# -AAA


# DE Q
State o f Orego n Departmen t o f Environmenta l Qualit y 

# Nationa l Pollutan t Discharg e Eliminatio n Syste m PERMI T EVALUATIO N AN D FACT SHEE T 

# Orego n Departmen t

o f Environmenta l Qualit y Northwes t Region 2020 S W 4 th

### Avenue Suit

e 400 Portland O

R9720 1 (503 ) 229-526 3

Permittee :

Existin g Permi t Information :

Sourc e Contact : Sourc e Location :
LLID : Receivin g Stream : Propose d Action :

Sourc e Categor y Permi tWriter : CityofWilsonvill e 2979 9 Tow n Cente r

Loo p Eas t Wilsonville , O R9707 0 Fil e Number : 9795 2 Permi t Number : 10188 8 Expiratio n Date : 12/31/200 9 EPA Referenc e Number : OR-002276- 4 Delor aKerber , 503-570-154 2 Publi c Work s Directo r 927 5 SWTauchma n Roa

d Wilsonville , Orego n 1227618456580-38. 6 D Willamett e Rive r Permi t Renewa l Applicatio n Number : 97144 9 Dat e Received : Jun e 30,200 9 amende d Jun e 28,201 0 NPDE S Majo r

- Domesti c Lyl e Christense n Natura l Resourc e Specialis t

### Tabl e o f

Content s 1. 0 Introductio n 3 2. 0 Facilit y descriptio n 3 2. 1 Genera

l 3 2. 2 Wastewate

r Treatmen t
... 4 2. 3 Change s in Operation 5 2. 4 Groundwate

r Issue s 5 2. 5 Stor mWate r 6 2. 6 Outfall s 6 2. 7 Industria

l Pretreatment

- majors onl y 6 2. 8 Biosolid s 6 2. 9 Inflow an

d Infiltratio n (I/I ) 7 3. 0 Permi tHistor y , 8 3. 1 Complianc e histor

y 8 4. 0 Receivin g Wate r 8 4. 1 Receiving Strea

mWate r Qualit y 9 4. 2 Mixing Zon

e Analysi s 9 4. 3 Environmenta

l Mapping ...• 1 1 5. 0 Permi tlimitation s 1 1 5. 1 Existin g Permi

t Limit s 1 1 5. 2 Technology-Based Effluen t Limit s 1 2 5. 3 Wate r Quality-Based Effluen

t Limit s 1 3 5. 5 Whole Effluen

t Toxicit y 1 6 5. 6 Antidegradatio n 1 7 6. 0 Permi tDraf

tDiscussio n 1 7 6. 1 Fac e Pag e 1 7 6. 2 Schedule A

- Wast

e Discharg e Limitation s 1 7 6. 3 Schedule B

- Minimu

mMonitoring an

d Reporting Requirement s 1 7 6. 4 Schedule C

- Complianc e Schedule s an d Condition s 1 7 6. 5 Schedule D - Specia

l Condition s 1 7 6.6 Schedule E - Pretreatmen

t 1 8 6. 7 Schedule F

- NPDE S Genera l Condition s 1 8 6. 8 Permit

Processing/Publi c Comment/Appea l Proces s 1 9 Appendi x A-Monitorin g summar

y 2 0 Appendi x B-Anti-degradation workshee t 2 1 Appendi x C - Reasonable Potentia

l Analysi s Worksheets 2 3

## 1. 0 INTRODUCTIO N

Th e existing Nationa

l Pollutan t Discharg e Elimination Syste m(NPDES ) Permi

t expire d o n Decembe

r 31 , 2009

. Th e Departmen

t received renewa

l application numbe

r 97144 9 fro

mCit y o f Wilsonville o

n June 30 , 200 9 an

d amendments to the applicatio n wer e received o

n June 28 , 2010

. A s thi s renewa l application wa

s submitted t o the Departmen

t i n atimel y manne r prio r to th e expiration dat

e o f th e permit , th e permi

t shall not b e deeme d to expir e until final action ha s bee

n take n o n th e renewa

l application to issue th e ne

w permi t a s pe r OA R340-045-0040

. Thi s permi

t evaluation repor

t describe s th e basi s an

d methodology used i

n developin

g the permit

. Th

e permi t i s divided int o severa l sections : Schedul e A - Wast

e discharg e limitation s Schedul e B - Minimu

mmonitoring an

d repor t requirements Schedul e D - Specia

l condition s Schedul e E - Pretreatmen

t Schedul e F - Genera

l condition s Th e propose d permi t contain s th e followin

g substantiv e change s fro

mth e 200 5 permit : I n Schedule A , the limitation s associated wit h exces s therma

l loa d wer e adde d to reflec t the finding s fro

mth e Willamett e Basi n Temperatur

e TMD L tha t indicat e tha t thi s facilit y ha s adefine

d wast e loa d allocation

. Anothe

r chang e i n thi s schedul e i s tha

t becaus e emergenc

y overflow point s ar

e n o longe r liste d o n th e cove r pag e o f the permit , th e limitation s fo

r emergency overflow s have bee n removed

. Overflow s ar

e no w covere d i n Schedul e F of th e permi t exclusively

. I n Schedule B , som

e additiona

l sampling i s no

w listed to reflect

dat arequirement s fo

r evaluating thi s permit

a t its nex t renewal

. Thes e ar

e no t ne w requirements , bu

t ar e listed fo r clarit y within th

e samplin g table

. Thoug

h effluen t temperatur e monitoring i s still required , i n addition , th e calculatio n o f hea t loa d i s necessar

y to determin

e complianc e wit

h th e assigned allocation

. Th

e monitoring of

emergency overflow s ha s als o bee n deleteda

s thes e event s must

no w b e reported i

n accordanc e wit

h Schedul e F of the permit

. Schedul e D include s som

e updated requirements regarding whole effluen t toxicit y (WET ) testing

. Schedul e E has bee

n update d to reflect curren t pretreatmen

t progra mrequirements

. Schedule F contain s substantia l revision s t

o the NPDE

S Genera l Condition s tha

t wer e completed i

n 2009

. I n particula r i t i s importan

t to not e substantia

l broadening of

the reporting requirements i n regar d t o spill s an

d unplanned discharge s fro

mwithin the collection system
. Th e Federa l Wate r Pollution Contro l Act

o f 197 2 an d subsequen

t amendments requir

e aNPDE S permi

t fo r the discharg e of

wastewate

r to surfac e waters
. Furthermore , Orego n Revised Statute s (OR

S 468B.050 ) als o requir

e a discharge r be grante d apermi t fo r the discharg e o f

wastewate

r t o surfac e waters
. Thi s proposed permi t action b y th e Departmen

t complie s wit

h bot h federa l an d stat e requirements

. 

## 2. 0 FACILIT Y DESCRIPTIO N 2. 1 Genera l Th e Wilsonville Wastewate r Treatmen t Plan t (WTP ) i s locate d a t 927 5 S W Tauchma

n Roa d within the Cit

y of Wilsonvill e i

n Clackamas Count

y along the Willamett

e Rive r (se e phot o nex t page)

. Th e treatmen t facilit y wa s constructed originall

y a t thi s sit e i n th e 1970s

. Majo

r plan t an d proces s upgrade s occurre

d i n 198 1 an d 1998

. Th e198 1 improvement s wer e th e installatio n o f rotatin g biologica l contactor s whic h wer e the n replace d wit h amor e conventiona l activate d sludg e proces s i n 1998

. Mino r

improvement s wer e mad e t o th e headwork s i n 199 3 an d 2007

. Odo r

contro l feature s wer e adde d originall y i n 199 3 an d wer e expande d i n 2004

. Th e permi t applicatio n indicate s tha

t additiona l planne d upgrade s wil l b e startin g i n 201 1 with completio n anticipate d i n abou t 2014

. Th e facility treat s primaril y domesti c wastewate r an ddischarge s th e treate d wastewate r directl y t o th e Willamett e Rive r a t abou t rive r mil e 38.6

. I n th e permi t

application , City o f

Wilsonvill e report s apopulatio n o f jus t ove r 1700 0 residents

. A n evaluatio n o f populatio n equivalen t

loadin g t o th e treatmen t

plan t ove r th e pas t thre e year s indicate s a populatio n equivalen t

loadin g tha t

i s greater than residen t

populatio n reported

. * 

# Populatio n Equivalent s Base d o n Influen t BO D

Loa d

3500 0 3000 0 2500 0 2000 0 1500 0 1000 0 500 0 0
o r-

. r- - o o 

### k > o o i Q

. <
_ (/ ) O o oooococooooocnaioiaicrto i

« > * n

0 1 IS) •> o 7 r

— » TO TO 2 2 Q.

t o o O

H O

*Populatio n equivalents = [influen

t flow (mgd

) X influen t BO D (mg/1 ) X 8.34 ] divide

d b y 0.25 lbs/person/da

y



## 2. 2 Wastewate r

Treatmen t Th e treatmen t

facilit y relie s o n an activate d sludg e proces s t o trea t wastewate r

t o mee t pollutan t discharg e standard s fo r discharg e t o th e Willamett e Rive r jus t upstrea mo f

th e Boon e Bridg e lnterstate- 5 crossing

. Currentl y th e plan t 4

### relie s o

n aplug flow configuration utilizin g anoxi c selector s t o achieve secondar

y treatment
. During dr

y weathe r month s travelin g bridg e san d filters ar e use d t o achiev e bette

r tha n secondar y limit s required

. A

n odo r control towe r an d abiofilte r have bee n used i n attempt s to mitigat

e plan t odors

. Anticipated growt

h within th e communit

y an d increasing loading to th

e plan t hav e necessitated the initiatio n of plan t expansion whic

h i s anticipated t

o occu r b y 2014

. 4^_* »



## 2. 3 Change s in Operatio n Sinc e the permit' s las t

renewa l i n 2005 , ther

e have bee n n o significan

t change s t o treatmen t a t thi s facility

. I

n 2007 , headworks screening improvements wer e completed

. Presentl

y Cit y of Wilsonville i s goin

g throug h adesign

build-operat

e proces s t o initiat e anumbe r of plan t sit e improvements i

n th e nex t fe w years . Th e facilit

y improvements ar

e intende d t o kee p th e facilit

y complian

t wit h al l permi t limitations

. A chang e note d i n the renewa

l application occurre

d wit h biosolid s processing wher e the y hav e started usin g acentrifuge t o dewate r solid s allowing the

mt o be transported a

t lowe r cos t to easter n Orego n during we

t winte r months

. 

## 2. 4 Groundwate r

Issue s N o groundwate

r concern s hav

e bee n identifie d i n association wit

h thi s facility

. All treatmen t occur s i n water-tigh

t basin s an d an y storag e of

digested biosolid s occur s i

n wate r tigh t storag e basin s totaling 412,000 gallons

.

