### Draft FACT SHEET FOR NPDES PERMIT WA 0001546

FACILITY NAME TransAlta Centralia Generation LLC

September 2010

PURPOSE of this Fact Sheet

This fact sheet explains and documents the decisions the Department of Ecology (Ecology) made in drafting th e proposed National Pollutant Discharge Elimination System (NPDES) permit for TransAlta Centralia Generation, LLC ( TCG )

.

The Environmental Protection Agency (EPA) developed the NPDES permitting program as a tool to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” EPA delegated to Ecology the power and duty to write, issue, and enf orce NPDES permits within Washington State. Both state and federal laws require any industrial facility to obtain a permit before discharging waste or chemicals to a water body.

An NPDES permit limits the types and amounts of pollutants the facility may discharge. Those limits are based either on (1) the pollution control or waste water treatment technology available to the industry, or on (2) the receiving water’s customary beneficial uses . This fact sheet complies with Section 173

- 220

- 060 of the Washin gton Administrative Code (WAC), which requires Ecology to prepare a draft permit and accompanying fact sheet for public evaluation before issuing an NPDES permit.

PUBLIC ROLE in the Permit

Ecology makes the draft permit and fact sheet available for public review and comment at least 30 days

before issu ing the final permit to the facility operator (WAC 173

- 220

- 050). Copies of the fact sheet and draft permit for TCG , NPDES permit WA 001546 are available for public review and comment from June
9, 2010, until the close of business July 9, 2010 . For more details on preparing and filing comments

about the se documents , please see Appendix A

- Public Involvement

.

Before pu blishing the draft NPDES permit, TCG , r eviewed it for factual accuracy. Ecology corrected any errors or omissions about the facility’s location, product type or production rate, discharges or receiving water, or its history.

After the public comment period closes, Ecology will summarize substantive comments and our responses to th em. Ecology will include our summary and responses to comments to this Fact Sheet as Appendix D Response to Comments , and publish it when issuing the final NPDES permit. Ecology will

not revise the rest of the fact sheet, but the full document will becom e part of the legal history contained in the facility’s permit file.

Aziz Mahar , P.E., prepared the permit and this fact sheet.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 2 of 70 TABLE OF CONTENTS

I. BACKGROUND INFORMATION

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

A. Facility Description

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

History

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

Wastewater Treatment

................................ ................................ ........................... 6 Solid Waste Management

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

D ischarge O utfalls

................................ ................................ ............................... 12

B. Permit Status

................................ ................................ ................................ ..................... 13

C. Summary of Compliance with Previous Permit Issued

................................ .................... 13

D. Wastewater Characterization

................................ ................................ ............................ 13

E. Description of the Receiving Water

................................ ................................ .................. 14

F. SEPA Compliance

................................ ................................ ................................ ............ 14

II. PROPOSED PERMIT CONDITIONS

................................ ................................ .......................... 14

A. Design Criteria

................................ ................................ ................................ .................. 15

B. Outfall 001 Technology

- Based Effluent Limits

................................ ................................ 15

Outfall 002 Technology

- Based Effluent Limits

................................ ................................ 16

C. Surface Water Quality

- Based Effluent Limits

................................ ................................ .. 17

Numerical Criteria for the Protection of Aquati c Life and Recreation

................ 17

Numerical Criteria for the Protection of Human Health

................................ ...... 17

Narrative Criteria

................................ ................................ ................................ . 18 Antidegradation

................................ ................................ ................................ ... 18 Mixing Zones

................................ ................................ ................................ ....... 19

D. Designated Uses and Surface Water Quality Criteria

................................ ....................... 20

E. Evaluation of Surface Water Quality

- Based Effluent Limits for Numeric Criteria

......... 21

F. Whole Effluent Toxicity

................................ ................................ ................................ ... 23

G. Human Health

................................ ................................ ................................ ................... 24

H. Sediment Quality

................................ ................................ ................................ .............. 24

I. Ground Water Quality Limits

................................ ................................ ........................... 24

J. Comparison of Effluent Limits with Limits of the Previous Permit Issued on June 30, 2005

................................ ................................ ................................ .................... 24

I V

. MONITORING REQUIREMENTS

................................ ................................ .............................. 26

A. Lab Accreditation

................................ ................................ ................................ ............. 27

V

. OTHER PERMIT CONDITIONS

................................ ................................ ................................ . 27

A. Reporting and Recordkeeping

................................ ................................ ........................... 27

B. Non Routine and Unanticipated Discharges

................................ ................................ ..... 27

C. Spill Plan

................................ ................................ ................................ ........................... 27

D. Solid Waste Control Plan

................................ ................................ ................................ .. 27

E. Treatment System Operating Plan

................................ ................................ .................... 27

F. General Conditions

................................ ................................ ................................ ........... 28

VI. PERMIT ISSUANCE PROCEDURES

................................ ................................ ......................... 28

A. Permit Modifications

................................ ................................ ................................ ........ 28

B. Proposed Permit Issuance

................................ ................................ ................................ . 28

VII. REFERENCES FOR TEXT AND APPENDICES

................................ ................................ ........ 29

APPENDIX A

-- PUBLIC INVOLVEMENT INFORMATION

................................ ................................ . 30FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 3 of 70 APPENDIX B

-- GLOSSARY

................................ ................................ ................................ ..................... 31

APPENDIX C

-- C OMPLIANCE HISTORY ANDTECHNICAL CALCULATIONS

.............................. 35

APPENDIX D

-- RESPONSE TO COMMENTS

................................ ................................ ........................ 45FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 4 of 70 INTRODUCTION

The Federal Clean Water Act (FCWA, 1972, and later amendments in 1977, 1981, and 1987) established water quality goals for the navigable (surface) waters of the United States. One mechanism for achieving the goals of the Clean Water Act is t he National Pollutant Discharge Elimination System of permits (NPDES permits), administered by the federal Environmental Protection Agency (EPA). The EPA

authorized the s tate of Washington to manage the NPDES permit program in our state. Our state legisl ature accepted the delegation and assigned the power and duty for conducting NPDES permitting

and enforcement to the Department of Ecology (Ecology) . The legislature defined Ecology's authority and obligations for the wastewater discharge permit program i n 90.48 RCW (Revised Code of Washington).

Ecology adopted rules describing how it exercise s its authority:

Procedures Ecology follows for issuing NPDES permits ( c hapter 173

- 220 WAC)

Water quality criteria for surface waters ( c hapter 173

- 201A WAC) and for ground waters ( c hapter 173

- 200 WAC)

Sediment management standards ( c hapter 173

- 204 WAC)

Submission of Plans and Reports for Construction of Wastewater Facilities ( c hapter 173

- 240 WAC)

These rules require any industrial facility operator to obtain an NPDES permit before discharging wastewater to state waters. They also help define the basis for limits on each discharge and for performance requirements imposed by the permit.

Under the NPDES permit program and in response to a complete and accepted p ermit application Ecology must prepare a draft permit and accompanying fact sheet, and make them available for public

review before final issuance . Ecology must also publish an announcement (public notice) telling people where they can read the draft permit, and where to send their comments, during a period of thirty days (WAC 173

- 220

- 050). (See Appendix A

-- Public Involvement for more detail about the Public Notice and Comment procedures). After the Public Comment Period ends , Ecology may make changes to the draft NPDES permit in response to comment s

. Ecology will summarize the responses to comments and any changes to the permit in Appendix D

.

I. BA CKGROUND INFORMATION

Table 1

- General Facility Information

Applicant: TransAlta Centralia Generation, LLC

Facility Name and Address: TransAlta Centralia Generation, LLC 913 Big Hanford Road Centralia, WA98531

Type of Treatment: Outfall 001: Coal Pile Runoff

- Settling Pond

Stormwater Runoff

- S ettling Pond Cooling Tower Blowdown

– Settling Pond

Outfall 002 (Sanitary Effluent)

– Activated Sludge,

Oxidation D itch and DisinfectionFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 5 of 70 SIC Code 4911

– Electric Power Generation

Discharge Location: Hanaford Creek

Figure 1. Facility Location Map

– TransAlta Power Plant

A. Facility Description

History

The TCG, a wholly owned subsidiary of TransAlta Corporation, operates a coal

- fired electricity generating power plant located approximately six miles northeast of Centralia, Washington. TCG operations consist of two, 702.5 Megawatt turbine units that are fueled by coal supplied from out of state coal providers located in t he Powder River Basin on the Montana/Wyoming border. In addition, TCG operates a 250 Megawatt natural gas power plant on the same site utilizing four gas turbine engines and a single heat recovery steam generator. The TCG has operated continuous ly since 1971 with no significant

alteration. Ecology and EPA classify it as a NPDES major facility.

Electricity d emand typically peaks in the winter and the plant occasional ly shutdowns in the spring and

summer when electricity demand is low

. TCG uses these periods to maintain the facility. When operating conditions are ideal, the facility generates electricity continuously for months at a time. TCG employ s approximately 325 employees . Operations personnel work two 12

- hour shifts, other personnelFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 6 of 70 (adminis trative) work 8

- hour shifts on regular Monday through Friday business hours, and maintenance personnel work 10

- hour shifts Monday through Thursday.

Industrial Process

TCG generates electrical power by burning coal mined in Montana and Wyoming. TCG utilizes its two boiler units to generate 1,405,000 kilowatts of electrical power per hour, typically totaling between 7,000,000 and 12,000,000 megawatt hours per year. TC G uses approximately 26,000,000 gallons of water per day when operating . A pproxima tely 17,250,000 gallons per day evaporates as the water cool s the steam

- electric generating process . TCG uses approximately 2,000,000 gallons per day for air pollution control in the current Wet Flue Gas Desulfurization (WFGD) (also referred as scrubber) operations.

TCG draws water for this operation from the Skookumchuck River and the process water discharges to
the Hanaford Creek. Domestic sewage is also generated on the TransAlta site both at the TCG and the TransAlta Centralia Mining (TCM) facility adjacent to the power plant. Table 2 summarizes wastewater generation.

Table 2

- Wastewater Generation

Source Approximate Discharge

, MGD

Sanitary Effluent 0.01

Scrubber wastewater 0.04

Coal pile stormwater runoff 0.5

Plant stormwater runoff 0.4

Cooling tower blowdown 2.4

Water Treatment

TCG owns and operates its own water treatment plant. Intake water is drawn from the Skookumchuck

River at a rate of 26 MGD

. The facility pumps intake water to the surge pond (Figure 3 ), then treats it with filtration, deionization, and reverse osmosis and then uses it for all power plant and potable water

demands.

Wastewater Treatment

A. General Description

T CG treats t he c oal pile storm water runoff (CPRO) using flocculation and settling. Sanitary effl uent is treated by the activated sludge process

. TCG treats its stormwater runoff and cooling tower blowdown in lagoons in the winter; however, during the summer, it treats th e s e wastewater stream s by discharging the

water to pond 3E and/or reusing it in the Wet Flue Gas Desulfurization ( WFGD ) (Figure 3 ) scrubbers

.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 7 of 70 Figure 2 . Wastewater Treatment System NetworkFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 8 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 9 of 70 B. Wastewater Treatment Procedure

1. Oil Skimmer Pond

TCG uses this 130,000

- gallon pond to contain any floating oil or other floating debris from potentially oil

contaminated areas. The areas that drain to this pond include :

Plant floor drain s

Transformer basin drains

Fuel oil and lube oil storage basin drains

Compressor building sump pump drains

Demineralizer neutralization tank drain

Turbine bay sumps

2. South Effluent Pond

The following areas drain to this 5,000, 000

- gallon pond

.

Circulating water cooling tower blowdown

Units 1 and 2 boiler drains

BHP facilities

Air pre

- heater wash drains

Cooling tower basin drains

Circulating water system drains

Bottom as h system surge tank overflows

Ultra

- pure water treatment plant

3. North Effluent Pond

This pond has a nominal capacity of 3,000,000 gallons. Water passes through a sub

- surface culvert from the south effluent pond to the north effluent pond. Due to the fact that this culvert is below the normal water level, and is further protected by a fl oating boom, all floating material is effectively trapped in the south pond. In addition, the pond’s detention time allows most of the suspended solids adequate time to settle out in the south pond. TCG re uses the North Effluent Pond water for:

The p lan t fire protection system

– the primary sources of fire system water are the north ef fluent pond wastewater pumps and the wastewater booster pumps (which are located on the south side of unit 2)

.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 10 of 70 Bottom ash system make

- up

.

Fly ash bin yard drain wash water

.

Dilution water for the CPRO chemicals

.

Wash

- down water

.

In the event wastewater levels exceed safe pond capacity, provision is made to dispose of excess wastewater by pumping to the coal pile runoff ( CPRO ) treatment ponds.

4. Wastewater Pumping Systems

TCG uses the following pumping systems to direct wastewater :

North Effluent Pond wastewater p umps

– Located just outside (south) of the north effluent pond pump house

Two wastewater pumps rated at 3,000 gallons per minute (gpm) and provide wastewater for most plant processes

One north effluent pond irrigation pump rated at 3,000 gpm and used to pump wastewater to the

wastewater system

5. Sewage (Domestic wastewater) Tr eatment Train

TCG operates a small, packaged, activated sludge sewage treatment plant designed for a maximum flow

rate of 36,000 gallons per day . This extended aeration, activated sludge; secondary treatment plant handles normal plant sewage from the T CG, Big Hanaford Project (BHP) and the TransAlta Centralia Mining ( TCM ) f

acilities. This process consists of four major components:

Raw s ewage p ump house

Treatment plant

Oxidation pond

Chlorination contact chamber

Raw sewage flows by gravity into the sump under the floor of the pump house and activates o ne of the two lift pumps. Sewage is pumped through a splitter gate which allows approximately 20 percent of the flow to enter the treatment plant and recycles 80 pe rcent back into the sump. This allows a relatively steady flow to enter the plant rather than a series of heavy, or “shock loads”.

From the splitter gate, the sewage flows into the aeration basin where diffused air is introduced at timed

intervals producing O 2 level high enough to sustain aerobic bacteria present in the sewage.

From the aeration basin, the sewage flows into the clarifier where the heavy floc formed in the aeration basin readily settle to the bottom and the clear, “treated”, super natant discharges to the oxidation pond.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 11 of 70 The settled floc, or sludge, is then returned by a sump system from the bottom of clarifier back to the

aeration basin where it re

- mixes with incoming sewage.

The oxidation pond serves a two

- fold purpose. It s approximate ten day retention period allows the O 2 level of the treated sewage to increase to a level more acceptable for discharge into a receiving stream. In addition, it provides a buffer zone for any occasional plant upsets that may allow heavier soli d materials to escape from the clarifier.

TCG treats the effluent from the oxidation pond with sodium hypochlorite to remove any possible

disease

- carrying bacteria before ultimate discharge into Hanaford Creek. Retention time in the chlorine

contact cham

ber is approximately 6 to 8 hours

. Effluent from the chlorine contact chamber enters the CPRO ditch and flows to the series of CPRO ponds before final discharge into Hanaford Creek

.

6. CP R O Operation

TCG contains runoff from the coal storage area within a system of dikes and directs it through a series of ponds for treatment to remove suspended solids before discharge into Hanaford Creek. In addition to water coming directly from the coal pile, sewage treatment plant effluent and yard drains from other areas within the plant drain to this outfall. The primary treatment method for the CPRO system consists of flocculation by the addition of aluminum sulfate and polymer.

A lum inum sulfate is pumped directly from the bulk storage tank to the culvert inlet next to the CPRO pump house. Laboratory personnel determine and set the correct pump stroke. Anionic or Cationic

p olymer is added at the mixing box located between the CPRO pump house and Hanaford Creek. This treatment makes larger and heavier floc par ticles, which then settles in the CPRO pond system.

7. Discharge to Mine Pond 3E

When the CPRO pond temperature rises due to ambient air temperatures, such that the facility cannot

meet the Outfall 001 temperature requirements, it pumps this w a s te water from the north effluent pond to

Mine Pond 3E and/or the WFGD and conduct s the applicable monitoring.

Solid Waste Management

Below is a listing and description of solid waste generated by TCG:

Recyclables

Scrap Steel

– Steel is collected from around the site in specially marked “scrap steel” recycling bins and are then aggregated into large dumpsters. Due to maintenance activities, the amount of the scrap metal recycled annually varies significantly but can be as much as 174 tons recycled in 2007.

Office Paper/Cardboard

– TCG recycles office paper and card boards in marked containers located in all office spaces and in the warehouse. Although estimated at over 75 percen t recycled, vendor recycling

this material do es not supply TCG with a mass of the recycled materials.

Plastics and Metals

- TCG has recently started recycling spent plastic (water bottles, etc) as well as aluminum cans. TCG has not started accounting for this material on a mass basis for tracking and reporting.

Tires

– All tires are recycled through TCG’s tire suppliers.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 12 of 70 Other

– Spent chemicals and oil and containers are all recycled with the product manufacturers. Many manufacturers hold a “deposit” for container which act s an incentive for recyc ling.

Standard Solid Waste Refuse

TCG aggressively pursues opportunities to re

- use and recycle solid wastes. Many wastes still require off

- site disposal and are wastes common to households , municipalities and businesses. They consist of packaging containers, non

- recyclable plastic and rubber material etc. All solid waste s are collected within TCG physical boundary, where it collects and monitors all stormwater and wastewater for contamina nts,
and treats as necessary prior to discharge.

