Tetra Tech, Inc.

10306 Eaton Place, Suite 340

Fairfax, VA 22030

phone 703-385-6000

fax 703-385-6007

TO: Paul Shriner, EPA

FROM: John Sunda (SAIC) and Kelly Meadows

DATE: March 23, 2011

SUBJECT: 316(b) Existing Facility Cost Tool

For the 2004 Phase II rule, EPA developed a 

application of a number of different intake technologies and upgrades to individual 

facility intakes. Various intake attributes, such as t

flow rate, existing control technologies, expected performance standards, and other 

parameters, were used to determine an appropriate compliance technology. 

use does vary by type of facility, the types of intake structures and intake t

not different between Phase II and Phase III facilities. 

same compliance technologies used in Phase II were appropriate for Phase III

For the Phase III Rule, EPA developed a cost tool that incorpo

equations and cost development methodology

tool was a spreadsheet program that created intake

compliance costs. The use of this program makes multiple cost cal

transparent, and reproducible. 

appropriate technologies based on compliance requirements

various EPA rule options.

The scope of facilities subject to the proposed existing facility rule includes both Phase II 

and Phase III facilities. Since Phase III already included 

power generating facilities, the 

facilities. EPA further updated and 

corrections, methodology changes

development of the existing facility rule, EPA evaluated a number of diffe

compliance options for both impingement mortality and entrainment mortality reduction. 

MEMORANDUM

10306 Eaton Place, Suite 340

Paul Shriner, EPA

John Sunda (SAIC) and Kelly Meadows

March 23, 2011

316(b) Existing Facility Cost Tool

EPA developed a compliance cost methodology based on the 

application of a number of different intake technologies and upgrades to individual 

Various intake attributes, such as the intake type, location, size,

flow rate, existing control technologies, expected performance standards, and other 

were used to determine an appropriate compliance technology. While water 

does vary by type of facility, the types of intake structures and intake technologies are 

not different between Phase II and Phase III facilities. EPA subsequently concluded the 

same compliance technologies used in Phase II were appropriate for Phase III

EPA developed a cost tool that incorporated the Phase II 

and cost development methodology for each compliance technology. 

tool was a spreadsheet program that created intake-specific or facility-specific 

The use of this program makes multiple cost calculations rapid

and reproducible. The cost tool also included algorithms that helped select 

appropriate technologies based on compliance requirements, known site conditions

The scope of facilities subject to the proposed existing facility rule includes both Phase II 

Since Phase III already included existing manufacturing and 

, the cost tool was already designed for use with both kinds of 

further updated and modified the Phase III cost tool to incorporate 

methodology changes, and additional compliance options. During the 

development of the existing facility rule, EPA evaluated a number of different 

compliance options for both impingement mortality and entrainment mortality reduction. 

based on the 

application of a number of different intake technologies and upgrades to individual 

he intake type, location, size, design 

flow rate, existing control technologies, expected performance standards, and other 

While water 

echnologies are 

concluded the 

same compliance technologies used in Phase II were appropriate for Phase III facilities.

Phase II cost 

for each compliance technology. The cost 

specific 

culations rapid, 

The cost tool also included algorithms that helped select 

known site conditions, and 

The scope of facilities subject to the proposed existing facility rule includes both Phase II 

existing manufacturing and 

h both kinds of 

cost tool to incorporate 

compliance options. During the 

rent 

compliance options for both impingement mortality and entrainment mortality reduction. 
- 2 -

As such, the technology selection component has been modified several times in order to 

model different approaches with respect to compliance requirements and technology

capabilities. Some methodology changes were made as well and are discussed in detail 

in Chapter 8 of the Technical Development Document (TDD).

A major modification to the compliance technology selection process resulted from the 

re-evaluation of the entrainment reduction capabilities of the suite of technologies. The 

result was that EPA’s compliance assumptions do not rely upon any of the intake 

technologies as the means to comply with entrainment mortality reductions. Entrainment 

reduction compliance costs are instead based on closed-cycle cooling and were developed 

using a separate methodology.

1 As a result, the current version of the cost tool was 

utilized to derive costs for compliance with IM reduction requirements only. Also,

certain input values (e.g., “Capacity Utilization, “River Proportional Flow”) that were 

used in the previous rulemaking efforts as criteria for specifying compliance 

requirements were not used in this effort. In addition, due to revisions to the technology

selection process, certain input values are not used in the active algorithms and are no 

longer functional, but have been retained in the current version of the cost tool. These are 

identified on the user input sheet and in the description below.

