FACT SHEET 

And 

NPDES WASTEWATER DISCHARGE PERMIT EVALUATION 

Department of Environmental Quality 

Northwest Region - Portland Office 

2020 SW 4th Ave, Suite 400, Portland, OR 97201 

Telephone: (503) 229-5263 

PERMITTEE; Clackamas County Service District No. 1 - Kellogg Creek WWTF 

9101 SE Sunnybrook Blvd., Suite 441 

Clackamas, OR 97015 

File Number: 16590 

SOURCE LOCATION: 11525 SE McLoughlin Blvd. 

SOURCE CONTACT: DougHarbaugh Telephone Number: (503)794-8050 

PERMIT WRITER: Beth Moore Telephone Number: (503)229-5586 

PROPOSED ACTION: Renewal of a National Pollutant Discharge Elimination System (NPDES) 

wastewater discharge permit 

SOURCE CATEGORY: Major Domestic 

TREATMENT SYSTEM CLASS: Level IV 

COLLECTION SYSTEM CLASS: Level IV 

PERMIT APPLICATION DATE: July 1,1997 

PERMIT APPLICATION NUMBER: 990856 

BACKGROUND 

Introduction 

Water Environment Services (WES), a Department of Clackamas County manages and operates the 

Kellogg Creek wastewater treatment plant located in Milwaukie, Oregon. The treatment plant is 

owned by Clackamas County Service District No, 1, a county service district. Wastewater is treated 

and discharged to Willamette River in accordance with National Pollutant Discharge Elimination 

System (NPDES) Permit number 100983. The renewal permit was issued on September 30, 1992 

with an expiration date of August 31, 1997. The permit was modified on January 19, 1994. 

The Department received a renewal application on July 1, 1997. A renewal permit is necessary to 

discharge to state waters pursuant to provisions of Oregon Revised Statutes (ORS) 468B.050 and 

the Federal Clean Water Act. The permit was administratively extended from September 1, 1997 

to the present. The Department proposes to renew the permit. 

March 1,2006 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 2 of 24 

Facility Description 

The Kellogg Creek wastewater treatment plant is located at 11525 SE McLoughlin Boulevard on 

the east side of the Willamette River in the City of Milwaukie. 

The facility consists of the headworks, influent pump station, bar screens with mechanical rakes 

and non-aerated grit structure, primary and secondary treatment a disinfection system and an 

outfall to the Willamette River. Anaerobic digesters are used for sludge stabilization. Biosolids 

are disposed of by spreading on land approved sites. 

In coming raw sewage is lifted about 40 feet from the main interceptor by three pumps to the 

headworks. In August 1997 a fourth main lift pump was added to the main lift station to add a 

significant level of redundancy to the raw sewage pumping. In 1995, there were upgrades to the 

headworks, the original comminutors were replaced with mechanical screens. The headworks 

include two physical treatment processes: screening and grit (detritus) removal. Screening is 

accomplished by two mechanically-cleaned bars screens (Schloss articulated rakes). The grit 

collector provides the detention time and the slow velocity for the grit to settle out. The screened 

material and grit is dewatered and conveyed to storage prior to landfilling. 

Treatment in the headworks is followed by primary treatment with two circular primary clarifiers. 

Settled solids and scum are mechanically removed from the primary clarifiers and pumped to the 

anaerobic digesters. In 1994 the primary clarifiers were covered for odor control. 

After primary clarification the effluent flows to the four aeration basins. Between October 1996 

and March 1997 3,232 diffusers contained in the four aeration basins were rebuilt. In July 1997 

the selector improvements were made to the aerators. The aeration basin can be operated in 

different modes: plug flow, contact stabilization, a modified step feed mode and anaerobic 

selector mode. 

The secondary treatment system consists of the blower building, aeration basins, secondary 

clarifiers, and secondary sludge pumping station. Air from the blower building is transported to 

the four aeration basins through two 18-inch header pipes. One header provides air to aeration 

basins 1 and 2 while the other provides air to aeration basins 3 and 4. Dissolved oxygen probes 

measure the dissolve oxygen concentration in each aeration basin. The fine bubble aeration 

system is used to keep the microorganisms in suspension and to provide dissolved oxygen to the 

organisms. The purpose of the secondary clarifier is to separate biological solids from the 

wastewater. The solids are concentrated as sludge in the clarifier and pumped back to the 

aeration basin for use as return activated sludge. The return activated sludge pumps were 

changed (in around 1998) from a constant speed to a variable frequency drive to stabilize the 

balance between the sewage entering the secondary treatment system and the microorganisms 

which provide the secondary treatment. 

Secondary Effluent is conveyed to the Ultraviolet Light (UV) disinfection system which was 

started up in January 1995. The UV facilities consist of two parallel concrete channels, each 

approximately 60 feet long, 4 feet wide and 6.5 feet deep. Each UV channel has three banks of 

UV lamps in series, with a separate power distribution center provided for each bank. UV 
Clackamas County Service District No, 1 Kellogg Creek Evaluation Report 

Page 3 of 24 

dosage is regulated by manually selecting the number of channels and automatically selecting the 

number of modules in operation based on flow rate and equipment status. The bulbs in the UV 

system are cleaned in a 10% phosphoric acid bath. The UV disinfection process replaced the 

former gaseous chlorine disinfection unit process. A sodium hypochlorite liquid application 

system is available for emergency back-up disinfection, for seasonal return activated sludge 

chlorination, for infrequent influent pump station odor control, and for non-potable water 

chlorination. Sodium bisulfite is used for dechlorination when the emergency back-up 

chlorination disinfection system is in use. Sodium Bisulfite is added to the upstream end of the 

UV channels through a plastic pipe diffuser by a flow-paced, manual stroke length metering 

pump. 

After disinfection the treated effluent is discharged to the Willamette River at river mile 18.5. 

The outfall is a single 48-inch diameter pipe that discharges at a depth of approximately 40 feet. 

The current average wet weather flow (November 1 through April 30), for the last two years were 

as follows (2003-2003) 9.2 MGD, (2003-2004) 9.3 MGD. The current average dry weather 

flow (May 1 through October 31) was as follows (2003) 7.1 MGD and (2004) 7.1 MGD. 

Significant portions of the plant have been enclosed over the years to capture and treat foul air 

for odors. Air from the headworks, primary clarifiers, anoxic selectors on the aeration basins, the 

solids handling, anaerobic digester gas and sludge load out is treated either through bio-filters or 

carbon adsorption. Improvements in odor control were made with the addition of the bio-filters 

in 2000. 

Compliance History 

The renewal permit was issued on September 30, 1992 and modified on January 19,1994 to 

include a revised total residual chlorine limit. A Stipulation and Final Order (SFO) WQMWNWR-93-189 was issued with the modification. The requirements of the SFO were satisfied by 

March 1995 when the chlorine gas disinfection system was replaced with an ultraviolet light 

disinfection system and a hypochlorite/sodium bisulfite disinfection backup system. 

The following Notices of Noncompliance (NONs) culminated into a Notice of Permit Violation: 

WQ-NWR-95-013 was issued on March 2, 1995 because TSS mass load and percent removal 

were exceeded: WQ-NWR-95-047 was issued on May 22, 1995 for exceeding TSS and CBOD 

mass load limit, and WQ-NWR-97-38 was issued on April 25, 1997 for exceeding TSS 

concentration and TSS and CBOD mass load limits. Notice of Permit Violation WQ/M-NWR97-134 was issued on July 31, 1997 for continuing to exceed permit limits for fecal coliform, 

BOD, CBOD and TSS. 

