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DIVISION OF SURFACE WATER

Antidegradation Addendum

In accordance with Ohio Administrative Code 3745-1-05 (Antidegradation), additional

information may be required to complete your application for a permit to install or

NPDES permit. For any application that may result in an increase in the level of

pollutants being discharged (NPDES and/or PTI)or for which there might be activity

taking place within a stream bed, the processing of the permit(s) may be required to

go through procedures as outlined in the antidegradation rule. The rule outlines

procedures for public notification and participation as well as procedures pertaining

to the levels of review necessary. The levels of review necessary depend on the

degradation being considered/requested. The rule also outlines exclusions from

portions of the applicati on and review requirements and waivers that the Director may

grant as specified in Section 3745-1-05(D) of the rule. Please complete the following

questions. The answers provided will allow the Ohio EPA to determine if additional

information is needed. All projects that require both an NPDES and PTI should submit

both applications simultaneously to avoid going through the antidegradation process

separately for each permit .

A. Applicant: 

Facility Owner: 

Facility Location (city and county): 

Application or Plans Prepared By: 

Project Name: 

NPDES Permit Number (if applicable): 

B. Antidegradation Applicability

Is the application for? (check as many as apply):

 Application with no direct surface water discharge (Projects that do

not meet the applicability section of 3745-1-05(B)1, i.e., on-site

disposal, extensions of s anitary sewers, spray irrigation, indirect

discharger to POTW, etc.). (Complete Section E)

 Renewal NPDES application or PTI application with no requested

increase in loading of currently permitted pollutants. (Complete

Section E, Do not complete Sections C or D).

 PTI and NPDES application for a new wastewater treatment works that

will discharge to a surface water. (Complete Sections C and E)

 An expansion/modification of an existing wastewater treatment works

discharging to a surface water that will result in any of the

following (PTI and NPDES):(Complete Sections C and E)

addition of any pollutant not currently in the discharge, or

an increase in mass or concentration of any pollutant

currently in the discharge, or 

an increase in any current pollutant limitation in terms of

mass or concentration.
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 PTI that involves placement of fill or installation of any portion

of a sewerage system (i.e., sanitary sewers, pump stations, WWTP,

etc.)within 150 feet of a stream bed. Please provide information

requested on the stream e valuation addendum (i.e., number of stream

crossings, fill placement, etc.) and complete Section E.

 Initial NPDES permit for an existing treatment works with a

wastewater discharge prio r to October 1, 1996. (Complete Sections D

and E)

 Renewal NPDES permit or modification to an effective NPDES permit

that will result in any o f the following:(Complete Sections C and E)

a new permit limitation for a pollutant that previously had no

limitation, or

an increase in any mass or concentration limitation of any

pollutant that currently has a limitation. 

C. Antidegradation Information

1. Does the PTI and/or NPDES permit application meet an exclusion as outlined

by OAC 3745-1-05(D)(1) of the Antidegradation rule?

 Yes (Complete Question C.2)

 No (Complete Questions C.3 and C.4)

2. For projects that would be eligible for exclusions provide the following

information: 

a. Provide justification for the exclusion.

b. Identify the substances to be discharged, including the amount of

regulated pollutants to be discharged in terms of mass and

concentration.

c. A description of any cons truction work, fill or other structures to

occur or be placed in or near a stream bed.

3. Are you requesting a waiver as outlined by OAC 3745-1-05(D)(2-7) of the

Antidegradation rule? 

 No

 Yes

If you wish to pursue one of the waivers, please identify the waiver and

submit the necessary information to support the request. Depending on the

waiver requested, the information required under question C.4 may be

required to complete the application.

4. For all projects that do not qualify for an exclusion a report must

accompany this application evaluating the preferred design alternative,

non-degradation alternatives, minimal degradation alternatives, and

mitigative techniques/measures for the design and operation of the

activity. The information outlined below should be addressed in this

report. If a waiver is requested, this section is still required.

a. Describe the availability, cost effectiveness and technical

feasibility of connecting to existing central or regional sewage

collection and treatment facilities, including long range plans for
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sewer service outlined in state or local water quality management

planning documents and applicable facility planning documents.

b. List and describe all government and/or privately sponsored

conservation projects that may have been or will be specifically

targeted to improve water quality or enhance recreational

opportunities on the affected water resource.

c. Provide a brief description below of all treatment/disposal

alternatives evaluated for this application and their respective

operational and maintenance needs. (If additional space is needed

please attach additional sheets to the end of this addendum).

Preferred design alternative:

Non-degradation alternative(s):

Minimal degradation alternative(s):

Mitigative technique/measure(s):

At a minimum, the following information must be included in the report for

each alternative evaluated.

d. Outline of the treatment/disposal system evaluated, including the

costs associated with the equipment, installation, and continued

operation and maintenance.

e. Identify the substances to be discharged, including the amount of

regulated pollutants to be discharged in terms of mass and

concentration.

f. Describe the reliability of the treatment/disposal system, including

but not limited to the possibility of recurring operation and

maintenance difficulties that would lead to increased degradation.

g. Describe any impacts to human health and the overall quality and

value of the water resource.

h. Describe and provide an estimate of the important social and

economic benefits to be realized through this proposed project.