The tool accepts site-specific intake data, executes the cost derivation methodology and 

analysis and then outputs a set of costs for use in compliance option evaluation. The 

intake-specific data and cost information used by EPA is generally handled as 

confidential business information (CBI), but EPA has made available this cost tool 

(without the facility-specific input data) so that the cost methodology is transparent. To 

provide for greater flexibility in use, an input variable has been added to allow users to 

select compliance technology modules under consideration and obtain separate costs for 

each. This allows potentially regulated facilities to use the cost tool to predict EPA’s 

compliance cost estimates for various alternatives.

The development of the cost technology modules is described in Chapter 1 of the Final 

Phase II Rule Technical Development Document (DCN 6-0004, FDMS ID EPA-HQOW-2002-0049-1462). The initial development of the cost tool is described in detail in 

Chapter 5, Section 2 of the Phase III Technical Development Document (DCN 9-0004, 

FDMS ID EPA-HQ-OW-2004-0002-1543). Additional modifications to the cost 

development methodology are described in Chapter 8 of the Technical Development 

Document for this existing facility proposed rule. The cost tool will compute compliance 

costs for the individual cost modules developed under Phase II plus several combinations 

listed in Table 1 below:

Table 1. Module Technology Description

Module # Description

1 Replace Traveling Screen with Ristroph Screen and Add Fish Handling and Return System

2 Replace Traveling Screen with Fine Mesh Ristroph Screen and Add Fish Handling and Return System

2a Add Fine Mesh Screen Overlays Only

3 Add New Larger Intake Structure with Double Entry, Single Exit Traveling Screen with Fish Handling and Return

 

1

See the TDD for a description of the EPRI tool for developing retrofit cooling tower costs.
- 3 -

4 Add Passive Fine Mesh Wedgewire Screens (1.75 mm mesh) at Shoreline

5 Add Fish Barrier Net

6 Add Aquatic Filter Barrier (Gunderboom)

7 Relocate Intake to Submerged Offshore with Passive Wedgewire Screen (1.75 mm mesh)

8 Add Velocity Cap at Inlet

9 Add Passive Fine Mesh Wedgewire Screen (1.75 mm mesh) at Inlet of Offshore Submerged

10.0 Combination of Module 2 and Module 5

10.1 Combination of Module 2a & Module 5

10.2 Combination of Module 3 & Module 5

10.3 Combination of Module 1 & Module 5

10.4 Combination of Module 1 & Module 8

11 Add Double-Entry, Single-Exit Traveling Screen with Fish Handling and Return

12 0.75 mm Passive Fine Mesh Wedgewire Screen at Shoreline (For Estuary & Ocean only)

13 0.75 mm Passive Fine Mesh Wedgewire Screen at Inlet of Offshore Submerged (For Estuary & Ocean only)

14 Relocate Intake to Submerged Offshore with 0.75 mm Passive Wedgewire Screen (For Estuary & Ocean only)

The Cost Tool Structure

The cost tool program makes use of basic database retrieval functions and logical 

statements to mirror the costing methodology hierarchy used by EPA for development of 

the existing facility technology costs to comply with impingement mortality reduction 

requirements. The cost model described here modifies the cost tool to Version 6.1 which 

calculates the costs the Agency developed and considered for the proposed existing 

facility rule. The cost tool combines the varied analyses and data presented in the TDD 

into an automated decision tree that ultimately assigns a technology cost to each facility.

In the “User Inputs” sheet of the cost tool, the user supplies data at the facility level, or 

the user may choose to input information at the intake level where multiple intakes at a 

single facility have different features that might affect which technology modules are 

feasible for each intake. Once the “user inputs” have been entered, and as long as the 

“Qualified Impingement?” box is left blank, the cost tool will apply EPA’s decision tree 

for assigning site-specific cost modules for IM reduction compliance; see Exhibit 8-1 in 

Chapter 8 of the TDD for a schematic of this decision tree. Finally, the costing 

methodology is performed through a combination of calculations and functions (that is, 

an algorithm). This work is mostly carried out in the sheet titled “Calc. and Data” and is 

supplemented by a few logical functions and data retrieval in the “Output” sheet. The 

cost outputs include capital costs, incremental O&M costs, and downtime (in weeks).

