## FACT SHEET FOR NPDES PERMIT NO. WA0037338
TRANSALTA CENTRALIA MINING LLC

4/ 29/ 2005FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC



## TABLE OF CONTENTS Page

INTRODUC TION

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

GENERAL INFO RMATION

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

BACKGROUND INFO RMATION.........................................................................................................

..... 4 DESCRIPTION OF THE FACILITY

.............................................................................................. 4 Discharge Outfalls

............................................................................................................. . 4 PERMIT STATUS

.................................................................................................................. ......... 4 SUMMARY OF COMPLIANCE WITH THE PREVIOUS PERMIT

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

WASTEWATER CHARACTERIZATION

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

PROPOSED PERMIT LIMITATIONS

.................................................................................................... .... 7 TECHNOLOGY-BASED EFFLUEN T LIMITATIONS

................................................................ 7 SURFACE WATER QUALITY-BASED EFFLUENT LIMITATIONS

........................................ 8 Narrative Cr iteria

............................................................................................................. ... 8 Antidegradation

................................................................................................................ .. 9 Description of the Receiving Water

.................................................................................... 9 Surface Water Quality Criteria

........................................................................................... 9 Hum a n Health

................................................................................................................... .. 9 GROUND WATER QUALITY LIMITATIONS

............................................................................ 9 COMPARISON OF EFFLUENT LIMITS WITH THE EXISTING PERMIT ISSUED JUNE 9, 2000.

.................................................................................................................. . 10

MONITORING re quirem e nts

........................................................................................................ ............. 10 LAB ACCREDI TATION

.............................................................................................................. 10

OTHER PERMIT CONDITI ONS

........................................................................................................ ...... 10 REPORTING AND RE CORDKEEPING

..................................................................................... 10 SPILL PLAN

..................................................................................................................... ............ 10 GENERAL C ONDITIONS............................................................................................................ 1 0

PERMIT ISSUANCE PROCEDURES

..................................................................................................... . 10 PERMIT MODIFICATIONS

........................................................................................................ 10 RECOMMENDATION FOR PERMIT ISSUANCE

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

REFERENCES FOR TEXT AND APPENDICES

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

APPENDIX A--PUBLIC INVOLVE MENT INFORMATION

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

APPENDIX B --GLOSSARY

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

Page 2 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

INTRODUCTION The Federal Clean Water Act (FCWA, 1972, and la ter m odifications, 1977, 1981, and 1987) established water quality goals for the navigable (surface) waters of the United States. One of the m echanism s for achieving the goals of the Clean Water Act is the National Pollutant Discharge Elim ination Sy stem (NPDES) of perm its which is adm i nistered by the Environm ental Protection Agency (EPA). The EPA has delegated responsibility to adm i nister the NPDES perm it program to the state of Washington on the basis of Chapter 90.48 RCW which defines the Departm e nt of Ecology ' s (Departm ent) authority and obligations in adm i nistering the wastewater discharge perm it program

. The regulations adopted by the state include pr ocedures for issuing perm its (Chapter 173-220 WAC), water quality criteria for surface and ground waters (Chapters 173-201A and 200 WAC), and sedim ent

m a nagem e nt standards (Chapter 173-204 WAC). These regul ations require that a perm it be issued before discharge of wastewater to waters of the state is allowed. The regulations also establish the basis for effluent lim itations and other requirem e nts which ar e to be included in the perm it. One of the requirem e nts (WAC 173-220-060) for issuing a perm it under the NPDES perm it program is the preparation of a draft perm it and an accom p any i ng fact sh eet. Public notice of the availability of the draft perm it is required at least thirty day s before the perm it is issued (WAC 173-220-050). The fact sheet and draft perm it are available for review ( s e e A p p e n d i x A

- - P u b l i c I n v o l v e m e nt of the fact sheet for m o re detail on the Public Notice procedures). The fact sheet and draft perm it have been reviewed by the Perm ittee. Errors and om issions identified in this review have been corrected before going to public notice. After the public com m e nt period has closed, the Departm e nt will sum m a rize the substantiv e com m e nts and the response to each com m e nt. The

sum m a ry and response to com m e nts will becom e part of the file on the perm it and parties subm itting

com m e nts will receive a copy of the Departm e nt' s response. The fact sheet will not be revised. Com m e nts and the resultant changes to the perm it will be sum m a rized in Appendix D--Response to C o mme n t s

.
GENERAL INFORMATION Applicant: TransAlta Utilities Corporation 110 12th Avenue SW Box 1900, Station M Calgary
, Alberta, Canada T2P-2MI Facility Nam e and Address: TransAlta Centralia Mining LLC 1015 Big Hanaford Road Centralia, WA 98531-9100 USA Ty pe of Facility : Surface Coal Mine SIC Code: 1221 Discharge Location: Hanaford Creek Sy stem Outfall 001 Latitude: 46° 45' 08" N Longitude: 122° 49' 47" W Outfall 002 Latitude: 46° 45' 47" N Longitude: 122° 49' 42" W Outfall 003 Latitude: 46° 45' 45" N Longitude: 122° 49' 45" W Outfall 004 Latitude: 46° 45' 27" N Longitude: 122° 49' 56" W Outfall 005 Latitude: 46° 45' 42" N Longitude: 122° 49' 59" W Outfall 006 Latitude: 46° 45' 42" N Longitude: 122° 49' 36" W Outfall 008 Latitude: 46° 45' 23" N Longitude: 122° 49' 04" W Outfall 009 Latitude: 46° 30' 00" N Longitude: 122° 51' 00" W

Mitchell Creek Sy stem Outfall 011 Latitude: 46° 41' 45" N Longitude: 122° 45' 31" W Water Body ID Num b er: WA-23-1040

Page 3 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

Departm e nt on June 21, 2004. Hanaford Creek is a tributary of the Skookum chuck Rive r, a tributary of the Chehalis River. Mitchell Creek is a tributary of the north fork of the Newaukum River, a tributary of the Chehalis River.

BACKGROUND INFORMATION

DESCRIPTION OF THE FACILITY
History : The TransAlta Centralia Mining LLC is locat ed in an area where coal has been m i ned for over 100 y ears. When the price of electricity m a de large scale steam electric generation econom ically feasible in the early 1970s, this facility was opened and activel y m i ned to provide coal to the adjacent generating station. It has been m i ned since 1971 when electrical generation began. The Departm e nt archives show that the m i ne has had a NPDES perm it since at least the early 1980s. This m i ne is a NPDES m a jor facility

. The treatm e nt sy stem for the m i ne consis ts of sedim entation ponds built under the supervision of the federal Office of Surface Mining and the Washi ngton State Departm e nt of Ecology Dam Safety section. Due to the ongoing m i ning, these ponds are built as excavation progresses and abandoned (at least as outfalls) as reclam ation progresses.

