6.2 5.1Inorganic contaminant removal0.2 7.4 1.1 9.7 10.0 10.5 6.9 3.9 5.8Radionuclides contaminant removal0.0 1.9 2.1 4.5 4.0 8.2 2.1 0.9 2.5Other0.0 0.0 0.0 1.3 6.6 2.9 0.6 1.6 1.3Observations 134 159 202 215 262 276 590 581 2,419Data: Q.13Notes: *No observations.Excludes plants that treat purchased water.35Table 20Treatment ObjectivesPercentage of Plants Having Each Treatment ObjectiveBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesGround Water PlantsAlgae control 0.0 0.0 2.3 1.3 12.7 0.0 1.0Corrosion control 9.6 26.9 36.2 39.3 18.7 0.0 27.1Disinfection 95.8 98.1 99.6 97.7 97.0 100.0 97.9Dechlorination 0.0 0.0 0.7 2.2 7.8 0.0 0.5Oxidation 2.2 9.3 19.0 24.5 26.5 0.0 12.4Iron Removal/Sequestration 34.3 51.2 43.9 39.7 74.1 0.0 44.1Manganese Removal/ Sequestration0.3 23.7 22.9 30.2 81.2 0.0 19.6Fluoridation 2.4 11.2 27.9 37.9 32.2 0.0 16.8Taste/odor control 0.0 8.1 14.5 17.1 29.1 0.0 9.5TOC removal 0.0 0.1 2.1 4.5 14.0 0.0 1.2Particulate/ Turbidity Removal8.7 2.6 11.9 18.3 24.7 0.0 8.5Softening18.1 10.4 16.1 20.6 20.4 0.0 15.0Recarbonation0.0 0.0 1.3 8.7 14.4 0.0 1.3Organic contaminant removal1.5 1.6 2.5 10.7 2.6 0.0 2.6Inorganic contaminant removal0.0 4.9 5.0 8.4 4.0 0.0 4.2Radionuclides contaminant removal0.0 1.1 3.2 4.2 1.2 0.0 1.6Other0.0 0.5 2.0 11.9 3.2 0.0 1.4Observations118 161 347 333 84 1 1,044Surface Water PlantsAlgae control 3.3 1.0 37.5 55.6 61.2 45.8 35.2Corrosion control 7.3 24.2 65.0 84.2 83.4 79.2 59.8Disinfection 95.2 100.0 99.5 100.0 100.0 100.0 99.5Dechlorination 0.0 0.0 2.4 4.2 5.7 4.2 2.6Oxidation 1.5 1.0 17.8 35.3 47.1 20.8 21.3Iron Removal/Sequestration 3.6 18.6 40.5 36.3 27.7 8.3 30.6Manganese Removal/ Sequestration3.6 18.6 34.4 40.2 31.0 16.0 30.3Fluoridation 3.9 10.4 51.6 68.8 79.8 70.8 47.4Taste/odor control 14.5 14.0 56.4 75.0 71.5 72.0 51.3TOC removal 5.2 2.6 27.2 56.0 58.6 37.5 32.4Particulate/ Turbidity Removal61.2 72.7 97.8 98.0 94.6 80.0 89.0Softening35.3 4.5 15.3 21.2 8.2 8.3 15.1Recarbonation0.0 0.0 9.5 8.3 7.0 4.2 6.1Organic contaminant removal0.0 2.6 22.1 33.1 19.5 8.3 19.3Inorganic contaminant removal5.9 16.8 15.3 21.9 17.1 8.3 17.1Radionuclides contaminant removal0.0 0.0 4.1 9.8 5.1 0.0 4.4Other0.0 3.7 1.3 3.6 2.6 12.0 2.5Observations28 80 138 179 247 25 697(Continued)36Table 20 (Cont.)Treatment ObjectivesPercentage of Plants Having Each Treatment ObjectiveBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100AllSizesMixed PlantsAlgae control 0.0 6.7 22.2 46.9 42.9 * 20.2Corrosion control 5.9 6.7 56.5 64.2 57.2 * 35.0Disinfection 100.0 100.0 100.0 100.0 100.0 * 100.0Dechlorination 0.0 0.0 0.0 0.0 5.5 * 0.6Oxidation 5.9 0.0 56.5 26.5 60.4 * 26.7Iron Removal/Sequestration 0.0 31.3 33.3 42.6 43.3 * 22.5Manganese Removal/ Sequestration0.0 0.0 45.4 41.4 45.7 * 23.6Fluoridation 5.9 0.0 44.4 82.1 50.6 * 35.4Taste/odor control 5.9 62.0 56.5 51.7 82.7 * 37.9TOC removal 5.9 6.7 23.2 52.1 71.3 * 27.5Particulate/ Turbidity Removal7.8 100.0 62.0 89.2 91.4 * 51.1Softening5.9 0.0 0.0 44.9 27.0 * 15.4Recarbonation5.9 0.0 0.0 33.8 20.7 * 12.3Organic contaminant removal0.0 0.0 11.1 22.7 27.4 * 10.5Inorganic contaminant removal0.0 0.0 11.1 21.3 16.5 * 8.9Radionuclides contaminant removal0.0 0.0 17.9 7.7 7.9 * 6.8Other0.0 0.0 8.9 0.0 0.0 * 2.0Observations3 3 8 17 30 * 61All PlantsAlgae control 0.2 0.1 8.1 25.8 44.2 43.8 7.2Corrosion control 9.3 26.6 40.9 59.0 60.7 75.6 32.7Disinfection 95.8 98.2 99.6 98.7 99.0 100.0 98.1Dechlorination 0.0 0.0 1.0 2.9 6.4 4.0 0.8Oxidation 2.3 8.4 19.2 29.1 41.4 19.9 14.1Iron Removal/Sequestration 32.2 48.0 43.3 38.4 44.1 8.0 41.8Manganese Removal/ Sequestration0.4 23.1 24.9 34.7 48.2 15.3 21.4Fluoridation 2.6 11.0 31.8 52.3 62.1 67.7 22.0Taste/odor control 1.1 9.0 22.2 43.1 58.6 68.9 17.4TOC removal 0.5 0.4 6.2 28.3 45.0 35.8 7.0Particulate/ Turbidity Removal12.2 12.5 29.9 54.8 71.9 76.6 24.7Softening18.5 9.7 15.8 21.6 13.5 8.0 15.0Recarbonation0.2 0.0 2.6 9.3 10.3 4.0 2.3Organic contaminant removal1.4 1.7 5.8 20.7 14.6 8.0 5.6Inorganic contaminant removal0.3 6.2 6.7 14.4 12.8 8.0 6.4Radionuclides contaminant removal0.0 1.0 3.5 6.6 4.1 0.0 2.0Other 0.0 0.7 2.0 8.2 2.6 11.5 1.5Observations 149 244 493 529 361 26 1,802Data: Q.13Notes: *No observations.Excludes plants that treat purchased water.37Table 21Treatment SchemesPercentage of Plants UsingEach Treatment SchemeBy Primary Source of Water and System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water PlantsDisinfection with no additional treatment 68.7 55.5 52.1 37.4 43.5 54.2 60.3 84.1 54.5Other chemical addition 7.7 21.7 11.4 30.5 15.8 15.0 2.7 0.6 16.1Ion exchange, Activated Alumina, Aeration 0.0 9.8 22.0 18.7 23.1 25.3 14.1 14.9 13.7Other filtration (not direct or conventional) 12.3 9.5 3.9 4.6 9.0 0.6 7.0 0.2 7.6Direct filtration 0.1 0.0 0.1 0.2 0.3 0.6 0.2 0.0 0.1Conventional filtration 0.0 0.0 0.0 2.6 0.0 0.0 0.0 0.0 0.3Membranes 1.1 0.0 0.1 0.5 0.0 0.6 0.6 0.0 0.3Softening 10.0 3.6 6.9 5.5 6.9 1.4 3.7 0.2 6.1Observations 83 98 127 125 168 191 394 469 1,655Surface Water PlantsDisinfection with no additional treatment 50.0 14.3 3.6 1.0 0.3 0.0 2.4 2.6 10.7Other chemical addition 0.0 0.0 4.3 1.0 0.0 1.0 4.2 6.0 1.5Ion exchange, Activated Alumina, Aeration 0.0 2.3 2.1 7.1 6.5 5.3 4.6 10.2 4.0Other filtration (not direct or conventional) 12.8 28.4 14.5 6.0 0.0 11.1 2.3 0.0 11.8Direct filtration 7.2 18.8 9.2 16.9 15.5 8.9 13.5 15.4 13.5Conventional filtration 11.9 8.9 37.4 35.7 59.2 60.7 64.5 45.4 34.7Membranes 6.4 5.8 1.3 1.0 0.0 0.0 0.6 0.9 2.5Softening 11.7 20.8 27.6 30.2 16.3 12.9 6.7 12.0 20.6Observations 50 58 76 82 85 81 169 115 716Mixed PlantsDisinfection with no additional treatment 0.0 89.8 100.0 46.7 14.2 0.0 3.2 0.0 51.5Other chemical addition 0.0 0.0 0.0 0.0 2.7 0.0 14.2 0.0 1.8Ion exchange, Activated Alumina, Aeration 0.0 0.0 0.0 14.6 0.0 28.5 16.3 0.0 5.9Other filtration (not direct or conventional) 0.0 3.4 0.0 0.0 0.0 0.0 3.2 0.0 1.6Direct filtration 0.0 6.8 0.0 7.3 9.6 0.0 3.2 0.0 6.8Conventional filtration 100.0 0.0 0.0 16.8 31.5 57.1 40.5 100.0 17.9Membranes 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Softening 0.0 0.0 0.0 14.6 42.0 14.4 16.3 0.0 14.2Observations1 3 1 9 11 4 29 6 64(Continued)38Table 21 (Cont.)Treatment SchemesPercentage of Plants UsingEach Treatment SchemeBy Primary Source of Water and System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesAll PlantsDisinfection with no additional treatment 67.0 52.9 47.5 31.8 33.5 37.3 43.9 68.6 49.4Other chemical addition 7.0 19.8 10.7 25.1 12.1 10.6 3.6 1.5 14.3Ion exchange, Activated Alumina, Aeration 0.0 9.1 20.1 16.7 19.0 19.3 11.9 13.9 12.5Other filtration (not direct or conventional) 12.4 10.8 4.9 4.7 6.9 3.7 5.7 0.2 8.0Direct filtration 0.7 1.5 1.0 3.1 3.8 3.1 3.6 2.8 1.7Conventional filtration 1.1 0.7 3.5 8.2 13.5 18.9 17.3 9.1 4.4Membranes 1.6 0.4 0.2 0.6 0.0 0.4 0.6 0.2 0.5Softening 10.2 4.8 8.9 9.6 9.7 5.0 4.9 2.3 7.8Observations 134 159 204 216 264 276 592 590 2,435Data: Q.14ANotes: Excludes plants that treat purchased water.Definitions: See treatment scheme description in Volume I.39Table 22Treatment SchemesPercentage of Plants UsingEach Treatment SchemeBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesGround Water PlantsDisinfection with no additional treatment 64.3 57.7 37.9 41.2 14.5 100.0 52.9Other chemical addition 11.0 16.9 18.4 12.2 6.5 0.0 15.5Ion exchange, Activated Alumina, Aeration 0.0 14.4 29.4 24.7 72.3 0.0 15.7Other filtration (not direct or conventional) 13.1 5.1 5.6 9.1 1.4 0.0 7.5Direct filtration 0.0 0.1 0.2 0.3 0.7 0.0 0.1Conventional filtration 0.0 0.0 1.3 0.0 0.0 0.0 0.4Membranes 0.9 0.1 0.3 0.4 0.0 0.0 0.4Softening 10.7 4.6 4.1 10.1 4.7 0.0 6.3Observations 118 161 347 333 84 1 1044Surface Water PlantsDisinfection with no additional treatment 32.6 26.9 5.5 0.3 0.9 8.0 10.7Other chemical addition 0.0 2.0 1.5 1.0 3.0 12.0 1.6Ion exchange, Activated Alumina, Aeration 0.0 2.8 3.6 6.7 6.0 0.0 4.1Other filtration (not direct or conventional) 15.6 28.1 11.8 2.3 0.6 0.0 12.4Direct filtration 11.8 16.6 14.2 10.5 18.9 20.0 14.1Conventional filtration 7.2 14.3 34.5 60.0 58.2 48.0 36.4Membranes 8.7 4.1 2.2 0.9 0.0 0.0 2.6Softening 24.2 5.1 26.2 16.3 11.2 12.0 17.3Observations 28 80 138 179 247 25 697Mixed PlantsDisinfection with no additional treatment 92.2 0.0 42.8 30.5 2.7 * 52.1Other chemical addition 0.0 0.0 0.0 0.0 5.9 * 0.6Ion exchange, Activated Alumina, Aeration 0.0 0.0 17.9 3.3 11.4 * 6.0Other filtration (not direct or conventional) 0.0 31.3 0.0 0.0 2.7 * 1.6Direct filtration 0.0 62.0 0.0 15.4 2.7 * 6.9Conventional filtration 2.0 6.7 30.4 16.8 57.7 * 18.1Membranes 0.0 0.0 0.0 0.0 0.0 * 0.0Softening 5.8 0.0 8.9 34.0 14.1 * 14.4Observations 3 3 8 17 30 * 61(Continued)40Table 22 (Cont.)Treatment SchemesPercentage of Plants UsingEach Treatment SchemeBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesAll PlantsDisinfection with no additional treatment 63.6 55.3 32.8 24.6 5.4 12.0 47.6Other chemical addition 10.4 15.7 15.5 7.3 4.3 11.5 13.5Ion exchange, Activated Alumina, Aeration 0.0 13.5 25.2 16.8 27.8 0.0 14.1Other filtration (not direct or conventional) 12.9 6.9 6.6 6.0 1.0 0.0 8.0Direct filtration 0.5 1.4 2.4 4.9 11.9 19.1 2.0Conventional filtration 0.3 1.1 6.8 24.4 39.4 45.9 5.1Membranes 1.2 0.4 0.6 0.6 0.0 0.0 0.6Softening 11.1 4.6 7.7 13.5 9.3 11.5 7.8Observations 149 244 493 529 361 26 1802Data: Q.14ANotes: *No data available for these cells.Excludes plants that treat purchased water.Definitions: See treatment scheme description in Volume I.41Table 23Treatment Practices for Surface Water PlantsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and System Service PopulationSystem Service Population CategorySurface Water Treatment Practice100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesChlorination only 49.5 32.4 7.9 6.0 0.3 1.0 6.8 10.2 16.2Raw water storage/Presedimentation basin 12.5 20.5 11.5 16.3 20.5 29.8 19.1 26.5 17.3Predisinfection/oxidation prior to sedimentationChlorine 18.6 2.9 37.6 50.9 51.7 45.8 52.2 45.4 34.5Chlorine dioxide 0.0 0.0 0.0 3.0 3.9 11.4 7.4 4.3 2.2Chloramines 0.0 0.0 0.0 1.0 8.3 0.0 10.0 11.1 2.4Ozone 0.5 0.9 0.0 1.0 0.0 5.3 3.9 6.0 1.0Potassium permanganate 0.0 1.1 24.9 29.4 37.1 29.2 27.8 26.6 20.3Other Predisinfection0.0 0.0 4.8 1.0 0.0 0.0 1.7 0.0 1.3Predisinfection/Oxidation prior to filtrationChlorine 7.4 11.9 24.2 24.3 35.4 38.3 31.5 37.7 23.0Chlorine dioxide 0.0 2.0 0.0 0.0 1.1 2.0 2.8 0.0 0.8Chloramines0.0 0.0 0.0 0.0 4.6 1.3 6.9 7.7 1.4Ozone0.0 15.3 0.0 0.0 1.1 2.3 4.1 6.0 3.5Potassium permanganate0.0 1.2 6.9 10.1 5.5 7.8 3.9 2.6 5.0Other Predisinfection0.0 0.0 4.4 0.0 0.0 2.0 0.0 0.0 1.0Rapid mix 7.8 13.1 43.3 67.5 90.9 75.6 77.8 62.4 48.9Coagulation/ Flocculation 11.0 22.6 63.1 87.9 96.4 82.0 85.2 77.0 60.8Polymers 15.5 21.5 54.4 63.7 62.1 53.4 58.4 53.9 46.0Settling/Sedimentation 11.9 15.9 60.8 67.9 79.8 74.7 71.7 63.3 51.5SofteningLime/soda ash 0.0 20.8 27.6 34.2 20.7 12.9 7.2 12.0 20.5Recarbonation 0.0 0.0 0.0 6.1 7.7 5.0 4.4 3.4 2.9Ion exchange 11.7 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.6FiltrationDirect filtration2.6 2.3 0.8 8.1 5.3 4.0 9.6 6.8 4.1Micro strainer 0.0 0.0 0.0 0.0 0.0 0.0 1.7 0.9 0.1Slow sand 4.9 10.8 4.8 3.1 0.0 0.0 1.7 0.0 4.3Bag and Cartridge 18.9 18.6 0.0 0.0 1.0 0.0 0.6 0.0 6.3Rapid sand0.0 9.4 24.5 32.5 17.6 7.9 16.2 23.2 17.3Green sand0.7 0.0 3.0 1.0 0.0 0.0 0.6 0.0 0.9Diatomaceous earth2.6 1.0 2.5 2.0 0.0 13.1 2.9 0.0 2.2Dual/Multi media13.7 14.0 51.8 46.6 73.2 68.7 59.3 52.1 43.5Pressure filtration9.5 20.7 2.2 2.6 0.0 2.0 0.0 0.0 6.2Other filtration0.6 0.8 4.1 0.0 3.9 2.3 3.0 2.6 2.1(Continued)42Table 23 (Cont.)Treatment Practices for Primarily Surface Water SystemsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and System Service PopulationSystem Service Population CategorySurface Water Treatment Practice100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPost-disinfection after filtersChlorine 27.8 58.3 77.4 85.3 83.7 75.3 74.5 53.9 68.7Chlorine dioxide 0.0 0.0 0.0 1.0 5.0 1.5 0.6 0.0 1.1Chloramines 0.0 0.0 0.0 4.1 22.5 18.9 23.6 21.3 7.1Ozone 0.0 0.7 0.0 0.0 0.0 5.3 0.0 1.7 0.4UV 11.7 0.0 0.0 0.0 0.0 0.0 0.6 0.0 1.6Other post disinfection 0.0 0.0 7.9 0.0 2.1 1.0 1.1 0.0 2.1Clearwell11.0 37.4 80.0 81.0 82.7 85.4 82.0 64.1 63.2MembranesReverse osmosis 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.3Micro filtration 6.4 5.8 1.3 1.0 0.0 0.0 0.6 0.9 2.5Ultrafiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Nanofiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Corrosion Control 1.5 14.1 40.8 48.9 70.6 62.9 69.7 72.6 40.2MiscellaneousIon exchange0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 0.2Granular activated carbon2.2 2.6 0.8 21.1 14.9 15.9 11.0 6.0 8.6Activated Alumina0.0 2.3 0.0 1.0 0.0 1.3 1.1 0.9 0.7Aeration0.0 0.0 2.1 6.1 7.6 5.0 5.7 10.2 3.6OtherFlouride 0.0 2.5 37.4 57.3 69.4 60.4 64.4 71.0 38.0PAC 0.0 1.1 5.7 6.1 18.7 12.3 18.1 20.5 7.6Ph Adjust 0.0 0.0 6.1 1.0 1.1 1.0 3.3 2.5 1.9Iron/Mag. removal/seq. 0.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4Taste/oder 0.0 0.0 0.0 1.0 0.3 0.0 1.2 0.0 0.3Filter aid 0.0 0.0 7.7 5.9 2.2 1.0 0.0 0.0 3.1Clarify 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Blending 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Data: Q.14ANotes: Represents treatment practices for plants treating water that comes entirely or partly from surface sources.Percentages may not sum to 100 percent because systems may perform more than one treatment.Definition: Cholorination only is indicated when a plant chlorinated but did not filter. It includes plants that onlychlorinated and plants that chlorinated and used other non-filtration practices.43Table 24Treatment Practices for Ground Water PlantsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and System Service PopulationSystem Service Population CategoryGround Water Treatment Practice100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesChlorination only 81.4 73.2 72.7 72.5 67.8 71.1 68.6 96.9 74.3Raw water storage/Presedimentation basin 1.5 0.0 0.4 1.6 1.4 1.2 5.8 0.0 0.8Predisinfection/oxidation prior to sedimentationChlorine 0.0 7.5 9.4 10.6 11.3 5.9 9.5 0.0 7.2Chlorine dioxide 0.0 0.0 0.0 0.0 0.7 10.5 0.4 0.0 0.2Chloramines 0.0 0.0 0.0 0.0 0.0 0.6 4.5 0.0 0.1Ozone 0.5 0.0 0.0 0.0 0.0 0.0 0.9 0.0 0.1Potassium permanganate 0.0 3.7 3.2 4.4 0.7 1.2 0.4 0.0 2.6Other Predisinfection1.3 0.0 0.0 0.0 0.7 0.0 4.9 0.0 0.4Predisinfection/Oxidation prior to filtrationChlorine 1.5 7.1 10.0 7.5 10.8 1.2 3.0 2.5 6.9Chlorine dioxide 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.0 0.0Chloramines0.0 0.0 0.0 0.0 0.0 1.2 0.4 0.0 0.0Ozone0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Potassium permanganate1.0 1.4 5.0 2.4 4.0 0.0 0.4 0.0 2.6Other Predisinfection0.0 1.2 0.0 0.0 0.0 0.0 0.0 0.0 0.4Rapid mix 0.0 0.0 2.4 5.0 0.0 3.0 2.7 0.0 1.3Coagulation/ Flocculation 0.0 0.0 4.3 6.0 2.6 4.7 1.7 0.0 2.1Polymers 0.1 0.0 8.4 3.5 2.2 2.2 1.0 0.0 2.9Settling/Sedimentation 0.0 0.0 4.3 8.1 5.4 3.6 3.0 0.2 2.6SofteningLime/soda ash 3.4 2.5 10.3 8.2 9.1 4.7 12.7 0.4 6.1Recarbonation 0.0 0.0 1.0 5.1 2.2 1.8 7.1 0.2 1.2Ion exchange 6.6 2.2 6.0 2.3 3.6 0.6 0.0 0.0 4.1FiltrationDirect filtration1.1 0.0 0.0 2.5 0.0 1.2 0.2 0.0 0.5Micro strainer 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Slow sand 0.0 0.0 1.0 3.4 0.0 0.0 0.2 0.0 0.7Bag and Cartridge 8.9 0.1 0.4 0.0 0.0 0.0 0.2 0.0 1.8Rapid sand0.0 0.9 2.7 7.2 4.4 1.2 2.0 0.0 2.2Green sand1.6 7.5 4.2 4.4 2.9 0.0 0.4 0.0 4.5Diatomaceous earth0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0Dual/Multi media0.1 0.0 4.6 3.4 5.7 3.2 10.5 2.5 2.4Pressure filtration0.0 3.7 8.1 2.6 7.2 1.2 1.0 0.0 4.2Other filtration0.8 2.1 0.0 0.3 0.3 0.8 0.0 0.0 0.8(Continued)44Table 24 (Cont.)Treatment Practices for Primarily Ground Water SystemsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and System Service PopulationSystem Service Population CategoryGround Water Treatment Practice100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPost-disinfection after filtersChlorine 8.5 7.8 15.3 21.0 19.9 3.3 11.5 2.7 12.3Chlorine dioxide 0.0 0.0 0.0 0.0 0.0 0.0 6.6 0.0 0.1Chloramines 0.0 0.0 0.0 0.8 1.4 1.8 3.4 0.0 0.3Ozone 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0UV 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Other post disinfection 0.0 0.0 1.4 0.0 0.0 5.8 0.0 0.0 0.5Clearwell11.4 15.4 24.7 23.6 16.0 6.9 13.3 0.4 17.7MembranesReverse osmosis 1.1 0.0 0.1 0.5 0.0 0.6 0.6 0.0 0.3Micro filtration 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.0Ultrafiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Nanofiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Corrosion Control 8.0 17.6 17.4 28.9 21.2 19.0 7.3 0.8 16.9MiscellaneousIon exchange0.0 0.0 0.0 0.0 1.4 0.0 0.0 0.0 0.1Granular activated carbon0.0 0.0 0.0 0.8 1.9 0.6 8.6 0.2 0.4Activated Alumina0.0 0.0 0.0 0.0 0.0 18.1 0.0 0.0 0.3Aeration0.0 9.8 22.0 19.0 21.7 7.9 17.4 14.9 13.4OtherFlouride0.0 4.4 18.3 27.6 20.5 9.4 12.1 0.6 11.4PAC0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.0Ph Adjust0.0 1.2 4.7 0.0 2.2 0.0 0.0 0.0 1.8Iron/Mag. removal/seq.2.3 3.8 3.0 4.7 1.4 0.6 0.0 0.0 3.1Taste/oder0.0 0.0 0.0 1.6 0.0 0.0 0.0 0.0 0.2Filter aid0.0 0.0 3.5 0.0 0.0 0.0 5.8 0.0 1.0Clarify0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Blending0.0 2.0 0.0 6.0 0.7 1.2 0.2 0.0 1.4Data: Q.14ANotes: Represents treatment practices for plants treating water that comes entirely or partly from ground sources.Percentages may not sum to 100 percent because systems may perform more than one treatment.Definition: Cholorination only is indicated when a plant chlorinated but did not filter. It includes plants that only chlorinated andplants that chlorinated and used other non-filtration practices.45Table 25Treatment Practices for Surface Water PlantsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Surface Water Treatment Practice0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesChlorination only 32.6 28.9 9.0 1.3 4.6 20.0 13.0Raw water storage/Presedimentation basin 25.9 19.5 11.3 22.0 23.0 28.0 18.1Predisinfection/oxidation prior to sedimentationChlorine 30.5 5.7 44.5 47.7 53.9 52.0 36.2Chlorine dioxide 0.0 0.0 1.5 4.1 8.4 4.0 2.3Chloramines 0.0 0.0 1.8 4.9 6.3 12.0 2.5Ozone 0.0 0.8 0.0 1.1 5.1 4.0 0.9Potassium permanganate 2.6 3.7 24.9 33.3 33.6 12.0 21.2Other Predisinfection0.0 0.0 3.0 0.8 0.6 0.0 1.3Predisinfection/Oxidation prior to filtrationChlorine 12.3 15.6 22.5 32.2 39.9 32.0 24.1Chlorine dioxide 0.0 0.0 1.1 1.1 1.9 0.0 0.8Chloramines0.0 0.0 0.0 3.8 5.7 4.0 1.5Ozone0.3 13.0 0.0 0.9 3.7 8.0 3.6Potassium permanganate0.0 1.0 7.9 7.8 3.0 4.0 5.3Other Predisinfection0.0 0.0 2.8 0.2 0.6 0.0 1.1Rapid mix 11.5 15.2 54.5 80.6 81.9 60.0 51.3Coagulation/ Flocculation 17.1 27.5 70.7 91.1 89.4 76.0 63.7Polymers 12.3 30.9 56.9 56.0 59.8 60.0 47.7Settling/Sedimentation 7.9 19.6 61.2 80.8 71.2 60.0 53.6SofteningLime/soda ash 0.7 5.1 28.3 19.5 11.5 12.0 17.2Recarbonation 0.0 0.0 1.6 8.4 4.5 0.0 3.1Ion exchange 23.5 0.0 0.0 0.0 0.0 0.0 1.7FiltrationDirect filtration1.8 2.5 3.8 6.8 5.6 12.0 4.3Micro strainer 0.0 0.0 0.0 0.3 0.3 0.0 0.1Slow sand 7.2 7.9 5.0 1.6 0.6 0.0 4.6Bag and Cartridge 35.0 16.8 0.0 0.7 0.3 0.0 6.6Rapid sand0.4 9.1 24.7 20.8 20.8 28.0 18.1Green sand0.0 1.9 1.0 0.7 0.0 0.0 1.0Diatomaceous earth0.0 2.5 2.2 3.4 1.2 0.0 2.3Dual/Multi media16.7 21.1 49.3 62.1 66.4 48.0 45.1Pressure filtration9.2 20.2 3.0 0.0 0.0 0.0 6.4Other filtration1.1 1.1 2.3 3.1 1.6 8.0 2.1(Continued)46Table 25 (Cont.)Treatment Practices for Primarily Surface Water SystemsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Surface Water Treatment Practice0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesPost-disinfection after filtersChlorine 29.0 58.1 80.6 82.2 72.7 44.0 71.2Chlorine dioxide 0.0 0.0 1.3 2.5 1.3 0.0 1.2Chloramines 0.0 0.0 2.3 18.7 20.4 40.0 7.5Ozone 0.0 0.0 0.4 0.4 1.8 0.0 0.4UV 23.5 0.0 0.0 0.0 0.3 0.0 1.7Other post disinfection 0.0 3.7 2.6 1.5 1.3 0.0 2.3Clearwell10.9 42.6 76.6 83.7 79.9 68.0 66.1MembranesReverse osmosis 4.0 0.0 0.0 0.0 0.0 0.0 0.3Micro filtration 8.7 4.1 2.2 0.9 0.0 0.0 2.6Ultrafiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0Nanofiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0Corrosion Control 2.9 17.9 38.5 68.7 73.9 68.0 42.0MiscellaneousIon exchange0.0 0.0 0.5 0.0 0.0 0.0 0.2Granular activated carbon1.8 3.0 10.0 14.9 10.8 4.0 9.1Activated Alumina0.0 2.8 0.0 0.4 0.6 0.0 0.8Aeration0.0 0.0 3.6 7.3 7.0 0.0 3.7OtherFlouride2.9 8.0 40.8 64.8 75.7 72.0 39.7PAC0.0 0.0 7.1 15.6 16.7 32.0 8.1Ph Adjust0.0 0.0 4.4 1.0 2.7 0.0 2.0Iron/Mag. removal/seq.0.0 0.0 1.1 0.0 0.0 0.0 0.4Taste/oder0.0 0.0 0.0 0.9 0.7 0.0 0.3Filter aid0.0 3.7 5.5 1.8 0.0 0.0 3.2Clarify0.0 0.0 0.0 0.0 0.0 0.0 0.0Blending0.0 0.0 0.0 0.0 0.0 0.0 0.0Data: Q.14ANotes: Represents treatment practices for plants treating water that comes entirely or partly. from ground sources. Percentages may not sum to 100 percent because systemsmay perform more than one treatment.Definition: Cholorination only is indicated when a plant chlorinated but did not filter. It includes plants thatonly chlorinated and plants that chlorinated and used other non-filtration practices.47Table 26Treatment Practices for Ground Water PlantsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Ground Water Treatment Practice0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100AllSizesChlorination only 80.7 72.5 66.5 52.8 67.6 100.0 71.9Raw water storage/Presedimentation basin 1.2 0.0 1.3 4.4 2.3 0.0 0.9Predisinfection/oxidation prior to sedimentationChlorine 0.0 9.1 13.3 17.2 7.7 0.0 8.3Chlorine dioxide 0.0 0.0 0.2 0.1 0.0 0.0 0.1Chloramines 0.0 0.0 0.0 1.4 3.9 0.0 0.1Ozone 0.0 0.2 0.0 0.4 0.0 0.0 0.1Potassium permanganate 0.5 3.1 5.1 3.4 2.8 0.0 3.0Other Predisinfection1.1 0.0 0.1 2.7 0.7 0.0 0.5Predisinfection/Oxidation prior to filtrationChlorine 6.3 6.7 9.0 20.5 8.5 0.0 7.9Chlorine dioxide 0.0 0.0 0.0 0.0 0.0 0.0 0.0Chloramines0.0 0.0 0.0 0.2 3.0 0.0 0.0Ozone0.0 0.0 0.0 0.0 0.0 0.0 0.0Potassium permanganate1.1 3.7 3.3 3.5 0.0 0.0 2.9Other Predisinfection0.0 1.0 0.0 0.0 0.0 0.0 0.4Rapid mix 0.0 0.0 4.8 3.3 5.3 0.0 1.5Coagulation/ Flocculation 0.0 0.8 6.3 7.8 5.3 0.0 2.5Polymers 0.1 3.4 6.3 3.9 4.6 0.0 3.4Settling/Sedimentation 0.0 0.0 9.5 8.8 5.6 0.0 3.1SofteningLime/soda ash 3.5 3.6 11.0 18.1 22.0 0.0 6.5Recarbonation 0.0 0.0 3.4 7.4 13.5 0.0 1.4Ion exchange 7.2 2.7 5.8 1.5 0.0 0.0 4.6FiltrationDirect filtration0.0 0.6 0.9 2.2 1.6 0.0 0.6Micro strainer 0.0 0.0 0.0 0.0 0.0 0.0 0.0Slow sand 0.0 0.0 2.9 0.0 0.0 0.0 0.8Bag and Cartridge 3.3 0.3 0.0 0.1 0.0 0.0 1.0Rapid sand0.0 1.5 5.3 10.3 4.3 0.0 2.6Green sand8.1 4.2 4.6 0.3 0.0 0.0 5.1Diatomaceous earth0.0 0.0 0.1 0.0 0.0 0.0 0.0Dual/Multi media0.0 0.1 7.4 10.6 22.9 0.0 2.8Pressure filtration0.0 4.3 9.4 10.8 0.0 0.0 4.9Other filtration1.6 1.2 0.3 0.2 0.0 0.0 1.0(Continued)48Table 26 (Cont.)Treatment Practices for Primarily Ground Water SystemsPercentage of Plants Performing Each TreatmentBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Ground Water Treatment Practice0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100AllSizesPost-disinfection after filtersChlorine 7.1 10.9 25.0 23.1 7.4 0.0 14.3Chlorine dioxide 0.0 0.0 0.0 1.3 10.4 0.0 0.1Chloramines 0.0 0.0 0.4 3.6 5.9 0.0 0.3Ozone 0.0 0.0 0.0 0.0 0.0 0.0 0.0UV 0.0 0.0 0.0 0.0 0.0 0.0 0.0Other post disinfection 0.0 0.0 1.7 1.2 0.0 0.0 0.5Clearwell8.0 21.4 26.6 27.5 24.0 0.0 19.7MembranesReverse osmosis 0.9 0.1 0.3 0.4 0.0 0.0 0.4Micro filtration 0.0 0.0 0.1 0.0 0.0 0.0 0.0Ultrafiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0Nanofiltration0.0 0.0 0.0 0.0 0.0 0.0 0.0Corrosion Control 11.9 13.3 26.3 21.4 12.3 0.0 16.9MiscellaneousIon exchange0.0 0.0 0.0 2.5 0.0 0.0 0.1Granular activated carbon0.0 0.0 0.6 2.2 1.4 0.0 0.3Activated Alumina0.0 0.0 0.0 0.0 48.9 0.0 0.3Aeration0.0 14.4 29.7 23.2 23.4 0.0 15.3OtherFlouride 1.2 9.1 25.3 29.6 24.2 0.0 12.6PAC 0.0 0.0 0.0 0.0 1.2 0.0 0.0Ph Adjust 0.0 3.2 2.0 3.8 0.0 0.0 2.1Iron/Mag. removal/seq. 1.9 