Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

August 2014

Purpose of this Fact Sheet

This fact sheet explains and documents the decisions the Department of Ecology (Ecology) made 

in drafting the proposed National Pollutant Discharge Elimination System (NPDES) permit for 

Intalco Aluminum Corporation (Intalco).

This fact sheet complies with Section 173-220-060 of the Washington Administrative Code 

(WAC), which requires Ecology to prepare a draft permit and accompanying fact sheet for public 

evaluation before issuing an NPDES permit.

Ecology makes the draft permit and fact sheet available for public review and comment at least 

thirty (30) days before issuing the final permit. Copies of the fact sheet and draft permit for 

Intalco, NPDES permit WA0002950, are available for public review and comment from August 

27, 2014 until October 27, 2014. For more details on preparing and filing comments about these 

documents, please see Appendix A - Public Involvement Information.

Intalco reviewed the draft permit and fact sheet for factual accuracy. Ecology corrected any 

errors or omissions regarding the facility’s location, history, discharges, or receiving water prior 

to publishing this draft fact sheet for public notice.

After the public comment period closes, Ecology will summarize substantive comments and 

provide responses to them. Ecology will include the summary and responses to comments in this 

fact sheet as Appendix H - Response to Comments, and publish it when issuing the final 

NPDES permit. Ecology will not revise the rest of the fact sheet, but the full document will 

become part of the legal history contained in the facility’s permit file.

Summary

Intalco Aluminum Corporation operates multiple wastewater treatment plants that combine and 

discharge to the Strait of Georgia. Ecology issued the existing permit for this facility on March 

15, 2007. The facility completed two major projects during the previous permit cycle that 

significantly reduced the amount of stormwater discharged from Outfall 002 and significantly 

reduced the amount of process wastewater that was discharged from Outfall 001. 

Major changes from the previous permit include the implementation of a new sampling point to 

monitor the process wastewater effluent without stormwater for Outfall 001, the requirement to 

submit discharge monitoring reports electronically, the requirement to develop a fugitive alumina 

pollution prevention plan and an Outfall 011 and 012 best management practices effectiveness 

study, and the removal of Outfalls 003, 004, and 005.

All of the permit limits and action levels included in the existing permit are maintained in the 

proposed permit. The stormwater allocations have been removed due to the addition of a 

sampling point for the treated process wastewater before it is combined with stormwater. 
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Table of Contents

I. Introduction............................................................................................................ 6

II. Background Information....................................................................................... 7

A. Facility Description............................................................................................... 9

History ................................................................................................................................9

Industrial Processes.............................................................................................................9

Wastewater Treatment Processes......................................................................................10

Solids Management...........................................................................................................15

Discharge Outfalls ............................................................................................................15

B. Description of the Receiving Water................................................................... 16

C. Wastewater Characterization............................................................................ 18

D. Summary of Compliance with Previous Permit Issued................................... 23

E. State Environmental Policy Act (SEPA) Compliance ..................................... 28

III. Proposed Permit Limits........................................................................................ 28

A. Design Criteria .................................................................................................... 29

B. Technology-Based Effluent Limits.................................................................... 30

C. Surface Water Quality-Based Effluent Limits................................................. 35

Numerical Criteria for the Protection of Aquatic Life and Recreation.............................35

Numerical Criteria for the Protection of Human Health...................................................36

Narrative Criteria ..............................................................................................................36

Antidegradation ................................................................................................................36

Mixing Zones....................................................................................................................37

D. Designated Uses and Surface Water Quality Criteria..................................... 42

E. Water Quality Impairments............................................................................... 43

F. Evaluation of Surface Water Quality-Based Effluent Limits for Numeric 

Criteria................................................................................................................. 43

Reasonable Potential Analysis..........................................................................................48

G. Human Health ..................................................................................................... 48

H. Sediment Quality................................................................................................. 50

I. Groundwater Quality Limits............................................................................. 50

J. Whole Effluent Toxicity ..................................................................................... 51

K. Conditionally Authorized Non-Stormwater Discharges and Non-Routine... 55

L. Comparison of Effluent Limits with the Existing Permit Issued in March 

2007....................................................................................................................... 55

IV. Monitoring Requirements.................................................................................... 57

A. Wastewater Monitoring...................................................................................... 57
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B. Lab Accreditation ............................................................................................... 63

C. Effluent Limits which are Near Detection or Quantitation Levels ................ 64

V. Other Permit Conditions...................................................................................... 64

A. Reporting and Record Keeping ......................................................................... 64

B. Operation and Maintenance Manual................................................................ 64

C. Solid Waste Control Plan................................................................................... 64

D. Application for Permit Renewal or Modification for Facility Changes......... 65

E. Facility Loading .................................................................................................. 65

F. Non-Routine and Unanticipated Discharges.................................................... 65

G. Spill Plan.............................................................................................................. 65

H. Stormwater Pollution Prevention Plan ............................................................ 65

I. Fugitive Alumina Pollution Prevention Plan................................................... 66

J. Sediment Monitoring.......................................................................................... 66

K. Outfall Evaluation............................................................................................... 67

L. Certified Operator .............................................................................................. 67

M. Acute Toxicity...................................................................................................... 67

N. Chronic Toxicity.................................................................................................. 68

O. Secondary Wastewater Treatment System Treatment Efficiency Study ...... 69

P. Anode Contact Cooling Water AKART Evaluation........................................ 70

Q. Ground Water Impact Study............................................................................. 70

R. Outfall 011 and Outfall 012 BMP Effectiveness Study.................................... 71

S. General Conditions............................................................................................. 71

VI. Permit Issuance Procedures................................................................................ 71

A. Permit Modifications.......................................................................................... 71

B. Proposed Permit Issuance .................................................................................. 72

VII. References for Text And Appendices .................................................................. 72

Appendix A - Public Involvement Information .......................................................................... 73

Appendix B - Your Right to Appeal............................................................................................. 74

Appendix C - Glossary ................................................................................................................. 75

Appendix D - Summary of DMR Data ........................................................................................ 83

Appendix E - Technical Calculations ....................................................................................... 109

Appendix F – Wet Test Results Summary................................................................................. 114
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Outfall 001 WET Test Results Summary...................................................................... 114

Outfall 002 WET Test Results Summary...................................................................... 117

Appendix G – Landfill Groundwater Seeps Monitoring Results............................................. 120

Appendix H - Response to Comments....................................................................................... 121

Attachment 1 : Flow Chart for Agreed Order No. 10887......................................................... 145

Table 1 General Facility Information ............................................................................................. 7

Table 2 Ambient Background Data .............................................................................................. 17

Table 3 Outfall 001 Wastewater Characterization........................................................................ 18

Table 4 Outfall 002 Wastewater Characterization........................................................................ 21

Table 5 Outfall 011 Wastewater Characterization........................................................................ 22

Table 6 Outfall 012 Wastewater Characterization........................................................................ 22

Table 7 Violations......................................................................................................................... 24

Table 8 Permit Submittals............................................................................................................. 24

Table 9 Intalco Design Criteria..................................................................................................... 29

Table 10 BPT Effluent Limit Guidelines...................................................................................... 30

Table 11 BAT Effluent Limit Guidelines..................................................................................... 31

Table 12 Outfall 001 Effluent Limits - Maximum Daily.............................................................. 32

Table 13 Effluent Limits – Average Monthly............................................................................... 33

Table 14 Technology Based Limits for the Sanitary Wastewater Treatment Plant...................... 34

Table 15 Critical Conditions Used to Model the Discharge from Outfall 001............................. 39

Table 16 Critical Conditions Used to Model the Discharge from Outfall 002............................. 39

Table 17 Marine Aquatic Life Uses and Associated Criteria ....................................................... 42

Table 18 Recreational Uses .......................................................................................................... 43

Table 19 Dilution Factors for Outfall 001 .................................................................................... 46

Table 20 Dilution Factors for Outfall 002 .................................................................................... 46

Table 21 Outfall 001 2010 Acute WET Test Results (Percent survival in 100% effluent).......... 52

Table 22 Outfall 001 Chronic Bioassay Results (Reported as Percent Effluent) ......................... 53

Table 23 Comparison of Existing and Proposed Effluent Limits for Outfall 001........................ 55

Table 24 Comparison of Existing and Proposed Effluent Limits for Outfall 002........................ 56

Table 25 Comparison of Existing and Proposed Effluent Limits for Sanitary Lagoon Discharges

....................................................................................................................................................... 56
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Table 26 Sanitary Lagoon Monitoring.......................................................................................... 60

Table 27 Number of Stormwater Treatment Pond Action Level Exceedances............................ 61

Table 28 Number of SEC Action Level Exceedances.................................................................. 61

Table 29 Action Levels................................................................................................................. 62

Table 30 Accredited Parameters................................................................................................... 63

Figure 1 Facility Location Map ...................................................................................................... 9

Figure 2 Intalco Water Balance (flows are approximate)............................................................. 14

Figure 3 Outfall 001...................................................................................................................... 44

Figure 4 Outfall 002...................................................................................................................... 45

Figure 5 Simplified diagram of wastewater streams, outfalls, and monitoring points for Outfalls 

001 and 002................................................................................................................................... 58

Figure 6 Aquatic Life and Human Health Reasonable Potential Analysis................................. 110

Figure 7 Temperature Analysis................................................................................................... 113
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I. Introduction

The Federal Clean Water Act (FCWA, 1972, and 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 (NPDES), administered 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 legislature accepted the delegation and assigned the power and duty for 

conducting NPDES permitting and enforcement to Ecology. The Legislature defined Ecology's 

authority and obligations for the wastewater discharge permit program in 90.48 RCW (Revised 

Code of Washington).

The following regulations apply to industrial NPDES permits:

• Procedures Ecology follows for issuing NPDES permits (chapter 173-220 WAC)

• Water quality criteria for surface waters (chapter 173-201A WAC) 

• Water quality criteria for ground waters (chapter 173-200 WAC)

• Whole effluent toxicity testing and limits (chapter 173-205 WAC)

• Sediment management standards (chapter 173-204 WAC)

• Submission of plans and reports for construction of wastewater facilities (chapter 173-240 

WAC)

These rules require any industrial facility owner/operator to obtain an NPDES permit before 

discharging wastewater to state waters. They also help define the basis for limits on each 

discharge and for performance requirements imposed by the permit.

Under the NPDES permit program and in response to a complete and accepted permit 

application, Ecology must prepare a draft permit and accompanying fact sheet, and make them 

available for public review before final issuance. Ecology must also publish an announcement 

(public notice) telling people where they can read the draft permit, and where to send their 

comments, during a period of thirty days (WAC 173-220-050). (See Appendix A-Public 

Involvement Information for more detail about the public notice and comment procedures). 

After the public comment period ends, Ecology may make changes to the draft NPDES permit in 

response to comment(s). Ecology will summarize the responses to comments and any changes to 

the permit in Appendix H.
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II. Background Information

Table 1 General Facility Information

Facility Information

Applicant: Intalco Aluminum Corporation

Facility Name and Address Intalco Aluminum Corporation

4050 Mountain View Road

Ferndale, WA 98248-0937

Contact at Facility Name: Kathryn Mitchell, Environmental and 

Laboratory Manager

Telephone #: 360-384-7206

Responsible Official Name: Barry Hullett

Title: President 

Address: 4050 Mountain View Road, Ferndale, 

WA 98248-0937

Telephone #: 360-384-7584

Industry Type Primary Aluminum Production

Categorical Industry 40 CFR Part 421 Subpart B

Type of Treatment Industrial: Neutralization, flocculation, 

chemical precipitation and sedimentation 

Domestic: Aeration and sedimentation followed 

by UV disinfection

SIC Codes 3334

NAIC Codes 331313

Facility Location (NAD83/WGS84 

reference datum)

Latitude: 48.845740 

Longitude: -122.705956

Discharge Waterbody Name and Location 

(NAD83/WGS84 reference datum)

Strait of Georgia

Outfall 001 Location Latitude: 48.840778 Longitude: 122.720444

Outfall 002 Location Latitude: 48.839444 Longitude: 122.715583
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Facility Information

Outfall 011 Location Latitude: 48.842500 Longitude: 122.714722

Outfall 012 Location Latitude: 48.840278 Longitude: 122.714722

Permit Status

Issuance Date of Previous Permit April 01, 2007

Application for Permit Renewal Submittal 

Date

September 29, 2011

Date of Ecology Acceptance of Application January 31. 2013

Inspection Status

Date of Last Sampling Inspection June 26, 2013

Date of Last Non-sampling Inspection Date February 7, 2013
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Figure 1 Facility Location Map

A. Facility Description

History

The Intalco Aluminum Corporation (Intalco) began operations of a primary aluminum 

smelter near Ferndale, Washington in 1966. The original owner of the facility was Alumax, 

Pechiney and Howmet and the current owner is Alcoa. The facility is currently operating at 

approximately two-thirds capacity and employs around 640 people. The first NPDES permit 

was issued to the smelter in 1973. It is classified as a major facility.

Industrial Processes

Intalco is a nonferrous metals manufacturing facility that produces primary aluminum metal 

from alumina ore using the Hall-Heroult reduction process. The Intalco facility includes 

three pot lines, which contain a total of 720 side worked, pre-bake anode reduction cells and 

a casting facility. The smelter is capable of producing approximately 307,000 tons of 

aluminum metal per year at full production. All metal produced is cast on-site into various 

sizes and forms: sows, tees, slabs, billets, and ingots.

Intalco’s three potlines (A, B, and C) were operated from 1997-2000, with an average of 709 

pots operating per day and a maximum monthly average production of 31,228 tons per 

month. All production was curtailed from June 2001 – April 2002. Between May 2002 to 

present, production has been continuous but each of the potlines have been operated at 

various periods of time. Production has also been gradually decreased due to the fact that 

failing pots have not been replaced in certain lines. During 2013, Intalco operated 
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approximately 589 pots on average with an average monthly production of 20,647 tons per 

month.

The facility operates 24 hours a day, seven days per week. Intalco requires a large amount of 

energy for the process and they recently signed a 10-year power contract with Bonneville 

Power Administration that will expire in September 2022.

The industrial process consists of many steps including converting alumina ore to molten 

aluminum, casting of the molten aluminum, creating carbon anodes from a paste consisting 

of petroleum coke, recycled carbon, and coal tar pitch, and reprocessing of the cathodes. 

Wastewater associated with the industrial process includes contact and non-contact cooling 

water for metal casting and anode production and wastewater generated from the wet air 

pollution control systems associated with the pot rooms.

There are a few additional sources of wastewater at the facility. Wastewater generated from 

general operation and maintenance of the facility includes domestic wastewater and 

wastewater from steam cleaning at the auto shop and annex. Stormwater that has the 

potential to come into contact with the industrial process is collected and treated prior to 

discharge.

Wastewater Treatment Processes

There are a number of wastewater treatment processes at the Intalco facility. Figure 2 below 

shows the various wastewater streams, the treatment plants and two of the outfalls. The five 

treatment processes are as follows: 1) Primary Water Treatment System, 2) Secondary Water 

Treatment System, 3) Anode Cooling Water Treatment System, 4) Sanitary Water Treatment 

Facility, and 5) Stormwater Settling Pond.

Primary Water Treatment System (PWTS)

Contact cooling water from the aluminum casting process and contaminated water from the 

wet air pollution control system (wet scrubbers) are sent to the PWTS for treatment prior to 

being discharged. The PWTS consists of an 800 gallon receiving tank, a polymer addition 

system, two clarifiers, two filter feed pumps, a mud recycle tank, a vacuum pump, a vacuum 

filter drum, a recycle tank, a caustic addition system, and three recycle pumps Intalco has two 

clarifiers at the PWTS, one is 680,000 gallons and the other is 250,000 gallons. The 

clarifiers provide treatment in the form of sedimentation to remove solids and to reduce the 

turbidity in the wet scrubber wastewater. Most of the treated effluent from the clarifiers is 

recycled back into the wet scrubbers after adjusting the pH, as necessary. The remainder of 

the effluent is routed to the secondary wastewater treatment system for removal of dissolved 

fluoride and suspended solids.

According to the “Water Treatment Plant Operations and Maintenance Plans”, revised April 

2008, the PWTS has the capacity to treat approximately 1,800 gallons per minute (gpm) and 

operates continuously concurrent with the potline wet scrubber system. Typically, 75 gpm is 

continuously purged to the equalization tank of the secondary wastewater treatment system. 

The water is purged to the secondary wastewater treatment system to prevent build-up of

fluoride and sulfates from the scrubber system.
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Secondary Wastewater Treatment System (SEC, formerly SWTS)

The SEC (formerly SWTS) is comprised of a one million gallon equalization tank and two 

treatment trains running in parallel. Each treatment train consists of a 6,909 gallon capacity 

reaction tank and a flocculation tank that feed into a single 106,000 gallon clarifier. 

Wastewater routed from the PWTS to the SEC for fluoride treatment is pumped into the 

equalization tank where it is combined with leachate from the on-site landfill leachate 

collection system. Pollutants in the PWTS effluent include high concentrations of particulate 

and fluoride and the landfill leachate contains high concentrations of fluoride with occasional 

high concentrations of cyanide. This wastewater is then pumped to the chemical addition 

tanks. First is the reaction tank where sulfuric acid is added to adjust the pH. Next is the 

flocculation tank where a liquid polymer coagulant is added to promote settling and calcium 

chloride is added as a precipitant. Lastly, the wastewater is sent to a clarifier to allow for 

sedimentation of the solids (floc and precipitate) prior to being discharged into a pipeline to 

Outfall 001. Solids from the bottom of the clarifier are recycled back to the flocculation tank 

to create larger floc which will further promote settling. The system is also equipped to treat 

ferro-cyanide complexes from the landfill leachate if necessary. The clarifier is covered to 

prevent free cyanide formation caused by ultraviolet degradation of the ferro-cyanide 

complexes.

According to the “Water Treatment Plant Operations and Maintenance Plans”, revised April 

2008, the SEC has the capacity to treat approximately 300 gpm total (150 gpm in each train) 

The system is operated in a batch mode and typically treats between 175 and 240 gpm 

depending on the day of the week and recent or anticipated precipitation events.

Anode Cooling Water Treatment System (ACWTS)

Anode contact cooling water is generated during the anode production process. Intalco’s 

anodes are made from petroleum coke and coal tar pitch in one of two production lines. The 

coke and pitch are mixed together and then shaped into an anode with a mechanical press 

under high temperature and pressure. Next the anodes are sprayed with a strong spray of 

cold water in one of two cooling tunnels after removal from the press. During the spray 

process, the contact water is contaminated with coke and pitch containing polycyclic 

aromatic hydrocarbons (PAHs) [including benzo(a)pyrene (B(a)P)]. The contaminated 

contact water is treated in a baffled settling chamber for removal of the carbon particles. The 

treated wastewater then flows by gravity to a manhole where it is mixed with other process 

wastewater before being discharged through Outfall 001.

According to the “Water Treatment Plant Operations and Maintenance Plans”, revised April 

2008, the ACWTS settling chambers are approximately 516 gallons each and have the 

capacity to treat approximately 40 gpm (80 gpm total) with a retention time of approximately 

13 minutes.

Sanitary Water Treatment Facility

Intalco’s sanitary wastewater treatment facility provides treatment for the domestic 

wastewater generated by the plant personnel at the site. The treatment facility consists of a 

collection system, inlet vault, lagoon system, outlet weir box, ultraviolet (UV) disinfection

system and discharge piping to Outfall 001. The inlet vault contains a circulating water 
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pump, a lagoon bypass valve, and an old lagoon inlet valve. In 2012, a screen was added to 

the inlet vault to filter out manufactured inert solids as required by WAC 173-308- 205. The 

wastewater flows by gravity from the inlet vault to the 3.2 million gallon sanitary lagoon for 

primary (settling) and secondary (biological) treatment. The lagoon is approximately 2.5 

acres and three to five feet deep. The first cell of the three cell lagoon is 2.3 million gallons, 

has two surface aerators, and is uncovered. The other two cells are covered. Effluent from 

the lagoon is further treated by ultraviolet (UV) disinfection before being combined with the 

process effluent and discharged out Outfall 001. Discharge volume is continuous and 

averaged 0.04 MGD during the permit cycle.

The sanitary treatment facility was designed and constructed in 1965. In 1998, the lagoon 

inlet was rerouted to the lagoon’s southwest corner and, in 2000, the chlorination system was 

replaced with a UV disinfection system. The lagoon was designed for 770 plant personnel at 

0.08 pounds of biochemical oxygen demand (BOD) per person. The UV system was 

designed for a peak hydraulic flow rate of 350,000 gallons per day with an effluent total 

suspended solids (TSS) concentration less than 30 milligrams per liter (mg/L).

Stormwater Settling Pond and Best Management Practices 

Due to the nature of the aluminum smelting process, there is potential for stormwater to 

contact raw materials, byproducts, or waste materials as it flows through the site. To mitigate 

the discharge of pollutants, the stormwater collected from the industrial portion of the plant 

site is routed through a stormwater settling pond in the southwest corner of the plant. The 

stormwater pond provides approximately 1.7 million gallons of capacity. The pond was 

constructed in 1992 and is a flow-through system designed to allow solids to settle from the 

stormwater. The stormwater pond is designed to treat maximum stormwater flow rates up to 

30 cubic feet per second (cfs). The pond was conservatively sized based on the 6-month, 24-

hour design storm volume of 1.5 million gallons. The hydraulic capacity of the stormwater 

system (including diversion structures) was designed for a 100-year, 24-hour (4.0 inches of 

rain) storm. All flow in excess of 28 cfs is diverted around the pond via a series of three 

overflow structures.

Stormwater from outside the industrially developed plant site flows through two separate 

ditches. The two separate ditches combine with the stormwater pond effluent at the diversion 

structure that directs the stormwater to Outfall 001 if there is sufficient hydraulic capacity or 

to Outfall 002 during overflow conditions. At this point, the water is treated to remove oil 

with a continuously operated mechanical oil skimmer. Absorbent materials (e.g. socks) are 

located immediately prior to the location where the effluent enters the discharge pipe.

There is one additional area where stormwater may potentially become contaminated from 

industrial activities. It is a silo storage area near the entrance to the pier. The facility utilizes 

best management practices such as good housekeeping to prevent stormwater from 

contacting pollutants in this area.

Non-stormwater wastewater is allowed to be discharged to the stormwater treatment pond if

it is approved by Ecology. Examples of such wastewater streams may include, but are not 

limited to, discharges from fire fighting activities, fire protection system flushing, testing, 

and maintenance, discharges of potable water including water line flushing, provided the
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water line flushing is de-chlorinated prior to discharge, uncontaminated air conditioning or 

compressor condensate, and landscape watering and irrigation drainage.

Additional Wastewater Streams

Intalco operates a steam-cleaning station in each of three maintenance shops (Automotive, 

Central, and Annex). These stations are used to clean various pieces of plant equipment prior 

to maintenance activities. The wastewater from these stations is treated with sand filtration 

to remove suspended solids and with a coalescing filter to remove oil and grease. The 

filtered wastewater is then discharged to the process sewer system without any additional 

treatment before it is discharged to Outfall 001.

Since the current permit was issued in March 2007, Intalco eliminated one of the largest

wastewater components discharged from Outfall 001. In September 2010, Intalco installed a 

closed-loop cooling system for their compressor to replace the existing once-through cooling 

water system. This project eliminated approximately 2.5 MGD of wastewater from being 

discharged to the Strait of Georgia.
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Figure 2 Intalco Water Balance (flows are approximate)
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Solids Management 

The facility has a solid waste control plan that was updated in September 2011 and submitted 

with the permit renewal application. Intalco’s solid waste disposal facility is composed of a 

permanently closed double-lined landfill (September 2007) and a permanently closed triplelined landfill (July 2011). With no active landfills, all solid and hazardous wastes generated 

on-site which cannot be beneficially reused are sent off-site to a solid waste landfill or a 

permitted hazardous waste treatment, storage, or disposal facility (TSDF) such as the Waste 

Management landfill in Arlington, Oregon. The following paragraphs discuss the solids 

generated by the wastewater treatment systems.

Solids from the clarifiers associated with the PWTS and SEC are sent to a vacuum filter 

system that dewaters the sludge and prepares the dried solids for disposal at an off-site 

TSDF. Some of the solids that settle out in the clarifier associated with the SEC are recycled 

back into the flocculation tank to promote larger floc formation.

The settlings tanks associated with the ACWTS are emptied approximately once per week 

and the solids are recycled back into the anode production process.

Solids also accumulate in the stormwater pond and sanitary lagoon. According to the 

Sanitary Water Treatment Facility Operations and Maintenance manual, it is estimated that 

solids removal will be necessary every 10-15 years from the sanitary lagoon. The Intalco 

laboratory monitors the sludge depth once per year. The last sludge removal activity at the 

stormwater pond occurred in 2011. The last sludge removal activity for the sanitary lagoon 

occurred in 1993.

Discharge Outfalls

Intalco has multiple outfalls that all discharge to the Strait of Georgia. Outfall 001 

discharges a combination of process wastewater, domestic wastewater, and stormwater.

Outfall 002 is an overflow for stormwater discharges that exceed the hydraulic capacity of 

Outfall 001. Outfalls 011 and 012 discharge stormwater.

Wastewater discharged from Outfall 001 is a combination of treated process wastewater from 

the secondary water treatment system and anode contact cooling water treatment system,

treated domestic wastewater from the sanitary water treatment system, filtered wastewater 

from the autoshop and annex steam cleaners, and various non-contact cooling water streams. 

Stormwater collected from the areas where industrial activity occurs at the site is treated in 

the stormwater pond and the effluent is combined with stormwater collected from outside of 

the active portion of the site. In February 2009, Intalco completed construction of a 

diversion structure to divert stormwater previously discharged through Outfall 002 to Outfall 

001. The wastewater discharged from Outfall 001 is conveyed continuously through a 24-

inch diameter fiberglass reinforced plastic pipe and discharged through a 24-inch diameter, 

120-foot long diffuser.

Whenever the hydraulic capacity of Outfall 001 is exceeded, stormwater is automatically 

diverted to Outfall 002. The discharge to Outfall 002 is conveyed through a 30-inch diameter 

fiberglass reinforced plastic pipe and has no diffuser.
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Outfall 011 and Outfall 012 are stormwater outfalls that are located along the northern and 

southern edge of the silo storage area, respectively.

Outfalls 003, 004, and 005 are part of the existing permit, but are not included in the 

proposed permit. These outfalls were included in the existing permit at the request of the 

Permittee. These outfalls are associated with groundwater seeps from three landfills that 

have been either remediated or closed and capped. Outfall 003 is associated with an area that 

was operated as a landfill between 1966 and 1978, Outfall 004 is associated with an area that 

was operated as a landfill between 1971 and 1984, and Outfall 005 is associated with a 

historic landfill known as the Construction Debris Landfill that was operated between 1966 

and 1973. Under the state of Washington’s Model Toxics Control Act (MCTA) and a 

Consent Decree entered by Whatcom County Superior Court on February 02, 2007 (Docket 

Number 07-2-00181-2), Intalco remediated the landfills associated with Outfall 003 and 

Outfall 004 and closed and capped the landfill associated with Outfall 005. These areas and 

outfalls are still regulated under the Consent Decree and the MCTA program at Ecology. See 

Appendix G for the results of the monitoring that was required as part of the Consent 

Decree.

Since these outfalls are currently covered under two regulatory authorities, NPDES and 

MTCA, Ecology reviewed the appropriateness of maintaining the outfalls in the proposed 

permit. Ecology decided to remove the outfalls from the NPDES permit for two reasons: 1) 

the groundwater seeps do not appear to meet the definition of a point source, and 2) the 

landfills are no longer being actively used and the monitoring/required actions are more 

appropriately regulated by the MCTA program. In accordance with WAC 173-220, a point 

source is defined as “any discernible, confined and discrete conveyance, including but not 

limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling 

stock, concentrated animal feeding operation, or vessel or other floating craft, from which 

pollutants are or may be discharged.” The drainage from the remediated landfills is 

groundwater that exits the bluff and flows into the Strait of Georgia. The location of the 

groundwater seeps are not discrete discharges of potentially contaminated wastewater. 

Therefore, an NPDES permit is not required for the discharge and the corresponding outfalls

have been removed from the proposed permit. Future monitoring requirements for the 

discharges from the landfills will be determined as part of the MCTA Consent Decree 

mentioned earlier.

B. Description of the Receiving Water

All outfalls discharge to the Strait of Georgia in Northern Puget Sound. Other nearby point 

sources include outfalls at the BP Cherry Point Refinery, Puget Sound Energy Whitehorn 

Generating Station, Birch Bay STP (municipal), and Phillips 66 Ferndale Refinery.

The ambient background data used for this permit was obtained from Ecology’s 

Environmental Assessment Program (EAP) and from a receiving water study conducted in 

July-September 1999. Ecology, through its ambient monitoring program, has collected water 

quality data, including temperature, pH, dissolved oxygen, ammonia, and salinity, at various

intervals from the surface down to 201 meters below the water surface in the Strait of 

Georgia since November 1989. The name of the ambient monitoring station closest to the 

Intalco outfalls is Georgia Strait – N. of Patos Island (GRG002). The maximum and 
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Intalco Aluminum Corporation

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minimum values associated with the ambient monitoring station are shown below in Table 2. 

These values are the results of discrete samples collected from the surface down to 

approximately 5 meters (16.5 feet) below the surface. The average values are the averages of 

the results down to the same depth.

Ambient metals concentrations in the water near the Intalco outfalls were obtained from the 

April 2000 report prepared by Eric Crecelius, Battelle Marine Sciences Laboratory entitled 

“Concentrations of Metals in Marine Water Effluent of the Alcoa Intalco Works”. The report 

presents the results of a receiving water study conducted in the Cherry Point area in JulySeptember 1999. The samples for the receiving water study were collected up current of the 

Intalco effluent mixing zone. There were a total of ten samples collected twice per day on 

five separate days between July and September 1999. The samples were analyzed for a 

number of parameters including aluminum, cadmium, copper, mercury, lead, zinc, cyanide, 

and fluoride. The results presented below are the average of the ten samples.

The ambient background data used for this permit is presented in Table 2 below. 

Table 2 Ambient Background Data

Parameter Value Used

Temperature (summer 1-DADMax) 15.2 oC

Temperature (winter 1-DADMax) 10.7 oC

pH (Maximum / Minimum) 8.90 / 6.90 standard units

Dissolved Oxygen 6.2 mg/L

Total Ammonia-N 16.3 ug/L

Salinity 24.54 g/kg

Lead, dissolved 0.01 μg/L

Copper, dissolved 0.47 μg/L

Zinc, dissolved 0.57 μg/L

Aluminum, dissolved 5.8 μg/L

Cadmium, dissolved 0.059 μg/L

Mercury, dissolved 0.65 ng/L

Fluoride, dissolved 0.75 mg/L
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Intalco Aluminum Corporation

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C. Wastewater Characterization

Intalco reported the concentration of pollutants in the discharge at Outfalls 001, 002, 011,

and 012 in the permit application submitted in September 2011 and updated in September 

2013. Additional data was also obtained from the discharge monitoring reports (DMR) that 

are required to be submitted on a monthly basis. The characterization data in the application 

includes the results from samples collected between August 1, 2010 and July 31, 2011 for 

Outfalls 001 and 002 and between April 2007 and September 2011 for Outfalls 011 and 012. 

The information for Outfalls 001 and 002 reflect the data gathered after the completion of the 

Closed Loop Compressor Cooling Project. Additional data is available between August 2011 

and October 2013 from the DMRs and priority pollutant testing. A summary of the DMR 

data submitted between April 2007 and October 2013 is included in Appendix D. The 

wastewater effluent for these outfalls is characterized as follows:

Table 3 Outfall 001 Wastewater Characterization

Parameter Units # of Samples Average Value Maximum Value

Biochemical Oxygen 

Demand (BOD5)

mg/L 2 N/A <1.0

Chemical Oxygen 

Demand (COD)

mg/L 1 N/A <3.0

Total Organic Carbon 

(TOC)

mg/L 2 4.0 5.20

Total Suspended Solids 

(TSS)

mg/L 56 8.45 37

TSS lbs/day 164 107 285

Ammonia (as N) mg/L 1 N/A 0.52

Temperature (winter) oC 1309 8.4 18.9

Temperature (summer) oC 1309 16.1 24.4

Bromide mg/L 2 4.47 8.94

Color mg/L 1 N/A 11

Fluoride mg/L 55 7.73 27.50

Fluoride Lbs/day 163 120.8 810

Nitrate-Nitrite (as N) mg/L 3 2.36 3.48
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Intalco Aluminum Corporation

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Table 3 Outfall 001 Wastewater Characterization

Parameter Units # of Samples Average Value Maximum Value

Total Organic Nitrogen 

(as N)

mg/L 1 N/A 4.49

Oil and Grease mg/L 42 0.79 4.4

Total Phosphorous (as 

P)

mg/L 1 N/A 0.111

Total Alpha Particles pCi/L 1 N/A 0

Total Beta Particles pCi/L 1 N/A 11.3

Total Radium mg/L 1 N/A 1.01

Total Radium-226 mg/L 1 N/A 1.01

Sulfate (as SO4) mg/L 2 578.5 1108

Total Aluminum mg/L 56 1.59 7.37

Aluminum Lbs/day 164 25.0 242.7

Total Barium ug/L 1 N/A 74

Total Boron ug/L 1 N/A 210

Total Iron ug/L 1 N/A 140

Total Magnesium mg/L 1 N/A 27.3

Total Molybdenum ug/L 1 N/A 108

Total Manganese ug/L 1 N/A 70

Total Antimony ug/L 9 3.6 17

Total Arsenic ug/L 5 27.4 50

Total Cadmium ug/L 5 0.6 1.5

Total Chromium ug/L 5 0.9 2.0
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Intalco Aluminum Corporation

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Table 3 Outfall 001 Wastewater Characterization

Parameter Units # of Samples Average Value Maximum Value

Total Copper ug/L 6 4.0 5.2

Total Lead ug/L 5 0.3 0.7

Total Mercury ng/L 6 2.5 3.54

Total Nickel ug/L 9 37 90

Total Selenium ug/L 5 3.0 12

Total Thallium ug/L 5 0.17 1

Total Zinc ug/L 5 53 62

Acenapthene ug/L 5 0.25 0.6

Anthracene ug/L 5 0.04 0.5

Benzo(a)Anthracene ug/L 5 0.53 1.6

Benzo(a)Pyrene ug/L 5 0.75 1.9

3,4-Benzofluoranthene ug/L 6 0.81 2.6

Benzo(ghi)Perylene ug/L 5 0.43 0.3

Benzo(k)fluoranthene ug/L 5 0.32 0.9

4-Chlorophenyl Ether ug/L 2 N/A 0.08

Chyrsene mg/L 5 0.53 1.7

Fluoranthene ug/L 5 1.09 3.3

Fluorene ug/L 5 0.07 0.2

Indeno (1,2,3-cd) 

Pyrene

ug/L 5 0.37 1.6

Methylene Chloride ug/L 2 0.30 0.59

Phenanthrene ug/L 5 0.25 1.2
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Intalco Aluminum Corporation

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Table 3 Outfall 001 Wastewater Characterization

Parameter Units # of Samples Average Value Maximum Value

Pyrene ug/L 5 0.92 2.8

Parameter Units # of Samples Maximum 

Monthly 

Geometric 

Mean

Maximum Daily 

Value

Fecal Coliform MPN/100 mL 1 N/A 4.5

Parameter Units # of Samples Minimum 

Value

Maximum Value

pH standard units 365 6.5 8.3

Table 4 Outfall 002 Wastewater Characterization

Parameter Units # of 

Samples

Average Value Maximum 

Value

Biochemical Oxygen 

Demand (BOD5)

mg/L 1 N/A 2.0

Chemical Oxygen Demand 

(COD)

mg/L 1 N/A 37.0

Total Organic Carbon 

(TOC)

mg/L 1 N/A 7.98

Total Suspended Solids 

(TSS)

mg/L 15 14.1 21.2

Ammonia (as N) mg/L 1 N/A 0.07

Temperature (winter) oC 15 15.83 6.61

Temperature (summer) oC 15 19.55 15.19

Fluoride mg/L 15 22.6 33.2

Aluminum mg/L 15 6.09 9.82
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Intalco Aluminum Corporation

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Parameter Units # of 

Samples

Minimum Value Maximum 

Value

pH standard units 15 6.4 7.5

Table 5 Outfall 011 Wastewater Characterization

Parameter Units # of Samples Average Value Maximum Value

Biochemical Oxygen 

Demand (BOD5)

mg/L 1 N/A 2.0

Chemical Oxygen Demand 

(COD)

mg/L 1 N/A 22.0

Total Organic Carbon 

(TOC)

mg/L 1 N/A 8.4

Total Suspended Solids 

(TSS)

mg/L 55 68.80 1157

Ammonia (as N) ug/L 1 N/A 90

Temperature (summer) oC 1 N/A 15.2

Fluoride mg/L 55 6.9 14.2

Aluminum mg/L 55 3.24 65.0

Table 6 Outfall 012 Wastewater Characterization

Parameter Units # of Samples Average Value Maximum Value

Biochemical Oxygen 

Demand (BOD5)

mg/L 1 N/A 2.0

Chemical Oxygen Demand 

(COD)

mg/L 1 N/A 33.0

Total Organic Carbon 

(TOC)

mg/L 1 N/A 3.4

Total Suspended Solids 

(TSS)

mg/L 50 55.2 468

Ammonia (as N) mg/L 1 N/A 0.17
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Intalco Aluminum Corporation

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Parameter Units # of Samples Average Value Maximum Value

Temperature (summer) oC 1 N/A 15.7

Fluoride mg/L 50 4.7 11.7

Aluminum mg/L 50 4.2 43.0

Parameter Units # of Samples Minimum Value Maximum Value

pH standard 

units

1 6.85 6.85

D. Summary of Compliance with Previous Permit Issued

The existing permit specifies effluent limits for TSS, fluoride, aluminum, benzo(a)pyrene, 

antimony, nickel, oil and grease, and pH for Outfalls 001 and 002. In addition, an effluent 

limit for free cyanide is also specified for Outfall 001. In February 2009, the facility 

completed construction of a diversion structure that diverts the stormwater flow from Outfall 

002 to Outfall 001 unless the hydraulic capacity of Outfall 001 would be exceeded. The

diversion of stormwater to Outfall 001 produced additional loadings of certain pollutants 

(TSS, fluoride, aluminum, and benzo(a)pyrene) at Outfall 001. Stormwater allocations for 

those pollutants are included in the existing permit for those instances when the additional 

stormwater causes the effluent from Outfall 001 to exceed established effluent limits. 

Whenever the hydraulic capacity of Outfall 001 is exceeded, any additional stormwater is 

discharged through Outfall 002. These discharges from Outfall 002 are required to meet the 

effluent limits specified for pH, TSS, aluminum, and fluoride. Lastly, the existing permit 

specifies effluent limits for BOD5, TSS, fecal coliform, minimum number of operating UV 

tubes, and pH for the sanitary lagoon effluent.

The existing permit specifies action levels for two internal monitoring points which require 

the facility to take certain steps if the effluent pollutant concentrations exceed those levels. 

Both the secondary wastewater treatment plant discharge and the stormwater pond discharge 

have action levels for TSS and fluoride. The stormwater pond discharge also has action

levels for aluminum and pH. It is not a permit violation if the action levels are exceeded, but 

failure to take the required steps when an action level is exceeded is a violation of the permit.

Intalco has generally complied with the effluent limits and permit conditions throughout the 

duration of the existing permit issued on April 01, 2007. Ecology assessed compliance based 

on its review of the facility’s information in the Ecology Permitting and Reporting 

Information System (PARIS), discharge monitoring reports (DMRs) and on inspections. All 

of the violations were appropriately addressed by Intalco.

The following table summarizes the violations that occurred during the permit term.
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Intalco Aluminum Corporation

Page 24 of 145

Table 7 Violations

Violation 

Date

Monitoring 

Point Parameter Statistical Base Units Value Max Limit

10/1/2008 Process 

WW Nickel Average Monthly Lbs/Day 2.6 1.9

10/1/2008 Process 

WW Nickel Daily Maximum Lbs/Day 14.5 2.7

The following table summarizes compliance with report submittal requirements over the 

permit term.

Table 8 Permit Submittals

Permit 

Section

Required Submittal Frequency/Due Date Status

S1.D. Engineering Report for 

Outfall 002 Diversion

Once/ January 1, 2008 Submitted as 

required

S1.D. Plans and Specifications Once/ July 1, 2008 Submitted as 

required

S1.D. Revision to O&M Manual 

for Diversion

As necessary/ December 1, 

2008

Submitted as 

required

S1.D. Diversion of Stormwater 

from Outfall 002 to Outfall 

001

Once/ March 1, 2009 Submitted as 

required

S1.I. Priority Pollutant Testing Annually/ Within 90 days of 

each sampling event

Submitted annually 

as required

S2.D. Discharge Monitoring Report Monthly/ 15th day of each 

month

Submitted as 

required

S3.A. Updated Operations and 

Maintenance Manual

As necessary/ October 1, 2011 Submitted as 

required

S5.C. Updated Solid Waste Control 

Plan

As necessary/ October 01, 2011 Submitted as 

required

S7. Updated Spill Plan As necessary/ April 1, 2008 Submitted as 

required
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Intalco Aluminum Corporation

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Table 8 Permit Submittals

Permit 

Section

Required Submittal Frequency/Due Date Status

S8.A. Acute Toxicity Effluent 

Characterization – Outfall 

001

Every other month for one year/

Within 60 after the diversion is 

completed and operational 

(March 2009)

Submitted as 

required

S8.D. Acute Toxicity Effluent 

Characterization – Outfall 

001 

Quarterly if Acute Toxicity 

Limit is established/ As 

determined

N/A

S8.D. Acute Toxicity Tests –

Outfall 002

Quarterly until completion of 

diversion (March 2009)/

Within 60 days of the sample 

date

Submitted as 

required

S8.E. Acute Toxicity TI/TRE Plan As necessary N/A

S8.F. Acute Toxicity Effluent 

Characterization – Outfall 

001

Twice if no acute toxicity limit 

established/ Summer 2010 and 

Winter 2010

Submitted as 

required

S9.A. Chronic Toxicity Effluent 

Characterization – Outfall 

001

Every other month for one year/ 

Within 60 after the diversion is 

completed and operational 

(March 2009)

Submitted as 

required

S9.D. Chronic Toxicity Tests –

Outfall 001

Quarterly if chronic toxicity 

limit established/ As determined

N/A

S9.D. Chronic Toxicity Tests –

Outfall 002

Quarterly until completion of 

the diversion (March 2009)/

Within 60 days of the sample 

date

Submitted as 

required

S9.E. Chronic Toxicity TI/TRE 

Plan

As necessary N/A

S9.F. Chronic Toxicity Tests –

Outfall 001

Twice if no chronic toxicity 

limit established/ Summer 2010 

and Winter 2010

Submitted as 

required
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Intalco Aluminum Corporation

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Table 8 Permit Submittals

Permit 

Section

Required Submittal Frequency/Due Date Status

S10.B. Treatment Efficiency Study 

Plan for the SWTS a

Once/ January 1, 2008 Submitted as 

required

S10.B. Treatment Efficiency Study 

for the SWTS a – Sampling

Once/ Within 90 days of 

Ecology’s approval of the plan

Not yet required. 

