Engine ering Report for Commingled Wastewater and Pond 3 Land Treatment

Northwest Alloys Inc. Addy, Washington October 2018 (Revised February 2019)

12720 E Nora Avenue, Suite A Spokane Valley, WA 99216 Ph. (509) 921-0290 Fax (509) 921-1788 cascade-earth.com

Engineering Report for Commingled Wastewater and Pond 3 Land Treatment Northwest Alloys Inc. – Addy, Washington

Prepared For: Northwest Alloys Inc. P.O. Box 115 Addy, Washington 99101-0015 (509) 935-3295

Prepared By: Cascade Earth Sciences 12720 E Nora Avenue, Suite A Spokane Valley, Washington 99216 (509) 921-0290

Author(s): Steven L. Venner, CCA-NW, Managing Soil Scientist David Sullivan, CCA, Staff Soil Scientist

Report Date: October 30, 2018 (Revised February 2019)

Project Number: 2017220017

Submitted By: Steven L. Venner, CCA-NW, Managing Soil Scientist

Disclaimer: The contents of this document are confidential to the intended recipient at the location to which it is addressed. The contents may not be changed, edited, and/or deleted. The information contained in this document is only valid on the date indicated on the original project file report retained by CES. By accepting this document, you understand that neither CES nor its parent company, Valmont Industries, Inc. (Valmont) accepts any responsibility for liability resulting from unauthorized changes, edits, and/or deletions to the information in this document.

Engineering Report for Commingled Wastewater and Pond 3 Land Treatment Northwest Alloys Inc. – Addy, Washington

This report, sealed by a Professional Engineer registered in the State of Washington, a Hydrogeologist Licensed in the State of Washington, and a certified Professional Soil Scientist, contains information and data developed by a team of professionals including soil scientists, geologists, engineers, testing laboratories, and other professionals. This report does not contain design plans and specifications.

Submitted By:

Greg L. Thurman, PE, Principal Engineer

Douglas R. Wanta, LHG, Senior Geologist II

CONTENTS 1.0 INTRODUCTION ...... 1 1.1 Commingled Wastewater ...... 1 1.2 Pond 3 Water ...... 1 1.3 Background ...... 1 1.4 Purpose ...... 2 1.5 Project Duration ...... 2 2.0 FACILITY DESCRIPTION ...... 2 2.1 Impoundments ...... 3 2.2 Production Processes ...... 3 2.3 Commingled Wastewater Sources and Source Quantities ...... 3 2.3.1 Stormwater ...... 3 2.3.2 Quarry Dewatering Well Water ...... 3 2.3.3 Covered Slag Pond Water ...... 3 2.3.4 Sanitary Treatment Facility Water ...... 4 2.3.5 Potable Water ...... 4 2.4 History of Pond 3 ...... 4 3.0 DESIGN CONSIDERATIONS ...... 4 3.1 Water Conservation, Flow Reduction, and Pollution Prevention ...... 4 3.2 Commingled Wastewater Quantity ...... 5 3.3 Fresh Potable Water Quantity and Quality ...... 5 3.4 Pond 3 Water Quantity ...... 5 3.5 Blending Commingled Wastewater and Pond 3 Water ...... 5 3.6 Commingled Wastewater Quality ...... 6 3.6.1 Metals ...... 6 3.6.2 Inorganic Constituents ...... 6 3.6.3 Organic Constituents ...... 6 3.7 Covered Slag Pond Quality ...... 6 3.8 Pond 3 Water Quality ...... 7 3.8.1 Metals ...... 7 3.8.2 Inorganic Constituents ...... 7 3.8.3 Organic Constituents ...... 7 3.9 Blended Water Quality ...... 7 3.9.1 Metals ...... 7 3.9.2 Inorganic Constituents ...... 8 3.9.3 Organic Constituents ...... 8 4.0 AKART ANALYSIS ...... 8 4.1 Discharge Alternatives ...... 8 4.1.1 Zero Discharge ...... 8 4.1.2 Evaporation and Landfill Disposal ...... 8 4.1.3 Surface Water Discharge ...... 9 4.1.4 Discharge to a Publicly-Owned Treatment Works ...... 9 4.1.5 Land Treatment/Reuse ...... 9 4.2 AKART Recommendations ...... 10

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5.0 LAND TREATMENT AREA AND USE CONSIDERATIONS ...... 10 5.1 Land Treatment System Size and Extent ...... 10 5.2 Historical Land Use, Land Ownership, and Neighboring Land Uses...... 10 5.3 Climate ...... 11 5.4 Topography and Surface Hydrology ...... 11 5.4.1 Surface Water Quality ...... 11 5.4.2 Wetlands ...... 11 5.5 Soil Characterization ...... 11 5.5.1 Soil Physical Properties ...... 13 5.5.2 Soil Chemical Properties ...... 13 5.5.3 Expected Infiltration Rates and Permeability ...... 13 5.5.4 Conclusions and Recommendations ...... 14 5.6 Regional and Local Geology ...... 14 5.7 Regional and Local Hydrogeology ...... 14 6.0 GROUNDWATER MONITORING OF LAND TREATMENT SITE...... 15 6.1 Monitoring Well Network ...... 15 6.1.1 West Area ...... 16 6.1.2 South Area ...... 16 6.2 Monitoring Frequency and Parameters ...... 16 6.3 Groundwater Elevation, Flow Direction, and Hydraulic Gradient ...... 16 6.4 Groundwater Quality Summary ...... 16 6.4.1 Prior to Land Application (Before 2004) ...... 17 6.4.2 Pond 3 and Commingled Wastewater Land Application (2004 to 2007) ...... 17 6.4.3 Commingled Wastewater Land Application (2009-2017) ...... 18 7.0 LAND TREATMENT SYSTEM MANAGEMENT...... 19 7.1 Blended Water Loadings ...... 20 7.1.1 Blended Water Hydraulic Loadings ...... 20 7.1.2 Blended Water Constituent Loadings ...... 20 7.1.3 Sulfur Loading ...... 20 7.1.4 Chloride Loading ...... 20 7.1.5 Total Dissolved Solids Loading ...... 21 7.1.6 Biochemical Oxygen Demand Loading ...... 21 7.2 Cropping ...... 21 7.2.1 Planting and Harvest Management ...... 22 7.2.2 Cropping Rotations ...... 22 7.2.3 Pesticide/Herbicide Application...... 22 7.2.4 Crop Nutrient Removal ...... 22 7.3 Agronomic Capacity ...... 23 7.3.1 Hydraulic Capacity ...... 23 Water Balance Calculations ...... 23 7.3.2 Inorganic Constituent Capacity ...... 24 Nitrogen Capacity and Design Limiting Parameter ...... 24 Phosphorus ...... 25 Potassium ...... 25 Sulfur ...... 25 Sulfur Application Rate Considerations and Management ...... 26

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Soil Salinity Management ...... 26 Projected Soil Salinity ...... 27 Sodium Adsorption Ratio ...... 27 Biochemical Oxygen Demand ...... 27 Total Suspended Solids ...... 28 7.4 Sanitary Treatment Facility Water Management ...... 28 7.5 Irrigation System Design and Operations...... 28 7.5.1 Irrigation Season ...... 28 7.5.2 Leaching Requirement ...... 29 8.0 MONITORING ...... 29 8.1 Reporting ...... 30 8.2 Emergency Plans...... 30 9.0 CONCLUSIONS AND RECOMMENDATIONS ...... 31 REFERENCES ...... 32

TABLES Table 1. Commingled Wastewater Hydraulic Loadings Table 2. Water Quality Table 3. Metals Loading Rates Table 4. Fields and Soil Types Table 5. Site Precipitation and Evapotranspiration Table 6. Dominant Soil Types and Physical Characteristics Table 7. Soil Physical Analysis Results Table 8. Soil Chemical Properties Table 9. Groundwater Monitoring Data – Mean Data Table 10. Example Blended Water Annual Loadings Table 11. Example Crop Rotations and Capacity Table 12. Crop Management and Nutrient Removal Table 13. Projected Nitrogen and Water Balance Summary Table 14. Soil Salinity Effects on Crop Yield Table 15. Monitoring

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CONTENTS (continued)

FIGURES Figure 1. Land Treatment Site Map Figure 2. Process Flow Diagram Figure 3. Site Topography Figure 4. Soil Survey Map Figure 5. Wells Within 1 Mile of the Site Figure 6. Groundwater Flow Map - 1st Quarter 2017 Figure 7. Groundwater Flow Map - 2nd Quarter 2017 Figure 8. Groundwater Flow Map - 3rd Quarter 2017 Figure 9. Groundwater Flow Map - 4th Quarter 2017

APPENDICES Appendix A. July 2009 Pond 3 Permit Renewal Application Excerpt Appendix B. Potable Water Quality Appendix C. Commingled Wastewater Quality 2006-2008 Appendix D. Commingled Wastewater Quality 2008-2017 Appendix E. Blended Water Quality and Land Treatment Guidelines Appendix F. Covered Slag Pond Water Quality 2018 Appendix G. Pond 3 Pesticide, PCB, Oil and Grease Water Quality Appendix H. Pond 3 Water Quality 2002 Appendix I. Well Inventory Summary and Well Logs (CD-Rom) Appendix J. Groundwater Quality Data 2000-2017 Appendix K. Groundwater Quality Charts Appendix L. Example Water Balance Calculations

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1.0 INTRODUCTION Northwest Alloys (NWA) formerly operated a magnesium mining and refining operation in Addy, Washington. The mine and refining facility has been closed and NWA is in the process of site closure. Mine and mine spoil reclamation has been completed including grading and planting of reclamation grasses and trees.

1.1 Commingled Wastewater When the facility was in operation, stormwater runoff was directed to storage ponds and used in refining operations. With operations shut down, another use for the stormwater was needed. The stormwater, along with sanitary treatment facility water and quarry dewatering well water, was used to irrigate mine reclamation areas and agricultural crops on NWA-owned farmland (land treatment site) adjacent to the facility. In addition, NWA initiated a treatment process to neutralize elevated- pH water identified in the south portions of the refining facility. After treatment, the pH-neutralized water was also available for irrigation. These source waters are commingled and collectively considered Commingled Wastewater (CW). Potable water is available and used to supplement the CW when necessary to meet crop water requirements.

As the CW is primarily stormwater and groundwater, it contains low concentrations of nutrients for crops. Therefore, it can be applied to crops based on crop water requirements as an irrigation source. Essential and valuable plant nutrients contained in the CW are nitrogen, potassium, calcium, magnesium, and sulfate-sulfur.

1.2 Pond 3 Water Triple-lined Waste Pond #3 (Pond 3) currently contains about 6 million gallons (MG) of water from the Brine Concentrator and Wet Scrubber systems and a limited amount of pH-elevated water captured from the South Ditch and Covered Slag Pond Sump which was added from 2003 through 2005.

1.3 Background NWA proposed and received approval from the State of Washington Department of Ecology (Ecology) to beneficially re-use CW and Pond 3 water through land application to crops on NWA- owned land. With the issuance of Temporary State Discharge Permit No. ST8088 on September 11, 2003, CW and Pond 3 water were successfully applied to the land treatment site in 2004, 2005, 2006, and 2007 (CES, 2005, 2006, 2007, 2008). During the Permit renewal process that was initiated in 2008, Ecology recommended that NWA submit separate permit applications for the CW and Pond 3 water and subsequently permitted land application of the CW. Only CW has been applied to the land treatment site since 2009, while the Pond 3 water has been retained in Pond 3 in anticipation of re-permitting in the future for land application.

During the Permit renewal process that was initiated in 2015, NWA proposed a combined permit for irrigating CW and Pond 3 water. NWA proposes to beneficially re-use both the CW and Pond 3 water through land application to crops on the NWA land treatment site. The proposed beneficial re- use operations will be based on the agronomic needs of the crops.

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An Irrigation and Crop Management Plan (ICMP), as required in Permit No. ST8088, has been submitted annually by NWA and includes summaries and evaluations of soil monitoring, crop monitoring, groundwater quality trend analyses, irrigation loading balances, and crop management information for the following cropping season including proposed crop acreages and estimated annual nitrogen and hydraulic capacities for each field’s planned crop rotation.

1.4 Purpose The purpose of this engineering report is to provide Ecology with operational information to support NWA’s request to permit the continued beneficial use of CW and Pond 3 water as an irrigation water and nutrient source for the crops during the growing season on NWA land treatment site (Figure 1). This engineering report presents site considerations and management aspects related to the proper design and operation of the land treatment site and supports the permit application. Specifically, this report has been prepared to meet the requirements of permit approval and to comply with the following: • Washington Administrative Code (WAC) 173-240-130 • Guidelines for Preparation of Engineering Reports for Industrial Land Treatment Systems (Ecology, 1993).

This land treatment engineering report includes consideration of climate, soils, crops, land use, treatment capacity, CW and Pond 3 water quality, irrigation and crop management, and land treatment system monitoring.

1.5 Project Duration The beneficial reuse of Pond 3 water will end when all water in Pond 3 has been applied to the land treatment site. It is important to note that this is anticipated to require approximately four application events (i.e., four cropping seasons) to complete its treatment. CW land application will continue after cessation of Pond 3 water land application.

2.0 FACILITY DESCRIPTION NWA is located immediately west of Addy, Washington in Stevens County. Figure 1 shows the facility including the CW ponds, Pond 3, and the land treatment site. The facility and land treatment site (Site) are located in Sections 11, 12, 13, 14, 23, and 24 of Township 33N, Range 39E of the Willamette Meridian (Figure 1). The facility is in the process of closure, as mentioned above, but stormwater, pH neutralized water mixed with stormwater, sanitary treatment facility water, and quarry dewatering hydraulic control well water will continue to be produced during the closure.

A center pivot irrigation system was installed in the fall of 2017 to replace wheel-line systems. The center pivot field consists of 66 acres and is referred to as Field 1 (Figure 1). Field 2 is wheel-line irrigated and has a total of 49 acres. The Site consists of 115 acres total. In addition to the 115 acres, there are 64.4 acres of NWA-owned agricultural farmland located to the south of the facility (fields 10 and 11), which are potentially available for CW and Pond 3 water application (Figure 1). However, irrigation infrastructure installation would be required.

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2.1 Impoundments The CW collected from the facility area is stored in three separate storage impoundments (ponds): the East Pit pond, Crusher Pond, and Storm Lake 1 (Figure 1). These ponds have a capacity of approximately 40 MG. The Crusher Pond and Storm Lake 1 impoundments were designed to achieve a standard permeability of 1 x 10 -6 centimeters per second within the impoundment. These ponds were approved for use to store the facility’s stormwater and crusher process water from the beginning of the facility's operating history and are being reused to store CW. The East Pit is not lined; however, any water migrating from the East Pit pond is expected to be contained by the quarry dewatering hydraulic control well northwest of the East Pit pond.

Additionally, a fourth impoundment is located within the facility area. It is the triple-lined Pond 3 that currently contains water from the Brine Concentrator and Wet Scrubber systems and a limited amount of alkaline water captured from the South Ditch and Covered Slag Pond Sump. The Pond 3 impoundment and its contents are not part of the CW storage and distribution system.

2.2 Production Processes There are no mining or refining production processes and no production process wastewater streams being generated from the processing facility.

2.3 Commingled Wastewater Sources and Source Quantities The largest component of the CW is stormwater received during the late fall, winter, and early spring. The second largest component is quarry dewatering hydraulic control well water. Together these two sources comprise approximately 36 of the 38 MG of CW collected on average annually (CES, 2010, 2011, 2012, 2013, 2014). The remaining sources are water collected at Covered Slag Pond #1 (CSP1) at approximately 1.8 MG per year, and chlorinated sanitary wastewater.

2.3.1 Stormwater The facility area comprises approximately 180 acres within a bermed wastewater collection system (approximately 155 acres unpaved, 5 acres paved, and 20 acres under cover). The storm drain collection system drains only into Storm Lake 1 and is managed by pumping to the Crusher Pond and East Pit pond for short-term storage.

2.3.2 Quarry Dewatering Well Water NWA operates a quarry dewatering hydraulic control well in the north landfill area located within the mine reclamation areas. The well operates on a batch cycle at a rate of 15 gallons per minute (gpm) based on level control. The water from this system is near neutral in pH and of low conductivity, but exits the well with elevated temperature and ammonia levels. Discharge from the hydraulic control well enters the Crusher Pond.

2.3.3 Covered Slag Pond Water Since facility closure in 2001 and Ecology’s 2003 issuing of discharge permit No. ST 8088, NWA has added an additional inflow to the CW collected annually and distributed through agricultural irrigation. Reclamation activities in 2002 and water balance issues in 2003 created a

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high pH water issue within the Covered Slag Pond at the south end of the facility. The Covered Slag Pond (CSP) was excavated in 2006, but material was never returned to the excavated area due to impending sale of the material for beneficial reuse. It is anticipated that the remainder of this material will be moved back to CSP and inflow to CW will no longer be required beyond 2020.

2.3.4 Sanitary Treatment Facility Water The NWA onsite sanitary treatment facility is an extended aeration type package plant that was installed during facility construction and currently serves up to two full time staff. The sanitary effluent is disinfected using chlorine tablets prior to being discharged to the CW. The sanitary waste stream is a very a small portion (approximately 2.7%) of the entire CW volume and has averaged about 1 MG annually from 2013-2017 as reported in discharge monitoring reports submitted to Ecology.

2.3.5 Potable Water During years when collected CW volume is below that volume needed to irrigate crops, potable water is used to supplement existing volumes and is pumped to Storm Lake #1, thus becoming an inflow to CW. The volume of Potable water available to supplement the CW for irrigation is not limited and can be provided within the operational limits of the irrigation system to maintain optimum crop growth, and thus maximum treatment capacity of the Site.

2.4 History of Pond 3 The Brine Concentrator was installed in the early 1980’s as a water treatment facility. The Brine Concentrator refined site captured industrial wastewaters as a replacement for Potable water use in the production cooling systems. The Wet Scrubber system consisted of the following two processes. The first process was a hydrochloric acid scrubber that used potassium hydroxide to capture air emissions and produced a solution of potassium chloride as a byproduct. The second process was an ammonia scrubber, which used sulfuric acid to capture air emissions and produced a solution of magnesium-ammonium sulfate as a byproduct. These waters were transferred to Pond 3 in November 2000. For additional information on the history and content of Pond 3, refer to Appendix A, which is an excerpt from the July 2009 Pond 3 permit renewal application package.

3.0 DESIGN CONSIDERATIONS Selection and design of an industrial wastewater treatment system is dependent upon the quantity and quality of the water to be treated and the quantity and quality of the water required for discharge. The parameters considered in this section for both CW and Pond 3 water are quantity, total metals, and both inorganic and organic constituents. The following sub-sections describe the importance of these parameters with respect to treatment system design characterization. They provide the engineering considerations for treatment system options recommendations.

3.1 Water Conservation, Flow Reduction, and Pollution Prevention Conservation and flow reduction of the CW is not feasible due to the natural systems and precipitation events at the Site. With the exception of limited “household” sanitation chemicals and

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chlorine within the sanitary treatment facility, there are no other chemicals added to the CW. Pond 3 does not currently receive water inputs from the facility.

3.2 Commingled Wastewater Quantity The accumulated CW is discharged during the spring, summer, and fall to meet crop water demand and empty the storage ponds to reestablish storage capacity for the upcoming stormwater season. Fresh (Potable) water is added to Storm Lake 1 or to the storm drain system and becomes a component of the CW to meet crop water demand. The annual combined CW and Potable water hydraulic loadings from the past four years have ranged from 38.8 to 54.0 MG (Table 1).

3.3 Fresh Potable Water Quantity and Quality Annual Potable water use is currently estimated by the use of a pump run timer. Historical volumes are estimated from the total CW irrigation. Assuming approximately 38 MG per year of CW without Potable water as described in Section 2.3, Potable water use has ranged from 0.8 to 16.0 MG with an average of 8.3 MG during 2014-2017 (Table 1). The constituent concentrations of the Potable water are all very low (Appendix B). As Potable water is a component of CW, the Potable water quality is accounted for in the monitored CW quality. The Potable water source is protected against backflow by double check valves and an air gap.

3.4 Pond 3 Water Quantity Approximately 6 MG of Pond 3 water is currently stored in Pond 3. Detailed calculations in this Engineering Report indicate that the Site will provide adequate acreage to utilize the remaining Pond 3 water and nutrients.

3.5 Blending Commingled Wastewater and Pond 3 Water A blended water (BW) approach is planned that will result in blending approximately 2.8% Pond 3 water (by volume) and 97.2% CW (by volume) for irrigation during the growing season each year. This blend ratio is based an injection pump sized to achieve a rate of 20 gpm of Pond 3 water into the existing 700 gpm CW irrigation flow rate. A process flow diagram for BW is presented in Figure 2. The Pond 3 water will be delivered through an approximate 1.5-inch schedule 80 polyvinyl chloride (PVC) pipeline into the existing 6-inch aluminum CW pipeline which transitions to steel and then PVC. The BW will be delivered to the land treatment fields through the existing underground 6-inch PVC distribution pipeline (Figure 1). Assuming a maximum CW hydraulic loading design basis of 54.0 MG (Table 1) and an injection rate of 2.8% Pond 3 water (by volume), the estimated total Pond 3 water loading is estimated at approximately 1.5 MG per year. The approach for re-use will be to apply BW during the growing season for irrigation. This approach will allow the crops to utilize the major nutrient constituents and the soils to attenuate or store the minor nutrients and metal constituents.

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3.6 Commingled Wastewater Quality The CW has been analyzed for pollutants and constituents of concern. Based on the analytical results, the CW meets relevant land treatment guidelines 1. Appendix C contains the analytical results of the CW for total metals, inorganic and organic constituents, petroleum hydrocarbons, and coliform during 2006 through 2008. Appendix D contains the inorganic and organic constituents and selected metals in the CW during 2008 through 2013 and for the CW combined with Potable water during 2014 through 2017. Table 2 presents the average quality of the combined CW and Potable water during 2014 through 2017. The CW and Potable water will continue to be combined for the foreseeable future. Therefore, the combined quality has been used for the projected loadings in this Engineering Report based on the values in Table 2.

3.6.1 Metals Metals concentrations in the CW are low and not the limiting parameter by which the CW application rate will be managed. All of the metal concentrations are below land treatment guidelines (Appendices D and E).

3.6.2 Inorganic Constituents Total nitrogen in the CW is mostly in the form of nitrite + nitrate-nitrogen and averages 2.6 milligrams per liter (mg/L; Table 2). Other inorganic constituents include: total phosphorus (0.08 mg/L), potassium (23 mg/L), calcium (38 mg/L), magnesium (49 mg/L), sulfate-sulfur (33 mg/L), sodium (30 mg/L), and chloride (75 mg/L). The average total dissolved solids (TDS or salts) concentration of the CW is moderate at 424 mg/L. The TDS is made up of many dissolved mineral components including cations (calcium, magnesium, sodium, potassium), and anions (bicarbonate, nitrate, sulfate, chloride). The majority of constituents that are in TDS are accounted for within the salts loading considerations discussed in agronomic capacity section of this report.

3.6.3 Organic Constituents The CW, which includes the treated sanitary wastewater, was tested between 2006 and 2008 for fecal and total coliform and biochemical oxygen demand (BOD; Appendix C). Analysis of total suspended solids (TSS) during 2008 to 2017 is presented in Table 2 and Appendix D. The test results for these parameters indicate concentrations below the maximum limit for domestic wastewater facility discharge standards and meet the land application pretreatment requirements for domestic wastewater listed in WAC 173-221-040 as well as the definition for disinfected wastewater listed in Design Criteria for Municipal Wastewater Land Treatment Systems for Public Health Protection (WSDOH, 1994).

3.7 Covered Slag Pond Quality CSP water is a component of CW and it’s quality is accounted for in the monitored CW quality. Characterization of CSP water is included in Appendix F. The CSP water has a high pH and contains a moderate amount of sulfate and TDS with very low amounts of nitrogen.

1 (A) Guidelines for Water Reuse, September 2012, Table 3-5. U.S. Environmental Protection Agency, AR-1530 EPA/600/R-12/618. U.S. Agency for International Development, Washington, D.C. (B) R.S. Ayers. Journal of the Irrigation and Drainage Division, ASCE. Vol 103, No. IR2, June 1977, p. 140. (C) EPA, 1981, Process Design Manual for Land Treatment of Municipal Wastewater, EPA 625/1-81-013, Washington, DC.

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3.8 Pond 3 Water Quality The Pond 3 water has been analyzed for pollutants and constituents of concern. Based on the analytical results, the Pond 3 water meets relevant land treatment guidelines (Appendix E). The Pond 3 water was also tested for pesticides, polychlorinated biphenyl (PCB), and oil and grease, which were not detected (Appendix G).

3.8.1 Metals Metals concentrations in the Pond 3 water are low compared to the land treatment guidelines referenced in Appendix E and not the limiting parameter by which the Pond 3 water application rate will be managed.

3.8.2 Inorganic Constituents The nitrogen in the Pond 3 water is mostly in the form of ammonia-nitrogen. The total nitrogen concentration of the Pond 3 water is 2,351 mg/L. Other Inorganic constituents include: total phosphorus (0.01 mg/L), potassium (3,980 mg/L), calcium (544 mg/L) magnesium (1,500 mg/L), sulfate-sulfur (6,600 mg/L), sodium (710 mg/L), and chloride (6,510 mg/L). The water has an average TDS concentration of 25,800 mg/L.

3.8.3 Organic Constituents Pond 3 was tested in 2018 for fecal and total coliform, BOD, and TSS (Appendix E). Fecal and Total Coliform, BOD, and TSS were 2 number most probable per 100 milliliters of water sample (MPN/100mL), 2 MPN/100mL, 2 mg/L, and 47 mg/L, respectively. There were no detectable levels of other organic contaminants except for 4-Nitrophenol that is commonly associated with decaying plant materials (Appendices G and H).

3.9 Blended Water Quality The calculated estimate of the BW quality is based on the blend ratio of 2.8% Pond 3 water (by volume) and 97.2% CW (by volume). This calculated estimate of BW water was reviewed for pollutants and constituents of concern and meets relevant land treatment guidelines (Appendix E). Table 2 also presents a summary of the calculated estimate of the BW quality.

3.9.1 Metals Table 3 presents a list of the metals included in the Washington standards for metals (WAC 16-200- 7064 2). It presents the calculated metals loadings for the blended CW and Pond 3 water based on the 54 MG of CW and 1.5 MG of Pond 3 water mention above. The combined loadings (i.e., the BW metals loadings) do not exceed any of the Washington standards for metals loading limits shown in Table 3. The most limiting metal is molybdenum, which is only 41% of the annual metals loading limit. Metals loadings will be well below the Washington standards.

2 WAC 16-200-7064. The standards for metals in Washington are the maximum acceptable annual metal additions to soils adopted in RCW 15.54.800 as determined by dividing the long-term (45 year) cumulative metals additions to soils identified in the Canadian standards (Canadian Trade Memorandum T-4-93, August 1993) by 45 and expressing in pounds per acre per year.

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3.9.2 Inorganic Constituents The calculated estimate of nitrogen in the BW is mostly in the form of ammonia-nitrogen. The calculated nitrogen content of BW is moderate with a total nitrogen concentration of 68 mg/L (Table 2). Other BW inorganic constituent calculated estimates include: total phosphorus (0.08 mg/L), potassium (133 mg/L), calcium (52 mg/L), magnesium (89 mg/L), sulfate-sulfur (215 mg/L), sodium (49 mg/L), and chloride (253 mg/L). The water has an estimated average TDS concentration of 1,129 mg/L.

3.9.3 Organic Constituents Calculated estimations of BW concentration for fecal and total coliform, BOD, and TSS are presented in Appendix E. Fecal Coliform, Total Coliform, BOD, and TSS are projected to be 16 MPN/100mL, 26 MPN/100mL, 6 mg/L, and 12 mg/L, respectively.

4.0 AKART ANALYSIS To assess the viability and applicability of various management alternatives, a number of disposal and unit treatment process options were reviewed and compared for managing the CW and Pond 3 water. The purpose of this exercise is to meet the state regulatory requirement that an analysis of all known available and reasonable means of prevention, control, and treatment (AKART) be used to demonstrate that the approaches used and/or selected for CW and Pond 3 water management are suitable and reasonable for the protection of water quality.

4.1 Discharge Alternatives Cations, anions, BOD, TSS, and nitrogen become present in the CW as it accumulates at various stages in the storage ponds across the facility. The CW requires treatment to remove the aforementioned constituents prior to discharge to waters of the State. There are five basic discharge alternatives for the management of the CW and Pond 3 water: 1) Zero Discharge, 2) Evaporation and Landfill Disposal, 3) Surface Water Discharge, 4) Discharge to a Publicly-Owned Treatment Works (POTW), and 5) Land Treatment/Reuse. Each of these alternatives provides treatment to control the constituents that may be released to the environment because of discharge of the CW and Pond 3 water.

4.1.1 Zero Discharge Zero discharge requires that all CW and Pond 3 water be stored and re-used at the processing facility in a closed loop system or evaporated. This could entail building sufficient storage to contain all of the CW and Pond 3 water, treating to applicable re-use standards, and recycling the treated water within the facility. With plant closure, this is not an option because there is limited or no water needed.

4.1.2 Evaporation and Landfill Disposal Before applying for a permit for land treatment of the Pond 3 water, NWA evaluated an alternative treatment option to evaporate the liquid phase via boiling and then disposing of the salt residue. This

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alternative was deemed not suitable for several reasons including unreasonable costs for purchasing a treatment system to be used for a short period of time, high equipment maintenance due to salt damage of steel components, and 24-hour operating costs for labor and natural gas. It would also require management and transportation of the salts residue to a land fill for disposal. Therefore, this alternative treatment process for the Pond 3 water would not necessarily be environmentally friendly or conserve natural resources or provide a beneficial reuse.

4.1.3 Surface Water Discharge Under a surface water discharge alternative, NWA would treat its effluent to appropriate quality standards and discharge to waters of the State. There is one possible surface water discharge point, the Colville River, approximately 3,000 feet east of the facility (bisects NWA property in the eastern half) . The BW flow of up to 36.5 MG per year (<0.2 MG per day) into the Colville River would most likely not be a significant effect with respect to flow or nutrient load, but would require substantial permitting prior to discharge.

The permitting process for a new discharge to the Colville River will be a significant deterrent and take an unacceptable amount of time. Challenges with this option include meeting any total maximum daily load and temperature limitations that might be considered for the receiving water. Direct surface water discharge does not appear to be a viable option at this time without significant investigation including multiple regulatory agency reviews and stakeholder involvement.

4.1.4 Discharge to a Publicly-Owned Treatment Works The facility is located approximately 1/2 miles from the town of Addy, Washington and NWA properties adjoin the town. The Addy/Blue Creek Service Area has a wastewater treatment system; however, it is not sized sufficiently to accept the combined CW and Pond 3 water. The treatment facility utilizes land application with a small application area (Permit No. 8084). Chewelah, Washington is the next closest city or town with a domestic wastewater treatment system. Chewelah is located about 10 miles south of the facility by road. A pipeline of this length would require significant design, permitting, and construction with an over extended timeframe, and, as with any long pipeline that impacts public as well as private lands, the challenge of attaining the appropriate pipeline easements including crossing the Colville River would be daunting. In addition, the low carbon content of the CW and Pond 3 water makes it unacceptable for discharge to a POTW. While technically possible, provided the facility would accept the discharge, this would not be a logical option nor does it meet the reasonable aspect of AKART; therefore, it was not considered for further study as part of this assessment.

4.1.5 Land Treatment/Reuse Land treatment is an efficient and cost effective alternative to standard mechanical treatment technologies. The benefits associated with land treatment include: 1) reduced pressure on local water resources by using BW instead of fresh/Potable water to irrigate agricultural land, 2) nutrient recycling reducing reliance on commercial fertilizers, 3) lower energy requirements,

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4) system resiliency inherent in land treatment systems provides a buffering capacity to nutrient and water loading compared to traditional mechanical treatment systems, and 5) the capability of handling thermal loads and thereby helping to prevent rivers and streams from becoming too warm for specific aquatic species. Land application must be managed by sizing the land treatment system such that the loads are maintained within the treatment capacity of the soil and crops in order to protect groundwater. As is discussed in this report, the current Site are appropriately sized from a hydraulic and nitrogen loading standpoint. Therefore, land application is an available and reasonable treatment methodology for preventing and controlling pollution associated with the discharge of CW and Pond 3 water.

The nitrogen, phosphorus, potassium, and sulfur described above are necessary crop nutrients. The low nutrient concentrations as well as the low levels of BOD, TSS, and salts in the CW and Pond 3 water make it well-suited for use as an irrigation water. The current quality of the BW is acceptable for land application, as proposed, and will not cause land application operational problems. No pre- treatment of BW is planned or needed.

4.2 AKART Recommendations Land treatment is the preferred discharge option for both the CW and Pond 3 water. The alternatives of zero-discharge, evaporation and landfill disposal, direct discharge to a surface waterway, or discharge to a POTW appear unfeasible or unreasonable and, therefore, inappropriate at this time. The remainder of this report provides information with respect to the Site to support the land treatment as the best technology for treatment for both CW and Pond 3 water.

5.0 LAND TREATMENT AREA AND USE CONSIDERATIONS This section presents the design elements of a land treatment system. These elements affect the performance of the system. The general design considerations include the size, use, history, and ownership of the land, climatic data, topography, wetlands, soils, and geology and hydrogeology.

5.1 Land Treatment System Size and Extent The Site currently consists of 115 acres of agricultural farmland within two irrigated fields (Figure 1 and Table 4). Field 1 contains 66 acres irrigated under center pivot. Field 2 has 49 acres irrigated with a wheel-line system.