4.8 3.5 2.0 1.6 0.0 3.5Taste/oder 0.0 0.0 0.4 2.0 0.0 0.0 0.2Filter aid 0.0 1.2 2.7 0.0 0.0 0.0 1.2Clarify 0.0 0.0 0.0 0.0 0.0 0.0 0.0Blending 0.0 1.7 2.6 3.7 0.0 0.0 1.6Data: Q.14ANotes: Represents treatment practices for plants treating water that comes entirely or partly fromground sources. Percentages may not sum to 100 percent because systems may performmore than one treatment.Definition: Cholorination only is indicated when a plant chlorinated but did not filter. It includes plants thatonly chlorinated and plants that chlorinated and used other non-filtration practices.49Table 27Concentration of Various Contaminants in Very Large Ground Water and Surface Water SystemsAcross All Wells and Intakes By Primary Source of Water(Average Raw Water Concentration in Parts per Million, Except for Radon, Which is pCi/L)Water Source and Contaminant% ReportingN/A% ReportingNo DetectMeanConcentrationMedianConcentration90th PercentileConcentration ObservationsGround WaterArsenic19.2 11.5 0.010 0.007 0.025 51Radon80.8 2.6 371.1 417.5 554.5 10MTBE33.3 48.7 0.175 0.004 0.050 12Atrazine33.3 57.7 0.043 0.001 0.210 5Metolachlor47.4 44.9 0.053 0.001 0.210 4Boron51.3 2.6 0.173 0.120 0.273 342,4-D34.6 57.7 0.001 0.001 0.001 4Simazine32.1 59.0 0.043 0.001 0.210 5Glyphosate34.6 56.4 0.002 0.001 0.006 5Surface waterArsenic31.1 17.8 0.004 0.002 0.005 41Radon67.8 13.3 75.3 51.0 219.0 10MTBE24.4 41.1 0.005 0.001 0.005 27Atrazine40.0 34.4 0.014 0.000 0.043 17Metolachlor44.4 36.7 0.001 0.001 0.005 12Boron55.6 22.2 0.082 0.059 0.180 152,4-D33.3 46.7 0.006 0.001 0.010 13Simazine38.9 40.0 0.001 0.000 0.001 14Glyphosate45.6 38.9 0.016 0.016 0.025 10Data: Q.15ANotes: The data presented in this table were requested only of systems serving populations of morethan 500,000.Unweighted data. Data are for wells and surface water intakes reported by systems inthe survey. Mean, median, 90th percentile, and number of observations are for wells andsurface water intakes with positive concentrations.This table reports results for the type of raw water treated, not the primary source of water ofthe sytem.Two systems reported very high arsenic concentrations and are excluded from the analysis.50Table 28Concentration of Various Contaminants in Very Large SystemsAcross All EntryPoints ByPrimarySource of Water(Average Finished Water Concentration in Parts per Million, Except for Radon, Which is pCi/L)Primary Source of Water andContaminant% ReportingN/A% ReportingNo DetectMeanConcentrationMedianConcentration90th PercentileConcentration ObservationsPrimarily Ground Water SystemsArsenic79.5 2.3 0.004 0.004 0.008 5Radon90.9 0.0 118.0 118.0 118.0 1MTBE79.5 13.6 0.000 0.000 0.000 0Atrazine79.5 9.1 0.205 0.205 0.210 2Metolachlor79.5 9.1 0.205 0.205 0.210 2Boron81.8 0.0 0.132 0.102 0.234 52,4-D84.1 9.1 0.000 0.000 0.000 0Simazine79.5 9.1 0.205 0.205 0.210 2Glyphosate84.1 9.1 0.000 0.000 0.000 0Primarily Surface Water SystemsArsenic9.1 40.4 0.003 0.002 0.005 43Radon52.5 23.2 60.4 47.0 189.0 17MTBE21.2 40.4 0.005 0.001 0.005 29Atrazine19.2 40.4 0.011 0.000 0.001 29Metolachlor21.2 49.5 0.001 0.000 0.004 20Boron60.6 9.1 0.123 0.056 0.500 142,4-D18.2 52.5 0.029 0.001 0.015 20Simazine21.2 39.4 0.001 0.000 0.001 25Glyphosate33.3 39.4 0.013 0.006 0.025 13Primarily Purchased Water SystemsArsenic0.0 5.5 0.009 0.010 0.014 44Radon21.8 10.9 460.1 447.0 646.0 26MTBE5.5 74.5 0.001 0.001 0.001 3Atrazine0.0 65.5 0.040 0.040 0.080 2Metolachlor1.8 67.3 0.000 0.000 0.000 0Boron78.2 1.8 0.155 0.164 0.200 62,4-D0.0 61.8 0.000 0.000 0.000 13Simazine0.0 83.6 0.001 0.001 0.001 1Glyphosate0.0 83.6 0.006 0.006 0.006 1Data: Q.15BNotes: The data presented in this table were requested only of systems serving populations of morethan 500,000.Unweighted data. Data are for wells and surface water intakes reported by systems inthe survey. Mean, median, 90th percentile, and number of observations are for test pointswith positive concentrations.(Continued)51Table 28 (Cont.)Concentration of Various Contaminants in Very Large SystemsBecause the test points for finished water may be in the distribution system, this table doesnot report results for the type of water treated; instead, it reports results by the primarysource of water for the system.Four systems were excluded because 1) reported arsenic concentrations may be incorrect,2) reported boron concentrations may be incorrect, or 3) they reported finished but not rawwater concentrations.52Table 29Residual Management Process OptionsPercentage of Plants UsingEach Residual Management ProcessBy Primary Source of Water and Water System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water PlantsMechanical dewatering 3.9 0.0 0.0 0.0 8.3 0.0 5.6 0.0 2.1Non-mechanical dewatering 3.6 0.0 3.5 5.7 5.2 4.8 17.8 0.0 3.6Chemical precipitation 0.0 0.0 0.0 0.3 1.0 5.5 4.3 0.0 0.3Land application 3.5 3.0 10.8 8.3 6.7 7.8 15.0 0.0 6.3Non-hazardous waste landfill 16.4 0.0 6.1 1.9 3.1 5.5 4.1 0.0 5.2Deep well Injection 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Evaporation Pond0.0 0.0 8.4 9.6 3.5 7.4 2.7 2.1 4.1French Drain 0.0 1.9 3.2 0.0 0.0 0.0 0.4 0.0 1.0Direct Discharge to Surface Water6.6 4.4 11.7 3.3 7.0 4.0 17.0 0.4 6.5Septic system 0.0 2.8 0.0 0.0 0.0 1.6 0.0 0.0 0.7Sanitary Sewer 0.8 6.0 12.5 7.0 15.1 12.4 6.0 4.2 7.7Surface Water PlantsMechanical dewatering 0.0 1.1 5.7 13.4 10.7 17.1 20.1 29.1 9.3Non-mechanical dewatering 3.6 21.4 34.4 44.9 36.2 58.2 51.1 49.9 34.1Chemical precipitation 0.0 0.0 1.4 22.0 7.2 18.2 16.8 17.2 8.8Land application 7.1 18.2 27.1 27.4 42.2 52.4 29.4 21.0 28.2Non-hazardous waste landfill 4.4 9.5 21.3 25.2 24.5 35.1 37.2 21.4 20.8Deep well Injection 0.0 0.0 0.0 0.0 0.0 0.0 0.6 0.0 0.0Evaporation Pond17.4 60.1 23.4 46.2 37.8 47.3 47.8 21.7 38.1French Drain 3.6 2.1 4.3 0.0 2.4 6.5 3.1 0.0 2.6Direct Discharge to Surface Water8.4 32.5 29.5 32.4 17.2 16.2 14.7 14.3 23.3Septic system 1.4 3.4 2.5 3.6 0.0 4.4 1.4 0.0 2.0Sanitary sewer0.0 5.6 23.0 15.2 29.1 22.2 13.1 28.2 16.0(Continued)53Table 29 (Cont.)Residual Management Process OptionsPercentage of Plants UsingEach Residual Management ProcessBy Primary Source of Water and Water System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesMixed PlantsMechanical dewatering 0.0 0.0 0.0 8.1 21.0 39.9 16.3 33.3 14.5Non-mechanical dewatering 0.0 0.0 0.0 31.4 41.1 71.5 56.8 0.0 36.6Chemical precipitation 0.0 0.0 0.0 8.1 0.0 39.9 24.2 0.0 7.7Land application 0.0 0.0 0.0 8.1 10.5 20.2 34.7 0.0 12.4Non-hazardous waste landfill 0.0 0.0 0.0 8.1 10.5 57.1 38.4 33.3 15.0Deep well Injection 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Evaporation Pond0.0 66.4 0.0 32.2 41.1 39.9 48.3 33.3 40.0French Drain 0.0 0.0 0.0 0.0 10.5 0.0 3.2 0.0 4.0Direct Discharge to Surface Water 100.0 33.6 0.0 24.1 31.5 39.9 19.5 66.7 28.6Septic system 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0Sanitary sewer0.0 0.0 0.0 14.6 10.5 0.0 19.5 0.0 7.8All PlantsMechanical dewatering 3.5 0.1 1.0 2.3 9.2 10.5 11.4 8.6 3.4Non-mechanical dewatering 3.6 2.3 9.4 12.7 13.5 36.9 32.2 13.3 9.3Chemical precipitation 0.0 0.0 0.2 4.0 2.4 13.3 10.0 4.4 1.9Land application 4.0 4.7 14.0 11.3 15.2 33.9 21.5 5.7 10.2Non-hazardous waste landfill 15.0 1.0 8.8 6.0 8.3 23.5 17.8 6.3 8.0Deep well Injection 0.0 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.0Evaporation Pond 2.1 6.8 11.1 16.1 12.7 30.9 21.7 7.6 10.5French Drain 0.4 1.9 3.4 0.0 0.8 3.7 1.5 0.0 1.3Direct Discharge to Surface Water 6.9 7.5 15.0 8.8 10.0 11.6 16.3 5.2 9.7Septic system 0.2 2.9 0.4 0.4 0.0 3.0 0.5 0.0 0.9Sanitary sewer0.7 5.9 13.4 8.5 18.0 16.4 8.8 11.3 8.6Data: Q.16ANotes:Excludes plants that treat purchased water.54Table 30Residual Management Process OptionsPercentage of Plants UsingEach Residual Management ProcessBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesGround Water PlantsMechanical dewatering 1.7 0.0 1.1 7.3 3.0 0.0 1.1Non-mechanical dewatering 1.5 0.1 3.5 9.4 13.6 0.0 2.0Chemical precipitation 0.0 0.0 0.3 1.2 3.9 0.0 0.2Land application 1.4 2.0 6.1 9.9 11.8 0.0 3.5Non-hazardous waste landfill 2.1 0.3 2.8 6.2 3.4 0.0 1.8Deep well Injection 0.0 0.0 0.0 0.0 0.0 0.0 0.0Evaporation Pond0.0 0.0 6.6 7.9 5.8 0.0 2.2French Drain 1.0 0.0 1.1 0.0 0.7 0.0 0.5Direct Discharge to Surface Water2.8 2.1 5.3 10.4 3.9 0.0 3.6Septic system 0.0 1.4 0.0 0.0 1.2 0.0 0.6Sanitary Sewer 2.2 7.5 15.0 16.1 8.2 0.0 8.6Surface Water PlantsMechanical dewatering 1.6 0.0 6.9 11.0 20.1 12.0 7.1Non-mechanical dewatering 1.1 12.8 29.5 36.9 45.4 44.0 26.9Chemical precipitation 1.1 0.0 7.4 11.0 12.8 16.0 6.7Land application 2.4 9.3 20.6 42.4 25.0 16.0 22.6Non-hazardous waste landfill 4.9 8.4 15.6 21.2 32.8 8.0 16.0Deep well Injection 0.0 0.0 0.0 0.0 0.3 0.0 0.0Evaporation Pond10.3 26.8 30.2 34.7 42.5 28.0 30.2French Drain 3.2 3.0 0.8 1.5 2.5 0.0 1.8Direct Discharge to Surface Water9.3 14.8 26.2 16.4 14.3 16.0 18.8Septic system 2.9 1.1 2.4 0.6 1.9 0.0 1.6Sanitary sewer2.6 6.7 17.3 28.7 18.7 24.0 16.9(Continued)55Table 30 (Cont.)Residual Management Process OptionsPercentage of Plants UsingEach Residual Management ProcessBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesMixed PlantsMechanical dewatering 5.8 0.0 8.9 11.7 16.2 * 8.9Non-mechanical dewatering 5.8 6.7 38.5 34.0 36.4 * 23.6Chemical precipitation 0.0 0.0 8.9 6.2 10.9 * 4.7Land application 0.0 0.0 0.0 19.0 25.5 * 7.6Non-hazardous waste landfill 0.0 6.7 8.9 15.0 29.9 * 9.2Deep well Injection 0.0 0.0 0.0 0.0 0.0 * 0.0Evaporation Pond0.0 68.7 27.6 48.3 27.1 * 24.3French Drain 0.0 0.0 0.0 8.4 2.7 * 2.5Direct Discharge to Surface Water7.8 31.3 29.6 20.1 23.8 * 18.5Septic system 2.0 0.0 0.0 0.0 0.0 * 0.7Sanitary Sewer 0.0 0.0 27.6 0.0 16.8 * 7.9All PlantsMechanical dewatering 1.7 0.0 2.1 8.9 14.3 11.5 2.0Non-mechanical dewatering 1.6 1.0 8.0 21.2 34.5 42.1 5.3Chemical precipitation 0.0 0.0 1.5 5.3 9.8 15.3 1.0Land application 1.4 2.6 8.4 23.1 20.8 15.3 5.9Non-hazardous waste landfill 2.2 0.9 4.9 12.4 23.1 7.7 3.6Deep well Injection 0.0 0.0 0.0 0.0 0.2 0.0 0.0Evaporation Pond0.4 2.1 10.6 20.0 29.6 26.8 6.0French Drain 1.0 0.2 1.0 0.9 1.9 0.0 0.7Direct Discharge to Surface Water3.2 3.1 8.9 13.1 11.6 15.3 5.7Septic system 0.1 1.4 0.4 0.2 1.5 0.0 0.7Sanitary sewer2.2 7.4 15.5 20.5 15.2 23.0 9.6Data: Q.16ANotes: *No data available for these cells.Excludes plants that treat only purchased treated water.56Table 31Residual Management Process OptionsPercentage of Plants That Discharge to Surface Water, Septic Systems, or SanitarySewersBy Primary Source of Water and Water System Service PopulationSystem Service Population CategoryWater Source100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesGround Water PlantsDirect Discharge to Surface Water100.0 100.0 100.0 63.9 66.7 100.0 95.9 100.0 88.1Septic system100.0 100.0 * 0.0 * 100.0 * * 84.7Sanitary sewer100.0 100.0 97.4 87.8 81.9 94.2 61.1 91.8 93.5Surface Water PlantsDirect Discharge to Surface Water100.0 100.0 92.1 80.2 48.7 54.1 62.2 82.5 76.2Septic system100.0 100.0 100.0 75.0 0.0 100.0 80.0 0.0 47.7Sanitary sewer* 100.0 93.9 66.9 69.0 88.2 62.6 94.3 78.3Mixed PlantsDirect Discharge to Surface Water100.0 100.0 * 40.2 61.0 100.0 75.5 100.0 56.0Septic system100.0 * * 0.0 0.0 * 0.0 0.0 6.8Sanitary sewer* * * 33.8 50.0 * 60.7 0.0 40.5All PlantsDirect Discharge to Surface Water100.0 100.0 97.0 69.7 57.6 59.4 80.2 86.4 81.1Septic system100.0 100.0 100.0 25.3 0.0 100.0 66.7 0.0 62.3Sanitary sewer100.0 100.0 96.8 76.3 76.2 90.6 61.7 89.8 88.7Data: Q.16ANotes: *No observations for these plantsExcludes plants that treat purchased water.These are the systems with the option to discard to surface water, septic systems, or sanitary sewers,and make use of these options.57Table 32Residual Management Process OptionsPercentage of Plants That Do Discharge to Surface Water, Septic Systems, or SanitarySewersBy Primary Source of Water and Plant Average Daily ProductionPlant Average Daily Production (MGD)Water Source0 -0.010.01 -0.10.1 -1.01.0 -10.010.0 -100.0Over100 All SizesGround Water PlantsDirect Discharge to Surface Water100.0 100.0 77.8 89.2 76.8 * 88.1Septic system * 100.0 0.0 0.0 100.0 * 84.7Sanitary sewer100.0 99.8 90.3 84.7 81.1 * 93.4Surface Water PlantsDirect Discharge to Surface Water100.0 89.2 92.3 54.9 48.2 100.0 76.1Septic system 100.0 100.0 56.3 12.9 75.9 0.0 47.7Sanitary sewer100.0 100.0 80.7 81.6 50.8 75.0 78.3Mixed PlantsDirect Discharge to Surface Water100.0 100.0 35.5 72.3 81.4 * 56.0Septic system 100.0 * 0.0 0.0 0.0 * 6.8Sanitary sewer* * 44.1 0.0 56.3 * 40.5All PlantsDirect Discharge to Surface Water100.0 95.8 80.8 67.5 53.5 100.0 81.1Septic system 100.0 100.0 28.4 11.0 73.3 * 62.3Sanitary sewer100.0 99.8 86.9 81.8 54.8 75.0 88.6Data: Q.16ANotes: *No observations for these plantsExcludes plants that treat purchased water.These are the systems with the option to discard to surface water, septic systems,or sanitary sewers, and make use of these options.58Please note that the unit of analysis changes for the following tables.The remaining tables report data for water systems except where noted.59Table 33Treated-Water Storage InformationPercentage of Systems That Have Each Type of Treated-Water StorageBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsClearwell storage after treatment16.3 21.3 26.9 28.9 45.6 56.2 40.4 13.1 22.8Confidence Interval+|- 10.2 +|- 9.8 +|- 10.7 +|- 12.6 +|- 14.1 +|- 19.7 +|- 26.0 +|- 15.7 +|- 5.3Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points26.4 36.7 17.0 23.1 18.5 33.9 22.3 42.6 27.2Confidence Interval+|- 9.6 +|- 12.7 +|- 8.3 +|- 10.1 +|- 11.0 +|- 17.4 +|- 14.3 +|- 23.9 +|- 5.8With a Common Inlet and Outlet18.4 15.3 15.6 8.8 10.1 23.0 8.0 42.6 15.6Confidence Interval+|- 9.8 +|- 8.8 +|- 11.4 +|- 9.5 +|- 8.3 +|- 26.8 +|- 6.9 +|- 23.9 +|- 5.0Storage within the distribution systemWith Dedicated Entry and Exit Points2.9 3.0 10.0 16.5 25.4 38.4 46.2 57.4 6.8Confidence Interval+|- 4.4 +|- 3.5 +|- 7.0 +|- 8.9 +|- 12.4 +|- 18.6 +|- 27.2 +|- 23.9 +|- 2.5With a Common Inlet and Outlet6.9 17.0 68.6 54.0 67.1 74.4 93.6 72.1 31.1Confidence Interval+|- 6.3 +|- 8.6 +|- 15.0 +|- 12.9 +|- 13.4 +|- 15.0 +|- 5.7 +|- 21.5 +|- 6.1Primarily Surface Water SystemsClearwell storage after treatment48.5 33.7 86.2 85.3 93.7 97.1 93.9 89.5 71.8Confidence Interval+|- 35.7 +|- 21.0 +|- 8.8 +|- 10.3 +|- 5.0 +|- 3.5 +|- 2.7 +|- 5.2 +|- 9.5Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points36.8 45.9 16.6 27.7 31.2 33.5 37.3 28.9 31.5Confidence Interval+|- 31.4 +|- 24.4 +|- 8.7 +|- 10.4 +|- 10.0 +|- 13.8 +|- 5.9 +|- 7.7 +|- 7.8With a Common Inlet and Outlet4.4 8.7 18.3 16.7 7.8 7.1 12.8 13.1 11.5Confidence Interval+|- 4.9 +|- 7.6 +|- 10.3 +|- 10.9 +|- 6.6 +|- 9.4 +|- 4.3 +|- 5.7 +|- 3.9Storage within the distribution systemWith Dedicated Entry and Exit Points1.3 10.8 4.1 29.2 33.9 45.7 54.0 63.3 18.5Confidence Interval+|- 2.8 +|- 13.0 +|- 4.0 +|- 11.1 +|- 10.0 +|- 13.6 +|- 5.9 +|- 8.2 +|- 4.4With a Common Inlet and Outlet10.2 30.8 73.6 73.0 69.5 76.2 72.9 71.1 54.8Confidence Interval+|- 9.7 +|- 26.7 +|- 12.0 +|- 11.9 +|- 10.1 +|- 15.0 +|- 5.3 +|- 7.7 +|- 8.4(Continued)60Table 33 (Cont.)Treated-Water Storage InformationPercentage of Systems That Have Each Type of Treated-Water StorageBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Purchased Water SystemsClearwell storage after treatment23.1 0.7 3.1 12.1 14.0 12.4 33.4 57.6 5.3Confidence Interval+|- 46.9 +|- 1.5 +|- 4.1 +|- 12.4 +|- 13.3 +|- 10.0 +|- 10.5 +|- 17.6 +|- 3.1Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points0.0 21.3 5.3 13.5 12.5 11.4 33.7 33.6 11.7Confidence Interval+|- 0.0 +|- 34.8 +|- 7.5 +|- 12.1 +|- 12.8 +|- 9.7 +|- 11.0 +|- 16.2 +|- 11.2With a Common Inlet and Outlet10.0 11.1 7.6 15.3 0.6 2.5 0.0 0.0 8.7Confidence Interval+|- 22.7 +|- 16.5 +|- 7.6 +|- 17.4 +|- 1.2 +|- 4.2 +|- 0.0 +|- 0.0 +|- 6.2Storage within the distribution systemWith Dedicated Entry and Exit Points0.0 7.1 8.8 22.6 34.2 36.9 53.6 60.0 13.2Confidence Interval+|- 0.0 +|- 11.2 +|- 11.2 +|- 17.1 +|- 20.0 +|- 15.6 +|- 11.8 +|- 17.4 +|- 6.8With a Common Inlet and Outlet0.0 28.9 55.4 61.6 72.3 55.6 70.8 58.4 50.1Confidence Interval+|- 0.0 +|- 25.9 +|- 17.5 +|- 19.0 +|- 18.6 +|- 16.4 +|- 10.9 +|- 17.8 +|- 12.8All SystemsClearwell storage after treatment18.5 19.5 25.5 36.9 54.2 62.8 61.0 71.9 25.4Confidence Interval+|- 10.0 +|- 8.2 +|- 7.5 +|- 8.7 +|- 8.2 +|- 6.7 +|- 11.9 +|- 5.5 +|- 4.2Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points26.9 35.3 13.8 22.2 21.3 27.8 30.9 31.8 25.3Confidence Interval+|- 9.2 +|- 10.9 +|- 6.8 +|- 7.0 +|- 6.7 +|- 8.5 +|- 7.6 +|- 7.0 +|- 4.7With a Common Inlet and Outlet17.4 14.3 13.6 11.6 7.2 10.5 8.3 13.4 14.1Confidence Interval+|- 9.1 +|- 7.3 +|- 7.8 +|- 7.1 +|- 4.3 +|- 9.9 +|- 3.2 +|- 5.1 +|- 3.9Storage within the distribution systemWith Dedicated Entry and Exit Points2.8 4.1 9.1 20.2 30.2 41.3 51.0 61.7 9.0Confidence Interval+|- 4.1 +|- 3.3 +|- 5.3 +|- 6.8 +|- 7.8 +|- 9.2 +|- 11.2 +|- 7.3 +|- 2.2With a Common Inlet and Outlet7.1 19.5 65.4 59.2 69.0 70.2 80.2 68.0 36.6Confidence Interval+|- 5.9+|- 8.0+|- 11.1 +|- 9.1 +|- 8.1 +|- 8.8+|- 5.5+|- 7.0+|- 5.1Data:Q.18Notes: Column totals do not sum to 100.61Table 34Treated-Water Storage Information - Average Capacity for Each Type of Treated-Water StorageByPrimarySource of Water(In Millions of Gallons)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000All SizesPrimarily Ground Water SystemsClearwell storage after treatment0.010 0.047 0.118 0.371 1.284 1.267 2.557 190.000 0.237Confidence Interval +|- 0.007 +|- 0.047 +|- 0.071 +|- 0.153 +|- 0.665 +|- 0.868 +|- 0.706 +|- 0.000 +|- 0.079Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points0.012 0.633 0.295 0.826 4.030 8.925 14.903 71.788 0.613Confidence Interval +|- 0.010 +|- 1.152 +|- 0.206 +|- 0.255 +|- 2.158 +|- 5.902 +|- 4.545 +|- 27.293 +|- 0.548With a Common Inlet and Outlet0.073 0.085 0.130 1.258 1.400 3.670 35.461 45.248 0.270Confidence Interval +|- 0.140 +|- 0.054 +|- 0.072 +|- 0.342 +|- 1.314 +|- 0.689 +|- 48.457 +|- 48.974 +|- 0.121Storage within the distribution systemWith Dedicated Entry and Exit Points0.009 0.038 0.175 0.931 1.932 6.316 13.202 53.785 1.131Confidence Interval +|- 0.003 +|- 0.048 +|- 0.205 +|- 0.412 +|- 1.280 +|- 3.237 +|- 4.115 +|- 24.077 +|- 0.419With a Common Inlet and Outlet0.187 0.097 0.221 1.002 3.947 12.387 9.783 71.228 0.835Confidence Interval +|- 0.187 +|- 0.037 +|- 0.055 +|- 0.282 +|- 1.576 +|- 5.451 +|- 6.516 +|- 22.441 +|- 0.215Total Storage Capacity0.050 0.325 0.271 1.092 4.652 17.232 21.170 157.065 0.723Confidence Interval +|- 0.047 +|- 0.507 +|- 0.065 +|- 0.210 +|- 1.299 +|- 4.946 +|- 11.816 +|- 54.295 +|- 0.209Primarily Surface Water SystemsClearwell storage after treatment0.131 0.102 0.162 0.421 1.379 3.075 11.626 63.908 1.819Confidence Interval +|- 0.143 +|- 0.084 +|- 0.058 +|- 0.116 +|- 0.474 +|- 0.772 +|- 2.138 +|- 17.437 +|- 0.337Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points0.030 0.109 0.374 1.061 2.874 6.438 29.628 114.200 3.001Confidence Interval +|- 0.026 +|- 0.080 +|- 0.178 +|- 0.360 +|- 0.933 +|- 3.805 +|- 7.982 +|- 36.100 +|- 0.871With a Common Inlet and Outlet0.042 0.217 0.359 1.556 2.653 1.023 7.356 27.000 1.414Confidence Interval +|- 0.035 +|- 0.176 +|- 0.183 +|- 1.096 +|- 0.746 +|- 1.801 +|- 2.003 +|- 11.778 +|- 0.382Storage within the distribution systemWith Dedicated Entry and Exit Points* 0.350 0.995 0.774 4.057 17.252 46.256 153.748 12.156Confidence Interval * +|- 0.127 +|- 0.593 +|- 0.195 +|- 1.456 +|- 12.894 +|- 17.009 +|- 47.937 +|- 2.969With a Common Inlet and Outlet0.214 0.192 0.487 1.294 4.088 6.775 17.810 98.164 3.601Confidence Interval +|- 0.153 +|- 0.035 +|- 0.132 +|- 0.389 +|- 1.138 +|- 1.535 +|- 2.454 +|- 34.980 +|- 0.680Total Storage Capacity0.113 0.203 0.682 2.034 6.576 17.992 60.729 249.612 6.718Confidence Interval +|- 0.097 +|- 0.077 +|- 0.124 +|- 0.346 +|- 1.367 +|- 6.486 +|- 10.636 +|- 47.716 +|- 1.155(Continued)62Table 34 (Cont.)Treated-Water Storage Information - Average Capacity for Each Type of Treated-Water StorageByPrimarySource of Water(In Millions of Gallons)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000All SizesPrimarily Purchased Water SystemsClearwell storage after treatment0.018 0.028 0.192 0.299 0.931 1.529 7.965 57.720 2.463Confidence Interval +|- 0.000 +|- 0.000 +|- 0.043 +|- 0.327 +|- 0.972 +|- 1.829 +|- 1.855 +|- 41.554 +|- 1.478Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points* 0.017 0.654 1.087 1.083 7.639 26.495 30.041 1.488Confidence Interval * +|- 0.001 +|- 0.252 +|- 0.410 +|- 0.574 +|- 3.860 +|- 11.631 +|- 22.275 +|- 1.519With a Common Inlet and Outlet0.053 0.046 0.227 0.184 116.500 3.000 * * 0.855Confidence Interval +|- 0.000 +|- 0.048 +|- 0.096 +|- 0.197 +|- 0.000 +|- 0.000 * * +|- 1.409Storage within the distribution systemWith Dedicated Entry and Exit Points* 0.020 0.228 1.053 3.118 8.256 26.016 122.328 3.794Confidence Interval * +|- 0.025 +|- 0.118 +|- 0.501 +|- 1.236 +|- 3.604 +|- 6.367 +|- 115.137 +|- 2.308With a Common Inlet and Outlet* 0.175 0.289 0.845 4.045 15.510 23.809 81.896 1.668Confidence Interval * +|- 0.155 +|- 0.153 +|- 0.300 +|- 1.498 +|- 6.176 +|- 5.711 +|- 35.725 +|- 0.656Total Storage Capacity0.029 0.088 0.313 1.116 5.626 17.403 44.501 182.287 2.244Confidence Interval +|- 0.021 +|- 0.073 +|- 0.133 +|- 0.494 +|- 2.356 +|- 5.954 +|- 7.554 +|- 83.215 +|- 0.820All SystemsClearwell storage after treatment0.031 0.054 0.134 0.389 1.316 2.533 9.075 65.773 0.794Confidence Interval +|- 0.022 +|- 0.043 +|- 0.050 +|- 0.094 +|- 0.371 +|- 0.660 +|- 1.854 +|- 16.542 +|- 0.125Storage after treatment, before distribution systemWith Dedicated Entry and Exit Points0.013 0.537 0.343 0.912 3.083 7.470 25.156 85.899 0.997Confidence Interval +|- 0.009 +|- 0.963 +|- 0.154 +|- 0.191 +|- 0.982 +|- 3.157 +|- 5.140 +|- 23.167 +|- 0.448With a Common Inlet and Outlet0.073 0.087 0.172 1.052 4.408 2.826 13.961 35.175 0.432Confidence Interval +|- 0.137 +|- 0.048 +|- 0.076 +|- 0.458 +|- 5.542 +|- 1.874 +|- 11.235 +|- 22.967 +|- 0.170Storage within the distribution systemWith Dedicated Entry and Exit Points0.009 0.091 0.224 0.915 3.053 12.093 30.863 133.088 4.169Confidence Interval +|- 0.003 +|- 0.069 +|- 0.154 +|- 0.242 +|- 0.827 +|- 6.310 +|- 8.935 +|- 41.981 +|- 0.888With a Common Inlet and Outlet0.190 0.122 0.263 1.040 4.018 10.363 15.448 90.937 1.453Confidence Interval +|- 0.169 +|- 0.042 +|- 0.055 +|- 0.194 +|- 0.850 +|- 2.515 +|- 4.410 +|- 24.049 +|- 0.222Total Storage Capacity0.055 0.289 0.318 1.286 5.518 17.637 42.835 222.130 1.696Confidence Interval+|- 0.043 +|- 0.411 +|- 0.053 +|- 0.175 +|- 0.902 +|- 3.689 +|- 9.901 +|- 36.962 +|- 0.220Data:Q.18Notes: *No data available for these cells.Clearwell storage after treatment for ground water systems serving over 500,000 people is based on 1 observation.63Table 35Distribution System Summary - PipesBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000All SizesPublic SystemsMiles of Pipe in Place3 5 25 61 203 339 560 2,382 61Confidence interval +|- 2 +|- 1 +|- 11 +|- 22 +|- 77 +|- 46 +|- 149 +|- 281 +|- 12Service Connections per Mile24 33 49 58 68 69 58 61 48Confidence interval +|- 11 +|- 9 +|- 10 +|- 9 +|- 20 +|- 5 +|- 11 +|- 6 +|- 6Average Annual Pipe Replaced in the Past 5 Years (miles)0 0 1 2 5 8 20 58 1Confidence interval +|- 0 +|- 0 +|- 0 +|- 1 +|- 2 +|- 2 +|- 12 +|- 17 +|- 0Average Cost per Mile of Pipe Replaced in the Past 5 Years(thousands of dollars)738 119 131 239 260 380 462 1,719 191Confidence interval +|- 557 +|- 51 +|- 49 +|- 89 +|- 67 +|- 109 +|- 93 +|- 1,209 +|- 34Observations16 67 158 113 108 82 139 44 727Private SystemsMiles of Pipe in Place1 4 37 217 390 871 777 2,771 20Confidence interval +|- 1 +|- 2 +|- 25 +|- 189 +|- 367 +|- 834 +|- 133 +|- 812 +|- 9Service Connections per Mile59 71 49 37 47 66 64 103 62Confidence interval +|- 14 +|- 21 +|- 27 +|- 18 +|- 23 +|- 22 +|- 9 +|- 7 +|- 11Average Annual Pipe Replaced in the Past 5 Years (miles)0 0 1 20 5 3 20 154 1Confidence interval +|- 0 +|- 0 +|- 1 +|- 33 +|- 5 +|- 2 +|- 11 +|- 130 +|- 1Average Cost per