Ecology in process 

of reviewing plan 

S10.B Treatment Efficiency Study 

Results for the SWTS a

Once/ Within 120 days of 

completing the study

Not yet required. 

Ecology in process 

of reviewing plan 

S10.B. Updated the O&M plan 

required by S3.A. to include 

design standards or any 

upgrades to the SWTS a as 

identified in the Treatment 

Efficiency Study and 

Engineering Report

Once/ Within 90 days of 

Ecology’s written determination 

that it meets design standards or 

90 days after completing 

upgrades

Not yet required. 

Ecology in process 

of reviewing plan 

S10.B. Engineering Report for 

SWTS a

Once/ Within 120 days of 

receipt of Ecology’s 

determination that SWTS does 

not meet design standards

Not yet required. 

Ecology in process 

of reviewing plan 

S10.B. Upgrades to SWTS a Once/ Within 2 years of receipt 

of Ecology’s written approval 

of the engineering report

Not yet required. 

Ecology in process 

of reviewing plan 

S10.B. Interim report on progress 

toward completion of SWTS

a upgrades

Once/ Within 1 year of 

Ecology’s written approval of

the engineering report

Not yet required. 

Ecology in process 

of reviewing plan 

S10.C. AKART Study Plan for the 

ACWTS

Once/ January 1, 2008 Submitted as 

required. 

S10.C. AKART Study Plan for the 

ACWTS - Sampling

Once/ Within 90 days of 

Ecology’s approval of the plan

Not yet required. 

Ecology in process 

of reviewing plan 

S10.C. Engineering Report with the 

AKART findings for 

Once/ Within 120 days of Not yet required. 

Ecology in process 
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Intalco Aluminum Corporation

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Table 8 Permit Submittals

Permit 

Section

Required Submittal Frequency/Due Date Status

ACWTS completion of AKART study of reviewing plan 

S10.C. Upgrades to ACWTS Once/ Within 2 years of receipt 

of Ecology’s written approval 

of the engineering report

Not yet required. 

Ecology in process 

of reviewing plan 

S10.C. Interim Report on Progress 

Toward Completion of 

ACWTS Upgrades

Once/ Within 1 year of receipt 

of Ecology’s written approval 

of the engineering report 

Not yet required. 

Ecology in process 

of reviewing plan 

S10.C. Update the O&M Plan 

required by S3.A. to include 

AKART design standards or 

any upgrades to the ACWTS 

as identified in the AKART

Study and Engineering 

Report for the ACWTS

Once/ 90 days after Ecology’s 

determination that the ACWTS 

meets AKART design standards

Not yet required. 

Ecology in process 

of reviewing plan

S11.A. Sediment Sampling and 

Analysis Plan

Once/ April 1, 2011 Submitted as 

required. 

S11.A. Sediment Monitoring Once/ First stable period (mid 

August through September) 

following Ecology’s approval 

of the plan

Not yet required. 

Ecology in process 

of reviewing plan 

S11.B. Sediment Data Report Once/ Within 180 days of 

completion of monitoring

Not yet required. 

Ecology in process 

of reviewing plan 

S12. Outfall Evaluation As necessary/ October 1, 2011 Submitted as 

required. 

S14.B. Updated Stormwater 

Prevention Pollution Plan 

As necessary/ January 1, 2008 Submitted as

required. 

S15.A. Ground Water Impact Study 

Plan

Once/ March 1, 2010 Submitted as 

required. 

S15.B. Ground Water Impact Study Once/ Within 180 days of 

Ecology’s approval of the plan

Not yet required. 

Ecology in process 
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Intalco Aluminum Corporation

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Table 8 Permit Submittals

Permit 

Section

Required Submittal Frequency/Due Date Status

of reviewing plan 

S15.C. Ground Water Impact Study 

Report

Once/ Within 120 days of 

completing the study

Not yet required. 

Ecology in process 

of reviewing plan 

G5. Engineering Report for 

Construction or Modification 

Activities 

As necessary Submitted as 

required. 

G7. Application for Permit 

Renewal 

Once/ October 1, 2011 Submitted as 

required. 

a. The acronym for the Secondary Wastewater Treatment System has been changed from SWTS 

to SEC in the draft permit.

E. State Environmental Policy Act (SEPA) Compliance

State law exempts the issuance, reissuance or modification of any wastewater discharge 

permit from the SEPA process as long as the permit contains conditions that are no less 

stringent than federal and state rules and regulations (RCW 43.21C.0383). The exemption 

applies only to existing discharges, not to new discharges. The proposed permit does not 

contain any permit conditions that are less stringent than federal or state rules or regulations. 

Therefore, SEPA is not required for this action.

III. Proposed Permit Limits

Federal and state regulations require that effluent limits in an NPDES permit must be either 

technology- or water quality-based.

• Technology-based limits are based upon the treatment methods available 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-case basis (40 CFR 125.3, and chapter 

173-220 WAC).

• Water quality-based limits are calculated so that the effluent will comply 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).

• Ecology must apply the most stringent of these limits to each parameter of concern. These 

limits are described below.

The limits in this permit reflect information received in the application and from supporting 

reports (engineering, WET, etc.). Ecology evaluated the permit application and determined the 
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Intalco Aluminum Corporation

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limits needed to comply with the rules adopted by the state of Washington. Ecology does not 

develop effluent limits for all reported pollutants. Some pollutants are not treatable at the 

concentrations reported, are not controllable at the source, are not listed in regulation, and do not 

have a reasonable potential to cause a water quality violation.

Ecology does not usually develop limits for pollutants not reported in the permit application but 

may be present in the discharge. The permit does not authorize discharge of the non-reported 

pollutants. During the five-year permit term, the facility’s effluent discharge conditions may 

change from those conditions reported in the permit application. The facility must notify 

Ecology if significant changes occur in any constituent [40 CFR 122.42(a)]. Until Ecology 

modifies the permit to reflect additional discharge of pollutants, a permitted facility could be 

violating its permit.

A. Design Criteria

Under WAC 173-220-150 (1)(g), flows and waste loadings must not exceed approved design 

criteria. There are two treatment systems associated with the Intalco facility that have 

approved design criteria, the ultraviolet disinfection (UV) system associated with the sanitary 

wastewater treatment plant and the stormwater pond. The facility submitted a stormwater 

pond characterization study in July 2001 specifying the maximum storm event that the 

stormwater system can properly treat. The facility also submitted an engineering report for 

the ultraviolet disinfection system prior to installation in 2002. Table 9 below shows the 

specific design criteria.

Table 9 Intalco Design Criteria

Sanitary Lagoon

Flow through the UV Disinfection 

System

350,000 gpd

Stormwater Pond

Influent Flow 30 cfs in any consecutive 10 

minute period*

*As determined by measuring stormwater pond effluent and adjusted for 

rainfall

Ecology has determined that the system meets AKART requirements based on the 

information presented in the Stormwater Pond Characterization Study submitted in July 

2001. Ecology understands that the intensity and frequency of all future storm events are 

difficult to predict when designing a stormwater treatment system. Ecology also understands 

that if the design criterion of the treatment system is exceeded during a storm event, the 

treatment efficiency of the system decreases significantly. Therefore, the facility is allowed 

to bypass the stormwater treatment pond for events that exceed the hydraulic design criteria. 

Ecology will not consider these individual bypasses as a violation of the bypass permit 

condition or the design criteria condition, as long as the bypass can meet water quality 

criteria.

AKART for stormwater is constantly progressing and, as technology advances, facilities will 

have more cost effective, more efficient, and higher capacity treatment system options 
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Intalco Aluminum Corporation

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available. Ecology expects Intalco to meet AKART and make the necessary improvements 

to its treatment system as the treatment technology evolves.

B. Technology-Based Effluent Limits

Process Wastewater 

The EPA has established technology-based limits for a number of industrial categories, 

including the nonferrous metals manufacturing industry. These limits are specified in 40 

CFR Part 41. The applicable federal effluent limit guidelines for the primary aluminum 

smelting subcategory (Subpart B) were first proposed on March 8, 1984. These guidelines 

contain effluent limits based on the degree of pollutant reduction attainable by the application 

of the best practicable control technology currently available (BPT) and the application of the 

best available technology economically achievable (BAT). Also, new source performance 

standards (NSPS) apply to sources constructed after the promulgation of the NSPS, which 

occurred on March 8, 1984.

The BPT guidelines apply to the total wastewater generated by the aluminum smelting 

process, but the BAT effluent limits guidelines apply to the different processes involved in 

aluminum smelting. According to the permit renewal application, the Intalco aluminum 

smelting process includes the following wastewater sources: anode contact cooling and 

briquette quenching, potroom wet air pollution control, and direct casting contact cooling. 

All of these units were constructed prior to March 8, 1984, so the new source performance 

standards do not apply to this facility.

EPA periodically reviews its effluent limit guidelines and determines when guidelines for 

specific industries need to be updated. The latest review of the nonferrous metals category 

occurred during the 2010 review and the results of the evaluation are described in EPA’s 

Technical Support Document for the 2010 Effluent Guidelines Program Plan. Based on 

EPA’s review, the nonferrous metals category was not considered a priority for updating.

The tables below specify the applicable BPT and BAT effluent limit guidelines for Intalco.

Table 10 BPT Effluent Limit Guidelines

Pollutant Maximum for any 1 Day Maximum for monthly 

average

lbs/thousand lbs of product

Fluoride 2.0 1.0

Total Suspended Solids 3.0 1.5

pH (1) (1)

(1) Within the range of 6 to 9 at all times.
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Intalco Aluminum Corporation

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Table 11 BAT Effluent Limit Guidelines

Pollutant

Anode Contact Cooling 

and Briquette Quenching

Potroom Wet Air 

Pollution Control

Direct Chill Casting 

Contact Cooling

Maximum 

for any 1 

Day

Maximum 

for monthly 

average

Maximum 

for any 1 

Day

Maximum 

for monthly 

average

Maximum 

for any 1 

Day

Maximum 

for 

monthly 

average

lbs/million lbs of anodes 

cast

lbs/million lbs of Al 

produced from 

electrolytic reduction

lbs/million lbs of Al 

product from direct chill 

casting

Benzo(a)-

pyrene

0.007 0.003 0.056 0.026 (1) (1)

Antimony 0.403 0.180 3.204 1.428 2.565 1.143

Nickel 0.115 0.077 0.913 0.614 0.731 0.492

Aluminum 1.277 0.566 10.140 4.499 8.120 3.602

Fluoride 12.440 5.518 98.770 43.830 79.080 35.090

(1) There shall be no discharge allowance for this pollutant.

The existing permit includes technology based limits for Outfall 001 that were established 

using the effluent limit guidelines (B(a)P, antimony, nickel, aluminum) and best professional 

judgment (BPJ) (TSS, fluoride, aluminum). The effluent limit guidelines presented in Tables 

11 and 12 above are based on the production of aluminum metal and the pounds of anodes 

cast during the aluminum production process. At full production, the facility is able to 

produce approximately 31,500 tons of aluminum per month, which is approximately 2.1 

million pounds of aluminum metal produced per day. However, the production rate at the 

facility may vary during a permit term based on market conditions. To account for this 

variability, Ecology established tiered production limits with the higher tier applicable when 

production exceeded 15,614 tons per month, the middle tier applied to production rates 

between 10,305 tons per month and 15,614 tons per month, and the lowest tier applies 

whenever the facility produces less than 10,305 tons per month. Tables 13 and 14 below 

present the technology- based limits calculated using the EPA effluent limit guidelines, BPJ,

and tiered production values.

In addition to ensuring that the facility meets the effluent limit guidelines established by 

EPA, Ecology must also ensure that facilities provide all known, available, and reasonable 

methods of prevention, control, and treatment (AKART) when it issues a permit. As 

described in Section I.A above, all of the process wastewater at the facility is treated at a 

minimum through settling to remove solids. The primary and secondary wastewater 

treatment plants also provide chemical addition to enhance treatment of solids and promote 

treatment of fluoride. The facility reuses the majority of the treated effluent from the primary 

treatment system which significantly reduces the amount of wastewater that is discharged 

from the facility. The quality of water needed to allow the water to be reused dictates the 

level of treatment necessary at the primary wastewater treatment system. With the exception 

of the anode contact cooling water, the facility appears to be providing AKART for the 

wastewater generated by the facility.
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Intalco Aluminum Corporation

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Preliminary sampling results from the Anode Contact Cooling Water Study indicate that a 

full AKART analysis will need to be performed for that particular wastewater stream. The

sample results demonstrate that the current treatment system is providing between 38% and 

68% removal of B(a)P from the wastewater stream. The results also show that the current 

treatment may not be consistently meeting the effluent limit guidelines specified in Table 11

above for that particular wastewater source, even though the Permittee has been able to meet 

the final effluent limits for B(a)P. One of the most common improvements to the treatment 

system would be to add chemical coagulants to the wastewater stream to enhance solids 

settling. Ecology acknowledges that the facility reuses solids that settle out during the 

treatment process and that chemical addition used to enhance the treatment efficiency would 

prohibit reuse of the solids. Therefore, the facility is investigating other options, including 

elimination of the discharge. Based on this information, the draft permit requires the 

Permittee to complete the AKART analysis for the Anode Contact Cooling Water wastewater 

stream during the next permit cycle. Ecology will evaluate the results of the analysis to 

determine if there are any additional treatment options that must be implemented to 

demonstrate that the facility is providing AKART for the anode contact cooling water.

The limits contained in the existing permit for TSS, fluoride, and aluminum were established 

using BPJ during the permitting process for the permit issued on September 1, 1998. The 

limits for Outfall 001 were based on the performance of the process wastewater treatment 

system. A statistical analysis was run on two years of representative monitoring data using a 

method consistent with EPA and Ecology effluent limit-setting guidelines. The limits were 

established when the facility was operating at full production. The TSS limit calculated 

using this method (27.5 lbs/day) was appealed and the TSS limit was reverted back to the 

limit established in the permit issued on January 15, 1991 (150 lbs/day). The BPJ limits are 

more stringent than the limits calculated using the effluent limit guidelines. 

Table 12 Outfall 001 Effluent Limits - Maximum Daily

Production TSS Fluoride Aluminum B(a)P Antimony Nickel 

Tons/Month lbs/ day lbs/day lbs/day lbs/day lbs/day lbs/day

10,305 2061.0 130.7 13.4 0.043 4.2 1.2

15,614 3122.8 198.1 20.0 0.065 6.4 1.8

23,250 4650.0 294.9 30.3 0.098 9.6 2.7

31,500 6300.0 399.6 41.0 0.132 13.0 3.7

31,500 (BPJ) 185 296 30 N/A N/A N/A
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Table 13 Effluent Limits – Average Monthly

Production TSS Fluoride Aluminum B(a)P Antimony Nickel 

Tons/Month lbs/ day lbs/day lbs/day lbs/day lbs/day lbs/day

10,305 1030.5 58.0 6.0 0.020 1.9 0.8

15,614 1561.4 87.9 9.0 0.030 2.9 1.2

23,250 2325.0 130.9 13.4 0.045 4.3 1.8

31,500 3150.0 177.3 18.2 0.061 5.8 2.5

31,500 (BPJ) 150 68 10.3 N/A N/A N/A

The limits in the existing permit are shown in bold in the tables above. The tiered effluent 

limits for B(a)P, antimony, nickel, and aluminum were established using the following 

production rates: 23,250 tons/month, 15,614 tons/month, and 10,305 tons/month. The 

average production rate between March 2011 and March 2013 was 20,305 tons per month 

and the highest production month during this time period was 21,576 tons. Based on these 

recent production rates, it appears that the technology based permit limits in the current 

permit are representative of the operations at the facility and are appropriate to maintain in 

the proposed permit.

Netting Out

The industrial water supplied to Intalco by Whatcom County PUD No.1 is treated Nooksack 

River water. The treatment process consists of coagulation/flocculation followed by settling. 

The treated water is not filtered and contains concentrations of TSS, aluminum, antimony 

and nickel. The TSS and aluminum levels in the incoming source water do not meet the 

technology-based limits for primary aluminum smelters that are based upon the amount of 

product produced. Since the TSS, aluminum, antimony, and nickel levels in the effluent at 

Outfall 001 are not fully representative of the impacts from the smelter, the NPDES permit 

allows Intalco to “net out” incoming pollutants in the intake water. Netting out allows 

Intalco to subtract the amount of TSS, aluminum, antimony and nickel in the intake water 

from the values in the effluent to determine compliance with the effluent limits. The effluent 

limits established for Outfall 001 are for the net discharge of TSS, aluminum, antimony, and 

nickel.

Netting out is allowed in federal regulation by 40 CFR 122.45(g). There is a restriction that 

the discharge is to the same water body as the intake water unless there is a finding of no 

environmental degradation. Ecology policy uses the results of whole effluent toxicity (WET) 

tests as the criteria for determining environmental degradation. There does not appear to be 

environmental degradation associated with the constituents in the intake water at this time. 

The draft permit states that Ecology will notify the Permittee in writing it if it determines that 

netting out is resulting in environmental degradation and is no longer allowed.
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Sanitary Wastewater

EPA has not established specific technology based guidelines for privately owned sanitary 

wastewater treatment plants. However, state regulations contain discharge standards for all 

domestic wastewater facilities, including privately owned facilities. The effluent from the 

sanitary wastewater treatment plant at Intalco must meet the effluent requirements specified 

in WAC 173-221-050 since they have a waste stabilization pond that treats less than a two 

million gallon per day. The effluent limit requirements for the sanitary wastewater treatment 

plant are specified in the table below.

Table 14 Technology Based Limits for the Sanitary Wastewater Treatment Plant

Parameter Average Monthly 

Limit

Weekly Average 

Limit

Biochemical Oxygen 

Demand (BOD)

45 65

TSS 45 65

Fecal Coliform 200 400

Parameter Minimum % Removal 

BOD and TSS 65%

Parameter Daily Minimum Daily Maximum

pH 6.0 standard units 9.0 standard units

Stormwater 

The EPA has not established technology based effluent limits for stormwater that is 

discharged from aluminum smelting facilities, so Ecology used BPJ to establish limits for the 

stormwater that is discharged to Outfall 001 and Outfall 002. There are two separate 

stormwater streams at the site, one that is collected from the active portion of the site where 

industrial activity is occurring and one that is collected from the portion of the site where no 

industrial activity is occurring. The stormwater from the active portion is treated in the 

stormwater treatment pond and then combined with the stormwater from the non-industrial 

area. In the past, the combined stormwater was discharged from Outfall 002. The NPDES 

permit that was issued to Intalco on September 1, 1998 established limits for the combined

stormwater using a statistical analysis method consistent with EPA and Ecology effluent 

limit setting guidelines. Ecology used monitoring data that was supplied by the Permittee at 

that time, which included storm events. These stormwater limits have not been changed in 

the proposed permit.

As discussed in Section A above, a stormwater diversion structure was completed in 

February 2009 to divert the majority of the stormwater discharges from Outfall 002 to Outfall 

001. The stormwater was combined with the process wastewater streams prior to discharge 

and prior to the monitoring point to demonstrate compliance with the permit limits for 
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Outfall 001. In order to account for the additional pollutants present in the stormwater 

diverted from Outfall 002, Ecology established stormwater allocations that add to the limits 

at Outfall 001. These allocations were based on the effluent limits for Outfall 002. Because 

the stormwater streams were no longer separate from the process wastewater streams and 

they were sampled as part of the Outfall 001 discharge, the stormwater stream was not given 

any effluent limits. Instead, Ecology established Action Levels at the stormwater pond 

discharge to ensure that the Permittee continued to use Best Management Practices (BMPs) 

in managing their stormwater and continued to operate the stormwater treatment system as 

designed.

As discussed in Section IV.A below, the Permittee will be installing a separate monitoring 

point for the process wastewater streams prior to combining with the stormwater (Monitoring 

Point 101). Please see the figure in Section IV.A of this fact sheet for a simplified diagram 

of the wastewater streams, outfalls, and monitoring points associated with this permit. The 

monitoring results from Monitoring Point 101 will be used to demonstrate compliance with 

the process wastewater limits at Outfall 001. Stormwater allocations will no longer be 

necessary at Outfall 001.

Stormwater will be monitored at D-10 where stormwater from the treatment pond combines 

with stormwater collected from the non-industrial area, as was the case for Outfall 002. The 

limits for Outfall 002 in the existing permit will be applied to the combined stormwater 

discharged at D-10. Because the limits for stormwater apply at Monitoring Point D-10, they 

are the same whether the stormwater is discharged from Outfall 001 or Outfall 002. The 

Action Levels for the stormwater pond discharge have been maintained in the draft permit to 

ensure continued use of best management practices at the facility and proper operation and 

maintenance of the stormwater treatment pond.

C. Surface Water Quality-Based Effluent Limits

The Washington State surface water quality standards (chapter 173-201A WAC) are 

designed to protect existing water quality and preserve the beneficial uses of Washington's 

surface waters. Wastewater discharge permits must include conditions that ensure that the 

discharge will meet the surface water quality standards (WAC 173-201A-510). Water 

quality-based effluent limits may be based on an individual waste load allocation or on a 

waste load allocation developed during a basin wide total maximum daily load study 

(TMDL).

Numerical Criteria for the Protection of Aquatic Life and Recreation

Numerical water quality criteria are listed in the water quality standards for surface waters 

(chapter 173-201A WAC). They specify the maximum levels of pollutants allowed in 

receiving water to protect aquatic life and recreation in and on the water. Ecology uses 

numerical criteria along with chemical and physical data for the wastewater and receiving 

water to derive the effluent limits in the discharge permit. When surface water quality-based 

limits are more stringent or potentially more stringent than technology-based limits, the 

discharge must meet the water quality-based limits.
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Numerical Criteria for the Protection of Human Health 

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

health that are applicable to dischargers in Washington State (EPA, 1992). These criteria are 

designed to protect humans from exposure to pollutants linked to cancer and other diseases, 

based on consuming fish and shellfish and drinking contaminated surface waters. The water 

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-240(1); 2006) limit the toxic, 

radioactive, or other deleterious material concentrations 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 all fresh waters 

(WAC 173-201A-200) and of all marine waters (WAC 173-201A-210) in the state of 

Washington.

Antidegradation

Description--The purpose of Washington's Antidegradation Policy 

(WAC 173-201A-300-330; 2006) is to:

• Restore and maintain the highest possible quality 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 likely to contribute to a lowering of water quality, at a 

minimum, apply all known, available, and reasonable methods of prevention, control, and 

treatment (AKART).

• Apply three tiers of protection (described below) for surface waters of the state.

Tier I ensures existing and designated uses are maintained and protected and applies to all 

waters and all sources of pollutions. Tier II ensures that waters of a higher quality than 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 listed as "outstanding resource waters," 

and applies to all sources of pollution.

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

• The facility is planning a new or expanded action.
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• Ecology regulates or authorizes the action.

• The action has the potential to cause measurable degradation to existing water quality at 

the edge of a chronic mixing zone.

Facility Specific Requirements--This facility must meet Tier I requirements.

• Dischargers must maintain and protect existing and designated uses. Ecology must not 

allow any degradation that will interfere with, or become injurious to, existing or 

designated uses, except as provided for in chapter 173-201A WAC.

Ecology’s analysis described in this section of the fact sheet demonstrates that the proposed 

permit conditions will protect existing and designated uses of the receiving water.

Mixing Zones

A mixing zone is the defined area in the receiving water surrounding the discharge port(s), 

where wastewater mixes with receiving water. Within mixing zones the pollutant 

concentrations may exceed water quality numeric standards, so long as the discharge doesn’t 

interfere with designated uses of the receiving water body (for example, recreation, water 

supply, and aquatic life and wildlife habitat, etc.) The pollutant concentrations outside of the 

mixing zones must meet water quality numeric standards.

State and federal rules allow mixing zones because the concentrations and effects of most 

pollutants diminish rapidly after discharge, due to dilution. Ecology defines mixing zone 

sizes to limit the amount of time any exposure to the end-of-pipe discharge could harm water 

quality, plants, or fish.

The state’s water quality standards allow Ecology to authorize mixing zones for the facility’s 

permitted wastewater discharges only if those discharges already receive all known, 

available, and reasonable methods of prevention, control, and treatment (AKART). Mixing 

zones typically require compliance with water quality criteria within a specified distance 

from the point of discharge and must not use more than 25% of the available width of the 

water body for dilution [WAC 173-201A-400 (7)(a)(ii-iii)].

Ecology uses modeling to estimate the amount of mixing that occurs within the mixing zone. 

Through modeling Ecology determines the potential for violating the water quality standards 

at the edge of the mixing zone and derives any necessary effluent limits. Steady-state models 

are the most frequently used tools for conducting mixing zone analyses. Ecology chooses 

values for each effluent and for receiving water variables that correspond 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 dilution factor (DF). A 

dilution factor represents the amount of mixing of effluent and receiving water that occurs at 

the boundary of the mixing zone. For example, a dilution factor of 5 means the effluent is

one-fifth, or 20%, and the receiving water is four-fifths, or 80%, of the total volume of water 

at the boundary of the mixing zone. Ecology uses dilution factors with the water quality 

criteria to calculate reasonable potentials and effluent limits. Water quality standards include 
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both aquatic life-based criteria and human health-based criteria. The former are applied at 

both the acute and chronic mixing zone boundaries; the latter are applied only at the chronic 

boundary. The concentration of pollutants at the boundaries of any of these mixing 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 that 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-based water quality criteria distinguish between those 

pollutants linked to non-cancer effects (non-carcinogenic) and those linked to cancer effects 

(carcinogenic). The human health-based water quality criteria incorporate 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). 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.

The proposed permit specifies the size and location of the allowed mixing zone (as specified 

below).

2. The facility must fully apply “all known, available, and reasonable methods of 

prevention, control and treatment” (AKART) to its discharge.

Ecology has determined that the treatment provided at Intalco meets the 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 discharge condition with the highest potential for adverse impact 

on the aquatic biota, human health, and existing or designated waterbody uses). The critical 

discharge condition is often pollutant-specific or waterbody-specific.

Critical discharge conditions are those conditions that result in reduced dilution or increased 

effect of the pollutant. Factors affecting dilution 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 rise. The rate of mixing is greatest when an 
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effluent is rising. The effluent stops rising when the mixed effluent is the same density as the 

surrounding water. After the effluent stops rising, the rate of mixing is much more gradual. 

Water depth can affect dilution when a plume might rise to the surface when there is little or 

no stratification. Ecology uses the water depth at mean lower low water (MLLW) for marine 

waters. Ecology’s Permit Writer’s Manual describes additional guidance on criteria/design 

conditions for determining dilution factors. The manual can be obtained from Ecology’s 

website at https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html.

Table 15 Critical Conditions Used to Model the Discharge from Outfall 001

Critical Condition Value

Water depth at MLLW of -4.92 feet 15.5 feet

Density profile with a difference of 4.78 (acute) and 7.07

(chronic) sigma-t units between 23 feet and the surface

10th percentile current speed for acute mixing zone 0.04 m/sec

50th percentile current speeds for chronic and human health 

mixing zones

0.15 m/sec

Maximum average monthly effluent flow for chronic and 

human health non-carcinogen

3.41 MGD

Annual average flow for human health carcinogen 1.61 MGD

Maximum daily flow for acute mixing zone 8.94 million 

gallons per day 

(MGD)

1 DAD MAX effluent temperature 22.1 degrees C

Table 16 Critical Conditions Used to Model the Discharge from Outfall 002

Critical Condition Value

Water depth at MLLW of -4.92 feet 9.1 feet

Density profile with a difference of 4.78 (acute) and 7.07 

(chronic) sigma-t units between 23 feet and the surface

10th percentile current speed for acute mixing zone 0.04 m/sec

50th percentile current speeds for chronic and human health 

mixing zones

0.15 m/sec
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Critical Condition Value

Maximum average monthly effluent flow for chronic and 

human health non-carcinogen

0.362 MGD

Annual average flow for human health carcinogen 0.362 MGD

Maximum daily flow for acute mixing zone 0.418 million 

gallons per day 

(MGD)

1 DAD MAX effluent temperature 19.6 degrees C

Ecology obtained ambient data at critical conditions in the vicinity of the outfall from the 

Outfalls 001 and 002 Dilution Ratio Study conducted in December 2006.

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

• Have a reasonable potential to cause the loss of sensitive or important habitat.

• Substantially interfere with the existing or characteristic uses.

• Result in damage to the ecosystem.

• Adversely affect public health.

Ecology established Washington State water quality criteria for toxic chemicals using EPA 

criteria. EPA developed the criteria using toxicity tests with numerous organisms and set the 

criteria to generally protect 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 one hour. They set chronic standards assuming organisms are 

exposed to the pollutant at the criteria concentration for four days. Dilution modeling under 

critical conditions generally shows that both acute and chronic criteria concentrations are 

reached within minutes of discharge.

The discharge plume does not impact drifting and non-strong swimming organisms because 

they cannot stay in the plume close to the outfall long 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 benthic 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 two 

seconds after discharge; and that the temperature of the water will not create lethal conditions 

or blockages to fish migration.

Ecology evaluates the cumulative toxicity of an effluent by testing the discharge with whole 

effluent toxicity (WET) testing.

Ecology conducted a reasonable potential analysis, using procedures established by the EPA 

and by Ecology, for each pollutant and concluded the discharge/receiving water mixture will 
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not violate water quality criteria outside the boundary of the mixing zone if permit limits are 

met.

5. The size of the mixing zone and the concentrations of the pollutants must be 

minimized.

At any given time, the effluent plume uses only 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 mixes as 

it rises through the water column therefore much of the receiving water volume at lower 

depths in the mixing zone is not mixed with discharge. Similarly, because the discharge may 

stop rising at some depth due to density stratification, waters above that depth will not mix 

with the discharge. Ecology determined it is impractical to specify 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 requiring dischargers to install diffusers 

when they are appropriate to the discharge and the specific receiving water body. When a 

diffuser is installed, the discharge is more completely mixed with the receiving water in a 

shorter time. Ecology also minimizes the size of the mixing zone (in the form of the dilution 

factor) using design criteria with a low probability of occurrence. For example, Ecology uses 

the expected 95th percentile pollutant concentration, the 90th percentile background 

concentration, the centerline dilution factor, and the lowest receiving water flow occurring 

once in every ten years to perform the reasonable potential analysis.

Because of the above reasons, Ecology has effectively minimized the size of the mixing zone 

authorized in the proposed permit.

6. Maximum size of mixing zone.

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

7. Acute mixing zone.

• The discharge/receiving water mixture must comply 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 distance of the chronic 

mixing zone.

• The pollutant concentration, duration, and frequency of exposure 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 organism 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 translocation of indigenous organisms near the point of 

discharge (below the rising effluent).

• Comply with size restrictions.
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The mixing zone authorized for this discharge complies with the size restrictions published in 

chapter 173-201A WAC.

8. Overlap of mixing zones.

This mixing zone does not overlap another mixing zone.

D. Designated Uses and Surface Water Quality Criteria

Applicable designated uses and surface water quality criteria are defined in chapter 

173-201A WAC. In addition, the U.S. EPA has established human health criteria for toxic 

pollutants (EPA 1992). The table included below summarizes the criteria applicable to this 

facility’s discharge.

• Aquatic life uses are designated using the following general categories. All indigenous 

fish and non-fish aquatic species must be protected in waters of the state.

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 migration, rearing, and spawning; clam, 

oyster, and mussel rearing and spawning; crustaceans and other shellfish (crabs, 

shrimp, crayfish, scallops, etc.) rearing and spawning.

c. Good quality salmonid migration and rearing; 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. 

d. Fair quality salmonid and other fish migration.

The Aquatic Life Uses and the associated criteria for this receiving water are identified 

below.

Table 17 Marine Aquatic Life Uses and Associated Criteria

Extraordinary Quality

Temperature Criteria – Highest 1D MAX 13°C (55.4°F)

Dissolved Oxygen Criteria – Lowest 

1-Day Minimum

7.0 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 0.2 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 
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samples (or any single sample when less than ten sample points exist) obtained for 

calculating the geometric mean value exceeding 43 colonies/100 mL.

• The recreational uses for this receiving water are identified below.

Table 18 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.

• The miscellaneous marine water uses are wildlife habitat, harvesting, commerce and 

navigation, boating, and aesthetics.

E. Water Quality Impairments

Ecology has not documented any water quality impairments in the receiving water in the 

vicinity of the outfall.

The Strait of Georgia is listed on the 2012 Clean Water Act 303(d) list. It is listed for two 

pollutants found in the sediments near the outfalls: phenol and 1, 2 ,4-Trichlorobenzene. 

Both of these pollutants are listed in Category 2 which indicates that there is evidence of a 

water quality problem, but not enough to require production of a Water Quality Improvement 

Project at this time. Based on this ranking, the water/sediment in the receiving water will 

continue to be tested in future water quality assessments. In addition, the sediments 

surrounding Outfalls 001 and 002 will be required to be sampled during this permit cycle.

F. Evaluation of Surface Water Quality-Based Effluent Limits for Numeric Criteria

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

(near-field) or at a considerable distance from the point of discharge (far-field). Toxic 

pollutants, for example, are near-field pollutants; their adverse effects diminish rapidly with 

mixing in the receiving water. Conversely, a pollutant such as biological oxygen 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 quality-based 

effluent limits varies with the point at which the pollutant has its maximum effect.

With technology-based controls (AKART), predicted pollutant concentrations in the 

discharge exceed water quality criteria. Ecology therefore authorizes a mixing zone in

accordance with the geometric configuration, flow restriction, and other restrictions imposed 

on mixing zones by chapter 173-201A WAC.

The diffuser at Outfall 001 is approximately 120 feet long with a diameter of 24 inches. The 

diffuser has a total of 12, 6-inch diameter ports. The distance between ports is 8.63 feet on 

average. The diffuser depth is assumed to be 6.6 feet above the sea floor. The mean lower 

low water (MLLW) depth is 15.5 feet. Ecology obtained this information from the Dilution 

Ratio Study Report submitted on August 7, 2006.
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30 inch HDPE Outfall Pipe 

Plan View

Side View

-8.9 ft MLLW

 21.6 ft

0 ft MLLW

Acute Mixing Zone 

Boundary

432 ft

Chronic Mixing 

Zone Boundary

21.6 ft

216 ft 216 ft

The discharge for Outfall 002 extends 250 feet from the shoreline. The open-ended pipe is 

30 inches in diameter. The pipe is 1.25 feet above the sea floor. The mean lower low water 

(MLLW) depth is 9.1 feet. Ecology obtained this information from the Dilution Ratio Study 

Report submitted on August 7, 2006.

The figures below are mixing zone diagrams for both outfalls.

Figure 3 Outfall 001
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207 ft

24 inch HDPE Outfall Pipe w/ open end port

Plan View

Chronic Mixing Zone 

Boundary

Side View

-7.9 ft MLLW

20.7 ft

0 ft MLLW

Acute Mixing 

Zone Boundary

Chronic Mixing Zone--WAC 173-201A-400(7)(b) specifies that mixing zones must not 

extend in any horizontal direction from the discharge ports for a distance greater than 200 

feet plus the depth of water over the discharge ports and may not occupy more than 25% of 

the width of the water body as measured during MLLW.

The horizontal distance of the chronic mixing zone is 216 feet for Outfall 001 and 207 feet 

for Outfall 002. The mixing zone extends from the top of the discharge ports to the water 

surface.

Acute Mixing Zone--WAC 173-201A-400(8)(b) specifies that in estuarine waters a zone 

where acute criteria may be exceeded must not extend beyond 10% of the distance 

established for the chronic zone. The acute mixing zone for Outfall 001 extends 21.6 feet in 

any direction from any discharge port. The acute mixing zone for Outfall 002 extends 20.7 

feet in any direction from any discharge port.

Ecology determined the dilution factors that occur within these zones at the critical condition 

using the information provided in both the “Outfalls 001 and 002 Dilution Ratio Study”

submitted in August 2011 and the previous “Outfalls 001 and 002 Dilution Ratio Study” 

submitted in November 2006. Ecology reviewed the updated study submitted in August 

2011 and modeled the effluents using the information provided in the 2006 and 2011 reports. 

The dilution factors included in the proposed permit and used in the reasonable potential 

Figure 4 Outfall 002
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analysis are those obtained from Ecology’s modeling efforts using the data provided by 

Intalco. The dilution factors are listed below.

Table 19 Dilution Factors for Outfall 001

Criteria Acute Chronic

Aquatic Life 21 52

Human Health, Carcinogen 105

Human Health, Non-carcinogen 77

Table 20 Dilution Factors for Outfall 002

Criteria Acute Chronic

Aquatic Life 19 33

Human Health, Carcinogen 48

Human Health, Non-carcinogen 48

Ecology used the dilution factors in the above tables to determine the potential impacts of 

pH, ammonia, metals, other toxics, and temperature of the effluent on the receiving water, as 

described below. The results of this analysis determine whether a water quality-based limit 

is required for any of the pollutants. The derivation of water quality-based limits takes into 

account the variability of pollutant concentrations in both the effluent and the receiving 

water.

pH--Compliance with the technology-based limits of 6.0 to 9.0 will assure compliance with 

the water quality standards of surface waters because of the high buffering capacity of marine 

water.

Turbidity--In accordance with Ecology’s Permit Writers Manual, control of particulates as 

TSS in an effluent usually results in low turbidity. The draft permit contains a technology 

based TSS limit which results in a small amount of TSS loading compared to the large 

amount of dilution occurring in the receiving water at critical conditions. The technology 

based limits are considered to be protective of the turbidity criteria in the receiving water.

Toxic Pollutants--Federal regulations (40 CFR 122.44) require Ecology to place a water 

quality-based limit in an NPDES permit for any toxic chemical in an effluent when there is a 

reasonable potential for that chemical to cause the receiving water body to exceed the surface 

water quality criteria. Ecology does not exempt facilities with technology-based effluent 

limits from meeting the surface water quality standards.

The following toxic pollutants are present in the discharge: ammonia, heavy metals, cyanide, 

phenols, and polycyclic aromatic hydrocarbons (PAHs). Ecology conducted a reasonable 
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potential analysis (See Appendix E) on these parameters to determine whether water qualitybased effluent limits would be required in the proposed permit.

Ammonia's toxicity depends on that portion which is available in the unionized form. The 

amount of unionized ammonia depends on the temperature, pH, and salinity of the receiving 

marine water. To evaluate ammonia toxicity, Ecology used the available receiving water 

information for ambient station GRG002 and Ecology spreadsheet tools.

Valid ambient background data were available for ammonia, aluminum, cadmium, copper, 

lead, mercury, and zinc (See Table 2). Ecology used all applicable data to evaluate 

reasonable potential for this discharge to cause a violation of water quality standards.

Ecology determined that all of the pollutants pose no reasonable potential to exceed the water 

quality criteria at the critical condition using procedures given in EPA, 1991 (Appendix E)

and as described above. Ecology’s determination assumes that this facility meets the other 

effluent limits of this permit.

Temperature--The state temperature standards (WAC 173-201A-210 and -612) for marine 

discharges include multiple elements:

• One day maximum temperature criteria

• Incremental warming restrictions

• Protections against acute effects

Ecology evaluates each criterion independently to determine reasonable potential and derive 

permit limits.

• One day maximum temperature criteria

Each water body has an annual maximum temperature criterion [WAC 173-201A-210(1)(c), 

and Table 612]. These threshold criteria (e.g., 13, 16, 19, 22°C) protect specific categories of 

aquatic life by controlling the effect of human actions on summer temperatures.

The threshold criteria apply at the edge of the chronic mixing zone. Criteria for marine 

waters and some fresh waters are expressed as the highest 1-Day annual maximum 

temperature (1-DMax).

• Incremental warming criteria

The water quality standards limit the amount of warming human sources can cause under 

specific situations [WAC 173-201A-210(1)(c)(i)-(ii)]. The incremental warming criteria 

apply at the edge of the chronic mixing zone.

At locations and times when background temperatures are cooler than the assigned threshold 

criterion, point sources are permitted to warm the water by only a defined increment. These 

increments are permitted only to the extent doing so does not cause temperatures to exceed 

either the annual maximum or supplemental spawning criteria.

At locations and times when a threshold criterion is being exceeded due to natural conditions, 

all human sources, considered cumulatively, must not warm the water more than 0.3°C above 

the naturally warm condition.
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When Ecology has not yet completed a TMDL for a water body that is warmer than the 

threshold criterion, our policy allows each point source to warm water at the edge of the 

chronic mixing zone by 0.3°C. This is true regardless of the background temperature and 

even if doing so would cause the temperature at the edge of a standard mixing zone to exceed 

the numeric threshold criteria. Allowing a 0.3°C warming for each point source is reasonable 

and protective where the dilution factor is based on 25% or less of the critical flow. This is 

because the fully mixed effect on temperature will only be a fraction of the 0.3°C cumulative 

allowance (0.075°C or less) for all human sources combined.

• Protections for temperature acute effects

Instantaneous lethality to passing fish: The upper 99th percentile daily maximum effluent 

temperature must not exceed 33°C, unless a dilution analysis indicates ambient temperatures 

will not exceed 33°C two seconds after discharge.

General lethality and migration blockage: Measurable (0.3°C) increases in temperature at the 

edge of a chronic mixing zone are not allowed when the receiving water temperature exceeds 

either a 1DMax of 23°C or a 7DADMax of 22°C.

Lethality to incubating fish: Human actions must not cause a measurable (0.3°C) warming 

above 17.5°C at locations where eggs are incubating.

Reasonable Potential Analysis

Annual summer maximum, supplementary spawning criterion, and incremental 

warming criteria: Ecology calculated the reasonable potential for the discharge to exceed 

the annual summer maximum, the supplementary spawning criterion, and the incremental 

warming criteria at the edge of the chronic mixing zone during critical conditions (See 

temperature spreadsheets in Appendix E).

The discharge is only allowed to warm the water by a defined increment when the 

background (ambient) temperature is cooler or warmer than the assigned threshold criterion. 

Ecology allows warming increments only when they do not cause temperatures to exceed 

either the annual maximum or supplemental spawning criteria.

The incremental increase for the Outfall 001 discharge is within the allowable amount. 

Therefore, the proposed permit does not include a temperature limit.

Outfall 002 only discharges treated stormwater. Ecology has determined temperature is not a 

significant stormwater pollutant parameter. Therefore, the proposed permit does not include 

a temperature limit and does not require the facility to monitor temperature in the stormwater 

discharges. Ecology may elect to develop procedures and guidance for regulating the effects 

of stormwater to comply with temperature water quality criteria in the future.