5.2 Historical Land Use, Land Ownership, and Neighboring Land Uses All current and potential acreage is owned and operated by NWA. The land around the Site are primarily used for production agriculture or permanent pasture. The current Site is used to produce primarily alfalfa. The additional 64.4 acres of agricultural farmland (fields 10 and 11) are currently planted to alfalfa and alfalfa/grass. The facility is located approximately ½ mile west of Addy, Washington. These areas are owned by NWA and described as follows: • Portions of Sections 11, 12, 13, 14, 23, and 24, Township 33N, Range 39E of the Willamette Meridian.

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• Latitude: 48 o, 21’, 24” north, Longitude: 117 o, 51’, 12” west

5.3 Climate The climate data and crop evapotranspiration (ET) estimates for the Site are presented in Table 5. The climate at the Site is described as hot dry summers and cold wet winters with snow covering the ground a majority the winter (USDA-SCS, 1982). Average monthly air temperature ranges from 26 degrees Fahrenheit (°F) in December to 68°F in July (Table 5). Soil temperature averages 48.5°F over the year with frozen soils typically in December, January, and February (USDA-SCS, 1982). The ET (crop water requirement) is greatest during the summer and early fall with a frost-free growing season of 100 to 125 days (USDA-SCS, 1982). Monthly average precipitation, based on a ten-year average of monthly average values from Springdale, Washington ranges from less than one inch in July through September to up to three inches during the winter months. The average annual precipitation of 21.0 inches is less than the potential ET estimate for the proposed crops. However, nearly one-half of the annual precipitation is received during the winter period (e.g., November through March). Prevailing wind direction is from the south-southwest with the average wind speed highest in April at approximately 10 miles per hour (USDA-SCS, 1982).

5.4 Topography and Surface Hydrology The topography of the Site is generally flat with small relief and slopes of approximately 0 to 2% that do not limit land application (Figure 3). Other NWA property areas vary in slope from nearly level to moderately sloping. Additional topography and surface hydrology of the mine facility is discussed in the 2002 Addy Plant Site Mine Reclamation Plan (CH2M Hill, 2002).

5.4.1 Surface Water Quality NWA contracts with the Steven's County Conservation District to monitor the water quality of Stensgar Creek and the South Ditch located to the south of the facility. NWA follows a “no application” buffer policy along the edge of all surface water bodies to avoid the potential for Pond 3 water application impact to any adjacent surface water. Stensgar Creek borders fields 10 and 11 and the South Ditch originates outside the industrial-bermed area of the facility and passes through field 11. The South Ditch water quality is influenced by historical NWA facility activities.

5.4.2 Wetlands There are no known wetlands on the Site proposed for BW irrigation based on the soils at the Site (USDA-SCS, 1982)

5.5 Soil Characterization The information presented in this section is based on soil maps and information published by the United States Department of Agriculture’s Natural Resource Conservation Service’s Web Soil Survey (USDA-NRCS, 2009) and on-site soil characterization conducted in 2009 by a CES Soil Scientist to confirm soil types. The dominant soil types at the site and their physical properties as mapped by the NRCS are presented in Table 6.

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A soil map for the Site is shown in Figure 4 and map units are listed in Table 6. Specifically, each of the soil types is described as follows: • Colville soils are very deep, artificially-drained soils commonly found in depressions and formed in mixed alluvium. • Martella and Cedonia soils are very deep, and moderately and well drained soils found on terraces. They were formed in glacial lake sediment and are mantled with volcanic ash and loess. • Hodgson soils are also deep, moderately well drained soils but found on undulating surfaces and also formed in glacial lake sediment and mantled with volcanic ash and loess. • Bridgeson soils are very deep, artificially-drained soils found in depressions and formed in mixed alluvium of igneous material, lacustrine sediment, volcanic ash, and loess. • Eloika soils are very deep, well-drained soils found on terraces and differ from the other soils in the area because they formed on mixed glacial outwash material and glacial till and are mantled in volcanic ash and loess. • Koerling soils are deep, moderately well drained soils found on terraces. They formed in glaciofluvial material, with an admixture of volcanic ash and loess, and are underlain by stratified, calcareous glacial lake sediment. • Narcisse soils are deep, moderately well drained soils found in bottomlands, around perimeters of lakes, and in depressional areas.

Soil profiles in seven test pits were characterized throughout the Site in order to confirm the soil survey mapping. The soils found in pit 1A (in field 1) were similar to the Martella soils found in the soil survey. A relatively thin and lighter A horizon was present in these soils compared to others throughout the Site, and redoximorphic features were not present. The clay content was relatively high, and these soils would most likely be classified as alfisols, as the soil survey indicates.

The soil found in test pit 1B (in field 1) is an intergrade of the soils found in test pits 1A and 2A (in fields 1 and 2, respectively). Higher clay content was found in test pit 1B, compared to test pit 2A, and more closely matched clay contents in test pit 1A. Both soils in test pit 1B and 2A had redoximorphic features in the form of gleying and iron masses, and therefore, have high water tables. The redoximorphic features occurred between the first and second feet. The soils in test pit 1B and 2A are similar to the Colville soil mapped in field 2, as they have visible carbonates and are likely calcareous, unlike the Bridgeson soil. A dark surface horizon approximately 13 and 19 inches thick, respectively, was found in both test pits 1B and 2A. The soil in test pit 2B was very similar to the Eloika soil mapped at this location in the soil survey, but only encompassed a small area of the southwest corner of field 2.

The soil characterized in fields 10 and 11 (test pit 11) was much sandier and had less clay than the Colville soil that was mapped in this field. Soil textures throughout the profile were silt loams rather than silty clay loams. This soil also had a much thicker dark A horizon than any other soil observed at the Site (approximately 42 inches).

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5.5.1 Soil Physical Properties The majority of the textures at the Site soils are silt loams or silty clay loams (Table 6 and 7), although a small area in the southeast corner of field 2 has gravelly sandy loams and extremely gravelly sands in the subsurface. The clay percentages generally decrease across the Site from the north to the south; however, the greatest clay contents were measured in field 1. Clay contents in soil pits 2B and 11 were much lower than the other pits and ranged from 2 to 10%, while soil in test pits 1A, 1B, and 2A ranged from 16 to 64%.

Overall, soil bulk density was less in the soil profiles of pits 2B and 11, ranging from 0.92 to 1.03 grams per cubic centimeter (g/cm 3), with the exception of the soil in the surface horizon of pit 11, which was 1.46 g/cm 3. The soil bulk densities in the remaining test pits (1A, 1B, and 1A) were similar ranging from 1.0 to 1.6 g/cm 3 (Table 7). Table 4 summarizes the average bulk density by field based on the soil characterization.

5.5.2 Soil Chemical Properties Soil samples were collected most recently in spring 2018 from fields 1, 2, 10, and 11. A separate composite sample for each of the agricultural fields was submitted for laboratory analysis. The soils of the agricultural fields are fertile and will support crop growth (Table 8). Average field soil pH ranges from above neutral (7.8) to alkaline (8.4). Lower depths tend to be more alkaline. Soluble salt (salinity) levels are below the threshold where they would significantly impair crop growth. Irrigated fields measured at 1.5 mmhos per centimeter (mmhos/cm) or less, to a depth of six feet. Unirrigated fields measured at 2.1 mmhos/cm or less, to a depth of six feet. Sufficient inorganic soil nitrogen is available to benefit crop establishment and/or spring growth. Levels of sulfate-sulfur and chloride are at moderate levels. Although the agricultural field soils are relatively fertile, supplemental amounts of nitrogen and phosphorus maybe needed for optimum crop production. There are no plans to apply commercial fertilizer at this time due to the application of BW nutrients, which will help maximum crop performance.

5.5.3 Expected Infiltration Rates and Permeability Permeability is the ease with which water passes through the soil, and in general the larger the soil particles the greater the permeability of the soil. The permeability of the soil surface horizon is reported to range from 0.6 to 2.0 inches per hour (in/hr; Table 6). This permeability rate is considered adequate for proper irrigation. In some instances, the permeability rates of subsurface horizons are similar to the surface. However, some of the soil types within the fields have lower permeability rates in the subsurface that range from 0.2 to 0.6 in/hr. The small area in the southeast corner of field 2 with coarse textured soils is reported to have greater soil permeability of 2.0 to 6.0 in/hr in the subsurface. Irrigation experience with similar soils in the immediate area coupled with the favorable permeability of the soil indicates low potential for runoff or ponding of water on the soil surfaces under proper irrigation design and management.

The plant available water holding capacity (AWHC) of a soil is defined as the difference between soil moisture at field capacity (maximum amount of water held against gravitational forces) and soil moisture at the permanent wilting point (maximum amount of water held by the soil not available to plants). The water content at field capacity (WCFC) and the AWHC is shown in Table 7. The WCFC and AWHC were calculated using the Saxton model (Saxton et al, 1986) with sand, clay,

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and organic matter percentages as inputs to the model. The total WCFC of the soils within the upper 60 inches ranges from 14.7 to 24.2 inches of water. Accounting for the permanent wilting point water, the AWHC of the soils within the upper 60 inches ranges from 8.6 to 13.2 inches of water. Table 8 summarizes the water content at field capacity by field based on the soil characterization.

5.5.4 Conclusions and Recommendations The majority of the soils characterized in November 2009 are similar to the soils mapped in the soil survey, with the exception of the soil mapped in field 11. The soils in field 11 had sand content greater than 15%, unlike the soil survey report, and the A horizon was very deep (approximately 42 inches). Soil physical and chemical properties suggest that the use of all soils investigated on the Site, including field 11 soils, are suitable for BW irrigation.

5.6 Regional and Local Geology The Site is situated in the Okanogan Highlands geologic province. The Highlands extend to the east and north into northern Idaho and southern British Columbia. These Highlands are characterized by rounded mountains with elevations up to 8,000 feet above mean sea level (amsl) and deep narrow valleys. The Columbia River divides the province into an east and west grouping of mountain ranges. The eastern group consisting of the Selkirk, Chewelah, and Huckleberry ranges contains the oldest sedimentary and metamorphic rocks of the state (Lasmanis, 1991).

Orogenic and glacial activity dominates the regional geology of the area. The rocks between the Columbia River and Chewelah belong to the Kootenay arc, which was once a quiet sediment- accumulating continental shelf along the western edge of the pre-North American continent beginning in the Pre-Cambrian Era (800 million years ago [mya]) to Mississippian Period (325 mya). Beginning about 200 mya, the Kootenay arc was crushed into the continental margin under complex tectonic processes as a subduction zone formed, causing extensive folding and metamorphism (Alt and Hyndman, 1994). Throughout the subduction period, the Kootenay arc was repeatedly folded and thrust faulted into a northeast-trending structure (WDNR, 1991) that extends for 150 miles into British Columbia. Some of the sedimentary (limestone, dolomite, and quartzite) and metamorphic rocks (quartzite) of this arc are the host rocks for many of the minerals mined in the area. Molten granitic rocks derived from melting of the subducted oceanic plate, intruded the tightly folded Pre-Cambrian rock in three separate events between 50 to 190 mya.

In the last ice age of the Pleistocene Epoch (2 mya to 10,000 years ago), the valley was covered by a continental glacier, which thinned as it fingered into the more southern valleys near Loon Lake. Glacial moraines that impound drainage, forming Loon Lake and Dear Lakes south of the area, are evidence of the southern extent of the glaciation. Due to the glaciation of the area, glacial deposits mantel the valley floor and many of the low areas in the region. The deposits range from undifferentiated sands, gravels, clays, and silts to heavily stratified profiles associated with extensive glacial lake deposits and involve depths of a few feet to in excess of 700 feet (Stevens County, 2002).

5.7 Regional and Local Hydrogeology Based on well driller logs (Ecology, 2018) for nearby wells (Figure 5), local geology of the Site is characterized as glacial sediments overlying primarily sedimentary bedrock. Glacial sediments are

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described as various combinations of gravel, sand, silt, and clay. Sedimentary rocks are described as limestone, dolomite, and shale and are present in the vicinity between 43 feet below ground surface (bgs) to depths exceeding 820 feet bgs. Geologic mapping of the area support the drillers logs characterizing the valley floor as glacial drift deposited from cordilleran ice sheet in the Pleistocene Epoch (WDNR, 1991).

The Colville River Basin was dominated by a system of glacial lakes. With stream deposition and time, the lake system ultimately yielded to marshes and swamps while the development of the Colville River channel represents a relatively recent feature (Stevens County, 2002). As a result of glaciation, drainage systems within the basin have been seriously disrupted and the distribution of groundwater is quite complicated. With the exceptions of a few marine and non-marine formations, most bedrock units lack adequate water storage and yield characteristics (Stevens County, 2002). Glacial drift sediments of coarse sands and gravels deposited by outwash streams provide the more significant groundwater aquifers while finer grained silts and clays associated with the Pleistocene glacial lake system yield limited quantities of water.

The local depth to groundwater, in wells screened in the upper portion of the glacial sediments, ranges from 5 to 33 feet bgs (Appendix I). Groundwater in wells screened in the deeper aquifer of the glacial sediments indicated artesian conditions with a couple potentiometric levels above ground surface. Groundwater levels in the sedimentary formations below the Site also indicate some with artesian conditions and are reported to be 10 to 200 feet bgs (Appendix I).

6.0 GROUNDWATER MONITORING OF LAND TREATMENT SITE Groundwater monitoring of the Northwest Alloys facility was a component of the original plant design, originating in the 1970’s. Groundwater monitoring of the Site has been conducted quarterly since the fall of 2000. The Site is comprised of two areas adjacent to the facility: fields 1 and 2, located west of the facility (West Area), and fields 10 and 11, located south of the facility (South Area) (Figures 6-9).

CW and Pond 3 water were applied to the Site from 2004 to 2007. Only Potable water was applied in 2008. Since 2009, only CW has been applied to the Site.

The most recent groundwater quality data is shown in Table 9 and historical groundwater data is included in Appendix J. Time-series charts for groundwater parameters are included in Appendix K.

6.1 Monitoring Well Network Monitoring wells MW-7A, MW-8A, MW-11A, and MW-12A were constructed in December 1998 in the land treatment fields along the west and south perimeter of the Site. In October 2009, MW-34 was constructed west of Stranger Creek tributary near Field 1, MW-35 and MW-36 were constructed in Field 1, and MW-37 and MW-38 were constructed in the southwest and southeast corner of field 11, respectively (Figures 6-9). The water quality in wells MW-7A, MW-8A, MW- 11A, MW-12A, and MW-38 reflects residual influence from historical facility operations, while MW-34 reflects valley background influences.

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6.1.1 West Area Monitoring wells MW-11A, MW-12A, MW-34, MW-35, and MW-36 monitor groundwater west of the Site (West Area). Wells MW-11A and MW-12A are upgradient of the fields, while MW-35 and MW-36 are downgradient. Well MW-34 is located on the west side of the Stranger Creek drainage and is hydraulically isolated from the previous mining and refining operations and current land application activities. The water quality in MW-34 represents off-site groundwater quality of the local valley area.

6.1.2 South Area Monitoring wells MW-7A, MW-8A, MW-37, and MW-38 monitor groundwater south of the Site (South Area). With respect to field 11, monitoring wells MW-8A and MW-37 are upgradient, while MW-7A and MW-38 are downgradient. Monitoring well MW-37 is also downgradient of field 10. Monitoring wells MW-7A, MW-8A, and MW-38 have been influenced by historical mining and refining operations. It is important to note that CW is not applied to fields 10 or 11.

6.2 Monitoring Frequency and Parameters The groundwater samples are tested quarterly for the laboratory parameters ammonia-nitrogen, chloride, nitrate-nitrogen, and sulfate from August 2000 to May 2008. From 2009 to present laboratory parameters pH, nitrate+nitrite-nitrogen, ammonia-nitrogen, total Kjeldahl nitrogen, TDS, chloride, sulfate, bicarbonate, phosphorus, potassium, calcium, magnesium, and sodium. The monitoring wells were measured monthly for groundwater elevation from January through April 2011, and were, thereafter, measured quarterly

Average groundwater quality data for 2017 is summarized in Table 9 and individual results by well are included in Appendix J. The parameter value versus time is presented in graphical form in Appendix K.

6.3 Groundwater Elevation, Flow Direction, and Hydraulic Gradient Groundwater in the West Area flows generally to the west with components of flow ranging from west to southwest (Figures 3-9). The flow direction was towards the west-southwest in all quarters in 2017. The hydraulic gradient for the west area averaged 0.0073 feet per foot. Generally, groundwater elevations were highest in the 1 st and 2 nd quarters and lowest in the 3rd and 4 th quarters (Appendix K).

Groundwater in the South Area flowed toward the east-southeast in the first three quarters of 2017 and to the southeast in the 4 th quarter (Figures 6-9). The hydraulic gradient averaged 0.010 feet per foot. In 2017, groundwater elevations were highest in the 1 st and 2 nd quarters, except in MW-7A when the elevation was highest in the 4 th quarter and elevations were lowest in the 4 th quarter except in MW-7A when the elevation was the lowest in the 3rd quarter (Appendix K).

6.4 Groundwater Quality Summary A discussion on groundwater quality is provided in three parts, one for initial groundwater quality prior to land application activities, a second for the period of CW and Pond 3 application, and a third for CW land application after Pond 3 water application was ceased.

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6.4.1 Prior to Land Application (Before 2004) Since most monitoring wells downgradient of the Site were not constructed until 2009, groundwater quality of the area can be represented by upgradient well MW-8A and downgradient well MW-7 in the south area and upgradient wells MW-11A and MW-12A in the west area before application of water began.

The west area nitrate-nitrogen ranged from 0.20 to 9.2 mg/L, chloride ranged from 14 to 386 mg/L, sulfate ranged from 20 to 51 mg/L, and ammonia-nitrogen was below the laboratory method reporting limit (MRL; Appendix I).

On an individual well basis, presented in the charts (Appendix K) as visual observations over time, the following trends were observed for the West Area: • Concentrations of nitrate-nitrogen, chloride, and sulfate were higher in MW-11A compared to MW-12. • A visual upward trend for chloride was present for MW-11A while MW-12A was steady. • A visual downward trend for nitrate-nitrogen was present for MW-11A and MW-12A. • No visual upward/downward trends for sulfate were noted for MW-11A and MW-12A. • A comparison of upgradient vs downgradient data could not be made because many of the downgradient wells were not constructed until 2009.

Groundwater data for the south area shows that nitrate-nitrogen ranged from below the MRL to 4.6 mg/L, chloride ranged from 108 to 222 mg/L, sulfate ranged from below the laboratory MRL to 97 mg/L, and ammonia-nitrogen ranged from below the laboratory MRL to 0.03 mg/L (Appendix I).

On an individual well basis, presented in the charts (Appendix K) as visual observations over time, the following trends were observed for the South Area: • Concentrations were generally higher in sulfate in downgradient well MW-7A compared to upgradient well MW-8A. • Nitrate-nitrogen and chloride concentrations varied and did not indicate one well consistently higher/lower than the other well. • A visual downward trend for nitrate-nitrogen was noted for MW-7A while MW-8A was steady. • A visual upward trend for chloride and sulfate was noted for both MW-7A and MW-8A.

6.4.2 Pond 3 and Commingled Wastewater Land Application (2004 to 2007) During the time CW and Pond 3 water were applied in the west area, MW11A and MW12A exhibited water quality similar to the time before land application operations. The nitrate-nitrogen ranged from below the laboratory MRL to 8.6 mg/L, chloride ranged from 15 to 396 mg/L, sulfate ranged from 19 to 83 mg/L, and ammonia-nitrogen ranged from below the laboratory MRL to 0.02 mg/L (Appendix I).

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On an individual well basis, presented in the charts (Appendix K) as visual observations over time, the following trends were observed for the West Area: • Nitrate-nitrogen indicated a visual upward trend in MW-11A and was steady for MW-12A. • Chloride indicated visual downward trend for MW-11A and was steady in MW-12A. • Sulfate indicated a visual upward trend for both wells. • A comparison of upgradient vs downgradient data could not be made because downgradient wells were not constructed until 2009.

Groundwater data for south area indicate that nitrate-nitrogen ranged from 1.1 to 3.6 mg/L, chloride ranged from 161 to 412 mg/L, sulfate ranged from 90.0 to 396 mg/L, and ammonia-nitrogen ranged from below the laboratory MRL to 0.15 mg/L (Appendix I).

On an individual well basis the following trends were observed for the South Area (Appendix K): • Concentrations of chloride and sulfate are higher in upgradient well MW-8A than downgradient well MW-7A. • Concentrations of nitrate-nitrogen is generally higher in downgradient well MW-7A than downgradient well MW-8A. • Both wells (MW-7A and MW-8A) indicated a visual upward trend for nitrate-nitrogen, chloride, and sulfate.

6.4.3 Commingled Wastewater Land Application (2009-2017) Generally, groundwater average constituent concentrations were higher in the upgradient wells than the downgradient wells in the West Area. The exception was for average calcium, which was higher in the downgradient wells. Some constituent concentrations in the off-site well (MW-34) were equal to or higher than average downgradient water quality in the West Area, including pH, nitrate+nitrite-nitrogen, total Kjeldahl nitrogen, potassium, and calcium (Table 9, Appendix I).

All West Area wells are below the drinking water standards for chloride, nitrogen, and sulfate. Groundwater TDS for the West Area is above the drinking water standard of 500 mg/L in upgradient wells 11A and 12A, and downgradient well MW-36.

On an individual well basis the following trends were observed for the West Area (Appendix K): • The constituent concentrations in the wells indicate relatively stable groundwater conditions since 2009 except an uncharacteristic drop in TDS in MW-35 in the 3 rd quarter of 2015, an uncharacteristic increase in TDS in upgradient MW-12A in the 2 nd quarter of 2017, and an uncharacteristic increase in sodium in all four wells (upgradient and downgradient) in the 4 th quarter of 2016. • A few increasing trends were indicated. These included chloride and sulfate in upgradient well MW-12A since the fourth quarter of 2009, sulfate in upgradient well MW-11A since the 4 th quarter of 2009, and sulfate and chloride in downgradient well MW-36 since the 4 th quarter of 2016.

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• A decreasing trend was indicated in TDS in downgradient well MW-36.

The CW was not applied to the South Area. Constituents that were higher in the upgradient wells compared to the downgradient wells included nitrate+nitrite-nitrogen, total Kjeldahl nitrogen, sulfate, and sodium. Constituents that were higher in the downgradient wells compared to the upgradient wells included pH, TDS, chloride, bicarbonate, phosphorous, potassium, calcium, and magnesium. Some constituent concentrations in the off-site well (MW-34) were equal to or greater than average downgradient water quality in the South Area, including nitrate+nitrite-nitrogen, ammonia-nitrogen, and total Kjeldahl nitrogen (Table 9, Appendix I).

All South Area wells are below the drinking water standard for nitrate (10 mg/L). As of the 3rd Quarter 2017, upgradient well MW-8A exceeds the drinking water standard for chloride (250 mg/L), but the corresponding downgradient well MW-7A is below the drinking water standard. All South Area downgradient wells are currently below the drinking water standard for sulfate (250 mg/L), but upgradient well MW-8A is in exceedance. All South Area wells except upgradient well MW-37 are in exceedance of the drinking water standard for TDS.

On an individual well basis, as presented in the charts (Appendix K), the following trends may be observed for the South Area: • The constituent concentrations in the wells indicate relatively stable groundwater conditions since 2009 except an uncharacteristic increase in sodium in MW-38 in the 2 nd quarter of 2015, sodium in all four wells (upgradient and downgradient) in the 4 th quarter of 2016, and TDS in MW-37 the 2 nd quarter of 2017. • A few increasing trends were indicated. An increasing trend for both chloride in upgradient well MW-7A and sulfate in upgradient well MW-37 since the 4 th quarter of 2016. In downgradient well MW-38, chloride, sulfate, and TDS increased through 2017 and sodium increased from 2009 through 2013. An increasing trend for sulfate in downgradient well MW-37 was also indicated. • Decreasing trends were indicated for sodium, chloride, and TDS in upgradient well MW-8A since the 1st quarter of 2011.

Groundwater constituent concentrations in the South Area generally fluctuated within the historic ranges. This is reflective of historical plant site influence on MW-8A, as well as, to a lesser degree, on MW-7A, MW-37, and MW-38 (which are further away from the facility).

Overall, groundwater concentrations in the West Area where the CW is applied were generally higher in the upgradient wells compared to the downgradient wells reflecting the impacts of the historical NWA facility operations.

7.0 LAND TREATMENT SYSTEM MANAGEMENT Irrigation of agricultural land with wastewater conserves water and plant nutrients. The success of BW beneficial reuse or recycling depends largely on the quality and quantity of BW, crops, climate conditions, and level of management. Cropping interacts with soils and climate to determine the Site

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nutrient and hydraulic capacities. Additionally, the crop rotation tolerance to salinity influences the leaching requirement. This section addresses crop, nutrient management, and irrigation management issues and describes the hydraulic and nutrient capacities. The daily operations of the Site can affect the treatment effectiveness. To maintain a highly effective treatment process in each application area a variety of application methods will need to be used to minimize wind drift, maximize water application uniformity, and utilize the maximum number of acres available. A combination of irrigation systems will be used including, but not limited to center pivot and wheel lines. These types of systems are currently in use in the Addy, Washington area and have adequate water distribution uniformity for distributing the BW for supplemental irrigation. Fifty-foot setbacks from all waterways and 25-foot setbacks from roadways and property boundaries are established and maintained to mitgate over-spray or runoff from leaving the intended agricultural cropping and mine reclamation areas.

NWA will oversee their contracted farmers in the implementation of the recommendations of this engineering report. Competent local farmers are under contract with NWA to farm the fields. They will be managed according to this Engineering Report. All BW irrigation activities will be supervised, controlled, and monitored by NWA.

7.1 Blended Water Loadings Table 10 presents an example summary of the example annual BW hydraulic and constituent loadings. The hydraulic, nutrient, and salts loading should be managed together for the protection of groundwater.

7.1.1 Blended Water Hydraulic Loadings The maximum CW hydraulic loading of 54 MG (Table 2) at the proposed 2.8% Pond 3 water (by volume) blending rate produces an example annual hydraulic loading of 55.5 MG (Table 10). This example loading applied across the 115 available acres provides approximately 17.8 inches of irrigation annually across the Site.

7.1.2 Blended Water Constituent Loadings The BW water is estimated to contain appreciable amounts of nitrogen, and potassium that can benefit crop production. Gross constituent loading rates, based on the example BW application rate of 17.8 inches, are presented in Table 10. The total loadings for nitrogen, phosphorus, and potassium are 274, 0.3, and 537 pounds per acre (lb/ac), respectively.

7.1.3 Sulfur Loading Sulfur is a secondary crop nutrient required in moderate amounts by crops. Sulfate-sulfur loading is estimated at 869 lb/ac (Table 10). At this rate, sulfate-sulfur loading will not negatively impact the Site soils or crops because the soil has the capacity to store large amounts without harmful effects based on current site experience of excellent crop yields.

7.1.4 Chloride Loading As with all nutrients, an acceptable application rate of chloride is one that does not negatively impact the crops or beneficial use of groundwater. Annual chloride loading is estimated at 1,023

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lb/ac (Table 10). Excellent crop yields to date under historical loading rates suggest no negative impact will occur from the applications of BW projected for this project. Similar to sulfur, there is a substantial accumulation of chloride in the soil as expected and desired (Table 8). As for all nutrients, continued soil monitoring in conjunction with groundwater monitoring will be used to confirm storage of chloride in the soil and that chloride loadings are not negatively impacting groundwater during this short-term BW project.

7.1.5 Total Dissolved Solids Loading The annual TDS (salts) mass load is estimated to be 4,560 lb/ac under an average BW loading rate of 17.8 inches (Table 10). Estimated changes in soil salts are not expected to negatively impact the Site soils or crop production. A slow, gradual build-up of salts is expected in the root zone based on soil profile characteristics and Site experience, since winter period precipitation and irrigation account for a minimum potential for leaching. Downward movement (leaching) of salts (including sulfate-sulfur) in the soil profile may occur naturally, but in limited amounts, based on Site experience and maintain a soil salts level that will not significantly impact soils and crops. The BW TDS loadings should therefore not significantly increase groundwater TDS quality.

7.1.6 Biochemical Oxygen Demand Loading The BOD is a measure of the biological requirement for oxygen placed upon the soil by the application of the BW water. The average calculated estimate for BOD loading is moderately low at approximately 26 lb/ac per year. Continuous loads of 50 to 100 pounds BOD per acre per year are considered acceptable limits for wastewater land application and more is often possible (USEPA, 1977). The BOD treatment capacity of the Site will not be the limiting parameter for land treatment of the BW.

7.2 Cropping Beneficial use of BW nutrients is achieved by harvest and removal of plant material. Higher yields and biomass removal increase Site-recycling capacity for wastewater loads. Perennial crops such as alfalfa take up nutrients and increase ET more effectively than annual crops, particularly in the spring and fall, and they typically produce larger amounts of biomass compared to annual crops. They limit the potential for migration of nitrogen beyond the root zone during winter precipitation events. Perennial crops also provide soil protection against wind and water erosion during winter and early spring.

Primarily alfalfa and triticale (with the possibility of wheat, canola, grass, and barley) is expected to be grown on the agricultural fields as part of the land application plan. These crops are capable of benefiting from BW irrigation and utilizing the small amount of crop macronutrients contained in the BW. All of the crops have good root systems that can effectively remove nutrients from the soil profile. Small grain crops and many grasses have roots that typically extend to at least 3 feet while alfalfa root depth is even greater, extending up to more than 6 feet. This report uses a 6-foot rooting depth for the currently established alfalfa based on the Site-specific soil characterization observation of roots at greater than 5 feet. This is considered adequately deep for effective management of the BW on the Site.

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For all crops grown on the Site, best agricultural cropping and management practices should be followed to achieve yield goals. Each crop will be managed using typical agriculture operations for this area (planting and harvesting, seeding rates, pesticide application, etc.).

7.2.1 Planting and Harvest Management All plantings shall be at normally accepted agronomic seeding rates and methods and typically will occur in the late summer or spring. Fields 1 and 2 currently have an established alfalfa or alfalfa/grass crop. All crops listed above can be planted with a standard seed drill or broadcast air seeder. A harrow may be used to incorporate the broadcast seed into the soil. Soil cultivation to prepare a seedbed or remove established crops will be conducted using standard farming equipment and may include field cultivators, disks, and harrows for example. Alfalfa is harvested will be by cutting and baling and possibly by green-chop for haylage. Following the first harvest in late spring, alfalfa harvest will be as often as every five to six weeks in addition to one to two weeks for curing, baling, and handling. The actual harvest schedule will vary depending on weather and crop growth. Combines will be used to harvest small grains (wheat or barley), once in late summer, if grown to maturity. Alternatively, small grain crops such as triticale may also be cut while immature and baled for forage (e.g., forage triticale).

7.2.2 Cropping Rotations Crop rotation may be necessary as a best management practice. Individual field rotations are to be staggered by different years so that most of the fields will be in alfalfa. The crop rotation summary (Table 11) outlines a potential seven-year crop rotation to demonstrate agronomic capacity over time. The summary is an example, planned or likely cropping, and not a comprehensive list of all possible crops or rotation timing. Additional crops with similar agronomic water and nutrient requirements may be substituted into the proposed rotation to meet product market demands while maintaining treatment capability.

7.2.3 Pesticide/Herbicide Application Pesticides will be used only if needed to treat specific problems. Herbicides are generally applied to grain crops at the end of April and in mid-May. Herbicide use will vary depending on the weed problem, crop, and time of year. Herbicide selection and application will depend on time, weather, soil wetness, suitability, and availability; and shall be applied according to labeled rates and methods.

7.2.4 Crop Nutrient Removal The projected crop production schedules, yields, and nutrient removals for each potential crop are presented in Table 12. The potential nutrient removals for wheat, barley, and alfalfa are based on site experience, local-area yields for these crops, and published crop nutrient concentrations. Crop nutrient removal is shown for nitrogen, phosphorus, potassium, and sulfur because these are important crop nutrients and present in the BW (Table 2). The proposed crops will remove lesser quantities of other nutrients such as calcium, magnesium, sodium, and chloride. Similar to normal agricultural irrigation, these nutrients are often applied in quantities greater than crop removal.

For planning purposes, it is important to evaluate nutrient and hydraulic balances (below) to define the overall nutrient and hydraulic load capacities. The “Year 1” crop rotation example was used to

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calculate the hydraulic and nutrient capacity of the Site (Table 13). Irrigated alfalfa at this Site produces about 5.2 tons of hay per acre and remove approximately 260 pounds nitrogen per acre (lb N/ac) or more based on recent site experience (Table 12).

7.3 Agronomic Capacity The capacity of a Site for nutrient and hydraulic loading is an important consideration for good management and design of a system that is protective of groundwater. Proper design and good management of treated effluent application and nutrients encompasses the requirements of AKART farming for land treatment. The term agronomic capacity is defined in the Implementation Guidance for the Ground Water Quality Standards (Ecology, 2005) as the “rate at which a viable crop can be maintained and there is minimal leaching of chemical downwards below the root zone. Crops should be managed for maximum nutrient uptake when used for wastewater treatment”. Therefore, agronomic rates can be used as a design basis in establishing the capacity of a land treatment area for both irrigation and nutrients.

The purpose of this section is to define the nutrient and hydraulic load capacities of the Site and evaluate the nutrient and hydraulic balances. This section also defines the capacities of other important parameters for land treatment design. The Year 1 crop rotation example (Table 11) represents the upper limit of crop harvest amount and nitrogen removal from the Site. It is be used to determine the maximum nutrient and hydraulic capacities of the Site, as the maximum number of acres would be in perennial, high yielding crops such as alfalfa (both fields 1 and 2). As the perennial crop acreage changes, hydraulic and nutrient capacities will also change at the Site.

The agronomic capacity will vary from year to year depending on the crop mix as stated above. According Permit Special Condition S1.B., the wastewater applied to the Site must not exceed the agronomic rates for nitrogen, water, and any other wastewater constituents, in order to protect groundwater quality. The agronomic capacity of the Site is established each year in the annual ICMP as required by Permit Special Condition S7. The Permit states that the total nitrogen and water applied to the Site must not exceed the crop requirements as determined by the ICMP (Permit Special Condition S1.B.). Therefore, the capacities defined in this Engineering Report are considered the potential maximum capacity examples. The capacities to which the Site must be managed and NWA is accountable for, will be established and reported each year in the annual ICMP as required by the Permit.