Sludge Disposal

Sludge disposal at TCG consists of three main types:

Sewage treatment plant sludge

CPRO sludge

Effluent pond cleaning sludge

Sewage Treatment Plant Sludge

A local contractor disposes of the normal operational sludge and its volume average s 3,000 to 5,000 gallons per quarter. As needed, the facility performs a general sewage treatment plant cleaning.

CPRO Sludge Disposal

The facility current ly disposes of the CPRO sediment by pump ing it with a floating dredge and booster pumps to a dewatering pond on the east appendage of the coal pile.

Effluent Pond Cleaning

TCG uses the wastewater from the north effluent pond for various plant processes. The largest portion is used in ash handling systems. Overflow from the ash system returns to the south effluent pond. This constitutes the major source of the settable suspended solids in the effluent ponds. Another source of solids is silt from various yard drain s. TCG periodically removes these solids using a floating dredge and dewaters the waste using the same method as for the CPRO sediment. The total volume of sediment

handled varies , but it range s from 5,000 to 10,000 cubic yards per year.

DISCHARGE OUTFAL LS

This NPDES permit authorizes wastewater discharge through two o utfalls (Outfall s 001 and 002).

Outfall 001

- The list below identifies the sources of discharge through outfall 001:

Outfall 002 (domestic wastewater effluent)

South and north effluent pond sFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 13 of 70 Coal pile runoff

The discharge flows for the TCG are conveyed through various drains and pipe lines from the TCG facility to a series of settling ponds. The CPR O treatment ponds are the confluence of the north and the south pond system. The coo ling tower blow down, coal pile runoff, site stormwater runoff and treated sanitary wastewater flows during the wet season operations. The CPR O ponds are divided by berms and curtains into eight cells. The final cell discharges to the monitoring station (parshall flume) and then Big

Hanford Creek.

Outfall 002

- TCG designed this internal outfall to monitor the quality of domestic waster (Sanitary sewage) system , with a rated capacity of 20,000 gallons per day (30

- day average). The wastewater through this outfall combines with the outfall 001 discharge at the CPRO treatment collection box.

B. Permit Status

TCG submitted an application for permit renewal on January 27, 2009

. Ecology accepted it as complete

on February 3, 2009

.

C. Summary of Compliance with Previous Permit Issued

Ecology staff last conducted a non

- sampling c ompliance inspection on December 4, 2008

.

TCG for the most part has complied with the effluent limits and permit conditions throughout the duration

of the permit issued on June 30, 2005

. There were a number of exceptions in which T CG failed to comply with the permit requirements. Ecology assessed facility compliance based on its review of the facility’s Discharge Monitoring Reports (DMRs) and inspections conducted by Ecology

. The permit violations are appended in appendix C of this fact sheet.

D. Wastewater Characterization

The concentration of pollutants in the discharge was reported in the NPDES application and in discharge monitoring reports. The tabulated data represents the quantity and quality of the effluent discharged during the time period of July 1 , 200 5

, through February 2010

. Th e following statistical analysis shows

that the P ermittee

, for the most part

, has remained within the permit limits.

Table 3 : Outfall 001 discharge characteristics, D ischarge to Hanaford Creek

Combined domestic and process wastewater discharge

Parameter Minimum Maximum Average Median No. of data point s Permit

limit

, maximum

Flow, MGD 0.56 8 3.57 3.3 39 12.12

Total Residual Chlorine, mg/L 0.00 0.87 0.095 0.04 39 0.20

Oil and Grease, mg/L 2 2.4 2.066 2 6 20

Total Suspended Solids, mg/L 1.5 36.7 7.143 4.8 39 100

Chromium, Total, mg/L 0.007 0.009 0.0074 0.007 5 0.2FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 14 of 70 Combined domestic and process wastewater discharge

Parameter Minimum Maximum Average Median No. of data point s Permit

limit

, maximum

Zinc, mg/L 0.001 0.02 0.008 0.006 5 1

Dissolved Oxygen, mg/L 8.25 13.7 10.61 10.60 39 8 ( minimum)

Temperature, Background,

o C 3.95 18 9.65816 8.9 49 N/A

Turbidity , Background , NTU 1.3 50 12.09 9.32 54 N/A

Table 4

- Domestic wastewater discharge characteristics

Outfall 002

– Domestic wastewater discharge

Parameter Minimum Maximum Average Median No. of data points Permit

Limit (maximum)

Flow, MGD 0.006 0.0251 0.0133 0.0130 56 0.036

BOD, mg/L 2 142 17.2 8 56 45

TSS, mg/L 0.4 36.8 11. 4 10.2 56 45

Total Residual Chlorine , mg/L 0.5 3.5 1.425 1.45 45 2 .0

Fecal Coliform #/100m L 0 336 41 4.5 56 400

E. Description of the Receiving Water

TCG discharges to Hanaford Creek . Other nearby point

- source s outfalls include

, TransAlta Centralia Mining and Limited Purpose Landfill discharges . Significant nearby non

- point sources of pollutants are not know n

.

F. SEPA Compliance

Regulation exempts reissuance or modification of any wastewater discharge permit from the SEPA process as long as the permit contains conditions are no less stringent than state rules and regulations. The exemption applies only to existing discharges, not to new discharges.

II. PROPOSED PERMIT COND ITIONS

Federal and s tate regulations require that effluent limits in an NPDES permit must b e either technology or water quality

- based

.

Technology

- based limits are based upon the treatment methods available to treat specific pollutants. Technology

- based limits are set by the EPA and published as a regulation, or Ecology develops the limit on a case

- by

- case basis (40 CFR 125.3, and chapter 173

- 220 WAC).FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 15 of 70 Water quality

- based limit s are calculated so that the effluent will comply with the Surface Water Quality Standards ( c hapter 173

- 201A WAC), Ground Water Standards ( c hapter 173

- 200 WAC), Sediment Quality Standards ( c hapter 173

- 204 WAC) or the National Toxics Rule (40 CFR 131.36).

Ecology must apply the most stringent of these limits to each parameter of concern. These limits

are described below.

The limits in this permit reflect information received in the application and from supporting reports (engineering, hydrogeology, etc.)

. Ecology evaluated the permit application and determined the limits needed to comply with the rules adopted by the s tate of Washington. Ecology does not develop effluent

limits for all reported pollutants

. Some pollutants are not treatable at the concentrations reported, are not controllable at the source, are not listed in regulation, and do not have a reasonable potential to cause a water quality viola tion.

Nor does Ecology usually develop permit limits for pollutants that were not reported in the permit application but that may be present in the discharge. T he permit does not authorize discharge of the non

reported pollutants. During the five

- year permit term, the facility’s e ffluent discharge conditions may change from those conditions reported in the permit application. The facility must notify Ecology , as described in 40 CFR 122.42(a), i f significant changes occur in any constituent

. Industrie s may be in

violation of their permit until Ecology modifies the permit t o reflect additional discharge of pollutants.

A. D esign Criteria

According to WAC 173

- 220

- 150 (1)(g), neither flows nor waste loadings may exceed approved design criteria, however, Ecology does not have an engineering report that specifies the design criteria for the wastewater treatment plant at this facility.

B. T echnology

- Based Eff luent Limit s

The applicable federal code for this type of discharge ( outfall 001) is 40 Code of Federal Regulations (CFR) 423 . T his code, 40 CFR 423, s tates the following:

“ 423.13 Effluent limitations guidelines representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

Except as provided in 40 CFR 125.30 through 125.32, any existing point source subject to this part must achieve the following effluent limitations representing the degree of effluent reduction attainable by the application of the best available technology economically achievable (BAT).

(a) There shall be no discharge of polychlorinated biphenyl compounds such as those commonly used for transformer fl uid.

(d)(1) The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown times the concentration listed below:

Table 5

- Cooling Tower Blowdown BAT Limits

Pollutan t or pollutant property BAT effluent limitations

Maximum Average concentration (mg/ L )FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 16 of 70 concentration (mg/ L )

Free available chlorine 0.5 0.2

Pollutant or pollutant property Maximum for any 1 day −(mg/

L ) Average of daily values for 30 consecutive days shall not exceed

=(mg/ L )

The 126 priority pollutants contained in chemicals added for cooling tower maintenance, except: ( 1 ) ( 1 )

Chromium, total 0.2 0.2

Zinc, total 1.0 1.0

1 No detectable amount.

(2) Neither free available chlorine nor total residual chlorine may be discharged from any unit for more than two hours in any one day and not more than one unit in any plant may discharge free available or total residual chlorine at any one time unless the utility can demonstrate to the Regional Administrator or State, if the State has NPDES permit issuing authority, that the units in a particular location cannot operate at or below this level of chlorination.

(3) At the permitting authority's discretion, instead of the monitoring specified in 40 CFR 122.11(b) compliance with the limitations for the 126 priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical m ethods in 40 CFR part 136. ”

Outfall 002

TCG has also domestic wastewater treatment plant and the applicable Code of F ederal R egulation (CFR) and Washington Administrative Code (WAC) are the following:

Technology

- Based Effluent Limits

Federal and state regulations define technology

- based effluent limits for municipal wastewater treatment plants. These effluent limits are given in 40 CFR Part 133 (feder al) and in chapter 173

- 221 WAC . These regulations are performance standards that constitute all known, available, and reasonable methods of prevention, control, and treatment (AKART) for municipal wastewater. Chapter 173

- 221 WAC lists the following technology

- based limits for pH, fecal coliform, BOD 5 , and TSS:

Table 6 : Technology

- based Limits for Outfall 002

.

Parameter Limit

pH The pH must measure within the range of 6 .0 to 9 .0 standard units.

Fecal Coliform Bacteria Monthly Geometric Mean = 200 organisms/100 mL Weekly Geometric Mean = 400 organisms/100 mLFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 17 of 70 Parameter Limit

BOD 5 (concentration) Average Monthly Limit is the most stringent of the following:

- 30 mg/L

- may not exceed fifteen percent (15 percent ) of the average

- influent concentration Average Weekly Limit = 45 mg/L

TSS (concentration) Average Monthly Limit is the most stringent of the following:

- 30 mg/L

- may not exceed fifteen percent (15 percent ) of the average

- influent concentration Average Weekly Limit = 45 mg/L

Chlorine Average Monthly Limit = 2.0 mg/L Maximum Daily Limit = 2.0 mg/L

The existing permit has a chlorine limit of 2.0 mg /L for outfall 002 and the facility is able to comply with it. The proposed permit includes the same limit. This chlorine limit is higher than the technology based and water quality based limits due to the fact that at this outfall 002, the P ermit t ee is not directly discharging their wastewater to the surface water. This outfall 002 is discharging to outfall 001 which does go to the surface water. The chlorine limit will change at outfall 001 to a stricter limit of 0.2 mg/L.

The technology

- based mass limits are based on WAC 173

- 220

- 130(3)(b) and 173

- 221

- 030(11)(b).

Monthly effluent mass loadings for both BOD5 and TSS (lbs/day) = maximum monthly design flow (0.036 MGD) x Concentration limit (30 mg/L) x 8.34 (conversion factor) = mass limit 9.0 lb/day.



### The weekly average effluent mass loading = 1.5 x monthly loading = 13.5 lbs/day

.

C. Surface Water Quality

- Based Effluent Limit s

The Washington State Surface Water Quality Standards ( c hapter 173

- 201A WAC) were designed to protect existing water quality and preserve the beneficial uses of Washington 's surface waters. W aste discharge permits must include conditions that ensure the discharge will meet established s urface w ater

q uality s tandards (WAC 173

- 201A

- 510 )

. W ater quality

- based effluent limits may be based on an

individual waste load allocation or on a waste load allocation developed during a basin wide total maximum daily loading study (TMDL).

Numerical Criteria for the Protection of Aquatic Life and Recre ation

Numerical water quality criteria are published in the Water Quality Standards for Surface Waters ( c hapter

173

- 201A WAC). They specify the levels of pollutants allowed in receiving water to protect aquatic life

and recreation in and on the water

. Ecology uses n umerical criteria along with chemical and physical data for the wastewater and receiving water to derive the effluent limits in the discharge permit. When surface water quality

- based limits are more stringent or potentially more stringent th an technology

- based

limits

, the discharge must meet the water quality

- based limits

.

Numerical Criteria for the Protection of Human HealthFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 18 of 70 The U.S. EPA has published 91 numeric water quality criteria for the protection of human health that are applicable to dischargers in Washington State ( 40 CFR 131.36 ). These criteria are designed to protect

humans from exposure to pollutants linked to cancer and other disease s , based on consuming fish and shellfish and drinking contaminated surface waters. The Water Quality Standards also include radionuclide criteria to protect humans from the effects of radioactive substances.

Narrative Criteria

Narrative water quality criteria ( e.g., WAC 173

- 201A

- 240 ( 1 ); 2006 ) limit the toxic, radioactive, or other

deleterious mate rial concentrations that the facility may discharge to levels below those which have the potential to :

A dversely affect designated water uses

.

C ause acute or chronic toxicity to biota

.

I mpair aesthetic values

.

A dversely affect human health.

Narrative criteria protect the specific designated uses of all fresh waters (WAC 173

- 201A

- 200 , 2006 ) and

of all marine waters (WAC 173

- 201A

- 210 ,; 2006 ) in the State of Washington.

Antidegradation

The purpose of Washington's Antidegradation Policy (WAC 173

- 201A

- 300

- 330; 2006) is to:

Restore and maintain the highest possible quality of the surface waters of Washington.

Describe situations under which water quality may be lowered from its current condition.

Apply to human activities that are likely to have an impact on the water quality of surface water.

Ensure that all human activities likely to contribute to a lowering of water quality, at a minimum, apply all known, available, and reasonable methods of prevention, control, and treatment (AKART).

A pply three Tiers of protection (described below) for surface waters of the state.

Tier I ensure s existing and designated uses are maintained and protected and applies to all waters and all sources of pollutions. Tier II ensure s that waters of a higher quality than the criteria assigned are not degraded unless such lowering of water quality is necessary and in the overriding public interest. Tier II applies only to a specific list of polluting activities. Tier III prevent s the degradation of waters formally listed as "outstanding resource waters," and applies to all sources of pollution.

A facility must prepare a Tier II analysis when a ll three of the following conditions are met :

The facility is planning a new or ex panded action

.

Ecology regulates or authorizes the action.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 19 of 70 The action has the potential to cause measurable degradation to existing water quality at the edge of a chronic mixing zone.

This facility must meet Tier I requirements.

Dischargers must maintain and protect existing and designated uses. Ecology may not allow any degradation that will interfere with, or become injurious to, existing or designated uses, except as provided for in chapter 173

- 201A WAC.

For waters that do not meet assigned criteria, or protect existing or designated uses, Ecology will take appropriate and definitive steps to bring the water quality back into compliance with the water quality standards.

Whenever the natural conditions of a water body are of a lower quality than the assigned criteria, the natural conditions constitute the water quality criteria. Where water quality criteria are not met because of natural conditions, human actions are not allowed to further lower the water quality, except where explicitly allowed in this chapter.

Ecology’s analysis described in this fact sheet demonstrates that the existing and designated uses of the receiving water will be protected under the conditions o f the proposed permit

.

Mixing Zones

A mixing zone is the defined area in the receiving water surrounding the discharge port(s), where wastewater mixes with receiving water. Within mixing zones the pollutant concentrations may exceed water quality numeri c criteria , so long as the diluting wastewater doesn’t interfere with designated uses of the receiving water body ( e.g., recreation, water supply , and aquatic life and wildlife habitat , etc .)

. The pollutant concentrations outside of the mixing zones must meet water quality numeric criteria

.

State and federal rules allow mixing zones because the concentrations and effects of most pollutants diminish rapidly after discharge, due to dilution. E cology defines mixing zone sizes to limit the amount of time any exposure to the end

- of

- pipe discharge could harm water quality, plants, or fish.

The state’s water quality standards allow Ecology to authorize mixing zones for the facility’s permitted wastewater discharges only if those discharges already receive all known, available, and reasonable methods of prevention, control and treatment (AKART ). Mixing zones typically require compliance with water quality criteria within a specified distance from the point of discharge; and use no more than 25

percent of the available width of the water body for dilution. Ecology uses modeling to estimate the amount of mixing within the mixing zone and determine the potential for violating the water quality

standards at the edge of the mixing zone and derive any necessary effluent limit s . Steady

- state models are the most frequently used tools for conducting m ixing zone analyses. Ecology chooses values for each

effluent and for receiving water variable s that correspond to the time period when the most critica l condition is likely to occur (see Ecology’s Permit Writer’ s Manual). Each critical condition parameter (by itself) has a low probability of occurrence and the resulting dilution factor is conservative. The term

“ reasonable worst

- case ” applies to these values.

The mixing zone analysis produces a numerical value called a d ilution factor (DF)

. A d ilution factor

represents the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. For example, a dilution factor of 10 means the effluent comprises 10 percent by volume and the

receivin g water comprises 90 percent of the total volume at the boundary of the mixing zone

. Ecology

uses d ilution factor s with the water quality criteria to c al culate reasonable potentials and effluent limits.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 20 of 70 Water quality standards include both aquatic life

- based criteria and human health

- based criteria. The former are applied at both the acute and chronic mixing zone boundaries ; the latter are applied only at the chronic boundary. The concentration of pollutants at the boundar ies of any of th ese mixing zones may

not exceed the numerical criteria for that zone.

