FACT SHEET FOR NPDES PERMIT WA-000076-1 

TESORO REFINING and MARKETING 

SUMMARY 

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TABLE OF CONTENTS

INTRODUCTION ...........................................................................................................................1 

BACKGROUND INFORMATION ................................................................................................2 

PERMIT STATUS...............................................................................................................3 

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

WASTEWATER CHARACTERIZATION ........................................................................4 

PROPOSED PERMIT LIMITATIONS...........................................................................................6 

DESIGN CRITERIA ...........................................................................................................6 

TECHNOLOGY-BASED EFFLUENT LIMITATIONS....................................................7 

Process Wastewater .................................................................................................7 

Ballast and Stormwater Allocations.......................................................................11 

OUTFALL 002/003/004 - STORMWATER/EMERGENCY OVERFLOW 

EFFLUENT LIMITATIONS AND CONDITIONS..............................................12 

POLLUTION PREVENTION PLANNING......................................................................13 

Pollution Prevention to Date..................................................................................13 

New Requirements.................................................................................................13 

SURFACE WATER QUALITY-BASED EFFLUENT LIMITATIONS .........................14 

Numerical Criteria for the Protection of Aquatic Life...........................................14 

Numerical Criteria for the Protection of Human Health........................................14 

Narrative Criteria ...................................................................................................15 

Antidegradation......................................................................................................15 

Critical Conditions.................................................................................................15 

Mixing Zones.........................................................................................................15 

Description of the Receiving Water.......................................................................15 

Surface Water Quality Criteria ..............................................................................16 

Consideration of Surface Water Quality-Based Limits for Numeric 

Criteria ...................................................................................................................16 

Human Health ........................................................................................................21 

Sediment Quality ...................................................................................................23 

GROUND WATER QUALITY LIMITATIONS..............................................................23 

MONITORING requirements........................................................................................................24 

EFFLUENT LIMITS BELOW QUANTITATION...........................................................24 

EFFLUENT LIMITS BELOW DETECTION...................................................................24 

LAB ACCREDITATION ..................................................................................................24 

OTHER PERMIT CONDITIONS .................................................................................................25 

REPORTING AND RECORDKEEPING .........................................................................25 

NON-ROUTINE AND UNANTICIPATED DISCHARGES...........................................25 

OUTFALL EVALUATION ..............................................................................................25 

TREATMENT SYSTEM OPERATING PLAN (TSOP)..................................................25 

GENERAL CONDITIONS ...............................................................................................26 

PERMIT ISSUANCE PROCEDURES .........................................................................................26 

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PERMIT MODIFICATIONS ............................................................................................26 

RECOMMENDATION FOR PERMIT ISSUANCE ........................................................26 

REFERENCES FOR TEXT AND APPENDICES........................................................................26 

APPENDIX A--PUBLIC INVOLVEMENT INFORMATION....................................................28 

APPENDIX B--GLOSSARY ........................................................................................................29 

APPENDIX C--TECHNICAL CALCULATIONS .......................................................................33 

APPENDIX D--RESPONSE TO COMMENTS ...........................................................................34 

APPENDIX F--SIZE AND PROCESS FACTOR CALCULATIONS...............................35 

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INTRODUCTION 

The Federal Clean Water Act (FCWA, 1972, and later modifications, 1977, 1981, and 1987) 

established water quality goals for the navigable (surface) waters of the United States. One of 

the mechanisms for achieving the goals of the Clean Water Act is the National Pollutant 

Discharge Elimination System of permits (NPDES permits), which is administered by the 

Environmental Protection Agency (EPA). The EPA has authorized the State of Washington to 

administer the NPDES permit program. Chapter 90.48 RCW defines the Department of 

Ecology's authority and obligations in administering the wastewater discharge permit program. 

The regulations adopted by the State include procedures for issuing permits (Chapter 173-220 

WAC), water quality criteria for surface and ground waters (Chapters 173-201A and 200 WAC), 

and sediment management standards (Chapter 173-204 WAC). These regulations require that a 

permit be issued before discharge of wastewater to waters of the state is allowed. The 

regulations also establish the basis for effluent limitations and other requirements which are to be 

included in the permit. One of the requirements (WAC 173-220-060) for issuing a permit under 

the NPDES permit program is the preparation of a draft permit and an accompanying fact sheet. 

Public notice of the availability of the draft permit is required at least thirty days before the 

permit is issued (WAC 173-220-050). The fact sheet and draft permit are available for review 

(see Appendix A--Public Involvement of the fact sheet for more detail on the Public Notice 

procedures). 

The fact sheet and draft permit have been reviewed by the Permittee. Errors and omissions 

identified in this review have been corrected before going to public notice. After the public 

comment period has closed, the Department will summarize the substantive comments and the 

response to each comment. The summary and response to comments will become part of the file 

on the permit and parties submitting comments will receive a copy of the Department's response. 

The fact sheet will not be revised. Comments and the resultant changes to the permit will be 

summarized in Appendix D--Response to Comments. 

GENERAL INFORMATION 

Applicant: Tesoro Refining and Marketing 

Company 

Outfall 001: Latitude: 48° 30' 30"N. 

Longitude: 122° 34' 00" W. 

Outfall 002: Latitude: 48° 29' 30" N. 

Longitude: 122° 34' 00" W. 

Outfall 003:, Latitude: 48°30' 00" N 

Longitude: 122°33' 41" W 

Outfall 004: Latitude: 48°29' 25" N 

Longitude: 122°34' 30" W 

Facility Name 

and Address: 

Tesoro Refining and Marketing 

Company 

West March Point Road 

PO Box 700 

Anacortes, Washington 

 98221 

Water Body ID 

Number: 

WA - 03 - 0020 

Type of 

Facility: 

Petroleum Refinery Discharge 

Location: 

Fidalgo Bay 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

BACKGROUND INFORMATION 

The refinery is located on the northwestern coast of Washington on March Point, which extends 

into Fidalgo Bay to the west and Padilla Bay to the east. The facility is located in Skagit County, 

approximately two miles east/southeast of the town of Anacortes, Washington. 

Industrial Process - The refinery was originally constructed in 1955. In 1965, the refinery 

processed 68,000 barrels (bbl) of crude oil per day. The facility currently processes 105,000 to 

115,000 bbl/stream day of crude oil. The main source of crude oil during the last five years has 

been Alaskan Northern Slope Crude via tankers and Canadian Crude via pipeline. Canadian 

crude has been the source for the past several years. The refinery separates crude oil into its 

various component parts then further processes and blends them into a variety of petroleum 

products. Those products include gasoline, turbine and jet fuel, diesel oil, liquid petroleum gas, 

and residual fuel oil. The refinery directly employs about 330 people, and estimates indirect 

employment at 280 jobs. 

Wastewater System – Sanitary wastewater (sewage) is collected in a septic tank where solids 

are separated from liquids. Effluent from the septic tank discharges into a neutralization pit. 

Chemical wastewater (spent process acid – pH range 2-4) is added to the pit once or twice a day 

in a batch process. Fecal coliform bacteria and other microorganisms in the septic tank effluent 

are killed in the neutralization pit by the low pH. The neutralization pit discharges to the API 

separator (head end of the industrial wastewater treatment system) where the low pH discharge 

mixes with process wastewater (pH range 10 – 12). Mixing of these two wastewater streams is 

controlled to maintain a pH range of 5.5 – 9.5. 

Tesoro’s industrial wastewater receives primary and secondary treatment in a system consisting 

of parallel API oil/water separators, primary clarifiers, activated sludge units, secondary 

clarifiers, and two final holding ponds. The total discharge volume generally ranges from 2.0 to 

6.0 million gallons per day. The highest daily discharge in the data reviewed was 12.2 million 

gallons per day recorded in January of 1991. The discharge is generally pumped into Fidalgo 

Bay between 10:00 hours and 16:00 hours Other potential discharge points, Outfall 002, Outfall 

003 and Outfall 004, occasionally discharge during high rainfall events. It is described later in 

the fact sheet in the stormwater/emergency overflow section. 

Discharge - All of Tesoro’s process water, sanitary wastewater, stormwater, and ballast water 

discharges via a 30-inch multi-port submerged diffuser at Outfall 001. The refinery's wastewater 

outfall is supported on the Tesoro shipping pier and extends approximately 3400 feet from the 

shore, in a north/northwesterly direction, into Fidalgo Bay. Tesoro uses Outfall (002) only 

during extreme storm events. 

 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

PERMIT STATUS 

Ecology issued the existing permit for this facility on March 23 1998. The limitations were 

based on three feedstock rates or tiers. The previous permit placed effluent limitations on the 

following parameters tabulated below. 

Effluent Limitations for the Previous Permit 

Parameter Units 

Tier 1 – 100,000 

bbls/day 

Tier 2 – 110,000 

bbls/day 

Tier 3 – 120,000 

bbls/day 

Average 

Monthly a

Maximum 

Daily b

Average 

Monthly a

Maximum 

Daily b

Average 

Monthly a

Maximum 

Daily b

Biochemical 

Oxygen Demand 

(5-day) 

lbs/day 650 1180 690 1260 730 1340 

Chemical Oxygen 

Demand 

lbs/day 4520 8750 4800 9300 5080 9860 

Total Suspended 

Solids 

lbs/day 520 820 560 870 590 930 

Oil and Grease lbs/day 190 360 200 380 220 400 

Oil and Grease mg/l The concentration of oil and grease in the discharge shall at no time exceed 15 

mg/l and shall not exceed 10 mg/l more than three days per month

Phenolic 

Compounds

lbs/day 4.3 8.8 4.5 9.3 4.8 9.9 

Ammonia as N lbs/day 400 890 440 970 480 1060 

Sulfide lbs/day 3.5 7.7 3.7 8.2 3.9 8.7 

Total Chromium lbs/day 6.7 17.3 7.4 18.5 8.1 19.6 

Hexavalent 

Chromium

lbs/day 0.5 1.2 0.6 1.3 0.6 1.4 

Fecal Coliforms Organis

ms/

200/100 mls average monthly limit, 400/100 mls maximum daily 

pH pH shall be maintained within the range of 6.0 to 9.0. Excursions between 5.0 and 6.0, 

or 9.0 and 10.0 shall not be considered violations provided no single excursion exceeds 60 

minutes in length and total excursions do not exceed 7 hours and 30 minutes per month. 