At this site approxim a tely 6 m illion tons of coal is m i ned and processed annually for use in the adjacent steam electric generating facility . The coal is washed to im prove its quality as fuel by rem oving nonflam m a ble m i nerals. Since the existing perm it was issu ed, the coal washing facility has been revised with a new clarifier installed. Coal is brought to the pro cessing facility in trucks where it is washed for use in the boilers. The facility em ploy s approxim a tely 565 workers operating 24 hours a day
, seven day s a week in three shifts. The m i ning perm it covers 14,450 acres. The m i ne stores the usual petroleum products for the operation of diesel engine powered m i ning equipm ent and coal processing m achinery

. Of the ten outfalls from sedim entation ponds, all treat runoff from active or partially reclaim e d m i ning areas and two (#001 and #002 ) treat runoff from both the surface and coal wash water from the coal processing area (see discharge outfalls below).

D ISCHARGE O UTF A LLS There are several outfalls in this sy stem . All of these outfalls discharge runoff from the m i ned areas which is treated by flocculation and sedim entation. Outfall 001 and 002 m a y discharge storm runoff in excess of the hy draulic capacity of the storm runoff ponds in the vicinity which are also used to treat coal washing water from the coal washing sy stem . The hy dr aulic capacity of the Pond 3 Sy stem is designed to carry the average y early rainfall and use this water in a recirculating sy stem that treats the coal without discharge except during storm events. The discharge outfalls are all overflow structures from treatm e nt ponds. The receiving waters are Hanaford Creek and its tributaries and Mitchell Creek and its tributaries. Hanaford Creek drains to the Skookum chuck River which in turn drains to the m a in stem of the Chehalis River. Mitchell Creek is a tributary of the north fork of the Newaukum River, a tributary of the Chehalis River. See the processing and pond flow schem atics in Appendix C.

PERMIT STATUS
The previous perm it for this facility was issued on June 9, 2000, and m odified on Novem b er 30, 2000, and Decem ber 12, 2003. The previous perm it placed effluent lim itations on turbidity , total suspended solids (TSS), pH, dissolved oxy gen, total petrol eum hy drocarbons, tem p erature, and total iron.
An application for perm it renewal was subm itted to the Departm e nt on June 3, 2004 and accepted by the

Page 4 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

SUMMARY OF COMPLIANCE WITH THE PREVIOUS PERMIT
The facility last received an inspection on April 4, 1994.

Performance Summary, Violations Begin Date Monitoring PT Param e ter Value Ty pe

1-Mar-02 9 IRON, TOTAL (AS FE) AVM 1-Dec-01 9 SOLIDS, TOTAL SUSPENDED AVM 1-Jan-02 9 SOLIDS, TOTAL SUSPENDED AVM 1-Mar-02 9 SOLIDS, TOTAL SUSPENDED AVM 1-Dec-02 9 SOLIDS, TOTAL SUSPENDED AVM 1-Jan-03 9 SOLIDS, TOTAL SUSPENDED AVM 1-Feb-03 9 SOLIDS, TOTAL SUSPENDED AVM 1-Dec-01 9 SOLIDS, TOTAL SUSPENDED MXD 1-Jan-02 9 SOLIDS, TOTAL SUSPENDED MXD 1-Mar-02 9 SOLIDS, TOTAL SUSPENDED MXD 1-Jan-02 10 IRON, TOTAL (AS FE) AVM 1-Dec-00 10 OXYGEN, DISSOLVED (DO) MIN 1-Jan-02 10 PETROLEUM HYDROCARBONS, TOTAL RECOVERABLE AVM 1

- D e c

- 0 0 1 0 P H M A X 1

- D e c

- 0 0 1 0 P H M I N 1-Dec-00 10 SOLIDS, TOTAL SUSPENDED AVM 1-Nov-01 10 SOLIDS, TOTAL SUSPENDED AVM 1-Dec-01 10 SOLIDS, TOTAL SUSPENDED AVM 1-Jan-02 10 SOLIDS, TOTAL SUSPENDED AVM 1-Feb-02 10 SOLIDS, TOTAL SUSPENDED AVM 1-Mar-02 10 SOLIDS, TOTAL SUSPENDED AVM 1-Dec-00 10 SOLIDS, TOTAL SUSPENDED MXD 1-Nov-01 10 SOLIDS, TOTAL SUSPENDED MXD 1-Dec-01 10 SOLIDS, TOTAL SUSPENDED MXD 1-Jan-02 10 SOLIDS, TOTAL SUSPENDED MXD 1-Feb-02 10 SOLIDS, TOTAL SUSPENDED MXD 1-Mar-02 10 SOLIDS, TOTAL SUSPENDED MXD 1-Dec-00 10 TEMPERATURE , WATER (DEG C) AVM 1

- D e c

- 0 0 1 0 T U R B I D I T Y A V M 1

- N o v

- 0 1 1 0 T U R B I D I T Y A V M 1

- D e c

- 0 1 1 0 T U R B I D I T Y A V M

WASTEWATER CHARACTERIZATION

OUTFALL NUMBER 001 Tem p erature °C pH S.U. D.O. mg / L Total Iron mg / L TPH mg / L TSS mg / L Turbidity NTU A v e r a g e 9

. 7 7

. 0 4 1 0

. 4 0

. 2 4 < 0

. 2 5 6

. 2 9 4

. 9 0 Maxim u m 1 6

. 2 7

. 9 8 1 3 0

. 6 0 < 0

. 3 0 2 1

. 8 5 1 8

. 3 4

Page 5 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

U T F A L L N U M Tem t u r e °C

. / L Total Iron / L g / L Turbidity T U O B E R 0 0 2
p e r a pH S

. U D.O. mg m g TPH mg / L TSS

m N A v e r a g e 1 0

. 1 7

. 1 6 1 0

. 7 0

. 1 8 < 0

. 2 5 5

. 0 4

. 7 6 M a x i m u m 16.5 8.15 13.6 0.40 <0.30 11.7 10.72

O U T F A L L N U M Tem t u r e °C

. / L Total Iron / L / L Turbidity T U B E R 0 0 3
p e r a pH S

. U D.O. mg m g TPH mg / L TSS

m g N A v e r a g e 9

. 9 7

. 0 6 1 0

. 3 0

. 2 6 < 0

. 2 5 3

. 5 6 3

. 4 5 M a x i m u m 16.8 7.95 12.1 0.40 < 0.30 6.69 6.96

O U T F A L L N U M Tem t u r e °C

. / L Total Iron / L / L Turbidity U B E R 0 0 4
p e r a pH S

. U D.O.

