1,2-Dichloroethane
                                       1
                                       1
                                      0.4

1,2-Dichloropropane
                                       1
                                       1
                                      0.4

1,2-Diphenylhydrazine
                                       1
                                       1
                                      0.4

1,2-Trans-Dichloroethylene
                                       1
                                       1
                                      0.4

1,3-Dichlorobenzene
                                       1
                                       1
                                      0.4

1,3-Dichloropropene
                                       1
                                       1
                                      0.4

1,4-Dichlorobenzene
                                       1
                                       1
                                      0.4

2,3,7,8-TCDD (Dioxin)
                                       1
                                       1
                                    0.0005

2,4,6-Trichlorophenol
                                       1
                                       1
                                       1

2,4-Dichlorophenol
                                       1
                                       1
                                       1

2,4-Dimethylphenol
                                       1
                                       1
                                       1

2,4-Dinitrophenol
                                       1
                                       1
                                       1

2,4-Dinitrotoluene
                                       1
                                       1
                                      0.4

2-Chloronaphthalene
                                       1
                                       1
                                      0.4

2-Chlorophenol
                                       1
                                       1
                                       1

Acenaphthene
                                       1
                                       1
                                      0.1

Acrolein
                                       1
                                       1
                                       2

Acrylonitrile
                                       1
                                       1
                                       2

Anthracene
                                       1
                                       1
                                      0.1

Antimony
                                       1
                                       1
                                       1

Arsenic (total)
                                       1

                                      46
                                      46
                                      46
Benzene
                                       1
                                       1
                                      0.4

Benzidine
                                       1
                                       1
                                      10

Benzo(a) Anthracene
                                       1
                                       1
                                      0.1

Benzo(a) Pyrene
                                       1
                                       1
                                      0.1

Benzo(b) Fluoranthene
                                       1
                                       1
                                      0.1

Benzo(k) Fluoranthene
                                       1
                                       1
                                      0.1

Bis(2-Chloroethyl) Ether
                                       1
                                       1
                                      0.4

Bis(2-Chloroisopropyl) Ether
                                       1
                                       1
                                      0.4

Bis(2-Ethylhexyl) Phthalate
                                       1
                                       1
                                      0.4

Bromoform
                                       1
                                       1
                                      0.4

Butylbenzyl Phthalate
                                       1
                                       1
                                      0.4

Carbon Tetrachloride
                                       1
                                       1
                                      0.4

Chlorobenzene
                                       1
                                       1
                                      0.4

Chloroform
                                       1
                                       1
                                      0.4

Chrysene
                                       1
                                       1
                                      0.1

Copper (total)
                                       1

                                      10
                                      10
                                      10
Cyanide
                                       1

                                       5

Dibenzo(a,h) Anthracene
                                       1

                                       1

Dichlorobromomethane
                                       1

                                      0.4

Diethyl Phthalate
                                       1

                                      0.4

Dimethyl Phthalate
                                       1

                                      0.4

Di-n-Butyl Phthalate
                                       1

                                      0.4

Ethylbenzene
                                       1

                                      0.4

Fluoranthene
                                       1

                                      0.1

Fluorene
                                       1

                                      0.1

Hexachlorobenzene
                                       1
                                       1
                                      0.4

Hexachlorobutadiene
                                       1
                                       1
                                      0.4

Hexachlorocyclopentadiene
                                       1
                                       1
                                      0.4

Hexachloroethane
                                       1
                                       1
                                      0.4

Indeno(1,2,3-cd) Pyrene
                                       1
                                       1
                                      0.1

Isophorone
                                       1
                                       1
                                      0.4

Methyl Bromide
                                       1
                                       1
                                      0.4

Methylene Chloride
                                       1
                                       1
                                      0.4

Nickel (total)
                                       1

                                      42
                                      42
                                      42
Nitrobenzene
                                       1
                                       1
                                      0.4

N-Nitrosodimethylamine
                                       1
                                       1
                                      0.4

N-Nitrosodi-n-Propylamine
                                       1
                                       1
                                      0.4

N-Nitrosodiphenylamine
                                       1
                                       1
                                      0.4

Pentachlorophenol (PCP)
                                       1
                                       1
                                       1

Phenol
                                       1
                                       1
                                       1

Pyrene
                                       1
                                       1
                                      0.1

Selenium (total)
                                       1

                                      83
                                      83
                                      83
Tetrachloroethylene
                                       1
                                       1
                                      0.4

Thallium (total)
                                       1

                                      0.5
                                      0.5
                                      0.5
Toluene
                                       1
                                       1
                                      0.4

Trichloroethylene
                                       1
                                       1
                                      0.4

Vinyl Chloride
                                       1
                                       1
                                      0.4

Zinc (total)
                                       1

                                      55
                                      55
                                      55
Mercury (total)
                                       1

                                    0.0114
                                    0.0114
                                    0.0114
Source: Based on discharge monitoring reports submitted to Washington Department of Ecology, 2012 to 2014.
QL = Quantification limit

Receiving Water
The Strait of Georgia has been categorized by Ecology as extraordinary marine receiving water with characteristic uses including fish, shellfish, clam, oyster, and mussel rearing, spawning, migration, and harvesting; wildlife habitat, primary contact recreation, sport fishing, commerce and navigation, boating, and aesthetic enjoyment. The Strait is also part of the Cherry Point Aquatic Reserve. The BP Cherry Point facility's NPDES permit contains requirements pursuant to the Cherry Point Reserve Plan. Further, the Strait of Georgia is on the 303(d) list for benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, and chrysene concentrations in tissue (mussels) approximately 15 miles from the facility.
Exhibit A-35 summarizes the available ambient receiving water concentrations based on data from 1999 and 2005.
Exhibit A-35. Ambient Receiving Water Concentrations: Strait of Georgia
Parameter
Geometric Mean Concentration (dissolved; ug/L)
Copper
                                     0.673
Mercury
                                     0.001
Zinc
                                      3.9
Source: reported in 2012 Fact Sheet for BP Cherry Point NPDES permit (Appendix I) from Ecology's reasonable potential analysis.

Baseline Scenario
The permit does not include any WQBELs based on the existing human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-36 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-34 and available ambient data in Exhibit A-35, there is reasonable potential to exceed human health criteria for arsenic
Exhibit A-36. Human Health Reasonable Potential Analysis for BP Cherry Point[1]  -  Baseline Scenario
Parameter
Effluent Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                      46
                                      NR
                                     0.842
                                     0.14
NR = not reported
1. See effluent concentrations in Exhibit A-34 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-35.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 136.
3. Consumption of organisms only.

Exhibit A-37 summarizes the calculated permit limits for arsenic under the baseline scenario.
Exhibit A-37. Human Health Based Effluent Limitations for BP Cherry Point  -  Baseline Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                      19
                                      38
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 19 ug/L and a MDL of 38 ug/L. Arsenic was observed in the effluent at of 46 ug/L. Since the effluent monitoring data exceeds the applicable effluent limitations under the baseline scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of non-compliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the baseline scenario.
End-of-pipe treatment technologies capable of controlling arsenic include options such as chemical precipitation, microfiltration, and reverse osmosis. Given the limited nature of the information available regarding the internal process operations at the facility, EPA has assumed the use of reverse osmosis for arsenic control. Reverse osmosis is capable of reliably controlling arsenic at levels below the limit of quantitation. Further, EPA has assumed that treatment of the entire plant flow will be necessary. This is a conservative assumption as it is possible that a detailed study of the facility's internal process operations would result in a more targeted treatment strategy -- for instance, if only a single internal process flow was the source of the contamination, then only the contaminated stream would require treatment. EPA estimated a reverse osmosis treatment cost for a 3.87 mgd flow at $7,054,000 per year assuming an interest rate of 7 percent over 20 years.
Policy Scenario
Exhibit A-38 summarizes the RP analysis under the policy scenario. Based on effluent concentrations in Exhibit A-34 and available ambient data in Exhibit A-35, there is reasonable potential to exceed human health criteria for arsenic and mercury. However, ambient concentrations for mercury exceed the criteria.
Exhibit A-38. Human Health Reasonable Potential Analysis for BP Cherry Point[1]  -  Policy Scenario
Parameter
Baseline Average Monthly Effluent Limit or Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                      19
                                      NR
                                     0.842
                                    0.0059
Mercury
                                    0.0114
                                     0.001
                                    0.0012
                                    0.00088
NR = not reported
1. See effluent concentrations in Exhibit A-34 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-35.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 136.
3. Consumption of organisms only.

