### FACT SHEET FOR NPDES PE RMIT WA-000178-3 FACILITY NAME: U.S. Oil & Refining Co. June 13, 2008

PURPOSE of this Fact Sheet

This fact sheet explains and documents the d ecisions Ecology made in drafting this proposed National Pollutant Discharge Elimination System (NPDES) permit.

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

An NPDES permit limits the types and amounts of pollution the permittee may discharge. Those limits are based either on (1) th e pollution control or wastewat er treatment technology available to the industry, or on (2) the receiving water’s customary beneficial us es. This fact sheet complies with Section 173-220- 060 of the Washington Administ rative Code (WAC), which requires Ecology to prepare a draft permit and ac companying fact sheet for public evaluation before issuing an NPDES permit.

P UBLIC R OLE in the Permit

Ecology places a copy of the draft perm it and fact sheet w ithin the community

, for public review and comment

, at least thirty (30) days before we issue the final permit to the facility operator (WAC 173-220-050). Copies of th e fact sheet and draft permit for U.S. Oil & Refining Co (USOR) NPDES permit WA-000178-3, ar e available for public review and comment from February 28, 2008 until the close of business March 31, 2008. For more details on reading the draft documents and on preparing and f iling comments about them, please see Appendix A - Public Involvement

. Before Ecology published this draft NPDES permit, USOR reviewed it for factual accuracy. Ecology corrected any errors or omissions a bout the facility’s lo cation, product type or production rate, discharges or recei ving water, or its history.

After the public comment period closes, Ecology will weigh the merits of each comment. Then we will summarize substantive comments and our responses to them. We will attach our summary and responses to comments to this Fact Sheet as Appendix D - Response to Comments , and publish it when we issue the final NPDES permit. The rest of the fact sheet will not be revised, but the full document will become part of the legal history contained in the facility’s permit file.

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

T ABLE OF C ONTENTS

I. INTRODUCTION............................................................................................................... ........1 Applicant..............................................................................................................................1 SIC Code..............................................................................................................................1 Discharge Locations............................................................................................................ .1 Process Wastewater Outfalls................................................................................................1

II. BACKGROUND INFORMATION...........................................................................................2 A. Facility Description....................................................................................................... .2 History--...................................................................................................................2 Industrial Process-....................................................................................................2 Wastewater Treatment--...........................................................................................3 Discharge Wastewater/water and Outfalls-- ............................................................3 B. Permit Status .............................................................................................................. ....3 C. Summary of Compliance with Previous Permit Issued..................................................5 D. Wastewater Characterization .........................................................................................5

III. PROPOSED PERMIT CONDITIONS.....................................................................................7 A. Design Criteria ...............................................................................................................7 B. Technology-Based Effluent Limits ................................................................................7 Process Wastewater--...............................................................................................8 Stormwater Allocations--.......................................................................................12 Marine Terminal Stormwater--..............................................................................12 Pollution Prevention to Date-- ...............................................................................13 New Requirements-- ..............................................................................................14 C. Surface Water Quality-Based Effluent Limits .............................................................15 Numerical Criteria for the Protection of Aquatic Life and Recreation--...............15 Numerical Criteria for the Pr otection of Human Health--.....................................15 Narrative Criteria--.................................................................................................15 Antidegradation--...................................................................................................15 Mixing Zones-- ......................................................................................................16 D. Description of the Receiving Water.............................................................................21 E. Designated Uses and Su rface Water Quality Criteria ..................................................21 F. Evaluation of Surface Water Quality -Based Effluent Limits for Numeric Criteria ...................................................................................................................22 G. Whole Effluent Toxicity ..............................................................................................23 H. Human Health ..............................................................................................................2 7 I. Sediment Quality ......................................................................................................... 28 J. Ground Water Quality Limits.......................................................................................28 K. Comparison Of Effluent Limits W ith The Previous Permit Issued January 2002........................................................................................................................29 L. Dangerous Waste - Perm it By Rule Requirements.........................................29

IV. MONITORING REQUIREMENTS.......................................................................................31 A. Lab Accreditation.........................................................................................................31

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

V. OTHER PERMIT CONDITIONS ...........................................................................................31 A. Reporting and Recordkeeping......................................................................................31 B. Non Routine and Unanticipated Discharges ................................................................31 C. Outfall Evaluation ........................................................................................................32 D. Treatment System Operating Plan ...............................................................................32 E. General Conditions.......................................................................................................32 F. Construction Stormwater..............................................................................................32

VI. PERMIT ISSUANCE PROCEDURES ..................................................................................33 A. Permit Modifications....................................................................................................33 B. Proposed Permit Issuance.............................................................................................33

VII. REFERENCES FOR TEXT AND APPENDICES................................................................34

APPENDIX A--PUBLIC INVOLVEMENT INFORMATION....................................................35

APPENDIX B--GLOSSARY ........................................................................................................37

APPENDIX C--TECHNICAL CALCULATIONS .......................................................................39

APPENDIX D--RESPONSE TO COMMENTS ...........................................................................40

APPENDIX E--PROCESS FACTOR AND TECHNICAL LIMITS DETERMINATION..........41

APPENDIX F--USOR VICINITY MAP.......................................................................................42

APPENDIX G--REASONABLE PO TNETIAL CALCULATION..............................................43

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

I. INTRODUCTION
Table 1: General Facility Information

Ap plicant U.S. Oil & Refining Co.

Facility Name and Address U.S. Oil & Refining Co.

3001 Marshall Ave
Tacoma, WA 98421 Type of Facility Petroleum Refinery

SI C Code 2911

Di scharge Locations Waterbody name: City storm drain line (Outfall #001-A) Blair Waterway (Outfall 001-B) , Lincoln Ave Ditch (Outfall #002), Ground Water (Outfall #003), and Marshall Ave Ditch (Outfall 004) Water Body ID Number WA-10-0020

Pr ocess Wastewater Outfall Outfall 001A Latitude: 47° 15' 25" N Longitude: 122° 23' 29" W Clean Water Outfalls (Hydro te st, Firewater, and Stormwater) Outfall 001B Latitude: 47° 15' 29" N Longitude: 122° 23' 38" W Outfall 002 Latitude: 47° 15' 27" N Longitude: 122° 23' 06" W Outfall 003 Latitude: 47° 15' 53" N Longitude: 122° 23' 53" W Outfall 004 Latitude: 47° 15' 14" N Longitude: 122° 23' 33" W

The Federal Clean Water Act (FCWA, 1972, a nd later amendments in 1977, 1981, and 1987) established water quality goals for the navigable (surface) waters of the United States. One mechanism for achieving the goals of the Clean Water Act is the National Pollutant Discharge Elimination System of permits (NPDES perm its), designed by the federal Environmental Protection Agency (EPA). The EPA authorized the State of Washington to manage the NPDES permit program in our state. Our state legisl ature accepted the delegati on and assigned the power and duty for conducting NPDES permitting and enfor cement to Ecology. The legislature defined Ecology's authority and obligations for the wastewater discharge permit program in Chapter 90.48 RCW (Revised Code of Washington).

Ecology adopted rules describing ho w we exercise our authority:

• Procedures Ecology follows for issuing NP DES permits (Chapter 173-220 WAC),

• Water quality criteria for surface waters (Chapter 173-201A WAC) and for ground waters (Chapter 173-200 WAC)

• Sediment management standard s (Chapter 173-204 WAC).

Page 1

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma These rules require any industrial facility operator to obtain an NPDES permit before discharging wastewater to state waters. They al so define the basis for limits on each discharge and for other performance requirements imposed by the permit.
Under the NPDES permit program Ecology must prepare a draft permit and accompanying fact sheet, and offer it for public review. Ecology must also publish an annou ncement (public notice) telling people where they can read the draft permit, and where to send their comments on the draft permit, during a period of th irty days (WAC 173-220-050). (See Appendix A --Public Involvementfor more detail about the Public Notice a nd Comment procedures). After the Public Comment Period closes, Ecology may change a condition or requirement in the draft NPDES permit, as suggested by a timely comment, to improve the facility’s environmental performance.

II. BACKGROUND INFORMATION

E. A. Facility Description

History
The refinery was constructed in 1957 from units of an old Spokane, Washington topping refinery and consists of two parts: the refinery and tank farm, and the Marine Terminal. The refinery houses the process units and the tank farm with its 2 million barrel capacity (the capacity will be increased to 2.84 million in 2008 when 5 new tank s are placed into service) on 122 acres. Approximately 3/4 mile north and on the Blair Wa terway is the marine terminal, where crude oil arrives and products are shipped out from the two pi ers. Four pipelines ranging in diameter from 8 to 24 inches transmit crude oil and products fr om the marine terminal and the tank farm. Products are also loaded onto tanker trucks from the loading rack at the refinery, via pipeline to the McChord Air Force Base, and can al so be shipped via rail lines.

Industrial Process
USOR has the capacity to process 39,000 bbls/ca lendar day of crude oil (Note: bbls means barrels, the most common measure of oil volume used in the U.S. One barrel equals 42 gallons). The highest daily average throughput for any one month was 38,703 bbls/calendar day for the month of September 2005. For the past five years from January 2002 through December of 2006 the average daily throughput of crude oil was 35,683 bbls/stream day. During this same period the highest average throughput for any consecu tive 12 month period (9 /05-8/06) was 37,690 bbls per calendar day. The crude unit does not always run at the maximum attainable rate every day of the month. As a result, the monthly averag e barrels per stream day are different than the average barrels per calendar day. (Note: bbls/calendar day means that the throughput is averaged over all of the days of a month; bbls/stream-d ay means that throughput is averaged over only those days of the month that the crude unit is operating. These values are the same if the refinery is in operation for every day of the month, but ca n differ significantly if the crude unit is shut down for some period of days in a month.)

The main source of crude oil has historically been from tankers delivering oil from Alaska's North Slope, however, crude oils from other sources are also processed. The refinery separates crude oil into its various com ponent parts. Separated compone nts are further processed and blended into a variety of petroleum products. Those products include gasoline, military and

Page 2

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma commercial jet fuel, ultra low sulfur diesel fuel, marine fuel, gas oils, and emulsified and road asphalts.

The refinery employs about 165 people.

Wastewater Treatment

Process water and contaminated stormwater from the refinery receive primary and secondary treatment in a wastewater treatment system pr ior to being discharged at Outfall 001A, which discharges into a WWT outfall line placed into service in November 2005 which goes from the Refinery to a City of Tacoma storm drain line.