Each aquatic life acute criteri on is based on the assumption that organisms are not exposed to that

concentration for more than one

- hour and more often than one exposure in three year s. Each aquatic life

chronic criteri on is based on the assumption that organisms are not exposed to that concentration for

more than four consecutive days and more often than once in three years.

The two types of human health

- based water quality criter ia distinguish between those pollutants linked to

non

- cancer effects (non

- carcinogenic) and those linked to cancer effects (carcinogenic). The human

health

- based water quality criteria incorporate several exposure and risk assumptions. These assumptions

include:

A 70

- year lifetime of daily exposures

.

A n ingestion rate for fish or shellfish measured in kg/day

.

A n ingestion rate of two liters/day for drinking water

A one

- in

- one

- million cancer r isk for carcinogenic chemicals.

The water quality standards impose certain conditions before allowing the discharger a mixing zone. This permit does not authorize a mixing zone.

D

. Designated Uses and Surface Water Quality Criteria

Applicable designated uses and surface water quality criteria are defined in c hapter 173

- 201A WAC. In addition, the U.S. EPA set human health criteria for toxic pollutants ( 40 CFR 131.36 ). Criteria applicable

to this facility’s discharge are summarized below in Table 7

.

Aquatic Life Uses are designated based on the presence of, or the intent to provi de protection for, the key uses. A ll indigenous fish and non

- fish aquatic species must be protected in waters of the state in addition to the key species. The Aquatic Life Uses for this rece iving water are identified

below

.

Table : 7 Aquatic Life Uses & Associated Criteria

Core Summer Salmonid Habitat

Temperature Criteria

– Highest 7DAD MAX 16°C (60.8°F)

Dissolved Oxygen Criteria 9.5 mg/L

Turbidity Criteria • 5 NTU over background when the background is
50 NTU or less; or

• A 10 percent increase in turbidity when the background turbidity is more than 50 NTU

Total Dissolved Gas Criteria Total dissolved gas shall not exceed 110 percent of saturation at any po int of sample collectionFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 21 of 70 pH Criteria pH shall be within the range of 6.5 to 8.5, with a

human

- caused variation within the above range of

less than 0.2 units

The recreational uses are extraordinary primary contact recreation, primary contact recreation, and secondary contact recreation. The recreational uses for this receiving water are identified

below.

Table 8 Recreational Uses & Associated Criteria

Recreational use Criteria

Primary Contact

Recreation Fecal coliform organism levels must not exceed a geometric mean value of 100

colonies /100 mL, with not more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 200 colonies /100 mL

The water supply use s are domestic, agricultural, industrial, and stock watering.

The miscellaneous fresh water use s are wildlife habitat, harvesting, commerce and navigation, boating, and aesthetics.

E. Evaluation of Surface Water Quality

- Based Effluent Limits for Numeri c Criteria

Pollutants in an effluent may affect the aquatic environment near the point of discharge (near field) or at a considerable distance from the point of discharge (far field). Toxic pollutants, for example, are near

- field pollutants

-- their advers e effects diminish rapidly with mixing in the receiving water. Conversely

, a pollutant such as biological oxygen demand (BOD) is a far

- field pollutant whose adverse effect occurs away from the discharge even after dilution has occurred. Thus, the method of calculating surface water quality

- based effluent limits varies with the point at which the pollutant has its maximum effect.

With technology

- based controls (AKART), the limits are higher than the water quality criteria limits for

chromium and chlorine

. Given an analysis of the past five years of data , this show ed that if there would have been water quality based limits; the P ermittee would have exceeded th ose limits for these t wo pollutants. In t his proposed NPDES permit , Ecology requires the P ermittee to continue to have the technology based limits for this permit cycle but within five years they must submit a plan and report to meet the water quality and technology based limits (see S1 1

. special condition of this permit )

.

Temperature

-- The state temperature standards (WAC 173

- 201A

- 200

- 210 and 600

- 612) include multiple

elements:

Annual summer maximum threshold criteria (June 15 to September 15)

Supplemental spawning and rearing season criteria (September 15 to June 15)

Incremental warming re strictions

Protections against acute effects

Ecology evaluates each criterion independently to determine reasonable potential and derive permit

limits.

Annual summer maximum and supplementary spawning/rearing criteriaFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 22 of 70 Each water body has an annual maxim um temperature criterion [WAC 173

- 201A

- 200(1 ) ( c), 210(1 )( c), and Table 602]. These threshold criteria (e.g., 12, 16, 17.5, 20°C) protect specific categories of aquatic life by controlling the effect of human actions on summer temperatures.

Some waters have an additional threshold criterion to protect the spawning and incubation of salmonids (9°C for char and 13°C for salmon and trout) [WAC 173

- 201A

- 602, Table 602]. These criteria apply during specific date

- windows.

The threshold criteria apply at the edge of the chronic mixing zone. Criteria for most fresh waters are expressed as the highest 7

- Day average of daily maximum temperature (7

- DADMax). The 7

- DADMax temperature is the arithmetic average of seven consecutive measures of daily maximum temperat ures. Criteria for marine waters and some fresh waters are expressed as the highest 1

- Day annual maximum temperature (1

- DMax).

Incremental warming criteria

The water quality standards limit the amount of warming human sources can cause under specific situations [WAC 173

- 201A

- 200(1)(c)(i)

- (ii), 210(1)(c)(i)

- (ii)]. The incremental warming criteria apply at the edge of the chronic mixing zone.

At locations and times when background temperatures are cooler than the assigned threshold criterion, point sou rces are permitted to warm the water by only a defined increment. These increments are permitted only to the extent doing so does not cause temperatures to exceed either the annual maximum or supplemental spawning criteria.

At locations and times when a threshold criterion is being exceeded due to natural conditions , all human sources, considered cumulatively, must not warm the water more than 0.3°C above the naturally warm

condition.

When Ecology has not yet completed a TMDL, our policy allows each poi nt source to warm water at the edge of the chronic mixing zone by 0.3°C. This is true regardless of the background temperature and even if doing so would cause the temperature at the edge of a standard mixing zone to exceed the numeric

threshold criteria

. Allowing a 0.3°C warming for each point source is reasonable and protective where

the dilution factor is based on 25 percent or less of the critical flow. This is because the fully mixed effect on temperature will only be a fraction of the 0.3°C cumulat ive allowance (0.075°C or less) for all human

sources combined.

Temperature Acute Effects

Instantaneous lethality to passing fish: The upper 99 th percentile daily maximum effluent temperature must not exceed 33°C; unless a dilution analysis indicates ambient temperatures will not exceed 33°C 2

- seconds after discharge.

General lethality and migration blockage: Measurable (0.3°C) increases in tempe rature at the edge of a chronic mixing zone are not allowed when the receiving water temperature exceeds either a 1DMax of

23°C or a 7DADMax of 22°C.

Lethality to incubating fish: Human actions must not cause a measurable (0.3°C) warming above

17.5°C at locations where eggs are incubating.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 23 of 70 Turbidity

-- The permit requires t urbidity monitoring to assess compliance with the water quality criteria for turbidity (see Table 8 ) because of potential fluctuations in turbidity of both the receiving water and the

effluent.

Toxic Pollutants

-- Federal regulations (40 CFR 122.44) require Ecology to place limits in NPDES permits on toxic chemicals in an effluent whenever there is a reasonable potential for those chemicals to exceed the surface water quality criteria. Ecology does not exempt f acilities with technology

- based effluent limits from meeting the surface w ater q uality s tandards

. Generally federal discharge limits are

more stringent than surface water quality standards, except zinc, chromium and total residual chlorine , for this type of discharge

.

40 CFR 423 requires that the P ermittee must achieve non

- detectable levels for the priority pollutants (priority pollutant less chromium and zinc) for the cooling tower blow down discharge before this water is discharged to the surface water ( Hanaford Creek ) . Th is NPDES permit requires the P ermit tee to conduct

and submit a priority pollutant an alysis report once per permit cycle . Ecology received an electronic copy of the priority pollutant analysis report on A pril 13, 2010. This report showed that the P ermittee has met the non detectable requirement for all priority pollutants except for the following parameters : Arsenic, Copper, Lead , Nickel, Selenium and Zinc

.

Ecology conducted a reasonable potential analysis (See Appendix C ) on chlorine, chromium

, arsenic and

selenium parameters to determine whether it would be necessary to require effluent limits in this permit. The reasonable potential analysis show ed that t here is no reasonable potential that the P ermittee would exceed the water quality criteria for arsenic. But this analysis did show that there wa s a reasonable potential that the P ermittee would exceed the water quality criteria for chlorine, chromium and selenium.

There were some parameters such as copper, lead, nickel and zinc which Ecology was unable to determine the reasonable potential that the P ermittee would exceed the water quality criteria because of the lack of the data. The new proposed permi t will require the P ermittee to collect hardness data for the

five year permit cycle

. This additional data will assist Ecology in calculating the water quality criteria

and reasonable potential analysis for the future

.

F. Whole Effluent Toxicity

Acute

WET testing conducted during effluent characterization showed no reasonable potential for effluent discharges to cause receiving water acute toxicity. The proposed permit does not impose an acute WET limit. TCG must retest the effluent before submitting an application for permit renewal. In addition:

If this facility makes process or material changes which, in Ecology's opinion, increase the potential for effluent toxicity, then Ecology may (in a regulatory order, by permit modification, or in the perm it renewal) require the facility to conduct additional effluent characterization.

If WET testing conducted for submittal with a permit application fails to meet the performance

standards in WAC 173

- 205

- 020, Ecology will assume that effluent toxicity has increased. TCG may demonstrate to Ecology that effluent toxicity has not increased, by performing additional WET testing after the process or material changes have been made.

ChronicFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 24 of 70 WET testing conducted during effluent characterization showed no reas onable potential for effluent discharges to cause receiving water chronic toxicity. The proposed permit does not impose a chronic WET limit. TCG must retest the effluent before submitting an application for permit renewal. In addition:

If this facility makes process or material changes which, in Ecology's opinion, increase the potential for effluent toxicity, then Ecology may (in a regulatory order, by permit modification, or in the permit renewal) require the facility to conduct additional effluent char acterization

If WET testing conducted for submittal with a permit application fails to meet the performance

standards in WAC 173

- 205

- 020, Ecology will assume that effluent toxicity has increased. TCG may demonstrate to Ecology that effluent toxicity has not increased by performing additional WET testing after the process or material changes have been made.

G. Human Health

Washington’s water quality standards include 91 numeric human health

- based criteria that Ecology must
consider when writing NPDES permits. These criteria were established in 1992 by the U.S. EPA in its

National Toxics Rule (40 CFR 131.36). The National Toxics Rule allows states to use mixing zone s to
evaluate whether discharges comply with human health criteria.

Ecology det ermined the effluent may contain chemicals of concern posing a risk to human health. Ecology determined this because data or process information indicat e s regulated chemicals occur in the discharge

.

H. Sediment Quality

The aquatic sediment standards ( WAC 173

- 204) protect aquatic biota and human health. Under t hese

standards Ecology may require a facility to evaluate the potential for its discharge to cause a violation of

sediment standards (WAC 173

- 204

- 400). You can obtain additional information about sed iments at the Aquatic Lands Cleanup Unit website. http://www.ecy.wa.gov/programs/tcp/smu/sediment.html Ecology could not determine at this time the potential for this discharge to cause a violation of sediment quality standards. If in the future Ecology determines a potential for violation of the Sediment Quality Standards, it will issue an order requir ing TCG to d emonstrate either :

The point of discharge i s not an area of deposition or,

Toxics do not accumulate in the sediments even though the point of discharge is a depositional

area

.

I. G round Water Quality Limits

The Ground Water Quality Standards

, (c hapter 173

- 200 WAC)

, protect beneficial uses of ground water. Permits issued by Ecology must not allow violations of those standards (WAC 173

- 200

- 100).

TCG does not discharge wastewater to ground and therefore Ecology imposed no permit limits to protect ground water.

J . Comparison o f Effluent Limits w ith Limits of t he Previous Permit Issued on June 30, 2005

Table 9 Comparison of Effluent LimitsFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 25 of 70 Basis of

Limit Previous Effluent Limits : Outfall # 001 Proposed Effluent Limits : Outfall # 001

Parameter Average Monthly Maximum Daily Average Monthly Maximum

Daily

Flow Technology 6.36 12.12 6.36 12.12
Total Suspended

Solids , mg/L Technology 30 100 30 100

Oil and Grease, mg/L Technology 15 20 15 20

Chromium, mg/L Technology 0.20 0.20 0.20 0.20
Zinc, mg/L Technology 1 .0 1 .0 1 .0 1 .0

Temperature, o C Water

Quality 18 ° C when

background is less

than 18 ° C. Background plus

0.3° C when background is greater than 18 ° C.

no increase more

than 28° C divided by background temperature plus 7. 1 8 ° C when

background is

less than 1 8 ° C. Background plus

0.3° C when background is greater than 1 8 °

C. no increase

more than 28° C divided by background temperature plus

7. 16 ° C when

background is

less than 16 °

C. Background plus 0.3° C

when background is greater than

16 ° C. No

increase more

than 28° C divided by background

temperature plus 7. 16 ° C when

background

is less than

16 ° C. Background plus 0.3° C

when background is greater

than 16 ° C.

N o increase

more than

28° C divided by background

temperature plus 7.

Oil and Grease

, visual No visible sheen No visible sheen No visible

sheen No visible

sheen

Dissolved Oxygen, mg/L Water

Quality Minimum, 8 mg/L N/A Minimum,

9.5 mg/L N/A

pH Technology 6.0

– 10.0 6.0

- 9 .0

Total Residual Chlorine , mg/L Technology 0.20 0. 5 0 0.20 0.20FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 26 of 70 Basis of

Limit Previous Effluent Limits : Outfall # 001 Proposed Effluent Limits : Outfall # 001

Parameter Average Monthly Maximum Daily Average Monthly Maximum

Daily

Turbidity (NTU) Water

Quality 5 NTU over

background when background is less

than 50 NTU.

Maximum 10%

increase over background when background is over

50 NTU. 5 NTU over

background

when background is

less than 50

NTU. Maximum

10% increase over background

when background is

over 50 NTU. 5 NTU over

background

when background is

less than 50

NTU.

Maximum

10% increase

over background

when background is

over 50 NTU. 5 NTU over

background

when background

is less than

50 NTU.

Maximum

10% increase

over background

when background

is over 50

NTU.
Priority

Pollutants less

chromium and zinc, μ g/L Technology Zero Zero Non

Detect able

amount Non

Detect able

amount

Basis of

Limit Previous Effluent Limits:

Outfall # 002 Proposed Effluent Limits:

Outfall # 002

Parameter Average Monthly Maximum Daily Average Monthly Average

weekly

Flow , MGD Technology 0.020 0.036 No Limit No Limit
Total Suspended

Solids Technology 30 mg/L 45 mg/L 30 mg/L, 9 lbs/day 45 mg/L,

13.5 lbs/day

BOD 5

, Technology 30 mg/L 45 mg/L 30 mg/L, 9 lbs/day 45 mg/L,

13.5 lbs/day

Parameter Average Monthly Maximum Daily Average Monthly Maximum

Daily

Fecal Coliform

#/100ml Technology 200 400 200 400

Total R esidual Chlorine , mg/L Technology 2.0 2.0 2.0 2.0

IV MONITORING REQUIREME NTS

Ecology requires m onitoring, recording, and reporting (WAC 173

- 220

- 210 and 40 CFR 122.41) to verify that the treatment process is functioning correctly and that the discharge complies with the permit’s

effluent limits

.

The monitoring schedule is detailed in the proposed pe rmit under Condition S.2. Specified monitoring frequencies take into account the quantity and variability of the discharge, the treatment method, past compliance, significance of pollutants, and cost of monitoring.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 27 of 70 A. Lab Accreditation

Ecology requires tha t facilities must use a laboratory registered or accredited under the provisions of chapter 173

- 50 WAC, Accreditation of Environmental Laboratories to prepare all monitoring data (with the exception of certain parameters)

.

V OTHER PERMIT CONDITI ONS

A. R eporting and Recordkeeping

Ecology base d permit condition S3

. on our authority to specify any appropriate reporting and recordkeeping requirements to prevent and control waste discharges (WAC 173

- 220

- 210).

B. N on Routine and Unanticipated Discharges

Occasionally, this facility may generate wastewater which was not characterized in the permit application because it is not a routine discharge and was not anticipated at the time of application. These wastes typically consist of waters used to pressure

- test storage tanks or fire water systems or of leaks from drinking water systems.

The permit authorizes non

- routine and unanticipated discharges under certain conditions . The facility

must characterize these waste waters for pollutants and examine the o pportunities for reuse. Depending on the nature and extent of pollutants in this wastewater and on any opportunities for reuse, Ecology may :

Authorize the facility to discharge the wastewater.

R equire the facility to treat the wastewater

.

R equire the fac ility to reuse the wastewater

.

C. S pill Plan

This facility stores a quantity of chemicals on

- site that have the potential to cause water pollution if accidentally released. Ecology can require a facility to develop best management plans to prevent this

accidental release [ section 402(a)(1) of the Federal Water Pollution Control Act (FWPCA) and RCW

90.48.080 ]

.

TCG developed a plan for preventing the accidental release of pollutants to state waters and for minimizing damages if such a spill occurs. The proposed permit requires the facility to update this plan

and submit it to Ecology

.