Include the number and types of jobs created and tax revenues

generated.

i. Describe environmental benefits to be realized through this proposed

project.

j. Describe and provide an estimate of the social and economic

benefits that may be lost as a result of this project. Include the

impacts on commercial and recreational use of the water resource.
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k. Describe the environmental benefits lost as a result of this

project. Include the impact on the aquatic life, wildlife,

threatened or endangered species.

l. A description of any construction work, fill or other structures to

occur or be placed in or near a stream bed.

m. Provide any other information that may be useful in evaluating this

application.

D. Discharge Information 

1. For treatment/disposal systems constructed pursuant to a previously issued

Ohio EPA PTI, provide the following information:

PTI Number 

PTI Issuance Date 

Initial Date of Discharge 

2. Has the appropriate NPDES permit application form been submitted including

representative effluent data?

 Yes (go to E)

 No (see below)

If no, submit the information as applicable under a OR b as follows: 

a. For entities discharging process wastewater attach a completed

2C form.

b. For entities discharging wastewater of domestic origin attach the

results of at least one chemical analysis of the wastestream for all

pollutants for which authorization to discharge is being requested

and a measurement of the daily volume (gallons per day) of

wastewaters being discharged. 

E. Based on my inquiry of the person or persons who manage the system or those

persons directly responsi ble for gathering the information, the information is,

to the best of my knowledge and belief, true, accurate and complete.

This section must be signed by the same responsible person who signed the

accompanying permit application or certification as per 40 CFR 122.22.

Signature 

Date 

h:revised.adm

June 30, 1997
Antidegradation Study 

Wastewater Treatment and Disposal Alternatives 

Miami Fort Station – Units 7 & 8 

Wet FGD System Retrofit Project 

North Bend, Hamilton County, Ohio 

Prepared for: 

Duke Energy Ohio, Inc. 

Cincinnati, Ohio 

October 7, 2008 

Revision No. 1.1 

Project No. 10444-712 

Prepared by: 

Sargent & Lundy, L.L.C. 

55 East Monroe Street 

Chicago, IL 60603-5780 USA 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 2 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

Table of Contents 

Table of Contents......................................................................................................................................2

List of Exhibits..........................................................................................................................................2

Introduction.................................................................................................................................................3

De Minimis Net Increase Exclusion...........................................................................................................3

Estimated Discharges................................................................................................................................3

Exclusion Justification ..............................................................................................................................3

In-Stream Construction Activities ............................................................................................................4

Antidegradation Evaluation for Boron.....................................................................................................4

Central or Regional Treatment Facilities ..................................................................................................4

Conservation Projects ...............................................................................................................................5

Treatment and Disposal Alternatives........................................................................................................5

Preferred Design Alternative ................................................................................................................5

Non-Degradation Alternative................................................................................................................6

Minimal Degradation Alternatives........................................................................................................7

Mitigative Technique and Measures.....................................................................................................8

Other Antidegradation Issues....................................................................................................................8

Impacts to Human Health and Water Resources...................................................................................8

Social and Economic Benefits ..............................................................................................................8

Environmental Benefits ........................................................................................................................9

Social and Economic Losses.................................................................................................................9

Environmental Benefits Lost ................................................................................................................9

In-Stream Construction Activities ......................................................................................................10

Conclusions................................................................................................................................................10

List of Exhibits 

Exhibit 1 Estimated Discharge 

Exhibit 2 Net Increase Evaluation Input Data 

Exhibit 3 Determination of Applicable De Minimis Thresholds 

Exhibit 4 Net Increase Evaluation 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 3 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

INTRODUCTION 

Sargent & Lundy, L.L.C. (Sargent & Lundy), on the behalf of Duke Energy Ohio, Inc. (Duke), has 

performed an antidegradation study to support the NPDES Permit renewal application for the Miami Fort 

Generating Station, specifically addressing wastewater treatment and disposal associated with the Wet 

FGD System Retrofit Project. 

The Ohio Environmental Protection Agency’s (EPA) Antidegradation Rule [Ohio Administrative Code 

(OAC) 3745-1-05 Antidegradation] generally applies to all new or increased discharges from wastewater 

treatment facilities into surface waters of the state. For an existing source like Miami Fort, the Ohio EPA 

Antidegradation Rule generally applies to the re-issuance of an NPDES that would result in any net 

increase of a regulated pollutant. Because the Wet FGD System Retrofit Project will result in a small net 

increase in the loading of regulated pollutants, the Antidegradation Rule applies to the NPDES Permit 

renewal. 