Primary treatment facilities for process wastewat er include an API oil/water separator and an induced air flotation (IAF) unit. All process wa stewater and stormwater runoff from the process area is routed to the primary wastewater treatmen t unit. The treated water then goes to Tank No. 80008, which provides retention capacity and serves as an equalization re servoir. The design capacity of the IAF unit is 330 gpm. Operating experience indicates the unit can satisfactorily process wastewater up to 400 gp m on a steady basis and up to 450 gpm on a short term basis.

Secondary treatment facilities for process wastew ater consist of an activated sludge biological unit (Orbal) followed by a clarifier. The Orba l was designed for flows at 451 gpm average and 687 gpm at peak flow. Based on its engineerin g report, USOR is running 430 gpm at maximum monthly average for the period of July 2001 thro ugh June 2004. If based on the operational data from 1995 to 2007, USOR should be able to run Orbal at 555 gpm hydrau lic loading without much increase for TSS at discharge from the clarif ier. USOR added a thir d disc to the Orbal in January 2002 to enhance aeration and increase contaminant loading pr ocessing capacities.

Treated effluent is then norma lly routed to Outfall 001A, although it can be diverted to two wastewater ponds (also called off test ponds) during upset c onditions or during routine maintenance. These ponds consist of the fo rmer equalization pond and south off test pond.

Sanitary waste is collected and discharged separa tely into the City of Tacoma sewer system for treatment in their municipal wastewater treatment plant. All other stormwater from the refinery site is sent to a concrete-lin ed basin for oil skimming, and is then pumped to a stormwater retention pond prior to being transferred to the Orbal for treatment. Waste activated sludge from the secondary clarifier is treated in an aerobic digester, then is dewatered and discharged to a concrete-lined pit. The solids are allowed to dry and then ultimately sent out for landfill disposal. Leachate from the pit is returned to the aerobic digester or to a geotextile dewatering system in the adjacent containment cell.

Discharge Wastewater/Water and Outfalls

The refinery storm water collection system norma lly will collect runoff water from general area drainage, tankage berm drains, and excess stormwater. Any st orm water that is processed through the primary and secondary treatment systems is discharged into Outfall 001A.

Page 3

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

The old Outfall 001 concrete structure is renamed as Outfall 001B which is used for discharging stormwater, firewater, and hydrot est water. The stormwater from the new tank area (Three tanks are complete as of March 2008, with two tanks st ill under construction. One of the new tanks is being constructed in an existing bermed area.) will be discharged th rough Outfall 002. Clean water discharges, such as hydrotest water from ne wly cleaned storage tanks or fire system test water, can be discharged at Outfalls 001-B, 002 and 003 on a case-by-case basis subject to certain criteria. Prior to discha rge of any clean water, the refine ry is required to report certain information/discharge water test results to the Washington Department of Ecology. Then Ecology may issue an authorization to discharge.

Stormwater from the Marine Terminal tank cont ainment area is handled two ways. Areas with the highest likelihood of generating contaminated stormwater, such as pump pads or valve pads, drain to sumps which are emptied by vacuum trucks . The trucks return the stormwater to the refinery for treatment. Stormwat er from the floor of the contai nment area drains to a vault, where any oil present can be retained by baffles in the vault. The water in the vault is then pumped to Outfall 003, an infiltration basin for release to groundwater.

In this permit, USOR proposed a new outfall, Outfall #004, for only discharging stormwater along Marshall Avenue. This na tural drainage point takes st ormwater from the unimproved Eastern section of the refinery pr operty to the ditch on the north side of Marshall Avenue, then into the city storm water line. The stormwater discharge has similar monitoring requirements as the cleanwater discharge at Outfalls, 001B, 002, and 003.

F. B. Permit Status

The previous permit for this facility was issued on April 8, 2002 and it was modified on April 16, 2002. The previous permit placed effl uent limitations on the following parameters tabulated below.

Effluent Limitations: Outfall 001-A

Parameter Units Effluent Limitation

Avg Monthly Max Daily

Biochemical Oxygen Demand (5-day) lbs/day 125 236

Chemical Oxygen Demand lbs/day 628 1215

Total Suspended Solids lbs/day 106 165

Oil and Grease lbs/day 38 74

Oil and Grease mg/l Shall at no time exceed 15 mg/l, and shall not exceed 10 mg/l more than three times per month

Page 4

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Parameter Units Effluent Limitation

Avg Monthly Max Daily

Phenolic Compounds lbs/day 0.65 1.77

Ammonia as N lbs/day 14 31

Sulfide lbs/day 0.71 1.56

Total Chromium lbs/day 0.87 2.28

Hexavalent Chromium lbs/day 0.06 0.13
pH pH shall be maintained w ithin the range of 6.0-9.0
Excursions between 5.0 and 6.0, or 9.0 and 10.0 must not be considered violations provided no single ex cursion 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.

C. Summary of Compliance with Previous Permit Issued

A compliance inspection at USOR was comple ted on May 9, 2007. This inspection included sampling of the discharge and labo ratory review. No deficiencies were noted at the inspection.

During the history of this permit term, the Perm ittee has generally remained in compliance based on Discharge Monitoring Reports (DMRs) submitted to Ecology and inspections conducted by the Department.

The daily maximum limit for total suspended solids (TSS) was exceeded by a factor of 5 on February 8, 2007, for which U.S. Oil was fine d $3,000. Multiple factors contributed to the violation including excessive solids in the API se parator and inadequately controlled contractor discharges to the system.

The previous permit required a number of special reports to be completed during the term of the permit. Studies included: Treatment Efficiency Study Results and Engineering Report (S3.A), Sediment Sampling and Analysis Pl an (S3.B.3), Human Health Criteria Sampling Results(S3.B.1), Outfall Line to Blair Waterway Engineering Design Report and Construction of New Outfall Line (S3.G).

G. D. Wastewater Characterization

An application for permit renewal was submitted to Ecology on November 3, 2006. Three submitted references of the application are: 1) Updated Treatment System Operating Plan, 2) Pollution Prevention Plan Update, an d 3) Engineering Report Update.

The proposed wastewater discharge was characte rized by USOR in the application process for conventional pollutants, metals, cyanide, phe nols, volatile organic compounds, acid organic compounds, base neutral organic compounds, and pesticides. Conventional parameter data

Page 5

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma reported below is based on data contained in the application, as well as on extensive (daily to weekly) monitoring completed during the term of the permit, and on the results of Class II water quality inspections (2002 to 2007). Maximum daily values of pollutants with significant concentrations and/or of interest are tabulated below . The maximum concentration and mass values for the various parameters did not necessarily occur on the same day. No organics are listed in the table below because none were quantifie d at greater than detection limits in any of the testing done during the term of the permit.

Maximum Daily Values of Pollutants

Parameter/ Date of Value Maximum Concentration Mass

BOD 10.0 mg/l 28.1 lb/day

COD 127 mg/l 661.8 lb/day

TOC 9.5 mg/l 34 lb/day

TSS 114 mg/l 605.7 lb/day

Ammonia 0.7 mg/l 2.8 lb/day

Flow 705.6 gpm
Temperature (winter) 23.9 °C
Temperature (summer) 27.2 °C
pH 6.4 minimum/9.1 maximum

Nitrate 7.2 mg/l 25.8 lb/day
Nitrogen (Total Organic) 1.0 mg/l 3.6 lb/day

Oil and Grease 8.0 mg/l 33.3 lb/day
Phosphorous 4.6 mg/l 16.4 lb/day

Sulfate 130 mg/l 466 lb/day
Sulfide (5/9/2002) 0.04 mg/l 0.73 lb/day

Surfactants 0.16 mg/l 0.6 lb/day
Antimony (4/21/2005) 2.06 μg/l 0.009 lb/day

Arsenic 44.0 μg/l 0.13 lb/day
Cadmium (5/19/2004) 1.22 μg/l 0.003 lb/day
Chromium (total) 5.0 μg/l 0.05 lb/day
Lead (5/19/2004) 1.11 μg/l 0.003 lb/day
Nickel (5/19/2004) 4.5 μg/l 0.016 lb/day

Page 6

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Parameter/ Date of Value Maximum Concentration Mass
Selenium (6/21/2006) 9.10 μg/l 0.02 lb/day
Zinc (6/21/2006) 16.7 μg/l 0.05 lb/day
Copper (5/19/2004) 2.3 μg/l 0.005 lb/day
Phenols (5/9/2007) 0.26 μg/l 0.0063 lb/day
Mercury (11/8/2006) 25.6 ng/l (nano grams/L)

III. PROPOSED PERMIT CONDITIONS

Federal and State regulations re quire that each NPDES permit se t forth either technology- or water quality-based effluent limits.

• Technology-based limits are based upon the treat ment methods availabl e to treat specific pollutants. Technology-based limits are set by the EPA and published as a regulation, or Ecology develops the limit on a case-by-ca se basis (40 CFR 125.3, and Chapter 173-220 WAC).

• Water quality-based limits 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 (40 CFR 131.36). The most stringent of these limits apply to each parameter of concern. These limits are described below.

The limits in this permit reflect information r eceived in the applicati on. Ecology evaluated the permit application and determined the limits need ed to comply with the rules adopted by the State of Washington. However, Ecology does not develop effluent limits for all reported pollutants. Some pollutants are not treatable at the concentrati ons reported, are not controllable at the source, are not listed in regulation, or do not have a reas onable potential to cause a water quality violation.

Nor does Ecology usually develop permit limits fo r pollutants that were not reported in the permit application but that may be present in the discharge. The permit does not authorize discharge of the non-reported pollu tants. During the five-year perm it term, the facility’s effluent discharge conditions may change from those cond itions reported in the permit application. The facility must notify Ecology, as described in 40 CFR 122.42(a), if significant changes occur in any constituent. Industries may be in violati on of their permit until the permit is modified to reflect additional discharge of pollutants.

H. A. Design Criteria

Under WAC 173-220-150 (1)(g), neither flows nor waste loadings may exceed approved design criteria. USOR submitted Wast ewater Treatment Efficiency Study and Engineering Report in

Page 7

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma August 2004; it compares actual wastewater load ing to the biological treatment unit (Orbal) values with design values for selected para meters as listed on the following table.

Parameter Units Design Value Value between 2001 to 2004 1995 -2007 Historical Data Maximum Average Monthly flow gpm Gallon/day 451 650,000 430 619,200 655

Peak Hourly Flow gpm 687 659 789

BOD Lbs/day 900 491 1,447 Ecology may determine the design criteria for hydr aulic loading and BOD loading to the Orbal in the permit.

B. Technology-Based Effluent Limits

Process Wastewater

Ecology based the effluent limits for USOR on Best Conventional Pollutant Control Technology (BCT), Best Available Technology Economically Ac hievable (BAT), Best Practicable Control Technology Currently Available (BPT), and on Ne w Source Performance Standards (NSPS), as developed by the Environmental Protection Agency (EPA).