m g m g TPH mg / L TSS

m g N T A v e r a g e 9

. 6 7

. 2 1 0

. 7 0

. 1 8 < 0

. 2 5 2

. 5 8 2

. 2 6 M a x i m u m 16.9 8,26 12.8 0.30 < 0.30 6.2 4.93

O U T F A L L N U Tem t u r e °C / L Total Iron / L / L Turbidity M B E R 0 0 5
p e r a pH S

. U

. D.O.

m g m g TPH mg / L TSS

m g NTU A v e r a g e 1 0

. 5 7

. 8 2 1 2

. 9 N o t Measured 1

. 8 3 1

. 4 Maxim u m 17.8 7.82 12.9 3.8 3.9 O U T F A L L N U Tem t u r e °C / L Total Iron / L / L Turbidity U M B E R 0 0 6
p e r a pH S

. U

. D.O.

m g m g TPH mg / L TSS

m g N T A v e r a g e 8

. 1 7

. 2 9 1 0

. 8 N o t Measured 2

. 7 2 1

. 9 8 M a x i m u m 17.0 7.72 12.6 5.5 2.98

O U T F A L L N U
t u r e °C / L n / L / L U M B E 0 8 R 0
p e r a T e m p H S

. U

. D

. O

. m g T o t a l g I r o

m T P H mg / L T S S

m g T u r b i d i t y N T

v e r a g e 9

. 6 6

. 5 6 1 0

. 6 1

. 0 2 < 0

. 2 5 4

. 3 7 4

. 4 2 A M a x i m u m 16.5 7.27 13.6 2.8 < 0.30 7.95 8.04

O U T F A L L N U
p e r a t u r e °C . / L I r o n / L L d i t y U M B E 0 9 R 0 T e m p H

. S

. U D

. O

m g T o t a l g m T P H mg / L T S S mg / T u r b i T N Average 7.1 6.99 10.3 0.88 <0.25 24.33 13.12 Maxim u m 10.0 7.8 13.0 1.9 < 0.30 39.39 21.9

Page 6 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

OUTFALL NUMBER 010
p e r a t u r e °C

. . / L I r o n g / L S / L i d i t y U T e m p H S

. U D

. O

m g T o t a l

m T P H mg / L T S

m g T u r b N T Average 9.3 7.05 10.1 0.30 <0.25 3.86 2.96 Maxim u 17.1 7.7 13.6 0.7 < 0.30 8.71 7.26

m

OUTFALL NUMBER 011

°C pH S.U. D.O. mg / L mg / L TPH mg / L TSS mg / L Turbidity NTU T e m p e r a t u r e Total Iron

Average No Discharge M a x i mu m

V o l u m e 57, No. 246, Tuesday
, Decem ber 22, 1992). The m o re

polluta nts are not treatable at the concentrations reported and they are not controllable at the source and they do not have a reasonable potential to cause a water

e r m ittee is required to notify the Departm e nt.

E C H

N

O

L O G Y

- B

A S E

D E F

F

L U E

N

T L I M

I

T

A T I

O

N

S

Technology Based Standards used in this perm it for daily m a xim u m s are:

t a n t PROPOSED PERMIT LIMITATIONS
Federal and state regulations require that effluent lim itations set forth in a NPDES perm it m u st be either technology - or water quality -based. Technology -based lim itations are based upon the treatm e nt m e thods available to treat specific pollutants. Technology -b ased lim itations are set by regulation or developed on a case-by -case basis (40 CFR 125.3, and Chapter 173-220 WAC). Water quality -based lim itations are based upon com p liance with the Surface Water Qu ality Standards (Chapter 173-201A WAC), Ground Water Standards (Chapter 173-200 WAC), Sedim e nt Quality Standards (Chapter 173-204 WAC) or the N a t i o n a l T o x i c s R u l e ( F e d e r a l R e g i s t e r , stringent of these two lim its m u st be chosen for each of the param e ters of concern. Each of these ty pes of lim its is described in m o re detail below.

The lim its in this perm it are based in part on inform ation received in the application. The effluent constituents in the application were evaluated on a technology - and water quality -basis and the lim its necessary to m eet the rules and regulations of the st ate of Washington were determ ined and included in this perm it. The Departm e nt does not develop efflue nt lim its for all pollutants that m a y be reported on the application as present in the effluent. Som e
quality violation. If significant changes occur in any constituent, as described in 40 CFR 122.42(a), the P

T

P o l l u D a i l y M a x M o n t h l y A

TSS 40 m g /L 20 m g /L i m u m v e r a g e

o n 3.5 m g /L 3.5 m g /L I r pH Range 6 to 9 S.U. Range 6 to 9 S.U. Total Petroleum Hy drocarbons 15 m g /L 15 m g /L

The lim its for pH are based on the categorical lim its s hown in the Code of Fede ral Regulations Title 40, P a r t 4 3 4
, s u b p a r t B

. T h i s r e g u l a t i o n a l s o e s t a b l i s hes a lim it for iron and TSS, but this perm i t ( a n d t h e

Page 7 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

e nt Manual for the Puget Sound Basin, previous perm it) uses a m o re restrictive lim it based on prior dem onstrated perform ance. The lim it for iron is 3.5 m g /L for the daily m a xim u m

. The lim it for TSS is 40 m g /L. The lim it for Total Petroleum Hy drocarbons is based on the 1992 Storm w ater M a n a g e m Washington Departm e nt of Ecology which sets these a ttainable lim its based on prior experience for oil i s s a m e lim it is attainable for total petroleum hy drocarbons, the only oily substance of concern.

s o f t h e s t a t e

. S u r f a c e w a t e r quality -based effluent lim itations m a y be based on an individual waste load allocation (WLA) or on a WL A developed during a basin wide total m a xim u m

its that stated as an in crease over background only apply when the background

a m pled just upstream and dow nstream of the point where the discharge enters

a f

f e c t e d a t e r b o y . For Outfall 011, UMTC is the upstream sam ple point and LMTC is the i n t

. F o r O u t f a l l 0 0 3
, U S H C i s t h e u p s t r e a m sam ple point and MSHC is the

r r a t i v e c r i t e r i a prot ect the specific beneficial uses of all fresh (WAC 3

- 2 0 1 A

- 1 3 0 ) a n d m a rine (WAC 173- 201A-140) waters in the state of Washington. The following

s t h e l i m its placed on this effluent that is based on narrative criteria. These lim its are identical

x i s t i n g

Pollutant and grease rem oval. Best professional judgm ent assum es that t h

SURFACE WATER QUALITY-BASED EFFLUENT LIMITATIONS

In order to protect existing water quality and preser ve the designated beneficial uses of Washington' s surface waters, WAC 173-201A-060 states that waste dischar ge perm its shall be conditioned such that the discharge will m eet established Surface Water Quality Standards. The Washington State Surface Water Quality Standards (Chapter 173-201A WAC) is a state regulation designed to protect the beneficial uses of the surface w a t e r
daily loading study (TMDL). Turbidity , tem p eratur e and dissolved oxy gen are regulated based on water quality lim itations.