Exhibit A-39 summarizes the calculated permit limits for arsenic under the policy scenario.
Exhibit A-39. Human Health Based Effluent Limitations for BP Cherry Point  -  Policy Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                     0.81
                                      1.6
Mercury
                                    0.00088
                                    0.0018
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Arsenic
Under the policy scenario, the discharger would have to meet an AML of 0.81 ug/L and a MDL of 1.6ug/L. Under the baseline scenario, EPA estimated that the discharger would incur costs for end-of-pipe treatment using reverse osmosis which would likely result in an effluent quality performance at or near the limit of quantitation. However, if the facility has not yet achieved a level of performance which would result in immediate compliance with effluent limitations under the policy scenario, EPA has included costs associated with a P2 program which is likely to result in compliance.
Mercury
Under the policy scenario, the discharger would have to meet an AML of 0.00088 ug/L and a MDL of 0.0018 ug/L. The maximum effluent concentration is 0.0029 ug/L and the average effluent concentration is 0.0019 ug/L. Based on the available data, the discharger will likely need to reduce mercury in its effluent to ensure that permit limits are consistently met.
Because there are no proven end-of-pipe treatment technologies that can achieve low mercury levels (e.g., <10 ng/L) on a consistent basis, the facility would likely implement a P2 program for compliance with the projected effluent limits. Annual P2 program costs for this industrial facility are estimated to be approximately $28,000. To ensure compliance in case a P2 program would not be sufficient to meet the projected effluent limitations, EPA assumed that the facility would incur costs for a variance.
Cosmo Specialty Fibers
Cosmo Specialty Fibers (NPDES permit WA0000809) operates a paper mill that produces dissolving pulp of the acetate, viscose, and ether grades with a permitted capacity of 550 tons per day. Average flow is approximately 24 mgd, and the facility discharges to Grays Harbor and Chehalis River.
Treatment Processes
Primary treatment consists of an ash clarifier, a disco strainer, a Brinkley screen, and a sweet sewer settling basin. Secondary treatment consists of four aeration lagoons, two clarifiers, and disinfection. Wastewater is routed to a system of storage ponds and then discharged through Outfall 1. Stormwater, truck wash overflow, and filter plant backwash are discharged through Outfall 2.
Effluent Data
Exhibit A-40 summarizes 2012 to 2014 effluent monitoring data for the facility discharge monitoring reports for Outfall 1. Data are not available for Outfall 2.
Exhibit A-40.  Summary of Effluent Data (2012-2014): Cosmo Specialty Fibers, Outfall 1
Pollutant
Number of Observations
Detected Values (ug/L)

Total
Nondetects
95[th] Percentile
Median
2,3,7,8-TCDD (dioxin)
                                      14
                                      13
                                   0.000002
                                     nd[1]
2,4,6-Tricholorophenol
                                      32
                                      32

Chloroform
                                      32
                                       1
                                     28.85
                                     19.1
Pentachlorophenol (PCP)
                                      32
                                      32

Source: Discharge monitoring reports, 2012 to 2014
nd = nondetect
1. Discharge monitoring report data notes various detection limits for dioxin, between 1 ug/L and 9.3 ug/L.

Receiving Water
The facility discharges to Grays Harbor (via Outfall 1), a Class B marine water, and Chehalis River (via Outfall 2), a Class A fresh water. Ambient data for these waters are not available.
Baseline Scenario
The NPDES permit for facility does not have WQBELs based on human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. Based on the effluent concentrations in Exhibit A-40, there is no reasonable potential to exceed criteria for the pollutants of concern. Therefore, there are no costs associated with achieving compliance with the baseline scenario.
Policy Scenario
Based on the effluent concentrations in Exhibit A-40, there is no reasonable potential to exceed criteria for the pollutants of concern. Therefore, there are no costs associated with achieving compliance with the policy scenario.
Intalco Aluminum Corporation
Intalco Aluminum Corporation operates multiple wastewater treatment plants that combine and discharge to the Strait of Georgia. The facility produces primary aluminum metal from alumina ore using the Hall-Heroult reduction process. Wastewater associated with the industrial process includes contact and non-contact cooling water for metal casting and anode production, and wastewater generated from wet air pollution control systems. Additionally, the facility generates domestic wastewater, wastewater from steam cleaning operating systems, and some stormwater. Average flow is 3 mgd.
Treatment Processes
The 2014 permit fact sheet for the facility (p. 10) states that the facility treats wastewater from the casting process and from the wet scrubbers using primary treatment consisting 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. Secondary treatment includes an equalization tank and two treatment trains consisting of reaction tanks and flocculation tanks that feed into a clarifier.
Anode cooling water, which is contaminated with coke and pitch containing benzo(a)pyrene, is treated using a baffled settling chamber (fact sheet, p. 11).
Domestic sanitary wastewater treatment consists of inlet vault, lagoon system, outlet weir box, and ultraviolet disinfection (fact sheet, p. 11).
Effluent Data
Exhibit A-41 summarizes 2010 to 2013 effluent monitoring data for the facility from the permit fact sheet.
Exhibit A-41. Summary of Effluent Data (2010 to 2013): Intalco Aluminum Facility
Pollutant
Number of Observations
Maximum (ug/L)
Average (ug/L)
Acenaphthene
                                       5
                                      0.6
                                     0.25
Anthracene
                                       5
                                      0.5
                                     0.04
Antimony
                                       9
                                      17
                                      3.6
Arsenic
                                       5
                                      50
                                     27.4
Benzo(a) Anthracene
                                       5
                                      1.6
                                     0.53
Benzo(a) Pyrene
                                       5
                                      1.9
                                     0.75
Benzo(k) Fluoranthene
                                       5
                                      0.9
                                     0.32
Copper
                                       6
                                      5.2
                                      4.0
Cyanide
                                       2
                                      0.7

Fluoranthene
                                       5
                                      3.3
                                     1.09
Fluorene
                                       5
                                      0.2
                                     0.07
Indeno(1,2,3-cd) Pyrene
                                       5
                                      1.6
                                     0.37
Mercury
                                       6
                                    0.00354
                                    0.0025
Methylene Chloride
                                       2
                                     0.59
                                      0.3
Nickel
                                       9
                                      90
                                      37
Phenol
                                       2
                                      25

Polychlorinated Biphenyls (PCBs)[1]
                                      36
                                      nd
                                      nd
Pyrene
                                       5
                                      2.8
                                     0.92
Selenium
                                       5
                                      12
                                       3
Thallium
                                       5
                                       1
                                     0.17
Zinc
                                       5
                                      62
                                      53
nd = nondetect
Source: 2014 Fact Sheet, Appendix E and Table 3.
1. Data for PCBs from Ecology's discharge monitoring reports; 36 observations below detection limits.

Receiving Water
Exhibit A-42 summarizes the available ambient receiving water concentrations based on data from the 2014 fact sheet for the permit.
Exhibit A-42. Ambient Receiving Water Concentrations: Strait of Georgia
Pollutant
Water Column Concentration (ug/L)

90[th] Percentile
Average
Chrysene
                                     0.47
                                      NR
Copper (dissolved)
                                      NR
                                     0.47
Indeno(1,2,3-cd) Pyrene
                                     0.012
                                      NR
Mercury (dissolved)
                                      NR
                                    0.00065
Selenium
                                     0.57
                                      NR
Zinc (dissolved)
                                      NR
                                     0.57
Source: 2014 fact sheet for the permit; 90[th] percentile values are from Appendix E (reasonable potential analysis); average values based on Table 2 (from 10 samples collected upstream from Intalco discharges in July and September 1999).
NR = not reported

Baseline Scenario
The facility does not have WQBELs based on human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-43 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-41 and available ambient data in Exhibit A-42, there is reasonable potential to exceed the baseline human health criteria for arsenic.
Exhibit A-43. Human Health Reasonable Potential Analysis for Intalco Aluminum[1]  -  Baseline Scenario
Parameter
Effluent Conc. (ug/L)
Ambient Conc. (ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
50.0
NR
0.6063
0.14
1. See effluent concentrations in Exhibit A-41 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-42.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 77 for carcinogens and 105 for non-carcinogens.
3. Consumption of organisms only.