The data fields requested in the “User Inputs” sheet (see Figure 1 below) come from 

questions in the 2000 industry technical questionnaires sent to facilities plus a few basic 

observations about the intake, such as a judgment about the degree of debris loading at 

the intake: “high” or “low.” The program reproduces the methodology the Agency

utilized to develop final costing decisions to determine which technology would best suit 

a particular intake.
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If multiple sets of intake/plant data are to be run, the input data can be entered on separate 

lines in the “Macro Input” worksheet. Then if the “AutoInput” macro is run, the 

corresponding output data is copied into the “Macro Output” worksheet. For individual 

computations, data can be entered directly into the “User Inputs” worksheet and the 

calculated costs can be read directly from the “Output” worksheet. Figure 1 presents a 

screen shot of the “User Inputs” page.

Figure 1

Screenshot of User Inputs Sheet

Cost Tool Inputs

This section describes the inputs to the Cost Tool (see Figure 1), and defines the default 

values used. The default values are used when input values are left blank. Modifications 

User Inputs -- At The Intake Level

Facility Information Tables/Keys

Facility Type = ( 3 = Manufacturer, 2 =Power Generation) (Required Field)

Cooling System Type = ( 1 = Full Recirculation, 2 = Cooling Ponds, 0 = All Others) Intake Location / Description

1 = Shoreline Intake (flush, recessed)

State Abbreviation = (Required Field) 2 = Intake Canal

3 = Embayment, Bay, or Cove

Waterbody Type = (1=Ocean, 2=Estuary, 3=Great Lake, 4=Fresh River, 5=Lake/Res.) 4 = Submerged Offshore Intake

5 = Near-shore submerged intake

Fuel Type = (1 = Nuclear, 0 = Non-Nuclear) 6 = Shoreline Submerged Intake

Capacity Utilization (1996-99) = % (No Longer in use) Impingment Technologies In-place

0 = None of those listed

Intake Location / Description (choose from Description table at right) (Required Field) 1 = Traveling Screens 

Distance Offshore for Submerged Inlet ft (use for submerged offshore technologies) Dam, Leaky Dike, 

3 = Barrier Net

Canal Length = ft (if canal is present between mouth and screens) 4 = Fish Diversion or Avoidance (Louvers, Acoustics, etc.)

5 = Wedgewire Screens

Navigation / Waterbody Use (1 = boat/barge navigation near intake, No longer in use) Through Screen Velocity Flow Basis

 1 = Existing Equipment Design Intake Flow 

Mean Intake Water Depth = ft 2 = New Design Intake Flow 

3 = Average Intake Flow

Intake Well Depth = ft

In-place Tech EPA "Qualified" for Impingment Reductions

River Proportional Flow = (No Longer in use) 0 = none

1 = Fish Handling and Return Systems & Ristroph Traveling Screens or 

Existing Equipment Design Intake Flow = gpm(Required Field) Passive Intakes (velocity cap, t-screens, porous dams, etc.)

2 = Through screen velocity of .5 fps or less only

New Design Intake Flow = gpm (Use only if new technology will use different design flow)

Entrainment Technologies In-place

Average Intake Flow = gpm(Required Field) 0 = None of those listed

1 = Traveling Screens w/ Fine Mesh

Existing Through Screen Velocity = fps (defaults will be used if left blank) 2 = Far Offshore Intake

3 = Passive Screens w/ Fine Mesh

Through Screen Velocity Flow Basis = ( Choose from Through Screen Velocity Flow Basis list at right

In-place Tech EPA "Qualified" for Entrainment Reductions

Water Type = (1 = marine, 0 = fresh) Fine Mesh Screens (passive or traveling screens)

Far Offshore Intake w/ Passive Intake at Inlet

Debris Loading = (1 = high, 0 = normal)

Recent ENR Construction Cost Indeces

Impingement Tech In-Place = (choose from Impingment Tech list at right) Year Index

2002 (Default) 6538

Qualified Impingement? = (1 or 2 = Qualified, 0 = none; see impingement reduction table to right) 2003 6694

2004 7115

Entrainment Tech In-Place = (choose from Entrainment Tech list at right - No Longer in use) 2005 7446

2006 7751

Qualified Entrainment? = (1 = Qualified, 0 = none; No longer in use) 2007 7966

2008 (October) 8623

avg annual generation '96 - '99 = (MWh, reported data, excluding outliers, EG only) 2009 (February) 8533

Selected Technology Module = (Technology Module will be selected for you if left blank)

Regional Cost Factor = ( 1.0 = National Average - Leave blank for default state average)