Mile of Pipe Replaced in the Past 5 Years(thousands of dollars)31 90 106 62 103 438 623 * 75Confidence interval +|- 15 +|- 36 +|- 130 +|- 51 +|- 80 +|- 63 +|- 238 * +|- 22Observations131 90 30 19 17 10 16 4 317(Continued)64Table 35 (Cont.)Distribution System Summary - PipesBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000All SizesAll SystemsMiles of Pipe in Place1 4 28 85 232 395 579 2,414 39Confidence interval +|- 1 +|- 1 +|- 10 +|- 37 +|- 85 +|- 100 +|- 141 +|- 268 +|- 7Service Connections per Mile57 58 49 55 65 68 59 64 55Confidence interval +|- 14 +|- 16 +|- 9 +|- 8 +|- 17 +|- 5 +|- 10 +|- 6 +|- 7Average Annual Pipe Replaced in the Past 5 Years (miles)0 0 1 4 5 7 20 65 1Confidence interval +|- 0 +|- 0 +|- 0 +|- 5 +|- 2 +|- 2 +|- 11 +|- 19 +|- 0Average Cost per Mile of Pipe Replaced in the Past 5 Years(thousands of dollars)45 107 129 222 252 386 481 1,719 163Confidence interval +|- 27 +|- 35 +|- 47 +|- 83 +|- 65 +|- 98 +|- 87 +|- 1,209 +|- 27Observations147 157 188 132 125 92 155 48 1,044Data:Q.19A, Q.20ANotes:*No observations.Systems reporting zero miles of distribution pipe are included in table.The cost per mile of pipe replaced reported by the 1999 Drinking Water Infrastructure Needs Survey is a good dealhigher than reported by the CWS Survey. There are important differences in the information collected by the twosurveys that account for some of the difference. The main difference is the time covered by the surveys. TheCWS Survey asks about pipe replaced in the past five years, and the Needs Survey asks about plans to replacepipe in the next 20 years. Sampling error also explains some of the difference; systems that responded to bothsurveys report similar cost per foot, while systems that did not provide data for both surveys report very different costs.Most publicly owned systems serving less than 100 people did not replace pipe in the last 5 years. The estimateof average cost per mile replaced is based on 3 observations.Costs for public systems serving over 500,000 excludes one project that cost over $50 million per mile. Ifincluded, the mean cost per mile of pipe replaced in the past 5 years is $9.7 million in this category.A public state prison serving 3,301-10,000. people was removed from calculations because of its largeconnections per mile.A private system serving 3,301-10,000 people with average cost per mile of $770,000 was dropped from theestimate. If included the average cost is $206,000 for private systems of this size.65Table 36Average Size of Distribution SystemByDiameter of Pipe and Ownership(Miles of Pipe)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000All SizesPublic SystemsDistribution Mains Less Than 6 Inches1.5 3.3 21.4 38.5 108.8 136.0 250.4 835.1 34.7Confidence interval +|- 0.7 +|- 1.3 +|- 10.1 +|- 18.9 +|- 57.4 +|- 33.7 +|- 68.7 +|- 119.1 +|- 8.6Distribution Mains 6 to 10 inches1.2 1.1 3.2 17.0 58.8 122.4 175.4 864.9 16.3Confidence interval +|- 1.5 +|- 0.6 +|- 1.4 +|- 5.1 +|- 26.1 +|- 20.8 +|- 49.9 +|- 147.7 +|- 3.5Distribution Mains Greater Than 10 Inches0.5 0.1 0.8 4.9 34.1 80.4 137.0 704.5 9.1Confidence interval +|- 0.6 +|- 0.3 +|- 0.4 +|- 1.4 +|- 11.2 +|- 12.8 +|- 35.1 +|- 88.5 +|- 1.8Observations16 67 160 119 109 82 142 44 739Private SystemsDistribution Mains Less Than 6 Inches1.1 3.5 33.9 190.3 191.0 192.7 361.3 676.9 13.8Confidence interval +|- 0.6 +|- 1.5 +|- 23.5 +|- 188.0 +|- 150.3 +|- 134.0 +|- 83.9 +|- 350.9 +|- 6.3Distribution Mains 6 to 10 inches0.0 0.1 2.4 23.8 184.6 114.1 249.5 1,484.0 4.2Confidence interval +|- 0.0 +|- 0.1 +|- 2.0 +|- 11.7 +|- 232.0 +|- 42.8 +|- 67.2 +|- 830.2 +|- 3.5Distribution Mains Greater Than 10 Inches0.0 0.0 0.3 2.5 14.6 63.6 166.5 454.6 0.7Confidence interval +|- 0.0 +|- 0.0 +|- 0.5 +|- 1.3 +|- 8.8 +|- 24.5 +|- 33.4 +|- 189.7 +|- 0.2Observations131 90 30 19 17 9 16 5 317All SystemsDistribution Mains Less Than 6 Inches1.1 3.4 23.9 60.8 121.4 141.6 259.9 819.0 23.7Confidence interval +|- 0.6 +|- 1.1 +|- 8.9 +|- 34.1 +|- 53.0 +|- 33.0 +|- 65.3 +|- 113.3 +|- 5.1Distribution Mains 6 to 10 inches0.1 0.5 3.0 18.0 78.0 121.6 181.8 915.7 9.9Confidence interval +|- 0.1 +|- 0.2+|- 1.1 +|- 4.5 +|- 41.9 +|- 19.2 +|- 47.4 +|- 156.6 +|- 2.3Distribution Mains Greater Than 10 Inches0.0 0.1 0.7 4.5 31.1 78.7 139.5 684.0 4.6Confidence interval +|- 0.0 +|- 0.1 +|- 0.4 +|- 1.2+|- 9.7 +|- 11.9 +|- 32.7 +|- 83.6 +|- 0.7Observations147 157 190 138 126 91 158 49 1,056Data:Q.19ANotes:Systems reporting zero miles of distribution pipe are included in table.The estimate for private systems serving greater than 500,000 people is based on 5 systems.In private systems serving 50,000-100,000 people, one system with 6,400 miles of pipe was dropped from the estimate.If included, the average length of six inch pipe for this category is 666 miles. Changes to the estimates inother categories are insignificant.66Table 37Distribution System Summary - Percentage of Pipe in Each Age CategoryBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsPercentage of Pipe that is:Less than 40 years old 93.2 92.6 84.5 75.3 68.9 62.5 61.6 78.3 75.2Between 40 and 80 years old 6.8 7.4 14.9 20.8 25.4 29.5 31.9 19.1 21.1More than 80 years old 0.0 0.0 0.6 3.9 5.7 8.0 6.5 2.6 3.8Observations103 91 88 57 45 26 35 6 451Primarily Surface Water SystemsPercentage of Pipe that is:Less than 40 years old 67.5 65.4 68.6 73.6 80.0 70.7 55.3 48.2 67.3Between 40 and 80 years old 32.0 34.0 23.0 19.6 15.8 22.1 30.8 39.8 24.6More than 80 years old 0.5 0.6 8.4 6.8 4.1 7.2 13.9 11.9 8.1Observations46 52 67 71 72 48 95 30 481Primarily Purchased Water SystemsPercentage of Pipe that is:Less than 40 years old 100.0 84.6 88.3 96.4 92.9 79.7 73.3 69.4 89.6Between 40 and 80 years old 0.0 15.4 11.2 3.3 6.4 18.4 23.7 26.4 9.6More than 80 years old 0.0 0.0 0.5 0.3 0.7 1.9 3.0 4.2 0.8Observations6 23 49 26 26 26 44 9 209All SystemsPercentage of Pipe that is:Less than 40 years old 90.6 88.3 85.7 84.3 81.4 70.2 60.9 56.3 78.0Between 40 and 80 years old 9.4 11.7 13.3 12.9 15.3 23.4 29.7 34.4 18.0More than 80 years old 0.1 0.1 1.0 2.8 3.4 6.4 9.4 9.2 4.0Observations155 166 204 154 143 100 174 45 1,141Data:Q.19A, Q.19BNotes:Table reports the percentage of pipe on average in each age category in the nation. It is not the percentageof pipe per system.67Table 38Distribution System Summary - Percentage of Pipe in Each Age CategoryBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsPercentage of Pipe that is:Less than 40 years old 76.3 81.5 81.1 77.6 76.2 65.2 61.4 54.9 72.6Between 40 and 80 years old 23.6 18.3 17.5 18.4 19.7 26.9 29.2 35.8 22.4More than 80 years old 0.1 0.1 1.4 4.0 4.2 7.9 9.4 9.3 5.0Observations18 72 173 135 122 88 160 40 808Private SystemsPercentage of Pipe that is:Less than 40 years old 92.4 92.8 98.7 96.2 95.8 86.6 56.5 67.7 92.9Between 40 and 80 years old 7.6 7.2 1.3 3.3 3.1 12.0 34.1 23.8 5.8More than 80 years old 0.0 0.0 0.0 0.6 1.1 1.4 9.4 8.5 1.3Observations137 94 31 19 21 12 14 5 333All SystemsPercentage of Pipe that is:Less than 40 years old 90.6 88.3 85.7 84.3 81.4 70.2 60.9 56.3 78.0Between 40 and 80 years old 9.4 11.7 13.3 12.9 15.3 23.4 29.7 34.4 18.0More than 80 years old 0.1 0.1 1.0 2.8 3.4 6.4 9.4 9.2 4.0Observations155 166 204 154 143 100 174 45 1,141Data:Q.19A, Q.19BNotes:Table reports the percentage of pipe on average in each age category in the nation. It is not the percentageof pipe per system.68Table 39Service Connections ProfileBy Ownership(Number of Connections)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean Residential Connections19 110 528 1,856 6,160 16,952 34,193 171,180 2,479Confidence Interval+|- 11 +|- 29 +|- 68 +|- 240 +|- 607 +|- 2,140 +|- 7,334 +|- 21,895 +|- 329Median Residential Connections20 80 440 1,725 5,367 17,498 30,600 146,482 442Mean Non-Residential Connections2 6 35 283 627 1,615 3,443 17,169 249Confidence Interval+|- 3 +|- 2 +|- 9 +|- 152 +|- 147 +|- 294 +|- 853 +|- 3,842 +|- 46Median Non-Residential Connections0 2 15 100 400 1,340 2,371 9,127 12Observations18 74 174 145 130 93 175 51 860Private SystemsMean Residential Connections24 105 446 1,609 6,457 20,784 44,192 222,922 427Confidence Interval+|- 3 +|- 16 +|- 146 +|- 386 +|- 1,528 +|- 4,576 +|- 6,970 +|- 41,015 +|- 83Median Residential Connections24 90 390 1,595 4,934 19,618 42,999 189,594 45Mean Non-Residential Connections1 1 9 153 631 1,512 4,207 17,956 30Confidence Interval+|- 1 +|- 2 +|- 6 +|- 86 +|- 491 +|- 519 +|- 843 +|- 4,676 +|- 11Median Non-Residential Connections0 0 0 82 230 1,411 3,158 21,270 0Observations138 92 31 22 22 16 19 6 346All SystemsMean Residential Connections23 107 512 1,819 6,205 17,434 35,082 176,431 1,425Confidence Interval+|- 3 +|- 14 +|- 60 +|- 212 +|- 566 +|- 1,990 +|- 6,865 +|- 20,425 +|- 123Median Residential Connections24 86 430 1,668 5,127 17,629 32,324 151,230 143Mean Non-Residential Connections1 3 30 264 627 1,603 3,510 17,236 137Confidence Interval+|- 1 +|- 2 +|- 7 +|- 130 +|- 146 +|- 267 +|- 793 +|- 3,513 +|- 20Median Non-Residential Connections0 0 12 100 386 1,401 2,788 13,590 0Observations156 166 205 167 152 109 194 57 1,206Data:Q.20A69Table 40Population ServedBy Ownership and System Service PopulationSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean Population Served61 250 1,440 5,847 21,245 71,091 211,219 1,582,013 12,939Confidence Interval+|- 19 +|- 38 +|- 163 +|- 407 +|- 1,693 +|- 3,985 +|- 20,488 +|- 330,128 +|- 2,176Observations18 76 179 148 138 101 183 52 895Private SystemsMean Population Served53 282 1,216 5,657 21,611 73,327 169,092 850,802 1,457Confidence Interval+|- 6 +|- 34 +|- 304 +|- 801 +|- 5,626 +|- 5,542 +|- 22,632 +|- 101,402 +|- 295Observations138 95 32 22 23 16 19 6 351All SystemsMean Population Served54 271 1,396 5,819 21,302 71,354 207,583 1,509,021 7,070Confidence Interval+|- 6 +|- 26 +|- 140 +|- 372 +|- 1,688 +|- 3,586 +|- 19,327 +|- 298,260 +|- 871Observations156 171 211 170 161 117 202 58 1,246Data:Q.20A70Table 41Annual Deliveries per Customer Service ConnectionBy Ownership(Thousands of Gallons)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean Residential Deliveries119 141 87 250 106 134 144 135 133Confidence Interval+|- 66 +|- 91 +|- 11 +|- 203 +|- 12 +|- 21 +|- 16 +|- 12 +|- 44Median Residential Deliveries65 70 76 84 87 107 118 119 78Mean Non-Residential Deliveries288 197 580 860 994 1,095 1,142 1,323 637Confidence Interval+|- 637 +|- 128 +|- 508 +|- 304 +|- 516 +|- 396 +|- 297 +|- 190 +|- 244Median Non-Residential Deliveries0 0 125 375 492 679 682 1,031 200Observations11 50 127 115 108 79 130 40 660Private SystemsMean Residential Deliveries74 109 91 100 100 112 111 117 93Confidence Interval+|- 15 +|- 33 +|- 27 +|- 29 +|- 23 +|- 32 +|- 26 +|- 24 +|- 17Median Residential Deliveries67 71 82 83 88 72 84 149 70Mean Non-Residential Deliveries35 240 256 719 1,348 718 1,315 530 308Confidence Interval+|- 40 +|- 233 +|- 174 +|- 697 +|- 1,606 +|- 347 +|- 520 +|- 109 +|- 154Median Non-Residential Deliveries0 0 120 341 535 413 915 534 83Observations85 81 23 18 17 15 16 5 260All SystemsMean Residential Deliveries76 119 88 227 105 131 141 133 113Confidence Interval+|- 15 +|- 36 +|- 10 +|- 173 +|- 11 +|- 19 +|- 14 +|- 11 +|- 23Median Residential Deliveries65 71 76 84 88 106 117 121 75Mean Non-Residential Deliveries61 210 536 844 1,040 1,047 1,159 1,254 563Confidence Interval+|- 61 +|- 109 +|- 440 +|- 282 +|- 499 +|- 348 +|- 276 +|- 177 +|- 192Median Non-Residential Deliveries0 0 120 364 495 635 695 1,017 169Observations96 131 150 133 125 94 146 45 920Data:Q.4, Q.10, Q.20Notes:Seven public systems with outliers greater than 123 million gallons of water in non-residential deliveriesaffecting population categories 3,301-10,000 people, 10,000-50,000 people and 100,000-500,000 people weredropped from the estimate. If included, non-residential deliveries are 5.9 million gallons of water, 2.6million gallons of water, and 1.1 million gallons of water, respectively.71Table 42Percentage of Systems that have Cross Connection Control ProgramsBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsPercentage of Systems 15.8 47.8 55.0 83.1 85.1 87.8 92.1 92.0 61.1Confidence Interval +|- 20.4 +|- 21.2 +|- 12.2 +|- 7.4 +|- 9.6 +|- 8.0 +|- 3.1 +|- 4.5 +|- 8.0Observations18 73 177 144 126 98 179 50 865Private SystemsPercentage of Systems15.9 26.4 39.2 77.8 82.7 94.5 91.7 100.0 25.5Confidence Interval+|- 10.6 +|- 13.3 +|- 20.8 +|- 21.6 +|- 18.9 +|- 9.2 +|- 7.2 +|- 0.0 +|- 7.7Observations137 94 32 20 23 16 19 6347All SystemsPercentage of Systems15.9 33.7 51.9 82.4 84.7 88.6 92.0 92.8 42.7Confidence Interval+|- 10.1 +|- 11.4 +|- 11.4 +|- 7.8 +|- 8.6 +|- 7.1 +|- 2.9 +|- 4.0 +|- 5.7Observations155 167 209 164 149 114 198 561,212Data: Q.2272Table 43Percentage of Systems that Have a Cross Connection Control Program that is Designed to Prevent Backflow from Reachinga PubliclyOwned Distribution System and Provides Protection within a Customer's Premises.By OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsPercentage of Systems 27.9 14.9 22.6 30.3 37.1 31.6 43.3 27.5 25.7Confidence Interval +|- 45.1 +|- 16.6 +|- 9.3 +|- 10.1 +|- 10.2 +|- 9.8 +|- 12.6 +|- 7.8 +|- 5.6Observations6 30 101 117 105 86 160 42 647Private SystemsPercentage of Systems 0.3 23.3 17.8 28.6 13.4 6.6 19.7 0.0 15.7Confidence Interval +|- 0.7 +|- 24.7 +|- 23.2 +|- 24.3 +|- 15.4 +|- 11.0 +|- 13.7 +|- 0.0 +|- 11.6Observations19 24 13 15 19 13 17 5125All SystemsPercentage of Systems 1.9 19.3 21.8 30.1 33.2 28.7 41.2 24.8 22.6Confidence Interval +|- 2.8 +|- 17.0 +|- 9.4 +|- 9.4 +|- 9.1 +|- 8.8 +|- 11.4 +|- 7.1 +|- 5.7Observations25 54 114 132 124 99 177 47772Data: Q.23Definitions: These systems have a Containment and Isolation program. This is often referred to as providing protection upto the tap. Containment-only programs are designed to prevent backflow from reaching a publicly owneddistribution system, but do not provide protection within the premises. This is often referred to as providingprotection up to the meter.73Table 44Percentage of Systems With Each Element in their Cross Connection Control ProgramsBy Water System Service PopulationSystem Service Population CategoryCross Connection Control ProgramElement100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesRight of entry85.7 93.3 98.6 93.1 89.6 82.8 85.2 84.6 93.6Confidence Interval+|- 0.0 +|- 7.7 +|- 1.5 +|- 4.5 +|- 5.6 +|- 8.3 +|- 4.6 +|- 5.4 +|- 2.7Surveys/inspections to identify crossconnections within the system/facility91.2 90.4 97.8 90.5 87.6 84.7 90.7 86.3 92.5Confidence Interval+|- 13.2 +|- 9.2 +|- 2.1 +|- 5.6 +|- 6.7 +|- 8.0 +|- 3.2 +|- 5.2 +|- 3.0Policy specifying which serviceconnections must be equipped withbackflow prevention device/assemblies91.4 97.0 98.4 95.9 93.7 90.0 97.1 92.3 96.2Confidence Interval+|- 13.2 +|- 3.9 +|- 2.1 +|- 3.8 +|- 5.1 +|- 7.2 +|- 1.7 +|- 4.1 +|- 2.0Enforcement authority to installdevices/assemblies86.2 97.7 97.7 84.5 90.8 80.6 89.5 82.4 92.9Confidence Interval+|- 14.7 +|- 3.4 +|- 2.1 +|- 7.2 +|- 5.0 +|- 7.8 +|- 4.0 +|- 5.7 +|- 2.4Enforcement authority to test assemblies85.7 98.0 94.2 85.9 84.5 75.2 76.9 78.9 91.0Confidence Interval+|- 15.1 +|- 3.4 +|- 6.7 +|- 6.6 +|- 6.8 +|- 11.9 +|- 16.0 +|- 6.0 +|- 3.2Penalties for non-compliance withordinance78.6 91.5 90.3 74.6 80.3 76.2 71.2 72.7 84.8Confidence Interval+|- 17.7 +|- 7.9 +|- 8.0 +|- 9.3 +|- 7.5 +|- 8.3 +|- 15.0 +|- 6.9 +|- 4.3Public education programs68.2 49.2 47.3 52.0 39.6 48.8 51.4 52.3 49.8Confidence Interval+|- 23.9 +|- 19.7 +|- 17.3 +|- 11.8 +|- 9.4 +|- 10.8 +|- 12.6 +|- 7.7 +|- 8.2Training/certification of testers andinspectors82.3 62.0 55.4 63.1 62.3 71.6 64.8 78.7 62.2Confidence Interval+|- 19.5 +|- 18.9 +|- 17.3 +|- 9.9 +|- 9.4 +|- 9.2 +|- 14.2 +|- 6.3 +|- 7.9Observations24 51 113 129 126 99 174 51 767Data: Q.2474Table 45Mean Percentage of Backflow Prevention Assemblies that are Tested and Fail Annually During InspectionBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsPercentage of Systems3.0 0.1 0.7 4.1 6.2 6.1 8.9 10.0 2.4Confidence Interval +|- 6.4 +|- 0.1 +|- 1.0 +|- 2.1 +|- 1.7 +|- 1.8 +|- 1.2 +|- 2.2 +|- 0.8Observations3 20 80 72 83 60 127 29 474Private SystemsPercentage of Systems 0.1 0.1 0.2 6.5 6.4 3.4 6.8 4.51.2Confidence Interval+|- 0.1 +|- 0.1 +|- 0.4 +|- 6.8 +|- 3.0 +|- 1.8 +|- 2.5 +|- 2.5 +|- 0.9Observations 13 18 12 12 16 9 14 397All SystemsPercentage of Systems 0.1 0.1 0.7 4.5 6.2 5.8 8.7 9.52.0Confidence Interval+|- 0.2 +|- 0.1 +|- 0.9 +|- 2.1 +|- 1.5 +|- 1.6 +|- 1.1 +|- 2.1 +|- 0.6Observations16 38 92 84 99 69 141 32571Data: Q.2575Table 46Total RevenueBy Primary Source of Water(Thousands of Dollars)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000All SizesPrimarily Ground Water SystemsMean5 23 146 622 2,179 7,878 14,013 75,183 286Confidence Interval +|- 2 +|- 6 +|- 31 +|- 118 +|- 431 +|- 982 +|- 7,219 +|- 13,978 +|- 42Median2 20 107 605 1,862 7,126 12,670 86,082 23% not charging directly for water43 32 4 5 6 0 0 0 25Confidence Interval +|- 17 +|- 13 +|- 4 +|- 7 +|- 8 +|- 0 +|- 0 +|- 0 +|- 7Observations86 80 89 62 44 27 40 7 435Primarily Surface Water SystemsMean17 55 350 961 3,133 8,027 23,839 151,432 3,291Confidence Interval +|- 10 +|- 20 +|- 85 +|- 147 +|- 502 +|- 1,613 +|- 2,122 +|- 31,259 +|- 575Median10 48 269 856 2,356 6,559 19,198 89,897 331% not charging directly for water22 5 3 1 0 2 0 0 5Confidence Interval +|- 26 +|- 6 +|- 3 +|- 3 +|- 0 +|- 3 +|- 0 +|- 0 +|- 4Observations41 50 68 72 78 53 106 36 504Primarily Purchased Water SystemsMean2 30 222 971 3,534 11,716 22,869 175,305 1,511Confidence Interval +|- 5 +|- 10 +|- 55 +|- 353 +|- 917 +|- 2,985 +|- 2,672 +|- 50,202 +|- 484Median0 19 166 751 2,473 8,899 20,346 115,947 156% not charging directly for water90 1 0 4 0 0 0 0 2Confidence Interval +|- 23 +|- 2 +|- 0 +|- 9 +|- 0 +|- 0 +|- 0 +|- 0 +|- 2Observations6 20 48 26 27 27 45 13 212All SystemsMean6 26 185 760 2,817 8,953 19,961 147,922 814Confidence Interval +|- 2 +|- 5 +|- 26 +|- 111 +|- 338 +|- 1,181 +|- 3,938 +|- 23,163 +|- 85Median2 20 144 648 2,302 7,313 16,187 99,807 46% not charging directly for water42 26 3 4 2 1 0 0 19Confidence Interval +|- 16 +|- 11 +|- 3 +|- 5 +|- 3 +|- 1 +|- 0 +|- 0 +|- 5Observations133 150 205 160 149 107 191 56 1,151Data: Q.26CNotes: Two ground water systems serving less than 100 people with large non residential sales are dropped. If thesesystems are included then revenues for ground water systems systems serving 100 or less are $18,100 andaverage revenues for all systems of this size are $6,00076Table 47Total RevenueBy Ownership(Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean14 33 186 756 2,811 8,857 19,608 148,745 1,396Confidence Interval+|- 8 +|- 9 +|- 31 +|- 117 +|- 340 +|- 1,278 +|- 4,169 +|- 25,328 +|- 209Median10 26 134 653 2,302 7,126 16,444 89,897 146% not charging directly for water20 5 2 4 1 0 0 0 3Confidence Interval+|- 33 +|- 6 +|- 2 +|- 5 +|- 2 +|- 0 +|- 0 +|- 0 +|- 2Observations13 72 176 142 132 95 176 51 15Private SystemsMean6 21 178 792 2,858 9,855 24,347 139,210 187Confidence Interval+|- 2 +|- 7 +|- 56 +|- 302 +|- 1,279 +|- 2,331 +|- 5,670 +|- 15,984 +|- 46Median2 17 194 633 2,397 10,133 15,970 122,075 6% not charging directly for water43 39 6 8 12 7 0 0 36Confidence Interval+|- 16 +|- 15 +|- 11 +|- 14 +|- 21 +|- 12 +|- 0 +|- 0 +|- 10Observations120 78 29 18 17 12 15 5 294All SystemsMean6 26 185 760 2,817 8,953 19,961 147,922 814Confidence Interval+|- 2 +|- 5 +|- 26 +|- 111 +|- 338 +|- 1,181 +|- 3,938 +|- 23,163 +|- 85Median2 20 144 648 2,302 7,313 16,187 99,807 46% not charging directly for water42 26 3 4 2 1 0 0 19Confidence Interval+|- 16 +|- 11 +|- 3 +|- 5 +|- 3 +|- 1 +|- 0 +|- 0 +|- 5Observations133 150 205 160 149 107 191 56 1,151Data: Q.26CNotes: Two public systems serving less than 100 people with large non residential sales are dropped. If these systemsare included then revenues for public systems systems serving 100 or less are $273,300 and average revenues forall systems of this size are $17,000.Refer to the next table for additional detail on private systems.77Table 48Total RevenuePrivate Systems, by Type(Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,300All SmallSystemsPrivate SystemsMean9.9 34.0 191.0 49.9Confidence Interval+|- 3.5 +|- 6.7 +|- 55.2 +|- 15.8Median6.0 25.8 194.3 21.3% not charging directly for water11.0 0.3 0.0 4.9Confidence Interval+|- 10.5 +|- 0.4 +|- 0.0 +|- 4.6Observations71 48 26 145Ancillary SystemsMean0.7 0.8 6.6 0.9Confidence Interval+|- 0.9 +|- 1.1 +|- 16.3 +|- 0.7Median0.0 0.0 0.0 0.0% not charging directly for water83.3 92.7 92.0 87.6Confidence Interval+|- 18.6 +|- 9.8 +|- 19.7 +|- 11.0Observations49 30 3 82All Private SystemsMean5.8 21.0 178.4 31.2Confidence Interval+|- 2.4 +|- 6.7 +|- 55.6 +|- 10.5Median2.3 16.7 194.3 6.0% not charging directly for water42.9 39.1 6.3 37.4Confidence Interval+|- 16.3 +|- 14.8 +|- 11.2 +|- 10.3Observations120 78 29 227Data: Q.26C78Table 49Total Revenue for Systems Reporting Positive Revenue and ExpensesByOwnership(Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean 18 35 191 778 2,784 8,913 21,773 150,214 1,393Confidence interval +|- 7 +|- 9 +|- 32 +|- 122 +|- 335 +|- 1,317 +|- 1,837 +|- 27,300 +|- 211Median 10 26 134 653 2,302 7,126 16,444 89,897 146Observations 11 64 169 132 124 91 169 47 807Private SystemsMean 10 37 191 850 3,477 9,783 23,675 115,584 257Confidence interval +|- 4 +|- 7 +|- 57 +|- 310 +|- 1,331 +|- 2,185 +|- 5,618 +|- 5,613 +|- 70Median 2 17 194 633 2,397 10,133 15,970 122,075 6Observations 66 43 26 16 14 9 13 3 190All SystemsMean 10 36 191 786 2,857 8,982 21,915 148,186 976Confidence interval +|- 3 +|- 6 +|- 27 +|- 115 +|- 337 +|- 1,228 +|- 1,754 +|- 25,684 +|- 11350th Percentile 2 20 144 648 2,302 7,313 16,187 99,807 46Observations 77 107 195 148 138 100 182 50 997Data: Q.26CNotes: Table reports systems who reported both positive revenue and positive expenses only.One public system serving less than 100 people with revenue of $1.8 million was dropped.If included, the mean revenue for public systems serving less than 100 people is $305,427.A private system serving 100 or less with revenue of $6,000 was dropped from the estimate.If included, revenue for this category is $5,795.79Table 50Revenue BreakdownByOwnership(Percentage of Systems with Each Type of Revenue)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsWater Sales100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0Confidence Interval+|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0Water-Related Operations26.3 36.9 58.1 88.7 84.1 79.9 72.4 73.6 60.9Confidence Interval+|- 33.5 +|- 14.4 +|- 14.4 +|- 7.0 +|- 7.2 +|- 9.9 +|- 15.7 +|- 7.2 +|- 7.9General Fund1.0 5.9 7.2 6.1 14.4 8.4 11.3 16.4 7.4Confidence Interval+|- 2.2 +|- 7.2 +|- 7.1 +|- 4.6 +|- 7.1 +|- 4.7 +|- 4.0 +|- 6.0 +|- 3.8Other Revenue Sources20.6 50.4 72.0 73.8 85.0 79.7 73.8 80.2 67.7Confidence Interval+|- 30.7 +|- 18.0 +|- 10.6 +|- 12.0 +|- 6.9 +|- 10.6 +|- 16.0 +|- 6.3 +|- 6.5Private SystemsWater Sales100.0 99.0 100.0 100.0 100.0 100.0 100.0 100.0 99.6Confidence Interval+|- 0.0 +|- 2.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.7Water-Related Operations18.9 32.7 35.0 72.0 74.0 35.2 32.0 75.7 29.5Confidence Interval+|- 12.7 +|- 17.9 +|- 21.4 +|- 24.4 +|- 23.3 +|- 24.9 +|- 17.4 +|- 26.1 +|- 9.4Other Revenue Sources10.1 31.9 52.9 55.3 61.0 70.6 70.6 80.5 27.7Confidence Interval+|- 7.9 +|- 17.7 +|- 22.1 +|- 28.4 +|- 26.0 +|- 24.5 +|- 20.4 +|- 21.5 +|- 9.0All SystemsWater Sales100.0 99.5 100.0 100.0 100.0 100.0 100.0 100.0 99.9Confidence Interval+|- 0.0 +|- 1.