### 2. 5 Stor mWate r

Plan t sit e stor mwate r i s allowe d to percolat

e int o th e groun

d within the plan

t sit e o r flow s of f vi aoverlan

d flow. Building sump s an

d drain s within the plan

t ar e routed throug

h the treatmen

t syste mvi athe influen

t pum p station

. Becaus e ther

e ar e n o designe

d stor mwate r discharg e point s fo

r thi s plan t site , astor mwate r discharg e permi

t i s no t required

. 

### 2. 6 Outfall s Th e curren t permi t identifie s te

n separat e outfalls

. Th

e treatmen t plan t discharg e poin

t (Outfal l 001 ) was constructed a s asingle por

t diffuser

. Th

e existing permi

t include s a n identified wate

r reus e outfal

l an d eigh t emergenc y outfall s associated wit

h pum p station s within th e collectio n system
. Th e Departmen

t ha s determined tha t i t wil l n o longe r lis t identifie d sewe r syste moverflo w (SSO ) point s a

s the monitorin

g an d reporting o f

SSO s i s no w explicitl y covered withi

n Schedule F of

th e propose

d permit

. 

### 2. 7 Industria l Pretreatmen t Th e curren t permi t fo r thi s facilit y require s Cit

y of Wilsonville t

o manage apretreatmen

t program . Th

e permi t application identifie s anumbe r of significan t industria l user s tha t ar e connected to the Wilsonville sewage syste m necessitatin g a

n industria l pretreatmen

t program . Pretreatmen

t progra mrelate d requirements wer e originally incorporate

d int o th e permi

t wit h progra mapprova l o n June 25 , 1996

. Th

e mos t recen t loca l limit s evaluation was approve d b y th e Departmen

t i n 2004

. A revisedloca

l limits evaluation date

d June 30,2009 , wa

s include d wit h th e permi t renewa l application packet

. Pretreatmen t annua l report s have bee

n submiitted eac

h yea r fo r thi s facility

. 

### 2. 8 Biosolid s Th e renewa l application packe

t fo r thi s facilit y include d acop y of abiosolid s managemen

t pla n dated June 30 , 2009

. Wast

e activated sludg e i s thickened an d the n digested i

n two aerobi c digester s wit

h acombine

d capacit y of 512,000 gallons

. Th

e digested sludg e i s the

n transferred to aerate

d storag e basin s wit

h acombine

d capacit y of 412,000 gallons

. Th

e biosolid s take

n fro mstorag e ca

n b e eithe r loade d directl y t o tanke r trucks fo r field application nearby o

r dewatere d usin g acentrifuge fo

r transpor t to distan t lan d application sites

. Annua l report s provid

e detail s of

biosolid s applications

. I

n 2009 Cit y of Wilsonville indicated tha

t the y sen t all 32 1 dr y ton s o f biosolid s produced t

o thei r lan d application sites

. Th

e 2009 annua

l repor t identifie d 1 6 site s b

y nam e tha t received biosolid s application

. Primaril y the y ar e gras s hay/pastur

e sites , thoug

h som e o f th e biosolid s (15 7 dr y tons ) wer

e applie d o n whea t an d camaiina

. Pathoge

n reductio n an

d vecto r attraction reduction to mee

t Clas s B biosolid s requirement s ar e generall y me t throug h th e volatil e solid s reduction afforde d b y the aerobi c digeste r process . A

n annua l averag e o f

th e monitorin

g result s fo r metal s conten

t i n the final product

to be lan d applied ar e note d below

. Al

l metal s concentration s appea r to be wel l below EP A pollutan t concentration limits

. Paramete r Arseni c Cadmiu m Chromiu m Coppe r Lead Mercur y Molybdenu m Nicke l Seleniu m Zin c Concentratio n (me/kef ) 1. 9 1. 8 17. 7 30 0 16. 1 0.8 2 13. 2 30. 1 5. 6 64 5 EP

A Pollutan t Concentratio

n Limit s fme/ke ) 4 1 3 9

— 

### 1500 30 0 1 7

— 

### 42 0 10 0 280 0

## 2. 9 Inflo w an d Infiltratio n (I/I ) Wastewate r treatmen t system s are required to have a n ongoing progra

mi n plac e tha t i s used to control an

d limi t th e volum e of I/ I entering the treatmen

t facility

. Inflo

w i s generall

y mor e easily remove

d a s i t i s ofte n foun d to b e surfac e water s flowing int

o th e collectio n syste

mfro mroo f an d stree t drainage , whil e infiltration i s ofte n mor e wide sprea d an d related t o leak y and/o r degrade dsewe r line s tha t requir e replacemen

t o r rehabilitation

. Cit

y o f Wilsonville' s application indicat e tha t the y averag e jus t

unde r 500,000 gallon s pe

r da y o f inflow/infiltraio

n t o th e dail y plan t flows. Flow monitoring record s sho w the seasona

l variation i

n flow fo r thi s facility

.

Cit y of Wilsonville ha s provide

d annua l I/ I report s tha

t summarize detail s regarding ongoin g maintenanc e activitie s within the collection system
. Th e mos t recen t repor t fo r 2009 was submitted i

n Marc h 2010

. Th

e repor t indicate s tha t the Cit y ha s approximatel

y 380,00 0 linea

l fee t of sanitar y sewe r line i n thei r system
. O

f thi s abou t 11,00 0 linea l fee t ar e identifie d a s priorit

y line s fo r annua l cleaning an

d o n th e th e remainde

r o f th e collection syste

mi t ha s bee n targeted s o tha

t 2 0 % be cleaned eac

h year . I n 2009 they indicated tha

t all the priorit

y line s ha d bee n cleaned bu t onl y abou t 50 % (abou

t 37000 li n feet ) o f the additiona

l targe t wa s achieved

. Th

e repor t als o indicate s tha

t eac h of th e eigh t cit y lif t station s ar e cleaned eac

h year .

## 3. 0 PERMI T HISTOR Y

Th e wastewate r

discharg e fro mCit y o f

Wilsonvill e wa s first

permitte d i n th e earl y 1970' s for ane w 0. 5 mg d desig n flow treatmen t

plan t a t thi s location

. Th e first

Nationa l Pollutan t

Discharg e Eliminatio n Syste m(NPDES ) permi t wa s issue d i n 1974

. Th e permi t wa s renewe d i n 197 8 an d the n modifie d i n 198 2 whe n th e facilit

y wa s expande d t o a2.2 5 mg d desig n flow facility

. Additiona l renewal s occurre d i n 1983 , 1988,1993,200 0 an d 2005

. 

## 3. 1 Complianc e history Th e complianc e history for thi s facilit

y sinc e it s las t

permi t renewa l wa s reviewe d i

n th e file record

. Fou r

warnin g letter s wer e issue d b y th e Departmen t sinc e th e 200 5 renewa l for permi t violation s relate d t o reportin g an d monitorin g i

n accordanc e wit

h th e permi t

and effluent

limi t violations

. Th e first

even t wa s addresse d i n aWarnin g Lette r (WL-WQ-NWR-05-0110 ) date d Octobe r 12,2005 , relate d t o exceedin g th e effluent limit s for

total suspende d solid s i n Augus t 2005

. Thi s wa s aClas s II I violatio n o f

th e permi t

whic h i s considere d t o b e mino r i n natur e an d n o furthe r

follow-u p wa s warranted

. Th e nex t Warnin g Lette r

(WL-NWR-WQ-08-0029 ) wa s date d Apri l 7,2008 , an d addresse d anothe r mino r Clas s II I violatio n o f

effluent limit s fo r suspende d solid s i n February 2008

. O n Novembe r

30 , 2009 , awarnin g lette r (WL-WQ-NWR-09-0122 ) wa s issue d t o Cit y o f Wilsonvill e fo r failur e t o repor

t th e minimu mnumbe r

o f sample s for

p H durin g th e wee k

o f Septembe r

2 7 throug h Octobe r

3

. Th e permi t require s aminimu mo f

thre e sample s eac h wee k an d ye t onl y tw o sample s wer e reporte d durin g thi s week

. Thoug h th e failur e t o repor t require d samplin g i s considere d aseriou s violatio n (Clas s I ) b y th e Department , thi s even t wa s considere d a

n oversigh t

an d n o further

actio n wa s necessary a t

thi s time

. Had additiona l reportin g violation s occurre d th e Departmen t woul d hav e include d thi s even t i n an y follow-u p action

. O n Marc h 30 , 2010 , Cit y o f Wilsonvill e sel f

reporte d noncomplianc e vi aemai l an d provide d additiona l informatio n wit h thei r Marc h 201 0 discharg e monitorin g report
. A Warnin g Lette r wit h Opportunity t o Correc t

(WL-WQ-NWR-2010-0062 ) date d Apri l 19 , 2010 , wa s issue d a s aresul t o f thi s violation

. A determinatio n wa s mad e base d on explanation s provide d b y th e City tha

t th e violation s occurre d du e t o aplan t "upset " precipitate d b y equipmen t failur e tha t

coul d no t hav e bee n anticipated

. N o further actio n wa s take n i

n respons e t o thi s se t

o f violations

. Complianc e assuranc e sit e visit s wer e conducte d b y th e Departmen t on Octobe r

25,2005 , Augus t

15 , 2006 , Augus t 21 , 2007 , an d Novembe r

20,2008

. N o complianc e issue s wer e note d durin g thes e sit e visits

. 