EPA published guidelines for developing efflue nt limitations on August 12, 1985 [under 40 CFR Part 419] for the topping subcateg ory of petroleum refining. EPA based these limits on terms of a settlement agreement dated April 17, 1984, between EPA and the Natural Resources Defense Council, resolving litigation a bout the EPA guidelines. The August 12, 1985 guidelines establish Best Available Technology (BAT) and Best Conve ntional Technology (BCT) as equal to Best Practicable Technology (BPT) for all paramete rs except phenols and chromium. Ecology regulates phenols and chromium by whichever guid eline is more stringent. USOR must use all known, available, and reasonable methods (AKART) to control toxicants in its wastewater.

On December 31, 2003 EPA published its intention to review the petroleum refining industry’s practices to decide whether it should revise the industry’s efflue nt guidelines. EPA evaluated pollution prevention opportunities, emerging trea tment technologies, tre nds reflected in the effluent guidelines, and expanding the list of regu lated pollutants. EPA reviewed information and comments on several issues including: co ntrol technologies for polycyclic aromatic hydrocarbons (PAHs), dioxin sources and reducti on/control technologies, sources of toxic metals, process modifications to reduce metals content, and toxics commonly released but remain unreported. EPA reviewed the availabl e dioxin information collected by refineries nationwide much of which was collected at the Washington state refineries.

On September 2, 2004 (Federal Register Volume 69 No. 170) EPA published its decision about the refinery effluent gui delines. EPA concluded:

• there is little evidence that PAHs are present in refinery wastewater discharges in concentrations above the detection limit.

Page 8

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

• the concentration of metals being discharged by refineries is at or very near treatable levels, leaving little to no opportunity to re duce metals discharges through conventional end-of-pipe treatment.

• dioxins are only occasionally discharged, in relatively low concentrations, in treated refinery effluent. In EPA’s opinion this data did not warrant the development of national categorical limitations on di oxin in refinery wastewater discharges. But EPA did note that on a case-by-case, best-p rofessional-judgment basis, pe rmit writers may decide to include effluent limita tions for dioxin.

As a result of the evaluation, EPA found no need to revise the federal efflue nt guidelines at this time. But EPA encourages permit writers and refineries to consider pollution prevention opportunities.

Ecology must decide whether the effluent guidelines also constitute “all known, available and reasonable methods of treatment” (AKART). As a general rule, if the effluent guidelines for a particular pollutant/source category are five years old or newer, Ecology presumes they will be AKART. If the effluent guideli nes are over 10 years old, Ecology reviews the federal effluent guidelines development document and analyzes unit processes design and efficiencies to determine that the effluent guidelines constitu te AKART and meet the intent of RCW 90.48.520. The federal effluent guidelines development doc ument describes production processes, pollutants generated, treatment efficiencies, and unit proc ess designs present nationwide in the specific industry at the time of effl uent guideline development

. In the 2002 permit, USOR was required to prep are an engineering report predicting design capacities for the facility ’s wastewater treatment system ba sed upon current operating conditions. This permit condition also required that USOR collect additional treatment unit influent and effluent data. The data was evaluated to determ ine current treatment unit operating efficiencies. The operating efficiencies and design/flow capaci ties detailed in the study yielded results better than standards and predicted loadings. Ecology re viewed the reports and determined that USOR is providing AKART for its wastewater. EP A’s 2003 effluent guideli nes evaluation also supports Ecology’s determination.

Ecology also applied new source performance st andards on the basis of AKART, making our permit limitations more stringent than those applie d in other states. Ecology began applying the more stringent new source performance stan dards to all crude th roughput increases in 1984.

Since the previous NPDES permit was issued on April 16, 2002, U.S. O il’s crude oil throughput rate has slowly increased. The rate changes in refinery processes are shown below along with the applicable size and process factors selected for the EPA guidelines. These factors are multiplied by the actual feed stock in barrels per stream day to obtain an adjusted feed stock used in determining effluent limitations, except for determining BAT limitations for phenols and chromium. The unit process rates of the proposed permit in the following table are based on the highest 12 consecutive months valu e in previous 5 years. The fo llowing table lists the refinery processes, flows, and process a nd size factors as calculated in Appendix E

.

Page 9

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Parameters 1990 Permit 2002 Permit Proposed Permit

Actual Feed Stock, bbls/stream day 30,500 37,220 37,690
Desalting, bbls /stream day 30,500 37,220 37,690
Atmospheric Distillation, bbls/stream day 30,500 37,220 37,690

Vacuum Distillation, bbls/stream day 17,300 18,650 16,030
Catalytic Reforming, bbls/stream day 3,800 4,140 5,750
Asphalt Production, bbls/stream day 5,300 3,770 5,630
Emulsified Asphalt, bbls/stream day 1,020 230

Process Factor 0.95 0.80 0.80

Size Factor 1.06 1.06 1.06
Adjusted Feed Stock, bbls/stream day 30,700 31,560 31,961

Increases in the feedstock rate are subject to limitations de termined by Ecology to be the treatment level obtained from using all known, available, and reasonable treatment methods. They are therefore subject to New Source Performance Standards. These limitations were calculated by multiplying the increase in adjusted feed stock, (31,961 - 27,189 = 4,772 barrels (bbls) per day) by New Source Performance St andards (NSPS). The resulting NSPS increment, based upon a current feedstock rate of 37,690 bbl s per day, was then added to BAT and BPT limitations, based upon the adjusted baseline feedstock rate of 27,189 bbls per day. BCT limitations were not included because they are equivalent to BPT limitations.

The EPA/NRDC settlement agreement provided separate factors for calculating phenols, total chromium, and hexavalent chromium for th e BAT limitation. These calculations required feedstock rate data for additional processes including: hydrotreating, cat alytic reforming, and alkylation. This information is included in the Table above.

The permit limit calculations are tabulated in Appendix E . The actual permit limit is the most stringent of the BAT and BPT determinati ons. The proposed technology-based effluent limitations are listed in the table below in pounds per day unless otherwise noted.

Parameters Proposed Technol ogy-Based Limits (Outfall 001A)

Units Monthly Average Daily Maximum
Biochemical Oxygen Demand (5-day) lbs/day 126 238

Chemical Oxygen Demand lbs/day 633 1,224

Page 10

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Parameters Proposed Technol ogy-Based Limits (Outfall 001A)
Units Monthly Average Daily Maximum
Total Suspended Solids lbs/day 107 167

Oil and Grease lbs/day 39 74

Oil and Grease mg/l Cannot at anytime exceed 15 mg/l, and cannot exceed 10 mg/l more than 3 times per month
Phenolic Compounds lbs/day 0.65 1.78

Ammonia as N lbs/day 14 32

Sulfide lbs/day 0.71 1.57

Total Chromium lbs/day 0.88 2.31

Hexavalent Chromium lbs/day 0.06 0.13
pH In the range of 6.0 to 9.0
Excursions between 5.0 and 6.0, or 9.0 and 10.0 must not be considered violations provid ed 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 EPA determined federal effluent guidelines for total and hexavalent chromium, back when chromium was commonly used in cooling water syst ems 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 at refine ries is any low levels of chromi um present in the crude oil.

Because federal effluent guidelines still includ e limits for chromium, Ecology must include an effluent limit for chromium in the proposed permit to ensure that refineries in Washington are subject to the same requirements as re fineries located in other states.

Ecology’s Best Professional Judgment conclu des that a 50 μg/l hexavalent chromium concentration limit is technologically achievabl e, reasonable, and protec tive of the receiving water quality. The 50 μg/l limit, at a 0.99 MGD effl uent flow, converts to 0.41 lbs/day--which is less stringent than the federal e ffluent guideline limit of 0.13 lbs/da y, a water quality-based limit. This technology-based limit, therefore, can not replace both the total chromium limit and the hexavalent chromium limit in the permit

. If chromium level changes in th e crude oil refined at USOR re sult in concentration increases, Ecology will modify the permit to increase the li mit as needed to allow continued facility compliance. We will evaluate any revised limit to ensure that the effluent continues to meet water quality standards within the authorized mixing zone, and to ensure that chromium concentrations do not exceed limits allowed under the federal effluent guidelines. In the event that federal effluent guidelines are promulgated without chromi um limitations, we will drop the

Page 11

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma limit from the permit unless the situation changes a nd Ecology determines a water quality limit is necessary. USOR will continue to perform semi-annual hexava lent chromium monitoring.

Stormwater Allocations

Contaminated stormwater from the process area is collected by the oily water sewer and is treated at the wastewater treatment facility.

In the previous Fact Sheet, USOR estimated dry weather flow by using a water flow balance for each water user in the refinery. The basis for the water balance report was an audit of water usage data for the calendar year 1998. Using the audit, the dry weather fl ow rate was determined to be 237 GPM. With the subt raction of hydrotest water gene rated during 1998, the dry weather flow was estimated to be 331,200 gallons per day (230 GPM).

USOR has conducted a Treatment Efficiency Study and Engineering Report and submitted the report to Ecology on August 3, 2004. An averag e dry weather flow rate of 227 gpm final effluent was determined based on the statistical anal ysis of the three-year (July 1, 2001 to June 30, 2004) flow data and data collected during the sampling period performed between January 2003 and September 2003. This value agrees with the 230 gpm dry weather flow calculated in the August 2000 wate r audit performed by CH2MHill. After car efully reviewing the engineering Report, Ecology accep ts the 227 gpm dry weather flow.

The stormwater allocations in the permit are based on guidelines in 40 CFR419.12(e). Phenolic compounds are not included in the stormwater a llocation because of the compliance record of U.S. Oil. During the period of January 1991 to December 2007 the refinery has been in compliance with the permit limits for phenolic co mpounds. The allocations for stormwater only apply to runoff from areas associated with indus trial activity, not outlying areas such as parking lots and surrounding acreage. During the months of June through Septembe r, U.S. Oil will only be allowed to claim the stormwater allocation when it can be demonstrated that measurable rainfall has occurred at the refi nery site during the previous 10 calendar days. The allocations are tabulated below.

Parameters Stormwater Allocation (Outfall 001A) pounds/Million gallons
Monthly Average Daily Maximum
Biochemical Oxygen Demand (5-day) 220 400

Chemical Oxygen Demand 1500 3000
Total Suspended Solids 180 280

Oil and Grease 67 130

Page 12

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Marine Terminal Stormwater

Outfall No. 003: The containment ar ea at the Marine Terminal generates stormwater that is of moderate risk of having petroleum contamination, due to past oil spills. The stormwater is collected in a vault that allows any oil present to sepa rate, and the water is discharged from under a weir leaving the oil, if any behind. The wa ter in this area is manua lly inspected by the dock operator for the presence of oil or any sheening prior to manu ally activating the discharge pump. The stormwater is pumped to the infiltration basi n, an area on the Marine Terminal property that has a sandy floor and is surrounded by be rms, for release to groundwater.