The tem p erature lim tem p erature is over 18 degrees Celsius. In this case the treatm e nt ponds outlets are shut off during hot weather so that the site becom es non-discharging. As a result, the tem p erature lim it is set at 18 degrees Celsius.
The turbidity lim it is set as an incr em ental increase at all levels of turbidity . As with tem p erature, the increm ental approach to lim it setting is som e tim es m a de im practical due to the inaccessibility of the stream and the location of the sam pling points at a c onsiderable setback from the stream . The lim its here

are set based on the prem ise that if the turbidity at any one of the outfall locations set back from the m a in stem of the affected stream s is l ess than the turbidity at a background point on the m a in stem , the treated effluent at the outfall cannot increase the turbidity of the m a in stem . To this end, background sam pling points are set at Sam p le Point UNHC2 for Outfall 004 on North Hanaford Creek and Sam p le Point USHC for Outfalls 001,002, 005, 006,008, 009, 010 on Big Hanaford Creek. Outfalls 003 and 011 can, however, be conveniently s t h e w d downstream sam p l e p o downstream sam ple point.

N ARRATIVE C RITERIA
In addition to num erical criteria, "narrative" water quality criteria (WAC 173-201A-030) lim it toxic, radioactive, or deleterious m a terial concentrations below those which have the potential to adversely affect characteristic water uses, cause acute or chroni c toxicity to biota, im pair aesthetic values, or

v e r s e l y affect hum a n h e a l t h

. N a a d 1 7 t a b l e s h o w to the lim i t s i n t h e e p e r m it.

. L i m i t D i s s o l v e d O x y g en Dissolved Oxy g en shall not fall below 8 m g /L
Tem p erature Tem p erature shall not exceed 18°C due to hum an activities. Increm ental tem p erature increases shall not at any tim e exceed t+28/(t+7).

Page 8 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

The Departm e nt has reviewed existing records and is unable to determ ine if am bient water quality is t e d c l a s s i fication criteria given in Chapter 173-201A WAC; therefore, the Departm e nt will use the designated classi fication criteria for this water body in the proposed

T h e f a c n a f o r d C r e e k
, P i n t h e vicinity a i r i e s

. C h a r a c t

s t r i a l
, agricultura l); stock watering; fish m i gration; fish rearing, spawning and harvesting; wildlife habitat; prim ary contact recreation; sport

URFACE W ATER Q UALITY C RITERIA

a a r e d e f i n I n a d d i t i o n , U

. S

. E P A h a s h e a l t h p o l l u t a nts (EPA 1992). Criteria for this discharge are l o w :

Fecal Coliform s : 100 organism s/100 m l m a xim u m geom etric m ean
D i s s o l v e d O x y g e n : 8 mg / L mi n i mu m 18 degrees Celsius m a xim u m or increm ental increases above background

e r q u a l i t y standards now include 91 num eric health-based criteria that m u st be

a w e r e p r om ulgated for the state by the U.S. EPA in its

e 57, No. 246, Tuesday , Decem ber 22, 1992).

m

ulgated Ground Water Qua lity Standards (Chapter 173-200 WAC) to protect

m a nner

h i s P e r m ittee has no discharge to ground and ther efore no lim itations are required based on potential effects to ground water. A NTIDEGRADATION

e i t h e r h i g h e r o r l o w e r t h a n t h e d e s i g n a

perm it. The discharges authorized by this proposed perm it should not cause a loss of beneficial uses.

D ES CRIP T ION OF THE R ECEIVING W ATER

i l i t y discharges to Big Hanaford Creek and its t r i b u t a r i e s , N o r t h H a n a f o r d C r e e k
, S o u t h H a
a c k w o o d C r e e k
, a n d M i t c h e l l C r e e k
, w h i c h a r e d e s i g n a t e d a s “ C l a s s A ” r e c e i v i n g w a t e r s of the outfalls. Significant nearby non-point sources of pollutants possibly i n c l u d e d

e r i s t i c u s e s i n c l u d e t h e f o l l o w i n g : water supply (dom estic, i n d u
fishing; boating and aesthetic enjoy m ent; co m m e rce and navigation. Water quality of this class shall exceed the requirem e nts for all or substantially all uses.

S

A p p l i c a b l e c r i t e r i e d i n C h a p t e r 1 7 3

- 2 0 1 A W A C for a q u a t i c b i o t a

. prom ulgated hum a n c r i t e r i a f o r t o x i c
sum m a r i z e d b e

Tem p erature: pH: 6.0 to 9.0 standard units
Toxics: No toxics in toxic am ounts

H UMAN H EALTH Washington’ s w a t considered in NPDES perm i t s

. T h e s e c r i t e r i N a t i o n a l T o x i c s R u l e ( F e d e r a l R e g i s t e r , V o l u m The Departm e nt has determ ined that the applicant's discharge is unlik ely to contain chem icals regulated for hum an health.

GROUND WATER QUALITY LIMITATIONS

The Departm e nt h a s p r o beneficial uses of ground water. Perm its issued by the Departm e n t s h a l l b e c o n d i t i o n e d i n s u c h a so as not to allow violations of those standards (WAC 173-200-100).

T

Page 9 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

C O M

P

A R I S O N O F E F

F

L U E

N

T I S

S U E

D J u n e 9

, 2 0 0 0

.

2 0

- 2 1 0 a n d 4 0 C F R 1 2 2

. 4 1 ) to verify that the treatm e nt process is functioning correctly a nd the effluent lim itations are being achieved.

The m onitoring schedule is detailed in the proposed perm it under Condition S.1. Specified m onitoring

o u n t t h e q u a n t i t y and variab ility of the discharge, the treatm e nt m e thod, past

com p liance, significance of pollutants, and cost of m onitoring.

I

O

N

W i t h t h e e x c e p t i o n o f c e r t a i n p a r i t o r i n g data to be prepared by a laboratory registered or accredited under the provisions of Chapter 173-50 WAC, Accreditation of

a t o r y at this facility is accredited for: Total Suspended Solids,

A N D R E C O R D K

E

E

P

I N

G

t h e P e r m ittee to develop best m a nagem e nt plans to prevent this accidental release under section 402(a)(1) of the Federal t ( F W P C A ) a n d R C W 9 0

. 4 8

. 0 8 0

.

itted and accepted.