## 4. 0 RECEIVIN G WATE R Th e Wilsonvill e STP discharge s t o th e Willamett e River

. Th e wate r quality standard s fo r

al l wate r bodie s (Orego n Administrativ e Rule s Chapte r 340 , Divisio n 41 ) an d specificall y th e Willamett e Basi n (OA R340-41-0340 ) wer e develope d t o protec t

th e beneficial use s for

th e basin

. Th e designate d beneficial use s ar e a s follows :

• publi c and privat e domesti c wate r supply , © industrial wate r

supply , • irrigation , ® livestoc k

watering , » anadromou s fish passage , • salmoni d spawnin g and rearing , • residen t

fish an d aquati c life , « wildlif

e an d hunting , ® fishing,
» boating , • wate r contac t recreation , ® aestheti c quality , and ® hydr o powe r

### 4. 1 Receivin g Strea m Wate r Qualit y

Th e Willamett

e Rive r Basi n drain s a n 11,50 0 squar e mile areaof

Orego n tha t include s th e largest

metropolita

n portion s of

Oregon

. Wate

r qualit y standard s violation s i

n thi s reac h of th e Willamett

e Rive r wer e reviewed fo

r thi s facilitiy' s discharge

. Tota

l Maximu mDail y Load s (TMDLs ) fo

r temperature , mercur

y an d bacteri awer

e approved b y EP A i n Septembe

r 2006

. Th e reac h of th e rive r tha t Cit y of Wilsonville discharge s int

o i s als o note

d i n th e 303 d (impaired wate

r quality ) listing s i

n the most recen t integrated assessmen

t of wate r qualit y fo r th e followin

g additiona l parameters : Aldrin , DDT , DDE , Dieldrin , PCB , iron an d biologica

l criteria

. Dat agathering effort

s fo r temperatur

e wa s use da s par t of th e TMD L developmen

t process . Th

e TMD L proces s established awast

e loa d allocatio n fo

r temperatur

e whic h i s proposed t

o be adde d t o the permit

. Furthe

r discussion of Temperatur

e ma y be foun d below i n Sectio n 4. 2 (Mixing Zon

e Analysis ) an

d Sectio n 5. 3 (Wate

r Quality-Based Effluen t Limitations)

. Throug h th e TMD

L proces s i

t wa s estimated tha

t all the domesti c facilitie s discharging wastewate r t o the Willamett e Rive r contributed les s tha

n 3 % of th e tota l mercur y loa d observed

. Th

e TMD L required tha

t furthe r evaluation b

e complete d to determin

e if specific wasteloa

d allocation s fo

r mercur y ar e appropriat

e fo r poin t source s an d wha t thos e shoul

d be

. Mercur

y monitoring will als o be continue d unde r th e nex t permi t an d tha t informatio n will be use d t o d o th e reasonable potentia

l analysi s fo

r tha t toxic

. Th e TMD L provided wasteloa

d allocation s fo

r bacteri atha

t se t th e permitted effluen

t limit s a t th e wate r qualit y standard

. Bacteri alimitation s i n the proposed permi

t continu e to requir

e tha t th e facilit y mee t th e sam e en d of pip e limitations

. Domesti c wastewate

r treatmen t plant s ar e not considered to be source s of thes e legac

y toxic s lik

e Aldrin , DDT , DDE , Dieldri

n an d PCB

. Iron i s listed a s exceedin

g th e drinking wate

r standar d becaus e iro

n ca n be aestheticall

y unappealing i

n drinking water
. Iro n a t low level s impart s atast

e to th e water
. Fo

r thes e reasons , drinking wate r shoul d not contai n >300 ug/ L o f iron

. N o effluen

t dat awa s available t

o evaluat e iron

. Iro n i s not expecte d t o b e contributed b

y thi s sourc e a t level s above background

. Thoug h th e listin g fo

r biologica l criteri aremain s i

n place , th e reason fo

r th e listing , skeleta

l deformitie s i

n fish ha d bee n evaluated i

n aseparat e study

. Thi s sourc e has no t bee n evaluated fo

r its contribution t

o skeleta l deformitie s i

n squawfish

. A stud

y entitled Environmenta

l Stresse s an

d Fis h Deformitie s i

n the Willamett

e Rive r Projec t Statu s Repor t (Decembe r 2003 ) conducte

d b y Departments o

f Environmenta

l an d Molecula

r Toxicology , Microbiology , an d Fisherie s an

d Wildlife , Orego

n Stat e University , Corvaliis , Oregon , indicate s tha t parasite s ar

e majo r contributor s t o hig

h prevalenc e o f

skeleta l deformitie s i

n fish fro mNewber g Poo l o f th e Willamett

e River

. 

## 4. 2 Mixin g Zon e Analysi s Federa l regulation s (4

0 CF R131.13 ) allo w fo

r the us e of mixing zones , als o know

n a s "allocate d impac

t zones"

. Thes e ar e smal l area s aroun

d adischarg e wher

e wate r qualit y standard s ma

y b e suspended

. Application of mixin g zone s mus t

ensur e acut e toxicit y t o driftin g organism s i s prevented an d th e integrit

y o f th e waterbod

y a s awhole i s not impaired

. EP

A doe s no t hav e specific regulation s pertaining t o mixing zones . Eac

h stat e ma y adopt it s ow n mixing zon

e regulation s tha

t ar e subject to revie w an d approva l b y EPA

. I n State s tha

t lac k approve d mixin g zone regulations , ambien

t wate r qualit y standard s must

be me t a t th e en d o f th e pipe

. OA

R340-041-0053(1 ) provide s tha t th e Departmen

t ma y suspen d al l o r par t o f the wate r qualit y standard s i

n adesignated portio

n of th e receiving wate r to serv e a s azon

e of dilutio n fo

r waste s an d receivin g water s to mi

x thoroughly

. Th e Departmen

t ha s developed mixing zon

e regulation s an

d policy base

d i n par t o n the acut e an d chroni c aquati c lif e criteria

. Base

d o n EP A guidanc e an

d th e Department' s mixin

g zone regulations , tw o mixin g zone s ma

y be developed fo

r eac h discharg e tha

t reflec t acut e an d chroni c effects : 1 ) Th

e acut e mixin g zone , als o know

n a s the"zon e o f

initial dilution " (ZID) , an d 2 ) th e chroni c mixin g zone , usuall y referre d t o a s "th e mixin g zone"

. Acut e criteri aar e suspende d withi n th e ZI D bu t it i s designe d t o preven t

lethality t o organism s passin g throug h th e ZID

. Chroni c criteri aar e suspende d withi n th e mixin g zon e an d it i s designe d t o protec t

th e integrity o f

th e entir e wate r bod y a s awhole

. Th e allowabl e siz e o f th e mixin g zon e shoul d b e base d upo n th e relativ e siz e o f th e discharg e t o th e receivin g stream , th e beneficial use s o f th e receivin g stream , locatio n o f othe r discharge s nearby , locatio n o f drinkin g wate r

intakes , an d othe r

considerations

. Mor e specifi c guidanc e i s availabl e fromEPA regardin g criteri a use d i n appropriatel y sizin g aZID

. Primaril y th e ZI D mus t b e designe d t o preven t

lethality t o driftin g organisms

. Th e City o f

Wilsonville' s presen t

permi t designate s th e curren t

mixin g zon e a s "that

portio n o f

th e Willamett e Rive r fromth e poin t

o f discharg e t o 15 0 fee t

downstreamo f

th e outfall

. Th e zon e o f

immediat e dilutio n (ZID ) shal l b e define d a s that

portio n o f

th e allowabl e mixin g zon e tha t i s withi n fifteen (15 ) fee t o f th e poin t o f discharge. " Th e outfal l i s asingl e 2 4 inc h por t diffuse r tha t terminate s i

n th e rive r

abou t 4 0 fee t fromth e nort

h rive r bank

. Th e discharg e plum e spread s downstreaman d wa s evaluate d for dilutio n a

t bot h th e mixin g zon e an d ZI D boundaries

. Th e Jun e 200 2 "Mixin g Zon e Study Repor t for th e City o f

Wilsonville' s WWTP " determine d tha t th e discharg e had minimu mdilution s o f 3: 1 a t th e ZI D an d 23: 1 a

t th e mixin g zon e boundary

. Th e Department' s mixin g zon e rule s provid e tha t wate r qualit y standard s includ e temperatur e therma l plum e limitation s i

n accordanc e with OA R340-0 4 l-0053(d)

. Thi s sectio n o f th e rule s contain s criteri at o preven t potentia l advers e impact s tha t ma y resul t

fromtherma l plumes

. Not e tha t th e temperatur e therma l plum e limitation s tha

t th e Departmen t

ha s adopte d ar e simila

r t o th e recommendation s i n th e Apri l 200 3 EP

A Regio n X temperatur e guidance

. Th e criteri aa s the y appl y t o th e Wilsonvill e ST P are discusse d below :

« OAR 340-041-0053(d)(A): Impairmen t o f an activ e salmoni d spawnin g are awher e spawnin g redd s ar e locate d o r likel y t o b e located

. WilsonviUe STPdischarge: Ther e i s n o identifie d salmoni d spawnin g nea r th e outfal l locatio n i

n thi s segmen t o f th e Willamett e River

. Thi s segmen t o f th e Willamett e Rive r

doe s serv e a s amigratio n corrido r fo r salmonid s bu t

th e streamha s bee n channelize d s o that th e are ai s often referre d t o a s th e "Newber g Pool"

. Th e mixin g zon e stud y repor t indicate s that

salmonid s d o no t

spaw n i n th e mainste mrive r

area s lik e this

.

• OAR 340-041-0053(d)(B)\ Acut e impairmen t o r instantaneou s lethality i s prevente d o r minimize d b y limitin g potentia l fish exposur e t o temperature s o f 3 2 ° C or mor e t o les s tha

n 2 seconds

. Wilsonville STPdischarge: Base d o n temperatur e dat asubmitte d wit h th e mixin g zon e study , th e maximu meffluent

temperatur e a

t outfal l 00 1 i s aroun d 2 5 °C

. Thus , th e discharg e i s no t expecte d t o caus e an acut e impairmen t o r instantaneou s lethality

.

• OAR 340-04 l-0053(d)(C): Therma l shoc k cause d b y asudde n increas e i n wate r temperatur e i s prevente d o r minimize d b y limitin g potential fish exposur e t o temperature s o f 25° C or mor e t o les s than 5 % o f

th e cross-sectio n o f

100 % o f th e 7Q1 0 flow o f

th e waterbody

. Wilsonville STPdischarge: Th e reporte d temperatur e o f thi s effluent

ha s seldo mexceede d 25° C an d th e discharg e i s no t

goin g caus e thermal shoc k a s th e plum e a t

th e edg e o f

th e mixin g zon e encompasse s les s tha n 5 % o f

th e strea mcros s section

. At thi s locatio n th e streami s 70 0 fee t wid e wit h a n averag e dept h o f abou t 2 5 feet

. 5 % o f

thi s cros s sectio n are awoul db e abou t 80 0 squar e feet

. Th e temperatur e plum e abov e 25° C woul d nee d t o b e greate r than 80 0 squar e feet

. Th e vertical and horizonta l plum e fro mth e outfal l woul d b e estimate d a t abou t 30 0 squar e fee t

whe n i t reache s th e mixin g zon e boundar y whic h woul d b e les s than 2 % o f th e cros s section

.

• OAR 340-041-0053(d)(D): Unles s ambien t temperatur e i s 2 1 ° C o r

greater , migratio n blockag e i s prevente d o r

minimize d b y limitin g potentia l fish exposur e t o temperature s o f 2 1 ° C o r mor e t o les s tha n 25 % o f th e cross-sectio n o f

100 % o f th e 7Q1 0 flow o f

th e waterbody

. Wilsonville STPdischarge: Base d o n informatio n provide d i n th e outfal l mixin g zon e field monitorin g an d modelin g study , th e Willamett e Rive r a t th e locatio n o f

th e outfal l plum e i n th e mixin g zon e 

### 1 0

### represent s abou t a300 squar

e fee t cros s section ou

t of atota l rive r cros s section of

ove r 1750 0 squar e feet

. A s suc

h migration blockage i s prevented sinc e thi s plum e represent s les s tha

n 2 % o f the cros s section

. Thus , the analysi s indicate s tha t th e discharg e fro

mth e Wilsonville ST

P meet s th e temperatur

e therma l plum e limitation s i

n OAR340-041-0053(d)

. 