The first part of the antidegradation study deals with analysis of the wastewater discharge quality and 

comparison with applicable water quality criteria, stream data, and calculated wasteload allocations, to 

determine which pollutants qualify for an exclusion from the antidegradation requirements because of a 

de minimis net increase, that which is less than 10% of the wasteload allocation. Thirty two regulated 

pollutants are evaluated. The second part of the antidegradation study provides an analysis of treatment 

and disposal options for boron, the only regulated pollutant of the 32 pollutants evaluated that exceeded 

the de minimis threshold. 

DE MINIMIS NET INCREASE EXCLUSION 

Estimated Discharge 

Sargent & Lundy estimated the amount of 32 regulated pollutants for which the Wet FGD System 

Retrofit Project could result in a new or increased discharge. Exhibit 1 provides the amount of the 32 

regulated pollutants that are discharged as a result of the Wet FGD System Retrofit Project, based on an 

analysis of actual effluent data, in terms of concentration. 

Exclusion Justification 

For general high quality waters, such as the Ohio River, a de minimis net increase in the discharge of a 

regulated pollutant, that which is less than 10% of the wasteload allocation (WLA), is excluded from the 

Ohio EPA antidegradation submittal and review requirements, provided the proposed lowering of water 

quality does not exceed 80% of the WLA. 

Sargent & Lundy evaluated 32 regulated pollutants for which the Wet FGD System Retrofit Project could 

result in a new or increased discharge, following the requirements of the Ohio EPA Antidegradation Rule 

and published guidance documents. Exhibit 2 provides a detailed listing of input data used in the 

evaluation. Exhibit 3 provides additional input data, such as applicable water quality criteria and 

background water quality, and the calculated wasteload allocation and de minimis threshold for each of 

the 32 regulated pollutants. 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 4 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

The de minimis net increase exclusion evaluation included the following steps: 

• Determination of the net wasteload increase as a result of the wet FGD process, and the total 

wasteload being discharged after the increase (Exhibit 1); 

• Determination of the applicable water quality criteria (WQC) at the point of the discharge (Exhibit 3); 

• Tabulation of the background pollutant load, based on available background water quality data, for 

each regulated pollutant (Exhibit 3); 

• Calculation of the wasteload allocation (WLA) required to maintain water quality standards, 

calculated using Ohio EPA total maximum daily load procedures, for each WQC (Exhibit 3); 

• Determination of both the 10% WLA threshold and the 80% WLA threshold for the lowest applicable 

WQC for each regulated pollutant (Exhibit 3); and finally, 

• Comparison (Exhibit 4) of: 

– The net wasteload increase to the 10% WLA threshold; and, 

– The total wasteload to the 80% WLA threshold. 

Of the 32 regulated pollutants, only one parameter, boron, exceeds the 10% WLA threshold. None of the 

32 parameters exceed the 80% WLA threshold. Therefore, based on the exclusion at OAC 3745-1-05 

(D)(1)(b)(i) for general high quality waters, the discharge of all regulated pollutants except boron is 

excluded from the submittal and review requirements in the Ohio EPA Antidegradation Rule. 

In-Stream Construction Activities 

Construction of the Preferred Design Alternative for wastewater treatment and disposal, which is 

described below, did not include any construction work, fill or other structures in or near a stream bed. 

The Wet FGD System Retrofit Project itself required construction work, fill and mooring structures in the 

Ohio River and adjacent wetlands. This aspect of the Project was addressed in the applications for a 404 

Permit and a 401 Water Quality Certification, and in the antidegradation assessment submitted with the 

401 application. 

ANTIDEGRADATION EVALUATION FOR BORON 

This section of the Miami Fort antidegradation study evaluates the Preferred Design Alternative, NonDegradation Alternatives, Minimal Degradation Alternatives, and Mitigative Techniques and Measures 

for the design and operation of the Wet FGD Retrofit Project. This section specifically addresses the 

treatment, disposal and discharge of boron, the single regulated pollutant that does not qualify for the 

de minimis discharge exclusion. 

Central or Regional Treatment Facilities 

The wastewater stream from the Wet FGD Retrofit Project is treated and discharged via the existing 

Miami Fort wastewater treatment system (e.g. the existing Ash Basins) to existing Outfall No. 002. 

Therefore, the project has not resulted in the creation of an additional new point source. 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 5 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

The plant is not located close to any other central or regional sewage collection and treatment facilities. 

The nearest publicly owned treatment facility is the Indian Creek WWTP, operated by the Metropolitan 

Sewer District of Greater Cincinnati (MSD), which is located approximately 3.5 miles from the Miami 

Fort Station. 

Conservation Projects 

There are no known government or privately sponsored conservation projects that may have been or will 

be specifically targeted to improve water quality of the Ohio River or it’s tributaries with respect to boron. 

There are, however, several projects intended to improve general water quality and to enhance the 

recreational opportunities of the affected water resources. 