The limitations listed below are similar to the on es required for stormwater from other, nearby petroleum storage tank containment areas. The monitoring for BOD 5 , COD, and NWTPH-D X , is intended to gather information about these pa rameters in stormwater from petroleum storage facilities. Sampling is only required during thos e months where stormwater is being discharged to the infiltration basin.

Parameter Marine Terminal Stormwater Limitation (Outfall 003) Monitoring Frequency/Sample
Oil and Grease The concen tration in the discharge shall at no time exceed 15 mg/l Once per month/grab when discharging pH In the range of 6.0 to 9.0 Once per month/grab when discharging Biochemical Oxygen Demand (5-day) Once per year/grab

Chemical Oxygen Demand Once per year/grab

NWTPH-Dx Once per year/grab

Pollution Prevention to Date

USOR submitted NPDES Pollution Prevention Plan phase I and II on December 2004 and 2005, respectively, as required by the current NPDES permit. In the phase I, USOR selected 11 pollution prevention opportunities for study and in the phase II, USOR added a new opportunity, underground piping inspection program.

On October 26, 2006, USOR sent Ecology a copy of Pollution Prevention Plan Biennial Progress Report. In the report USOR summarized the stat us of the first 11 opportunities. There are six opportunities were rejected by “E conomically Infeasible” or “L ow Probability of Success”, which are: 1) reduction of boiler blowdown, 2) reduction of cooling towe r blowdown, 3) install secondary desalting system, 4) brine recycling at the desalter, 5) segreg ate B area drain system, and 6) pretreatment of CR U regeneration caustic wash.

The opportunities USOR is st ill working on are listed as in the following table:

Page 13

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

1 Employee Training on Surfactant Delayed due to facility workload. New Target is 3 rd quarter 2008. 2 Development of Refinery-wide Chemical Approval Procedure Complete and fully implemented.

3 Recovery of Lab Hydrocarbon Samples Due to safety concerns regarding the accumulation of low flash point hydrocarbons, additional study is required. Target 4 th quarter 2009 for completion. 4 Recovery of Steam Condensate Complete and fully implemented. 5 Evaluation of Refinery Containment Systems Delayed due to SPCC rule delay. New Target is 3 rd quarter 2009. 6 Underground Piping Inspection Program Program developed and implemented. The execution of this program will be impacted by Department of Ecology Administrative Order DE5020.

New Requirements
In the proposed permit, Ecology requires USOR to update the water-or iented NPDES Pollution Prevention plan. Ecology’s goa ls and objectives for devel oping and implementing pollution prevention plans are to identify, reduce, eliminat e, and prevent the gene ration 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 sedi ment quality standards. The objective of this update is to identify any new sources of pollutant s, to reevaluate previ ously identified pollution prevention opportunities

, and to identify any new opportunities and implement those that are technically and economically achievable.

Required NPDES Pollution Prevention plan elemen ts include identification and implementation of Best Management Practices (BMPs). Purs uant to 90.48 RCW and Sections 302 and 402 of the Clean Water Act, Ecology may incorporate BMPs as permit conditions. BMPs are actions or procedures that prevent or minimize the poten tial for release of po llutants or hazardous substances, in significant quantities, to surf ace waters. BMPs, though normally qualitative, are most effective when used in conjunction with nu merical (quantitative) effluent limits in NPDES permits.

The NPDES Pollution Prevention plan also addr esses stormwater. Ecology published guidance for the prevention of stormwater runoff contamination, titled Stormwater Pollution Prevention Planning for Industrial Facilities (September 1993). USOR may incorporate (into the pollution prevention plan) the appropriate sections of Ecology’s guidance

-- or any other plans previously developed by the refinery

-- which include procedures for pr evention of stormwater runoff contamination. These plans, however, will not n ecessarily include all of the BMPs necessary for preventing stormwater contamination by more c onventional pollutants – in particular, total suspended solids (TSS). Pollution Prevention plan s do not generally address “clean” areas of the facility (those areas where petroleum products or hazardous materials are not stored or used). These “clean” areas may contribute conventiona l pollutants to the f acility’s stormwater.

Ecology included a review of solid waste hand ling and disposal procedures in the NPDES Pollution Prevention Plan to prevent solid wast e and solid waste leachate from causing pollution

Page 14

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma of state waters. In addition, USOR’s latest plan describes measures alre ady taken to prevent the accidental release of pollutants to state waters and to minimize damages if such a spill should

occur.

I. C. Surface Water Quality-Based Effluent Limits

The Washington State Surface Water Quality Standards (Chapter 173-201A WAC) were designed to protect existing wate r quality and preserve the bene ficial uses of Washington's surface waters. Waste discharge permits must incl ude conditions that ensure the discharge will meet established surface water quality sta ndards (WAC 173-201A-060). The Water qualitybased effluent limits may be based on an indivi dual waste load allocation or on a waste load allocation developed during a basin wide total maximum daily loading study (TMDL).

Numerical Criteria for the Protection of Aquatic Life and Recreation "Numerical" water quality criteria are numerical values published in the State of Washington's Water Quality Standards for Surface Waters (Chapt er 173-201A WAC). They specify the levels of pollutants allowed in receiving wa ter to protect aquatic life and re creation in and on the water. Ecology uses numerical criteria along with chem ical and physical data for the wastewater and receiving water to derive the effluent limits in the discharge permit. When surface water qualitybased limits are more stringent or potentially more stringent than t echnology-based limits, the permit must include the water quality-based limits.

Numerical Criteria for the Prot ection of Human Health The U.S. EPA has published 91 numeric water qualit y criteria for the protection of human health that are applicable to dischargers in Washingt on State (EPA 1992). Thes e criteria are designed to protect humans from cancer and other dise ases, based on consuming fish and shellfish and drinking contaminated surface waters. The Wate r Quality Standards also include radionuclide criteria to protect humans from the effects of radioactive substances.

Narrative Criteria Narrative water quality criteria (e.g., WAC 173- 201A-260(2); 2006) limit the toxic, radioactive, or other deleterious material con centrations that the facility may discharge to levels below those which have the potential to:

• Adversely affect designated water uses.

• Cause acute or chronic toxicity to biota.

• Impair aesthetic values.

• Adversely affect human health.
Narrative criteria protect the specific designated uses of a ll fresh waters (WAC 173-201A-600, and WAC 173-201A-602; 2006) and of all mari ne waters (WAC 173-201A-610, 612; 2006) in the State of Washington.

Antidegradation The purpose of Washington's Antidegradation Policy (WAC 173-201A-300- 330; 2006) is to:

Page 15

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

• Restore and maintain the highest possible qu ality of the surface waters of Washington.

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

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

• Ensure that all human activities that are li kely to contribute to a lowering of water quality, at a minimum, apply all known, availa ble, and reasonable methods of prevention, control, and treatment (AKART).

• Apply three Tiers of protection (described be low) for surface waters of the state.

Tier I ensures existing and designated uses are main tained and protected and applies to all waters and all sources of pollutions. Ti er II ensures that waters of a higher quality th an the criteria assigned are not degraded unless such lowering of water quality is necessary and in the overriding public interest. Tier II applies only to a specific list of polluting activities. Tier III prevents the degradation of waters formally liste d as "outstanding resource waters," and applies to all sources of pollution.

A facility must prepare a Tier II analysis when all three of the follo wing conditions are met:

• The facility is planning a new or expanded action.

• Ecology regulates or authorizes the action.

• The action has the potential to cause measurab le degradation to ex isting water quality at the edge of a chronic mixing zone.

This facility must meet Tier I requirements.

• Existing and designated uses must be mainta ined and protected. No degradation may be allowed that would interfere with, or become injurious to, existing or designated uses, except as provided for in this chapter.

Ecology’s analysis described in th is section of the fact sheet de monstrates that the existing and designated uses of the receiving water will be protected under th e conditions of the proposed permit.

Mixing Zones
A mixing zone is the defined area in the receivi ng water surrounding the di scharge port(s), where wastewater mixes with receiving water. Within mixing zones the pollutant concentrations may exceed water quality numeric standards, so long as the diluting wastewater doesn’t interfere with designated uses of the receiving water body (e.g., recreation, water supply, and aquatic life and wildlife habitat, etc.) The pollutant concentratio ns outside of the mixing zones must meet water quality numeric standards.

State and federal rules allow mixing zones becau se the concentrations and effects of most pollutants diminish rapidly after discharge, due to dilution. Ecology define s mixing zone sizes to limit the amount of time any exposure to the end- of-pipe discharge could harm water quality, plants, or fish.

Page 16

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma The state’s water quality standard s allow Ecology to authorize mi xing zones for the facility’s permitted wastewater discharges only if those discharges already receive all known, available, and reasonable methods of prev ention, control and treatment (AKART). Mixing zones typically require compliance with water qualit y criteria within 200 to 300 feet from the point of discharge; and use no more than 25% of the available width of the water body for dilution. We use modeling to estimate the amount of mixing w ithin the mixing zone. Through modeling we determine the potential for viola ting the water quality standards at the edge of the mixing zone and to derive any necessary effluent limits. St eady-state models are the most frequently used tools for conducting mixing zone analyses. Ecol ogy chooses values for each effluent and for receiving water variables that co rrespond to the time period when the most critical condition is likely to occur (see Ecology’s Permit Writer’s Manual). Each critical condition parameter (by itself) has a low probability of occurrence and the resulting dilution factor is conservative. The term “reasonable worst-case” applies to these values.

The mixing zone analysis produces a numerical value called a dilu tion factor (DF). A dilution factor represents the amount of mixing of effluent and receiv ing water that occurs at the boundary of the mixing zone. For example, a dilu tion factor of 10 means the effluent comprises 10% by volume and the receiving water comprises 90% of the total volume at the boundary of the mixing zone. We use dilution factors with th e water quality criteria to calculate reasonable potentials and effluent limits. Water quality st andards include both aquatic life-based criteria and human health-based criteria. The former ar e applied at both the acute and chronic mixing zone boundaries; the latter are a pplied only at the chronic bounda ry. The concentration of pollutants at the boundaries of any of these mi xing zones may not exceed the numerical criteria for that zone.

Each aquatic life acute criterion is based on the assumption that organisms are not exposed to that concentration for more than one-hour and more often than one exposure in three years. Each aquatic life chronic criterion is based on the assumption th at organisms are not exposed to that concentration for more than four consecutive days and more often than once in three years.