Any excursions below 5.0 and above 10.0 are violations. The instantaneous maximum and 

minimum pH shall be reported monthly. In the event of a failure of continuous monitoring 

equipment hourly grab samples shall meet the frequency requirements. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Technology Based Limits 0.5 mg/l monthly average; 1.0 mg/l daily maximum 

Water Quality Based Limits 0.1 mg/l monthly average; 0.26 mg/l daily maximum 

Total Residual 

Chlorine 

Water quality based limits will be effective on November 1, 1999. Total residual chlorine 

monitoring is required to be monitored on a daily basis during those times when the effluent 

is being actively chlorinated. Monitoring will also be required for two additional days 

following cessation of chlorination. 

a

 The average monthly effluent limitation is defined as the highest allowable average of daily 

discharges over a calendar month, calculated as the sum of all daily discharges measured during 

a calendar month divided by the number of daily discharges measured during that month. 

Additional allocation may be permitted for stormwater runoff and ballast water according to 

Permit Condition S1.C. 

b

 The maximum daily effluent limitation is defined as the highest allowable daily discharge. The 

daily discharge means the discharge of a pollutant measured during a calendar day. For 

pollutants with limitations expressed in units of mass, the daily discharge is calculated as the 

total mass of the pollutant discharged over the day. For other units of measurement, the daily 

discharge is the average measurement of the pollutant over the day. Additional allocation may 

be permitted for stormwater runoff and ballast water according to Permit Condition S1.C. 

Tesoro submitted an application for permit renewal to the Department in October 2002. 

Additional information was submitted to Ecology in 2003 and 2004 and was accepted by the 

Department shortly thereafter. 

SUMMARY OF COMPLIANCE WITH THE PREVIOUS PERMIT 

Ecology conducted the most recent compliance inspection, including sampling, on April 26-27 

2005. 

Tesoro reported chlorine residual limits exceedances on one day in each month of August and 

September 1998. The maximum daily TSS limit was exceeded on September 18, 2000. High 

BOD concentrations (69.3 mg/l) for 10 November 2004 resulted in total mass discharge for the 

day to exceed the permitted level. 

The permit required submittal of various reports. These included Human Health Study, Dioxin 

Study, Treatment System Efficiency Study, Water Quality Pollution Prevention Plan, Sediment 

Monitoring, Acute and Chronic Toxicity Monitoring. These reports were submitted to the 

Department as required. Ecology used the data from these reports to prepare this permit. 

WASTEWATER CHARACTERIZATION 

The proposed wastewater discharge is characterized for the following regulated parameters: 

Wastewater Characterization 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

The following data comes from the current permit renewal application (revision 2) submitted 

October 2004, and from report submittals required by the permit. 

MAXIMUM DAILY VALUES OF POLLUTANTS 

PARAMETER CONCENTRATION MASS 

BOD 19.7 mg/l 554 lb/day 

COD 124 mg/l 3440 lb/day 

TSS 44 mg/l 1197 lb/day 

Ammonia 5 mg/l 129 lb/day 

Flow 8 MGD 

Temperature (winter) 23°C 

Temperature (summer) 30 °C 

pH 6.2 minimum/8.6 maximum 

Fecal coliforms 500 organisms/100ml 

Nitrate .2 mg/l 4.7 lb/day 

Nitrogen (Total Organic) <1.0 mg/l <24 lb/day 

Oil and Grease 11 mg/l 218 lb/day 

Phosphorous .1 mg/l 2.4 lb/day 

Sulfate 170 mg/l 4000 lb/day 

Sulfide .03 mg/l 0.87 lb/day 

Surfactants .20 mg/l 4.7 lb/day 

Antimony 0.102 mg/l 2.5 lb/day 

Chromium (Total) .002 mg/l 0.05 lb/day 

Copper .006 mg/l 0.15 lb/day 

Lead .002 mg/l .05 lb/day 

Mercury 0.007 mg/l 0.18 lb/day 

Selenium .022 mg/l 0.55 lbs/day 

Silver <.0005 mg/l <0.01 lbs/day 

Zinc .053 mg/l 1.31 lb/day 

Cyanide .039 mg/l 1 lb/day 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

MAXIMUM DAILY VALUES OF POLLUTANTS 

Phenols .040 mg/l 1.376 lb/day 

Chloroform .0064 mg/l 0.15 lb/day 

PROPOSED PERMIT LIMITATIONS 

Effluent limitations set forth in a NPDES permit must be either technology- or water qualitybased as required by state and federal regulations. Technology-based limitations are based upon 

the treatment methods available to treat specific pollutants. Technology-based limitations are set 

by regulation or developed on a case-by-case basis (40 CFR 125.3, and Chapter 173-220 WAC). 

Water quality-based limitations are based upon compliance with the Surface Water Quality 

Standards (Chapter 173-201A WAC), Ground Water Standards (Chapter 173-200 WAC), 

Sediment Quality Standards (Chapter 173-204 WAC) or the National Toxics Rule (Federal 

Register, Volume 57, No. 246, Tuesday, December 22, 1992). The more stringent of these two 

limits must be chosen for each of the parameters of concern. Each of these types of limits is 

described in more detail below. 

The limits in this permit are based in part on information received in the application. The 

effluent constituents in the application were evaluated on a technology- and water quality-basis. 

The limits necessary to meet the rules and regulations of the State of Washington were 

determined and included in this permit. Ecology does not develop effluent limits for all 

pollutants that may be reported on the application as present in the effluent. Some pollutants are 

not treatable at the concentrations reported, are not controllable at the source, are not listed in 

regulation, and do not have a reasonable potential to cause a water quality violation. Effluent 

limits are not always developed for pollutants that may be in the discharge but not reported as 

present in the application. In those circumstances the permit does not authorize discharge of the 

non-reported pollutants. Effluent discharge conditions may change from the conditions reported 

in the permit application. If significant changes occur in any constituent, as described in 40 CFR 

122.42(a), the Permittee is required to notify the Department of Ecology. The Permittee may be 

in violation of the permit until the permit is modified to reflect additional discharge of pollutants. 

DESIGN CRITERIA 

In accordance with WAC 173-220-150 (1)(g), flows or waste loadings shall not exceed approved 

design criteria. 

The design criteria for this treatment facility are obtained from Tesoro correspondence dated 

January 4, 2005 and July 25, 2005 and the April 2000 engineering report prepared by Tesoro 

Northwest Co. and are as follows: 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Design Standards. 

Flows or waste loadings of the following design criteria for the permitted treatment 

facility shall not be exceeded: 

Process Wastewater treatment plant capacity 

(excludes storm water) 

Average monthly flow for the maximum month1 4.3 MGD 

Average monthly COD for the maximum month2 1700 mg/l 

 1 as measured at influent to treatment 

 2 as measured at the primary clarifier 

TECHNOLOGY-BASED EFFLUENT LIMITATIONS 

PROCESS WASTEWATER

The Tesoro refinery effluent limitations in the proposed permit are based on Guidelines 

developed by the Environmental Protection Agency (EPA): Best Conventional Pollutant Control 

Technology (BCT), Best Available Technology Economically Achievable (BAT), Best 

Practicable Control Technology Currently Available (BPT), and New Source Performance 

Standards (NSPS). On April 17, 1984 the EPA and the Natural Resources Defense Council 

finalized a settlement agreement resolving litigation about the EPA guidelines for calculating 

specific limitations for the petroleum refining industry. Amended Federal Effluent Guidelines 

were published on August 12, 1985 (40 CFR Part 419) by the Environmental Protection Agency 

(EPA) for the cracking subcategory of petroleum refining. The amended guidelines established 

BCT and BAT as equal to BPT for all parameters except phenols and chromium, which are 

regulated by whichever federal guideline is most stringent. In addition, Ecology requires the 

Permittee to use all known, available, and reasonable methods to control toxicants (AKART) in 

the applicant's wastewater as required under Washington State regulations. Because Ecology has 

applied new source performance standards (NSPS) on the basis of our AKART requirements, the 

NPDES permit limitations applied have been more stringent than those in other states. We have 

applied these more stringent NSPS limits to all crude throughput increases since 1984. 

On December 31st, 2003 EPA published their intention to review the petroleum refining industry 

to decide the necessity for revising their effluent guidelines. They evaluated pollution prevention 

opportunities, emerging treatment technologies, revising the effluent guidelines, and expanding 

the list of regulated pollutants. EPA reviewed information and comments on several issues 

including: control technologies for polycyclic aromatic hydrocarbons (PAHs), dioxin sources 

and reduction/control technologies, sources of toxic metals, process modifications to reduce 

metals, and what toxics are being released and remain unreported. On September 2, 2004 

(Federal Register Volume 69 No. 170) EPA published their decision regarding revising the 

refinery effluent guidelines. EPA concluded that there is little evidence that PAHs are present in 

refinery wastewater discharges in concentrations above the detection limit. They also concluded 

that the concentration of metals being discharged by refineries is at or very near treatable levels, 

leaving little to no opportunity to reduce metals discharges through conventional end-of-pipe 

treatment. EPA reviewed the available dioxin information collected by refineries nationwide 

much of which was collected at the Washington state refineries. The overall data indicated that 

dioxins are only occasionally discharged in relatively low concentrations in treated refinery 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

effluent. In their opinion this data did not warrant the development of national categorical 

limitations on dioxin in refinery wastewater discharges. EPA did note that on a case-by-case, 

best professional judgment basis permit writers may decide to include effluent limitations for 

dioxin. They also encouraged permit writers and refineries to consider pollution prevention 

opportunities. As a result of their evaluation, EPA has concluded that there is not a significant 

need to revise the federal effluent guidelines at this time. 