G. 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.
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Ecology determined the effluent may contain chemicals of concern for human health, based 

on data or information indicating the discharge contains regulated chemicals.

Ecology evaluated the discharge's potential to violate the water quality standards as required 

by 40 CFR 122.44(d) by following 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 to make a reasonable potential determination. The evaluation 

showed that the discharge has no reasonable potential to cause a violation of water quality 

standards, except as discussed below, and an effluent limit is not needed.

Arsenic--In 1992 the EPA adopted risk-based arsenic criteria for the protection of human 

health for the State of Washington. The criterion for marine waters is 0.14 μg/L inorganic 

arsenic, and is based on exposure from fish and shellfish tissue ingestion. The freshwater 

criterion is 0.018 μg/L, and is based on exposure from fish and shellfish tissue and water 

ingestion. These criteria have caused confusion in implementation because they differ from 

the drinking water maximum contaminant level (MCL) of 10 μg/L, which is not risk-based, 

and because the human health criteria are sometimes exceeded by natural background 

concentrations of arsenic in surface water and ground water.

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

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

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

industrial source-water would need additional treatment to meet numeric effluent limits even 

though no arsenic was added as waste. Although this is not the case for all dischargers, we 

do not have data at this time to quantify the extent of the problem.

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

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

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

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

are:

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

sources with high arsenic concentrations causing municipal treatment plant effluent 

to exceed criteria. The revision of the drinking water MCL for arsenic offered a national 

opportunity to discuss how drinking water sources can affect NPDES wastewater 

dischargers, however Ecology was unsuccessful in focusing the discussion on developing 

a national policy for arsenic regulation that acknowledges the risks and costs associated 

with management of the public exposure to natural background concentrations of arsenic 

through water sources. The current arsenic MCL of 10 μg/L could also result in 

municipal treatment plants being unable to meet criteria-based effluent limits. Ecology 

will continue to pursue this issue as opportunity arises.

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

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

require dischargers to test for source water arsenic concentrations, and will pursue 

development of a proposal to have Ecology's Environmental Assessment Program 

conduct drinking water source monitoring as well as some additional ambient monitoring 
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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 EPA as they work to develop new riskbased criteria for arsenic and as they develop a strategy to regulate arsenic.

The proposed permit adds total arsenic as one of the parameters to monitor in the PUD 

intake water. Total arsenic has been added to the grab sample that is required to be 

collected twice per year.

H. Sediment Quality

The aquatic sediment standards (chapter 173-204 WAC) protect aquatic biota and human 

health. Under these standards Ecology may require a facility to evaluate the potential for its 

discharge to cause a violation of sediment standards (WAC 173-204-400). Additional 

information can be obtained about sediments at the Aquatic Lands Cleanup Unit website. 

http://www.ecy.wa.gov/programs/tcp/smu/sediment.html

The existing permit required the facility to submit a Sediment Sampling and Analysis Plan to 

recharacterize the sediment in the vicinity of Outfalls 001 and 002. This plan was submitted 

and is currently being reviewed by Ecology. The proposed permit requires that the facility 

conduct sediment sampling during the next stable period (mid-August through midSeptember) following Ecology’s approval of the plan.

In addition to the sediment quality in the vicinity of the outfalls, concerns have been raised 

about spillage of alumina ore during ship unloading and possible accumulation in sediments 

around Intalco’s marine terminal. To address this concern, Intalco has implemented best 

management practices (BMPs) including upgrading and maintaining the integrity of the seal 

on the clamshell and operating the clamshell in way that minimizes the fugitive emissions to 

reduce the amount of fugitive alumina released during unloading activities. Some of these 

BMPs have been incorporated into the proposed permit. Ecology has also issued an order to 

Intalco requiring them to evaluate the impact of historical fugitive alumina emissions on 

local benthic communities. The results of the evaluation will be used to assist in the 

development of the fugitive alumina pollution prevention plan discussed in Section V.I 

below, as well as identify whether there are any significant impacts to benthic communities. 

If any significant impacts are identified, Intalco is required to propose actions address those 

impacts.

I. Groundwater Quality Limits

The groundwater quality standards (chapter 173-200 WAC) protect beneficial uses of 

groundwater. Permits issued by Ecology must not allow violations of those standards (WAC 

173-200-100).

Intalco does not directly discharge wastewater to the ground. No permit limits are required 

to protect the ground water at this time. There are two wastewater treatment ponds at the

Intalco facility: the stormwater treatment pond and the sanitary lagoon. The stormwater pond 

is lined with a PVC liner. The sanitary lagoon consists of an unlined native clay bottom that 

could potentially discharge to ground water.
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The PVC liner associated with the stormwater pond should prevent leakage from the pond to 

the groundwater. But there is no data available to determine if there is a potential to impact 

groundwater beneath the sanitary lagoon. As a result, Intalco was required to submit a 

groundwater impact study plan to Ecology for review and approval during the previous 

permit cycle. The plan was submitted in February 2010 and is being reviewed by Ecology. 

The proposed permit requires that the facility conduct the study within 180 days of Ecology’s 

approval of the plan. The results of the study will be used to determine whether monitoring 

wells will need to be installed to determine if there are any actual effects on the ground 

water.

J. Whole Effluent Toxicity

The water quality standards for surface waters forbid discharge of effluent that has the 

potential to cause toxic effects in the receiving waters. Many toxic pollutants cannot be 

measured by commonly available detection methods and some pollutants may be toxic when

an organism is exposed to them in conjunction with other pollutants in the same wastewater 

stream. Laboratory tests have been developed to measure effluent toxicity directly by 

exposing living organisms to the wastewater and measuring their responses. These tests 

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

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

measure chronic toxicity.

• Acute toxicity tests measure mortality as the significant response to the toxicity of the 

effluent. Dischargers who monitor their wastewater with acute toxicity tests find early 

indications of any potential lethal effect of the effluent on organisms in the receiving 

water.

• Chronic toxicity tests measure various sublethal toxic responses, such as reduced growth 

or reproduction. Chronic toxicity tests often involve either a complete life cycle test on 

an organism with an extremely short life cycle, or a partial life cycle test during a critical 

stage of a test organism's life. Some chronic toxicity tests also measure organism 

survival.

Laboratories accredited by Ecology for WET testing know how to use the proper WET 

testing protocols, fulfill the data requirements, and submit results in the correct reporting 

format. Accredited laboratory staff know about WET testing and how to calculate an NOEC, 

LC50, EC50, IC25, etc. Ecology gives all accredited labs the most recent version of Ecology 

Publication No. WQ-R-95-80, Laboratory Guidance and Whole Effluent Toxicity Test 

Review Criteria (https://fortress.wa.gov/ecy/publications/SummaryPages/9580.html), which 

is referenced in the permit. Ecology recommends that Intalco send a copy of the acute or 

chronic toxicity section(s) of its NPDES permit to the laboratory.

The existing permit does not contain WET limits for Outfalls 001 and 002. In May 1999, the 

stormwater discharge from Outfall 002 failed the acute and chronic toxicity testing required 

by the permit at that time. The discharge also failed additional subsequent testing which 

triggered the submittal of a Toxicity Identification/Reduction Evaluation (TI/RE) Plan to 

Ecology for review and approval. The results of Intalco’s Toxicity Identification Evaluation 

identified aluminum as the source of toxicity with complicating factors resulting from the 
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presence of fluoride. As a result, Intalco ultimately proposed to divert the stormwater flow 

from Outfall 002 to Outfall 001. This diversion was completed in February 2009. The 

existing permit removed the acute and chronic WET limits for Outfall 002 once the diversion 

was operational under the assumption that discharges from Outfall 002 would be infrequent. 

The permit also required that Intalco characterize the new discharge from Outfall 001 with 

the additional stormwater flow to demonstrate that acute or chronic toxicity did not increase 

in the effluent.

The following sections discuss the results of the combined Outfall 001 WET testing and the 

effect of the diversion structure on discharges from Outfall 002.

Outfall 001

The existing permit required Intalco to perform WET testing to characterize the new 

discharge that resulted from combining the stormwater from Outfall 002 with the process 

wastewater discharges at Outfall 001. The results of this characterization showed no 

reasonable potential for the combined discharge to cause receiving water acute toxicity or 

chronic toxicity (see Appendix F). Based on these results, no limits for acute toxicity or 

chronic toxicity were established for Outfall 001.

Since there were no WET limits established for Outfall 001, the existing permit required that 

the facility test the discharge for acute and chronic toxicity once in the last summer and once 

in the last winter of the permit term. The results of those WET tests were submitted with the 

permit renewal application and are summarized below.

Acute Toxicity

The performance standard for acute toxicity is a median of at least 80% survival in 100% 

effluent with no single test showing less than 65% survival in 100% effluent. The acute 

WET test results in Table 23 provide the percent survival of the testing organism in 100% 

effluent. All of the survival rates are greater than 80%; therefore, the proposed permit will 

not include an acute WET limit for Outfall 001. 

Table 21 Outfall 001 2010 Acute WET Test Results (Percent survival in 100% effluent)

Sample Date Organism Endpoint Percent Survival

08/30/10 Rainbow Trout 96-Hour Survival 100

08/30/10 Daphnid 48-Hour Survival 100

10/18/10 Rainbow Trout 96-Hour Survival 100

10/18/10 Daphnid 48-Hour Survival 100

12/14/10 Rainbow Trout 96-Hour Survival 100

12/14/10 Daphnid 48-Hour Survival 100
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Chronic Toxicity

The performance standard for chronic toxicity is no toxicity in a concentration of effluent 

representing the edge of the acute mixing zone. Based on the mixing zone analysis submitted 

in November 2006, the acute critical effluent concentration (ACEC) for combined Outfall 

001 was predicted to be 3.8% and the chronic critical effluent concentration (CCEC) was 

predicted to be 2.5%. The chronic WET tests were performed using multiple effluent 

concentrations (0%, 2.5%, 3.8%, 10%, 30%, and 59.9% for the echinoderms and 0%, 2.5%, 

3.8%, 25%, 50%, and 100% for the other species). Table 24 shows the effluent concentration 

that had no observable effects (NOEC) on the test species and the lowest effluent 

concentration that did show an observable effect on the test species (LOEC).

Table 22 Outfall 001 Chronic Bioassay Results (Reported as Percent Effluent)

Sample Date Organism Endpoint NOEC LOEC

09/13/10 Mysid Shrimp

7-day Survival 30 100

Biomass 30 100

Weight 30 100

09/13/10 Pacific 

Topsmelt

7-day Survival 100 >100

Biomass 100 >100

Weight 100 >100

09/15/10 Echinoderm

Development 59.5 >59.5

Survival 59.5 >59.5

10/18/10 Mysid Shrimp

7-day Survival 30 100

Biomass 10 30

Weight 30 100

10/18/10 Inland 

Silverside

7-day Survival 100 >100

Biomass 100 >100

Weight 100 >100

10/18/10 Echinoderm Development <2.5 2.5
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Sample Date Organism Endpoint NOEC LOEC

Survival 61.3 >61.3

12/13/10 Mysid Shrimp

7-day Survival 100 >100

Biomass a a

Weight a a

12/13/10 Pacific 

Topsmelt

7-day Survival 100 >100

Biomass 100 >100

Weight 100 >100

12/15/10 Echinoderm

Development 30 59.9

Survival 59.9 >59.9

a. Test produced anomalous results. 

As seen in Table 22, the toxicity results from the echinoderm test in October 2010 and the 

mysid shrimp test in December 2010 failed to meet the whole effluent toxicity performance 

standards described above or the results were anomalous and it appears that chronic toxicity 

may have increased. Therefore, under WAC 173-205-060, Intalco must repeat the chronic 

effluent characterization for the combined discharge at Outfall 001.

The new characterization will be required to be conducted with the ACEC and CCEC derived 

from the new dilution factors as discussed in Section III.F.

Outfall 002

Historically, WET testing of the discharge from Outfall 002 has shown a reasonable potential 

for both acute and chronic toxicity. However, monitoring to demonstrate compliance with 

the acute and chronic WET limits was not required once the diversion to Outfall 001 was 

complete based on the assumption that discharges from Outfall 002 would be infrequent (i.e. 

less than once per year). Looking at flow data during the last permit cycle, Intalco 

discharged stormwater 76 times since May 2009 from Outfall 002, with an average of 

approximately 17 discharges per year. The average flow rate for these discharges was 

approximately 0.55 MGD with a maximum daily discharge of 4.2 MGD. While this is a 

significant reduction in the amount of stormwater that is being discharged from Outfall 002, 

there are still a number of substantial discharge events each year.

In addition to installing the diversion structure, Intalco has also improved their housekeeping 

best management practices (BMPs) to reduce the pollutant loading in the stormwater. 

Because stormwater is being discharged more frequently than anticipated at Outfall 002 and 

there have been other changes in stormwater management at the site, the proposed permit 
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requires Intalco to re-characterize the discharge from Outfall 002 to determine whether WET 

limits are necessary. The re-characterization will be required to be conducted with the 

ACEC and CCEC derived from the new dilution factors discussed in Section III.F.

K. Conditionally Authorized Non-Stormwater Discharges and Non-Routine

Occasionally, Intalco may generate wastewater which was not characterized in the permit 

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

application. Permit Condition S8 of the proposed permit authorizes non-routine and 

unanticipated discharges from Outfall 001 and non-stormwater discharges to the stormwater 

treatment pond under certain conditions. The facility must characterize these waste waters 

for pollutants and examine the opportunities for reuse. Intalco must request prior approval 

for these discharges, and, depending on the nature and extent of pollutants in the wastewater 

and the opportunities for reuse, Ecology may:

• Authorize the facility to discharge the wastewater.

• Require the facility to treat the wastewater.

• Require the facility to reuse the wastewater.

L. Comparison of Effluent Limits with the Existing Permit Issued in March 2007

Table 23 Comparison of Existing and Proposed Effluent Limits for Outfall 001

Previous Effluent Limits: 

Outfall # 001

Proposed Effluent Limits: 

Outfall # 001

Parameter Basis of 

Limit

Average 

Monthly

Daily 

Maximum

Average 

Monthly

Daily 

Maximum

Total 

Suspended 

Solids (TSS)

Technology 150 185 150 185

Fluoride Technology 58/68/68 140/198/296 58/68/68 140/198/296

Aluminum Technology 5.9/9.0/10.3 13.4/20/30 5.9/9.0/10.3 13.4/20/30

Free Cyanide WaterQuality <0.012 0.012 <0.012 0.012

Benzo(a)-

Pyrene Technology

0.02/0.03/

0.045

0.043/0.065/

0.098

0.02/0.03/

0.045

0.043/0.065/

0.098

Antimony Technology 1.9/2.9/4.3 4.2/6.4/9.6 1.9/2.9/4.3 4.2/6.4/9.6

Nickel Technology 0.8/1.2/1.9 1.2/1.8/2.7 0.8/1.2/1.9 1.2/1.8/2.7

Oil and 

Grease

WaterQuality 5 10 5 10

Parameter Basis of Limit Previous Limit Proposed Limit

pH Technology 6.0 to 9.0 6.0 to 9.0
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Table 24 Comparison of Existing and Proposed Effluent Limits for Outfall 002

Previous Effluent 

Limits: Outfall # 002

Proposed Effluent 

Limits: Outfall # 002

Parameter Basis of Limit Average 

Monthly

Maximum 

Daily

Average 

Monthly

Maximum 

Daily

TSS Technology 35 75 35 75

Fluoride Technology 35 50 35 50

Aluminum Technology 10 15 10 15

Benzo(a)Pyrene Technology <0.01 <0.01

Oil and Grease Technology 5 10 5 10

Parameter Basis of Limit Previous Limit Proposed Limit

pH Technology 6.0 to 9.0 6.0 to 9.0

Table 25 Comparison of Existing and Proposed Effluent Limits for Sanitary Lagoon 

Discharges

Previous Effluent 

Limits: Sanitary 

Lagoon 

Proposed Effluent 

Limits: Sanitary 

Lagoon

Parameter Basis of 

Limit

30-Day 

Average

7-Day 

Average

30-Day 

Average

7-Day 

Average

Biochemical 

Oxygen Demand (5-

day BOD)

Technology 45 65 45 65

TSS Technology 45 65 45 65

Minimum Number 

of Operating UV 

Tubes

Technology 12 12

Minimum % 

removal of BOD 

and TSS

Technology 65% 65%
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Previous Effluent Limits: 

Sanitary Lagoon 

Proposed Effluent 

Limits: Sanitary Lagoon

Parameter Basis of 

Limit

Monthly 

Geometric 

Mean Limit

Weekly 

Geometric 

Mean Limit

Monthly 

Geometric 

Mean 

Limit

Weekly 

Geometric 

Mean Limit

Fecal Coliform 

Bacteria Technology

200 

organisms/ 

100 ml

400 

organisms/ 

100 ml

200 

organisms/ 

100 ml

400 

organisms/ 

100 ml

Parameter Basis of Limit Previous Limit Proposed Limit

pH Technology 6.0 to 9.0 6.0 to 9.0

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 functioning correctly and that the discharge complies with 

the permit’s effluent limits.

If a facility uses a contract laboratory to monitor wastewater, it must ensure that the laboratory 

uses the methods and meets or exceeds the method detection levels required by the permit. The 

permit describes when facilities may use alternative methods. It also describes what to do in 

certain situations when the laboratory encounters matrix effects. When a facility uses an 

alternative method as allowed by the permit, it must report the test method, DL, and QL on the 

discharge monitoring report or in the required report.

A. Wastewater Monitoring

Monitoring is the primary means of ensuring that the permit limitations are met and 

demonstrating that the characteristics of the wastewater stream have not changed 

significantly. Chapter XIII of Ecology’s Permit Writer’s Manual provides a detailed 

discussion of monitoring guidelines that permit writer’s use to establish monitoring schedules 

for a facility. The monitoring schedule for Intalco is specified in Special Condition S2 of the 

proposed permit. Specified monitoring frequencies take into account the quantity and 

variability of the discharge, the treatment method, past compliance, significance of 

pollutants, and cost of monitoring. Intalco has a number of monitoring points and the figure 

below has been provided to show a simplified diagram of the wastewater streams, outfalls, 

and monitoring points.
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Figure 5 Simplified diagram of wastewater streams, outfalls, and monitoring points for 

Outfalls 001 and 002
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Outfalls 001 and 002

Section 1.3.3 of Chapter XIII of Ecology’s Permit Writer’s Manual allows for a reduction in 

monitoring frequency for exemplary performance. Reduction of monitoring frequency is 

generally granted at the time of a permit renewal by examination of performance in the two 

years preceding renewal. The amount of reduction is dependent upon the ratio of 

performance for the last two years to the monthly average effluent limitation, as specified in 

Table XIII-1A1. The monitoring frequency was reduced during the last permit renewal for 

B(a)P, antimony, nickel, copper, cyanide, and oil and grease at Outfall 001 and for copper, 

cyanide, B(a)P, and oil and grease at Outfall 002. These reductions were implemented based 

on reviews of historical monitoring data and the fact that the sources of the respective 

pollutants had either been eliminated or were being controlled.

In February 2009, the facility completed a diversion project to divert stormwater from Outfall 

002 to Outfall 001. The combined flow of the treated process wastewater and stormwater at 

Outfall 001 was sampled and analyzed to demonstrate compliance with permit limits. 

Stormwater allocations were used to account for pollutants introduced by the stormwater 

stream. The additional stormwater flow made it difficult to determine if the monitoring 

results for the process wastewater showed exemplary performance during the past two years. 

Therefore, the monitoring frequency in the proposed permit is the same as the existing 

permit. The Permittee is installing an additional monitoring point to sample the process 

wastewater before combining with stormwater. The Permittee may request a reduced 

monitoring frequency after monitoring at the new location for at least 12 months, as specified 

in the Permit Condition S2.E of the proposed permit.

The monitoring frequency for Outfall 002 will be once per discharge event, with no more 

than 3 samples required per week. Wastewater is only discharged from Outfall 002 when the 

hydraulic capacity of the diversion structure or the Outfall 001 outlet pipe has been exceeded. 

Samples collected from the diversion structure (monitoring point D-10) will be considered

representative of the water being discharged from Outfall 002. A footnote has been added to 

the table in S2.A.1 to state that samples collected from monitoring point D-10 to demonstrate 

compliance with the stormwater pond action levels can be used to satisfy the Outfall 002 

monitoring requirements as long as the sample was collected less than 24 hours prior to the 

discharge event.

Sanitary Lagoon 

As part of the permit renewal process, Ecology reviewed the sampling results from the past 

two years at the sanitary lagoon to determine if the facility would qualify for reduced 

monitoring for any of the parameters. Table XIII-1A1 in Chapter XIII of Ecology’s Permit 

Writer’s Manual was used to determine the appropriate monitoring frequencies for the 

qualifying parameters. The table below shows the pollutant, the long term average (LTA) 

concentration from the last two years of monitoring, the ratio of the LTA to the average 

monthly limit (AML), and the applicable reduced monitoring.
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Table 26 Sanitary Lagoon Monitoring

Pollutant LTA LTA

AML

Allowable 

Monitoring 

Frequency

Recommended 

Min. 

Monitoring 

Frequency for 

POTWs <0.1 

MGD

Existing 

Monitoring 

Frequency

Proposed 

Monitoring 

Frequency

BOD5 15.1 

mg/L

34% 2/month 1/week 1/week 2/month

TSS 6.0 

mg/L

13% 1/ 2 months 1/week 1/week 2/month

Fecal 

Coliform

5/100 

mL

2.5% 1/ 2 months 1/week 1/week 2/month

The sanitary lagoon for Intalco is not a POTW, but the recommended minimum monitoring 

frequency for a similar plant is included in the table above to provide context. Based on the 

allowable monitoring frequency and considering the recommended minimum monitoring 

frequency for a similar publicly owned treatment works ( POTW), the monitoring frequency 

for all of the pollutants (BOD5, TSS and fecal coliform) is proposed to be reduced to twice 

per month. The monitoring frequency was reduced based on the fact that the treated sanitary 

wastewater is mixed with process wastewater prior to being discharged, unlike a POTW that 

would directly discharge to a surface water body. Any exceedance of the monthly average 

permit limits will revert the monitoring frequency back to the baseline monitoring frequency 

of once per week.

The facility also requested that the monitoring frequency for the minimum number of 

operating UV tubes be reduced to once per week. This request was granted in the proposed 

permit. The facility consistently report that 14 UV tubes were operating during inspections. 

The facility also has an alarm system that will alert them if power is lost to the UV 

disinfection system.

Secondary Wastewater Treatment System and Stormwater Pond Action Levels

Ecology established action levels in the existing permit for TSS, fluoride, and aluminum 

discharged from the stormwater pond and for TSS and fluoride discharged from the SEC. 

These action levels were placed in the permit to ensure that the Permittee is consistently: 1)

implementing the required BMPs designed to reduce or eliminate the respective pollutants, 2) 

evaluating the cause of any upward trends in pollutant discharges, and 3) taking corrective 

action to reverse those trends. Ecology determined the action levels in the existing permit by 

analyzing the monthly monitoring data submitted in 2003 and 2004. The tables below show 

the number of exceedances of the action levels between April 2007 and October 2013 for the 

stormwater treatment pond and the SEC.
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Table 27 Number of Stormwater Treatment Pond Action Level Exceedances

Monthly Average Daily Maximum

TSS 11 26

Fluoride 4 8

Aluminum 15 19

Table 28 Number of SEC Action Level Exceedances

Monthly Average Daily Maximum

TSS 1 12 

Fluoride 0 2 

The majority of the TSS exceedances at the SEC occurred between May 2011 and October 

2012. The facility appears to have addressed this issue and no changes will be made to the 

“action levels” in the proposed permit.

The facility has consistently exceeded the action levels for TSS and aluminum and 

occasionally exceeded the action level for fluoride at the stormwater treatment pond. 

However, the facility did not exceed any permit limits at Outfall 001 after stormwater was 

diverted from Outfall 002. It appears that the monitoring data used by Ecology to establish 

the action levels at the stormwater treatment pond was the monitoring data for Outfall 002. 

Outfall 002 is the discharge point for the stormwater pond, but there is also stormwater 

collected from non-process areas that is discharged through Outfall 002. The additional 

stormwater could have affected the results for Outfall 002 such that the monitoring data may 

not have adequately represented the performance of the stormwater pond.

Ecology has noted during multiple inspections that the facility has made great improvements 

in their stormwater BMPs during the previous permit cycle and the data collected during that 

time period would be representative of good BMPs for the process stormwater collection and 

treatment system. Based on the data provided in the DMRs between April 2007 and October 

2013 for the stormwater treatment pond, the facility was able to meet the following discharge 

concentrations 90% of the time: 35 mg/L for TSS, 37 mg/L for fluoride, and 13 mg/L for 

aluminum. Finally, Ecology notes that the previous monthly average permit limits for 

Outfall 002 were 35 mg/l for TSS, 35 mg/l for fluoride, and 10 mg/l for aluminum.

With these considerations in mind, Ecology increased the action levels for the stormwater 

pond in the proposed permit. The new action levels for the SEC effluent and the stormwater 

pond effluent are as follows:
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Table 29 Action Levels

TSS Fluoride Aluminum

Secondary Wastewater 

Treatment System 

120 mg/l 50 mg/l N/A

Stormwater Pond 35 mg/l 35 mg/l 10 mg/l

The existing permit requires the Permittee to monitor the SEC three times per week for TSS 

and fluoride. As discussed above, Section 1.3 of Chapter XIII of Ecology’s Permit Writer’s 

Manual allows for reduced monitoring based on exemplary performance. This is usually 

demonstrated by comparing the long term monthly average effluent concentration to the 

monthly average limit. In this instance, the long term daily maximum average was compared 

to the action level. The long term daily maximum average for TSS is approximately 61% of 

the action level and the long term daily maximum average for fluoride is 58% of the action 

level. Therefore, Ecology reduced the monitoring frequency from 3 times per week to 2 

times per week for the SEC. The proposed permit also specifies that the 24-hour sample will 

be a flow proportional batch sample based on a request from the facility.

The existing permit specifies that the Permittee monitor for PCBs in the SEC discharge after 

the material from the Beach and Construction Landfills were moved to the SPL Landfill. 

The permit also allowed the Permittee to petition the Department to reduce or eliminate the 

monitoring after two years of testing. The facility has monitored for PCBs since April 2007 

and has not detected PCBs in the effluent. Therefore, the monitoring frequency in the 

proposed permit has been reduced from quarterly to semi-annually.

The Permittee has requested to remove the monitoring requirement for aluminum in the SEC

discharge. They stated that the levels of aluminum that have been discharged from the SEC 

have been consistently low and they requested that Ecology review the data to determine if 

the monitoring could be eliminated. Based on the DMRs for the past 2 years, the average 

aluminum concentration in the SEC discharge was 0.1 mg/L and the maximum concentration 

was 1.5 mg/L. At an average flow of 0.1 MGD from the SEC during the same time period, 

the aluminum loading contribution is approximately 0.08 lbs/day, which is less than 1% of 

the monthly loading limit for aluminum at Outfall 001. Ecology also notes that there are no 

action levels for aluminum in the SEC effluent. Therefore, Ecology concurs that monitoring 

for aluminum in the SEC effluent is not necessary and it has been removed in the proposed 

permit. 

The proposed monitoring frequency for the stormwater pond (at D-10) will remain the same 

as the current permit since the action levels have been changed. The Permittee is required to 

monitor the stormwater pond effluent (at D-10) whenever the average 2-hour flow from the 

stormwater pond is ≥ 3.7 cfs (with a maximum required frequency of 3 days per week).

Outfalls 003, 004, and 005

Outfalls 003, 004, and 005 have been removed from the proposed permit. Please refer to 

Section II.A above. 
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Outfalls 011 and 012

Outfalls 011 and 012 were newly identified outfalls in the last permit renewal application. 

Both of the outfalls are located along the shoreline and are difficult to access. The facility 

proposed to collect samples from the catch basins that discharge to these outfalls. Based on 

this request, the existing permit requires the facility to collect monthly grab samples from the 

catch basin sumps for these outfalls when flow is available. The samples are required to be 

analyzed for TSS, aluminum, and fluoride. The intent of this sampling was to determine 

whether BMPs implemented by the facility would sufficiently reduce the pollutant 

concentrations in the discharges. However, Ecology has noted during wastewater inspections 

that it is difficult to collect representative samples from these locations and questions

whether the results of the samples collected during the last permit term are representative of 

the discharge from these outfalls.

Based on this uncertainty, a BMP effectiveness study for Outfalls 011 and 012 has been

included in the proposed permit. The study requires that the facility identify safe, accessible, 

and representative sampling locations for these outfalls. The facility will then be required to

begin routine monitoring at the new locations. The facility will also submit a report that will 

include an assessment of the current BMPs and whether additional BMPs are necessary for 

the drainage area. Ecology will review the results of the routine monitoring during the next 

permit renewal process to establish action levels in the next permit, if necessary.

B. Lab Accreditation

Ecology requires that facilities must use a laboratory registered or accredited under the 

provisions of chapter 173-50 WAC, Accreditation of Environmental Laboratories, to prepare 

all monitoring data (with the exception of certain parameters). Ecology accredited the 

laboratory at this facility for the parameters in Table 30 below. Their accreditation number is 

I629-12.

Table 30 Accredited Parameters

General Chemistry

Parameter Name Analyte Code Method Description NELAC Code Matrixa

Total Suspended 

Solids

1960 SM 2540 D-97 20051201 N

Fluoride 1730 SM 4500-F E-97 20104409 N

pH 1900 SM 4500- H+ B-00 20105219 N

Specific 

Conductance

1610 EPA 120.1_1982 10006403 N

a. N= Nonpotable
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C. Effluent Limits which are Near Detection or Quantitation Levels

The water quality-based effluent concentration limits for benzo(a)pyrene for Outfall 002 and 

free cyanide (WAD) for Outfall 001 are near the limits of current analytical methods to 

detect or accurately quantify. The method detection level (MDL) also known as detection 

level (DL) is the minimum concentration of a pollutant that a laboratory can measure and 

report with a 99 percent confidence that its concentration is greater than zero (as determined 

by a specific laboratory method). The quantitation level (QL) is the level at which a 

laboratory can reliably report concentrations with a specified level of error. Estimated 

concentrations are the values between the DL and the QL. Ecology requires permitted 

facilities to report estimated concentrations. When reporting maximum daily effluent 

concentrations, Ecology requires the facility to report “less than X” where X is the required 

detection level if the measured effluent concentration falls below the detection level.

V. Other Permit Conditions

A. Reporting and Record Keeping

Ecology based Special Condition S3 on its authority to specify any appropriate reporting and 

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

Special Condition S3 specifies the reporting requirements for the Permittee and is similar to 

the current permit, except that the discharge monitoring reports will be required to be 

submitted electronically. The draft permit allows the Permittee to submit the reports in paper 

form until December 31, 2014 to allow them time to implement procedures for submitting 

the reports electronically.

B. Operation and Maintenance Manual

Ecology requires industries to take all reasonable steps to properly 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 facility 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). Implementation of the procedures in 

the operation and maintenance manual ensures the facility’s compliance with the terms and 

limits in the permit. Permit Condition S4.A of the proposed permit requires that the 

Permittee review the O&M Manual at least annually and confirm the review by letter to 

Ecology. The Permittee must also submit any substantial changes or updates to Ecology for 

review.

C. Solid Waste Control Plan

Intalco could cause pollution of the waters of the state through inappropriate disposal of solid 

waste or through the release of leachate from solid waste.

Permit Condition S5 of the proposed permit requires this facility to update their currently

approved solid waste control plan designed to prevent solid waste from causing pollution of 

waters of the state. The facility must submit the updated plan to Ecology for approval (RCW 
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90.48.080). Ecology has a guidance document which describes how to develop a Solid 

Waste Control Plan, available at: http://www.ecy.wa.gov/pubs/0710024.pdf

D. Application for Permit Renewal or Modification for Facility Changes

In accordance with WAC 173-220-180, any Permittee that wishes to continue the permitted 

activity after the expiration date of the permit must submit an application for replacement to 

an existing permit or continuation of a discharge beyond the expiration date at least 180 days 

prior to its expiration. Permit Condition S6 requires the facility to submit their permit 

renewal application no later than six months prior to the expiration date of the permit.

Additionally, WAC 173-220-150 requires that the Permittee must submit a new application 

or supplement to an existing application at least one hundred eighty (180) days prior to 

commencement of discharges resulting from any facility expansions, production increases, or 

other planned changes, such as process modifications, which may result in permit violations.

E. Facility Loading

As discussed in Section III.B above, Permittees are required to provide AKART for their 

wastewater effluent before discharging it to a surface water body. These treatment 

technologies must be designed to provide the required treatment efficiencies. The design 

parameters generally include a maximum loading capacity that the treatment system is able 

to handle and still provide the desired treatment efficiency. Permit Condition S7 specifies 

certain Ecology approved design criteria that Intalco must not exceed. Permit Condition S2 

includes appropriate monitoring parameters to demonstrate that these design criteria are not 

being exceeded.

F. Non-Routine and Unanticipated Discharges

Ecology understands that the facility may occasionally generate wastewater that was not 

identified in the permit application. Permit Condition S8 allows for the discharge of nonroutine and unanticipated discharges of wastewater to Outfall 001 and non-stormwater 

discharges to the stormwater pond as long as certain conditions are met, such as 

characterization of the wastewater and whether there are any alternatives to discharging the 

wastewater.

G. Spill Plan

This facility stores a quantity of chemicals on-site that have the potential to cause water 

pollution if accidentally released. Ecology can require a facility to develop best management 

plans to prevent this accidental release [Section 402(a)(1) of the Federal Water Pollution 

Control Act (FWPCA) and RCW 90.48.080].

Intalco has developed a plan for preventing the accidental release of pollutants to state waters 

and for minimizing damages if such a spill occurs. Permit Condition S9 of the proposed 

permit requires the facility to update this plan and submit it to Ecology.

H. Stormwater Pollution Prevention Plan

Special Condition S10 of the proposed permit addresses the stormwater pollution prevention 

measures required for the facility. Special Condition S10 requires the facility to update their 

stormwater pollution prevention plan (SWPPP) in accordance with the guidance document 
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entitled Guidance Manual for Preparing/Updating a Stormwater Prevention Plan for 

Industrial Facilities (Ecology Publication No. 04-10-030) and to submit the update to 

Ecology for approval. The SWPPP must identify potential sources of stormwater 

contamination from industrial activities and identify how the Permittee plans to mange those 

sources of contamination to prevent or minimize contamination of stormwater. Once the 

update is approved, the facility will be required to implement the updated SWPPP. Intalco 

must continuously review and revise the SWPPP as necessary to assure that stormwater 

discharges do not degrade water quality. They must retain the SWPPP on-site or within 

reasonable access to the site and make it available for review by Ecology.

Special Condition S10 also requires the facility to conduct two inspections per year – once 

during the wet season and once during the dry season. The wet season inspection shall be 

conducted during a rainfall event by personnel trained by Intalco in the requirements of the 

SWPPP to verify that the description of potential pollutant sources required under this permit 

are accurate; that the site map required in the SWPPP has been updated or otherwise 

modified to reflect current conditions; and that the controls to reduce pollutants in 

stormwater discharges associated with industrial activity identified in the SWPPP are being 

implemented and are adequate. The dry season inspection shall determine the presence of 

unpermitted non-stormwater discharges such as domestic wastewater, noncontact cooling 

water, or process wastewater (including leachate) to the stormwater drainage system.

One of the components of the SWPPP is identifying Best Management Practices (BMPs) for 

the stormwater generated at the site. BMPs include both pollution prevention measures as 

well as treatment technologies. Treatment BMPs include Best Conventional Pollutant 

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

and “all known, available, and reasonable methods of prevention, control, and treatment” 

(AKART) for stormwater discharges. Special Condition S10 requires the Permittee to update 

the BMPs that are currently identified in their SWPPP.

I. Fugitive Alumina Pollution Prevention Plan 

Ecology has determined that the Permittee must use best management practices in unloading 

alumina ore to minimize the release of fugitive alumina to the Strait of Georgia. The 

Permittee must submit a pollution prevention plan to Ecology for review and approval within 

eighteen months after permit issuance. The pollution prevention plan must identify the 

points, areas, and activities that would likely generate fugitive alumina emissions, evaluate 

potential measures to minimize the discharge of fugitive alumina, identify the measures 

selected and the timeframes for implementation, include a training plan for employees that 

operate the equipment used to unload the alumina ore, and include the procedures that will be 

used to demonstrate compliance with the pollution prevention plan. The Permittee must 

implement the pollution prevention plan within 60 days of approval of the plan by Ecology.

J. Sediment Monitoring

As discussed in Section III.H above, the existing permit required that the facility submit a 

Sediment Sampling and Analysis Plan to re-characterize the sediment in the vicinity of 

Outfalls 001 and 002. This plan was submitted and is currently being reviewed by Ecology. 

The proposed permit requires that the facility conduct the sediment sampling during the next 
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stable period (mid-August through mid-September) following Ecology’s approval of the 

plan. Once the sampling has been conducted, the Permittee is required to submit a report 

containing the results of the sediment sampling and analysis within six months of collecting 

the samples. Ecology will review the results and determine if additional actions will be 

required.

K. Outfall Evaluation

The proposed permit requires Intalco to conduct an outfall inspection at least once every five 

years and submit a report detailing the findings of that inspection (Special Condition S13). 

The inspection must evaluate the physical condition of the discharge pipe and diffusers, and 

evaluate the extent of sediment accumulations in the vicinity of the outfall. The inspection 

report must be submitted to Ecology no later than 90 days after conducting the evaluation. 

The first report is due October 1, 2016.

L. Certified Operator

The existing permit classifies the domestic wastewater treatment plant as a Class I treatment 

plant. The facility has not modified or upgraded their domestic wastewater treatment plant 

and the plant is still a Class I treatment plant. Special Condition S14 requires that the facility 

must be operated by an operator certified by the state of Washington for at least a Class I 

plant. Permit Condition S14 has been modified to require that an operator certified for at 

least a Class I plant must be in charge during all regularly scheduled shifts, as required by 

WAC 173-230.

M. Acute Toxicity

Outfall 001

As discussed in Section III.J, an acute toxicity limit is not required for Outfall 001. While no 

permit limit has been established, the facility will continue to be required to periodically 

monitor the acute toxicity of the effluent. Permit Condition S15.F.1 requires that the facility 

conduct acute toxicity testing on the final effluent once in the last winter and once in the last 

summer prior to submission of the application for permit renewal. The species specified for 

these tests have been changed to saltwater species in the proposed permit to account for 

pacific herring, a sensitive species in the Cherry Point area. More discussion regarding 

pacific herring is provided below.

Outfall 002

As discussed in Section III.J, Outfall 002 must be re-characterized for acute toxicity. Permit 

Condition S15 specifies that the Permittee conduct quarterly acute toxicity tests on the 

effluent for one year. The following acute toxicity tests must be performed for each sample: 

1) topsmelt 96-hour static-renewal test, and 2) myside 48-hour static test, and 3) daphnid 48-

hour static test. Saltwater species are specified for two of the tests to account for pacific 

herring, a sensitive species in the Cherry Point Area. Daphnid, a freshwater species, is also 

specified due to a potential for acute toxicity that was demonstrated in previous tests. A 

quarterly written report must be submitted within 45 days of each sampling event and must 

provide the results of the sample analysis. The testing must be performed using a dilution 

series consisting of a minimum of five concentrations, including the ACEC of 5.3% effluent, 
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and a control. The results of the tests must be able to demonstrate that the median survival of 

any species in 100% effluent is above 80% and none of tests may exhibit less than 65% 

survival in 100% effluent. If the test results do not meet these criteria, an effluent limit for 

acute toxicity will be established for Outfall 002 and quarterly testing will be required to 

demonstrate compliance with the acute toxicity limit. If an acute toxicity effluent is not 

required, the Permittee will be required to conduct acute toxicity testing on the final effluent 

once in the last winter and once in the last summer prior to submission of the application for 

permit renewal.

Herring Toxicity Testing

Pacific herring, which spawn in the Cherry Point area, have dramatically declined in 

abundance in the last 10-15 years and remain at record low levels. Over the years, Ecology 

has worked with several stakeholders including other state agencies, area industries, and local 

tribes to investigate the Cherry Point herring decline. Ecology worked with the Western 

Washington University’s Shannon Point Marine Center (SPMC) to develop herring tests to 

evaluate effluent toxicity as a source of the decline and to evaluate risks from industrial 

discharges to other herring stocks. As a result of these efforts, SPMC developed three 

herring tests, all of which were successfully validated.

In November 2005, Ecology approved the regulatory use of the 96-hour larval acute survival 

test (acute toxicity) and the 10-day embryo survival and normal development test (chronic 

toxicity).

In April 2006, Ecology issued Agreed Order (No. 3192) to five industries, including Intalco, 

requiring them to conduct larval acute survival tests twice annually at each of their process 

wastewater and stormwater outfalls. Ecology would then review the results of the studies 

required under the Order and include validated herring or equivalent EPA surrogate test 

requirements in the renewed NPDES permit. 

Intalco completed the required acute toxicity tests for herring and the results demonstrated 

that the currently approved EPA tests are as sensitive to the wastewater effluent for Intalco.

Based on this, the EPA approved acute toxicity testing required by the proposed permit is 

sufficient to measure if the effluent is acutely toxic to herring. The results of the acute 

herring tests conducted by Intalco are included in Appendix F. A copy of the Ecology report 

discussing the results of the study is available on the Ecology website at: 

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

N. Chronic Toxicity

Outfall 001

As discussed in Section III.J, Outfall 001 must be re-characterized for chronic toxicity. 

Permit Condition S16.A.1 specifies that the Permittee must conduct quarterly chronic 

toxicity tests on the effluent for one year. The following chronic toxicity tests must be 

performed for each sample: 1) mysid shrimp survival and growth, and 2) sea urchin/sand 

dollar survival and development. A quarterly written report must be submitted within 45 

days of each sampling event and must provide the results of the sample analysis. The testing 

must be performed using a dilution series consisting of a minimum of five concentrations, 

including the ACEC of 4.8% effluent, and a control. The series of dilutions should also 
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contain the CCEC of 1.9% effluent. The results of the tests must be able to demonstrate that 

there is not a significant difference between the control and the ACEC at the 0.05 level of 

significance using hypothesis testing. If the test results do not meet these criteria, an effluent 

limit for chronic toxicity will be established for Outfall 001 and quarterly testing will be 

required to demonstrate compliance with the chronic toxicity limit. If a chronic toxicity 

effluent is not required, the Permittee will be required to conduct chronic toxicity testing on 

the final effluent once in the last winter and once in the last summer prior to application for 

permit renewal.

Outfall 002

As discussed in Section III.J, Outfall 002 must be re-characterized for chronic toxicity. 