D. Solid Waste Control Plan

TCG could cause pollution of the waters of the state through inappropriate disposal of solid waste or through the release of leachate from solid waste. This proposed permit requires this facility to update the approved solid waste control plan designed to prevent solid waste from causing pollution of waters of the

state. The updated plan must be subm itted to Ecology for approval (RCW 90.48.080).

E. T reatment System Operating PlanFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 28 of 70 Ecology requires industries to take all reasonable steps to properly operate and maintain the ir wastewater treatment system i n accordance with state and federal regulations (40 CFR 122.41(e) and WAC 173

- 220

- 150 (1)(g) )

. The facility has prepared and submitted a n operation and maintenance manual as required by state regulation for the construction of wastewater treatment facilities (WAC 173

- 240

- 150).

I mplementation of the proce dures in the Treatment System Operating Plan ensures the facility’s compliance with the terms and limits in the permit.

F. G eneral Conditions

Ecology bases the standardized G eneral Conditions on state and federal law and regulations . They are

included in all individual industrial NPDES permits issued by Ecology

.

VI. PERMIT ISSUANCE PROC EDURES

A. P ermit Modifications

Ecology may modify this permit for any of the reasons specified in state or federal regulations. Ecology may modify this permit to impose num erical limit s , if necessary to comply with water quality standards

for s urface waters, with s ediment q uality s tandards, or with water quality standards for g round w aters, after obtaining new information from sources such as inspections, effluent monitoring, outfall studies, and effluent mixing studies. Ecology may also modify this permit to comply with new or amended state or federal regulations.

B. Proposed Permit Issuance

This proposed permi t includes all statutory requirements for Ecology to authorize a wastewater discharge

. The permit includes limit s and conditions to protect human health and aquatic life, and the beneficial uses

of waters of the s tate of Washington. Ecology proposes to is sue this permit for a term of five years.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 29 of 70 VII. REFERENCES FOR TEXT AND APPENDICES

Environmental Protection Agency (EPA)

1991. Technical Support Document for Water Quality

- based Toxics Control . EPA/505/2

- 90

- 001.

1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling

. USEPA Office of Water, Washington, D.C.

1985. Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in

Surface and Ground Water . EPA/600/6

- 85/002a.

1983. Water Quality Standards Handbook. USEPA Office of Water, Washington, D.C.

Tsivoglou, E.C., and J.R. Wallace.

1972. Characterization of Stream Reaeration Capacity . EPA

- R3

- 72

- 012. (Cited in EPA 1985 op.cit.)

Washington State Department of Ecology.

1994. Permit Writer’ s Manual . Publication Number 92

- 109

Washington State Department of Ecology.

2007. Focus Sheet on Solid Waste Control Plan, Developing a Solid Waste Control Plan for Industrial Wastewater Discharge Permittees. Publication Number 07

- 10

- 024

Washington Sta te Department of Ecology.

Laws and Regulations( http://www.ecy.wa.gov/laws

- rules/index.html )

Permit and Wastewater Related Information ( http://www.ecy.wa.gov/programs/wq/wastewater/index.html

Wright, R.M., and A.J. McDonnell.

1979. In

- stream Deoxygenation Rate Prediction . Journal Environmental Engineering Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.)FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 30 of 70 APPENDIX A

-- PU BLIC INVOLVEMENT INF ORMATION

Ecology proposes to reissue a permit to (insert the facility name) . The permit prescribes operating

conditions and wastewater discharge limit s. This fact sheet describes the facility and Ecology’s reasons for requiring permi t conditions

.

Ecology placed a P ublic N otice of A pplication on June 4,2009, and June 11, 2009, in the Daily Chronicle to inform the public about the submitted application and to invite comment on the reissuance of this permit.

Ecology will place a Public Notice on June 9, 2010, in the Daily Chronicle to inform the public and to invite comment on the proposed reissuance of this National Pollutant Discharge Elimination System permit as drafted.

The Notice

–

T ells where copies of the draft Permit and Fact Sheet are available for public evaluation (a local public library, the closest Regional or Field Office, posted on our website.).

O ffers to provide the documents in an alternate format to accommodate special needs.

A sks people to tell us how well the proposed permit would protect the receiving water.

I nvites people to suggest fairer conditions, limits, and requirements for the permit.

I nvites comments on Ecology’s determination of compliance with antidegradation rules.

U rges people to submit their comm ents, in writing, before the end of the c omment p eriod

T ells how to request a public hearing about the proposed NPDES Permit.

E xplains the next step(s) in the permitting process.

Ecology has published a document entitled Frequently Asked Questions about Effective Public Commenting which is available on our website at http://www.ecy.wa.gov/biblio/0307023.html

.

You may obtain f

urther information from Ecology by teleph one, 360

- 407

- 6280, or by writing to the permit writer at the address listed below

.



### Water Quality Permit Coordinator Department of Ecology Southwest Regional Office

P.O. Box 47775 Olympia, WA 98504

- 7775FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 31 of 70 APPENDIX B

-- GLOSSARY

1

- DMax or 1

- day maximum temperature

-- T he highest water temperature reached on any given day. This measure can be obtained using calibrated maximum/minimum thermometers or continuous monitoring probes having sampling intervals of thirty minutes or less.

7

- DADMax or 7

- day average of the daily maximum temperatures

-- T he arithmetic average of seven consecutive measures of daily maximum temperatures. The 7

- DADMax for any individual day is calculated by averaging that day's daily maximum temperature with the daily maximum temperatures of the three days prior and the three days after that date.

Acute Toxicity

-- The lethal effect of a compound on an organism that occurs in a short period of time, usually 48 to 96 hours.

AKART

-- The acronym for “all known, available, and reasonable methods of prevention, control and treatment.” AKART is a technology

- based approach to limiting pollutants from wastewater discharges which requires an engineering judgment and an economic judgment. AKART must be applied to all wastes and contaminants prior to e ntry into waters of the state in accordance with RCW 90.48.010 and 520, WAC 173

- 200

- 030(2)(c)(ii), and WAC 173

- 216

- 110(1)(a).

Ambient Water Quality

-- The existing environmental condition of the water in a receiving water body.

Ammonia

-- Ammonia is produced b y the breakdown of nitrogenous materials in wastewater. Ammonia is toxic to aquatic organisms, exerts an oxygen demand, and contributes to eutrophication. It also

increases the amount of chlorine needed to disinfe ct wastewater.

Annual Average Design Flow (AADF)

-- The average of the daily flow volumes anticipated to occur over a calendar year.

Average Monthly Discharge Limit

-- The average of the measured values obtained over a calendar

month's time.

Best Management Practices (BMPs)

-- Schedules of activities, prohibitions of practices, maintenance procedures, and other physical, structural and/or managerial practices to prevent or reduce the pollution of waters of the State. BMPs include treatment systems, operating procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw material storage. BMPs may be further categorized as operational, source control, erosion and sediment control, and treatment BMPs.

BOD 5 -- Determining the Biochemical Oxygen Dem and of an effluent is an indirect way of measuring the quantity of organic material present in an effluent that is utilized by bacteria. The BOD 5 is used in modeling to measure the reduction of dissolved oxygen in receiving water s after effluent is

discha rged. Stress caused by reduced dissolved oxygen levels makes organisms less competitive and less able to sustain their species in the aquatic environment. Although BOD is not a specific compound, it is defined as a conventional pollutant under the federa l Clean Water Act.

Bypass

-- The intentional diversion of waste streams from any portion of a treatment facility.

Chlorine

-- Chlorine is used to disinfect wastewaters of pathogens harmful to human health. It is also extremely toxic to aquatic life.

Chronic Toxicity

-- The effect of a compound on an organism over a relatively long time, often 1/10 of an organism's lifespan or more. Chronic toxicity can measure survival, reproduction or growth rates, or other parameters to measure the toxic effects of a compoun d or combination of compounds.

Clean Water Act (CWA)

-- The Federal Water Pollution Control Act enacted by Public Law 92

- 500, as amended by Public Laws 95

- 217, 95

- 576, 96

- 483, 97

- 117; USC 1251 et seq.FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 32 of 70 Compliance Inspection

- Without Sampling

-- A site visit for the purpose of determining the compliance of a facility with the terms and conditions of its permit or with applicable statutes and regulations.

Compliance Inspection

- With Sampling

-- A site visit for the purpose of determining the compliance of

a facility with the terms and conditions of its permit or with applicable statutes and regulations. In addition it includes as a minimum, sampling and analysis for all parameters with limits in the permit to ascertain compliance with those limits; and, for municipal facilities, sampling of influent to ascertain compliance with the 85 percent removal requirement. Ecology may conduct additional sampling.

Composite Sample

-- A mixture of grab samples collected at the same sampling point at different times,

forme d either by continuous sampling or by mixing discrete samples. May be "time

composite"(collected at constant time intervals) or "flow

- proportional" (collected either as a constant sample volume at time intervals proportional to stream flow, or collected b y increasing the volume of each aliquot as the flow increased while maintaining a constant time interval between the aliquots.

Construction Activity

-- Clearing, grading, excavation and any other activity which disturbs the surface of

the land. Such activit ies may include road building, construction of residential houses, office buildings, or industrial buildings, and demolition activity.

Continuous Monitoring

-- Uninterrupted, unless otherwise noted in the permit.

Critical Condition

-- The time during which the combination of receiving water and waste discharge conditions have the highest potential for causing toxicity in the receiving water environment. This situation usually occurs when the flow within a water body is low, thus, its ability to dilute effluent is

reduced.

Detection Limit

-- See Method Detection L evel.

Dilution Factor (DF)

-- A measure of the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. Expressed as the inverse of the percent effluent fraction e.g. , a dilution factor of 10 means the effluent comprises 10 percent by volume and the receiving water 90

percent

. Engineering Report

-- A document which thoroughly examines the engineering and administrative aspects of a particular domestic or industrial wastewater facility. The report must contain the appropriate information required in WAC 173

- 240

- 060 or 173

- 240

- 130.

Fecal Coliform Ba cteria

-- Fecal coliform bacteria are used as indicators of pathogenic bacteria in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are controlled by disinfecting the wastewater. The presence of high numbers of fecal co liform bacteria in a water body can indicate the recent release of untreated wastewater and/or the presence of animal feces.

Grab Sample

-- A single sample or measurement taken at a specific time or over as short a period of time

as is feasible.

Industrial W astewater

-- Water or liquid

- carried waste from industrial or commercial processes, as distinct from domestic wastewater. These wastes may result from any process or activity of industry, manufacture, trade or business, from the development of any natural r esource, or from animal operations such as feed lots, poultry houses, or dairies. The term includes contaminated storm water and, also, leachate from solid waste facilities.

Major Facility

-- A facility discharging to surface water with an EPA rating score of > 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 33 of 70 Maximum Daily Discharge Limit

-- The highest allowable daily discharge of a pollutant measured during a calendar day or any 24

- hour period that reasonably represents the calendar day for purposes of sampling. The daily discharge is calculated as the average measurement of the pollutant over the day.

Maximum Day Design Flow (MDDF)

-- The largest volume of flow anticipated to occur during a one

- day period, expressed as a daily average.

Maximum Month Design Flow (MMDF)

-- The largest volume of flow anticipated to occur during a

continuous 30

- day period, expressed as a daily average.

Maximum Week Design Flow (MWDF)

-- The largest volume of flow anticipated to occur during a

continuous 7

- day period, expressed as a daily average.

Method Detection Level (MDL)

-- The minimum concentration of a substan ce that can be measured and reported with 99 percent confidence that the pollutant concentration is above zero and is determined from analysis of a sample in a given matrix containing the pollutant

. Minor Facility

-- A facility discharging to surface water w ith an EPA rating score of < 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.

Mixing Zone

-- An area that surrounds an effluent discharge within which water quality criteria may be

exceeded. The area of th e authorized mixing zone is specified in a facility's permit and follows procedures outlined in state regulations ( c hapter 173

- 201A WAC).

National Pollutant Discharge Elimination System (NPDES)

-- The NPDES (Section 402 of the Clean Water Act) is the Federal wastewater permitting system for discharges to navigable waters of the United States. Many states, including the s tate of Washington, have been delegated the authority to issue these permits. NPDES permits issued by Washington State permit writers are j oint NPDES/State permits issued under both State and Federal laws.

pH

-- The pH of a liquid measures its acidity or alkalinity. It is the negative logarithm of the hydrogen ion

concentration. A pH of 7 .0 is defined as neutral, and large variations above or below this value are considered harmful to most aquatic life.

Peak Hour Design Flow (PHDF)

-- The largest volume of flow anticipated to occur during a one

- hour period, expressed as a daily or hourly average.

Peak Instantaneous Design Flow (PIDF)

-- The maximum anticipated instantaneous flow.

Quantitation Level (QL)

-- The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision &bias) achieves the objectives of the intended purpose. This may also be called Minimum Level or Reporting Level.

Reasonable Potential

-- A reasonable potential to cause a water quality violation, or loss of sensitive and/or important habitat.

Responsible Corporate Officer

-- A president, secretary, treasurer, or vice

- president of the corporation in charge of a principal business function, or any other person who performs similar policy

- or decision

making functions for the corporation, or the manager of one or more manufacturing, production, or operating facilities employing more than 250 persons or have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 dollars), if authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures (40 CFR 122.22).

Techno logy

- based Effluent Limit

-- A permit limit that is based on the ability of a treatment method to reduce the pollutant.

Total Suspended Solids (TSS)

-- Total suspended solids is the particulate material in an effluent. Large quantities of TSS discharged to re ceiving water s may result in solids accumulation. Apart from anyFACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 34 of 70 toxic effects attributable to substances leached out by water, suspended solids may kill fish, shellfish, and other aquatic organisms by causing abrasive injuries and by clogging the gills a nd respiratory passages of various aquatic fauna. Indirectly, suspended solids can screen out light and can promote and maintain the development of noxious conditions through oxygen depletion.

Solid waste

-- All putrescible and non

- putrescible solid and semisolid wastes including, but not limited to, garbage, rubbish, ashes, industrial wastes, swill, sewage sludge, demolition and construction wastes, abandoned vehicles or parts thereof, contaminated soils and contaminated dredged material, and recyclable materials.

State Waters

-- Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and watercourses within the jurisdiction of the state of Washington.

Stormwater

-- That portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water drainage system into a defined surface water body, or a constructed infiltration facility.

Upset

-- An exceptional incide nt in which there is unintentional and temporary noncompliance with technology

- based permit effluent limits because of factors beyond the reasonable control of the facility

. An upset does not include noncompliance to the extent caused by operational error

, improperly designed treatment facilities, lack of preventative maintenance, or careless or improper operation.

Water Quality

- based Effluent Limit

-- A limit on the concentration of an effluent parameter that is intended to prevent the concentration of that parameter from exceeding its water quality criterion after it is discharged into receiving water s

.FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 35 of 70 APPENDIX C

- COMPLIANCE HISTORY A ND

- TECHNICAL CALCULATIO NS

Several of the Excel ® spreadsheet tools used to evaluate a discharger’s ability to meet Washin gton State water quality standards can be found on Ecology ’s homepage at : http://www.ecy.wa.gov/programs/eap/pwspread/pwspread.html

.FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 36 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 37 of 70 Table 2

- Priority Pollutant Laboratory Report Submitted on April 13, 2010

Matrix Date

Sampled Date

Received Date

Analyzed Method Compound Result Qualifiers Units MDL PQL

Water 11/20/2008 11/20/2008 11/20/2008 EPA 150.1 pH 8.02 pH Units NA NA

Water 11/20/2008 11/20/2008 12/1/2008 EPA 1664

- A Oil and Grease 2 U mg/L 1.84 2

Water 11/20/2008 11/20/2008 11/26/2008 EPA 200.7 Boron 2000 μg/L 40 150

Water 11/20/2008 11/20/2008 11/26/2008 EPA 200.7 Tin 50 U μg/L 32 50

Water 11/20/2008 11/20/2008 11/26/2008 EPA 200.7 Titanium 10 U μg/L 4.9 10

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Aluminum 210 μg/L 0.17 0.82

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Antimony 2 μg/L 0.07 0.21

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Arsenic 5 μg/L 0.08 0.24

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Barium 180 μg/L 0.05 0.15

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Beryllium 0.15 U μg/L 0.05 0.15

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Cadmium 0.18 U μg/L 0.06 0.18

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Chromium 7 μg/L 0.07 0.2

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Cobalt 0.13 μg/L 0.04 0.11

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Copper 2 μg/L 0.06 0.18

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Iron 1 U μg/L 5.6 28

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Lead 0.22 μg/L 0.06 0.17

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Magnesium 19000 μg/L 5.9 29

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Manganese 54 μg/L 0.05 0.15

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Molybdenum 21 μg/L 0.66 0.29

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Nickel 1 μg/L 0.05 0.14

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Selenium 3 μg/L 0.13 0.39

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Silver 0.22 U μg/L 0.08 0.22

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Thallium 0.28 U μg/L 0.06 0.28

Water 11/20/2008 11/20/2008 11/21/2008 EPA 200.8 Zinc 1 μg/L 0.11 0.33

Water 11/20/2008 11/20/2008 11/25/2008 EPA 350.3 Ammonia 0.2 U mg/L

- N 0.08 0.20

Water 11/20/2008 11/20/2008 12/3/2008 EPA 375.4 Sulfate 440 mg/L 0.98 5.0

Water 11/20/2008 11/20/2008 11/24/2008 EPA 420.1 Total

Phenolics 0.01 U mg/L 0.006 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 4,4'