Where federal effluent guidelines are over 5 years old, Ecology’s process is to review the EPA 

development document and compare the production processes, the pollutants generated, the 

treatment efficiencies and unit process design. This comparison allows Ecology to verify 

whether the effluent guidelines meet the intent of RCW 90.48.520 (AKART). 

The permit issued in 1998 required Tesoro to conduct a treatment efficiency study to evaluate 

wastewater treatment system capacities and determine in an engineering report whether the 

treatment system was adequate to treat current and future wastewater flows. The 1998 permit 

also required a study to determine the levels of dioxin in the refinery discharge, in the API 

sludge, and in catalytic regeneration wastewater. To prepare this permit, Ecology reviewed the 

engineering report and study information provided by Tesoro along with the data and 

information that formed the basis for the existing federal effluent guidelines. Through this 

analysis, Ecology determined that the Tesoro refinery continues to apply AKART to their 

wastewater for all pollutants with the exception of dioxin. Therefore federal effluent guidelines 

were used to develop permit limits for conventional parameters. Tesoro is required by the 

proposed NPDES to prepare an AKART study to prevent dioxin and furan congeners from being 

discharged in the final effluent. The proposed permit includes a requirement that treatment 

system capacity be reevaluated at the end of the permit cycle to ensure that the facility will 

continue to provide all known, available, and reasonable methods to control toxicants (AKART) 

in their wastewater. 

The feedstock rate stabilized over the last permit term. The rate changes in refinery processes 

are shown below along with the applicable size and process factors selected from the EPA 

guidelines. Ecology’s size and process factor determination is documented in Appendix F. We 

multiplied these factors by the actual feed stock rate to obtain an adjusted feed stock rate that we 

used in determining effluent limitations (except for determining BAT limitations for phenols and 

chromium). 

The following table lists the refinery processes, flows, process and size factors as calculated in

Appendix F. 

FEEDSTOCK [BARRELS PER DAY] 

1990 

Permit 

1998 Permit Proposed 

Permit 

Tier 1 Tier 2 Tier 3 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

1990 

Permit 

Proposed 

Permit 

1998 Permit 

Tier 1 Tier 2 Tier 3 

Actual Feed Stock, bbls/day 85400* 100000 110000 120000 113600 

Desalting, bbls /day 85400 106500 117100 127800 119600 

Atmospheric Distillation, 

bbls/day 

85400 100000 110000 120000 113600 

Vacuum Distillation, bbls/day 34000 30900 34000 37100 42800 

Fluid Catalytic Cracking, 

bbls/day 

35900 40300 44300 48300 43300 

Propane Deasphalting, bbls/day 15100 12500 13800 15000 14000 

Hydrotreating, bbls/day 19000 63500 69900 76200 61000 

H2SO4 Alkylation, bbls/day 9000 11300 12400 13600 11300 

Catalytic Reforming, bbls/day 15000 21100 23200 25300 23800 

* All feedstock rates specified in this table represent actual crude throughput less slop oil 

and other recycled material. 

Increases in the feedstock rate are subject to limitations determined by Ecology to be the 

treatment level obtained from using all known available and reasonable treatment methods. 

Those increases are therefore subject to New Source Performance Standards. These limitations 

were calculated by multiplying the increase in Tesoro’s adjusted feed stock rate by New Source 

Performance Standards (NSPS). Ecology then added the resulting NSPS increment BAT and 

BPT limitations, based upon the adjusted baseline feedstock rate (BCT limitations are equivalent 

to BPT limitations). 

The EPA/NRDC settlement agreement provided separate factors for calculating phenols, total 

chromium, and hexavalent chromium for the BAT limitation. These calculations required rate 

data for additional processes including: hydrotreating, catalytic reforming, and alkylation. This 

information is included in the above table. 

Federal effluent guidelines for total and hexavalent chromium were determined when chromium 

was commonly used in cooling water systems and discharged at much higher levels in the 

effluent. Since the EPA banned chromium from use in cooling systems, in the early 1990’s, the 

only remaining source of chromium is that which is present in the crude oil. But because federal 

effluent guidelines still include a limits for chromium, we have included an effluent limit in the 

proposed permit. Based on the reduction of chromium in the effluent, to levels bordering on 

non-detectable, the guideline derived effluent limitation is artificially high. All detectable 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

samples of chromium in the Tesoro effluent have been within the range of 5 – 10 μg/l which is 

less than 1/10th the marine chronic water quality standard of 50 μg/l of Hex Cr (acute standard = 

1100 μg/l). Approximately half of the sample results obtained during the past 5 years were nondetectable for chromium. Based on this information, Ecology decided that an alternative 

hexavalent chromium concentration limit of 50 μg/l (the chronic marine standard) is 

achievable, reasonable, and protective. The standard is more stringent than the federal effluent 

guidelines and it adequately replaces both the total chromium limit and hexavalent chromium 

limit in the permit.

In the event that chromium levels change in the crude oil refined at Tesoro and result in 

concentration increases, Ecology will modify the permit to increase the limit as necessary to 

allow continued facility compliance. Any revised limit will be evaluated to ensure that the 

effluent continues to meet water quality standards within the authorized mixing zone and to 

ensure it does not exceed limits that allowed under federal effluent guidelines. In the event that 

federal effluent guidelines are promulgated without chromium limitations, the limit will be 

dropped from the permit unless the situation changes and Ecology determines a water quality 

limit is necessary. Tesoro will continue semi-annual hexavalent chromium monitoring. 

The permit limit calculations are tabulated in Appendix F. The actual permit limit is the most 

stringent of the BAT and BPT determinations. BPT limitations are more stringent for phenol and 

BAT limits are more stringent for chromium. The proposed effluent limitations are listed in the 

table below in pounds per day. 

PROPOSED EFFLUENT LIMITS 

Parameter Units 

Limits 

Average 

Monthly 

Maximum Daily 

Biochemical 

Oxygen Demand 

(5-day) 

lbs/day 710 1280 

Chemical Oxygen 

Demand 

lbs/day 4900 9500 

Total Suspended 

Solids 

lbs/day 560 890 

Oil and Grease lbs/day 210 380 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Parameter Units 

Limits 

Average 

Monthly 

Maximum Daily 

Oil and Grease mg/l The concentration of oil and grease in 

the discharge shall at no time exceed 

15 mg/l, and shall not exceed 10 mg/l 

more than three days per month. 

Phenolic 

Compounds 

lbs/day 4.6 9.5 

Ammonia as N lbs/day 450 1010 

Sulfide lbs/day 3.8 8.4 

Hexavalent 

Chromium 

mg/l -- 0.050 

Fecal Coliforms organisms/ 

100mls 

200/100 mls average monthly limit, 

400/100 mls maximum daily 

BALLAST AND STORMWATER ALLOCATIONS

Tesoro discharges contaminated stormwater from the process area to the oily water sewer which 

conveys it to the wastewater treatment facility. Stormwater runoff generated from the 

wastewater treatment facility ordinarily is discharged to the stormwater flume but it can be 

diverted and treated if necessary. Tesoro collects stormwater from the tank farms and the rest of 

the industrial site and discharges it into stormwater flume adjacent to the west retention pond on 

the treatment plant site. Some settling occurs in this pond and oil and grease can be skimmed 

from the surface as necessary. Tesoro then discharges stormwater into the west retention pond 

where it is commingled with the treated process wastewater prior to final discharge. Tesoro 

occasionally discharges petroleum contaminated ballast water into the process wastewater 

treatment system. 

Flow measurement devices are not available to directly measure stormwater volume. Direct 

measurement would be difficult since a portion of the stormwater is diverted into the oily water 

sewer at many collection points, and a portion of the stormwater is collected in the stormwater 

system. The stormwater flow is calculated by subtracting an estimated dry weather flow from 

the total flow discharged each day. The dry weather flow estimate is tied to the feedstock rate. 

Dry weather flow for current conditions was estimated by evaluating total flow during dry 

weather time periods at the facility. This estimate was determined to be 2.7 MGD 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

The ballast and stormwater allocations in the permit are based on federal effluent guidelines 

published in 40 CFR 419.12(c) and 419.22(e). A stormwater allocation for chromium as 

provided for in the federal effluent guidelines has not been included in this proposed permit. The 

stormwater allocations in the federal effluent guidelines apply to runoff from areas associated 

with industrial activity, not to outlying areas such as parking lots and surrounding acreage. 

Employee parking lots do, however, discharge into the stormwater flume. During the summer 

months of June through October the permittee may only claim the stormwater allocation after 

demonstrating that measurable rainfall fell at the refinery site during the previous 10 calendar 

days. The allocations are tabulated below. 

Parameters Stormwater Allocation 

lbs/million gallons 

Ballast Water Allocation 

lbs/million gallons 

Monthly 

Average 

Daily 

Maximum 

Monthly 

Average 

Daily 

Maximum 

Biochemical Oxygen 

Demand (5-day) 

220 400 210 400 

Chemical Oxygen 

Demand 

1500 3000 2000 3900 

Total Suspended Solids 180 280 170 260 

Oil and Grease 67 130 67 126 

Phenolic Compounds 1.4 2.9 

OUTFALL 002/003/004 – STORMWATER/EMERGENCY OVERFLOW EFFLUENT

LIMITATIONS AND CONDITIONS 

During extremely heavy rainfall events, Tesoro may discharge water from a retention pond on 

the west side of the refinery to prevent damage to refinery equipment and treatment facilities. 