## 4. 3 Environmenta l Mappin g Environmenta

l mappin g was no t complete d a s par t o f the mixin g zone stud

y completed i

n 2002

. Howeve

r a t thi s locale , th e Willamett

e Rive r outfal l i s i n alocation o

f the rive r tha t ha s bee n described a s "generally slow moving " an d i s popula r fo r recreationa

l us e b y bot h fisherma n an d othe r watercraf t activities

. A s mentioned befor e thi s segmen t of the rive r i s amigrator

y passag e fo

r fish

. Ther

e ar e man y privat e boa t docks upstrea

man d downstrea

m fro mth e discharg e location

. Th e outfal l i s abou t 40 fee t fro mshor e i n abou t 1 5 fee t of wate r a t lo w wate r dept h an d shoul d no t conflict wit h thes e uses . Mos

t of the rive r ban k i n thi s are aha s large lo

t size s an d i s substantiall

y alread y developed , s o acces s to thi s outfal l i s limited

. A marin aan

d boa t ram p exist s o n th e fa r shor e jus t upstrea m an d acros s fro

mthe outfal

l area . Publi c park

s ar e locate d jus t upstrea m(Boone s Ferr

y Park ) an d slightl y mor e tha n Vi mil e downstrea

m(Memoria

l Park ) fro mth e outfal

l location

. Bot

h park s hav e rive

r frontage fo

r publi c acces s an d Memoria l Par k ha s aboa t dock

. Th e neares t drinking wate

r intak e i s locate d abou t V

_mil e upstrea

mfro mthe Cit y of Wilsonville STP

. 

## 5. 0 PERMI T LIMITATION S Two categorie s of

effluen t limitation s exis t

fo r NPDE S permits : 1 ) Technology base d effluen t limits , an d 2 ) Wate r qualit y base d effluen t limits

. Technology base

d effluen t limit s ar e developed b

y applying th e secondar

y treatmen t standard s a s foun

d i n 4 0 CF RPar t 133

. Technolog

y base d effluen t limit s wer

e established to requir

e aminimu

m leve l of treatmen t fo r municipa l source s using available technology

. Wate r qualit y base d effluen t limit s ar e designe d to b e protectiv e of

th e beneficia

l use s o f the receiving wate

r an d ar e independen

t o f the available treatmen t technology

. I

n addition , whe

n performin

g apermi t renewal , ther

e ar e existing permi

t limits

. Thes e ma

y be technology-based limits , wate r quality-based limits , o

r limit s base

d o n bes t professiona

l judgment

. Whe

n renewing apermit , th e most stringen t of technology base

d o r wate r qualit y base d limit s apply

.
5. 1 Existin g Permi tLimit s Treated Effluen

t Outfal l 00 1 (1 ) Ma y 1-Octobe r

31 : Paramete r CBOD 5 TS S (2 ) Novembe r

1 Averag e Effluent Concentration s Monthl y Weekl y lOmg/ L 15mg/ L lOmg/ L 15mg/ L

- Apri l 30 :

Paramete r BOD 5 TS S Averag e Effluen t Concentration s Monthl y Weekl y 30mg/L 4 5 mg/

L 3 0 mg/ L 4 5 mg/

L Monthly * Averag e lb/da y 19 0 19 0
Monthly * Averag e Ib/da y 56 0 56 0 Weekly *

Averag e lb/da y 28 0 28 0
Weekly * Averag e lb/da y 84 0 84 0 Daily *

Maximu m lb s 38 0 38 0
Daily * Maximu m lb s 110 0 110 0


### 1 1* Thoug h th e existin g averag e dr y weathe r desig n flow(desig n year

2015 ) t o th e facilit

y equal s 2. 7 MGD , th e mas s load limit s ar e base d o n th e previou s permit

.


### (3) Othe r

parameter s (year-round ) E. coli Bacteri a

p H BOD 5 an d TS S Remova l Efficienc y Limitation s Shal l no t excee d 12 6 organism s pe r 10 0 mL monthl y geometri c mean . N o singl e sampl e shal l excee d 40 6 organism s pe r 10 0 mL

. Shal l b e withi n th e rang e o f 6. 0 - 9. 0 Shal l no t b e les s than 85 % monthl y averag e fo r BOD 5 and 85 % monthl y fo

r TSS

.



## 5. 2 Technology-Base d Effluent Limit s Secondary treatmen t

require s a

t minimu mth e followin g standard s b e me t for biochemica l oxyge n deman d (BOD 5 ) , carbonaceou s biochemical oxyge n deman d (CBOD 5 ) , tota l suspende d solid s (TSS ) an d pH :
• BOD 5 shal l no t

excee d a30-da y averag e o f 3 0 mg/ I and a7-da

y averag e o f

4 5 mg/ 1 and th e 30-day averag e percen t removal shal l no t

b e les s tha

n 8 5 percent
.

• CBOD 5 ma

y b e use d a s a n alternativ e fo r BOD 5 provide d i t

i s doe s no t

excee d a30-day averag e o f 2 5 mg/ 1 an d a7-da

y averag e o f

4 0 mg/ 1 an d th e 30-day averag e per-cen t remova l shal l no t

b e les s than 8 5 percent
.

• TS S shal l no t

excee d a30-da y averag e o f 3 0 mg/ 1 an d a7-da

y averag e o f

4 5 mg/ 1 and th e 30-day averag e percen t remova l shal l no t b e les s tha n 8 5 percent
.

• p H shal l b e maintaine d withi n th e limit s o f 6. 0 t o 9.0

. Th e Cit y o f

Wilsonvill e STP limitation s fo r BOD 5 , CBOD 5 , TS S an d p H ar e a t leas t a s stringen t

a s th e federa l requirement s i

n tha t th e followin g mus t

b e met :

• Fro mMay throug h Octobe r (typicall y dry weathe r

w/lowe r streamflow) CBOD 5 shal l no t excee d a monthl y averag e o f

1 0 mg/ 1 an d aweekl y averag e o f 1 5 mg/ 1 an d th e monthl y averag e percen t remova l shal l no t b e les s tha n 8 5 percent
. Fro mNovembe r throug h Jun e (typicall y we t weathe r w/highe r strea m flow ) BOD 5 shal l equal th e federal requirements

.

• Fro mMay throug h Octobe r TS S shal l no t

excee d amonthl y averag e o f 1 0 mg/ I an d aweekl y averag e o f 1 5 mg

_an d th e monthl y averag e percen t removal shal l no t

b e les s tha

n 8 5 percent
. Fro mNovembe r throug h Jun e TS S i s equal t o th e federa l requirement

.

• p H shal l b e maintaine d withi n th e limit s o f 6. 0 t o 9.0

. I n additio n DE Q require s tha t mas s loa d limitation s for

BOD 5 ,CBOD 5 an d TS S mus t b e me t whe n dischargin g t o surfac e waters
. Thes e load s ar e require d t o b e reporte d i n pound s pe r

day an d includ e amonthl y average , weekl y averag e an d dail y mas s limitation

. Fo r thi s facilit

y thes e limi t

wer e establishe d base d on adr y weathe r desig n flow o f 2.2 5 mg d tha t

wa s establishe d i

n 1982

. Weekl y limit s ar e 1.5 time s th e monthl y mas s an d th e dail y limi t i s twic e th e monthl y mass . Limit s ar e calculate d a s follows :



### 1 2Hig h streamflo w BOD 5 -

Averag e Monthl y Limi t

= (2.2 5 mgd ) (3 0 mg/1 ) (8.3 4 lbs/gal ) -56 0 lbs/day Averag e Weekl y Limi t

= (1.5)(56 0 lbs ) - 84 0 lbs/da y Dail y Limit = (2.0)(56 0 lbs) = 110 0 lb s Hig h streamflow TSS

Averag e Monthl y Limi t

= (2.2 5 mgd ) (3 0 mg/I ) (8.3 4 lbs/gal ) =56 0 lbs/day Averag e Weekl y Limi t

= (1.5)56 0 lb s = 84 0 lbs/da y Dail y Limit = (2.0)56 0 lbs = 110 0 lb s Lo w streamflow CBOD 5 an d TSS

Averag e Monthl y Limi t

- (2.2 5 mgd ) (1 0 mg/1 ) (8.3 4 lbs/gal ) =19 0 lbs/day Averag e Weekl y Limi t

- (1.5)19 0 lb s (Averag e Monthl y Limit ) = 28 0 lbs/day Dail y Limit

- (2.0)19 0 lbs = 38 0 lb s 

## 5. 3 Wate r Quality-Base d Effluent

Limit s Reasonable

Potential

Analysis Th e Departmen t

perform s an analysi s t o determin e i f ther e i s areasonabl e potentia l t o caus e o r contribut e t o violation s o f

instrea mwate r

qualit y criteria

. Th e Departmen t ha s adopte d EPA' s recommende d methodolog y fo r performin g areasonabl e potentia l analysi s (RPA)

. Thi s methodolog y wa s develope d primaril y for acut e an d chroni c criteri abu t

can b e adapte d t o othe r

criteri abase d on differen t frequencie s an d durations

. Thi s RP A take s int o accoun t

effluent variability , availabl e dilutio n (i f applicable) , an d receivin g streamwate r quality

. Th e RPA fo

r specifi c parameter s ar e discusse d below

. I n accordanc e with DEQ' s "Interna l Managemen t Directiv e for

Reasonabl e Potentia l Analysi s for Toxi c Pollutants " (Septembe r

2005) , domesti c source s lik e City o f Wilsonvill e wit

h adi y weathe r

desig n flow greater

than 1.0 mg d mus t b e characterize d for

chlorin e an d ammoni aa s well a s othe r potentiall y toxi c parameter s identifie d i n thei r renewa l application

. Th e RP A spreadshee t usin g dat afromth e mos t recen t permi t cycl e indicate s that

ther e i s n o reasonabl e potentia l for

toxi c pollutant s t o caus e o r contribut e t o an excursio n abov e Stat e wate r qualit y standards

. N o evaluatio n fo r

wa s mad e for

chlorin e becaus e thi s facilit y disinfect s wit

h U V ligh t and th e permi t

explicitl y prohibit s th e us e o f

chlorin e o r

chlorin e compound s wher e the y ma y affec t th e effluent

. Th e RP A spreadsheet s ar e attache d (Appendi x C)

. 