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.0 +|- 0.3Water-Related Operations19.4 34.8 53.9 87.0 82.9 76.1 69.3 73.8 48.6Confidence Interval+|- 12.0 +|- 11.5 +|- 11.8 +|- 6.8 +|- 7.0 +|- 9.5 +|- 14.2 +|- 7.0 +|- 5.9General Fund0.1 2.9 5.9 5.4 12.6 7.7 10.4 15.2 4.5Confidence Interval+|- 0.1 +|- 3.5 +|- 5.9 +|- 4.1 +|- 6.3 +|- 4.4 +|- 3.6 +|- 5.6 +|- 2.3Other Revenue Sources10.8 41.0 68.5 71.9 82.0 78.9 73.5 80.3 52.1Confidence Interval+|- 8.4 +|- 14.2+|- 9.2+|- 11.1 +|- 7.0+|- 9.9+|- 14.8+|- 6.1 +|- 6.0Data: Q.26Notes: Systems have more than one type of revenue; therefore column totals may not sum to 100.Table includes systems with positive revenue from water sales and water related operations only.80Table 51Revenue BreakdownByOwnership(Percentage of Revenue By Type of Revenue Source)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsWater Sales85.0 89.7 90.9 89.1 88.5 87.7 88.9 86.1 89.9Confidence Interval+|- 21.5 +|- 4.8 +|- 2.4 +|- 2.6 +|- 2.1 +|- 2.5 +|- 2.9 +|- 2.1 +|- 1.7Water-Related Operations8.0 3.2 2.0 5.3 5.6 5.6 4.6 4.5 3.4Confidence Interval+|- 13.5 +|- 2.8 +|- 0.9 +|- 2.0 +|- 1.9 +|- 2.1 +|- 1.3 +|- 1.2 +|- 0.9General Fund0.3 0.9 1.4 1.5 0.6 0.9 0.9 1.0 1.2Confidence Interval+|- 0.7 +|- 1.1 +|- 1.6 +|- 1.6 +|- 0.4 +|- 0.8 +|- 0.5 +|- 0.5 +|- 0.8Other Revenue Sources6.6 6.2 6.0 4.2 5.4 5.9 5.7 8.4 5.7Confidence Interval+|- 9.5 +|- 4.7 +|- 1.5 +|- 1.4 +|- 1.2 +|- 1.7 +|- 1.8 +|- 1.8 +|- 1.3Private SystemsWater Sales96.6 95.4 92.6 92.5 90.4 98.3 97.8 96.1 95.3Confidence Interval+|- 3.3 +|- 2.8 +|- 6.2 +|- 3.5 +|- 5.4 +|- 1.2 +|- 1.2 +|- 2.1 +|- 2.0Water-Related Operations2.8 2.0 4.0 4.9 4.7 0.8 0.9 3.8 2.8Confidence Interval+|- 3.2 +|- 1.7 +|- 5.6 +|- 2.6 +|- 2.8 +|- 1.1 +|- 0.7 +|- 2.5 +|- 1.7Other Revenue Sources0.6 2.5 3.5 3.0 4.7 1.1 1.4 0.6 1.9Confidence Interval+|- 0.6 +|- 2.2 +|- 3.3 +|- 2.2 +|- 4.6 +|- 0.8 +|- 1.0 +|- 0.5 +|- 1.0All SystemsWater Sales95.9 92.7 91.2 89.5 88.7 88.7 89.6 87.0 92.0Confidence Interval+|- 3.4 +|- 3.1 +|- 2.3 +|- 2.4 +|- 2.0 +|- 2.4 +|- 2.6 +|- 2.0 +|- 1.3Water-Related Operations3.2 2.6 2.4 5.2 5.5 5.2 4.3 4.4 3.2Confidence Interval+|- 3.1 +|- 1.6 +|- 1.2 +|- 1.8 +|- 1.7 +|- 2.0 +|- 1.2 +|- 1.1 +|- 0.9General Fund0.0 0.3 1.1 1.2 0.5 0.8 0.8 0.9 0.5Confidence Interval+|- 0.0 +|- 0.4 +|- 1.2 +|- 1.4 +|- 0.3 +|- 0.7 +|- 0.5 +|- 0.4 +|- 0.4Other Revenue Sources1.0 4.3 5.5 4.1 5.4 5.5 5.3 7.9 4.2Confidence Interval+|- 0.9+|- 2.8+|- 1.4 +|- 1.3+|- 1.2+|- 1.5+|- 1.7+|- 1.7+|- 1.0Data: Q.2681Table 52Water Sales Revenue ProfileByOwnership(Percentage of Revenue from Each Customer Category)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsResidential91.3 85.8 85.9 72.3 64.3 57.5 51.5 39.4 80.3Confidence Interval+|- 14.7 +|- 9.0 +|- 4.6 +|- 5.5 +|- 5.1 +|- 7.7 +|- 3.8 +|- 4.1 +|- 3.3Non-Residential8.7 14.8 11.6 21.9 26.9 25.5 25.9 28.0 16.0Confidence Interval+|- 14.7 +|- 10.0 +|- 3.6 +|- 5.5 +|- 4.2 +|- 4.2 +|- 2.8 +|- 3.1 +|- 3.2Wholesale0.0 1.4 1.8 4.7 8.2 14.8 18.7 32.2 3.3Confidence Interval+|- 0.0 +|- 2.5 +|- 1.7 +|- 2.8 +|- 3.3 +|- 9.0 +|- 6.6 +|- 6.1 +|- 1.1Observations12 51 128 102 111 80 154 45 701Private SystemsResidential99.0 98.2 91.2 85.9 79.6 74.3 59.6 71.5 96.7Confidence Interval+|- 1.2 +|- 2.5 +|- 10.2 +|- 7.4 +|- 11.0 +|- 10.8 +|- 10.1 +|- 6.2 +|- 1.9Non-Residential1.0 0.6 8.2 9.0 13.0 17.3 32.3 21.6 2.4Confidence Interval+|- 1.1 +|- 0.6 +|- 9.7 +|- 5.7 +|- 7.7 +|- 6.0 +|- 7.8 +|- 7.6 +|- 1.6Wholesale0.2 1.2 0.1 3.6 6.0 13.4 8.2 1.4 0.9Confidence Interval+|- 0.4 +|- 2.4 +|- 0.2 +|- 4.5 +|- 7.9 +|- 13.9 +|- 6.7 +|- 1.0 +|- 0.9Observations67 47 23 16 13 9 14 4 200All SystemsResidential98.5 93.0 86.9 74.2 66.0 59.0 52.2 42.1 87.4Confidence Interval+|- 1.3 +|- 5.1 +|- 4.0 +|- 5.1 +|- 4.6 +|- 7.2 +|- 3.6 +|- 4.2 +|- 2.2Non-Residential1.4 7.0 10.9 20.0 25.4 24.7 26.5 27.3 10.2Confidence Interval+|- 1.3 +|- 5.0 +|- 3.2 +|- 4.8 +|- 3.9 +|- 3.8 +|- 2.7 +|- 2.9 +|- 2.0Wholesale0.2 1.3 1.5 4.5 7.9 14.7 18.0 29.2 2.3Confidence Interval+|- 0.4 +|- 2.4 +|- 1.5 +|- 2.5 +|- 3.0 +|- 8.3 +|- 6.1 +|- 5.7 +|- 0.9Observations79 98 151 118 124 89 168 49 901Data: Q.26ANotes: Column totals may not sum to 100 due to rounding.82Table 53Total RevenueBy Ownership(Dollarsper 1,000 Gallons Sold)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean4.47 3.28 3.51 2.46 2.57 2.19 1.72 1.91 3.13Confidence Interval+|- 1.42+|- 0.75+|- 0.52+|- 0.32+|- 0.48+|- 0.23+|- 0.36+|- 0.12+|- 0.30Median5.10 2.32 2.88 2.14 2.23 1.78 1.81 1.86 2.57Observations9 66 167 139 130 95 174 51 831Private SystemsMean4.39 3.76 4.50 3.90 2.88 2.84 2.50 3.07 4.08Confidence Interval+|- 1.22+|- 0.77+|- 1.03+|- 0.94 +|- 0.54 +|- 0.57+|- 0.32+|- 0.51 +|- 0.58Median1.80 2.02 3.84 3.41 2.70 3.10 2.48 2.96 2.41Observations58 48 25 17 16 11 15 5 195All SystemsMean4.39 3.53 3.67 2.62 2.61 2.25 1.78 2.01 3.48Confidence Interval+|- 1.17+|- 0.54 +|- 0.48+|- 0.32+|- 0.42+|- 0.22+|- 0.34 +|- 0.12+|- 0.29Median1.99 2.17 3.08 2.19 2.32 1.84 1.82 1.87 2.53Observations67 114 192 156 146 106 189 56 1,026Data: Q.26C, Q.5Notes: Includes wholesale deliveries and unaccounted for water.Outliers were dropped from public systems serving 25-100 and 501-3,300 and private systems serving 25-100 and500-3,301. If included in the estimate, these cells are 6.46, 3.59, 4.04, and 5.43, respectively.83Table 54Water Sales RevenueBy Ownership(Dollars per 1,000 Gallons Sold)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean3.89 3.09 3.13 2.10 2.23 1.84 1.46 1.61 2.81Confidence Interval+|- 1.74 +|- 0.74 +|- 0.43 +|- 0.25 +|- 0.44 +|- 0.17 +|- 0.30 +|- 0.10 +|- 0.27Median5.10 2.32 2.62 1.85 1.85 1.61 1.59 1.56 2.38Observations9 68 169 137 128 94 174 51 830Private SystemsMean4.31 3.88 3.99 3.39 2.59 2.78 2.46 2.97 4.00Confidence Interval+|- 1.19 +|- 0.94 +|- 0.73 +|- 0.84 +|- 0.50 +|- 0.56 +|- 0.32 +|- 0.52 +|- 0.60Median1.99 2.01 3.84 3.12 2.38 2.31 2.47 2.66 2.37Observations59 48 25 18 16 11 15 5 197All SystemsMean4.30 3.50 3.27 2.26 2.27 1.92 1.53 1.73 3.25Confidence Interval+|- 1.15 +|- 0.64 +|- 0.39 +|- 0.27 +|- 0.39 +|- 0.18 +|- 0.30 +|- 0.11 +|- 0.29Median1.99 2.24 2.84 2.04 1.95 1.65 1.64 1.62 2.37Observations68 116 194 155 144 105 189 56 1,027Data: Q.26A, Q.5Notes: Outliers were dropped from public systems serving 25-100 and 501-3,300 and private systems serving 25-100 and500-3,301. If included in the estimate, these cells are 6.06, 3.25, 5.54, and 4.93, respectively.84Table 55Water Sales Revenue--Customer BreakdownByOwnership(Dollars per 1,000 Gallons Sold)System Service Population Category100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsResidentialMean3.25 3.39 3.66 2.78 2.83 2.48 2.08 2.01 3.31Confidence Interval+|- 2.70 +|- 0.96 +|- 0.69 +|- 0.45 +|- 0.58 +|- 0.23 +|- 0.10 +|- 0.12 +|- 0.39Median5.10 3.43 3.03 2.46 2.72 2.49 2.02 1.85 2.95Observations8 48 110 95 94 70 122 35 582Non-ResidentialMean1.82 3.03 4.23 3.05 2.86 2.43 3.06 1.81 3.52Confidence Interval+|- 0.58 +|- 1.56 +|- 1.48 +|- 1.12 +|- 0.84 +|- 0.46 +|- 1.03 +|- 0.17 +|- 0.74Median2.08 2.84 2.79 1.92 2.05 1.90 1.86 1.66 2.55Observations2 9 70 78 90 69 121 37 476WholesaleMean* * 1.93 1.67 1.70 1.89 1.54 1.45 1.77Confidence Interval* * +|- 0.86 +|- 0.50 +|- 0.59 +|- 0.40 +|- 0.24 +|- 0.240.36Median* * 1.96 1.65 1.24 1.56 1.45 1.24 1.56Observations0 0 18 32 58 48 107 42 305Private SystemsResidentialMean2.86 2.64 4.29 3.97 2.78 3.72 3.12 3.02 2.93Confidence Interval+|- 1.12 +|- 1.03 +|- 0.79 +|- 1.84 +|- 1.09 +|- 0.95 +|- 0.58 +|- 0.77 +|- 0.66Median2.00 2.14 4.82 3.19 2.75 3.44 3.26 2.60 2.39Observations84 68 20 15 12 10 12 4 225Non-ResidentialMean0.00 2.93 6.28 2.05 3.01 3.38 2.36 3.18 3.52Confidence Interval+|- 0.00 +|- 0.39 +|- 4.63 +|- 1.34 +|- 2.49 +|- 2.03 +|- 0.56 +|- 0.25 +|- 2.09Median0.00 2.81 5.02 1.61 1.83 2.57 2.35 3.06 1.61Observations4 3 8 10 10 12 12 3 62WholesaleMean1.09 * 1.16 1.77 2.15 2.47 1.64 1.94 1.87Confidence Interval+|- 1.35 * +|- 1.54 +|- 0.36 +|- 1.18 +|- 0.76 +|- 0.36 +|- 1.03 +|- 0.50Median1.59 * 2.22 1.67 2.26 2.00 1.28 1.16 1.67Observations2 0 2 3 6 7 9 3 32(Continued)Ownership Type85Table 55 (Cont.)Water Sales Revenue--Customer BreakdownByOwnership(Dollars per 1,000 Gallons Sold)System Service Population Category100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesAll SystemsResidentialMean2.87 2.89 3.78 2.95 2.83 2.63 2.18 2.12 3.11Confidence Interval+|- 1.09 +|- 0.76 +|- 0.58 +|- 0.54 +|- 0.52 +|- 0.24 +|- 0.11 +|- 0.14 +|- 0.39Median2.34 2.79 3.27 2.47 2.72 2.60 2.05 1.89 2.72Observations92 116 130 110 106 80 134 39 807Non-ResidentialMean0.04 3.01 4.53 2.93 2.88 2.56 2.99 1.91 3.52Confidence Interval+|- 0.09 +|- 1.28 +|- 1.45 +|- 0.99 +|- 0.79 +|- 0.49 +|- 0.93 +|- 0.16 +|- 0.70Median0.00 2.81 2.79 1.91 2.05 1.93 1.86 1.71 2.51Observations6 12 78 88 100 81 133 40 538WholesaleMean1.09 * 1.92 1.68 1.74 1.95 1.55 1.48 1.78Confidence Interval+|- 1.35 * +|- 0.84 +|- 0.46 +|- 0.55 +|- 0.37 +|- 0.23 +|- 0.24 +|- 0.33Median1.59 * 1.96 1.67 1.32 1.67 1.43 1.20 1.58Observations92 116 130 110 106 80 134 39 337Q 26 Q.26Notes: *No data collected for these systems.Wholesale revenue for public systems serving 101-500 people contained only 1 county cluster of systems. In order tocalculate the design-based 95% confidence interval, this cluster was moved to the 501-3,301 stratum for this table only.Outliers were dropped from residential revenue for public systems serving 25-100 and 501-3,300, residential revenue forprivate systems serving 25-100 and 500-3,301, non-residential revenue for public systems serving 3,301-10,000 and50,001-100,000, and wholesale systems serving 50,001-100,000 and 100,001-500,000. If included in the estimate,these cells are 5.75, 3.75, 3.77, 5.36, 4.90, 3.02, 2.86, and 32.47 respectively.Ownership Type86Table 56Residential Revenue per ConnectionByOwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean Residential Revenues per Connection 363 258 272 238 255 276 286 261 264Confidence interval +|- 239 +|- 60 +|- 35 +|- 33 +|- 32 +|- 34 +|- 23 +|- 23 +|- 23Median Residential Revenues per Connection 329 220 237 217 227 261 260 219 228Observations 13 54 128 101 103 72 130 35 636Private SystemsMean Residential Revenues per Connection 230 218 358 341 320 439 333 364 243Confidence interval +|- 101 +|- 76 +|- 142 +|- 111 +|- 85 +|- 145 +|- 75 +|- 46 +|- 58Median Residential Revenues per Connection 172 250 333 318 287 439 314 385 237Observations 113 72 24 16 12 10 14 4 265All SystemsMean Residential Revenues per Connection 235 232 289 253 262 295 290 272 253Confidence interval +|- 98 +|- 54 +|- 42 +|- 34 +|- 30 +|- 36 +|- 23 +|- 22 +|- 33Median Residential Revenues per Connection 175 235 258 228 237 273 263 240 231Observations 126 126 152 117 115 82 144 39 901Data: Q.26A2, Q.20AbNotes: One public system serving 25-100 people was dropped from the estimate. If included, residential revenues perconnection are $431.Two private systems serving 25-100 people were dropped from the estimate. If included, residential revenuesper connection connection are $423.(Dollars)87Table 57Residential Revenue per ConnectionPrivate Systems, by Type(Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,300SmallSystemsPrivate SystemsMean Residential Revenues per Connection 382 319 383 356Confidence interval +|- 124 +|- 70 +|- 128 +|- 64Median Residential Revenues per Connection 277 291 336 291Observations 67 47 23 137Ancillary SystemsMean Residential Revenues per Connection 20 12 0 17Confidence interval +|- 33 +|- 17 +|- 0 +|- 21Median Residential Revenues per Connection 0 0 0 0Observations 46 25 1 72All SystemsMean Residential Revenues per Connection 230 218 358 239Confidence interval +|- 94 +|- 71 +|- 132 +|- 56Median Residential Revenues per Connection 149 250 333 222Observations 113 72 24 209Data: Q.28Notes: Two private systems serving 25-100 peoplewere dropped from the estimate. If included,mean residential revenues per connectionare $706 for this category.88Table 58Residential Rate Structure and Billing ProfileByOwnership(Percentage of Systems with Each Structure)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMetered ChargesUniform Rate11.6 52.2 52.9 55.1 55.1 45.4 51.1 39.4 52.0Declining Block Rate0.0 14.1 29.0 31.4 32.1 21.7 21.0 18.4 25.2Increasing Block Rate2.6 10.2 14.3 12.4 16.7 29.3 24.1 34.1 13.4Seasonal Rate0.0 0.0 0.4 2.3 0.6 3.6 8.9 9.7 0.8Unmetered ChargesSeparate Flat Fee for Water41.0 21.9 6.3 21.7 23.8 24.5 25.7 11.3 15.8Combined Flat Fee for Water and OtherServices31.5 0.0 0.1 3.3 3.7 7.9 2.3 0.0 2.0Other billing methods3.0 0.1 1.4 4.5 2.0 2.7 3.3 5.5 1.8Observations18 76 179 148 138 101 183 52 895Private SystemsMetered ChargesUniform Rate25.3 28.2 47.8 39.2 44.8 70.4 48.6 80.5 29.4Declining Block Rate0.0 4.7 19.6 42.6 44.7 29.6 33.3 39.0 5.8Increasing Block Rate3.4 3.6 17.5 14.5 9.7 0.0 13.9 0.0 5.2Seasonal Rate0.0 0.1 0.0 0.0 2.9 0.0 0.0 19.5 0.1Unmetered ChargesSeparate Flat Fee for Water16.5 17.0 16.4 2.5 33.8 22.3 9.0 41.4 16.6Combined Flat Fee for Water and OtherServices17.1 10.9 0.1 1.5 9.7 0.0 0.0 0.0 12.4Other billing methods1.7 0.5 0.0 0.0 0.0 0.0 0.0 0.0 1.0Observations138 95 32 22 23 16 19 6 351(Continued)89Table 58 (Cont.)Residential Rate Structure and Billing ProfileByOwnership(Percentage of Systems with Each Structure)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesAll SystemsMetered ChargesUniform Rate24.5 36.6 52.0 52.7 53.7 48.4 50.9 42.9 40.5Declining Block Rate0.0 8.0 27.3 33.0 33.8 22.6 22.1 20.2 15.3Increasing Block Rate3.4 5.9 14.9 12.7 15.7 25.8 23.2 31.2 9.2Seasonal Rate0.0 0.0 0.3 1.9 0.9 3.2 8.2 10.5 0.4Unmetered ChargesSeparate Flat Fee for Water17.9 18.7 8.1 18.9 25.2 24.3 24.2 13.9 16.2Combined Flat Fee for Water and OtherServices17.9 7.1 0.1 3.0 4.5 7.0 2.1 0.0 7.3Other billing methods1.8 0.4 1.1 3.9 1.7 2.4 3.0 5.0 1.4Observations156 171 211 170 161 117 202 58 1,246Data:Q.29Notes:These rate structures only apply to residential customers.Column totals may not sum to 100.90Table 59Total ExpensesBy Primary Source of Water(Thousands of Dollars)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsMean 7 25 133 568 2,147 6,779 18,175 62,201 253Confidence interval +|- 3 +|- 5 +|- 30 +|- 110 +|- 479 +|- 751 +|- 2,899 +|- 15,786 +|- 40Median 3 18 99 501 1,705 6,969 13,412 80,727 22Observations 91 82 86 60 43 26 36 6 430Primarily Surface Water SystemsMean 19 72 313 980 2,714 6,548 18,604 139,308 2,856Confidence interval +|- 8 +|- 21 +|- 62 +|- 311 +|- 434 +|- 1,297 +|- 1,657 +|- 32,605 +|- 516Median 21 54 279 720 2,356 5,747 15,048 75,567 340Observations 37 45 68 69 73 52 104 32 480Primarily Purchased Water SystemsMean 7 28 208 816 3,704 10,535 18,932 137,757 1,258Confidence interval +|- 7 +|- 10 +|- 49 +|- 300 +|- 1,260 +|- 2,769 +|- 2,233 +|- 39,154 +|- 407Median 2 18 170 603 2,426 8,721 17,992 87,158 148Observations 6 20 47 22 24 25 43 12 199All SystemsMean 7 28 169 699 2,673 7,617 18,561 129,320 684Confidence interval +|- 3 +|- 5 +|- 25 +|- 115 +|- 385 +|- 1,020 +|- 1,278 +|- 22,377 +|- 75Median 3 19 128 588 2,299 6,969 14,969 82,283 44Observations 134 147 201 151 140 103 183 50 1,109Data: Q.7, Q.31Notes: One system ground water system serving 25-100 with expenses of $406,808 was dropped from the estimate. Ifincluded, the category is $8,900.91Table 60Total ExpensesByOwnership(Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean 15 36 167 704 2,675 7,630 18,408 131,490 1,212Confidence interval +|- 10 +|- 9 +|- 29 +|- 126 +|- 406 +|- 1,101 +|- 1,309 +|- 23,714 +|- 186Median 13 30 110 603 2,299 6,469 14,031 80,727 135Observations 13 69 173 133 125 94 170 47 824Private SystemsMean 7 23 180 667 2,664 7,470 20,466 94,419 135Confidence interval +|- 3 +|- 6 +|- 50 +|- 246 +|- 1,216 +|- 1,393 +|- 5,319 +|- 6,018 +|- 34Median 3 14 173 495 1,855 7,366 15,572 90,830 10Observations 121 78 28 18 15 9 13 3 285All SystemsMean 7 28 169 699 2,673 7,617 18,561 129,320 684Confidence interval +|- 3 +|- 5 +|- 25 +|- 115 +|- 385 +|- 1,020 +|- 1,278 +|- 22,377 +|- 75Median 3 19 128 588 2,299 6,969 14,969 82,283 44Observations 134 147 201 151 140 103 183 50 1,109Data: Q.31Notes: A public system serving 100 or less that has expenses of over $400,000 due to large commercial sales isexcluded. If included, expenses for this category are $66,000.92Table 61Total Expenses for Systems Reporting Positive Revenues and ExpensesByOwnership(Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean 15 36 168 706 2,695 7,685 18,497 131,490 1,241Confidence interval +|- 11 +|- 10 +|- 29 +|- 127 +|- 409 +|- 1,121 +|- 1,317 +|- 23,716 +|- 190Median 13 30 110 603 2,299 6,469 14,031 80,727 136Observations 11 64 169 132 124 91 169 47 807Private SystemsMean 10 32 180 736 3,034 7,470 20,466 94,419 221Confidence interval +|- 5 +|- 8 +|- 51 +|- 273 +|- 1,190 +|- 1,394 +|- 5,320 +|- 6,019 +|- 60Median 3 14 173 495 1,855 7,366 15,572 90,830 10Observations 66 43 26 16 14 9 13 3 190All SystemsMean 10 34 170 709 2,731 7,668 18,644 129,320 867Confidence interval +|- 5 +|- 6 +|- 26 +|- 118 +|- 388 +|- 1,036 +|- 1,285 +|- 22,379 +|- 102Median 3 19 128 588 2,299 6,969 14,969 82,283 44Observations 77 107 195 148 138 100 182 50 997Data: Q.31Notes: Table reports systems who reported both positive revenues and positive expenses only.A public system serving 100 or less that has expenses of over $400,000 due to large commercial sales isexcluded. If included, expenses for this category are $76,000.A private system serving 100 or less that has expenses of $400 has been dropped from the estimate.If included, expenses for this category are $9,000.93Table 62Expense Breakdown By Major CategoriesByOwnership(As Percentage of Total Expenses)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsEmployee Expenses 34.2 31.6 32.4 33.0 30.1 27.7 34.1 27.9 32.1Confidence interval +|- 13.2 +|- 7.7 +|- 4.8 +|- 2.8 +|- 3.2 +|- 2.3 +|- 10.9 +|- 2.0 +|- 2.9Routine Operating Expenses 44.9 52.5 52.2 46.4 44.0 45.8 38.5 40.4 50.1Confidence interval +|- 15.7 +|- 7.6 +|- 4.4 +|- 4.6 +|- 5.0 +|- 3.8 +|- 5.8 +|- 3.1 +|- 3.0Debt Service Expenses: 16.2 10.7 12.2 15.8 20.5 20.7 16.8 21.7 13.5Confidence interval +|- 17.6 +|- 3.4 +|- 3.1 +|- 4.4 +|- 5.2 +|- 3.4 +|- 3.9 +|- 1.9 +|- 1.9Other Expenses: 4.7 5.7 3.4 5.3 5.8 5.7 10.8 8.8 4.6Confidence interval +|- 7.4 +|- 4.9 +|- 2.8 +|- 2.9 +|- 2.4 +|- 2.6 +|- 4.9 +|- 2.6 +|- 1.8Private SystemsEmployee Expenses 27.7 28.6 31.8 39.9 34.1 27.2 22.7 35.1 28.8Confidence interval +|- 8.0 +|- 9.3 +|- 10.5 +|- 19.4 +|- 11.7 +|- 6.7 +|- 3.8 +|- 2.4 +|- 5.4Routine Operating Expenses 71.7 68.6 52.6 56.1 50.8 62.0 63.2 43.2 68.0Confidence interval +|- 8.0 +|- 8.9 +|- 9.3 +|- 18.8 +|- 12.6 +|- 12.5 +|- 10.6 +|- 10.5 +|- 5.4Debt Service Expenses: 1.5 2.6 9.9 3.8 8.8 8.2 8.4 21.7 2.8Confidence interval +|- 2.0 +|- 1.7 +|- 6.4 +|- 3.4 +|- 5.3 +|- 6.3 +|- 3.0 +|- 8.1 +|- 1.4Other Expenses: 1.1 0.9 6.0 3.0 7.8 4.1 6.5 0.0 1.6Confidence interval +|- 1.4 +|- 1.6 +|- 9.6 +|- 4.1 +|- 9.6 +|- 6.6 +|- 5.6 +|- 0.0 +|- 1.3All SystemsEmployee Expenses 28.0 29.8 32.3 33.8 30.6 27.6 33.5 28.2 30.5Confidence interval +|- 7.7 +|- 6.6 +|- 4.1 +|- 3.4 +|- 3.2 +|- 2.2 +|- 10.4 +|- 2.0 +|- 3.0Routine Operating Expenses 70.5 62.1 52.3 47.6 44.8 47.1 39.8 40.5 58.7Confidence interval +|- 8.0 +|- 6.8 +|- 4.2 +|- 4.5 +|- 4.7 +|- 3.7 +|- 5.8 +|- 3.0 +|- 3.3Debt Service Expenses: 2.1 5.8 11.8 14.3 19.2 19.8 16.3 21.7 8.4Confidence interval +|- 2.2 +|- 2.0 +|- 2.8 +|- 4.0 +|- 4.8 +|- 3.3 +|- 3.6 +|- 1.9 +|- 1.3Other Expenses: 1.3 2.8 3.7 5.0 6.1 5.6 10.6 8.5 3.2Confidence interval+|- 1.4 +|- 2.4 +|- 2.7+|- 2.6+|- 2.4 +|- 2.4 +|- 4.7+|- 2.5+|- 1.2Data: Q.31Notes: Column totals may not sum to 100 due to rounding.Employee expenses includes contract employees.94Table 63Total ExpensesBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsMean 4.16 2.53 2.97 1.95 2.01 1.70 2.02 1.36 3.01Confidence interval +|- 1.93 +|- 0.50 +|- 0.59 +|- 0.42 +|- 0.30 +|- 0.23 +|- 0.30 +|- 0.26 +|- 0.56Median 2.24 1.91 2.41 1.59 1.90 1.67 1.95 1.49 2.00Observations 72 79 86 60 43 26 36 6 408Primarily Surface Water SystemsMean 2.72 3.84 4.19 3.22 2.01 1.67 1.55 1.61 3.17Confidence interval +|- 1.06 +|- 1.14 +|- 1.32 +|- 0.88 +|- 0.25 +|- 0.23 +|- 0.10 +|- 0.14 +|- 0.47Median 8.15 3.72 2.95 2.34 1.90 1.54 1.41 1.59 2.42Observations 30 44 66 69 72 51 103 32 467Primarily Purchased Water SystemsMean 2.49 4.48 5.05 2.52 3.90 2.63 2.02 2.05 4.41Confidence interval +|- 0.13 +|- 1.17 +|- 1.15 +|- 0.35 +|- 1.42 +|- 0.51 +|- 0.23 +|- 0.18 +|- 0.68Median 2.47 3.37 4.24 2.38 3.24 2.52 2.08 2.06 3.48Observations 6 20 47 22 24 24 43 12 198All SystemsMean 4.08 2.90 3.63 2.32 2.43 1.91 1.82 1.70 3.26Confidence interval +|- 1.84 +|- 0.46 +|- 0.54 +|- 0.34 +|- 0.46 +|- 0.20 +|- 0.16 +|- 0.11 +|- 0.44Median 2.25 2.25 2.90 2.00 2.11 1.67 1.93 1.71 2.41Observations 108 143 199 151 139 101 182 50 1,073Data: Q.31Notes: Two surface water systems serving 25-100 people with expenses greater than $20 per thousand gallonsproduced were dropped from the estimate. If included, the mean expenses are $12.59.(Dollars per Thousand Gallons Produced)95Table 64Total ExpensesByOwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean 3.83 3.53 3.35 2.22 2.44 1.88 1.80 1.69 3.08Confidence interval +|- 1.86 +|- 0.86 +|- 0.61 +|- 0.37 +|- 0.51 +|- 0.21 +|- 0.17 +|- 0.12 +|- 0.35Median 2.86 3.19 2.76 1.97 2.05 1.67 1.93 1.70 2.41Observations 13 66 171 133 124 93 169 47 816Private SystemsMean 4.10 2.50 4.98 2.92 2.31 2.27 2.08 1.89 3.46Confidence interval +|- 1.94 +|- 0.51 +|- 1.23 +|- 0.69 +|- 0.67 +|- 0.54 +|- 0.35 +|- 0.21 +|- 0.87Median 2.24 2.00 3.25 2.72 2.30 2.11 2.09 2.05 2.35Observations 95 77 28 18 15 8 13 3 257All SystemsMean 4.08 2.90 3.63 2.32 2.43 1.91 1.82 1.70 3.26Confidence interval +|- 1.84 +|- 0.46 +|- 0.54 +|- 0.34 +|- 0.46 +|- 0.20 +|- 0.16 +|- 0.11 +|- 0.44Median 2.24 2.25 2.90 2.00 2.11 1.67 1.93 1.71 2.39Observations 108 143 199 151 139 101 182 50 1,073Data: Q.7, Q.31Notes: Two private systems serving 25-100 people with expenses greater than $20 per thousand gallonsproduced were dropped from the estimate. If included, the mean expenses are $4.84 per thousand gallons.