The two types of human health-bas ed water quality criteria dis tinguish between those pollutants linked to non-cancer effect s (non-carcinogenic) and those linked to cancer effects (carcinogenic). The human health-based wate r quality criteria incorporat e several exposure and risk assumptions. These assumptions include:

• A 70-year lifetime of daily exposures.

• An ingestion rate for fish or shellfish measured in kg/day.

• An ingestion rate of two liters/day for drinking water

• A one-in-one-million cancer risk for carcinogenic chemicals.

This permit authorizes a small acute mixing zone, surrounded by a chronic mixing zone around the point of discharge (WAC 173-201A-400; 2006). The water quality standards impose certain conditions before allowing the discharger a mixing zone:

1. Ecology must specify both the allowed size and location in a permit. This permit specifies the size and lo cation of the allowed mixing zone.

Page 17

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma 2. The facility must fully apply “all kn own available and reasonable methods of prevention, control and treatment” (AKART) to its discharge. Ecology has determined that the treatment pr ovided and the pollution prevention activities practiced at USOR meet th e requirements of AKART (see “Technology based Limits”).

3. Ecology must consider critical discharge conditions. Surface water quality-based limits are derived for the water body’s critical condition, (the receiving water and waste discha rge condition with the highest potential for adverse impact on the aquatic biota, human health, and existing or designated water body uses). The critical discharge condition is of ten pollutant-specific or water body-specific.

Critical discharge conditions are those conditions that result in reduced dilution or increased effect of the pollutant. Factors affecting d ilution include the depth of water, the density stratification in the water column, the currents and the rate of discharge. Density stratification is determined by the salinity and temperature of the receiving water. Temperatures are warmer in the surface waters in summer. Therefore, density stratification is generally greatest during the summer months. Density stratification affects how far up in the water column a freshwater plume may raise. The rate of mixing is greatest when an effluent is risi ng. The effluent stops rising when the mixed effluent is the same density as the surroundi ng water. After the effluent stops rising, the rate of mixing is much more gr adual. Water depth can affect dilution when a plume might rise to the surface when there is li ttle or no stratification. Ecology uses the water depth at mean lower low water (MLLW) for ma rine waters. Ecology’s Permit Writer’s Manual describes additional guidance on criteria/design cond itions for determining dilution factors. The Manual can be obtained from Ecology’s website at: http://www.ecy.wa.gov/biblio/92109.html

. Ecology used the following critical c onditions to model the discharge:

• The mixing zone calculations were to refl ect acute and chronic mixing zone boundaries of 20 and 200 feet, respectively.

• Use of linear diffusivity instead of the 4/3 Law for far –field dilution modeling.

• Choice of the far-field dispersion coefficient.

• The modeling procedure for an intermittent discharge.

• The effluent flow rates selected for the in itial dilution PLUMES model for the acute and chronic cases were 19.8 mgd and 9.8 mgd, respectively.

• Predicted dilution at the mixing zone boundari es are 2.0 for acute and 5.8 for chronic.

• Adjustment factor to calculate applicable di lution at the mixing zone boundaries adjusted by the ratio of peak hourly flow rate used in the model (9.8 mgd) to the maximum 4-day average flow rate (0.8mgd). The adjustment factors for calculation of critical acute and chronic dilution are 1.0 for acute and 12.3 for chronic.

• The applicable dilution at the mixing zone boundaries is calculated by multiplying the predicted dilution at each boundary by the respective adjustment factor. Therefore, the applicable acute and chronic dilutio n factors are 2.0 x1.0 = 2.0 and 5.8 x 12.3 = 71.3.

4. Supporting information must clearly i ndicate the mixing zone would not:

• Have a reasonable potential to cause the lo ss of sensitive or important habitat,

Page 18

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

• Substantially interfere with the existing or characteristic uses,

• Result in damage to the ecosystem, or

• Adversely affect public health.

Ecology established Washington State water quality criteria for toxic chemicals using EPA criteria. EPA developed the crite ria using toxicity tests with nu merous organisms, and set the criteria to generally protect 95% of the species tested and to fully protect all commercially and recreationally important species.

EPA sets acute criteria for toxic chemicals assuming organisms are exposed to the pollutant at the criteria concentration for 1-hour. They set chronic standards assuming organisms are exposed to the pollutant at the cr iteria concentration for 4 days. Dilution modeling under critical conditions generally shows that both acute and chr onic criteria concentrations are reached within minutes of being discharged.

The discharge plume does not impact drifting and non-strong swimming organisms because they cannot stay in the plume close to the outfall l ong enough to be affected. Strong swimming fish could maintain a position within the plume, but they can also avoid the discharge by swimming away. Mixing zones generally do not affect be nthic organisms (bottom dwellers) because the buoyant plume rises in the water column. Ecology has additionally determined that the effluent will not exceed 33 degrees C for more than 2 seconds after discharge; and that the temperature of the water will not create lethal conditions or blockages to fish migration.

Ecology evaluates the cumulative to xicity of an effluent by tes ting the discharge with whole effluent toxicity (WET) testing. See Ecology’s Permit Writer’s Manual for details. http://www.ecy.wa.gov/biblio/92109.html

Ecology reviewed the above information, the specif ic information on the characteristics of the discharge, the receiving water characteristics

, and the discharge location. Based on this review we conclude that the discharge does not have a re asonable potential to cause the loss of sensitive or important habitat, substantially interfere with existing or characteristic s uses, result in damage to the ecosystem or adversely affect public health

5. The discharge/receiving water mixture mu st not exceed water quality criteria outside the boundary of a mixing zone. Ecology conducted a reasonable pote ntial analysis, using procedur es established by the EPA and by Ecology, for each pollutant. We concluded th e discharge/receiving water mixture will not violate water quality criteria outs ide the boundary of the mixing zone.

6. The size of the mixing zone and the concen trations of the pollutants must be minimized. At any given time, the effluent plume uses onl y a portion of the acute and chronic mixing zone, which minimizes the volume of water involved in mixing. Because tidal currents change direction, the plume orientation within the mixing zone changes. The plume rises through the water column as it mixes therefore much of th e receiving water volume at lower depths in the mixing zone is not mixed with discharge. Si milarly, because the discharge may stop rising at some depth due to density stratification, waters a bove that depth will not mix with the discharge.

Page 19

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma Ecology determined it is impractical to specif y in the permit the actual, much more limited volume in which the dilution occurs as the plume rises and moves with the current.

Ecology minimizes the size of mixing zones by requi ring dischargers to install diffusers when they are appropriate to the discharge and the sp ecific receiving waterbody. When a diffuser is installed the discharge and the receiving water is more completely mixed in a shorter time period. Ecology also minimizes the size of the mi xing zone (in the form of the dilution factor) using design criteria with a low probability of occurrence. For example, Ecology uses the expected 95 th percentile pollutant concentration, the 90 th percentile background concentration, the centerline dilution factor and the lowest flow occurring once in every 10 years to perform the reasonable potential analysis.

The facility continues to conduct pollution pr evention activitie s and has completed pollution prevention projects. These activities also mini mize the concentrations of pollutants in the discharge.

Because of the above reasons, Ecology has effect ively minimized the size of the mixing zone authorized in the proposed permit.

7. Maximum size of mixing zone. The authorized mixing zone does not exceed the maximum size restriction.

8. Acute Mixing Zone.

• The discharge/receiving water mixture must co mply with acute criteria as near to the point of discharge as practicably attainable. Ecology determined the acute criteria will be met at 10% of the di stance of the chronic mixing zone.

• The pollutant concentration, dur ation and frequency of exposur e to the discharge, will not create a barrier to migration or translocation of indigenous organisms to a degree that has the potential to cause damage to the ecosystem.

As described above, the toxicity of any pollutant depends upon the exposure, the pollutant concentration and the time the orga nism is exposed to that concentration. Authorizing a limited acute mixing zone for this discharge assures that it will not create a barrier to migration. The effluent from this discharge will rise as it enters the receiving water, assuring that the rising effluent will not cause transloc ation of indigenous organisms near the point of disc harge (below the rising effluent).

• Comply with size restrictions. The mixing zone authorized for this disc harge complies with the size restrictions published in Chapter 173-201A WAC.

9. Overlap of Mixing Zones. This mixing zone does not overlap another mixing zone

.

Page 20

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

D

. Description of the Receiving Water

The receiving water classification of the Blair Wa terway has been designated a Class B marine waterbody. The characteristic uses include the following: industrial and; fish migration and shellfish spawning, rearing and ha rvesting; wildlife ha bitat; secondary contact recreation; sport fishing; boating and aesthetic en joyment; commerce and navigation.
The ambient background data used for this permit includes the following from Ecology’s Water quality monitoring data:

Ambient Background Data

Parameter Value used Temperature (highest annual 1- DADMax) 17.9 o C

pH (high) 8.2 Dissolved Oxygen 6.5 mg/L

Total Ammonia-N N/A

Fecal Coliform N/A Turbidity 3.4 NTU

Hardness N/A Alkalinity N/A
Lead (dissolved) 0.020 ug/L Copper (dissolved) 0.81 ug/L
Zinc (dissolved) 3.7 ug/L
Arsenic (unfiltered) 1.3 ug/L
Cadmium (dissolved) 0.061 ug/L Mercury (tot. Recoverable) 0.0023 ug/L

J. E. Designated Uses and Surface Water Quality Criteria
Applicable designated uses and surface water qu ality criteria are define d in chapter 173-201A WAC. In addition, the U.S. EPA set human heal th criteria for toxic pollutants (40 CFR 131.36). Criteria applicable to this facili ty’s discharge are summarized in Table below.

• Aquatic life uses are designated using the following general categories. All indigenous fish and nonfish aquatic species must be protected in waters of the state.

Page 21

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma (a) Extraordinary quality salmonid and other fish migration, rearing, and spawning; clam, oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, shrimp, crayfish, scallops, etc.) rearing and spawning. (b) Excellent quality salmonid and other fish migrati on, rearing, and spawning; clam, oyster, and mussel rearing and spawning; crus taceans and other shellfish (crabs, shrimp, crayfish, scallops, etc. ) rearing and spawning. (c) Good quality salmonid migration and rearing; ot her fish migration, rearing, and spawning; clam, oyster, and mussel rearing a nd spawning; crustaceans and other shellfish (crabs, shrimp, crayfish, scall ops, etc.) rearing and spawning. (d) Fair quality salmonid and other fish migration.

The Aquatic Life Uses for this receiving water are identified below.