In response to the Notice of Permit Violation, CCSD No. 1 took actions ,such as, diverting flows to 

the Tri-City wastewater treatment plant, rebuilding the aeration basin diffusers, and controlling the 

solids balance to improve the treatment efficiencies at the Kellogg Creek plant. In June 1997, the 

Milwaukie Brookside Pump Station was modified to divert flow to the City of Portland 

Columbia Boulevard Treatment Plant. Approximately 250,000 gallons per day of dry weather 

flow was diverted. (This flow has since been re-directed back to the Kellogg Creek plant.) In 

October 1998, CCSD No. 1 received project approval for diverting the existing Clackamas Pump 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 4 of24 

Station flow to a new force main to the Tri-City treatment plant. Approximately 0.5 million 

gallons per day of raw sewage was diverted from the North Clackamas Service District 

Wastewater Pollution Control Facility. A Notice of Noncompliance was written in 2002 (WQNWR-02-0043) to document the CBOD and TSS mass violations which occurred in 1998 & 1999 

prior to completing the actions planned to resolve the 1997 Notice of Permit Violation. The 2002 

Notice of Noncompliance also required the submittal of the Inflow and Infiltration Report. 

Current monitoring reports and conditions for this plant were reviewed. Kellogg Creek plant is 

operating in compliance with the current permit. 

Biosolids Management and Utilization 

The anaerobic digestion facilities at the Kellogg Creek Plant were constructed in 1986-1987 and 

became operational in March 1987. Raw primary sludge is pumped directly to the anaerobic 

digesters. Waste activated sludge is pumped from the secondary clarifier and concentrated by 

dissolved air floatation with polymer prior to pumping to the anaerobic digesters. Scum from the 

primary and secondary clarifiers is pumped directly to the anaerobic digesters, to the flotation 

thickener and then the anaerobic digester or directly to the digested sludge loading area. 

Sludge completing anaerobic digestion can be thickened by the use of two Somat thickeners. Once 

the sludge has been thickened it is returned to the digester. In 1999 the solids handling dissolved 

air floatation thickener (DAFT) and recuperative thickener (Somat) processes were up graded. 

The Recuperative thickener process was moved inside to capture and control odors. 

All waste sludge must be managed in accordance with the Department approved Biosolids 

Management Plan, Land Application Plan and site authorization letter to ensure compliance with 

the federal (40 CFR Part 503) and state (OAR 340-050) biosolids regulations. 

Inflow and Infiltration (I/I) 

The Kellogg Creek plant serves a population of the north Clackamas urban area, City of Milwaukie, 

City of Happy Valley and Johnson City and also serves small portions of the Cities of Gladstone 

and Damascus. Water Environment Services has continued to have an active program to identify 

I/I. The collection system is on a regular schedule of inspections and maintenance. An annual 

report on inflow and infiltration is required as part of this permit. WES compiles an annual report 

entitled "Wastewater Maintenance Service Year End Report", which contains this information on 

the sewer collection maintenance. 

In a letter dated August 8, 2002, Water Environment Services stated that the wet weather flow 

evaluation for the Kellogg Creek Plant system has and average peaking factor of 2.5 for the years 

1996 through 2001, and an average peaking factor of 2.46 for the years 1992 through 2001. The 

peaking factor for the Kellogg Creek Plant system is below the 2.70 peaking factor used by the 

Environmental Protection Agency to detemiine if additional sewer system maintenance is needed, 

and is well below the normal range for peaking factors in western Oregon of 4.0 to 6.0. Based on 

the evaluation, the Kellogg Creek Plant sanitary sewer system is not experiencing excessive 

infiltration and inflow. 
Clackamas Countv Service District No, 1 Kellogg Creek Evaluation Report 

Page 5 of 24 

Pretreatment 

The Clackamas Comity Service District No. 1 implements an industrial pretreatment program 

approved by the Department on December 21, 1983. Subsequent Federal and state pretreatment 

requirements were included in the NPDES permit for this facility when the previous permit was 

issued. 

Schedule E of the permit requires CCSD No. 1. to submit substantial program modification 

requests to the Department for approval. The following approvals and modifications have been 

made to the industrial pretreatment program since the last permit modification on January 19, 

1994. 

In a Permit Action Letter dated August 14, 1995, CCSD No. 1 received approval of the local 

limits evaluation, after public notice and review by the Department and EPA. 

On March 1, 1999, the procedures manual received approval. Subsequent approvals to revisions 

of the manual were received on December 28, 2001, March 1, 2002 and June 7, 2004. 

A RCRA reporting modification was approved on August 6, 1999. 

On November 13, 2002 the Department approved the Enforcement Response Guides to be 

incorporated into the NPDES permit at the time of renewal. 

On September 2, 2003, the Department proposed to approve the July 25, 2002 interjurisdictional 

government agreement (IGA) between Clackamas County Service District #1 and the City of 

Milwaukie for industrial pretreatment in the City of Milwaukie. The action is a non-substantial 

program modification because it strengthens and clarifies the original agreement rather than relax 

the legal authority of the District. The change is incorporated with this permit renewal. 

An audit of the pretreatment program was conducted during the week of December 6-10, 2004, 

the pretreatment program was determined to be well organized and functioning in compliance 

with the federal pretreatment requirements (40 CFR Part 403) and Schedule E of the permit. 

Pollutants Discharged 

The current permit allows Clackamas County Service District No. 1 to discharge treated effluent 

from the wastewater treatment plant year round and included and option for land irrigation. The 

current permit sets limits on the following pollutants: CBOD5, TSS, Fecal Coliform bacteria, total 

residual chlorine, pH and 85 % removal efficiency of BOD5 and TSS. Total coliform limits and 

management practices were also included for the land irrigation option. 

The proposed permit will regulate CBOD5, TSS, E. coll bacteria, total residual chlorine, pH, 85 % 

removal efficiency of BOD5 and TSS, The bacteria standard was changed In 1996 from fecal 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report. 

Page 6 of 24 

coliform to E-coli. This permit renewal includes bacteria limits for E-coli. The requirements 

associated with land irrigation have been removed. Permit limits total residual chlorine have 

been revised and permit limits for ammonia have been added. 

Outfalls 

Treated wastewater Is discharged to the Willamette River through a 48-inch diameter pipe that 

discharges at a depth of approximately 40 feet. The distance from the edge of the bank is 

approximately 65 feet when measured during 7Q10 flows. The discharge is located at river mile 

18.5. 

CORMIX1 was used for the modeling in a mixing zone study that was conducted for WES and is 

entitled "Mixing Zones Evaluations for CCSD No. 1 Outfalls of the Kellogg Creek, Boring & 

Hoodland WPCPs" (Volume 1 of 3)(October 2001). The results of the CORMIX1 modeling were 

adjusted for field data that was collected in August 2001. The Willamette River 7Q10 flow of 5910 

cfs and 10 MGD effluent flow were used to evaluate the single outfall pipe mixing. 40 CFR Part 

131.36(c)(2)(H) states in part that a State cannot use a low flow value below which numeric 

standards can be exceeded that is less stringent than the 1Q10 (or 1B3) for acute criteria and the 

7Q10 (or 4B3) for chronic criteria. The modeling is representative of the velocity and depth at 

these flow regimes. The resulting zone of initial dilution (4.3) and edge of the mixing zone dilution 

(19.9) were used in the reasonable potential analysis. 