(Dollars per Thousand Gallons Produced)96Table 65Ratio of Total Revenue to Total ExpensesBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsAverage Ratio 2.1 1.1 1.3 1.2 1.1 1.3 1.2 1.2 1.2Confidence interval +|- 1.0 +|- 0.2 +|- 0.2 +|- 0.1 +|- 0.0 +|- 0.2 +|- 0.0 +|- 0.0 +|- 0.110th Percentile 0.8 0.6 0.8 0.9 0.8 0.9 0.9 0.9 0.825th Percentile 1.2 0.9 0.9 1.0 1.0 1.0 1.0 1.0 0.950th Percentile 1.7 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.175th Percentile 3.4 1.4 1.4 1.3 1.2 1.2 1.3 1.2 1.490th Percentile 3.4 1.6 2.3 1.7 1.4 1.6 1.5 1.6 1.9Observations 11 64 169 132 124 91 169 47 807Private SystemsAverage Ratio 1.5 1.5 1.1 1.3 1.2 1.3 1.2 1.2 1.4Confidence interval +|- 0.3 +|- 0.3 +|- 0.1 +|- 0.3 +|- 0.2 +|- 0.2 +|- 0.2 +|- 0.1 +|- 0.210th Percentile 0.5 0.8 0.9 0.8 1.0 1.0 1.0 1.1 0.725th Percentile 1.0 0.8 1.0 1.1 1.0 1.1 1.0 1.1 0.950th Percentile 1.2 1.1 1.1 1.2 1.2 1.2 1.1 1.2 1.175th Percentile 1.8 1.8 1.2 1.3 1.3 1.4 1.2 1.4 1.690th Percentile 2.8 2.5 1.3 2.2 1.6 2.1 1.8 1.4 2.5Observations 66 43 26 16 14 9 13 3 190All SystemsAverage Ratio 1.5 1.3 1.3 1.2 1.1 1.3 1.2 1.2 1.3Confidence interval +|- 0.3 +|- 0.1 +|- 0.1 +|- 0.1 +|- 0.0 +|- 0.1 +|- 0.0 +|- 0.0 +|- 0.110th Percentile 0.5 0.7 0.8 0.9 0.8 0.9 0.9 0.9 0.825th Percentile 1.0 0.9 1.0 1.0 1.0 1.0 1.0 1.0 0.950th Percentile 1.2 1.1 1.1 1.1 1.1 1.1 1.1 1.1 1.175th Percentile 1.8 1.5 1.3 1.3 1.2 1.2 1.3 1.2 1.490th Percentile 3.0 2.0 2.0 1.8 1.4 1.6 1.6 1.6 2.2Observations 77 107 195 148 138 100 182 50 997Data: Q.26C, Q.31ENotes: Refer to next table for additional detail on private systems.One public system in Colorado serving less than 100 people with a large ratio of revenue to expenses of4.54 was dropped. If included the ratio for public systems serving less than 100 people is 2.5.One private system serving 25-100 with a revenue to expense ratio of 15 was dropped. If included, theaverage ratio is 1.8.97Table 66Ratio of Total Revenue to Total ExpensesBy TypeSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,300 All SizesPrivate SystemsAverage Ratio 1.5 1.5 1.1 1.4Confidence interval +|- 0.4 +|- 0.3 +|- 0.1 +|- 0.210th Percentile 0.5 0.8 0.9 0.625th Percentile 0.9 0.8 1.0 0.950th Percentile 1.2 1.1 1.1 1.175th Percentile 2.0 1.8 1.2 1.690th Percentile 3.0 2.5 1.3 2.5Observations 62 41 25 128Ancillary SystemsAverage Ratio 1.3 0.6 0.6 1.2Confidence interval +|- 0.4 +|- 0.1 +|- 0.0 +|- 0.310th Percentile 1.0 0.6 0.6 0.725th Percentile 1.0 0.6 0.6 1.050th Percentile 1.4 0.6 0.6 1.075th Percentile 1.8 0.7 0.6 1.890th Percentile 15.0 0.7 0.6 15.0Observations4217All Private SystemsAverage Ratio 1.5 1.5 1.1 1.4Confidence interval +|- 0.3 +|- 0.3 +|- 0.1 +|- 0.210th Percentile 0.5 0.8 0.9 0.625th Percentile 1.0 0.8 1.0 0.950th Percentile 1.2 1.1 1.1 1.175th Percentile 1.8 1.8 1.2 1.790th Percentile 3.0 2.5 1.3 2.5Observations 66 43 26 135Data: Q.7, Q.26, Q.31Notes: One ancillary system serving 25-100 with a revenue toexpense ratio of 15 has been dropped from the meanestimate but included in the median. If included in themean, the mean ratio is 3.7.98Table 67Number of Employees and Annual Labor CostsBy Primary Source of Water(Labor Costs in Thousands of Dollars)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsMean Number of Employees 1.3 1.6 2.8 5.7 15.2 42.1 64.6 374.7 4.6Confidence interval +|- 0.3 +|- 0.4 +|- 0.6 +|- 1.1 +|- 2.6 +|- 13.7 +|- 34.7 +|- 115.5 +|- 0.6Mean Annual Labor Costs 5 12 38 190 636 1,755 2,616 17,669 115Confidence interval +|- 3 +|- 4 +|- 9 +|- 40 +|- 137 +|- 231 +|- 1,495 +|- 5,151 +|- 19Primarily Surface Water SystemsMean Number of Employees 1.2 8.3 3.6 8.2 23.8 45.6 117.6 680.8 23.5Confidence interval +|- 0.3 +|- 9.0 +|- 0.8 +|- 1.5 +|- 8.3 +|- 8.4 +|- 11.2 +|- 104.2 +|- 3.0Mean Annual Labor Costs 6 25 117 270 798 1,865 5,312 37,356 874Confidence interval +|- 6 +|- 9 +|- 28 +|- 39 +|- 114 +|- 415 +|- 507 +|- 6,236 +|- 147Primarily Purchased Water SystemsMean Number of Employees * 1.4 2.7 6.7 25.4 35.3 75.0 394.6 8.2Confidence interval * +|- 0.4 +|- 0.5 +|- 1.4 +|- 19.4 +|- 8.6 +|- 11.2 +|- 146.3 +|- 2.9Mean Annual Labor Costs * 4 39 188 618 1,853 3,714 21,438 267Confidence interval * +|- 3 +|- 10 +|- 50 +|- 265 +|- 436 +|- 576 +|- 7,234 +|- 88All SystemsMean Number of Employees 1.3 2.5 2.9 6.4 20.4 42.0 88.3 586.9 8.3Confidence interval +|- 0.3 +|- 1.5 +|- 0.4 +|- 0.8 +|- 5.3 +|- 5.9 +|- 18.4 +|- 78.1 +|- 0.9Mean Annual Labor Costs 5 12 46 206 686 1,829 3,983 30,731 256Confidence interval+|-2+|-3+|-8+|- 28+|- 95+|- 223+|- 854+|- 4,406+|- 30Data: Q.31ANotes: *No data collected for purchased water systems with a population of less than 100 people.Labor costs includes wages, salaries, fringe benefits, and contractors.Two ground water sytems serving 25-100 people were dropped from the calculations because they areoutliers. This had little effect on the calculations.99Table 68Number of Employees and Annual Labor CostsByOwnership(Labor Costs in Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean Number of Employees 1.6 1.6 2.8 6.4 21.7 43.1 89.5 608.8 10.1Confidence interval +|- 0.7 +|- 0.3 +|- 0.4 +|- 0.9 +|- 6.2 +|- 6.5 +|- 19.8 +|- 83.9 +|- 1.4Annual Labor Costs 13 12 46 201 703 1,843 3,922 30,066 326Confidence interval +|- 5 +|- 5 +|- 8 +|- 27 +|- 104 +|- 242 +|- 896 +|- 4,509 +|- 48Private SystemsMean Number of Employees 1.3 3.5 3.3 6.7 12.6 31.8 72.4 358.4 4.1Confidence interval +|- 0.3 +|- 3.2 +|- 1.4 +|- 1.7 +|- 3.5 +|- 6.7 +|- 25.3 +|- 94.6 +|- 1.2Annual Labor Costs 5 12 44 244 568 1,677 4,864 41,208 89Confidence interval +|- 2 +|- 5 +|- 17 +|- 112 +|- 228 +|- 369 +|- 1,743 +|- 10,486 +|- 26All SystemsMean Number of Employees 1.3 2.5 2.9 6.4 20.4 42.0 88.3 586.9 8.3Confidence interval +|- 0.3 +|- 1.5 +|- 0.4 +|- 0.8 +|- 5.3 +|- 5.9 +|- 18.4 +|- 78.1 +|- 0.9Annual Labor Costs 5 12 46 206 686 1,829 3,983 30,731 256Confidence interval+|-2+|-3+|-8+|- 28+|- 95+|- 223+|- 854+|- 4,406+|- 30Data: Q.31Notes: Labor costs includes wages, salaries, fringe benefits, and contractors.Two public systems serving 25-100 people were dropped from the calculations do to high labor costs. If included, themean number of employees are 2.0 and annual labor costs are $37,000 for this category.100Table 69Percentage of Systems Making Major Capital Improvements in the Past 5 YearsBy Primary Source of WaterSystem Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsPercentage of Systems 43.2 49.9 51.4 69.6 80.3 89.6 73.6 86.9 51.1Confidence interval +|- 12.0 +|- 12.4 +|- 11.7 +|- 11.8 +|- 10.8 +|- 9.4 +|- 24.2 +|- 15.7 +|- 6.4Observations 104 93 92 67 50 29 44 7 486Primarily Surface Water SystemsPercentage of Systems 21.0 74.5 77.9 76.4 87.0 79.7 91.3 86.9 70.7Confidence interval +|- 16.6 +|- 20.6 +|- 12.2 +|- 9.4 +|- 7.0 +|- 13.8 +|- 3.2 +|- 5.7 +|- 8.7Observations 46 55 69 76 83 58 110 38 535Primarily Purchased Water SystemsPercentage of Systems 15.8 57.8 47.9 57.3 86.4 86.8 83.2 93.6 55.9Confidence interval +|- 27.1 +|- 26.2 +|- 18.4 +|- 18.4 +|- 13.2 +|- 10.7 +|- 8.8 +|- 8.0 +|- 11.7Observations 6 23 50 27 28 30 48 13 225All SystemsPercentage of Systems 41.6 52.7 52.8 68.6 83.9 84.4 82.9 88.6 53.9Confidence interval +|- 11.2 +|- 10.5 +|- 8.6 +|- 8.3 +|- 6.1 +|- 7.6 +|- 9.4 +|- 4.6 +|- 5.0Observations 156 171 211 170 161 117 202 58 1,246Data: Q.32A7101Table 70Percentage of Systems Making Major Capital Improvements in the Past 5 YearsBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean 65.1 58.7 52.0 69.1 84.3 84.8 83.7 92.8 40.2Confidence interval +|- 35.4 +|- 15.0 +|- 9.0 +|- 9.2 +|- 6.7 +|- 8.3 +|- 10.2 +|- 3.9 +|- 11.0Observations 18 76 179 148 138 101 183 52 138Private SystemsMean 49.4 55.9 65.4 81.7 81.5 74.3 51.0 41.6 52.7Confidence interval +|- 13.7 +|- 21.0 +|- 22.1 +|- 14.6 +|- 16.8 +|- 15.6 +|- 23.2 +|- 11.2 +|- 10.5Observations 95 32 22 23 16 19 6 156 171All SystemsMean 52.8 68.6 83.9 84.4 82.9 88.6 61.2 47.1 53.9Confidence interval +|- 8.6 +|- 8.3 +|- 6.1 +|- 7.6 +|- 9.4 +|- 4.6 +|- 5.7 +|- 7.9 +|- 5.0Observations 211 170 161 117 202 58 895 351 1,246Data: Q.32A102Table 71Total Capital Investment in the Past 5 YearsBy Primary Source of Water(Thousands of Dollars)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsMean 35 97 309 923 3,392 7,001 17,656 160,507 624Confidence interval +|- 17 +|- 59 +|- 93 +|- 287 +|- 1,056 +|- 1,393 +|- 12,506 +|- 40,079 +|- 124Median 9 21 156 550 2,700 6,782 4,896 182,990 55Observations 49 51 49 46 38 23 35 6 297Primarily Surface Water SystemsMean 111 387 892 1,763 3,514 14,277 33,868 304,107 6,942Confidence interval +|- 91 +|- 280 +|- 393 +|- 774 +|- 878 +|- 3,844 +|- 3,824 +|- 69,944 +|- 1,356Median 17 140 370 919 2,194 8,675 24,986 165,500 609Observations 23 38 50 55 71 49 99 33 418Primarily Purchased Water SystemsMean 16 229 346 962 8,743 13,410 20,656 202,524 3,063Confidence interval +|- 12 +|- 290 +|- 184 +|- 677 +|- 6,855 +|- 5,771 +|- 4,696 +|- 82,573 +|- 1,588Median 23 12 100 325 2,127 6,466 15,077 86,936 250Observations 2 12 27 16 23 25 39 12 156All SystemsMean 38 144 392 1,119 4,648 11,895 25,649 259,328 1,903Confidence interval +|- 17 +|- 68 +|- 91 +|- 275 +|- 1,861 +|- 2,398 +|- 6,062 +|- 48,594 +|- 312Median 9 23 189 512 2,232 7,468 17,069 157,151 96Observations 74 101 126 117 132 97 173 51 871Data: Q.32A103Table 72Total Capital Investment in the Past 5 YearsByOwnership(Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsMean 204 291 385 1,128 4,940 11,591 24,732 266,778 3,124Confidence interval +|- 128 +|- 164 +|- 94 +|- 302 +|- 2,165 +|- 2,581 +|- 6,360 +|- 51,256 +|- 614Median 110 105 189 512 2,232 6,778 15,954 157,151 350Observations 11 44 109 102 115 85 159 48 673Private SystemsMean 21 49 418 1,056 3,053 14,446 36,474 137,160 390Confidence interval +|- 11 +|- 26 +|- 239 +|- 639 +|- 1,388 +|- 6,360 +|- 10,478 +|- 53,571 +|- 112Median 8 14 373 500 2,700 9,620 27,422 100,963 18Observations 63 57 17 15 17 12 14 3 198All SystemsMean 38 144 392 1,119 4,648 11,895 25,649 259,328 1,903Confidence interval +|- 17 +|- 68 +|- 91 +|- 275 +|- 1,861 +|- 2,398 +|- 6,062 +|- 48,594 +|- 312Median 9 23 189 512 2,232 7,468 17,069 157,151 96Observations 74 101 126 117 132 97 173 51 871Data: Q.32A104Table 73Type of Capital Expenses in the Past 5 YearsBy Primary Source of Water(Percentage of Systems Reporting Each Type of Expense)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsLand 1.1 2.5 5.0 26.5 27.7 13.6 28.9 34.0 7.0Water Source 30.6 48.7 31.0 49.6 47.8 64.6 47.6 83.0 40.0Distribution and Transmission System 40.7 61.7 73.2 70.6 84.9 96.4 100.0 100.0 61.5Treatment 27.6 32.3 34.0 39.5 59.7 61.9 42.0 66.0 34.0Storage 30.4 35.1 40.0 43.1 47.9 60.1 80.2 49.1 37.0Other 11.9 19.8 17.5 28.7 41.7 65.6 45.9 83.0 19.8Observations 49 51 49 46 38 23 35 6 297Primarily Surface Water SystemsLand 0.0 3.6 3.8 21.4 18.8 24.0 38.7 61.7 13.0Water Source 25.2 12.3 22.7 30.2 21.8 42.5 52.8 76.6 24.3Distribution and Transmission System 39.7 53.2 62.2 82.3 82.7 98.1 89.0 100.0 70.5Treatment 55.0 71.5 38.5 63.7 65.4 90.3 89.1 100.0 61.8Storage 25.1 38.7 28.5 33.3 48.6 52.9 64.8 76.0 38.6Other 23.7 13.2 9.8 27.3 40.6 49.0 63.8 96.2 25.8Observations 23 38 50 55 71 49 99 33 418Primarily Purchased Water SystemsLand 0.0 0.0 0.0 27.4 36.3 26.7 33.3 78.6 9.9Water Source 0.0 0.0 5.8 4.3 8.6 30.3 39.6 34.2 5.8Distribution and Transmission System 0.0 71.2 84.3 68.8 100.0 85.1 97.8 100.0 81.2Treatment 0.0 0.8 1.2 4.3 22.2 17.2 41.5 69.2 5.6Storage 100.0 39.9 20.9 54.9 42.4 27.5 65.6 77.8 34.3Other 0.0 1.1 2.9 27.4 12.2 43.4 57.0 70.1 9.0Observations 2 12 27 16 23 25 39 12 156All SystemsLand 1.1 2.3 3.6 25.5 26.6 21.6 34.1 63.0 8.3Water Source 30.4 38.7 23.5 37.9 30.4 46.0 48.1 64.4 32.6Distribution and Transmission System 40.5 62.1 74.6 73.0 87.6 94.1 94.7 100.0 65.8Treatment 28.4 32.2 26.2 39.4 53.4 61.9 62.5 85.8 33.6Storage 30.3 36.1 33.7 42.8 46.9 48.3 70.2 72.7 36.8Other 12.3 16.7 12.8 28.2 34.8 52.6 56.2 86.3 19.0Observations 74 101 126 117 132 97 173 51 871Data: Q.32A105Table 74Type of Capital Expenses in the Past 5 YearsBy Primary Source of Water(Thousands of Dollars)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsLand 1 277 350 102 147 282 841 3,231 197Water Source 8 11 71 307 823 2,475 4,337 31,796 201Distribution and Transmission System 41 97 176 490 1,772 3,285 6,488 58,732 424Treatment 29 57 191 401 1,261 1,301 12,276 40,408 383Storage 26 17 162 431 979 795 1,897 11,326 216Other 3 7 54 278 560 1,392 4,360 50,630 313Observations 49 51 49 46 38 23 35 6 297Primarily Surface Water SystemsLand 0 35 39 164 117 139 1,185 17,897 1,041Water Source 2 17 285 442 1,194 1,254 9,778 26,170 2,067Distribution and Transmission System 174 155 610 842 2,057 5,347 14,339 158,182 3,891Treatment 63 327 943 1,169 1,189 7,604 12,595 74,103 3,004Storage 12 111 253 411 773 1,677 2,998 79,483 2,054Other 11 34 282 153 515 1,847 5,086 27,833 1,835Observations 23 38 50 55 71 49 99 33 418Primarily Purchased Water SystemsLand 0 0 0 65 452 4,871 1,399 4,542 818Water Source 0 0 49 3,863 343 10,699 6,389 21,423 3,190Distribution and Transmission System 0 107 303 605 7,681 5,938 10,247 90,905 2,413Treatment 0 18 30 3,367 619 7,264 9,612 68,509 6,527Storage 16 78 420 376 1,713 2,599 3,905 35,230 1,054Other 0 6 82 128 482 4,993 2,671 36,940 2,413Observations 2 12 27 16 23 25 39 12 156All SystemsLand 1 239 309 108 232 1,746 1,130 11,658 498Water Source 8 11 96 396 883 3,456 7,320 26,405 479Distribution and Transmission System 45 104 258 599 3,407 4,846 10,566 122,691 1,328Treatment 31 117 329 739 1,172 5,652 12,092 69,084 1,223Storage 26 36 213 416 1,055 1,483 2,747 57,944 607Other 4 9 78 227 536 2,374 4,350 33,180 758Observations 74 101 126 117 132 97 173 51 871Data: Q.32A106Table 75Type of Capital Expenses in the Past 5 YearsBy Primary Source of Water(Percentage of Funds Allocated for Each Type of Expense)System Service Population CategoryPrimary Source of Water100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPrimarily Ground Water SystemsLand 0.0 7.1 5.7 2.9 1.2 0.5 1.4 0.7 2.2Water Source 7.3 5.5 7.2 16.0 11.6 22.8 11.8 16.4 12.8Distribution and Transmission System 46.9 61.2 41.8 36.3 44.3 45.2 37.1 36.6 41.6Treatment 22.4 18.7 21.1 16.6 22.2 11.5 29.5 16.6 20.8Storage 22.2 6.1 21.1 19.9 13.8 6.8 8.7 3.5 12.8Other 1.2 1.4 3.1 8.4 6.9 13.0 11.5 26.2 9.9Observations 49 51 49 46 38 23 35 6 297Primarily Surface Water SystemsLand 0.0 0.3 0.2 2.0 0.7 0.2 1.3 3.2 2.1Water Source 0.4 0.6 7.1 7.5 7.8 3.7 14.8 5.9 7.7Distribution and Transmission System 62.9 22.5 41.8 38.8 50.9 36.2 36.7 44.4 42.2Treatment 31.6 63.7 40.0 41.7 23.3 47.4 32.3 21.7 28.6Storage 2.7 11.7 7.9 7.7 11.1 6.1 5.5 16.9 12.1Other 2.4 1.2 3.1 2.3 6.3 6.3 9.3 7.8 7.3Observations 23 38 50 55 71 49 99 33 418Primarily Purchased Water SystemsLand 0.0 0.0 0.0 1.8 1.8 9.5 2.2 1.8 2.5Water Source 0.0 0.0 0.8 16.8 0.3 23.6 12.0 3.6 5.8Distribution and Transmission System 0.0 70.9 73.2 42.3 87.8 36.8 47.5 44.9 62.0Treatment 0.0 0.1 0.1 14.6 1.5 9.1 18.9 23.4 11.5Storage 100.0 28.9 25.2 20.9 7.9 5.2 12.1 13.5 11.4Other 0.0 0.1 0.7 3.6 0.6 15.8 7.2 12.8 6.9Observations 2 12 27 16 23 25 39 12 156All SystemsLand 0.0 4.4 2.8 2.4 1.3 3.1 1.5 2.7 2.2Water Source 6.6 3.4 5.7 13.1 5.8 13.3 13.6 6.2 8.4Distribution and Transmission System 48.4 50.9 48.9 38.0 64.9 38.0 38.7 43.9 47.3Treatment 23.2 29.9 21.9 25.3 13.4 29.2 29.3 21.7 22.2Storage 20.5 10.3 18.2 15.7 10.6 6.0 7.4 15.1 12.1Other 1.3 1.2 2.5 5.5 4.0 10.4 9.5 10.5 7.8Observations 74 101 126 117 132 97 173 51 871Data: Q.32ANotes: Column totals may not sum to 100 due to rounding.107Table 76Major Capital Expense Categories in the Past 5 YearsByOwnership(Percentage of Systems Investing Capital Funds in Each Category)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsWater Quality Improvements 91.9 26.9 18.1 38.5 58.3 54.7 79.1 78.0 33.9Replacement or Major Repair 33.4 74.9 65.6 87.5 77.9 87.9 78.3 92.7 73.3System Expansion 1.8 23.6 49.0 65.4 64.4 74.7 83.9 79.1 48.2Observations 11 42 106 90 109 82 139 41 620Private SystemsWater Quality Improvements 29.7 50.1 63.2 77.6 54.6 81.1 87.1 100.0 45.1Replacement or Major Repair 74.5 75.7 53.9 65.4 71.8 100.0 94.1 100.0 72.1System Expansion 17.6 22.2 76.9 89.9 86.8 81.1 87.1 100.0 32.2Observations 61 53 17 13 17 11 13 3 188All SystemsWater Quality Improvements 35.6 40.6 27.9 43.3 57.7 57.4 79.8 79.4 38.9Replacement or Major Repair 70.7 75.4 63.1 84.7 76.9 89.2 79.6 93.1 72.7System Expansion 16.1 22.8 55.1 68.4 68.1 75.4 84.2 80.5 41.1Observations 72 95 123 103 126 93 152 44 808Data: Q.32A, Q.32BNotes: Includes systems with positive capital expenses only.108Table 77Major Capital Expense Categories in the Past 5 YearsByOwnership(Capital Funds Invested Per System in Each Category, in Thousands of Dollars)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000 Over 500,000 All SizesPublic SystemsWater Quality Improvements 90 84 72 340 774 1,768 3,816 43,573 511Replacement or Major Repair 87 124 178 506 1,231 4,753 8,759 92,941 1,021System Expansion 27 81 141 293 3,041 5,364 11,851 128,082 1,419Observations 11 42 106 90 109 82 139 41 620Private SystemsWater Quality Improvements 2 8 44 345 600 5,088 8,837 15,659 83Replacement or Major Repair 7 20 86 340 985 6,852 17,517 40,396 141System Expansion 12 22 287 477 1,469 2,897 10,630 81,105 177Observations 61 53 17 13 17 11 13 3 188All SystemsWater Quality Improvements 10 39 66 340 746 2,109 4,226 41,732 322Replacement or Major Repair 15 62 158 486 1,191 4,969 9,473 89,475 630System Expansion 13 46 172 315 2,786 5,111 11,751 124,983 867Observations 72 95 123 103 126 93 152 44 808Data: Q.32A, Q.32BNotes: Includes systems with positive capital expenses only.109Table 78Major Capital Expense Categories in the Past 5 YearsByOwnership(Percentage of Capital Funds Invested in Each Category)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsWater Quality Improvements 44.0 29.2 18.4 29.8 15.3 14.9 15.6 16.5 17.3Replacement or Major Repair 42.8 42.9 45.6 44.5 24.4 40.0 35.9 35.1 34.6System Expansion 13.2 28.0 36.0 25.7 60.3 45.1 48.5 48.4 48.1Observations 11 42 106 90 109 82 139 41 620Private SystemsWater Quality Improvements 7.8 16.2 10.5 29.7 19.7 34.3 23.9 11.4 20.5Replacement or Major Repair 35.4 39.8 20.6 29.3 32.3 46.2 47.4 29.5 35.2System Expansion 56.8 44.0 68.9 41.0 48.1 19.5 28.7 59.1 44.2Observations 61 53 17 13 17 11 13 3 188All SystemsWater Quality Improvements 26.0 26.6 16.6 29.7 15.8 17.3 16.6 16.3 17.6Replacement or Major Repair 39.1 42.3 39.9 42.6 25.2 40.8 37.2 34.9 34.7System Expansion 34.8 31.1 43.5 27.7 59.0 41.9 46.2 48.8 47.7Observations 72 95 123 103 126 93 152 44 808Data: Q.32A, Q.32BNotes: Column totals may not sum to 100 due to rounding.Table reports the percentage of funds invested in each category in the nation and the aggregate. It isnotthepercentage of funds invested on average by each system.110Table 79Source of Capital Funds in the Past 5 YearsByOwnership(Percentage of Systems Making Capital Expenditures)System Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsCurrent Revenues 6.3 63.8 70.1 73.9 79.9 81.7 90.4 95.9 69.5DWSRF Loans 24.4 9.4 12.6 3.4 7.7 8.8 9.3 25.7 9.8DWSRF Principal Repayment Forgiveness 16.3 14.0 6.9 1.5 4.3 3.5 2.9 2.1 7.1Other Government Loans 0.0 13.1 12.6 14.2 16.4 8.3 7.4 2.1 12.9Other Government Grants 6.5 28.3 17.9 28.0 21.6 13.8 6.0 6.2 21.8Borrowing from Private Sector 3.2 10.0 12.6 27.3 36.0 50.5 40.8 75.1 19.5Other 46.9 0.0 3.0 3.5 1.1 2.7 3.6 2.0 3.6Observations 11 43 111 94 113 85 157 45 659Private SystemsCurrent Revenues 79.2 86.5 71.6 67.5 85.9 73.6 92.9 64.0 81.2DWSRF Loans 0.0 0.0 0.0 0.0 3.2 0.0 14.1 36.0 0.1DWSRF Principal Repayment Forgiveness 0.1 0.0 0.0 11.6 0.0 0.0 0.0 0.0 0.5Other Government Loans 3.3 0.3 8.6 2.4 22.6 17.6 15.3 0.0 3.3Other Government Grants 0.0 4.9 14.8 11.6 18.3 8.8 0.0 0.0 4.8Borrowing from Private Sector 12.4 6.1 24.1 51.1 36.6 55.8 70.6 68.0 13.4Other 7.5 3.9 6.9 9.3 10.4 0.0 0.0 0.0 6.0Observations 64 59 16 14 15 10 12 3 193All SystemsCurrent Revenues 72.6 77.6 70.4 73.0 80.8 81.0 90.5 93.9 74.8DWSRF Loans 2.2 3.5 10.0 2.9 7.0 8.0 9.6 26.3 5.4DWSRF Principal Repayment Forgiveness 1.6 5.3 5.5 2.9 3.6 3.2 2.7 1.9 4.1Other Government Loans 3.0 5.2 11.8 12.6 17.3 9.1 7.9 1.9 8.5Other Government Grants 0.6 14.2 17.3 25.7 21.1 13.3 5.6 5.8 14.3Borrowing from Private Sector 11.5 7.6 15.0 30.6 36.1 51.0 42.7 74.7 16.8Other 11.0 2.4 3.8 4.3 2.6 2.4 3.4 1.9 4.7Observations 75 102 127 108 128 95 169 48 852Data: Q.32CNotes: Systems can receive funds by more than one source; therefore column totals may not sum to 100.This table reports sources of capital funds only for those systems making capital expenditures in the past 5 years.The DWSRF program may forgive all or a portion of the loan principal repayment by disadvantaged systems.Thequestionnaire refers to principal payment forgiveness as grants. This was done to distinguish principal that must berepaid from principal whose repayment is forgiven.111Table 80Source of Capital Funds in the Past 5 YearsPercentage Distribution of the Sources of Funds for Investment for the Average SystemBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsCurrent Revenues 6.1 50.3 52.8 50.1 56.8 50.8 67.3 52.6 51.1DWSRF Loans 24.4 4.6 10.8 3.0 3.2 3.7 3.9 1.4 7.0DWSRF Principal Repayment Forgiveness 16.3 9.3 4.2 0.1 1.3 1.3 0.6 0.0 4.3Other Government Loans 0.0 4.7 8.2 11.4 10.0 4.6 1.9 1.4 7.8Other Government Grants 4.7 22.7 10.8 15.6 5.1 1.9 1.2 0.7 12.9Borrowing from Private Sector 2.1 9.9 10.9 17.1 23.3 35.9 23.6 45.0 14.3Other 46.3 0.0 2.5 2.0 0.2 1.6 1.3 0.1 2.9Observations 11 43 111 94 113 85 157 45 659Private SystemsCurrent Revenues 78.0 84.8 65.1 52.1 56.2 54.9 67.8 56.0 77.7DWSRF Loans 0.0 0.0 0.0 0.0 3.0 0.0 0.6 4.3 0.1DWSRF Principal Repayment Forgiveness 0.1 0.0 0.0 4.7 0.0 0.0 0.0 0.0 0.2Other Government Loans 3.3 0.3 4.7 1.8 5.0 5.3 5.4 0.0 2.2Other Government Grants 0.0 4.8 10.0 4.1 10.9 1.6 0.0 0.0 3.7Borrowing from Private Sector 12.2 3.3 13.3 28.3 24.9 38.2 26.2 39.7 9.6Other 6.3 3.9 6.9 9.3 3.1 0.0 0.0 0.0 5.4Observations 64 59 16 14 15 10 12 3 193All SystemsCurrent Revenues 71.5 71.4 55.3 50.4 56.7 51.2 67.3 52.8 63.1DWSRF Loans 2.2 1.7 8.6 2.6 3.1 3.3 3.7 1.5 3.9DWSRF Principal Repayment Forgiveness 1.6 3.5 3.4 0.7 1.1 1.2 0.6 0.0 2.5Other Government Loans 3.0 2.0 7.5 10.1 9.3 4.7 2.1 1.3 5.3Other Government Grants 0.4 11.9 10.6 13.9 6.0 1.9 1.1 0.6 8.8Borrowing from Private Sector 11.3 5.8 11.4 18.6 23.5 36.1 23.8 44.6 12.2Other 9.9 2.4 3.4 3.0 0.7 1.4 1.2 0.1 4.0Observations 75 102 127 108 128 95 169 48 852Data: Q.32CNotes: This table reports sources of capital funds only for those systems making capital expenditures in the past 5 years.The DWSRF program may forgive all or a portion of the loan principal repayment by disadvantaged systems.Thequestionnaire refers to principal payment forgiveness as grants. This was done to distinguish principal that must berepaid from principal whose repayment is forgiven.This table shows how much of each (average) system's total capital expenditures came from each funding source. Itis not the percentage of funds acquired from each funding source for the nation in the aggregate. That is reported intable 81.112Table 81Source of Capital Funds in the Past 5 YearsPercentage Distribution of the Sources of Funds for Investment for the NationBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsCurrent Revenues 2.3 14.5 27.2 34.0 49.9 38.9 54.5 29.0 38.8DWSRF Loans 38.5 12.4 23.4 4.4 3.0 5.6 3.8 1.2 4.1DWSRF Principal Repayment Forgiveness 8.3 13.3 11.1 0.5 0.9 0.8 0.3 0.0 1.2Other Government Loans 0.0 13.4 14.6 17.3 20.7 6.2 2.2 0.3 7.9Other Government Grants 9.4 42.6 10.6 13.7 7.0 1.3 3.0 0.5 4.8Borrowing from Private Sector 16.7 3.9 10.9 26.3 18.5 43.1 34.1 68.7 42.0Other 24.9 0.0 2.2 3.8 0.0 4.1 2.0 0.1 1.2Observations 11 43 111 94 113 85 157 45 659Private SystemsCurrent Revenues 64.1 51.8 62.8 35.6 30.7 21.5 62.5 31.3 42.3DWSRF Loans 0.0 0.0 0.0 0.0 4.7 0.0 0.9 7.5 2.4DWSRF Principal Repayment Forgiveness 0.8 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.0Other Government Loans 2.9 0.7 8.2 2.2 6.3 8.6 5.6 0.0 4.9Other Government Grants 0.0 12.0 14.9 11.7 10.1 2.2 0.0 0.0 6.4Borrowing from Private Sector 20.2 7.7 12.1 46.5 46.3 67.7 31.0 61.1 41.0Other 11.9 27.8 1.9 3.9 2.0 0.0 0.0 0.0 2.9Observations 64 59 16 14 15 10 12 3 193All SystemsCurrent Revenues 33.5 21.5 33.5 34.2 48.1 37.2 55.3 29.1 39.1DWSRF Loans 19.1 10.0 19.3 3.8 3.2 5.1 3.5 1.5 3.9DWSRF Principal Repayment Forgiveness 4.5 10.8 9.1 0.5 0.8 0.7 0.3 0.0 1.1Other Government Loans 1.5 11.0 13.5 15.4 19.3 6.4 2.5 0.3 7.7Other Government Grants 4.6 36.8 11.4 13.5 7.3 1.4 2.7 0.5 5.0Borrowing from Private Sector 18.5 4.6 11.1 28.8 21.2 45.5 33.8 68.4 41.9Other 18.3 5.2 2.1 3.9 0.2 3.7 1.8 0.1 1.3Observations 75 102 127 108 128 95 169 48 852Data: Q.32A, Q.32CNotes: This table reports sources of capital funds only for those systems making capital expenditures in the past 5 years.The DWSRF program may forgive all or a portion of the loan principal repayment by disadvantaged systems.Thequestionnaire refers to principal payment forgiveness as grants. This was done to distinguish principal that must berepaid from principal whose repayment is forgiven.Of all capital expenditures spent nationally, this table reports how much that came from each funding source. It doesnot report how much came from each source for each system on average. That is reported in table 80.113Table 82Average Interest Rate for Capital Funds Lending SourcesBy OwnershipSystem Service Population CategoryOwnership Type100or Less101 -500501 -3,3003,301 -10,00010,001 -50,00050,001 -100,000100,001-500,000Over500,000 All SizesPublic SystemsDWSRF Loans * 0.3 4.3 1.6 3.9 3.0 3.1 3.3 3.1Other Government Loans * 1.2 2.0 3.5 3.4 4.2 3.8 5.3 2.5Borrowing from Private Sector 6.0 6.8 4.6 4.8 4.3 5.1 5.4 5.2 4.9Other * * 0.9 1.5 * * 5.5 * 1.3Observations 1 8 32 30 42 41 71 30 255Private SystemsDWSRF Loans* * * * 2.5 * 1.9 4.3 2.6Other Government Loans * 4.5 5.3 * 6.2 3.3 5.4 * 5.4Borrowing from Private Sector 4.8 1.4 0.5 9.5 3.3 5.6 7.6 5.0 2.2Other***** * * * *Observations2 7 3 1 6 5 5 2 31All SystemsDWSRF Loans * 0.3 4.3 1.6 3.8 3.0 3.0 3.4 3.1Other Government Loans * 1.3 2.6 3.5 3.9 3.9 3.9 5.3 2.8Borrowing from Private Sector 4.8 3.8 3.2 5.0 4.2 5.2 5.6 5.2 4.1Other * * 0.9 1.5 * * 5.5 * 1.1Observations 3 15 35 31 48 46 76 32 286Data: Q.32CNotes: *No data available for these systemsThis table reports systems making capital expenditures in the past 5 years and reporting their interestrates.114