Exhibit A-44 summarizes the calculated permit limits for arsenic under the baseline scenario.
Exhibit A-44. Human Health Based Effluent Limitations for Intalco Aluminum  -  Baseline Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
11
22
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Arsenic
Under the baseline scenario, the discharger would have to meet an AML of 11 ug/L and a MDL of 22 ug/L. Arsenic was observed in the effluent at a concentration of 50 ug/L. Since the effluent monitoring data exceed the applicable effluent limitations under the baseline scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of noncompliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the baseline scenario.
End-of-pipe treatment technologies capable of controlling arsenic include options such as chemical precipitation, microfiltration, and reverse osmosis. Given the limited nature of the information available regarding the internal process operations at the facility, EPA has assumed the use of reverse osmosis for arsenic control. Reverse osmosis is capable of reliably controlling arsenic at levels below the limit of quantitation. Further, EPA has assumed that treatment of the entire plant flow will be necessary. This is a conservative assumption as it is possible that a detailed study of the facility's internal process operations would result in a more targeted treatment strategy -- for instance, if only a single internal process flow was the source of the contamination, then only the contaminated stream would require treatment. EPA estimated a reverse osmosis treatment cost for a 3.0 mgd flow at $5,907,000 per year assuming an interest rate of 7 percent over 20 years.
Policy Scenario
Based on effluent concentrations in Exhibit A-41 and available ambient data in Exhibit A-42, there is reasonable potential to exceed human health criteria for the pollutants shown in Exhibit A-45.
Exhibit A-45. Human Health Reasonable Potential Analysis for Intalco Aluminum[1]  -  Policy Scenario
Parameter
Baseline Average Monthly Effluent Limit (ug/L)
Ambient Conc. (ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                     11.0
                                      NR
                                    0.6063
                                    0.0059
1. See effluent concentrations in Exhibit A-41 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-42.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 77 for carcinogens and 105 for non-carcinogens.
3. Consumption of organisms only.

Exhibit A-46 summarizes the calculated permit limits for arsenic under the policy scenario.
Exhibit A-46. Human Health Based Effluent Limitations for Intalco Aluminum  -  Policy Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                     0.46
                                     0.92
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.46 ug/L and a MDL of 0.92 ug/L. Under the baseline scenario, EPA assumed that end-of-pipe treatment (i.e., reverse osmosis) would be necessary to meet effluent limitations. Since reverse osmosis is capable of treating the effluent to levels below the QL on a regular basis and further treatment below the QL is infeasible, EPA estimated that the discharger would incur costs for a P2 program to assist in ensuring compliance.
Quincy Industrial Wastewater Treatment Facility
The City of Quincy owns an industrial wastewater treatment facility (NPDES permit number WA0021067) that treats process wastewater from a potato and vegetable processor (ConAgra Foods and Quincy Foods, respectively). The facility discharges to a U.S. Bureau of Reclamation wasteway..Ecology has developed a proposed NPDES permit which contains requirements to develop a special study and reapplication to direct the discharge to a new location. The average flow is 1.5 mgd.
Treatment Processes
The fact sheet for the 2012 NPDES permit for the facility lists primary and secondary treatment processes consisting of primary settling, anaerobic digestion, sequencing batch reactors, disinfection, summer season cooling, and re-aeration.
Effluent Data
Effluent monitoring data for the pollutants of interest are not available for this facility. Ecology has determined that the discharge is not likely to contain any pollutants addressed by the proposed human health criteria.
Receiving Water
Quincy Industrial discharges treated process wastewater to the U.S. Bureau of Reclamation wasteway DW237. The wasteway joins with other wasteways and eventually discharges to Potholes Reservoir. The entire water system is part of the federal Columbia Basin Irrigation Project.
According to the 2012 fact sheet for the NPDES permit (p. 25), Potholes Reservoir, downstream of the discharge point, is impaired for dieldrin, 2,3,7,8-TCDD, 4-4-DDE, and PCB. Another downstream waterbody, Frenchman Hills Waterway, is impaired for temperature and pH. Ecology finds that the travel distance from the facility's discharge to these impairments is large and the influence of the discharge is negligible.
Baseline Scenario
The NPDES permit for the facility does not have WQBELs based on human health criteria for the pollutants of concern. Due to the lack of available monitoring data, EPA could not evaluate reasonable potential and compliance costs for the facility under the baseline scenario.
Policy Scenario
Due to the lack of available monitoring data, EPA could not determine reasonable potential and estimate compliance costs under the policy scenario.
Steelscape Inc.
Steelscape, Inc., located in Kalama, Washington, is an industrial facility (NPDES permit WA0040851) for the cold rolling and coating of steel strip. The facility is composed of four primary production lines: Pickle Line, Cold Rolling Mill, Metallic (zinc) Coating Line, and Coil Paint Line.
Treatment Processes
The facility has two distinct wastewater treatment systems: one for treating "oily waste" from all process waters that are potentially contaminated with oil or grease, and the other for treating "metal waste." Domestic waste is treated by the Port of Kalama Municipal Wastewater Treatment System.
The oil waste system treats wastewater from the Cold Roll Mill, Metallic Coating, and Coil Paint lines, using collection and blending, oil water separation, holding systems, and feeding systems for hydrochloric acid, de-emulsifier, coagulant, and polymer.
The metal waste system treats waste streams from the Pickle line, Metallic Coating line, Coil Paint line, and other auxiliary waste water from the facility (e.g., demineralizer regenerant waste, cooling tower blowdowns, and clear effluent from the oily waste system). The metal wastewater is chemically reduced, neutralized, oxidized, coagulated, precipitated, clarified, filtered, and dewatered (2010 fact sheet for the permit, p. 7).
Effluent Data
Exhibit A-47 summarizes available effluent monitoring data for the facility for 2012 through 2014. Concentration-based effluent monitoring data were not available for the reasonable potential analysis.
Exhibit A-47. Summary of Effluent Data (2012 to 2014): Steelscape Inc.

Pollutant
Number of Observations
Quantified Values

Maximum
Average
Units
Arsenic (total)
                                      32
                                       7
                                     1.34
                                    kg/day
Copper (total)
                                      32
                                     0.004
                                    0.0011
                                    kg/day
Cyanide
                                      32
                                     0.004
                                    0.00032
                                    kg/day
Nickel (total)
                                      32
                                     0.005
                                    0.0016
                                    kg/day
Zinc (total)
                                      32
                                     0.024
                                    0.0019
                                    kg/day
Source: Based on discharge monitoring reports submitted to Ecology.

Receiving Water
The facility discharges to the Columbia River through a submerged outfall that is shared with the Port of Kalama Municipal Wastewater Treatment Plant.
Exhibit A-48 summarizes the available ambient receiving water concentrations.
Exhibit A-48. Ambient Receiving Water Concentrations: Columbia River
Pollutant
Water Column Concentration (ug/L)

90[th] Percentile
Geometric Mean
Arsenic (dissolved)
                                     1.53
                                     0.879
Copper (dissolved)
                                     1.29
                                     0.741
Nickel (dissolved)
                                     0.842
                                    0.4839
Zinc (dissolved)
                                     2.76
                                    1.5862
Source: 2010 Fact Sheet (Table 23).

Baseline Scenario
The NPDES permit for the facility does not have WQBELs based on human health criteria for the pollutants of concern. Due to the lack of available concentration-based effluent monitoring data, EPA could not evaluate reasonable potential and compliance costs for the facility under the baseline scenario.
Policy Scenario
Due to the lack of available concentration-based effluent monitoring data, EPA could not determine reasonable potential and estimate compliance costs under the policy scenario.
Sonoco Products
Sonoco Products (NPDES permit WA0000884) is a recycled paperboard manufacturing facility in Sumner Washington, producing an average of 138 tons of paperboard per day from recycled materials (based on data between 2007 and 2012). The facility discharges to the White River. Average flow is 0.14 mgd.
Treatment Processes
The 2013 permit fact sheet indicates that the current treatment consists of primary clarification, activated sludge aeration, and secondary clarification.
Effluent Data
The fact sheet for the 2013 NPDES permit states that the effluent contains some heavy metals. Exhibit A-49 summarizes available effluent monitoring data for the facility from the 2013 permit fact sheet and a 2014 inspection report from Ecology.
Exhibit A-49. Summary of Effluent Data (2012-2014): Sonoco Products
Pollutant
Number of Observations
Concentration (total recoverable; ug/L)
Antimony
                                       1
                                     1.18
Arsenic
                                       1
                                     2.16
Copper1
                                      12
                                  5.56 -28.6
Mercury
                                       1
                                     0.007
Nickel
                                       1
                                     3.04
Selenium[2]
                                       2
                                   0.82 - 10
Thallium
                                       1
                                   nondetect
Zinc[3]
                                       2
                                   28.6 - 40
Source: 2013 fact sheet for the permit and 2014 inspection report.
1. The 2013 fact sheet reports a maximum copper concentration of 28.6 out of 12 samples; the 2014 inspection report has 5.56 ug/L.
2. The 2013 fact sheet reports a concentration of 10 ug/L for selenium; the 2014 inspection report has 0.82 ug/L.
3. The 2013 fact sheet reports a concentration of 40 ug/L for zinc; the 2014 inspection report has 28.6 ug/L.