7.3.1 Hydraulic Capacity The BW will be applied to fields 1 and 2. Irrigation shall be managed to meet and not exceed the crop water requirement or the soil water holding capacity. This will minimize the potential for excess percolation of soil water below the root zone. The actual hydraulic and nitrogen capacity of the site will be dictated by the actual crop rotation designed within the ICMP each year.

Water Balance Calculations The hydraulic capacity of the Site depends on the crop water needs (ET), precipitation, soil water holding capacity, and leaching requirements. Soil hydraulic budgets were developed using these variables to determine the hydraulic capacity of the Site (Appendix L). They were constructed using the Year 1 crop rotation scenario (Table 11) and take into account the average 10-year precipitation

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and ET (Table 5) and the individual soil water holding capacity for each field (Table 7). The BW example flow of 55.5 MG (Table 10) was used for an operational year beginning October 1 and ending September 30. The hydraulic budgets were constructed with the initial and ending soil water content based on sampled historical fall averages (Appendix L). This results in a realistic estimate of moisture stored in the soil and expresses the typical percolate loss to be shown in the budget. A leaching requirement was determined based on the projected EC of the BW with the desired equilibrium soil salinity of 2 mmhos/cm.

The BW water has an EC of 2,081 micromhos per centimeter (Table 2). The calculated leaching requirement is 10.6% for fields 1 and 2 (Table 13 and Appendix L). While the projected leaching fraction is 9.6% for field 2, it does not exceed the leaching requirement (Table 13). All of the projected leaching occurs during the non-irrigation months of December and March as a result of winter precipitation. During the winter period when evaporation rates are low and precipitation rates total about 13 inches (Table 5), the water holding capacity of the soil may be exceeded slightly depending on the initial soil water content in the late fall, soil type, and crop type. Irrigation will typically occur as needed in the months of April through October, with limited irrigation during September and October to allow the soil profile to dry down and create extra water holding capacity for winter precipitation. Adjustments to the irrigation management recommendations toward the end of the season can be used to increase or decrease the potential for leaching over the winter months.

The hydraulic budgets determine the total irrigation capacity. The sum of the monthly BW inputs represent the irrigation capacity of the Site since they were balanced with the precipitation, ET, soil water holding capacity, and leaching requirement. Based on the example crop rotation, the hydraulic budgets demonstrate that a BW flow of 55.5 MG could be managed on the Site within the Site hydraulic capacity and the salts leaching requirement. Since the BW loading capacity is well below the site hydraulic loading capacity, process water hydraulic loading is not a design limiting parameter.

7.3.2 Inorganic Constituent Capacity Inorganic constituents shown in Tables 2 and 10 are within the capacity of the Site based on physical, chemical, and microbial properties of the soil and vegetation to remove contaminants from the applied water by using the upper soil-plant zone to stabilize, transform, or immobilize constituents and support crop growth. This is dependent on crop type, crop tolerances, crop nutrient uptake, soil type, soil characteristics, soil attenuation, local climate, irrigation water quality, water application timing, application method, and Site management.

Nitrogen Capacity and Design Limiting Parameter Nitrogen is a crop macronutrient vital to plant functions. There are several mechanisms of nitrogen treatment at a Site. The first and largest is uptake by the crops growth and subsequent removal during harvest of the crop. Another treatment mechanism is volatilization. Ammonia makes up a large percentage of the total nitrogen in the process water. The effect of irrigation spray, evaporation from leaf surfaces, and evaporation from soil surface should result in a minimum 12% volatilization rate (88% availability) according to the estimation methods described by Meisinger and Randall (1991).

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The moderate nitrogen concentration of the BW (68 mg/L, Table 2) suits its use as irrigation water. At the example hydraulic loading of 55.5 MG per year, the total annual example net nitrogen load of 27,683 pounds compared to the projected site capacity of 29,900 pounds nitrogen indicates that the example load is significantly below the agronomic capacity of the treatment system (Table 13). The BW irrigated at an average rate of 17.8 inches per acre per season would supply an approximate net nitrogen loading of 241 lb N/ac compared to the estimated average crop uptake of 260 lb N/ac (Table 13).

Nitrogen is the design limiting parameter that will limit BW application rates. The BW water nitrogen loading rate must be considered before other BW constituents to minimize potential impacts to groundwater. Other nutrients such as phosphorus, potassium, calcium, magnesium, sulfate-sulfur, sodium, and chloride are important for crop productivity and soil fertility and will be applied at rates within the capacity of the soils and crops at the Site when the BW water is applied to meet the Site’s agronomic nitrogen capacity.

BW application rates are determined on a crop by crop basis based on the BW nitrogen content and projected crop-specific nitrogen need as established in the annual ICMP. The BW nitrogen will be applied at an agronomic rate. The annual net nitrogen load, as determined in the annual ICMP, will be designed to stay within the nitrogen capacity of the Site. The agronomic rate may vary from year to year depending on actual crop performance and Site conditions. Reserve soil nitrogen available to the crop will be considered each year when planning BW water loading rates. Table 11 presents site capacities of example crop rotations at the Site. In example years 2, 4, 8, and 10, acreage is rotated out of alfalfa to forage triticale and overall Site capacity is reduced. Pond 3 water loadings, as a component of BW, will be reduced accordingly each year to stay within the total Site nitrogen capacities as proposed in the annual ICMP.

Phosphorus Phosphorus is a crop macronutrient vital to plant functions. Soil phosphorus is present in both organic and inorganic forms. Phosphorus is strongly attracted to the soil and may become tied up indefinitely (non-labile) in the soil. Supplemental phosphorus fertilizers are limited in their availability to a crop because of soil adsorption. Based on the appropriate BW application rate for crop irrigation requirements, phosphorus would be applied at less than 0.3 lb/ac. This is a relatively insignificant load of phosphorus and additional commercial fertilizer phosphorus may be required to maintain a healthy crop.

Potassium Potassium is a crop macronutrient vital to plant functions. Potassium loadings using BW are estimated at 537 lb/ac. This loading value exceeds the expected crop removal rates for potassium of 300 lb/ac (Table 12). Similar to phosphorus, potassium is strongly adsorbed to the soil or fixed (immobilized) by soil clays and will tend to remain in the upper soil profile for future uptake as a plant nutrient.

Sulfur The extent of the sulfate-sulfur treatment and retention reactions is dependent on pH, clay content, and organic matter content of the soil. Sulfate-sulfur added to soil has multiple potential fates such

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as precipitation with calcium or barium, immobilization by microorganisms, sorption on organic matter by formation of sulfate esters, sorption to clay minerals by displacement of hydroxyl groups, co-precipitation with calcium carbonate, leaching, and loss by conversion to hydrogen sulfide (Bohn et al., 1986).

With time, the potential for sulfur loss by leaching of soluble forms can decrease as sorption and precipitation increase and create less soluble forms. Sorption is not entirely reversible so not all sorbed sulfate-sulfur can be desorbed and transported to groundwater by leaching conditions. High soil organic matter concentrations, such as at the Site, increases the potential for sulfur sorption, as can high concentrations of layer silicates and iron and aluminum sesquioxides. Under wet conditions that promote anaerobic conditions in the soil or in microsites in the soil, such as in some of the soils at the Site, hydrogen sulfide can form and gas off (i.e., volatilize) or combine with iron or other metals to form insoluble sulfides.

A reduction of the soluble forms of sulfur in the soil that could leach to groundwater is expected due to immobilization and chemical precipitation, as described above, under the light irrigations events practiced at the Site (amounts that supplement crop water need but do not exceed the soil water holding capacity). Soil wetting and drying cycles drive immobilization and chemical precipitation. The calcium in the local soils will partially and temporarily immobilize some of the sulfate as gypsum (calcium sulfate).

Sulfur Application Rate Considerations and Management Sulfate-sulfur application rate in excess of crop utilization rate is acceptable if it does not negatively impact the crops or beneficial use of groundwater. There is a substantial accumulation of sulfate- sulfur in the soil as expected and desired (Table 8), and crop yields at the Site are very good. The good crop yields indicate no negative impact from the high application rates in the past and suggest no negative impact will occur from the annual applications projected for this project. There is no concern at this time based on site experience that additional sulfur application will cause negative crop growth.

Continued soil monitoring in conjunction with groundwater monitoring shall be used to confirm storage of sulfate-sulfur in the soil and that sulfate-sulfur loadings are not negatively impacting groundwater during this short-term project. Additionally, NWA will carefully manage the irrigation rate and hydraulic balance in the soil profile, and therefore as suggested above, sulfate-sulfur could be held indefinitely in the soil column until crops are able to utilize it after termination of the short- term Pond 3 water injection project.

Soil Salinity Management Soil salinity (soluble salts) management is focused on maintaining sufficiently low soil salt concentrations to allow good root relations that achieve desired crop growth. Established alfalfa may tolerate salinity up to approximately 3 or 4 mmhos/cm while more tolerant crops such as wheat, triticale and barley grow in salinity as high as 8 mmhos/cm. Table 14 presents a list of several crop types and the respective soil salinity concentrations where a ten percent yield reduction may be expected. However, current soil salinity levels at the Site (Table 8) are low and favorable for crop production.

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Projected Soil Salinity Although soil salinity and crop yields will be monitored annually (Table 15) to assess the potential for negative impact on crop production and the need to reduce BW loadings, soil salinity level is expected to remain below levels that would cause a significant reduction in crop production. This is based on the limited change (only 0.4 mmhos/cm) in average soil salinity from 0.6 mmhos/cm before the first Pond 3 water application in 2004 to 1.0 mmhos/cm after the 5th Pond 3 water application event in 2007.

Based on the limited change, soil salinity is expected to remain below levels that would require scheduled leaching of salts. Scheduled leaching of salts should not be required for the short duration of this project and the salts (anions and cations) would not be intentionally moved below the root zone as is typically the case for land application, but retained in the upper soil profile. Groundwater monitoring will be used to confirm storage of salts in the soil and that salts loadings are not negatively impacting groundwater.

Sodium Adsorption Ratio Because land application is a preferred option for the BW and the current practice at the Site, sodium adsorption ratio (SAR) should be considered. Too much sodium in a soil can cause the soil particles to disperse sealing the surface of the soil and limiting the ability of water to penetrate into the soil resulting in runoff and poor crop growth. The SAR is computed from the calcium, magnesium, and sodium concentrations. The BW SAR was calculated to be 1.0 (Table 2). This indicates that the application of BW will not cause a significant build-up of sodium in the soil. An SAR of 0 to 3 is considered to be no risk to a slight risk of soil sealing according to the USDA National Engineering Handbook as summarized in the Washington Irrigation Guide (USDA-NRS, 1992). As such, the SAR should not be a limiting factor. Unless the SAR of the BW increases to more than 5, soil monitoring of sodium concentration should not be necessary.

Biochemical Oxygen Demand The treatment capacity for BOD depends on soil, temperature, and irrigation practices. The soil needs to allow sufficient oxygen transfer, the temperature affects the rate of microbial digestion of the organic components, and the irrigation practices provide sufficient water to maintain microbial function without saturating the soil and preventing oxygen transfer. The BOD capacity is most influenced by the soil texture and drainage rate because that affects the rate of oxygen diffusion into the soil. Crops also require an oxygenated soil. If the BOD load is too great, the soil will become anaerobic and the crops will suffer stress that reduces performance, nutrient uptake, and yield. The crop harvest and nitrogen removal rates during the 2017 operational year (CES, 2018) suggest adequate crop performance, which indicates low potential of crop stress due to the BOD loadings.

Based on 115 acres and 122 irrigation days (June through September), the annual BOD load of 26 lb/ac represents approximately 0.2 lb/ac per day. This is far below the commonly referenced 50 lb/ac per day maximum recommended by the Idaho Department of Environmental Quality (IDEQ, 2007), and below the 45 to 450 lb/ac per day recommendation by the Environmental Protection Agency (EPA, 2006). Therefore, BOD loading is not a design limiting parameter at this Site.

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Total Suspended Solids The TSS loading impacts on the performance of the Site would be similar to a BOD overload. The result would be poor crop performance and odors. The TSS loads, if in excess, could plug irrigation nozzles causing non-uniform irrigation or plugged soil pores causing ponding, runoff, and anaerobic conditions. The current performance of the Site, as discussed under the BOD section indicates that the loading rates for these constituents are well below the capacity of the system.

7.4 Sanitary Treatment Facility Water Management The sanitary treatment facility wastewater is disinfected prior to entry into the CW and makes up a minuscule amount of the CW (2.6%). Because it is disinfected, human pathogens would not be present in the CW, and ultimately BW. The risk of exposure to human pathogens from the CW, and ultimately BW is considered essentially nonexistent. Therefore, fencing and signage is not planned at this time. The CW, and ultimately BW poses insufficient health risk at this time or in the foreseeable future to warrant measures beyond the twenty five foot setbacks from roadways and property boundaries and 50-foot setbacks from waterways for the land treatment operations.

7.5 Irrigation System Design and Operations A center pivot irrigation system is used on field 1. A wheel-line irrigation system is used on field 2. Irrigation is not currently practiced or available on fields 10 and 11. The function of the wheel-line offers a dose and rest cycle with each scheduled move from one location to the next location. Dose and rest cycles are ideal for treatment of water and nutrients.

Uniform application of the water is important to avoid creating puddles and properly meet the crop’s irrigation water needs, as well as to ensure uniform loading across each field. A wheel-line irrigation system and additional hand-lines have been successfully operated at the site applying CW for the past several years. Therefore, reasonably uniform application, within the limits of the irrigation equipment, is expected and assumed for the purpose of this report.

7.5.1 Irrigation Season Irrigation typically occurs as needed in the months of June through September, which coincides with the primary crop growing season. BW may be applied once in May (e.g., before the first alfalfa cutting), and then consistently after first and second cuttings. Irrigation is typically finished for the season prior to the third cutting in early September. Irrigation is limited during September and October to allow the soil profile to dry down and create extra water holding capacity for winter precipitation. The potential monthly irrigated flow of BW will vary depending on Site specific conditions and available BW. Irrigation is not typically expected during October through May, although limited amounts of BW may be applied in October or May to meet the hydraulic needs of the site. BW irrigation during November through April is not expected and would occur only under temporary bypass conditions.

BW applications will be timed to occur with the crop’s water requirement. Application frequency will depend on the irrigation water requirement of the crops and is anticipated to be highest in the months of July and August. This coincides with the hottest summer weather and drier soil conditions when the crops are growing most actively. Previous field and soil monitoring shows that

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the irrigation loading has been less than the soil water holding capacity. Application frequency can affect the potential for runoff and surface ponding, however under the proposed application rates, off-site runoff and surface ponding should not occur regardless of application frequency or irrigation method.

7.5.2 Leaching Requirement The need for a salts leaching requirement with the BW is not anticipated nor planned at this time due to the estimated BW salt loading rate and relatively low soil salinity of the Site. Therefore, the following discussion is for reference only at this time as an agronomic management practice common to most irrigation systems. The leaching requirement is the fraction of the total crop water supply from all sources that would percolate through the soil to control salt build-up in the soil profile. Leaching can be required in some systems to prevent excessive amounts of salts from accumulating in the root zone. Depending on the system, if not leached regularly, salts from irrigation water can build up in the soil profile to levels that could inhibit crop production. Growers try to maintain the root zone salinity at or below the point of yield decline. The general desired electrical soil conductivity limit of < 2 mmhos/cm for most irrigated crops was used to generate the appropriate leaching requirements. The land application fields do not currently exceed 2 mmhos/cm and therefore do not require salts leaching at this time.

The leaching requirement, presented as a percentage of total irrigation, depends on the average electrical conductivity of the total water supply to the crop for the year. A leaching requirement equation developed by Rhodes et al., is as follows (USDA/SCS/WSU, 1985): ECiw LR = ------((5*ECe) - ECiw) where: LR = Percentage of applied irrigation water that should become deep percolation ECiw = Electrical conductivity of the irrigation water ECe = Desired soil electrical conductivity of a saturated paste extract

The estimated electrical conductivity of the BW averages 2,081 micromhos per centimeter, which is a tolerable salt level for irrigation water (Table 2). As an example, the calculated leaching requirement for the BW would only be 10.5% of the hydraulic load (Table 13 and Appendix L).

8.0 MONITORING Monitoring the performance of the BW land application operations shall be conducted using visual observations, measurements, and sampling to collect appropriate information about system function. Specific objectives of the monitoring will are: • Record Site operation and management practices • Monitor BW quality and quantity • Evaluate soil and crop treatment effectiveness

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• Monitor ground water quality The components of the monitoring plan include: • BW sampling and analysis • BW application rate measurement and recordkeeping • Loading and removal calculations, including crop and soil sampling and analysis • Groundwater sampling, analysis and elevation monitoring

The monitoring plan is summarized in Table 15. The suite of measurements proposed meets the permit reporting requirements, management evaluation, and assessment of environmental impacts. Forms for monitoring data should be organized to promote accurate and orderly data collection and to allow ready data evaluation.

8.1 Reporting The monitoring data to be utilized in an annual report that will include the following items: • Climate Data • BW and Potable water quality • BW and nutrient application records • BW supplemental Potable irrigation water, and commercial fertilizer (if applied) application rates to individual fields • Loadings and removals for each field for nitrogen, potassium, magnesium, sulfate-sulfur, chloride, phosphorus, TDS, lead, and arsenic • Soil analysis and general fertility records including a continuous trend of soil profile data by field for nitrate, conductivity, chloride, and sulfate-sulfur, starting with the fall of 2018 and extending for 5 years. • Water, nitrogen, and salt balances for each field

These products will provide a basis for determining whether land treatment management practices are protective of groundwater.

8.2 Emergency Plans Emergency plans can prevent or minimize damage to equipment, the Site, and to the environment. This emergency response plan includes action items in order of priority, notification procedures, and identifies planned alternative methods of operation.

The land application system will include a pump and valve at the CW ponds and Pond 3 and pressurized pipelines with valves to carry the water from these ponds to the irrigation systems. Possible emergencies could be limited to include inadvertent CW or Pond 3 water discharges while transferring or transporting the water from the pond(s) to the land via pipes, hoses, and irrigation systems

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All operating staff will be trained on emergency shut down and notification procedures. In the event that an inadvertent discharge occurs (e.g., water leaking from a pipe, hose, or irrigation infrastructure) the following actions will be taken in order of priority: 1. Stop further discharge. In the event of a pipe, hose or irrigation system leak, shutting off the appropriate pump and closing the appropriate valve will stop further discharge. 2. Notify the following individuals immediately, in order of availability, once the discharge has been stopped: Johnie McCanna (Site Manager) at (509) 675-4037 (mobile) Michele Maidman at (843) 296-4619 (mobile) 3. Document the date, time, operator in charge, location, description of the emergency situation including an estimate of the duration and extent (size of the area impacted and amount of water discharged). 4. Cease BW land application until the appropriate repairs are made or utilize an approved alternative method of applying the BW (e.g., using a mobile ground sprayer instead of the irrigation system or vice versa). 5. Notify Ecology by telephone at (360) 407-6942 and prepare an incident report for submittal to Ecology.

9.0 CONCLUSIONS AND RECOMMENDATIONS The BW and proposed Site is suitable for land treatment under the permit. General design considerations including climate, topography, soils, crops, and land use have been evaluated and do not limit BW land treatment under the management proposed in this Engineering Report.

Land treatment of the BW is recommended as described above. Estimated loading, crop management, and water management will beneficially utilize the BW, while not negatively impacting being protective of the environment. A BW permit will allow continued success of the NWA beneficial reuse program by supplying BW as supplemental irrigation water to agricultural crops in a manner that is protective of groundwater and the environment.

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REFERENCES Alt, David D. and Hyndman, Donald W., 1994. Roadside Geology of Washington, Ninth Printing, Mountain Press Publishing Company, Missoula, Montana.

Ayers, R.S. and D.W. Westcot, 1985. Water quality for agriculture. Irrig. And Drain. Paper No. 29, Rev. 1. FAO, Rome, Italy.

Bohn, H. L., N. J. Barrow, S. S. S. Rajan, and R. L. Parfitt, 1986. Reactions of inorganic sulfur in soils. In : M. A. Tabatabai, ed., Sulfur in Agriculture, Agronomy Monogram No. 27. ASA- SSSA-CSSA, Madison, WI. 233-249 pp.

CES, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013, and 2014. Annual Irrigation and Crop Management Plans. Northwest Alloys, Inc., Addy, Washington. Cascade Earth Sciences.

CES, 2018. 2018 Irrigation and Crop Management Plan, Northwest Alloys, Inc., Addy, Washington. Cascade Earth Sciences. April 3, 2018.

CH2M-HILL, 2002. Addy Plant Site Mine Reclamation Plan.

Ecology, 2018. State of Washington Water Well Reports. Washington Department of Ecology - Eastern Regional Office. October 2018. Spokane, Washington.

Ecology, 2005. Implementation Guidance for the Ground Water Quality Standards. Publication # 96-02. State of Washington Department of Ecology. Revised October 2005.

Ecology, 1993. Guidelines for Preparation of Engineering Reports for Industrial Wastewater Land Application Systems, WDOE 93-36. Washington Department of Ecology, Olympia, Washington.

EPA, 2006. Process Design Manual for Land Treatment of Municipal Wastewater Effluents. EPA 625/R-06/016. U.S. Environmental Protection Agency. Cincinnati, Ohio. September 2006.

IDEQ, 2007. Guidance for Reclamation and Reuse of Municipal and Industrial Wastewater. Idaho Department of Environmental Quality. September 2007.

Lasmanis, Raymond, 1991. The geology of Washington: Rocks and Minerals, v. 66, no. 4, p. 262- 277. Heldref Publications (Helen Dwight Reid Educational Foundation).

Meisinger, J.J. and G.W. Randall, 1991. Estimating Nitrogen Budgets for Soil-Crop Systems, Ch 5. p. 85-124. In: R. F. Follett, D. R. Keeney, and R. M. Cruse, Editors. Managing Nitrogen for Groundwater Quality and Farm Profitability. Soil Science Society of America. Madison, Wisconsin.

CES – Spokane Valley, WA NWA – Eng Rpt Doc: 2017220017 NWA Eng Rpt Rev.docx October 2018 (Revised February 2019)| Page 32

Saxton, K.E., W.J. Rawls, J.S. Ronberger, and R.I. Papenlick, 1986, revised 11/2005. Estimating Generalized Soil- Water Characteristics From Texture. Soil Sci. Soc. Am. J. 50: 1031- 1036. http://hydrolab.arsusda.gov/soilwater/Index.htm .

Stevens County, 2002. Basic Policy Plan, Stevens County Planning Department, Colville, Washington.

US Salinity Lab Staff, 1954. Diagnosis and Improvement of Saline and Alkali Soils. U.S. Govt Printing Office, Wash. D.C

USDA-NRCS, 2009. Web Soil Survey for Northwest Alloys Land Application Fields. United States Department of Agriculture – Natural Resource Conservation Service. Website: http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx .

USDA-NRS, 1992. Washington Irrigation Guide - National Engineering Handbook Irrigation Guide. United States Department of Agriculture and National Resource Conservation Service

USDA-SCS, 1982. Soil Survey of Stevens County, Washington.

USEPA, 1992. Guidelines for Water Reuse. EPA/625/R-92?004. U.S. Environmental Protection Agency.

USEPA, 1977. Pollution abatement in fruit and vegetable industry. EPA-625/3-77-0007. U.S. Environmental Protection Agency.

WDNR, 1991. The Geology of Washington: The Okanogan Highlands. Washington Department of Natural Resources. http://www.dnr.wa.gov/ResearchScience/Topics/GeologyofWashington/Pages/okanogan.aspx

WSDOH, 1994. Design Criteria for Municipal Wastewater Land Treatment Systems for Public Health Protection. Washington State Department of Health.

CES – Spokane Valley, WA NWA – Eng Rpt Doc: 2017220017 NWA Eng Rpt Rev.docx October 2018 (Revised February 2019)| Page 33

TABLES Table 1. Commingled Wastewater Hydraulic Loadings Table 2. Water Quality Table 3. Metals Loading Rates Table 4. Fields and Soil Types Table 5. Site Precipitation and Evapotranspiration Table 6. Dominant Soil Types and Physical Characteristics Table 7. Soil Physical Analysis Results Table 8. Soil Chemical Properties Table 9. Groundwater Monitoring Data – Mean Data Table 10. Example Blended Water Annual Loadings Table 11. Example Crop Rotations and Capacity Table 12. Crop Management and Nutrient Removal Table 13. Projected Nitrogen and Water Balance Summary Table 14. Soil Salinity Effects on Crop Yield Table 15. Monitoring

Table 1. Commingled Wastewater Hydraulic Loadings

Year 2014 2015 2016 2017 Average Month million gallons Nov ------Mar ------Apr ------May 8.1 9.8 -- -- 9.0 Jun 11.4 14.2 19.4 3.6 12.1 Jul 18.2 15.6 -- 18.3 17.3 Aug 7.0 8.1 19.4 16.0 12.6 Sep ------16.1 16.1 Oct ------Total 44.6 47.6 38.8 54.0 46.3 Estimated Potable Water Volumes Potable Water 1 6.6 9.6 0.8 16.0 8.3

NOTES: Commingled wastewater includes potable water blended in before irrigation and sampling. Abbreviations: -- = No Commingled Wastewater irrigated. 1 Potable Water = Annual total - assumed 38 million gallons of commingled wastewater. References: CES, 2015. 2015 Irrigation and Crop Management Plan, Northwest Alloys, Inc., Addy, Washington. Cascade Earth Sciences. April 7, 2015. CES, 2016. 2016 Irrigation and Crop Management Plan, Northwest Alloys, Inc., Addy, Washington. Cascade Earth Sciences. April 6, 2016. CES, 2017. 2017 Irrigation and Crop Management Plan, Northwest Alloys, Inc., Addy, Washington. Cascade Earth Sciences. April 13, 2017. CES, 2018. 2018 Irrigation and Crop Management Plan, Northwest Alloys, Inc., Addy, Washington. Cascade Earth Sciences. April 3, 2018.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T1 CW Hyd October 2018 (Revised February 2019) Table 2. Water Quality

NO 3+ Total pH EC NH -N TKN P K Ca Mg SO -S Na Cl TDS TSS BOD Alk Pb As Ni 3 NO -N N 4 Source 2 SAR 4 µmhos s.u. mg/L /cm Commingled Wastewater 8.2 772 0.4 1.1 1.5 2.6 0.08 23 38 49 33 30 75 424 11 6.5 176 < 0.002 < 0.006 0.008 0.8 with Potable Water 1

Pond 3 4.2 47,900 1,320 1.4 2,350 2,351 0.01 3,980 544 1,500 6,600 710 6,510 25,800 47 2.0 -- 0.001 0.008 0.057 3.6 Water 2

Estimate of Blended 8.1 2,081 37 1.1 67 68 0.08 133 52 89 215 49 253 1,129 12 6.4 171 0.002 0.006 0.009 1.0 Water 3

NOTES: Abbreviations: -- = not available, Alk = alkalinity, As = arsenic, BOD = biochemical oxygen demand, Ca = calcium, Cl = chloride, EC = electrical conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter,

N = nitrogen, Na = sodium, NH 3 N = ammonia, Ni = nickel, NO 3 + NO 2-N = nitrate + nitrite nitrogen, P = total phosphorous, Pb = lead, SO 4-S = sulfate sulfur, s.u. = standard units, SAR = sodium adsorption ratio,

TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, Total N = total nitrogen (TKN + NO 3 + NO 2-N), TSS = total suspended solids, µmhos/cm = micromhos per centimeter. 1 All values except BOD are averages of the analytical results from samples collected by Northwest Alloys, Inc. and analyzed by Anatek Labs Inc. in Spokane, Washington between 2014-2017 and include potable water. BOD value is an average of the analytical results from samples collected by Northwest Alloys, Inc. and analyzed by Anatek Labs Inc. in Spokane, Washington between 2006-2008 and do not include potable water. 2 Pond 3 values are analytical results from samples collected Northwest Alloys, Inc. in 2018. Laboratory analyses conducted by Anatek Labs Inc. in Spokane, Washington. 3 Blended water values are calculated estimates using an example blend ratio of 2.8% Pond 3 water to 97.2% commingled wastewater. 4 SAR is unitless and calculated from the milliequivalent content of Ca, Mg, and Na (US Salinity Lab Staff, 1954. Diagnosis and Improvement of Saline and Alkali Soils. U.S. Govt Printing Office, Wash. D.C.). For soil types at the site, a SAR of 5.0 or less indicates low potential to negatively affect soil structure and soil hydraulic properties.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T2 Qual October 2018 (Revised February 2019) Table 3. Metals Loading Rates

Arsenic Cadmium Cobalt Lead Mercury Molybdenum Nickel Selenium Zinc Item pounds per acre per year Commingled 0.0225 0.0039 0.0118 0.0059 0.0004 0.0314 0.0319 0.0039 0.0846 Wastewater 1

Pond 3 Water 2 0.0009 0.0001 0.0005 0.0001 0.0011 0.0001 0.0064 0.0004 0.0016

Total 0.0234 0.0040 0.0122 0.0060 0.0015 0.0315 0.0383 0.0043 0.0862 (Blended Water) 3 WAC Annual Metals 0.297 0.079 0.594 1.981 0.019 0.079 0.713 0.055 7.329 Loading Limits 4 Blended Water Loading as a Percentage of the Loading Limits Percent of Limit 7.9% 5.1% 2.1% 0.3% 8.0% 40% 5% 8% 1.2%

NOTES: 1 Commingled wastewater loadings based on average water quality from samples collected by Northwest Alloys, Inc. in 2006-2008 except arsenic, lead, and nickel, which were collected in 2014-2017. Laboratory analyses conducted by Anatek Labs Inc. in Spokane, Washington. 2 Pond 3 wastewater loadings based on water quality samples collected by Northwest Alloys, Inc. in 2018 and analyzed by Anatek Labs Inc. in Spokane, Washington. 3 Loadings based on an annual blended water application rate of approximately 54 million gallons of commingled wastewater and 1.5 million gallons of Pond 3 water. 4 Washington Administrative Code (WAC) 16-200-7064. The standards for metals in Washington are the maximum acceptable annual metal additions from fertilizers to soils adopted in Revised Code of Washington 15.54.800 as determined by dividing the long-term (45 year) cumulative metals additions to soils identified in the Canadian standards (Canadian Trade Memorandum T-4-93, August 1993) by 45 and expressing in pounds per acre per year.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T3 Metals October 2018 (Revised February 2019) Table 4. Fields and Soil Types

Current (2018) Average Bulk Density WCFC Field Acres Crop g/cm 3 inches 1 66.0 Alfalfa 1.36 24.1

2 49.0 Alfalfa 1.40 20.1

Subtotal 115.0

10 24.1 Alfalfa 1.12 14.7

11 40.3 Alfalfa/Grass 1.12 14.7

Subtotal 64.4

Total 179.4

NOTES: Fields 10 and 11 do not currently receive comingled water or Pond 3 water and would require irrigation infrastructure installation to do so in the future. Abbreviations: g/cm 3 = grams per cubic centimeter, WCFC = Water content at field capacity.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T4 Field Info October 2018 (Revised February 2019) Table 5. Site Precipitation and Evapotranspiration

Average Evapotranspiration Precipitation Month Temperature Alfalfa Triticale degrees Fahrenheit inches Oct 44.5 2.1 2.0 2.0 Nov 34.5 2.8 0.7 0.7 Dec 25.7 2.9 0.3 0.3 Jan 27.3 2.2 0.5 0.5 Feb 30.5 1.9 0.9 0.9 Mar 38.1 3.0 2.1 2.1 Apr 45.0 1.7 3.6 0.6 May 54.3 1.3 5.4 3.6 Jun 60.1 1.7 5.9 6.2 Jul 67.9 0.4 7.7 7.7 Aug 66.4 0.2 6.8 3.6 Sep 56.8 0.7 4.5 1.9 Total 45.9 21.0 40.3 30.0

NOTE: 1 Data are 10 year monthly averages obtained from the US Bureau of Reclamation AgriMet system for the Chamokane (CHAW) weather station south of Springdale, Washington.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T5 Climate October 2018 (Revised February 2019) Table 6. Dominant Soil Types and Physical Characteristics

Map Unit Map Unit General Series Landforms and Horizons 3 Texture 4 Permeability 5 AWHC 6 Name 1 Symbol 2 Comments Parent Material

A - 0 - 17" silt loam 0.6 - 2.0" 0.19 - 0.21" Colville silt Very deep, artificially Depressions; Mixed 59 B - 17 - 27" silty clay loam 0.2 - 0.6" 0.19 - 0.21" loam, drained drained soils. Alluvium C - 27 - 60" silt loam or silty clay loam 0.2 - 0.6" 0.19 - 0.21" A - 0 - 12" silt loam 0.6 - 2.0" 0.19 - 0.21" Martella silt B 2 - 12 - 33" silt loam or silty clay loam 0.6 - 2.0" 0.17 - 0.21" Terraces; Volcanic ash Very deep, moderately loam, 0-15 143, 144 silt loam or stratified very and loess over glacial well drained soils. percent slopes C - 33 - 60" fine sandy loam to silty clay 0.2 - 0.6" 0.17 - 0.21" lake sediments loam Cedonia silt A - 0 - 8" silt loam 0.6 - 2.0" 0.19 - 0.21" Terraces; Volcanic ash Very deep, well drained loam, 0-5 45 B - 8 - 32" silt loam 0.6 - 2.0" 0.17 - 0.21" and loess over glacial soils. percent slopes C - 32 - 60" silt loam 0.2 - 0.6" 0.17 - 0.20" lake sediments A - 0 - 10" silt loam 0.6 - 2.0" 0.19 - 0.21" Undulating terraces; Hodgson silt Very deep, moderately Volcanic ash and loess loam, 3-15 100 B - 10 - 28" silty clay & silty clay loam 0.2 - 0.6" 0.18 - 0.20" well drained soils. over glacial lake percent slopes C - 28 - 60" silty clay & silty clay loam 0.2 - 0.6" 0.18 - 0.20" sediments A - 0 - 10" silt loam 0.6 - 2.0" 0.19 - 0.21" Depressions; Mixed alluvium with igneous Bridgeson silt Very deep, artificially 40 material, lacustrine loam, drained C - 10 - 60" silty clay loam 0.2 - 0.6" 0.18 - 0.20" drained soils. sediments, volcanic ash and loess E or B - 0 - 6" silt loam 0.6 - 2.0" 0.18 - 0.21" B2 - 6 - 24" loam 0.6 - 2.0" 0.12 - 0.14" Terraces; Volcanic ash Eloika silt C - 24 - 44" gravelly loam 2.0 - 6.0" 0.10 - 0.12" Very deep, well drained and loess over glacial loam, 0-15 80 C1 - 44 - 53" gravelly sandy loam 2.0 - 6.0" 0.08 - 0.10" soils. outwash and glacial percent slopes extremely gravelly coarse till C2 - 53 - 60" >20" 0.03 - 0.05" sand

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T6 Soils October 2018 (Revised February 2019) | Page 1 of 2 Table 6. Dominant Soil Types and Physical Characteristics

Map Unit Map Unit General Series Landforms and Horizons 3 Texture 4 Permeability 5 AWHC 6 Name 1 Symbol 2 Comments Parent Material

A - 0 - 9" fine sandy loam 2.0 - 6.0" 0.12 - 0.15" Terraces; Glaciofluvial Koerling fine B - 9 - 40" fine sandy loam 2.0 - 6.0" 0.11 - 0.15" material with sandy loam, Very deep, moderately admixture of volcanic 118 0-5 percent well drained soils. ash and loess, slopes C - 40 - 60" silty clay loam 0.6 - 2.0" 0.14 - 0.18" underlain by glacial lake sediment. A - 0 - 18" silt loam 0.6 - 2.0" 0.16 - 0.20" Depressions; Mixed B - 18 - 26" loam 0.6 - 2.0" 0.14 - 0.18" Narcisse silt Very deep, moderately alluvium with an 164 loam well drained soils. admixture of volcanic C - 26 - 60" sandy loam 0.6 - 2.0" 0.11 - 0.14" ash and loess.