For example, Oxbow, Inc. (Oxbow) is a Cincinnati-based wetland preservation organization that was 

established to protect seasonal wetlands and floodplains from development along the Great Miami River 

and Ohio River. To date, Oxbow has acquired 960 acres of fee title or easement property within these two 

river basins. Duke and the Miami Fort Generating Station have demonstrated their commitment to 

preserving wetland areas near the station by donating a 20-acre parcel of land on the east side of an island 

located in the mouth of the Great Miami River to Oxbow in perpetuity. 

Treatment and Disposal Alternatives 

Preferred Design Alternative 

System Description

The Preferred Design Alternative for the FGD wastewater treatment system consists of a physicalchemical process to remove suspended solids and heavy metals. The treatment system consists of a series 

of reaction tanks that have the optimum mixing energy, retention time and chemical conditions to 

equilibrate the calcium sulfate in the wastewater and to render the various contaminants insoluble, using 

both hydroxide and sulfide precipitation. The precipitated contaminants are then removed through 

clarification of the wastewater. 

The preferred FGD wastewater treatment system is designed to treat 200 gallons per minute (gpm), which 

is approximately 125% of the combined wet FGD bleed stream from both wet FGD systems. The design 

basis raw wastewater quality is based on the characteristics of the coal, limestone, makeup water and 

cycles of concentration associated with an FGD chloride limit of 20,000 parts per million (ppm). 

The physical-chemical treatment system includes the following processes: 

• Wastewater equalization 

• Gypsum desaturation, with sludge recirculation to aid desaturation process 

• Hydroxide precipitation of heavy metals, using lime 

• Sulfide precipitation of heavy metals, using an organosulfide compound or sodium hydrosulfide 

• Coagulation with ferric chloride 

• Polymer dosing to aid flocculation 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 6 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

• Clarification 

• Sludge dewatering with plate and frame filter presses 

Treated effluent from the FGD wastewater treatment system is pumped to the existing Ash Basins. The 

Ash Basins are designed to manage several wastewater streams, and provide settling prior to discharge 

through Outfall No. 002 to the Ohio River. The filter cake produced by the FGD wastewater treatment 

system consists primarily of gypsum solids and limestone inert solids which are trucked offsite for 

disposal at a properly permitted landfill. 

System Costs

The actual cost for the Preferred Design Alternative for treatment and disposal of FGD wastewater is 

$11 million. The cost includes approximately $5.5 million for equipment and materials, $3.3 million for 

labor, and $2.2 million for construction management, subcontractor indirects, engineering, and 

miscellaneous project costs. The estimated annual operating cost for the treatment system is $800,000, 

which includes chemicals, contract labor, sludge disposal and maintenance parts. 

Boron Removal

The Preferred Design Alternative for treatment and disposal of FGD wastewater successfully removes 

substantial amounts of most of the 32 regulated pollutants. The system, however, only removes 

approximately 10% of the boron entering the system. The exact mechanism of this removal is not known. 

Boron is known in the power and wastewater treatment industries to be difficult to remove from process 

streams. 

Reliability and O&M Issues

There are approximately a twelve treatment systems of this type operating in the U.S. and 36 operating in 

Europe. Available data shows that hydroxide and organosulfide wastewater treatment systems 

consistently remove most metals to very low levels. 

The operation of the Preferred Design Alternative requires 11⁄2 operators during the day shift and 1⁄2 of an 

operator during the night shift. The chemicals used in this type of plant are common industrial chemicals 

and readily available. The solid waste from the preferred system is disposed of in a properly permitted 

landfill. 

Non-Degradation Alternative 

System Description

The Non-Degradation Alternative is to add a zero-liquid discharge (ZLD) system to the Preferred Design 

Alternative to achieve a near-zero discharge of boron. The ZLD system would consist of a brine 

concentrator and a brine crystallizer to further treat the 200-gpm effluent from the heavy metals 

precipitation process. The ZLD process would produce approximately 196 gpm of distillate for reuse and 

a salt cake for disposal, so no liquid wastewater would be discharged. Other zero-discharge technology 

options, such as evaporation ponds or ion exchange processes, are either not technically feasible for 

Miami Fort or are not commercially proven at this time. 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 7 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

The ZLD treatment system would include the following processes: 

• Regenerative feedwater preheater; 

• Deaerator to remove dissolved gases; 

• Brine concentrator to initiate crystal growth; 

• Brine crystallizer to produce a concentrated slurry of salt crystals; 

• Rotary dryer to minimize the moisture in the slurry and produce the salt cake; 

• Auxiliary boiler to provide steam to the brine concentrator; and 

• Fabric filter collector to remove fine solid particles from the rotary dryer’s exhaust. 

The selection of the brine concentrator option involves several processes and waste management 

activities. Essentially, this alternative results in “zero liquid discharge”. All constituents of the Miami Fort 

FGD wastewater would be removed: Borates and other dissolved salts, trace metals (both dissolved and 

particulate), and suspended solids. Because this option seeks to achieve “zero liquid discharge”, 

considerable amounts of solid waste would need to be disposed of in properly permitted landfills. The 

effluent water produced by the system will be of sufficient high-quality to be reused in the plant, rather 

than discharged. 