Receiving Water
The facility discharges to the White River, which has designated uses of salmonid spawning, rearing and migration, habitat, and primary contact recreation. Exhibit A-50 summarizes the available ambient receiving water concentrations based on data reported in the 2013 permit fact sheet.
Exhibit A-50. Ambient Receiving Water Concentrations: White River
Pollutant
Water Column Concentration (total recoverable; ug/L)
Copper
                                     1.94
Zinc
                                     1.91
Source: 2013 fact sheet for the permit (Table 2); average of 8 samples.

Baseline Scenario
The NPDES permit for facility does not have WQBELs based on human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit.  In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-51 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-49 and available ambient data in Exhibit A-50, there is reasonable potential to exceed the human health arsenic criterion.
Exhibit A-51. Human Health Reasonable Potential Analysis for Sonoco Products[1]  -  Baseline Scenario
Parameter
Effluent Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                     2.16
                                      NR
                                    0.0414
                                    0.0045
NR = not reported
1. See effluent concentrations in Exhibit A-49 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-50.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 130.
3. Consumption of water and organisms.

Exhibit A-52 summarizes the calculated permit limits for arsenic under the baseline scenario.
Exhibit A-52. Human Health Based Effluent Limitations for Sonoco Products  -  Baseline Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                      2.3
                                      4.7
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 2.3 ug/L and a MDL of 4.7 ug/L. Effluent arsenic was observed at an average concentration of 2.16 ug/L. Since the effluent monitoring data are less than the effluent limitations under the baseline scenario, EPA anticipates that immediate compliance with effluent limitations under the baseline scenario will be feasible, and that no compliance activities are necessary.
Policy Scenario
Exhibit A-53 summarizes the reasonable potential analysis under the policy scenario. Based on effluent concentrations in Exhibit A-49 and available ambient data in Exhibit A-50, there is reasonable potential to exceed the human health arsenic criterion.
Exhibit A-53. Human Health Reasonable Potential Analysis for Sonoco Products[1]  -  Policy Scenario
Parameter
Effluent Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                     2.16
                                      NR
                                    0.0414
                                    0.0045
NR = not reported
1. See effluent concentrations in Exhibit A-49 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-50.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 130.
3. Consumption of water and organisms.

Exhibit A-54 summarizes the calculated permit limits for arsenic under the policy scenario.
Exhibit A-54. Human Health Based Effluent Limitations for Sonoco Products  -  Policy Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                     0.59
                                      1.2
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.59 ug/L and a MDL of 1.2 ug/L. Effluent arsenic was observed at an average concentration of 2.16 ug/L. Since this value exceeds the applicable effluent limitations under the policy scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of non-compliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the policy scenario.
End-of-pipe treatment technologies capable of controlling arsenic include options such as chemical precipitation, microfiltration, and reverse osmosis. Given the limited nature of the information available regarding the internal process operations at the facility, EPA has assumed the use of reverse osmosis for arsenic control. Reverse osmosis is capable of reliably controlling arsenic at levels below the limit of quantitation. Further, EPA has assumed that treatment of the entire plant flow will be necessary. This is a conservative assumption as it is possible that a detailed study of the facility's internal process operations would result in a more targeted treatment strategy -- for instance, if only a single internal process flow was the source of the contamination, then only the contaminated stream would require treatment. EPA estimated a reverse osmosis treatment cost for a 0.14 mgd flow at $2,136,000 per year assuming an interest rate of 7 percent over 20 years.
Tesoro Refining and Marketing LLC - Anacortes
Tesoro Refining and Marketing LLC operates a wastewater treatment plant (NPDES permit WA0000761) that discharges to Fidalgo Bay in northwestern Washington. The refinery processes crude oil from Alaska's Northern Slope, Canada, and the Bakken Shale Reserves of Montana and North Dakota. The wastewater treatment plant treats process water, sanitary wastewater, stormwater, and ballast water. The permit also authorizes the treatment of wastewater from an onsite crude railcar offloading facility. Average flow is 2.8 mgd.
During extremely heavy rainfall events, Tesoro may also discharge water from a retention pond that would consist almost entirely of stormwater, but may contain small amounts of oily wastewater. Tesoro has increased the volume of the retention pond and no discharges have occurred since December 1996.
Treatment Processes
The 2013 draft fact sheet for the permit states that the facility uses primary and secondary treatment for process wastewater and contaminated stormwater. This system consists of API oil/water separators, primary clarifiers, activated sludge units, secondary clarifiers, and holding ponds. Sanitary wastewater is treated with a septic tank and a neutralization pit.
Effluent Data
Exhibit A-55 summarizes the effluent data for the treated wastewater for the pollutants of concern for which data are available, based on Ecology's reasonable potential analysis (Appendix H in the 2013 draft permit fact sheet).
Exhibit A-55. Summary of Effluent Data: Tesoro Refinery, Outfall 1
Pollutant
Number of Observations
Quantification Limit (ug/L)
Summary of Detected Values (ug/L)[1]

Total
Nondetect

Maximum
Average
1,1-Dichloroethylene
                                       4
                                       4
                                      0.2

1,2-Dichlorobenzene
                                       1
                                       1
                                       2

1,2-Dichloroethane
                                       4
                                       4
                                      0.1

1,2-Dichloropropane
                                       4
                                       4
                                      0.4

1,2-Diphenylhydrazine
                                       4
                                       4
                                      0.5

1,3-Dichlorobenzene
                                       1
                                       1
                                       2

1,4-Dichlorobenzene
                                       1
                                       1
                                       2

2,4-Dichlorophenol
                                       4
                                       4
                                       1

2,4-Dimethylphenol
                                       1
                                       1
                                       2

2,4-Dinitrophenol
                                       4
                                       4
                                       1

2,4-Dinitrotoluene
                                       4
                                       4
                                      0.1

2-Chloronaphthalene
                                       1
                                       1
                                       2

3,3'-Dichlorobenzidine
                                       1
                                       1
                                       2

Anthracene
                                       1
                                       1
                                       2

Antimony
                                       2

                                      1.4

Arsenic
                                       1

                                     5.33
                                     5.33
Benzene
                                       4

                                     44.9

Benzidine
                                       1
                                       1
                                       2

Benzo(a) anthracene
                                       1
                                       1
                                       2

Benzo(a) pyrene
                                       1
                                       1
                                       2

Benzo(b) Ffuoranthene
                                       1
                                       1
                                       2

Benzo(k) fluoranthene
                                       1
                                       1
                                       2

Bis(2-chloroethyl) ether
                                       1
                                       1
                                       2

Bis(2-ethylhexyl) phthalate
                                       1
                                       1
                                       1

Bromoform
                                       4

                                      0.6

Butylbenzyl phthalate
                                       1
                                       1
                                       2

Carbon tetrachloride
                                       4
                                       4
                                      0.4

Chlordane
                                       4
                                       4
                                      0.1

Chlorobenzene
                                       4
                                       4
                                      0.4

Chlorodibromomethane
                                       4

                                      1.9

Chloroform
                                       4

                                     13.7

Chrysene
                                       4
                                       4
                                       2

Copper
                                       4

                                       7
                                     5.01
Cyanide
                                       4

                                      15
                                      7.0
Dibenzo(a,h) anthracene
                                       1
                                       1
                                       2

Dichlorobromomethane
                                       1

                                      2.4

Diethyl phthalate
                                       4

                                       4

Dimethyl phthalate
                                       1
                                       1
                                       2

Di-n-butyl phthalate
                                       4
                                       4
                                      0.5

Endosulfan sulfate
                                       4
                                       4
                                      0.1

Endrin
                                       4
                                       4
                                      0.1

Endrin aldehyde
                                       4
                                       4
                                      0.1

Ethylbenzene
                                       4
                                       4
                                      0.4

Fluoranthene
                                       4
                                       4
                                      0.5

Fluorene
                                       4
                                       4
                                      0.5