GENERAL CONDITIONS

d i r e c t l y on state and fede ral law and regulations and have been standardized for all individual industrial NPDES perm its issued by the Departm e nt.

e r Quality Standards for Surface Waters, Sedim e nt Qua lity Standards, or Water Quality Standards for L I

M

I

T

S W I

T

H T H

E E X

I

S T I N

G P E

R M I

T No change in lim its.

MONITORING REQUIREMENTS
Monitoring, recording, and reporting are required ( W A C 1 7 3

- 2

f r e q u e n c i e s t a k e i n t o a c c

Monitoring frequency has been sim p lified to two separ ate intervals, m onthly and once every two m onths.

L

A B A C C R E D

I

T

A T

a m e ters the perm it requires all m o n

Environmental Laboratories. T h e l a b o r

u r

b i d i t y , and pH

. T

OTHER PERMIT CONDITIONS

R E P O R T I N

G

The conditions of S2 are based on the authority to specify any appropriate reporting and recordkeeping requirem e nts to prevent and control waste discharges (WAC 273-220-210).

SPILL PLAN
The Departm e nt has determ ined that the Perm ittee stor es a quantity of chem icals that have the potential to cause water pollution if accidentally released. The Depa rtm e nt has the authority t o r e q u i r e

W a t e r P o l l u t i o n C o n t r o l A c

The Perm ittee has developed a plan for preventing the accidental release of pollutants to state waters and for m i nim i zing dam a ges if such a spill occurs. T h i s p l a n h a s b e e n s u b m

G e n e r a l C o n d i t i o n s a r e b a s e d

PERMIT ISSUANCE PROCEDURES

PERMIT MODIFICATIONS

The Departm e nt m a y m odify this perm it to im pose num erical lim itations, if necessary to m e e t W a t

Page 10 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

t a i n e d from sources such as inspections, effluent

m onitoring, outfall studies, and effluent m i xing studies.

This proposed perm it m eets all statutory requirem e nts for authorizing a wastewater discharge, including those lim itations and conditions believed necessary to c ontrol toxics, protect hum an health, aquatic life, and the beneficial uses of waters of the state of W ashington. The Departm e nt proposes that this proposed perm it be issued for a period corresponding to the waters hed approach re-perm itting cy cle, that is to say until June 30, 2010. Ground Waters, based on new inform a t i o n o b

The Departm e nt m a y also m odify this perm it as a resu lt of new or am ended state or federal regulations.

RECOMMENDATION FOR PERMIT ISSUANCE

Page 11 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

REFERENCES FOR TEX T AND APPENDICES

Environm ental Protection Agency (EPA).

1 9 9 2

. N a t i o n a l T o x i c s R u l e

. Federal Register, V. 57, No. 246, Tuesday , Decem ber 22, 1992.

1 9 9 1

. T e c h n i c a l S u p p o r t D o c u m e nt for Water Quality -based Toxics Control . EPA/505/2-90-001.

1 9 8 8

. T e c h n i c a l G u i d a n c e o n S u p p l e m entary Stream Design Conditions for Steady State Modeling

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

1 9 8 5

. W a t e r Q u a l i t y Assessm ent: A Screening Proce dure for Toxic and Conventional Pollutants in Surface and Ground Water . EPA/600/6-85/002a.

1 9 8 3

. W a t e r Q u a l i t y Standards Handbook. USEPA Office of Water, Washington, D.C.
Tsivoglou, E.C., and J.R. Wallace.

1 9 7 2

. C h a r a c t e r i z a t i o n o f S t r e a m Reaeration Capacity . EPA-R3-72-012. (Cited in EPA 1985 op.cit.)

W a s h i n g t o n S t a t e D e p a r t m e n t o f E c o l o g y

. 1994. Perm i t W r i t e r ’ s M a n u a l . Publication Num b er 92-109

W r i g

1 9 h t , R

. M

. , a n d A

. J

. M c D o n n e l l

. 7 9

. I n

- s t r e a m Deoxy genation Rate Prediction

. J o u r n a l E n v i r o n m ental Engineering Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.)

Page 12 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

APPENDIX A--PUBLIC INVOLVEMENT INFORMATION
The Departm e nt has tentatively determ ined to reissue a perm it to the applicant listed on page 1 of this fact sheet. The perm it contains conditions and effluent lim ita tions which are described in the rest of this fact sheet.
Public notice of application was published on March 20, 2004 and March 27, 2004, in the Daily Chron icle to inform the public that an application had been subm itted and to invite com m e nt on the reissuance of this perm it.

The Departm e nt will publish a Public Notice of Draft (PNOD) on February 16, 2005, in the Daily Chronicle to inform the public that a draft perm it and f act sheet are available for review. Interested persons are invited to subm it written com m e nts regardi ng the draft perm it. The draft perm it, fact sheet, and related docum ents are available for inspection and copy ing between the hours of 8:00 a.m

. and 4:30 p.m

. weekday s , by appointm e nt, at the regional o ffice listed below. Written com m e nts should be m a iled to:

Industrial Unit Perm it Coordinator Departm e nt of Ecology Southwest Regional Office – Water Quality P.O. Box 47775 Oly m pia, WA 98504-7775.
Any interested party m a y com m e nt on the draft perm it or request a public hearing on this draft perm it within the thirty (30) day com m e nt period to the a ddress above. The request for a hearing shall indicate the interest of the party and reasons why the hearing is warranted. The Departm e nt will hold a hearing if it determ ines there is a significant public interest in the draft perm it (WAC 173-220-090). Public notice regarding any hearing will be circulated at least th irty (30) day s in advance of the hearing. People expressing an interest in this perm it will be m a ile d an individual notice of hearing (WAC 173-220-100).

The Departm e nt will consider all com m e nts received with in thirty (30) day s from the date of public notice of draft indicated above, in form ulating a final determ ination to issue, revise, or deny the perm it. The Departm e nt' s response to all significant com m e nts is available upon request and will be m a iled directly to people expressing an interest in this perm it.

Further inform ation m a y be obtained from the Depa rtm e nt by telephone, (360) 407-6285 or by writing to the address listed above.
This perm it and fact sheet were written by Gary Anderson, P.E.

Page 13 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

Co m

o f each aliquot as the flow increased while m a intaining a constant tim e interval between the aliquots. APPENDIX B--GLOSSARY
Acute Toxicity --The lethal effect of a com pound on an organism that occurs in a short period of tim e, usually 48 to 96 hours.

