Preliminary Assessment Sportsmen’s Club Quarry 13050 SW Tonquin Road Sherwood, Washington County, SEMS No. ORN001010130

June 30, 2020

Site Assessment Section 700 NE Multnomah St., Suite 600 Portland, OR 97213 Phone: 503-229-5069 800-304-3513 Fax: 503-229-6124 Contact: Ray Hoy www.oregon.gov/DEQ

DEQ is a leader in restoring, maintaining and enhancing the quality of Oregon’s air, land and water.

Oregon Department of Environmental Quality

Report Preparation & Distribution

This report was prepared by:

Ray Hoy Oregon Department of Environmental Quality 700 NE Multnomah St., Suite 600 Portland, OR 97213 503-229-5069 [email protected]

This report was prepared for:

Ken Marcy US Environmental Protection Agency, Region 10 805 SW Broadway, Suite 500 Portland, OR 97205

Documents can be provided upon request in an alternate format for individuals with disabilities or in a language other than English for people with limited English skills. To request a document in another format or language, call DEQ in Portland at 503-229-5696, or toll-free in Oregon at 1-800-452-4011, ext. 5696; or email [email protected].

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Table of Contents

1. Introduction ...... 1 2. Site Description, Operational History, and Waste Characteristics ...... 2 2.1 Project Location ...... 2 2.2 Site Description and Current Use ...... 2 2.3 Site Ownership History ...... 3 2.4 Site Operations, Waste Characteristics, and Source Areas ...... 4 2.5 Previous Investigations ...... 4 2.6 Site Visit ...... 4 3. Ground WaterSampling ...... 5 3.1 Sample Collection Methods and Rationale ...... 6 3.2 Laboratory Analytical Methods ...... 6 3.3 Analytical Results and Risk-Based Screening ...... 7 4. Ground water Migration Pathway ...... 8 4.1 Geology ...... 8 4.2 Hydrogeology & Aquifers ...... 8 4.3 Ground water Targets ...... 8 4.3.1 Community Water Systems Information ...... 9 4.3.2 Domestic Well Information ...... 9 4.3.3 Ground water Resources ...... 9 4.4 Ground water Conclusions...... 9 5. Surface Water Pathway ...... 10 5.1 Area Setting ...... 10 5.2 Surface Water Conclusions ...... 10 6. Soil Exposure Pathway ...... 11 6.1 Physical Conditions ...... 11 6.2 Soil Targets ...... 11 6.3 Soil Exposure Pathway Conclusions ...... 11 7. Air Migration Pathway ...... 12 7.1 Likelihood of a Release ...... 12 7.2 Air Targets ...... 12 7.3 Air Migration Pathway Conclusions ...... 12 8. Summary and Conclusions ...... 13 9. References ...... 13

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FIGURES Figure 1 – Site Location Map Figure 2 – Site with Neighboring Properties Figure 3 – Ground Water Wells Location Map Figure 4 – Site Radial Distance Map Figure 5 – Wetlands Acreage Summary Map

TABLES Table 1 – Ground water Data Table 2 – Water Well and Ground Water Drinking Water Population Summary Table 3 – Population Summary Table 4 – Summary of Threatened and Endangered Species Table 5 –Wetlands Acreage Summary

APPENDICES Appendix A – Site Visit Photographs Appendix B – Aerial Images Appendix C – Piezometer Well Logs, Ground water Report & Lab Results Appendix D – Well Logs Appendix E – IPAC Species Lists

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Ave. Avenue bgs Below ground surface cfs Cubic feet per second DEQ Oregon Department of Environmental Quality DWP Drinking Water Program ECSI Environmental Cleanup Site Identification EPA Environmental Protection Agency EROS Earth Resources and Observation Science ID Identification IPAC Information for Planning and Consultation N North NW Northwest NOAA National Oceanic and Atmospheric Administration ODF&W Oregon Department of Fish & Wildlife ODHS Oregon Department of Human Services OR Oregon OWRD Oregon Water Resource Department PAHs Polycyclic aromatic hydrocarbons PCBs Polychlorinated biphenyl POD Point of diversion PPE Probable point of entry PWS Public Water System RCRA Resource Conservation and Recovery Act SE Southeast SEMS Superfund Enterprise Management System St. Street SVOC Semi-volatile organic compounds SW Southwest TDL Target distance limit TCGC Tri-County Gun Club TVSC Tualatin Valley Sportsmen’s Club US United States USDA United States Department of Agriculture VOCs Volatile organic compounds

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1. Introduction Pursuant to a Cooperative Agreement (V-96089704-0) between the Environmental Protection Agency (EPA) and the Oregon Department of Environmental Quality (DEQ), the DEQ conducted a Preliminary Assessment at Tualatin Valley Sportsmen’s Club (TVSC) located at 13050 SW Tonquin Road in Sherwood, Oregon (Site).

