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# 1 SURVEY OBJECTIVES, KEY VARIABLES, AND OTHER

PRELIMINARIES

1(a) Survey Objectives

For CWNS 2012, s tates will have the option to use the “Traditional” CWNS Method or a

new “Gap Approach” option. The primary objective of the statistical methods applied in

Section B of this information collection is for EPA to identify and select a sample of

wastewater s ys tems that is representative of s ys tems within each state that chooses to

participate in the GAP Approach to estimate the needs for the 2012 CWNS. For the

selected sample of wastewater s ys tems, states will collect information about asset

inventory that will be used by

EPA to estimate asset replacement cost. The

representativeness of this sample of s ys tems at the state level is critical to the CWNS

because the estimated costs will be used to generate the CWNS Report to Congress,

which presents costs data at the state level.

1(b) Key Variables

The key variables associated with selecting a representati ve sample of wastewater

sy stems at the state level are: s ys tem size (by population served), CWNS 2008 needs, and

sy stem t ype (i.e., combined sewer s ys tem or separate sewer s ys tem).

1(c) Statistical Approach

In the previous data collection efforts for the CWNS a census approach (Traditional

Approach) was used. For the CWNS 2012 EPA is providing states the option of using a

more compressive infrastructure GAP Approach to estimate the needs for wastewater

sy stems. This new approach will require participating states to submit significantly more

information for each s ys tem, so selection of a sample of sy stems for participation allows

for significant burden and costs savings as compared to a census approach.

1(d) Feasibility

EPA anticipates that the survey (the statistical sample) objectives are achievable given

the existing time and resource constraints.

 State participation in the GAP Approach for CWNS is voluntary

.

 There will be an electronic version of the form (with picklists and calculations

coded in).

 The statistical approach to this data collection requires only a fraction of sy stems

to complete the GAP form, resulting in equivalent or smaller cost and burden at

the state level than would be incurred if all s ys tems participate in CWNS

 The survey

resu lts will be completed in time to inform the corresponding cy cle of

CWNS.

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# 2 SURVEY DESIGN

2(a) Target Population and Coverage

Existing p ublic wastewater sy stems are the target population for CWNS GAP Approach

methodology

.

2(b) Sample Design

2(b)(i) Sampl ing Frame

For each participating state, EPA will develop the sample frame for the statistical

selection of wastewater systems. Initial data will be pulled from the 2008 CWNS

. Only

those sy stems in operation in 2008, expected to be in operation in the futur e, and

reporting documented needs were used to estimate the sample characteristics, but the

sample size calculations was applied to all wastewater sy stems , regardless of their

reporting of needs. The initial universe will be adjusted to account for known a nomalies

inventory reporting (For example, states will be able to inform EPA about existing

sy stems that were not entered in the 2008 CWNS or that were entered but not submitted

for review).

2(b)(ii) Sample Size

Final sample sizes for participating states will be determine once the state makes a

decision to be part of the GAP Approach methodology . Preliminary sample sizes were

estimated by

EPA and are presented in Appendix A. T he sample design limits strata with

less than 10,000 people to having a maximum error of 80% and strata of more than

10,000 people to having a maximum error of 40%. All facilities in the state’s top 3%

based on population will be included in the sample frame.

Ty pical sample rates are expected to be:

 10

- 25% for facilities serving less than 10,000 people

 30

- 60% for facilities serving between 10,000 and 100,000 people

 100% (census survey ) for the largest 3% of facilities in each state

2(b)(iii) Stratification Variables

In developing the representative sample, EPA considers factors such a s population served

and geographic location. For each state the sample sy stems will be stratified by

population served (s ys tem size).

2(b)(iv) Sampling Method

The proposed sampling design is stratified random sampling. For each state t he number

of strata and stratification limits will be determined based on the population

characteristics of the state and a representative sample of sy stems from each of the strata

will account for different sy stem sizes . EPA will include at least three s ys tems from each

str atum for each state.

# 3 2(b)(v) Multi

- Stage Sampling

EPA does not anticipate the need for multi

- stage sampling. Wastewater s ys tems statuses

often change little over short periods of time, so significant changes from the 2008 are

not expected.

2(c) Precision Requirements

2(c)(i) Precision Targets

For each state the sample design is selected based on two conditions:

 The total needs would be estimated within close to ± 10 percent of the amount of

the true need within a 95% confidence interval, and

 Each stratum consisting of less than 10,000 people would have an error of ± 80

percent, and each stratum consisting of more than 10,000 people would have an

error of ± 40 percent.

For most states one of the two conditions above drives the sample design. In cases wher e the individual stratum error drives the results, the total error will be less than 10 percent.

Alternativel y, where the total error drives the results, states will have stratum errors that

are less than the 80 percent or 40 percent bounds.