Receiving Streams/Impact 

The Department Is required by the Federal Clean Water Act, Section 303(d) to identify all water 

bodies in Oregon that do not meet water quality standards. Once identified, the stream segments 

are placed on the DEQ's "303(d) list". This listing means that the standards that protect the most 

sensitive beneficial uses of the water are not being met and the Department is required to establish a 

plan with goals and pollution control targets for improving water quality. 

The "303(d) list" provides a way to identify and prioritize water quality problems. The list also 

serves as a guide for developing and implementing watershed pollution reduction plans to achieve 

water quality standards and protect beneficial uses. 

From river mile 0 to 24.8, the Willamette River is listed on the 2002 "303(d)" list for the following 

parameters: 

Parameter 

Temperature 

Fecal Coliform 

Toxics 

Criteria/Standard 

Fish Rearing, anadromous fish passage 

17.8 C (64°F) (Note standard is now 20°C) 

Geometric Mean of 200, no more than 10% 

>400 organisms per 100 ml 

FishTissue-DDT 

and DDT Metabolite (DDE) 

DDT RM 12.7-Table 20 >0.000024 ug/L 

Fish Tissue-PCB 

Season 

Summer 

Winter/Spring/Fall 

Year Round 

Year Round 

Year Round 
Clackamas County Service District No. I Kellogg Creek. Evaluation Report 

Page 7 of 24 

Iron 

Manganese 

Biological Criteria 

Fish Tissue -Aldrin 

Fish Tissue -Dieldrin 

Fish Tissue -Mercury 

Polynuclear Aromatic Hydrocarbons RM 6 

Table 20 >2800 pg/L 

Pentachlorophenol - Table 20 

Sediment in the area of McCormick and 

Baxter due to soils and sediment 

contaminated by creosote. 

RM 6.9 and 13.1 Table 20 > 300 ug/L 

drinking water 

RM 13.1-Table 20 >50 ug/L 

drinking water 

Skeletal deformities in squawfish 

Year Round 

Year Round 

Year Round 

Year Round 

NA 

Year Round 

Year Round 

NA 

A Total Maximum Daily Load (TMDL) for the Willamette River for temperature, bacteria and 

mercury has been through an extended public comment period which ended on January 31, 2005. 

Upon approval of a TMDL for temperature for this sub-basin, this permit may be re-opened and 

temperature and/or thermal load limits assigned. In the proposed TMDL for bacteria individual 

municipal discharges will need to comply with the water quality standard. A permit limit for 

bacteria has been set. Continued monitoring for mercury is proposed in the Willamette River 

TMDL and as part of this permit. 

Toxics such as Aldrin, Dieldrin, PCB, DDE and DDT, Polynuclear Aromatic Hydrocarbons and 

Pentachlorophenol are not known to be introduced to the domestic wastewater treatment facility 

through production or manufacturing processes. They are not considered to be present above 

trace background levels. Priority Pollutant scans will be required prior to the next permit 

renewal. This Information will be used to further evaluate the toxic pollutants at that time. 

Skeletal deformities in fish is a separate study, this source has not been evaluated for its 

contribution to skeletal deformities in squawfish, A recent study entitled Environmental Stresses 

and Fish Deformities in the Willamette River Project Status Report (December 2003)conducted 

by Departments of Environmental and Molecular Toxicology, Microbiology, and Fisheries and 

Wildlife, Oregon State University, Corvallis, Oregon, indicates that parasites are major 

contributors to high prevalence of skeletal deformities in fish from Newberg Pool of the 

Willamette River. 

Iron and manganese are listed as exceeding the drinking water standards because iron and 

manganese can be aesthetically unappealing in drinking water. Iron at low levels imparts a taste 

to the water. For these reasons, drinking water should not contain >300ug/L of Iron or > 50ug/L 

of manganese. Effluent data was not available, to evaluate the effluent for iron or manganese. 

The proposed permit does not allow for an increase in mass load limits from the previous permit. 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 8 of 24 

Reasonable Potential Analysis 

A discussion of the reasonable potential analysis using the EPA Technical Support Document for 

Water Quality-based Toxics Control (EPA/505/2-90-001) for chlorine, ammonia and metals 

follows. Based on facility data, ambient river data, a dilution of 4.3 at the zone of initial dilution 

and 19.9 at the edge of the mixing zone, the reasonable potential analysis indicates that the 

facility has the reasonable potential to cause or contribute to a violation of water quality 

standards for chlorine and ammonia and.seems to indicate that the facility has the reasonable 

potential to cause or contribute to a violation of water quality standards for metals. 

An evaluation effluent temperature data collected over 2002-2003 indicates that temperature 

criteria is met at the edge of the mixing zone. The permit may be reopened when the allocation 

from the temperature TMDL is incorporated into the permit as a permit limit. 

Toxic Substances (chlorine, ammonia and metals) 

OAR 340-041-0033 requires that the levels of toxic substances shall not exceed the criteria listed 

and toxic substances shall not be introduced above the natural background levels in amounts 

which may be harmful in the environment or may accumulate in sediments or bioaccumulate in 

aquatic life. From this facility the primary toxic substance of concern are chlorine, ammonia and 

metals. 

Chlorine Residual 

Water quality standards for chlorine are based on preventing both acute and chronic toxicity. 

The acute chlorine standard is 0.019 mg/L and the chronic chlorine standard is 0.011 mg/L. The 

facility uses UV for disinfection of the effluent to comply with the effluent limits for bacteria. A 

sodium hypochlorite liquid application system is available for emergency back-up disinfection. 

Sodium bisulfite is used for dechlorination when the emergency back-up chlorination 

disinfection system is In use. 

PARAMETER 

CHLORINE 

Effluent Data 

Hot 

_Samgles_ 

1673 

Highest 

Cone. 

mg/l 

0,07 

Coef. of 

Variance 

0.21 

Calc Max 

Effluent 

Cone. 

mg/l 

0.1 

Stream Data 

Background 

Cone. 

mg/l 

0.00 

Max 

Cone, 

ZID 

mg/l 

0.013 

Max 

Cone. 

MZ 

mg/l 

0,003 

CRITERIA 

1 Hour 

(CMC) 

mg/l 

0.019 

4 Day 

(CCC) 

mg/l 

0.01 S 

REASONABLE 

POTENTIAL ? 

(YES/NO) 

ACUTE 

NO 

CHRONIC 

NO 

The effluent data for the reasonable potential reflects the use of UV disinfection with 

chlorination/dechlorination back up. A permit limit remains in the permit to indicate the amount 

of chlorine residual that would cause a water quality violation if the equipment were not 

operating properly. 

Ammonia 

The Environmental Quality Commission adopted OAR 340-041 Table 33 (EPA 1999 criteria for 

ammonia) on May 20, 2004 and is waiting for EPA to approve the new criteria. Therefore, the 
Clackamas County Service District No. I Kellogg Creek Evaluation Report 

Page 9 of 24 

reasonable potential analysis for ammonia was conducted using both OAR 340-041Table 33 and 

Table 20 (EPA 1986 criteria for ammonia). 