Permit Condition S16.A.2 specifies that the Permittee must conduct quarterly chronic 

toxicity tests on the effluent for one year. The chronic toxicity test for Outfall 002 that must 

be performed for each sample is the sea urchin/sand dollar survival and development. A 

quarterly written report must be submitted for each quarter within 45 days of the sampling 

event and must provide the results of the sample analysis. The testing must be performed 

using a dilution series consisting of a minimum of five concentrations, including the ACEC 

of 5.3% effluent, and a control. The series of dilutions should also contain the CCEC of 

3.0% effluent. The results of the tests must be able to demonstrate that there is not a 

significant difference between the control and the ACEC at the 0.05 level of significance 

using hypothesis testing. If the test results do not meet these criteria, an effluent limit for 

chronic toxicity will be established for Outfall 002 and quarterly testing will be required to 

demonstrate compliance with the chronic toxicity limit. If a chronic toxicity effluent is not 

required, the Permittee will be required to conduct chronic toxicity testing on the final 

effluent once in the last winter and once in the last summer prior to submission of the 

application for permit renewal.

Herring Toxicity Testing

As discussed above, Ecology worked with SPMC to develop two chronic herring toxicity 

tests. The 10-day embryo survival and normal development test (chronic toxicity) was 

approved for regulatory use in November 2005. A 7-day larval survival and growth test 

(chronic toxicity) was validated and approved for regulatory use in December 2011.

In October 2013, Ecology issued Agreed Order No. 10300 to Intalco for the completion of 

herring chronic bioassay testing. The basic goal of the testing conducted under this Order is 

to determine if existing EPA chronic WET test methods are adequate to determine if 

Intalco’s discharges have unacceptable toxicity to herring. The Order requires the facility to 

conduct at least six comparison tests by March 1, 2017. Ecology will then review the results 

of these tests and include validated herring or equivalent EPA surrogate test requirements in 

the next NPDES permit.

O. Secondary Wastewater Treatment System Treatment Efficiency Study

The wastewater from the PWTS and landfill leachate are treated through chemical 

precipitation and sedimentation in the SEC, which consists of several treatment tanks and a 

clarifier. As discussed in Sections III.A and III.B, flows or waste loadings to a wastewater 

treatment facility must not exceed approved design criteria and the facility must apply all 
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known available and reasonable methods of prevention, control, and treatment (AKART) for 

the pollutants in the wastewater. The existing permit requires the Permittee to conduct a 

treatment efficiency study on the SEC to determine if it is meeting the design criteria and to 

propose and implement any changes needed to upgrade the system. The facility was first 

required to submit a treatment efficiency study plan and schedule to Ecology for review and 

approval. This plan was received by Ecology on January 3, 2008. Due to a heavy workload, 

Ecology has not yet reviewed or approved this plan. The requirement to conduct the SEC 

efficiency study has been included in the proposed permit as Special Condition S17. Since 

the plan was submitted about 5 years ago, Ecology is requiring that the facility review and 

update, as necessary, the plan that was previously submitted. This plan must be submitted to 

Ecology within six months of permit issuance. Once the plan is approved, the Permittee is 

required to conduct the study and submit the results in an engineering report within 120 days 

of completing of the study.

P. Anode Contact Cooling Water AKART Evaluation

Anode contact cooling water is generated during the anode production process. This 

wastewater is treated using a baffled settling tank prior to mixing with the other wastewater 

streams that are discharged through Outfall 001. As discussed in Section III.B above, 

preliminary sampling of the anode contact cooling water indicate that a full AKART analysis 

will need to be performed for that particular wastewater stream. Permit Condition S18

requires that the Permittee evaluate whether the current treatment system for the anode 

contact cooling water meets AKART requirements for B(a)P, antimony, nickel, aluminum, 

and fluoride. The Permittee must provide the results of this AKART analysis, consisting of 

an economic analysis, an environmental analysis, and an industry analysis of wastewater 

treatment technologies for the anode contact cooling water, in an engineering report no later 

than twelve months after permit issuance. The Permittee has communicated to Ecology that 

they are evaluating an option that would eliminate the anode contact cooling water discharge 

from Outfall 001. The draft permit includes an alternative to the AKART analysis that 

allows the Permittee to submit documentation to demonstrate that the discharge has been 

eliminated and an AKART evaluation is not necessary.

Q. Ground Water Impact Study

As discussed in Section III.I above, Ecology has promulgated Ground Water Quality 

Standards (Chapter 173-200 WAC) to protect beneficial uses of ground water. Permits 

issued by Ecology shall be conditioned in such a manner so as not to allow violations of 

those standards (WAC 173-200-100).

The sanitary lagoon in Intalco’s wastewater treatment system consists of an unlined native 

clay bottom that could potentially discharge to groundwater. There is no data available to 

determine if there is a potential for an impact to ground water beneath the sanitary lagoon. 

Intalco was required to submit a ground water impact study plan to Ecology for review and 

approval during the previous permit cycle. The plan was submitted in February 2010 and is 

being reviewed by Ecology. Permit Condition S19 of the proposed permit requires that the 

facility conduct the study within 180 days of Ecology’s approval of the plan. The Permittee 

is then required to submit a report detailing the results of the study for review and approval 

by Ecology within 120 days of completing the study. If the results indicate that there is a 
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potential for the wastewater to impact the ground water, the report must also include a 

monitoring plan. Ecology has guidance regarding preparation of a monitoring plan entitled 

Implementation Guidance for the Ground Water Quality Standards (Publication #96-02, 

April 1996).

R. Outfall 011 and Outfall 012 BMP Effectiveness Study

The storage area for the alumina ore prior to processing is located at the entrance to the pier 

and includes three 100-foot diameter alumina storage silos. The drainage area for the 

alumina silo storage area is about 550 feet by 200 feet (2.5 acres) and is divided into two 

watersheds.

The northern portion of the silo storage area drains to a single catch basin and discharges to 

Outfall 011. This outfall is embedded deep in the riprap shoreline along the northern edge of 

the silo storage area. Major pollutants include TSS, fluoride, and aluminum. The middle and 

southern portion of the silo storage area drain to three catch basins arranged in a north-south 

alignment and are connected in series in a single pipe. The three southern most catch basins 

discharge to Outfall 012. This outfall is embedded deep in the riprap shoreline along the 

southern edge of the silo storage area. Outfall 012 is located in an area that is difficult to 

access due to vegetation and is only accessible on foot. Major pollutants include TSS, fecal 

coliform, fluoride, and aluminum.

As discussed in Section IV.A above, it is uncertain if the results of the samples collected for 

Outfalls 011 and 012 during the previous permit cycle are representative of the discharge 

from the silo storage area. As a result, Permit Condition S20 requires the Permittee to 

conduct a BMP effectiveness study for that area. The study requires the facility to evaluate 

the area for alternative accessible and representative sampling locations for both outfalls and 

conduct an assessment of the best management practices that have been implemented to 

reduce the amount of pollutants discharged from that area.

Ecology has noted during wastewater inspections segments of the curbing for the storage silo 

drainage area where collected stormwater may be able to leave the site. An assessment of the 

secondary containment for this area and recommendations for repair or additional BMPs are 

also required as part of the study.

S. 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.

VI. Permit Issuance Procedures

A. Permit Modifications

Ecology may modify this permit to impose numerical limits, if necessary to comply with 

water quality standards for surface waters, with sediment quality standards, or with water 

quality standards for groundwaters, after obtaining new information from sources such as 

inspections, effluent monitoring, outfall studies, and effluent mixing studies.
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Ecology may also modify this permit to comply with new or amended state or federal 

regulations.

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 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.

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 Water Quality-based Toxics Control. EPA/505/2-90-

001.

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

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

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

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

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

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

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

1985 op.cit.) 

Washington State Department of Ecology.

December 2011. Permit Writer’s Manual. Publication Number 92-109 

(https://fortress.wa.gov/ecy/publications/SummaryPages/92109.html)

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

Permit and Wastewater Related Information 

(http://www.ecy.wa.gov/programs/wq/permits/guidance.html)

February 2007. Focus Sheet on Solid Waste Control Plan, Developing a Solid Waste 

Control Plan for Industrial Wastewater Discharge Permittees, Publication Number 

07-10-024. http://www.ecy.wa.gov/pubs/0710024.pdf

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

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

Division, ASCE. 105(EE2). (Cited in EPA 1985 op.cit.)
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Appendix A - Public Involvement Information

Ecology proposes to renew a permit toIntalco. The permit includes wastewater discharge limits 

and other conditions. This fact sheet describes the facility and Ecology’s reasons for requiring 

permit conditions. 

Ecology will place a Public Notice of Draft on August 27, 2014 in the Ferndale Record to inform 

the public and to invite comment on the proposed draft National Pollutant Discharge Elimination 

System permit and fact sheet.

The notice:

• Tells where copies of the draft Permit and Fact Sheet are available for public evaluation (a 

local public library, the closest Regional or Field Office, posted on our website).

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

• Urges people to submit their comments, in writing, 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.

Ecology has published a document entitled Frequently Asked Questions about Effective Public 

Commenting which is available on our website at 

https://fortress.wa.gov/ecy/publications/SummaryPages/0307023.html. 

You may obtain further information from Ecology by telephone, (360) 407-6355, or by writing 

to the address listed below.

Water Quality Permit Coordinator

Department of Ecology

Industrial Section 

PO Box 47600

Olympia, WA 98504-7600

The primary author of this permit and fact sheet is Stephanie Ogle, P.E.
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Appendix B - Your Right to Appeal

You have a right to appeal this permit to the Pollution Control Hearing Board (PCHB) within 30 

days of the date of receipt of the final permit. The appeal process is governed by chapter 43.21B 

RCW and chapter 371-08 WAC. “Date of receipt” is defined in RCW 43.21B.001(2) (see 

glossary).

To appeal you must do the following within 30 days of the date of receipt of this permit:

• File your appeal and a copy of this permit with the PCHB (see addresses below). Filing 

means actual receipt by the PCHB during regular business hours.

• Serve a copy of your appeal and this permit on Ecology in paper form - by mail or in person. 

(See addresses below.) E-mail is not accepted.

You must also comply with other applicable requirements in chapter 43.21B RCW and chapter 

371-08 WAC.

ADDRESS AND LOCATION INFORMATION

Street Addresses Mailing Addresses

Department of Ecology

Attn: Appeals Processing Desk

300 Desmond Drive SE

Lacey, WA 98503

Department of Ecology

Attn: Appeals Processing Desk

PO Box 47608

Olympia, WA 98504-7608

Pollution Control Hearings Board 

1111 Israel RD SW

STE 301

Tumwater, WA 98501

Pollution Control Hearings Board

PO Box 40903

Olympia, WA 98504-0903
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Appendix C - Glossary

1-DMax or 1-Day Maximum Temperature--The highest water temperature reached on any 

given day. This measure can be obtained using calibrated maximum/minimum thermometers 

or continuous monitoring probes having sampling intervals of thirty minutes or less. 

7-DADMax or 7-Day Average of the Daily Maximum Temperatures--The arithmetic average 

of seven consecutive measures of daily maximum temperatures. The 7-DADMax for any 

individual day is calculated by averaging that day's daily maximum temperature with the 

daily maximum temperatures of the three days prior and the three days after that date.

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

period, usually 48 to 96 hours. 

AKART--The acronym for “all known, available, and reasonable methods of prevention, control 

and treatment.” AKART is a technology-based approach to limiting pollutants from 

wastewater discharges, which requires an engineering judgment and an economic judgment. 

AKART must be applied to all wastes and contaminants prior to entry into waters of the state 

in accordance with RCW 90.48.010 and 520, WAC 173-200-030(2)(c)(ii), and WAC 173-

216-110(1)(a).

Alternate Point of Compliance--An alternative location in the groundwater from the point of 

compliance where compliance with the groundwater standards is measured. It may be 

established in the groundwater at locations some distance from the discharge source, up to, 

but not exceeding the property boundary and is determined on a site specific basis following 

an AKART analysis. An “early warning value” must be used when an alternate point is 

established. An alternate point of compliance must be determined and approved in 

accordance with WAC 173-200-060(2).

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

water body.

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

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

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

Annual Average Design Flow (AADF)--Average of the daily flow volumes anticipated to occur 

over a calendar year.

Average Monthly (Intermittent) Discharge Limit--The average of the measured values 

obtained over a calendar months time taking into account zero discharge days. 

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

calendar month's time.

Background Water Quality--The concentrations of chemical, physical, biological or 

radiological constituents or other characteristics in or of groundwater at a particular point in 

time upgradient of an activity that has not been affected by that activity, [WAC 173-200-

020(3)]. Background water quality for any parameter is statistically defined as the 95% 

upper tolerance interval with a 95% confidence based on at least eight hydraulically 
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upgradient water quality samples. The eight samples are collected over a period of at least 

one year, with no more than one sample collected during any month in a single calendar year.

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

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

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

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

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

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

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

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

bacteria. The BOD5 is used in modeling to measure the reduction of dissolved oxygen in 

receiving waters after effluent is discharged. Stress caused by reduced dissolved oxygen 

levels makes organisms less competitive and less able to sustain their species in the aquatic 

environment. Although BOD5 is not a specific compound, it is defined as a conventional 

pollutant under the federal Clean Water Act.

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

Categorical Pretreatment Standards--National pretreatment standards specifying quantities or 

concentrations of pollutants or pollutant properties, which may be discharged to a POTW by 

existing or new industrial users in specific industrial subcategories.

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

also extremely toxic to aquatic life. 

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

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

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

combination of compounds. 

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

92-500, as amended by Public Laws 95-217, 95-576, 96-483, 97-117; USC 1251 et seq.

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

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

and regulations.

Compliance Inspection-with Sampling--A site visit for the purpose of determining the 

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

and regulations. In addition it includes as a minimum, sampling and analysis for all 

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

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

requirement. Ecology may conduct additional sampling.

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

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

constant sample volume at time intervals proportional to stream flow, or collected by 
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increasing the volume of each aliquot as the flow increased while maintaining a constant time 

interval between the aliquots).

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

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

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

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

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

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

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

its ability to dilute effluent is reduced.

Date of Receipt--This is defined in RCW 43.21B.001(2) as five business days after the date of 

mailing; or the date of actual receipt, when the actual receipt date can be proven by a 

preponderance of the evidence. The recipient's sworn affidavit or declaration indicating the 

date of receipt, which is unchallenged by the agency, constitutes sufficient evidence of actual 

receipt. The date of actual receipt, however, may not exceed forty-five days from the date of 

mailing.

Detection Limit--The minimum concentration of a substance that can be measured and reported 

with 99 percent confidence that the pollutant concentration is above zero and is determined 

from analysis of a sample in a given matrix containing the pollutant. 

Dilution Factor (DF)--A measure of the amount of mixing of effluent and receiving water that 

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

fraction, for example, a dilution factor of 10 means the effluent comprises 10% by volume 

and the receiving water 90%.

Distribution Uniformity--The uniformity of infiltration (or application in the case of sprinkle or 

trickle irrigation) throughout the field expressed as a percent relating to the average depth 

infiltrated in the lowest one-quarter of the area to the average depth of water infiltrated.

Early Warning Value--The concentration of a pollutant set in accordance with WAC 

173-200-070 that is a percentage of an enforcement limit. It may be established in the 

effluent, groundwater, surface water, the vadose zone or within the treatment process. This 

value acts as a trigger to detect and respond to increasing contaminant concentrations prior to 

the degradation of a beneficial use.

Enforcement Limit--The concentration assigned to a contaminant in the groundwater at the 

point of compliance for the purpose of regulation, [WAC 173-200-020(11)]. This limit 

assures that a groundwater criterion will not be exceeded and that background water quality 

will be protected.

Engineering Report--A document that thoroughly examines the engineering and administrative 

aspects of a particular domestic or industrial wastewater facility. The report must contain the 

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

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

in the effluent that are harmful to humans. Pathogenic bacteria in wastewater discharges are 
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controlled by disinfecting the wastewater. The presence of high numbers of fecal coliform 

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

presence of animal feces.

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

of time as is feasible.

Groundwater--Water in a saturated zone or stratum beneath the surface of land or below a 

surface water body.

Industrial User--A discharger of wastewater to the sanitary sewer that is not sanitary 

wastewater or is not equivalent to sanitary wastewater in character.

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

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

of industry, manufacture, trade or business; from the development of any natural resource; or 

from animal operations such as feed lots, poultry houses, or dairies. The term includes 

contaminated storm water and, also, leachate from solid waste facilities.

Interference--A discharge which, alone or in conjunction with a discharge or discharges from 

other sources, both:

• Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge 

processes, use or disposal; and

• Therefore is a cause of a violation of any requirement of the POTW's NPDES permit 

(including an increase in the magnitude or duration of a violation) or of the prevention of 

sewage sludge use or disposal in compliance with the following statutory provisions and 

regulations or permits issued hereunder (or more stringent State or local regulations): 

Section 405 of the Clean Water Act, the Solid Waste Disposal Act (SWDA) (including 

title II, more commonly referred to as the Resource Conservation and Recovery Act 

(RCRA), and including State regulations contained in any State sludge management plan 

prepared pursuant to subtitle D of the SWDA), sludge regulations appearing in 40 CFR 

Part 507, the Clean Air Act, the Toxic Substances Control Act, and the Marine 

Protection, Research and Sanctuaries Act.

Local Limits--Specific prohibitions or limits on pollutants or pollutant parameters developed by 

a POTW.

Major Facility--A facility discharging to surface water with an EPA rating score of > 80 points 

based on such factors as flow volume, toxic pollutant potential, and public health impact.

Maximum Daily Discharge Limit--The highest allowable daily discharge of a pollutant 

measured during a calendar day or any 24-hour period that reasonably represents the calendar 

day for purposes of sampling. The daily discharge is calculated as the average measurement 

of the pollutant over the day. 

Maximum Day Design Flow (MDDF)--The largest volume of flow anticipated to occur during 

a one-day period, expressed as a daily average.
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Maximum Month Design Flow (MMDF)--The largest volume of flow anticipated to occur 

during a continuous 30-day period, expressed as a daily average.

Maximum Week Design Flow (MWDF)--The largest volume of flow anticipated to occur 

during a continuous 7-day period, expressed as a daily average.

Method Detection Level (MDL)--See Method Detection Level.

Minor Facility--A facility discharging to surface water with an EPA rating score of < 80 points 

based on such factors as flow volume, toxic pollutant potential, and public health impact.

Mixing Zone--An area that surrounds an effluent discharge within which water quality criteria 

may be exceeded. The permit specifies the area of the authorized mixing zone that Ecology 

defines following procedures outlined in state regulations (chapter 173-201A WAC).

National Pollutant Discharge Elimination System (NPDES)--The NPDES (Section 402 of the 

Clean Water Act) is the federal wastewater permitting system for discharges to navigable 

waters of the United States. Many states, including the state of Washington, have been 

delegated the authority to issue these permits. NPDES permits issued by Washington State 

permit writers are joint NPDES/State permits issued under both state and federal laws.

pH--The pH of a liquid measures its acidity or alkalinity. It is the negative logarithm of the 

hydrogen ion concentration. A pH of 7 is defined as neutral and large variations above or 

below this value are considered harmful to most aquatic life.

Pass-Through--A discharge which exits the POTW into waters of the state in quantities or 

concentrations which, alone or in conjunction with a discharge or discharges from other 

sources, is a cause of a violation of any requirement of the POTW's NPDES permit 

(including an increase in the magnitude or duration of a violation), or which is a cause of a 

violation of State water quality standards.

Peak Hour Design Flow (PHDF)--The largest volume of flow anticipated to occur during a 

one-hour period, expressed as a daily or hourly average.

Peak Instantaneous Design Flow (PIDF)--The maximum anticipated instantaneous flow.

Point of Compliance--The location in the groundwater where the enforcement limit must not be 

exceeded and a facility must comply with the Ground Water Quality Standards. Ecology 

determines this limit on a site-specific basis. Ecology locates the point of compliance in the 

groundwater as near and directly downgradient from the pollutant source as technically, 

hydrogeologically, and geographically feasible, unless it approves an alternative point of 

compliance.

Potential Significant Industrial User (PSIU)--A potential significant industrial user is defined 

as an Industrial User that does not meet the criteria for a Significant Industrial User, but 

which discharges wastewater meeting one or more of the following criteria:

a. Exceeds 0.5 % of treatment plant design capacity criteria and discharges <25,000 gallons

per day or;

b. Is a member of a group of similar industrial users which, taken together, have the 

potential to cause pass through or interference at the POTW (e.g. facilities which develop 
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photographic film or paper, and car washes).

Ecology may determine that a discharger initially classified as a potential significant 

industrial user should be managed as a significant industrial user.

Quantitation Level (QL)--Also known as Minimum Level of Quantitation (ML) – The lowest 

level at which the entire analytical system must give a recognizable signal and acceptable 

calibration point for the analyte. It is equivalent to the concentration of the lowest calibration 

standard, assuming that the lab has used all method-specified sample weights, volumes, and 

cleanup procedures. The QL is calculated by multiplying the MDL by 3.18 and rounding the 

result to the number nearest to (1,2,or 5) x 10n, where n is an integer. (64 FR 30417). 

ALSO GIVEN AS: 

The smallest detectable concentration of analyte greater than the Detection Limit (DL) where 

the accuracy (precision & bias) achieves the objectives of the intended purpose. (Report of 

the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in 

Clean Water Act Programs Submitted to the US Environmental Protection Agency December 

2007).

Reasonable Potential--A reasonable potential to cause a water quality violation, or loss of 

sensitive and/or important habitat.

Responsible Corporate Officer--A president, secretary, treasurer, or vice-president of the 

corporation in charge of a principal business function, or any other person who performs 

similar policy, or decision-making functions for the corporation, or the manager of one or 

more manufacturing, production, or operating facilities employing more than 250 persons or 

have gross annual sales or expenditures exceeding $25 million (in second quarter 1980 

dollars), if authority to sign documents has been assigned or delegated to the manager in 

accordance with corporate procedures (40 CFR 122.22).

Significant Industrial User (SIU)--

1) All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 

40 CFR Chapter I, Subchapter N and;

2) Any other industrial user that: discharges an average of 25,000 gallons per day or more of 

process wastewater to the POTW (excluding sanitary, noncontact cooling, and boiler blowdown wastewater); contributes a process waste stream that makes up 5 percent or more of 

the average dry weather hydraulic or organic capacity of the POTW treatment plant; or is 

designated as such by the Control Authority* on the basis that the industrial user has a 

reasonable potential for adversely affecting the POTW's operation or for violating any 

pretreatment standard or requirement [in accordance with 40 CFR 403.8(f)(6)].

Upon finding that the industrial user meeting the criteria in paragraph 2, above, has no 

reasonable potential for adversely affecting the POTW's operation or for violating any 

pretreatment standard or requirement, the Control Authority* may at any time, on its own 

initiative or in response to a petition received from an industrial user or POTW, and in 

accordance with 40 CFR 403.8(f)(6), determine that such industrial user is not a significant 

industrial user.

*The term "Control Authority" refers to the Washington State Department of Ecology in 

the case of non-delegated POTWs or to the POTW in the case of delegated POTWs.
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Slug Discharge--Any discharge of a non-routine, episodic nature, including but not limited to an 

accidental spill or a non-customary batch discharge to the POTW. This may include any 

pollutant released at a flow rate that may cause interference or pass through with the POTW 

or in any way violate the permit conditions or the POTW’s regulations and local limits.

Soil Scientist--An individual who is registered as a Certified or Registered Professional Soil 

Scientist or as a Certified Professional Soil Specialist by the American Registry of Certified 

Professionals in Agronomy, Crops, and Soils or by the National Society of Consulting 

Scientists or who has the credentials for membership. Minimum requirements for eligibility 

are: possession of a baccalaureate, masters, or doctorate degree from a U.S. or Canadian 

institution with a minimum of 30 semester hours or 45 quarter hours professional core 

courses in agronomy, crops or soils, and have 5,3,or 1 years, respectively, of professional 

experience working in the area of agronomy, crops, or soils.

Solid Waste--All putrescible and non-putrescible solid and semisolid wastes including, but not 

limited to, garbage, rubbish, ashes, industrial wastes, swill, sewage sludge, demolition and 

construction wastes, abandoned vehicles or parts thereof, contaminated soils and 

contaminated dredged material, and recyclable materials.

Soluble BOD5--Determining the soluble fraction of Biochemical Oxygen Demand of an effluent 

is an indirect way of measuring the quantity of soluble organic material present in an effluent 

that is utilized by bacteria. Although the soluble BOD5 test is not specifically described in 

Standard Methods, filtering the raw sample through at least a 1.2 um filter prior to running 

the standard BOD5 test is sufficient to remove the particulate organic fraction.

State Waters--Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and 

all other surface waters and watercourses within the jurisdiction of the state of Washington.

Stormwater--That portion of precipitation that does not naturally percolate into the ground or 

evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water 

drainage system into a defined surface water body, or a constructed infiltration facility.

Technology-based effluent limit--A permit limit based on the ability of a treatment method to 

reduce the pollutant.

Total Coliform Bacteria--A microbiological test, which detects and enumerates the total 

coliform group of bacteria in water samples.

Total Dissolved Solids--That portion of total solids in water or wastewater that passes through a 

specific filter.

Total Maximum Daily Load (TMDL) -- A determination of the amount of pollutant that a 

water body can receive and still meet water quality standards.

Total Suspended Solids (TSS)--The particulate material in an effluent. Large quantities of TSS 

discharged to a receiving water may result in solids accumulation. Apart from any toxic 

effects attributable to substances leached out by water, suspended solids may kill fish, 

shellfish, and other aquatic organisms by causing abrasive injuries and by clogging the gills 

and respiratory passages of various aquatic fauna. Indirectly, suspended solids can screen 

out light and can promote and maintain the development of noxious conditions through 

oxygen depletion. 
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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 facilities, lack of preventative maintenance, 

or careless or improper operation.

Water Quality-Based Effluent Limit--A limit imposed on the concentration of an effluent 

parameter to prevent the concentration of that parameter from exceeding its water quality 

criterion after discharge into receiving waters.
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Appendix D - Summary of DMR Data

Intalco 2007 Water Pollutant Discharges (April through December)

PARAMETERS 

UNITS LIMITS1 APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

OUTFALL 001

TSS - MA2 lbs/day 150 14 0 0 0 7 18 5 68 82 21.6

TSS - DM3 lbs/day 185 86 0 0 0 29 44 23 143 149 52.7

FLUORIDE - MA lbs/day 68 38 41 26 35 21 36 57 41 46 37.9

FLUORIDE - DM lbs/day 296 57 68.0 36 61 26 74 176 91 120 78.8

ALUMINUM - MA lbs/day 10.3 0.4 0.0 0.0 0.0 0.0 1.2 0.2 5.0 4.0 1.2

ALUMINUM - DM lbs/day 30 2.0 0 0 0 0 3 1 11 8.0 2.8

FREE CN - MA mg/l <0.012 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.0

FREE CN - DM mg/l 0.012 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

B(a)P - MA lbs/day 0.06 0.0067 0.01 4/2/2007 0.015 7/5/2007 7/5/2007 0.024 10/11/2007 10/11/2007

B(a)P - DM lbs/day 0.13 0.0067 0.01 4/2/2007 0.015 7/5/2007 7/5/2007 0.024 10/11/2007 10/11/2007

ANTIMONY - MA lbs/day 5.7 0.07 0.01 5/15/2007 5/15/2007 0.29 7/16/2007 7/16/2007 7/16/2007 7/16/2007

ANTIMONY - DM lbs/day 12.8 0.01 5/15/2007 5/15/2007 0.31 7/16/2007 7/16/2007 7/16/2007 7/16/2007

NICKEL - MA lbs/day 2.5 1.25 0.6 5/15/2007 5/15/2007 0.26 7/16/2007 7/16/2007 7/16/2007 7/16/2007

NICKEL - DM lbs/day 3.7 0.7 5/15/2007 5/15/2007 0.28 7/16/2007 7/16/2007 7/16/2007 7/16/2007

C0PPER - MA ug/l none 0 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007

C0PPER - DM ug/l none <5 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007

O & G - MA mg/l 5 1 1 <1 <1 1 1 0 1 1

O & G - DM mg/l 10 1 1 <1 <1 1 1 <1 1 1

pH - Minimum std units ≥6 7.7 7.7 7.5 7.5 7.6 7.7 7.2 7.3 7.0 7.5

pH - Maximum std units ≤9 8.2 8.2 8.1 8.1 8.1 8.1 8.0 7.9 8.1 8.1

Temp - MA oF none 56 60 63 69 68 65 58 52 47.0 59.8

Temp - DM oF none 64 68 70 73 73 70 63 59 52.0 65.8

Flow - MA MGD none 3.388 3.574 3.722 3.861 3.836 3.668 3.357 3.511 3.542 3.6

Flow - DM MGD none 3.624 4.121 4.053 4.162 4.109 3.913 3.667 4.012 3.755 3.9

Al Production4 tons/day none 618.6 605.3 593.9 581.2 615.5 619.4 614.2 622.9 616.9 609.8

Potdays (average number of pots 

operating/day) Number none 533 528 532 533 532 536 535 535 538.0 533.6

% of total number of pots (720) 

operating/day % none

74 73 74 74 74 74 74 74 75 74.1

OUTFALL 002: UNITS LIMITS APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

TSS - MA mg/l 35 8 10 10 13 11 11 9 14 15 11.2

TSS - DM mg/l 75 13 13 12 24 16 11 10 22 37 17.6

FLUORIDE - MA mg/l 35 12 15 25 28 34 33 31 29 16 24.8
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 84 of 145

Intalco 2007 Water Pollutant Discharges (April through December)

OUTFALL 002: UNITS LIMITS APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

FLUORIDE - DM mg/l 50 15 17 29 32 37 35 38 33 18 28.2

Al - MA mg/l 10 2 3 5 5 6 6 9 9 4 5.4

Al - DM mg/l 15 3 4 6 8 7 6 11 10 6 6.8

B (a)P - DM mg/l <0.01 <0.0001 <0.0001 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 <0.0001

Copper-MA ug/l none 0 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 <20

Copper-DM ug/l none <20 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 <20

Free CN - DM mg/l none 0.00 0.00 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007 4/2/2007

O & G - MA mg/l 5 1 1 <1 1 1 1 1 1 1 1.0

O & G - DM mg/l 10 1 1 <1 1 1 1 1 1 1 1.0

pH - Minimum std units ≥6 6.9 6.9 6.7 6.9 7.0 7.2 6.6 6.7 6.6 6.8

pH - Maximum std units ≤9 7.3 7.4 7.3 7.6 7.4 7.4 7.7 7.1 7.3 7.4

Temp - MA oF none 52 59 63 67 65 62 51 42 39 55.6

Temp - DM oF none 61 68 68 73 72 68 59 50 50 63.2

Flow - MA MGD none 0.349 0.183 0.099 0.083 0.024 0.040 0.360 0.218 1.380 0.3

Flow - DM MGD none 1.922 3.467 0.488 0.861 0.138 0.110 2.695 1.373 12.0105 2.6

Sanitary Lagoon UNITS LIMITS APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

BOD: 30-day Avg lbs/day 22.4 4.4 3.1 3.0 3.2 2.0 2.4 0.8 1.6 3.2 2.6

BOD: 7-day Avg lbs/day 32.4 5.1 6.8 6.8 7.7 6.2 3.7 1.3 2.2 5.5 5.0

BOD: 30-day Avg mg/l 45.0 17.3 12.5 15.8 8.4 10.2 10.4 3.4 7.6 9.7 10.6

BOD: 7-day Avg mg/l 65.0 22.0 20.0 34.0 15.0 30.0 21.1 4.9 16 12.0 19.4

% BOD Removal % 65 77 83 78 87 84 86 95 88 86 84.9

TSS: 30-day Avg lbs/day 22.4 2.8 0.7 1.5 3.2 0.5 0.5 0.6 0.5 2.3 1.4

TSS: 7-day Avg lbs/day 32.4 3.8 1.4 4.7 7.1 0.8 1.4 0.8 0.8 4.7 2.8

TSS: 30-day Avg mg/l 45.0 10.8 3.4 7.7 8.6 3.9 1.2 2.4 2 6.5 5.2

TSS: 7-day Avg mg/l 65.0 16.8 6.1 23.1 13.8 5.5 3 3 3.4 8.0 9.2

% TSS Removal % 65 89 97 93 90 95 99 98 97 94 94.7

Fecal Coli: 30-day Avg #/100mls 200 0.0 0.0 <2 <5 <2 <2 <2 <2 <4

Fecal Coli: 7-day Avg #/100mls 400 <2 <2 <2 110 2 2 <2 <2 30

pH - Min std units ≥6 6.6 6.5 6.6 6.7 6.7 6.5 6.3 6.2 6.5 6.5

pH - Max std units ≤9 7.1 7.0 7.0 7.0 6.9 7.0 6.9 6.7 7.1 7.0

Flow - MA MGD none 0.034 0.026 0.024 0.035 0.017 0.037 0.026 0.024 0.039 0.0

Flow - DM MGD none 0.072 0.070 0.036 0.062 0.034 0.065 0.046 0.068 0.082 0.1

Personnel working onsite # of personnel >400 591 602 614 607 633 641 636 636 620.0

Date UV Tubes cleaned Date Once/90 days 4/4/07 5/16/07 5/16/07 7/26/07 8/30/07 8/30/07 8/30/07 11/19/07 11/19/07

UV Tubes Operating Number Min. of 12 14 14 14 14 14 14 14 14 14 14.0

Date UV Tubes replaced Date Annually 1/4/07 1/4/07 1/4/07 7/3/2007 7/3/2007 7/3/2007 7/3/2007 7/3/2007 7/3/2007
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 85 of 145

Intalco 2007 Water Pollutant Discharges (April through December)

Stormwater Pond UNITS Action Level APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

TSS-DM5 mg/l 20 11.5 28.8 NS6 NS NS NS 23.1 NS 42.2 26.4

FLUORIDE-DM5 mg/l 35 23.0 26.0 NS NS NS NS 40.2 NS 22.0 27.8

ALUMINUM-DM5 mg/l 8 5.7 7.8 NS NS NS NS 13.2 NS 7 8.4

pH - Min (continuous recording) std units <6.0 6.8 6.7 6.8 6.8 6.7 6.8 6.6 6.4 6.6 6.7

pH - Max (continuous recording) std units >9.0 7.6 7.3 7.2 7.1 7.1 7.3 7.2 7.5 7.3 7.3

Flow - MA (continuous recording) MGD none 0.196 0.127 0.101 0.108 0.074 0.076 0.187 0.152 0.471 0.166

Flow - DM (continuous recording) MGD none 0.802 1.091 0.327 0.524 0.237 0.191 0.761 0.545 3.45 0.881

COMMENTS 1. The SW pond was drained on 09/18/07 and >75 tons of sludge was removed.

2. The sludge levels were surveyed and found to be below storage capacity.

Secondary Wastewater Treatment 

Plant UNITS Action Level APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - MA mg/l none 27.6 28.6 20.5 12.5 13.8 17.5 22.0 22.5 30.8 21.8

TSS - DM mg/l 120 43.7 51.2 36.4 19.8 22.2 25.8 47.8 44.0 52.8 38.2

FLUORIDE - MA mg/l none 20.4 18.1 15.8 21 18.8 24.6 27.4 40.5 19.9 22.9

FLUORIDE - DM mg/l 50 26.0 21.0 18.0 31 22.0 48.0 43.0 75.0 32.0 35.1

ALUMINUM - MA mg/l none 0.1 0.1 0.1 0.4 0.1 0.3 0.6 0.9 0.5 0.3

ALUMINUM - DM mg/l none 0.2 0.2 0.2 0.8 0.1 0.8 1.1 2.3 0.9 0.7

FREE CN - MA mg/l none 0.000 0.001 0.002 0.001 0.004 0.002 0.000 0.010 0.003 0.003

FREE CN - DM mg/l none 0.000 0.005 0.006 0.005 0.007 0.006 <0.005 0.015 0.013

PCBs ppb none <0.1 4/2/2007 4/2/2007 <0.1 7/16/2007 7/16/2007 <0.1 10/11/2007 10/11/2007

Flow - MA MGD none 0.065 0.067 0.056 0.055 0.047 0.095 0.074 0.049 0.061 0.1

Flow - DM MGD none 0.243 0.197 0.140 0.184 0.112 0.314 0.185 0.143 0.192 0.2

pH - Min (continuous recording) std units none 7.4 7.1 6.9 6.9 6.8 6.5 6.6 6.8 7.2 6.9

pH - Max (continuous recording) std units none 7.8 8.0 7.8 7.8 7.7 7.5 7.5 7.8 7.6 7.7

Outfall 011 UNITS LIMITS APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - Monthly grab when there is flow mg/l none 19.6 0.9 1.0 1.4 2.4 19.6 18.6 24.6 36.7 13.9

FLUORIDE - Monthly grab when there is 

flow mg/l none

7.7 2.8 2.3 0.8 4.3 9.0 6.0 0.8 8.0 4.6

ALUMINUM - Monthly grab when there is 

flow mg/l none

2 0.08 0.1 2.9 0.2 1.5 2.2 3.54 1.2 1.5

Outfall 012 UNITS LIMITS APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - Monthly grab when there is flow mg/l none 85 IF7 20.7 27.1 29.5 97.7 48.2 28.7 779.1 139.5

FLUORIDE - Monthly grab when there is 

flow mg/l none

2 IF 4.4 0.2 3.8 4.7 2.8 0.68 6.2 3.1

ALUMINUM - Monthly grab when there is 

flow mg/l none

9 IF 1.7 1.1 2 1.4 1.3 2.54 3.1 2.8
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 86 of 145

Intalco 2007 Water Pollutant Discharges (April through December)

1 LIMITS for the renewed NPDES permit issued on March 15, 2007

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the number of daily 

discharges measured during that month.

3 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations expressed in units of mass, 

the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the day. The pH shall not be averaged. 