NOTES: Based on information from the Web Soil Survey of Stevens County, Washington. (http://websoilsurvey.nrcs.usda.gov/app/WebSoilSurvey.aspx.) 1 Soil map units generally consist of one or several soil series that dominate the map unit. Other soil types may be present. 2 Map unit numbers correspond to the information and maps contained in the Stevens County Soil Survey. 3 A layer of soil having distinct characteristics. A = mineral horizon at or near the surface where organic and mineral material is mixed. B = mineral horizon below an A horizon and a transition from the A to C horizon. C = mineral horizon that does not have the properties typical of the A or B horizons and have been little affected by soil forming processes. 4 Texture based on U.S. Department of Agriculture criteria. 5 The quality of the soil that defines the maximum rate that water can move downward through the profile. It is measured in inches of water per hour. 6 Available water holding capacity is the amount of water available for use by plants in inches of water per inch of soil (field capacity minus wilting point).

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T6 Soils October 2018 (Revised February 2019) | Page 2 of 2 Table 7. Soil Physical Analysis Results

Bulk WCFC AWHC 5 Depth 1 Sand 2 Silt Clay Gravel WCWP 4 WCFC 4 OM Texture 3 Density (60 in) (60 in)

in % g/cm 3 % in in % NWA-1A 0 to 13 6.0 60.0 34.0 0 Silty Clay Loam 1.3 20.9 38.4 5.0 2.3 2.4 13 to 29 20.0 54.0 26.0 0 Silt Loam 1.4 16.1 32.6 5.2 2.6 0.7 29 to 60 4.0 60.0 36.0 0 Silty Clay Loam 1.5 21.6 38.6 12.0 5.3 0.4 Total 22.2 10.2 NWA-1B 0 to 13 18.0 48.0 34.0 0 Silty Clay Loam 1.3 21.4 37.4 4.9 2.1 3.7 13 to 30 20.0 34.0 46.0 0 Silty Clay 1.4 27.4 40.8 6.9 2.3 1.5 30to60 10.0 46.064.0 0 Clay 1.2 27.2 41.4 12.4 4.3 0.7 Total 12.4 8.6 NWA-2A 0 to 19 30.0 52.0 18.0 0 Silt Loam 1.0 13.8 31.5 6.0 3.4 4.5 19 to 34 14.0 70.0 16.0 0 Silt Loam 1.4 10.5 30.2 4.5 3.0 0.6 34 to 60 4.0 74.0 30.0 0 Silty Clay Loam 1.6 18.3 36.7 9.5 4.8 0.3 Total 20.1 11.1 NWA-2B 0 to 8 44.0 48.0 8.0 15 Silt Loam 1.0 9.3 26.1 2.1 1.3 5.2 8 to 19 52.0 42.0 6.0 20 Gravelly Sandy Loam 1.0 5.8 19.9 2.2 1.6 2.3 19 to 60 94.0 4.0 2.0 80 Exremely Gravelly Sand ND 2.7 27.8 11.4 10.3 0.4 Total 15.7 13.2 NWA-11 0to19 52.0 40.08.0 3 Loam 1.5 9.0 23.5 4.5 2.8 4.8 19 to 42 46.0 44.0 10.0 3 Silt Loam 1.0 9.1 24.1 5.5 3.5 3.7 42 to 60 30.0 66.0 4.0 0 Silt Loam 0.9 6.0 26.1 4.7 3.6 0.5 Total 14.7 9.8

NOTES: Samples collected on November 11, 2009 by Cascade Earth Sciences and analyzed by Kuo Testing in Othello, Washington. Abbreviations: % = percent, AWHC = available water holding capacity, g/cm 3 = grams per cubic centimeter, in = inches, OM = organic matter, WCFC = water content at field capacity, WCWP = water content at wilting point. 1 Depth based on field observations of main soil horizons. 2 Sand, Silt, Clay percent determined by laboratory analysis. Gravel percent based on visual observation. 3 Texture based on U.S. Department of Agriculture criteria. 4 WCWP and WCFC calculated using method developed by Saxton (1986). 5 Available water holding capacity was calculated from the soil texture data using the method developed by Saxton (1986) and represents the sum of the AWHC of the depth intervals to 60 inches deep. Reference: Saxton, K.E., W.J. Rawls, J.S. Ronberger, and R.I. Papenlick. 1986 (revised 11/2005). Estimating Generalized Soil - Water Characteristics From Texture. Soil Sci. Soc. Am. J. 50: 1031-1036. http://hydrolab.arsusda.gov/soilwater/Index.htm.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T7 Soil Phys October 2018 (Revised February 2019) Table 8. Soil Chemical Properties

Soil Depth pH ECe Moisture NO -N NH -N Available N SO -S Cl Field 3 4 4 inches s.u. µmhos/cm % mg/kg lb/ac mg/kg 0-12 6.8 0.6 13 4.1 5.7 36 22 44 12-24 7.4 0.8 16 2.7 4.7 27 27 135 24-36 7.8 1.4 18 2.0 4.9 25 116 41 1 36-48 8.2 1.2 20 1.1 3.5 17 60 72 48-60 8.2 1.3 22 1.0 4.7 21 78 80 60-72 8.2 1.5 23 0.7 3.4 15 88 96 Average 7.8 1.1 19 1.9 4.5 24 65 78 0-12 8.0 0.8 26 7.2 8.0 58 39 49 12-24 8.3 0.8 20 2.8 4.1 26 29 33 24-36 8.2 0.9 16 2.4 4.1 25 27 34 2 36-48 8.5 1.1 17 1.4 3.0 17 30 35 48-60 8.7 1.2 20 0.8 2.9 14 39 51 60-72 8.6 1.2 24 1.3 3.1 17 42 63 Average 8.4 1.0 21 2.6 4.2 26 34 44 0-12 7.8 0.6 14 3.3 5.1 26 9 6 12-24 8.2 0.9 21 3.4 3.9 22 78 6 24-36 8.2 2.1 30 8.2 4.3 38 341 16 10 36-48 8.2 1.7 31 11.6 4.1 48 170 62 48-60 8.2 1.4 29 6.3 5.1 35 95 60 60-72 8.4 0.9 20 3.1 3.0 19 25 23 Average 8.2 1.2 24 6.0 4.2 31 120 29 0-12 7.6 1.1 26 10.5 7.0 53 59 53 12-24 8.0 0.9 32 5.9 4.6 32 56 54 24-36 8.4 1.2 28 3.9 4.3 25 59 85 11 36-48 8.3 1.2 26 2.0 3.6 17 65 95 48-60 8.2 1.9 26 1.6 4.5 18 86 158 60-72 8.1 1.7 26 1.6 4.8 19 59 125 Average 8.1 1.3 27 4.2 4.8 28 64 95 0-12 7.6 0.7 20 6 6.4 43 32 38 12-24 8.0 0.9 22 4 4.3 27 48 57 24-36 8.2 1.4 23 4 4.4 28 136 44 36-48 8.3 1.3 24 4 3.6 25 81 66 48-60 8.3 1.4 24 2 4.3 22 75 87

SiteAverage 60-72 8.3 1.3 23 2 3.6 17 54 77 Average 8.1 1.2 23 3.7 4.4 27 71 61

NOTES: Soil samples collected by Cascade Earth Sciences in July 2018 and analyzed by Kuo Testing in Othello, Washington.

Abbreviations: % = percent, Available N = (NO 3-N + NH 4-N)*soil bulk density, Cl = chloride, ECe = electrical conductivity by saturation paste extract (estimates soluble salts), lb/ac = pounds per acre, mg/kg = milligrams per kilogram,

NH 4-N = ammonium-nitrogen, NO 3-N = nitrate-nitrogen, SO 4-S = sulfate-sulfur, s.u. = standard units, µmhos/cm = micromhos per centimeter.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T8 Soil Chem October 2018 (Revised February 2019) Table 9. Groundwater Monitoring Data - Mean Data

NO 3+ Well pH NH 3-N TKN TDS Cl SO 4 HCO 3 P K Ca Mg Na Position 1 NO -N Name 2 s.u. milligrams per liter West Area 12A Upgradient 7.3 < 0.05 < 0.02 0.46 726 43 56 603 0.02 1.9 73 90 76 11A Upgradient 7.6 8.2 < 0.02 1.04 965 193 169 575 0.06 3.1 77 153 84 35 Downgradient 7.4 0.07 < 0.02 0.50 430 4 53 428 0.02 2.0 73 47 47 36 Downgradient 7.2 2.1 < 0.02 0.50 854 150 133 553 0.01 1.9 142 98 77 Upgradient Average 7.4 4.1 < 0.02 0.75 846 118 112 589 0.04 2.5 75 122 80 Downgradient Average 7.3 1.1 < 0.02 0.50 642 77 93 490 0.02 2.0 107 73 62 Off Site 34 Off Site 2 7.3 1.5 < 0.03 0.50 442 2 37 447 0.01 2.0 95 46 25 South Area 8A Upgradient 7.4 4.6 < 0.02 0.50 1,293 245 463 371 0.01 4.9 158 107 139 37 Upgradient 7.2 < 0.08 < 0.04 0.51 354 9 36 214 0.28 2.2 74 13 9 7A Downgradient 7.3 0.7 < 0.02 0.49 1,058 239 178 558 0.01 4.2 148 114 69 38 Downgradient 7.4 < 0.08 < 0.03 0.50 855 132 196 369 0.64 3.6 196 45 49 Upgradient Average 7.3 2.3 < 0.03 0.51 823 127 249 293 0.15 3.5 116 60 74 Downgradient Average 7.4 0.4 < 0.02 0.50 956 186 187 464 0.33 3.9 172 80 59 Off Site 34 Off Site 2 7.3 1.5 < 0.03 0.50 442 2 37 447 0.01 2.0 95 46 25

NOTES: The values shown in this table are an average of the four quarterly test results obtained during the 1st, 2nd, 3rd, and 4th quarters of 2017 reported to the State of Washington Department of Ecology by Northwest Alloys in monthly discharge monitoring reports. Shaded values indicate the average water quality data that are highest within their respective area (West or South).

Abbreviations: HCO 3 = bicarbonate alkalinity as calcium carbonate, Ca = calcium, Cl = chloride, K = potassium, Mg = magnesium, Na = sodium, NH 3-N = ammonia-nitrogen, NO3+NO2-N = nitrate + nitrite-nitrogen, P = phosphorus, SO4 = sulfate, s.u. = standard units, TDS = total dissolved solids, TKN = total Kjeldahl nitrogen. 1 Position is based on the groundwater elevation between the monitoring wells within the same land application area (West or South). 2 Off Site values shown in bold indicate where Off Site water quality is equal to or greater than average downgradient water quality in West and/or South areas.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T9 GW Qual October 2018 (Revised February 2019) Table 10. Example Blended Water Annual Loadings

Total Average Flow TKN P K Ca Mg SO 4-S Na Cl TDS TSS BOD Acres N Site Loadings 1 MG inches pounds per acre CW 115 54.0 17.3 6 10 0.3 91 151 191 129 120 293 1,666 43 26

Pond 3 115 1.54 0.5 264 264 0.001 446 61 168 740 80 730 2,894 5 0.2

Total BW 115 55.5 17.8 270 274 0.3 537 212 359 869 199 1,023 4,560 49 26

NOTES:

Abbreviation: BOD = biochemical oxygen demand, Ca = calcium, Cl = chloride, K = potassium, Mg = magnesium, MG = million gallons, Na = sodium, P = phosphate, SO 4-S = sulfate-sulfur, TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, Total N = total nitrogen (TKN + nitrite-nitrogen + nitrate-nitrogen), TSS = total suspended solids. 1 Average Site nutrient loadings were calculated from estimated Commingled Wastewater, Pond 3 water, and Blended Water irrigation loadings and their respective constituent quality.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T10 Load October 2018 (Revised February 2019) Table 11. Example Crop Rotations and Capacity

Field Acres Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 Year 10

Forage Forage 1 66 Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Triticale Triticale Forage Forage 2 49 Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Alfalfa Triticale Triticale N Uptake Crop Crop Rotation Acreage Summary (acres) (lb/ac)

Alfalfa 260 115 66 115 49 115 115 115 66 115 49

Forage 175 0 49 0 66 0 0 0 49 0 66 Triticale

Site Nitrogen Capacity

Average (lb/ac) 260 224 260 211 260 260 260 224 260 211

Total (lb) 29,900 25,735 29,900 24,290 29,900 29,900 29,900 25,735 29,900 24,290

NOTES: Rotations are based on typical and expected cropping. Actual timing of crops is subject to change depending on crop conditions and rotational needs determined in the annual Irrigation Crop Management Plan. The land treatment site cropping will focus primarily on alfalfa and forage triticale. Other crops will be utilized as needed to meet crop best management practices and market demands. Crop selection will be managed within the nutrient and hydraulic capacity of the site. Abbreviations: lb = pounds per acre, lb/ac = pounds per acre.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T11 Rotations October 2018 (Revised February 2019) Table 12. Crop Management and Nutrient Removal

Projected Planting Harvest Harvest Yield Potential Nutrient Removal 2 Crops Month Month Stage Goal 1 N P K Mg S Irrigated April, Aug, or June, Aug, Hay 5.2 50.0 260 5.0 26 50.0 260 5.0 26 5.0 26 Alfalfa early Sept Sept/Oct early bloom tons/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac Forage Late boot stage 3.5 24 83 11.2 39 60 210 4 14 5 18 April June/July Barley for forage ton/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac April, Aug, or Late boot stage 3.5 50 175 11.2 39.2 60 210 4 14 5 17.5 Triticale July/Aug early Sept for forage ton/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac Grain hard-dough 65 1.9 122 0.6 36 0.3 22 0.1 7 0.2 10 stage bu/ac lb/bu lb/ac lb/bu lb/ac lb/bu lb/ac lb/bu lb/ac lb/bu lb/ac Wheat Sept/Oct June/July 2 14.0 28 3.3 7 45.0 90 4.0 8 5.0 10 Straw tons/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac Grain hard-dough 65 1.5 99 0.3 16 1.3 83 0.2 13 0.1 7 stage bu/ac lb/bu lb/ac lb/bu lb/ac lb/bu lb/ac lb/bu lb/ac lb/bu lb/ac Barley April July 2 14.0 28 3.3 7 45.0 90 4.0 8 5.0 10 Straw tons/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac Dryland April, Aug, or June, Aug, Hay 4 60.0 240 11.9 48 60.0 240 5.0 20 5.0 20 Alfalfa early Sept Sept/Oct early bloom tons/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac Forage 3 Established Not -- 90 -- 12.0 -- 90 -- 3 -- 3 Not Harvested N/A (RMA) 2002 Harvested lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac lb/ton lb/ac

NOTES: The land treatment site cropping will focus primarily on alfalfa and forage triticale. Other crops will be utilized as needed to meet crop best management practices and market demands. Crop selection will be managed within the nutrient and hydraulic capacity of the site. Production and nutrient removal based on published and site-specific data. 1 Alfalfa yields expressed on a 10% moisture basis which approximates the moisture content of baled hay. 2 Values reflect annual nutrient removal rates in plant parts and may not represent the amount required for growth and full crop production. 3 A permanent forage mix was established on reclaimed mine areas in accordance with an approved reclamation plan. The nutrient values shown represent the potential annual crop need to maintain good growth and reclamation.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T12 Crops October 2018 (Revised February 2019) Table 13. Projected Nitrogen and Water Balance Summary

Gross Blended Estimated Example Net N N Estimated Leaching Leaching Water Crop Field Year Acres Load 3 Balance Salts Load Requirement 4 Fraction Irrigation N Need 2 Crop 1 MG lb/ac % 1 Alfalfa 66.0 31.9 260 241 -19 4,549 10.6% 0.0% 2 Alfalfa 49.0 23.7 260 241 -19 4,552 10.6% 9.6% Average 27.8 260 241 -19 4,550 10.6% 4.1% Acres MG lb Total 115.0 55.5 29,900 27,683 -2,217

NOTES: Summarized from individual field-by-field water balances for projected year crops. Actual results will vary from this model due to actual climate and system management needs. Abbreviations: % = percent, MG = million gallons, lb = pounds, lb/ac = pounds per acre, N = nitrogen. 1 Example year is based off a typical crop rotation for the Northwest Alloys site. 2 Estimated nitrogen needed to grow the crop. Actual nitrogen need may vary depending on actual soil residual nitrogen, climate, and yield. 3 Net N Load accounts for net Blended Water nitrogen after volatilization and denitrification losses. Net N Load = Gross N Load * 0.88. Net nitrogen of 88% is calculated using rates based on recommendations in Meisinger and Randall (1991): [((total Kjeldahl nitrogen - ammonia-nitrogen) + (ammonia-nitrogen * 0.80) + (nitrate-nitrogen)) * 0.96] ÷ (total Kjeldahl nitrogen + nitrate-nitrogen), [(67 mg/L - 37 mg/L) + (37 mg/L * 0.80) + 1.1 mg/L) * 0.96] ÷ (67 mg/L + 1.1 mg/L), where all concentrations are in milligrams per liter (mg/L). Source: Meisinger, J.J. and G.W. Randall, 1991. Estimating Nitrogen Budgets for Soil-Crop Systems, Ch 5. p. 85-124. In: R. F. Follett, D. R. Keeney, and R. M. Cruse, Editors. Managing Nitrogen for Groundwater Quality and Farm Profitability. Soil Science Society of America. Madison, Wisconsin 4 Leaching requirement based on a target soil salinity of 2.0 micromhos per centimeter.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T13 N-WB October 2018 (Revised February 2019) Table 14. Soil Salinity Effects on Crop Yield

Threshold Soil Electrical Conductivity (mmhos/cm) 1 Slope Electrical % Yield Crop Conductivity 1 2 3 4 5 6 7 8 910

µmhos/cm Relative Yield (%) Alfalfa 2.0 7.3 100 100 93 85 78 71 64 56 49 42

Triticale 6.1 2.5 100 100 100 100 100 100 98 95 93 90

Barley 8.0 5 100 100 100 100 100 100 100 100 95 90

Orchardgrass 1.5 6.2 100 97 91 85 78 72 66 60 54 47

Fescue, Tall 3.9 5.3 100 100 100 99 94 89 84 78 73 68

Wheat, semi dwarf 6.0 7.1 100 100 100 100 100 100 93 86 79 72

NOTES: Abbreviations: % = percentage, mmhos/cm = millimhos per centimmeter, µmhos/cm = millimhos per centimeter. 1 Saturation paste extract conductivity. Reference: Maas, E.V. and S. R. Grattan. 1999. Crop yields as affected by salinity. In: R.W. Skaggs and J. Van Schilfgaarde, eds. 1999. Agricultural Drainage. Agronomy Monograph No. 38. ASA-CSSA-SSSA. Madison, WI. p55-108. and E.V. Maas, 1990. Relative Salt Tolerance of Herbaceous Crops.).

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T14 Soil Salinity October 2018 (Revised February 2019) Table 15. Monitoring

Item Frequency Location Sample Parameter Commingled Wastewater Alk, As, BOD, Ca, Cl, EC, K, Mg, Na, NH - Monthly when 3 Quality Before Pond 3 Water Injection Grab N, Ni, NO -N, P, Pb, pH, SO -S, TDS, Irrigating 3 4 TKN, TSS

Per Quantity Pump Logbook run time, total gallons Occurrence Pond 3 Water Alk, As, BOD, Ca, Cl, EC, K, Mg, Na, Monthly when Before Injecting into the Quality Grab NH3-N, Ni, NO3-N, P, Pb, pH, SO4-S, Irrigating Commingled Wastewater TDS, TKN, TSS

Per Quantity Pump Logbook run time, total gallons Occurrence Blended Wastewater Alk, As, BOD, Ca, Cl, EC, K, Mg, Na, Monthly when At flow meter piping or Quality Grab NH3-N, Ni, NO3-N, P, Pb, pH, SO4-S, Irrigating sprinkler head TDS, TKN, TSS

Per Logbook and Quantity Each Field run time, total gallons Occurrence Totalizer Supplemental Potable Irrigation Water

Alk, As, BOD, Ca, Cl, EC, K, Mg, Na, NH 3-

Quality Annually Pump Station Grab N, NO 3-N, P, Pb, pH, SO 4-S, TDS, TKN, TSS

Per Quantity Pump Calculation BW - (CW + Pond 3 water) Occurrence

Crop

Planting, Per none Date and operation performed Tillage Occurrence

Composite Per Weight, moisture content, As, Cl, K, Mg, Harvest Each Field tissue sample, Occurrence N, NO -N, P, Pb, SO -S truck weight. 3 4

Visual Observations Periodic Crop health, surface water management, etc observations Soils Each Field at 0-12, 12-24, 24- Spring and Composite soil Cl, ECe, NO 3-N, NH 4-N, pH, soil moisture, Soils Data 1 36, 36-48, 48-60, and 60-72 Fall 2 samples SO -S inch depths 4

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | T15 Monitoring October 2018 (Revised February 2019) | Page 1 of 2 Table 15. Monitoring

Item Frequency Location Sample Parameter Climate Data

Air temperature (high, low), precipitation, Climate Data Daily Local Station or On-Farm and evapotranspiration

Groundwater Depth to Water Elevation Monthly Elevation above mean sea level Table

Quality Monthly Each Well as Required in Grab NO 3-N, TDS Groundwater Monitoring Plan Alk, As, Ca, Cl, EC, HCO 3, K, Mg, Na,

Quality Quarterly Grab NH 3-N, NO3-N, Ni, Pb, pH, SO 4, TDS, TKN

NOTES: Abbreviations: Alk = alkalinity, As = arsenic, BOD = biochemical oxygen demand, Ca = calcium, Cl = chloride, EC = electrical conductivity,

ECe = electrical conductivity of soil saturation paste extract, HCO 3 = bicarbonate, K = potassium, Mg = magnesium, N = nitrogen, Na = sodium,

NH 3-N = ammonia-nitrogen, NH 4-N = ammonium-nitrogen, Ni = nickel, NO 3-N= nitrate-nitrogen, OM = organic material, P = phosphorus,

Pb = lead, SO 4-S = sulfate-sulfur, TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, TSS = total suspended solids, Zn = zinc. 1 The annual report submitted to the State of Washington Department of Ecology shall include a continuous 5-year trend of the end-of-crop year soil profile data for nitrate-nitrogen, conductivity, chloride, and sulfate-sulfur for all fields receiving Blended Wastewater. 2 Fall samples will be collected to represent soil conditions near the end of the crop growing season. Spring samples will be collected to represent soil conditions after the winter period and prior to the primary crop growing season to assist in nutrient planning.

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FIGURES Figure 1. Land Treatment Site Map Figure 2. Process Flow Diagram Figure 3. Site Topography Figure 4. Soil Survey Map Figure 5. Wells Within 1 Mile of the Site Figure 6. Groundwater Flow Map - 1st Quarter 2017 Figure 7. Groundwater Flow Map - 2nd Quarter 2017 Figure 8. Groundwater Flow Map - 3rd Quarter 2017 Figure 9. Groundwater Flow Map - 4th Quarter 2017

COLVILLE

RIVER

HIGHWAY 395

MARBLE VALLEY BASIN RD

COLVILLE

RIVER

ADDY-GIFFORD RD SOUTH DITCH

ALCOA SOUTH RD

CREEK

STENSGAR ZIMMER RD ZIMMER

EXPLANATION 10 NWA Field BW Blended Water CW Commingled Wastewater

(SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) CASCADE EARTH SCIENCES CASCADE EARTH SCIENCES COLVILLE

RIVER

COLVILLE

RIVER

CREEK

STENSGAR

EXPLANATION 10 NWA Field

(SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) CASCADE EARTH SCIENCES COLVILLE

RIVER

COLVILLE

RIVER

CREEK

STENSGAR

EXPLANATION 10 NWA Field

SOIL MAP UNITS AND BOUNDARIES

(SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) CASCADE EARTH SCIENCES EXPLANATION Wells

(SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) CASCADE EARTH SCIENCES COLVILLE

RIVER

MW-12A

MW-11A

COLVILLE

RIVER

MW-8A

CREEK

STENSGAR MW-37

EXPLANATION 6 NWA Field MW-7A Monitoring Well Static Groundwater Elevation

1630 Groundwater Contour Interval = 2 feet (Dashed Where Inferred) Groundwater Flow Direction Hydraulic Gradient: 0.007 ft/ft in Western Area 0.008 ft/ft in Southern Area CASCADE EARTH SCIENCES (SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) COLVILLE

RIVER

MW-12A

MW-11A

COLVILLE

RIVER

MW-8A

CREEK

STENSGAR MW-37

EXPLANATION 6 NWA Field MW-7A Monitoring Well Static Groundwater Elevation

1630 Groundwater Contour Interval = 2 feet (Dashed Where Inferred) Groundwater Flow Direction Hydraulic Gradient: 0.008 ft/ft in Western Area 0.009 ft/ft in Southern Area CASCADE EARTH SCIENCES (SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) COLVILLE

RIVER

MW-12A

MW-11A

COLVILLE

RIVER

MW-8A

CREEK

STENSGAR MW-37

EXPLANATION 6 NWA Field MW-7A Monitoring Well Static Groundwater Elevation

1628 Groundwater Contour Interval = 2 feet (Dashed Where Inferred) Groundwater Flow Direction Hydraulic Gradient: 0.008 ft/ft in Western Area 0.010 ft/ft in Southern Area CASCADE EARTH SCIENCES (SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä) COLVILLE

RIVER

MW-12A

MW-11A

COLVILLE

RIVER

MW-8A

CREEK

STENSGAR MW-37

EXPLANATION 6 NWA Field MW-7A Monitoring Well Static Groundwater Elevation

1628 Groundwater Contour Interval = 2 feet (Dashed Where Inferred) Groundwater Flow Direction Hydraulic Gradient: 0.006 ft/ft in Western Area 0.013 ft/ft in Southern Area CASCADE EARTH SCIENCES (SOURCE: Google Earth Pro Image July 2016, Ó2016 Googleä)

APPENDICES Appendix A. July 2009 Pond 3 Permit Renewal Application Excerpt Appendix B. Potable Water Quality Appendix C. Commingled Wastewater Quality Data 2006-2008 Appendix D. Commingled Wastewater Quality Data 2008-2017 Appendix E. Blended Water Quality and Land Treatment Guidelines Appendix F. Covered Slag Pond Water Quality 2018 Appendix G. Pond 3 Pesticide, PCB, Oil and Grease Water Quality Appendix H. Pond 3 Water Quality 2002 Appendix I. Well Inventory Summary and Well Logs (CD-ROM) Appendix J. Groundwater Quality Data 2000-2017 Appendix K. Groundwater Quality Charts Appendix L. Example Water Balance Calculations

Appendix A.

July 2009 Pond 3 Permit Renewal Application Excerpt

Northwest Alloys Application for Discharge of Industrial Wastewater to Groundwater:

Pond 3 Wastewater Project

Northwest Alloys Inc. (NWA) discharged two separate industrial wastewaters under Washington Department of Ecology (Ecology) Temporary State Waste Discharge Permit No. ST 8088 for the period September 1, 2003 through September 1, 2008. Permit No. ST 8088 allowed annual application of Pond 3 wastewater stored within triple-lined Pond 3 and use of collected comingled industrial wastewater for irrigation on NWA owned-adjoining agricultural/mine reclaim areas .

Cascade Earth Sciences submitted a request on NWA’s behalf for renewal of Permit No. ST 8088 on March 3, 2008. Subsequently, NWA requested that, for clarity and ease of understanding, Ecology issue separate permits for the two distinct wastewaters:

1) A renewal of Permit No. ST 8088 for NWA’s use of the confined wastewater stored within Pond 3 as a soil amendment applied once annually for about three more years and,

2) A new permit for the application of NWA’s annually-collected commingled industrial wastewater (CW) as an irrigation source for agriculture and reclamation areas.

a. On April 30, 2009 NWA submitted an application for discharge of industrial wastewater to groundwater (including an abridged engineering report) requesting Ecology issue a separate permit for irrigation of CW to adjoining NWA owned properties to support crop water demand.

This application package is for renewal of Permit Number ST8088 for the Pond 3 Water. NWA Pond 3 Water is applied once annually by mechanical spreader to NWA owned agricultural Fields 3-11 (Engineering Report Figure 1, attached) that adjoin the industrial site located in Addy, Washington.

Background: Northwest Alloys, Inc (NWA) manufactured magnesium metal (SIC 3339), as well as commercial fertilizer from 1974 until the magnesium metal smelting was permanently curtailed in October, 2001. The production of commercial fertilizer and site mine reclamation activities (under the direction of the Dept. of Natural Resources (DNR), including the East Pit Pond) were completed in 2003.

NWA’s operational design through 1999 included two bentonite lined ponds for concentrated wastewater storage (i.e., the water that subsequently was put into Pond 3). In 2000, NWA constructed a 23 million gallon synthetic triple-lined storage pond designated as Pond 3. The contents of the above mentioned bentonite lined ponds (~13 million gallons) were transferred to the lined Pond 3. One of the bentonite lined ponds is backfilled and the other is used for emergency storage of seasonally collected CW, which will be regulated under a separate permit as submitted to Ecology on April 30, 2009 (revised in June 2009 based on Ecology comments).

The bentonite lined ponds were used for emergency storage of CW during the winter runoff of 2003-2004. Contact between the CW and residual Pond 3 Water and the subsequent transfer to the East Pit for storage likely caused elevated chloride and sulfate in the East Pit in 2004. The elevated chloride/sulfate found in the East Pit analysis of March 23, 2004 was referenced in CES’s technical memorandum dated August 3, 2004.

NWA- Pond 3 Wastewater Discharge Permit Application July 2009 1

Sources of Pond 3 Wastewater: The bulk of the water now residing in Pond 3 came from the brine concentrator installed in the early 1980’s as a site water treatment facility to refine captured CW for use in the production cooling systems as a replacement for potable water. Concentrated blowdown from the brine concentrator was discharged to the concentrated wastewater ponds. As a result Pond 3 is a concentrated wastewater containing total dissloved solids, nitrogen, chloride, potassium, magnesium, and sulfate, but no significant level of heavy metals. Other major contributors to the inventory of Pond 3 were air scrubbers and waste treatment processes utilized in the production of magnesium metal.

Sulfur was brought on NWA’s site in the form of concentrated sulfuric acid and used in three locations in the production of magnesium metal. • A small amount was used to control the pH in the process water. • An even smaller amount was used to clean the filter tubes used in the reduction furnace vacuum port to protect the vacuum pumps from damage. In the course of normal operation these tubes would plug with oxides bound with magnesium metal deposited from the fume stage. Normally mechanical cleaning would remove most of the unwanted material. Eventually the tubes had to be chemically cleaned using sulfuric acid to convert the magnesium to soluble magnesium sulfate. • Due to losses of water from these two process systems, sulfate from these sources would migrate to the storm ponds. • The major consumption of sulfuric acid on the NWA site was for use in trapping ammonia fume generated by the treatment of both the reduction and casting department waste streams. This was performed in dedicated scrubbers located in the hydration department and in the flux bar processing department. o When magnesium burns in air, it consumes not only the oxygen but also the nitrogen forming the combustion products of magnesium oxide and magnesium nitride. The magnesium nitride is hygroscopic and will extract moisture from the air, resulting in hydrolysis and producing magnesium oxide and ammonia. The presence of the ammonia producing nitride prevented the waste streams from being classified as “disposable waste” suitable for placement in the onsite class B landfill. To remove the ammonia, the waste streams were mixed with water in a controlled manner, allowing the ammonia generated to be captured and converted into ammonium sulfate. Effluent from the scrubber was transported by tanker truck and placed in NWA’s Pond 3.