Hexachlorobutadiene
                                       4
                                       4
                                      0.5

Hexachlorocyclopentadiene
                                       4
                                       4
                                      0.5

Hexachloroethane
                                       4
                                       4
                                      0.5

Indeno(1,2,3-cd) pyrene
                                       1
                                       1
                                      0.1

Isophorone
                                       4
                                       4
                                      0.5

Mercury[2]
                                      35

                                     0.44
                                     0.069
Methyl bromide
                                       4
                                       4
                                      0.4

Methylene chloride
                                       4

                                      0.6

Nickel
                                       4

                                       7
                                     5.33
Nitrobenzene
                                       4
                                       4
                                      0.5

N-Nitrosodimethylamine
                                       1
                                       1
                                      0.2

N-Nitrosodi-n-propylamine
                                       1
                                       1
                                      0.2

N-Nitrosodiphenylamine
                                       1
                                       1
                                      0.2

Pentachlorophenol (PCP)
                                       4
                                       4
                                      0.5

Phenol
                                      52

                                       2
                                     0.009
Pyrene
                                       4

                                      0.8

Selenium
                                       4

                                      21

Tetrachloroethylene
                                       4
                                       4
                                      0.6

Thallium
                                       4
                                       4
                                       1

Toluene
                                       4

                                      8.2

Toxaphene
                                       4
                                       4
                                      0.5

Trichloroethylene
                                       4
                                       4
                                      0.4

Vinyl chloride
                                       4
                                       4
                                      0.4

Zinc
                                       4

                                      66
                                      66
Source: 2013 draft permit fact sheet (Appendix H and Table 2); based on the 2010 permit application and annual priority pollutant scans (years not specified).
1. Metal concentrations are total recoverable.
2. Data for mercury is from 2012 to 2014 discharge monitoring reports.

Receiving Water
Tesoro discharges to Fidalgo Bay, which Ecology has designated as an extraordinary marine receiving water. Exhibit A-56 summarizes the available ambient receiving water concentrations based on data in the permit fact sheet for 1998 through 2005.
Exhibit A-56. Ambient Receiving Water Concentrations: Fidalgo Bay[1]
Pollutant
Geometric Mean Concentration (ug/L)
Concentration at 90[th] Percentile Temperature (ug/L)
Arsenic
                                     1.15
                                      NR
Copper
                                     0.512
                                     0.673
Nickel
                                     0.522
                                      NR
Selenium
                                    0.0713
                                      NR
Zinc
                                     1.26
                                      3.9
Mercury
                                    0.0007
                                     0.001
Source: 2013 Draft Fact Sheet Table 3 and Appendix H (reasonable potential analysis).
NR = not reported
1. Metal concentrations are dissolved.

Baseline Scenario
The permit does not include any WQBELs based on the existing human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-57 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-55 and available ambient data in Exhibit A-56, there is reasonable potential to exceed the baseline human health arsenic criterion.
Exhibit A-57. Human Health Reasonable Potential Analysis for Tesoro Facility[1]  -  Baseline Scenario
Parameter
Effluent Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                     5.33
                                     1.15
                                     13.3
                                     0.14
1. See effluent concentrations in Exhibit A-55 (reasonable potential analysis uses the maximum or 95th percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-56.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using end-of-pipe limitations.
3. Consumption of organisms only.

Exhibit A-58 summarizes the calculated permit limits for arsenic and mercury under the baseline scenario.
Exhibit A-58. Human Health Based Effluent Limitations for Tesoro Facility  -  Baseline Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                     0.14
                                     0.28
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.14 ug/L and a MDL of 0.28 ug/L. According to the draft 2013 Fact Sheet for the facility, arsenic was observed in the effluent with a long-term average concentration of 5.3 ug/L. Since this value exceeds the applicable effluent limitations under the baseline scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of non-compliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the baseline scenario.
Crude petroleum is an important source of metals at petroleum refining and processing facilities, including arsenic. Metals found in crude petroleum, and their concentrations, depend on the origin of the crude oil. Other sources include arsenic contaminated process equipment and other manufacturing inputs (i.e., spent catalyst). A P2 program that identifies likely sources of arsenic in the facility's waste stream can provide adequate levels of control through updated source control and P2 best management practices. Costs for designing and implementing a P2 program for arsenic is estimated to be $28,000 per year. However, if the facility determines that source water derived from ground water, surface waters, or drinking water is the source of high arsenic values in the wastewater, or if it is determined that control of arsenic in the discharge is infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the facility would pursue a variance.
Due to the fact that ambient receiving water concentrations exceed the proposed human health criteria, the discharger may pursue obtaining a water quality standards variance. The one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal costs associated with renewal.
Policy Scenario
Exhibit A-59 summarizes the reasonable potential analysis under the policy scenario. Based on effluent concentrations in Exhibit A-55 and available ambient data in Exhibit A-56, there is reasonable potential to exceed the human health arsenic and mercury criteria.
Exhibit A-59. Human Health Reasonable Potential Analysis for Tesoro Facility[1]  -  Policy Scenario
Parameter
Baseline Average Monthly Effluent Limit or Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                     0.14
                                     1.15
                                     13.3
                                    0.0059
Mercury
                                     0.44
                                    0.0007
                                     0.069
                                     0.017
1. See effluent concentrations in Exhibit A-55 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-56.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 93 for arsenic and 91 for mercury.
3. Consumption of organisms only.

Exhibit A-60 summarizes the calculated permit limits for arsenic and mercury under the policy scenario.
Exhibit A-60. Human Health Based Effluent Limitations for Tesoro Facility  -  Policy Scenario
Parameter
Average Monthly Effluent Limit
(total; ug/L)[1]
Maximum Daily Effluent Limit
(total; ug/L)[1]
Arsenic
                                    0.0059
                                     0.012
Mercury
                                     0.017
                                     0.042
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Arsenic
Under the policy scenario, the discharger would have to meet an AML of 0.0059 ug/L and a MDL of 0.12 ug/L. Under the policy scenario, where the projected effluent limitations are below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. Since the projected effluent limitations under the policy scenario are also below the QL, no additional compliance strategy would be required under the policy scenario (i.e., the discharger would not pursue a second variance).
Mercury
Under the policy scenario, the discharger would have to meet an AML of 0.017 ug/L and a MDL of 0.042 ug/L. The average effluent concentration is 0.069 ug/L and the maximum effluent concentration is 0.44 ug/L. The average ambient mercury concentration is 0.0007 ug/L. Based on the available data, the discharger will likely need to reduce mercury in its effluent to ensure that permit limits are consistently met. Fidalgo Bay is not listed on the State's 303(d) list for mercury.
Because there are no proven end-of-pipe treatment technologies that can achieve low mercury levels (e.g., <10 ng/L) on a consistent basis, the facility would likely implement a P2 program for compliance with the projected effluent limits. Annual P2 program costs for this industrial facility are estimated to be approximately $28,000.
TransAlta Centralia Generating Station
The TransAlta Centralia Generating Station (NPDES permit WA0001546) is a coal-fired power plant with two 702.5 Megawatt turbine units as well as a 250 Megawatt natural gas power plant on the same site. The facility generates process wastewater, stormwater runoff, and sanitary effluent, as well as sanitary effluent from the adjacent TransAlta Centralia Mining facility. Average flow for the facility is 3.57 mgd.
Treatment Processes
The fact sheet for the facility's 2010 NPDES permit lists current treatment processes as an oil skimmer pond and two effluent detention ponds. Sanitary effluent from the facility, TransAlta Centralia Mining, and the Big Hanaford Project is treated using an activated sludge process.
Effluent Data
Exhibit A-61 summarizes the results of a 2008 priority pollutant scan, from the 2010 fact sheet for the permit (Appendix C).
Exhibit A-61. Summary of Effluent Data (2008): Transalta Centralia Generation, Outfall 1
Pollutant
Number of Observations
Quantitation Level (ug/L)
Detected Value (ug/L)[1]

Total
Nondetect

1,1,2,2-Tetrachloroethane
                                       1
                                       1
                                       1

1,1,2-Trichloroethane
                                       1
                                       1
                                       1

1,1-Dichloroethylene
                                       1
                                       1
                                       1

1,2,4-Trichlorobenzene
                                       1
                                       1
                                      2.5

1,2-Dichlorobenzene
                                       1
                                       1
                                      2.5

1,2-Dichloroethane
                                       1
                                       1
                                       1

1,2-Dichloropropane
                                       1
                                       1
                                       1