The discharge points are designated Outfall 002 and Outfall 004. This wastewater would be 

almost entirely stormwater, but may contain small amounts of oily wastewater from drainage of 

the diesel loading rack pad and maintenance of the line supplying the loading rack. This pond 

receives no process wastewater from the refinery's process units. Under normal circumstances, 

Tesoro pumps this stormwater into the refinery's sewer system for processing at the wastewater 

treatment plant. Stormwater was discharged from this outfall in November 1990, November 

1995 and December 1996. Since those incidents, Tesoro has increased the volume of this 

retention pond which has decreased the chances of an overflow or emergency discharge. No 

discharges have occurred at this outfall since December 1996. 

During extremely heavy rainfall events, Tesoro may discharge water through the emergency 

overflow, Outfall 003, located between the East and West Polishing Ponds. The discharge would 

consist of high quality wastewater, treated to secondary treatment levels and would be 

discharged due to a heavy rain exceeding the storage capacity of either pond. Tesoro has not 

discharged from Outfall 003 since at least 1990. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

In the event of a discharge from Outfall 002, 003, or 004, the NPDES permit requires Tesoro to 

characterize the quality of the effluent discharged. Parameters to be monitored include pH, 

BOD, TSS, COD, oil and grease, lead, zinc, volatile organics, base neutral acids (BNA'S), and 

phenols. These parameters were chosen based on knowledge of the characteristics of the 

materials handled at the truck rack, and on the constituents detected in the stormwater flume 

discharge, when contaminated with oily materials and are additional consistent with the types of 

analyses required for the final discharge to bay. 

POLLUTION PREVENTION PLANNING 

POLLUTION PREVENTION TO DATE

Tesoro submitted a Pollution Prevention Plan as required by the current NPDES permit. 

Projects that resulted from the plan included: 

Pollution prevention activities since at least 1991 as a result of the requirements of Chapter 173-

307 WAC which is aimed at reducing toxic and hazardous waste. Five year Hazardous Waste 

Pollution Prevention Plans with annual progress reports have been submitted since 1991. Many 

of the pollution prevention projects completed as a result of those requirements have had an 

impact at the wastewater treatment plant. Examples include: substitution of chromium based anti 

fouling agents with phosphate based agents and capital projects and operational changes to 

reduce the amount of hydrocarbons entering the process wastewater stream. Tesoro includes 

pollution prevention elements in its ongoing training for employees at the facility. 

Although many of the pollution prevention strategies identified and implemented under 

Hazardous Waste Planning requirements also reduce pollutant impacts on water quality, the 

Permittee had not been directed to specifically review and evaluate facility processes and 

activities for the source reduction and control of water pollutants until the last NPDES permit 

cycle. The NPDES Pollution Prevention Plan as incorporated in the last permit is intended to be 

an ongoing process to achieve continued improvements. 

NEW REQUIREMENTS

The proposed permit requires Tesoro to update the water-oriented NPDES Pollution Prevention 

plan. Ecology’s goals and objectives for developing and implementing pollution prevention 

plans are to identify, reduce, eliminate, and prevent the generation and release of pollutants to 

influent wastewater streams, stormwater, and/or waters of the state and to prevent violations of 

surface water, ground water, and sediment quality standards. The objective of this update is to 

identify any new sources of pollutants, to reevaluate previously identified pollution prevention 

opportunities and to identify any new opportunities and implement those that are technically and 

economically achievable. 

The NPDES Pollution Prevention plan requirements include the identification and 

implementation of Best Management Practices (BMPs). Pursuant to 90.48 RCW and Sections 

302 and 402 of the Clean Water Act, BMPs may be incorporated as permit conditions. BMPs 

are actions or procedures to prevent or minimize the potential for the release of pollutants or 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

hazardous substances in significant quantities to surface waters. BMPs, though normally 

qualitative, are most effective when used in conjunction with numerical effluent limits in NPDES 

permits. 

The NPDES Pollution Prevention plan also addresses stormwater. Ecology has published 

guidance for the prevention of stormwater runoff contamination, entitled Stormwater Pollution 

Prevention Planning for Industrial Facilities (September 1993). The pollution prevention plan 

may incorporate the appropriate sections of Ecology’s guidance or any other plans previously 

developed by the refinery, which include procedures for prevention of stormwater runoff 

contamination. These plans, however, will not necessarily be all inclusive of the BMPs 

necessary for preventing stormwater pollution by more conventional pollutants – in particular, 

total suspended solids. They generally do not address “clean” areas of the facility (those areas 

where petroleum products or hazardous materials are not stored or used). These “clean” areas 

may contribute conventional pollutants to the facility’s stormwater. 

The NPDES Pollution Prevention plan includes a review of solid waste handling and disposal 

procedures to prevent solid waste and solid waste leachate from causing pollution of state waters. 

In addition, the plan describes measures already taken to prevent the accidental release of 

pollutants to state waters and to minimize damages if such a spill should occur. 

SURFACE WATER QUALITY-BASED EFFLUENT LIMITATIONS 

In order to protect existing water quality and preserve the designated beneficial uses of 

Washington's surface waters, WAC 173-201A-060 states that waste discharge permits shall be 

conditioned such that the discharge will meet established Surface Water Quality Standards. The 

Washington State Surface Water Quality Standards (Chapter 173-201A WAC) is a state 

regulation designed to protect the beneficial uses of the surface waters of the state. Surface 

water quality-based effluent limitations may be based on an individual waste load allocation 

(WLA) or on a WLA developed during a basin wide total maximum daily loading study 

(TMDL). 

NUMERICAL CRITERIA FOR THE PROTECTION OF AQUATIC LIFE

"Numerical" water quality criteria are numerical values set forth in the State of Washington's 

Water Quality Standards for Surface Waters (Chapter 173-201A WAC). They specify the levels 

of pollutants allowed in a receiving water while remaining protective of aquatic life. Numerical 

criteria set forth in the Water Quality Standards are used along with chemical and physical data 

for the wastewater and receiving water to derive the effluent limits in the discharge permit. 

When surface water quality-based limits are more stringent or potentially more stringent than 

technology-based limitations, they must be used in a permit. 

NUMERICAL CRITERIA FOR THE PROTECTION OF HUMAN HEALTH 

The U.S. EPA has promulgated 91 numeric water quality criteria for the protection of human 

health that are applicable to Washington State (EPA 1992). These criteria are designed to protect 

humans from cancer and other disease and are primarily applicable to fish and shellfish 

consumption and drinking water from surface waters. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

NARRATIVE CRITERIA

In addition to numerical criteria, "narrative" water quality criteria (WAC 173-201A-030) limit 

toxic, radioactive, or deleterious material concentrations below those which have the potential to 

adversely affect characteristic water uses, cause acute or chronic toxicity to biota, impair 

aesthetic values, or adversely affect human health. Narrative criteria protect the specific 

beneficial uses of all fresh (WAC 173-201A-130) and marine (WAC 173-201A-140) waters in 

the State of Washington. 

ANTIDEGRADATION 

The State of Washington's Antidegradation Policy requires that discharges into a receiving water 

shall not further degrade the existing water quality of the water body. In cases where the natural 

conditions of a receiving water are of lower quality than the criteria assigned, the natural 

conditions shall constitute the water quality criteria. Similarly, when the natural conditions of a 

receiving water are of higher quality than the criteria assigned, the natural conditions shall be 

protected. More information on the State Antidegradation Policy can be obtained by referring to 

WAC 173-201A-070. 

CRITICAL CONDITIONS

Surface water quality-based limits are derived for the waterbody's critical condition, which 

represents the receiving water and waste discharge condition with the highest potential for 

adverse impact on the aquatic biota, human health, and existing or characteristic water body 

uses. 

MIXING ZONES

The Water Quality Standards allow the Department of Ecology to authorize mixing zones around 

a point of discharge in establishing surface water quality-based effluent limits. Both "acute" and 

"chronic" mixing zones may be authorized for pollutants that can have a toxic effect on the 

aquatic environment near the point of discharge. The concentration of pollutants at the boundary 

of these mixing zones may not exceed the numerical criteria for that type of zone. Mixing zones 

can only be authorized for discharges that are receiving all known, available, and reasonable 

methods of prevention, control and treatment (AKART) and in accordance with other mixing 

zone requirements of WAC 173-201A-100. 

The National Toxics Rule (EPA, 1992) allows the chronic mixing zone to be used to meet human 

health criteria. 

DESCRIPTION OF THE RECEIVING WATER

The facility discharges to Fidalgo Bay which is designated as a Class A receiving water in the 

vicinity of the outfall. Characteristic uses include the following: 

fish migration; fish and shellfish rearing, spawning and harvesting; wildlife habitat; primary 

contact recreation; sport fishing; boating and aesthetic enjoyment; commerce and navigation. 

Water quality of this class shall meet or exceed the requirements for all or substantially all uses. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Other nearby point source outfalls includes the Shell Oil Products US - Puget Sound Refining 

Company. The Shell wastewater treatment plant outfall is located in the vicinity of the Tesoro 

outfall at a Latitude of 48N 30' 34' and a Longitude of 122W 34' 37". The outfalls are physically 

located within 3000 feet of each other. 