Chloride was brought on NWA’s site in the form of chloride salts used as flux in the cleaning and casting operation. In addition, dolomite rock, from which magnesium was extracted, contains small quantities of the chloride anion.

The metal generated in the reduction furnaces is contaminated with metallic calcium, silicon, fines from the raw material entrained in the vapor stream and oxides generated from air leaks in the condenser. To remove these contaminants the raw metal was melted and a quantity of a flux consisting predominately of chloride salts was stirred into the metal. Most of the contaminants were attracted to the flux and encapsulated. Due to a difference in density, the metal and flux separated upon being allowed to stand quietly.

During the process of mixing, the calcium was removed by reaction with magnesium chloride present in the flux. The calcium converted to the chloride while the magnesium was reduced and entered into the product metal. The silicon was removed through dissolution in fine iron particles when ferric chloride was introduced to the molten magnesium. The ferric chloride converted was reduced to iron and the magnesium was oxidized to form magnesium chloride. The silicon migrated into the iron particles that were removed with the settled flux.

NWA- Pond 3 Wastewater Discharge Permit Application July 2009 2 The spent flux was then cast into blocks for transportation and handling. The flux bars were crushed and screened to remove recoverable magnesium then further processed and applied as a dry agricultural soil amendment to croplands in Eastern Washington, Idaho and Oregon requiring pH adjustment and the nutrients present in the salt mix, predominately potassium, magnesium and calcium.

A significant effort was expended in containing these materials but due to their nature a quantity was lost as fines and fume. When the site experienced precipitation, the runoff would dissolve this material and transport it to the storm water storage ponds.

Fumes from the casting operation were trapped and transported to a baghouse and scrubber for treatment. The baghouse catch from the casting operation was packaged into super sacks and transported off site for disposal in a regulated landfill. Potassium hydroxide was used in the wet scrubber to trap the chloride ions lost from the baghouse in the form of a hydrochloric acid fume. The scrubber blowdown was transported by tanker truck to NWA’s wastewater storage ponds.

During 2003 through 2005, a limited amount of alkaline water, captured from NWA’s South Ditch and Covered Slag Pond, was added to Pond 3. This alkaline water is believed to have originated from precipitation contacting alkaline materials in NWA’s south plant area during 2001-2002. The alkaline water was initially collected in the Covered Slag Pond, which was overfilled in 2002, requiring removal to Pond 3. Subsequent Pond 3 analysis indicated no significant impact due to the addition of the alkaline water. After 2005, alkaline water was no longer added to Pond 3 but was neutralized and mixed with the CW per agreement with Ecology.

Pond 3 currently contains an estimated 6 million gallons of wastewater. It is anticipated that it will take three (3) annual applications of Pond 3 water, based on approximately 1/3 inch each fall, to consume the remaining inventory and complete this project.

NWA- Pond 3 Wastewater Discharge Permit Application July 2009 3

Appendix B.

Potable Water Quality

Appendix B. Potable Water Quality

Constituent Units Results 1 pH s.u. 7.9 Electrical Conductivity µmhos/cm 336 Ammonia-Nitrogen mg/L < 0.02 Nitrate + Nitrite-Nitrogen mg/L 1.1 Total Kjeldahl Nitrogen mg/L < 0.5 Total Nitrogen mg/L 1.6 Total Phosphorous mg/L 0.03 Potassium mg/L 1.4 Calcium mg/L 50 Magnesium mg/L 14 Sulfate-Sulfur mg/L 27 Sodium mg/L 5 Chloride mg/L 0.7 Total Dissolved Solids mg/L 173 Total Suspended Solids mg/L 2 Alkalinity mg/L 155 Lead mg/L 0.00902 Arsenic mg/L 0.0075 Nickel mg/L < 0.005

NOTES: Abbreviations: < = not detected at that laboratory method detection limit, mg/L = milligrams per liter, s.u. = standard units, µmhos/cm = micromhos per centimeter. 1 Potable water samples were collected by CH2M Hill on March 8, 2017 and analyzed by Anatek Labs Inc. Spokane, Washington.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App B Potable Qual 2017 October 2018 (Revised February 2019)

Appendix C.

Commingled Wastewater Quality 2006-2008

Appendix C. Commingled Wastewater Quality 2006-2008

Land Constituent Units 2006 2007 2008 Average Treatment 1 Guidelines Aluminum mg/L -- -- < 0.50 ND 0.50 5 Ammonia-Nitrogen mg/L 0.4 0.1 0.2 0.2 capacity Arsenic mg/L 0.003 0.001 < 0.050 0.018 0.1 Barium mg/L 0.06 0.06 0.09 0.07 NR Beryllium mg/L -- -- < 0.05 ND 0.05 0.1 BOD mg/L 7 10 3 7 see COD Cadmium mg/L < 0.001 < 0.001 < 0.05 * ND 0.001 0.01 Calcium mg/L 51 73 113 79 capacity Chloride mg/L 142 77 84 101 capacity Chromium mg/L < 0.001 < 0.001 < 0.05 ND 0.02 0.1 Cobalt mg/L < 0.005 < 0.001 < 0.05 * ND 0.003 0.05 COD mg/L 29 7 29 22 50-100 Conductivity µmhos/cm 1,130 1,028 881 1,013 1,300-5,300 Copper mg/L 0.003 0.001 < 0.05 < 0.02 0.2 Dissolved Oxygen mg/L 9 12 10 10 NR Fecal Coliform 2 MPN/100 ml 93 7 6 16 NR Fluoride mg/L < 100 * < 0.1 0.2 < 0.1 1.0 Iron mg/L 0.37 0.03 < 0.5 0.3 5 Lead mg/L < 0.001 < 0.001 < 0.05 ND 0.02 5 Lithium mg/L -- -- < 0.05 ND 0.05 2.5 Magnesium mg/L 82 57 58 66 capacity Manganese mg/L 0.05 0.01 0.05 0.04 0.2 Mercury mg/L < 0.0001 < 0.0001 < 0.0001 ND 0.0001 NR Molybdenum mg/L < 0.008 0.008 < 0.05 * 0.008 0.01 Nickel mg/L 0.005 0.006 < 0.05 0.020 0.2 Nitrate + Nitrite-Nitrogen mg/L 1 4 4 3.01 capacity Ortho-phosphate-P mg/L < 100 0.1 0.02 < 33 capacity pH s.u. 8.6 8.3 8.5 8.5 6 - 8 Potassium mg/L 36 25 25 29 capacity Selenium mg/L < 0.001 < 0.001 < 0.05 * ND 0.001 0.02 Silver mg/L < 0.005 < 0.001 < 0.05 ND 0.02 NR Sodium mg/L 39 31 34 35 capacity Sulfate-Sulfer mg/L 82 70 57 69 capacity Total Dissolved Solids mg/L 719 646 535 633 <2,000 Tin,Tungsten, and Titanium mg/L -- -- < 0.05 ND 0.05 NR Total Coliform 2 MPN/100 ml 240 7 12 27 NR Total Nitrogen mg/L 2 4 4 3 capacity Total Oil & Grease mg/L < 1 1.0 1.0 1.0 NR Total Residual Chlorine mg/L < 0.2 0.1 0.3 0.2 NR Total-phosphate-P mg/L 0.03 0.05 0.03 0.04 capacity

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App C CW Qual 06-08 October 2018 (Revised February 2019) | Page 1 of 2 Appendix C. Commingled Wastewater Quality 2006-2008

Land Constituent Units 2006 2007 2008 Average Treatment 1 Guidelines TPH mg/L < 1 1.0 1.0 1.0 NR Total Suspended Solids mg/L 15 6 < 5 9 NR Vanadium mg/L -- -- < 0.05 ND 0.05 0.1 Zinc mg/L 0.008 0.007 < 0.05 0.022 2

NOTES: Samples collected on September 14, 2006; May 14, 2007; and May 13, 2008 and analyzed by Anatek Labs Inc. in Spokane, Washington. Abbreviations: * = detection limit too high for comparison to crop application guidelines and not used in the average, -- indicates not tested, < = not detected at that laboratory method detection limit, BOD = biochemical oxygen demand, COD = chemical oxygen demand, mg/L = milligrams per liter, MPN/100 ml = number most probable per 100 milliliters of water sample, ND followed by the laboratory method detection limit = not detected during any testing event, NR = no recommendation, s.u. = standard units, Sulfate-Sulfur = Sulfate (mg/L)/3, Total Nitrogen = total Kjeldahl nitrogen + nitrite-nitrogen + nitrate-nitrogen, TPH = total petroleum hydrocarbons, µmhos/cm = micromhos per centimeter. 1 Crop application guidelines focused on land application treatment system capacity and based on the following: (a) pH, TDS, As, Ag, Be, Cd, Co, Cr, Cu, Fe, Fl, Li, Mn, Mo, Ni, Pb, Se, Sn, W, Zn = Guidelines for Water Reuse, September 2012, Table 3-5. U.S. Environmental Protection Agency, AR-1530 EPA/600/R-12/618. U.S. Agency for International Development, Washington, D.C. (b) EC = R.S. Ayers. Journal of the Irrigation and Drainage Division, ASCE. Vol 103, No. IR2, June 1977, p. 140. (c) COD = EPA, 1981, Process Design Manual for Land Treatment of Municipal Wastewater, EPA 625/1-81-013, Washington, DC. (d) Site capacity based on physical, chemical, and microbial properties of the soil and vegetation to remove contaminants from the applied water by using the upper soil-plant zone to stabilize, transform, or immobilize constituents and support crop growth. This is dependent on crop type, crop tolerances, crop nutrient uptake, soil type, soil characteristics, soil attenuation, local climate, irrigation water quality, water application timing, application method, and site management. 2 The geometric mean was used for calculated averages of Fecal Coliform and Total Coliform

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Appendix D.

Commingled Wastewater Quality 2008-2017

Appendix D. Commingled Wastewater Quality 2008-2017

NO 3 + Total Sample pH EC NH 4-N TKN P K Ca Mg SO 4-S Na Cl TDS TSS Alk Pb As Ni NO N N Date 2 s.u. µmhos/cm mg/L 5/13/08 8.3 679 0.2 2.1 -- 2.3 0.0 ------37 -- 51 411 -- -- < 0.03 0.03 -- 10/1/09 8.9 736 0.1 2.7 0.7 3.4 0.1 26 36 47 34 31 66.8 406 1 -- < 0.01 < 0.01 0.010 7/8/10 8.4 945 0.1 1.0 1.1 2.1 0.1 26 46 47 39 33 98 527 5 191 < 0.001 0.004 -- 8/5/10 8.3 800 0.1 1.4 0.6 2.0 0.0 24 62 83 39 40 69 469 2 183 < 0.001 0.002 -- 9/8/10 8.4 811 0.1 1.8 1.3 3.1 0.0 19 41 60 38 29 72 486 18 184 < 0.001 0.002 -- 7/8/11 8.6 891 0.3 1.3 0.8 2.1 0.1 55 45 52 57 50 90 529 2 188 < 0.001 0.004 0.008 8/5/11 9.2 561 0.1 1.0 0.8 1.8 0.0 20 19 46 25 27 57 331 3 161 < 0.001 0.002 0.004 6/14/12 8.4 1,260 0.0 2.5 0.4 2.9 0.0 71 50 59 77 59 147 742 2 130 < 0.001 0.005 0.010 7/20/12 8.0 1,100 0.1 0.7 0.6 1.3 0.0 73 55 57 53 59 114 601 1 163 < 0.001 0.005 0.008 8/7/12 8.3 1,060 0.2 3.7 0.7 4.4 0.1 31 49 65 45 44 146 611 4 162 < 0.001 0.002 0.010 9/7/12 8.7 1,000 0.2 4.2 0.4 4.6 0.0 28 41 72 46 45 167 670 1 144 < 0.001 0.002 0.010 5/14/13 8.1 1,210 0.9 2.9 3.9 6.8 0.3 50 57 75 67 55 141 702 9 177 < 0.001 < 0.003 0.014 7/20/13 8.7 1,006 0.5 2.2 1.7 4.0 0.0 41 30 54 50 41 113 565 1 150 < 0.001 < 0.005 0.012 8/7/13 8.2 929 0.2 1.1 1.6 2.7 0.1 24 41 67 43 37 114 520 2 180 < 0.001 0.003 0.010 5/14/14 7.9 988 2.7 1.8 3.9 5.6 0.1 16 50 60 45 29 124 551 2 176 < 0.001 < 0.002 0.016 6/11/14 8.1 973 0.2 1.5 0.8 2.3 0.0 17 45 68 43 33 119 532 4 180 < 0.001 < 0.004 0.013 7/20/14 8.5 586 0.1 0.8 0.8 1.6 0.1 8 37 36 20 16 43 326 25 155 < 0.001 < 0.005 0.005 8/4/14 8.5 376 0.3 0.1 1.0 1.1 0.1 3 36 19 10 8 10 138 6 136 < 0.001 < 0.006 0.002 5/14/15 8.7 1,400 0.3 1.4 1.3 2.7 0.1 99 34 59 83 91 154 750 1 150 < 0.001 < 0.016 0.014 6/11/15 8.2 958 0.1 0.9 0.9 1.8 0.1 28 39 65 37 39 94 502 4 180 < 0.001 < 0.006 0.011 7/20/15 8.6 413 0.0 0.1 0.5 0.6 0.0 4 31 21 13 10 17 224 1 138 < 0.001 < 0.007 0.002 8/4/15 8.5 371 0.1 0.1 0.6 0.7 0.1 4 29 19 11 8 12 187 10 132 < 0.001 < 0.006 0.002 6/11/16 7.6 969 1.1 1.9 5.7 7.6 0.4 41 47 56 53 44 116 658 17 211 -- < 0.008 0.011 8/4/16 7.3 666 0.1 1.0 1.3 2.3 0.0 16 30 52 24 27 64 412 3 192 -- < 0.003 0.006 6/26/17 8.1 858 0.1 < 0.1 0.8 0.9 0.1 16 46 67 38 29 93 482 1 206 < 0.001 0.0038 0.012 7/5/17 8.0 792 0.3 3.1 1.6 4.7 0.0 16 44 57 28 28 72 440 1 206 < 0.005 < 0.005 0.009 8/1/17 8.7 713 0.1 1.4 0.7 2.0 0.0 28 30 48 31 31 69 316 1 192 < 0.001 < 0.005 0.005 9/7/17 8.3 745 0.1 1.9 1.4 3.3 0.1 28 41 54 24 34 58 424 79 208 < 0.003 < 0.005 0.007 Average Quality 2008-2013 1 8.5 928 0.2 2.1 1.1 3.1 0.1 38 44 60 46 42 103 541 4 168 < 0.004 0.006 0.010 2014-2017 2 8.2 772 0.4 1.1 1.5 2.6 0.1 23 38 49 33 30 75 424 11 176 < 0.002 0.006 0.008

NOTES: All samples were taken at the point of discharge to the fields during the month of irrigation, collected by Northwest Alloys, Inc. and analyzed by Anatek Labs Inc. in Spokane, WA. Abbreviation: -- indicates data not available, < = not detected at that laboratory method detection limit, Alk = alkalinity, As= arsenic, Ca = calcium, Cl = chloride, EC = electrical conductivity, K = potassium, Mg = magnesium,

mg/L = milligrams per liter, N = nitrogen, Na = sodium, NH 4-N = ammonium nitrogen, Ni = nickel, NO 3 + NO 2-N = nitrate + nitrite nitrogen, P = total phosphorous, Pb = lead, SO 4-S = sulfate-sulfur, s.u. = standard units,

TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, Total N = total nitrogen (TKN + NO 3 + NO 2-N), TSS = total suspended solids, µmhos/cm = micromhos per centimeter. 1 Average commingled wastewater quality based on values from 2008-2013 when potable water was not a component of the commingled wastewater. 2 Average commingled wastewater quality based on values from 2014-2017 when potable water was a component of the commingled wastewater.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App D CW Qual 08-17 October 2018 (Revised February 2019)

Appendix E.

Blended Water Quality and Land Treatment Guidelines

Appendix E. Blended Water Quality and Land Treatment Guidelines

Commingled Pond 3 Land 1 2 Blended Constituent units Wastewater Water 3 Treatment Water 4 2006-08 2014-17 2018 Guidelines Alkalinity mg/L X 176 -- 171 NR Aluminum mg/L ND 0.50 -- 1.19 0.5 5 Ammonia-Nitrogen mg/L X 0.4 1,320 37 capacity Arsenic mg/L X 0.006 0.008 0.0058 0.1 Barium mg/L 0.07 -- 0.06 0.07 NR Beryllium mg/L ND 0.05 -- ND 0.001 0.05 0.1 BOD mg/L 6.5 -- < 2.0 6 see COD Boron mg/L -- -- 0.346 0.01 0.75 Cadmium mg/L ND 0.001 -- ND 0.001 0.001 0.01 Calcium mg/L X 38 544 52 capacity Chloride mg/L X 75 6,510 253 capacity Chromium mg/L ND 0.02 -- 0.00137 0.02 0.1 Cobalt mg/L ND 0.003 -- 0.004 0.00 0.1 COD mg/L 22 -- 157 26 50-100 Conductivity µmhos/cm X 772 47,900 2,081 1,300-5,300 Copper mg/L < 0.02 -- 0.00197 0.02 0.2 Diesel mg/L -- -- ND 0.1 0.003 NR Dissolved Oxygen mg/L 10.3 -- 9.3 10.3 NR Fecal Coliform MPN/100mL 16 -- 2 16 NR Fluoride mg/L < 0.13 -- 1.87 0.18 1 Iron mg/L 0.3 -- 0.858 0.3 5 Lead mg/L X < 0.002 0.001 0.002 5 Lithium mg/L ND 0.05 -- 0.134 0.05 2.5 Lube Oil mg/L -- -- ND 0.5 0.014 NR Magnesium mg/L X 49 1,500 89 capacity Manganese mg/L 0.04 -- 1.14 0.07 0.2 Mercury mg/L ND 0.0001 -- ND 0.01 0.0004 NR Molybdenum mg/L 0.01 -- ND 0.001 0.008 0.01 Nickel mg/L X 0.008 0.057 0.01 0.2 Nitrate+Nitrite-Nitrogen mg/L X 1.1 1.39 1.1 capacity Ortho-phosphate-P mg/L < 33 -- ND 0.01 32.45 capacity pH s.u. X 8 4 8 6 - 8 Potassium mg/L X 23 3,980 133 capacity Selenium mg/L ND 0.001 -- 0.00339 0.001 0.02 Silver mg/L ND 0.02 -- ND 0.001 0.02 NR Sodium mg/L X 30 710 49 capacity Sulfate-Sulfur mg/L X 33 6,600 215 capacity Total Dissolved Solids mg/L X 424 25,800 1,129 <2,000 Thallium mg/L -- -- ND 0.001 0.00003 NR Tin mg/L ND 0.05 -- ND 0.01 0.05 NR Titanium mg/L ND 0.05 -- ND 0.001 0.05 NR Total Kjeldahl Nitrogen mg/L -- 1.5 2,350 67 capacity Total Coliform MPN/100mL 27 -- 2 26 NR Total Nitrogen mg/L X 3 2,351 68 capacity Total Oil & Grease mg/L 1 -- -- 1 NR Total Residual Chlorine mg/L 0.2 -- ND 0.05 0.2 NR Total-phosphate-P mg/L X 0.1 0.05 0.08 capacity

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App E Blended October 2018 (Revised February 2019) | Page 1 of 2 Appendix E. Blended Water Quality and Land Treatment Guidelines

Commingled Pond 3 Land 1 2 Blended Constituent units Wastewater Water 3 Treatment Water 4 2006-08 2014-17 2018 Guidelines TPH mg/L 1 -- -- 1 NR Total Suspended Solids mg/L X 11 47 12 NR Tungsten mg/L ND 0.05 -- ND 0.01 0.05 NR Vanadium mg/L ND 0.05 -- ND 0.001 0.05 0.1 Zinc mg/L 0.022 -- 0.014 0.02 2

NOTES: Abbreviations: * = detection limit too high for comparison to crop application guidelines and not used in the average, -- indicates not tested, < = not detected at that laboratory method detection limit, BOD = biochemical oxygen demand, COD = chemical oxygen demand, mg/L = milligrams per liter, MPN/100 ml = number most probable per 100 milliliters of water sample, ND followed by the laboratory method detection limit = not detected during any testing event, NR = no recommendation, s.u. = standard units, Sulfate-Sulfur = Sulfate (mg/L)/3, Total Nitrogen = total Kjeldahl nitrogen + nitrite-nitrogen + nitrate-nitrogen, TPH = total petroleum hydrocarbons, µmhos/cm = micromhos per centimeter, X = older data available - not used because more recent data was available. 1 The constituent concentrations are an average of the analytical results from samples collected by Northwest Alloys and analyzed by Anatek Labs Inc. in Spokane, Washington. 2 Samples collected by Northwest Alloys on September 12, 2018 and analyzed by Anatek Labs Inc. and TestAmerica, both in Spokane, Washington. 3 Blended water constituent concentrations are calculated estimates using a blend ratio of 2.8% Pond 3 Water to 97.2% Commingled Wastewater. The most recent analytical results were used for the Commingled Wastewater as shown for 2006-08 or 2014-17. 4 Land treatment system guidelines based on the following: (a) pH, TDS, As, Ag, Be, Bn, Cd, Co, Cr, Cu, Fe, Fl, Li, Mn, Mo, Ni, Pb, Se, Sn, Tl, W, Zn = Guidelines for Water Reuse, September 2012, Table 3-5. U.S. Environmental Protection Agency, AR-1530 EPA/600/R-12/618. U.S. Agency for International Development, Washington, D.C. (b) EC = R.S. Ayers. Journal of the Irrigation and Drainage Division, ASCE. Vol 103, No. IR2, June 1977, p. 140. (c) COD = EPA, 1981, Process Design Manual for Land Treatment of Municipal Wastewater, EPA 625/1-81-013, Washington, DC. (d) Site capacity based on physical, chemical, and microbial properties of the soil and vegetation to remove contaminants from the applied water by using the upper soil-plant zone to stabilize, transform, or immobilize constituents and support crop growth. This is dependant on crop type, crop tolerances, crop nutrient uptake, soil type, soil characteristics, soil attenuation, local climate, irrigation water quality, water application timing, application method, and site management.

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Appendix F.

Cover Slag Pond Water Quality 2018

Anatek Labs, Inc. 1282 Alturas Drive • Moscow, ID 83843 • (208) 883-2839 • Fax (208) 882-9246 • email [email protected] 504 E Sprague Ste. D • Spokane WA 99202 • (509) 838-3999 • Fax (509) 838-4433 • email [email protected]

Client: NORTHWEST ALLOYS, INC. Batch #: 180824029 Address: P.O. BOX 115 Project Name: NWA COVERED SLAG ADDY, WA 99101 POND AUGUST 2018 Attn: JOHNIE McCANNA

Analytical Results Report

Sample Number 180824029-001 Sampling Date 8/24/2018 Date/Time Received 8/24/2018 2:55 PM Client Sample ID NWA CSP AUGUST 2018 Sampling Time 11:15 AM Extraction Date Matrix Water Sample Location Comments

Parameter Result UnitsPQL Analysis Date Analyst Method Qualifier Alkalinity 122mg CaCO3/L 5 8/27/2018 9:45:00 AM BAS SM2320B Ammonia-nitrogen <0.02mg/L 0.02 8/28/2018 9:13:00 AM TLM SM4500NH3G Arsenic 0.0520mg/L 0.001 9/5/2018 4:58:00 PM BAG EPA 200.8 Calcium 11.5mg/L 0.1 9/6/2018 1:32:00 PM BAG EPA 200.8 Chloride 44.5mg/L 0.2 8/24/2018 8:46:00 PM LMD EPA 300.0 Conductivity 1820µmhos/cm 10 8/28/2018 9:20:00 AM CME SM2510B Lead NDmg/L 0.001 9/5/2018 4:58:00 PM BAG EPA 200.8 Magnesium 3.50mg/L 0.1 9/6/2018 1:32:00 PM BAG EPA 200.8 Nickel NDmg/L 0.001 9/5/2018 4:58:00 PM BAG EPA 200.8 NO3/N+NO2/N <0.2mg/L 0.2 8/24/2018 8:46:00 PM LMD EPA 300.0 pH 10.7 ph Units8/24/2018 10:00:00 AM CME SM 4500pH-B Potassium 272mg/L 0.1 9/6/2018 1:32:00 PM BAG EPA 200.8 Sodium 146mg/L 0.1 9/6/2018 1:32:00 PM BAG EPA 200.8 TDS 2090mg/L 200 8/28/2018 10:00:00 AM BAS SM 2540C TSS 52mg/L 2 8/29/2018 12:00:00 PM BAS SM 2540D Sulfate 333mg/L 2 9/4/2018 2:36:00 PM LMD EPA 300.0 TKN 2.28mg/L 0.5 8/31/2018 3:49:00 PM TLM SM4500NORGC Total P 0.163mg/L 0.2 8/30/2018 4:48:00 PM TLM SM4500PF

Authorized Signature

Kathleen A. Sattler, Lab Manager

MCL EPA's Maximum Contaminant Level ND Not Detected PQL Practical Quantitation Limit

This report shall not be reproduced except in full, without the written approval of the laboratory. The results reported relate only to the samples indicated. Soil/solid results are reported on a dry-weight basis unless otherwise noted.

Certifications held by Anatek Labs ID: EPA:ID00013; AZ:0701; FL(NELAP):E87893; ID:ID00013; MT:CERT0028; NM: ID00013;NV:ID00013; OR:ID200001-002; WA:C595 Certifications held by Anatek Labs WA: EPA:WA00169; ID:WA00169; WA:C585; MT:Cert0095; FL(NELAP): E871099

Monday, September 17, 2018 Page 1 of 1 Anatek Labs, Inc. 1282 Alturas Drive • Moscow, ID 83843 • (208) 883-2839 • Fax (208) 882-9246 • email [email protected] 504 E Sprague Ste. D • Spokane WA 99202 • (509) 838-3999 • Fax (509) 838-4433 • email [email protected]

Login Report

Customer Name: NORTHWEST ALLOYS, INC. Order ID: 180824029 P.O. BOX 115 Order Date: 8/24/2018 ADDY WA 99101 Contact Name: JOHNIE McCANNA Project Name: NWA COVERED SLAG POND AUGUST 2018 Comment:

Sample #: 180824029-001 Customer Sample #: NWA CSP AUGUST 2018

Recv'd: Matrix: Water Collector: OLY MCCANNA Date Collected: 8/24/2018 Quantity: 1 Date Received: 8/24/2018 2:55:00 PM Time Collected: 11:15 AM Comment:

TestLab Method Due Date Priority ALKALINITY S SM2320B 8/26/2018 Normal (~10 Days) AMMONIA-NITROGEN SPOAS SM4500NH3G 8/24/2018 Normal (~10 Days) ARSENIC S EPA 200.8 9/3/2018 Normal (~10 Days) CALCIUM S EPA 200.8 9/3/2018 Normal (~10 Days) CHLORIDE S EPA 300.0 9/3/2018 Normal (~10 Days) CONDUCTIVITY S SM2510B 9/3/2018 Normal (~10 Days) LEAD S EPA 200.8 9/3/2018 Normal (~10 Days) MAGNESIUM S EPA 200.8 9/3/2018 Normal (~10 Days) NICKEL S EPA 200.8 9/3/2018 Normal (~10 Days) NITRATE+ NITRITE AS NS EPA 300.0 9/3/2018 Normal (~10 Days) pH S SM 4500pH-B 9/3/2018 Normal (~10 Days) POTASSIUM S EPA 200.8 9/3/2018 Normal (~10 Days) SODIUM S EPA 200.8 9/3/2018 Normal (~10 Days) SOLIDS - TDS S SM 2540C 9/3/2018 Normal (~10 Days) SOLIDS - TSS S SM 2540D 9/3/2018 Normal (~10 Days) SULFATE S EPA 300.0 9/3/2018 Normal (~10 Days) TKN S SM4500NORGC 9/3/2018 Normal (~10 Days) TOTAL P FIA S SM4500PF 9/3/2018 Normal (~10 Days) Customer Name: NORTHWEST ALLOYS, INC. Order ID: 180824029 P.O. BOX 115 Order Date: 8/24/2018 ADDY WA 99101 Contact Name: JOHNIE McCANNA Project Name: NWA COVERED SLAG POND AUGUST 2018 Comment:

SAMPLE CONDITION RECORD

Samples received in a cooler? Yes Samples received intact? Yes What is the temperature of the sample(s)? (°C) 7.4/7.5 Samples received with a COC? Yes Samples received within holding time? Yes Are all sample bottles properly preserved? Yes Labels and chain agree? Yes Total number of containers? 3 ' rro824 o2e IMEE H"] st3t2o18 Anatek Chain of Custody Record .r rr SAMP 812412018 1st RcvD 8l24l2o1g Labs, I^/A COVERED SLAG POND Inc. o 1282 Alturas Drive, Moscow ID 83843 (208) 883'2839 FAX St2-9246 Q ,\ Q SM e Sprague Ste D, Spoksne WA 99202 (509) 838-3999 FAX E38-4433 Q I IJGUST 2018 Company Name Project Manager: .,,,'a q \cPu'ur19 NORTHWEST ALLOYS INC JOHNIE 'OLY" MCCANNA ' Address Projecl Namo & # Please lefer to our normal lurn around limes al: 1560A Marble Valley Basin Rd - PO Box 115 NWA Covered Slag Pond August 2'108 htlpJ/wwrv.anateklabs.clm/servicos/guidelines/rcportrng.asp City State: Zip: EmailAddress Phone ADDY WA gg101 [email protected] -aNormal "All rush order Next Day' Mail Phone Purchase Order # requests must be (509) 675,4037 270418868 2nd Day. Fa\ prior approved . Email Faxi Sampler Name & phone Other. oLY MCCANNA (s09) 67s4037 Provide Llst Anal ses Note Speclal lnstruclions/Comments Grab water sample of NWA Covered Slag Pond It llt c :E .9 a g € 9a s; o 2 Lab E 9H 3i ID Sample ldentification Sampling Date/Time Matrix NWA CSPAUGUST2OlS 8124h8 11 15 H20 3 / x x x It I ttl IIIIrIIT I IIIII IIII I IIIIIrIIIT IIII I IIIII III IIII I I I III IIII I r r III rIII lnspection Chertlist I I I IIT IITI Received lntact? v)N I IIIII III IIII Labels & Chains Agree? YN Containers Sealed? YN I IIIII III IIII .N I IIIII III IIII VOC Head Space? I IITII III IIII I leL Printed Nam€ Sigoature Company Date Time ,,/O.-C -l: Relinquished by PdA lre Temperature ("C 1 5 rcA Ethr@; 'w v/<{ ) Received by L uf LLA/{t Ir v I tq\ \ Preservative Relinquish6d by II -Received by II Date & Time Relinquished by II lnspected By: Received by II

Appendix G.

Pond 3 Pesticide, PCB, Oil and Grease Water Quality

Appendix G. Pond 3 Pesticide, PCB, Oil and Grease Water Quality

Constituent Units Method 2018 4,4-DDD mg/L EPA 608.3 ND 0.01 4,4-DDE mg/L EPA 608.3 ND 0.01 4,4-DDT mg/L EPA 608.3 ND 0.01 Aldrin µg/L EPA 608.3 ND 0.01 Alpha-BHC µg/L EPA 608.3 ND 0.01 Aroclor 1016 (PCB-1016) µg/L EPA 608.3 ND 0.2 Aroclor 1221 (PCB-1221) µg/L EPA 608.3 ND 0.2 Aroclor 1232 (PCB-1232) µg/L EPA 608.3 ND 0.2 Aroclor 1242 (PCB-1242) µg/L EPA 608.3 ND 0.2 Aroclor 1248 (PCB-1248) µg/L EPA 608.3 ND 0.2 Aroclor 1254 (PCB-1254) µg/L EPA 608.3 ND 0.2 Aroclor 1260 (PCB-1260) µg/L EPA 608.3 ND 0.2 beta-BHC µg/L EPA 608.3 ND 0.01 Chlordane µg/L EPA 608.3 ND 0.1 Delta-BHC µg/L EPA 608.3 ND 0.01 Dieldrin µg/L EPA 608.3 ND 0.01 Endosulfan I µg/L EPA 608.3 ND 0.01 Endosulfan II µg/L EPA 608.3 ND 0.01 Endosulfan sulfate µg/L EPA 608.3 ND 0.01 Endrin µg/L EPA 608.3 ND 0.01 Endrin aldehyde µg/L EPA 608.3 ND 0.01 Endrin ketone µg/L EPA 608.3 ND 0.01 gamma-BHC (Lindane) µg/L EPA 608.3 ND 0.01 Heptachlor µg/L EPA 608.3 ND 0.01 Heptachlor expoxide µg/L EPA 608.3 ND 0.01 Methoxychlor µg/L EPA 608.3 ND 0.01 Toxaphene µg/L EPA 608.3 ND 0.1 Hexane extractable material mg/L EPA 1664A PQL 1 SG Treated HEM mg/L EPA 1664A PQL 1

NOTES: Samples collected on September 12, 2018 and analyzed by Anatek Labs Inc. and TestAmerica, both in Spokane, Washington. Abbreviations: BHC = Hexachlorocyclohexane, DDD = Dichlorodiphenyldichloroethane, DDE = Dichlorodiphenyldichloroethylene, DDT = Dichlorodiphenyltrichloroethane, EPA = Environmental Protection Agency, HEM = hexane extractable material, mg/L = milligrams per liter, ND followed by the laboratory method detection limit = not detected during any testing event, PCB = polychlorinated biphenyl, PQL followed by the laboratory practical quantitation limit = constituent at or below practical quantitation limit during testing event, SG = Silica Gel, µg/L = micrgrams per liter.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App G Pond3 October 2018 (Revised February 2019)

Appendix H.