Water quality standards for ammonia (NH3-N) are based on preventing both acute and chronic 

toxicity. The Reasonable Potential Analysis for ammonia takes into consideration effluent and 

ambient ammonia, effluent and ambient water temperature, pH, dilution and the presence or 

absence of salmonids in the receiving water in the summer and the winter. 

Summer data 

pH (6.5-9 S. U.) = 

•"••"' Temp°C = 

Alkalinity = 

Salmonids Present? (Y/N) 

• ' Fresh Water ? (Y/N) 

Effluent 

7.1 

20 

85 

Stream 

7.5 

20 

25 

y 

y 

ZID 

7.2 

20 

MZ 

7.4 

20 

PARAMETER 

AMMONIA 

AMMONIA** 

AMMONIA** 

(monthly) 

Effluent Data 

#of 

Samples 

761 

761 

36 

Highest 

Cone. 

mg/l 

48.2 

48.2 

25.6 

Coef. of 

Variance 

0.35 

0.35 

0.18 

Calc Max 

Effluent 

Cone. 

mg/l 

33,7 

33.7 

28.2 

Stream Data 

Background 

Cone. 

mg/l 

0.06 

0.06 

0.08 

Max 

Cone, 

ZID 

mg/l 

7.9 

7.9 

n/a 

Max 

Cone. 

MZ 

mg/l 

1.8 

1.8 

1.5 

CRITERIA 

1 Hour 

(CMC) 

mg/l 

16.9 

20.2 

n/a 

4 Day 

(CCC) 

mg/l 

1.2 

8.5 

3.4 

REASONABLE 

POTENTIAL ? 

(YES/NO) 

ACUTE 

NO 

NO 

n/a 

CHRONIC 

YES 

NO 

NO 

**Proposed Ammonia Standard - 1999 Update of Ambient Water Quality Criteria for Ammonia (EPA-882-R-99-014) 

'Winter data 

pH (6.5-9 S. U.) = 

'• Temp°C = 

Alkalinity = 

Salmonids Present? (Y/N) 

Fresh Water ? (Y/N) 

' Effluent • 

7.5 

15 

85 

Stream 

7.6 

15 

25 

y 

y 

ZID 

7.5 

15 

MZ " 

7.6 

15 

PARAMETER 

AMMONIA 

AMMONIA** 

Effluent Data 

#of 

Samples 

729 

729 

Highest 

Cone. 

mg/l 

59 

59 

Coef. of 

Variance 

0.30 

0.30 

Calc Max 

Effluent 

Cone. 

mg/l 

47,2 

47.2 

Stream Data 

Background 

Cone. 

mg/l 

0.06 

0.06 

Max 

Cone. 

ZID 

mg/l 

11.0 

11.0 

Max 

Cone. 

MZ 

mg/l 

2.4 

2.4 

CRITERIA 

I Hour 

(CMC) 

____mj/l___ 

11.6 

12.4 

4 Day 

(CCC) 

__mg_/l_ 

1.8 

9.8 

REASONABLE 

POTENTIAL ? 

(YES/NO) 

ACUTE 

NO 

NO 

CHRONIC 

YES 

NO 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 10 of 24 

AMMONIA** 

(monthly) 37 23 0.27 25.3 0.09 

1 

n/a/ ! 1.4 n/a 3.9 n/a NO 

** Proposed Ammonia Standard - 1999 Update of Ambient Water Quality Criteria for Ammonia (EPA-882-R-99-014) 

Winter data 

pH (6,5-9 S, U.) = 

Temp°C = 

Alkalinity = 

':• Salmonids Present? (Y/N) 

Fresh Water ? (Y/N) 

Effluent 

7.5 

10 

85 

Stream 

7.6 

10 

25 

y 

y 

ZID 

7.5 

10 

MZ 

7.6 

10 

PARAMETER 

AMMONIA 

AMMONIA** 

AMMONIA** 

(monthly) 

Effluent Data 

#of 

Samples 

729 

729 

37 

Highest 

Cone, 

mg/l 

59 

59 

23,0 

Coef. Of 

Variance 

0.30 

0.30 

0,27 

Calc Max 

Effluent 

Cone. 

mg/l 

47.2 

47.2 

25.3 

Stream Data 

Background 

Cone. 

mg/l 

0.06 

0.06 

0.09 

Max 

Cone. 

ZID 

mg/l 

11.0 

11.0 

n/a 

Max 

Cone. 

MZ 

mg/l 

2.4 

2,4 

1,4 

CRITERIA 

1 Hour 

(CMC) 

_^nsA_j 

12.0 

12.4 

n/a 

4 Day 

(CCC) 

mg/l 

1.9 

13.5 

5.4 

REASONABLE 

POTENTIAL? 

(YES/NO) 

ACUTE 

NO 

NO 

n/a 

CHRONIC 

YES 

NO 

NO 

*^Propose * d Ammonia Standard- 1999 Update of Ambient Water Quality Criteria for Ammonia (EPA-882-R-99-014) 

The reasonable potential analysis indicates that the facility has the reasonable potential to 

contribute to an in-stream excursion of the OAR 340-041 Table 20 ammonia criteria (EPA 1986). 

When a discharge has the reasonable potential to cause or contribute to an in-stream excursion 

above the allowable WQ criterion, NPDES permit regulations in 40CFR 122,44(d)(l)(iii) 

requires that permit limits be established. Permit limits are set for OAR 340-041 Table 20 

ammonia criteria as a part of this permit. 

The same analysis shows that there is no reasonable potential to exceed the EPA 1999 criteria for 

ammonia; therefore, the OAR 340-041 Table 20 ammonia limits will be in effect until the EPA has 

approved the OAR 340-041 Table 33 ammonia criteria. 

Metals 

The EPA method of reasonable potential analysis was perforated using both OAR 340-041 Table 

20 and Table 33 for the following metals: arsenic, cadmium, chromium, copper, lead, mercury, 

nickel, silver and zinc. The reasonable potential analysis was performed using effluent metals from 

the facility and two samples from the Willamette River. Current metals data (June 2002 to June 

2005) was used to evaluate the reasonable potential analysis. For those metals that are hardness 

dependent the hardness that was used is 35 mg/L CaC03 at the ZID and 27 mg/L at the edge of the 

mixing zone. 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 11 of 24 

PARAMETER 

ARSENIC V 

ARSENIC III 

ARSENIC III** 

CADMIUM2 

CADMIUM2** 

CHROMIUM VI 

CHROMIUM III2 

CHROMIUM III2** 

COPPER2 

COPPER2'** 

LEAD2 

MERCURY 

NICKEL

 2 

NICKEL

 2 " 

SILVER

 2 

SILVER

 2 ** 

ZINC2 

ZINC

 2 " 

Effluent Data 

tfof 

Samples 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

32 

Highest 

Cone. 

Mg/l 

1.10 

1.10 

1.10 

0.2 

0.2 

4,8 

4.8 

4.8 

9.0 

9.0 

1.15 

0.2 

2.9 

2.9 

1.58 

1,58 

40.2 

40,2 

Coef. of 

Variance 

0,18 

0.1S 

0.18 

0.65 

0.65 

0,65 

0.65 

0.65 

0,17 

0.17 

0.4 

1.65 

0.19 

0,19 

0.45 

0,45 

0.22 

0.22 

Calc. Max 

Effluent 

Cone, 

Hg/1 

1.21 

1.21 

1.21 

0.28 

0.28 

6.72 

6.72 

6.72 

9.9 

9.9 

1.38 

0.38 

3.19 

3.19 

2.05 

2.05 

44.22 

44.22 

Stream Data 

Background* 

Cone. 