The closest Department of Ecology long-term core monitoring station is BLL009 in Bellingham 

Bay. This station is influenced by activity in Bellingham and is not suitable for a background 

data station. The next closest long-term core monitoring station is GRG002, located in the 

Georgia Strait. We used the substantial data for this station in our analysis for this permit. The 

closest long-term rotating station is FID001 in Fidalgo Bay. There is very limited data available 

for this monitoring station. A similar embayment with somewhat more extensive data is 

LOP001 in Lopez Sound. The quantity of data for the last two identified stations was 

insufficient to be used in the analysis for this permit. 

SURFACE WATER QUALITY CRITERIA

Applicable criteria are defined in Chapter 173-201A WAC for aquatic biota. In addition, U.S. 

EPA has promulgated human health criteria for toxic pollutants (EPA 1992). Criteria for this 

discharge are summarized below: 

Fecal Coliforms 14 organisms/100 mL maximum geometric mean 

Dissolved Oxygen 6 mg/L minimum 

Temperature 16 degrees Celsius maximum or incremental increases above 

background 

pH 7 to 8.5 standard units 

Turbidity less than 5 NTU above background 

Toxics No toxics in toxic amounts (see Appendix C for numeric criteria 

for toxics of concern for this discharge) 

CONSIDERATION OF SURFACE WATER QUALITY-BASED LIMITS FOR NUMERIC CRITERIA

Pollutant concentrations in the proposed discharge exceed water quality criteria with technologybased controls which the Department has determined to be AKART. A mixing zone is 

authorized in accordance with the geometric configuration, flow restriction, and other restrictions 

for mixing zones in Chapter 173-201A WAC. 

Diffuser Information 

Tesoro's diffuser is 26 feet long with a diameter of 30 inches. It has 3 ports, each 10 inches in 

diameter. The distance between ports is 11 feet. The mean lower low water (MLLW) depth at 

the diffuser is 25 feet. This information and additional information is available in the Dilution 

Ratio Study submitted to Ecology by Shell (now Tesoro) in February of 1991. 

Chronic Mixing Zone 

WAC 173-201A-100(4)(b)(i) specifies: mixing zones shall not extend in any horizontal direction 

from the discharge ports for a distance greater than 200 feet plus the depth of water over the 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

discharge ports as measured during MLLW. Given a MLLW water depth of 25 feet (7.6 meters) 

for Shell Oil's outfall, the horizontal distance therefore is 225 feet (68.6 meters). The mixing 

zone extends vertically from the seabed to the top of the water surface. 

Acute Mixing Zone 

WAC 173-201A-100(8)(b) specifies that in estuarine waters a zone where acute criteria may be 

exceeded shall not extend from the discharge point beyond 10% of the distance established for 

the maximum or chronic zone as measured independently from the discharge ports. The acute 

zone therefore extends 23 feet (7 meters) from the discharge ports. 

The dilution factors of effluent to receiving water that occur within these zones were determined 

at the critical condition in the dilution and dye study entitled “Dilution Ratio Study Shell Oil 

Company Anacortes Refinery” prepared by CH2M Hill in February 1991. Ecology verified the 

information in the report in 1992. Ecology modified the original work in November 1995 to 

reflect current conditions. The model used for near field effects was the EPA funded dilution 

model UDKHDEN. Far field effects were predicted using the Brooks equation as described in 

the (1960) Model of Far-field Dilution of Initially Diluted Sewage Discharges From Marine 

Outfalls (Fischer, et al.) Ecology reevaluated the 1991 dye study and the 1995 modeling in 

2003. The dilution analysis is available in Ecology’s files. 

Ecology has determined the dilution factors to be: 

Acute Chronic 

Aquatic Life 20 91 

Human Health, Carcinogen 93 

Human Health, Non-carcinogen 91 

Pollutants in an effluent may affect the aquatic environment near the point of discharge (near 

field) or at a considerable distance from the point of discharge (far field). Toxic pollutants, for 

example, are near-field pollutants--their adverse effects diminish rapidly with mixing in the 

receiving water. Conversely, a pollutant such as BOD is a far-field pollutant whose adverse 

effect occurs away from the discharge even after dilution has occurred. Thus, the method of 

calculating surface water quality-based effluent limits varies with the point at which the pollutant 

has its maximum effect. 

The derivation of surface water quality-based limits also takes into account the variability of the 

pollutant concentrations in both the effluent and the receiving water. 

BOD5-- Technology-based limitations results in a discharge with a small amount of BOD 

loading relative to the large amount of dilution occurring in the receiving water at critical 

conditions. Technology-based limitations should ensure that dissolved oxygen criteria in the 

receiving water will meet criteria. 

Fecal Coliforms –The permit requires the refinery to comply with domestic technology based 

effluent limits for fecal coliforms in their effluent, since domestic wastewater is treated in their 

wastewater facility. Domestic wastewater standards are established in Chapter 173-221 WAC, 

entitled "Discharge Standards and Effluent Limitations For Domestic Wastewater Facilities". 

Domestic effluent limits for fecal coliforms are 200 organisms/100 ml on a monthly average 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

basis with a maximum of 400 organisms/100 ml in any one sample. Tesoro must meet the water 

quality standard for marine Class A receiving waters (14 organisms/100 ml) at the edge of the 

chronic zone. With a dilution of 91:1 at the edge of the chronic zone the predicted fecal coliform 

concentration at the boundary of the chronic mixing zone is 4.3 organisms/100 ml if the 

maximum technical concentration standard of 400 is met and there are no fecal coliforms present 

in the background receiving water. Ecology calculated this concentration using a simple mass 

balance equation as follows: 

[0(91) + 400(1)]/92 = 4.3. 

The technological standard is therefore protective of the water quality standard. 

Temperature—Ecology modeled the impact of the discharge on the temperature of the receiving 

water by simple mixing analysis at critical condition. The receiving water temperature critical 

condition was determined using the 90th percentile value of the temperatures recorded at the 

ambient monitoring station GRG002. The receiving water temperature at the critical condition is 

13.3o C and the maximum summertime effluent temperature is 30o C. With a dilution of 91:1 at 

the edge of the chronic zone the predicted resultant temperature at the boundary of the chronic 

mixing zone is 13.5o C. We used a simple mass balance equation to calculate a predicted 

temperature as follows: [13.3(91) + 30(1)]/92 = 13.5. This temperature meets the water quality 

standards. 

The highest recorded temperature at GRG002 (from 1988 to 2002) was 19.54°C (Sept. ’98). The 

incremental temperature increase allowance ( t = 12/(19.54-2) ) is equal to 0.68°C. With a 

receiving water temperature of 19.54°C and an effluent temperature of 30°C the predicted 

temperature at the edge of the dilution zone is equal to 19.65°C. The temperature increase of 

0.11°C is less than the incremental temperature allowance and the maximum increase of 0.3°C 

allowed by water quality standards. The receiving water temperature at the edge of the dilution 

zone was calculated as follows: [19.54(91) + 30(1)] /92 = 19.65°C. 

Based on our calculations, Ecology predicts there will be no violation of Water Quality 

Standards for Surface Waters under critical conditions. Therefore, no effluent limitation for 

temperature was placed in the proposed permit. 

pH--Because of the high buffering capacity of marine water, compliance with the technologybased limits of 6 to 9 will assure compliance with the Water Quality Standards for Surface 

Waters. 

Turbidity--The impact of turbidity was evaluated based on the range of turbidity in the effluent 

and turbidity of the receiving water. Due to the large degree of dilution, it was determined that 

the turbidity criteria would not be violated outside the designated mixing zone. 

Toxic Pollutants--Federal regulations (40 CFR 122.44) require NPDES permits to contain 

effluent limits for toxic chemicals in an effluent whenever there is a reasonable potential for 

those chemicals to exceed the surface water quality criteria. This process occurs concurrently 

with the derivation of technology-based effluent limits. Facilities with technology-based effluent 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

limits defined in regulation are not exempted from meeting the Water Quality Standards for 

Surface Waters or from having surface water quality-based effluent limits. 

Tesoro’s discharge contains the following toxics: cyanide, sulfide, copper, zinc, lead, silver, 

chloroform, dichlorobromomethane, antimony, arsenic, mercury, nickel, thallium, nitrate, 

phosphorus, chromium, phenol, selenium, and ammonia. Ecology conducted a reasonable 

potential analysis (See Appendix C) on these parameters to determine whether or not we would 

require effluent limitations in this permit. 

The determination of the reasonable potential for cyanide, sulfide, copper, zinc, lead, silver, 

chloroform, dichlorobromomethane, antimony, arsenic, mercury, nickel, thallium, nitrate, 

phosphorus, chromium, phenol, selenium, and ammonia to exceed the water quality criteria was 

evaluated with procedures given in EPA, 1991 (Appendix C) at the critical condition. The 

parameters used in the critical condition modeling are as follows: acute dilution factor 20, 

chronic dilution factor 91. 

Water quality criteria for metals in Chapter 173-201A WAC are based on the dissolved fraction 

of the metal. 

The Permittee may provide data clearly demonstrating the seasonal partitioning of the dissolved 

metal in the ambient water in relation to an effluent discharge. Metals criteria may be adjusted 

on a site-specific basis when data is available clearly demonstrating the seasonal partitioning in 

the ambient water in relation to an effluent discharge. 

Metals criteria may also be adjusted using the water effects ratio approach established by 

USEPA, as generally guided by the procedures in USEPA Water Quality Standards Handbook, 

December 1983, as supplemented or replaced. 

Valid ambient background data was available for copper, zinc, lead, silver, arsenic, mercury, 

nickel, chromium, selenium. Calculations using all applicable data resulted in a determination 

that there is no reasonable potential for this discharge to cause a violation of water quality 

standards. This determination assumes that the Permittee meets the other effluent limits of this 

permit. 

Ammonia 

Ecology evaluated ammonia’s reasonable potential to exceed water quality standards. 