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# Part 2

Methodology Report

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# 117 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 Suveys (CWSSs) 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 identify, evaluate and develop guidance on Best Management Practices used in water treatment and distribution systems. Previous surveys of Community Water Systems were conducted in 1976, 1982, 1986, and 1995.

1.2 Survey Overview

This section is intended to provide the reader with an overview of the design and conduct of the CWSS. The topics presented in this section will then be discussed at greater length in the following chapters.

The CWSS 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 the questionnaire in the mail. Water system professionals were assigned to each system that received the mailed questionnaire to help the systems respond to the survey’s questions. A toll-free telephone number and an e-mail address also were provided to the systems to provide technical support.

The Community Water System survey was based on a nationally representative sample of community water systems. The sample was drawn from a list of approximately 53,000 systems in the Safe Drinking Water Information System (SDWIS). 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 costsinvolved in visiting each small system in the sample, they were selected in geographic clusters in a twostage design. A sample of 1,806 systems was selected, including a census of all systems serving populations of 100,000 or more.

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A separate version of the questionnaire was developed for systems serving more than 500,000 people. Additional questions were asked of these very large systems regarding concentrations of several contaminants in raw and finished water and average well depth. 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 mailout, each system receiving the questionnaire was notified by telephone that they would receive the questionnaire in the mail. Phone calls were made throughout the data collection period to encourage non-respondents to participate and to provide technical support when needed. Requests to re-mail the questionnaire were received through the toll-free support line and during the phone calls to the system; the questionnaires were re-mailed as the requests were received.

As completed questionnaires were returned, they were logged into a receipt control system using an on-line data tracking system. The completed questionnaires went through an extensive data quality review. Water system analysts reviewed each mailout questionnaire and contacted the systems to clarify answers, correct anomalous items, or collect missing responses. The questionnaires were then reviewed by senior engineering staff. The senior staff also reviewed the site visits reports for each small system. The questionnaires were then key-entered using independent double-key entry. Finally, the electronic form of the data were 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 Community Water Systems 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 August of 1999. A pre-test of the questionnaire was conducted in July 2000. The pilot test was conducted from April to May, 2001, and the final design was developed in May 2001. Data collection took place from June through October, 2001. Data processing and analysis continued through February 2002.

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. Abt Associates, Inc. served as a subcontractor, as did Norfolk Data, Inc. The site visits were conducted through subcontracts with several experienced water system professionals. The Cadmus Group has been supporting EPA and other clients in the assessment and analysis of the water industry for over 20 years. Cadmus’ primary responsibilities were for overall project management; design of the questionnaire; sample design; selection of the medium, large, and very large system sample; design, administration, and management of the data collection; technical support to water systems in the sample; expert quality assurance review of the survey data; data tabulations; and report preparation. Abt Associates assisted with the development of the survey instrument, selected the small system sample, developed and maintained the on-line data tracking system, edited and

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prepared the data into final form for data entry, managed the data entry, calculated the sample weights, assisted in the data tabulations, and developed the final data with documentation. Norfolk Data keyed

the data into the electronic data base.

EPA also requested comments on the survey from several independent reviewers. EPA consulted with Jeanne Bailey in the office of Regulatory Affairs at the American Water Works Association in Washington, DC. Drafts of the questionnaire were reviewed by Diane Moles, from the Iowa Department of Natural Resources, in Des Moines, IA, and James K. Cleland of the Drinking Water and Radiological Protection Division of the Michigan DEQ in Lansing, MI. EPA also consulted with Robert W. Mann of the Water Supply Engineering Bureau of the State of New Hampshire's Department of Environmental Services.

# 120 2. SAMPLE DESIGN AND WEIGHTING

2.1 Sample Design and Selection

This section describes the sample design for the 2000 Community Water System Survey (CWSS). It includes a description of the sampling frame, target sample size, stratification variables, and sampling methods.

The survey relied on a probability sample of Community Water Systems. 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 is developed from the federal Safe Drinking Water Information System (SDWIS/Fed). 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 Population served



# C Primary source (surface water or ground water)



# C Public water system identification number (PWSID)



# C Ownership type



# C Consecutive system (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.

# 121

SDWIS is the appropriate sampling frame because:



# C It fully covers 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 is the best choice for a sample frame because of its inclusive coverage of all units of observation for this survey. In addition, SDWIS 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 is not designed to be such a sample frame; many properties of SDWIS, and some lingering problems of system classification in SDWIS, can result in many inaccuracies for such sample frame applications and sample selection.

For EPA's 1999 Drinking Water Infrastructure Needs Survey (Needs Survey), EPA and Cadmus made a considerable effort to improve the SDWIS information and create an inventory list more suitable as a sample frame. The Needs Survey took several steps to prepare SDWIS for use as a sample frame. Problematic data were first identified based on the experience of the 1995 Needs Survey. EPA then provided the confirmed inventory data to the States (including the Virgin Islands and Puerto Rico) for review and asked the States to provide any necessary changes.

EPA also worked with the States to identify the total "consecutive" population served (including the population of retail buyers) by many prominent large systems, to group systems into size and type categories that more accurately reflect actual populations served by a particular water system. For instance, the reported population served by the Metropolitan Water District of Southern California (MWD) is categorized as a small system serving less than 3,300 people in SDWIS; in fact, MWD serves nearly 16 million consumers. Therefore, the system was reclassified as a large system, which accurately reflects the way this system is regulated under the Safe Drinking Water Act.

Criteria used to determine the accuracy of SDWIS data include: (1) 1995 inventory verification showing a discrepancy rate greater than 1 percent; or (2) the number of community water systems in a State in SDWIS as of March 1998 being at least 3 percent greater than in the sampling frame used for the 1995 Needs Survey. On site inventory verifications were also conducted for States that contributed to at least 0.8 percent of total national need in the 1995 Needs Survey, and if EPA determined that SDWIS inventory may not accurately reflect a State's inventory, based on experience with the 1995 Needs Survey. Inventory verifications were conducted in Arizona, Arkansas, California,

# 122

Colorado, New York, North Carolina, Ohio, Oklahoma, and Tennessee. SDWIS-Fed inventory information for Virginia was replaced with SDWIS/State inventory information, since SDWIS/Fed was known to be an inaccurate source of current inventory.

The process of State corrections included a variety of inventory review procedures and data

verification:



# C A stratified random sample of systems was used to select systems within each State to verify the inventory. (A two-staged cluster sampling approach was used to select systems in New York, since data in this State are managed by numerous district offices.)



# C Sanitary survey information, bacteriological results, or other chemical records in State files and/or databases were reviewed on site to ensure that inventory data were accurate. If inventory information was different between SDWIS and the State files and/or database, a discrepancy was issued. Each State so identified was then given an opportunity to provide monitoring results or other documentation of a system's characteristics, and in some cases, a system's actual existence. Systems that were inactive were removed from the Needs Survey sampling frame, while other systems were re-categorized if necessary.



# C Based on results of the inventory verification, the total inventory for each State was further refined. The inventory verification results were extrapolated to all systems in each State to estimate the number of active systems in each size and type category.

In addition to these changes, the inventory of systems serving Alaskan native populations in SDWIS was replaced with data developed by EPA Region 10 and the State of Alaska.

The Needs Survey sample frame was further refined during the course of the data collection period. System status as of January 1, 1999 was used to determine inclusion and placement within the sample frame.

The sample frame used for the Needs Survey is based on the SDWIS from 1998; to account for changes in SDWIS, we compared the SDWIS available from the first quarter of 2000 to the Needs Survey list. New systems were verified and added. This revised list of systems will be used as the sample frame for the CWSS.