### pH Th e p H i s ameasur e o f

ho w acidi c o

r basi c asolutio n is

. A t

ap H o f 7. 0 s.u . th e solutio n i s considere d neutral

. Th e purpos e o f

a n in-strea mwate r qualit y p H standard i s generall y th e protectio n o f aquati c lif

e sinc e mos t

aquati c organism s ca

n onl y tolerate afairl y narro w rang e aroun d 7. 0 s.u . Th e Willamette Basi n Water Qualit y Standard for

p H i s found i

n OA R340-04 1 -0345( 1 )(a)

. Th e allowe d rang e i s 6. 5 t o 8. 5 s.u . Th e propose d permi t limit s p H t o th e rang e 6. 0 t o 9. 0 s.u . Thi s limi t i s base d on Federa

l secondar y treatment standard s for

wastewate r

treatmen t facilitie s (4 0 CFRPar

t 133.102) , and i s applie d t o th e majorit y o f domesti c NPDE S permittee s i

n th e state
. Withi n th e permittee' s mixin g zone , th e wate r qualit y standard fo

r p H doe s no t

hav e t o b e met
. Th e Departmen t

evaluate d p H usin g aspreadshee t tha t derive s th e p H a

t th e mixin g zon e boundary

.



### 1 3Calculatio n o

f p H o f amixture o

f tw o flows

. Base d on th e procedur e i

n EPA' s DESCO

N program(EPA, 1988

. Technica l Guidanc e o n Supplementary Strea mDesign Condition s fo r Stead y Stat e Modeling

. USEP

A Offic e o f Water , Washingto n D.C. )



### INPU T ;

1

. DILUTIO N FACTO

R A T M Z BOUNDAR

Y - (Qe+Qr)/Q e 2

. UPSTREAM/BACKGROUN D CHARACTERISTIC S Temperatur

e (de g C) ; PH : Alkalinit y (mgCaC03/L) : 3

. EFFLUEN

T CHARACTERISTIC

S Temperatur

e (de q C) : pH : Alkalinity (mqCaC03/L) ; 4

. APPLICABL

E P H CRITERI A OUTPU T 1

. IONIZATIO N CONSTANT S Upstream/Backgroun d pKa : Effluen t pKa : 2

. IONIZATIO N FRACTION S Upstream/Backgroun d Ionizatio n Fraction : Effluen t Ionizatio n Fraction ; 3

. TOTAL INORGANI C CARBO N Upstream/Backgroun d Tota l Inorqani c Carbo n (m q CaC03/L) : Effluen t Tota l Inorqani c Carbo n (m q CaC03/L) : 4

. CONDITION S A

T MIXIN G ZON E BOUNDAR Y Temperatur

e (de g C) : Alkalinity (m q CaC03/L) ; Tota l Inorqani c Carbo n (m q CaC03/L) : pKa : p H a t Mixin g Zon e Boundary : I s ther e Reasonabl e Potential ? RP A fo r p H Lowe r P H Criteri a 23

22. 2 7. 4 24. 4

24. 0 6. 0 190. 0 6. 5

6.3 7 6.3 6 0.92 0.3 1 26.6 6 621.1 9 22.2 8 31.6 0 52.5 1 6.37 6. 5 N o Uppe r

P H Criteri a 2 3

22. 2 7. 6 24. 4

24. 0 9. 0 190. 0 8. 5

6.3 7 6.3 6 0.9 4 1.0 0 25.8 3 190.43 22.2 8 31.6 0 32.9 8 6.3 7 7. 7 N o Mixin g wit

h ambient wate r withi n th e mixin g zon e wil l ensure tha t th e p H a t th e edg e o f

th e mixin g zon e meet s th e ambien t criteria

. Therefore , th e Department consider s th e propose d permi t limit s t o b e protectiv e o f

th e water quality standard

. 

### 1 4

### Bacteria

Th e propose d permit limit s ar e base d o n th e E. colt

standar d contained i

n OA R340-041-0009(5)

. Th

e proposed limit s ar e amonthl y geometri c mea

n of 12 6 E. coli pe

r 10 0 mL , wit h n o singl e sampl

e exceeding 40 6 E. coli pe

r 10 0 mL

. I f asingl e sample exceed s 40 6 E. coli pe r 10 0 mL , then th e permittee ma y tak e five consecutiv e re samples

. I f th e log mea

n of th e five re-sample s i s les s tha n o r equa l to 126 , aviolation i s no

t triggered

. Th e re samplin g mus t b e take n a t fou r hou r interval s beginning within 2 8 hour s afte r the origina

l sampl e wa s taken

. Th e propose d limit s ar e take n directl y fro mth e Orego

n bacteri arul e whic

h i s foun d i n OA R340-041-0009

. Thi s rul e establishe s numeri c in-strea mwate r qualit y standard s (OA

R340-041-0009(1) ) an

d establishe s effluen

t limitation s an

d the methodolog

y fo r establishing aviolatio n (OA R340-041-0009(5))

. Regardin g the genera

l condition 6 foun

d i n Sectio n B of Schedul e F i n thi s permi

t whic h prohibit s overflow s fro

m wastewate r conveyanc e systems , th e Environmenta l Qualit y Commissio

n (EQC ) recognize s tha

t i t i s impossible t

o design an d construct

aconveyanc e syste

mtha t will preven

t overflow s unde

r all stor mconditions

. Th

e applican t i s no t seeking permi

t coverag e fo

r overflow s an

d the permi

t doe s no t authoriz e suc

h discharges

. Th

e Stat e o f Orego n ha s determine

d tha t al l wastewate

r conveyanc e system s shoul

d be designe

d to transpor

t stor mevent s u

p t o a specific size to th e treatmen t facility

. Therefore , i

n exercising it s enforcemen

t discretion regarding Sanitar y Sewe r Overflows , the Departmen

t will conside

r th e following : (1 ) Whethe

r th e permittee ha s conveyance an d treatmen t facilitie s adequat

e to preven t overflow s except

during astor meven t greate r tha n the one-in-five-year , 24-hou r duration stor

mfro mNovembe

r 1 throug h Ma y 2 1 an d excep t during astor

meven t greate r tha n th e one-in-ten-year , 24-hou r duration stor

mfro mMa y 2 2 throug h Octobe r 31

. I n addition , DE

Q will als o conside

r usin g enforcemen

t discretion fo

r overflow s tha

t occu r during astor

meven t les s tha n th e one-in-five-year , 24-hou r duration stor

mfro mNovembe

r 1 throug h Ma y 2 1 if th e permittee ha

d separat e sanitar y an d stor msewer s o

n Januar y 10 , 1996 , ha

d experienced sanitar

y sewe r overflow s du e to inflo

w an d infiltration problems , an

d ha s submitte

d a n acceptable pla

n t o th e Departmen

t t o addres s thes e sanitar

y sewe r overflow s b

y Januar y 1 , 2010 ; (2 ) Whethe

r th e permitte e ha s provide

d the highes t

an d bes t practicabl e treatmen

t and/o r contro l of wastes , activities , an

dflows an d has properl

y operated th e conveyanc e an d treatmen t facilities ; (3 ) Whethe

r th e permitte e ha s minimize d th e potentia

l environmenta

l an d public healt

h impacts fro

mthe overflow ; an

d (4 ) Whethe

r th e permitte e ha s properl

y maintained th e capacit

y of the conveyanc e system
. DE Q wil l revie w the permittee' s determination o f the one-in-five-year , 24-hou r duration winte

r stor man d th e one in-te n year , 24-hou

r duration summe

r stor ma s described above i

n th e permi

t holder' s facilitie s plan

. I

n th e even t tha t apermi t holde r report s a n overflow even

t associated wit

h astor meven t an d DE Q doe s no t have informatio

n fro mthe permi

t holde r sufficien t t o determin e whethe r o r not the stor meven t exceed s stor

mevent s a

s specified i

n OA R340-041-0009(6 ) & (7) , DE Q will perfor

mth e determination usin g the informatio n contained i

n Figur e 2 6 of th e 197 3 NOA

A Atla s 2 entitle d "Precipitation-Frequency Atla s of th e Wester

n Unite d States , Volum

e X - Oregon"

. Thi s figur

e i s entitle d "Isopluvial s of

5-y r 24-h r precipitatio n i

n tenth s o f a n inch"

. Th

e Atla s ca n b e obtaine d o n line a t http://hdsc.nws.noaa.gov/iKisc/pfds/other/or_pfdsJitml

. howeve r th e file i s vei y large

. A scanne d version o

f Figur e 2 6 i s available at : http://www.wrcc.dri.edu/pcpnfreq/or5y24.gif

. DE Q will compar

e the informatio n i n thi s figure wit

h rainfal l dat aavailable fro

mth e Nationa

l Weathe r Service , o r othe r sourc e a s necessary . Temperature Willamett e Basi n TMDL

. Th

e Cit y o f Wilsonvill e discharg e i s include

d unde r th e "Individua

l wast e loa d allocation s fo r lo w streamflo

w conditions " fo

r therma l contribution , pe

r the Willamett

e Basi n temperatur

e TMD L (Pag e 4-69 ) a

s follows :


### 1 5Th e Willamett e Basi n TMD L identifie d 3 0 separat e individual wast e loa d allocation s (WLA ) an d City o f Wilsonvill e ST P receive d a n explici t summe r 7Q1 0 WL

A o f 3 9 millio n Kca l pe r

day

. Th e TMD L wa s structure d suc h tha t potentiall y highe r

heat load s migh t

b e assigne d provide d th e city can documen t ambien t streamflo w an d temperatur e i n th e Willamett e Rive r t o accommodat e th e highe r exces s therma l loads

. Effluent temperatur e monitorin g wil l b e require di n th e permi t an d woul d b e use d fo r

determinatio n o f

complianc e with th e wast e loa

d allocation

. Monitorin g wil l b e require donl y durin g Jun e throug h Septembe r whic h include s th e perio d considere d critical for thi s salmo n migratio n corrido r withi n th e Willamett e River

.