- DDD 0.01 U μg/L 8E

- 04 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 4,4'

- DDE 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 4,4'

- DDT 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Aldrin 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 alpha

- BHC 0.01 U μg/L 0.001 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Alpha

Chlordane 0.01 U ug/L 0.001 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 beta

- BHC 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 12/1/2008 EPA 608 Decachlorobip henyl 110 % N/A N/AFACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 38 of 70 Matrix Date

Sampled Date

Received Date

Analyzed Method Compound Result Qualifiers Units MDL PQL

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 delta

- BHC 0.01 U μg/L 8E

- 04 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Dieldrin 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Endosulfan I 0.01 U μg/L 0.001 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Endosulfan II 0.01 U μg/L 9E

- 04 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Endosulfan

Sulfate 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Endrin 0.01 U μg/L 0.001 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Endrin Aldehyde 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Endrin Ketone 0.01 U μg/L 0.008 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 gamma

- BHC (Lindane) 0.01 U μg/L 0.001 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 gama

Chlordane 0.01 U μg/L 0.001 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Heptachlor 0.01 U μg/L 0.007 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Heptachlor Epoxide 0.01 U μg/L 0.002 0.01

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Methoxychlor 0.01 U μg/L 0.006 0.01

Water 11/20/2008 11/20/2008 12/1/2008 EPA 608 PCB 0.1 U μg/L 0.012 0.1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Tetrachloro

M

- Xylene 99 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 608 Toxaphene 1 U μg/L 0.11 1.0

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,1,1

- Trichloroethan

e 1 U μg/L 0.26 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,1,2,2

- Tetrachloroeth

ane 1 U μg/L 0.15 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,1,2

- Trichloroethan

e 1 U μg/L 0.19 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,1

- Dichloroethane 1 U μg/L 0.20 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,1

- Dichloroethyle

ne 1 U μg/L 0.39 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,2

- Dichloroethane 1 U μg/L 0.15 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,2

- Dichloroethane

- d4 104 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 1,2

- Dichloropropa

ne 1 U μg/L 0.31 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 2

- Chloroethylvin yl Ether 10 U μg/L 0.72 10

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 4

- Bromofluorobe

nzene 110 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Acrolein 10 U μg/L 5.92 10

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Acrylonitrile 10 U μg/L 0.65 10

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Benzene 1 U μg/L 0.32 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Bis

chloromethyl

ether 1 U μg/L 0.72 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Bromoform 1 U μg/L 0.16 1FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 39 of 70 Matrix Date

Sampled Date

Received Date

Analyzed Method Compound Result Qualifiers Units MDL PQL

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Carbon

Tetrachloride 1 U μg/L 0.08 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Chlorobenzene 1 U μg/L 0.17 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Chlorodibromo

methane 1 U μg/L 0.17 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Chloroethane 1 U μg/L 0.5 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Chloroform 1 U μg/L 0.11 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 cis

- 1,3

- Dichloroprope

ne 1 U μg/L 0.24 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Dibromofluoro

methane 85 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Dichlorobromo

methane 1 U μg/L 0.20 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Dichlorodifluo

romethane 1 U μg/L 0.20 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Ethylbenzene 1 U μg/L 0.20 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Methyl

Bromide 1 U μg/L 0.29 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Methyl

Chloride 1 U μg/L 0.29 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Methylene

chloride 1 U μg/L 1.32 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Tetrachloroeth ylene 1 U μg/L 0.38 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Toluene 1 U μg/L 0.26 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Toluene

- d8 116 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 trans

- 1,2

- Dichloroethyle

ne 1 U μg/L 0.28 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 trans

- 1,3

- Dichloroprope

ne 1 U μg/L 0.15 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Trichloroethyl

ene 1 U μg/L 0.22 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Trichlorofluor

omethane 1 U μg/L 0.16 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 624 Vinyl chloride 1 U μg/L 0.11 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 1,2,4

- Trichlorobenze

ne 2.5 U μg/L 0.27 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 1,2

- Dichlorobenze

ne 2.5 U μg/L 0.19 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 1,3

- Dichlorobenze

ne 2.5 U μg/L 0.18 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 1,4

- Dichlorobenze

ne 2.5 U μg/L 0.24 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,4,6

- Tribromophen

ol 112 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,4,6

- Trichlorophen

ol 2.5 U μg/L 0.32 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,4

- Dichloropheno

l 2.5 U μg/L 0.41 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,4

- Dimethylphen

ol 2.5 U μg/L 0.43 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,4

- Dinitrophenol 10 U μg/L 0.69 10FACT SHEET FOR NPDES PERMIT WA 0001546

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### Page 40 of 70 Matrix Date

Sampled Date

Received Date

Analyzed Method Compound Result Qualifiers Units MDL PQL

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,4

- Dinitrotoluene 2.5 U μg/L 0.35 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2,6

- Dinitrotoluene 2.5 U μg/L 0.37 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2

- Chloronaphtha

lene 2.5 U μg/L 0.14 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2

- Chlorophenol 2.5 U μg/L 0.26 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2

- Fluorobiphenyl 71 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2

- Fluorophenol 79 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 2

- Nitrophenol 2.5 U μg/L 0.38 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 3,3

- Dichlorobenzi

dine 20 U μg/L 11.2 20

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 3,4

- Benzofluorant

hene 1 U μg/L 1.00 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 4,6

- Dinitro

- o

Cresol 10 U μg/L 0.66 10

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 4

- Bromophenyl

phenylether 2.5 U μg/L 0.25 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 4

- Chlorophenyl

phenylether 2.5 U μg/L 0.29 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 4

- Nitrophenol 2.5 U μg/L 0.9 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Acenaphthene 1 U μg/L 0.21 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Acenaphthylen

e 1 U μg/L 0.25 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Anthracene 1 U μg/L 0.21 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Azobenzene 2.5 U μg/L 0.24 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Benzidine 20 U μg/L 0.38 20

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Benzo(a)Anthr

acene 1 U μg/L 0.15 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Benzo(a)Pyren

e 1 U μg/L 0.53 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Benzo(ghi)Per ylene 1 U μg/L 0.49 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Benzo(k)Fluor

anthene 1 U μg/L 0.76 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 bis(2

- Chloroethoxy)

Methane 2.5 U μg/L 0.24 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Bis(2

- Chloroethyl)Et

her 2.5 U μg/L 0.21 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 bis(2

- chloroisopropy l)Ether 2.5 U μg/L 0.23 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 bis(2

- Ethylhexyl)Pht

halate 2.5 U μg/L 0.33 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Butylbenzyl phthalate 2.5 U μg/L 0.50 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Chrysene 1 U μg/L 0.24 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Dibenz(a,h)An

thracene 1 U μg/L 0.56 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Diethylphthala

te 2.5 U μg/L 0.19 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Dimethyl

Phthalate 2.5 U μg/L 0.19 2.5FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 41 of 70 Matrix Date

Sampled Date

Received Date

Analyzed Method Compound Result Qualifiers Units MDL PQL

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Di

- n

Butylphthalate 2.5 U μg/L 0.22 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Di

- n

- Octyl

Phthalate 2.5 U μg/L 1.12 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Fluoranthene 1 U μg/L 0.46 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Fluorene 1 U μg/L 0.33 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Hexachloroben

zene 2.5 U μg/L 0.13 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Hexachlorobut

adiene 2.5 U μg/L 0.24 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Hexachlorocyc lopentadiene 2.5 U μg/L 0.77 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Hexachloroeth

ane 2.5 U μg/L 0.27 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Indeno(1,2,3

- cd)Pyrene 1 U μg/L 0.56 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Isophorone 2.5 U μg/L 0.25 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Naphthalene 1 U μg/L 0.12 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Nitrobenzene 2.5 U μg/L 0.28 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Nitrobenzene

d5 73 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 N

nitrosodimethy

lamine 2.5 U μg/L 0.83 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 N

- Nitroso

- Di

n

- Propylamine 2.5 U μg/L 0.30 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 N

Nitrosodiphen ylamine 2.5 U μg/L 1.60 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 P

- Chloro

- m

Cresol 2.5 U μg/L 0.43 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Pentachloroph

enol 10 U μg/L 0.28 10

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Phenanthrene 1 U μg/L 0.22 1

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Phenol 2.5 U μg/L 0.28 2.5

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Phenol

- d6 80 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 p

- Terphenyl

d14 94 % N/A N/A

Water 11/20/2008 11/20/2008 11/26/2008 EPA 625 Pyrene 1 U μg/L 0.29 1

Water 11/20/2008 11/20/2008 12/2/2008 SM 2120B Color 43 Color

Units 5.8 15

Water 11/20/2008 11/20/2008 11/25/2008 SM 2540

- D Total Suspended

Solids 4 mg/L 0.49 0.50

Water 11/20/2008 11/20/2008 11/25/2008 SM 4500

- F C Fluoride 2.1 mg/L 0.025 0.20

Water 11/20/2008 11/20/2008 11/26/2008 SM 5210 B BOD 5.2 mg/L N/A 2.0

Water 11/20/2008 11/20/2008 11/26/2008 SM 5220

- D COD 2 U mg/L 0.31 2.0

Water 11/20/2008 11/20/2008 11/21/2008 SM 9222D Fecal Coliform by MF 40 CFU/100

ml N/A 1

Water 11/20/2008 11/20/2008 11/20/2008 SM4500

- Cl

G Total Residual

Chlorine 0.04 mg/L 0.017 0.04

Water 11/20/2008 11/20/2008 11/21/2008 SM4500CN

E Total Cyanide 0.01 U mg/L 0.004 0.01

Water 11/20/2008 11/20/2008 11/21/2008 SM4500NO2

B Nitrite 0.04 mg/L

- N 0.004 0.01

Water 11/20/2008 11/20/2008 11/25/2008 SM4500NO3

E Nitrate 4.8 mg/L

- N 0.24 0.5

Water 11/20/2008 11/20/2008 11/26/2008 SM4500

- P E Total Phosphorus 0.2 mg/L 0.066 0.2FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 42 of 70 Matrix Date

Sampled Date

Received Date

Analyzed Method Compound Result Qualifiers Units MDL PQL

Water 11/20/2008 11/20/2008 12/2/2008 SM4500

- S2

- E Sulfide 0.5 U mg/L 0.18 0.5

Water 11/20/2008 11/20/2008 12/3/2008 SM4500

- SO3

- B Sulfite 2 U mg/L 1.2 2.0

Water 11/20/2008 11/20/2008 12/4/2008 SM5310 B Total Organic

Carbon 6 mg/L 0.60 2.5

Water 11/20/2008 11/20/2008 11/24/2008 SM5540 C Surfactants (MBAS) 0.04 mg/L 0.026 0.03

Water 11/20/2008 11/20/2008 12/3/2008 Summation Total Organic Nitrogen as N 0.5 U mg/L

- N 0.24 0.5

Water 11/20/2008 11/20/2008 11/21/2008 SW846 3010 Digestion d N/A N/A

Water 11/20/2008 11/20/2008 11/25/2008 EPA 350.3 Ammonia 3.4 mg/L

- N 0.08 0.2

Water 11/20/2008 11/20/2008 11/26/2008 SM 5210 B BOD 3.3 mg/L N/A 2.0

Water 11/20/2008 11/20/2008 11/26/2008 SM 5220

- D COD 2 U mg/L 0.31 2.0

Water 11/20/2008 11/20/2008 12/4/2008 SM5310 B Total Organic

Carbon 5 mg/L 0.60 2.5

Table 3

- Reasonable Potential to exceed the water quality standards

State Water Quality Standard Max concentration at edge of ...

Metal

Criteria

Translator

as decimal Metal

Criteria

Translator

as decimal Ambient

Conc. (metals as dissolved) Acute Chroni

c Acute Mixing

Zone Chronic

Mixing

Zone LIMIT

REQ’D

Parameter Acute Chronic μ g/L μ g/L μ g/L μ g/L μ g/L

Total Residual

Chlorine 0 19 11 1149.88 1149.88 YES

Arsenic 1 1 0 360 190 30.99 30.99 NO

Chromium 0.99 0.99 0 15 10 16.11 16.11 YES

Selenium 1 1 0 20 5 185.96 185.96 YES

Table 3

- Reasonable Potential to exceed the water quality standards

- continued

Effluent percentile

value Max

effluent

conc. measured Coeff of

Variation # of

samples Multiplier Acute

Dil’n

Factor Chronic

Dil’n

Factor

Parameter Pn μ g/L CV s n 1 1

Total

Residual

Chlorine 0.95 0.911 870 1.17 0.93 32 1.32 1 1

Arsenic 0.95 0.05 5 0.6 0.55 1 6.2 1 1

Chromium 0.95 0.05 7 0.6 0.55 5 2.32 1 1

Selenium 0.95 0.05 80 0.6 0.55 1 2.32 1 1

Table 4

– Reasonable Potential Analysis based on EPA recommended water quality criteria (Memo June 7, 2010)FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 43 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 44 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 45 of 70 APPENDIX D

-- RESPONSE TO COMMENTS

Earthjustice submitted comments on July 9, 2010

Comment 1

Waste Streams

The proposed Permit and Fact Sheet disclose that several waste streams make up TransAlta’s wastewater discharge covered by this Permit. See pages 6

- 10 Fact Sheet. Included in those waste streams is circulating water cooling tower blowdown, units 1 and 2 boil er drains, cooling tower basin drains, bottom ash system surge tank overflows, coal pile runoff, and flue gas desulfurization ( FGD ) wastewater. It appears that TransAlta, for the industrial (as opposed to sanitary effluent) wastewater uses settling ponds. Some flocculation is used, but it is unclear from the Fact Sheet to which wastes, exactly, the chemical treatment is applied. It appears to be only to the coal pile runoff. There is no apparent case

- by

- case analysis of BAT demonstrated in the Permit, Fact Sheet, or file for this Permit. The Fact Sheet discloses application of the old, existing BAT effluent limitation guidelines f or cooling tower blowdown only. Fact Sheet, pp. 15

- 16. It also appears that Ecology has not assessed/applied AKART for the industrial process

wastewater.

Ecology Response

TransAlta Centralia Generation (TCG), Figure 3, flow treatment schematic on page 8 of the fact sheet shows that wastewater chemical treatment occurs at the coal pile runoff collection pond. In addition, the

WFGD

- scrubber wastewater is treated before it reaches to the coal pile runoff treatment pond . The fact

sheet has addressed EPA’s guidelines for the cooling tower blowdown industrial process (please see page

15 & 16 of the TCG fact sheet). The other industrial process wastewaters have been determined by Ecology to be all known available reasonable treatment methods (AKART) through approval of engineering or use of effluent guidelines

. For example, the wet flue gas desulfurization ( WFGD )

scrubber wastewater used AKART when TCG treated the wastewater before discharging to the coal pile

runoff treatment unit. Figures 1 and 2 show a t reatment train for WFGD generated at the TCG operation. Ecology reviewed and approved this WFGD treatment engineering report on December 16, 2005

.

Ecology has used the best available technology ( BAT ) guidelines for the cooling tower blowdown as the final effluent monitoring as the interim standard for all industrial process waste streams at the TCG site. Even though the permit does not directly specify individual limits on every waste stream that does not mean those streams are not subject to the sa me limits as those applied to the cooling tower blowdown wastewater. The cooling tower blowdown pollutant limits are the most stringent limits except for chromium, zinc and chlorine as federal law requires.

TCG’s WFGD scrubber wastewater treatment is nea rly identical to EPA’s proposed guidance for WFGD scrubber wastewater treatment in their study of October 2009 (Figure 3). In addressing the coal combustion residue solid waste (bottom and fly ash), Ecology has issued a separate NPDES permit for

this indu strial process in 2009. The proposed compliance schedule requires the P ermittee to produce an AKART analysis which will lead to potential AKART limits (Please see response to comment 7C).

Action Taken : Added documentation confirming the WFGD blowdown i s treated.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 46 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 47 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 48 of 70FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 49 of 70 Comment 2

Waterbodies Affected

TransAlta discharges these wastes to Hanaford Creek at Outfall 001. The discharge is approximately 1⁄2 to

3⁄4 mile from the confluence of Hanaford Creek and the Skookumchuck River. The Skookumchuck is a tributary of the Chehalis River. According to the Washington Department of Fish and Wildlife’s website,

Hanaford Creek has a winter steelhead run and the Skookumchuck has fall Chinook and chum salmon

runs.

A sibling company, TransAlta Centralia Mining, L .L.C. is the permittee on two other NPDES permits related to the facility in Centralia, Washington. Permit No. 0040215 covers discharges from a new landfill TransAlta has created in an existing coal mine pit. The landfill appears to accept fly and bottom

ash from the coal

- plant steam generation operation. In its first year, the landfill has had problems complying with its NPDES Permit requirements. Permit No. 0037338 covers non

- continuous discharges from a series of other existing mine pits on the large r facility site. The mine pit permit is linked to the Permit under review here in that industrial process wastewater and coal pile runoff which is covered under this Permit, is routed to the Pond 3E mine

- pit system of ponds during summer low

- flow months, and ultimately discharged under Permit 0037338. Fact Sheet at p. 11. It appears that there is no treatment other than settling for the pollutants that go this route. All three permits discharge within the Skookumchuck watershed, some to Hanaford Creek, some to other creeks that join the Skookumchuck.