4 The monthly average of daily production.

5 Sampled when the stormwater pond discharge exceeds 3.7 cfs over any consecutive 120 minute period. 

6 NS = Not sampled because the stormwater pond discharge did not exceed 3.7 cfs over any consecutive 120 minute period.

7 IF = Insufficient flow to collect a representative sample.

Intalco 2008 Water Pollutant Discharges

OUTFALL 001 UNITS LIMITS1 JAN FEB MARCH APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - MA2 lbs/day 150 25 25 10 60 65 63 29 1 5 5 28 61 31.4

TSS - DM3 lbs/day 185 51 64 40 78 135 105 58 5 26 21 47 157 65.6

FLUORIDE - MA lbs/day 584

/685/686 34 39 36 39 31 44 33 35 27 17 23 20 31.5

FLUORIDE - DM lbs/day 1404

/1985/2966 41 44 45 59 47.0 77 61 62 58 37 28 32 49.3

ALUMINUM - MA lbs/day 5.94

/9.05/10.36 2.9 1.8 0.4 3.5 1.3 2.7 1.1 0.4 0.5 0.2 0.1 2.3 1.4

ALUMINUM - DM lbs/day 13.44

/205/306 5 3.0 1 5.0 3.6 6 3.8 1.4 2.6 1.3 0.3 7.2 3.4

FREE CN - MA mg/l <0.012 0.000 0.000 0.000

ND7

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

FREE CN - DM mg/l 0.012 <0.005 <0.005 <0.005

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

B(a)P - MA lbs/day 0.024

/0.035/0.0456 10/11/07 10/11/07 <0.002

ND

(<0.002) 04/01/08 0.0031 0.06 07/15/08 07/15/08 0.009 10/24/08 10/24/08

B(a)P - DM lbs/day 0.0434

/0.0655/0.0986 10/11/07 10/11/07 <0.002

ND

(<0.002) 04/01/08 0.0031 0.13 07/15/08 07/15/08 0.024 10/24/08 10/24/08

Mercury ug/l none

ND

(<0.0002)

ND

(<0.005)

ANTIMONY - MA lbs/day 1.94

/2.95/4.36 07/16/07 07/16/07 0.01 03/14/08 03/14/08

ND

(<0.00001) 06/04/08 06/04/08 06/04/08 0.024 10/24/08 10/24/08

ANTIMONY - DM lbs/day 4.24

/6.45/9.66 07/16/07 07/16/07 0.01 03/14/08 03/14/08

ND

(<0.00001) 06/04/08 06/04/08 06/04/08 0.066 10/24/08 10/24/08

NICKEL - MA lbs/day 0.84

/1.25/1.96 07/16/07 07/16/07 1.31 03/14/08 03/14/08 0.3140 06/04/08 06/04/08 06/04/08 2.643 10/27/08 10/27/08

NICKEL - DM lbs/day 1.244

/1.855/2.766 07/16/07 07/16/07 1.31 03/14/08 03/14/08 0.3140 06/04/08 06/04/08 06/04/08 14.472 10/27/08 10/27/08

C0PPER - MA ug/l none 04/02/07 04/02/07 04/02/07

ND

(<0.020) 04/01/08

ND

(<0.00002) 06/04/08 06/04/08 06/04/08

ND

(<0.003) 10/24/08 10/24/08

C0PPER - DM ug/l none 04/02/07 04/02/07 04/02/07

ND

(<0.020) 04/01/08

ND

(<0.00002) 06/04/08 06/04/08 06/04/08

ND

(<0.003) 10/24/08 10/24/08

O & G - MA mg/l 5 0 0 0

ND

(<1)

ND

(<1)

ND

(<1)

ND

(<1)

ND

(<1)

ND

(<1)

ND

(<1)

ND

(<1.4)

ND

(<1.4)

O & G - DM mg/l 10 <1 <1 <1 ND ND ND ND ND ND ND ND ND
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 87 of 145

Intalco 2008 Water Pollutant Discharges

(<1) (<1) (<1) (<1) (<1) (<1) (<1) (<1.4) (<1.4)

pH - Daily Min std units ≥6 7.3 7.1 7.3 7.6 7.4 7.4 7.4 7.1 7.6 7.3 7.2 7.2 7.3

pH - Daily Max std units ≤9 8.2 8.1 8.2 8.1 8.0 7.8 10.0 7.9 8.0 8.0 8.1 8.0 8.2

Temp - MA oF none 46 48 50 53 55 58 64 64.5 62 55.8 53 46.0 54.6

Temp - DM oF none 52 54 54 59 62 66 69 72.7 67 63 58 56.0 61.1

Flow - MA MGD none 3.544 3.654 3.622 3.628 3.483 3.783 3.709 3.853 3.815 3.623 3.628 3.540 3.7

Flow - DM MGD none 3.726 3.856 3.816 4.107 3.833 4.005 3.899 4.310 4.117 4.117 3.843 4.147 4.0

Al Production8 tons/day none 634.1 638.1 648.3 653.8 658.9 675.7 668.0 666.1 667.2 676.6 596.1 540.1 643.6

Number of days in the 

month none 31 29 31 30 31 30 31 31 30 31 30 31 30.5

Al Production -

Maximum

tons/mont

h none 19657 18505 20097 19614 20426 20271 20708 20649 20016 20975 17883 16743 19629

OUTFALL 002 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - MA mg/l 35 7.1 9.3 8.4 7.6 16.4 29.4 12 16.8 13.3 15.5 15.1 4.2 12.9

TSS - DM mg/l 75 11.7 16.3 12.9 11.4 19.8 64.9 17.6 31 15.6 22.8 32.2 5.3 21.8

FLUORIDE - MA mg/l 35 12.4 13.5 13.8 13.4 19.0 25.1 25.8 32.5 28 32.3 22.6 14.2 21.1

FLUORIDE - DM mg/l 50 17.0 16 17 18 24.3 30.2 29 37.3 31 33 33.7 16 25.2

ALUMINUM - MA mg/l 10 2.8 2.8 3.3 2.6 4.7 6.2 3.4 7 6.3 9.1 5.6 3.1 4.7

ALUMINUM - DM mg/l 15 3.7 3.9 4.7 3.6 7.1 10.0 4.5 9.1 7.7 9.4 9.4 3.4 6.4

B (a)P - DM mg/l <0.01 12/11/07 12/11/07 12/11/07

ND

(<0.0001

) 04/01/08 0.0002 06/04/08 06/04/08 06/04/08 06/04/08 06/04/08 06/04/08

Copper-DM ug/l none 12/11/07 12/11/07 12/11/07

ND

(<0.020) 04/01/08

ND

(<0.00002) 06/04/08 06/04/08 06/04/08 06/04/08 06/04/08 06/04/08

Free CN - DM mg/l none 04/02/07 04/02/07 04/02/07

ND

(<0.005) 04/01/08

ND

(<0.005) 06/04/08 06/04/08 06/04/08 06/04/08 06/04/08 06/04/08

O & G - MA mg/l 5 0 0 0

ND

(<1)

ND

(<1) 2.3

ND

(<1) 1 1

ND

(<1)

ND

(<1.4)

ND

(<1.4)

O & G - DM mg/l 10 <1 <1 <1

ND

(<1)

ND

(<1) 2.3

ND

(<1) 1 1

ND

(<1)

ND

(<1.4)

ND

(<1.4)

pH - Daily Min std units ≥6 6.6 6.8 6.7 6.7 6.8 6.8 7.1 6.4 6.9 6.5 6.4 6.5 6.7

pH - Daily Max std units ≤9 7.2 7.1 7.1 7.4 7.4 7.4 7.6 7.4 7.3 7.3 7.3 7.3 7.3

Temp - MA oF none 38 40 44 50 58 60 65.9 64.1 59 51.1 47 38 51.3

Temp - DM oF none 45 46 54 55 66 71 88 82.4 68 59.6 53 49 61.4

Flow - MA MGD none 1.075 0.641 0.795 0.157 0.264 0.163 0.091 0.292 0.102 0.197 1.179 3.093 0.671

Flow - DM MGD none 5.131 2.074 3.988 0.652 2.533 1.167 0.125 1.512 0.574 1.189 7.474 25.610 4.336

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

BOD: 30-day Avg lbs/day 22.4 3.0 4.6 3.3 3.1 3.0 2.2 1.5 4.0 2.7 1.8 2.1 3.0 2.9

BOD: 7-day Avg lbs/day 32.4 5.3 6.4 5.3 5.5 5.8 3 2.4 9.9 4.9 5.7 3.4 4.3 5.2
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 88 of 145

Intalco 2008 Water Pollutant Discharges

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

BOD: 30-day Avg mg/l 45.0 10.4 15.3 18.4 13.6 11.8 7.5 7.4 18.4 10.3 8.5 7.0 11.6 11.7

BOD: 7-day Avg mg/l 65.0 14.0 22.0 30.0 19.0 18.0 10.0 9.2 29.0 14.0 18 12 16.0 17.6

TSS: 30-day Avg lbs/day 22.4 3.1 6.5 4.2 4.6 4.2 0.9 2.6 1.5 0.5 0.8 1.1 1.8 2.7

TSS: 7-day Avg lbs/day 32.4 6.4 11.4 7.1 7.9 6.6 1.8 7.0 3.8 1.0 1.5 2.4 5.0 5.2

TSS: 30-day Avg mg/l 45.0 10.4 22.5 19.4 32.4 16.5 3.1 12.6 8.2 1.6 4.2 3.8 6.2 11.7

TSS: 7-day Avg mg/l 65.0 15.6 26.3 22.5 24.9 21.1 6.2 25.5 18.1 2.9 6.1 8.8 12.9 15.9

Fecal Coli: 30-day Avg #/100mls 200 7 <5 <2

ND

(<2) 2.3 3.8 2

ND

(<2)

ND

(<2)

ND

(<2)

ND

(<2)

ND

(<2)

Fecal Coli: 7-day Avg #/100mls 400 30 23 <2

ND

(<2) 4.0 4.0 2

ND

(<2)

ND

(<2)

ND

(<2)

ND

(<2) 2

pH - Daily Min std units ≥6 6.7 6.7 6.7 6.8 6.5 6.6 6.6 6.5 6.6 6.5 6.4 6.5 6.6

pH - Daily Max std units ≤9 6.9 7.1 7.0 7.0 7.1 6.9 6.9 6.8 7.0 7.0 7 6.9 7.0

Flow - MA MGD none 0.034 0.03 0.031 0.022 0.027 0.034 0.024 0.028 0.024 0.020 0.036 0.026 0.028

Flow - DM MGD none 0.083 0.072 0.052 0.044 0.042 0.039 0.039 0.041 0.042 0.038 0.048 0.047 0.049

% BOD Removal -MA % 55%/65%9 80 81 75 80 87 91 93 77 88 92 91 89 85

% TSS Removal - MA % 55%/65%9 89 83 79 82 88 97 93 92 98 97 96 96 91

# of personnel 

working onsite Number 

none 636 644 641 657 647 641 663 665 661 658 614 587 643

Date UV Tubes were 

cleaned 

Date

90 days 11/19/07 02/04/08 02/04/08 04/16/08 05/28/08 06/17/08 07/09/08 07/09/08 09/02/08 10/28/08 11/05/08 11/05/08

UV Tubes Operating 7 day avg Minimum of 12 14 14 14 14 14 14 14 14 14 14 14 14 14

Date UV Tubes were 

replaced 

Date Annually

07/03/07 01/03/08 01/03/08 01/03/08 01/03/08 01/03/08 07/09/08 07/09/08 07/09/08 07/09/08 07/09/08 07/09/08

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 20 19.1 NS10 16.0 NS 15.7 50.2 NS 27.2 NS 12.3 27.2 18.1 23.2

FLUORIDE - DM mg/l 35 25.1 NS 21.2 NS 28.0 36.3 NS 44.3 NS 38.8 31.7 27.0 31.6

ALUMINUM - DM mg/l 8 7.8 NS 6.3 NS 8.6 15 NS 14.1 NS 9.4 11.5 7.2 10.0

pH - Daily Min std units <6.0 6.6 6.8 6.8 6.8 6.6 6.6 6.6 6.4 6.4 6.4 6.0 6.6 6.6

pH - Daily Max std units >9.0 7.4 7.3 7.3 7.5 7.5 7.2 7.2 7.2 7.0 7.0 7.3 7.7 7.3

Flow - MA MGD none 0.340 0.246 0.302 0.129 0.158 0.122 0.083 0.217 0.107 0.137 0.242 0.146 0.186

Flow - DM MGD none 2.135 0.681 1.339 0.374 1.308 0.703 0.145 0.991 0.280 0.443 1.534 0.836 0.897

Secondary 

Wastewater 

Treatment Plant

UNITS Action Level JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 120 43.9 67.3 72.1 52.7 56.8 78.1 53.8 26.6 41.0 132.6 65.2 135.6 68.8

FLUORIDE - DM mg/l 50 25.0 24 25 39.0 30.0 38.3 32.3 44.0 34.8 34.0 24.8 28.5 31.6

ALUMINUM - DM mg/l none 0.9 0.3 1.0 0.4 1.1 0.4 0.4 1.4 1.2 0.5 0.3 0.7 0.7
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 89 of 145

Intalco 2008 Water Pollutant Discharges

Secondary 

Wastewater 

Treatment Plant

UNITS Action Level JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

FREE CN - DM mg/l none 0.006 <0.005 <0.005

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

ND

(<0.005) 0.005 0.005

ND

(<0.005)

ND

(<0.005)

ND

(<0.005)

PCBs ppb none 10/11/07 <0.1 2/20/2008

ND

(<0.1) 04/01/08

ND

(<0.1) 06/04/08 07/15/08 07/15/08 07/15/08 <0.01 10/30/08

Flow - MA MGD none 0.072 0.056 0.055 0.061 0.062 0.061 0.054 0.058 0.064 0.031 0.059 0.034 0.056

Flow - DM MGD none 0.125 0.131 0.180 0.154 0.165 0.178 0.191 0.186 0.185 0.142 0.125 0.155 0.160

Outfall 011 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS mg/l none 105.9 103.2 29.1 19.7 14.0 1.2 3.0 14.9 43.3 51.8 20.2 24.5 35.9

FLUORIDE mg/l none 8.7 8.2 14.2 6.2 6.2 6.2 5.8 7.5 12.0 9.3 5.3 10.0 8.3

ALUMINUM mg/l none 3.8 2.7 4.5 1.3 0.5 0.2 0.4 0.5 1.4 1.8 1.0 2.1 1.7

Outfall 012 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS mg/l none 31.8 39.2 21 30.1 9.4 16.1 37.0 40.8 5.1 27.1 5.6 10.6 22.8

FLUORIDE mg/l none 4.8 5.5 8.2 3.7 4.8 6.2 8.0 4.2 2.7 6.5 2.2 3.0 5.0

ALUMINUM mg/l none 2.0 2.0 5.1 4.5 1.2 4.5 3.7 1.3 1.2 4.1 0.9 2.5 2.8

1 LIMITS for modified NPDES permit issued on June 15, 2008 (effective July 15, 2008).

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the 

number of daily discharges measured during that month.

3 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations 

expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the 

day. The pH shall not be averaged. 

4 Tiered limit, applies when monthly aluminum production is less than or equal to 10,305 tons. 

5 Tiered limit, applies when monthly aluminum production is greater than 10,305 and less than or equal to 15,614 tons.

6 Tiered limit, applies when monthly aluminum production is greater than 15,614 tons.

7 ND = Nondetect.

8 The monthly average of daily production.

9 The limit is 55 % if there are <400 people working onsite and the limit is 65% if there are > 400 people working on site.

10 NS = Not sampled because the stormwater pond discharge never exceeded 3.7 cfs over any consecutive 120 minute period.

Intalco 2009 Water Pollutant Discharges

PARAMETERS 

UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG OUTFALL 001

TSS - MA2 lbs/day 150 30 34 97.2 9.7 71.4 1.2 22.1 36.5 20.3 45.2 329.5 111.4

TSS - Stormwater Allocation 

(SWA)3 lbs/day Calculated3 DNTA4 DNTA DNTA DNTA DNTA DNTA DNTA DNTA DNTA DNTA 696.0 DNTA
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 90 of 145

Intalco 2009 Water Pollutant Discharges

OUTFALL 001 UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - DM5 lbs/day 185 62 43 134.6 29.6 142.4 4.0 41.1 329 60.7 169.8 1144.4 217.3

TSS -Stormwater Allocation 

(SWA)6 lbs/day Calculated6 DNTA DNTA DNTA DNTA DNTA DNTA DNTA 1897.5 DNTA DNTA 2910.0 1391.3

FLUORIDE - MA lbs/day 587

/688/689 30 31 121.3 50.1 122.4 53.9 40.2 73.3 44.9 110.3 288.6 101.5

FLUORIDE - SWA3 lbs/day Calculated3 DNTA DNTA 339.6 DNTA 517.7 DNTA DNTA 143.9 DNTA 348.3 614.0 333.7

FLUORIDE - DM lbs/day 1407

/1988/2969 42 33 176.2 66.5 197.4 157.8 58.4 585.1 84.6 306.2 766.7 203.7

FLUORIDE - SWA6 lbs/day Calculated6 DNTA DNTA DNTA DNTA DNTA DNTA DNTA 1340.6 DNTA 1198.8 2016.1 1002.8

ALUMINUM - MA lbs/day 5.97

/9.08/10.39 1.8 2.0 23.7 3.9 26.8 0.7 1.4 12.9 4.6 29.8 81.3 21.3

ALUMINUM - SWA3 lbs/day Calculated3 DNTA DNTA 87.5 DNTA 136.8 DNTA DNTA 30.6 DNTA 88.7 164.2 84.5

ALUMINUM - DM lbs/day 13.47

/208/309 4.9 3.2 42.9 7.0 55.3 2.2 4.3 120.7 11.6 95.5 243.1 57.4

ALUMINUM - SWA6 lbs/day Calculated6 DNTA DNTA 273.8 DNTA 310.0 38.8 38.8 362.5 DNTA 320.0 565.0 261.3

FREE CN - MA mg/l <0.012

ND10 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

FREE CN - DM mg/l 0.012

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

B(a)P - MA lbs/day

0.027/0.038/ 

0.0459 10/24/08 0.005 02/23/09 02/23/09 0.005 05/12/09 05/12/09 05/12/09 0.009 09/14/09 09/14/09 0.030

B(a)P - SWA3 lbs/day Calculated3 10/24/08 DNTA 02/23/09 02/23/09 DNTA 05/12/09 05/12/09 05/12/09 DNTA 09/14/09 09/14/09 0.030

B(a)P - DM4 lbs/day

0.0437/0.0658/0

.0989 10/24/08 0.005 02/23/09 02/23/09 0.005 05/12/09 05/12/09 05/12/09 0.009 09/14/09 09/14/09 0.034

B(a)P - SWA6 lbs/day Calculated6 10/24/08 DNTA 02/23/09 02/23/09 DNTA 05/12/09 05/12/09 05/12/09 DNTA 09/14/09 09/14/09 DNTA

ANTIMONY - MA lbs/day 1.97

/2.9 8/4.39 10/24/08 0.04 02/23/09 02/23/09 0.00 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 0.11

ANTIMONY - DM lbs/day 4.27

/6.48/9.69 10/24/08 0.04 02/23/09 02/23/09 0.00 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 0.11

NICKEL - MA lbs/day 0.87

/1.28/1.99 10/27/08 1.71 02/23/09 02/23/09 0.00 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 0.06

NICKEL - DM lbs/day 1.27

/1.88/2.79 10/27/08 1.71 02/23/09 02/23/09 0.00 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 0.06

C0PPER - MA ug/l none 10/24/08 <0.02 02/23/09 02/23/09

ND 

(<0.24) 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09

C0PPER - DM ug/l none 10/24/08 <0.02 02/23/09 02/23/09

ND 

(<0.24) 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09 05/12/09

O & G - MA mg/l 5 1.9 <1.4 <1.4 <1.4 ND (<1.4) ND (<1.4) ND (<1.4) ND (<1.4)

ND 

(<1.4) ND (<1.4) 2.0

ND 

(<1.4)

O & G - DM mg/l 10 1.9 <1.4 <1.4 <1.4 ND (<1.4) ND (<1.4) ND (<1.4) ND (<1.4)

ND 

(<1.4) ND (<1.4) 2

ND 

(<1.4)

pH - Daily Min std units ≥6 7.2 6.7 7 6.6 6.5 7.1 7.2 6.7 7.1 6.5 6.6 6.8 6.8

pH - Daily Max std units ≤9 8.2 8.7 7.9 8.1 7.9 7.9 8.0 8.0 8.0 7.9 7.9 8.1 8.1

PARAMETERS UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

Temp - MA oF none 47 48 48 54 57 62 67 67 63 55 50 44.0 55.2

Temp - DM oF none 52 53 53 63 65 71 74 72 69 60 64 51.0 62.3
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 91 of 145

Intalco 2009 Water Pollutant Discharges

PARAMETERS UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

Flow - MA MGD none 3.666 3.602 3.885 3.646 3.549 3.631 3.832 3.838 4.116 5.057 5.742 4.482 4.1

Flow - DM MGD none 4.022 4.342 5.231 7.142 6.135 4.367 4.416 5.946 4.645 7.865 8.619 7.088 5.8

Al Production11 tons/day none 532.6 521.9 514.6 506.8 495.4 481.4 485.3 485.8 485.2 487.7 497.6 499.3 499.5

Number of days in the month none 31 28.0 31.0 30 31 30 31.0 31 30 31 30 31 30.4

Al Production - Maximum

tons/mo

nth none 16511 14613 15953 15204 15357 14442 15044 15060 14556 15119 14928 15478

OUTFALL 00212 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - MA mg/l 35 3 7.3 NA13 NA NA NA NA 13.8 NA 10.4 11.9 NA 9.3

TSS - DM mg/l 75 5.6 11.2 NA NA NA NA NA 13.8 NA 15.7 18 NA 12.9

FLUORIDE - MA mg/l 35 12.4 12.5 NA NA NA NA NA 30.2 NA 25.6 21.1 NA 20.4

FLUORIDE - DM mg/l 50 15.7 14.3 NA NA NA NA NA 30.2 NA 30.2 25.2 NA 23.1

ALUMINUM - MA mg/l 10 1.9 3.1 NA NA NA NA NA 8.2 NA 7.1 5.5 NA 5.2

ALUMINUM - DM mg/l 15 2.6 4.2 NA NA NA NA NA 8.2 NA 9.0 6.8 NA 6.2

B(a)P - MA mg/l none <0.0001 01/14/09 NR14 NR NR NR NR 01/14/09 NR 01/14/09 01/14/09 NR

B(a)P - DM mg/l <0.01 <0.0001 01/14/09 NR NR NR NR NR 01/14/09 NR 01/14/09 01/14/09 NR

Copper - MA ug/l none <0.003 01/14/09 NR NR NR NR NR 01/14/09 NR 01/14/09 01/14/09 NR

Copper - DM ug/l none <0.003 01/14/09 NR NR NR NR NR 01/14/09 NR 01/14/09 01/14/09 NR

Free CN - MA mg/l none <0.005 01/14/09 NR NR NR NR NR 01/14/09 NR 01/14/09 01/14/09 NR

Free CN - DM mg/l none <0.005 01/14/09 NR NR NR NR NR 01/14/09 NR 01/14/09 01/14/09 NR

O & G - MA mg/l 5 <1.4 <1.4 NR NR NR NR NR NR14 NR NR NR NR

O & G - DM mg/l 10 <1.4 <1.4 NR NR NR NR NR NR NR NR NR NR

pH - Minimum std units ≥6 6.1 6.7 NA NA NA NA NA 6.6 NA 6.3 6.4 NA 6.4

pH - Maximum std units ≤9 7.1 7.2 NA NA NA NA NA 7.6 NA 7.2 7.2 NA 7.3

Temp - MA oF none 39 40 NA NA NA NA NA 65 NA 51 46 NA 48.2

Temp - DM oF none 46 46 NA NA NA NA NA 75 NA 59 50 NA 55.2

Flow - MA MGD none 2.510 0.711 NA NA NA NA NA 0.256 NA 0.955 1.868 NA 1.3

Flow - DM MGD none 14.427 3.829 NA NA NA NA NA 2.74 NA 3.93 6.84 NA 6.4

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

BOD: 30-day Avg lbs/day 22.4 8.3 3 6.4 3.9 2.8 1.2 0.5 0.8 0.7 1.6 3 3.1 2.9

BOD: 7-day Avg lbs/day 32.4 17.1 5.3 11.7 5.3 6.1 2.1 0.6 1.6 1.1 2.5 5.3 4.7 5.3

BOD: 30-day Avg mg/l 45.0 14.8 17.8 25 14.4 8.2 5.2 4.3 3.2 4.8 4.6 9.8 11.5 10.3

BOD: 7-day Avg mg/l 65.0 34.0 31.0 32.0 17.0 11.0 8.3 5.3 3.4 8.0 5.2 25 18.0 16.5

TSS: 30-day Avg lbs/day 22.4 7.9 3.3 5.4 4.2 6.4 1.6 0.7 1.9 1.7 2.2 4.1 2.7 3.5

TSS: 7-day Avg lbs/day 32.4 15.6 4.0 7.2 6.2 12.4 2.8 1.2 3.6 4.6 3.5 6.5 3.8 6.0

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS: 30-day Avg mg/l 45.0 12.9 20 22.4 16.5 16.6 7.1 6.1 7.9 9.3 6.4 11.4 9.6 12.2
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 92 of 145

Intalco 2009 Water Pollutant Discharges

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS: 7-day Avg mg/l 65.0 19.3 25.3 28.9 24.2 23.2 11.1 10.9 10.6 13.7 7.3 14.6 13.9 16.9

Fecal Coli: 30-day Avg

#/100ml

s 200 2.3 2.0 2.8 5.9 2.0 2 2.0 2.0 2.0 2.0 2.4 4.2 2.6

Fecal Coli: 7-day Avg

#/100ml

s 400 4 <2 8.0 23 2 4 2 2 ND (<2) ND (<2) 4 8

pH - Daily Min std units ≥6 6.6 6.8 6.7 6.7 6.7 6.8 6.7 6.7 6.6 6.6 6.6 6.6 6.7

pH - Daily Max std units ≤9 7.3 7.2 7.1 7.1 7.1 7.1 7.0 7.0 7.0 6.9 6.8 7.0 7.1

Flow - MA MGD none 0.060 0.026 0.028 0.030 0.026 0.023 0.013 0.021 0.013 0.038 0.039 0.03 0.029

Flow - DM MGD none 0.097 0.077 0.075 0.043 0.067 0.031 0.016 0.059 0.040 0.07 0.057 0.046 0.057

% BOD Removal -MA % 55%/65%15 86 68.6 93.8 88.4 88.4 89.5 90.9 94.7 91.7 91.1 82.6 86 87.6

% TSS Removal - MA % 55%/65%15 95 80.7 97.4 94.2 89.2 93.0 94.9 95.3 94.2 97.1 94.2 93.7 93.2

# of personnel working onsite Number none 545 535 526 516 515 509 503 500 517 529 530 525 521

Date UV Tubes were cleaned Date 90 days 11/05/08 02/03/09 3/12/2009 4/17/09 5/29/09 6/24/09 6/24/09 8/13/09 8/13/09 10/14/09 10/14/09 12/17/09

UV Tubes Operating 

7 day 

avg

Minimum of 

12 14 14 14 14 14 14 14 14 14 14 14 14 14

Date UV Tubes were replaced Date Annually 01/15/09 01/15/09 01/15/09 01/15/09 01/15/09 01/15/09 07/02/09 7/2/09 7/2/09 7/2/09 7/2/09 7/2/09

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 20 18.9 NS16 14.1 12.2 13.7 NS NS 12.3 22.1 22.3 14.1 NS 16.2

FLUORIDE - DM mg/l 35 23.2 NS 19 17.3 21.0 NS NS 32.8 33.2 26.8 23.8 NS 24.6

ALUMINUM - DM mg/l 8 7.3 NS 5.6 4.4 6.4 NS NS 7.6 8.1 8.1 7.7 NS 6.9

pH - Daily Min std units <6.0 6.5 6.8 6.6 6.4 6.7 6.9 7.1 6.7 6.6 6.4 6.8 6.9 6.7

pH - Daily Max std units >9.0 7.8 7.7 7.5 7.6 7.7 7.6 7.5 7.4 7.3 7.2 7.7 7.7 7.6

Flow - MA MGD none 0.260 0.066 0.372 0.365 0.352 0.054 0.071 0.132 0.127 0.693 1.084 0.336 0.3

Flow - DM MGD none 1.714 0.437 1.360 3.631 2.194 0.437 0.409 2.337 0.679 2.749 4.212 1.503 1.8

Secondary Wastewater 

Treatment Plant UNITS Action Level JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 120 42.4 61.5 89.3 59.7 50.7 65.3 48.6 120 63.2 46.5 50.2 63.3 63.4

FLUORIDE - DM mg/l 50 22.0 22.5 30.3 17.8 19.5 21.5 24.8 19.5 22.0 18.5 19.3 23.0 21.7

ALUMINUM - DM mg/l none 0.2 0.3 0.2 0.1 0.3 10 6.3 0.5 0.2 0.4 0.3 0.1 1.6

FREE CN - DM mg/l none <0.005 0.006 <0.005 0.006 0.006 0.005 0.005 0.006

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

ND 

(<0.005)

PCBs ppb none 10/30/08 <0.1 2/23/2009 2/23/2009

ND 

(<0.08) 5/21/2009 5/21/2009 5/21/2009

ND 

(<0.08) 9/14/2009 9/14/2009

ND 

(<0.08)

Flow - MA MGD none 0.0558 0.065 0.060 0.063 0.065 0.062 0.071 0.056 0.071 0.074 NR 0.078 0.066

Flow - DM MGD none 0.140 0.117 0.134 0.121 0.122 0.118 0.135 0.118 0.118 0.149 NR 0.195 0.133

TSS mg/l none 256.1 37.3 74.5 59.3 1.1 278.6 10.4 12 49.9 2.8 1.7 42.2 68.8

FLUORIDE mg/l none 8.7 8.8 8.0 9.8 2.3 1.2 7.5 6.7 6.5 9.5 6.3 6.7 6.8
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 93 of 145

Intalco 2009 Water Pollutant Discharges

Secondary Wastewater 

Treatment Plant UNITS Action Level JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

ALUMINUM mg/l none 7.0 1.7 3.0 1.4 0.10 3.3 2.2 0.8 0.6 0.9 0.3 0.7 1.8

Outfall 012 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS mg/l none 72.6 33.7 22.4 29.9 3.6 71.7 50.3 18.8 21.9 10.4 26.3 400.5 63.5

FLUORIDE mg/l none 3.8 11.7 3.8 10.3 3.0 1.7 3.1 1.9 4.5 3.7 8.7 5 5.1

ALUMINUM mg/l none 5.4 6.2 4.7 5.1 1.9 2.9 1.2 0.6 2.3 1.2 6.4 4.3 3.5

1 LIMITS for modified NPDES permit issued on June 15, 2008 (effective July 15, 2008).

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the 

number of daily discharges measured during that month.

3 SW allocation Monthly Average limit.

4 DNTA: Did not take stormwater allocation.

5 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations 

expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the 

day. The pH shall not be averaged. 

6 SW allocation Daily Max limit.

7 Tiered limit, applies when monthly aluminum production is less than or equal to 10,305 tons. 

8 Tiered limit, applies when monthly aluminum production is greater than 10,305 and less than or equal to 15,614 tons.

9 Tiered limit, applies when monthly aluminum production is greater than 15,614 tons.

10 ND = Nondetect.

11The monthly average of daily production.

12 Intalco notified Ecology (in a letter dated February 27, 2009) that they had completed the diversion structure to divert all flow from Outfall 002 into Outfall 001.

13 NA = No discharge through outfall 002 because the hydraulic capacity at 001 was not exceeded.

14 NR = After the diversion Intalco is not required to monitor this parameter at Outfall 002.

15 The limit is 55 % if there are <400 people working onsite and the limit is 65% if there are > 400 people working on site.

16 NS = Not sampled because the stormwater pond discharge never exceeded 3.7 cfs over any consecutive 120 minute period.

Intalco 2010 Water Pollutant Discharges

PARAMETERS 

UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG OUTFALL 001

TSS - MA2 lbs/day 150 335.8 57.4 156.3 326.1 14.4 40.2 16.8 214.1 140.5 42.8 168.0 84.6

TSS - Stormwater Allocation 

(SWA)3 lbs/day Calculated3 573.4 DNTA4401.1 263.9 DNTA DNTA DNTA 283.7 DNTA DNTA 507.4 DNTA

TSS - DM5 lbs/day 185 713.4 203.8 597.8 410.1 68.5 146.4 67.0 1053.6 277.5 144.3 393.2 208.8
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 94 of 145

Intalco 2010 Water Pollutant Discharges

OUTFALL 001 UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS -Stormwater Allocation 

(SWA)6 lbs/day Calculated6 4097.5 1816.3 2328.8 291.3 DNTA DNTA DNTA 1616.3 785.0 DNTA 2666.3 1947.5

FLUORIDE - MA lbs/day 587

/688/689 284.9 125.1 140.3 48.7 46.7 63.5 6.3 187.5 174.7 53.1 157.9 109.6

FLUORIDE - SWA3 lbs/day Calculated3 491.4 301.6 319.1 DNTA DNTA DNTA DNTA 201.7 117.8 DNTA 169.6 162.4

FLUORIDE - DM lbs/day 1407

/1988/2969 654.4 267.9 378.1 32.4 149.6 150.6 19.9 809.8 349.2 149.6 342.7 258.6

FLUORIDE - SWA6 lbs/day Calculated6 2906.4 1286.4 1726.3 DNTA DNTA DNTA DNTA 1250.9 696.3 DNTA 1951.5 DNTA

ALUMINUM - MA lbs/day 5.97

/9.08/10.39 77.6 20.9 36.4 13.5 6.3 11.0 0.3 42.7 37.6 8.6 30.5 9.0

ALUMINUM - SWA3 lbs/day Calculated3 130.7 75.4 81.7 42.7 DNTA 47.7 DNTA 48.3 60.1 DNTA 111.9 DNTA

ALUMINUM - DM lbs/day 13.47

/208/309 184.5 55.7 117.7 18.2 27.7 26.0 0.0 213.7 85.0 30.0 64.3 75.7

ALUMINUM - SWA6 lbs/day Calculated6 812.5 346.3 458.8 DNTA DNTA DNTA DNTA 316.3 150.0 115.0 526.3 382.5

FREE CN - MA mg/l <0.012 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

FREE CN - DM mg/l 0.012 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005

B(a)P - MA lbs/day 0.027

/0.038/ 0.0459 0.028 1/25/10 1/25/10 1/25/10 0.008 5/26/10 5/26/10 5/26/10 0.023 9/16/10 9/16/10 0.009

B(a)P - SWA3 lbs/day Calculated3 DNTA 1/25/10 1/25/10 1/25/10 DNTA 5/26/10 5/26/10 5/26/10 DNTA 9/16/10 9/16/10 DNTA

B(a)P - DM4 lbs/day 0.0437

/0.0658/0.0989 0.028 1/25/10 1/25/10 1/25/10 0.008 5/26/10 5/26/10 5/26/10 0.023 9/16/10 9/16/10 0.009

B(a)P - SWA6 lbs/day Calculated6 DNTA 1/25/10 1/25/10 1/25/10 DNTA 5/26/10 5/26/10 5/26/10 DNTA 9/16/10 9/16/10 DNTA

ANTIMONY - MA lbs/day 1.97

/2.9 8/4.39 0.060 1/25/10 1/25/10 1/25/10 0.00 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 0.1

ANTIMONY - DM lbs/day 4.27

/6.48/9.69 0.060 1/25/10 1/25/10 1/25/10 0.00 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 0.1

NICKEL - MA lbs/day 0.87

/1.28/1.99 1.52 1/25/10 1/25/10 1/25/10 3.78 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 1.7

NICKEL - DM lbs/day 1.27

/1.88/2.79 1.52 1/25/10 1/25/10 1/25/10 3.78 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 5/26/10 1.7

C0PPER - DM ug/l none <0.003 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10 1/25/10

O & G - MA mg/l 5 <1.0 <2.5 <0.87 <2.5 <0.87 <2.5 <2.5 <2.5 <2.5 <2.5 <2.5 <0.6

O & G - DM mg/l 10 <1.0 <2.5 <0.87 <2.5 <2.5 <2.5 <2.5 <2.5 <2.5 <2.5 <2.5 <0.6

pH - Daily Min std units ≥6 6.9 7.0 6.9 7.1 6.7 6.8 7.6 7.2 6.8 6.9 6.8 6.5 6.9

pH - Daily Max std units ≤9 8.0 8.7 8 8.0 8.0 8.0 8.1 8.2 8.3 8.2 8.0 8.1 8.1

Temp - MA oF none 47 49 52 54 57 60 65 67 63 58 47 45 55.3

Temp - DM oF none 52 52 56 59 6.805 65 74 74 70 67 59 53 57.3

Flow - MA MGD none 5.238 3.602 4.765 4.325 4.452 4.349 3.030 1.018 1.312 0.889 1.480 2.301 3.1

Flow - DM MGD none 10.125 4.746 7.784 5.198 6.805 6.877 4.343 3.531 4.012 2.789 5.105 8.937 5.9

Al Production10 tons/day none 513.2 526.8 533.4 538.3 550.4 561.1 544.7 540.6 548 547 551 542 541.4

Number of days in the month none 31 28 31 30 31 30 31 31 30 31 30 31 30.4

Al Production - Maximum tons/month none 15909 14750 16535 16149 17062 16833 16886 16759 16440 16957 16530 16802 16467.7

OUTFALL 00211 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

TSS - MA mg/l 35 9.5 12.1 NA12 NA 19.3 NA NA 18.6 10.1 13.1 12.2 21.2 14.5

OUTFALL 00211 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVE

TSS - DM mg/l 75 9.5 12.1 NA NA 19.3 NA NA 18.6 12.3 13.1 12.5 21.2 14.8
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OUTFALL 00211 UNITS LIMITS JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVE

FLUORIDE - MA mg/l 35 16.3 18.7 NA NA 29.5 NA NA 33.2 28.3 27.3 26.7 18.7 24.8

FLUORIDE - DM mg/l 50 16.3 18.7 NA NA 29.5 NA NA 33.2 28.7 27.3 27.7 18.7 25.0

ALUMINUM - MA mg/l 10 4.8 4.8 NA NA 9.6 NA NA 9.9 7.8 6.5 7.4 5.8 7.1

ALUMINUM - DM mg/l 15 4.8 4.8 NA NA 9.6 NA NA 9.9 8.0 6.5 8.0 5.8 7.2

pH - Minimum std units ≥6 6.5 6.8 NA NA 6.7 NA NA 7.0 6.6 6.9 6.9 6.3 6.7

pH - Maximum std units ≤9 7.2 7.3 NA NA 7.7 NA NA 7.8 7.2 7.7 7.4 7.3 7.5

Temp - MA oF none 43 44 NA NA 56 NA NA 65 NR 59.3 51.7 46.3 45.7

Temp - DM oF none 48 50 NA NA 64 NA NA 73 66 60.5 53.7 47.8 57.9

Flow - MA MGD none 1.448 0.8 NA NA 0.540 NA NA NR NR 0.321 0.788 1.818 0.7

Flow - DM MGD none 6.26 2.61 NA NA 3.52 NA NA 2.29 3.80 2.01 3.97 8.18 4.1

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

BOD: 30-day Avg lbs/day 22.4 8.5 6.6 7.2 4.1 1.6 2.0 1.7 0.6 2.1 1.2 0.9 7.1 3.6

BOD: 7-day Avg lbs/day 32.4 16.2 9.7 8.6 5.7 3.1 3.6 2.5 1 3.6 1.5 1.2 8.3 5.4

BOD: 30-day Avg mg/l 45.0 23.5 29.8 28.2 15.3 9.5 9.1 5.1 6.3 5.7 3.9 3.4 11.8 12.6

BOD: 7-day Avg mg/l 65.0 33.0 44.0 32.0 20.0 13.0 13.0 6.1 7.8 10.0 4.8 4.4 14.0 16.8

TSS: 30-day Avg lbs/day 22.4 7 5.3 4.3 3 0.4 1.6 2.2 0.5 8.6 0.5 1.000 3.4 3.2

TSS: 7-day Avg lbs/day 32.4 10.3 9.4 6.6 5.2 0.9 4.1 4.7 1.7 18.6 0.9 2 4.4 5.7

TSS: 30-day Avg mg/l 45.0 20.4 24 16.7 12.6 2.3 6.7 6.3 4.6 20.7 1.5 3.9 6.0 10.5

TSS: 7-day Avg mg/l 65.0 25.3 42.7 24.4 27.9 3.2 9.5 11.4 12.5 52.1 1.9 7.9 8.2 18.9

Fecal Coli: 30-day Avg #/100mls 200 27.6 5.7 2.0 2.6 3.1 5 2.3 2.0 3.9 2.0 5.0 25.4 7.2

Fecal Coli: 7-day Avg #/100mls 400 50 130 <2 4 11 60 4 <2 7 2 80 50

pH - Daily Min std units ≥6 6.52 6.61 6.67 6.7 6.7 6.71 6.67 6.61 6.60 6.91 6.73 6.53 6.7

pH - Daily Max std units ≤9 7.07 6.97 7.00 7.00 7.1 7.0 6.9 7.00 7.82 7.59 7.30 7.36 7.2

Flow - MA MGD none 0.042 0.025 0.031 0.033 0.024 0.027 0.038 0.036 0.183 0.135 0.047 0.065 0.1

Flow - DM MGD none 0.061 0.030 0.051 0.049 0.045 0.0363 0.054 0.065 0.269 0.203 0.17 0.11 0.1

% BOD Removal -MA % 55%/65%13 88.2 85.5 89.8 84.3 87.6 91.6 89.9 88.3 85.0 91.1 98.3 87.9 89.0

% TSS Removal - MA % 55%/65%13 89.9 93.0 93.6 88.9 97 95.3 90.9 92.5 78.5 96.9 99.1 93.7 92.4

# of personnel working 

onsite Number 

none 526 521 521 520 530 529 520 526 522 522 526 526 524.1

Date UV Tubes were cleaned Date once every 90 days 01/07/10 02/08/10 03/15/10 04/20/10 05/26/10 06/23/10 07/22/10 08/24/10 09/26/10 10/25/10 10/28/10 12/16/10

UV Tubes Operating 7 day avg Minimum of 12 14 14 14 14 14 14 14 14 14 14 14 14 14

Date UV Tubes were 

replaced Date Annually07/02/09 02/11/10 02/11/10 02/11/10 02/11/10 02/11/10 07/01/10 07/01/10 07/01/10 07/01/10 07/01/10 12/29/10

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

TSS - DM mg/l 20 15.9 17.9 19.0 14.8 23.6 15.9 NS14 28.5 35.6 20.3 15.4 32.4 21.8

FLUORIDE - DM mg/l 35 19 21.2 22.2 21.3 25.8 25.2 NS 35.0 30.5 26.7 27.8 18.5 24.8
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Intalco 2010 Water Pollutant Discharges

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

ALUMINUM - DM mg/l 8 6.8 5.1 6.2 5.1 8.3 7.1 NS 12.7 10.6 7.3 8.1 7.8 7.7

pH - Daily Min std units <6.0 6.8 6.9 7.0 7 6.8 6.8 6.9 6.9 6.6 6.7 6.8 6.5 6.8

pH - Daily Max std units >9.0 7.4 7.4 7.5 7.5 7.4 7.3 7.6 7.6 7.1 7.3 7.6 7.5 7.4

Flow - MA MGD none 0.772 0.461 0.499 0.253 0.348 0.302 0.059 0.141 0.542 0.224 0.435 0.820 0.4

Flow - DM MGD none 3.160 1.547 1.845 0.654 1.979 1.432 0.065 1.984 2.391 1.722 2.750 4.322 2.0

Secondary Wastewater 

Treatment Plant UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

TSS - DM mg/l 120 83.2 42.4 104.5 91.2 44.8 17.4 38.6 28.1 33.2 21.7 75.0 40 51.7

FLUORIDE - DM mg/l 50 30.8 22.5 21.5 23.3 24.8 20.5 24.8 23.3 20.0 19.0 22.3 23.5 23.0

ALUMINUM - DM mg/l none 0.2 0.1 0.1 0.6 0.3 0.2 0.2 0.4 0.1 0.2 0.3 1.9 0.4

FREE CN - DM mg/l none <0.005 <0.005 0.006 0.005 <0.005 <0.005 0.007 <0.005 0.006 <0.005 0.006 <0.005

PCBs ppb none <0.1 1/25/10 1/25/10 1/25/10 1/25/10 5/26/10 5/26/10 5/26/10 <1 9/16/10 9/16/10 <3.36

Flow - MA MGD none 0.084 0.060 0.086 0.060 0.073 0.081 0.069 0.066 0.066 0.061 0.061 0.071 0.1

Flow - DM MGD none 0.190 0.184 0.199 0.202 0.209 0.230 0.215 0.19 0.173 0.172 0.159 0.201 0.2

Outfall 011 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

TSS - Monthly grab when 

there is flow mg/l none 68.3 13.5 56.3 16.1 82.2 4.1 0.6 48.5 43.3 9.7 4.6 125.3 39.4

FLUORIDE - Monthly grab 

when there is flow mg/l none 8.0 6.0 5.2 8.2 8.7 7.3 2.2 6.8 8.5 8.0 7.1 7.0 6.9

ALUMINUM - Monthly 

grab when there is flow mg/l none 3.0 0.7 1.5 1.5 2.0 0.8 0.1 5.6 1.2 2.1 1.2 12.0 2.6

Outfall 012 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC AVG

TSS - Monthly grab when 

there is flow mg/l none 11.3 5.6 49.9 11 31.0 12.2 IF15 145.1 8.6 4.3 1.6 111.7 35.6

FLUORIDE - Monthly grab 

when there is flow mg/l none 3.0 4.5 1.5 2.2 2.3 3.8 IF 2.4 3.3 10.4 7.0 3.6 4.0

ALUMINUM - Monthly 

grab when there is flow mg/l none 2.5 6.2 4.3 1.5 2.1 1.9 IF 2.9 0.8 5.8 2.9 12.0 3.9

1 LIMITS for modified NPDES permit issued on June 15, 2008 (effective July 15, 2008).

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by 

the number of daily discharges measured during that month.

3 SW allocation Monthly Average limit.

4 DNTA: Did not take stormwater allocation.

5 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations 

expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the 

day. The pH shall not be averaged. 

6 SW allocation Daily Max limit.
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Page 97 of 145

Intalco 2010 Water Pollutant Discharges

7 Tiered limit, applies when monthly aluminum production is less than or equal to 10,305 tons. 

8 Tiered limit, applies when monthly aluminum production is greater than 10,305 and less than or equal to 15,614 tons.

9 Tiered limit, applies when monthly aluminum production is greater than 15,614 tons.

10The monthly average of daily production.

11 Intalco notified Ecology (in a letter dated February 27, 2009) that they had completed the diversion structure to divert all flow from Outfall 002 into Outfall 001.

12 NA = No discharge through outfall 002 because the hydraulic capacity at 001 was not exceeded.

13 The limit is 55 % if there are <400 people working onsite and the limit is 65% if there are > 400 people working on site.