Aquatic Life Uses & Associated Criteria Excellent quality Temperature Criteria – Highest 1D MAX 16°C (60.8°F) Dissolved Oxygen Criteria – Lowest 1 Day Minimum 6.0 mg/L

Turbidity Criteria • 5 NTU over background when the background is 50 NTU or less; or • A 10 percent increase in turbidity when the background turbidity is more than 50 NTU. pH Criteria pH must be within the range of 7.0 to 8.5 with a human-caused variation within the above range of less than 0.5 units.

• To protect shellfish harvesting , fecal coliform organism levels must not exceed a geometric mean value of 14 colonies/100 mL, and not have more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 43 colonies/100 mL. (Note 1.)

• The recreational uses are primary contact recreation and secondary contact recreation.

The recreational uses for this receiving water are identified below.

Recreational Uses

Recreational use Criteria Primary Contact Recreation Fecal coliform organism levels must not exceed a geometric mean value of 14 colonies/100 mL, with not more than 10 percent of all samples (or any single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 43 colonies /100 mL. (Note 1.) Secondary Contact Enterococci organism levels must not exceed a geometric mean value of 70 colonies/100 mL, with not more than 10 percent of all samples (or any

Page 22

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Recreation single sample when less than ten sample points exist) obtained for calculating the geometric mean value exceeding 208 colonies/100 mL. (Note 1.) Note 1. Since U.S. Oil does not treat sanitary wastes, the discussions regarding fecal coliform and enterococci organisms do not apply.

• The miscellaneous marine water uses are wildlife habitat, harvesting, commerce and navigation, boating, and aesthetics.

K. F. Evaluation of Surface Water Quality -Bas ed Effluent Limits for Numeric Criteria
Pollutants in an effluent may affect the aquati c environment near the poi nt of discharge (near field) or at a considerable dist ance from the point of discharge (far field). Toxic pollutants, for example, are near-field pollutants--their advers e effects diminish rapidly with mixing in the receiving water. Conversely, a pollutant such as biological oxyge n demand (BOD) is a far-field pollutant whose adverse effect occurs away from the discharge even after dilution has occurred. Thus, the method of calculating surface water qualit y-based effluent limits varies with the point at which the pollutant has its maximum effect.
Pollutant concentrations in the proposed discha rge exceed water quality criteria despite using technology-based controls which Ecology dete rmined fulfills AKART. Ecology therefore authorizes a mixing zone in accordance with the geometric configuration, flow restriction, and other restrictions imposed on mixing z ones described in chapter 173-201A WAC.
Outfall Configuration – Outfall 001
U. S. Oil’s treated wastewater is conveyed to a City of Tacoma storm sewer and is ultimately discharged along with collected stormwater to an 84-inch pipe that connects with the Lincoln Avenue ditch with a Red Valve Series 35 check valve. The check valve is a rubber duckbill check sleeve that prevents backflow of tidewat ers into Lincoln Avenue Ditch during high tide. The U. S. Oil treated wastewater and stormwater is discharged out of a slot check valve rather than an open pipe. Information on the outfall is available in the Operation & Maintenance Manual for the new outfall line, submitted to Ecology in August of 2005. Additional information can be found in the Mixing Zone Ev aluation for U. S. Oil’s Discharge to Blair Waterway submitted to Ecology in May of 2000.
Chronic Mixing Zone
WAC 173-201A-100(8)(b)(I) specifies mixing zones sh all not extend in any horizontal direction from the discharge point or ports for a distance gr eater than 200 feet plus the depth of water over the discharge ports as measur ed during mean lower low water (MLLW). The chronic zone therefore extends 200 feet horizont ally from the discharge point.
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 beyond 10% of the dist ance established for th e maximum or chronic zone as measured independently from the discha rge point. The acute zone therefore extends 20 feet from the discharge slot.

Page 23

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma The dilution factors of effluent to receiving water that occur within these zones have been determined at the critical flow condition of May through October by the use of modeling mentioned above. The dilution factors have been determined to be:

Acute Chronic Aquatic Life 2.0 71.3 Human Health, Carcinogen 71.3 Human Health, Non-carcinogen 71.3

The mixing zone analysis was completed for the a quatic life chronic criteria dilution factor using the highest monthly average flow as a design criteria. Ecolo gy’s permit writer’s manual allows the permittee to use the annual average flow to make the mixing zone evaluation for carcinogenic human health criteria. This lower flow value will increase the amount of available dilution. In the absence of that informa tion Ecology has based the dilution factor for carcinogenic human health criteria on the more st ringent value obtained for the chronic aquatic life criteria. The derivation of water quality-b ased limits also takes into a ccount the variability of the pollutant concentrations in both th e effluent and the receiving wate r. Water quality-based limits are derived for the waterbody's critical condition , which represents the receiving water and waste discharge condition with the hi ghest potential for adverse im pact on the aquatic biota and existing or characteristic water body uses. The cr itical condition for the Blair Waterway occurs in the late summer when there is little or no st ormwater runoff in the Lincoln Avenue Ditch and when the discharge from U.S. Oil comprises nearly all of the flow in the D itch and is in its most concentrated form.

Dissolved Oxygen and BOD 5 U.S. Oil has limited informati on on the dissolved oxygen (DO) concentration in their effluent, since they were not required to monitor it in their existing permit. U.S. Oil had, however, previously monitored fo r this parameter daily during the month of December 1999. DO concentrations during this period were generally much higher than the water quality standard for DO in the receiving wate r (for a class B marine waterway the standard is 5 mg/l), with an average of 7 mg/l. Ecology is not aware of any information that indicates that the Blair Waterway is impaired due to reduced DO. It is Ecol ogy’s judgment that the effluent will not cause a violation of the DO standard in the receiving water.
Temperature. The water quality standards state the temperature shall not exceed 19 o C due to human activities. When na tural conditions exceed 19 o C no temperature increases will be allowed which will raise the receiving water temperature greater than 0.3 o C. Incremental temperature increases resulting fr om point source activ ities shall not, at any time, exceed t=16/(T). "T" represents the background temperat ure and represents the highest ambient water temperature in the vicinity of the discharge a nd "t" represents the maximum possible temperature increase measured at the mixing zone boundary.

The impact of the discharge on the temperature of the receivi ng water was modeled by simple mixing analysis at critical condition. Temperatur e is evaluated using the critical chronic mixing zone dilution factor of 71.3, the 95 th percentile effluent temperature of 27.5 o C, and the maximum observed surface water temperature of 15.3 o C (9/24/97) at the Ecology ambient monitoring station in Commencement Bay (CMB 003). Based on these data water quality

Page 24

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacomacompliance for temperature depends on comparison to the allowable incremental change in farfield receiving water temperature. The incremen tal temperature increase allowance in marine water (i.e. t=16/T where T is the ma ximum receiving water temperature 1.04 o C=16/15.3 o C) is equal to 1.04 o C. The predicted far-field temperature following initial dilution (T final ) is calculated using the following equation:

T final = T ambient + (T effluent – T ambient ) / D cmz where:

T ambient = Maximum receiving water temperature in ° C. T effluent = 95 th percentile effluent temperature in ° C (un-stratified data). D cmz = Critical chronic mixing zone dilution factor.

T final = 15.3 + (27.5 – 15.3) / 71.3

The predicted temperature is 15.47 o C at the edge of the chronic mixing zone. The incremental increase in temperature is therefore 0.17 o C (15.47 – 15.3), which is within the allowable incremental change of 1.04 o C. Under these conditions there is no predicted violation of The Water Quality Standards. An effluent limita tion was determined not to be necessary.

pH . Because of the high buffering capacity of marine water, compliance with the technologybased limits of 6 to 9 should assure compliance with the Water Quality Standards of 6.5 – 8.5 pH units for Class B Surface Waters at the edge of the mixing zone.

Fecal coliforms The domestic sewage generated at the U.S. Oil refinery enters the Tacoma sanitary sewer via a segregated collection system and is treated at the municipal wastewater treatment plant. Since there is no domestic com ponent to the wastewater treated in the U.S. Oil wastewater system, no chlorination of the effl uent is necessary and no fecal coliforms are expected in the effluent.

Toxic pollutants . Federal regulations (40 CFR 122.44) re quire Ecology to place limits in NPDES permits on toxic chemicals in an effluent when ever there is a reasonable potential for those chemicals to exceed the surface water quality crit eria. Ecology does not exempt facilities with technology-based effluent limits from mee ting the surface water quality standards.
The following toxic pollutants are present in the discharge: arsenic, mercury, nickel, sulfide, copper, lead, selenium, zinc, chlorine, and a mmonia. We conducted a reasonable potential analysis on these parameters to determine whet her effluent limits would be required in this permit.
The reasonable potential for exceeding marine wa ter quality criteria was evaluated with procedures given in EPA’s Technical Support document for Wate r Quality-Based Toxics Control (1991) . The procedure with paramete rs specific to U.S. Oil is s hown in the spreadsheet included

as Appendix G . The dilution factors determined above were used in the analysis.
Valid ambient background data was available for the metals listed above and ammonia. Ecology determined no reasonable potential for this disc harge to cause a violation of water quality

Page 25

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma standards, using all applicable data. Our determin ation assumes that this facility meets the other effluent limits of this permit.
USOR may provide data clearly demonstrating th e seasonal partitioning of the dissolved metal in the ambient water in relation to an effluent disc harge. Ecology may adjust metals criteria on a site-specific basis when data is available clearly demonstrating the seasonal partitioning in the ambient water in relation to an effluent discharge.
Ecology may also adjust metals cr iteria using the water effects ratio approach established by the EPA, as generally guided by the procedures in U.S. EPA Water Quality Standards Handbook

, December 1983, as supplemented or replaced.

L. G. Whole Effluent Toxicity
The Water Quality Standards for Surface Waters requi re that the effluent not cause toxic effects in the receiving waters. Ma ny toxic pollutants cannot be de tected by commonly available detection methods. However, toxicity can be m easured directly by exposing living organisms to the wastewater in laboratory te sts and measuring the response of the organisms. Toxicity tests measure the aggregate toxicity of the whole efflue nt, and therefore this approach is called whole effluent toxicity (WET) testing. Some WET te sts measure acute toxicity and other WET tests measure chronic toxicity.
Acute toxicity tests measure mortality as the signif icant response to the toxi city of the effluent. Dischargers who monitor their wast ewater with acute toxicity test s are providing an indication of the potential lethal effect of the effluent to organisms in the receiving environment.
Chronic toxicity tests measure various subletha l toxic responses such as reduced growth or diminished reproduction. Chronic toxicity tests i nvolve either a complete life cycle test of an organism with an extremely short life cycle or a pa rtial life cycle test on a cr itical stage of one of a test organism's life cycles. Orga nism survival is also measured in some chronic toxicity tests.
All of the compliance monitoring du ring the term of the previous permit met the acute toxicity performance standard and WAC 173-205-120(1). The Permittee is required to test effluent for acute toxicity during the la st year of this permit term to verify that there is no acute toxicity in excess of the performance standard.
When the WET tests during effluent characterizati on indicate that no reasonable potential exists to cause receiving water toxicity, the Permittee will not be given WET limits and will only be required to retest the effluent pr ior to application for permit renewal in order to demonstrate that toxicity has not increased in the effluent. All chronic WET testing conducted in previous permit terms has met the performance standard for ch ronic toxicity so no chronic WET limit or additional effluent characterization is needed. The Permittee is required to test effluent for chronic toxicity during the last year of this permit term to verify that there is no chronic toxicity in excess of the performance standard.
If the Permittee makes process or material ch anges which, in Ecology's opinion, result in an increased potential for acute or chronic efflue nt toxicity, then Ecology may require additional effluent characterization in a re gulatory order, by permit modifica tion, or in the permit renewal. Toxicity is assumed to have increased if W ET testing conducted for submission with a permit

Page 26

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma application fails to meet the performance standards in WAC 173-205- 020, "whole effluent toxicity performance standard". The Permittee may demonstrate to Ecology that changes have not increased effluent toxicity by performing additional WET testing after the time the process or material changes have been made.