1,3-Dichlorobenzene
                                       1
                                       1
                                      2.5

1,4-Dichlorobenzene
                                       1
                                       1
                                      2.5

2,4,6-Trichlorophenol
                                       1
                                       1
                                      2.5

2,4-Dichlorophenol
                                       1
                                       1
                                      2.5

2,4-Dinitrophenol
                                       1
                                       1
                                      10

2,4-Dinitrotoluene
                                       1
                                       1
                                      2.5

2-Chloronaphthalene
                                       1
                                       1
                                      2.5

2-Chlorophenol
                                       1
                                       1
                                      2.5

3,3'-Dichlorobenzidine
                                       1
                                       1
                                      20

4,4'-DDD
                                       1
                                       1
                                     0.01

4,4'-DDE
                                       1
                                       1
                                     0.01

4,4'-DDT
                                       1
                                       1
                                     0.01

Acenaphthene
                                       1
                                       1
                                       1

Acrolein
                                       1
                                       1
                                      10

Acrylonitrile
                                       1
                                       1
                                      10

Aldrin
                                       1
                                       1
                                     0.01

alpha-BHC
                                       1
                                       1
                                     0.01

Anthracene
                                       1
                                       1
                                       1

Antimony
                                       1

                                     0.21
                                       2
Arsenic
                                       1

                                     0.24
                                       5
Benzene
                                       1
                                       1
                                       1

Benzidine
                                       1
                                       1
                                      20

Benzo(a) anthracene
                                       1
                                       1
                                       1

Benzo(a) pyrene
                                       1
                                       1
                                       1

Benzo(k) fluoranthene
                                       1
                                       1
                                       1

beta-BHC
                                       1
                                       1
                                     0.01

Bis(2-chloroethyl) ether
                                       1
                                       1
                                      2.5

Bis(2-chloroisopropyl) ether
                                       1
                                       1
                                      2.5

Bis(2-ethylhexyl) phthalate
                                       1
                                       1
                                      2.5

Bromoform
                                       1
                                       1
                                       1

Butylbenzyl phthalate
                                       1
                                       1
                                      2.5

Carbon tetrachloride
                                       1
                                       1
                                       1

Chlorobenzene
                                       1
                                       1
                                       1

Chlorodibromomethane
                                       1
                                       1
                                       1

Chloroform
                                       1
                                       1
                                       1

Chrysene
                                       1
                                       1
                                       1

Copper
                                       1

                                     0.18
                                       2
Dibenzo(a,h) anthracene
                                       1
                                       1
                                       1

Dichlorobromomethane
                                       1
                                       1
                                       1

Dieldrin
                                       1
                                       1
                                     0.01

Diethyl phthalate
                                       1
                                       1
                                      2.5

Dimethyl phthalate
                                       1
                                       1
                                      2.5

Di-n-butyl phthalate
                                       1
                                       1
                                      2.5

Endosulfan sulfate
                                       1
                                       1
                                     0.01

Endrin
                                       1
                                       1
                                     0.01

Endrin aldehyde
                                       1
                                       1
                                     0.01

Ethylbenzene
                                       1
                                       1
                                       1

Fluoranthene
                                       1
                                       1
                                       1

Fluorene
                                       1
                                       1
                                       1

Heptachlor
                                       1
                                       1
                                     0.01

Heptachlor epoxide
                                       1
                                       1
                                     0.01

Hexachlorobenzene
                                       1
                                       1
                                      2.5

Hexachlorobutadiene
                                       1
                                       1
                                      2.5

Hexachlorocyclohexane (gamma-BHC; lindane)
                                       1
                                       1
                                     0.01

Hexachlorocyclopentadiene
                                       1
                                       1
                                      2.5

Hexachloroethane
                                       1
                                       1
                                      2.5

Indeno(1,2,3-cd) pyrene
                                       1
                                       1
                                       1

Isophorone
                                       1
                                       1
                                      2.5

Methyl bromide
                                       1
                                       1
                                       1

Methylene chloride
                                       1
                                       1
                                       1

Nickel
                                       1

                                     0.14
                                       1
Nitrobenzene
                                       1
                                       1
                                      2.5

N-Nitrosodi-n-propylamine
                                       1
                                       1
                                      2.5

Pentachlorophenol (PCP)
                                       1
                                       1
                                      10

Phenol
                                       1
                                       1
                                      2.5

Polychlorinated biphenyls (PCBs)
                                       1
                                       1
                                      0.1

Pyrene
                                       1
                                       1
                                       1

Selenium[2]
                                       1

                                     0.39
                                       3
Tetrachloroethylene
                                       1
                                       1
                                       1

Thallium
                                       1
                                       1
                                     0.28

Toluene
                                       1
                                       1
                                       1

Toxaphene
                                       1
                                       1
                                       1

Trichloroethylene
                                       1
                                       1
                                       1

Vinyl chloride
                                       1
                                       1
                                       1

Zinc
                                       1

                                     0.33
                                       1
Source: 2010 Fact Sheet, Appendix C.
1. Metal concentrations are total recoverable.
2. Appendix C, Table 2 lists the selenium detected value as 3 ug/L; however Ecology used a maximum value of 80 ug/L in the reasonable potential analysis (Appendix C Table 3).

Receiving Water
The facility discharges to Hanaford Creek. Ambient water quality data are not available for this receiving water.
Baseline Scenario
The NPDES permit for facility does not have WQBELs based on human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-62 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-61, there is reasonable potential to exceed human health criteria for arsenic.
Exhibit A-62. Human Health Reasonable Potential Analysis for Transalta Centralia Generation[1]  -  Baseline Scenario
                                   Parameter
                         Effluent Conc. (total; ug/L)
                       Ambient Conc. (dissolved; ug/L)
                    Conc. at Edge of Mixing Zone[2] (ug/L)
                       Human Health Criterion[3] (ug/L)
Arsenic
                                      5.0
                                      NR
                                    12.448
                                     0.018
NR = not reported
1. See effluent concentrations in Exhibit A-61 (reasonable potential analysis uses the maximum or 95th percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean).
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 1.
3. Consumption of water and organisms.

Exhibit A-63 summarizes the calculated permit limits for arsenic under the baseline scenario.
Exhibit A-63. Human Health Based Effluent Limitations for Transalta Centralia Generation  -  Baseline Scenario
                                   Parameter
               Average Monthly Effluent Limit (total; ug/L)[1]
                Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
                                     0.018
                                     0.036
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.018 ug/L and a MDL of 0.036 ug/L. Arsenic was observed in the effluent at of 5 ug/L. No ambient data are available and Hanaford Creek near the discharge is not listed on the State's 303(d) list as impaired for arsenic. Since the effluent monitoring data exceeds the applicable effluent limitations under the baseline scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of non-compliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the baseline scenario.
A P2 program is a possible pathway to achieve compliance with effluent limitations for arsenic. A P2 program that identifies likely sources of arsenic in the facility's waste stream can provide adequate levels of control through updated source control and P2 best management practices. Costs for designing and implementing a P2 program for arsenic is estimated to be $28,000 per year. However, if the facility determines that source water derived from ground water, surface waters, or drinking water is the source of high arsenic values in the wastewater, or if it is determined that control of arsenic in the discharge is infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the facility would pursue a variance.
Due to the fact that ambient receiving water concentrations exceed the proposed human health criteria, the discharger may pursue obtaining a water quality standards variance. The one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal costs associated with renewal.
Policy Scenario
Exhibit A-64 summarizes the reasonable potential analysis under the policy scenario. Based on effluent concentrations in Exhibit A-61, there is reasonable potential to exceed human health criteria for antimony, arsenic, and selenium.
Exhibit A-64. Human Health Reasonable Potential Analysis for Transalta Centralia Generation[1]  -  Policy Scenario
Parameter
Baseline Average Monthly Effluent Limit or Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Antimony
                                      2.0
                                      NR
                                     4.98
                                     2.49
Arsenic
                                     0.018
                                      NR
                                    12.448
                                    0.0045
Selenium
                                     80.0
                                      NR
                                    199.16
                                     24.69
NR = not reported
1. See effluent concentrations in Exhibit A-61 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean).
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 1.
3. Consumption of water and organisms.