System Costs

The estimated total cost for the Non-Degradation Alternative is $37.8 million, which includes 

$13.0 million for equipment and materials and $24.8 million for labor, construction management, 

subcontractor indirects, engineering, and miscellaneous project costs. The equipment costs include the 

evaporator, crystallizer, dewatering equipment and the auxiliary boiler. The miscellaneous project costs 

include site-specific site development costs for the Miami Fort station. The estimated annual operating 

cost for the Non-Degradation Alternative is $2.5 million. 

Boron Removal

A wastewater treatment system that incorporates a brine concentrator will not discharge any boron. Any 

boron in the wastewater will be concentrated into a solid form for disposal in a landfill. 

Reliability and O&M Issues

Brine concentrator treatment systems are known for having significant operation and maintenance issues. 

The operation of brine concentrators typically requires 4 to 5 dedicated trained operators and a managing 

engineer whose sole job is troubleshooting the equipment. Due to the down-time associated with this type 

of system and the inability of the generating plant to operate without a working brine concentrator, the 

ability of the Miami Fort Station to produce electric power would be closely tied to brine concentrator 

availability. 

Minimal Degradation Alternatives 

Minimal degradation alternatives are treatment and disposal alternatives, including pollution prevention 

alternatives, that would result in a lesser lowering of water quality with respect to boron. 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 8 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

There is a general consensus in the power and wastewater treatment industries that boron treatment is 

very difficult, if not technically infeasible for many applications. Wastewater treatment options, including 

selective ion-exchange, hot or cold lime softening, bioremediation, precipitation, and adsorption, are 

mentioned in the literature, but the references are few and the results are conflicting. Lab and pilot studies 

are needed to verify the performance of these processes. As a result, there are no commercially available 

treatment technologies capable of removing significant amounts of boron that do not have impractical 

construction costs and requirements, high operating costs, or the creation of significant waste streams. 

There are no known pollution prevention alternatives to reduce boron in the FGD wastewater stream. The 

presence of boron in the wastewater is a fundamental result of the scrubbing of the plant’s flue gas in the 

FGD system. 

Mitigative Techniques and Measures 

Mitigative Techniques and Measures include alternative on-site or off-site control measures designed to 

offset all or part of the lowering of water quality with respect to boron, preferably within the same 

watershed. No such mitigative techniques or measures are proposed for this project, due, in part, to the 

fact that boron is not generally considered to be present at significant levels in the Ohio River or the 

watershed. Furthermore, as previously discussed, boron is extremely difficult to treat from any source. 

Duke has demonstrated its commitment to preserving wetlands and improving water quality near the 

Miami Fort Generating Station, through its support of the Oxbow organization, as discussed above. 

Other Antidegradation Issues 

Impacts to Human Health and Water Resources 

The Wet FGD System Retrofit Project with the Preferred Design Alternative for wastewater treatment 

will result in a very minor lowering of water quality with respect to boron, but should have no impact to 

human health, overall water quality or the value of the water resource. The lowering of water quality will 

not result, either individually or cumulatively with other discharges, in the exceedance of any applicable 

water quality standards, including human health, agricultural use, and aquatic life, or interfere with the 

achievement of any designated beneficial uses of the Ohio River. 

Social and Economic Benefits 

The Miami Fort Generating Station site has been critical to the long-term generation of electric power in 

southwestern Ohio since the 1920’s. The need for electric power has increased with the increased 

urbanization and development of the service region. Given the site history and increased regional need for 

electricity, it would be economically infeasible to move the existing generating operations to a site remote 

from the existing location. The Wet FGD System Retrofit Project has had a substantial positive impact on 

maintaining the ability of the plant to continue to meet the electric power needs of the region as well as 

meeting the increasingly stringent air quality requirements. 

The Wet FGD System Retrofit Project increased the tax assets of the Miami Fort Generating Station 

property and provides potential future tax incentives. Additionally, the project has the potential to 

increase the property values of the surrounding parcels as a result of improved ambient air quality. 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 9 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

Construction of the Project has had a positive impact on the local economy, as a result of the jobs and 

state income tax revenues that were generated, local trade for goods and services that occurred (e.g. food, 

fuel, lodging, etc.), and the local materials that were required for construction activities. The original 

estimated tax income is provided in the following table. 

Item Calculation Basis Estimated 

Tax Income

Construction Jobs Created 250 jobs x 2,000 hours x 2 years x 

$25/hour = $25,000,000 

$1,125,000 

Permanent Staff Created 6 jobs x 2,000 hours x 30 years x 

$35/hour = $12,600,000 

$567,000 

TOTAL $1,692,000 

Environmental Benefits 

Since being placed in operation, the Wet FGD System Retrofit Project has substantially reduced air 

emissions of sulfur dioxide (SO2), acid gases, and metals, such as mercury, from the Miami Fort 

Generating Station, thereby improving air quality within the greater tri-state region and the Ohio River 

Valley. From an air quality standpoint, the implementation of the Project with the Preferred Design 

Alternative has had a significant positive environmental impact on the environment and the overall health 

of people living and working within in the southwest Ohio region. 