AKART -- An acrony m for “all known, available, and reasonable m e thods of treatm e nt”. Ambient Water Quality --The existing environm ental condition of the water in a receiving water body

. Ammo nia --Am m onia is produced by the breakdown of nitrogenous m a terials in wastewater. Am m onia is toxic to aquatic organism s, exerts an oxy gen dem a nd, and contributes to eutrophication. It also increases the am ount of chlorine need ed to disinfect wastewater. Best Management Practices (BMPs) --Schedules of activities, prohibitions of practices, m a intenance procedures, and other phy sical, structural and/or m a nagerial practices to prevent or reduce the pollution of waters of the state. BMPs include treatm e nt sy stem s, operating procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste disposal, or drainage from raw m a terial storage. BMPs m a y be further categorized as operational, source control, erosion and sedim ent control, and treatm e nt BMPs.

BOD 5 --Determ i ning the Biochem i cal Oxy g en Dem a nd of an effluent is an indirect way of m easuring the quantity of organic m a terial present in an effluent that is utilized by bacteria. The BOD 5 is used in

m odeling to m easure the reduction of dissolved oxy gen in a receiving water after effluent is discharged. Stress caused by reduced dissolved oxy gen levels m a kes organism s less com p etitive and less able to sustain their species in the aquatic environm ent. Although BOD is not a specific

com pound, it is defined as a conventional pollu tant under the federal Clean Water Act.
Bypass --The intentional diversion of waste stream s from any portion of a treatm e nt facility

. Chlorine --Chlorine is used to disinfect wastewaters of pa thogens harm ful to hum an health. It is also extrem ely toxic to aquatic life.

Chronic Toxicity --The effect of a com pound on an organism over a relatively long tim e, often 1/10 of an organism ' s lifespan or m o re. Chronic toxicity can m easure survival, reproduction or growth rates, or other param e ters to m easure the toxic effect s of a com pound or com b ination of com pounds.

Clean Water Act (CWA) --The Federal Water Pollution Control Act enacted by Public Law 92-500, as

am ended by Public Laws 95-217, 95-576, 96-483, 97-117; USC 1251 et seq. Compliance Inspection - Without Sampling --A site visit for the purpose of determ ining the com p liance of a facility with the term s and conditions of its perm it or with applicable statutes and regulations. Compliance Inspection - With Sampling --A site visit to accom p lish the purpose of a Com p liance Inspection - Without Sam p ling and as a m i nim u m , sam pling and analy s is for all param e ters with lim its in the perm it to ascertain com p liance with t hose lim its; and, for m unicipal facilities, sam pling of influent to ascertain com p liance with the 85 percent rem oval requirem e nt. Additional sam pling

m a y be conducted.

p o s ite Sa mple --A m i xture of grab sam ples collected at the sam e sam pling point at different tim e s , form ed either by continuous sam pling or by m i xing discrete sam ples. May be "tim ecom posite"(collected at constant tim e intervals) or "flow-proportional" (collected either as a constant

sam ple volum e at tim e intervals proportional to stream flow, or collected by increasing the volum e

Page 14 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

such factors as flow volum e, toxic pollutant potential, and public health im pact.

M i x
n a f a c i l i t y ' s perm it and follows procedures outlined in state regulations (Chapter 173-201A WAC). Monthly Average --The average of the m easured values obtained over a calendar m onth's tim e. Construction Activity --Clearing, grading, excavation and any other activity which disturbs the surface of the land. Such activities m a y include road build ing, construction of residential houses, office buildings, or industrial build ings, and dem o lition activity

. Critical Condition --The tim e during which the com b ination of receiving water and waste discharge conditions have the highest potential for causing toxi city in the receiving water environm ent. This situation usually occurs when the flow within a water body is low, thus, its ability to dilute effluent is reduced. Daily Maxim u m Discharge Lim i tation --The highest allowable daily discharge of a pollutant m easured during a calendar day or any 24-hour period that reasonably represents the calendar day for purposes of sam pling. The daily discharge is calculated as the average m easurem e nt of the pollutant over the day

. Dilution Factor --A m easure of the am ount of m i xing of effluent and receiving water that occurs at the boundary of the m i xing zone. Expressed as the inverse of the percent effluent fraction e.g., a dilution factor of 10 m eans the effluent com p rises 10 percent by volum e and the receiving water 90 percent. Engineering Report --A docum ent which thoroughly exam ines the engineering and adm i nistrative aspects of a particular dom estic or industrial w astewater facility . The report shall contain the appropriate inform ation require d in WAC 173-240-060 or 173-240-130.

Fecal Coliform Bacteria --Fecal coliform bacteria are used as indi cators of pathogenic bacteria in the effluent that are harm ful to hum ans. Pathogenic b acteria in wastewater discharges are controlled by disinfecting the wastewater. The presence of high num bers of fecal coliform bacteria in a water body can indicate the recent release of untreated wast ewater and/or the presence of anim al feces. Grab Sample --A single sam ple or m easurem e nt taken at a specific tim e or over as short period of tim e as is feasible.

Industrial Wastewater --Water or liquid-carried waste from industrial or com m e rcial processes, as distinct from dom estic wastewater. These wastes m a y result from any process or activity of industry
, m a nufacture, trade or business, from the developm ent of any natural resource, or from anim al operations such as feed lots, poultry houses, or dairi es. The term includes contam inated 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 volum e, toxic pollutant potential, and public health im pact. Method Detection Level (MDL)-- The m i nim u m concentration of a substance that can be m easured and reported with 99 percent confidence that the analy t e concentration is above zero and is determ ined from analy s is of a sam ple in a given m a trix containing the analy t e. Minor Facility-- A facility discharging to surface water with an EPA rating score of < 80 points based on

i n g Z o ne --An area that surrounds an effluent discharge within which water quality criteria m a y be exceeded. The area of the authorized m i xing zone i s s p e c i f i e d i

Page 15 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

g a b l e w a t e r s o f t h e
a u t h o r i t y to

s a r e j o i n t

pH easures its acidity or alkalin ity . A pH of 7 is defined as neutral, and large

Q u a
T e c

Total Suspended Solids (TSS) --Total suspended solids is the particulate m a terial in an effluent. Large

n d e p l e t i o n

.