Determining the site specific acute and chronic criteria for ammonia is more complicated than 

simply obtaining the criteria from the regulations and comparing to the effluent data. Ammonia's 

toxicity depends on that portion which is available in the unionized form. The amount of 

unionized ammonia depends on the pH, dissolved oxygen, and salinity of the receiving water in 

the marine environment. To evaluate ammonia toxicity, we therefore needed receiving water 

information. 

Ecology evaluated Georgia Strait ambient receiving water data (station GRG 002) to determine 

the site specific acute and chronic criteria and to obtain background ammonia data. GRG002, 

located in the Georgia Strait, is a long term core station for which substantial data exists. We 

calculated the acute and chronic ammonia criteria using Hampson's model in a spreadsheet form. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

From those criteria, we chose the 90th percentile value to represent the critical condition as 

recommended by the Ecology Permit Writer's Manual. We used the value for the ambient 

station and the 90th percentile value for background total ammonia concentration in the 

reasonable potential calculation as shown in Appendix C. 

When a large quantity of data is available, Ecology generally uses the 95th percentile value to 

determine reasonable potential for a parameter to violate water quality standards. Effluent 

ammonia is measured each day at the Tesoro refinery and Ecology used this data as part of the 

evaluation. To expedite the analysis because of the large volume of data available, we used the 

maximum ammonia value which results in a more conservative analysis. 

Based on the data, calculations and analyses described above, and given the dilution available at 

Tesoro, Ecology determined that there is no reasonable potential for ammonia in the effluent to 

result in water quality standards violations at the edge of the dilution zone. To violate water 

quality standards the effluent concentration would have to be greater than 52 mg/l. The 

maximum level found in the available data for 1999 - 2003 was 5 mg/l. An average 

concentration of 18 mg/l of ammonia a day for any month would be a violation of the technology 

based standards (450 lbs/day for monthly avg.) for the Tesoro refinery (assuming 3 MGD, 

approx avg.) With the available dilution at Tesoro the technology based effluent limit for 

ammonia is sufficiently protective of water quality standards. 

Whole Effluent Toxicity 

The Water Quality Standards for Surface Waters require that the effluent not cause toxic effects 

in the receiving waters. Many toxic pollutants cannot be detected by commonly available 

detection methods. However, toxicity can be measured directly by exposing living organisms to 

the wastewater in laboratory tests and measuring the response of the organisms. Toxicity tests 

measure the aggregate toxicity of the whole effluent, and therefore this approach is called whole 

effluent toxicity (WET) testing. Some WET tests measure acute toxicity and other WET tests 

measure chronic toxicity. 

Acute toxicity tests measure mortality as the significant response to the toxicity of the effluent. 

Dischargers who monitor their wastewater with acute toxicity tests are providing an indication of 

the potential lethal effect of the effluent to organisms in the receiving environment. 

Chronic toxicity tests measure various sublethal toxic responses such as retarded growth or 

reduced reproduction. Chronic toxicity tests often involve either a complete life cycle test of an 

organism with an extremely short life cycle or a partial life cycle test on a critical stage of one of 

a test organism's life cycles. Organism survival is also measured in some chronic toxicity tests. 

Accredited WET testing laboratories have the proper WET testing protocols, data requirements, 

and reporting format. Accredited laboratories are knowledgeable about WET testing and capable 

of calculating an NOEC, LC50, EC50, IC25, etc. All accredited labs have been provided the most 

recent version of the Department of Ecology Publication # WQ-R-95-80, Laboratory Guidance 

and Whole Effluent Toxicity Test Review Criteria which is referenced in the permit. Any 

Permittee interested in receiving a copy of this publication may call the Ecology Publications 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Distribution Center 360-407-7472 for a copy or visit online 

http://www.ecy.wa.gov/programs/wq/wet. Ecology recommends that Permittees send a copy of 

the acute or chronic toxicity sections(s) of their permits to their laboratory of choice. 

The WET tests during effluent characterization indicate that no reasonable potential exists to 

cause receiving water acute or chronic toxicity, and the Permittee will not be given an acute or 

chronic WET limit and will only be required to retest the effluent prior to application for permit 

renewal in order to demonstrate that acute and chronic toxicity has not increased in the effluent. 

If the Permittee makes process or material changes which, in the Department's opinion, results in 

an increased potential for effluent toxicity, then the Department may require additional effluent 

characterization in a regulatory order, by permit modification, or in the permit renewal. Toxicity 

is assumed to have increased if WET testing conducted for submission with a permit application 

fails to meet the performance standards in WAC 173-205-020, "whole effluent toxicity 

performance standard". The Permittee may demonstrate to the Department that changes have not 

increased effluent toxicity by performing additional WET testing after the time the process or 

material changes have been made. 

In cooperation with the Cherry Point refineries, Ecology has developed WET tests using herring 

indigenous to Puget Sound. These tests include: a chronic test (embryo survival and 

development), an acute test (larval survival) and a chronic test (larval growth). These tests are 

now available for regulatory use. Ecology requires Tesoro to use these tests in the permit. These 

herring tests are not at this time included in WAC 173-205-050(1)(d) and cannot be used to 

determine the need for toxicity limits or for monitoring compliance. 

HUMAN HEALTH

Washington’s water quality standards now include 91 numeric health-based criteria that must be 

considered in NPDES permits. These criteria were promulgated for the state by the U.S. EPA in 

its National Toxics Rule (Federal Register, Volume 57, No. 246, Tuesday, December 22, 1992). 

The Department has determined that the effluent is likely to have chemicals of concern for 

human health. The discharger's high priority status is based on the discharger’s status as a major 

discharger and knowledge of data or process information indicating regulated chemicals occur in 

the discharge. 

Samples were taken for the 91 listed Human Health criteria pollutants. These occurred in four 

separate events over four years. Of the 91 parameters, 9 were detected in the effluent. 

A determination of the discharge's potential to cause an exceedance of the water quality 

standards for Human Health was conducted as required by 40 CFR 122.44(d). The reasonable 

potential determination was evaluated with procedures given in the Technical Support Document 

for Water Quality-Based Toxics Control (EPA/505/2-90-001) and the Department's Permit 

Writer's Manual (Ecology Publication 92-109, July, 1994). The determination indicated that the 

discharge has no reasonable potential to cause a violation of water quality standards, thus an 

effluent limit is not warranted. 

In 1992 the USEPA adopted risk-based arsenic criteria for the protection of human health for the 

State of Washington. The criterion for marine waters is 0.14 μg/L inorganic arsenic, and is 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

based on exposure from fish and shellfish tissue ingestion. The freshwater criterion is 0.018 

μg/L, and is based on exposure from fish and shellfish tissue and water ingestion. These criteria 

have caused confusion in implementation because they differ from the drinking water maximum 

contaminant level (MCL) of 10 μg/L, which is not risk-based, and because the human health 

criteria are sometimes exceeded by natural background concentrations of arsenic in surface water 

and ground water. 

In Washington, when a natural background concentration exceeds the criterion, the natural 

background concentration becomes the criterion, and no dilution zone is allowed. This could 

result in a situation where natural groundwater or surface water used as a municipal or industrial 

source-water would need additional treatment to meet numeric effluent limits even though no 

arsenic was added as waste. Although this is not the case for all dischargers, we do not have data 

at this time to quantify the extent of the problem. 

A regulatory mechanism to deal with the issues associated with natural background 

concentrations of arsenic in groundwater-derived drinking waters is currently lacking. 

Consequently, the Water Quality Program, at this time, has decided to use a three-pronged 

strategy to address the issues associated with the arsenic criteria. The three strategy elements 

are: 

1. Pursue, at the national level, a solution to the regulatory issue of groundwater sources 

with high arsenic concentrations causing municipal treatment plant effluent to exceed 

criteria. The revision of the MCL for arsenic offered a national opportunity to discuss how 

drinking water sources can affect NPDES wastewater dischargers, however Ecology was 

unsuccessful in focusing the discussion on developing a national policy for arsenic regulation 

that acknowledges the risks and costs associated with management of the public exposure to 

natural background concentrations of arsenic through water sources. The current arsenic MCL 

of 10 ug/L could also result in municipal treatment plants being unable to meet criteria-based 

effluent limits. Ecology will continue to pursue this issue as opportunities arise. 

2. Additional and more focussed data collection. The Water Quality Program will in some 

cases require additional and more focussed arsenic data collection, will encourage or require 

dischargers to test for source water arsenic concentrations, and will pursue development of a 

proposal to have Ecology's Environmental Assessment Program conduct drinking water source 

monitoring as well as some additional ambient monitoring data. At this time, Washington 

NPDES permits will contain numeric effluent limits for arsenic based only on treatment 

technology and aquatic life protection as appropriate. 

3. Data sharing. Ecology will share data with USEPA as they work to develop new risk-based 

criteria for arsenic and as they develop a strategy to regulate arsenic. 

Ecology must evaluate whether or not the discharge has reasonable potential to violate human 

health criteria at the edge of the chronic zone. To more thoroughly evaluate human health 

criteria the permit requires Tesoro to recharacterize the effluent by sampling for the 91 human 

health criteria listed pollutants (priority pollutants) , excluding PCB’s, PBB’s, asbestos, and all 

pesticides except any listed pesticide that is used on the refinery site. In addition to the human 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

health criteria, Tesoro shall analyze the final effluent for dibenzofuran, using EPA Method 8270 

or its equivalent. The effluent shall be sampled and analyzed annually during the life of the 

permit. At least two of these sampling events shall coincide with the discharge of pollutants 

from the catalytic reformer regeneration process. 