Mg/l 

0,6 

0.6 

0.6 

0.05 

0.05 

0.6 

0.6 

0.6 

1.3 

1.3 

0.22 

0.0024 

0.70 

0.70 

0.02 

0,02 

3.41 

3,41 

Max 

Cone. 

ZID 

fig/1 

0.74 

0.74 

0.74 

0.10 

0.10 

2.02 

2.02 

2.02 

3.3 

3.3 

0.49 

0.09 

1.28 

1.28 

0.49 

0.49 

12.9 

12.9 

Max 

Cone. 

MZ 

Ug/1 

0.63 

0.63 

0.63 

0.06 

0.06 

0.91 

0.91 

0.91 

1.73 

1.73 

0.28 

0.02 

0.83 

0.83 

0,12 

0.12 

5.46 

5.46 

FRESHWATER 

CRITERIA 

1 Hour 

(CMC) 

M-g/l 

850 

360 

340 

1.22 

0.74 

16.0 

743 

771.7 

6.67 

5.27 

21.82 

2.4 

590.0 

195.5 

0,68 

0.64 

48.62 

49.78 

4 Dav 

(CCC) 

ug/1 

48 

190 

150 

0.41 

0.10 

11.0 

71.4 

29.7 

3.89 

3,07 

0.61 

0.012 

52.5 

17.4 

0.12 

0.12 

35,24 

39.83 

REASONABLE 

POTENTIAL ? 

{yes/no) 

ACUTE 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

CHRONIC 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

NO 

YES 

NO 

NO 

YES 

YES 

NO 

NO 

(1) Not a DEQ Criteria. 

(2) Hardness Dependent 

Bold = the detection limit 

*Background concentrations in 

** Proposed standard Water 

the Willamette River 

Quality Criteria Revisions for Toxic Pollutants Table 33 

The maximum of the two background water samples were used in the reasonable potential. The 

maximum used in the reasonable potential analysis for silver was reported as < 0.02 ug/L with a 

method reporting limit (MRL) of 0.02 ug/L. The other background sample result for silver was 

<0.01 ug/L. The maximum used in the reasonable potential analysis for mercury was reported as 

0.0024 ug/L with an MRL of 0.001 ug/L. The other background sample result for mercury was 

0.0009 ug/L. 

The amount of data and the detection level of the analytical results used in the reasonable 

potential analysis play an important part in determining whether there is an actual in-stream 

excursion above the allowable water quality criterion. Because the recommended number of 

samples for the reasonable potential analysis is a minimum of four, the Department will require 

additional samples to be taken. The data analysis will also require reporting of the method 

detection limit (MDL) and hardness for the sample analysis. The internal management directive 
Clackamas County Service District No, 1 Kellogg Creek Evaluation Report 

Page 12 of 24 

on the reasonable potential analysis requires the MDL be reported and taken into consideration 

with the practical quantification level (PQL) when evaluating the data. 

The range of effluent data for silver and mercury are shown below. Metals data that was reported 

with the discharge monitoring reports in previous years does not. distinguish between the 

different types of detection limits. 

1.8 

1.6 

J 1.2 

fe 0,8 

£ 0.6 

• 

* • 

• 

• 

• 

** 

* » • 

* 

* 

* 

• 

• 

* 

*» 

«* 

• 

0.4 

0.2 

0 

Apr-01 Sep-02 jan-04 May-05 Ocf-06 

month/year 

3 

as 

3 

£• 

33 

G 

0.2 " * * • * * 

• 

0.15 •• 

0.1 • 

0.05 -

0 i .. • . • •.??.•••••••*.••*?*«•*•••• * 

& &<&<$> <£> j? S? $y> & ^ & p\j£ & & 

month/year 

After completion of the monitoring, an RPA will be performed, and the permit potentially 

reopened and modified based on the results of the analysis. 

Temperature 

This segment of the Willamette River serves as a migration corridor for salmonids. OAR 340-

041-0028(4)(d) states that the 7-day maximum temperature of a stream identified as a migration 

corridor may not exceed 20°C(68°F). In addition, for streams that do not meet water quality 

standards, OAR-041-0028(12)(b)(A) states that prior to the completion of a temperature TMDL or 

other cumulative effects analysis, no single NPDES point source that discharges into temperature 

water quality limited water may cause the temperature of the water body to increase more than 

0.3°C above the applicable criteria after mixing with either twenty-five percent of the stream flow 

or the temperature mixing zone whichever is more restrictive. A temperature TMDL has not been 

completed for the Willamette River, therefore the above provision from OAR 340-041-

0028(12)(b)(A) applies. In this case, the amount of dilution at the edge of the 200 foot mixing 

zone of 19.9 is more restrictive. 

The District collected continuous temperature data of the effluent and upstream in the Willamette 

River from June 2002 through January 2003. The data was used to establish a 7-day rolling 

average of the maximum temperatures. The effluent data was evaluated for its impact on the 

receiving stream. 

The following equation was used to determine if the effluent temperature from the facility would 

cause an increase of 0.3°C (0.5°F) above the biologically based numeric criteria of 20°C (68°F). 

TMz=(TE+DTr)/(EH-l) 

Where: 

TMZ

 = temperature of the stream at the edge of the mixing zone (0.3°C or 0.5°F or above the 

applicable criteria) 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 13 of 24 

TE ~ effluent temperature = 7 day moving average of the maximum daily temperature from 

continuous monitoring in June 2002 to January 2003. 

Tr = river temperature data 

D = dilution at the edge of the mixing zone 

The graph below shows the amount of dilution at the edge of the mixing zone that is necessary 

for an increase that is less than or equal to a measurable increase of 0.5°F (0.3°C) in the 

biologically based numeric temperature criteria is shown in the graph below. The long dash line 

represents the 7 day moving average of the effluent temperature (Te°C). The thin solid line 

represents the temperature criteria in the Willamette River (Tr°C). The thick solid line represents 

the dilution (D). 

CCSD No. 1 - Kellogg Creek 

25.000 - 10.0 

-5.0 

c 

o 

5 

0.000 4— 

L

 -10.0 

- -15.0 

-20.0 

%, 

<S/ 

V \ 4, 

'<? ~oe 

& 

O 

<2? °A 

% a. 

'<?? * P •vp 

Date 

Based on the data available, a dilution of 8 is sufficient to meet the biologically based numeric 

criteria. The biologically based numeric criteria will be met. 

The Willamette River is currently listed as water quality limited for temperature. A TMDL 

addressing water quality has not yet been approved for the sub-basin. Upon approval of a TMDL 

for temperature for this sub-basin, this permit may be re-opened and temperature and/or thermal 

load limits assigned. 

The Department's water quality standards also include the temperature thermal plume limitations 

in OAR 340-041 -0053(2)(d). This section of the rules contains criteria to prevent potential 

adverse impacts that may result from thermal plumes within the mixing zone. 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 14 of 24 

The impairment of an active salmonid spawning area where spawning redds are located or likely 

to be located [OAR 340-04I-0053(d)(A)]. This segment of the Willamette River is a migration 

corridor for salmonids. Based on Figure 304B in OAR 340-041-028, spawning in this segment 

of the river does not occur. 