ENR Construction Cost Index = ( Inflation Index for desired cost year - see table at right)

Compliance Screen Mesh (mm) = (Select from 9.5, 2.0, 1.0, 0.5 - default = 2.0))

Screen Velocity for Module 3 (fps) = (default is 1.0 fps)

Maximum Acceptable Screen Velocity (fps) = (Used to dertermine if existing technology must be replaced)

2 = Passive Intake (Velocity Cap)
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to the previous Phase III version of the cost tool include the addition of the following 

input variables:

 New Design Intake Flow (gpm)

 ENR Construction Cost Index 

 Compliance Screen Mesh (mm)

 Screen Velocity for Module 3 (fps)

 Maximum Acceptable Screen Velocity (fps)

The input variables in the current cost tool are described below:

Facility Type: This input value was added to allow for proper selection of default input 

values to the cost tool for different types of facilities (“3” = Manufacturer; “2” = Power 

Generation). Facility type is a required input variable in the cost tool.

Cooling System Type: Used to identify whether the cooling system is once-through or 

recirculating. In the current version of the tool, this input is not used in the active 

algorithms since intakes must meet impingement reduction requirements regardless of 

cooling type.

State Abbreviation: The two letter state abbreviation is used to identify the state where 

the intakes are located. The state is used to assign state-specific capital cost factors 

developed for the Phase III Rule. The state also is used to identify whether zebra mussels 

are a potential problem at a facility, requiring the use of more costly CuNi alloys in 

wedgewire screens.

Waterbody Type: The numeric values 1 through 5 represent the waterbody type for each 

intake’s location. These values are “1” = Ocean, “2” = Estuary, “3” = Great Lake, “4” = 

Fresh River, “5” = Lake/Reservoir. This input variable affects technology selection and 

certain cost components. Waterbody type is a required input variable in the cost tool.

Fuel Type: A value of “1” (one) indicates the intake is part of a nuclear facility and 

results in additional cost factors applied to both capital and O&M costs. A value of “0” 

(zero) indicates the intake is non-nuclear.

Capacity Utilization Rate (CUR): In the current version of the tool, this input is not used 

in the active algorithms. This percentage value reflects the ratio between the average 

annual net generation of power by the facility (in MWh) and the total net capability of the 

facility to generate power (in MW), multiplied by the number of hours during a year.

Intake Location: The numeric values 1 through 6 represent the location and description 

for each intake. These values are “1” = shoreline intake (flushed, recessed), “2” = intake 

canal, “3” = embayment, bank, or cove, “4” = submerged offshore intake, “5” = nearshore submerged intake, “6” = shoreline submerged intake. This input variable affects 

technology selection and certain cost components such as costs for longer fish returns. 

Intake Location/Description is a required input variable in the cost tool.
- 6 -

Distance Offshore for Submerged Intakes: Submerged offshore intake distance affects 

construction and civil costs as well as O&M costs, and is a critical parameter for 

relocating intakes and adding wedgewire screens to existing offshore intakes. The 

default distance of submerged offshore intakes is the median of all reported values from 

Phase II facilities by waterbody type as follows in Table 2:

Table 2. Default Values for Distance Offshore for Submerged Intakes

Waterbody Code Distance Offshore 

(Meters)

Ocean 1 500

Estuaries/Tidal Rivers 2 125

Great Lakes 3 500

Rivers and Streams 4 125

Lakes/Reservoirs 5 125

Canal Length: This variable is used to determine the length of the fish return system. 

The default value for the constructed canal length is the median of all reported values 

from Phase II facilities as follows in Table 3:

Table 3. Default Values for Canal Length

Waterbody Code Canal Length (Ft)

Ocean 1 3,370

Estuaries/Tidal Rivers 2 1,650

Great Lakes 3 1,460

Rivers and Streams 4 690

Lakes/Reservoirs 5 800

Navigation/Waterbody Use: In the current version of the tool, this input is not used in the 

active algorithms. A value of “1” indicates the intake is located where boat/barge 

navigation near the intake is a consideration when making any modifications to the 

intake. A value of “0” (zero) indicates navigation does not occur in the vicinity of the 

intake.