SEDIMENT QUALITY

The Department has promulgated aquatic sediment standards (Chapter 173-204 WAC) to protect 

aquatic biota and human health. These standards state that the Department may require 

Permittees to evaluate the potential for the discharge to cause a violation of applicable standards 

(WAC 173-204-400). 

Review of previous sediment surveys in 1995 and 2001, by Ecology’s sediment management 

unit, shows no violation of sediment standards. There has been a concern that more study of 

possible ammonia impacts may be needed in the future. 

The Department has determined through this review, and of the discharger characteristics, 

sediment samples, and effluent characteristics that this discharge has no reasonable potential to 

violate the Sediment Management Standards. We will reevaluate Tesoro’s potential to violate 

sediment standards at the next permit cycle. 

GROUND WATER QUALITY LIMITATIONS

The Department has promulgated Ground Water Quality Standards (Chapter 173-200 WAC) to 

protect beneficial uses of ground water. Permits issued by the Department shall be conditioned 

in such a manner so as not to allow violations of those standards (WAC 173-200-100). 

Tesoro has two unlined final wastewater polishing ponds that could potentially discharge to 

groundwater. These ponds are located within approximately 200 feet of Fidalgo Bay at high 

tide. If a discharge to ground water from these ponds is occurring, it discharges almost directly 

into the Bay, where the final effluent is currently discharged via a marine outfall. The discharge 

would consist of high quality wastewater, treated to secondary treatment levels. Concentrations 

of most pollutants in Tesoro’s effluent were found to be less than the groundwater quality 

criteria. Only three metals, mercury, selenium, and arsenic, and the organic compound 

chloroform exceeded the criteria. Chloroform and arsenic were the only parameters present at 

levels that were significantly higher than the criteria. Incidental leakage of effluent of this 

quality, and in this location, should have undetectable or minimal impacts to ground water 

quality. The volume of groundwater, which would potentially be impacted, would be very small; 

and impacts would occur just prior to its entering the marine receiving water (the current 

discharge location). Therefore no limitations or actions are required based on potential effects to 

ground water. 

Dangerous Wastes – Permit By Rule Requirements

The permit authorizes Tesoro to treat dangerous wastes whether generated on or off-site at the 

wastewater treatment facility, under the permit by rule provisions of WAC 173-303-802(5). This 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

authorization is limited to the on-site and off-site waste streams identified and characterized on 

the permit application and application amendments approved by Ecology. Offsite wastes include 

ballast water and retail distribution water. Ecology reviewed the offsite waste streams identified 

and has determined that they are similar in nature to those generated on-site and concludes that 

they should be treated effectively at Tesoro’s wastewater treatment facility. Established effluent 

sampling and monitoring should be adequate to address the pollutants in these wastestreams. 

Permit by rule provisions cover the identified waste streams as long as the permittee complies 

with the conditions of the permit, and complies with the dangerous waste requirements 

pertaining to: notification and identification numbers, designation of dangerous wastes, 

performance standards, general waste analysis, security, contingency plans and emergency 

procedures, emergencies, the manifest system, the operating record and facility reporting. 

MONITORING REQUIREMENTS 

Monitoring, recording, and reporting are required (WAC 173-220-210 and 40 CFR 122.41) to 

verify that the treatment process is functioning correctly and the effluent limitations are being 

achieved. 

The monitoring schedule is detailed in the proposed permit under Condition S.2. Specified 

monitoring frequencies take into account the quantity and variability of the discharge, the 

treatment method, Tesoro’s past compliance, significance of pollutants, and the cost of 

monitoring. Ecology has determined that the TSS and Oil/Grease frequency will be at minimum 

5/wk; these are indicator parameters for refining facilities and serve to demonstrate ongoing 

system performance. 

EFFLUENT LIMITS BELOW QUANTITATION 

The Quantitation Level is the level at which concentrations can be reliably reported with a 

specified level of error. For maximum daily effluent limits, if the measured effluent 

concentration is below the Quantitation Level, the Permittee reports NQ for non-quantifiable. 

For average monthly effluent limits, all effluent concentrations below the Quantitation Level but 

above the Method Detection Level are used as reported for calculating the average monthly 

value. 

EFFLUENT LIMITS BELOW DETECTION 

The Method Detection Level (MDL) is the minimum concentration of an analyte that can be 

measured and reported with a 99 percent confidence that it's concentration is greater than zero as 

determined by a specific laboratory method. For maximum daily limits, if the concentrations are 

below the MDL the Permittee reports ND for non-detectable. For average monthly limits, all 

values above the MDL are used as reported and all values below the MDL are calculated as zero. 

LAB ACCREDITATION 

With the exception of certain parameters the permit requires all monitoring data to be prepared 

by a laboratory registered or accredited under the provisions of Chapter 173-50 WAC, 

Accreditation of Environmental Laboratories. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

OTHER PERMIT CONDITIONS 

REPORTING AND RECORDKEEPING 

The conditions of S3. are based on the authority to specify any appropriate reporting and 

recordkeeping requirements to prevent and control waste discharges (WAC 173-220-210). 

NON-ROUTINE AND UNANTICIPATED DISCHARGES 

Occasionally, this facility may generate wastewater which is not characterized in their permit 

application because it is not a routine discharge and was not anticipated at the time of 

application. These typically are waters used to pressure test storage tanks or fire water systems 

or leaks from drinking water systems. These are typically clean waste waters but may be 

contaminated with pollutants. The permit contains an authorization for non-routine and 

unanticipated discharges. The permit requires a characterization of these waste waters for 

pollutants and examination of the opportunities for reuse. Depending on the nature and extent of 

pollutants in this wastewater and opportunities for reuse, Ecology may authorize a direct 

discharge via the process wastewater outfall or through a stormwater outfall for clean water, 

require the wastewater to be placed through the facilities wastewater treatment process or require 

the water to be reused. 

OUTFALL EVALUATION 

The facility submitted an outfall inspection report in 2002, indicating no problems with the 

outfall. 

Proposed permit condition S12. requires the Permittee to conduct an outfall inspection and 

submit a report detailing the findings of that inspection. The purpose of the inspection is to 

determine the condition of the discharge pipe and diffusers and to evaluate the extent of sediment 

accumulations in the vicinity of the outfall. 

TREATMENT SYSTEM OPERATING PLAN (TSOP) 

During the previous permit term, on October 30, 1998, Tesoro submitted a TSOP to Ecology. 

Updates to this plan will be required in the proposed permit. 

In accordance with state and federal regulations, the Permittee is required to take all reasonable 

steps to properly operate and maintain the treatment system (40 CFR 122.41(e)) and WAC 173-

220-150 (1)(g). An operation and maintenance manual was submitted as required by state 

regulation for the construction of wastewater treatment facilities (WAC 173-240-150). It has 

been determined that the implementation of the procedures in the Treatment System Operating 

Plan is a reasonable measure to ensure compliance with the terms and limitations in the permit. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

GENERAL CONDITIONS 

General Conditions are based directly on state and federal law and regulations and have been 

standardized for all individual industrial NPDES permits issued by the Department. 

PERMIT ISSUANCE PROCEDURES 

PERMIT MODIFICATIONS 

The Department may modify this permit to impose numerical limitations, if necessary to meet 

Water Quality Standards for Surface Waters, Sediment Quality Standards, or Water Quality 

Standards for Ground Waters, based on new information obtained from sources such as 

inspections, effluent monitoring, outfall studies, and effluent mixing studies. 

The Department may also modify this permit as a result of new or amended state or federal 

regulations. 

RECOMMENDATION FOR PERMIT ISSUANCE 

This proposed permit meets all statutory requirements for authorizing a wastewater discharge, 

including those limitations and conditions believed necessary to control toxics, protect human 

health, aquatic life, and the beneficial uses of waters of the State of Washington. The 

Department proposes that this proposed permit be issued for 5 years. 

REFERENCES FOR TEXT AND APPENDICES 

Environmental Protection Agency (EPA) 

1992. National Toxics Rule. Federal Register, V. 57, No. 246, Tuesday, December 22, 1992. 

1991. Technical Support Document for Water Quality-based Toxics Control. EPA/505/2-

90-001. 

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

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

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

Pollutants in Surface and Ground Water. EPA/600/6-85/002a. 

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

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

1972. Characterization of Stream Reaeration Capacity. EPA-R3-72-012. (Cited in EPA 

1985 op.cit.) 

Washington State Department of Ecology. 

 1994. Permit Writer’s Manual. Publication Number 92-109 

Washington State Department of Ecology. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

 Laws and Regulations( http://www.ecy.wa.gov/laws-rules/index.html ) 

 Permit and Wastewater Related Information 

(http://www.ecy.wa.gov/programs/wq/wastewater/index.html 

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

1979. In-stream Deoxygenation Rate Prediction. Journal Environmental Engineering 

Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.) 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

APPENDIX A--PUBLIC INVOLVEMENT INFORMATION 

The Department has tentatively determined to reissue a permit to the applicant listed on page 1 of 

this fact sheet. The permit contains conditions and effluent limitations which are described in the 

rest of this fact sheet. 

Public notice of application was published on (date) and (date) in (name of publication) to 

inform the public that an application had been submitted and to invite comment on the reissuance 

of this permit. 

The Department will publish a Public Notice of Draft (PNOD) on (date) in (name of publication)

to inform the public that a draft permit and fact sheet are available for review. Interested persons 

are invited to submit written comments regarding the draft permit. The draft permit, fact sheet, 

and related documents are available for inspection and copying between the hours of 8:00 a.m. 

and 5:00 p.m. weekdays, by appointment, at the regional office listed below. Written comments 

should be mailed to: 

 Water Quality Permit Coordinator 

 Department of Ecology 

 Industrial Section 

 PO Box 47706 

 Olympia, Washington 98504. 