14 NS = Not sampled because the stormwater pond discharge never exceeded 3.7 cfs over any consecutive 120 minute period.

15 IF = Insufficient flow to collect a representative sample.

Intalco 2011 Water Pollutant Discharges

PARAMETERS 

UNITS LIMITS1 JAN FEB MAR APR MAY JUNE JULY AUG SEPT OCT NOV DEC AVG

OUTFALL 001

TSS - MA2 lbs/day 150 158.5 50.1 51.1 259.4 113.3 9.1 0.0 28.0 15.8 99.1 70.8 37.8

TSS - Stormwater Allocation 

(SWA)3 lbs/day Calculated3 784.2 DNTA4309.4 777.8 DNTA DNTA DNTA DNTA DNTA DNTA DNTA DNTA

TSS - DM5 lbs/day 185 634.2 165.8 148.1 762 386.9 32.2 0.0 140.2 63.0 337.4 105.7 79.2

TSS -Stormwater Allocation 

(SWA)6 lbs/day Calculated6 4847.5 DNTA DNTA 4272.5 1491.3 DNTA DNTA DNTA DNTA 497.5 DNTA DNTA

FLUORIDE - MA lbs/day 587

/688/689 180.5 94.3 83.1 235.8 101.7 42.2 32.1 66.8 26.7 93.4 97.6 50.3

FLUORIDE - SWA3 lbs/day Calculated3 248.3 125.8 113.3 246.5 125.1 DNTA DNTA DNTA DNTA 118.8 161.4 DNTA

FLUORIDE - DM lbs/day 1407

/1988/2969 562.7 143.7 180.8 617.8 195.7 44.8 7.8 115.2 62.9 261.5 141.6 89.7

FLUORIDE - SWA6 lbs/day Calculated6 3406.8 DNTA DNTA 3023.2 DNTA DNTA DNTA DNTA DNTA DNTA DNTA DNTA

ALUMINUM - MA lbs/day 5.97

/9.08/10.39 42.8 11.5 14.4 77.4 26.2 1.1 0.3 4.2 1.5 14.9 19.3 8.0

ALUMINUM - SWA3 lbs/day Calculated3 190.6 66.8 55.6 188.8 67.4 DNTA DNTA DNTA DNTA 24.7 36.9 29.4

ALUMINUM - DM lbs/day 13.47

/208/309 162.6 31.0 49.4 206.5 94.5 4.7 0.0 8.7 5.2 62.1 33.6 19.9

ALUMINUM - SWA6 lbs/day Calculated6 962.5 161.3 167.5 847.5 291.3 DNTA DNTA DNTA DNTA 92.5 87.5 DNTA

FREE CN - MA2 mg/l <0.012 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 0.001 0.0 <0.005 <0.00 <0.0024

FREE CN - DM3 mg/l 0.012 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 0.004 0.005 <0.0024 <0.005 <0.0024

B(a)P - MA lbs/day 0.027

/0.038/ 0.0459 12/15/10 12/15/10 0.002 3/15/11 0.009 0.002 5/18/11 5/18/11 0.007 0.015 10/3/11 10/3/11

B(a)P - SWA3 lbs/day Calculated3 12/15/10 12/15/10 DNTA 3/15/11 DNTA DNTA 5/18/11 5/18/11 DNTA DNTA 10/3/11 10/3/11
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Intalco Aluminum Corporation

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Intalco 2011 Water Pollutant Discharges

OUTFALL 001 UNITS LIMITS1JAN FEB MAR APR MAY JUN JULY AUG SEPT OCT NOV DEC AVG

B(a)P - DM4 lbs/day

0.0437/0.0658/0.098

9 12/15/10 12/15/10 0.002 3/15/11 0.009 0.002 5/18/11 5/18/11 0.007 0.015 10/3/11 10/3/11

B(a)P - SWA6 lbs/day Calculated6 12/15/10 12/15/10 DNTA 3/15/11 DNTA DNTA 5/18/11 5/18/11 DNTA DNTA 10/3/11 10/3/11

ANTIMONY - MA lbs/day 1.97

/2.9 8/4.39 0.010 1/10/11 1/10/11 1/10/11 0.017 0.04 0.03 7/18/11 7/18/11 0.02 10/3/11 10/3/11

ANTIMONY - DM lbs/day 4.27

/6.48/9.69

0.010 1/10/11 1/10/11 1/10/11 0.017 0.04 0.03 7/18/11 7/18/11 0.02 10/3/11 10/3/11

NICKEL - MA lbs/day 0.87

/1.28/1.99 0.38 1/10/11 1/10/11 1/10/11 0.4268 0.77 0.71 7/18/11 7/18/11 0.30 10/3/11 10/3/11

NICKEL - DM lbs/day 1.27

/1.88/2.79 0.38 1/10/11 1/10/11 1/10/11 0.4268 0.77 0.71 7/18/11 7/18/11 0.30 10/3/11 10/3/11

C0PPER - DM3 ug/l none 0.00 1/10/11 1/10/11 1/10/11 1/10/11 4.5 6/22/11 6/22/11 6/22/11 3 10/3/11 10/3/11

O & G - MA2 mg/l 5 <0.6 <1.4 <2.9 3.1 2.2 <1.4 <1.4 <1.4 <1.40 <1.4 <1.0 3.3

O & G - DM3 mg/l 10 <1.4 <1.4 <2.9 3.1 4.4 <1.4 <1.4 <1.4 <1.40 <1.4 <1.0 3.3

pH - Daily Min std units ≥6 6.6 6.6 7.0 7.1 6.9 7.5 7.1 7.2 7.1 7.04 6.8 7.0 7.0

pH - Daily Max std units ≤9 8.2 8.3 8.2 8.2 8.2 8.2 8.2 8.2 8.3 8.1 8.0 7.8 8.2

Temp - MA oF none 42 43 47 51 56 60 62 66 64 56 48 43 53.2

Temp - DM oF none 49 49 56 64 62 68 73 72 76 64 57 51 61.8

Flow - MA MGD none 3.405 1.688 1.779 2.024 1.675 0.906 1.045 1.008 1.047 1.071 1.483 1.133 1.5

Flow - DM MGD none 8.604 5.486 8.633 8.370 5.698 1.648 3.094 1.273 2.431 2.001 4.938 3.483 4.6

Al Production10 tons/day none 536 557 640.0 650 668 662 662 662 671 655 650 637 637.5

Number of days in the month none 31 28 31 30 31 30 31 31 30 31 30 31 30.4

Al Production - Maximum

tons/mont

h none 16616 15596 19840 19500 20708 19860 20522 20522 20130 20305 19500 19747

19403.

8

OUTFALL 00211 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - MA mg/l 35 11.8 12.9 16.7 15.8 NA12 NA 17 NA NA NA 34.3 NA 18.1

TSS - DM mg/l 75 15.7 12.9 17.4 15.8 NA NA 17 NA NA NA 34.3 NA 18.9

FLUORIDE - MA mg/l 35 16.4 16 19.4 16.7 NA NA 29.7 NA NA NA 29.7 NA 21.3

FLUORIDE - DM mg/l 50 25.5 16 22.3 16.7 NA NA 29.7 NA NA NA 29.7 NA 23.3

ALUMINUM - MA mg/l 10 4.3 3.5 5.8 3.6 NA NA 6.8 NA NA NA 12.9 NA 6.2

ALUMINUM - DM mg/l 15 6.0 3.5 5.9 3.6 NA NA 6.8 NA NA NA 12.9 NA 6.5

pH - Minimum std units ≥6 6.5 6.2 6.8 6.8 NA NA 6.5 NA NA NA 6.4 NA 6.5

pH - Maximum std units ≤9 7.2 7.4 7.4 7.3 NA NA 7.4 NA NA NA 7.2 NA 7.3

Temp - MA oF none 47.8 43.3 49.8 52.1 NA NA 69.2 NA NA NA 42.5 NA 50.8

Temp - DM oF none 46.5 45.1 53.9 99 NA NA 70.8 NA NA NA 47.9 NA 60.5

Flow - MA MGD none 2.700 1.004 0.936 1.091 NA NA 0.23 NA NA NA 0.670 NA 1.1

Flow - DM MGD none 8.06 4.13 7.72 6.54 NA NA 1.97 NA NA NA 4.55 NA 5.5

BOD - MA lbs/day 22.4 8.3 8.6 8.3 9.2 6.3 3.2 2.1 1.2 1 1.8 2.0 4.0 4.7
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Intalco Aluminum Corporation

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Saintary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

BOD - DM lbs/day 32.4 16.8 12.8 15.1 12.6 10.8 9.0 3.2 1.8 1.9 2.2 3.0 8.6 8.2

BOD - MA mg/l 45.0 12.2 16 18.4 19.5 13.8 12.1 9.6 5.3 6.1 5.7 11.1 11.8

BOD - DM mg/l 65.0 22.0 20.0 24.0 29.0 26 18 12.0 7.2 7.6 8.3 8.4 15.0 16.5

TSS - MA lbs/day 22.4 7.3 6.8 6.9 8.2 7.9 1.7 2.3 2.1 0.7 2.4 1.5 2.5 4.2

TSS - DM lbs/day 32.4 13.7 8.6 14.3 15.7 22.6 4 3.7 5.2 0.9 3.3 3.0 5.2 8.4

TSS - MA mg/l 45.0 10.9 13.1 15.1 17.9 18.0 9.6 10.3 10.9 4 7.9 3.7 9.7 10.9

TSS - DM mg/l 65.0 17.9 15.5 22.7 36.2 54.5 20.9 13.4 27.9 6.2 12.3 6.5 19.6 21.1

Fecal Coli. - MA #/100mls 200 36.2 21.0 4.3 4.0 24.1 11.5 2.0 2.0 2.0 2.0 2.0 2.0 9.4

Fecal Coli. - DM #/100mls 400 300 110 22 8 240 240 <2 <2 <2 <2 <2 <2

pH - Minimum std units ≥6 6.68 6.68 6.54 6.58 6.54 6.16 6.10 6.32 6.14 6.25 6.22 6.27 6.4

pH - Maximum std units ≤9 7.44 7.26 7.47 7.36 7.3 7.0 6.91 6.93 7.00 6.76 6.50 7.10 7.1

Flow - MA MGD none 0.069 0.056 0.050 0.055 0.053 0.027 0.029 0.025 0.022 0.034 0.037 0.037 0.0

Flow - DM MGD none 0.09 0.090 0.08 0.07 0.070 0.06 0.08 0.050 0.03 0.04 0.08 0.08 0.1

% BOD Removal -MA % 55%/65%13 82.7 79.8 89.1 79.8 81.1 82.8 85.6 90.9 88.3 88.4 89.6 80.8 84.9

% TSS Removal - MA % 55%/65%13 87.1 78.4 91.7 87.3 83.7 81.0 86.0 87.8 93.1 89.1 95.5 85.0 87.1

Personnel Onsite

# of 

personnel >400 572 582 604 616 604 608 611 620 614 614 597 603 603.8

Date UV Tubes were cleaned Date once/90 days 01/17/11 02/09/11 03/03/11 04/20/11 05/03/11 06/21/11 06/21/11 06/21/11 09/06/11 10/05/11 06/21/11 12/13/11

UV Tubes Operating Number 12.0 14 14 14 14 14 14 14 14 14 14 14 14 14.0

Date UV Tubes were replaced Date Annually 12/29/10 12/29/10 12/29/10 12/29/10 12/29/10 06/21/11 06/21/11 06/21/11 06/21/11 06/21/11 06/21/11 06/21/11

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 20 21.1 22.6 22.8 16.9 24.4 NS14 39.0 NS NS 14.1 51.0 5 28.4

FLUORIDE - DM mg/l 35 17.3 19.3 19.5 17.9 29.0 NS 35.0 NS NS 38.3 40.8 28.2 31.1

ALUMINUM - DM mg/l 8 7.1 5.9 7.8 5.7 8.9 NS 11.4 NS NS 9.2 17 8.8 10.4

pH - Daily Min std units <6.0 6.6 6.8 6.8 6.7 6.8 6.8 6.8 6.9 6.6 6.7 6.4 6.6 6.7

pH - Daily Max std units >9.0 7.5 7.6 7.4 7.4 7.2 7.5 7.4 7.3 7.0 7.3 7.3 7.2 7.3

Flow - MA MGD none 0.949 0.332 0.45 0.536 0.476 0.106 0.158 0.103 0.071 0.186 0.401 0.223 0.3

Flow - DM MGD none 2.808 1.399 3.631 3.079 2.414 0.585 1.524 0.322 0.072 0.965 2.964 1.431 1.8

Secondary Wastewater 

Treatment Plant UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 120 70.4 37.8 66.0 42.1 129.0 96.2 64.8 137.9 131.4 86.4 58.0 59.2 81.6

FLUORIDE - DM mg/l 50 23.0 28.5 26.8 24.5 27.5 30.3 23 29.0 24.3 23.3 25.0 27.5 26.1

ALUMINUM - DM mg/l none 0.8 0.8 14.0 5.8 0.2 0.2 0.2 0.1 0.1 0.0 0.1 0.2 1.9

FREE CN - DM mg/l none <0.005 0.005 0.007 <0.005 <0.005 <0.005 <0.005 <0.005 0.007 0.006 0.007 0.013

PCBs ppb none 12/15/10 12/15/10 1/5/11 1/5/11 <0.7 5/18/11 5/18/11 5/18/11 <0.1 9/8/11 <0.1 11/2/11

Flow - MA MGD none 0.081 0.079 0.062 0.062 0.075 0.076 0.057 0.061 0.079 0.070 0.055 0.059 0.1
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 100 of 145

Intalco 2011 Water Pollutant Discharges

Secondary Wastewater 

Treatment Plant UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

Flow - DM MGD none 0.208 0.177 0.225 0.188 0.199 0.193 0.174 0.184 0.200 0.203 0.174 0.137 0.2

Outfall 011 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - Monthly grab when 

there is flow mg/l none 5.7 49.0 1157.4 100.7 424.7 169.6 15.7 19.6 27.0 251.3 101.5 230.5 212.7

FLUORIDE - Monthly grab 

when there is flow mg/l none 5.9 6.8 13.9 9.3 6.4 6.2 6.4 9.7 6.7 10.0 7.8 12.6 8.5

ALUMINUM - Monthly grab 

when there is flow mg/l none 0.7 0.9 65.0 6.1 14.0 1.5 1.3 2 0.9 25.7 10.0 28.3 13.0

Outfall 012 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - Monthly grab when 

there is flow mg/l none 32.1 79.7 468.2 32 57.0 169.6 227.5 18.6 6.4 55.6 24.2 29.7 100.1

FLUORIDE - Monthly grab 

when there is flow mg/l none 10.7 5.2 11.7 8.3 2.5 6.2 2.4 11.7 2.3 3.2 1.1 5.1 5.9

ALUMINUM - Monthly grab 

when there is flow mg/l none 4.9 7.5 43.0 8.1 3.8 1.5 2.7 6.2 1.5 12.2 6.7 1.8 8.3

1 LIMITS for modified NPDES permit issued on June 15, 2008 (effective July 15, 2008).

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the 

number of daily discharges measured during that month.

3 SW allocation Monthly Average limit.

4 DNTA: Did not take stormwater allocation because they were in compliance with the respective permit limit.

5 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations 

expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the 

day. The pH shall not be averaged. 

6 SW allocation Daily Max limit.

7 Tiered limit, applies when monthly aluminum production is less than or equal to 10,305 tons. 

8 Tiered limit, applies when monthly aluminum production is greater than 10,305 and less than or equal to 15,614 tons.

9 Tiered limit, applies when monthly aluminum production is greater than 15,614 tons.

10The monthly average of daily production.

11 Intalco notified Ecology (in a letter dated February 27, 2009) that they had completed the diversion structure to divert all flow from Outfall 002 into Outfall 001.

12 NA = No discharge through outfall 002 because the hydraulic capacity at 001 was not exceeded.

13 The limit is 55 % if there are <400 people working onsite and the limit is 65% if there are > 400 people working on site.

14 NS = Not sampled because the stormwater pond discharge never exceeded 3.7 cfs over any consecutive 120 minute period.
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 101 of 145

Intalco 2012 Water Pollutant Discharges

PARAMETERS 

UNITS LIMITS1 JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

OUTFALL 001

TSS - MA2 lbs/day 150 107.5 82.6 86.2 68.1 109.3 40.5 31.9 52.2 29.2 189.3 140.9 116.6

TSS - Stormwater Allocation (SWA)3 lbs/day Calculated3 DNTA4 DNTA DNTA DNTA DNTA DNTA DNTA DNTA DNTA 429.2 DNTA DNTA

TSS - DM5 lbs/day 185 278 156.0 134.5 136.5 219.5 81.3 87.4 182.6 84.8 464.6 477.6 226.5

TSS -Stormwater Allocation (SWA)6 lbs/day Calculated6 803.8 DNTA DNTA DNTA 728.8 DNTA DNTA DNTA DNTA 1853.8 1647.5 3197.5

FLUORIDE - MA lbs/day 587

/688/689 112.4 187.2 210.5 134.5 107.5 58.8 78.7 33.1 78.1 319.4 249 225.6

FLUORIDE - SWA3 lbs/day Calculated3 241.4 368.8 544 257.2 131.5 DNTA 113.6 DNTA 90.6 347.2 452 686.3

FLUORIDE - DM lbs/day 1407

/1988/2969 151.5 428.3 519.1 205.3 249.1 90.1 177.4 87.2 154.0 665.4 427.2 350

FLUORIDE - SWA6 lbs/day Calculated6 DNTA 1342.7 2122.5 DNTA DNTA DNTA DNTA DNTA DNTA 1409.4 1271.8 2305.9

ALUMINUM - MA lbs/day 5.97

/9.08/10.39 20.4 41.6 42.8 17.8 14.8 3.600 9.3 2.3 2.4 77.4 60.2 55.5

ALUMINUM - SWA3 lbs/day Calculated3 59.6 95.8 145.6 64.1 28.4 10.3 DNTA DNTA DNTA 89.6 119.4 186.1

ALUMINUM - DM lbs/day 13.47

/208/309 36.6 124.8 121.8 39.9 55.4 7.4 37.3 4.3 7.0 176.8 123.1 109.2

ALUMINUM - SWA6 lbs/day Calculated6 153.8 343.8 577.5 168.8 138.8 DNTA 90.0 DNTA DNTA 363.8 322.5 632.5

FREE CN - MA2 mg/l <0.012 0.001 0.0

ND10 

<0.0024 0.001

ND 

<0.0024

ND 

<0.0024

ND 

<0.0024

ND 

<0.0024

ND 

<0.0024 0.0

ND 

<0.0024

ND 

(<0.0024)

FREE CN - DM3 mg/l 0.012 0.006 0.005

ND 

<0.0024 0.005

ND 

<0.0024

ND 

<0.0024

ND 

<0.0024

ND 

<0.0024

ND 

<0.0024 0.01

ND 

<0.0024

ND 

(<0.005)

B(a)P - MA lbs/day

0.027/0.038/ 

0.0459 0.003 01/09/12 0.008 0.012 04/24/12 04/24/12 04/24/12 0.006 08/06/12 0.019 10/15/12 10/15/12

B(a)P - SWA3 lbs/day Calculated3 DNTA 01/09/12 DNTA DNTA 04/24/12 04/24/12 04/24/12 DNTA 08/06/12 0.048 10/15/12 10/15/12

B(a)P - DM4 lbs/day

0.0437/0.0658/0

.0989 0.003 01/09/12 0.008 0.024 04/24/12 04/24/12 04/24/12 0.006 08/06/12 0.019 10/15/12 10/15/12

B(a)P - SWA6 lbs/day Calculated6 DNTA 01/09/12 DNTA DNTA 04/24/12 04/24/12 04/24/12 DNTA 08/06/12 DNTA 10/15/12 10/15/12

ANTIMONY - MA lbs/day 1.97

/2.9 8/4.39 0.020 01/09/12 0.00 0.00 04/24/12 04/24/12

ND 

(<0.004) 07/30/12 07/30/12 07/30/12 07/30/12 07/30/12

ANTIMONY - DM lbs/day 4.27

/6.48/9.69

0.020 01/09/12 4.30 0.00 04/24/12 04/24/12

ND 

(<0.001) 07/30/12 07/30/12 07/30/12 07/30/12 07/30/12

NICKEL - MA lbs/day 0.87

/1.28/1.99 0.62 01/09/12 0.00 0.43 04/24/12 04/24/12 0.00 07/30/12 07/30/12 07/30/12 07/30/12 07/30/12

NICKEL - DM lbs/day 1.27

/1.88/2.79 0.62 01/09/12 9.60 0.43 04/24/12 04/24/12 0.00 07/30/12 07/30/12 07/30/12 07/30/12 07/30/12

C0PPER - DM3 ug/l none 10/3/11

ND 

(<0.003) 3 03/12/12 03/12/12 03/12/12 03/12/12 03/12/12 03/12/12 03/12/12 03/12/12 03/12/12

O & G - MA2 mg/l 5 <1.0

ND 

(<1.4) ND (<1.0)

ND 

(<1.0)

ND 

(<1.0)

ND 

(<1.0)

ND 

(<1.0) 3.1

ND 

(<1.4)

ND 

(<1.4)

ND 

(<1.4) ND (<1.4)
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 102 of 145

Intalco 2012 Water Pollutant Discharges

OUTFALL 001 UNITS LIMITS1 JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

O & G - DM3 mg/l 10 <1.0

ND 

(<1.4) ND (<1.0)

ND 

(<1.0)

ND 

(<1.0)

ND 

(<1.0)

ND 

(<1.0) 3.1

ND 

(<1.4)

ND 

(<1.4)

ND 

(<1.4) ND (<1.4)

pH - Daily Min std units ≥6 6.8 6.8 6.9 6.8 7.2 7.1 6.9 7.5 7.5 6.8 6.9 6.7 7.0

pH - Daily Max std units ≤9 7.8 7.8 7.9 7.9 8.2 8.1 8.1 8.2 8.5 8.5 8.2 8.0 8.1

Temp - MA oF none 41 44 45 52 57 59 63 66 62 55 50 43 53.1

Temp - DM oF none 50 52 52 59 63 66 71 73 69 66 57 50 60.7

Flow - MA MGD none 1.880 2.294 2.506 1.810 1.145 1.282 1.140 1.017 1.123 2.099 1.623 3.153 1.8

Flow - DM MGD none 4.406 7.367 6.102 4.737 2.180 3.092 3.988 1.245 1.389 7.069 4.388 7.218 4.4

Al Production11 tons/day none 641 663 665 666 665 669 673 651 674 676 688 687 668.2

Number of days in the month none 31 29 31 30 31 30 31 31 30 31 30 31 30.5

Al Production - Maximum

tons/mont

h none 19871 19227 20615 19980 20615 20070 20863 20181 20220 20956 20640 21297

20377

.9

OUTFALL 00212 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - MA mg/l 35 NA13 8.6 8.6 27.6 NA NA 15.7 NA NA 10.7 16.7 4.2 13.2

TSS - DM mg/l 75 NA 11.8 10.1 27.6 NA NA 15.7 NA NA 11.5 41.2 4.7 17.5

FLUORIDE - MA mg/l 35 NA 18.4 16.6 20.5 NA NA 27 NA NA 29.5 20.4 17.3 21.4

FLUORIDE - DM mg/l 50 NA 19.7 17.7 20.5 NA NA 27 NA NA 32.8 26.5 19.2 23.3

ALUMINUM - MA mg/l 10 NA 4.4 4.0 6.5 NA NA 7.2 NA NA 8.2 6.2 4.9 5.9

ALUMINUM - DM mg/l 15 NA 4.4 4.0 6.5 NA NA 7.2 NA NA 8.4 8.9 5.3 6.4

pH - Daily Min std units ≥6 NA 6.6 6.1 6.6 NA NA 6.9 NA NA 6.4 6.6 6.5 6.5

pH - Daily Max std units ≤9 NA 7.2 7.2 7.2 NA NA 7.3 NA NA 7.6 7.1 7.2 7.3

Temp - MA oF none NA 41.5 43.2 53.3 NA NA 65.4 NA NA 46.1 45.9 41.6 48.1

Temp - DM oF none NA 47.2 49.3 58.5 NA NA 71.5 NA NA 58.9 53.6 46.9 55.1

Flow - MA MGD none NA 1.194 1.411 0.781 NA NA 0.245 NA NA 1.080 0.994 2.150 1.1

Flow - DM MGD none NA 5.33 4.38 3.76 NA NA 2.39 NA NA 7.47 3.52 7.85 5.0

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

BOD - MA lbs/day 22.4 11.8 13.9 11.0 6.8 4.4 7.7 2.6 1.5 1 1.4 6.1 5.3 6.1

BOD - DM lbs/day 32.4 17.5 18.1 11.9 7.7 8.6 10.7 3.4 1.7 1.5 1.8 9.8 10.4 8.6

BOD - MA mg/l 45.0 21.4 26.2 21.0 13.8 11.8 18.5 11.2 5.2 3.4 5.7 15 9.1 13.5

BOD - DM mg/l 65.0 25.0 30 24.0 14.0 19.0 27 14.0 5.9 4.9 7.8 29 15.0 18.0

TSS - MA lbs/day 22.4 3.9 10.8 14.0 5.0 1.4 0.8 0.9 0.5 0.5 0.5 6.8 1.4 3.9

TSS - DM lbs/day 32.4 7.6 15.6 19.5 5.5 2.7 1.3 1.4 0.7 1.3 0.7 27.5 3.0 7.2

TSS - MA mg/l 45.0 6.6 22.1 26.7 10.2 5.4 2.1 3.7 1.6 1.5 1.9 19.3 2.6 8.6

TSS - DM mg/l 65.0 13.9 38.8 40.3 12.0 8.0 3.2 6.6 2.1 4 3 41.9 4.7 14.9

Fecal Coli. - MA #/100mls 200 79.3 5.8 2.0 ND (<2) 2.0 3.0 2.0 2.0 2.0 5.0 2.0 2.0
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 103 of 145

Intalco 2012 Water Pollutant Discharges

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

Fecal Coli. - DM #/100mls 400 300 17.0 2.0 ND (<2) ND (<2) 8 2.0 2.0 ND (<2) 80.0 ND (<2) ND (<2)

pH - Daily Min std units ≥6 6.27 6.45 6.46 6.55 6.69 6.98 6.91 6.7 6.80 6.50 6.48 6.36 6.6

pH - Daily Max std units ≤9 7.04 6.88 7.07 7.02 7.2 7.3 7.11 7.02 7.33 7.01 6.81 7.10 7.1

Flow - MA MGD none 0.063 0.061 0.066 0.056 0.034 0.055 0.025 0.034 0.035 0.04 0.061 0.07 0.050

Flow - DM MGD none 0.09 0.080 0.08 0.07 0.070 0.06 0.05 0.040 0.04 0.12 0.12 0.09 0.1

% BOD Removal -MA % 55%/65%14 90.8 93.8 93.4 92.7 93.4 96.5 98.6 98.9 98.1 97.0 96.3 98.4 95.7

% TSS Removal - MA % 55%/65%14 94.5 97.2 98.0 97.0 98.7 99.7 99.9 99.6 99.7 99.2 96.0 99.1 98.2

Personnel Onsite

# of 

personnel >400 597 590 595 614 603 609 584 599 608 622 622 620 605.3

Date UV Tubes were cleaned Date once/90 days 01/12/12 02/18/12 02/22/12 04/18/12 04/18/12 06/14/12 07/10/12 08/18/12 08/18/12 10/20/12 10/20/12 02/12/12

UV Tubes Operating Number 12.0 14 14 14 14 14 14 14 14 14 14 14 14 14.0

Date UV Tubes were replaced Date Annually 01/12/12 01/12/12 01/12/12 01/12/12 01/12/12 06/14/12 06/14/12 06/14/12 06/14/12 06/14/12 06/14/12 12/28/12

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 20 6.6 28.7 29.6 6.2 NS15 32.8 14.1 NS NS 33.6 20.4 21.3 21.5

FLUORIDE - DM mg/l 35 21.3 21.7 19 20.0 NS 31.8 26.3 NS NS 39.5 23.5 22.7 25.1

ALUMINUM - DM mg/l 8 6.8 6.0 7 5.2 NS 10.0 7.3 NS NS 12.6 10 8.4 8.1

pH - Daily Min std units <6.0 6.7 6.8 6.8 6.6 6.9 6.7 6.8 7.2 6.8 6.3 6.7 6.7 6.8

pH - Daily Max std units >9.0 7.3 7.4 7.3 7.4 7.5 7.3 7.3 7.5 7.7 7.8 7.3 7.3 7.4

Flow - MA MGD none 0.443 0.586 0.67 0.407 0.164 0.262 0.176 0.07 0.109 0.767 0.657 1.114 0.5

Flow - DM MGD none 1.573 2.437 2.097 2.191 0.769 1.628 1.832 0.089 0.332 4.575 3.905 3.66 2.1

Secondary Wastewater Treatment 

Plant UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - DM mg/l 120 198.9 205.8 57.2 262.7 172.0 71.6 70.8 232.8 144.3 119.9 48.7 57.5 136.9

FLUORIDE - DM mg/l 50 27.5 27.3 23.5 44.5 26.3 24.0 28.5 40.3 37.8 34.5 43.3 34.8 32.7

ALUMINUM - DM mg/l none 1.5 0.2 0.1 0.7 0.1 0.2 0.1 0.1 0.1 0.1 0.2 0.1 0.3

FREE CN - DM mg/l none 0.009 0.007 0.007 0.006 0.007 0.006 0.009 0.01 0.010 0.008 0.006 0.009 0.0

PCBs ppb none <0.05 01/09/12 01/09/12

ND 

(<0.05) 04/25/12 04/25/12

ND 

(<0.05) 07/24/12 07/24/12 07/24/12 07/24/12 ND (<0.1)

Flow - MA MGD none 0.049 0.053 0.056 0.066 0.044 0.06 0.055 0.037 0.035 0.056 0.055 0.041 0.1

Flow - DM MGD none 0.159 0.276 0.207 0.211 0.188 0.211 0.248 0.225 0.223 0.258 0.204 0.258 0.2

Outfall 011 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC AVG

TSS - Monthly grab when there is flow mg/l none 26 201.3 630.2 IF16 17.3 25.6 306.9 IF IF 142.9 694.9 41.7 231.9

FLUORIDE - Monthly grab when there 

is flow mg/l none 13.8 15.0 6.5 IF 8.3 11 7.4 IF IF 11.3 5.9 8.3 9.7

ALUMINUM - Monthly grab when 

there is flow mg/l none 5.8 26.8 45.8 IF 2.6 3.4 16.8 IF IF 14.0 35.2 6.8 17.5
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 104 of 145

Intalco 2012 Water Pollutant Discharges

Outfall 012 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC 

AVG

TSS - Monthly grab when there is flow mg/l none 4.4 46.8 154.5 IF 12.5 32.7 141.5 IF IF 23.0 95.2 31.3 60.2

FLUORIDE - Monthly grab when there 

is flow mg/l none 5.1 8.6 2.1 IF 2.2 2.1 1.9 IF IF 4.6 3.5 8.0 4.2

ALUMINUM - Monthly grab when 

there is flow mg/l none 1.9 10.6 13.8 IF 2.6 6.1 10.5 IF IF 3.3 6.5 5.0 6.7

1 LIMITS for modified NPDES permit issued on June 15, 2008 (effective July 15, 2008).

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the 

number of daily discharges measured during that month.

3 SW allocation Monthly Average limit.

4 DNTA: Did not take stormwater allocation because they were in compliance with the respective permit limit.

5 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations 

expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over the 

day. The pH shall not be averaged. 

6 SW allocation Daily Max limit.

7 Tiered limit, applies when monthly aluminum production is less than or equal to 10,305 tons. 

8 Tiered limit, applies when monthly aluminum production is greater than 10,305 and less than or equal to 15,614 tons.

9 Tiered limit, applies when monthly aluminum production is greater than 15,614 tons.

10 ND = Nondetect.

11The monthly average of daily production.

12 Intalco notified Ecology (in a letter dated February 27, 2009) that they had completed the diversion structure to divert all flow from Outfall 002 into Outfall 001.

13 NA = No discharge through outfall 002 because the hydraulic capacity at 001 was not exceeded.

14 The limit is 55 % if there are <400 people working onsite and the limit is 65% if there are > 400 people working on site.

15 NS = Not sampled because the stormwater pond discharge never exceeded 3.7 cfs over any consecutive 120 minute period.

16 IF = Insufficient flow to collect a representative sample.

Intalco 2013 Water Pollutant Discharges

PARAMETERS 

UNITS LIMITS1 JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT AVG

OUTFALL 001

TSS - MA2 lbs/day 150 109.4 47.3 142.9 56.4 105.2 68.5 12.0 35.6 65.8 160.2

TSS SW allocation Monthly Average limit3 lbs/day Calculated3 DNTA4 DNTA DNTA DNTA DNTA DNTA DNTA DNTA DNTA 257.3

TSS - DM5 lbs/day 185 289.1 76.0 420.6 161.4 272.5 211.4 51.0 83.8 130.2 956.2
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 105 of 145

Intalco 2013 Water Pollutant Discharges

OUTFALL UNITS LIMITS1 JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT AVG

TSS SW allocation Daily Max limit6 lbs/day Calculated6 3128.8 DNTA 841.3 DNTA 1235 438.1 DNTA DNTA DNTA 1441.3

FLUORIDE - MA lbs/day 587

/688/689 165.4 85.1 152.9 118.4 153.6 94.5 43.0 73.8 83.7 158.6

FLUORIDE - SWA3 lbs/day Calculated3 487.3 180.4 275.3 263.6 243.2 114.6 DNTA 86.3 100.7 175.3

FLUORIDE - DM lbs/day 1407

/1988/2969 441.4 94.2 286.9 259.5 363.1 143.5 64 152.7 187.8 585.7

FLUORIDE - SWA6 lbs/day Calculated6 2260.1 DNTA DNTA DNTA 996.6 DNTA DNTA DNTA DNTA 1134.2

ALUMINUM - MA lbs/day 5.97

/9.08/10.39 37.3 8.6 18.9 14.6 31.8 7.9 0.0 1.4 11.1 39.9

ALUMINUM - SWA3 lbs/day Calculated3 129.5 DNTA 69.2 65.9 60.1 DNTA DNTA DNTA 19.6 40.8

ALUMINUM - DM lbs/day 13.47

/208/309 132.2 13.6 34.6 59.7 93.9 30.7 0.0 7.0 40.2 242.7

ALUMINUM - SWA6 lbs/day Calculated6 618.8 DNTA 161.3 277.5 240 80.6 DNTA DNTA 68.8 281.3

FREE CN - MA2 mg/l <0.012 0.002 0.0 0.003 0.0 0.0 0.0 0.0 0.005

ND10 

(<0.003) 0.004

FREE CN - DM3 mg/l 0.012 0.007 0.007 0.007 0.005 0.007 0.006 0.008 0.007

ND 

(<0.010) 0.007

B(a)P - MA lbs/day 0.027

/0.038/ 0.0459 10/15/12 0.005 2/4/13 0.010 4/15/13 0.004 6/25/13 6/25/13 0.004 9/9/13

B(a)P - SWA3 lbs/day Calculated3 10/15/12 DNTA 2/4/13 DNTA 4/15/13 DNTA 6/25/13 6/25/13 DNTA 9/9/13

B(a)P - DM4 lbs/day

0.0437/0.0658/0.098

9 10/15/12 0.005 2/4/13 0.010 4/15/13 0.007 6/25/13 6/25/13 0.004 9/9/13

B(a)P - SWA6 lbs/day Calculated6 10/15/12 DNTA 2/4/13 DNTA 4/15/13 DNTA 6/25/13 6/25/13 DNTA 9/9/13

ANTIMONY - MA lbs/day 1.97

/2.9 8/4.39 0.00 1/7/13 1/7/13 1/7/13 1/7/13 0.02 6/25/13 6/25/13 6/25/13 6/25/13

ANTIMONY - DM lbs/day 4.27

/6.48/9.69

0.00 1/7/13 1/7/13 1/7/13 1/7/13 0.03 6/25/13 6/25/13 6/25/13 6/25/13

NICKEL - MA lbs/day 0.87

/1.28/1.99 0.57 1/7/13 1/7/13 1/7/13 1/7/13 0.30 6/25/13 6/25/13 6/25/13 6/25/13

NICKEL - DM lbs/day 1.27

/1.88/2.79 0.57 1/7/13 1/7/13 1/7/13 1/7/13 0.41 6/25/13 6/25/13 6/25/13 6/25/13

C0PPER - DM3 ug/l none ND (<3) 1/21/13 1/21/13 1/21/13 1/21/13 5.2 6/25/13 6/25/13 6/25/13 6/25/13

O & G - Minimum mg/l none

ND 

(<0.54)

ND 

(<1.1)

ND 

(<2.5)

ND 

(<1.1)

ND 

(<1.1)

ND 

(<1.1) ND (<1.1) ND (<2.5) ND (<1.1) 2.2

O & G - MA2 mg/l 5

ND 

(<0.54)

ND 

(<1.1)

ND 

(<2.5)

ND 

(<1.1)

ND 

(<1.1)

ND 

(<1.1) ND (<1.1) ND (<2.5) ND (<1.1) 2.2

O & G - DM3 mg/l 10

ND 

(<0.54)

ND 

(<2.5)

ND 

(<2.5)

ND 

(<1.1)

ND 

(<1.1)

ND 

(<1.1) ND (<1.1) ND (<2.5) ND (<1.1) 2.2

pH - Daily Min std units ≥6 6.9 6.9 6.9 7.0 7.1 7.0 7.5 7.4 6.9 6.8 7.0

pH - Daily Max std units ≤9 8.1 8.1 8.1 8.1 8.2 8.3 8.1 8.2 8.1 8.2 8.2

Temp - MA oF none 41 46 48 52 58 62 67 67 63 56 56.0

Temp - DM oF none 47 51 56 60 65 69 73 73 73 61 62.8

Flow - MA MGD none 2.528 1.603 2.361 2.031 1.213 1.175 1.070 1.051 1.363 1.208 1.6
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 106 of 145

Intalco 2013 Water Pollutant Discharges

OUTFALL UNITS LIMITS1 JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT AVG

Flow - DM MGD none 9.865 5.900 6.332 5.248 2.379 3.227 1.38 1.622 4.02 5.068 4.5

Al Production11 tons/day none 689 697 696 691 688 679 684 691 691 696 690.2

Number of days in the month none 31 28 31 30 31 30 31 31 30 31 30.4

Al Production - Maximum tons/month none 21359 19516 21576 20730 21328 20370 21204 21421 20730 21576 20981.0

OUTFALL 00212 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

TSS - MA mg/l 35 5.5 11.0 NA13 9.2 NA 8.4 NA NA 35 NA 13.8

TSS - DM mg/l 75 5.5 11.0 NA 9.2 NA 8.4 NA NA 35 NA 13.8

FLUORIDE - MA mg/l 35 17.3 19.0 NA 17.8 NA 24.5 NA NA 33.3 NA 22.4

FLUORIDE - DM mg/l 50 17.3 19.0 NA 19.2 NA 24.5 NA NA 33.3 NA 22.7

ALUMINUM - MA mg/l 10 5.0 6.7 NA 4.6 NA 5.5 NA NA 13.2 NA 7.0

ALUMINUM - DM mg/l 15 5.0 6.7 NA 4.8 NA 5.5 NA NA 13.2 NA 7.0

pH - Daily Min std units ≥6 6.6 6.7 NA 6.8 NA 6.9 NA NA 6.7 NA 6.7

pH - Daily Max std units ≤9 7.3 7.4 NA 7.3 NA 7.3 NA NA 7.2 NA 7.3

Temp - MA oF none 38.8 42.0 NA 51.3 NA 64.1 NA NA 62.1 NA 51.7

Temp - DM oF none 44 46.4 NA 59.3 NA 70.9 NA NA 71 NA 58.3

Flow - MA MGD none 1.68 0.035 NA 0.843 NA 0.13 NA NA 0.264 NA 0.6

Flow - DM MGD none 4.71 0.05 NA 3.98 NA 1.87 NA NA 2.46 NA 2.6

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

BOD - MA lbs/day 22.4 7.8 7.3 5.8 4.7 4.2 2.1 1.9 1.7 2.3 4.9 4.3

BOD - DM lbs/day 32.4 11.5 12.7 7.8 8.0 12.4 2.5 2.5 7 4.6 6 7.5

BOD - DM mg/l 65.0 28.0 32.0 14.0 13.0 47.0 9.5 6.4 34 14.0 14 21.2

TSS - MA lbs/day 22.4 1.9 2.6 4.5 0.9 0.3 0.2 0.0 0.0 0.0 0.0 1.0

TSS - DM lbs/day 32.4 3.1 4.4 7.4 1.6 1.6 0.5 0.0 0.0 0.0 0.0 1.9

TSS - MA mg/l 45.0 3.9 8.5 8.2 1.9 0.9 0.7 0 0.0 0.0 0.0 2.4

TSS - DM mg/l 65.0 5.3 11.1 11.9 2.7 3.8 2.1 0.0 0.0 0.0 0.0 3.7

Fecal Coli. - MA #/100mls 200 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0 2.0

Fecal Coli. - DM #/100mls 400 ND (<2) ND (<2) ND (<2) ND (<2) ND (<2) ND (<2) ND (<2) ND (<2) ND (<2) ND (<2)

pH - Daily Min std units ≥6 6.44 6.28 6.61 6.64 6.85 6.69 6.75 6.54 6.42 6.51 6.6

pH - Daily Max std units ≤9 7.04 7.09 7.09 7.00 7.3 7.1 7.07 7.01 7.03 7.21 7.1

Flow - MA MGD none 0.058 0.035 0.052 0.061 0.032 0.039 0.041 0.014 0.031 0.055 0.0

Flow - DM MGD none 0.07 0.050 0.08 0.08 0.050 0.06 0.06 0.030 0.04 0.07 0.1

% BOD Removal -MA % 55%/65%14 99.0 97.1 97.2 96.2 98.2 99.0 98.2 94.9 93.2 95.6 96.9

% TSS Removal - MA % 55%/65%14 99.6 99.2 97.7 99.3 99.9 99.9 100.0 100.0 100.0 100.0 99.6

Personnel Onsite

# of 

personnel >400 612 612 604 601 594 594 604 598 592 586 599.7
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 107 of 145

Intalco 2013 Water Pollutant Discharges

Sanitary Lagoon UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

Date UV Tubes were cleaned Date once/90 days 12/12/12 02/19/13 02/19/13 04/24/13 04/24/13 06/11/13 07/10/13 08/31/13 08/31/13 08/31/13 41413.1

UV Tubes Operating Number 12.0 14 14 14 14 14 14 14 14 14 14 14.0

Date UV Tubes were replaced Date Annually 12/28/12 12/28/12 12/28/12 12/28/12 12/28/13 06/11/13 06/11/13 06/11/13 06/11/13 06/11/13

Stormwater Pond UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

TSS - DM mg/l 20 9.7 15.8 6.9 14.1 15.7 22.4 NS15 NS 44.8 25.9 19.4

FLUORIDE - DM mg/l 35 18.3 20.8 19 19.0 21.8 26.3 NS NS 36.5 19.5 22.7

ALUMINUM - DM mg/l 8 6.4 7.2 5.1 5.1 5.1 9.5 NS NS 18.0 11.2 8.5

pH - Daily Min std units <6.0 6.7 6.9 6.7 6.7 6.9 6.7 6.8 7 6.2 6.6 6.7

pH - Daily Max std units >9.0 7.5 7.5 7.4 7.4 7.5 7.5 7.5 7.6 7.4 7.3 7.5

Flow - MA MGD none 0.794 0.323 0.596 0.48 0.265 0.183 0.066 0.094 0.311 0.209 0.3

Flow - DM MGD none 5.890 2.356 2.332 2.263 1.109 1.529 0.071 0.428 2.400 2.736 2.1

Secondary Wastewater Treatment Plant UNITS Action Level JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

TSS - DM mg/l 120 70.8 47.5 64.1 46.6 57.6 59.6 49.4 78.8 52.7 48.7 57.6

FLUORIDE - DM mg/l 50 25.3 21.5 19.3 22.8 22.3 28.8 18.5 16.8 19.0 21.3 21.6

ALUMINUM - DM mg/l none 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.015 0.1 0.1 0.1

FREE CN - DM mg/l none 0.009 0.009 0.028 0.006 0.010 0.007 0.016 0.015

NQ16 

(<0.010) 0.010

PCBs ppb none 12/12/12 12/12/12

ND 

(<0.1)

ND 

(<0.1) 4/15/13

ND 

(<0.1) 6/25/2013 6/25/2013 ND (<0.1) 09/10/13

Flow - MA MGD none 0.096 0.113 0.129 0.125 0.143 0.124 0.119 0.139 0.121 0.102 0.1

Flow - DM MGD none 0.401 0.433 0.473 0.435 0.442 0.463 0.302 0.310 0.316 0.346 0.4

Outfall 011 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

TSS - Monthly grab when there is flow mg/l none 198.4 78.1 412.1 48.5 42.6 102.8 IF17 26.1 25.5 36.2 107.8

FLUORIDE - Monthly grab when there is 

flow mg/l none 14.4 19.5 12.2 6.4 9.9 10.7 IF 14.3 13.7 2.2 11.5

ALUMINUM - Monthly grab when there is 

flow mg/l none 31.1 33.1 29.5 5.0 5.5 2.1 IF 3.9 8.3 0.1 13.2

Outfall 012 UNITS LIMITS JAN FEB MAR APR MAY JUN JUL AUG SEP OCT AVG

TSS - Monthly grab when there is flow mg/l none 21 45.0 170.4 10.9 75.7 45.6 IF 12.5 48.7 56.7 54.1

FLUORIDE - Monthly grab when there is 

flow mg/l none 3.3 8.7 5.7 3.6 4.6 5.9 IF 14.6 5.5 2.3 6.0

ALUMINUM - Monthly grab when there is 

flow mg/l none 2.9 11.9 17.7 3.0 4.8 6 IF 14.2 10.5 0.6 8.0

1 LIMITS for modified NPDES permit issued on June 15, 2008 (effective July 15, 2008).

2 Monthly average (MA) effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided 

by the number of daily discharges measured during that month.