Acute impairment or instantaneous lethality is prevented or minimized by limiting potential fish 

exposure to temperatures of 32°C or higher to less than 2 seconds [OAR 340-04l-0053(d)(B)]. 

Based on temperature data collected using a continuous recording device, the maximum effluent 

temperature of 23°C is less than 32°C. 

Thermal shock caused by a sudden increase in water temperature is prevented or minimized by 

limiting potential fish exposure to temperatures of 25°C or higher to less than 5% of the crosssection of the 7Q10 flow of the water body [OAR 340-041 -0053(d)(C)]. Effluent temperatures of 

25°C or higher are limited to less than 5% of the cross section of the 7Q10 flow of the waterbody. 

The maximum effluent temperature recorded from June 2002to January 2003 was 23°C. Effluent 

temperatures will be reduced to 25°C in less than 5% of the cross section of the 7Q10 of the 

waterbody. The low water width of the Willamette River in the area of the outfall is approximately 

1000 feet across and 60 feet deep. 

Unless ambient temperature is 21°C or greater, migration blockage is prevented or minimized by 

limiting potential fish exposure to temperatures of 21°C or higher to less than 25% of the crosssection of 100% of the 7Q10 flow of the water body [OAR 340-041-0053(d)(D)]. The 

temperature data collected to date indicates that the maximum effluent temperature is 23°C. 

Effluent temperatures will be reduced to 21°C in less than 25% of the cross section of the 7Q10 of 

the waterbody. The low water width of the Willamette River in the area of the outfall is 

approximately 1000 feet across and 60 feet deep. A temperature of 21°C will be within a cross 

section that is much less than 25%. 

Groundwater 

Based on the Department's current information, this facility has a low potential for adversely 

impacting groundwater quality. Therefore, Schedule D of the proposed permit states that no 

groundwater evaluations will be required during this permit cycle. The permit also includes a 

condition in Schedule A that prohibits any adverse impact on groundwater quality. 

Stormwater 

General NPDES permits for stormwater are required for facilities with a design flow of greater 

than 1 MGD if stormwater is collected and discharge from the plant site. Because this facility 

does not discharge stormwater from the plant site, a separate stormwater permit is not necessary. 

PERMIT DISCUSSION 

Pollutants Discharged 

The NPDES permit 100983 was renewed on September 30, 1992. The permit set limits on the 

following pollutants: CBOD5, TSS, Fecal Coliform bacteria, pH, percent removal of BOD5 and 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 15 of 24 

TSS and a total residual chlorine limit. This NPDES permit also included a condition in Schedule 

C to conduct a mixing zone study to determine if water quality based effluent chlorine limits 

needed to be revised. The NPDES permit was modified on January 19, 1994 to include a revised 

chlorine limit. The modification was issued with a Stipulation and Final Order to give the facility 

time to meet the effluent chlorine limit. 

The proposed permit will regulate CBOD5, TSS, E. coli bacteria, percent removal of BOD5 and 

TSS. Revised effluent chlorine limits are included based on the most recent mixing zone study. 

The revised effluent chlorine limit is more restrictive. The facility will be able to meet the limits at 

the time of permit issuance with the UV disinfection system and the chlorination/dechlorination 

system backup. The permit also includes new limits for ammonia. 

PERMIT DISCUSSION 

Face Page 

The permittee is authorized to construct, install, modify, or operate a wastewater collection, 

treatment, control and disposal system. Penults discharge of treated effluent to the Willamette 

within limits set by Schedule A and the following schedules. All other discharges are prohibited. 

Schedule A - Waste Discharge limitations 

BOD and TSS concentration and mass limits 

A monthly average effluent concentration of 15 mg/L for CBOD5 and 20 mg/L TSS is required 

from May 1.-October 31. From November 1 - April 30, a minimum of secondary treatment or 

equivalent is required. Secondary treatment for this facility is defined as monthly average 

concentration limit of 30 mg/L for BOD5 (or 25 mg/L for CBOD5) and 30 mg/L for TSS. 

The mass limits for CBODS and TSS are based on the design average dry weather flow of 10 

MGD. 

CBOD^ BOD^and TSS 

The limits are: 

(1) May 1-October 31: 

Parameter 

CBOD5 

TSS 

Average 

Concei 

Monthly 

15 mg/L 

20 mg/L 

; Effluent 

ltrations 

Weekly 

25 mg/L 

30 mg/L 

Monthly 

Average 

lb/day 

1300 

1700 

Weekly 

Average 

lb/day 

2000 

2600 

Daily 

Maximum 

Lbs 

2600 

3400 

(2) November 1 - April 30: 

Parameter 

CBOD5 

TSS 

Average 

Concei 

Monthly 

25 mg/L 

30 mg/L 

Effluent 

ltrations 

Weekly 

40 mg/L 

45 mg/L 

Monthly 

Average 

lb/day 

2100 

2500 

Weekly 

Average 

lb/day 

3200 

3800 

Daily 

Maximum 

Lbs 

4200 

5000 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 16 of 24 

Calculations: 

(1) Summer CBOD5 

(a) 10 MGD x 8.34 lbs/gal x 15 mg/L monthly avg. = 1300 lbs/day 

(b) 1300 lbs/day monthly avg. x 1.5 = 2000 lbs/day weekly avg. 

(c) 1300 lbs/day monthly avg. x 2.0 = 2600 lbs/day daily max. 

(2) Summer TSS 

(a) 10 MGD x 8.34 lbs/gal x 20 mg/L monthly avg. = 1700 lbs/day 

(b) 1700 lbs/day monthly avg. x 1.5 = 2600 lbs/day weekly avg. 

(c) 1700 lbs/day monthly avg. x 2.0 = 3400 lbs/day daily max. 

(3) Winter CBOD5 

(a) 10 MGD x 8.34 lbs/gal x 25 mg/L monthly avg. = 2100 lbs/day 

(b) 2100 lbs/day monthly avg. x 1.5 - 3200 lbs/day weekly avg. 

(c) 2100 lbs/day monthly avg. x 2.0 = 4200 lbs/day daily max. 

(4) Winter TSS 

(a) 10 MGD x 8.34 lbs/gal x 30 mg/L monthly avg. = 2500 lbs/day 

(b) 2500 lbs/day monthly avg. x 1.5 = 3800 lbs/day weekly avg. 

(c) 2500 lbs/day monthly avg. x 2.0 = 5000 lbs/day daily max. 

No changes from the previous permit are proposed. 

BOD and TSS Percent Removal Efficiency 

A minimum level of percent removal for BOD5 and TSS for municipal dischargers is required by 

the Code of Federal Regulations (CFR) secondary treatment standards (40 CFR, Part 133). An 85 

percent removal efficiency limit is included in the proposed permit to comply with federal 

requirements. 