Any interested party may comment on the draft permit or request a public hearing on this draft 

permit within the thirty (30) day comment period to the address above. The request for a hearing 

shall indicate the interest of the party and reasons why the hearing is warranted. The Department 

will hold a hearing if it determines there is a significant public interest in the draft permit (WAC 

173-220-090). Public notice regarding any hearing will be circulated at least thirty (30) days in 

advance of the hearing. People expressing an interest in this permit will be mailed an individual 

notice of hearing (WAC 173-220-100). 

Comments should reference specific text followed by proposed modification or concern when 

possible. Comments may address technical issues, accuracy and completeness of information, 

the scope of the facility’s proposed coverage, adequacy of environmental protection, permit 

conditions, or any other concern that would result from issuance of this permit. 

The Department will consider all comments received within thirty (30) days from the date of 

public notice of draft indicated above, in formulating a final determination to issue, revise, or 

deny the permit. The Department's response to all significant comments is available upon 

request and will be mailed directly to people expressing an interest in this permit. 

Further information may be obtained from the Department by writing to the address listed above. 

This permit and fact sheet were written by J. Mark Dirkx, P.E. and Nancy Kmet, P.E. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

APPENDIX B--GLOSSARY 

Acute Toxicity--The lethal effect of a compound on an organism that occurs in a short period of 

time, usually 48 to 96 hours. 

AKART-- An acronym for “all known, available, and reasonable methods of treatment”. 

Ambient Water Quality--The existing environmental condition of the water in a receiving 

water body. 

Ammonia--Ammonia is produced by the breakdown of nitrogenous materials in wastewater. 

Ammonia is toxic to aquatic organisms, exerts an oxygen demand, and contributes to 

eutrophication. It also increases the amount of chlorine needed to disinfect wastewater. 

Average Monthly Discharge Limitation --The average of the measured values obtained over a 

calendar month's time.

Best Management Practices (BMPs)--Schedules of activities, prohibitions of practices, 

maintenance procedures, and other physical, structural and/or managerial practices to prevent 

or reduce the pollution of waters of the State. BMPs include treatment systems, operating 

procedures, and practices to control: plant site runoff, spillage or leaks, sludge or waste 

disposal, or drainage from raw material storage. BMPs may be further categorized as 

operational, source control, erosion and sediment control, and treatment BMPs. 

BOD5--Determining the Biochemical Oxygen Demand of an effluent is an indirect way of 

measuring the quantity of organic material present in an effluent that is utilized by bacteria. 

The BOD5 is used in modeling to measure the reduction of dissolved oxygen in a receiving 

water after effluent is discharged. Stress caused by reduced dissolved oxygen levels makes 

organisms less competitive and less able to sustain their species in the aquatic environment. 

Although BOD is not a specific compound, it is defined as a conventional pollutant under the 

federal Clean Water Act. 

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

Chlorine--Chlorine is used to disinfect wastewaters of pathogens harmful to human health. It is 

also extremely toxic to aquatic life. 

Chronic Toxicity--The effect of a compound on an organism over a relatively long time, often 

1/10 of an organism's lifespan or more. Chronic toxicity can measure survival, reproduction 

or growth rates, or other parameters to measure the toxic effects of a compound or 

combination of compounds. 

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

500, as amended by Public Laws 95-217, 95-576, 96-483, 97-117; USC 1251 et seq. 

Compliance Inspection - Without Sampling--A site visit for the purpose of determining the 

compliance of a facility with the terms and conditions of its permit or with applicable statutes 

and regulations. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Compliance Inspection - With Sampling--A site visit to accomplish the purpose of a 

Compliance Inspection - Without Sampling and as a minimum, sampling and analysis for all 

parameters with limits in the permit to ascertain compliance with those limits; and, for 

municipal facilities, sampling of influent to ascertain compliance with the 85 percent removal 

requirement. Additional sampling may be conducted. 

Composite Sample--A mixture of grab samples collected at the same sampling point at different 

times, formed either by continuous sampling or by mixing discrete samples. May be "timecomposite"(collected at constant time intervals) or "flow-proportional" (collected either as a 

constant sample volume at time intervals proportional to stream flow, or collected by 

increasing the volume of each aliquot as the flow increased while maintaining a constant time 

interval between the aliquots. 

Construction Activity--Clearing, grading, excavation and any other activity which disturbs the 

surface of the land. Such activities may include road building, construction of residential 

houses, office buildings, or industrial buildings, and demolition activity. 

Continuous Monitoring –Uninterrupted, unless otherwise noted in the permit. 

Critical Condition--The time during which the combination of receiving water and waste 

discharge conditions have the highest potential for causing toxicity in the receiving water 

environment. This situation usually occurs when the flow within a water body is low, thus, 

its ability to dilute effluent is reduced. 

Dilution Factor--A measure of the amount of mixing of effluent and receiving water that occurs 

at the boundary of the mixing zone. Expressed as the inverse of the percent effluent fraction 

e.g., a dilution factor of 10 means the effluent comprises 10% by volume and the receiving 

water 90%. 

Engineering Report--A document which thoroughly examines the engineering and 

administrative aspects of a particular domestic or industrial wastewater facility. The report 

shall contain the appropriate information required in WAC 173-240-060 or 173-240-130. 

Fecal Coliform Bacteria--Fecal coliform bacteria are used as indicators of pathogenic bacteria 

in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are 

controlled by disinfecting the wastewater. The presence of high numbers of fecal coliform 

bacteria in a water body can indicate the recent release of untreated wastewater and/or the 

presence of animal feces. 

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

of time as is feasible. 

Industrial Wastewater--Water or liquid-carried waste from industrial or commercial processes, 

as distinct from domestic wastewater. These wastes may result from any process or activity 

of industry, manufacture, trade or business, from the development of any natural resource, or 

from animal operations such as feed lots, poultry houses, or dairies. The term includes 

contaminated storm water and, also, leachate from solid waste facilities. 

Major Facility--A facility discharging to surface water with an EPA rating score of > 80 points 

based on such factors as flow volume, toxic pollutant potential, and public health impact. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Maximum Daily Discharge Limitation--The highest allowable daily discharge of a pollutant 

measured during a calendar day or any 24-hour period that reasonably represents the calendar 

day for purposes of sampling. The daily discharge is calculated as the average measurement 

of the pollutant over the day. 

Method Detection Level (MDL)--The minimum concentration of a substance that can be 

measured and reported with 99% confidence that the analyte concentration is above zero and 

is determined from analysis of a sample in a given matrix containing the analyte. 

Minor Facility--A facility discharging to surface water with an EPA rating score of < 80 points 

based on such factors as flow volume, toxic pollutant potential, and public health impact. 

Mixing Zone--An area that surrounds an effluent discharge within which water quality criteria 

may be exceeded. The area of the authorized mixing zone is specified in a facility's permit 

and follows procedures outlined in state regulations (Chapter 173-201A WAC). 

National Pollutant Discharge Elimination System (NPDES)--The NPDES (Section 402 of the 

Clean Water Act) is the Federal wastewater permitting system for discharges to navigable 

waters of the United States. Many states, including the State of Washington, have been 

delegated the authority to issue these permits. NPDES permits issued by Washington State 

permit writers are joint NPDES/State permits issued under both State and Federal laws. 

pH--The pH of a liquid measures its acidity or alkalinity. A pH of 7 is defined as neutral, and 

large variations above or below this value are considered harmful to most aquatic life. 

Quantitation Level (QL)-- A calculated value five times the MDL (method detection level). 

Responsible Corporate Officer-- A president, secretary, treasurer, or vice-president of the 

corporation in charge of a principal business function, or any other person who performs 

similar policy- or decision-making functions for the corporation, or the manager of one or 

more manufacturing, production, or operating facilities employing more than 250 persons or 

have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 

dollars), if authority to sign documents has been assigned or delegated to the manager in 

accordance with corporate procedures (40 CFR 122.22). 

Technology-based Effluent Limit--A permit limit that is based on the ability of a treatment 

method to reduce the pollutant. 

Total Suspended Solids (TSS)--Total suspended solids is the particulate material in an effluent. 

Large quantities of TSS discharged to a receiving water may result in solids accumulation. 

Apart from any toxic effects attributable to substances leached out by water, suspended solids 

may kill fish, shellfish, and other aquatic organisms by causing abrasive injuries and by 

clogging the gills and respiratory passages of various aquatic fauna. Indirectly, suspended 

solids can screen out light and can promote and maintain the development of noxious 

conditions through oxygen depletion. 

State Waters--Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and 

all other surface waters and watercourses within the jurisdiction of the state of Washington. 

Stormwater--That portion of precipitation that does not naturally percolate into the ground or 

evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water 

drainage system into a defined surface water body, or a constructed infiltration facility. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

Upset--An exceptional incident in which there is unintentional and temporary noncompliance 

with technology-based permit effluent limitations because of factors beyond the reasonable 

control of the Permittee. An upset does not include noncompliance to the extent caused by 

operational error, improperly designed treatment facilities, lack of preventative maintenance, 

or careless or improper operation. 

Water Quality-based Effluent Limit--A limit on the concentration of an effluent parameter that 

is intended to prevent the concentration of that parameter from exceeding its water quality 

criterion after it is discharged into a receiving water. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

APPENDIX C--TECHNICAL CALCULATIONS 

Several of the Excel® spreadsheet tools used to evaluate a discharger’s ability to meet 

Washington State water quality standards can be found on the Department’s homepage at 

http://www.ecy.wa.gov. 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

APPENDIX D--RESPONSE TO COMMENTS 

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FACT SHEET FOR NPDES PERMIT WA-000076-1 

APPENDIX F--SIZE AND PROCESS FACTOR CALCULATIONS 

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