M. H. Human Health
Washington’s water quality standards include 91 numeric human health-based criteria that Ecology must consider when writing NPDES permits . These criteria were established in 1992 by the U.S. EPA in its National Toxics Rule ( 40 CFR 131.36). The National Toxics Rule allows states to use mixing zones to evaluate whether discharges comply with human health criteria.
Ecology determined the effluent may contain ch emicals of concern posing a risk to human health. Ecology determined this because the volume of wastewater flow to the receiving water, and data or process information indicate re gulated chemicals occur in the discharge.
Ecology conducted a determination of the discha rge's potential to cause an exceedance of the water quality standards as requi red by 40 CFR 122.44(d). We follo wed the procedures published in the Technical Support Document for Water Quality-Based Toxics Control (EPA/505/2-90- 001) and Ecology's Permit Writer's Manual (Ecol ogy Publication 92-109, July, 1994) to make this reasonable potential determ ination. Our evaluation showed that the discharge has no reasonable potential to cause a violation of wa ter quality standards ex cepting arsenic, thus effluent limits are not warranted.

Arsenic
In 1992 the USEPA adopted risk-based arsenic criter ia for the protection of human health for the State of Washington. The criter ion for marine waters is 0.14 μ g/L inorganic arsenic, and is based on exposure from fish and shellfish tissue ingestion. The freshwater criterion is 0.018
μ g/L, and is based on exposure from fish and shel lfish tissue and water ingestion. These criteria have caused confusion in implementation becaus e they differ from the drinking water maximum contaminant level (MCL) of 10 μ g/L, which is not risk-based, and because the human health criteria are sometimes exceeded by natural backgr ound 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, a nd 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 additiona l treatment to meet numeric effluent limits even though no arsenic was added as waste. Alt hough 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-deriv ed 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 th e arsenic criteria. The three strategy elements

are:

Page 27

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma 1. Pursue, at the national level, a solution to the regulatory issue of groundwater sources with high arsenic concentrations causing m unicipal treatment plant effluent to exceed criteria. The revision of the MCL for arsenic o ffered a national opportun ity to discuss how drinking water sources can affect NPDES wa stewater discharges, however Ecology was unsuccessful in focusing the discussion on deve loping 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 sour ces. The current arsenic MCL of 10 ug/L could also result in municipal treatme nt plants being unable to meet criteria-based effluent limits. Ecology will continue to pursue this issue as opportunities arise.

2. Additional and more focused data collection . The Water Quality Program will in some cases require additional and more focused arsenic data collecti on, will encourage or require dischargers to test for source water arsenic c oncentrations, and will pursue development of a proposal to have Ecology's E nvironmental 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 deve lop a strategy to regulate arsenic.

Ecology must evaluate whether or not the disc harge has reasonable potential to violate human health criteria at the edge of the chronic zone. To thoroughly ev aluate human health criteria the permit requires USOR to re-characterize the e ffluent by sampling for the 91 human health criteria listed pollutants (pri ority pollutants), excluding PCB’ s, PBB’s, asbestos, and all pesticides except any listed pesticide that is used on the refinery site. The effluent shall be sampled and analyzed annually duri ng the life of the permit.

N. I. Sediment Quality
The aquatic sediment standards (Chapter 173-204 WAC) protect a quatic biota and human health. Under these standards Ecology may re quire a facility to evaluate th e potential for its discharge to cause a violation of sediment standards (WAC 173-204-400).
Review of previous sediment surveys in 1994, 2004, and 2007 by Ecology’s sediment management unit, shows no viola tion of sediment standards.
Through this review and of the di scharger characteristics and of the effluent characteristics, Ecology determined that this discharge has no reasonable potential to violate the Sediment Management Standards.

O. J. Ground Water Quality Limits
The Ground Water Quality Standards, (Chapter 173-200 WAC), protect be neficial uses of ground water. Permits issued by Ecology must not al low violations of those standards (WAC 173-200-100).

Page 28

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma USOR has no unpermitted direct discharges to ground. USOR has several small surface impoundments lined with HDPE that are used prim arily for storage of firewater and treated
stormwater.

If wastes (firewater is not a waste) from these holding ponds were to leak into the groundwater, then those wastes could discharg e very slowly into the Blair Waterway--where the refinery’s final (treated) effluent discharges via a mari ne outfall. The ponds’ discharge to groundwater would consist of high quality wastew ater (having been treated to s econdary levels). It should be noted that the refinery is underl ain by a shallow, non-potable fres h water aquifer. The gradient in this aquifer is relatively fl at, so there is minimal groundwat er movement toward the Blair Waterway.

The concentrations of ground water quality paramete rs in USOR’s effluent measured, in general, less than that allowed by groundwater quality criteria. Only 2 metal parameters—selenium and arsenic—exceeded the allowed criteria. Arsenic was the only parameter that was significantly higher than its exceptionally low criteria (influenced by drinking water standards). Incidental leakage of effluent of this quality and in this location will have undetectable or minimal impacts to ground water quality. The volume of potentiall y impacted groundwater would be very small, and any impacts would occur just prior to the gr oundwater flowing into su rface water, which is the current discharge location.

Currently, it is the policy of Ecology to requir e all surface impoundments that regularly store or treat process water to demonstr ate compliance with the Ground Water Standards by performing a hydro geological study of the pond and the receivi ng water below. Stormwater impoundments are not subject to the same requirements at this time. The process wa ter impoundments are lined and there should be no leakage from the treatment systems. Therefore no limitations or actions are required based on potential effects to groundwater.

Based on our analysis (above) Ecology did not incl ude groundwater limitations, or monitoring or studies requirements as cond itions in the proposed permit.

P. K. Comparison Of Effluent Limits Wi th The Previous Pe rmit Issued April 2002

USOR’s production has increased slightly sin ce Ecology issued the previous permit, thus allowing for slight changes to the discha rge limits provided by federal guidelines. Table 12: Comparison of Effluent Limits (pounds per day)

Basis of Limit Previous Effluent Limits: Outfall # 001A Proposed Effluent Limits: Outfall # 001A
Parameter Average Monthly Maximum Daily Average Monthly Maximum Daily
Biochemical Oxygen Demand (5-day) Technology 125 236 126 238

Chemical Oxygen Demand Technology 628 1215 633 1224

Page 29

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

Previous Effluent Limits: Proposed Effluent Limits: Basis of Limit Outfall # 001A Outfall # 001A
Parameter Average Monthly Maximum Daily Average Maximum Monthly Daily Total Suspended Solids Technology 106 165 107 167

pH

Technology Within the range of 6.0 to 9.0. Excursions between 5.0 and 6.0, or 9.0 and 10.0 must 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
Oil & Grease Technology 38 74 39 74

Phenolic Compounds Technology 0.65 1.77 0.65 1.78

Ammonia as N Technology 14 31 14 32

Sulfide Technology 0.71 1.56 0.71 1.57

Total Chromium Technology 0.87 2.28 0.88 2.31

Hexavalent Chromium Technology 0.06 0.13 0.06 0.13

L. Dangerous Wastes – Permit By Rule Requirements

The proposed permit authorizes USOR to treat dangerous wastes--w hether generated on or offsite—at the wastewater treatment facility, unde r the state’s permit-by-ru le provisions of WAC 173-303-802(5). Ecology limited this authorization to the on-sit e and off-site waste streams identified and characterized on USOR’s permit application and to application amendments approved by Ecology. Off-site wastes include ballast water and retail distribution water. Ecology reviewed descriptions of those identified o ff-site waste streams and determined that they are similar in nature to the wastes generated on-site. We concluded that USOR wastewater facility should effectively treat the off-site wa stes and that establishe d effluent sampling and monitoring adequately addr ess the pollutants in these waste streams.

Permit-by-rule provisions cover the identified waste streams so 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

Page 30

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

• security

• contingency plans and emergency procedures

• emergencies

• the manifest system

• the operating record

• facility reporting

IV. MONITORING REQUIREMENTS

Ecology requires monitoring, recording, and reporting (WAC 173-220- 210 and 40 CFR 122.41) to verify that the treatment process is functioni ng correctly and that the discharge complies with the permit’s effluent limits. The monitoring sche dule is detailed in the proposed permit under Condition S.2. Specified monitoring frequencies ta ke into account the quan tity and variability of the discharge, the treatment method, past complian ce, significance of pol lutants, and cost of monitoring. The monitoring frequencies for BOD, Ammonia, Phenols, and Sulfides have been reduced based on the excellent perf ormance of the facility. If performance levels deteriorate during the term of the permit, the monitoring fr equencies shall revert to daily monitoring. Ecology will notify the facility by letter to in crease monitoring upon Ecology’s determination of deteriorating performance.

Q. A. Lab Accreditation
Ecology requires that all monitori ng data (with the exception of cer tain parameters) be prepared by a laboratory registered or accredited under the provisions of Chapter 173-50 WAC, Accreditation of Environmental Laboratories. USOR is accredited for the following parameters: ammonia, BOD, COD, dissolved oxygen, hexane extractable O&G, pH, total phenolics, TSS, and sulfide. Testing of all ot her parameters is contracted to outside accredited laboratories.

V. OTHER PERMIT CONDITIONS

R. A. Reporting and Recordkeeping
Ecology bases permit condition S3 on the authority to specify any appropriate reporting and recordkeeping requirements to prevent and control waste discharges (WAC 173-220-210).