Preliminary Assessments are intended generally to identify potential hazards at a site, identify sites that require immediate action, and to establish priorities for sites requiring in-depth investigations. The Preliminary Assessment is based on readily available information about the Site and is not a full investigation or characterization of the Site. Additionally, the information identified during a Preliminary Assessment is used to:

• Determine the potential threat to public health or the environment posed by the site; • Determine the potential for a release of hazardous constituents into the environment; and • Determine the potential for placement of the site on the National Priorities List.

The TVSC Preliminary Assessment was conducted to identify potential public health and environmental threats related to the portion of the site known as the quarry pit. The Preliminary Assessment is based on data derived from the sources listed in the reference section of this report. The scope of the investigation includes review of available file information, interviews, a comprehensive target survey, and a review of ground water sampling data.

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2. Site Description, Operational History, and Waste Characteristics The TVSC site has operated as a gun range since at least 1944. A site location map is included as Figure 1.

2.1 Project Location Site Name: Tualatin Valley Sportsmen’s Club SEMS No.: ORN (To Be Determined) Site Address: 13050 SW Tonquin Road, Sherwood, OR 97140 County: Washington County Congressional District: Oregon’s 3rd District Latitude: 45.355780 North decimal degrees Longitude: -122.813526 West decimal degrees Legal Description: Washington County, Tax Lots 100, 402, 700, 800 Township 2 South, Range 1 West, Section 33, Willamette Meridian

Site Owner: Tualatin Valley Sportsmen’s Club Site Contact: President Craig Hopkins (503) 822-5413

Site Operator: George Pitts 13050 SW Tonquin Road, Sherwood, OR 97140 (503) 822-5413

Directions to site: The site is located on the west side of Interstate 5. From Interstate 5, follow Lower Boones Ferry Road, left on SW Day Road, right on Graham’s Ferry, left on SW Tonquin Road to the Site.

2.2 Site Description and Current Use

TVSC was established in 1944 and is located at 13050 SW Tonquin Road in Sherwood, Oregon collectively known as the “site” or “TVSC” (Figure 1). The property consists of Tax Lots 100, 402, 700, and 800 of Washington County Assessor’s Tax Map 2S1 33. The site consists of approximately 220 acres, and is located along SW Tonquin Road near SW Oregon Street between the cities of Sherwood and Tualatin. TVSC is a non-profit organization for firearms training. The site is also sometimes referred to as the Tri-County Gun Club (TCGC), which is the name of an entity which leases the property (1). The site lies in a semi-industrial-use and natural area. The TVSC property is zoned EFC, “Exclusive Forest and Conservation District” and is intended to provide for forest uses and to provide for the continued use of lands for renewable forest resource production, retention of water resources, recreation, agriculture and other related or compatible uses, as set forth in Statewide Planning Goal 4, OAR 660-006 and ORS 215 (2).

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The topography is relatively flat in areas but has areas with variable terrain. The site’s elevation is 41 feet above mean sea level. The site is located in the flood plain and not near any natural surface water bodies. The site lies between Tualatin Sherwood Highway and west of Interstate- 5. Washington County records indicate there are five multi-purpose buildings, a multi-purpose shed, and 6 gazebos on the property (Figure 2). Construction dates for the buildings were not available. The rest of the property consists of five gun ranges surrounded mostly by natural areas. There is one entrance to the property accessed from SW Tonquin Road in the SW corner of the property.

The property is currently leased to the Tri County Gun Club, and is an active shooting range. The TCGC is a membership-only club and many local law enforcement officers are members that use the range as a training facility. A total of five firing ranges are located in the eastern portion of the property as shown in Figure 2.

The quarry pit is the focus of this preliminary assessment because of the potential for a contaminant migration pathway to ground water. In 2016, TVSC began to fill the quarry pit with imported fill material that ceased after a complaint was made to Washington County Permitting. A complaint was reported to DEQ on February 24, 2018 which cited concerns for ground water contamination by the unknown origins of imported fill material (3). This evaluation included the quarry pit only. The shooting ranges are a source of potential heavy metal contamination to soil backstops, however the shooting ranges have been following EPA Best Management Practices as recommended by EPA in 200. The site was given a “no further action determination” by DEQ in 2003 citing precipitation infiltrates storm water at the site, no surface water drainages leave the site, and DEQ’s investigation of the pipline release was satisfactory. Background and historical information regarding shooting ranges is provided in this report to provide context for the site and the ongoing shooting range operations.

The quarry pit has been a feature at the site since some time in the 90’s as displayed on an aerial image from 1990 showing forested land at the location of the quarry pit. In 1996, an image shows excavation activities beginning at the quarry pit (Appendix B). The quarry pit has an area of approximately 28 acres. The features of the quarry pit include a conglomeration of artificially created surface water bodies separated by topographic ridges as a result from years of excavation activities. One dirt road was created in the SE corner of the property to access the quarry pit (Figure 2). Ground water flow is a south east to north westerly direction. Currently, TVSC, is filling the quarry pit with imported soil under guidance from DEQ Solid Waste.