Social and Economic Losses 

There have been no jobs or revenues lost from the implementation of the Wet FGD System Retrofit 

Project with the Preferred Design Alternative. The commercial and recreational uses of the Ohio River 

have not been impacted by the project. The construction, operation, and maintenance of the project have 

had positive impacts to the socioeconomic characteristics of the project area (see Social and Economic 

Benefits, above). 

Environmental Benefits Lost 

No existing environmental benefits have been lost as a result of the implementation of the project with the 

Preferred Design Alternative, nor would any be lost as a result of the implementation of the NonDegradation Alternative. The existing uses of the Ohio River have been and would be maintained. The 

project has not had an impact on aquatic life, wildlife, threatened or endangered species. 

As discussed above, the Wet FGD System Retrofit Project itself required construction work, fill and other 

structures in the Ohio River and adjacent wetlands. This aspect of the Project was addressed in 

applications for a 404 permit and a 401 Water Quality Certification, including the antidegradation 

assessment submitted with the 401 application. Neither the Preferred Design Alternative nor the NonDegradation Alternative would result in additional impacts. 
Duke Energy Ohio, Inc. Antidegradation Study Rev. 1.1 

Miami Fort Station – Units 7 & 8 October 7, 2008 

Wet FGD System Retrofit Project Page 10 of 10 

Sargent & Lundy, L.L.C. Project No. 10444-712 

Duke has evaluated threatened and endangered species habitat adjacent to the Ohio River and along Dark 

Hollow Creek, which flows to the Ohio River near the eastern boundary of the site. Based on an on-site 

monitoring program, literature review, and correspondence with the Ohio Department of Natural 

Resources – Natural Areas and Preserves (ODNR-DNAP) and the U.S. Fish and Wildlife Service 

(USFWS), there are no unique habitats on the site nor is there indication of the presence of any threatened 

and endangered wildlife species. 

In-Stream Construction Activities 

Construction of the Preferred Design Alternative for wastewater treatment and disposal did not include 

any construction work, fill or other structures in or near a stream bed. Due to the congestion of the Miami 

Fort site, the Non-Degradation Alternative would require site development activities in or near the Ohio 

River stream bed. 

As discussed above, the Wet FGD System Retrofit Project itself required construction work, fill and other 

structures in the Ohio River and adjacent wetlands. This aspect of the Project was addressed in the 

application for a 401 Water Quality Certification, including the antidegradation assessment submitted 

with the 401 application. 

CONCLUSIONS 

The Wet FGD System Retrofit Project has had a substantial positive impact on maintaining the ability of 

the Miami Fort Generating Station to continue to meet the electric power needs of the region as well as 

the applicable air quality requirements. 

With the implementation of the Preferred Design Alternative, only one parameter, boron, out of 32 

regulated pollutants evaluated by Sargent & Lundy, exceeds the 10% WLA threshold, and none of the 32 

parameters exceed the 80% WLA threshold. Therefore, the discharge of all regulated pollutants except 

boron is excluded from the submittal and review requirements in the Ohio EPA Antidegradation Rule. 

The Preferred Design Alternative for the treatment and disposal of wastewater from the FGD system, a 

hydroxide and sulfide precipitation process for removal of metals, results in the least lowering of water 

quality with respect to all regulated pollutants, including boron. There are no cost-beneficial, technically 

feasible, and commercially available treatment and disposal alternatives that would result in a lesser 

lowering of water quality with respect to boron. 
Duke Energy Ohio, Inc.

Miami Fort – Units 7 & 8

Wet FGD System Retrofit Project

Exhibit 1

Estimated Discharge

Anti-Degradation Study

Rev. 1.1

10/7/2008

Page 1 of 1

Discharge Parameter Estimated Discharge

Parameter Units

Aluminum, total μg/L 0.016 0.664

Ammonia, summer mg/L 0.017 0.1

Ammonia, winter mg/L 0.017 0.1

Antimony, total μg/L 0.01 0.01

Arsenic, total μg/L 37.56 37.56

Barium, total μg/L 180.2 180.2

Beryllium, total μg/L 0.000037 0.005

Boron, total μg/L 3,601 4,418

Cadmium, total μg/L 0.309 2.38

Chloride, total mg/L 90.06 147.5

Chromium, total μg/L 0.495 7.67

Cobalt, total μg/L 0.05 0.05

Copper, total μg/L 6.19 10.8

Iron, total μg/L 7.43 271

Lead, total μg/L 0.198 9.5

Magnesium, total mg/L 50.68 70.74

Manganese, total μg/L 0.134 0.184

Mercury, total μg/L 0.0124 0.0172

Molybdenum, total μg/L 0.00495 0.17

Nickel, total μg/L 1.24 20.7

Nitrate + Nitrite mg/L 0.225 2.149

Nitrite mg/L 0.00124 0.115

Phosphorus, total mg/L 0.00495 0.1467

Selenium, total μg/L 12.38 17.984

Silver, total μg/L 0.005 0.005

Solids, dissolved mg/L 411.73 972

Sulfate, total mg/L 140.26 408.67

Thallium, total μg/L 0.000111 0.01

Tin, total μg/L 0.1 0.1

Titanium, total μg/L 0.05 0.05

Vanadium, total μg/L 0.198 25.5

Zinc, total μg/L 0.470 27.9

Total 

Wasteload 

after 

Increase

Net 

Wasteload 

Increase 

from FGD

Sargent & Lundy, L.L.C. Project No. 10444-712
Duke Energy Ohio, Inc.