3 SW allocation Monthly Average limit.
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 108 of 145

Intalco 2013 Water Pollutant Discharges

4 DNTA: Did not take stormwater allocation because they were in compliance with the respective permit limit.

5 Daily maximum (DM) effluent limitation is defined as the highest allowable daily discharge. The daily discharge means the discharge of a pollutant measured during a calendar day. For pollutants with limitations 

expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged over the day. For other units of measurement, the daily discharge is the average measurement of the pollutant over 

the day. The pH shall not be averaged. 

6 SW allocation Daily Max limit.

7 Tiered limit, applies when monthly aluminum production is less than or equal to 10,305 tons. 

8 Tiered limit, applies when monthly aluminum production is greater than 10,305 and less than or equal to 15,614 tons.

9 Tiered limit, applies when monthly aluminum production is greater than 15,614 tons.

10 ND = Nondetect.

11The monthly average of daily production.

12 Intalco notified Ecology (in a letter dated February 27, 2009) that they had completed the diversion structure to divert all flow from Outfall 002 into Outfall 001.

13 NA = No discharge through outfall 002 because the hydraulic capacity at 001 was not exceeded.

14 The limit is 55 % if there are <400 people working onsite and the limit is 65% if there are > 400 people working on site.

15 NS = Not sampled because the stormwater pond discharge never exceeded 3.7 cfs over any consecutive 120 minute period.

16 NQ = Special Condition S2.D. of the permit defines Non-Quantifiable (NQ) as values above the Method Detection Level (MDL) but below the Practical quantitation limit (PQL). The sample results were between the 

PQL and MDL (between 0.003 mg/L and 0.010 mg/L). 

17 IF = Insufficient flow to collect a representative sample.
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 109 of 145

Appendix E - Technical Calculations

Several of the Excel® spreadsheet tools used to evaluate a discharger’s ability to meet 

Washington State water quality standards can be found on Ecology’s Water Quality Permit 

Guidance page under Permit Tools at

http://www.ecy.wa.gov/programs/wq/permits/guidance.html .

Simple Mixing:

Ecology uses simple mixing calculations to assess the impacts of certain conservative pollutants, 

such as the expected increase in fecal coliform bacteria at the edge of the chronic mixing zone 

boundary. Simple mixing uses a mass balance approach to proportionally distribute a pollutant 

load from a discharge into the authorized mixing zone. The approach assumes no decay or 

generation of the pollutant of concern within the mixing zone. The predicted concentration at the 

edge of a mixing zone (MC) is based on the following calculation:

MC = [EC + (AC X (DF-1))]/DF

where:

EC = Effluent Concentration

AC Ambient Concentration

DF Dilution Factor

Reasonable Potential Analysis:

The spreadsheets REASPOT.XLS, and LIMIT.XLS in Ecology’s TSDCALC Workbook 

determine reasonable potential (to violate the aquatic life water quality standards) and calculate 

effluent limits. The spreadsheet HUMAN-H.XLS determines reasonable potential and calculates 

effluent limits for human health pollutants. The process and formulas for determining reasonable 

potential and effluent limits in these spreadsheets are taken directly from the Technical Support 

Document for Water Quality-based Toxics Control, (EPA 505/2-90-001). The adjustment for 

autocorrelation is from EPA (1996a), and EPA (1996b).
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 110 of 145

Figure 6 Aquatic Life and Human Health Reasonable Potential Analysis AMMONIA, Criteria as Total NH3 ACENAPTHENE 83329 1B ALUMINUM, total recoverable, pH 6.5-9.0 7429905 ANTHRACENE 120127 3B ANTIMONY (INORGANIC) 7440360 1MARSENIC (dissolved) 7440382 2MARSENIC (inorganic) BENZO(a)ANTHRACENE 56553 

5BBENZO(a)PYRENE 50328 6BBENZO(b)FLUORANTHENE 205992 7BBENZO(k) FLUORANTHENE 207089 9B

1 5 56 5 9 5 5 5 5 5 5

0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

520 0.6 7370 0.5 17 50 50 1.6 1.9 2.6 0.9

16.000

Acute 5,505 - - - - 69 - - - - -

Chronic 827 - - - - 36 - - - - -

- 990 - 110000 4300 - 0.14 0.031 0.031 0.031 0.031

Acute - - - - - 1 - - - - -

Chronic - - - - - - - - - - -

N N N N N Y Y Y Y Y Y

Aquatic Life Reasonable Potential

0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950

s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555

Pn 0.050 0.549 0.948 0.549 0.717 0.549 0.549 0.549 0.549 0.549 0.549

6.20 2.32 1.00 2.32 1.81 2.32 2.32 2.32 2.32 2.32 2.32

Acute 169 0.066 350.952 0.055 1.466 5.534 5.534 0.177 0.210 0.288 0.100

Chronic 78 0.027 141.731 0.022 0.592 2.235 2.235 0.072 0.085 0.116 0.040

NO n/a n/a n/a n/a NO n/a n/a n/a n/a n/a

Human Health Reasonable Potential

s 0.555 0.55451 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.554513 0.5545 0.55451

Pn 0.050 0.549 0.948 0.549 0.717 0.549 0.549 0.549 0.549 0.549 0.549

2.490 0.93363 0.4061 0.9336 0.7276 0.9336 0.9336 0.9336 0.933632 0.9336 0.93363

77 77 77 77 77 105 105 105 105 105 105

16.812 0.00728 38.874 0.0061 0.1606 4.4E-01 ###### 0.0142 0.016894 0.0231 0.008

n/a NO n/a NO NO n/a YES NO NO NO NO

WQ Criteria for Protection of 

Human Health, ug/L

Multiplier

Max concentration (ug/L) at edge of...

Reasonable Potential? Limit Required?

Pn=(1-confidence level)1/n

s2=ln(CV2+1)

Multiplier

Dilution Factor

s2=ln(CV2+1)

Pn=(1-confidence level)1/n

Effluent percentile value

Effluent Data

# of Samples (n)

Effluent Concentration, ug/L 

(Max. or 95th Percentile)

Pollutant, CAS No. & 

NPDES Application Ref. No.

Aquatic Life Criteria, 

ug/L

Carcinogen?

Water Quality Criteria

Coeff of Variation (Cv)

Calculated 50th percentile 

Effluent Conc. (when n>10)

Receiving Water Data 90th Percentile Conc., ug/L

Geo Mean, ug/L

Metal Criteria 

Translator, decimal

Max Conc. at edge of Chronic Zone, ug/L

Reasonable Potential? Limit Required?
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 111 of 145

CADMIUM - 7440439 4M Hardness dependentCHROMIUM(HEX) 18540299CHRYSENE 218019 18BCOPPER - 744058 6M Hardness dependentCYANIDE 57125 14MFLUORANTHENE 206440 31BFLUORENE 86737 32BINDENO(1,2,3-cd)PYRENE 193395 37BLEAD - 7439921 7M Dependent on hardnessMANGANESE 7439965 METHYLENE CHLORIDE 75092 22V

5 5 5 6 2 5 5 5 5 1 2

0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

1.5 2 1.7 5.2 0.7 3.3 0.2 1.6 0.7 70 0.59

0.47 0.012 0.0007

Acute 42 1100 - 4.8 9.1 - - - 210 - -

Chronic 9.3 50 - 3.1 2.8 - - - 8.1 - -

- - 0.03 - 2E+05 370 14000 0.031 - 100 1600

Acute 0.994 0.993 - 0.83 - - - - 0.951 - -

Chronic 0.994 0.993 - 0.83 - - - - 0.951 - -

N N Y N N N N Y N N Y

Aquatic Life Reasonable Potential

0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950

s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555

Pn 0.549 0.549 0.549 0.607 0.224 0.549 0.549 0.549 0.549 0.050 0.224

2.32 2.32 2.32 2.14 3.79 2.32 2.32 2.32 2.32 6.20 3.79

Acute 0.165 0.220 0.636 0.440 0.126 0.365 0.022 0.189 0.074 20.659 0.107

Chronic 0.067 0.089 0.537 0.178 0.051 0.148 0.009 0.083 0.030 8.343 0.043

NO NO n/a NO NO n/a n/a n/a NO n/a n/a

Human Health Reasonable Potential

s 0.5545 0.5545 0.55 0.5545 0.555 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545

Pn 0.549 0.549 0.549 0.607 0.224 0.549 0.549 0.549 0.549 0.050 0.224

0.9336 0.9336 0.93 0.8603 1.524 0.9336 0.9336 0.9336 0.9336 2.4895 1.5242

77 77 105 77 77 77 77 105 77 77 105

0.0182 0.0243 0.02 0.0581 0.014 4.0E-02 2.4E-03 0.0142 0.0085 2.2632 0.0086

n/a n/a NO n/a NO NO NO NO n/a NO NO

Receiving Water Data 90th Percentile Conc., ug/L

Geo Mean, ug/L

Water Quality Criteria

Metal Criteria 

Translator, decimal

Multiplier

Max concentration (ug/L) at edge of...

Reasonable Potential? Limit Required?

Pollutant, CAS No. & 

NPDES Application Ref. No.

Effluent Data

# of Samples (n)

Coeff of Variation (Cv)

Effluent Concentration, ug/L 

(Max. or 95th Percentile)

Calculated 50th percentile 

Effluent Conc. (when n>10)

Aquatic Life Criteria, 

ug/L

WQ Criteria for Protection of 

Human Health, ug/L

Carcinogen?

s2=ln(CV2

+1)

Pn=(1-confidence level)1/n

Effluent percentile value

s2

=ln(CV2+1)

Pn=(1-confidence level)1/n

Multiplier

Dilution Factor

Max Conc. at edge of Chronic Zone, ug/L

Reasonable Potential? Limit Required?
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 112 of 145

MERCURY 7439976 8MNICKEL - 7440020 9M - Dependent on hardnessPYRENE 129000 45BSELENIUM 7782492 10MSILVER - 7740224 11M dependent on hardness. SOLIDS,SUSPENDED AND TURBIDITYTHALLIUM 7440280 12MZINC- 7440666 13M hardness dependentPHENOL 108952 10A

6 9 5 5 5 56 5 5 2

0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6

0.0035 90 2.8 12 0.03 37000 1 62 25

0.57

0

Acute 1.8 74 - 290 1.9 - - 90 - #N/A #N/A

Chronic 0.025 8.2 - 71 - - - 81 - #N/A #N/A

0.15 4600 11000 4200 - - 6.3 - 5E+06 #N/A #N/A

Acute 0.85 0.99 - - 0.85 - - 0.946 - #N/A #N/A

Chronic - 0.99 - - - - - 0.946 - #N/A #N/A

N N N N N N N N N #N/A #N/A

Aquatic Life Reasonable Potential

0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950 0.950

s 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555 0.555

Pn 0.607 0.717 0.549 0.549 0.549 0.948 0.549 0.549 0.224 #DIV/0! #DIV/0!

2.14 1.81 2.32 2.32 2.32 1.00 2.32 2.32 3.79 #DIV/0! #DIV/0!

Acute 0.000 7.685 0.310 1.871 0.003 ###### 0.111 6.492 4.517 #N/A #N/A

Chronic 0.000 3.104 0.125 1.095 0.001 711.538 0.045 2.622 1.824 #N/A #N/A

NO NO n/a NO NO n/a n/a NO n/a #N/A #N/A

Human Health Reasonable Potential

s 0.5545 0.55451 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545 0.5545

Pn 0.607 0.717 0.549 0.549 0.549 0.948 0.549 0.549 0.224 #DIV/0! #DIV/0!

0.8603 0.72756 0.9336 0.9336 0.9336 0.4061 0.9336 0.9336 1.5242 #DIV/0! #DIV/0!

77 77 77 77 77 77 77 77 77 #N/A #N/A

4E-05 0.8504 0.034 0.1455 0.0004 2.0E+02 1.2E-02 0.7518 0.4949 #DIV/0! #DIV/0!

NO NO NO NO n/a n/a NO n/a NO #N/A #N/A

Receiving Water Data 90th Percentile Conc., ug/L

Geo Mean, ug/L

Water Quality Criteria

Aquatic Life Criteria, 

ug/L

Metal Criteria 

Translator, decimal

Carcinogen?

Effluent Data

# of Samples (n)

Coeff of Variation (Cv)

Effluent percentile value

Reasonable Potential? Limit Required?

Multiplier

Max concentration (ug/L) at edge of...

Dilution Factor

Effluent Concentration, ug/L 

(Max. or 95th Percentile)

Calculated 50th percentile 

Effluent Conc. (when n>10)

WQ Criteria for Protection of 

Human Health, ug/L

s2

=ln(CV2

+1)

Pn=(1-confidence level)1/n

s2

=ln(CV2+1)

Pn=(1-confidence level)1/n

Pollutant, CAS No. & 

NPDES Application Ref. No.

Max Conc. at edge of Chronic Zone, ug/L

Reasonable Potential? Limit Required?

Multiplier
Fact Sheet for NPDES Permit WA0002950

Intalco Aluminum Corporation

Page 113 of 145

Figure 7 Temperature Analysis

INPUT May-Sep Oct-Apr

1. Chronic Dilution Factor at Mixing Zone Boundary 52 52

2. Annual max 1DADMax Ambient Temperature (Background 90th percentile) 15.2 °C 10.7 °C

3. 1DADMax Effluent Temperature (95th percentile) 23.5 °C 19.4 °C

4. Aquatic Life Temperature WQ Criterion 13.0 °C 13.0 °C

OUTPUT

5. Temperature at Chronic Mixing Zone Boundary: 15.36 °C 10.83 °C

6. Incremental Temperature Increase or decrease: 0.16 °C 0.17 °C

7. Incremental Temperature Increase 12/(T-2) if T< crit: --- 1.39 °C

8. Maximum Allowable Temperature at Mixing Zone Boundary: 15.50 °C 12.05 °C

A. If ambient temp is warmer than WQ criterion

9. Does temp fall within this warmer temp range? YES NO

10. Temp increase allowed at mixing zone boundary, if required: NO LIMIT ---

B. If ambient temp is cooler than WQ criterion but within 12/(Tamb-2) and within 0.3 °C of the criterion 

11. Does temp fall within this incremental temp. range? --- NO

12. Temp increase allowed at mixing zone boundary, if required: --- ---

C. If ambient temp is cooler than (WQ criterion-0.3) but within 12/(Tamb-2) of the criterion

13. Does temp fall within this Incremental temp. range? --- NO

14. Temp increase allowed at mixing zone boundary, if required: --- ---

D. If ambient temp is cooler than (WQ criterion - 12/(Tamb-2))

15. Does temp fall within this Incremental temp. range? --- YES

16. Temp increase allowed at mixing zone boundary, if required: --- NO LIMIT

RESULTS

17. Do any of the above cells show a temp increase? NO NO

18. Temperature Limit if Required? NO LIMIT NO LIMIT

Marine Temperature Reasonable Potential and Limit Calculation

Based on WAC 173-201A-200(1)(c)(i)--(ii) and Water Quality Program Guidance. All Data inputs must 

meet WQ guidelines. The Water Quality temperature guidance document may be found at: 

http://www.ecy.wa.gov/biblio/0610100.html
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Intalco Aluminum Corporation

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Appendix F – Wet Test Results Summary

Outfall 001 WET Test Results Summary

Intalco Combined Outfall 001 

Acute WET Test Results as % Survival in 100% Effluent

Sample Date Start Date Organism Endpoint %Survival

20-Apr-09 21-Apr-09 Rainbow Trout 96-Hour Survival 100.00%

20-Apr-09 21-Apr-09 Daphnid 48-Hour Survival 80.00%

15-Jun-09 16-Jun-09 Rainbow Trout 96-Hour Survival 100.00%

15-Jun-09 16-Jun-09 Daphnid 48-Hour Survival 85.00%

31-Aug-09 1-Sep-09 Rainbow Trout 96-Hour Survival 100.00%

26-Aug-09 27-Aug-09 Daphnid 48-Hour Survival 100.00%

9-Nov-09 10-Nov-09 Rainbow Trout 96-Hour Survival 100.00%

9-Nov-09 10-Nov-09 Daphnid 48-Hour Survival 100.00%

22-Feb-10 23-Feb-10 Rainbow Trout 96-Hour Survival 100.0%

22-Feb-10 23-Feb-10 Daphnid 48-Hour Survival 100.0%

30-Aug-10 31-Aug-10 Rainbow Trout 96-Hour Survival 100.0%

30-Aug-10 31-Aug-10 Daphnid 48-Hour Survival 100.0%

18-Oct-10 19-Oct-10 Rainbow Trout 96-Hour Survival 100.0%

18-Oct-10 19-Oct-10 Daphnid 48-Hour Survival 100.0%

14-Dec-10 18-Dec-10 Rainbow Trout 96-Hour Survival 100.00%

14-Dec-10 16-Dec-10 Daphnid 48-Hour Survival 100.00%

Intalco Combined Outfall 001 

Acute WET Test Results as NOEC/LOEC in % Effluent

Sample Date Organism Endpoint NOEC LOEC PMSD

20-Apr-09 Rainbow Trout 96-Hour Survival 100 >100 3%

20-Apr-09 Daphnid 48-Hour Survival 50 100 19%

15-Jun-09 Rainbow Trout 96-Hour Survival 100 >100 3%

15-Jun-09 Daphnid 48-Hour Survival 50 100 11%

31-Aug-09 Rainbow Trout 96-Hour Survival 100 >100 2.50%

26-Aug-09 Daphnid 48-Hour Survival 100 >100 11.30%

9-Nov-09 Rainbow Trout 96-Hour Survival 100 >100 2.50%

9-Nov-09 Daphnid 48-Hour Survival 100 >100 9.20%

22-Feb-10 Rainbow Trout 96-Hour Survival 100 >100 4.02%

22-Feb-10 Daphnid 48-Hour Survival 100 >100 5.00%

30-Aug-10 Rainbow Trout 96-Hour Survival 100 >100 2.50%

30-Aug-10 Daphnid 48-Hour Survival 100 >100 5.00%
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Sample Date Organism Endpoint NOEC LOEC PMSD

18-Oct-10 Rainbow Trout 96-Hour Survival 100 >100 2.50%

18-Oct-10 Daphnid 48-Hour Survival 100 >100 5.00%

14-Dec-10 Rainbow Trout 96-Hour Survival 100 >100 2.50%

14-Dec-10 Daphnid 48-Hour Survival 100 >100 9.20%

Intalco Outfall 001 Combined

Chronic WET Test Results as NOEC/LOEC in % Effluent

Sample 

Date Start Date Organism Endpoint NOEC LOEC PMSD

20-Apr-09 21-Apr-09 Pacific 

Topsmelt

7-Day 

Survival 10 30 20.00%

Biomass 100 >100 27.60%

Weight 100 >100 16.50%

20-Apr-09 21-Apr-09 Mysid 

Shrimp

7-Day 

Survival 10 30 14.20%

Biomass 100 >100 16.40%

Weight 100 >100 18.10%

20-Apr-09 21-Apr-09 Sea Urchin Development 10 30 2.80%

Survival 51.5 >51.5 14.20%

15-Jun-09 16-Jun-09 Pacific 

Topsmelt

7-Day 

Survival 100 >100 19.60%

Biomass 100 >100 24.60%

Weight 100 >100 19.80%

15-Jun-09 16-Jun-09 Mysid 

Shrimp

7-Day 

Survival 100 >100 16.90%

Biomass 100 >100 24.10%

Weight 100 >100 16.90%

15-Jun-09 16-Jun-09 Echinoderm Development 57.8 >57.8 1.63%

Survival 57.8 >57.8 7.13%

26-Aug-09 27-Aug-09 Pacific 

Topsmelt

7-Day 

Survival 100 >100 9.74%

Biomass 100 >100 17.00%

Weight 100 >100 18.50%

26-Aug-09 27-Aug-09 Mysid 

Shrimp

7-Day 

Survival 100 >100 14.80%

Biomass 100 >100 19.40%

Weight 100 >100 15.00%

26-Aug-09 27-Aug-09 Echinoderm Development 30 58.5 6.86%

Survival 58.5 >58.5 23.70%
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Sample 

Date Start Date Organism Endpoint NOEC LOEC PMSD

26-Oct-09 27-Oct-09 Inland 

Silverside

7-Day 

Survival 100 >100 7.46%

Biomass 100 >100 10.40%

Weight 100 >100 10.90%

26-Oct-09 27-Oct-09 Mysid 

Shrimp

7-Day 

Survival 30 100 14.60%

Biomass 30 100 17.60%

Weight 100 >100 13.00%

28-Oct-09 29-Oct-09 Echinoderm Development 48.8 >48.8 1.02%

Survival 48.8 >48.8 5.91%

22-Feb-10 23-Feb-10 Pacific 

Topsmelt

7-Day 

Survival 100 >100 23.30%

Biomass 100 >100 36.70%

Weight 100 >100 23.30%

22-Feb-10 23-Feb-10 Mysid 

Shrimp

7-Day 

Survival 100 >100 17.00%

Biomass 100 >100 18.00%

Weight 100 >100 14.50%

22-Feb-10 23-Feb-10 Echinoderm Development 50 >50 4.05%

Survival 50 >50 23.00%

31-Aug-10 13-Sept10

Pacific 

Topsmelt

7-Day 

Survival 100 >100 17.50%

Biomass 100 >100 19.00%

Weight 100 >100 17.50%

13-Sept1014-Sept10Mysid 

Shrimp

7-Day 

Survival 30 100 15.40%

Biomass 30 100 16.60%

Weight 30 100 15.30%

15-Sept1016-Sept10 Echinoderm Development 59.5 >59.5 13.20%

Survival 59.5 >59.5 16.50%

18-Oct-10 19-Oct-10 Inland 

Silverside

7-Day 

Survival 100 >100 8.75%

Biomass 100 >100 13.90%

Weight 100 >100 15.70%

18-Oct-10 19-Oct-10 Mysid 

Shrimp

7-Day 

Survival 30 100 18.90%

Biomass 10 30 18.70%

Weight 30 100 14.00%
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Sample 

Date Start Date Organism Endpoint NOEC LOEC PMSD

18-Oct-10 19-Oct-10 Echinoderm Development <2.5 2.5 10.30%

Survival 61.3 >61.3 30.90%

13-Dec-10 14-Dec-10 Pacific 

Topsmelt

7-Day 

Survival 100 >100 9.74%

Biomass 100 >100 16.30%

Weight 100 >100 17.40%

13-Dec-10 14-Dec-10 Mysid 

Shrimp

7-Day 

Survival 100 >100 18.50%

Biomass 10 30 20.90%

Weight 2.5 3.8 15.40%

15-Dec-10 16-Dec-10 Echinoderm Development 30 59.9 5.59%

Survival 59.9 >59.9 2.10%

Outfall 002 WET Test Results Summary

Intalco Outfall 002 

Acute WET Test Results as % Survival in 100% Effluent

Sample Date Start Date Organism Endpoint %Survival

30-Mar-07 31-Mar-07 Fathead 

Minnows

96-Hour 

Survival 100.0%

9-May-07 10-May07 Daphnid 48-Hour 

Survival 60.0%

12-Nov-07

13-Nov07 Daphnid48-Hour 

Survival 25.0%

14-Nov-07 15-Nov07

Fathead 

Minnows

96-Hour 

Survival 92.5%

19-Feb-08 20-Feb-08 Fathead 

Minnows

96-Hour 

Survival 97.5%

11-Aug-08 12-Aug08

Fathead 

Minnows

96-Hour 

Survival 97.5%
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 Intalco Outfall 002 - Acute WET Test Results as NOEC/LOEC in % Effluent

Sample Date Start Date Organism Endpoint NOEC

LOE

C PMSD

30-Mar-07 31-Mar-07 Fathead 

Minnows

96-Hour 

Survival 100 >100 2.50%

9-May-07 10-May07 Daphnid 48-Hour 

Survival 50 100 14.88%

12-Nov-07 13-Nov07 Daphnid 48-Hour 

Survival 25 50 25.80%

14-Nov-07 15-Nov07

Fathead 

Minnows

96-Hour 

Survival 100 >100 8.16%

19-Feb-08 20-Feb-08 Fathead 

Minnows

96-Hour 

Survival 100 >100 9.14%

11-Aug-08 12-Aug08

Fathead 

Minnows

96-Hour 

Survival 100 >100 6.45%

Intalco Outfall 002

Chronic WET Test Results as NOEC/LOEC in % Effluent

Sample 

Date Start Date Organism Endpoint NOEC LOEC PMSD

2/28/2007 3/1/2007 Mussel Development 63.3 >63.3 6.75%

Survival 25 50 4.55%

05/09/07 05/10/07 Pacific 

Topsmelt

7-Day 

Survival 100 >100 11.85%

Biomass 100 >100 19.38%

05/09/07 05/10/07 Bivalve

7-Day 

Survival 55.2 >55.2 10.30%

Biomass 3 16.7 12.40%

11/12/07 11/13/07 Pacific 

Topsmelt

7-Day 

Survival 100 >100 10.60%

Biomass 100 >100 17.70%

Weight 100 >100 13.90%
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Sample 

Date Start Date Organism Endpoint NOEC LOEC PMSD

05/09/07 05/10/07 Echinoderm

7-Day 

Survival 50 55.2 10.30%

Biomass 3 16.7 12.20%

11/14/2007 11/15/2007 Mussel Development 52.35 >52.35 13.10%

Survival 52.35 >52.35 3.93%

08/11/08 08/12/08 Echinoderm

7-Day 

Survival 50 >50 16.10%

Biomass 25 50 3.80%
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Appendix G – Landfill Groundwater Seeps Monitoring Results

Outfall 003 Fluoride 

(mg/L) 

Fluoride 

(mg/L) 

Total 

Cyanide/WAD 

Cyanide 

(mg/L) 

Total 

Cyanide/WAD 

Cyanide 

(mg/L) 

Total 

PCBs 

(ug/L) 

Total 

PCBs 

(ug/L) 

2/23/2007 15.9 14.1 0.01 / NA 0.177 / NA 0.177 0.161

2/17/2009 10.1 9.2 0.03 / 0.0005 0.03/ 0.0005 0.062 0.057

8/10/2009 8.3 8.9 0.03/0.01 0.07/0.009 0.032 0.031

1/26/2011 11.6 11.7 0.028/0.0037 0.03 J / 0.0047 0.16 0.16

7/28/2011 7.64 8.53 0.017/0.005 0.016/0.0047 0.071 0.08

Outfall 004 Flouride (mg/L) Cyanide (Total/WAD) (mg/L) Total PCBs 

(ug/L) 

2/23/2007 11.1 0.01 6.1

2/17/2009 Dry Dry Dry

8/10/2009 Dry Dry Dry

1/26/2011 9.44 0.01/0.0047 0.28

7/28/2011 Dry Dry Dry

Outfall 005 Fluoride Cyanide (Total/ WAD) PCBs 

mg/L mg/L ug/L

2/23/2007 20.2 N/A N/A

2/17/2009 14.8 0.01/ 0.0005 0.14

8/10/2009 11.3 N/A N/A

1/26/2011 20.8 N/A N/A

7/28/2011 13.7 N/A N/A
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Appendix H - Response to Comments

Ecology published notice of an opportunity to comment on the renewal of the NPDES Permit 

No. WA0002950 in the Ferndale Record on August 27, 2014. The proposed permit will allow

the Intalco Aluminum Corporation (Intalco) to discharge process wastewater and stormwater to 

the Strait of Georgia. In the notice, Ecology invited public review of the proposed permit and 

provided a 62-day public comment period. The deadline for submittal of written comments was 

October 27, 2014. 

Ecology received written comments from four entities through email during the public comment 

period. Three of the entities submitted their comments together as a group. Changes were made 

to the permit, where appropriate, to improve clarity and address the comments. Ecology also 

made additional administrative change to improve clarity. The comments and the response to 

comments are presented below. Comments appear in regular text, followed by Ecology’s 

response in italicized text. 

Ecology will send a copy of this response to comments to each individual who provided 

comments. A copy of the final permit will be sent to all interested parties upon issuance and 

posted on the Industrial Section website at http://apps.ecy.wa.gov/industrial/ . 

Comments from Puget Soundkeeper Alliance/Friends of the Earth/ RE Sources for 

Sustainable Communities (Comments 1 – 5)

1. Fugitive Alumina Emissions Impacts

Soundkeeper is concerned about the impacts of fugitive emissions of alumina ore released 

into the environment via aerial deposition during ship unloading. As such, Soundkeeper 

strongly supports the imposition of a requirement for Intalco to conduct a study to determine 

the nature and scale of effects on benthic communities in the marine environment of the 

Strait of Georgia from fugitive emissions associated with the loading/unloading of alumina 

ore at Intalco’s pier. (Agreed Order No. 10887, August 19, 2014) Soundkeeper also 

supports the requirement for Intalco to create and submit a Fugitive Alumina Pollution 

Prevention Plan. (Draft Permit Condition S11, page 40)

Soundkeeper is, however, concerned that the plan laid out in Agree Order No. 10887 falls 

short of adequately protecting Puget Sound because it contains too much ambiguity. The 

agreed order states that “It is understood that should this Study identify significant impacts to 

benthic communities, Ecology will require Intalco to propose actions to address the impact.” 

(Agreed Order, page 2) How does Ecology define “significant impacts”? Does Ecology’s 

definition align with how Intalco defines “significant impacts”? Does Ecology’s definition 

align with how Intalco defines “significant impacts”? Do these definitions adequately protect 

water quality and the marine environment in the Strait of Georgia? If there is an 

understanding between Intalco and Ecology about what rises to the level of “significant 

impacts”, that should be written into the agreed order so that it is enforceable. 
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It appears that tiers 2 and 3 of the assessment will only be required if Ecology determines 

“the need” for these assessments. By these terms, Intalco is only required to move forward if 

Ecology takes affirmative action to instruct them to do so. Soundkeeper is concerned about 

the risk of delay inherent in the way this is written. Instead, Intalco should be required to 

move forward with subsequent tiers of the assessment unless Ecology decided they are not 

required for specific reasons. To prevent undue delays, and maintain compliance with the 

18-month deadline for Fugitive Alumina Pollution Prevention (Draft Permit, page 40), 

Ecology should amend the agreed order to include specific deadlines for Tiers 2 and 3.

Soundkeeper is concerned that the plan ultimately provides for impermissible “selfregulation.” By the terms of the agreed order, Intalco would decide for itself whether it’s 

fugitive alumina emissions harm Puget Sound, and if so, what they are willing to do to 

address it. Federal case law cautions against “self-regulatory schemes” like this for strong 

policy reasons. See Waterkeeper Alliance v. EPA, 399 F.3d 486, 500 (2nd Cir. 2005); 

Environmental Defense Center v. EPA, 344 F3.3d 832, 855 (9th Cir. 2003) (“...stormwater 

management programs that are designed by regulated parties must, in every instance, be 

subject to meaningful review by an appropriate regulating entity to ensure that each such 

program reduced the discharge of pollutants” to meet applicable standards”). How will 

Ecology ensure that Intalco’s plan will effectively reduce the discharge of fugitive alumina 

ore to the Strait of Georgia?

In addition, Soundkeeper is concerned that alumina dust is very lightweight and likely travels 

by wind and/or water current to a wide area surrounding Intalco’s loading dock. Does 

Ecology contemplate this broad range of impact? Or, is Ecology’s concern narrowly focused 

on the area immediately surrounding Intalco’s dock? Soundkeeper urges Ecology to consider 

the wider range of impacts to the Strait of Georgia. Ecology should require Intalco, as part of 

its Fugitive Alumina Emissions Impacts Study, to evaluate how far the dust travels from the 

dock both at the surface of the water and at the bottom. Intalco’s response to address its 

fugitive alumina dust discharges must consider the full range of impacts.

Response to Comment 1: The public comment period was for the proposed NPDES permit 

only. Agreed Order #10887 has already been issued to Intalco. No changes have been 

made to the permit based on this comment. 

However, Ecology will provide a response to the questions presented in the comment. 

Ecology notes that Attachment 1 of the Agreed Order was mistakenly not included in the 

version that was posted on our website. It has been attached to this Response to Comments 

to provide additional clarity on the Agreed Order. 

Comment #1: The agreed order states that “It is understood that should this Study 

identify significant impacts to benthic communities, Ecology will require Intalco to 

propose actions to address the impact.” (Agreed Order, page 2) How does Ecology 

define “significant impacts”? Does Ecology’s definition align with how Intalco 

defines “significant impacts”? Does Ecology’s definition align with how Intalco 
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defines “significant impacts”? Do these definitions adequately protect water quality 

and the marine environment in the Strait of Georgia? If there is an understanding 

between Intalco and Ecology about what rises to the level of “significant impacts”, 

that should be written into the agreed order so that it is enforceable. 

Condition V.2 of the Agreed Order requires that Washington State regulations, 

protocols, and guidance must be used in the Study, including the Sediment 

Sampling and Analysis Plan Appendix (SAPA): Guidance on the Development of 

Sediment Sampling and Analysis Plans Meeting the Requirements of the Sediment 

Management Standards (Chapter 173-204 WAC). Publication #03-09-043. Revised 

February 2008. Available at www.ecy.wa.gov/biblio/0309043. What is considered 

to be a significant impact is specified in that document. 

Comment #2: Instead, Intalco should be required to move forward with subsequent 

tiers of the assessment unless Ecology decided they are not required for specific 

reasons. To prevent undue delays, and maintain compliance with the 18-month 

deadline for Fugitive Alumina Pollution Prevention (Draft Permit, page 40), Ecology 

should amend the agreed order to include specific deadlines for Tiers 2 and 3.

While Ecology understands the concerns about delays, it is important that Ecology 

review the sample results and conclusions at the end of each tier to ensure that the 

steps taken in the next tier, when applicable, will be necessary and appropriate to 

adequately assess the potential impacts. Without the results of each tier, it is 

difficult to determine everything that might be required during the next phase of 

the assessment. 

A flow chart that was included as an attachment to the Agreed Order has been 

included as an attachment (Attachment 1) to this Response to Comments to provide 

additional clarity about the process. 

Comment #3: Soundkeeper is concerned that the plan ultimately provides for 

impermissible “self-regulation.” By the terms of the agreed order, Intalco would 

decide for itself whether it’s fugitive alumina emissions harm Puget Sound, and if so, 

what they are willing to do to address it. Federal case law cautions against “selfregulatory schemes” like this for strong policy reasons. See Waterkeeper Alliance v. 

EPA, 399 F.3d 486, 500 (2nd Cir. 2005); Environmental Defense Center v. EPA, 344 

F3.3d 832, 855 (9th Cir. 2003) (“...stormwater management programs that are 

designed by regulated parties must, in every instance, be subject to meaningful review 

by an appropriate regulating entity to ensure that each such program reduced the 

discharge of pollutants” to meet applicable standards”). How will Ecology ensure 

that Intalco’s plan will effectively reduce the discharge of fugitive alumina ore to the 

Strait of Georgia?

The Agreed Order requires Intalco to conduct the study and for Ecology to assess 

the information provided in each tier of the study. As such, Intalco is not the one 
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making a decision about whether the sediments are being impacted; Ecology will be 

making that determination. And as stated in the last sentence of Condition V.6, 

“Ecology will determine the need for follow up action including source control and 

monitoring, mitigation, or remediation”. 

As the commenter noted, the permit includes a requirement to develop a fugitive 

alumina pollution prevention plan to effectively reduce the discharge of fugitive 

alumina to the Strait of Georgia. This plan is required irrespective of the findings 

of the fugitive alumina impact study. Ecology will review and approve the pollution 

prevention plan and Intalco will be required to implement it.

Comment #4: In addition, Soundkeeper is concerned that alumina dust is very 

lightweight and likely travels by wind and/or water current to a wide area surrounding 

Intalco’s loading dock. Does Ecology contemplate this broad range of impact? Or, is 

Ecology’s concern narrowly focused on the area immediately surrounding Intalco’s 

dock? Soundkeeper urges Ecology to consider the wider range of impacts to the 

Strait of Georgia. Ecology should require Intalco, as part of its Fugitive Alumina 

Emissions Impacts Study, to evaluate how far the dust travels from the dock both at 

the surface of the water and at the bottom. Intalco’s response to address its fugitive 

alumina dust discharges must consider the full range of impacts.

Ecology concurs with this statement that there is a potential for the fugitive 

alumina to travel by wind and water currents to a wider area and be deposited both 

horizontally and vertically. That’s why the third bullet in Condition V.4 requires 

the facility to “identify the likely fate of these emissions – spatially (x and y) and 

temporally”. 

2. Increased Stormwater Pond Action Levels

Soundkeeper notes that the stormwater pond action levels for total suspended solids (TSS) 

and aluminum at monitoring point STRMP are higher in the draft permit than they were in 

the 2007 permit. (Draft Permit, Condition S1.D.1 page 12) However, in the Fact Sheet, 

Ecology identifies that Intalco exceeded the previous TSS and aluminum stormwater pond 

action levels many times (11 for TSS, 15 for aluminum) between April 2007 and October 

2013. (Fact Sheet, page 61) How can Ecology justify raising the action levels when the 

facility’s track record demonstrated a pattern of exceedences?

In the Fact Sheet, Ecology justifies raising the stormwater pond action levels by looking at 

the Facility’s “great improvements” in stormwater BMPs and ability to meet outfall effluent 

limits. (Fact Sheet, page 61) Soundkeeper is not persuaded that these are adequate reasons 

to increase these numbers. Aren’t the action levels designed to gauge the effectiveness of 

stormwater source control BMPs? How can Ecology conclude that Intalco’s stormwater 

source control BMPs are adequate when it consistently exceeded previous action levels? 

Even if Ecology observed “great improvements”, the lower action levels should be retained 

so that Intalco continues to improve its sources control BMPs. Aren’t the action levels also 
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designed to alert the facility of potential spills to the stormwater drainage system in time to 

prevent discharge of the spill to surface water? How does raising the action levels maintain 

protection against the discharge of a spill to surface water?

Soundkeeper also notes that the time period during which an inspection of the drainage area 

is required following an action level exceedence was increased from 48 hours in the 2007 

permit, to 72 hours in the current draft. (Draft Permit, page 12) How does Ecology justify 

loosening this requirement? If one purpose of an inspection is to prevent ongoing 

exceedences, wouldn’t the loosening of this requirement increase the likelihood of ongoing 

exceedences? And, wouldn’t this revision render an inspection less useful because as the 

period of time from exceedence increases, information to explain the exceedence may 

become less available?

Soundkeeper further notes that the 2007 permit requirement for Intalco to produce a report in 

the event that it exceeded an action level more than 5 times in a 12 month period is missing 

from the current draft. (2007 Permit, Condition S.1.C.2(d), page 15) Why was this 

requirement removed from the permit?

Response to Comment 2: There are many questions and comments presented in this 

comment. They have been divided below with the associated response.

1. How can Ecology justify raising the action levels when the facility’s track 

record demonstrated a pattern of exceedences? Aren’t the action levels 

designed to gauge the effectiveness of stormwater source control BMPs? 

How can Ecology conclude that Intalco’s stormwater source control BMPs are 

adequate when it consistently exceeded previous action levels? Aren’t the 

action levels also designed to alert the facility of potential spills to the 

stormwater drainage system in time to prevent discharge of the spill to surface 

water? How does raising the action levels maintain protection against the 

discharge of a spill to surface water?

There are two reasons the action levels were adjusted in the proposed 

permit: 1) the sample point for the stormwater stream changed during the 

permit cycle and 2) the fact that the previous action levels were established 

using best professional judgment (BPJ) based on the data collected during 

the previous permit cycle. As discussed in the fact sheet, there have been a 

number of changes to the discharges at the facility during the last permit 

cycle. During the previous permit cycle, stormwater from the stormwater 

treatment pond combined with stormwater that was collected from the nonprocess areas of the site. The combined stormwater was discharged from 

Outfall 002 and the sample results from that stormwater were used to 

establish performance based action levels, using BPJ, in the previous permit 

renewal process. In 2010, the facility diverted the stormwater that was 

originally discharged from Outfall 002 to Outfall 001. After the diversion 
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structure was operational, the facility began collecting their stormwater 

samples directly from the stormwater pond effluent, instead of the combined 

stormwater. Since the stormwater stream was no longer the same stream as 

the stormwater stream that was used to establish the previous action levels, 

Ecology decided that new action levels should be established for the new 

stormwater stream. 