Exhibit A-65 summarizes the calculated permit limits for antimony and arsenic under the policy scenario. For this analysis, EPA did not consider limitations for selenium further since under the policy scenario the discharger would face more stringent limitations established on the basis of aquatic life criteria.
Exhibit A-65. Human Health Based Effluent Limitations for Transalta Centralia Generation  -  Policy Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Antimony
                                      2.5
                                      5.0
Arsenic
                                    0.0045
                                    0.0091
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Antimony
Under the policy scenario, the discharger would have to meet an AML of 2.5 ug/L and a MDL of 5.0 ug/L. Based on the available effluent data, the facility will be capable of immediate compliance with antimony effluent limitations under the policy scenario. Therefore, EPA estimates there will be no compliance cost associated with effluent limitations.
Arsenic
Under the policy scenario, the discharger would have to meet an AML of 0.0045 ug/L and a MDL of 0.0091 ug/L. Under the baseline scenario, where the projected effluent limitations are below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. Since the projected effluent limitations under the policy scenario are also below the QL, no additional compliance strategy would be required under the policy scenario (i.e., the discharger would not pursue a second variance).
TransAlta Centralia Mining
TransAlta Centralia Mining (NPDES permit number WA0037338) mines and processes approximately 6 million tons of coal annually for use at the adjacent TransAlta Centralia Generating Station. The mine discharges stormwater overflow to Big Hanaford Creek and its tributaries. Average monthly flow is approximately 8 cubic feet per second (or 5 mgd).
Treatment Processes
The 2011 NPDES permit fact sheet for the facility lists current treatment processes as sedimentation ponds, which are built as excavation progresses and abandoned as reclamation progresses. Discharges from the facility consist of stormwater overflows. Sanitary effluent from the facility is treated by the TransAlta Centralia Generating Station.
Effluent Data
Exhibit A-66 summarizes 2014 and 2015 effluent monitoring data for the mine.
Exhibit A-66. Summary of Effluent Data (2014 to 2015): Transalta Centralia Mining, Outfall[1]
Pollutant
Number of Observations
Water Column Concentrations (total recoverable; ug/L)

Median
Average
95[th] Percentile
Maximum
Arsenic
                                      12
                                      2.8
                                     3.567
                                    22.275
                                     12.1
Mercury
                                       3
                                    0.00195
                                   0.001907
                                       0
                                    0.00294
Source: discharge monitoring data submitted to Ecology.

Receiving Water
The facility discharges to Big Hanaford Creek and several tributaries, which are designated as "Class A" receiving waters. Ambient water quality data are not available for this receiving water.
Baseline Scenario
The permit does not include any water quality-based effluent limitations (WQBELs) based on the existing human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-67 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-66, there is reasonable potential to exceed the baseline human health arsenic criterion.
Exhibit A-67. Human Health Reasonable Potential Analysis for Transalta Centralia Mining[1]  -  Baseline Scenario
Parameter
Effluent Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                      2.8
                                      NR
                                      2.8
                                     0.018
NR = not reported
1. See effluent concentrations in Exhibit A-66 (reasonable potential analysis uses the maximum or 95th percentile concentration if the number of observations is less than 10, and otherwise uses the median).
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 1.
3. Consumption of water and organisms.

Exhibit A-68 summarizes the calculated permit limits for arsenic under the baseline scenario.
Exhibit A-68. Human Health Based Effluent Limitations for Transalta Centralia Mining  -  Baseline Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
0.018
0.060
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.018 ug/L and a MDL of 0.060 ug/L. Arsenic was observed in the effluent at of 2.8 ug/L. No ambient data are available and Hanaford Creek near the discharge is not listed on the State's 303(d) list as impaired for arsenic. Since the effluent monitoring data exceeds the applicable effluent limitations under the baseline scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of non-compliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the baseline scenario.
A P2 program is a possible pathway to achieve compliance with effluent limitations for arsenic. A P2 program that identifies likely sources of arsenic in the facility's waste stream can provide adequate levels of control through updated source control and P2 best management practices. Costs for designing and implementing a P2 program for arsenic is estimated to be $28,000 per year. However, if the facility determines that source water derived from ground water, surface waters, or drinking water is the source of high arsenic values in the wastewater, or if it is determined that control of arsenic in the discharge is infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the facility would pursue a variance.
Due to the fact that ambient receiving water concentrations exceed the proposed human health criteria, the discharger may pursue obtaining a water quality standards variance. The one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal costs associated with renewal.
Policy Scenario
Exhibit A-69 summarizes the reasonable potential analysis under the policy scenario. Based on effluent concentrations in Exhibit A-66, there is reasonable potential to exceed human health criteria for arsenic and mercury.
Exhibit A-69. Human Health Reasonable Potential Analysis for Transalta Centralia Mining[1]  -  Policy Scenario
Parameter
Baseline Average Monthly Effluent Limit or Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
0.018
NR
2.8
0.0045
Mercury
0.0029
NR
0.0035
0.00088
NR = not reported
1. See effluent concentrations in Exhibit A-66 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the median).
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 1.
3. Consumption of water and organisms.

Exhibit A-70 summarizes the calculated permit limits for arsenic and mercury under the policy scenario.
Exhibit A-70. Human Health Based Effluent Limitations for Transalta Centralia Mining  -  Policy Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit (total; ug/L)[1]
Arsenic
0.0045
0.015
Mercury
0.00088
0.0018
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Arsenic
Under the policy scenario, the discharger would have to meet an AML of 0.0045 ug/L and a MDL of 0.015 ug/L. Under the baseline scenario, where the projected effluent limitations are below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. Since the projected effluent limitations under the policy scenario are also below the QL, no additional compliance strategy would be required under the policy scenario (i.e., the discharger would not pursue a second variance).
Mercury
Under the policy scenario, the discharger would have to meet an AML of 0.00088 ug/L and a MDL of 0.0018 ug/L. The maximum effluent concentration is 0.0029 ug/L and the average effluent concentration is 0.0019 ug/L. Based on the available data, the discharger will likely need to reduce mercury in its effluent to ensure that permit limits are consistently met.
Because there are no proven end-of-pipe treatment technologies that can achieve low mercury levels (e.g., <10 ng/L) on a consistent basis, the facility would likely implement a P2 program for compliance with the projected effluent limits. Annual P2 program costs for this industrial facility are estimated to be approximately $28,000. To ensure compliance in case a P2 program would not be sufficient to meet the projected effluent limitations, it is assumed that the facility would incur costs for a variance.
U.S. Oil & Refining Corporation
U.S. Oil and Refining Corporation (NPDES permit WA0001783) in Tacoma consists of an oil refinery, tank farm, and marine terminal. The facility encompasses 122 acres and has a daily throughput of 36,000 barrels per day (based on output between 2002 and 2006). The refinery separates crude oil into component parts and blends them into petroleum products including gasoline, jet fuel, diesel fuel, marine fuel, gas oils, and asphalts. The average wastewater flow for the maximum month is 0.62 mgd.
Treatment Processes
The 2008 permit fact sheet for the facility indicates that the facility employs primary and secondary treatment for process wastewater and contaminated stormwater before discharging to a City of Tacoma storm drain. Primary treatment includes an oil/water separator and an induced air flotation unit, and secondary treatment is an activated sludge biological unit and a clarifier. Sanitary waste from the facility is collected separately and treated by the City of Tacoma's municipal wastewater treatment plant.
Effluent Data
Exhibit A-71 summarizes effluent monitoring data for the facility from a 2014 monitoring report, which reports detected concentrations only for the pollutants of concern. According to the 2008 NPDES permit fact sheet, monitoring data for organic toxics are not reported because all samples were below detection limits.
Exhibit A-71. Summary of Effluent Data (2013-2014): US Oil & Refining Facility[1]
Pollutant
Number of Observations
Average (ug/L)
Maximum (ug/L)
Antimony
                                       2
                                     0.47
                                     0.54
Arsenic
                                       2
                                      6.5
                                      8.6
Copper
                                       2
                                     0.58
                                      0.6
Mercury
                                       2
                                    0.00245
                                    0.0028
Nickel
                                       2
                                     1.295
                                      1.4
Phenols
                                       2
                                      nd
                                      nd
Selenium
                                       2
                                     3.08
                                     3.56
Thallium
                                       2
                                      nd
                                     0.02
Zinc
                                       2
                                      3.7
                                      5.7
nd = nondetect
Source: 2014 Inspection Report (Table 1 and Table 2); includes one sample taken by Washington Department of Ecology (2014) and one sample submitted by the facility (2013).
1. Metal concentrations are in total recoverable.