Pond 3 Water Quality 2002

Appendix I.

Well Inventory Summary and Well Logs (CD-ROM)

Appendix I. Well Inventory Summary

Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet Township 33N, Range 39E, Section 10 1 21471 Jerry Burnett 5/17/1993 SE of NW D 260 +1.5 to 18.5 (6) None Sand, Clay 0-7 200 193 S 46th 0 to 260 (4) Limestone 7-260 Limestone Springfield, OR 2 55282 Leonard Homer 12/31/1991 SW of NE D 95 +1.5 to 95 (6) None Gravel 0-21 ~93 1779 Marble Valley Basin Rd Clay 2-83 Glacial Till Addy, WA 99101 Gravel 83-95 3 57486 Howard Ainsworth 7/20/1992 SW of NE D, R 92 NR NR NR NR 1779 Marble Valley Basin Rd Unknown Addy, WA 99101 4 NR George Voile 7/14/1987 NE of SW D 145 0 to 80 (6) 52-57 Topsoil 0-4 0 Addy, WA 99101 Clay 4-51 Glacial Till, Sand, Gravel 51-100 Shale Shale 100-145 5 57136 Mike Trimble 10/9/1991 SE of SW D 500 +2 to 18 (6) None Clay, Sand, Gravel 0-10 150 1799 Hutchinson Rd Limestone 12-90 Addy, WA 99101 Shale 90-150 Limestone, Basalt 150-260 Basalt, Limestone 260-310 Shale Shale 310-340 Limestone 340-500 6 16044 George Voile 8/4/1988 SE of SW D 162 +1 to 161 (6) None Clay 0-135 13 Clay, Sand 135-142 Clay, Gravel 14-154 Glacial Till Shale 154-156 Clay, Gravel 156-162 7 16044 George Voile 5/17/1988 SE of SW D 155 +3 to 152 (6) None Topsoil 0-2 20 Addy, WA 99101 Clay 2-132 Glacial Till, Sand 132-148 Shale Sand, Gravel 148-155 Shale 155-160 8 2497A Karl Peterson 5/5/1989 SE of SE I 225 +2 to 218 (8) 215-226 Clay 0-95 2 20634 Addy, WA 99101 Clay, Sand 95-190 Gravel, Clay 190-205 Clay, Sand 205-215 Glacial Till Sand 215-226 Sand, Clay 226-250 Boulders 250

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App I Wells October 2018 (Revised February 2019) | Page 1 of 10 Appendix I. Well Inventory Summary

Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 9 806 Carl Peterson 3/29/1988 SE of SE I,T 240 2 to 238 (6) 230-235 Topsoil 0-2 0 Addy, WA 99101 235-240 Clay 2-93 Clay, Gravel 93-130 Glacial Till Clay 130-158 Clay, Sand 158-169 Sand, Gravel 169-240 10 3619 Jesse Koerner 10/1/1955 E1/2 of SE NR 10 NR NR NR 10 Unconfined 2497-A Addy WA 99101 Township 33N, Range 39E, Section 12 11 NR Wendell Johnson 5/15/1979 SE of SW D 129 +2 to 119 (6) 118-129 Sand, Gravel 0-35 30 RT3 Water Bearing 35-50 Collville, WA Clay, Sand 50-100 Glacial Till Sand, Gravel 100-129 Sand, Clay 129-135 Township 33N, Range 39E, Section 13 12 AEJ513 Northwest Allows 12/16/1998 NW of NW T 480 +3-220 (2) 220-480 Fill 0-5 129 P-1 1560A Marble Valley Rd Dolomite 5-480 Dolomite Addy, WA 99101 13 AEJ600 Northwest Allows 12/17/1998 NW of NW T 420 +4-210 (2) 210-420 Fill 0-4 71 P-3 1560A Marble Valley Rd Dolomite 4-420 Dolomite Addy, WA 99101 14 G3-20482 Northwest Alloys 9/12/1972 NE of NW In 520 0 to 50 (18) 485-520 Clay, Sand, Gravel 0-140 2.3 PO Box 115 0 to 485 (14) Clay 140-225 Addy, WA 99101 Clay and Gravel 225-280 Glacial Till Clay 280-370 Sand, Clay, Gravel 370-480 Sand and Gravel 480-520 15 AEJ514 Northwest Allows 12/18/1998 SW of NW T 280 +3-70 (2) 70-280 Fill 0-4 20 P-2 1560A Marble Valley Rd Dolomite 4-280 Dolomite R0351120 Addy, WA 99101 16 G3-20481 Northwest Alloys 11/28/1972 SE of NW In 639 0 to 128 (18) 523-633 Clay Sand 0-33 +2 0 to 477 (14) Sand, Gravel, Clay 33-53 461 to 523 (8) Clay, Sand 53-63 Glacial Till Clay Sand 63-123 Sand and Gravel 123-636 Clay and Rock 636-668 17 G3-28087C Aluminum Co. of America 9/1/1971 SE of NW In 489 0 to 489 (6) 478-488 Sand, Gravel, Clay, Cobbles 0-489 Glacial Till +1.5 Addy, WA

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 18 NR Northwest Alloys 3/9/1977 NW of SW T 31 0 to 31 (6) 20-30 Gravel 0-21 Unconfined 29 Clay 24-31 Township 33N, Range 39E, Section 14 19 NR Forney and Egland Nov-56 NW of NW O 8 N/A N/A NR Unconfined 5-8 Addy, WA 20 AEP999 Herbert Curtis 10/12/2000 NW of NW D 300 +1 to 122 (6) 100-300 Clay 2-115 20 PO Box 65 20 to 300 (4) Limestone 115-300 Limestone Pateros, WA 98846 21 ALN887 Ken Egland 7/27/2007 NW of NW D 300 +2 to 132 (6) 180-300 Clay 3-118 10 WEO7050 101 N Baker Space 17 40 to 300 (4) Clay, Gravel 118-127 Limestone Chewelah, WA 99109 Limestone 127-300 22 AKT340 Stephen Habmlin 6/30/2005 NW of NW D 460 +2 to 148 (6) 200-460 Clay 3-142 30 W186772 1649 Hutchinson Rd 140 to 480 (4) Limestone 142-460 Limestone Addy, WA 99101 23 BBH952 Northwest Alloys 10/27/2009 SE of NW R 23 +0.5 to 13 (2) 13-23 Silty Clay Sand 0-4 12 MW-34 1560A Marble Vally Basin Rd Brown Clay Sand 4-12 Unconfined Addy, WA Blue Clay 12-23 24 BBH953 Northwest Alloys 10/27/2009 SE of NW R 23 +0.5 to 13 (2) 13-23 Silty Clay Sand 0-5 22.5 MW-35 1560A Marble Vally Basin Rd Brown Clay Sand 5-15 Unconfined Addy, WA Blue Clay 15-23 25 NR Northwest Alloys 9/17/1993 NE of NE T 130 +1 to 43 (6) 90 - 130 Fill 0-6 54 Limestone/ PO Box 115 0 to 90 (2) Sand Gravel 6-43 Dolomite Addy, WA 99101 Rock 43-134 26 NR Northwest Alloys 9/16/1993 NE of NE T N/A N/A N/A Sand and Gravel N/A Limestone/ PO Box 115 Limestone/Dolomite Dolomite Addy, WA 99101 27 AEJ512 Northwest Alloys 12/22/1998 NE of NE T 120 +3 to 100 (2) 100-120 Overburden 0-5 34 MW-14A PO Box 115 Clay 5-59 Dolomite R035119 Addy, WA 99101 Dolomite 59-120 28 Northwest Alloys 12/3/1998 SE of NE T 25 +3 to 12 (2) 13-22 Clay 0-5 3 MW-12A PO Box 115 Clay, Sand 5-10 Unconfined Addy, WA Clay, Silt 10-25 29 MW-24 Northwest Alloys 6/24/1995 SE of NE T 21 0 to 8 (2) 8-18 Cemented Slag 0-18 6 17793 PO Box 115 18 to 21 (2) Clay 18-21 Unconfined Addy, WA 99101 30 MW-55B Northwest Alloys 1997 SE of NE T 28 0 to 18 (2) 18-28 Clay 0-28 20 461A0211 PO Box 115 Unconfined R03071 Addy, WA 99101

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 31 ABY322 Northwest Alloys 8/9/1995 NW of SW T 140 +2 to 140 (2) 88-138 Topsoil 0-1 86 R17796 PO Box 115 Silt, Clay 1-10 Addy, WA 99101 Gravel 10-16 Dolomite Granite 16-24 Dolomite 24-175 32 Northwest Alloys 11/25/1998 SE of SW T 25 +3 to 12 (2) 13-22 Clay 0-5 3 MW-11A PO Box 115 Clay, Sand 5-10 Unconfined Addy, WA Clay, Silt 10-25 33 BBH951 Northwest Alloys 10/27/2009 NW of SE T 20 +0.5 to 10 (2) 10-20 Silty Clay Sand 0-4 16 MW-36 1560A Marble Vally Basin Rd Brown Clay Sand 4-15 Unconfined RE03920 Addy, WA Blue Clay 15-20 34 MW-25 Northwest Alloys 6/25/1995 SE of SE T 19.5 0-9.5 (2) 9.5-19.5 Fill 0-10 16 17793 1560A Marble Vally Basin Rd Gravel 10-15 Unconfined Addy, WA Clay 15-25 35 MW-27 Northwest Alloys 6/26/1995 SE of SE T 27.5 0-14.5 (2) 14.5-24.5 Fill 0-5 6 17794 1560A Marble Vally Basin Rd 24.5-27.5 (2) Clay 5-12 Unconfined Addy, WA Sand, Clay 12-25 Clay 25-30 36 MW-28 Northwest Alloys 6/27/1995 SE of SE T 21 0-8 (2) 8-18 Fill 0-6 6 17794 1560A Marble Vally Basin Rd 18-21 (2) Clay 6-22 Unconfined Addy, WA 37 MW-29 Northwest Alloys 6/28/1995 SE of SE T 40 0-27 (2) 27-37 Gravel 0-6 22 17795 1560A Marble Vally Basin Rd 37-40 (2) Silt 6-40 Unconfined Addy, WA 38 MW-30 Northwest Alloys 6/29/1995 SE of SE T 39 0-26 (2) 26-36 Gravel fill 0-6 21 17795 1560A Marble Vally Basin Rd 36-39 (2) Silt 6-39 Unconfined Addy, WA Township 33N, Range 39E, Section 15 39 NR Wendell Johnson 3/22/1979 NW of NE D 131 6 to 123 (6) 121-126 Sand, Gravel 0-125 30 RT 3 126-131 Sand 125-131 Unconfined Colville, WA 40 58243 Ron Miller 8/19/1992 NW of NE D 180 +2 to 119 (6) 160-180 Topsoil 0-3 60 Box 24 100 to 180 (4) Clay 3-76 Limestone/ Addy, WA 99101 Sand, Clay 76-77 Dolomite Clay, Gravel 77-162 Rock 162-180

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 41 3126 Evald Peterson NR NW of NE NR 8 N/A N/A NR NR Unconfined 1847-A Addy, WA 99101 42 AEP735 Elsie Peterson 10/19/2000 NE of NE D 300 +1 to 211 (6) 200-300 Clay 0-125 25 716 Lynn St 200 to 300 (4) Clay, Gravel 125-135 Wenatchee, WA 98801 Silty Sand 135-185 Coarse 185-200 Limestone Silty Sand 200 Limestone 200-210 Silt 210 Limestone 210-300 43 NR Karl Peterson 8/30/1977 NR of NE D 185 +1 to 170 (6) 160-170 Top Soil 0-9 NR Limestone/ Addy, WA 99101 Clay 9-150 Dolomite Rock 150-185 44 AAJ948 Denzil McKinney 9/13/1993 NE of SW D 305 +1 to 128 (6) 105-305 Topsoil 0-1 100 W21800 PO Box 157 105 to 305 (4) Sand, Gravel 1-9 Addy, WA 99101 Clay 9-24 Limestone/ Clay, Gravel 24-118 Dolomite Clay 118-124 Rock 124-305 45 W21753 Denzil McKinney 8/10/1993 NE of SW D 160 +1 to 53 (6) None Topsoil 0-2 PO Box 157 Sand, Gravel, Clay 2-13 Addy, WA 99101 Sand, Clay 13-24Limestone/ NR Clay, Gravel 24-54 Dolomite Rock, Shale 54-125 Rock 125-160 46 G3-21043P Johnie McCanna NR NE of SE T 320 0 to 308 (6) NR NR 14 NR Addy, WA 99101 47 ALB588 Randy Stanley 7/20/2004 SW of SE D 166 +2 to 166 (6) None Topsoil 0-3 50 W172244 15716 Rd 3 SE Sand, Gravel, Clay 316 Moses Lake, WA 98837 Clay 16-30 Silty Clay, Gravel 30-60 Boulder 60-62 Glacial Till Sand, Gravel 62-75 Boulder 75-77 Sand, Gravel 77-166 Sand 166-168

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 48 57038 L.M. Hastings 7/10/1992 NR of SE D 340 +1 to 313 (6) N/A Topsoil 0-1 NR 1614 Swiss Valley Rd Sand, Gravel 1-35 Addy, WA 99101 Sand, Clay 35-48 Clay 48-60 Shale/ Clay, Gravel 60-80 Dolomite Clay 80-314 Shale Rock 314-316 Rock 316-340 Township 33N, Range 39E, Section 22 49 ACC927 John & Doris Woelk 9/12/1995 NE of NW D 220 +1 to 116 (6) None Overburden 0-2 35 W62385 1575-B Swiss Valley Rd Sand, Clay 2-19 Shale Addy, WA 99101 Clay 19-115 Shale 115-220 50 NR Ervine Hickey 12/4/1984 SW of NE D 100 NR (6) NR Overburden 0-2 NR Stevens County Sand, Gravel 2-51 Clay 51-59 Clay, Sand 59-69 Glacial Till Sand 69-80 Sand, Gravel 80-84 Sand 84-97 Clay 97-100 51 ABH529 Dale Anderson 10/21/2002 SE of SW D 820 +2 to 87 (6) 140-820 Topsoil 0-1 15 W165970 1736 Dearinger Rd Clay, Gravel 1-22 Addy, WA 99101 Clay 22-82 Limestone Shale 82-87 Limestone 87-820 52 BAT652 Dale Anderson 7/30/2007 SE of SW D 47 +2 to 47 (6) None Topsoil 0-2 5 W250553 1736 Dearinger Rd Clay, Gravel 2-14 Addy, WA 99101 Clay 14-30 Sand, Gravel, Clay 30-33 Samd, Gravel 33-38 Glacial Till Clay, Sand 38-40 Clay 40-42 Sand, Gravel 42-47 Clay 47-49 53 ALN888 Dale Anderson 7/27/2007 SE of SW D 240 +2 to 72 (6) 140-240 Sand, Gravel, Clay 0-60 90 W250554 1736 Dearinger Rd Clay Gravel 60-66 Limestone Addy, WA 99101 Shale 66-92 Limestone 92-240

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet Township 33N, Range 39E, Section 23 54 ALB579 Marvin Sandow 12/27/2004 NW of NW D, R 294 +2 to 289.5 (6) 289-294 Existing Well 0-100 60 W181945 1565 Swiss Valley Rd Clay 100-285 Glacial Till Addy, WA 99101 Sand 285-295 55 NR John McCanna 2/6/1984 NW of NW D 76 +2 to 71 (6) 71-76 Overburden 0-2 29 Unconfined Addy, WA 99101 Sand 2-76 56 AAT-845 Wendall Tadlock 11/26/1994 SW of NW D 305 0 to 115 (6) 140-305 Topsoil 0-2 80 W57636 1631C Addy Gifford Rd -5 to 305 (4) Rocks, Clay 2-25 Addy, WA 99101 Gravel, Clay 60-100 Shale Clay, Gravel 100-110 Shale 110-305 57 NR Wendall Tadlock 4/10/1978 SW of NW D 280 +1 to 30 (6) None Topsoil 0-1 8 Addy, WA 99101 Sand, Clay, Gravel 1-27 Siltstone/ Siltstone 27-51 Dolomite/ Dolomite 15-54 Shale Shale 54-90 Shale 90-280 58 Northwest Alloys 11/24/1998 NW of NE T 25 +3 to 12 (2) 13-22 Clay 0-5 20 MW-10A PO Box 115 Clay, Sand 5-10 Unconfined Addy, WA Clay, Silt 10-25 59 Northwest Alloys 12/3/1998 NE of NE T 25 +3 to 12 (2) 13-22 Clay 0-15 20 MW-8A PO Box 115 Clay, Silt 15-25 Unconfined Addy, WA 60 Northwest Alloys 12/2/1998 NE of NE T 25 +3 to 12 (2) 13-22 Clay 0-15 18 MW-9A PO Box 115 Clay, Silt 15-25 Unconfined Addy, WA 61 ACN099 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2) 62 AAL552 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2) 63 AAL553 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2) 64 AAL554 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2) 65 AAL555 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2) 66 AAL561 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2)

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 67 AAL567 NW Alloys - South Fields 12/16/1998 NE of NE T 25 0 to 12 (2) 12-22 Clay 0-25 5 Unconfined R03078 Addy, WA 99101 22 to 25 (2) 68 AHT960 NW Alloys 11/5/2003 NE of NE T 85 +0.5 to 75 (2) 75-85 Fill/Dirt 0-75 79 GSP-1 1560A Marble Valley Rd Diacal 75-85 Unconfined R54085 Addy, WA 99101 69 AHT962 NW Alloys 11/11/2003 NE of NE T 40 +0.5 to 30 (2) 30-40 Clay 0-40 33 MW-80 1560A Marble Valley Rd Unconfined R04085 Addy, WA 99101 70 AHT963 NW Alloys 11/14/2003 NE of NE T 151 +0.5 to 101 (2) 101-151 Silty Sand and Gravel 0-54 105 MW-21 1560A Marble Valley Rd Dolomite 54-151 Dolomite R04085 Addy, WA 99101 71 AHT964 NW Alloys 11/10/2003 NE of NE T 56 +0.5 to 46 (2) 46-56 Fill/Dirt 0-27 54 GSP-3 1560A Marble Valley Rd Diacal 27-57 Glacial Till R54085 Addy, WA 99101 Silt 57-60 72 AHT965 NW Alloys 11/10/2003 NE of NE T 23 +0.5 to 13 (2) 13-23 Sand, Gravel, Cobbles 0-3 10 GSP-4 1560A Marble Valley Rd Silt 3-15 Unconfined R54085 Addy, WA 99101 Clay 15-30 73 57227 Northwest Alloys 9/14/1991 NE of NE NR 380 +1 to 379 (6) 18-20 Sand, Gravel 0-17 8 PO Box 115 Gravel 17-20 Glacial Till Addy, WA 99101 Clay 20-400 74 NR Frank Bendixon 9/27/1977 NE of SE D 340 +1 to 340 (6) 334-340 Topsoil 0-15 40 Addy, WA 99101 Sand 15-80 Glacial Till Clay 80-110 Sand 110-340 Township 33N, Range 39E, Section 24 75 Northwest Alloys 12/4/1998 NW of NW T 25 +3 to 12 (2) 13-22 Clay 0-15 23 MW-7A PO Box 115 Clay, Silt 15-25 Unconfined Addy, WA 76 Northwest Alloys 12/4/1998 NW of NW T 25 NR NR Clay 0-15 NR MW-31 PO Box 115 Clay, Silt 15-25 Unconfined Addy, WA 77 BBH954 Northwest Alloys 10/28/2009 NW of NW T 22 +0.5 to 12 (2) 12-22 Silty Sand and Gravel 0-3 17 MW-37 1560A Marble Vally Basin Rd Silt 3-6 Addy, WA 99101 Black Clay 6-17 Unconfined Sand and Gravel 17-19 Black Clay 19-22

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 78 BBH955 Northwest Alloys 10/28/2009 NW of NW T 20 +0.5 to 10 (2) 10-20 Silty Sand 0-3 17 MW-38 1560A Marble Vally Basin Rd Black Clay 3-17 Unconfined Addy, WA 99101 Black Clay Sand with Gravel 17-20 79 NR Curtis W. Ott 10/25/1973 SW of NW D 220 0 to 213 (6) 208-215 Topsoil 0-2 15 Rt 1 Box 91A 215-220 Clay 2-185 Addy, WA 99101 Clay, Sand 185-200 Sand, Clay 200-210 Glacial Till Sand 210-215 Sand, Gravel 215-220 Sand 220-230 80 60518 P. Maresca 9/28/1992 NE of NE D 305 +1 to 23 (6) None Topsoil 0-3 40 Addy, WA 99101 Dolomite, Slate 3-114 Dolomite Quartz 114-115 Dolomite 115-305 81 APC396 Donna Slater 10/8/2007 NE of SW D 170 +3 to 120 (6) None Clay 0-170 No W179093 1/2 mile South of Addy Glacial Till Water West of Highway 95 82 ARL331 Donna Slater 9/17/2007 NE of SW D 80 +5-75 (6) 75-80 Brown Clay 0-20 20 W179088 1/2 mile South of Addy White Clay 20-30 Glacial Till West of Highway 95 Blue Clay with Fine Sand 30-58 Sand 58-80 83 8696 WA State Highway Dept 7/25/1967 W½ of SE D, I 310 0 to 301 (8) 200-210 Loam, Gravel 0-40 53 8370 2714 Mayfair St Shale 40-85 Spokane, WA 99205 Clay 85-170 Sand 170-212 Glacial Till Clay 212-258 Sand, Gravel 258-315 Solid Rock 315 84 AEH491 Stevens County PUD 2/26/2002 SE of SE T 45 0 to 7 (2) 7-45 Sand, Silt and Gravel 0-10 NR Highway 395 Silt and Clay 10-45 Unconfined Addy, WA 99101 85 AEH495 Stevens County PUD 2/26/2002 SE of SE T 39 0 to 29 (2) 29-39 Sand, Gravel, Cobbles 0-10 NR Highway 395 Silt and Clay 10-40 Unconfined Addy, WA 99101 86 AEH498 Stevens County PUD 2/26/2002 SE of SE T 68 0 to 68 (2) 10-68 Sand, Silt and Gravel 0-15 NR Highway 395 Silt and Clay 15-80 Unconfined Addy, WA 99101

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Total Static Well Well ID Well Casing Screened Well Well Screened Water Inventory / Well Owner Completion Use 1 (diameter) 2 Interval 3 Drilled Lithology Location Depth Aquifer Level 4 Number Name Date feet ft bgs ft bgs feet 87 AEH500 Stevens County PUD 2/26/2002 SE of SE T 38 0 to 10 (2) 10-38 Sand, Silt, Gravel 0-10 NR Highway 395 Silt and Clay 10-40 Unconfined Addy, WA 99101 Township 33N, Range 39E, Section 25 88 AGL222 PUD of Stevens County 8/9/2001 NW of NE D 102 +2 to 98 (6) 97-102 Topsoil 0-1 49 W150992 PO Box 592 Sandy 1-8 Loon Lake, WA 99148 Sand, Clay 8-60 Glacial Till Clay 60-98 Sand 98-102 Rock 102-105 Township 33N, Range 39E, Section 26 89 BAT653 Pat Tibbetts 8/7/2007 NW of NE D 400 +2 to 155 (6) 300-400 Topsoil 0-3 180 WEO7089 8811 N Seven Mile Rd Sand, Gravel 3-10 Nine Mile Falls, 99026 Sand, Gravel, Clay 10-30 Quartzite Clay, Gravel 30-85 Sand, Gravel, Clay 85-150 Quartzite 150-400 Township 33N, Range 39E, Section 27 90 AHG462 Don Teeguarden 6/12/2003 NW of NE D 500 15 to 185 (6) 120-470 Topsoil 0-3 90 W168724 1723 Dearinger Rd Sand, Gravel, Clay 3-10 Shale/ Addy, WA 99101 Limestone 10-70 Limestone Shale 70-215 Limestone 215-500 91 NR Leroy Mulkey 8/12/1985 NE of NE D 63 0 to 63 (6) None Dirt, Boulders 0-10 NR Rt 1 Box 9 Clay 10-60 Shale Addy, WA 99101 Shale 60-63

NOTES: All information based on original State of Washington Department of Ecology well log data. Field variations of location and current use status were not made with the exceptions the locations of inventory well numbers 21 and 22. Abreviations: ft bgs = feet below ground surface, N/A = Not applicable, NR = Not reported. 1 A = abandoned, D = domestic, I = irrigation, In = industrial, O - other (stock, trench), T = test well, R = Reconditioned. 2 Casing diameter, e.g., (12), reported in inches. 3 Where no screen was reported, open borehole well construction was assumed. 4 Static water level based on original well log data.

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Appendix J.

Groundwater Quality Data 2000-2017

Appendix J1. Groundwater Data - MW 7A

Groundwater Quality NO + Sampling pH 3 NH -N 1 TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm 3rd Qtr 00 4.70 ND 0.05 146 67.7 1st Qtr 01 2.60 ND 0.05 163 72.7 2nd Qtr 01 2.30 ND 0.05 168 71.7 3rd Qtr 01 2.40 ND 0.05 169 83.8 4th Qtr 01 4.10 ND 0.05 179 84.8 4th Qtr 01 4.60 ND 0.05 170 72.9 1st Qtr 02 2.20 ND 0.05 140 82.6 2nd Qtr 02 2.60 ND 0.05 156 84.5 3rd Qtr 02 3.50 ND 0.05 158 91.1 4th Qtr 02 3.40 ND 0.05 154 92 1st Qtr 03 2.80 ND 0.05 164 89 2nd Qtr 03 2.50 ND 0.05 184 97 3rd Qtr 03 2.00 ND 0.05 185 9.2 4th Qtr 03 2.00 ND 0.05 184 90 1st Qtr 04 ND 0.05 178 91 2nd Qtr 04 2nd Qtr 04 1.60 ND 0.05 177 93.2 3rd Qtr 04 2.90 ND 0.05 185 91.1 4th Qtr 04 2.60 ND 0.05 171 91.3 1st Qtr 05 2.10 ND 0.05 170 100 2nd Qtr 05 2.20 ND 0.05 182 106 3rd Qtr 05 3.10 ND 0.05 194 110 4th Qtr 05 3.10 ND 0.05 161 116 1st Qtr 06 2.20 ND 0.05 187 117 2nd Qtr 06 2.10 ND 0.05 181 101 3rd Qtr 06 3.30 ND 0.05 209 112 4th Qtr 06 3.60 ND 0.05 196 108 1st Qtr 07 2.70 ND 0.05 199 102 2nd Qtr 07 2.40 ND 0.05 214 116 3rd Qtr 07 2.40 ND 0.05 207 103 4th Qtr 07 3.40 ND 0.05 195 109 1st Qtr 08 2.80 ND 0.05 207 106 2nd Qtr 08 2.90 ND 0.05 201 112 4th Qtr 09 7.2 2.65 0.088 1.4 1,040 205 115 560 3.7 149 114 71 1,810 1st Qtr 10 7.3 3.02 ND 0.05 0.8 936 177 84 547 2.9 131 105 68 1,650 2nd Qtr 10 7.2 2.89 ND 0.05 1.1 979 190 97 533 3.0 130 106 66 1,670 3rd Qtr 10 7.3 2.58 ND 0.05 1,000 208 122 509 0.019 3.3 139 106 67 1,500 4th Qtr 10 7.3 2.01 ND 0.05 1,070 207 115 571 ND 0.01 3.6 144 111 67 1,950 1st Qtr 11 7.3 2.98 ND 0.05 0.9 1,030 221 116 537 0.03 3.1 134 105 67 1,840 2nd Qtr 11 7.5 2.98 ND 0.05 1.4 976 210 113 539 0.01 3.1 138 110 66 1,520 3rd Qtr 11 7.4 2.65 ND 0.05 0.9 1,060 220 129 569 0.01 3.4 155 112 70 1,790 4th Qtr 11 7.4 2.03 ND 0.05 1.0 1,130 220 115 567 0.02 3.7 157 118 75 1,860 1st Qtr 12 7.4 2.31 ND 0.05 0.9 1,140 190 104 576 0.01 3.2 140 109 65 1,810 2nd Qtr 12 7.5 2.20 ND 0.05 0.9 983 210 115 507 0.03 3.1 138 110 68 1,790 3rd Qtr 12 7.6 1.77 ND 0.05 0.9 1,060 205 114 571 0.02 3.3 141 114 69 4th Qtr 12 7.6 1.68 ND 0.05 0.7 1,100 213 110 599 0.01 3.6 149 111 73 1,730 1st Qtr 13 7.5 1.70 ND 0.05 0.6 1,030 202 110 584 0.02 3.4 148 120 71 1,780 2nd Qtr 13 7.4 1.74 ND 0.05 0.8 1,090 206 124 553 0.03 3.3 143 111 70 3rd Qtr 13 7.5 1.57 ND 0.05 0.8 1,070 198 111 589 0.04 3.5 144 116 69 4th Qtr 13 7.7 1.70 ND 0.05 0.7 1,030 210 127 613 0.01 3.7 146 123 73 1st Qtr 14 7.6 1.88 ND 0.05 1.0 1,040 207 127 475 0.01 3.4 141 110 71 2nd Qtr 14 7.5 2.04 ND 0.02 1.1 974 208 126 537 ND 0.01 3.1 139 115 70 3rd Qtr 14 7.4 1.62 ND 0.05 0.7 959 208 127 436 ND 0.01 3.2 135 111 68 4th Qtr 14 7.0 1.22 ND 0.02 ND 0.5 923 190 132 557 0.02 3.7 137 104 63 1st Qtr 15 7.1 1.51 ND 0.02 ND 0.5 1,020 185 121 544 ND 0.01 3.4 121 107 65 2nd Qtr 15 7.2 1.40 ND 0.02 ND 0.5 984 208 156 522 0.03 3.8 157 127 77 3rd Qtr 15 7.5 1.03 ND 0.02 ND 0.5 1,070 200 156 542 0.02 4.4 145 115 71 4th Qtr 15 7.2 1.18 ND 0.02 ND 0.5 1,020 202 151 560 0.03 4.2 157 121 79 1st Qtr 16 6.9 1.48 ND 0.02 0.7 995 213 146 531 0.04 3.9 158 132 81 2nd Qtr 16 7.1 1.27 ND 0.02 ND 0.5 940 202 153 502 0.01 3.9 155 123 78 1,811 3rd Qtr 16 7.2 0.66 ND 0.02 ND 0.5 950 208 160 513 0.02 3.7 136 108 68 1,779 4th Qtr 16 7.0 0.77 ND 0.02 ND 0.5 972 185 132 541 0.03 5.1 185 159 109 1,762 1st Qtr 17 7.5 0.48 ND 0.02 ND 0.5 1,090 234 174 537 0.02 3.9 160 124 70 1,813 2nd Qtr 17 7.3 1.11 ND 0.02 0.464 1,120 256 186 534 0.011 3.6 162 122 76 1,980 3rd Qtr 17 7.3 0.90 ND 0.02 ND 0.5 1,090 250 177 559 ND 0.01 2.7 116 89 57 1,920 4th Qtr 17 7.2 0.37 ND 0.02 ND 0.5 930 216 176 603 ND 0.01 6.7 152 120 75 1,796

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 1 of 2 Appendix J1. Groundwater Data - MW 7A

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 7.76 1,622.48 Feb-10 4.63 1,625.61 Mar-10 4.56 1,625.68 NOTES: Apr-10 4.65 1,625.59 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 4.69 1,625.55 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 4.84 1,625.40 the Permit issued in June 2011. Jul-10 6.48 1,623.76 1 From 2000-2008, detection limits were not available. The maximum detection limit (0.05 mg/L) Aug-10 7.32 1,622.92 from 2009-2017 results was used. Sep-10 7.62 1,622.62 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Oct-10 7.98 1,622.26 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Nov-10 7.52 1,622.72 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Dec-10 4.68 1,625.56 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Jan-11 4.13 1,626.11 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Feb-11 4.54 1,625.70 Mar-11 3.99 1,626.25 Apr-11 4.51 1,625.73 2nd Q, '11 4.48 1,625.76 3rd Q, '11 5.79 1,624.45 4th Q, '11 7.46 1,622.78 1st Q, '12 4.62 1,625.62 2nd Q, '12 4.61 1,625.63 3rd Q, '12 6.43 1,623.81 4th Q, '12 6.48 1,623.76 1st Q, '13 3.99 1,626.25 2nd Q, '13 4.54 1,625.70 3rd Q, '13 6.49 1,623.75 4th Q, '13 7.04 1,623.20 1st Q, '14 4.60 1,625.64 2nd Q, '14 4.54 1,625.70 3rd Q, '14 6.38 1,623.86 4th Q, '14 7.57 1,622.67 1st Q, '15 4.36 1,625.64 2nd Q, '15 5.25 1,624.99 3rd Q, '15 8.01 1,622.23 4th Q, '15 10.02 1,620.22 1st Q, '16 4.50 1,625.74 2nd Q, '16 4.55 1,625.69 3rd Q, '16 7.45 1,622.79 4th Q, '16 5.11 1,625.13 1st Q, '17 3.89 1,626.35 2nd Q, '17 4.43 1,625.81 3rd Q, '17 6.31 1,623.93 4th Q, '17 6.45 1,630.24

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 2 of 2 Appendix J2. Groundwater Data - MW 8A