The Conservation Organizations are concerned with separation of the subject Permit and Permit 0037338 when the same pollutants and sources of pollutants are discharged under each. They should be treated as one NPDES permit with multiple outfalls. Also, routing cooling tower blowdown and FGD wastewater to mine pits where acidic conditions are likely present, contributes to the dissolution of metals in the

blowdown and FGD waste streams which in turn contrib utes to higher discharges of dissolved metals under the mine pit Permit. It is clear that Permit 0037338 does not impose BAT and is also not in compliance with the CWA. By treating them separately, TransAlta and the state deprive the public of the

opport unity to understand and comment on the entirety of the system and the cumulative damage to the environment. Ecology should consolidate these permits and reissue them as one with full public process.

Ecology’s Response

Ecology’s Water Quality Program has issued TransAlta Centralia Operation three separate NPDES permits for different industrial processes so Ecology could accurately monitor the wastewater of each industrial process and set the appropriate limits for each process. It is important that Ecolo gy regulate and monitor these wastes streams/pollutants at the source. Each permit that Ecology has issued to TransAlta (TransAlta Centralia Mining, TransAlta Centralia Generation LLC and Limited Purpose Landfill) has different applicable federal regulati ons. Each type of permit has different limits based on the concentrations of the pollutants allowed by federal and state law for surface water. This practice by Ecology to require each creek and tributary which is receiving treated wastewater to meet the federal and state water quality standards is a stricter standard for TransAlta to meet than just monitoring the overall water quality at downstream Hanaford Creek and Skookumchuck River. Each permit is significantly complex and an attempt to combine them would not result in an improved and understandable permit. Also, when TCG discharge s to pond 3E, the P ermittee is required to comply with all applicable permit

effluent limits

, except temperature and dissolved oxygen. Currently, pond 3E is not state des ignated surface water, therefore temperature and dissolved oxygen limits are not applied.

Action Taken : NoneFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 50 of 70 Comment 3

Pollutants

There are a variety of pollutants in TransAlta’s discharge to Outfall 001 of this Permit as well as

temperature limitations. Some of them are conventional pollutants and, consistent with EPA’s Final Study, many of the pollutants are priority pollutants of concern such as mercury, selenium, copper, chromium, lead, and arsenic. The Fact Sheet also identifies sulfate s. TransAlta has recorded violations of Permit conditions for BOD, TSS, and chlorine during the previous 5 years. Correspondence in the file appears to indicate that TransAlta blames these violations, for the most part, on algae growth in its pond

system . While that may be the cause, it does not excuse the violations. There is no discussion in the Fact Sheet or file of how these violations will be avoided in the future (one of the BOD violations was June of 2009).

It also appears from correspondence b etween TransAlta and Ecology in the spring of 2010 that TransAlta has improperly measured temperature 600 feet downstream of outfall 001 in violation of the permit requirements to sample for temperature 300 feet from the outfall. Therefore, it appears tha t on some occasions, TransAlta has also violated the permit temperature limits.

Ecology’s Response

Whenever any permit violation occurs, the P ermittee is issued a warning letter and this requires the

P ermittee to investigate and resolve the problem. Dur ing the five yea r permit cycle, Ecology issued 23 warning letters to TCG. These warning letters occurred infrequently and Trans Alta was able to correct the problem within a short time frame. These problems have not persisted, so further action by Ecolog y was not needed.

There was correspondence between Ecology and Trans Alta pertaining to the distance downstream that TCG was monitoring the temperature for outfall 001. This correspondence is not pertinent to the requirements in this permit. The 2005 TCG NPDES permit only requires Trans Alta to monitor the background temperature of upstream from the outfall 001 on Hanaford Creek. TCG has been doing their own downstream monitoring of temperature which is not part of the permit requirements.

Action Taken : None

Comment 4

Antidegradation

The Fact Sheet outlines Washington antidegradation requirements, but simply states, with no explanation or supporting information, that the TransAlta coal plant must meet Tier I levels of antidegradation. This

sugg ests the most minimal level of antidegradation protection. It is unclear from the Fact Sheet whether this applies to Hanaford Creek only or also to the Skookumchuck and other downstream waters. Downstream is relevant because many of the pollutants of con cern are conservative (e.g. nutrients) and/or bioaccumulative meaning that they are not necessarily more dilute or less damaging the further downstream they travel. Moreover, because there is no discussion or supporting information regarding the antidegra dation consideration for this Permit, it is impossible to discern whether the antidegradation analysis was properly made pollutant by pollutant. A waterbody may be Tier I for some pollutants, but Tier II for others, requiring a higher level of protection.

Ecology’s ResponseFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 51 of 70 Tier I criteria ensures that existing and designated uses are maintained and protected and it applies to all

waters and all sources of pollutants . By default, TCG facility is to meet the Tier I criteria. Tier II criteria applies onl y to a new or expanded facility causing a measureable increase of pollutant in the receiving

water

. TCG is not a new or expanded facility.

The receiving water body of outfall 001 is Hanaford Creek and the limits apply to the wastewater discharge to Hanaf

ord Creek.

Action Taken : None

Comment 5

Mixing Zone

It is unclear whether the Permit includes a mixing zone in Hanaford Creek for Outfall 001. The Fact Sheet describes in detail Washington’s regulations regarding mixing zones and how they are calcula ted, but it contains no information specific to this Permit and simply concludes with the following statement: “The water quality standards impose certain conditions before allowing the discharger a mixing zone.” Fact Sheet at p. 20. It appears that the previous version of the Permit included requirements for a mixing zone study. Later in the Fact Sheet, in the section describing temperature requirements in Washington, there is a statement that “[t]he threshold criteria apply at the edge of the chronic m ixing zone.” Fact Sheet at p. 22. It is unclear whether this reference is to a mixing zone to be included in the Permit or if it is a general reference regarding general Washington requirements. Correspondence from TransAlta in May of 2010 suggests that TransAlta expects a mixing zone for pH. Finally, there is no disclosure of a mixing zone in the Permit itself. Reading the Fact Sheet and the Permit as a whole, the Conservation Organizations understand that this Permit does not allow a mixing zone

. If this is incorrect, please clarify the requirements and see mixing zone comments below.

Ecology Response

The current permit does not authorize mixing zone to meet the technology based effluent limits. In the current permit, Ecology has corrected the per mit limit for pH. TCG is required to meet the technology based limits for pH 6.0 to 9.0, and these changes are reflected in the new proposed permit.

Action Taken : Changed pH maximum limit from 10.0 to 9.0 to comply with the federal law requirements

Comment 6

WQBELs

The Fact Sheet discloses that for chromium and chlorine, AKART is less stringent than the Water Quality standards and that for the previous five years of the permit, Water Quality Based Effluent Limits (“WQBELs”) would have been exceeded for these two pollutants. Fact Sheet at p. 21. More clearly stated, for the last 5+ years, TransAlta’s discharge has been causing and/or contributing to violations of water quality standards for chlorine and chromium. It should be noted that even the lenient chlorine limit in the Permit, admittedly inadequate to meet water quality standards, was exceeded several times.”

For toxic, priority pollutants discharged by TransAlta, the Fact Sheet is confusing. It appears that, according to an April 2010 rep ort to Ecology by TransAlta, TransAlta does not meet no

- detect requirements for: arsenic, copper, lead, nickel, selenium, and zinc. Fact Sheet at p. 23

. Further, EcologyFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 52 of 70 finds that there is a reasonable potential for TransAlta’s discharge of pollutants t o violate water quality standards for chlorine, chromium and selenium. Ecology discloses that it was unable to determine whether TransAlta’s discharge of pollutants will violate or have the potential to violate water quality standards for copper, lead, ni ckel, and zinc. The Fact Sheet discloses only that Ecology was unable to so determine due to “lack of data.” There is no information as to why the data was lacking, especially given TransAlta’s permit renewal obligation to supply adequate data.

All of t hese pollutants are of significant concern, some for human health, but especially for aquatic ecosystem health. For example, copper interferes with salmonids’ (and likely other fish) olfactory abilities which in turn affects predator avoidance and other f unctions upon which the fish depend on a heightened sense of smell. The National Marine Fisheries Service, based upon research it has participated in, advises that copper causes these adverse effects in salmon at levels as low as 2 ug/L, which level is

mo re stringent than Washington’s numeric criteria for copper.

Based upon this research, in order to be protective of designated uses for salmonids and other fish in Hanaford Creek and the Skookumchuck River and to meet narrative water quality standards, E cology must apply a 2 μ g/L criteria for copper and impose effluent limits in this Permit sufficient to comply with that criteria.” Selenium contamination, especially in conjunction with mercury (also present in coal plant discharges), contributes to incre ased mortality, reduced growth, and reproductive failures in fish. The footnote on page 10 of the comments states that “See, e.g., A. Dennis Lemly, “Pathology of Selenium Poisoning in Fish”, Environmental Chemistry of Selenium, 281, 282 (William T. Franke nberger, Jr. & Richard A. Engberg, eds.,1998); Dennis A. Lemly, Aquatic Cycling of Selenium: Implications for Fish and Wildlife, 5 UDOI FWS Fish and wildlife Leaflet 12 (1987); Dennis A. Lemly, Symptoms and Implications of Selenium Toxicity in Fish: The B elews Lake Case Example, Aquatic Toxicology 57 (2002).” The selenium in the industrial process wastewater is likely increased when the industrial wastewater is routed through the mine pits during the summer months.

Despite these findings, the Permit does not set new or more stringent limits for chromium or chlorine. In fact, the maximum daily limit for total residual chlorine increases from the last version of the permit to this Permit; from 0.20 mg/L to 0.50 mg/L. Fact Sheet at p. 25. The Permit sets no limit for selenium or any of the other priority pollutants other than retaining the continuously

- violated “no

- detect” limit for the cooling tower blowdown.

This is confusing. In the Fact Sheet, the no

- detect limit is represented as for cooling tower b lowdown with no apparent limits for the other waste streams. However, there is no internal outfall to which the cooling tower blowdown requirements apply. Rather there is only one outfall to Hanaford Creek and it appears from the Permit that the no

- detec t limit applies at the 001 outfall. The actual limits and their basis need to be clarified.” Rather, for all of these pollutants, including those Ecology has determined have the reasonable potential to violate water quality standards (and that have been v iolating water quality standards), Ecology requires a study, to be completed in 2013. Fact Sheet at pp. 21 and 23; Permit at S.11. There are no requirements that the study result in limits or impose particular treatment technologies. There is no require ment in the Permit for implementation of study results. Finally, there is no reference to the EPA Final Study which already sets forth treatment technologies that work for many, if not all, of these pollutants.

Ecology’s Response

The permit that Ecology issued to TCG in June 2005 required the P ermittee to meet the non

- detect levels for all priority pollutants, except zinc and chromium (Cooling Tower Blowdown criteria

- 40 CFR 423, page 15 of the fact sheet) at the discharge point (outfall 001) . Ecology’s permit renewal analysis found that some priority pollutants were detected in the TCG’s effluent and they were: antimony arsenic,FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 53 of 70 copper, lead, nickel, selenium, and zinc. Since TCG violated the non

- detect limits for the above pollutants, Ecology has give n TCG a compliance schedule to meet these non

- detect requirements.

In response to the Earthjustice comment that Ecology was unable to determine whether surface water quality standards for copper, lead, nickel and zinc were violated, this result occurred d ue to not having data on the hardness of the receiving water. The hardness data was not a requirement in the permit of 2005 because it used technology based limits and not water quality standards for these priority pollutants. In this permit, Ecology is requiring TCG to collect hardness data and this will be used by Ecology to establish site specific water quality criteria and evaluate the reasonable potential for these pollutants. In

the absence of Washington State surface water quality standards for these pollutants, Ecology used EPA National recommended water quality standards in a memo dated June 7, 2010, to conduct the reasonable potential analysis for copper, lead, nickel and zinc. This analysis revealed that TCG will not exceed surface water qua lity standards for lead, nickel and zinc. On the other hand, copper is expecting to exceed the surface water quality standards (See Table 4 of this fact sheet in Appendix C ). Based on these results, Ecology has established effluent limits for these param eters (See Table 1 of the permit). Th ese effluent limits will be effective December 1, 2014

.

In response to the Earthjustice comment that Ecology does not set new or more stringent limits for chromium or chlorine and that the chlorine limit was raised, i t is true that Ecology changed the chlorine limit to correct a mistake made in the 2005 permit. The current limit for chlorine is the limit stated in

40CFR 423. After reconsideration, Ecology has determined that the effluent of 0.20 mg/L is reasonably

me t by TCG and will be maintained as a performance based limit until a WQBEL is established.

Ecology has added in the permit that TCG evaluate the cooling tower blowdown separately as specified in the 40 CFR 423. This is part of the compliance schedule and the P ermittee is required to submit the

results of this evaluation (cooling tower blowdown evaluation)

. Ecology has determined at this time that the permittee must monitor outfall 001 and adhere to the cooling tower blowdown effluent limits at the

discha rge point to protect the receiving water body (Hanaford Creek) from the priority pollutants. These interim limits will be in place until the final effluent limits are implemented.

The prior permit as well as this new permit requires the P ermittee to conduct and report the Whole Effluent Toxicity (WET) tests. These tests ensure that all toxic effects from pollutants are accounted for

in the wastewater effluent. If these tests indicate that toxicity exists in the wastewater, then Ecology requires the P ermittee to treat the wastewater and remediate the problem.

Action Taken:

1. Evaluation of the cooling tower blowdown waste stream separately as specified in the 40 CFR 423

2. Chlorine permit limit changed from 0.50 mg/L to 0.20 mg/L

Comment 7

THE PERMIT F AILS TO CONFORM TO REQUIREMENTS OF THE CLEAN WATER ACT AND

WASHINGTON LAW

The Conservation Organizations object to issuance of the Permit as proposed. The Permit fails to apply BAT and AKART, allows for the violation of water quality standards, fails to properly apply antidegradation requirements, and results in backsliding.

Comment 7AFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 54 of 70 The Permit Does Not Require BAT and AKART

BAT and AKART must be required in the Permit regardless of the status of the receiving waters and the discharge’s effects on th e water. The Permit reflects no analysis or determination of best treatment technologies or of all known and reasonable treatment technologies for the pollutants and waste streams at issue. The EPA Final Study and June 2010 Guidance clearly demonstrate a nd find that settling ponds (even with some chemical treatment for some pollutants) are not BAT for steam generating electrical plants like TransAlta. The Final Study clearly demonstrates and EPA finds that the treatment technologies in use at TransAlta’s coal plant cannot achieve the purported “no detect” limits in the Permit and likely cannot achieve the limits for chromium. Ecology cannot rely solely on the cooling tower blowdown effluent limitation guidelines for pollutant control requirements. Rathe r, Ecology should, consistent with the EPA Final Study and June 2010 Guidance, require additional treatments such as biological treatment and/or the zero discharge treatments already in use at other facilities in the U.S. and Europe for TransAlta’s industr ial waste streams (including coal pile runoff.)

Ecology’s Response

This existing and new permit requires BAT for all industrial processes at the TCG site. The requirements for the cooling tower blowdown which are based on BAT also apply to all other waste streams at the TCG

site. In this new permit TCG is required to perform studies which will lead to future AKART limits which meet the state surface water quality standards for the parameters that currently TCG has potential

to exceed

. This type of detailed analysis is allowed under federal and state laws in order to give the

P ermittee time to evaluate the AKART.

The priority pollutant analysis that the P ermittee submitted to Ecology showed that the P ermittee has met

most of the non

- detect levels requirements (see Table 2 of appendix C of the fact sheet). This indicates that the TCG settling ponds in combination with chemical treatment has achieved compliance with the majority of the technology based requirements and limits.

For the pollutants that were detected in the effluent wastewater, Ecology conduc ted a reasonable potential analysis against surface water quality standards. Based on this analysis, Ecology determined that there is a reasonable potential that the P ermittee would exceed the surface water quality standards for certain pollutants (See Ta ble 3 and 4 in Appendix C). Based on the reasonable potential analysis, Ecology has established final effluent limits (See Table 1

- Final Effluent Limits, of the permit ) and given TCG a compliance schedule. These final effluent permit limits will be effe ctive December 1, 2014

.

Action Taken:

TCG does treat the WFGD blowdown by a lime precipitation, polymer chemical coagulation / flocculation, and sedimentation system. See Ecology’s response to comment 1.

Comment 7B

The Permit Violates 40 C.F.R. 122.44(d) and WAC 173

- 220

- 130.

Ecology has already found that the TransAlta discharge violates (and has been violating) water quality standards for chromium and chlorine and has the reasonable potential to violate water quality standards

for selenium. It is likely that the discharge violates narrative water quality standards for copper given that the testing shows copper at or in excess of the 2 μ g/L that can adversely affect fish.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 55 of 70 The Conservation Organizations are further concerned regarding sulfates. Washington does not have a numeric water quality standards for sulfates, therefore, the narrative standard applies to protect designated uses of Hanaford Creek and other downstream waters. 40 C.F.R. § 122.44(d)(1)(vi) requires states to assess pollutants against narratives standards and designated uses, and if the pollutant has the reasonable potential to cause a violation of the narrative standard, to set calculated effluent limits designed to attain

the narrative standard. It is unclear to what extent Ecology has properly assessed sulfate against its narrative criterion.” Further, Ecology has failed to actually make a proper reasonable potential assessment in that it has not made the effort to acquire data necessary to make such an assessment, as it

ap pears that TransAlta’s discharge may violate water quality standards for lead, nickel, and zinc.