Miami Fort – Units 7 & 8

Wet FGD System Retrofit Project

Exhibit 2

Net Increase Evaluation Input Data

Anti-Degradation Study

Rev. 1.1

10/7/2008

Page 1 of 1

Parameter Season Value Basis

Stream Flows

1Q10 annual 8,670 cfs ORSANCO 2006

7Q10 annual 10,600 cfs "

7Q10 summer 10,600 cfs "

7Q10 winter 10,600 cfs "

30Q10 summer 10,600 cfs "

30Q10 winter 10,600 cfs "

HMQ annual 45,300 cfs "

Mixing assumptions average 10% OAC 3745-2-05(A)(2)(f)

maximum 1% "

Stream Water Quality Parameters

Instream hardness (H) annual 133.1 mg/L n=102

Instream pH summer 7.5 S.U. n=10

Instream pH winter 7.5 S.U. n=6

Instream temp summer 17 °C

Instream temp winter 13 °C

Background Water Quality

Data See Exhibit 3

Data Source STORET:

Station OR502.2M

Ohio River at Anderson Ferry, OH

Organization 31ORWUNT (ORSANCO)

Available data, August 2008

Effluent Parameters

Discharge Flow - Outfall 002 average 23.05 cfs Miami Fort NPDES permit application

14.90 mgd

maximum 27.23 cfs Miami Fort NPDES permit application

17.60 mgd

Effluent hardness 400 mg/L Maximum hardness value per Table 7-9, footnote 6

(The reported average effluent hardness = 561 mg/L)

De minimis net increase exclusion

Receiving waters Ohio River at River Mile 490.5

Designated uses Agricultural water supply OAC 3745-1-32

Bathing waters "

Industrial water supply "

Public water supply "

Warmwater habitat "

Antidegradation classification General high quality waters OAC 3745-1-05(A)(10)

De minimis net increase 10% % of WLA OAC 3745-1-05(D)(1)(b)(i)

"Total impact limit" 80% % of WLA "

Sargent & Lundy, L.L.C. Project No. 10444-712
Duke Energy Ohio, Inc.

Miami Fort – Units 7 & 8Wet FGD System Retrofit Project

Exhibit 3

Determination of Applicable De Minimis Thresholds

Anti-Degradation Study

Discharge Parameter Applicable Water Quality Criteria Background Pollutant Load Calculated Wasteload Allocation

Outside Mixing Zone Outside Mixing Zone

Average Background Water Quality Average

Parameter Units Human Health Agriculture Aquatic Life Value / Number of Samples Human Health Agriculture Aquatic Life 

Aluminum, total μg/L -- -- -- -- -- 1209 n=48 -- -- -- Ammonia, summer* mg/L -- -- 2.2 13 49 0.08778 n=27 -- -- 99 Ammonia, winter* mg/L -- -- 6.0 13 54 0.1371 n=28 -- -- 276 Antimony, total μg/L 14 -- 190 900 1800 0.1388 n=48 6,388 -- 8,921 4Arsenic, total μg/L 50 100 150 340 680 1.214 n=54 22,485 19,514 6,992 Barium, total μg/L -- -- 220 2,000 4,000 51.94 n=55 -- -- 7,949 9Beryllium, total μg/L 16 100 15 130 250 0 No Data Available 7,374 19,753 705 Boron, total μg/L -- -- 950 8,500 17,000 0 No Data Available -- -- 44,638 4Cadmium, total† μg/L -- 50 3.08 6.24 43.2 0.1050 n=63 -- 9,856 140 