S t o

r f a c e w a t e r b o d y , or a constructed infiltration facility

.

e n o n c o m plian ce to the extent caused by operational error, im properly designed treatm e nt facilities, lack of preventative m a intenance, or careless or im proper operation. Water Quality-based Effluent Limit --A lim it on the concentration of an effluent param e ter that is intended to prevent the concentration of that pa ram e ter from exceeding its water quality criterion after it is discharged into a receiving water. National Pollutant Discharge Elim ination System (NPDES) --The NPDES (Section 402 of the Clean Water Act) is the federal wastewater perm itting sy stem f o r d i s c h a r g e s t o n a v i United States. Many states, including the state of W a s h i n g t o n , h a v e b e e n d e l e g a t e d t h e issue these perm its. NPDES perm its issued by Washington state perm i t w r i t e r NPDES/State perm its issued under both state and federal laws. --The pH of a liquid m variations above or below this value are considered harm ful to m o st aquatic life.

n t i t a t i o n L e v e l ( Q L )

- - A calculated value five tim es the MDL (m ethod detection level).

h n o l o g y - b a s e d E f f l u e n t L i m i t --A perm it lim it that is based on the ability of a treatm e nt m e thod to reduce the pollutant.

quantities of TSS discharged to a receiving water m a y result in solids accum u lation. Apart from any toxic effects attributable to substances leached out by water, suspended solids m a y kill fish, shellfish, and other aquatic organism s by causing abrasive injuries and by clogging the gills and respiratory passages of various aquatic fauna. Indirectly , susp ended solids can screen out light and can prom ote and m a intain the developm ent of noxious conditions through oxy g e
State Waters --Lakes, rivers, ponds, stream s, inland waters, underground waters, salt wa ters, and all other surface waters and watercourses within the ju risdiction of the state of Washington.

r m w ater --That portion of precipitation that does not natu rally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and othe r features of a storm water drainage sy stem into

a d e f i n e d s u Upset --An exceptional incident in which there is unintentional and tem porary noncom pliance with technology -based perm it effluent lim itations because of factors bey ond the reasonable control of the Perm i t t e e

. A n u p s e t d o e s n o t i n c l u d

Page 16 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

APPENDIX C – FLOW DIAGRAMS

Page 17 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

Page 18 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

APPENDIX D – RESPONSE TO COMMENTS

Page 19 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

APPENDIX D-RESPONSE TO COMMENTS

TRANSALTA CENTRALIA COAL MINE NPDE S PE RMIT NUMB E R WA0037338 C o m m e nt 1.

Eco l o g y d o e s n o t sh o w th e resu lts o f th e p r io rity p o llu tan t s req u i red b y th e p e rm it ap p licatio n fo rm fo r th is facility.

R e sponse 1.

A pollutant scan has been done for the facility. A table s howing the potentially toxic subs tances detected is shown bel o w:

DETECTED SUBSTANCES CONCENTRATION Un its in μg /L Su b s tan c e O u t f a l l 002 Ou tfall 003 Ou tfall 004 St at ut ory Li m i t , W A C 173-201A Nat i onal Toxi cs Rule, FR 64, Nov 9, 1999 EPA 822-R

- 02- 47

Ni t r at e/ Ni t r i t e 1 3 0 0 6 0 0 N D N., Tt l Org. 600 500 300 P h o s p h o r u s 2 0 2 0 4 0 Sul f at e 2 1 2
, 0 0 0 3 3 9
, 0 0 0 3 3 0
, 0 0 0 Al um i num 3 8 3 4 6 8 5 4 9 7 5 0 B a ri um 4 8 4 9

. 8 1 2

. 2 B o r o n 3 3 8 0 1 3 0 2 0 6 C obal t 4

. 2 9

. 5 8 1

. 3 3 M a gnesi um 1 2
, 2 0 0 1 6
, 8 0 0 2 4
, 2 0 0 M o l y bdenum 6

. 4 0

. 1 0

. 6 M a n g a n e s e 4 1 4 8 7 6 2 1 0 5 0 Ti n 0.1 0.1 0.1 Ti t a ni um 2 6

. 8 2 2

. 2 2 8

. 8 Ant i m ony 0

. 1 5 0

. 0 5 0

. 0 7 1 4 Arseni c 0

. 5 0

. 5 0

. 5 1 9 0 Berylliu m 0

. 0 4 0

. 0 4 0

. 0 3 C a dm i u m 0

. 0 7 0

. 1 8 0

. 1 1 0

. 3 7 C h rom i um 0

. 3 0

. 6 0

. 6 5 7 C o p p e r 2

. 3 2

. 6 3

. 4 3

. 5 L e a d 0

. 0 6 0

. 1 3 0

. 0 8 0

. 5 M e rcury 0

. 2 0

. 2 0

. 2 0

. 0 1 2 Ni ckel 1 0

. 8 2 1

. 3 1 0

. 2 4 9 Sel e ni um 1

. 3 1

. 0 1

. 0 5 Si l v e r 0

. 0 2 0

. 0 2 0

. 0 5 1 Th alliu m 0

. 0 2 0

. 0 2 0

. 0 2 1

. 7 Zi n c 1 1

. 1 1 3

. 8 1 0

. 0 3 2 Of t h e above, obvi ousl y , t h ere are several t h at have no o ffi ci al l i m i t s . Onl y m a nganese has a publ i s hed l i m i t and th at lim it is fo r p o t ab le water.

C o m m e nt 2.

Federal R e gul at i on 40 C F R 424.23 requi res t h at when pH of t h e wast ewat er i s l e ss t h an 6.0, t h at t h e concent r at i on of m a nganese be l i m i t e d.

R e sponse 2.

Page 20 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

a. A st eam el ect ri c power generat i ng poi nt source i s consi d erabl y di fferent from a covered el ect ri c furnace or other sm elting operation with wet air pollu tion control equipm ent. It is a considerable stretch to req u i re th e fo rm er to m eet th e req u i rem e n t s o f th e latter. b. The W a shi ngt on Depart m e nt of Ecol ogy i s aut hori zed by l a w t o onl y enforce st at e l a ws.
c. The t a bul at i on bel o w shows t h at t h e m i ni m u m pH of t h e t h ree out fal l t e st ed has not fal l e n bel o w 6.6 in the period from July 1, 200 until January 1, 2005. Months not tabulated were m onths of zero di scharge.