Ecology fails to impose limits in the Permit sufficient to ensure that water quality standards are met, in violation of 40 C.F.R. § 122.44(d) and WAC 173

- 220

- 130. Rather, Ecology requires only a three

- year study and no implementation of any actual pollutant limits. This is particularly egregious given EPA’s Final Study demonstrating that biological treatment or zero discharge technologies can remove many of

t hese pollutants. There is no need for a study. The study will simply serve to delay what is required now

for this Permit. The work has already been done by EPA.

A compliance schedule may not be used in this case for some, if not all, pollutants. After July 1, 1977, NPDES permits must require immediate compliance for effluent limitations that are based on water quality standards adopted before July 1, 1977. For standards adopted after that date, Ecology may allow compliance schedules only if they have first clearly indicated in its water quality standards submitted to EPA that it intends to allow compliance schedules for meeting WQBELs. See EPA Memorandum “Compliance Schedules for Water Quality

- Based Effluent Limitations in NPDES Permits,” May 10,

2007 , copy enclosed [citing In the Matter of Star

- Kist Caribe, Inc., 3 E.A.D. 172, 175, 177 (1990)]. To the extent that any of the standards in question (including narrative standards) were adopted prior to July 1, 1977, Ecology cannot allow a compliance sche dule for TransAlta to meet WQBELs necessary to achieve or maintain those standards. For standards adopted after July 1977, Ecology must comply with the requirements for compliance schedules set forth in the EPA May 2007 Memorandum.

The study is decidedly not a “compliance schedule.” It is wholly inconsistent with requirements for compliance schedules. Under both federal and state permitting requirements, a compliance schedule must bring a permittee into compliance as soon as possible, but not later than a pplicable CWA statutory deadlines, and it must do so with interim deadlines requiring specific actions. 40 C.F.R. § 122.47; WAC

173

- 220

- 140. As stated by EPA in its May 2007 Memorandum, any compliance schedule in an NPDES permit must be an “enforceable se quence of actions or operations leading to compliance with a [water quality

- based] effluent limitation [“WQBEL”] as required by the definition of “schedule of compliance in section 502(17) of the CWA.” EPA May 2007 Memorandum, p. 2 (emphasis added.) EPA em phasizes throughout the memorandum that schedules of compliance must actually set and require compliance with the WQBEL. Id. Further, EPA sets out very specific findings before a compliance schedule is warranted,

none of which have been made here. Finall y, EPA is clear that compliance schedules cannot be used to wait for completion of TMDL studies or for the development of Use Attainability Analyses.

The provisions in the permit regarding a study are not a compliance schedule as they do nothing to bring TransAlta into compliance with the requirement of the Clean Water Act to apply BAT and WQBELs or with state law to comply with AKART. Further, TransAlta has three years to complete a study of information that should have been developed and provided as par t of TransAlta’s permit renewal application obligations. There is nothing in the record demonstrating that it takes three years to develop and implement a study that is primarily simply characterizing TransAlta’s waste. Waiting for the study is

akin to wa iting for a TMDL or UAA. Finally, and most importantly, the study is entirely unnecessary in light of EPA’s Final Study regarding coal plant wastewater. Ecology must amend the permit to provide for BAT and AKART and set actual WQBELs.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 56 of 70 Ecology’s Response

Ecology’s new draft permit analysis found that some priority pollutants were detected in the TCG’s effluent and they were antimony, arsenic, copper, lead, nickel, selenium, and zinc. Since TCG violated

the non

- detect limits for the above pollutants, Ecology has given TCG a compliance schedule to meet

these non

- detect requirements.

In response to the Earthjustice comment that Ecology was unable to determine whether water quality standards for copper, lead, nickel and zinc were violated, this result occurred due to not having data on the hardness of the ambient water. The hardness data was not a requirement in the permit of 2005

becau se it used technology based limits and not water quality standards for these priority pollutants. In this permit, Ecology is requiring TCG to collect hardness data and this will be used by Ecology to evaluate the reasonable potential for these pollutants. This proposed permit has non

- detect interim limits for all priority pollutants except zinc and chromium. In the absence of Washington State surface water quality standards for these pollutants, Ecology used EPA National recommended water quality standar ds in a memo dated June 7, 2010, to conduct the reasonable potential analysis for copper, lead, nickel and zinc. This analysis revealed that TCG will not exceed surface water quality standards for lead, nickel and zinc. On the other hand, copper is expec ting to exceed the surface water quality standards (Se e Table 3 of this fact sheet). Based on these results, Ecology has established effluent limits for these parameters (See Table 1 of the permit). This will be effective in the next permit cycle of 2015

.

Ecology has determined that BAT is met by the inclusion of federal effluent guidelines technology based limits. Furthermore Ecology has determined that the WFGD blowdown discharge meets AKART with the lime coagulation/flocculation/sedimentation treatm ent system.

Action Taken : None

Comment 7C

The Permit Violates Federal Requirements For Variances From Water Quality Standards And For Downgrading of Water Quality

Because the Permit fails to include limits necessary to ensure that water quality standar ds are met in receiving waters, and because the Permit does not include a valid compliance schedule, the Permit allows a variance from water quality standards for at least the term of the Permit and will allow for the downgrading and failure to protect ben eficial uses for the term of the Permit. Given these circumstances, Ecology has failed to comply with the requirements of 40 C.F.R. §§ 131.1, 131.10(g), 131.10(h) and the EPA NPDES Permit Writers Manual and EPA Water Quality Standards Handbook.

Federal la w and permitting requirements are clear on when a state may allow a variance from water quality standards or under what circumstances a state may allow a downgrading of a waterbody. EPA’s NPDES Permit Writers Manual, chapter 10 sets forth the procedures a nd requirements for state or EPA permit writers when assessing a variance like the one that will effectively be in place for TransAlta in this Permit. Section 10.2.3 provides:

Water quality standards variances require similar substantive and procedural re quirements as removing a designated use, but unlike use removal, variances are both discharger and pollutant specific, are time

limited, and do not forego the currently designated use of a water body. A variance is appropriate where

the state believes that the standard can be ultimately attained. By maintaining the standard rather thanFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 57 of 70 changing it, the state will assure that further progress is made in improving the water quality and attaining

the standard.

USEPA NPDES Permit Writers Manual, EPA 833

- B

- 96

- 003, Office of Water (Dec. 1996). See also USEPA Water Quality Standards Handbook: Second Edition, EPA 823

- B

- 94

- 005a, Office of Water, § 2.7 (updated July 2007).

Removal of a use or granting of a variance is subject to very specific conditions. To remove a designated use (or grant a variance from water quality standards) the state must adhere to 40 C.F.R. § 131.10(g). There is no demonstration here that Ecology has applied the factors and done the analysis required for a variance from water quality standa rds for TransAlta. Moreover, given the factors required for such analysis, and given that technology standards have not been met in this Permit, Conservation Organizations assert that a variance (or a downgrading in the use) is not supported in this case and the Permit should not allow the implicit variance that is currently part of the proposed Permit.

Ecology’s Response

Ecology is not removing the applicable federal requirements. Ecology is requiring the P ermittee to comply with the surface water quality standards in accordance with a compliance schedule. The compliance schedule provides a timeline for the P ermittee to conduct AKART analysis and ultimately comply with the water quality standards. Ecology h as modified the compliance schedule from the PNOP draft permit and this new compliance schedule reflects the requirements under the Federal Water Pollution Control Act, Section 301, 40 CFR 122.47 and WAC 173

- 220

- 140.

Action Taken : Modified the complianc e schedule to conform with the federal and state law s requirements.

Compliance Schedule

The following compliance schedule is designed to pr ovide guidance to the permittee to meet the effluent limits that permittee was unable to att ain and the surface water quality standards that the permittee has potential to exceed

1. Submit c ooling tower blowdown evaluation as specified under 40 CFR 423, by March 1, 2011

.

2. Submit draft AKART /engineering report to address the technology based wastewater effluent

limits (currently the permittee is unable to meet) and surface water quality standards ( the permittee has potential to exceed )

, by December 1, 201 1

.

3. Ecology review draft AKART/ engineering report and provide comments by February 1, 201 2

. 4. Submit f

inal e ngineering r eport by December 1, 201 2

.

5. Ecology approves f inal e ngineering r eport by March 1, 201 3

.

6. Complete the i mplement ation of final engineerin g report by March 1 , 201 4

.

7. New proposed final effluent limits effective December 1, 2014

.

Comment 7D

A Mixing Zone Is Inappropriate For These Pollutants And For Hanaford Creek

.FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 58 of 70 As noted above, it is not clear that a mixing zone has been applied in this Permit. In the event a mixing zone is contemplated, Conservation Organizations object to allowance of a mixing zone when TransAlt a has not been required to fully apply BAT or AKART prior to being allowed a mixing zone. Conservation Organizations also object to any mixing zone for toxic and accumulative pollutants such as copper or

mercury o r ammonia or pollutants that accumulate and express problems downstream such as nutrients. A mixing zone is also inappropriate where, as here, anadromous fish use the receiving water. Conservation Organizations further object to any mixing zone that fail s to follow the constraints of WAC

173

- 201A

- 400 to meet the most restrictive combination of the following:

The mixing zone may not extend in a downstream direction for a distance from outfall 001 greater than three hundred feet plus the depth of the water over outfall 001, or extend upstream for a distance of over one hundred feet;

The mixing zone may not utilize greater than 25% of the flow; and The mixing zone may not occupy greater than 25% of the width of the water body.

Ecology’s Response

In the ne w proposed permit, Ecology has not authorized a mixing zone for Outfall 001 discharge. This language has been amended to clarify this finding.

Action Taken : Permit language clarified to assign no mixing zone.

Comment 7E

The Permit Appears To Violate th e Anti

- Backsliding Provisions of the Clean Water Act

The proposed Permit appears to include a less

- stringent maximum daily effluent limitation for chlorine than was previously required. The previous permit imposed a maximum daily effluent limit for chlor ine of 0.20 mg/L. The proposed Permit relaxes the maximum daily effluent limit for chlorine to 0.50. Fact Sheet at p. 25. This is particularly troublesome given the evidence in Ecology’s file that at 0.20 mg/L TransAlta was causing or contributing to vio lations of the water quality standard and the evidence that TransAlta has violated the chlorine limit in the past. It appears Ecology is allowing TransAlta to address those problems by simply relaxing the limit. This violates 33 U.S.C. § 1342(o).

Ecolog y’ Response

The permit of 2005 was in error in imposing a limit of 0.20 mg/L for chlorine. It should have been 0.5 mg/L as stated in 40 CFR 423. This is addressed in the TCG’s fact sheet please see page 15 of the draft permit fact sheet, Technology base d limits. This change in the chlorine limit is not backsliding. After reconsideration, Ecology has determined that the effluent of 0.20 mg/L is reasonably met by TCG and will be maintained as a performance based limit until a WQBEL is established.

Actio n Taken : Chlorine effluent limit changed from 0.50 mg/L to 0.20 mg/L

Comment 7F

The Antidegradation Analysis Is InadequateFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 59 of 70 First, Ecology has not applied AKART or BAT to TransAlta’s discharges which alone appears to violate Ecology’s antidegradation policy. WAC 173

- 201A

- 300(2)(d).

Second, the Fact Sheet for the Permit flatly states that Tier I (WAC 173

- 301A

- 310) applies to this Permit. There is no discussion or explanation or evidence as to why, on a pollutant by pollutant basis, this is the

case as opposed to Tier II. Further, it is apparent from the information in the Fact Sheet and file that in fact this Permit will violate even Tier I requirements in that Ecology has determined that for some pollutants there is a reasonable potential to violate (not just degrade towards) water quality standards and for others Ecology has not made the determination. There is no indication of “appropriate and definitive steps to bring the water quality back into compliance with water quality standards” in this Per mit.

Further, as noted above, TransAlta discharges under three different NDPES permits. This Permit and Permit 0037338 are interconnected in that wastewater from this Permit is sometimes discharged through

Permit 0037338. There is no indication in the r ecord that a proper, cumulative antidegradation analysis has been done, not just for impacts to Hanaford Creek from multiple discharge points from the totality of TransAlta’s discharges, but also to the Skookumchuck River.

Ecology’s Response

The existing and new permits require BAT for all industrial processes at the TCG site. It is not accurate to state that Ecology has not applied AKART or BAT to TCG discharges and that this violates Ecology’s antidegradation policy. The requirements for the cooling t ower blowdown are based on BAT and also apply to all other waste streams at the TCG site. In this new permit TCG will be required to perform studies which will lead to potential future AKART limits. It is inaccurate to say that this permit does not requi re AKART because Ecology is intending to implement more stringent WQBELs once further investigation is completed. This type of detailed analysis is allowed under federal and state law in order to give the P ermittee time to evaluate AKART, and meet the sur face water quality standards that currently TCG has potential to exceed

.

Tier II antidegradation requirements only apply to “new or expanded actions ... that are expected to cause a measurable change in the quality of the water.” TCG’s discharge is not a n ew or expanded action, and Tier II requirements therefore do not apply to TCG’s discharge. Ecology believes Tier I antidegradation requirements are met because TCG’s NPDES permit includes water quality based effluent limits and other requirements that wil l maintain and protect existing and designated uses in the receiving water

.

Action Taken : None

Comment 8

– Summary

ECOLOGY MUST REVISE THE PERMIT

The Conservation Organizations request that Ecology revise the proposed Permit or otherwise take action

as follows:

Assess and impose BAT (for example, biological treatment or zero discharge treatment) in accordance with EPA’s Final Study and June 2010 Guidance;

Assess and impose AKART (for example, biological treatment or zero discharge treatment);FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 60 of 70 Impose Water Quality Based Effluent Limits in accordance with 40 C.F.R. § 122.44(d) for chlorine, chromium, selenium, copper (for copper, Ecology should impose an effluent limit below

2 μ g/L in order to protect fish habitat and uses), lead, nickel, and zinc;

Asse ss the need for a WQBEL for sulfate and impose an effluent limit if necessary;

Perform antidegradation analysis consistent with the requirements of federal and state law and cumulatively for impacts to Hanaford Creek and the Skookumchuck River from all Tra nsalta’s discharges;

Impose a 0.20 maximum daily limit for chlorine or more stringent limits as necessitated by 40 C.F.R. § 122.44(d) (addressing the backsliding issue);

Disallow a mixing zone (to the extent that this is currently contemplated or allowed); and

Assess TransAlta’s discharge and limits under this Permit together with the mine pit and landfill permits or consolidate this permit with the mine pit permit

Ecology’s Response

Please see Ecology’s responses 1 through 7

Action Taken : NoneFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 61 of 70 COMMEN T RECEIVED FROM QUINAULT INDIAN NATION JULY 9, 2010

Comment 1

As the TransAlta site is considered a major NPDES facility that appears to not have had any inspections conducted in the most recent NPDES permit, Ecology should perform multiple site inspecti ons during the new NPDES permit five year period to gather information on the TransAlta facilities, to gather independent water quality samples, and confirm that past observed exceedences of permit limits does not constitute a more frequent problem for wat er quality and QIN treaty sources.

Ecology’s Response

Ecology conducted four non

- sampling inspections during the current five year permit cycle. In the next

five year permit cycle, Ecology will conduct more than one inspection and one would include samp ling.

Action Taken : In the next five year permit cycle, Ecology will conduct more than one inspection and one would include sampling.

Comment 2

Ecology should identify in the current permit renewal whether the agency conducted any site inspections,

any actions Ecology considered during the review of the expired permit that would either identify and/or address TransAlta activities to reduce or eliminate past exceedences of permit limits or water quality

standards.

Ecology’s Response

Ecology conducted fo ur non

- sampling inspections during the current five year permit cycle. Ecology’s proposed draft permit has evaluated the P ermittee’s effluent characteristics against the surface water quality standards and they are discussed on page 23 of the fact sheet of proposed draft. Also appendix C shows the violation history, priority pollutant detection levels and the reasonable pote ntial analysis. Ecology has given the P ermittee a compliance schedule to meet the surface water quality standards.

Action Taken : Please see Ecology’s response to Earthjustice comment 7C

Comment 3

Ecology should not increase the new discharge permit li mit for total chlorine but rather maintain past permit limits for this quality parameter.

Ecology’s Response

Ecology has corrected a mistake in the 2005 permit for the chlorine limit for the discharge to conform

with the 40 CFR 423

- BAT limits, please see page 15 of the draft fact sheet. After reconsideration, Ecology has determined that the effluent of 0.20 mg/L is reasonably met by TCG and will be maintained as a performance based limit until a WQBEL is established.

Action Taken : Chlorine effluent limit changed from 0.50 mg/L to 0.20 mg/L

Comment 4FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 62 of 70 Based on the number of metal exceedences from just one sample event, potential harm to aquatic life and likely not being consistence with the antidegradation provision of the Clean water Act, Ecology sho uld require TransAlta to take annual priority samples and should undertake every effort in the new draft permit to ensure outfall001 discharges do not exceed water quality standards or permit levels (Table 2 of the draft permit). Ecology should also requi re TransAlta to identify the facility practices that contribute to these discharges and to seek practical ways to reduce these discharges to protect water quality and designated uses. Lastly, Ecology should require TransAlta in this NPDES permit renewal t o immediately undertake actions to reduce discharges of priority pollutant metals to Hanaford Creek that were documented to exceed standards in the last permit.