 

Mean Intake Water Depth: This value is used for estimating total existing screen width 

and selecting compliance technologies. Default values are shown in Table 4 below:

Table 4. Default Values for Mean Intake Water Depth

Facility type Code Mean Intake Water Depth (ft) 

DIF ≥ 50 MGD DIF < 50 MGD

Electric 

Generating

2 15 12

Manufacturing 3 19 16
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Intake Well Depth: The intake well depth is the distance from the intake deck to the 

bottom of the screen well, and includes both water depth and distance from the water 

surface to the deck. The intake well depth is used to select the total height of the required 

traveling screen. For a given screen width, deeper screens result in higher capital costs. 

If not entered, then screen well depth is calculated by adding the freeboard depths in the 

following Table 5 to the mean intake water depth:

Table 5. Default Values for Intake Well Depth

Waterbody Code Assumed Distance from Mean 

Water Surface to Screen Deck 

(ft)

Ocean 1 15

Estuaries/Tidal Rivers 2 15

Great Lakes 3 15

Rivers and Streams 4 30

Lakes/Reservoirs 5 20

River Proportional Flow: This input value was used in selecting compliance 

requirements in previous rulemaking efforts. In the current version of the tool, this input 

is not used in the active algorithms. A value of “1” (one) indicates the design intake flow 

is greater than 5 percent of the mean annual flow of a freshwater river or stream. A value 

of “0” (zero) indicates the design intake flow is less than or equal to 5 percent of the 

mean annual flow of a freshwater river or stream.

Existing Equipment Design Intake Flow (DIF): The DIF is the numerical value 

assigned during the facility’s design to the total maximum volume of water withdrawn. 

Design Intake Flow (DIF) is a required input variable in the cost tool.

New Design Intake Flow: This value is intended to represent current maximum intake 

flow requirements, as opposed to the DIF, which is based on maximum design flow 

capacities and may include pumping capacity no longer used or needed. This value is 

used to develop costs for compliance technologies that do not involve upgrade or 

replacement of existing traveling screens (e.g., wedgewire screens, fish barrier nets, new 

intake, velocity cap).

Average Intake Flow (AIF): This input variable was added to allow for adjustment of the 

variable portion of the O&M costs to reflect actual equipment operating costs. Average 

Intake Flow is a required input variable in the cost tool.

Existing Through-Screen Velocity: This input variable is used to estimate the existing 

screen width as well as for selecting the appropriate compliance technology. The power 

generation default values shown in Table 6 below are the mean reported values for all 

electric generators with greater than 50 MGD design intake flow. For manufacturing 

facilities, the default values are the mean reported values of Phase III Facilities.
- 8 -

Table 6. Default Values for Existing Through-Screen Velocity

Facility Type Code Screen Velocity (Ft/Sec)

DIF ≥ 50 MGD DIF < 50 MGD

Electric 

Generating 2 1.5 0.6

Manufacturing 3 1.2 0.8

Through-Screen Velocity Flow Basis: This input variable is used to identify the flow 

basis of the “Existing Through-Screen Velocity” and is used in the selection of the proper 

flow for calculation of existing screen width (“1” = Existing Equipment Design Intake 

Flow; “2” = New Design Intake Flow; “3” = Average Intake Flow). If left blank, default 

is Existing Equipment Design Intake Flow (“1”).

Water Type: A value of “1” indicates the water type is marine. A value of “0” indicates 

the water type is freshwater. The default is “0.”

Debris Loading: This input variable is used to estimate O&M costs for wedgewire 

screens. A value of “1” indicates high levels of debris and trash near the intake. A value 

of “0” indicates debris is low or negligible. The default is “1.”

Impingement Technology In-Place: This input variable is used to select compliance 

technologies and baseline O&M costs. A numerical value of 0 through 5 is used to 

indicate the intake has impingement technologies reported as in-place by the facility. A 

value of “1” = Traveling Screens, “2” = Passive Intake (Velocity Cap, Porous Dam, 

Leaky Dike, etc.), “3” = Barrier Net, and “4” = Fish Diversion or Avoidance (Louvers, 

Acoustics, etc.). The default is “0” (no controls). 

Qualified Impingement: This input variable identifies intakes that are already compliant 

with IM reduction requirements. A value of “1” means the existing intake is compliant 

and will receive no costs. A value of “0” or if left blank means IM compliance 

technology upgrades are needed. For facilities with traveling screens, this input value 

indicates whether a fish return mechanism is in-place. This in turn affects the cost 

module selected, as well as baseline O&M costs. Qualified Impingement is a required 

input variable in the cost tool.

Entrainment Tech in-Place: This input value was used in selecting compliance 

requirements in previous rulemaking efforts. In the current version of the tool, this input 

is not used in the active algorithms.