2(c)(ii) Non

- sampling error

Sy stems that do not complete the questionnaire will be considered as s ys tems without

justification for needs, and will be included as such in the anal ys is. This is consistent

with how these facilities are handled in the CWNS Traditional Met hod. Given that many

less facilities are involved under the Gap Approach, states utilizing the gap approach will

have a much greater ability to follow up with facilities on completing the form. Since

non

- completion of questionnaire will be assessed as a sy stem not having justification for

needs, and since CWNS 2012 results may be used to determine states’ Clean Water State

Revolving Fund allocations, states will have a high incentive to obtain very close to

100% form completion.

2(d) Questionnaire Design

The GAP Data Request form was design to minimize data entry by pre

- populating it with

data currentl y in the CWNS DEP. See Appendix B for the draft form.

Other features of the form are:

 The form will have optional extra pages for entering additional asset inventory

(section 5) information.

 The form will have a companion (~2 page) instructions document.

 There will be an electronic, editable version of the form (with picklists and

calculations coded in). Like the hard cop y form, this electronic Gap Approach

form will be pre

- populated with the most current CWNS data.

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 Asset replacement costs are not requested in an y versions of the form. These

costs will be calculated in the CWNS DEP based on other data entered in the form

 All data in the form is required, e xcept where indicated b y the italic text (several

rows in page 4 tables, and far right 3 table columns on pages 5

- 7)

The form is divided into 6 sections, each with data item request that meet a clear and

specific objective:

Sections 1 to 4 : Basic s ys tem d ata. These four sections provide the information

necessary to identify

and characterize the s ys tem. Most of the information will be

pre

- populated but the respondents will have the ability to change any

of the data

items.

Section 5 : Revenues and Expenses . D ata items in this section are necessary to

anal yz e the financial situation of the sy stem. Most data item are voluntary with

only the totals denoted as mandatory

. Section 6 : Asset I nventory . This is the most extensive section of the questionnaire

and will allow EPA to estimate the ty pe of asset, anticipated failure and

replacement or rehabilitation costs. The data items required should be readily

available to most operators or managers.

Section 7 : Certification . Signature requirements guarantee the validity of the data.

EPA is implementing a tiered certification with smaller sy stems having less

stringent requirements.



# 3 PRETESTS AND PILOT TESTS

The “Gap Approach” option is modeled after an asset management needs assessment

approach used in Penns yl vania’s 20 08 Governor’s Report on Sustainable Infrastructure.

For the 2008 CWNS, the state of Penns yl vania, in collaboration with EPA, conducted a

sample of their wastewater s ys tems and estimated their infrastructure needs using a GAP

methodology

approach. This stud y in Pennsylvania served as the pilot test for the nation

wide CWNs GAP initiative to be included in the 2012 CWNS. The original Form used in

Pennsy lvania has been modified based on lessons learned and input from the other states

that are interested in usi ng the GAP methodology for 2012.



# 4 COLLECTION METHODS AND FOLLOW

- UP

4(a) Collection Methods

CWNS coordinators from states participating in the GAP approach methodology will

have flexibility

to choose the collection method that best fits the characterist ics of their

state. EPA is providing multiple options and flexibility to facilitate the data collection

effort b y states:

 Forms will being pre

- populated with data currently in the 2008 CWNS.

 Forms will have a barcode CWNS I D #, so that forms faxed in can be connected

for facilities within the CWNS DEP.

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 There will be either an electronic version of the form (with picklists and

calculations coded in)

4(b) Survey Response and Follow

- up

High compliance levels (97%) during Penns yl vania’s effort in 2008 have given EPA

confidence that equivalent levels can be achieved during 2012 in other states. EPA plans

to continue outreach and compliance assistance efforts, as needed.



# 5 ANALYZING AND REPORTING SURVEY RESULTS

5(a) Data Preparation

States are ultimately

responsible for collecting and entering the information into the

CWNS DEP and for the quality of the data entered. The DEP is equipped with automatic

error checks to identify

sy stems tha t fall outside certain normal parameter and during the

data entry period of the CWNS 2012 EPA and its contractors will perform reviews of the

information and documentation submitted.

5(b) Analysis

Data collected with the Gap Approach will be analyzed alon gside other CWNS data to

develop a much more complete picture of wastewater facility sustainability, with s tate

level estimates on capital and O&M needs, revenues, and gaps projected over 20 years.

5(c) Reporting Results

Capital needs from the Gap Approach will be reported alongside Traditional Method

capital needs in the CWNS 2012 Report to Congress. Additionally , a new section will be

added to the Report that summarizes data from states participating in the Gap Approach

to draw sustainable infrastructure conclusions (e.g. the gap between projected capital and

O&M needs and expected revenues).