Groundwater Quality NO + Sampling pH 3 NH -N 1 TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm 3rd Qtr 00 2.30 ND 0.05 92 35 1st Qtr 01 1.20 ND 0.05 222 64 2nd Qtr 01 1.40 ND 0.05 187 0 3rd Qtr 01 2.30 ND 0.05 169 49 4th Qtr 01 3.40 ND 0.05 173 56 4th Qtr 01 2.00 ND 0.05 108 40 1st Qtr 02 2.40 ND 0.05 175 55 2nd Qtr 02 3.50 ND 0.05 133 48 3rd Qtr 02 3.40 ND 0.05 122 56 4th Qtr 02 0.00 0.03 146 68 1st Qtr 03 2.90 ND 0.05 216 74 2nd Qtr 03 3.10 ND 0.05 192 61 3rd Qtr 03 2.00 ND 0.05 175 66 4th Qtr 03 1.80 ND 0.05 190 79 1st Qtr 04 ND 0.05 325 154 2nd Qtr 04 2nd Qtr 04 1.40 ND 0.05 283 120 3rd Qtr 04 2.20 ND 0.05 214 90 4th Qtr 04 2.00 ND 0.05 205 96 1st Qtr 05 1.70 ND 0.05 268 130 2nd Qtr 05 1.90 ND 0.05 241 110 3rd Qtr 05 1.90 ND 0.05 258 129 4th Qtr 05 1.80 ND 0.05 264 170 1st Qtr 06 1.10 ND 0.05 351 180 2nd Qtr 06 1.80 ND 0.05 306 154 3rd Qtr 06 2.30 ND 0.05 290 186 4th Qtr 06 2.30 ND 0.05 295 291 1st Qtr 07 2.40 ND 0.05 412 325 2nd Qtr 07 3.00 ND 0.05 369 272 3rd Qtr 07 3.40 ND 0.05 347 310 4th Qtr 07 3.40 0.15 320 371 1st Qtr 08 2.90 ND 0.05 379 396 2nd Qtr 08 3.30 ND 0.05 351 317 4th Qtr 09 7.3 4.00 0.07 1.4 1,850 320 477 353 4.5 200 142 183 2,490 1st Qtr 10 7.3 3.20 ND 0.05 0.8 1,580 299 408 367 4.4 179 126 169 2,430 2nd Qtr 10 7.3 2.68 ND 0.05 0.9 1,580 325 403 369 4.1 171 124 158 2,480 3rd Qtr 10 7.3 2.86 0.10 1,420 294 365 382 0.020 4.1 157 111 151 1,960 4th Qtr 10 7.3 3.26 ND 0.05 1,720 338 486 359 ND 0.01 4.6 176 124 148 2,620 1st Qtr 11 7.4 3.24 ND 0.05 0.8 1,640 344 465 370 0.03 4.0 170 119 173 2,640 2nd Qtr 11 7.3 3.39 ND 0.05 1.0 1,530 324 407 370 0.01 3.8 165 116 163 2,320 3rd Qtr 11 7.7 4.03 ND 0.05 1.5 1,250 236 296 383 0.02 3.6 139 94 153 1,980 4th Qtr 11 7.5 4.36 ND 0.05 1.9 1,290 247 338 354 0.01 3.6 143 97 154 2,050 1st Qtr 12 7.5 4.56 ND 0.05 0.9 1,410 247 377 387 0.01 3.6 140 102 147 2,170 2nd Qtr 12 7.6 4.19 ND 0.05 1.0 1,430 278 391 364 ND 0.01 3.7 153 110 163 2,200 3rd Qtr 12 7.9 3.99 ND 0.05 0.9 1,450 247 347 390 0.01 3.9 143 103 166 4th Qtr 12 7.5 3.91 ND 0.05 1.0 1,560 285 433 395 ND 0.01 4.4 162 110 179 2,200 1st Qtr 13 7.5 2.90 ND 0.05 0.8 1,420 275 454 407 0.025 4.3 173 125 180 2,355 2nd Qtr 13 7.5 3.30 ND 0.05 1.2 1,430 230 356 385 0.013 3.9 145 100 164 3rd Qtr 13 7.6 3.41 ND 0.05 0.9 1,290 201 316 394 ND 0.01 3.9 135 95 153 4th Qtr 13 7.8 3.37 ND 0.05 1.2 1,410 244 420 412 0.01 4.4 149 112 172 1st Qtr 14 7.6 2.91 ND 0.05 1.1 1,500 263 457 342 0.01 4.2 163 113 171 2nd Qtr 14 7.5 2.76 ND 0.05 1.3 1,490 281 474 390 ND 0.01 4.2 170 127 177 3rd Qtr 14 7.3 2.25 ND 0.02 0.5 1,500 280 463 406 ND 0.01 4.5 162 115 169 4th Qtr 14 7.1 2.23 ND 0.02 ND 0.5 1,570 264 489 408 0.02 4.7 162 111 160 1st Qtr 15 7.1 1.95 ND 0.02 ND 0.5 1,730 257 507 398 ND 0.01 4.4 182 115 160 2nd Qtr 15 7.2 2.61 ND 0.02 ND 0.5 1,350 251 441 381 0.03 4.6 169 122 180 3rd Qtr 15 7.3 2.58 ND 0.02 ND 0.5 1,410 225 390 386 0.01 4.2 148 103 153 4th Qtr 15 7.2 2.40 ND 0.02 ND 0.5 1,410 238 427 388 0.02 4.5 162 111 175 1st Qtr 16 6.9 2.38 ND 0.02 0.603 1,460 246 441 388 0.02 4.8 180 132 190 2nd Qtr 16 7.2 5.83 ND 0.02 ND 0.6 1,330 229 381 357 0.01 4.4 229 114 166 2,063 3rd Qtr 16 7.3 3.27 ND 0.02 ND 0.5 1,290 228 409 382 0.02 3.9 134 95 139 2,042 4th Qtr 16 7.1 2.36 ND 0.02 0.393 1,280 205 378 381 0.02 5.0 178 133 211 2,007 1st Qtr 17 7.5 5.14 ND 0.02 ND 0.5 1,460 261 537 366 0.02 6.8 178 121 145 2,121 2nd Qtr 17 7.5 6.56 ND 0.02 ND 0.5 1,460 234 489 356 0.02 4.2 168 111 153 2,078 3rd Qtr 17 7.5 4.11 ND 0.02 ND 0.5 1,080 209 331 375 ND 0.01 3.2 133 89 126 1,883 4th Qtr 17 7.2 2.47 ND 0.02 0.500 1,170 275 494 388 ND 0.01 5.3 153 106 133 1,966

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 3 of 2 Appendix J2. Groundwater Data - MW 8A

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 11.93 1,629.06 Feb-10 8.02 1,632.97 Mar-10 7.78 1,633.21 NOTES: Apr-10 7.45 1,633.54 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 7.62 1,633.36 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 7.79 1,633.20 the Permit issued in June 2011. Jul-10 10.31 1,630.68 1 From 2000-2008, detection limits were not available. The maximum detection limit (0.05 mg/L) Aug-10 12.53 1,628.46 from 2009-2017 results was used. Sep-10 12.88 1,628.11 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Oct-10 13.32 1,627.67 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Nov-10 12.26 1,628.73 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Dec-10 8.19 1,632.80 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Jan-11 6.87 1,634.12 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Feb-11 7.53 1,633.46 Mar-11 6.24 1,634.75 Apr-11 6.93 1,634.06 2nd Q, '11 6.98 1,634.01 3rd Q, '11 8.74 1,632.25 4th Q, '11 12.32 1,628.67 1st Q, '12 8.22 1,632.77 2nd Q, '12 7.57 1,633.42 3rd Q, '12 10.94 1,630.05 4th Q, '12 11.60 1,629.39 1st Q, '13 6.29 1,634.70 2nd Q, '13 7.63 1,633.36 3rd Q, '13 11.03 1,629.96 4th Q, '13 11.88 1,629.11 1st Q, '14 8.63 1,632.36 2nd Q, '14 7.93 1,633.06 3rd Q, '14 11.11 1,629.88 4th Q, '14 12.08 1,628.91 1st Q, '15 7.93 1,633.06 2nd Q, '15 7.99 1,633.00 3rd Q, '15 12.13 1,628.86 4th Q, '15 12.94 1,628.05 1st Q, '16 8.18 1,632.81 2nd Q, '16 7.67 1,633.32 3rd Q, '16 11.91 1,629.08 4th Q, '16 10.10 1,630.89 1st Q, '17 4.87 1,636.12 2nd Q, '17 6.42 1,634.57 3rd Q, '17 9.55 1,631.44 4th Q, '17 11.73 1,629.26

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 4 of 2 Appendix J3. Groundwater Data - MW 11A

Groundwater Quality NO + Sampling pH 3 NH -N 1 TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm 3rd Qtr 00 8.20 ND 0.05 128 66 1st Qtr 01 8.70 ND 0.05 212 56 2nd Qtr 01 8.90 ND 0.05 225 56 3rd Qtr 01 8.10 ND 0.05 258 57 4th Qtr 01 8.20 ND 0.05 283 56 4th Qtr 01 9.20 ND 0.05 193 62 1st Qtr 02 7.40 ND 0.05 342 51 2nd Qtr 02 8.50 ND 0.05 344 59 3rd Qtr 02 7.30 ND 0.05 317 65 4th Qtr 02 9.00 ND 0.05 325 64 1st Qtr 03 8.00 ND 0.05 361 55 2nd Qtr 03 5.70 ND 0.05 386 58 3rd Qtr 03 5.00 ND 0.05 338 55 4th Qtr 03 5.00 ND 0.05 340 56 1st Qtr 04 ND 0.05 348 56 2nd Qtr 04 4.30 ND 0.05 353 58 2nd Qtr 04 3rd Qtr 04 4.80 ND 0.05 363 55 4th Qtr 04 5.10 0.02 347 49 1st Qtr 05 5.30 ND 0.05 396 61 2nd Qtr 05 4.90 ND 0.05 373 62 3rd Qtr 05 5.30 ND 0.05 356 63 4th Qtr 05 5.40 ND 0.05 345 60 1st Qtr 06 5.50 ND 0.05 313 64 2nd Qtr 06 6.10 ND 0.05 321 56 3rd Qtr 06 6.60 ND 0.05 351 68 4th Qtr 06 6.80 ND 0.05 329 62 1st Qtr 07 7.00 ND 0.05 357 72 2nd Qtr 07 5.80 0.09 341 76 3rd Qtr 07 7.30 ND 0.05 311 68 4th Qtr 07 7.00 ND 0.05 307 71 1st Qtr 08 8.60 ND 0.05 309 81 2nd Qtr 08 8.00 ND 0.05 301 83 4th Qtr 09 7.6 9.16 0.10 1.9 960 244 91 444 2.9 71 142 85 1,760 1st Qtr 10 7.7 10.30 ND 0.05 1.4 951 217 94 480 2.9 74 159 87 1,740 2nd Qtr 10 7.6 10.00 ND 0.05 1.5 987 225 96 476 2.6 72 142 81 1,750 3rd Qtr 10 7.7 10.10 0.08 1,010 225 102 468 0.029 2.5 67 133 82 1,510 4th Qtr 10 7.6 10.30 ND 0.05 920 208 99 481 0.015 2.8 69 137 75 1,830 1st Qtr 11 8.0 11.50 ND 0.05 1.5 939 207 113 503 0.037 2.4 67 129 82 1,790 2nd Qtr 11 7.8 11.50 ND 0.05 1.6 927 188 103 474 0.016 2.3 68 130 83 1,660 3rd Qtr 11 8.0 11.10 ND 0.05 1.4 959 193 108 499 0.026 2.5 71 134 89 1,660 4th Qtr 11 7.7 11.30 ND 0.05 2.0 953 189 108 474 0.02 2.4 70 134 85 1,680 1st Qtr 12 7.9 10.80 ND 0.05 2.2 1,020 157 100 504 0.025 2.4 64 131 78 1,680 2nd Qtr 12 8.0 11.30 ND 0.05 1.8 935 175 110 467 0.02 2.4 68 136 86 1,400 3rd Qtr 12 7.8 11.10 ND 0.10 1.9 979 167 105 567 0.14 3.1 71.5 138 82 4th Qtr 12 7.7 11.70 ND 0.05 2.0 1,000 174 112 514 0.05 2.9 71.1 137 88 1,620 1st Qtr 13 8.0 11.20 ND 0.05 1.1 956 162 117 537 0.08 2.7 71 145 85 1,668 2nd Qtr 13 7.9 10.80 ND 0.05 1.9 979 159 118 517 0.02 2.6 69 135 87 3rd Qtr 13 7.9 10.60 ND 0.05 1.4 896 156 114 534 0.04 2.5 69 138 82 4th Qtr 13 7.8 10.90 ND 0.05 1.5 959 169 135 528 0.03 2.7 69 149 88 1st Qtr 14 8.0 10.90 ND 0.05 1.8 992 172 133 416 0.03 2.6 70 142 89 2nd Qtr 14 7.9 10.90 ND 0.05 1.5 948 175 135 522 0.03 2.6 72 153 90 3rd Qtr 14 7.5 9.64 ND 0.02 ND 0.5 939 170 133 552 ND 0.01 2.6 71 145 86 4th Qtr 14 7.3 10.40 ND 0.02 ND 0.5 894 154 121 551 0.02 2.6 67 111 77 1st Qtr 15 7.1 10.50 ND 0.02 ND 0.5 954 156 124 540 0.01 2.8 80 146 86 2nd Qtr 15 7.5 11.00 ND 0.02 ND 0.5 912 171 137 541 0.05 3.0 80 169 101 3rd Qtr 15 7.5 10.50 ND 0.02 ND 0.5 986 167 137 540 0.02 2.6 74 147 87 4th Qtr 15 7.5 10.60 ND 0.02 ND 0.5 947 167 134 470 0.02 2.9 76 152 95 1st Qtr 16 8.3 10.80 ND 0.02 ND 0.5 968 177 139 557 0.02 2.9 79 170 100 2nd Qtr 16 7.2 11.40 ND 0.02 ND 0.5 946 160 131 557 0.02 3.0 80 162 97 1,761 3rd Qtr 16 7.5 10.20 ND 0.02 ND 0.5 938 173 139 563 0.12 3.1 70 142 82 1,782 4th Qtr 16 7.3 9.78 ND 0.02 ND 0.5 944 157 130 551 0.04 3.9 4 160 126 1,738 1st Qtr 17 7.8 9.95 ND 0.02 ND 0.5 974 191 148 570 0.17 2.6 75 152 79 1,775 2nd Qtr 17 7.6 7.82 ND 0.02 2.66 945 171 145 573 0.01 2.7 77 149 88 1,772 3rd Qtr 17 7.6 7.58 ND 0.02 ND 0.5 948 190 169 572 0.04 2.4 75 141 84 1,807 4th Qtr 17 7.4 7.49 ND 0.02 ND 0.5 993 221 213 584 ND 0.01 4.5 82 171 83 1,870

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 5 of 2 Appendix J3. Groundwater Data - MW 11A

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 7.69 1,640.08 Feb-10 4.56 1,643.21 Mar-10 4.69 1,643.08 NOTES: Apr-10 5.00 1,642.77 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 5.78 1,641.99 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 6.85 1,640.92 the Permit issued in June 2011. Jul-10 7.15 1,640.62 1 From 2000-2008, detection limits were not available. The maximum detection limit (0.05 mg/L) Aug-10 6.15 1,641.62 from 2009-2017 results was used. Sep-10 6.94 1,640.83 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Oct-10 7.32 1,640.45 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Nov-10 6.44 1,641.33 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Dec-10 4.67 1,643.10 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Jan-11 3.69 1,644.08 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Feb-11 5.16 1,642.61 Mar-11 3.38 1,644.39 Apr-11 5.09 1,642.68 2nd Q, '11 5.29 1,642.48 3rd Q, '11 7.48 1,640.29 4th Q, '11 7.88 1,639.89 1st Q, '12 5.63 1,642.14 2nd Q, '12 6.18 1,641.59 3rd Q, '12 7.51 1,640.26 4th Q, '12 5.85 1,641.92 1st Q, '13 3.12 1,644.65 2nd Q, '13 6.50 1,641.27 3rd Q, '13 8.06 1,639.71 4th Q, '13 8.29 1,639.48 1st Q, '14 5.80 1,641.97 2nd Q, '14 6.66 1,641.11 3rd Q, '14 6.62 1,641.15 4th Q, '14 8.07 1,639.70 1st Q, '15 4.83 1,642.94 2nd Q, '15 6.78 1,640.99 3rd Q, '15 7.38 1,640.39 4th Q, '15 10.29 1,637.48 1st Q, '16 4.87 1,642.90 2nd Q, '16 7.70 1,640.07 3rd Q, '16 8.37 1,639.40 4th Q, '16 6.99 1,640.78 1st Q, '17 3.57 1,644.20 2nd Q, '17 6.34 1,641.43 3rd Q, '17 7.68 1,640.09 4th Q, '17 5.61 1,642.16

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 6 of 2 Appendix J4. Groundwater Data - MW 12A

Groundwater Quality

NO 3+ Sampling pH NH -N 1 TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 1 3 4 Date 2 s.u. mg/L µmhos/cm 3rd Qtr 00 0.20 ND 0.05 15 18 1st Qtr 01 0.30 ND 0.05 23 20 2nd Qtr 01 3rd Qtr 01 0.40 ND 0.05 14 18 4th Qtr 01 4th Qtr 01 1st Qtr 02 2nd Qtr 02 3rd Qtr 02 4th Qtr 02 1st Qtr 03 0.20 ND 0.05 36 36 2nd Qtr 03 3rd Qtr 03 4th Qtr 03 1st Qtr 04 ND 0.05 15 19 2nd Qtr 04 2nd Qtr 04 3rd Qtr 04 ND 0.05 ND 0.05 34 31 4th Qtr 04 1st Qtr 05 ND 0.05 ND 0.05 37 39 2nd Qtr 05 ND 0.05 ND 0.05 35 37 3rd Qtr 05 ND 0.05 ND 0.05 30 34 4th Qtr 05 ND 0.05 ND 0.05 21 25 1st Qtr 06 ND 0.05 ND 0.05 34 40 2nd Qtr 06 ND 0.05 ND 0.05 34 35 3rd Qtr 06 ND 0.05 ND 0.05 29 34 4th Qtr 06 ND 0.05 ND 0.05 27 29 1st Qtr 07 ND 0.05 ND 0.05 33 39 2nd Qtr 07 ND 0.05 ND 0.05 28 33 3rd Qtr 07 0.10 ND 0.05 29 33 4th Qtr 07 ND 0.05 ND 0.05 19 24 1st Qtr 08 ND 0.05 ND 0.05 28 31 2nd Qtr 08 0.13 ND 0.05 32 39 4th Qtr 09 7.2 0.15 ND 0.05 0.8 739 30 34 733 2.7 89 97 78 1,300 1st Qtr 10 7.3 0.21 ND 0.05 0.4 724 34 47 656 1.9 73 94 79 1,280 2nd Qtr 10 7.3 0.22 ND 0.05 1.1 712 37 49 618 1.9 72 94 73 1,270 3rd Qtr 10 7.2 0.20 0.07 771 27 31 694 0.022 2.4 82 95 76 1,160 4th Qtr 10 7.1 0.20 ND 0.05 804 19 22 716 0.022 2.7 89 99 71 1,410 1st Qtr 11 7.4 0.15 ND 0.05 0.5 736 40 48 638 0.025 1.8 71 89 76 1,340 2nd Qtr 11 7.3 0.16 ND 0.05 0.4 715 35 45 608 0.015 1.8 71 88 75 1,100 3rd Qtr 11 7.4 0.12 ND 0.05 0.5 701 30 40 712 0.022 2.1 81 92 80 1,270 4th Qtr 11 7.2 0.12 ND 0.05 0.5 759 20 26 724 0.044 2.4 87 94 81 1,320 1st Qtr 12 7.4 0.11 ND 0.05 ND 0.4 741 35 45 616 0.019 1.8 68 89 74 1,280 2nd Qtr 12 7.5 0.10 ND 0.05 0.4 729 36 48 601 ND 0.01 1.8 68 83 79 1,190 3rd Qtr 12 7.5 0.05 ND 0.05 0.5 731 25 35 735 0.02 2.1 76 88.4 79 4th Qtr 12 7.1 ND 0.05 ND 0.05 0.6 719 20 28 760 0.01 2.3 80 89 80 1,270 1st Qtr 13 7.5 ND 0.05 ND 0.05 0.5 696 39 52 633 0.03 1.8 70 85 79 1,232 2nd Qtr 13 7.7 ND 0.05 ND 0.05 0.5 721 31 44 628 0.04 2.1 75 91 84 1,260 3rd Qtr 13 7.4 ND 0.05 ND 0.05 0.3 744 27 37 730 0.02 2.3 78 92 77 4th Qtr 13 7.5 ND 0.05 ND 0.05 0.3 711 22 28 800 ND 0.01 2.5 84 97 80 1st Qtr 14 7.7 0.054 ND 0.05 9.0 632 44 54 542 0.02 1.8 69 87 79 2nd Qtr 14 7.6 ND 0.05 ND 0.05 0.5 683 36 52 570 0.02 1.9 70 92 79 3rd Qtr 14 7.1 ND 0.10 ND 0.02 ND 0.5 716 34 44 666 ND 0.01 2.3 77 96 83 4th Qtr 14 7.0 ND 0.10 ND 0.02 ND 0.5 714 25 32 702 0.02 3.0 87 97 83 1st Qtr 15 7.6 ND 0.10 ND 0.02 ND 0.5 636 41 54 588 0.01 1.8 72 84 72 2nd Qtr 15 7.2 ND 0.10 ND 0.20 ND 0.5 633 39 51 598 0.02 1.8 67 85 75 3rd Qtr 15 7.3 ND 0.10 ND 0.02 ND 0.5 734 30 40 660 0.02 2.5 85 99 88 4th Qtr 15 7.1 ND 0.10 ND 0.02 0.3 716 24 31 730 ND 0.01 2.6 86 94 86 1st Qtr 16 7.1 ND 0.10 ND 0.02 ND 0.5 679 45 54 595 0.02 1.9 69 95 83 2nd Qtr 16 6.9 ND 0.10 ND 0.00 < 0.50 701 38 50 602 0.02 2.3 78 100 89 1,239 3rd Qtr 16 7.1 ND 0.10 ND 0.02 ND 0.50 674 30 39 416 ND 0.02 2.2 76 92 80 1,318 4th Qtr 16 7.1 ND 0.10 ND 0.02 ND 0.50 696 41 51 605 0.06 4.5 99 140 140 1,249 1st Qtr 17 7.4 0.03 ND 0.02 ND 0.5 654 51.2 63 575 0.02 1.7 69 90.7 69 1,203 2nd Qtr 17 7.0 0.02 ND 0.02 0.394 856 40.7 54 586 0.01 1.9 73 90.5 80 1,144 3rd Qtr 17 7.4 ND 0.10 ND 0.02 ND 0.5 668 36.1 49 648 0.02 2.1 77 89.2 78 1,276 4th Qtr 17 1,342

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 7 of 2 Appendix J4. Groundwater Data - MW 12A

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 9.24 1,649.79 Feb-10 4.30 1,654.73 Mar-10 4.66 1,654.37 NOTES: Apr-10 4.25 1,654.78 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 4.41 1,654.62 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 4.98 1,654.05 the Permit issued in June 2011. Jul-10 6.98 1,652.05 1 From 2000-2008, detection limits were not available. The maximum detection limit (0.05 mg/L) Aug-10 7.91 1,651.12 from 2009-2017 results was used. Sep-10 8.47 1,650.56 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Oct-10 8.88 1,650.15 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Nov-10 8.58 1,650.45 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Dec-10 5.01 1,654.02 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Jan-11 4.28 1,654.75 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Feb-11 4.69 1,654.34 Mar-11 3.93 1,655.10 Apr-11 4.02 1,655.01 2nd Q, '11 4.18 1,654.85 3rd Q, '11 6.57 1,652.46 4th Q, '11 9.11 1,649.92 1st Q, '12 4.69 1,654.34 2nd Q, '12 4.54 1,654.49 3rd Q, '12 7.28 1,651.75 4th Q, '12 8.02 1,651.01 1st Q, '13 3.86 1,655.17 2nd Q, '13 5.71 1,653.32 3rd Q, '13 7.87 1,651.16 4th Q, '13 9.47 1,649.56 1st Q, '14 4.76 1,654.27 2nd Q, '14 4.86 1,654.17 3rd Q, '14 7.96 1,651.07 4th Q, '14 9.34 1,649.69 1st Q, '15 4.47 1,654.56 2nd Q, '15 6.49 1,652.54 3rd Q, '15 8.92 1,650.11 4th Q, '15 10.91 1,648.12 1st Q, '16 4.60 1,654.43 2nd Q, '16 5.73 1,653.30 3rd Q, '16 8.88 1,650.15 4th Q, '16 6.12 1,652.91 1st Q, '17 4.02 1,655.01 2nd Q, '17 4.35 1,654.68 3rd Q, '17 7.62 1,651.41 4th Q, '17 9.45 1,649.58

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 8 of 2 Appendix J5. Groundwater Data - MW 34

Groundwater Quality NO + Sampling pH 3 NH -N TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm

4th Qtr 09 7.5 3.94 ND 0.05 1.3 501 3 33 449 2.7 100 47 25 864 1st Qtr 10 7.3 4.33 ND 0.05 0.9 503 2 36 458 2.4 101 50 26 880 2nd Qtr 10 7.3 3.62 ND 0.05 1.2 494 3 35 446 2.2 95 49 25 902 3rd Qtr 10 7.3 3.28 ND 0.05 484 2 33 447 0.022 2.1 95 48 25 761 4th Qtr 10 7.2 2.99 ND 0.05 496 2 29 448 0.015 2.0 92 43 23 805 1st Qtr 11 2nd Qtr 11 7.4 2.89 ND 0.05 1.1 461 2 32 439 0.013 1.9 95 46 25 752 3rd Qtr 11 7.4 2.70 ND 0.05 0.5 476 2 30 442 0.018 2.0 97 46 26 839 4th Qtr 11 7.3 2.62 ND 0.05 1.2 478 2 33 423 0.027 2.0 98 47 27 851 1st Qtr 12 7.4 2.40 ND 0.05 0.6 481 2 33 448 0.016 1.9 93 45 24 858 2nd Qtr 12 7.5 2.56 ND 0.05 0.6 498 2 33 421 0.01 1.9 91 44 27 726 3rd Qtr 12 7.5 2.61 ND 0.05 0.7 532 2 31 452 0.02 2.0 93.8 46 25 4th Qtr 12 7.4 2.63 ND 0.05 0.6 528 2 32 442 0.02 2.1 95 48 26 835 1st Qtr 13 7.5 3.03 ND 0.05 0.5 500 1 32 461 0.05 1.9 101 47 26 872 2nd Qtr 13 7.5 3.10 ND 0.05 0.6 529 1 32 446 0.02 1.9 97 48 27 3rd Qtr 13 7.5 3.10 ND 0.05 0.4 487 1 31 454 0.02 2.0 100 48 24 4th Qtr 13 7.5 2.58 ND 0.05 1.0 476 2 31 459 0.01 2.1 96 46 24 1st Qtr 14 7.6 2.65 ND 0.05 0.8 474 2 32 458 0.01 1.9 96 45 25 2nd Qtr 14 7.7 2.30 ND 0.05 1.2 481 2 32 439 0.03 1.9 99 46 25 3rd Qtr 14 7.2 2.03 ND 0.02 0.7 462 2 31 407 ND 0.01 2.1 93 48 26 4th Qtr 14 7.1 1.85 ND 0.02 ND 0.5 455 2 31 447 0.02 2.1 88 43 23 1st Qtr 15 7.1 1.44 ND 0.02 ND 0.5 448 2 28 432 ND 0.01 1.9 94 44 23 2nd Qtr 15 7.2 1.66 ND 0.02 ND 0.5 464 2 31 435 0.03 2.1 99.8 49.6 27 3rd Qtr 15 7.5 1.53 ND 0.02 ND 0.5 964 2 31 435 0.02 2.4 96 49.3 28 4th Qtr 15 7.2 1.36 ND 0.02 ND 0.5 482 2 29 448 0.02 2.5 104 50.2 29 1st Qtr 16 6.9 1.24 0.05 ND 0.5 464 2 29 445 0.02 2.3 100 48.5 26 2nd Qtr 16 6.9 2.09 ND 0.02 ND 0.5 490 2 30 433 0.02 2.2 95.8 50.8 28 850 3rd Qtr 16 7.2 1.48 0.09 ND 0.5 464 3 25 444 0.02 1.8 83.2 41.3 21 862 4th Qtr 16 7.0 1.45 ND 0.02 ND 0.5 442 2 27 440 0.03 2.7 116 62.1 37 817 1st Qtr 17 7.5 1.61 ND 0.02 ND 0.5 446 1.5 33 452 0.02 1.5 100 45.9 22 847 2nd Qtr 17 7.3 1.50 0.04 ND 0.5 413 1.67 38 440 0.01 2.0 98 47.3 28 859 3rd Qtr 17 7.3 1.56 ND 0.02 ND 0.5 416 1.62 37 451 0.01 1.7 85 42.1 23 869 4th Qtr 17 7.0 1.21 ND 0.02 ND 0.5 493 3.55 41 446 ND 0.01 2.7 98 47.7 26 858

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 9 of 2 Appendix J5. Groundwater Data - MW 34

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 9.64 1,637.36 Feb-10 9.00 1,638.00 Mar-10 8.99 1,638.01 NOTES: Apr-10 8.80 1,638.20 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 8.78 1,638.22 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 8.96 1,638.04 the Permit issued in June 2011. Jul-10 9.63 1,636.36 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Aug-10 10.04 1,636.96 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Sep-10 9.56 1,636.44 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Oct-10 9.47 1,636.53 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Nov-10 9.27 1,636.73 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Dec-10 8.84 1,638.16 Jan-11 7.81 1,639.19 Feb-11 8.67 1,638.33 Mar-11 Apr-11 8.24 1,638.76 2nd Q, '11 8.44 1,638.56 3rd Q, '11 8.94 1,638.06 4th Q, '11 9.14 1,637.86 1st Q, '12 8.84 1,638.16 2nd Q, '12 8.59 1,638.41 3rd Q, '12 9.22 1,637.78 4th Q, '12 8.91 1,638.09 1st Q, '13 8.23 1,638.77 2nd Q, '13 8.50 1,638.50 3rd Q, '13 9.26 1,637.74 4th Q, '13 8.74 1,638.26 1st Q, '14 8.62 1,638.38 2nd Q, '14 8.21 1,638.79 3rd Q, '14 8.72 1,638.28 4th Q, '14 8.62 1,638.38 1st Q, '15 8.12 1,638.88 2nd Q, '15 8.47 1,638.53 3rd Q, '15 11.51 1,635.49 4th Q, '15 9.35 1,637.65 1st Q, '16 8.38 1,638.62 2nd Q, '16 8.63 1,638.37 3rd Q, '16 9.38 1,637.62 4th Q, '16 8.44 1,638.56 1st Q, '17 7.87 1,639.13 2nd Q, '17 8.35 1,638.65 3rd Q, '17 8.89 1,638.11 4th Q, '17 8.62 1,638.38

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 10 of 2 Appendix J6. Groundwater Data - MW 35

Groundwater Quality NO + Sampling pH 3 NH -N TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm

4th Qtr 09 7.7 0.10 0.06 0.6 477 3 56 366 3.0 63 38 60 808 1st Qtr 10 7.5 0.10 ND 0.05 0.6 500 3 56 431 2.2 71 48 53 848 2nd Qtr 10 7.4 0.10 ND 0.05 0.5 479 3 52 442 2.0 69 47 48 875 3rd Qtr 10 7.5 0.20 0.11 474 3 47 431 0.025 2.0 71 48 49 749 4th Qtr 10 7.1 0.20 0.06 528 2 43 438 0.032 1.9 72 44 46 896 1st Qtr 11 7.5 0.10 ND 0.05 0.8 506 3 47 467 0.032 1.8 74 47 44 918 2nd Qtr 11 7.4 0.09 ND 0.05 0.4 509 2 44 423 0.021 1.8 74 47 48 748 3rd Qtr 11 7.7 0.09 ND 0.05 0.5 464 2 42 440 0.023 1.8 76 47 50 837 4th Qtr 11 7.5 0.06 ND 0.05 0.5 470 2 49 421 0.037 1.8 74 48 51 841 1st Qtr 12 7.6 0.08 ND 0.05 ND 0.4 497 2 46 420 0.028 1.8 71 46 46 850 2nd Qtr 12 7.8 ND 0.05 ND 0.05 0.4 445 2 43 410 0.01 1.8 69 44 50 807 3rd Qtr 12 7.7 ND 0.05 ND 0.05 0.4 492 2 41 444 0.03 1.7 68 46 49 4th Qtr 12 7.6 ND 0.05 ND 0.05 0.7 478 3 43 435 0.04 1.8 69 47 52 818 1st Qtr 13 7.6 ND 0.05 ND 0.05 0.6 453 3 50 457 0.05 1.8 78 45 49 848 2nd Qtr 13 7.6 0.054 ND 0.05 0.5 514 3 47 432 0.01 1.8 71 48 51 3rd Qtr 13 7.8 ND 0.05 ND 0.05 0.6 484 2 44 435 0.03 1.8 69 45 50 4th Qtr 13 7.6 ND 0.05 ND 0.05 0.5 470 4 46 399 0.02 1.9 69 45 51 1st Qtr 14 7.9 0.09 ND 0.05 0.5 462 4 47 421 0.02 1.8 72 46 49 2nd Qtr 14 7.8 ND 0.08 ND 0.05 0.4 482 3 47 425 0.02 1.9 74 49 52 3rd Qtr 14 7.4 ND 0.10 0.04 ND 0.5 445 3 45 424 ND 0.01 1.9 68 47 50 4th Qtr 14 7.2 ND 0.10 0.03 1.7 414 3 46 432 0.02 1.8 62 41 44 1st Qtr 15 7.3 0.08 ND 0.02 0.5 419 3 43 421 ND 0.01 1.9 80 46 46 2nd Qtr 15 7.2 ND 0.10 ND 0.02 ND 0.5 443 3 45 421 0.03 2.0 78 51 55 3rd Qtr 15 7.6 ND 0.10 ND 0.02 ND 0.5 232 3 44 426 0.02 1.8 69 46 50 4th Qtr 15 7.3 ND 0.10 0.02 0.5 446 3 44 420 0.01 2.0 73 49 57 1st Qtr 16 7.0 ND 0.02 ND 0.02 ND 0.5 455 4 44 429 0.02 2.1 82 53 55 2nd Qtr 16 7.1 ND 0.10 ND 0.02 ND 0.5 469 3 43 430 0.02 2.2 78 51 54 845 3rd Qtr 16 1.8 ND 0.10 ND 0.02 ND 0.5 448 3 46 425 0.01 1.8 64 44 47 865 4th Qtr 16 7.1 ND 0.10 ND 0.02 ND 0.5 452 3 40 421 0.03 2.3 83 60 70 825 1st Qtr 17 7.6 0.06 ND 0.02 ND 0.5 420 4 53 434 0.04 1.6 76 48 42 827 2nd Qtr 17 7.3 0.04 ND 0.02 ND 0.5 411 4 47 429 0.02 1.9 72 45 50 833 3rd Qtr 17 7.3 ND 0.10 ND 0.02 ND 0.5 428 3 51 427 ND 0.01 1.7 68 46 51 853 4th Qtr 17 7.2 ND 0.10 ND 0.02 ND 0.5 460 5 61 423 ND 0.01 2.7 74 49 44 864