### 5. 5 Whol e Effluen t

Toxicit y I n additio n t o analyzin g th e effluent for individua l pollutants , th e effluent i s als o teste d t o determin e th e aggregat e effec t th e effluent

ha s on aquati c organisms

. Thes e test s ar e know n a s whol e effluent toxicity (WET ) tests
. Effluent sample s ar

e collecte d an d aquati c organism s are subjecte d t o variou s effluen t concentration s i n controlle d laboratory experiments

. EP A ha s develope d WE T tes t protocol s usin g bot

h freshwate r

an d marine/estuarin e tes t species

. EPA recommend s runnin g test s usin g a n invertebrat e (crustacean) , vertebrat e (fish ) an d aplan t (alga)

. Organism s use d i

n WE T test s ar e indicator s o r surrogate s fo r

th e aquati c communit y t o b e protected , an d ameasur e o f th e rea l biologica l impac t fromexposur e t o th e toxi c pollutants

. T o protec t wate r quality , EP

A recommend s tha t WE T test s b e use d i

n NPDE S permit s togethe r wit h requirement s base d o n chemical-specifi c wate r qualit y criteria

. WE T test s ar e use d t o determin e th e percentag e o f effluent that produce s a

n advers e effec t

on agrou p o f

tes t organisms

. Th e measure d effec t ma y b e fertilization , growth , reproduction , o r survival

. EPA' s methodolog y include s bot

h a n acute tes t

and achroni c test
. A n acut e WE T tes t i s considere d t o sho w toxicity i f advers e affect s occu r a t effluent concentration s les s than that whic h i s found a

t th e edg e o f

th e zon e o f

immediat e dilutio n (ZID) , A chroni c WE T tes t

i s considere d t o sho w toxicity i f advers e affect s occu r

a t effluen t concentratio n les s tha n that whic h i s know n t o occu r

a t th e edg e o f

th e mixin g zone . Fiv e WE T test s wer e include d a s par t o f thi s renewa l application

. Thes e test s represente d annual samplin g ove r th e 5 year s prio r

t o th e expiratio n o f

th e permit

. N o acut e toxicity wa s note d i n an y o f thes e test s for

100 % effluent

. I n addition , n o chroni c toxicity wa s observe d a t wors t cas e effluen

t concentration s expecte d t o b e foun d a t th e edg e o f th e mixin g zon e (4.3% ) whic h occur s wit h 23: 1 dilution

. Th e DE Q recommend s tha t apoin t estimat e (IC25 ) b e use d t o asses s th e likelihoo d o f chroni c toxicity

. Th e tabl e that follow s demonstrate s th e effluent concentration s tha t cause d i n a25 % reductio n i n abiologica l measuremen t (i.e

. growth , reproduction ) an d th e correspondin g dilutio n i n whic h chroni c toxicity woul d b e anticipate d fromth e effluent

. For example : I

n 2008 , asignifican t reductio n wa s estimate d i n reproductio n for

th e crustacea n wate r

fle aa t a n effluent concentratio n o f

7.1%

. Th e correspondin g dilutio n (14:1 ) ca n b e compare d t o th e demonstrate d dilutio n (23:1 ) whic h occur s a t th e mixin g zon e boundary

. Th e mixin g zon e stud y demonstrate d dilutio n i s greate r than th e dilution s a t

whic h chroni c toxicit y wa s estimate d an d thu s thes e advers e effect s note d d o no t occu r a t concentration s les s tha n th e 4.3 % wors t cas e effluent concentratio n expecte d t o b e foun d a t th e mixin g zon e boundary

. Th e WE T result s indicat e th e effluen t i s no t causin g eithe r

a n advers e acut e o r

chroni c aggregat e effec t

o n th e aquati c community

. Samplin g month/vear June/Jul y 200 9 Novembe r

200 8 Sept/Oc t 200 7 Decembe r

200 6 Septembe r

200 5 Ceriodaphni adubi a

(Wate r Flea ) Concentratio n >100 % 7.1 % >100 % 32.4 % >100 % Dilutio n

1: 1 14: 1 1: 1 3: 1 1: 1 Pimephale s pomela s

(Fathea dMinnow ) Concentratio n >100 % >100 % >100 % >100 % >100 % Dilutio n

1: 1 1: 1 1: 1 1: 1 1: 1 Raphidoceliu s subcapitat a

(Algae ) Concentratio n 59.9 % 24.0 % >I00 % 80.4 % >100 % Dilutio n

1.7: 1 4.2: 1 1: 1 1.2: 1 1: 1


### 1 6

## 5. 6 Antidegradatio n

A n Antidegradation Revie

w wa s performe

d fo r thi s discharge

. Th

e permi t i s bein g renewe d withou t an y increas e i

n discharg e loadings

. Permi

t renewal s wit

h th e sam e discharg e loading s a s the previou s permi t ar e no t considered t

o lowe r wate r qualit y fro mth e existin g condition

. Based o n the antidegradatio n review , th e Departmen t determined th e propose

d discharg e complie s wit

h th e Antidegradation Policy fo r Surface Waters foun

d i n OA R340-041-002 6 (se e Appendi

x B)

.


## 6. 0 PERMI T DRAF T DISCUSSIO N 6. 1 Fac e Pag e Th e fac e pag e provide s informatio

n abou t th e permittee , description of the wastewater , outfal

l locations , receiving strea minformation , permi

t approva l authority , an

d adescription of

permitted activities

. Th

e permittee i s authorized to construct , install , modify , or operat e awastewate

r collection , treatment , control an d disposa l system
. Th

e permi t allow s discharg e t

o the Willamett

e Rive r withi n limit s se t b y Schedule A an

d th e followin

g schedules

. Al

l othe r discharge s ar

e prohibited

. 

## 6. 2 Schedul e A , Wast e Discharg e Limitation s Th e proposed permi

t contain s th e exact

sam e limitation s a s the previou s permi t wit h the exception of

exces s therma l load

. Th e curren t permi t will reflect

th e TMD L conclusion tha

t th e DEQ shoul

d assign a n exces s therma

l wast e loa d allocation fo

r thi s source . 

## 6. 3 Schedul e B - Minimu mMonitorin g an d Reportin g Requirement s Du e to th e type s of

treatmen t processe s utilized to trea

t domestic wastewater , th e DE Q developed recommende

d monitorin g frequencie s fo

r parameter s base

d o n th e siz e an

d typ e of treatmen t facility

. Wastewate

r discharg e permi t monitoring frequencie s o

f simila r typ e facilitie s wer

e reviewed (e.g. , lagoons ) fo r specific parameters i

n relation to the facilit

y design flow. Simila

r monitoring frequencie s fo

r parameter s allow fo

r statewid e consistency base d o n facilit y desig n flow an d type
. Th e monitoring an

d reporting requirement s i

n thi s pennit

ar e i n accordanc e wit h the DEQ' s monitoring matrix fo r a n activated sludg e facilit

y wit h adesign flow greate

r tha n 1 MG D bu t les s tha n 5 MGD

. Appendi x A provide s amonthl y summar y of dat areported o

n th e Cit y o f Wilsonville' s discharg e monitoring report s fo

r the pas t thre e year s Additiona l samplin g requirement s have bee

n adde d t o thi s permi

t t o mee t th e effluen t testing fo r th e EP A For m2 A renewa l application date

d Januar y 199 9 an d th e monitoring requirement s prescribed i n th e DE Q Interna l Managemen

t Directiv e fo

r th e Reasonable Potentia

l Analysi s fo

r Toxi c Pollutant s date

d Septembe

r 2005

. 

## 6. 4 Schedul e C , Complianc e Schedule s an d Condition s Thi s permi t include s n o complianc e schedule s o

r conditions

. 6. 5 Schedul e D - Specia l Condition s Thi s permi t include s eigh

t specia l conditions

. Th e first tw o condition s ar

e relate d to the bio-solid s managemen t practice s tha

t ar e to b e followe d an d includ e a reopene r condition shoul

d th e standar

d bio-solid s practice s be change d s o tha t the y becom e mor e stringen t tha n the propose d permi t unde r th e Clea n Wate r Act

.

1 7Th e third conditio n detail s th e requirement s relate d t o whol e effluent toxicity (WET ) testin g o r bioassay testin g t o look for th e potentia l for

toxi c effect s fromthi s wastewate r discharge

. Th e conditio n specifie s th e organism s an d protocol s for

bot h acut e an d chroni c testing , ho w thos e test s shoul d b e evaluated , th e quality assuranc e an d reportin g specific s an d areopene r fo r th e permi t

shoul d i t becom e appropriat e base d o n th e WE T results

. Th e nex t conditio n define s th e operato r certificatio n requirement s that mus t b e adhere d t o i n accordanc e with Orego n Administrativ e Rules , Chapte r 340 , Divisio n 49

. Tw o condition s ar e th e sam e condition s tha t wer e foun d i n Schedul e C o f th e previou s permi t

i n regard t o offerin g th e City th e opportunity t o demonstrat e awe t weathe r desig n flo w fo r

th e facility

. Potentiall y tha t engineerin g exercis e coul d resul t

i n highe r mas s limit s durin g we t

weather , bu t

th e cit y woul d als o hav e t o provid e t o DE Q a propose d programan d schedul e for inflo w identificatio n an d reductio n t o qualif y fo r th e we t weathe r mas s allowance

. Th e permi t

require s tha t

notificatio n b e mad e t o th e Departmen t for malfunction s a

t th e treatmen t

facilit y suc h that correctiv e action s ca

n b e coordinate d i

f appropriate

. Th e final specia l conditio n require s tha t th e permitte e hav e i

n plac e acontingenc y plan that lay s ou t preventio n measure s an d arespons e plan for spill s or unplanne d discharges

. Thi s conditio n i s include d t o reinforc e th e ne w requiremen t

withi n th e permit' s General Condition s (Schedul e F , Sectio n B.8 ) fo r a n "Emergenc y Respons e an d Publi c Notificatio n Plan"

. Thoug h no t totall y ane w requirement , th e Departmen t believe s that

thi s plan i s critica l for th e protectio n o f

publi c healt

h a s it relate s t o sewag e overflow s and unpermitte d release s fro mwithi n th e collectio n system
. 

## 6.6 Schedul e E , Pretreatmen t Progra mActivitie s City o f Wilsonvill e ha s had an approve d industria l pretreatmen t progra msinc e 1996

. Th e progra mrequirement s are lai d ou t

i n thi s schedul e o f

th e permit

. Th e Programwa s recognize d i n 199 9 and agai n i

n 200 5 with EPA' s Nationa l Pretreatmen t

Excellenc e Award

. 

## 6. 7 Schedul e F , NPDE S General Condition s Al l NPDE S permit s issue d i n th e Stat e o f

Orego n contai n certai n condition s that remai n th e sam e regardles s o f th e typ e o f discharg e an d th e activity causin g th e discharge

. Thes e condition s ar e calle d General Conditions

. Sectio n A contain s standar d condition s whic h includ e complianc e wit h th e permit , assessmen t

o f penalties , mitigatio n o f noncompliance , permi t

renewa l application , enforcemen t actions , toxi c discharges , property right s an d reference d rule s an d statutes
. Sectio n B contain s requirement s fo r operatio n and maintenanc e o f th e pollutio n contro l facilities

. Thi s sectio n include s condition s fo r prope r operatio n an d maintenance , dut y t o hal t o r reduc e activity i n orde r t o maintai n compliance , bypas s o f treatmen t

facilities , upse t

conditions , treatmen t

o f singl e operationa l events , overflow s fro mwastewate r conveyanc e system s an d associate d pump stations , publi c notificatio n o f effluent violatio n o r

overflow , and disposa l o f remove d substances

. Sectio n C contain s requirement s for monitorin g an d reporting

. Thi s sectio n include s condition s fo r representativ e sampling , flow measurement , monitorin g procedures , penaltie s o f tampering , reportin g o f monitorin g results , additiona l monitorin g b y th e permittee , averagin g o f

measurements , retentio n o f records , content s o f

records , an d inspectio n and entry
. Sectio n D contain s reportin g requirement s an d include s condition s for reportin g planne d changes , anticipate d noncompliance , permi t

transfers , progres s on complianc e schedules , noncomplianc e whic h may endange r publi c healt h o r th e environment , othe r noncompliances , and othe r information

. Sectio n D als o contain s signatory requirement s an d th e consequence s o f falsifyin g reports
. Sectio n E contain s th e definition s use d throughou t th e permit