Qualified Entrainment: This input value was used in selecting compliance requirements 

in previous rulemaking efforts. In the current version of the tool, this input is not used in 

the active algorithms. Users of the tool can still hardcode a entrainment technology for 

purposes of cost estimation.
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Avg Annual Generation '96 - '99: This input value was used in estimating power 

generation downtime costs and “per MWh” costs in previous rulemaking efforts. In the 

current version of the tool, this input is not used in the active algorithms.

Regional Cost Factor: This input value is used to adjust capital cost estimates to reflect 

regional labor and material cost considerations. If left blank, a regional cost factor based 

on the reported state will be used. A value of “1.0” should be entered if a national 

average value is desired.

Screen Velocity for Module 3: This input variable selects the design screen velocity to 

be used for estimating the size of technology Module 3 (new larger intake), which in turn 

will affect costs of the new intake. The default value is “1.0” fps.

Maximum Acceptable Screen Velocity: This input variable is used for selecting 

compliance technologies and establishes the maximum existing velocity acceptable for 

continued use of existing traveling screens. The referenced existing screen velocity is 

calculated based on the “New Design Intake Flow.” The default value is “2.51” fps.

Cost Tool Outputs

The cost tool outputs can be found on the “Output” worksheet or in the “Macro Output” 

worksheet if the macro is used for multiple entries. Many of the values represent interim 

computations and only the following are extracted and used in economic impact analyses:

Assigned Costing Module: This output identifies the selected compliance technology

module.

Costing Module Service Life: This output identifies the service life of the selected 

technology module and is the time period to amortize capital costs or calculate present 

value of annual O&M costs.

Baseline O&M: This output provides the estimated O&M cost of the existing compliance 

technology.

Gross Module O&M: This output provides the estimated total O&M of selected 

technology module.

Baseline O&M Fixed Factor: This output provides an estimate of the proportion of the 

baseline O&M costs that are fixed (i.e., do not vary regardless of intake use).

Gross Module O&M Fixed Factor: This output provides an estimate of the proportion of 

the gross module O&M costs that are fixed (i.e., do not vary regardless of intake use).

Compliance Tech Capital: This output provides an estimate of the total capital costs of 

the selected technology module.
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Compliance Net Annual O&M: This output provides the net increase in O&M costs 

based on the difference between the Gross Module O&M and Baseline O&M.

All costs are adjusted using the ENR Construction Cost Index (CCI) value entered as a 

User Input. The base costs derived for Phase II are in 2002 Dollars (ENR CCI = 6538), 

which is the default cost basis if no ENR CCI value is specified.

Cost Tool Limitations

The cost tool, with the exception of a few selected combinations, assumes that a single 

technology will be sufficient to meet compliance requirements, while in reality a 

combination of technologies may be necessary. Compliance costs for such combinations 

can be developed by calculating costs for each intake or for multiple selected technology

modules and aggregating the costs. Care must be taken to avoid double counting baseline 

O&M costs (i.e., do not sum up net O&M costs).

The compliance costs for wedgewire screens were originally calculated for fine mesh 

requirements (1.75mm and 0.75mm), which were intended to provide for entrainment 

reduction in addition to impingement reduction. Use of smaller mesh sizes results in a 

larger screen area requirement and thus either larger or more screens, which increases the 

costs compared to coarse mesh. The impingement reduction technology requirements do 

not require screen sizes smaller than 9.5 mm; however, the cost tool modules involving 

wedgewire screens were not adjusted to account for different mesh sizes. Thus, the 

estimated screen sizes and costs for wedgewire screens may represent an overestimation 

of compliance costs if smaller mesh sizes are not required.

The purpose of the tool is to generate national level compliance costs. The industry

questionnaire database contained only a limited amount of data and so the input options 

are limited as well. Due to these limitations, the technologies selected by the cost tool 

may not actually be economically or technically feasible at the specified intake; the cost 

tool is not intended to assess financial conditions or feasibility of a technology at a site. 

Recognizing these limitations, the compliance costs are derived for economic analyses 

using the cost tool, and are considered to represent model facility/intake costs that are 

representative of additional facilities with similar attributes. These model facility costs 

are then extrapolated to the entire universe of facilities subject to the proposed rule. For 

this reason, the user should not necessarily rely upon the technology selected by the cost 

tool as being the best fit. Additionally, the estimated costs are intended to reflect average 

conditions and actual costs may differ considerably depending on local site conditions.