In order to establish new action levels, Ecology evaluated the sample results 

from a time period where inspections noted implementation of good BMP 

practices. As noted in the fact sheet, inspections of the facility during the 

permit cycle demonstrated greatly improved BMPs and Ecology did not 

identify any areas where additional improvement was necessary. Therefore, 

the sample results from the previous permit cycle were used to establish the 

new action levels for the stormwater pond effluent. Please refer to the fact 

sheet for more details about how the action levels were established. The 

action levels are still considered to be sufficient to detect a spill to the 

stormwater pond. 

Finally, the permit now includes permit limits for the stormwater at the 

diversion structure in addition to the action levels at the stormwater pond 

discharge. An exceedance of the permit limits will be a violation of the 

permit. 

2. Soundkeeper also notes that the time period during which an inspection of the 

drainage area is required following an action level exceedence was increased 

from 48 hours in the 2007 permit, to 72 hours in the current draft. (Draft 

Permit, page 12) How does Ecology justify loosening this requirement? If 

one purpose of an inspection is to prevent ongoing exceedences, wouldn’t the 

loosening of this requirement increase the likelihood of ongoing exceedences? 

And, wouldn’t this revision render an inspection less useful because as the 

period of time from exceedence increases, information to explain the 

exceedence may become less available?

While the maximum amount of time allowed before an inspection must be 

conducted has been increased, the requirement still states the inspection 

must be done as promptly as possible after receipt of sampling results. 

Ecology increased the timeframe within which to conduct an inspection 

from 48 hours to 72 hours to be consistent with a similar notification 

requirement in the Industrial Stormwater General Permit (ISGP). Ecology 

did not feel it was necessary to be more stringent at the Intalco facility, 

especially considering that they have a treatment system for their 

stormwater. 
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In addition, the permit now includes permit limits for the stormwater at the 

diversion structure. This provides additional incentive for the facility to 

conduct the inspection as soon as possible to ensure that they don’t exceed 

their permit limit and to prevent ongoing exceedances as well. 

3. Soundkeeper further notes that the 2007 permit requirement for Intalco to 

produce a report in the event that it exceeded an action level more than 5 

times in a 12 month period is missing from the current draft. (2007 Permit, 

Condition S.1.C.2(d), page 15) Why was this requirement removed from the 

permit?

The aforementioned requirement has been retained in the draft permit. It is 

now located in Permit Condition S1.D.3 Action Level Exceedances Report. 

Item d is the same requirement from the existing permit. The Action Level 

Exceedances Report was created to provide a better place for such analyses 

to be tracked and documented. 

No changes to the permit have been made to the permit in response to these comments. 

3. Removal of requirement to monitor for Aluminum in Secondary Wastewater Treatment 

System (SEC) Discharges

Intalco’s 2007 permit required it to monitor its SEC discharges for TSS, Flouride, 

Aluminum, Free Cyanide, PCBs and Flow. The draft permit eliminates the requirement to 

monitor SEC discharges for the latter four constituents. While the Fact Sheet identifies 

specific circumstances to justify removal of the PCB monitoring requirement, it does not 

adequately justify removal of the other three constituents.

In particular, Soundkeeper patently disagrees that Intalco should be relieved of the 

requirement to monitor for Aluminum based purely on two years of low discharge levels. 

Ecology has clear authority under RCW 90.48.260(1)(a) to require Intalco to continue 

monitoring its SEC discharges for the discharge of pollutants to the Strait of Georgia, and it 

should exercise that authority despite pressures from Intalco to scale back monitoring 

requirements. 

That an aluminum smelter, capable of producing approximately 307,000 tons of aluminum 

metal each year, would be relieved of the requirement to monitor its SEC discharges for 

aluminum is baffling.

Response to Comment 3: First, aluminum is the only monitoring requirement that has 

been removed in the proposed permit. As specified by Permit Condition S2.A.1(12), 

Intalco is still required to monitor for flow, free cyanide, and PCB’s, in addition to TSS 

and fluoride. The frequency of monitoring for PCBs was decreased, as discussed in the 

fact sheet. Second, the monitoring required at the effluent is to demonstrate compliance 
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with action levels for TSS and fluoride and as a potential indicator of a leak from one of 

the landfills for free cyanide and PCBs. The action levels were developed to ensure that 

the Permittee was consistently implementing the required BMPs designed to reduce or 

eliminate the respective pollutants, evaluating the cause of any upward trends in pollutant 

discharges, and taking corrective action to reverse those trends. The previous permit did 

not have an action level for aluminum and it was not being used as an indicator of a leak 

from the landfills. As part of the permit renewal process, Ecology evaluated whether action 

levels should be developed for aluminum and determined that it was not necessary. As a 

result, Ecology felt that the monitoring the SEC effluent for aluminum was no longer 

necessary. 

Please note that aluminum is still required to be monitored in the combined process 

wastewater effluent (monitoring point 101) before it is discharged from Outfall 001. There 

is a limit for aluminum at this point and an exceedance of this limit would be a violation of 

the permit. 

No change was made to the permit in response to this comment. 

4. Whole Effluent Toxicity (WET) Provisions

Intalco’s 2007 permit did not even contain WET limits for Outfalls 001 and 002. 

Soundkeeper supports the inclusion of WET limits in this permit. Simply including WET 

limits is a substantial improvement over the previous permit. However, Soundkeeper has 

some concerns about the WET requirements as laid out in draft conditions S15 and S16.

Soundkeeper was a party to the 2012 appeal of the BP Cherry Point Refinery permit and 

Pollution Control Hearings Board (PCHB) proceedings resulting in the PCHB’s decision on 

the acute WET effluent limitation (order on summary judgment, July 26, 2013). The Court 

of Appeals granted direct review of that decision in February 2014. The pending Court of 

Appeals case is fully briefed, and a hearing is expected this winter. Soundkeeper has also 

appealed the December 2, 2013, modification to the BP permit to the PCHB. Soundkeeper 

also appealed the 2014 Phillips 66 permit to the PCHB.

For the following reasons, Soundkeeper asserts that the WET provisions in Intalco’s draft 

permit, specifically conditions S15 and S16, are inadequate to comply with either state law of 

the terms of the July 26, 2013 PCHB order in the BP Appeal.

a. The Permit Should Prohibit Toxic Discharges

The August 2014 fact sheet issued along with Intalco’s draft permit did not mention the 

July 26, 2013 PFHB order in the BP appeal or address whether Ecology purports to 

comply with that order with this draft permit. As noted above, that order has been 

appealed to the Court of Appeals. As part of this ongoing legal debate, Soundkeeper 

insists that the order reflects a faulty interpretation of state law on WET effluent 

limitations.
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Soundkeeper maintains that the permit may not authorize a discharge that fails the 

compliance test for acute or chronic WET, thus violation the effluent limit for acute of 

chronic toxicity. Washington’s water quality standards prohibit the discharge of toxic 

substances that cause acute or chronic toxicity in the receiving waters. WAC 173-

3201A-240. The following prohibition is found in state statue: “In no event shall the 

discharge of toxicants be allowed that would violate any water quality standard, including 

toxicant standards, sediment criteria, and dilution zone criteria.” RCW 90.48.520. The 

purpose of the WET testing under WAC 173-205 is to determine whether a discharge is 

toxic and subject to the prohibition. This regulation describes monitoring for compliance 

with WET limits, and states that the compliance test “shall be considered to be a 

maximum daily discharge permit limitation.” WAC 173-205-070(1)(d) and 173-205-

070(2)(d).

The test for permit compliance must be the same as the compliance test for acute and 

chronic toxicity, as defined by the regulation. The permit may not authorize a toxic 

discharge, which is one that fails the acute of chronic toxicity compliance test. Sections 

15 and 16 already provide procedures for Intalco to demonstrate that a failing WET test is 

an anomaly to invalidate it. There is not legal, practical, or rational basis for 

interpretation of these state laws and regulations that would allow authorization of any 

discharge that fails a WET compliance test. Sections 15 and 16 should be rewritten to 

effect the prohibition on toxic discharges be equating and failure of the compliance test 

with violation of the acute of chronic WET effluent limitation and the permit.

b. The Anomaly Allowance Should be Singular, Not Quarterly

Even assuming acceptance of the PCHB’s interpretation in its July 2013 order in the BP 

case, the proposed provisions in Intalco’s draft permit are problematic. These provisions 

as drafted make violation of the permit contingent on the failure of a follow-up WET test 

for each regularly scheduled acute and chronic WET compliance test failure. In other 

words, no failure of a regularly scheduled WET test would constitute a permit violation 

unless a subsequent test is also failed. This is unacceptable. Repeated failures of 

regularly scheduled WET test indicate an ongoing pattern of toxicity regardless of the 

results of each follow-up test. S15 and S16 should clarify that any failure of any WET 

test following the first failure recorded during the permit constitutes a permit violation.

Soundkeeper recognizes that the proposed language represents a minor improvement over 

similar language in other permits, including BP’s. Specifically, S15.C. and S16.C. 

include mention of a situation where a toxicity test may be “a violation of the permit”. 

However, the language still fails for lack of clarity, and the provisions still suffer from 

the fundamental problems noted above. 

Soundkeeper would point to the WET limit language that Ecology’s Northwest Regional 

Office incorporated into NPDES Permit No. WA0031968 for Seattle Iron & Metals 
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Corporation as a more appropriate permit drafting response to the PCHB’s order on WET 

Limitations.

Response to Comment 4: With respect to part a of the comment, the WET language in 

Conditions S15. and S16. is consistent with the PCHB’s decision regarding 

exceedances of WET limitations. The Board deferred to Ecology’s determination that 

a single WET limit exceedance does not indicate a pattern of toxicity. Instead, it 

triggers additional testing aimed at determining if there is continued toxicity and a 

violation of the toxicity standard in the permit. If any of the subsequent tests fail the 

WET limit, that test failure is a violation of the permit. 

Ecology does intend to follow the decision made by the Court of Appeals if the PCHB 

ruling is overturned. How that decision will be implemented in the permit will be based 

upon the Court’s direction to Ecology.

With respect to part b of the comment, while the proposed permit language may not 

cover the exact scenario described in the comment, the permit is not the only tool that 

Ecology has to address this situation. Follow up testing for repeated failures in 

compliance monitoring would be a very costly scenario for any permittee. As such, the 

permittee would have an incentive to initiate the TI/RE process on their own accord, in 

accordance with WAC 173-205-090(4). An additional incentive is the ability for 

Ecology to reduce compliance monitoring during the TI/RE process if the conditions of 

WAC 173-205-100(4) are met. 

WAC 173-205-090(2) requires that any permittee failing the compliance test for a 

whole effluent toxicity limit shall take all reasonable actions to achieve compliance 

including conducting a TI/RE. If the described scenario occurred and the permittee 

did not initiate the TI/RE on their own accord, Ecology would have the authority to 

issue an order requiring the facility to conduct a TI/RE. 

5. Creosote Pilings

Intalco’s dock, which was built in 1971, is supported by creosote-treated wood piling. This 

concerns Soundkeeper because it is well-established that creosote is highly toxic to forage 

fish, including the genetically unique stock of Cherry Point Pacific Herring. Soundkeeper is 

especially worried by reports that the artificial surface lighting on Intalco’s dock attracts 

herring to the pilings, and that the polycyclic aromatic hydrocarbon (PAHs) in the creosote 

cause Herring spawning failure. Given that creosote leached into the environment and 

contributes to the decline of the Cherry Point Pacific Herring stock, Intalco should be 

required to eliminate its discharge of creosote to the Strait of Georgia. Soundkeeper urges 

Ecology to create a schedule to require Intalco to either replace or encapsulate its creosote

pillions with a more benign material. Ecology should look at the Squamish Streamkeepers 

work in Howe Sound as a cost-effective example of piling encapsulation. 

http://www.sqterminals.com/community/involvement/squamish-streamkeepers/
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Response to Comment 5: While Ecology understands the concern expressed in this 

comment, the transfer of pollutants from the pilings to the surface water is not considered 

to be within the scope of this permit, which regulates the point source discharge of

pollutants. The Department of Natural Resources (DNR), the Army Corps of Engineers, 

or another agency that regulates the dock may be able to require the measures that you 

propose and you should contact them for more information. 

No change was made to the permit based on this comment. 

Comments received from Intalco (Comments 6 – 36)

6. S1.D.3 Action Level Exceedance Report (pg. 13 of 79): Intalco is requesting the 

following language clarification to ensure the semi-annual action level Exceedance report 

can be completed on time with all of the necessary data. The semi-annual report 

requirement in the draft permit does not clearly define the time-periods for each of the 

semi-annual reports. Accordingly, Intalco requests that Ecology include the following 

additional language in permit condition S1.D.3:

“The Permittee shall submit an Action Level Exceedance Report no later than July 15th

and January 15th of each year. The semi-annual reports shall represent January through 

June and July through December, respectively. The semi-annual report shall include...”

Response to Comment 6: Ecology concurs that the suggested language provides clarity 

to the requirements of Permit Condition S1.D.3. The changes were made as requested.

 

7. S1.D.4 Visual Inspections of the Stormwater Discharges (pg.14 of 79): Intalco requests 

to continue to use facility specific Best Management Practices (BMPs) and remove the 

more generalized S1.D.4 language from the permit.

Response to Comment 7: The visual inspections required by permit Condition S1.D.4 

are necessary to evaluate the effectiveness of the BMPs associated with the discharge. 

The visual inspections are essential to ensure that the stormwater is being 

appropriately managed prior to discharge. However, when Ecology compared the new 

language in the proposed permit to the inspection language in the existing permit, we 

noted that the proposed language specifically requires inspection of the stormwater 

discharge. In this case, the term discharge can either be interpreted as the discharge 

point or, more specifically, the flow of stormwater from the discharge point. Ecology 

recognizes that there will be some months during the year where stormwater is not 

discharged, but it is still important to inspect the stormwater discharge points to 

identify illicit discharges or other pollutants that could indicate that the BMPs need to 

be evaluated. 

The first two sentences of Permit Condition S1.D.4 have been modified as follows: 

“The Permittee must conduct monthly inspections of the stormwater pond discharge 
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point (Monitoring Point STRMP), Outfall 011, and Outfall 012. The inspections must 

be conducted by qualified personnel. 

Each inspection must include visual observations of the stormwater sampling locations 

and areas where stormwater is discharged to waters of the state for the presence of 

potentially deleterious pollutants, such as floating materials, visible sheen, 

discoloration, turbidity, odor, or presence of illicit discharges, such as domestic 

wastewater, noncontact cooling water, process wastewater, etc.“

8. S2.A.1 Monitoring Schedule, MP51 (pg. 17 of 79): Intalco has an extensive set of data 

documenting the consistent nature of the pH from the sanitary lagoon, which 

demonstrates that since 2011 the pH has very low variability. Minimum pH since 2011: 

6.10 Maximum pH since 2011: 7.63. From October 2013 to October 2014: pH 

variability: pH Max: 7.63, pH Min: 6.44. Thus, Intalco requests a reduction in 

minimum sampling frequency from 3 times per week to 1 time per week.

Response to Comment 8: Based on the information provided in this comment, the 

monitoring frequency for pH in the sanitary effluent has been reduced from three 

times per week to one time per week, as requested. 

An additional footnote (footnote aa) has been added to the monitoring table associated 

with all the parameters that have received reduced monitoring during the previous 

permit renewal process and this permit renewal process. The footnote states “The 

monitoring frequency for this parameter has been reduced based on exemplary 

performance. To remain eligible for these reductions, the Permittee may not have any 

violations off effluent limitations or exceedances of the action level for this parameter 

or fail to submit DMRs. Violations of the effluent limit or exceedance of the action 

level for the parameter, failure to submit DMRs, or any other formal enforcement 

action may require increased monitoring. If such increased monitoring is deemed 

necessary by Ecology, the new monitoring frequency will be established by a minor 

permit modification or an Administrative Order.” 

9. S2.A.1 Monitoring Schedule (11) Stormwater Pond Action Level Monitoring MP 

STRMP (pg. 20 of 79):-pH grab sample-The facility continuously monitors pH of the 

stormwater at the STRMP monitoring point, during a storm event Intalco is required to 

collect a grab sample and measure pH. Intalco requests the ability to use pH data from 

the calibrated continuous monitoring pH probes, which collects data from the same 

stormwater flow, to meet this requirement in lieu of collecting grab samples. This pH 

characterization method meets the intent of the requirement and offers equivalent 

environmental protection. 

Response to Comment 9: Ecology concurs that continuous monitoring for pH will 

demonstrate compliance with the action levels for the Stormwater Pond. The permit 

has been modified to require continuous pH monitoring during the storm event and to 
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require that the instantaneous maximum and minimum be recorded once per storm 

event. 

10. S2.A.1 Monitoring Schedule, MP SEC (pg. 21 of 79): Intalco requests addition of a new 

footnote for the potential of a Natural Engineering Wastewater Treatment (NEWT) 

system, designed to treat free cyanide. With completion of the project, Ecology may 

approve discontinuation of free cyanide testing at the SEC upon written request.

Response to Comment 10: Ecology concurs that the addition of the NEWT system has 

the potential to address the concern that free cyanide may possibly be discharged to the 

SEC from the closed landfills. However, Ecology will need to evaluate the monitoring 

data before allowing a reduction in the monitoring frequency at the SEC for free 

cyanide. A new footnote has been added to the monitoring table to reflect this 

possibility. Footnote bb states “The Permittee may request a reduction in the 

monitoring frequency of free cyanide at the SEC once the Natural Engineering 

Wastewater Treatment (NEWT) system has been operational for at least 12 months. 

Based on the free cyanide results at the SEC for a 12 month period, the monitoring 

frequency may be reduced upon written notification from the Department.”

11. S2.A.1 (14) Monitoring Schedule, Production Data (pg. 21 of 79): Intalco is requesting 

the units be changed from “People on-site/Day” to “monthly personnel count.” This 

change would make the units consistent with the language in S1.A. footnote (c) for 

Monitoring Point 51: “monthly average of personnel working on site...”.

Response to Comment 11: Ecology concurs that language between the limits table in 

Permit Condition S1.A and the monitoring table in Permit Condition S2.A.1for a 

specific parameter should be the same. The units and specification column for 

“personnel” has been modified to “personnel working onsite”, as specified by 

footnote(c) for Permit Condition S1.A. 

12. S2.A.1 Footnote (i) (pg. 22 of 79): Footnote (i) requires continuous monitoring 

instruments to achieve an accuracy of 0.2 degrees C. This provision appears to be a 

typographical error which is inconsistent with temperature calibration and tolerance 

requirements as specified by the EPA Code of Federal Regulations (40 CFR 136) and 

standard methods for the examination of water and waste water. 

Preamble language to the CFR mentioned above suggests that the EPA has adopted the 

National Environmental Laboratory Accreditation Committee (NELAC) requirement for 

temperature requirements. The NELAC standard provides 4 ± 2 oC for sample 

preservation temperature. Moreover, the EPA has proposed a ≤6.00 oC (unfrozen) 

sample preservation temperature because maintenance of a 4 ± 2 oC temperature requires 

an active refrigeration system (which will raise sample shipping costs), and because EPA 

is not aware of any evidence to suggest that allowing refrigeration below 2 oC (the lower 

limit of NELAC standard) will adversely affect samples. 
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Based on the above, Intalco respectfully request that the agency change the language of 

this requirement to require that continuous monitoring instruments be maintained to +/- 2 

degrees C, or to the manufacturer’s recommended tolerance.

Response to Comment 12: The referenced NELAC standard is for the preservation 

temperature required for storage of samples prior to analysis; it is not referring to the 

accuracy of temperature gauges for measuring the temperature of the wastewater 

effluent. An accurate measurement of the temperature of the effluent is important to 

be able to demonstrate that there is not a reasonable potential for the effluent to 

degrade the water quality of the receiving water. However, since the permit does not 

include any limits for temperature at any of the outfalls, the footnote has been revised 

to state “continuous monitoring instruments must achieve an accuracy of 0.2 degrees 

C (or as otherwise approved by Ecology)”.

 

13. S2.A.1 Monitoring Schedule, MP D10, Footnote (r) (pg. 23 of 79): The requirement to 

sample at MP D10 shall trigger based on a storm event defined in footnote (r) except that 

the required monitoring frequency should be changed in the footnote to not to exceed 

once per week.

Response to Comment 13: The footnote for the parameters in this section should have 

been (v). This has been corrected in the final permit

14. S2.A.1 Footnote (n) (pg. 23 of 79): Intalco requests the third sentence of footnote (n) be 

removed. The sanitary lagoon system only treats facility sanitary wastewater in a 

continuously operating passive system. As a 24/7 facility Intalco’s sanitary operations 

have a very low level of variability week to week, with limited inputs to the system. The 

required 24 hour composite samples will be similar irrespective of which week of the 

month is sampled. Data analysis and review demonstrates that in the past year the 

maximum TSS discharge was 7.4 lbs/day, which is only 22% of the weekly maximum 

limit. Similarly, the BOD maximum discharge was 15.5 lbs/day, which is 48% of the 

weekly maximum limit. All other results were below these values, with average TSS of 

1.26 lbs/day (1.73 lbs/day std dev) and average BOD at 5.41 lbs/day (4.5 lbs/day std dev).

Response to Comment 14: Because the information provided with the comment 

demonstrates the low variability of BOD in the sanitary effluent, Ecology has made the 

change as requested. 

Please note that Permit Condition S2.B requires that sampling be representative of the 

discharge, including any unusual discharge or discharge condition. 

15. S2.A.1 Monitoring Schedule, PUD Intake Water: S2A.1 Footnote (z) (pg. 24 of 79): 

Intalco requests that Ecology replace the second sentence of footnote (z) with the 

following: “Sampling is required at the PUD inlet only when Intalco nets out pollutants.”
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Response to Comment 15: Permit Condition S1.A.1 allows the facility to net out certain 

pollutants that are present in the water that is supplied to the facility. In order to be 

able to net out, the facility must be able to characterize the intake water appropriately. 

As such, Ecology considers sampling of the influent water to be required sampling for 

the facility. However, Ecology understands that the facility may choose not to net out 

the pollutants at certain times, and indicated that sampling is not required during those 

instances in Footnote (z) for Permit Condition S2A.1. The comment does not describe 

the concern with the proposed language in the draft permit and does not provide a 

justification for the changed language. Without an explanation as to how the facility 

would be able to predict when sampling of the intake water would not be necessary, 

Ecology has retained the requirement for sampling the intake water. 

While reviewing this comment, Ecology noted that the language was specific to the 

months when the facility does not net out, which does not represent all of the sampling 

periods. The language has been modified as follows: “Sampling is not required 

during a respective sampling period if Intalco does not plan to net out during that 

sampling period for that pollutant.” 

Ecology also noted that the reporting requirements specified in the Monitoring 

Requirements condition (Permit Condition S2) did not include a requirement to report 

the net loading rate for the pollutants that are allowed to net out. A requirement to 

report the calculated net loading rate has been added for TSS, aluminum, nickel, and 

antimony. Language has also been added to Footnote a to specify how the net loading 

rate should be calculated. In addition, the language in Permit Condition S1.A.1

describing the information that must be included in the DRM summary sheets has been 

removed. This data will be required to be submitted with the electronic DMR instead of 

on a summary sheet. 

16. S2.A.2 Temporary Curtailment Reduced Monitoring Frequencies, MP 101 (pg. 24 of 

79): Intalco recommends adding fluoride and free cyanide to the table for Outfall 001 

(monitoring Point 101) at a monitoring frequency of once per month. Curtailment 

activity will similarly lead to reduced risk of contamination from these pollutants, thus 

justifying a reduction to a once per month monitoring frequency.

Response to Comment 16: While Ecology understands that curtailment activity will 

lead to reduced risk of contamination from fluoride and free cyanide generated by 

production activities at the facility, production activities are not the only source of 

fluoride and free cyanide to Outfall 001. The leachate collection systems for the closed 

landfills at the facility are also sources of these contaminants to the wastewater 

generated by the facility and discharged from Outfall 001. The leachate from the 

closed landfills will not be affected by curtailment activities and monitoring for these 

contaminants in the discharge at the same frequency as when the plant is fully 

operational is still considered to be necessary during curtailment periods. The facility 

can petition for a reduction in monitoring in accordance with Permit Condition S2.E if 
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sufficient data is gathered to demonstrate that the specified frequency is no longer 

necessary. 

No changes have been made to the permit. 

17. S2.A.2 Temporary Curtailment Reduced Monitoring Frequencies, MP STRMP (pg. 24 of 

79): Intalco is requesting a reduction in the stormwater pond action level monitoring if 

the facility enters a curtailment scenario. The facility requests sampling for all 

parameters listed in the table occur a maximum of once per week. The potential 

concentration of stormwater pollutants will be reduced with the reduction in operations 

during a curtailment. 

Response to Comment 17: As specified by Permit Condition S2.A.2(3), monitoring for 

TSS, Fluoride, and Aluminum has already been reduced to once per week during 

curtailment and only if there is a storm event. The heading for this subsection was 

changed to “Stormwater Pond Action Level Monitoring (Monitoring Point STRMP)” 

to better distinguish this requirement. The only monitoring that continues to be 

required during curtailment is flow and pH, both of which are continuously monitored. 

Flow is required to determine if a storm event has occurred and pH is an indicator of a 

potential spill to the stormwater pond. 

No change has been made to the permit with respect to the comment. 

18. S2.A.2 Temporary Curtailment Reduced Monitoring Frequencies, Footnote (a) (pg. 25 of 

79): Footnote (a) – Intalco recommends adding to the footnote “Monthly means once 

every calendar month, alternating weeks within the month when practicable.”

Response to Comment 18: Ecology has made the change as requested. 

19. S2.C.3.b Flow Measurement, Field Measurement and Continuous Monitoring Devices 

(pg. 26 of 79): This calibration requirement is inconsistent with calibration based on 

manufacturer’s recommendations. Intalco recommends changing the language to the 

following:

“The Permittee shall calibrate the continuous monitoring probes using a 2 point 

calibration with standard pH buffers or per the manufacturer’s recommendations.”

Calibrating the continuous monitoring probes in the manner is consistent with 

manufacturer’s recommendations and better meets the intent of the requirement.

Response to Comment 19: Ecology has made the change as requested. 

20. S3.A.1. Reporting (pg. 27 of 79): Intalco requests that a secondary process be established 

in the permit to submit the DMR data if there are unforeseen circumstances. For 

example, if the Department of Ecology website is down, then there should be an 

alternative procedure for timely submittal of DMRs. Intalco recommends the following 
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language be added: “If unable to submit electronically, the Permittee may submit paper 

or email copies of results to their industrial section contact along with documentation of 

the reason for submitting the alternate copies. The facility will resubmit the data to the 

Ecology web system as soon as practicable, when it again becomes available.”

Response to Comment 20: Ecology is requiring the electronic submittal of DMRs in 

response to EPA’s proposed NPDES Electronic Reporting Rule. It is expected that the 

final rule will have language to address the concern presented in this comment. 

Ecology does not want to include language, such as the proposed language, in NPDES 

permits at this time in case it is less stringent than the final rule. Ecology will have 

enforcement discretion if such a violation were to occur and would take the unforeseen

circumstances into account. The permit does not preclude Intalco from taking the 

actions described in the above comment. Ecology would also take such actions into 

consideration. No changes have been made to the permit.

21. S3.A.5.b. Reporting (pg. 27 of 79): Intalco believes that the methods of averaging data 

identified in this section could inadvertently bias data. Accordingly, Intalco is 

recommending adding the language, “or by the agency”, to allow for increased agency 

flexibility in order to accommodate unanticipated circumstances that could unduly bias 

results.

“Calculate average values (unless otherwise specific in the permit, or by the agency) 

using:

a. The reported numeric value for all parameters measured between the agency-required 

detection value and the agency-required quantitation value....

b. One-half the detection value (for values reported below detection) if the lab detected 

the parameter in another sample from the same monitoring point for the reporting 

period.”

Response to Comment 21: Calculating an average value for pollutants that are 

detected in one sampling event but not in another during the same monitoring 

period will always create a potential bias, no matter what method you use to 

calculate the average (i.e. assuming zero or assuming half of the detection level). 

However, the detection of the analyte in another sample during the same 

monitoring period provides evidence that the analyte is present in the effluent 

stream. As such, the agency is establishing a standard procedure for all permittees 

so that everyone is performing the calculation in a consistent way. Adding the 

requested language would potentially create an inconsistency between your facility 

and other permitted facilities around the state and the comment does not provide 

sufficient information to demonstrate that such an inconsistency is necessary for 

this facility. 

No change has been made to the permit based on this comment.
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22. S3.A.3 Reporting (pg. 27 of 79): The permit states that if values are reported as below 

the detection level, the Permittee should document the method detection level of the 

method used. However, due to the high level of variability or inaccuracy of values below 

the method quantitation level, data below the quantitation level should not be used for 

compliance purposes. As a result Intalco recommends that all values below the 

quantitation and detection levels should be treated as zero.

Response to Comment 22: As stated in Section 4.3 of Chapter VI in Ecology’s Permit 

Writer’s Manual, “an analytical result that falls between the method detection limit 

(MDL) and the quantitation level (QL) means there is a level of certainty that the 

analyte is in the sample”. As such, assuming a value of zero for such samples is 

inappropriate. 

No change has been made to the permit. 

23. S3.E.2 Reporting Permit Violations (pg. 29 of 79): Intalco is requesting that when repeat 

sampling and analysis is required per this section, results of the analysis be submitted in 

the applicable monthly DMR, rather than within 30 days. Reporting of permit violations 

is already triggered in the 24 hour reporting requirements, which also includes a 

requirement to submit a 5 day follow-up report. Section S3.E.e also requires information 

submittal with the applicable monthly DMR. This will make the information more easily 

traceable and reports more complete.

Response to Comment 23: Ecology concurs that submitting any repeat sampling and 

analysis with the applicable monthly DMR will make it easier to track. The change has 

been made as requested. 

24. S4 Operations and Maintenance (pg. 31 of 79): Paragraph 1- Replace the sentence 

“Proper operations and maintenance also includes keeping operational logbooks (paper or 

electronic)’ with “Proper operation and maintenance also includes, but is not limited to, 

operational logbooks (paper or electronic), laboratory controls, and quality assurance 

procedures.”

Response to Comment 24: The requested change has been made to the permit. 

25. S4 Operations and Maintenance (pg. 32 of 79): Paragraph 2 – Intalco conducts both 

scheduled and unscheduled maintenance activities. Intalco has systems in place which 

are designed to minimize and to the greatest extent possible, avoid discharges which 

degrade effluent quality to waters of the state. These practices meet the intent of this 

provision and therefore Intalco requests the removal of paragraph 2 from the draft permit. 

Response to Comment 25: Meeting the intent of a requirement is not sufficient reason 

to delete the requirement from the permit. No change has been made to the permit. 
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26. S4.B. Bypass Procedures (pg. 33 of 79): Intalco requests addition of the following 

underlined language to clarify the intent of this provision: “this permit prohibits a 

bypass, which is the intentional diversion of waste streams from any portion of a 

treatment facility, unless the bypass meets the conditions listed below.”

Response to Comment 26: As stated in the third paragraph of Permit Condition S4.B, 

“Ecology may take enforcement action against a Permittee for a bypass unless one of 

the following circumstances (1, 2, or 3) applies”. The bypass is still prohibited. The 

conditions only indicate the circumstances under which Ecology will not enforce on 

the violation. This is a federal rule as specified by 40 CFR 122.41(m)(4). No change 

has been made to the permit. 

27. S4.B.3 Bypass Procedures (pg. 34 of 79): Intalco recommends the following language 

for S4.B.3.a: “The Permittee must notify Ecology at least thirty (30) days before the 

planned date of bypass, if possible.” While Intalco intends to notify Ecology 30 days in 

advance of any planned or anticipated bypass scenarios, there may be other 

circumstances, such as emergencies, that arise that could make 30-day advance 

notification impossible.

Response to Comment 27: Emergency situations as described in the comment are 

covered by S4.B.2. No change has been made to the permit. 

28. S10. Stormwater Pollution Prevention (pg. 38 of 79): Intalco recommends removal of the 

language “Comply with applicable federal technology-based treatment requirements 

under 40 CFR 125.3.” The remaining three conditions already meet the intent of this 

provision.

Response to Comment 28: The specified language was originally included because it is 

part of the Industrial Stormwater General Permit (ISGP). With stormwater being 

included as part of the Intalco’s individual NPDES permit, Ecology evaluated whether

Intalco was applying technology-based treatment for the stormwater generated on site. 

Ecology has determined that the stormwater pond is providing all known, available, 

and reasonable treatment technologies (AKART) for the facility stormwater. As such, 

Ecology concurs that the referenced language is not necessary for this permit. The 

permit has been modified as requested. 

29. S10.A Stormwater Pollution Prevention Plan Update (pg. 39 of 79): Intalco requests that 

the requirements referenced in bullet #3 for Permit Condition S3.B.1 of the Industrial 

Stormwater General Permit be added into the Intalco NPDES Permit for ease of 

reference. 

Response to Comment 29: The permit has been modified as requested. 

30. S15.A. Acute Toxicity – Outfall 002 Effluent Characterization (pg. 42 of 79): Intalco 

requests elimination of the requirement to conduct quarterly acute toxicity testing starting 
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in 4th Quarter 2014. Rather, quarterly acute toxicity testing should begin the first quarter 

after permit issuance, to be consistent with other toxicity characterization stated in the 

permit. 

Response to Comment 30: Comment noted. The permit has been revised to include the 

correct quarter to begin the effluent characterization for Outfall 002. 

31. Throughout Permit: Intalco has reviewed the timing of the study plans, studies, reporting 

requirements and other water related improvement projects at the facility and request the 

following changes to the project due dates to levelize project planning and execution and 

ensure quality outcomes. Specifically, Intalco is proposing to move 2 of these project 

timelines to manage the project load. The first project is the SEC Efficiency Study Plan 

(From the Summary of Permit Report Submittals (pg. 6 of 79)). Intalco requests 

changing the submittal of the plan from “within 6 months of Permit Issuance” to “Within 

24 months of permit issuance.” The second project is the Ground Water Impact Study 

(S19.1 (pg. 56 of 79)). Intalco requests changing “Conduct a Ground Water Impact 

Study within 180 days of Ecology’s approval of the Ground Water Impact Study Plan 

Submitted by Intalco dated February 26, 2010” to “Conduct a Ground Water Impact 

Study within 180 days of Ecology’s approval of the Ground Water Impact Study Plan 

Submitted by Intalco dated February 26, 2010, beginning no earlier than January 2017.”

Response to Comment 31: Many of the studies included in the draft permit are studies 

that were required in the previous permit. Ecology wants to ensure that the plans for 

these studies, where applicable, and the study itself are conducted during this permit 

cycle. At least some of the studies will require time to collect representative samples or 

may include schedules for implementing the results of the study. Therefore, the two 

requirements mentioned were scheduled to provide sufficient time to conduct the 

studies, provide the results, and implement any necessary actions, if applicable, before 

the next permit renewal application is due. 

The SEC Efficiency Study Plan will need to include a schedule for conducting the 

study. The facility may propose a schedule that takes into account the various other 

studies that will be occurring at the same time. 

No change has been made to the permit in response to this comment. 

32. Intalco Fact Sheet, Solids Management, (pg. 15 of 121) paragraph 4: In this paragraph, 

it is mentioned that Intalco will require removal of solids from the Sanitary Lagoon every 

10 to 15 years. The population of employees at the facility is approximately one half of 

the population used to develop the estimate, therefore the time between solids removal 

should be doubled to 20-30 years.

33. Permit Fact Sheet: Technology based effluent limits (pg. 32 of 121): To remain 

consistent between the Permit and Fact Sheet documents, Intalco is recommending the 
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following change to the language in paragraph 1, which discusses the anode cooling 

preliminary sampling results: Remove: “..., the draft permit requires the Permittee to 

complete the AKART analysis...” with, “if Intalco AKART analysis during the next 

permit cycle.”

34. Intalco Fact Sheet, (pg. 54 of 121): Intalco requests that the statement referencing Table 

22, regarding the whole effluent toxicity (WET) results from December 2010, be 

corrected. As enumerated in the Draft Permit and affirmed by Ecology, the December 

2010 WET results were anomalous. Therefore it is not correct to state that results from 

this test fail to meet the requirements of the WET performance standards. If Ecology 

elects to Comment, then an accurate statement would be that the 2010 WET results were 

inconclusive.

35. Intalco Fact Sheet, (pgs. 68 & 69 of 121): Intalco requests that the herring embryo test 

duration be restated as 16 days, rather than 10 days, to be consistent with the 

requirements specified in Washington State Department of Ecology guidelines. 

Response to comments 32 through 35: Comments 32 through 35 are on the fact sheet, 

which provides information on how the permit conditions were established. The fact 

sheet is provided for informational purposes only and is not a legally enforceable 

document. As stated on Page 1 of the Fact Sheet, Ecology does not revise the fact sheet 

in response to public comments. Occasionally, Ecology will revise the fact sheet if 

there are significant changes made to the permit and it is necessary for the fact sheet to 

be revised to explain the changes or there is incorrect information in the fact sheet. 

Comments 32 through 34 do not require any changes be made to the permit and they 

did not identify errors in the fact sheet. 

Comment 35 does identify an error. Intalco is correct that the chronic toxicity test for 

herring is a 16-day test embryo development test and a 7-day larval survival and growth 

test, rather than a 10-day embryo survival and normal development test. However, the 

herring WET tests are not included as part of the NPDES permit and the facility is 

required by an order to follow the appropriate protocols when conducting the tests. 

The fact sheet is not a legal document and, therefore, does not affect the requirements 

for the herring testing. 

The fact sheet has not been revised based on these comments. These comments will be 

included in Appendix H of the fact sheet to document the observations made by Intalco 

about the contents of the fact sheet.

Comment received from the Department of Health (Comment 36)

36. The Health Department contact phone numbers are wrong on the top of page 30 on the 

permit (Section S3.E.a. Immediate Reporting). The numbers you have listed gets you 

our NW Regional Office for the Drinking Water Program (both business and after 

hours). The correct numbers are (360) 236-3330 (business hours) and (360) 789-8962 
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(after hours). The latter number goes to our rotating on-call smart phone. Alternately, 

you call also e-mail us at sf.growingarea@doh.wa.gov, which will also connect with 

whoever is carrying the smart phone. Thank you for your attention to this matter.

Response to Comment 36: Ecology appreciates the comment. The correct phone 

numbers and the email address have been included in the final permit. 

Internal Review Comments and Other Administrative Changes

As part of the permit finalization process, the proposed permit is reviewed by our permit 

database coordinator. She identified a few administrative changes that will provide 

clarity to the permit and assist in setting up the electronic DMR submittal forms. The 

changes that were made based on her review are as follows:

• The following changes were made to the Summary of Permit Report Submittals 

table on Page 5 of 80:

o The “First Submittal Dates” were updated to include specific dates, where 

applicable,

o Three discharge monitoring reports were added to clarify that there are 

monthly, quarterly, semi-annual, and annual discharge monitoring reports 

associated with this permit. The first submittal dates were included to 

specify when the first discharge monitoring report is due for each 

applicable monitoring report, 

o The toxicity test results required by Permit Condition S15.F and S16.F 

were split into the winter and summer submittals (4 submittals total) and 

the first submittal date for each of the submittals was updated to indicate 

the results are due within 45 days of sampling. The first submittal date 

also now includes a “no later than” due date to further clarify when the 

samples must be collected (i.e. no later than November 15, 2018 for the 

final summer samples and no later than May 1, 2019 for the final winter 

samples). 

The proposed permit indicated that the WET test results should be 

submitted with the permit renewal application, but that may be too late to 

address potentially anomalous results. Submitting the test results within 

45 days of sampling will provide Ecology the opportunity to review the 

results and alert the facility if there are any issues with the test results. 
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o Permit Condition S18 was modified to indicate that the facility is required 

to submit either an AKART evaluation or documentation of elimination of 

the anode contact cooling water discharge. 

• Permit Condition S1.A.1 was modified to remove the language about how to 

calculate the net loading rates for certain pollutants and how to report the results 

of those calculations. The language on how to calculate the net loading rates was 

moved to footnote a of the monitoring in Permit Condition S2.A.1. And the same 

monitoring table specifies the reporting requirements for those pollutants.

• The following changes were made to the monitoring table for Permit Condition 

S2.A.1:

o Added the requirement to report the calculated net loading rate in lbs/day 

on a monthly basis for TSS and aluminum and on a semi-annual basis for 

nickel and antimony.

o Added the requirement to monitor the flow of the PUD Intake Water (13). 

The parameter was added because the flow rate is necessary to calculate 

the lbs/day loading rate required for the pollutants monitored in the PUD 

intake water.

o As discussed above, footnote a was modified to include the method for 

calculating the net loading rate for those pollutants that are required to 

report a net loading rate. 

• Permit Condition S3.A.8.d has been modified to indicate that the priority pollutant 

monitoring results must be included with the annual DMR.

• Permit Condition S3 was modified to indicate that submittals must be submitted 

through the Water Quality Permitting Portal – Permit Submittals application. 

This requirement was added as Permit Condition S3.B and the existing Permit 

Condition S3.B was renumbered as S3.C, S3.C was renumbered as S3.D, etc. All 

requirements to submit a paper copy and PDF copy of a submittal were removed 

throughout the permit. 

• Permit Conditions S15.F.1.ii, S15.F.2.ii, S16.F.1.ii, and S16.F.2.ii were modified 

to indicate that the results of the toxicity tests required at the end of the permit 

cycle must be submitted within 45 days of collecting the sample, instead of with 

the permit renewal application. A “no later than” due date was also included to 
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clarify when the samples should be collected. These changes were implemented 

so that Ecology may review the results as soon as possible and identify any issues 

with the results. That way, if issues are indentified, the facility will have time to 

address those issues. 

Two additional changes were made during the permit finalization process:

• Intalco realized after the close of the comment period that the proposed permit 

changed the sample type from grab samples to 24-hour composite samples for the 

priority pollutant testing and for the toxicity testing at the Outfall 001 discharge. 

In order to maintain consistency with past sampling events, they requested that 

the priority pollutant testing and the toxicity testing be changed back to a grab 

sample. Even though this request was made after the end of the comment period 

and Ecology was not required to consider the request, we acknowledge the 

consistency will allow for better comparison of past and future sampling results. 

Ecology made the changes as requested. 

• Based on internal discussions about the permit renewal application, Ecology 

modified Permit Condition S6 to clarify the forms that will be required to be 

submitted with the new permit renewal application.
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Attachment 1 : Flow Chart for Agreed Order No. 10887