Ecology’s Response

Please see Ecology’s response to Earthjustice comment 7A

.

Action Taken : N one

Comment 5

While not certain, it is likely (depending on liner exists and the nature of the liner) that Pond 3E may be hydraulically connected to Hanaford Creek (pond waters to groundwater, and groundwater moves downgradient and discharges to surface water). If this is the case and depending on the geologic characteristics of the deposits present, it is possible that pond 3E may discharge to Hanaford Creek. If this is the case and pond 3E is located close Hanford Creek in geologic materials with a hi gh hydraulic conductivity, it is conceivable that this pond may not cool outfall 001 waters to meet permit limits or water quality standards for Hanaford Creek.

Thus, we request Ecology require TransAlta to document conditions of pond 3E, including the na ture of any pond liner (hydraulic conductivity and engineering design), T he hydraulic conductivity of the geologic materials present at pond 3E and down gradient toward Hanford Creek, and examine the potential for TransAlta wastewater discharges to pond 3E to harm Hanaford Creek water temperatures or exceed proposed permit limits. This may require characterization of alluvial materials present at pond 3E and in/adjacent to Hanford Creek and to conduct additional surface water monitoring for water

temperatu re n Hanaford Creek (upstream and downstream of pond 3E). If pond 3E’s discharge is found adversely impact Hanaford Creek water temperature, the QIN would request that Ecology require TransAlta to cease such discharges and relocate the current location of outfall 001 to a larger nearby waterbody (Skookumchuck River is a possibility) where meeting permit limits and water quality standards may be attainable due to greater stream discharge.

Ecology’s Response

Comments noted

Action Taken : Ecology will investigate this issue.

Comment 6

The QIN supports raising TransAlta’s permit limit for DO vial outfall 001 as this higher value is more conducive to salmonid survival and maintaining habitat quality for the rearing needs of juvenile Coho

salmon.

Ecolog y’s ResponseFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 63 of 70 Comments noted

Action Taken : NoneFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 64 of 70 TransAlta Centralia Generation LLC submitted comments on July 8, 2010

Comment 1

Page 6, Condition S 1.A, Table 1, Lines 2 and 9 The draft permit contains proposed limits for Dissolved Oxygen (DO) and Temperature at Outfall 001 based upon the water quality standard for "Core Summer

Salmonid Habitat" at WAC 170

- 201A200(1 )(d) for "Hanaford Creek and all the tributaries from the east boundary of Sec. 25

- T15N

- R2W (river mile 4.1) to the unnamed tributary a t latitude 46.7295 longitude

- 122.6812 except where designated Char." This reach, which includes the TransAlta's Outfall 001, has been identified by the Department as incorrectly listed as "Core Summer Salmonid Habitat". It should be

listed as "Salmonid Spawning, Rearing, and Migration" (See attached e

- mail message from Susan Braley dated July 1, 2010). Therefore the DO and Temperature limits in the permit for the Outfall 001 should be based upon "Salmonid Spawning, Rearing, and Migration" requirements.

Ecology’s Response

The temperature and dissolved oxygen limits in the proposed permit are based on WAC 173

- 201A which currently has temperature set at 16.0 o C and dissolved oxygen at 9.5 mg/L for Hanaford Creek. If these temperature and DO limits for Hanaford Creek are revised to 17.5 o C for temperature and dissolved oxygen to 8.0 mg/L, these interim limits will be adjusted to reflect this regulation change.

Action Taken : None

Comment 2

Page 6, Condition S 1.A, T able 1, Line 2 The draft permit contains a proposed limit for Dissolved Oxygen (DO) at Outfall 001 that is listed as "Minimum, 9.5 mg/L" as a monthly average. As noted above, this should be based upon the water quality standard for "Salmonid Spawning, Rea ring, and Migration" which is "Minimum, 8.0 mg/L". TransAlta has limited data for Dissolved Oxygen in Hanaford Creek during the summer period, but the data submitted to the Department indicates that the DO in the creek may be lower than 8.2 mg/L at times during the year. Therefore, the standard at WAC

170

- 201A

- 200(1)(d)(i) should be included in the limit for situations when the natural conditions in the creek (or the plant effluent) does not achieve 8.0 mg/L, just as the temperature limit in the permit

cu rrently incorporates 170

- 201A

- 200(1)(c)(i) and 170

- 201A

- 200(1)(c)(ii). The permit should not require a specific DO at Outfall 001, but instead should require Outfall 001 not to decrease DO in the stream by more than 0.2 mg/L. This would be applied throug h upstream and downstream DO monitoring to document the DO in Hanaford Creek just as the temperature limit is expressed in allowable increase in temperature of the creek.

Ecology’s Response

The temperature and dissolved oxygen limits in the proposed perm it are based on WAC 173

- 201A which currently has temperature set at 16.0 o C and dissolved oxygen at 9.5 mg/L for Hanaford Creek. If these temperature and DO limits for Hanaford Creek are revised to 17.5 o C for temperature and dissolved oxygen to 8.0 mg/L, these interim limits will be adjusted to reflect this regulation change. Ecology has set this permit’s DO limits based on WAC 173

- 201A water quality criteria. At this point, Ecology does

not have sufficient information to alter th e water quality criteria for DO.

Action Taken : NoneFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 65 of 70 Comment 3

Page 6, Condition S 1.A, Table 1, Line 11

- The draft permit contains limits for "priority pollutants less

chromium and zinc" at Outfall 001 that are listed as "No detectable amount". The basis for the limit, as described on page 23 of the Fact Sheet, is incorrectly stated as "40 CFR 423 requires that the Permittee

must achieve non

- detectable levels for the priority pollutants (priority pollutant less chromium and zinc) for the cooling tower blo w down discharge before this water is discharged to the surface water (Hanaford Creek)." This section of the Fact Sheet (II E) is discussing the basis for surface water quality based limits, not technology based limits. The condition in Table 1 of the pe rmit related to Outfall 001 should address compliance with the surface water quality standards. Additionally, it is clear that the technology based standard does not require "No detectable amount" of the priority pollutants at Outfall 001

.

The referenced standard, as quoted on pages 15

- 16 of the Fact Sheet, states at 40 CFR 423.13(d)(1) "The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown times the conce ntrations listed below: The 126 priority pollutants contained in chemicals added for cooling tower maintenance, no detectable amount, except:" Chromium, total and Zinc, total. Additionally, 40 CFR 423 .13( d)(3) states "At the permitting authority's disc retion, instead of the monitoring specified in 40 CFR 122.11(b) compliance with the limitations for the 126 priority pollutants in paragraph (d)(1) of this section may be determined by engineering calculations which demonstrate that the regulated pollutant s are not detectable in the final discharge by the analytical methods in 40 CFR part 136."

It is clear that this standard is intended to prohibit power plants from adding chemicals containing the priority pollutants for cooling tower maintenance in quantities that would result in a detectable amount of

any added chemical that is a priority pollu tant being discharged to Outfall 001. We suggest that Line 11 of Table 1 be eliminated and the technology based standard be applied through a study under condition S 1l as described at 40 CFR 423.13(d)(3). However, if the Department feels that a technolo gy based limit on priority pollutants is required, we suggest that language of 40 CFR 423. 13(d)(1) be used to address the technology based standard. Suggested language is: "No amount of the 126 priority pollutants in Appendix B of this permit can be cont ained in chemicals added for cooling tower maintenance that will result in a detectable amount in the discharge". We believe that this language will clarify where the basis for the requirement for "No detectable amount" comes from and allow TransAlta and the Department to address this requirement through a study under condition S 11. If the Department feels a water q uality based limit on Outfall 001 is required, it should not use the "No detectable amount" language that applies

for added cooling tower maintenance chemicals but should instead use a limit based upon the water quality standards in WAC 173

- 201A

- 240 for an y chemicals relating to Outfall 001, not the list of 126 priority pollutants in 40 CFR 423.

Ecology’s Response

The fact sheet has addressed EPA’s guidelines for the cooling tower blowdown industrial process. Ecology has used the BAT guidelines for the c ooling tower blowdown as the standard for all industrial process waste streams for the TCG NPDES permit at this time. In the new proposed permit the cooling tower blowdown pollutant limits are applied as an interim permit limits. Ecology will revise and adjust the final permit limits based on the AKART analysis required in the compliance schedule of new proposed permit.

Action Taken : NoneFACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 66 of 70 Comment 4

Page 6, Condition S 1.A, Table 1

- It should be clarified for DO, Temperature, and Turbidity that backgro und readings are taken upstream of Outfall 001 and compared to the downstream reading to determine compliance. Perhaps an additional footnote on the conditions for DO, Temperature, and Turbidity explaining the monitoring locations would clarify the requir ement. If necessary, TransAlta can provide the coordinates for the upstream and downstream monitoring locations currently used.

Ecology’s Response

Changes are made in the new proposed permit. This permit adds the location for the background sampling fo r Turbidity and Temperature. Ecology is not changing the permit requirements for DO.

Action Taken : Permits adds the location for the background turbidity and temperature.

Comment 5

Page 7, Condition S 1.A, Table 2, Line 3 There appears to be an error in the units on the Fecal Coliform Bacteria limit. We believe the units on the limit should be expressed in "#/100 mL" instead of "#/mL".

Ecology’s Response

It is a typographical error. The fact sheet of the draft permit has the correct unit (see page 2 6 of the fact sheet). The unit for fecal coliform in the permit is changed from #/mL” to “#/100 mL”

Action Taken : Fecal coliform unit corrected in the permit

Comment 6

Page 7, Condition S1.A, Table 2

- The reference "b" on the header "Maximum dailyb" in Table 2 appears to be referring to footnote "b" of Table 1. A footnote "b" similar to Table 1 should be added in Table 2 for "Maximum daily" and the other references in the table corrected as necessary.

The current footnote "b" correctly references the proper sampling location for BOD. However, it should include references for sampling Fecal Coliform Bacteria, Total Chlorine residual, and pH at the same sampling location. These parameters in the table should also get the reference to the footnote for t he sampling location at the outlet of the oxidation pond.

Ecology’s Response

Corrections are made in the permit (please see page 8 table 3 of the permit).

Action Taken : Footnotes added/clarified regarding the effluent sampling collection location

Comment 7FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 67 of 70 Condition S2.A The draft permit increases the frequency for testing Chromium, Zinc, and Hardness in Outfall 001 from annually to monthly. Since test data submitted annually for the previous permit have

shown the results for Chromium and Zinc to be well below the permit limits in condition S 1.A, continuing the testing requirement at once per year will give the Department enough data to document continued compliance with these limits. If the Department is concerned about compliance with the water quality standards for Chromium and Zinc (which vary depending upon water hardness), testing twice per year (once in the winter and once in the summer) for these parameters (including hardness at the same time) will give the Department enough data to docum ent compliance with these standards.

Ecology’s Response

Ecology determined that in order to have a good pool of data for Chromium, and Zinc, it is necessary to conduct the effluent testing monthly. Therefore the sampling frequency will remain as stated in the draft permit (except hardness )

. Ecology has changed hardness monitoring frequency from monthly to quarterly. This frequency of sampling is a common criteria in many NPDES permits administered by Ecology.

Action Taken : None

Comment 8

Condition S 11.A The language in this condition, "This work plan will address methods to meet the surface water quality standards (WAC 173

- 201) and technology based limits to achieve the applicable permit limits that currently permit is unable to attend" i mplies that the plant currently does not meet the water quality and technology based limits. We believe that we currently do meet all the technology based limits in 40 CFR 423.13(d). The study should be formulated to document that we do meet the limits as described in the comments on "Condition S 1.A, Table 1, Line 11" above. A study to demonstrate compliance with the limitations for the 126 priority pollutants in paragraph 40 CFR 423.13(d)(1) " ... determined by engineering calculations which demonstrate that the regulated pollutants are not detectable in the final discharge by the analytical methods in 40 CFR part 136" is sufficient and appropriate to document compliance with the technology based standards. If the Department includes water quality

based limits in Table 1, we suggest that the language of this section be modified to include something like: "This work plan may also address methods to determine that the surface water quality standards
(WAC 173

- 201A) are met."

Ecology’s Response

The lab results and reasonable potential analysis showed that the TCG has a reasonable potential to

exceed the surface water quality and non

- detect priority pollutants requirements (Please see table 2 lab

report, and 3 and 4 reasonable potential analysis, of Appendix C of the fact sheet).

Action Taken : None

Comment 9FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 68 of 70 Fact Sheet, Pages 13, Section I.C

- Summary of Compliance It should be noted that 10 of the exceptions listed were for groundwater monitoring of the irrigation outfalls. These outfalls were eliminated in a permit revision in 2008.

Ecology’s Response

This Summary of Compliance is required to cover the five year permit compliance history (July 2005 through June 30, 2010). This NPDES permit covered all types of water bodi es, including groundwater. During the course of the 2005 permit, TCG was land applying wastewater in the summers and TCG violated the groundwater quality limits for certain pollutants. That’s what the summary of compliance
indicates in the permit.

Action Taken : None

Comment 10

Fact Sheet, Pages 13 and 14, Section I.D

- Wastewater Characterization Some of the data in Tables 3 and 4 appear different than what was submitted in the permit application. It is not clear where this information

came from. It ma y be appropriate to review and correct this.

Ecology’s Response

Ecology has analyzed not only the permit application data but also five years of monitoring data that TCG has submitted to Ecology during the five year permit cycle.

Action Taken : None

Comment 11

Fact Sheet, Page 20, Section II.D and E

- Designated Uses, Evaluation of Surface Water Quality Section II.D of the Fact Sheet discusses the designated uses for Hanaford Creek as "Core Summer Salmonid Habitat". As noted above, this segment of Han aford Creek should be listed as "Salmonid Spawning, Rearing, and Migration", so these sections should address those parameters in Table 7 and the discussion, not the "Core Summer Salmonid Habitat" parameters listed in the Fact Sheet.

Ecology’s Response

T he temperature and dissolved oxygen limits in the proposed permit are based on WAC 173

- 201A which currently has the temperature limit set at 16.0 o C and dissolved oxygen at 9.5 mg/L for Hanaford Creek.

If these temperature and DO limits for Hanaford Creek are revised to 17.5 o C for temperature and dissolved oxygen to 8.0 mg/L, these interim limits will be adjusted to reflect this regulation change.

Action Taken : None

Comment 12FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 69 of 70 Fact Sheet, Page 23, Section II.E

- Toxic Pollutants Section II.E of the Fact Sheet states in paragraph 2, that "40 CFR 423 requires the Permittee must achieve non

- detectable levels for the priority pollutants (priority pollutant less chromium and zinc) for the cooling tower blowdown discharge ... " This is not a correct interpretation of the standard. As stated on page 16 of the Fact Sheet, the standard requires "The quantity of pollutants discharged in cooling tower blowdown shall not exceed the quantity determined by multiplying the flow of cooling tower blowdown times the concentrations listed below: The 126 priority pollutants contained in chemicals added for cooling tower maintenance, no detectable amount, except"
Chromium, total and Zinc, total. Dete ctable amounts of naturally occurring pollutants are allowed in the discharge as long as those pollutants were not "added for cooling tower maintenance." The Fact Sheet

should be corrected to address this.

Ecology’s Response

The fact sheet has addressed federal regulations for the cooling tower blowdown industrial process. Ecology has used the BAT guidelines for the cooling tower blowdown as the standard for all industrial process waste streams for the TCG NPDES permit at this time. In the new proposed permit the cooling tower blowdown pollutant limits are applied as interim permit. Ecology will revise and adjust the final permit limits based on the completion of the compliance schedule required in the compliance schedule of new proposed permit.

Action Taken : None

Comment 13

Fact Sheet, Page 25 and 26, Table 9 Table 9 should be updated to address "Salmonid Spawning, Rearing, and Migration" requirements. The table should also be updated to correct the technology based limits for priority pollutants described above.

Ecology’s Response

Please see responses to the comments 1 and 1 2

Action taken : None



### .FACT SHEET FOR NPDES PERMIT WA 0001546

TRANSALTA CENTRALIA GENERATION LLC (TCG)



### Page 70 of 70 References

1. EPA Memorandum of June 7, 2010, James A. Hanlon, Director, Office of Waste Management, Water Division Directors Regions 1

- 10, National Pollutant Discharge Elimination System (NPDES) Permitting of Wastewater Discharge form Flue Gas Desulfurization (FGD) and Coal Residuals (CCR) Impoundments at St eam Electric Power Plant

2. Water Quality Program Guidance, Implementing the State’s Temperature Standards through
NPDES Permits, July 2010

3. EPA 821

- R

- 09

- 008, Steam Electric Power Generating Point Source Category: Final Detailed Study Report, October 2009

4. Engineering Report, Treatment of Scrubber (Flue Gas Desulfurization System) Blowdown for Discharge to the Existing Plant Wastewater Treatment System, Submitted to Washington Department of Ecology Water Quality program, by TransAlta Centralia Generation, LL C on
November 29, 2005

5. Technical Memorandum

– TransAlta Centralia

– Dewatered Lime Sludge Characterization Summary, Submitted to Ecology on February 15, 2005