EH 

The Willamette Basin Water Quality Standard for pH is found in OAR 340-041-0445(2)(d). The 

allowed range is 6.5 to 8.5. The proposed permit limits pH to the range 6.0 to 9.0. This limit is 

based on Federal wastewater treatment guidelines for sewage treatment facilities, and is applied to 

the majority of NPDES permittees in the state. Mixing with ambient water within the mixing zone 

will ensure that the pH at the edge of the mixing zone meets the standard, and the Department 

considers the proposed permit limits to be protective of the water quality standard. 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 17 of 24 

Bacteria 

The proposed permit limits are based on an E. coli standard approved in January 1996. The 

proposed limits are a monthly geometric mean of 126 E. coli per 100 mL, with no single sample 

exceeding 406 E. coli per 100 mL. The new bacteria standard allows that if a single sample 

exceeds 406 E coli per 100 mL, then the permittee may take five consecutive re-samples. If the 

log mean of the five re-samples is less than or equal to 126, a violation is not triggered. The new 

rule states that the re-samples should be taken at four hour intervals beginning as soon as 

practicable (preferably within 28 hours) after the original sample was taken. 

Chlorine Residual 

The treatment facility uses ultra-violet light to disinfect the treated wastewater with a 

chlorination/dechlorination disinfection system for backup. The permit limit for total chlorine 

residual was changed to reflect the dilution available in the mixing zone based on the updated 

mixing zone study " Mixing Zones Evaluations for CCSD No. 1 Outfalls of the Kellogg Creek, 

Boring & Hoodland WPCPs (October 2001)". 

Chlorine is a known toxic substance and as such is subject to limitation under Oregon 

Administrative Rules. The fresh water criteria for chlorine were used to calculate permit 

limitations. Chlorine concentrations of 0.011 mg/L can result in chronic toxicity in fresh waters 

while 0.019 mg/L can result in acute chlorine toxicity in fresh water; therefore, permit limits based 

on the acute and chronic criteria were calculated. Since the acute and chronic criteria are based on 

different durations, the durations are equated to a long tenn average. Using EPA's guidance 

document, Technical Support Document for Water Quality-based Toxics control, effluent limits 

were established to meet the in-stream criteria. 

Permit Limit calculation for Total Residual Chlorine 

Acute Criteria mg/L 

Chronic Criteria mg/L 

ZID Dilution 

MZ Dilution 

Wasteload Allocation (acute) mg/L 

WLAa = ZID x Acute criteria 

WLAa includes an ambient residual chlorine of 0.0 mg/L 

Wasteload Allocation (chronic) mg/L 

WLAc = MZ x Chronic criteria 

WLAc includes an ambient residual chlorine of 0.0 mg/L 

Long Term Average (acute) mg/L 

LTAa = WLAa * exp(0.5sigma~ - Z * sigma) 

sigma2= 0.3075 

Z = 2.326 based on 99th % 

Long Term Average (chronic) mg/L 

LTAc = WLAc x exp(0.5sigma4

2

 - Z x sigma,)) 

Z = 2.326 based on 99th % 

sigma4

2

= 0.0862 

Minimum Long Term Average mg/L 

0.019 

0.011 

4.3 

19.9 

0.05 

0.17 

0.03 

0.12 

0.03 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 18 of 24 

LTA = min (LTAc, LTAc) 

Maximum Daily Limit mg/L 

MDL = LTA x exp(Z x sigma - 0.5sigma2) 

Z = 2.326 based on 99th % 

sigma~= 0.3075 

Average Monthly Limit mg/L 

AML = LTA x exp(Z * sigma,, - 0.5sigman

2

) 

Z= 1.645 based on 95th % 

Sigma„2= 0.01193 

0.08 

0.03 

Ammonia 

Compliance with acute toxicity criteria is required at the edge of the ZID and compliance with 

chronic toxicity criteria is required at the edge of the MZ. Using EPA's guidance document, 

Technical Support Document for Water Quality-based Toxics control effluent limits were 

established to meet the in-stream criteria for ammonia in the summer and winter. The permit limits 

shown below are based on a dilution of 4.3 at the edge of the ZID and 19.9 at the edge of the MZ. 

Summer Ammonia Criteria: 

Summer Permit Limit calculation for Ammonia 

Acute Criteria mg/L 

Chronic Criteria mg/L 

ZID Dilution 

MZ Dilution 

Wasteload Allocation (acute) mg/L 

WLAa = ZID x Acute criteria 

WLAa includes ambient ammonia of 0.06 mg/L 

Wasteload Allocation (chronic) mg/L 

WLAc = MZ x Chronic criteria 

WLAc includes ambient ammonia of 0.06 mg/L 

Long Term Average (acute) mg/L 

LTAa = WLAa x exp(0.5sigma2 - Z x sigma) 

sigma2 = 0.1156 

Z = 2,326 based on 99th % 

Long Term Average (chronic) mg/L 

LTAc = WLAc x exp(0,5sigma4

2

 - Z x sigma4) 

Z = 2.326 based on 99th % 

sigma42 = 0.0302 

Minimum Long Term Average mg/L 

LTA = minimum of either LTAa or LTAc) 

Maximum Daily Limit mg/L 

MDL = LTA x exp(Z x sigma - O.Ssigma2) 

Z = 2.326 based on 99th % 

sigma = 0.1156 

Average Monthly Limit mg/L 

AML = LTA x exp(Z x sigma,, - 0.5sigma„2) 

Z= 1.645 based on 95 th % 

Sigma„ = 0.01016 

16.9 

1.2 

4.3 

19.9 

72.44 

23.42 

34.8 

15.87 

15.87 

33.0 

18.6 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Paael9of24 

An evaluation of the data shows that the monthly average effluent limits for the summer and at 

times the dailv maximum will be exceeded. 

* Monthly 

A«rage 

Monthly 

Limit 

May-05 May-04 May-03 May-02 May-01 May-00 May-99 

• MAX Daily j 

Daily Limit! 

fay-05 May-04 May-03 May-02 May-01 May-00 May-99 

Winter Ammonia Criteria: 

Winter Permit Limit calculation for Ammonia 

Acute Criteria mg/L 

Chronic Criteria mg/L 

ZID Dilution 

MZ Dilution 

Wasteload Allocation (acute) mg/L 

11.6 

1.8 

4.3 

19.9 

49.71 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 2.0 of 24 

WLAa = ZID x Acute criteria 

WLAa includes ambient ammonia of 0.06 mg/L 

Wasteload Allocation (chronic) mg/L 

WLAc = MZ x Chronic criteria 

WLAc includes ambient ammonia of 0,06mg/L 

Long Term Average (acute) mg/L 

LTAa = WLAa x exp(0.5sigma2 - Z x sigma) 

sigma2 = 0.0862 

Z - 2.326 based on 99th % 

Long Term Average (chronic) mg/L 

LTAc = WLAc x exp(0.5sigma4

2

 - Z x sigma4) 

Z = 2.326 based on 99th % 

sigma4

2

 = 0.0223 

Minimum Long Term Average mg/L 

LTA = min (LTAc, LTAc) 

Maximum Daily Limit mg/L 

MDL = LTA x exp(Z x sigma - O.Ssigma2) 

Z = 2.326 based on 99th % 

sigma2= 0.0862 

Average Monthly Limit mg/L 

AML = LTA x exp(Z x sigma,, - 0.5sigman

2

) 

Z= 1.645 based on 95th % 

Sigma„2= 0.00747 

34.52 

26.21 

24.67 

24.67 

46.8 

28.3 

An evaluation of the data shows that the monthly average effluent limits will be met in the winter 

and with one exception the daily maximum will be met. 