O u t f a l l P a r a m e t e r U n i t T y p e R e a d i n g D a t e 2 P H S.U. MIN 6.9 1 -Oc t -00 2 P H S.U. MIN 7.1 1 -Nov-00 2 P H S.U. MIN 7.4 1 -Dec-00 2 P H S.U. MIN 7.4 1 -Jan-01 2 P H S.U. MIN 7.5 1 -Feb-01 2 P H S.U. MIN 7.2 1 -Mar-01 2 P H S.U. MIN 8.1 1 -Apr-01 2 P H S.U. MIN 7.7 1 -May-01 2 P H S.U. MIN 8 1 -Jun-01 2 P H S.U. MIN 7.1 1 -Nov-01 2 P H S.U. MIN 7.2 1 -Dec-01 2 P H S.U. MIN 6.6 1 -Jan-02 2 P H S.U. MIN 7.35 1-Feb-02 2 P H S.U. MIN 7.3 1 -Mar-02 2 P H S.U. MIN 7.3 1 -Apr-02 2 P H S.U. MIN 7.37 1-May-02 2 P H S.U. MIN 7.16 1-Dec-02 2 P H S.U. MIN 7.14 1-Jan-03 2 P H S.U. MIN 7.05 1-Feb-03 2 P H S.U. MIN 6.6 1 -Mar-03 2 P H S.U. MIN 6.8 1 -Apr-03 2 P H S.U. MIN 7 1 -May-03 2 P H S.U. MIN 7.72 1-Oct-03 2 P H S.U. MIN 6.6 1 -Nov-03 2 P H S.U. MIN 6.6 1 -Dec-03 2 P H S.U. MIN 7.01 1-Jan-04 2 P H S.U. MIN 7.62 1-Feb-04 2 P H S.U. MIN 8.15 1-Mar-04 2 P H S.U. MIN 7.3 1 -Apr-04 O u t f a l l P a r a m e t e r U n i t T y p e R e a d i n g D a t e 2 P H S.U. MIN 7.65 1-May-04 2 P H S.U. MIN 7.35 1-Sep-04 2 P H S.U. MIN 7.66 1-Oct-04 2 P H S.U. MIN 7.43 1-Nov-04 2 P H S.U. MIN 6.8 1 -Dec-04 2 P H S.U. MIN 7.2 1 -Jan-05 3 P H S.U. MIN 7.6 1 -Dec-00 3 P H S.U. MIN 8.46 1-Jan-01 3 P H S.U. MIN 8.6 1 -Feb-01 3 P H S.U. MIN 7.8 1 -Mar-01 3 P H S.U. MIN 7.4 1 -Apr-01 3 P H S.U. MIN 7.8 1 -May-01

Page 21 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANS A LTA CENTRALIA MINING LLC

3 P H S.U. MIN 7.7 1 -Oc t -01 3 P H S.U. MIN 7 1 -Nov-01 3 P H S.U. MIN 7.2 1 -Dec-01 3 P H S.U. MIN 6.7 1 -Jan-02 3 P H S.U. MIN 7.46 1-Feb-02 3 P H S.U. MIN 6.82 1-Mar-02 3 P H S.U. MIN 6.63 1-Apr-02 3 P H S.U. MIN 7.15 1-May-02 3 P H S.U. MIN 7.4 1 -Dec-02 3 P H S.U. MIN 6.75 1-Jan-03 3 P H S.U. MIN 7.1 1 -Feb-03 3 P H S.U. MIN 6.9 1 -Mar-03 3 P H S.U. MIN 7.35 1-Apr-03 3 P H S.U. MIN 6.84 1-May-03 3 P H S.U. MIN 6.8 1 -Oc t -03 3 P H S.U. MIN 6.32 1-Nov-03 3 P H S.U. MIN 6.6 1 -Dec-03 3 P H S.U. MIN 6.81 1-Jan-04 3 P H S.U. MIN 6.9 1 -Feb-04 3 P H S.U. MIN 7.95 1-Mar-04 3 P H S.U. MIN 7.9 1 -Apr-04 3 P H S.U. MIN 7.6 1 -May-04 3 P H S.U. MIN 7.3 1 -Sep-04 3 P H S.U. MIN 6.8 1 -Oc t -04 3 P H S.U. MIN 6.8 1 -Nov-04 3 P H S.U. MIN 6.78 1-Dec-04 3 P H S.U. MIN 6.94 1-Jan-05 4 P H S.U. MIN 7.6 1 -Nov-00 4 P H S.U. MIN 7.6 1 -Dec-00 4 P H S.U. MIN 7.2 1 -Jan-01 4 P H S.U. MIN 7.6 1 -Feb-01 4 P H S.U. MIN 7.1 1 -Mar-01 4 P H S.U. MIN 7.8 1 -Apr-01 4 P H S.U. MIN 7.8 1 -May-01 4 P H S.U. MIN 7.9 1 -Jun-01 4 P H S.U. MIN 7.3 1 -Oc t -01 4 P H S.U. MIN 7.3 1 -Nov-01 4 P H S.U. MIN 7.1 1 -Dec-01 4 P H S.U. MIN 6.8 1 -Jan-02 O u t f a l l P a r a m e t e r U n i t T y p e R e a d i n g D a t e 4 P H S.U. MIN 7.4 1 -Feb-02 4 P H S.U. MIN 7.9 1 -Mar-02 4 P H S.U. MIN 7.2 1 -Apr-02 4 P H S.U. MIN 8.26 1-May-02 4 P H S.U. MIN 7.12 1-Nov-02 4 P H S.U. MIN 6.92 1-Dec-02 4 P H S.U. MIN 6.73 1-Jan-03 4 P H S.U. MIN 6.7 1 -Feb-03 4 P H S.U. MIN 7.4 1 -Mar-03 4 P H S.U. MIN 7.3 1 -Apr-03 4 P H S.U. MIN 7.5 1 -May-03 4 P H S.U. MIN 6.95 1-Oct-03

Page 22 of 23FACT SHEET FOR NPDES PERMIT NO. WA0037338 TRANSALTA CENTRALIA MINING LLC

Page 23 of 23 4 PH S.U. MIN 6.7 1-Nov-03 4 PH S.U. MIN 6.92 1-Dec-03 4 PH S.U. MIN 6.73 1-Jan-04 4 PH S.U. MIN 7.6 1-Feb-04 4 PH S.U. MIN 7.72 1-Mar-04 4 PH S.U. MIN 7.5 1-Apr-04 4 PH S.U. MIN 7.4 1-May-04 4 PH S.U. MIN 7.9 1-Sep-04 4 PH S.U. MIN 7.26 1-Oct-04 4 PH S.U. MIN 7.25 1-Nov-04 4 PH S.U. MIN 7.21 1-Dec-04 4 PH S.U. MIN 7.07 1-Jan-05

Comment 3.

Given that sampling for background is mostly awkward if not impossible at most of the outfalls, it would be advantageous to assign a single maximum limit for turbidity for all but periods of excessive rainfall at outfalls where active mining operations are under way.

Response 3.

A performance limit based on the Ecology sand and gravel general permit AKART determination gives a limit of 25 NTU for inactive mining areas (outfalls 001, 002, 003, 004, 005, 006, 008, and 011) and a limit of 50 NTU for areas of active mining (outfalls 009 and 010). When a rainstorm of greater intensity than one and one-half inches in 24 hours occurs, the limit for the areas of active mining (outfalls 009 and 010) shall revert to a ten percent increase over background limit.