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 11 of 2 Appendix J6. Groundwater Data - MW 35

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 12.58 1,632.04 Feb-10 8.89 1,635.73 Mar-10 8.71 1,635.91 NOTES: Apr-10 8.58 1,636.04 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 8.69 1,635.93 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 9.18 1,635.44 the Permit issued in June 2011. Jul-10 9.95 1,634.67 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Aug-10 10.49 1,634.13 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Sep-10 10.29 1,634.33 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Oct-10 10.21 1,634.41 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Nov-10 9.84 1,634.78 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Dec-10 8.69 1,635.93 Jan-11 7.46 1,637.16 Feb-11 7.68 1,636.94 Mar-11 5.55 1,639.07 Apr-11 6.59 1,638.03 2nd Q, '11 7.00 1,637.62 3rd Q, '11 8.31 1,636.31 4th Q, '11 8.67 1,635.95 1st Q, '12 7.06 1,637.56 2nd Q, '12 7.06 1,637.56 3rd Q, '12 8.10 1,636.52 4th Q, '12 7.74 1,636.88 1st Q, '13 5.51 1,639.11 2nd Q, '13 7.05 1,637.57 3rd Q, '13 7.97 1,636.65 4th Q, '13 7.26 1,637.36 1st Q, '14 6.49 1,638.13 2nd Q, '14 6.60 1,638.02 3rd Q, '14 7.08 1,637.54 4th Q, '14 7.11 1,637.51 1st Q, '15 5.84 1,638.78 2nd Q, '15 6.88 1,637.74 3rd Q, '15 8.85 1,635.77 4th Q, '15 8.56 1,636.06 1st Q, '16 6.09 1,638.53 2nd Q, '16 6.65 1,637.97 3rd Q, '16 7.30 1,637.32 4th Q, '16 5.81 1,638.81 1st Q, '17 4.91 1,639.71 2nd Q, '17 5.93 1,638.69 3rd Q, '17 6.52 1,638.10 4th Q, '17 6.52 1,638.10

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 12 of 2 Appendix J7. Groundwater Data - MW 36

Groundwater Quality NO + Sampling pH 3 NH -N TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm

4th Qtr 09 7.2 2.25 ND 0.05 1.1 899 73 82 666 2.0 134 89 77 1,520 1st Qtr 10 7.1 2.30 ND 0.05 0.8 927 90 94 811 1.7 144 99 80 1,640 2nd Qtr 10 7.0 1.95 ND 0.05 0.7 960 100 91 754 1.8 146 104 79 1,670 3rd Qtr 10 7.1 1.69 0.062 961 114 97 424 0.017 1.8 139 99 79 1,470 4th Qtr 10 7.4 1.33 ND 0.05 888 94 85 651 0.012 2.2 122 77 71 1,460 1st Qtr 11 2nd Qtr 11 7.1 3.02 ND 0.05 1.3 1,010 149 101 639 0.015 1.8 145 102 87 1,540 3rd Qtr 11 7.3 2.98 ND 0.05 0.8 963 149 100 617 0.013 1.8 148 97 82 1,650 4th Qtr 11 7.1 2.61 ND 0.05 1.0 972 144 96 623 0.049 1.9 143 99 86 1,710 1st Qtr 12 7.2 2.47 ND 0.05 0.8 973 142 102 652 0.015 1.8 141 100 80 1,770 2nd Qtr 12 7.3 2.27 ND 0.05 0.7 964 147 90 607 ND 0.01 1.7 139 99 83 1,660 3rd Qtr 12 7.3 2.73 ND 0.05 1.0 1,130 189 111 652 0.01 1.7 154 111 86 4th Qtr 12 7.5 2.39 ND 0.05 0.7 1,030 161 98 621 0.01 2.0 144 101 89 1,640 1st Qtr 13 7.3 2.72 ND 0.05 0.8 1,110 181 118 641 0.02 1.8 161 115 88 1,801 2nd Qtr 13 7.2 2.60 ND 0.05 0.9 1,080 161 93 606 0.02 1.8 144 99 83 3rd Qtr 13 7.2 2.33 ND 0.05 0.8 1,030 164 97 623 0.03 1.8 146 104 84 4th Qtr 13 7.8 1.42 ND 0.05 0.6 904 121 97 618 0.02 2.1 128 100 83 1st Qtr 14 7.5 4.11 ND 0.05 1.4 812 151 98 514 0.02 1.7 126 83 66 2nd Qtr 14 7.4 4.17 ND 0.05 1.4 820 134 96 523 0.01 1.7 127 89 71 3rd Qtr 14 7.1 2.70 ND 0.02 ND 0.5 809 106 81 550 ND 0.01 2.1 116 87 76 4th Qtr 14 7.0 1.86 ND 0.02 1.9 753 97 85 569 0.02 2.2 106 76 70 1st Qtr 15 7.0 5.31 ND 0.02 ND 0.5 740 100 79 506 ND 0.01 1.7 115 72 58 2nd Qtr 15 7.1 3.92 ND 0.02 ND 0.5 780 112 95 519 0.03 2.0 125 93 79 3rd Qtr 15 7.1 3.00 ND 0.02 ND 0.5 934 144 105 532 0.01 1.8 139 96 77 4th Qtr 15 7.1 1.92 ND 0.02 ND 0.5 790 98 94 545 0.03 2.3 118 87 85 1st Qtr 16 8.3 2.65 ND 0.02 ND 0.5 860 133 111 533 0.02 1.6 110 81 71 2nd Qtr 16 6.9 2.51 ND 0.02 ND 0.5 859 122 110 528 0.01 2.1 131 94 82 1,522 3rd Qtr 16 7.2 2.00 ND 0.02 ND 0.5 761 112 110 536 0.01 1.9 105 79 72 1,490 4th Qtr 16 7.0 1.56 ND 0.02 ND 0.5 694 86 90 537 0.04 3.2 134 109 113 1,358 1st Qtr 17 7.4 2.71 ND 0.02 ND 0.5 878 105 104 532 0.02 1.9 135 95 74 1,551 2nd Qtr 17 7.2 1.77 ND 0.02 ND 0.5 885 148 120 569 0.01 2.1 149 102 86 1,620 3rd Qtr 17 7.2 2.38 ND 0.02 ND 0.5 822 156 121 562 0.02 1.7 133 91 75 1,608 4th Qtr 17 7.1 1.61 ND 0.02 ND 0.5 830 191 185 547 ND 0.01 2.1 149 105 76 1,662

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 13 of 2 Appendix J7. Groundwater Data - MW 36

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 10.49 1,638.67 Feb-10 5.33 1,643.83 Mar-10 5.65 1,643.51 NOTES: Apr-10 6.29 1,642.87 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 6.57 1,642.59 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 7.88 1,641.28 the Permit issued in June 2011. Jul-10 10.22 1,638.94 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Aug-10 11.41 1,636.75 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Sep-10 12.94 1,636.22 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Oct-10 13.95 1,635.21 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Nov-10 14.83 1,634.33 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Dec-10 8.93 1,640.23 Jan-11 4.26 1,644.90 Feb-11 5.02 1,644.14 Mar-11 Apr-11 4.01 1,645.15 2nd Q, '11 4.41 1,644.75 3rd Q, '11 6.96 1,642.20 4th Q, '11 8.95 1,640.21 1st Q, '12 4.91 1,644.25 2nd Q, '12 5.36 1,643.80 3rd Q, '12 10.94 1,638.22 4th Q, '12 13.92 1,635.24 1st Q, '13 3.19 1,645.97 2nd Q, '13 5.94 1,643.22 3rd Q, '13 11.56 1,637.60 4th Q, '13 16.68 1,632.48 1st Q, '14 4.93 1,644.23 2nd Q, '14 5.53 1,643.63 3rd Q, '14 8.86 1,640.30 4th Q, '14 11.93 1,637.23 1st Q, '15 4.15 1,645.01 2nd Q, '15 7.85 1,641.31 3rd Q, '15 13.12 1,636.04 4th Q, '15 17.51 1,631.65 1st Q, '16 10.76 1,638.40 2nd Q, '16 6.91 1,642.25 3rd Q, '16 13.30 1,635.86 4th Q, '16 14.80 1,634.36 1st Q, '17 3.32 1,645.84 2nd Q, '17 5.31 1,643.85 3rd Q, '17 8.03 1,641.13 4th Q, '17 8.07 1,641.09

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 14 of 2 Appendix J8. Groundwater Data - MW 37

Groundwater Quality NO + Sampling pH 3 NH -N TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm

4th Qtr 09 7.4 0.10 0.07 0.7 325 7 27 236 2.4 80 15 9 526 1st Qtr 10 7.3 0.10 ND 0.05 0.7 327 7 27 248 2.4 84 15 9 521 2nd Qtr 10 7.2 0.10 ND 0.05 0.4 293 7 27 216 2.3 80 15 9 511 3rd Qtr 10 7.2 0.20 0.13 312 8 28 665 0.290 2.3 79 15 9 454 4th Qtr 10 7.5 0.20 ND 0.05 317 6 22 259 0.150 2.0 77 13 8 497 1st Qtr 11 7.4 ND 0.05 ND 0.05 0.5 289 6 20 250 1.270 2.1 73 13 8 520 2nd Qtr 11 7.4 ND 0.05 ND 0.05 0.4 270 6 20 221 1.1 2.0 71 13 8 411 3rd Qtr 11 7.6 ND 0.05 ND 0.05 0.5 296 8 27 213 0.8 2.1 77 13 8 468 4th Qtr 11 7.2 ND 0.07 ND 0.05 0.7 320 10 45 233 0.0 2.3 89 16 9 552 1st Qtr 12 7.4 ND 0.05 ND 0.05 0.4 336 6 20 222 2.0 2.0 70 12 8 470 2nd Qtr 12 7.6 ND 0.05 ND 0.05 0.5 264 6 19 197 1.2 2.1 68 12 8 393 3rd Qtr 12 7.5 ND 0.05 ND 0.05 0.6 316 5 18 239 0.2 2.0 64 12 8 4th Qtr 12 7.6 ND 0.05 ND 0.05 0.5 300 7.3 24 222 0.1 2.3 71 13 9 471 1st Qtr 13 7.6 ND 0.05 ND 0.05 0.4 272 5.6 21 222 0.4 2.2 71 13 9 463 2nd Qtr 13 7.7 ND 0.05 ND 0.05 0.7 282 5.9 21 216 0.5 2.2 70 13 9 3rd Qtr 13 7.5 ND 0.05 ND 0.05 0.4 282 4.9 18 219 0.3 2.1 66 13 8 4th Qtr 13 7.5 ND 0.05 ND 0.05 ND 0.4 262 6.8 25 232 0.3 2.4 74 14 9 1st Qtr 14 7.7 0.06 ND 0.05 1.08 296 6.6 21 231 0.5 2.2 70 13 9 2nd Qtr 14 7.6 ND 0.05 ND 0.05 ND 0.7 265 5.6 18 216 0.8 2.2 69 13 9 3rd Qtr 14 7.3 ND 0.10 0.06 0.5 251 5.7 17 226 0.3 2.2 65 13 8 4th Qtr 14 7.1 ND 0.10 0.04 0.8 202 5.6 20 243 0.5 2.4 71 13 9 1st Qtr 15 7.1 ND 0.10 ND 0.02 ND 0.5 207 5.6 18 226 1.1 2.2 77 13 8 2nd Qtr 15 7.2 ND 0.10 0.05 ND 0.5 266 4.7 14 211 0.8 2.3 69 13 9 3rd Qtr 15 7.4 ND 0.10 0.06 ND 0.5 270 5.1 16 216 1.6 2.3 74 13 9 4th Qtr 15 7.2 ND 0.10 0.04 ND 0.5 262 5.0 17 234 0.2 2.3 72 13 10 1st Qtr 16 6.8 ND 0.10 0.04 0.6 281 5.4 18 233 0.7 2.5 79 15 10 2nd Qtr 16 7.4 ND 0.10 0.54 ND 0.5 266 4.7 17 207 0.6 2.5 74 14 10 454 3rd Qtr 16 7.4 ND 0.10 ND 0.02 0.55 268 4.5 19 209 0.2 2.0 60 11 8 470 4th Qtr 16 7.0 ND 0.01 0.03 ND 0.5 277 4.6 20 218 0.3 2.9 85 17 13 467 1st Qtr 17 7.5 ND 0.10 ND 0.02 ND 0.5 240 5.4 21 215 0.72 1.8 69 13 8 436 2nd Qtr 17 6.9 0.03 0.10 0.55 602 11.1 42 211 0.18 2.2 71 13 8 508 3rd Qtr 17 7.4 ND 0.10 ND 0.02 ND 0.5 282 10.6 36 215 0.21 2.3 76 14 9 505 4th Qtr 17 7.1 ND 0.10 0.04 ND 0.5 290 10.8 45 214 ND 0.01 2.8 78 14 9 511

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 15 of 2 Appendix J8. Groundwater Data - MW 37

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 12.08 1,624.01 Feb-10 11.26 1,624.83 Mar-10 11.27 1,624.82 NOTES: Apr-10 10.99 1,626.10 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 10.93 1,626.16 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 11.22 1,625.87 the Permit issued in June 2011. Jul-10 11.99 1,625.10 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Aug-10 12.46 1,624.63 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Sep-10 12.13 1,624.96 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Oct-10 12.12 1,624.97 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Nov-10 11.78 1,625.31 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Dec-10 11.28 1,625.81 Jan-11 10.48 1,626.61 Feb-11 10.67 1,626.42 Mar-11 9.69 1,627.40 Apr-11 9.15 1,627.94 2nd Q, '11 9.36 1,627.73 3rd Q, '11 10.91 1,626.18 4th Q, '11 11.82 1,625.27 1st Q, '12 10.62 1,626.47 2nd Q, '12 9.92 1,627.17 3rd Q, '12 11.51 1,625.58 4th Q, '12 9.33 1,627.76 1st Q, '13 9.17 1,627.92 2nd Q, '13 10.26 1,626.83 3rd Q, '13 11.48 1,625.61 4th Q, '13 11.43 1,625.66 1st Q, '14 10.68 1,626.41 2nd Q, '14 10.50 1,626.59 3rd Q, '14 11.73 1,625.36 4th Q, '14 11.63 1,625.46 1st Q, '15 10.27 1,626.82 2nd Q, '15 11.07 1,626.02 3rd Q, '15 12.02 1,625.07 4th Q, '15 11.85 1,625.24 1st Q, '16 10.90 1,626.19 2nd Q, '16 10.60 1,626.49 3rd Q, '16 11.73 1,625.36 4th Q, '16 11.02 1,626.07 1st Q, '17 7.65 1,629.44 2nd Q, '17 9.13 1,627.96 3rd Q, '17 11.17 1,625.92 4th Q, '17 11.42 1,625.67

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 16 of 2 Appendix J9. Groundwater Data - MW 38

Groundwater Quality NO + Sampling pH 3 NH -N TKN TDS Cl SO Bicarb P K Ca Mg Na Cond NO -N 3 4 Date 2 s.u. mg/L µmhos/cm

4th Qtr 09 7.5 0.10 ND 0.05 0.9 636 64 117 325 3.0 142 30 36 994 1st Qtr 10 7.4 0.10 ND 0.05 0.8 559 52 104 343 2.8 132 28 31 955 2nd Qtr 10 7.3 0.10 ND 0.05 0.5 654 76 138 345 3.1 152 34 36 1,110 3rd Qtr 10 7.2 0.20 0.2 757 99 161 235 0.116 3.2 157 36 43 1,080 4th Qtr 10 7.2 0.20 ND 0.05 260 85 144 338 ND 0.01 3.0 158 32 38 1,050 1st Qtr 11 7.4 ND 0.05 ND 0.05 0.6 817 119 195 341 2.39 3.1 185 39 45 1,410 2nd Qtr 11 7.4 ND 0.05 ND 0.05 0.6 935 165 237 370 0.384 3.3 210 46 55 1,360 3rd Qtr 11 7.5 ND 0.05 ND 0.05 0.6 1,020 191 264 373 0.24 3.5 235 49 58 1,600 4th Qtr 11 7.3 ND 0.05 ND 0.05 0.6 915 140 222 348 0.03 3.2 203 44 49 1,460 1st Qtr 12 7.4 ND 0.05 ND 0.05 0.5 725 84 143 367 3.89 2.8 159 35 39 1,190 2nd Qtr 12 7.4 ND 0.05 ND 0.05 0.5 1,010 177 254 365 1.00 3.4 220 48 57 1,470 3rd Qtr 12 7.5 ND 0.05 ND 0.05 0.7 1,070 171 255 424 0.48 3.4 216 49 59 4th Qtr 12 7.6 ND 0.05 ND 0.05 0.7 992 149 221 368 0.09 3.4 197 44 51 1,410 1st Qtr 13 7.5 ND 0.05 ND 0.05 0.5 1,090 175 248 415 0.41 3.5 234 50 61 1,674 2nd Qtr 13 7.6 ND 0.05 ND 0.05 0.7 1,140 184 278 407 0.57 3.7 241 55 68 3rd Qtr 13 7.4 ND 0.05 ND 0.05 0.6 1,000 156 227 398 0.15 3.5 213 48 58 4th Qtr 13 7.6 ND 0.05 ND 0.05 1.5 844 112 182 382 0.19 3.3 179 41 52 1st Qtr 14 7.7 ND 0.05 ND 0.05 0.6 770 99 154 328 0.42 3.0 159 36 44 2nd Qtr 14 7.6 ND 0.05 ND 0.05 0.8 894 147 220 374 0.26 3.4 204 49 53 3rd Qtr 14 7.2 ND 0.10 0.05 0.5 802 125 179 364 0.32 3.0 167 39 45 4th Qtr 14 7.1 ND 0.10 0.02 0.6 694 90 139 356 0.10 3.0 142 32 37 1st Qtr 15 7.1 ND 0.10 ND 0.02 ND 0.5 565 84 135 336 0.33 2.9 158 33 36 2nd Qtr 15 7.1 ND 0.10 0.02 ND 0.5 827 119 178 282 0.44 6.3 360 86 96 3rd Qtr 15 7.7 ND 0.10 ND 0.02 ND 0.5 762 103 154 350 0.09 3.2 165 39 45 4th Qtr 15 7.3 ND 0.10 ND 0.02 ND 0.5 741 93 142 352 0.11 3.2 158 37 45 1st Qtr 16 7.1 ND 0.10 ND 0.02 ND 0.5 651 80 126 340 1.61 2.8 144 35 39 2nd Qtr 16 7.0 ND 0.10 ND 0.02 ND 0.5 779 109 165 534 0.20 3.6 195 47 51 1,279 3rd Qtr 16 7.2 ND 0.10 ND 0.02 ND 0.5 722 96 151 346 0.14 2.8 143 35 39 1,229 4th Qtr 16 7.0 0.02 ND 0.02 ND 0.5 678 79 129 384 0.14 3.7 187 48 57 1,130 1st Qtr 17 7.5 ND 0.10 ND 0.02 ND 0.5 746 53 81 349 1.02 2.8 172 40 39 1,240 2nd Qtr 17 7.3 0.02 0.05 ND 0.5 976 163 226 376 0.35 3.4 207 47 54 1,581 3rd Qtr 17 7.3 ND 0.10 ND 0.02 ND 0.5 914 177 254 382 0.28 3.4 216 50 58 1,590 4th Qtr 17 7.2 ND 0.10 ND 0.02 ND 0.5 784 136 224 369 0.92 5.0 188 44 46 1,425

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 17 of 2 Appendix J9. Groundwater Data - MW 38

Depth to Groundwater (feet) and Elevation of the Groundwater (feet above mean sea level) Date Depth Elevation Dec-09 9.76 1,615.13 Feb-10 7.17 1,617.72 Mar-10 7.17 1,617.72 NOTES: Apr-10 6.26 1,618.63 Blank cells indicated sample was not analyzed. Cond testing not required as of June 2011. May-10 6.77 1,618.12 Groundwater elevation monitoring changed from monthly to quarterly as of the 2nd Quarter of 2011 according to Jun-10 7.63 1,617.26 the Permit issued in June 2011. Jul-10 9.42 1,615.47 Abbreviations: Bicarb = bicarbonate alkalinity reported as calcium carbonate, Ca = calcium, Cl = chloride, Aug-10 10.62 1,614.27 Cond = conductivity, K = potassium, Mg = magnesium, mg/L = milligrams per liter, Na = sodium, ND = not detected

Sep-10 10.82 1,614.07 above laboratory method report limit, NH 3-N = ammonia-nitrogen, NO 3-N+NO 2-N = nitrate+nitrite-nitrogen,

Oct-10 10.94 1,613.95 P = phosphorus, pH = negative log of the hydrogen ion concentration, SO 4 = sulfate, s.u. = standard units, Nov-10 10.33 1,614.56 TDS = total dissolved solids, TKN = total Kjeldahl nitrogen, µmhos/cm = micromhos per centimeter. Dec-10 8.23 1,616.66 Jan-11 5.63 1,619.26 Feb-11 6.09 1,618.80 Mar-11 5.03 1,619.86 Apr-11 5.50 1,619.39 2nd Q, '11 5.62 1,619.27 3rd Q, '11 8.43 1,616.46 4th Q, '11 10.66 1,614.23 1st Q, '12 7.34 1,617.55 2nd Q, '12 6.33 1,618.56 3rd Q, '12 9.58 1,615.31 4th Q, '12 9.90 1,614.99 1st Q, '13 4.92 1,619.97 2nd Q, '13 7.32 1,617.57 3rd Q, '13 9.79 1,615.10 4th Q, '13 10.03 1,614.86 1st Q, '14 7.55 1,617.34 2nd Q, '14 7.00 1,617.89 3rd Q, '14 10.41 1,614.48 4th Q, '14 11.02 1,613.87 1st Q, '15 6.50 1,618.39 2nd Q, '15 8.67 1,616.22 3rd Q, '15 11.52 1,613.37 4th Q, '15 11.90 1,612.99 1st Q, '16 7.64 1,617.25 2nd Q, '16 7.77 1,617.12 3rd Q, '16 10.89 1,614.00 4th Q, '16 10.12 1,614.77 1st Q, '17 4.25 1,620.64 2nd Q, '17 6.24 1,618.65 3rd Q, '17 9.30 1,615.59 4th Q, '17 9.78 1,615.11

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App J GW Data October 2018 (Revised February 2019) | Page 18 of 2

Appendix K.

Groundwater Quality Charts

Chart 1. West Area Groundwater Chloride

MW 11A Upgradient MW 12A Upgradient MW 35 Downgradient MW 36 Downgradient

450

400

350

300

250

200

150

100

50

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch1 W Cl October 2018 (Revised February 2019) | Page 1 of 1 Chart 2. West Area Groundwater NO3+NO2 - N

MW 11A Upgradient MW 12A Upgradient MW 35 Downgradient MW 36 Downgradient

14

12

10

8

6 milligrams milligrams per liter

4

2

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch2 W NO3+NO2-N October 2018 (Revised February 2019) | Page 2 of 12 Chart 3. West Area Groundwater NH3 -N

MW 11A Upgradient MW 12A Upgradient MW 35 Downgradient MW 36 Downgradient

0.25

0.20

0.15

0.10 milligrams milligrams per liter

0.05

0.00

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch3 W NH3-N October 2018 (Revised February 2019) | Page 3 of 12 Chart 4. West Area Groundwater Sulfate

MW 11A Upgradient MW 12A Upgradient MW 35 Downgradient MW 36 Downgradient

250

200

150

100 milligrams milligrams per liter

50

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch4 W SO4 October 2018 (Revised February 2019) | Page 4 of 12 Chart 5. West Area Groundwater Total Dissolved Solids

MW 11A MW 12A MW 35 MW 36

1,200

1,000

800

600 milligrams milligrams per liter

400

200

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch5 W TDS October 2018 (Revised February 2019) | Page 5 of 12 Chart 6. West Area Groundwater Sodium

MW 11A MW 12A MW 35 MW 36

160

140

120

100

80

milligrams milligrams per liter 60

40

20

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch6 W Na October 2018 (Revised February 2019) | Page 6 of 12 Chart 7. South Area Groundwater Chloride

MW 7A Downgradient MW 8A Upgradient MW 37 Upgradient MW 38 Downgradient

450

400

350

300

250

200 milligrams milligrams per liter

150

100

50

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch7 S Cl October 2018 (Revised February 2019) | Page 7 of 12 Chart 8. South Area Groundwater NO3+NO2 -N

MW 7A Downgradient MW 8A Upgradient MW 37 Upgradient MW 38 Downgradient

7

6

5

4

3 milligrams milligrams per liter

2

1

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch8 S NO3+NO2-N October 2018 (Revised February 2019) | Page 8 of 12 Chart 9. South Area Groundwater NH3 -N

MW 7A Downgradient MW 8A Upgradient MW 37 Upgradient MW 38 Downgradient

1

1

0

0 milligrams milligrams per liter

0

0

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch9 S NH3-N October 2018 (Revised February 2019) | Page 9 of 12 Chart 10. South Area Groundwater Sulfate

MW 7A Downgradient MW 8A Upgradient MW 37 Upgradient MW 38 Downgradient

600

500

400

300 milligrams milligrams per liter

200

100

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch10 S SO4 October 2018 (Revised February 2019) | Page 10 of 12 Chart 11. South Area Groundwater Total Dissolved Solids

MW 7A MW 8A MW 37 MW 38

2,000

1,800

1,600

1,400

1,200

1,000

800 milligrams milligrams per liter

600

400

200

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch11 S TDS October 2018 (Revised February 2019) | Page 11 of 12 Chart 12. South Area Groundwater Sodium

MW 7A MW 8A MW 37 MW 38

250

200

150

100 milligrams milligrams per liter

50

0

Quarter

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Apps J-K.xlsx | App K Ch12 S Na October 2018 (Revised February 2019) | Page 12 of 12

Appendix L.

Example Water Balance Calculations

Appendix L1. Example Water Balance Calculations - Field 1

Field: 1 Acres: 66 Soil Water Holding Capacity: 6 24.1 7 Crop: Alfalfa Rooting Depth: 60 Initial Soil Water Content: 15.8 5 1 Blended Water Total Evapotranspiration Soil Water 9 Month ppt 4 8 Surplus Gross 2 Net 3 Input Potential Estimated Content October 2.1 0.0 0.0 1.9 2.0 1.3 16.4 0.0 November 2.8 0.0 0.0 2.5 0.7 0.4 18.5 0.0 December 2.9 0.0 0.0 1.7 0.3 0.2 20.0 0.0 January 2.2 0.0 0.0 1.3 0.5 0.4 21.0 0.0 February 1.9 0.0 0.0 1.1 0.9 0.7 21.4 0.0 March 3.0 0.0 0.0 2.4 2.1 1.6 22.3 0.0 April 1.7 0.0 0.0 1.3 3.6 2.7 20.9 0.0 May 1.3 0.0 0.0 0.9 5.4 4.0 17.8 0.0 June 1.7 1.2 0.8 2.0 5.9 4.2 15.6 0.0 July 0.4 6.0 4.2 4.5 7.7 5.1 15.0 0.0 August 0.2 5.2 3.7 3.8 6.8 4.5 14.4 0.0 September 0.7 5.3 3.7 4.3 4.5 2.9 15.8 0.0 Total 21.0 17.8 12.4 27.9 40.3 28.0 0.0 Leaching Fraction 10 0.0% 11 NOTES: Leaching Requirement 10.6% All units in inches unless otherwise noted. 1 Precipitation (ppt) data are 10 year averages from the US Bureau of Reclamation AgriMet System for the Chamokane (CHAW) weather station south of Springdale, Washington. 2 Gross water application delivered to the irrigation system discharge point (e.g. sprinkler heads). 3 Net irrigation is gross irrigation multiplied by an estimated irrigation efficiency for May 80% and Jun-Sep 70%. 4 Total input is net irrigation plus effective ppt estimated for Oct-Nov 90%; Dec-Feb 60% due to frozen soils; Apr, May, Sep 80%, and Jun-Aug 70%. 5 Potential evapotranspiration (ET) rates for alfalfa are from the US Bureau of Reclamation AgriMet system for the Chamokane (CHAW) weather station south of Springdale, Washington. Estimated ET is the Potential ET * (previous month's Soil Water Content / Soil Water Holding Capacity) * a variable exponent to further adjust ET values to calibrate the calculated soil moisture levels similar to previously measured soil moisture levels. 6 Soil water holding capacity based on soil characterization data collected November 11, 2009 and calculated using the method developed by Saxton (1986). 7 Initial soil water content is an average of the measured soil moisture values collected approximately mid september 2012, 2013 2014, 2015 and 2016 and adjusted to account for crop ET (moisture uptake/removal) and projected precipitation (input) during the last half of September and all of October. 8 Soil water content (at month end) = the previous month's soil water content + total water input - ET estimated; cannot exceed soil water holding capacity. 9 Surplus is the soil moisture in excess of the soil water holding capacity which percolates beyond the root zone. Not necessarily in excess of leaching requirement. 10 Leaching fraction = percent of gross input estimated to percolate beyond root zone = total surplus / total precipitation + gross application. 11 Leaching requirement = the percentage of surplus required to move beyond the root zone to manage soil salts to levels that do not impede crop productivity.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App L1 Fd1 October 2018 (Revised February 2019) Appendix L2. Example Water Balance Calculations - Field 2

Field: 2 Acres: 49 Soil Water Holding Capacity: 6 20.1 7 Crop: Alfalfa Rooting Depth: 60 Initial Soil Water Content: 16.8 5 1 Blended Water Total Evapotranspiration Soil Water 9 Month ppt 4 8 Surplus Gross 2 Net 3 Input Potential Estimated Content October 2.1 0.0 0.0 1.9 2.0 1.2 17.5 0.0 November 2.8 0.0 0.0 2.5 0.7 0.4 19.6 0.0 December 2.9 0.0 0.0 1.7 0.3 0.2 20.1 1.1 January 2.2 0.0 0.0 1.3 0.5 0.3 20.1 1.0 February 1.9 0.0 0.0 1.1 0.9 0.6 20.1 0.5 March 3.0 0.0 0.0 2.4 2.1 1.3 20.1 1.1 April 1.7 0.0 0.0 1.3 3.6 2.3 19.0 0.0 May 1.3 0.0 0.0 0.9 5.4 3.4 16.6 0.0 June 1.7 1.2 0.8 2.0 5.9 3.6 15.0 0.0 July 0.4 6.0 4.2 4.5 7.7 4.4 15.1 0.0 August 0.2 5.3 3.7 3.9 6.8 3.9 15.1 0.0 September 0.7 5.3 3.7 4.2 4.5 2.6 16.8 0.0 Total 21.0 17.8 12.5 28.0 40.3 24.3 3.7 Leaching Fraction 10 9.6% 11 NOTES: Leaching Requirement 10.6% All units in inches unless otherwise noted. 1 Precipitation (ppt) data are 10 year averages from the US Bureau of Reclamation AgriMet System for the Chamokane (CHAW) weather station south of Springdale, Washington. 2 Gross water application delivered to the irrigation system discharge point (e.g. sprinkler heads). 3 Net irrigation is gross irrigation multiplied by an estimated irrigation efficiency for May 80% and Jun-Sep 70%. 4 Total input is net irrigation plus effective ppt estimated for Oct-Nov 90%; Dec-Feb 60% due to frozen soils; Apr, May, Sep 80%, and Jun-Aug 70%. 5 Potential evapotranspiration (ET) rates for alfalfa are from the US Bureau of Reclamation AgriMet system for the Chamokane (CHAW) weather station south of Springdale, Washington. Estimated ET is the Potential ET * (previous month's Soil Water Content / Soil Water Holding Capacity) * a variable exponent to further adjust ET values to calibrate the calculated soil moisture levels similar to previously measured soil moisture levels. 6 Soil water holding capacity based on soil characterization data collected November 11, 2009 and calculated using the method developed by Saxton (1986). 7 Initial soil water content is an average of the measured soil moisture values collected approximately mid september 2012, 2013 2014, 2015 and 2016 and adjusted to account for crop ET (moisture uptake/removal) and projected precipitation (input) during the last half of September and all of October. 8 Soil water content (at month end) = the previous month's soil water content + total water input - ET estimated; cannot exceed soil water holding capacity. 9 Surplus is the soil moisture in excess of the soil water holding capacity which percolates beyond the root zone. Not necessarily in excess of leaching requirement. 10 Leaching fraction = percent of gross input estimated to percolate beyond root zone = total surplus / total precipitation + gross application. 11 Leaching requirement = the percentage of surplus required to move beyond the root zone to manage soil salts to levels that do not impede crop productivity.

CES - Spokane Valley, WA NWA - Addy, WA | Eng Rpt Doc: 2017220017 NWA Eng Rpt Tbls and Apps.xlsx | App L2 Fd2 October 2018 (Revised February 2019)