# 123

2.1.2 Sample Design and Selection

Sample Eligibility

To be eligible for the CWSS, 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 CWSS 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. To the extent possible, all ineligible systems were identified in SDWIS 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.

After it drew the initial sample, EPA decided to exclude systems in the trust territories. The original sample included 64 systems in Puerto Rico, the U.S. Virgin Islands, and the Pacific territories. EPA decided not to select a new sample because this would affect the site visit schedule. Instead, EPA dropped the systems in the trust territories, and classified these systems as non-respondents when calculating the sample weights.

Sample Design

The CWSS 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 domains of the population of interest for EPA are based on two characteristics of the
systems:

1. The source of water . Systems that rely on ground water are distinguished from surface water systems.

2. The size of the population served by the system . Eight size categories will be 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.

The two water sources and the eight system sizes produce sixteen strata.

# 124

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 systems 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 aboutsystems serving populations of less than 10,000 or 3,300. We can ensure that estimates of the subpopulations 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 Community Water Systems 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 six 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 six small systems was combined with geographically adjacent counties to form the primary sampling units.) At the first stage of sampling, a sample of 100 PSUs were selected with probabilities proportional to size. The measure of size was the number of small systems in the PSU. A large PSU could be selected ("hit") more than one time. PSUs were re-

# 125

sampled to account for potential non-response. The over-sampling rate was determined based on EPA’s experience with the 1999 EPA DWINS and the 1995 CWS Survey. States were provided with a list of small CWSs in the counties selected, and EPA asked States 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 of systems in the stratum in that PSU, and summed over all strata in each primary sampling unit (county or group of counties).

# 126 Table 2-1. Frame and Sample Sizes by Strata

Source of Water Population Served Frame Size Required Sample

Ground 100 or less 14,972 95

101-500 16,025 95

501 - 3,300 12,341 95

3,301 - 10,000 3,300 92

10,001-50,000 1,921 89

50,001 - 100,000 260 60

100,001 - 500,000 126 126

More than 500,000 17 17

Surface 100 or less 538 88

101-500 789 91

501 - 3,300 1,551 93

3,301 - 10,000 988 91

10,001-50,000 970 91

50,001 - 100,000 215 74

100,001 - 500,000 189 189

More than 500,000 66 66

All 54,268 1,452

For systems serving populations of 3,301 – 100,000, the sample was obtained by drawing a random sample of systems from the cleaned SDWIS frame, within each sampling stratum serving populations of this size. Systems in these strata were oversampled to account for non-response. As with the small systems, the over-sampling rate was based on EPA’s experience with the 1999 DWINS and the 1995 CWSS. Systems serving populations of more than 100,000 were selected with certainty. The resulting increase in sample size is warranted for the following reasons:

# 127



# 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 1,870 systems were selected into the sample. The sample size by strata and the and sampling rate are shown in table 2-2.

2.1.3 Stratum Migration

Errors in the SDWIS 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, 87 percent reported the same population served category as indicated by the frame. Just over 91 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, more than 80 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. While migration across size categories is small, several systems reported to serve 3,300 or fewer people in the frame moved into larger categories; 20 moved into the 3,301-10,000 category, and 4 moved into larger population categories. Also, 19 systems moved into small system categories from the larger categories.

# 128 Table 2-2. Sample Size and Sampling Rate by Strata

Source of

Water Population Served Sample
Size Sampling

Rate (%)

Ground 100 or less 128 0.9

101-500 124 0.8

501 - 3,300 124 1.0

3,301 - 10,000 155 4.7

10,001-50,000 152 7.9

50,001 - 100,000 116 44.6

100,001 - 500,000 126 100.0

More than 500,000 17 100.0

Surface 100 or less 94 17.5

101-500 85 10.8

501 - 3,300 90 5.8

3,301 - 10,000 145 14.7

10,001-50,000 144 14.8

50,001 - 100,000 110 51.2

100,001 - 500,000 194 102.6

More than 500,000 66 100.0

All 1,870 3.4

# 129Table 2-3. Survey Respondents by the Frame-Based and Sample-Based Size CategoriesSample-Based PopulationServed CategoriesFrame-Based Population Served Category25-100101-500501-3,3003,301-10,00010,001-50,00050,001-100,000100,001-500,000Over500,00025-100Count14213000010Percent918000010101-500Count161441010000Percent9846100000501-3,300Count611177151010Percent3584700003,301-10,000Count101913910010Percent101182601010,001-50,000Count10113136910Percent10188461050,001-100,000Count1000410840Percent100049230100,001-500,000Count10001141824Percent100017902Over 500,000Count000001255Percent000002395

# 130

Source of Water

Table 2-4 shows the cross-tabulation of the frame-based and response-based water source classifications. Approximately 86 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.

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 323 42 146 12 123 19 592 73

Percent 88 12 92 8 87 13 89 11

Surface Count 9 164 10 163 15 220 34 547

Percent 5 95 6 94 6 94 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 ± 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 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. The planned sample size is the sample that would be needed if the frame had correctly identified all subdomain members. The required sample size is the sample needed, given the inaccuracies in the frame. 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 subdomain. The increase in the half-width for mid-sized ground water systems is modest. 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. The width increased substantially for ground water systems in these strata and slightly for surface water systems serving greater than 500,000 people categories due to the strata migration, as the number of systems in these strata is larger than expected. It also increased for surface water systems serving populations of more than 500,000.

# 131

Table 2.5. Sample Sizes and the Impact on Precision of Estimates of Strata Migration

Source Population Served Required Planned Half width of
95% Confidence

Interval

Ground 100 or less 95 95 0.100

101 - 500 95 95 0.100 501 - 3,300 95 95 0.100 3,301 - 10,000 93 92 0.101 10,001 - 50,000 91 89 0.101 50,001-100,000 70 60 0.111 100,001-500,000 125 73 0.074 Over 500,000 17 8 0.260

Surface 100 or less 79 88 0.094

101 - 500 85 91 0.096 501 - 3,300 90 93 0.099 3,301 - 10,000 88 91 0.098 10,001 - 50,000 87 91 0.098 50,001-100,000 66 74 0.092 100,001-500,000 191 257 0.000 Over 500,000 66 50 0.069

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 nonresponse. 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 Nonresponse 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.

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.

# 132 

# B N

n h h

h 

# =

B P N

n mh

m mh

mh 

# =             1 2. Within clusters a stratified element sample of small systems was drawn.

After the initial sample was drawn, it was decided to go back to some of the clusters and draw additional small systems from specific strata to make up for a short fall in sample size due to a larger than expected number of ineligible small systems. Also, sample clusters located in U.S. territories were not included in the actual data collection for cost reasons and are treated as nonrespondents.

The EPA SDWIS data file was used as the sampling frame for sample selection. 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. For the medium and large 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 h th 

# stratum,
B h 

# , is:

where N h 

# represents the number of systems in the stratum in SDWIS, and n h 

# represents the number of systems sampled from the stratum.

For the small systems the base sampling weight equals the product of the reciprocal of the probability of selection of the cluster times the reciprocal of the within cluster probability of selection of the small system. For large clusters selected with certainty the cluster base sampling weight component equals one. The reciprocal of the within cluster selection probability equals the number of small systems in a stratum divided by the number selected from that stratum. The base weight for a sample system in

the h th 

# stratum in the m th 

# cluster is given by B mh 

# :

where P

m 

# is the probability of selection of the m th 

# cluster.

Nonresponse adjustment

The second step in the weighting methodology was to make a unit nonresponse adjustment to

# 133 

# d h h h

h 

# n r

n = +



# W B h f
h h 

# = d

W B mh mh h 

# = d

r h h

mhj j R mhj

j I 

# N

W B

h h 

# = +

∈ ∈ 

# ∑ ∑ the base sampling weights. For each medium and large system stratum, the nonresponse adjustment factor is equal to the ratio of the number of systems that completed the survey plus the number of nonrespondents 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 nonresponse adjustment. The adjustment factor for the h th 

# stratum is given by 

# * h 

# :

Where r

h 

# is the number of refusals and other nonrespondents in the h th 

# stratum.

For the small system sample the unit nonresponse 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 nonresponse adjustment factor 

# * h 

# was multiplied by the base sampling weight, B h 

# , to obtain the nonresponse adjusted base sampling weight. The nonresponse adjusted base sampling weight for the medium and large systems that completed the survey is the final weight for use in analysis. The nonresponse adjusted weights can be written as:

for medium and large systems, and

for small systems.

The final step in the weight calculations for small systems was a ratio adjustment to the SDWIS data file 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 104 sample clusters, may not have the same stratum distribution as the entire EPA data file of small systems. For each small system stratum, the sum of the nonresponse 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 SDWIS was then divided by this sum. This yielded a ratio adjustment factor for each small system

# 134 

# W W mh f
mh h 

# = r stratum, 

# D

h 

# :

Where: R h 

# is the set of systems that responded to the survey, and

I h 

# is the set of systems sampled that were ineligible.

j designates the j th 

# sample system.

For the small systems with a completed survey their nonresponse adjusted base sampling weight was multiplied by the ratio adjustment factor to yield a final weight for use in analysis:

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 – for 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 2000 CWSS 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.

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 were 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

# 1 

# See Cochran, W.G. 1977, Sampling Techniques , New York: John Wiley & Sons for amore

information about variance estimates..

135



# ( ) ( ) ( ) ( ) 

# { } $ $

$ $ $ $ $ $

, $ $ $ $ V R X V Y R C o v Y X R V X =

− + 1 2 2 2



# ( ) d X y R x hij hij hij 

# =

− 1

$ $ 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:

where , the ratio of estimates of two population totals. is equal to , and 

# $ $

$ R Y X = $ Y w y hij hij j n

i m

h L hi

h



# = = = 

# ∑ ∑ ∑

1 1 1


# is equal to . L is the number of strata, m h 

# is the number of primary sampling units in 

# $ X w x hij hij j n

i m

h L hi

h



# = = = 

# ∑ ∑ ∑

1 1 1 

# strata h, and n

hi 

# is the number of elements in the i th 

# primary sampling unit in the h th 

# strata.

Most of the estimates produced in this volume are either means or proportions. A mean is simply a ratio in which x hij 

# is equal 1. A proportion is simply a mean in which y hij 

# is equal to a 0/1

variable. 1



# 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:

We then define the weighted total of the ratio residual as

# 136 

# z w d dhi hij hij j n hij



# =

= 

# ∑

1



# z m z dh
h dhi

i m h



# =

= 

# ∑ 1

1



# ( ) ( ) ( ) $ $ V R f m

m z z h
h L h

h dhi dh

i n h



# =

−

− −

= = 

# ∑ ∑ 1 1 1 2

1 

# and the weighted average of the residual as:

We can then define the variance estimate as:

where f

h 

# 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.

# 137 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

The Cadmus Group, working closely with EPA staff responsible for regulatory development, developed the questionnaire. 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 1995 CWSS were eliminated from the 2000 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 survey instrument is in Appendix A. The questionnaire in Appendix A is a composite of the two questionnaires used; the questions that are asked only of systems serving over 500,000 people or only systems serving up to 500,000 people are noted.

Cadmus worked with EPA on the wording and organization of the questionnaire. It 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 fo 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 cross connection control, 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. EPA also established a process to provide extensive technical assistance and guidance to recipients of the mailed questionnaire. 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. As a 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. was simplified.

# 138

3.2 Data Verification

EPA forwarded the list of water systems selected in the sample to the states. For small systems, the states were asked to verify that the systems were active systems serving up to 3,300 people, as well as the address, telephone, and the contact information. The states identified 27 systems that were not active Community Water Systems. To replace the systems that were inactive, 22 additional systems were selected from each of the clusters that contained inactive systems. Not every inactive system could be replaced because each cluster did not have enough systems in the sample frame to replace all the inactive systems.

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 systems participated in the pilot test. (One system was inactive, and one refused to participate.) 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.

Three contractors were selected to conduct the site visits. The contractors were:



# C International Studies and Training Institute, Inc.,



# C Southwest Environmental Engineering, and



# C McNenny Environmental Engineering and Consulting.

Cadmus also conducted several site visits.

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.

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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 objectives only if the facility was “designed” 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.



# C Operators on-call are not the same as on-site; therefore, if a system only has an operator on-call, it should not be classified as having an operator on-site 24 hours a day.



# C SCADA for process monitoring was defined as information on values (i.e. elevations, pressures, pH, cl2, etc.). It was classified as process control if it had the capability to automatically control equipment ( i.e. pump controls, feed equipment controls, pacing control, etc)



# 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 Collect a service area map or draw the service area on a map (USGS, MapBlast, Microsoft, etc) for each system.



# C The cross connection control program must be more than the plumbing code. The program should be specifically designed as a backflow prevention/cross connection control program.



# C Financial data. If there is no other information, get the average annual bill (question26). Again, if the information was not available in a manner that it could be

# 140 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.

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 inspections; 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 an letter introducing the site visitor and explaining the survey. The site visitor inspected 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 insure consistent responses from the 6 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 insure 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.

Site visits were not done in Alaska or Hawaii. For Alaska, two clusters of small systems were surveyed using a combination of telephone interviews with system, state regulatory, and EPA personnel. The remoteness and reluctance of some of the systems in Alaska made on-site visits infeasible. The information that was collected from these system was abbreviated to promote response. The data reflect the Alaska systems, but may not be easily compared to the remaining small system surveys.

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3.5 Mail Survey Operations

Cadmus produced camera-ready versions of the two questionnaires, which EPA printed at its facility. Cadmus produced three mailing information and control labels for each system’s questionnaire. Information for the mailing label was extracted from the sample frame and attached to the envelope for mailing. A second label that included contact information, the mailing address, and a telephone number was produced and attached to the questionnaire itself. This label explicitly instructed the respondent to respond only to the sampled system when answering the questions. Both labels included a public water system identification number (PWSID), in both alpha-numeric and bar-code. The third label contained the toll-free telephone support line and e-mail information. Included in the envelope, along with the questionnaire, was an introductory letter from the president of the Cadmus Group, a brief list of instructions, and a pre-addressed pre-paid FedEx envelope for systems to return the completed questionnaire.

The questionnaires were mailed to approximately 1,200 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 informed the system of the survey, told them they would receive the questionnaire, and gave the systems a name and telephone number to call with any questions. If a system did not receive the questionnaire, the analyst responsible for that system sent them another copy of the questionnaire via FedEx. 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 filled-out the questionnaire through a telephone interview.

As questionnaires were received from the water systems, Cadmus logged them into the on-line tracking system. The analyst responsible for the questionnaire reviewed it for data quality and to identify potential problems. When necessary, senior engineering or financial staff were consulted regarding potential problems. If a problem or question could not be resolved by Cadmus staff, the analyst contacted the Community Water System. 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, the completed questionnaire was forwarded to data entry.

3.6 Data Entry

Upon review by the senior staff, all questionnaires were logged as completed, and sent to Abtfor data review and editing, and preparation for data processing. The questionnaires were then keyentered 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, and checked skip patterns. 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.)

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Status reports were sent to the EPA project managers 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.

# 143 Table 3-1. Example of Data from Status Report

Ground Water Systems

Population Served 25-100 101-500 501- 3,300 Subtotal,

25-3,300 3,301-

10,000 10,001-

50,000 50,001-

100,000 100,001-

500,000 >500,00 Subtotal, >3,300 Total

Sample selected 128 124 124 376 155 152 116 127 17 567 943

Sample needed to meet precision requirements* 95 95 95 285 93 91 70 127 17 398 683

Appointments scheduled or questionnaires mailed 113 110 121 344 153 151 115 126 17 562 906

Questionnaires re-mailed 0 0 0 0 26 28 22 30 4 110 110

System found to be

inactive 10 6 0 16 1 1 0 1 0 3 19

Questionnaires

undeliverable 2 0 0 2 2 1 0 2 0 5 7

Water systems that refused to participate 1 1 0 2 30 15 22 25 1 93 95

Site visits complete/ questionnaires received 96 95 121 312 73 67 61 68 11 280 592

Questionnaires reviewed for quality assurance and ready to enter into database 91 94 121 306 49 44 36 40 3 172 478

Completed questionnaires

entered into database 0 0 0 0 0 0 0 0 0 0 0

# Table 3-1. Example of Data from Status Report



# 144 Surface Water Systems

Population Served 25-100 101-500 501- 3,300 Subtotal,

25-3,300 3,301-

10,000 10,001-

50,000 50,001-

100,000 100,001-

500,000 >500,00 Subtotal, >3,300 Total

Sample selected 94 85 90 269 145 144 110 193 66 658 927

Sample needed to meet precision requirements* 77 84 90 251 87 87 66 198 66 504 755

Appointments scheduled or questionnaires mailed 65 63 85 213 143 138 106 189 66 642 855

Questionnaires re-mailed 0 0 0 0 14 21 14 24 11 84 84

System found to be

inactive 7 4 0 11 0 0 0 1 0 1 12

Questionnaires

undeliverable 0 0 2 2 0 2 0 2 0 4 6

Water systems that refused to participate 0 1 0 1 15 20 14 20 4 73 74

Site visits complete/ questionnaires received 61 59 77 197 86 82 67 120 47 402 599

Questionnaires reviewed for quality assurance and ready to enter into database 59 57 77 193 59 63 41 82 27 272 465

Completed questionnaires

entered into database 0 0 0 0 0 0 0 0 0 0 0

# Table 3-1. Example of Data from Status Report



# 145 Total, Ground and Surface Water Systems

Population Served 25-100 101-500 501- 3,300 Subtotal,

25-3,300 3,301-

10,000 10,001-

50,000 50,001-

100,000 100,001-

500,000 >500,00 Subtotal, >3,300 Total

Sample selected 222 209 214 645 300 296 226 320 83 1,225 1,870

Sample needed to meet precision requirements* 172 179 185 536 180 178 136 325 83 902 1,438

Appointments scheduled or questionnaires mailed 178 173 206 557 296 289 221 315 83 1,204 1,761

Questionnaires re-mailed 0 0 0 0 40 49 36 54 15 194 194

System found to be

inactive 17 10 0 27 1 1 0 2 0 4 31

Questionnaires

undeliverable 2 0 2 4 2 3 0 4 0 9 13

Water systems that refused to participate 1 2 0 3 45 35 36 45 5 166 169

Site visits complete/ questionnaires received 157 154 198 509 159 149 128 188 58 682 1,191

Questionnaires reviewed for quality assurance and ready to enter into database 150 151 198 499 108 107 77 122 30 444 943

Completed questionnaires

entered into database 0 0 0 0 0 0 0 0 0 0 0

Note: includes systems that were in the pilot test.

* Systems serving populations of over 100,000 are sampled with certainty.

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3.7 Survey Response

The data collection effort was closed out October 31, 2001. Of the 1,807 systems included in the sample, 1,246 responded to the survey. The overall response rate was 67 percent. Table 3.2 shows the response rate by strata. Excluding the trust territories, the overall response rate was 69
percent.

Table 3-2. CWSS Responses and Response Rate by Strata

Source of

Water Population Served CompletedQuestionnaires Response

Rate (%)

Ground 100 or less 107 83.6

101-500 106 85.5

501 - 3,300 124 100.0

3,301 - 10,000 77 49.7

10,001-50,000 70 46.1

50,001 - 100,000 62 53.4

100,001 - 500,000 69 54.8

More than 500,000 11 64.7

Surface 100 or less 61 64.9

101-500 62 72.9

501 - 3,300 83 92.2

3,301 - 10,000 91 62.8

10,001-50,000 82 56.9

50,001 - 100,000 70 63.6

100,001 - 500,000 123 63.4

More than 500,000 48 72.7

All 1,246 66.6

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# 148 4. QUALITY ASSURANCE AND PEER REVIEW

The quality assurance plan for the CWSS 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. A Quality Assurance Project Plan (QAPP) was developed for the survey and was approved prior to the start of data collection. The Office for Environmental Information reviewed the methodology and the data presented in the body of the report. The report results and statistical methods also were peer reviewed by subject matter experts. Drafts of the questionnaire were reviewed by Diane Moles, from the Iowa Department of Natural Resources, in Des Moines, IA, and James K. Cleland of the Drinking Water and Radiological Protection Division of the Michigan DEQ in Lansing, MI. OGWDW also consulted with Robert W. Mann of the Water Supply Engineering Bureau of the State of New Hampshire’s Department of Environmental Services. Finally, the sampling design was reviewed by senior statisticians at as part of the external QAPP review, as well as by Cadmus, Abt , and within EPA; it is the same basic design used for the 1999

DWINS.

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 data processing quality assurance procedures. The last section describes the quality assurance steps taken during the preparation of this report.

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. Confirming the validity and effectiveness of these designs, or revising them when the tests revealed problems, errors, or difficulties, led to design and process improvements that would have a positive effect on the quality of the survey 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 7 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.

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The recruited systems received the questionnaire in July, 2000. EPA then convened a focus group meeting of the 7 water systems, facilitated by survey research staff from Abt Associates and 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 aresult of the pre-test, some questions were re-worded, and others were shortened. Otherwise, the pretest 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 April and May, 2001. 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 May, 2001. The full on-line tracking system was developed during the pilot, and the mail-out and receipt logging procedures were finalized.

Twelve small systems and 42 medium, large, and very large systems were selected from the full sample for use in the pilot. Of these, 10 of the small systems and 26 of the medium, large, and very large systems responded. The response rate was consistent with the target rate for the survey as a

whole.

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 19 (length of distribution mains) and 32 (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 CWSS 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 1999 DWINS frame, the 2000 CWSS was able to take advantage of the extensive data verification effort undertaken the 1999 DWINS. The 1999 DWINS frame was updated with data collected through the survey. This updated frame was

# 150

then compared to the data in SDWIS in the first quarter of 2000 to identify systems that were either added or removed from SDWIS since the DWINS was completed. 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.

Sampling Software . The CWSS sample of systems serving up to 3,300 people was drawn using SAS-based program designed to draw two-stage cluster samples of this type. The same program was used to draw the 1999 DWINS. The sample of systems serving population s of 3,301 to 100,000 was a stratified random sample and was drawn using Stata-based program to select random samples.

4.3 Data Collection Quality Assurance

Each component of the CWS survey was implemented pursuant to detailed written specifications that clearly stipulated how the design was to be implemented.

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 pre-test and pilot test.



# C Questionnaire version control was maintained through the various drafts by handwriting all changes onto the hard copy master of the current version. After the changes were made to the master word processing file, the previous hard copy version was filed. Each version was dated and serially numbered.



# 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 small systems have with filling out complex questionnaires like the CWSS, site visitors were sent to small systems to ensure the questionnaires were filled out correctly.

# 151

Mail Data Collection



# C Workers preparing the questionnaire for mailing were provided with detailed written specifications for the job and were supervised by a mail operations manager.



# C Mail clerks worked in tandem to produce the packages to be mailed to each respondent. One clerk applied identification labels and assembled the packet; the second applied the corresponding address label to the mail out envelope. This procedure effectively provided a 100% check that the mailing and questionnaire labels were for the same water system.



# C A survey manager conducted spot checks of the questionnaires before they were sealed to ensure the respondent was receiving the appropriate form and that the

address label and CWS information label matched.



# C The prepared questionnaires were counted prior to mailing to verify that the correct number of questionnaires were mailed.



# 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 at least the first 25 surveys received to ensure analysts were using consistent procedures for each survey.



# C The on-line 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 on-site training at a cluster of small systems.



# C Detailed instructions were provided to each site visitor regarding the conduct of the onsite surveys.



# C Regular contact was maintained with all site visitors. Site visitor questions and Cadmus

# 152 responses were sent to all site visitors to ensure each 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

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 survey evaluated the analysts’ reviews at the beginning of the review process, and 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 the 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 quesitons (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.

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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 Manual Editing, Coding, and Data Entry

Following the expert review, the questionnaires were subjected to a 100 percent editing review in preparation for entering the data. This editing process examined every response field on every form, to check skip patterns, clarify handwriting that would be difficult for the data entry staff to read, standardize the recording of quantitative data, and identify any potential problems, such as marginal notes or potential order-of-magnitude reporting errors in the volumetric questions. General protocols were developed to guide the data preparation staff in reviewing the forms and in handling generic problems. Data Preparation supervisors performed a 100% quality control review of edited forms before they were data entered. During the editing process any questions, including the creation of open-ended codes, that could not be answered by the general protocols were passed on to Cadmus by staff at Abt Associates for final decisions. The editing protocol was updated to reflect coding decisions.

After the initial edit, the questionnaires moved to the data entry process. Each form was entered with 100 percent verification, that is, using independent double key entry. The automated data entry program was customized to each form.

As the data were entered, the batches of entered records passed through a data cleaning process, consisting of standard computer edits that examined each variable for conformity to appropriate values or data ranges and also checked the small number of skip patterns that existed in the survey instruments. A report identified each variable for each case that failed any of these tests. A data preparation supervisor then examined the original questionnaire forms to determine whether the anomaly occurred in the original data and, if so, whether to confirm it as correct or to refer to Cadmus for resolution as described above. The standard computerized edits were repeated for all the data until no cases failed the edits, except for any that had been specifically confirmed as valid outliers during a previous review.

After all questions were edited, entered, and cleaned to the degree permitted by these processes, the resulting keyed data passed to a process of detailed automated logical edits that enabled expert staff to conduct a highly focused review of data values and relationships.

# 154

4.5.2 Automated Data Validation Checks

In preparing the final database, EPA, Cadmus, and Abt 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, 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

# 155 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. In addition to these specifications, the processing of files and flow of data throughout these steps were planned, controlled, and documented through data flow diagrams. The diagrams are schematic representations of how files, data record, data elements, and individual data point values are handled, combined, extracted, and moved from one stage to the next. These diagrams are crucial quality assurance tools to help ensure that programmers and systems analysts have aclear an 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, an 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 was the current version and it always was clear of sequential changes that had been made from one version to the next. 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, data flow diagrams, 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;

# 156



# 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;



# 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:

– Consistency with the design of the table of contents;

– Conformity with the definitional and programming specifications; and

– Reasonable agreement with expected valuesbased 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.

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4.6 Quality Assurance During Report Preparation

EPA requested comments on the survey from several independent reviewers. EPA consulted with Jeanne Bailey in the office of Regulatory Affairs at the American Water Works Association in Washington, DC. Drafts of the questionnaire were reviewed by Diane Moles, from the Iowa Department of Natural Resources, in Des Moines, IA, and James K. Cleland of the Drinking Water and Radiological Protection Division of the Michigan DEQ in Lansing, MI. EPA also consulted with Robert W. Mann of the Water Supply Engineering Bureau of the State of New Hampshire's Department of Environmental Services. As noted in the introduction to this part of the report, EPA’s Office of Environmental Information reviewed the data presented in this report to ensure the findings were appropriately described and presented. Additional peer review was provided by Jan Beecher of Michigan State University and John Petersen of George Mason University.

# 158

# 159 

# Appendix A

Community Water System Survey

Questionnaire

# 160

# United States

Environmental Protection Agency

SURVEY OF SMALL, MEDIUM, LARGE,

AND VERY LARGE

COMMUNITY WATER SYSTEMS

(Composite of questionnaire sent to small, medium, and large systems,

and to very large systems)

OMB No. 2040-0227 Expiration date: 2/29/04

# Please return this questionnaire in the enclosed Federal Express envelope

or mail to:

EPA Community Water System Survey c/o The Cadmus Group, Inc. 135 Beaver St., Suite 2 Waltham, MA 02452

Participation in the survey is voluntary. However, as a matter of policy, EPA will not disclose the identity of any respondent to this questionnaire, nor the identity of any participating water system. While no respondent has ever claimed that the information asked for in this survey contains confidential business information (CBI), EPA will offer you the opportunity of claiming CBI in the event that we receive a Freedom of Information Act request for any data that would identify you or your system. It should be noted, however, that EPA has never received a Freedom of Information Act request for such information in prior surveys.

The public reporting and record keeping burden for this collection of information is estimated to average 2.27 hours per response or to range from 1 hour to 4 hours per respondent annually. Burden means the total time, effort, or financial resources expended by persons to generate, maintain, retain, or disclose or provide information to or for a Federal agency. This includes the time needed to review instructions; develop, acquire, install, and utilize technology and systems for the purposes of collecting, validating, and verifying information, processing and maintaining information, and disclosing and providing information; adjust the existing ways to comply with any previously applicable instructions and requirements; train personnel to be able to respond to a collection of information; search data sources; complete and review the collection of information; and transmit or otherwise disclose the information. An agency 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 control number. The OMB control numbers for EPA's regulations are listed in 40 CFR Part 9 and 48 CFR Chapter 15.

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 methods for minimizing respondent burden, including through the use of automated collection techniques to the Director, Collection Strategies Division, U.S. Environmental Protection Agency (2822), 1200 Pennsylvania Ave., NW, Washington, D.C. 20460; and to the Office of Information and Regulatory Affairs, Office of Management and Budget, 725 17th Street, NW, Washington, DC 20503, Attention: Desk Officer for EPA. Include the EPA ICR number and OMB control number in any correspondence. Do not send the completed survey to this address.

# Dear Owners and Operators of Community Water Systems:

The United States Environmental Protection Agency (EPA) is conducting a national survey of drinking water systems using the attached questionnaire. About 1,500 water systems have been randomly selected to participate in this survey, and yours was one such system. This survey is conducted approximately every five years, the last one being in 1995. We are sending you this questionnaire because you were identified in your state's database (State Drinking Water Information System) as the most appropriate person to provide information about your water system. Participation in the survey is voluntary.