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# Appendix A

– Draft Sample Sizes by State

N

(s ys tems) n

(s ys te ms ) n/N, %

(s yst ems ) N

(F ac il it ies ) n (faci lities

es timated) N

(s ys tems) n

(s ystems ) n/N, %

(s yst ems ) N

(Fa ci li ti es ) n ( fac il it ies

es timated) N

(s ystems ) n

(s ystems ) n/N , %

(s ystems) N

(F ac ili ties) n ( fac il it ie s

es timated)

AL 218 26 11.9% 223 28 55 18 32.7% 62 20 273 44 16.1% 285 48

AR 336 279 83.0% 376 315 36 36 100.0% 62 62 372 315 84.7% 438 377

AZ 52 7 13.5% 61 9 48 21 43.8% 88 55 100 28 28.0% 149 64

CA 51 12 23.5% 54 13 110 28 25.5% 260 113 161 40 24.8% 314 126

CO 203 52 25.6% 212 56 26 26 100.0% 31 31 229 78 34.1% 243 87

CT 44 17 38.6% 55 23 35 28 80.0% 63 51 79 45 57.0% 118 74

DE 13 9 69.2% 23 17 3 3 100.0% 12 12 16 12 75.0% 35 29

FL 173 17 9.8% 177 20 178 43 24.2% 240 85 351 60 17.1% 417 105

GA 259 12 4.6% 275 15 41 14 34.1% 60 27 300 26 8.7% 335 42

ID 147 25 17.0% 164 30 16 12 75.0% 38 29 163 37 22.7% 202 59

IL 509 252 49.5% 535 262 76 64 84.2% 160 143 585 316 54.0% 695 405

IN 284 250 88.0% 303 269 19 19 100.0% 28 28 303 269 88.8% 331 297

IA 709 136 19.2% 722 142 19 19 100.0% 37 37 728 155 21.3% 759 179

KS 580 246 42.4% 598 252 35 22 62.9% 81 59 615 268 43.6% 679 311

KY 122 26 21.3% 143 35 30 26 86.7% 44 39 152 52 34.2% 187 74

LA 121 26 21.5% 141 31 33 15 45.5% 57 27 154 41 26.6% 198 58

MA 64 20 31.3% 69 22 34 15 44.1% 76 42 98 35 35.7% 145 64

MD 118 17 14.4% 140 24 27 15 55.6% 52 31 145 32 22.1% 192 55

ME 97 63 64.9% 110 74 4 4 100.0% 9 9 101 67 66.3% 119 83

MI 324 90 27.8% 371 114 65 52 80.0% 336 296 389 142 36.5% 707 410

MN 108 12 11.1% 124 16 27 21 77.8% 150 140 135 33 24.4% 274 156

MO 619 242 39.1% 689 269 44 42 95.5% 123 121 663 284 42.8% 812 390

MS 268 113 42.2% 316 136 35 32 91.4% 117 110 303 145 47.9% 433 246

MT 116 42 36.2% 121 46 8 8 100.0% 15 15 124 50 40.3% 136 61

NC 240 13 5.4% 338 21 73 27 37.0% 198 82 313 40 12.8% 536 103

NE 449 198 44.1% 451 200 12 12 100.0% 15 15 461 210 45.6% 466 215

NH 69 38 55.1% 77 42 12 12 100.0% 28 28 81 50 61.7% 105 70

NJ 67 7 10.4% 90 10 70 53 75.7% 284 245 137 60 43.8% 374 255

NV 31 12 38.7% 34 15 11 10 90.9% 37 36 42 22 52.4% 71 51

NY 433 32 7.4% 527 48 67 36 53.7% 194 113 500 68 13.6% 721 161

OH 503 256 50.9% 623 326 88 78 88.6% 178 161 591 334 56.5% 801 487

OK 446 266 59.6% 448 267 39 32 82.1% 46 39 485 298 61.4% 494 306

OR 86 39 45.3% 90 42 36 16 44.4% 75 42 122 55 45.1% 165 84

PA 589 262 44.5% 818 396 104 99 95.2% 337 324 693 361 52.1% 1,155 720

PR 18 6 33.3% 19 7 25 9 36.0% 25 9 43 15 34.9% 44 16

SC 136 103 75.7% 148 115 17 17 100.0% 45 45 153 120 78.4% 193 160

SD 20 12 60.0% 20 12 5 5 100.0% 5 5 25 17 68.0% 25 17

TN 182 128 70.3% 202 144 54 48 88.9% 85 76 236 176 74.6% 287 220

TX 291 15 5.2% 318 19 149 65 43.6% 382 227 440 80 18.2% 700 246

UT 80 14 17.5% 97 19 23 12 52.2% 94 63 103 26 25.2% 191 82

VA 176 11 6.3% 258 18 42 26 61.9% 103 68 218 37 17.0% 361 86

VT 62 43 69.4% 70 51 3 3 100.0% 5 5 65 46 70.8% 75 56

WA 59 10 16.9% 69 14 19 10 52.6% 43 27 78 20 25.6% 112 41

WI 531 77 14.5% 669 105 56 40 71.4% 263 225 587 117 19.9% 932 330

WV 176 54 30.7% 201 67 11 11 100.0% 27 27 187 65 34.8% 228 94

WY 84 75 89.3% 92 83 11 11 100.0% 25 25 95 86 90.5% 117 108

TO TAL 9,939 3,572 35.9% 11,290 4,125 1,866 1,163 62.3% 4,359 3,173 11,805 4,735 40.1% 15,649 7,708 < 10 K > 10 K To ta l