Chloride, total mg/L 250 -- -- -- -- 31.19 n=55 100,876 -- -- Chromium, total† μg/L -- 100 109 2,279 11,223 2.251 n=55 -- 19,310 5,015 1Cobalt, total μg/L -- -- 24 220 440 0 No Data Available -- -- 1,128 Copper, total† μg/L 1300 500 11.9 18.3 103.4 3.731 n=63 597,415 98,031 388 Iron, total μg/L -- 5000 -- -- -- 2183 n=63 -- 558,716 -- Lead, total† μg/L -- 100 9.24 176 1,430 2.894 n=53 -- 19,184 301 Magnesium, total mg/L -- -- -- -- -- 10.98 n=63 -- -- -- Manganese, total μg/L -- -- -- -- -- 155.5 n=63 -- -- -- Mercury, total μg/L 0.012 10 0.91 1.7 3.4 0.005178 n=53 3.15 1,974 42.5 Molybdenum, total μg/L -- -- 110 2,400 4,700 0 No Data Available -- -- 5,169 1Nickel, total† μg/L 610 200 66.5 598 3,031 4.575 n=55 279,027 38,607 2,912 2Nitrate + Nitrite mg/L 10 100 -- -- -- 1.052 n=55 4,125 19,546 -- Nitrite mg/L 1.0 -- -- -- -- 0 No Data Available 461 -- -- Phosphorus, total mg/L -- -- -- -- -- 0.1547 n=55 -- -- -- Selenium, total μg/L 170 50 5.0 -- -- 0.6190 n=55 78,063 9,755 206 Silver, total μg/L 50 -- 1.3 2.2 4.4 0.09365 n=55 23,000 -- 57 Solids, dissolved mg/L -- -- 1,500 -- -- 63 n=20 -- -- 67,583 Sulfate, total mg/L 250 -- -- -- -- 69.07 n=55 83,456 -- -- Thallium, total μg/L 1.7 -- 17 79 160 0 Non-Detect 783 -- 799 Tin, total μg/L -- -- -- -- -- 0 No Data Available -- -- -- Titanium, total μg/L -- -- -- -- -- 0 No Data Available -- -- -- Vanadium, total μg/L -- -- 44 150 300 0 No Data Available -- -- 2,067 Zinc, total† μg/L 9,100 25,000 153 153 776 14.86 n=62 4,187,080 4,935,311 6,491 

* Aquatic life OMZA and OMZM are temperature and pH dependent Stream design flows and percentages [per 3745-2-05 (A

† Aquatic life OMZA, OMZM and IMZM are hardness (H) dependent: OMZA (human health) : 100% of 7Q10

the OMZA and OMZM WQC are based on instream-H; IMZM WQC are based on effluent-H OMZA (agriculture) : 10% of HMQOMZA = outside mixing zone average. OMZA (aquatic life) : 10% of 7Q10OMZM = outside mixing zone maximum; OMZM (aquatic life) : 1% of 7Q10IMZM = inside mixing zone maximum; IMZM no mixing considered

Maximum 

Aquatic Life

Inside Mixing 

Zone 

Maximum

Maxim

Aquat

Sargent & Lundy, L.L.C. 
Duke Energy Ohio, Inc.

Miami Fort – Units 7 & 8

Wet FGD System Retrofit Project

Exhibit 4

 Net Increase Evaluation

Anti-Degradation Study

Rev. 1.1

10/7/2008

Page 1 of 1

Discharge Parameter Net Increase Evaluation

Parameter Units

Aluminum, total μg/L 0.016 No 0.664 No

Ammonia, summer mg/L 0.017 No 0.1 No

Ammonia, winter mg/L 0.017 No 0.1 No

Antimony, total μg/L 0.01 No 0.01 No

Arsenic, total μg/L 37.56 No 37.56 No

Barium, total μg/L 180.2 No 180.2 No

Beryllium, total μg/L 0.000037 No 0.005 No

Boron, total μg/L 3,601 YES 4,418 No

Cadmium, total μg/L 0.309 No 2.38 No

Chloride, total mg/L 90.06 No 147.5 No

Chromium, total μg/L 0.495 No 7.67 No

Cobalt, total μg/L 0.05 No 0.05 No

Copper, total μg/L 6.19 No 10.8 No

Iron, total μg/L 7.43 No 271 No

Lead, total μg/L 0.198 No 9.5 No

Magnesium, total mg/L 50.68 No 70.74 No

Manganese, total μg/L 0.134 No 0.184 No

Mercury, total μg/L 0.0124 No 0.0172 No

Molybdenum, total μg/L 0.00495 No 0.17 No

Nickel, total μg/L 1.24 No 20.7 No

Nitrate + Nitrite mg/L 0.225 No 2.149 No

Nitrite mg/L 0.00124 No 0.115 No

Phosphorus, total mg/L 0.00495 No 0.1467 No

Selenium, total μg/L 12.38 No 17.984 No

Silver, total μg/L 0.005 No 0.005 No

Solids, dissolved mg/L 411.73 No 972 No

Sulfate, total mg/L 140.26 No 408.67 No

Thallium, total μg/L 0.000111 No 0.01 No

Tin, total μg/L 0.1 No 0.1 No

Titanium, total μg/L 0.05 No 0.05 No

Vanadium, total μg/L 0.198 No 25.5 No

Zinc, total μg/L 0.470 No 27.9 No

Exceeds 

10% WLA 

Threshold?

Exceeds 

80% WLA 

Threshold?

Total 

Wasteload 

after 

Increase

Net 

Wasteload 

Increase 

from FGD

Sargent & Lundy, L.L.C. Project No. 10444-712