70.0 

• Max Daily 

Daily Limit 

Apr- Dec- Feb- Apr- Dec- Feb- Apr- Dec- Feb05 04 04 03 02 02 01 00 00 
jlackamas County Service District No. 1 Kellogg Creek Evaluation Report 

y&m 21 of 24 

30.0 

25.0 

20.0 

15,0 

10.0 

5,0 

0,0 

* Monthly Average! 

—-Monthly Limit 

Apr- Dec- Feb- Apr- Dec- Feb- Apr- Dec- Feb05 04 04 03 02 02 01 00 00 

The OAR 340-041 Table 20 ammonia limits are in effect until the EPA has approved the OAR 340-

041 Table 33 ammonia criteria. Upon EPA approval of the revised water quality criteria for 

ammonia, the final ammonia limit shall be 'no limit.' Until EPA approval of the revised limits, 

Schedule C contains a condition to proceed with corrective action that will result in compliance 

with the summer ammonia permit limits. 

Mixing Zone and Zone of Immediate Dilution 

The allowable mixing zone is that portion of the Willamette River that is within 200 feet 

downstream of the point of discharge. The Zone of Initial Dilution (ZID) shall be defined as that 

portion of the allowable mixing zone that is within 20 feet of the point of discharge. 

The Department believes that the beneficial uses of the receiving stream will not be affected by the 

discharge and this mixing zone and that the defined mixing zone meets the criteria in the rule. The 

size of the zone of initial dilution is the more restrictive of the options, such as, 5 times the local 

water depth and 50 times the discharge length scale in any special direction in the EPA Technical 

Standards Document for sizing the zone of initial dilution in mixing zones. 

Groundwater 

Schedule D of the proposed permit states that no groundwater evaluations will be required during 

this permit cycle. The permit also includes a condition in Schedule A that prohibits any adverse 

impact on groundwater quality. 

Schedule B - Minimum Monitoring and Reporting Requirements 

In 1988, the Department developed a monitoring matrix for commonly monitored parameters. 

Proposed monitoring frequencies for all parameters are based on this matrix and, in some cases, 

may have changed from the current permit. The proposed monitoring frequencies for all 

parameters correspond to those of facilities of similar size and complexity in the state. 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 22 of 24 

The permittee is required to have a laboratory Quality Assurance/Quality Control program. The 

Department recognizes that some tests do not accurately reflect the performance of a treatment 

facility due to quality assurance/quality control problems. These tests should not be considered 

when evaluating the compliance of the facility with the permit limitations. Thus, the Department is 

also proposing to include in the opening paragraph of Schedule B a statement recognizing that some 

test results may be inaccurate, invalid, do not adequately represent the facility's performance and 

should not be used in calculations required by the permit. 

Monitoring for E. coli must be performed in accordance with one of the methods approved by the 

Department. 

Daily monitoring of effluent flow is required in this permit. In addition, calibration of the flow 

meter is required on a regular basis. 

Monitoring for Carbonaceous Biochemical Oxygen Demand (CBOD5) has been substituted for 

BOD5 monitoring. Whenever one or more permit limitations are based on CBOD5, Department 

policy requires monitoring for ammonia concentration in the same sample. Ammonia and total 

residual chlorine sampling is also required to verify permit limits are met. 

Temperature monitoring of the effluent is required. Monitoring may be waived for certain months 

after two full years of monitoring are completed, provided the following condition is met: No 

single daily effluent temperature in that month for the past two years has exceeded the applicable 

stream temperature criteria. 

Monitoring for temperature is only required during the summer periods. 

Because this facility has a pretreatment program, the proposed permit includes a requirement to 

conduct quarterly whole effluent toxicity (WET) or bioassay tests using three species. Bioassay 

tests are to be conducted in accordance with EPA test methods and procedural requirements as 

defined in Schedule D. 

The Department recognizes that the bioassay tests are quite expensive to conduct. If the results 

of the first year's bioassay tests show that the effluent samples are not toxic at the dilutions 

determined to occur at the Zone of Immediate Dilution and the Mixing Zone, no further bioassay 

testing will be required during this permit cycle. Additional bioassay testing is required prior to 

the application for renewal. 

Priority pollutant tests are required prior to the renewal of the permit. The effluent metals 

sampling under Schedule B can be used to satisfy the priority pollutant effluent metal analysis 

provided the time frames for the sampling requirements are met. Metal sample results will be 

reported with method detection limits. Ambient river samples are required for mercury and 

silver. 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Pag-*t>e 23 of 24 w 

Volatile solids reduction in the biosolids is the process used to demonstrate compliance with 

vector attraction reduction requirements. Monitoring of volatile solids reduction is proposed in 

the renewal permit. 

Monitoring of indicator organisms (i.e. Fecal coliform per gram total solids (dry weight basis)) 

will be used to demonstrate compliance with pathogen reduction requirements. Monitoring the 

duration and temperature of biosolids digestion is proposed in the renewal permit. 

Discharge monitoring reports must be submitted to the Department monthly by the 15th day of the 

following month. The monitoring reports need to identify the principal operators designated by the 

Permittee to supervise the treatment and collection systems. The reports must also include records 

concerning application of biosolids and all applicable equipment breakdowns and bypassing. 

Schedule B of the permit includes the requirement for the submittal of annual reports. The 

conditions are standard language requirements concerning: 

Annual report on inflow and infiltration removal 

Annual report on land application of biosolids 

Schedule C - Compliance Conditions 

The proposed permit includes three compliance conditions with a compliance deadline. The 

requirement includes: 

The permittee is required to identify any pump stations or other points that may overflow no later 

than 90 days after the permit is issued. The overflow points that are identified will be included as 

emergency overflows on page one of the permit during the next permit renewal. 

The permittee is required to submit a plan with time lines for evaluating compliance and if 

necessary making modifications to achieve summer ammonia limits. 

A condition to document that Schedule B monitoring for cyanide and phenol may be changed upon 

written notice from the Department. 

The final condition requires the permittee to meet the compliance dates established in this schedule 

or notify the Department within 14 days following any lapsed compliance date. 

Schedule D - Special Conditions 

The proposed permit includes 8 special conditions. The requirements include: 
Clackamas County Service District No. 1 Kellogg Creek Evaluation Report 

Page 24 of 24 

Conditions requiring the permittee to manage the land application of biosolids in accordance 

with the approved biosolids management plan, land application plan and site authorization 

letters. 

A condition specifying the necessary procedures for conducting whole effluent toxicity testing. 

A condition requiring a priority pollutant scan with the application for permit renewal. 

Condition requiring the permittee to have the facilities supervised by personnel certified by the 

Department in the operation of treatment and/or collection systems. 

A condition requiring the development and implementation of a contingency plan for the 

prevention and handling of spills and unplanned discharges. 

A condition requiring the permitee to notify the Department of a malfunction, which would 

require the reporting under the General Conditions of the permit. 

A condition that prohibits any adverse impact on groundwater quality. 

Schedule E - Pretreatment Program 

The proposed permit includes a Schedule E condition that requires implementation of the 

industrial pretreatment program. 

General Conditions (Schedule F) 

The General Conditions applicable to all holders of the NPDES permits are listed. These are 

divided into the following sections: Standard Conditions; Operation and Maintenance of 

Pollution Controls; Monitoring and Records; Reporting Requirements and Definitions. The 

General Conditions have been revised. The most current revision is included in the permit.