Receiving Water
USOR discharges to the Lincoln Avenue Ditch, where it flows to the Blair Waterway which is a tidal inlet to Commencement Bay. The Blair Waterway is a Class B marine waterbody, with uses including industrial uses; fish migration; shellfish spawning, rearing and harvesting; wildlife habitat; secondary contact recreation; sport fishing; boating and aesthetic enjoyment; commerce; and navigation.
Exhibit A-72 summarizes the available ambient receiving water concentrations from the 2008 permit fact sheet.
Exhibit A-72. Ambient Receiving Water Concentrations: Blair Waterway
Pollutant
Water Column Concentration (ug/L)
Arsenic (unfiltered)
                                      1.3
Copper (dissolved)
                                     0.81
Mercury (total recoverable)
                                    0.0023
Zinc (dissolved)
                                      3.7
Source: 2008 permit fact sheet (p. 21).

Baseline Scenario
The permit does not include any WQBELs based on the existing human health criteria for the pollutants of concern. In this case, EPA performed a reasonable potential analysis for each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL would have been included in the NPDES permit. In cases of reasonable potential, EPA calculated a WQBEL using the existing human health criteria and evaluated compliance with this baseline WQBEL.
Exhibit A-73 summarizes the reasonable potential analysis under the baseline scenario. Based on effluent concentrations in Exhibit A-71 and available ambient data in Exhibit A-72, there is reasonable potential to exceed the baseline human health arsenic criterion.
Exhibit A-73. Human Health Reasonable Potential Analysis for U.S. Oil & Refining Facility[1]  -  Baseline Scenario
Parameter
Effluent Conc. (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                      8.6
                                      1.3
                                     1.466
                                     0.14
1. See effluent concentrations in Exhibit A-71 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-72.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 1025.
3. Consumption of organisms only.

Exhibit A-74 summarizes the calculated permit limits for arsenic under the baseline scenario.
Exhibit A-74. Human Health Based Effluent Limitations for U.S. Oil & Refining Facility  -  Baseline Scenario
Parameter
Average Monthly Effluent Limit (total; ug/L)[1]
Maximum Daily Effluent Limit
(total; ug/L)[1]
Arsenic
0.14
0.28
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.14 ug/L and a MDL of 0.28 ug/L. Arsenic was observed in the effluent at a concentration of 8.6 ug/L and in the ambient receiving water at a concentration of 1.3 ug/L. Blair Waterway near the discharge is not listed on the State's 303(d) list as impaired for arsenic, though ambient data used in the reasonable potential analysis does exceed criteria. Since the effluent monitoring data exceeds the applicable effluent limitations under the baseline scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits are consistently met. It is possible that more recent or future monitoring data could provide evidence that the facility is in compliance with the projected effluent limits and no costs would be incurred for compliance. However, additional data could provide further evidence of non-compliance. Based on the available information, EPA assumes the discharger will need to reduce discharge concentrations for compliance with the baseline scenario.
A P2 program is a possible pathway to achieve compliance with effluent limitations for arsenic. A P2 program that identifies likely sources of arsenic in the facility's waste stream can provide adequate levels of control through updated source control and P2 best management practices. Costs for designing and implementing a P2 program for arsenic is estimated to be $28,000 per year. However, if the facility determines that source water derived from ground water, surface waters, or drinking water is the source of high arsenic values in the wastewater, or if it is determined that control of arsenic in the discharge is infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the facility would pursue a variance.
Due to the fact that ambient receiving water concentrations exceed the proposed human health criteria, the discharger may pursue obtaining a water quality standards variance. The one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal costs associated with renewal.
Policy Scenario
Exhibit A-75 summarizes the reasonable potential analysis under the policy scenario. Based on effluent concentrations in Exhibit A-71 and available ambient data in Exhibit A-72, there is reasonable potential to exceed human health criteria for arsenic.
Exhibit A-75. Human Health Reasonable Potential Analysis for US Oil & Refining Facility[1]  -  Policy Scenario
Parameter
Baseline Average Monthly Effluent Limit (total; ug/L)
Ambient Conc. (dissolved; ug/L)
Conc. at Edge of Mixing Zone[2] (ug/L)
Human Health Criterion[3] (ug/L)
Arsenic
                                     0.14
                                      1.3
                                     1.466
                                    0.0059
NA = not available
1. See effluent concentrations in Exhibit A-71 (reasonable potential analysis uses the maximum or 95[th] percentile concentration if the number of observations is less than 10, and otherwise uses the geometric mean) and available ambient concentrations in Exhibit A-72.
2. Based on Washington Department of Ecology's Permit writer spreadsheet tool using a dilution factor of 71.
3. Consumption of organisms only.

Exhibit A-76 summarizes effluent limitations for arsenic applicable to the facility under the policy scenario.
Exhibit A-76. Human Health Based Effluent Limitations for US Oil & Refining Facility  -  Policy Scenario
Parameter
Average Monthly Effluent Limit
(total; ug/L)[1]
Maximum Daily Effluent Limit
(total; ug/L)[1]
Arsenic
                                    0.0059
                                     0.012
1. Based on Washington Department of Ecology's Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0059 ug/L and a MDL of 0.012 ug/L. Under the baseline scenario, where the projected effluent limitations are below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. Since the projected effluent limitations under the policy scenario are also below the QL, no additional compliance strategy would be required under the policy scenario (i.e., the discharger would not pursue a second variance).
References and Sources
City of Pasco. 2014. NPDES Permit Application Form 2A.
Fairfield-Suisun Sewer District (SD).  2003.  2003 NPDES Permit Renewal Infeasibility Analyses.  June 17.  Online at http://www.swrcb.ca.gov/rwqcb2/Agenda/08-20-03/08-20-03-5ainfeasibilityrev.doc.
King County Department of Natural Resources. 2013. Receiving Water Characterization Study: King County NPDES Monitoring Program. Final Report prepared for the King County Department of Natural Resources and Parks and the Washington State Department of Ecology.
King County Department of Natural Resources and Parks. 2012. 2012 King County Long-term Combined Sewer Overflow Control Plan Amendment.
Washington Department of Ecology. 2014. Fact Sheet for NPDES Permit WA0029181: West Point Wastewater Treatment Plant (WWTP) and Combined Sewer Overflow (CSO) System.
Washington Department of Ecology. 2013. Fact Sheet for NPDES Permit No.WA0023451, Lakehaven Utility District Redondo Wastewater Treatment Plant.
Washington Department of Ecology. 2013. Addendum to the Fact Sheet for National Pollutant Discharge Elimination System (NPDES) Permit No. WA0022772, March 1, 2013.
Washington Department of Ecology. 2009. Fact Sheet for NPDES Permit WA0029581: King County South Wastewater Treatment Plant (WWTP).
Washington Department of Ecology. 2008. Fact Sheet for NPDES Permit No. WA0044962 City of Pasco Wastewater Treatment Works.
Washington Department of Ecology. 2003. Fact Sheet for NPDES Permit WA0022772, Southwest Suburban Sewer District Salmon Creek Wastewater Treatment Plant.
U.S. Environmental Protection Agency (EPA). 2014. Fact Sheet: The U.S. Environmental Protection Agency (EPA) Proposes to Reissue a National Pollutant Discharge Elimination System (NPDES) Permit to Discharge Pollutants Pursuant to the Provisions of the Clean Water Act (CWA) to: City of Puyallup Wastewater Treatment Plant, 1602 18th St NW, Puyallup, WA 98371.
U.S. Environmental Protection Agency (EPA). 2014. Response to Comments: City of Puyallup Wastewater Treatment Plant, NPDES Permit WA0037168, September 23, 2014.
U.S. Environmental Protection Agency (EPA). 2004. Technical Support Document for the 2004 Effluent Guidelines Program Plan for the Petroleum Refining Category. EPA-821-R-04-014
 -  Sample Facility Results and Statewide Extrapolation
This appendix provides a summary of the sample facility results (facility-specific details are provided in Appendix A), and shows the extrapolation of statewide costs for the baseline scenario and the policy scenario.
EPA annualized capital costs, including study (e.g., dilution, variance) and program (e.g., pollution prevention) costs over 20 years using a 7% discount rate to obtain total annual costs per facility, then calculated a minimum and maximum annual cost for each facility in the sample.
Baseline Scenario Extrapolation
Exhibit B-1 summarizes the estimated annual compliance costs for the sample facilities under the baseline scenario.
Exhibit B-1. Potential Total Annual Compliance Costs for Sample Facilities, Baseline Scenario
Facility Name
Permit Number
Category