This survey will accomplish a number of important objectives. First, it will give us current data that will allow us to better consider the costs and benefits to water systems when we develop new national drinking water regulations. It will also allow us to measure the impact of drinking water regulations that have been put in place since the last survey. This, in turn, will help us determine more affordable approaches to drinking water treatment. Furthermore, the answers you provide in this questionnaire will help us in developing more effective programs to safeguard our nation's drinking water, provide guidance to the states and measure the effectiveness of programs already in existence, such as the Drinking Water State Revolving Fund.

As 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 other water systems in the same size category as yours. We will never disclose your name or the name of your water system in any public documents. Please see the inside cover of the questionnaire if you'd like more details on how your privacy will be protected.

Answers to this questionnaire will help EPA to understand your circumstances better than any other single tool we have. If you have ever wanted to have a larger say in the development of national rules that could directly effect you and your water system, providing answers to this questionnaire is an important contribution. Because only 1,500 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 more weight. If you have ever felt that Federal regulators don't understand your situation, then please take this opportunity to tell us, in detail, just what your situation is. It will make a difference.

Sincerely,

Brian C. Rourke Program Analyst Standards and Risk Management Division

# Please respond about:

Please return you completed questionnaire in the enclosed pre-paid Federal Express envelope by July 13, 2001

# Page 1 of 22 

# 2000 Community Water Systems Survey

Small, Medium Large / Very Large Systems Questionnaire

GENERAL INSTRUCTIONS

This questionnaire asks two preliminary questions and then is divided into two parts.

PART I – OPERATING CHARACTERISTICS (Questions 3 – 25); and
PART II – FINANCIAL CHARACTERISTICS (Questions 26 – 32).

Please complete the questionnaire.

Make a copy of the completed questionnaire for your records before sealing it in the enclosed envelope.

Please include a map of your service area or delineate your service area on the enclosed map.

[VERY LARGE SYSTEMS: ]
Please enclose a schematic of your system, site plans of your treatment facilities, and the latest available financial report. If the schematics, diagrams, financial or other reports contain the information requested by a question, you may refer to the documentation rather than fill out the question

.

[SMALL/MEDIUM/LARGE SYSTEMS]:

Your are strongly encouraged to enclose schematics, diagrams, financial reports, or other information that will help provide a complete picture of your water system. If schematics, diagrams, financial or other reports contain the information requested by a question, you may enclose and refer to the documentation rather than fill out the question

.

If you require more space to answer an question than is provided, please record the information on a photocopy of the question or use a blank sheet of your own.

# Page 2 of 22



# 1. Please provide the name, title, and telephone number of the most knowledgeable person to contact for

information on:

(A) Part I – Operating Characteristics

Name: Title:

Tel. No. Fax No.

e-mail:

(B) Part II – Financial Characteristics

(Write “SAME” if same as above)

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.

A. Operating information

...................................... / / (mm / dd / yy)

B. Financial information

...................................... / / (mm / dd / yy)



# Part I – Operating Characteristics

For Part I of the survey, please use the period indicated in Question 2(a) to report “last year’s” operating data.

3. Please classify your water system using the following criteria (circle one)

.

Owned or operated by a government or public agency (including government-owned systems that hire a private company to operate the system)

........................ 1

Owned privately and operated for profit primarily as a

water business

........................................... 2

Owned privately and not operated for profit (e.g., a homeowners association or a non-profit cooperative)

....................... 3

Owned privately and operated as a necessary part of another business (e.g., a mobile home park)

............... 4

# Page 3 of 22



# 4. If your system is owned or operated by the government, please select one of following that best describes the form of government (circle one)

.

A local or municipal government (e.g. towns, townships, cities, counties, boroughs, parishes, and special districts)

............... 1

State government

......................................... 2

The Federal government

.................................... 3

Some other government (Please specify) 4



# A. PRODUCTION and TREATMENT

5. What was the amount of water that was produced and delivered to each of the following customer categories during the last year [as defined by your answer to Question 2A]? (In millions of gallons. Note: if you cannot distinguish among the different types of non-residential customers, enter the total for your non-residential customers in line c.4.)

Customer Type Total

a. Sold to other public water suppliers:

1. Treated water

................................ Million Gallons/Yr.

2. Untreated water

.............................. Million Gallons/Yr.

b. Residential

.......................................... Million Gallons/Yr.

c. Non-residential

1. Commercial/industrial

......................... Million Gallons/Yr.

2. Agricultural

................................. Million Gallons/Yr.

3. Other (specify) Million Gallons/Yr

4. Subtotal, non-residential

........................ Million Gallons/Yr

d. Unaccounted for water not included above (including uncompensated usage and system losses)

.................. Million Gallons/Yr

e. Total, all customer types (including unaccounted for water)

.... Million Gallons/Yr



# 6. Provide the name of each public water supplier included in the response to Question 5a, above.

a. Treated water

b. Untreated water

# Page 4 of 22



# 7. How much of the water reported in Question 5 came from each of the following sources during the twelve month period reported in Question 2A ? (in millions of gallons; answer ‘none’ if a source does not apply)

.

a. Surface water (non-purchased) (including Ground Water Under the Direct Influence of Surface Water)

........................... Million Gallons/Yr.

b. Ground water (non-purchased)

.............................. Million Gallons/Yr.

c. Purchased water

1) Treated water

....................................... Million Gallons/Yr.

2) Untreated water

...................................... Million Gallons/Yr.

d. Other ( specify ) Million Gallons/Yr.

e. Total

............................................... Million Gallons/Yr



# 8. What was the maximum daily water production from all sources for this utility over a single 24 hour period during the twelve month period reported in Question 2A?

................................... Million Gallons/day

The following definitions of the components of a water system are used in this survey. Figure 1 is an example of a schematic of a water system, showing water sources, treatment plants, transmission lines, and the distribution system.

Please refer to these definitions and the schematic for an explanation of the terms used in questions 10 through 18. Please submit diagrams or schematics, using figure 1 as a guide

.
Please note that the identifier numbers used in the questions do not refer to specific items in the

schematic. For example, use ‘S1' to refer to your first surface water source, regardless of whether it is a flowing stream, as depicted in the schematic, or another surface water source.

# Page 5 of 22



# Term Definition Code in the
Schematic

Surface water

intake A surface water intake refers to the transmission of untreated water from a

surface water source (flowing stream, lake, reservoir, or ground water under the direct influence of surface water) to a water treatment plant at the utility (see accompanying diagram). S1, S2

Ground water

intake A ground water intake refers to the transmission 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 into the treatment plant or distribution system, the combined flow is considered one ground water intake (see accompanying diagram). G1 – G4

Purchased

water intake A purchased water intake refers to the transmission of water from the seller’s

utility to a water treatment plant or directly into the distribution system of the purchaser’s utility. P1, P2

Water treatment plant A facility where water is filtered, disinfected, and/or otherwise treated prior to its

transmission into the distribution system (or its conveyance to another purchasing water utility). For the purposes of this survey, simple disinfection only or pH adjustment prior to entry into the distribution system are considered to be a water treatment plant. WTP 1,

WTP 2

Entry point An entry point is where treated or untreated potable water enters into the

utility’s distribution system. E1 – E4

Figure 1: Sample Diagram of Intakes, Treatment Plants, and Entry Points

# Page 6 of 22



# 9. Please draw your schematic here or submit a schematic on a separate sheet of paper.

# Page 7 of 22



# 10. Provide the following information for the surface water, ground water, and purchased water intakes for this utility: MGD refers to millions of gallons daily. If the source is used on a seasonal basis, the average daily

amount is for the months in which water is drawn from the source.

A. Surface Source.

Surface

water
intake

identifiers What is the source type for each

surface water intake? (circle the appropriate number) Is this a

seasonal

source?

(Circle 1 for yes

and 2 for no)

Yes No What was the

average daily

amount of water

drawn from each

surface water intake during the reporting period in Question 2A? (MGD) What is the estimated

potential maximum daily amount of water

that can be drawn

from each surface water intake, given water availability constraints only (e.g. source capacity

contractual obligations, permits, or legal constraints)? (MGD)* What is the estimated

potential maximum daily amount of water

that can be drawn from

each surface water intake, given current pumping and equipment constraints only (e.g. system components and physical constraints ) ? (MGD) Flowing

stream Reservoir

or lake Groundwater
under the

direct

influence

of surface

water

S1 1 2 3 1 2

S2 1 2 3 1 2

S3 1 2 3 1 2

S4 1 2 3 1 2

S5 1 2 3 1 2

* If not limited enter “no limit” here. Q10A Totals



# B. Ground water source.

Ground

water
wells How many

individual

wells supply

each ground

water
intake? [Very

Large Systems Only]:

What is

the

average well depth? (In feet) [Very Large

Systems Only]: Is the

intake a

confined aquifer? (Circle 1 for yes or 2 for

no e.g. unconfined)

Yes No Is this a

seasonal

source?

(Circle 1 for yes and 2 for no)

Yes No What was the

average daily

amount of water

drawn from each groundwater well during the reporting period in Question 2A? (MGD) What is the

estimated potential maximum daily

amount of water

that can be drawn

from each groundwater well, given water availability constraints only (e.g. source capacity

contractual obligations, permits, or legal constraints)? (MGD)* What is the

estimated potential maximum daily

amount of water

that can be drawn

from each goundwater well, given current pumping and equipment constraints only (e.g. system components and physical

constraints ) ? (MGD)

G1 1 2 1 2

G2 1 2 1 2

G3 1 2 1 2

G4 1 2 1 2

G5 1 2 1 2

* If not limited enter “no limit” here. Q10B Totals

# Page 8 of 22 

# C. Purchased water source.

Purchased

water
intake

identifiers Provide the names of the sellers for this

water Is this a

seasonal

source?

(Circle 1 for yes and 2 for no)

Yes No What was the

average daily

amount of water

drawn from each purchased water intake during the reporting period in Question 2A? (MGD) What is the

estimated potential

maximum

amount drawn

from each purchased water intake given water availability constraints only (e.g. source capacity

contractual obligations, permits, or legal constraints)? (MGD)* What is the

estimated potential

maximum

amount drawn

from each purchased water intake, given current pumping and equipment constraints only (e.g. system components and physical

constraints ) ? (MGD)

P1 1 2

P2 1 2

P3 1 2

P4 1 2

P5 1 2

Q10C Totals

Totals for all intakes Q10A-Q10C (MGD)

* If not limited enter “no limit” here.



# 11. Does your system provide treatment? (Circle one)

Yes

.............................................. 1

No (go to Question 18)

.............................. 2

# Page 9 of 22



# 12. Provide the following information for each water treatment plant or other facility at this utility. Design Capacity refers to the maximum amount the plant can produce in a single 24 hour period with all treatment trains operating at capacity. Peak daily production refers to the maximum amount produced in a single day over the twelve month reporting period in Question 2A. Please submit site plans and flow charts of each treatment facility in your

water system.

Water treatment plant

identifiers List all of the surface, ground, and purchased

water intake identifiers from Question 10 that

feed into each water treatment plant or other facility. What was the average

daily production for

each water treatment plant or other facility? (MGD) What was the peak

daily production for

each water treatment plant or other facility? (MGD) What was the design

capacity for each water treatment plant or other facility? (MGD)

WTP1

WTP2

WTP3

WTP4

WTP5

Note: WTP refers to a treatment plant or any other facility that provides treatment.



# 13. Using the water treatment plant identifiers from Question 12, indicate which water treatment objectives apply to each plant. (Circle 1 for Yes and 2 for No).

Do you have this treatment objective in the following water treatment plant? (use the plant number from Question 12)

WTP1 WTP2 WTP3 WTP4 WTP5

Yes No Yes No Yes No Yes No Yes No

Algae control

....................................... 1 2 1 2 1 2 1 2 1 2

Corrosion control

.................................... 1 2 1 2 1 2 1 2 1 2

Disinfection

........................................ 1 2 1 2 1 2 1 2 1 2

Dechlorination

...................................... 1 2 1 2 1 2 1 2 1 2

Oxidation

.......................................... 1 2 1 2 1 2 1 2 1 2

Iron removal

........................................ 1 2 1 2 1 2 1 2 1 2
Manganese removal

.................................. 1 2 1 2 1 2 1 2 1 2

Fluoridation

........................................ 1 2 1 2 1 2 1 2 1 2

Taste/odor control

................................... 1 2 1 2 1 2 1 2 1 2

TOC removal

....................................... 1 2 1 2 1 2 1 2 1 2
Particulate/Turbidity Removal

.......................... 1 2 1 2 1 2 1 2 1 2
Softening (hardness removal)

........................... 1 2 1 2 1 2 1 2 1 2

Recarbonation

...................................... 1 2 1 2 1 2 1 2 1 2
Organic contaminant removal (e.g., VOCs, pesticides)

....... 1 2 1 2 1 2 1 2 1 2
Inorganic contaminant removal (e.g., arsenic)

.............. 1 2 1 2 1 2 1 2 1 2

Radionuclides contaminant removal

..................... 1 2 1 2 1 2 1 2 1 2

Other ( specify ) 1 2 1 2 1 2 1 2 1 2

# Page 10 of 22



# 14 A. Using the Water Treatment plant identifiers from Question 12, characterize the treatment used and the sequence of treatment for each plant by entering a number to identify the order in which each treatment process occurs for each water treatment plant. (See example. If you have the option of more than one treatment type for a single step – e.g., you can use either chlorine or chlorine dioxide for disinfection – assign the same sequence number to each alternative).

Water Treatment Plant Number (from Question 12)



# Treatment Category Example 1 

# WTP1 WTP2 WTP3 WTP4 WTP5



# Chlorination only Raw water storage/Presedimentation basin Predisinfection/oxidation prior to sedimentation

Chlorine 2

Chlorine dioxide

Chloramines

Ozone Potassium permanganate 3

Other Predisinfection Predisinfection/Oxidation prior to filtration

Chlorine

Chlorine dioxide

Chloramines

Ozone Potassium permanganate

Other Predisinfection Rapid mix Coagulation/ Flocculation Polymers Settling/Sedimentation 4 Softening

Lime/soda ash

Recarbonation Ion exchange

Filtration

Direct filtration

Micro strainer

Slow sand Bag and Cartridge Rapid sand

Green sand 5

Diatomaceous earth

Dual/Multi media

Pressure filtration Other (specify)

Post-disinfection after filters

Chlorine 7

Chlorine dioxide

Chloramines

Ozone

UV Other post disinfection

Clearwell

# Water Treatment Plant Number (from Question 12)



# Treatment Category Example 1 

# WTP1 WTP2 WTP3 WTP4 WTP5

Page 11 of 22 

# Membranes

Reverse osmosis

Micro filtration

Ultrafiltration

Nanofiltration

Corrosion Control

Miscellaneous Ion exchange

Granular activated carbon

Activated Alumina

Aeration 1 Other ( please specify ) 6 1. This is an example of a green sand filter plant for treating ground water for Iron and Manganese removal. In this example

‘other ‘ is contact basin.



# B. Using the Water Treatment plant identifiers from Question 12, indicate which filter backwash techniques you use for each treatment plant that uses filtration. ( Check all that apply ).

Water Treatment Plant Number (from Question 12)

Filter backwash Example WTP1 WTP2 WTP3 WTP4 WTP5

Air scouring

Surface wash x Recycle filter backwash

Filter to waste x
Other filter backwash x

None

# Page 12 of 22



# [QUESTION 15 ASKED OF VERY LARGE SYSTEMS ONLY]

15. Using the identifiers from questions 10 and 12, please list the intake or entry point identifier number and concentration for each water quality parameter (contaminant) for the reporting period recorded in Question 2A. If you conducted multiple tests of a source over the reporting period, report the average concentration. If you did not test for a contaminant mark N/A; if you did not detect a contaminant mark ND. If you require additional space for entry points/well identifiers please attach an additional sheet.

A. Using the source identifiers from questions 10, please provide raw water concentration in units of parts per million (ppm) for each compound:

Intake

Identifier Raw Water Concentration (units- ppm, except Radon - pCi/L)

Arsenic Radon MTBE Atrazine Metolachlor Boron 2,4-D Simazine Glyphosat

e

Example 1:

G-1/W-1 <0.002 N/A N/A N/A N/A N/A ND 0.001 0.01

Example 2:

G-1/W-2 0.002 100 N/A 0.002 N/A N/A ND ND ND

# Page 13 of 22



# B. Using the treatment plant identifiers from question 12, please provide post-treatment concentration in units of parts per million (ppm) for each compound:

Entry

Point

Identifier Treated Water Concentration (units- ppm, except Radon - pCi/L)

Arsenic Radon MTBE Atrazine Metolachlor Boron 2,4-D Simazine Glyphosat

e

Example 1:

WTP-1 <0.002 N/A N/A ND N/A N/A ND 0.001 0.01

Example 3:

WTP-2 0.002 ND N/A ND N/A N/A ND ND ND

# Page 14 of 22



# 16 A. Using the water treatment facility identifiers from Question 12, indicate if the specified residuals management practices are used and provide the requested information regarding potential discharge. ( Circle 1 for Yes and 2 for No ).

Do you use the following residual management process in the following water treatment plants? (use the water treatment plant numbers from Question 12)

Residual Management WTP1 WTP2 WTP3 WTP4 WTP5

Category Yes No Yes No Yes No Yes No Yes No

Mechanical dewatering

........................ 1 2 1 2 1 2 1 2 1 2

Non-mechanical dewatering

.................... 1 2 1 2 1 2 1 2 1 2

Chemical precipitation

........................ 1 2 1 2 1 2 1 2 1 2

Land application

............................. 1 2 1 2 1 2 1 2 1 2

Nonhazardous waste landfill

................... 1 2 1 2 1 2 1 2 1 2

Deep well injection

........................... 1 2 1 2 1 2 1 2 1 2

Evaporation pond

............................ 1 2 1 2 1 2 1 2 1 2

French drain

................................ 1 2 1 2 1 2 1 2 1 2

Direct discharge to surface water

................ 1 2 1 2 1 2 1 2 1 2

If no, is direct discharge to surface water an option? 1 2 1 2 1 2 1 2 1 2

Septic system

............................... 1 2 1 2 1 2 1 2 1 2

If no, is discharge to a septic system an option?

... 1 2 1 2 1 2 1 2 1 2

Sanitary sewer

.............................. 1 2 1 2 1 2 1 2 1 2

If no, is discharge to a sanitary sewer an option?

... 1 2 1 2 1 2 1 2 1 2



# B. Please describe any current limitations on the use of direct discharge to surface water, septic systems, and discharge to sanitary sewer for residuals management at any of the water treatment plants at this utility.

# Page 15 of 22



# 17. Using the water treatment plant identifiers from Question 12, provide the following information regarding operators and SCADA usage at each water treatment plant at this utility. (SCADA Supervisory Control and Data Acquisition system is an automated system for monitoring, controlling, and /or transmitting information on water treatment plant processes).

Water Treatment Plant (use the water treatment plant numbers from

Question 12)

Operator Information WTP1 WTP2 WTP3 WTP4 WTP5

Yes No Yes No Yes No Yes No Yes No

1. Is there an operator on-site 24 hours per day seven days per

week? (Circle yes or no)

........................... 1 2 1 2 1 2 1 2 1 2

2. If the above answer is no, estimate the total number of hours per week that an operator is on site

..................

3. Is there a SCADA in use for process monitoring? (Circle yes
or no)

......................................... 1 2 1 2 1 2 1 2 1 2

4. Is there a SCADA in use for process control? (Circle yes or
no)

........................................... 1 2 1 2 1 2 1 2 1 2



# B. STORAGE AND DISTRIBUTION SYSTEM INFORMATION

18. Please indicate whether you have the following types of treated-water storage, and if so, the number of storage facilities and their capacity, in millions of gallons.

Yes No If yes, what is the total capacity of the storage (in millions of gallons)?

A. Do you have clearwell storage after treatment?

...................... 1 2

B. Do you have storage after treatment (and after clearwell, if any), but before the distribution system with dedicated entry and exit points?

........... 1 2

C. Do you have storage after treatment (and after clearwell, if any), but before the distribution system with a common inlet and outlet (i.e., rides the line) 1 2

D. Do you have storage within the distribution system with dedicated entry and exit points?

.............................................. 1 2

E. Do you have storage within the distribution system with a common inlet and outlet (i.e., rides the line)?

................................... 1 2

# Page 16 of 22



# 19 A. Estimate the length of the distribution mains pipe in your system, and length of pipe replaced in the last five

years.

Pipe Diameter Length of Pipe (In Miles) Length of Pipe Replaced in

the Last 5 Years 1


# (In Miles) Total Cost of Pipe Replaced in

the Last 5 Years 1


# (In Dollars)

Less than or equal to

6"

Greater than 6" but less than or equal to

10"

Greater than 10"


# 1.Ending on the date shown in your answer to Question 2A.

B. What percentage of the total length of pipe in the distribution system is less than 40 years old, between 40 and 80 years old, and more than 80 years old? ( The percentages should total 100 percent .)

1. Less than 40 years old

.............................. %

2. Between 40 and 80 years old

........................ %

3. More than 80 years old

............................. %

20. A. How many people and connections does your system currently serve year round ? Please indicate the number of connections and number of people served by your system for all customer types that apply. (If you cannot distinguish among the different types of non-residential customers, enter the total for your

non-residential customers in line c.4. )

Customer Type Connections Number of People

a. Sold to other public water suppliers

1. Treated water

................................

2. Untreated water

..............................

b. Residential

..........................................

c. Non-residential

1. Commercial/industrial

.........................

2. Agricultural

.................................

3. Other (specify)

4. Subtotal, non-residential

........................

# Page 17 of 22



# [QUESTIONS 20 B. AND 20 C. ASKED OF SMALL, MEDIUM, LARGE SYSTEMS ONLY]

B. Does your system serve a residential population that changes on a seasonal basis (for example, is it a winter or summer resort area)? (Circle one)

Yes

.............................................. 1

No (Go to Question 21)

.............................. 2

C. If your system serves a population that changes on a seasonal basis, please indicate the highest seasonal number of people (residential only), the highest number of residential connections and the number of months each year during which the seasonal population is the highest.

1. Highest seasonal population

..........................

2. Highest number of seasonal residential connections

.......

3. Number of months when seasonal population is highest

....

21. Please enclose a map of your service area

C. CROSS CONNECTION CONTROL

22. Does your system have a cross connection control (CCC) program? (Circle one)

Yes

............................................... 1

No (Go to Question 26)

............................... 2

Don’t Know (Go to Question 26)

....................... 3

23. Please indicated the type of program your system has. (Circle one)

Containment (A program that is designed to prevent backflow from reaching a publicly

owned distribution system, but does not provide protection within the premises. This often is referred to as providing protection up to the meter.)

......... 1

Containment

and isolation (A program that is designed to prevent backflow from reaching a publicly

owned distribution system and provides protection within a customer's premises. This often is referred to as providing protection up to the tap.)

........... 2

# Page 18 of 22



# 24. Please indicate which elements are included in the CCC program: (Circle 1 for "ye s" and 2 for "no")

Cross Connection Control Does your program

include this element?

Program Elements Yes No

a. Right of entry

.................................. 1 2

b. Surveys/inspections to identify cross connections within the system/facility

............................... 1 2

c. Policy specifying which service connections must be equipped with backflow prevention device/assemblies

. . 1 2

d. Enforcement authority to install devices/assemblies.

.... 1 2

e. Enforcement authority to test assemblies

............. 1 2

f. Penalties for non-compliance

with ordinance

................................. 1 2

g. Public education programs

........................ 1 2

h. Training/certification of testers and inspectors

.................................. 1 2



# 25. What percentage of backflow prevention assemblies that are tested fail annually during inspection? ( An assembly is a device that can be tested)

................ %

# Page 19 of 22



# Part II – Financial Characteristics

Reporting period : For Part II of the survey, please use the period indicated in Question 2(B) to report “last year’s” financial data.

Providing estimates : Please provide exact information from your system’s records. Otherwise, provide your best estimate of financial information that is applicable to your drinking water system.

If your system is a joint drinking water/wastewater facility, please be careful to record only data that are relevant to the drinking water part of the facility. If data for the drinking water part of the facility are not kept separately, please provide your best estimate of the share that is attributed to drinking water.

Rounding: Please record your dollar amounts to the nearest dollar. Do NOT record cents.

26 A. During the last year [as defined in your response to Question 2(B)] what were your drinking water system’s revenues from water sales for each of the following customer categories. (If zero, enter "0". Note: if you cannot distinguish among the different types of non-residential customers, enter the total for your non-residential customers in line d.)

Water Sales Customer Categories Water Sales Revenues

1. Sold to other water suppliers

a. Treated water

...................................... $

b. Untreated water

.................................... $

2. Residential

............................................ $

3. Non-residential

a. Commercial/industrial

............................... $

b. Agricultural

....................................... $

c. Other (please specify) $

d. Subtotal, nonresidential (a - c)

......................... $

4. Total water sales revenues (1-3)

............................ $

# Page 20 of 22



# B. Please indicate your water system’s revenues during the last year from other water-related revenue sources. (If zero, enter ‘0’)

Water-related Revenues

5. Connection fees

....................................... $

6. Development fees

...................................... $

7. General fund revenues (e.g., from municipalities)

............. $

8. Other water revenues not reported in the categories above (e.g., fines, penalties, other fees)
( Please specify) $

9. Total water-related revenues

............................. $



# C. Please indicate your total water system revenues from lines 4 and 9 above.

10. Total water system revenues (lines 4 + 9)

................ $

[QUESTION 27 ASKED OF SMALL, MEDIUM, AND LARGE SYSTEMS ONLY]

27. If your primary business is not water-related and you reported no revenues in Question 26 A or B, please indicate the revenues you receive from your primary, non-water related business, including rental income and the sale of other goods or services

........ $

Note : Questions 28 - 30 Refer to Residential Customers Only

28. What is the average annual bill for a residential customer?

............ $

29. Please identify your drinking water system’s billing structure for residential customers (circle all that apply)

.

Billing

structure (Circle all that apply)

Metered charges

Uniform rates

..................................................................... 1

Declining block rate

................................................................ 2

Increasing block rate

................................................................ 3

Peak period rate (e.g., seasonal)

...................................................... 4

Unmetered charges

Separate flat fee for water

............................................................ 5

Combined flat fee for water and other services (e.g., rental fees, associate feeds, pad fees)

......... 6

Other billing methods ( Please specify ) 7

# Page 21 of 22



# 30 A. Does your system use rates that may lower the cost of drinking water for low-income or fixed-income households? (e.g., lifeline rates) (Circle one) ?

Yes

............................................... 1

No (Go to Question 31)

............................... 2

B. If your system uses rates that lower the cost of drinking water for low-income or fixed-income households, please answer the following:

1. How many households receive these rates?

............ (Number of households)

2. What is the highest annual income that qualifies for these

rates? .

........................................ (Dollars per year)

3. How much does it cost your system to provide these rate reductions (i.e., what is the total dollar amount of the reductions)?

.................................... (Dollars per year)



# 31. Question 31 is intended to account for all of your drinking water expenses related to the revenues referred to in question 26 A and B.

A. Please enter the number of people employed by your drinking water system and your system’s total compensation expenses (including direct compensation and fringe benefits) in the last year: If your system is operated by or employs a contractor, enter the number of contract employees and total expenses of the

contractor on line 2.

Last year’s employment and compensation

1. Number of Employees 2. Total Expenses, including fringe benefits (in Dollars)

1. Employment and employee expenses

....... $

2. Contractor expenses

.................... $



# B. Please enter other routine operating expenses in the last year (in dollars)

...... $

C. Please enter the amount of debt service expenditures in the last year for borrowing to finance capital expenses (i.e., excluding expenditures for borrowing to finance operating expenses, in dollars)

...................... $

D. Please enter the amount of other expenses (excluding operating and debt service expenses reported in Parts A, B, and C, but including any debt service expenditures for borrowing to finance operating expenses) in the last year (in dollars) ( Please specify )

..... $

E. Total expenses, Parts A through D. (in dollars)

.......................... $

# Page 22 of 22



# 32. A. If you have paid for major capital improvements, repairs, or expansion in the last five years ending on the date reported in Question 2B, allocate those expenditures to the following categories.

Type of Expense Total

1. Land

................................................ $

2. Water source

.......................................... $

3. Distribution and transmission system

....................... $

4. Treatment

............................................ $

5. Storage

.............................................. $

6 All other not included above

............................. $

7. Total capital expenses

.................................. $



# B. What percent of the total capital expenditures from Line 7 of Part A was for water quality improvement, replacement or major repair, or system expansion.? ( The percentages should total to 100 percent. )

1. Water quality improvements

....................................... %

2. Replacement or major repair

...................................... %

3. System expansion

............................................... %

C. How were the total expenses from Line 7 in Part A funded?

Source of funds Percentage of capital expenses

funded from

each source (Should sum to 100%) Average Interest

Rate

1. Current revenues

......................................... %

2. Grants from the Drinking Water State Revolving Fund

............ %

3. Other government grants (either Federal or State)

................ %

4 Borrowing from the Drinking Water State Revolving Fund

......... % %

5. Borrowing from other public sector sources (e.g., state or regional authorities)

.............................................. % %

6. Borrowing from private sector sources (e.g., banks or the bond market) % %

7. Other (please specify ) % %

# THIS PAGE INTENTIONALLY LEFT BLANK

# Office of Water (4607M)

E P A 815-R-02-005B

December 2002
www.epa.gov/safewater

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