. Thes e condition s can b e change d or modifie d onl y o n astatewid e basis

. Th e lates t editio n o f

th e NPDE S General Condition s i s fro m200 9 an d thi s editio n i s include d a s Schedul e F o f th e draf t permit

. Th e summary o f th e 200 9 change s i s a s follows : 1 8

### • Ther e ar e additiona l citation s to th e federa

l Clea n Wate r Act an d CFR, including reference s t o standard s fo

r sewag e sludg e us e o

r disposal

. • Ther e i s additiona

l language regarding federa

l penalties

. • Bypas s languag e ha s bee n mad e consisten t wit h th e Cod e o f Federa l Regulations

. • Overflo

w languag e ha s bee

n modified

. Formerl

y th e languag e stated tha

t overflow s i

n respons e to the five or te n yea r even t woul d no t violat e th e permit

. No

w i t state s tha t overflow s ar

e prohibited

. DE Q will continu e to exercis e enforcemen t discretio n wit

h respect t o overflow s consisten

t wit h th e provision s of

th e Bacteri aRul

e (OA R340-041-0009)

. • Reporting requirement s regarding overflow s hav e bee n mad e mor e explicit

. • Requirements regarding emergenc y respons e an

d publi c notification plan s hav e bee n mad e mor e explicit

. • Language pertaining to dut y to provid

e informatio

n ha s bee n mad e mor e explicit

. • Confidentialit

y o f informatio n i s addressed


### 6. 8 Permi t

Processing/Publi c Comment/Appea l Proces s Th e beginning an

d en d dat e of th e publi c commen

t perio d to receiv e writte

n comment

s regarding thi s permit , an

d th e contact nam e an d telephone numbe

r ar e include d i n the publi c notice

. Th

e permittee i s the onl

y part y having standing t o file apermi

t appeal

. I f th e permittee i s dissatisfie

d wit h th e condition s of

the permi t whe n issued , the

y ma y reques t ahearing befor

e the EQ C o r its designated hearin

g officer, within 20 day s o f

the final permi

t being mailed

. Th

e reques t fo r hearing mus t

be sen t to the Directo

r o f th e Department

. An

y hearing hel

d shal l b e conducted pursuan

t to regulation s of

the Department

.



### 1 9

### Appendix A

- Wilsonvill e ST P DM RSummar y

Mont h Aug-1 0 Jul-1 0 Jun-1 0 May-1 0 Apr-1 0 Mar-1 0 Feb-1 0 Jan-1 0 Dec-0 9 Nov-0 9 Oct-0 9 Sep-0 9 Aug-0 9 Jul-0 9 Jun-0 9 May-0 9 Apr-0 9 Mar-0 9 Feb-0 9 Jan-0 9 Dec-0 8 Nov-0 8 Oct-0 8 Sep-0 8 Aug-0 8 Jul-0 8 Jun-0 8 May-0 8 Apr-0 8 Mar-0 8 Feb-0 8 Jan-0 8 Dec-0 7 Nov-0 7 Oct-0 7 Sep-0 7 Aug-0 7 Jul-0 7 Jun-0 7 May-0 7 Apr-0 7 Mar-0 7 Feb-0 7 Jan-0 7 Influen t BO D mg/ L 43 8 55 2 29 6 47 0 37 9 38 9 28 2 34 6 31 8 33 5 32 2 33 9 29 9 37 0 33 6 31 0 34 6 29 2 31 5 27 9 33 5 31 3 35 0 36 3 32 9 40 7 33 5 35 3 31 1 32 3 27 4 23 4 24 2 32 4 32 3 34 6 37 5 33 3 34 4 34 1 32 2 26 6 26 7 27 3 TS S mg/ L 41 6 61 2 28 4 35 1 26 1 29 6 22 4 23 4 25 7 31 3 30 9 31 4 33 3 31 8 30 5 33 8 33 1 29 7 29 6 28 7 32 1 31 4 31 8 31 4 33 5 41 0 31 3 31 7 28 2 33 5 27 7 21 6 22 8 28 4 29 5 29 4 30 1 28 2 28 8 27 1 26 7 22 5 23 4 23 3 P H
ma x 7. 9 9. 1 7. 7 9. 5 8 7. 7 7. 7 7. 7 8 7. 8 8 7. 8 8 7. 6 8. 2 7. 7 7. 9 8. 2 8. 6 7. 9 8. 2 7. 9 7. 9 8. 2 7. 9 8. 6 8. 1 8. 5 8. 5 8. 2 8. 1 7. 7 8. 5 8. 4 8. 1 8 8 8 8. 6 8. 2 8. 5 8. 8 8 8 mi n 7. 3 7. 1 7. 3 7. 3 7. 1 7 7. 2 7. 2 7 7. 4 7. 2 7. 3 7. 2 7. 1 7. 3 7. 3 7. 2 7. 2 7. 3 7. 2 7. 4 7. 2 6. 6 6. 8 7. 2 7. 2 7. 3 7. 3 7. 3 7. 4 7. 2 7. 2 7. 1 7. 3 7. 2 7. 3 7. 2 7. 2 7. 4 7. 3 7. 4 7. 3 7. 3 7. 2 Flo w mg d 1.59 2 1.60 2 1.97 8 1.82 5 2.05 2 1.96 5 1.97 4 2.38 8 1.96 3 1. 8 1.60 3 1.58 7 1.58 2 1.55 1 1.62 1 1.77 4 1.70 7 1.8 8 1.72 5 2.30, 9 1.85 3 1.70 4 1.63 1 1.56 8 1.57 5 1.56 8 1.65 8 1.71 8 1.89 4 2.05 2 2.26 2 2.51 9 2.43 4 1.93 6 1.86 2 1.70 5 1,72 5 1.69 7 1.7 4 1.75 6 1.85 8 2.09 2 2.11 7 2.35 6 Effluent BO D mg/ L 5 7 7 7 1 2 3 6 1 1 1 1 1 5 1 0 3 4 4 5 6 7 1 2 9 9 8 1 1 1 0 4 4 4 5 5 9 9 1 0 1 4 9 9 9 3 4 5 5 4 3 8 9 9 1 0 %

re m 9 9 9 9 9 8 9 9 9 7 9 1 9 6 9 7 9 5 9 7 9 9 9 9 99 9 9 9 8 9 8 9 6 9 7 9 7 9 7 9 7 9 7 9 9 9 9 9 9 9 9 9 8 9 8 9 7 9 7 9 5 9 6 9 6 9 7 9 9 9 9 9 9 9 8 9 9 9 9 9 7 9 7 9 6 9 6 CBO D mg/ L 4 6 5 6

2 3 3 4 5 6 8 5

5 3 3 3 4 4 5 5

2 3 4 4 4 2 6 5 TSS mg/ L 5 6 4 5 1 2 3 1 1 1 9 1 1 9 2 4 4 4 3 4 9 1 1 9 9 1 2 8 4 2 2 3 3 4 1 0 1 2 2 2 1 2 1 3 8 3 3 4 3 4 2 8 ^ 1 2 1 0 %

re m 9 9 9 9 9 9 9 8 9 5 8 9 9 5 9 6 9 6 9 7 9 9 9 9 9 9 9 9 9 9 9 9 9 7 9 6 9 7 9 7 9 6 9 7 9 9 9 9 9 9 9 9 9 9 9 9 9 6 9 6 9 1 9 4 9 4 9 7 9 9 9 9 9 9 9 9 9 9 9 9 9 7 9 6 9 5 9 6 E.col i
ma x 6 9 3 6 1 4 3 7 7 6 241 9 34 5 7 0 4 7 30 8 9 1 12 1 32 6 14 4 32 6 14 4 43 5 6 9 8 8 3 5 13 6 27 6 5 0 13 6 34 5 16 5 24 8 18 6 46 1 57 9 30 8 18 7 6 5 6 0 120 3 173 3 173 3 51 7 1 7 241 9 14 4 1 0 3 6 21 9 ge o 7 9 3 5 3 3 4 7 2 6 1 8 1 9 1 4 1 3 2 4 4 8 2 1 3 6 1 4 4 2 6 2 5 1 1 5 1 5 3 1 0 3 0 7 9 5 3 3 6 1 7 1 1 1 3 4 5 3 5 4 0 2 1 9 1 3 6 0 3 9 3 8 1 2 5 9 6 1 P H
ma x 7 7 6. 9 6. 7 6. 9 7. 1 6. 9 6. 8 6. 9 6. 9 6. 8 6. 8 7. 6 6. 9 6. 9 7. 7 7. 1 6. 8 7 6. 9 6. 9 7. 6 6. 8 6. 9 6. 8 6. 9 6. 8 6, 8 6. 9 6. 9 6. 9 6. 8 6. 8 6. 9 7 6. 9 7 6. 8 6. 9 7 7. 3 7. 3 7. 2 7 Ammoni a mi n 6. 7 6. 7 6. 5 6. 4 6. 4 6. 4 6. 3 6. 3 6. 2 6. 6 6. 4 6. 5 6. 6 6. 6 6. 5 7. 3 6. 7 6. 6 6. 7 6. 6 6. 6 6. 7 6. 6 6. 5 6. 6 6. 5 6. 6 6. 6 6. 5 6. 6 6. 5 6. 5 6. 5 6. 6 6. 5 6. 7 6. 7 6. 6 6. 6 6. 6 6. 6 7 6. 8 6. 7 ma x 0. 8 4. 2 7. 7 6. 7

8. 1 9. 9 6. 4

0. 8 2 0. 4 0. 8 9. 2 8. 6 6. 9

4. 7 2. 1 0. 3 4. 7 5. 2 5 10. 6 8. 9

1. 4

0. 1 0. 4 1 0. 2 1. 6 5 2. 1 23. 6 av e 0. 3 0. 7 3 3. 5

6. 7 7. 7 4. 5

0. 3 0. 3 0. 2 0. 3 4. 5 5. 3 6

4. 7 1. 1 0. 2 1. 5 1. 8 2 6. 5 4. 9

1. 4

0. 1 0. 1 0. 7 0. 1 0. 6 1. 5 0. 6 1 3 i n tem p 72. 4 70. 8 65. 4 65. 2 6 2 62. 3 6 1 60. 2 61. 8 66. 5 69. 6 73. 5 73. 6 72. 1 68. 7 65. 1 63. 4 61. 1 61. 8 60. 6 62. 4 66. 5 69. 9 7 3 73. 7 71. 4 66. 4 65. 2 61. 4 59. 8 59. 4 59. 4 61. 9 66. 3 69. 4 73. 3 73. 7 72. 7 69. 8 66. 7 63. 8 61. 5 60. 5 60. 2 ef

f tem p 74. 4 72. 8 6 7 6 6 62. 4 62. 1 6 1 59. 8 61. 5 66. 1 70. 4 74. 3 75. 4 74. 5 70. 6 6 6 63. 7 60. 6 60. 9 59. 9 62. 5 66. 9 70. 6 73. 4 74. 5 7 3 68. 3 66. 2 62. 2 60. 8 5 9 58. 3 60. 8 65. 5 6 9 73. 8 75. 2 74. 4 7 1 67. 2 63. 4 61. 2 59. 6 58. 6 b-soli d gal(00 C 35 2 35 7 43 7 39 9 53 0 65 1 48 2 42 6 59 1 32 9 36 0 26 8 27 2 20 4 60 2 37 5 35 5 25 6 28 0 74 7 23 2 19 2 34 0 36 0 27 6 40 5 17 5 22 0 25 7 33 4 70 6 47 9 35 6 28 4 45 6 31 6 28 8 32 0 25 6 32 4 52 3 59 0 16 6 46 4