S. B. Non Routine and Unanticipated Discharges
Occasionally, this facility may generate wastewater which was not characterized in the permit application because it is not a routine discha rge and was not anticip ated at the time of application. These wastes typically consist of waters used to pre ssure-test storage tanks or fire water systems , or of leaks from drinking water systems. These generally clean waste waters may be contaminated with pollutants.

Page 31

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma The permit authorizes non-routin e and unanticipated discharges under certain conditions. The facility must characterize th ese waste waters for pollutants and examine the opportunities for reuse. Depending on the nature and extent of pollutants in this wastewater and on any opportunities for reuse, Ecology may:

• Authorize the facility to discharge the water di rectly via the process wastewater outfall or through a stormwater outf all for clean water.

• Require the facility to treat the wastewater.

• Require the facility to reuse the wastewater.

T. C. Outfall Evaluation
Ecology does not require USOR to conduct an outf all inspection because th ere is a check valve at the discharge pipe.

U. D. Treatment System Operating Plan

Ecology requires industries to take all reasonable steps to proper ly operate and maintain their wastewater treatment system in accordance with state and federal regulations (40 CFR 122.41(e) and WAC 173-220-150 (1)(g)). The fac ility has prepared and submitted an operation and maintenance manual as required by state regulation for the construction of wastewater treatment facilities (WAC 173-240-150). Impl ementation of the procedures in the Treatment System Operating Plan ensures the facility’s complian ce with the terms and limits in the permit.

V. E. General Conditions

Ecology bases the standardized General Conditions on state and federal law and regulations. They are included in all individual industrial NPDES permits issued by Ecology.

W. F. Construction Stormwater

The proposed permit authorizes the discharge of st ormwater associated with construction activity and construction support activity from Outfall 001B, Outfall 002, Outfall 003, and Outfall 004, subject to a number of requirements and limitations . Construction activity refers to the clearing, grading, excavation, and othe r land disturbing activities which result in the disturbance of one or more acres. Construction support activity includ es equipment staging yards, material storage areas, borrow areas, etc.
The permit states that stormwater discharges mu st comply with water quality standards and it presumes that discharges are in compliance with water quality standards if the Permittee is in compliance with permit conditions, unless site-s pecific information shows otherwise.
The permit establishes a narra tive technology-based effluent limitation of AKART. AKART specifically includes the prepara tion and implementation of an adequate Stormwater Pollution Prevention Plan (SWPPP), with all appropriate BMPs installed and maintained in accordance with the SWPPP and the terms and conditions of this permit.

Page 32

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma The permit includes an enforceable adaptive management tool called a benchmark. Ecology is using a turbidity benchmark in this permit because it is an effective management tool for highly variable stormwater discharges. A benchmark va lue is not a water quality standard or a numeric effluent limit. Rather it is an indicator value used to determ ine the effectiveness of BMPs on

site. Meeting the benchmark established in the proposed permit in no way precludes the requirement for discharges to be in complian ce with applicable perm it conditions and water quality standards. If the benchmark is exceeded, the Permittee is required to take appropriate actions to identify and correct the problems causing the exceedance.

The proposed permit also includes basic m onitoring and reporting requirements.

VI. PERMIT ISSUANCE PROCEDURES

X. A. Permit Modifications
Ecology may modify this permit to impose numerica l limits, if necessary to comply with water quality standards for surface waters, with sedime nt quality standards, or with water quality standards for ground waters, after obtaining new in formation from sources such as inspections, effluent monitoring, outfall studie s, and effluent mixing studies.
Ecology may also modify this permit to comp ly with new or amended state or federal regulations.

Y. B. Proposed Permit Issuance
This proposed permit includes all statutory requirements for Ecology to authorize a wastewater discharge. The permit includes limits and conditions to control toxics as needed to, protect human health and aquatic life, and the beneficial uses of waters of the State of Washington. Ecology proposes to issue this permit for a term of 5 years.

Page 33

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

VII. 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 Wa ter Quality-based Toxics Control . EPA/505/2- 90-001.

1988. Technical Guidance on Supplementary St ream 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 Re-aeration 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.
Laws and Regulations( http://www.ecy.wa.gov/laws-rules/index.html )

Permit and Wastewater Related Information ( http://www.ecy.wa.gov/program s/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.)

Page 34

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX A--PUBLIC INVOLVEMENT INFORMATION

Ecology proposes to reissue a permit to (insert the facility name). The permit prescribes operating conditions and wast ewater discharge limits. This fact sheet describes the facility and Ecology’s reasons for requiring permit conditions.
Ecology will place a Public Noti ce on February 28, 2008 in the Tacoma News Tribune to inform the public and to invite comment on the proposed re issuance of this Nati onal Pollutant Discharge Elimination System permit as drafted.

The Notice –

• tells where copies of the draft Permit and F act Sheet are available for public evaluation (a local public library, the closest Regiona l or Field Office, pos ted on our website.).

• offers to provide the documents in an alternate format to accommodate special needs.

• asks people to tell us how well the proposed permit would protect the receiving water.

• invites people to suggest fairer conditi ons, limits, and requirements for the permit.

• invites comments on Ecology’s determination of compliance with antidegradation rules.

• urges people to submit their comments, in writ ing, before the end of the Comment Period

• tells how to request a public hearing of comments about the proposed NPDES Permit.

• explains the next step(s) in the permitting process.

Interested persons are invited to submit written comments regarding the draft permit. The draft permit, fact sheet addendum, and fact sheet ar e available for inspection and copying between the hours of 8:00 a.m. and 5:00 p.m. weekdays, by appoint ment, at the regional office listed below. Written comments should be mailed to:

Bob King Department of Ecology Industrial Section PO Box 47600 Olympia WA 98504-7600

Any interested party may comment on the draft pe rmit or request a public hearing on this draft permit within the 30-day comment period to the a ddress above. The request for a hearing shall indicate the interest of the party and the reasons why the hearing is warranted. Ecology 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 h earing will be circulated at l east 30 days in advance of the hearing. People expressing an inte rest in this permit will be mailed an individual notice of hearing (WAC 173-220-100).

Comments should reference specific text follo wed by proposed modification or concern when possible. Comments may address technical is sues, accuracy and completeness of information,

Page 35

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma the scope of the facility’s proposed coverage, adequacy of environmental protection, permit conditions, or any other concern that would result from reauthorization of this permit.

Ecology will consider all comments received within 30 days from the date of the public notice indicated above, in formulating a final determination to issue, revise, or deny the permit. Ecology’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 Ecology by telephone at (360) 407-7563, or by writing to the address listed above.

Page 36

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX B--GLOSSARY

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

AKART -- An acronym for “all known, available, and reasonable methods of prevention, control and treatment”. Ambient Water Quality --The existing environmental conditi on 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, struct ural 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 s ite runoff, spillage or leaks, sludge or waste disposal, or drainage from ra w material storage. BMPs ma y be further categorized as operational, source control, erosion and sediment control, and treatment BMPs.

BOD 5 --Determining the Biochemical Oxygen Demand of an effluent is an indirect way of measuring the quantity of organic ma terial present in an effluent that is utilized by bacteria. The BOD 5 is used in modeling to measure the re duction of dissolved oxygen in receiving waters after effluent is discharged. Stress caused by reduced dissolved oxygen levels makes organisms less competitive and less able to sustai n their species in the aquatic environment. Although BOD is not a specific compound, it is defi ned as a conventional pollutant under the federal Clean Water Act. Bypass --The intentional diversion of waste stream s 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 orga nism over a relatively long time, often 1/10 of an organism's lifespan or more. Chr onic 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 conditi ons of its permit or with applicable statutes and regulations.

Page 37

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma 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 asce rtain 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 pr oportional to stream fl ow, 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, excava tion and any other activity which disturbs the surface of the land. Such activities may include road building, constr uction of residential houses, office buildings, or industria l buildings, and demolition activity.
Continuous Monitoring –Uninterrupted, unless otherw ise 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 wh en the flow within a water body is low, thus, its ability to dilute effluent is reduced. Dilution Factor (DF) --A measure of the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. Expre ssed as the inverse of the percent effluent fraction e.g., a dilution factor of 10 means the effluent co mprises 10% by volume and the receiving water 90%. Engineering Report --A document which thoroughly ex amines the engineering and administrative aspects of a particular domestic or industrial wastewater facility. The report must contain the appropriate informa tion 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. Pa thogenic bacteria in wast ewater discharges are controlled by disinfecting the wastewater. Th e 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 a 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 developmen t of any natura l resource, or from animal operations such as feed lots, poultry houses, or dairies. The term includes contaminated storm water and, also, l eachate from solid waste facilities. Major Facility-- A facility discharging to surface water w ith an EPA rating score of > 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact.

Page 38

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma Maximum Daily Discharge Limitation --The highest allowable dail y discharge of a pollutant measured during a calendar day or any 24-hour period that reas onably represents the calendar day for purposes of sampling. The daily discharg e 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 pollutant concentration is above zero and is determined from analys is of a sample in a given matrix containing the pollutant. 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 disc harge within which wa ter quality criteria may be exceeded. The area of the authorized mi xing zone is specified in a facility's permit and follows procedures outlined in st ate regulations (Cha pter 173-201A WAC). National Pollutant Discharge Elimination System (NPDES) --The NPDES (Section 402 of the Clean Water Act) is the Federal wastewater pe rmitting system for discharges to navigable waters of the United States. Many states, in cluding 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 ar e 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, treasure r, or vice-president of the corporation in charge of a principal busine ss function, or any other person who performs similar policy- or decision-mak ing functions for the corporati on, or the manager of one or more manufacturing, production, or operating facilities employing more than 250 persons or have gross annual sales or expenditures ex ceeding $25 million (in second quarter 1980 dollars), if authority to sign documents has b een 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 materi al in an effluent. Large quantities of TSS discharged to receivi ng waters may result in solids accumulation. Apart from any toxic effects attr ibutable 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 wate rs, 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.

Page 39

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma Upset --An exceptional incident in which there is unintentional and temporary noncompliance with technology-based permit effluent limits 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 f acilities, 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 th at parameter from exceeding its water quality criterion after it is discha rged into receiving waters.

Page 40

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX C--TECHNICAL CALCULATIONS

Several of the Excel ® spreadsheet tools used to evaluate a discharger’s ability to meet Washington State water quality standard s can be found on Ecology’s homepage at http://www.ecy.wa.gov.

Page 41

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX D--RESPONSE TO COMMENTS

Page 42

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX E—PROCESS FACTOR AND TECHNICAL LIMITS DETERMINATION

Page 43

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX F—USOR VICINITY MAP

Page 44

### FACT SHEET FOR NPDES PE RMIT WA-000178-3 U.S. Oil, Tacoma

APPENDIX G— REASONABLE POTNETIAL CALCULATION

Page 45