### Appendi x B : Antidegradatio n Revie w Shee t ANTIDEGRADATIO N REVIE W SHEE T FO RA PROPOSE D INDIVIDUA L NPDE S DISCHARG E 1

. What

i s th e nam e o f

Surfac e Wate r

tha t receive s th e discharge ? Willamett e Rive r Briefl y describ e th e propose d activity : Discharg e o f treate d municipa l wastewater
. I s this revie w fo

r a(renewal ) O Rne w (circl e one ) permi t application ? G o t o Ste p 2

. 2

. I s this surfac e wate r a n Outstandin g Resourc e Wate r o r upstrea m fro ma

n Outstandin g Resourc e Water ?
Yes

. G o t o Ste p 5

. CNo D G O t o Ste p 3

. 3

. I s thi s surfac e wate r aHig h Quality Water ?
Yes

. G o t o Ste p 8

. CjMo ) G o t o Ste p 4

. 4

. I s thi s surfac e wate r aWate r Qualit y Limite d Water ?
G o t o Ste p 14

. G o t o Step 2

. Note : Th e surfac e wate r mus t fal l int o on e o f

thre e (3 ) categories : Outstandin g Resourc e Wate r (Ste p 2) , Hig h Quality Wate r (Ste p 3) , o r

Wate r Quality Limite d Wate r

(Ste p 4)

. 14

. Wil l th e propose d activit y resul t i n aLowerin g o f

Wate r Quality i n th e Wate r Quality Limite d Water ? [se e OA R340-041-0004(3)-(5 ) for adescriptio n i n rul e o f

discharge s that

d o no t resul t i n lowerin g o f

wate r quality o r

d o no t constitut e ane w and/o r increase d discharg e or

ar e otherwis e exemp t fro mantidegradatio n review ; otherwis e se e "I s a n Activit y Likel y t o Lowe r Wate r Quality? " i n Antidegradation Policy Implementation Infernal Management

Directive for

NPDES Permits and Section 401 Water

Quality Certifications^ Yes

. Go t o Ste p 15

. (Ht£ ) Procee d wit h Permi t Application

. Applican t

shoul d provid e basi s fo r conclusion

. G o t o Ste p 21

.

2 1

### 21

. O

n the basi s o f

th e Antidegradation Review , the following i s recommended : _X

_Proceed wit

h Application t

o Interagency Coordination an d Publi c Commen

t Phase

. Den y Application ; retur

n t o applican t an d provide publi c notice

. Actio n Approve d Section : Northwes t Region Wate

r Qualit y Sourc e Control Section Revie w Prepared By : Lyl e Christense n Phone : 503-229-529 5 Dat e Prepared : Septembe r 201 0

22

### Appendix C - Reasonable Potentia l Analysi s

Facilit y Name : Dilutio n Values? (V/t

i » v-i>A:. _*vFtow__ft> n @ ZI D mm lov/FbwD_tt)n©MZ(7O10 1 Lo W Ffa w DMfo n & m

(30O5 I Hiat i FbwDiAbn ®

__DflO10 1 Hqhfb w DkMX>

& MZfTOiO ) Hq h Fb * DM_bn @ M

Z (3005 ) Ente rdata ' taifi w i f ' n o 'd i S uHtr a d a Dat a toestimat e dilution"-;?^; : :

EfnueitFUvfrnod ) = 1010fCfS l = 7O10fCFS) = 30O5fO- l = %<Jijti_)natM Z = %d_tonatZI D = Confrfenc e Leve l = Probabt vBasi s =

PARAMETE R
Lo w Ro w Se a so n CHLORIN E AMMONI A - Freshwate r AMMONIA-Saltwate r AMfiSONM

- Proposed

lhr/4dav* AWiONlA -

Proposed3tkfsy* Hia h Flo w Seaso n CHLORIN E AMMONI A - Freshwate r AMMONI A - Saltwate r AfilMONlA -

Proposed

ihr/4dav* At-IMONIA - Proposed'30day* B______Hl e ST P V 3 2 3 * 3 2 3 * '•• eatu_te d * * * * * * tals'ava!fa'W_'~"v , - ; : Summe r * * * * * * 99 % 95 %

# o f Sample s * 20 6 * * * * 1 6 * * t •-"••

Winte r * * * * * *

Hiahes t Cone

. mq/ l * 15. 5 * * *

t 9.90 0 * * * _[

i !

1 Coef

. o f Varianc e * 0.9 0 * * * * 0,9 0 * t * Calculate d Maximu m Cone

. mil * 15.5 0 * * * * 20.7 9 * * * Summe r'data..-.:.
- '• ; :•••}• ',

• EH * = Tem p * = Akaift v= Sahiona s Resent ? (Y/N ) Sarnon H Eoawiira ? (Y/N ) Freshwater ? fY/H ) Satttvfppt l Winte rdat a ;'•:•'.- ; '•<••%-•;

DH * = Tem o * = Afc__ v= Sahicn_ ; Present

? CflU) Shioni d Soawihq ? (Y/M ) Fres h Wate r?Ci7N ) Saiit y foot )
1
BacK q roun d Cone

. mtj/ l * 0,2 0 t i * * 0.2 0 * * * Maximu m Cone , a t ZI D nw/ l * 5.3 0 * * n/ a * 7.0 6 * * n/ a ^'Effluents ;

6. 5 2 5 5 5 n/ a n/ a n/ a * 7 1 7 5 5 n/ a n/ a n/ a *

Maximu m Cone , a t M Z nw/ i * 0.8 7 * * * * 1.1 0 * * * Strea m 7. 4 2 2 2 4 v n v * 7. 2 1 5 2 4 v n V 1 Date : I 9/21/201 0

i V f &/-Mixe d v--
. "••• : __>;.- i 6. 7 23. 0 ?' ; MZ* '

7. 2 22. 1 16.5-9 1

° C

* 7. 1 15. 7 *

7. 2 15. 1 f 6.5-9 1

° C

* 1 * 1 i

W O CRITERIA
Acute ! (CMC ) IW/I : 0.01 9 17. 8 n/ a 29. 1 n/ a 0.01 9 18. 6 n/ a 22. 2 n/ a Chroni c (CCC ) V'flWfl
0.01 1 1.0 5 n/ a 8.3 0 3. 3 0,01 1 1. 8 n/ a 13.1 4 5. 3 .
REASONABL E POTENTIAL ? ACUT E * N O * * n/ a * H O * * n/ a CHRONI C * N O * * • * N O * * *
Facilit y Name : bilytioh fVa l ues>?

' (if/N); : • Diitb n @ ZI D Dkitb n @ H Z City o

A^;A 3 2 3 I f 'h o dtafe m value s enterWb'beSw':^'
- FacSt veffluen t Fb w 7Q1 0 Ifil O % dkitb n a t ZI D % diutb n a t M Z Fres h Water ? (Y/N )

PARAMETE R
ANTIMON Y * ARSENI C V * (inorqanfc ) ARSENI C I H fhoraanfc V CADMIU M + CHROMIU M II I + CHROMIU M V I COPPE R + CYANID E IRO N * UEA D + MERCURY NICKE L + SELENIU M SILVE R + THALLIU M * ZIN C + * * * * * y

# o f Sampte s
9 5 1 * 5 1 5 1 5 1 5 1 4 5 * 5 1 4 5 5 1 5 1 5 1 9 5 1 FWilso m
catiilate_; : ! * *
MG D CF S CF S % %

Highes t Cqnc

. Se e 1KB MQ/ I 0.2 7 0.6 0 * 0.5 0 1.5 5 1.5 5 13.0 3 31.0 0 * 0.9 0 0.02 3 58.5 0 1,7 0 1.2 0 0.0 1 105.1 0 rill e ST I

Coef

. o f Varianc e
0.6 0 0.2 6 * 0.9 9 0.3 3 0.3 3 0,3 9 1.0 3 * 0,4 0 0,9 4 1,6 6 0.5 4 0.9 8 0.5 4 0.2 2 _ >

Cafcubte d Ma x Effluen t Cone

. UO/ f 0.5 9 0.6 6 * 0.6 5 1.7 1 1.7 1 14.3 3 40.3 0 * 0.9 9 0.0 3 81.9 0 2.0 4 1.5 6 0.0 1 115.6 1 Hardnes s :

Effluen t Strea m Mixe d ^ ZI D M Z m_/LCaC0 3 . 6 9 2 5
4 0 2 7
Confidenc e Leve l Probabilit y E

Backgroun d Cone

. Sn e 1MD ua/ l 0. 3 0. 4 * 0,06 0 * 1.0 0 2. 1 0.1 0 * 0.4 1 0.00 3 0.5 2 2.0 6 0.0 1 0.1 0 3.3 2 •asl s

Maxrnu m Cone , a t ZI D UG/ 1 0.4 0 0.4 9 * 0.2 6 * 1.2 4 6.1 8 13.5 0 * 0.6 0 0.0 1 27.6 5 2.0 5 0.5 3 0.0 7 40.7 5 (Hard n

be> 2

9 9 % 9 5 %

Maxftiu m Cone , a t M Z ua/ l 0.3 1 0.4 1 * 0.0 9 * 1.0 3 2.6 3 1.8 5 * 0.4 4 0.0 0 4.0 6 2.0 6 0.0 8 0.1 0 8.2 0 Date :

. s i i es s value s shoul d >and<4G Q mg/1 )

1 W Q CRITERI A lHou r (CMC ) ua/ l 900 0 85 0 36 0 1.3 8 81 4 1 6 7. 4 22, 0 200 0 2 5 2.4 0 64 9 26 0 0.8 3 140 0 5 3 4 Da / (CCC ) pq/ l 160 0 4 8 19 0 0.4 0 7 1 1 1 3. 9 5. 2 100 0 0.6 0 0.01 2 5 2 3 5 0.1 2 4 0 3 5 09/22/201 0

i ! i !

REASONABL E POTENTIA L ?
ACUT E N O N O
— N O
— N O N O N O

- - N O N O N O N O N O N O N O CHRONI C

N O N O

- . N O

- - N O N O N O

- - N O N O N O N O N O N O N O 

### 2 3