2.3 Site Ownership History TVSC has owned the 220-acre property and established itself as a gun range in 1944. TVSC registered as a non-profit establishment with the State in 1988 (4). According to Oregon Corporate Division Records, TVSC has been in continuous operation from 1948 through 2020 and continues the shooting range operation today. Mr. George Pitts is the Public Information Officer for TVSC and Craig Hopkins is the President of TVSC. The site is believed to have been used for timber management and agriculture prior to development of the firearm training facility (5).

Aerial Photographs were obtained from the University of Oregon from 1990 to 2000, from the US Geological Survey from 2002 to 2012 and Google Earth was used to obtain 2014, 2016, and 2019 aerial photographs (Appendix B).

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2.4 Site Operations, Waste Characteristics, and Source Areas The TVSC site is currently and has been used as a gun range since 1944. The TGGC operates a variety of firing ranges, including known-distance rifle ranges, pistol ranges, a black powder range, and skeet- and trap-shooting ranges. The site has been established as a training facility for local law enforcement (1). According to information obtained by the former vice president of the TVGC, the TVSC used the site as a gravel mining operation over the past two decades (3). Aerial images dating back to 1996-2012 display excavation activities in the western part of the site (Appendix B). Information was received which indicated excavation activities breached the water table which caused the quarry pit to fill with ground water. Photos of fill material that were placed in the quarry pit documented construction debris waste such as 2x4 wood fragments, PVC pipe, and other construction materials in the fill (Appendix A).

The contaminants of interest (COIs) for the site in general are heavy metals, which include copper and lead. Gun and rifle shooting is known to discharge lead shot, and copper shells as remnants of firing ammunition. The source area of concern is the quarry pit, located on the west-side of the property. The quarry pit was created from over a decade of mining rock at the site. Because imported soil was previously placed in the quarry pit without a soil assessment or soil management plan, there is a concern that solid waste materials are present in soil, and there is a potential for soil placed in the quarry pit originating from other locations at the gun range. The quarry pit is a vulnerable area of concern due to the potential pathway to ground water at this location.

2.5 Previous Investigations In 2002, a strategy recommendation was completed by DEQ which highlighted whether shooting range backstops are being appropriately managed and whether the 1999 Kinder Morgan pipeline release was appropriately cleaned up as reasons for recommending further investigation.

In 2003, the DEQ issued a No Further Action Determination to TVSC based on the review of an Expanded Preliminary Assessment Report, submitted by AMEC on behalf of TVSC, 2003 (7). The report cited Best Management Practices for cleaning up metals at range backstops following EPA guidelines, infiltration of storm water and no surface water drainages that leave the site with potential to impact Rock Creek, and a Kinder Morgan Pipeline release in 1999 concluded by DEQ that no further action was necessary to address environmental impacts from the release.

The reports referenced above may be accessed and viewed from DEQ’s Environmental Cleanup Site Information (ECSI) database at www.deq.state.or.us/lq/ecsi/ecsiquery.asp (Search Site ID 3050).

2.6 Site Visit A site visit was conducted by DEQ, in November 2019, to evaluate the conditions at the site, in particular to make observations on the quarry pit and to assess the locations of the monitoring wells. Monitoring wells were installed in 2016 to support future land use and engineering design of the future Lower Range Complex (LRC) (Figure 2). Photos from the site visit are included in Appendix A. DEQ met with Wood Environment & Infrastructure Solutions, Inc. Consultants (Wood Consultants) at the site and carefully observed areas surrounding the quarry pit for specific signs that would relate to burial of

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solid waste such as construction debris, land clearing debris and domestic garbage. These signs included:

 Odors (hydrogen sulfide and methane)  Bubbling of gas through standing water, or hissing of gas from cracks in the soil  Staining and discolored seeps from the backfill  Visual siting of waste materials in the backfill

DEQ observed some scattered woody debris but the amounts were minimal and not environmentally significant. DEQ did not observe any of the other signs that suggested solid waste was a part of the imported fill that was already placed. DEQ was provided a tour of the locations of the four piezometers and was made aware that one of the piezometers (Piezo No. 2) was installed within the backfill of the quarry pit (Figure 3). DEQ also learned that the Gun Club works with DEQ on Environmental stewardship and management of lead shot. DEQ requested Wood Consultants provide the following information:

 Drilling logs and construction details for the four on-site piezometers.  Methane, CO2 and O2 levels at Piezo No. 2 (1.e., perform gas testing at this piezometer constructed within backfill).

3. Ground Water Sampling Event

TVSC performed a ground water sampling event in May 2019 to further evaluate the quarry pit and soil fill (8). Ground water was evaluated to determine if contamination was present.

The TVSC has been engaged in ongoing development of its property. Future development plans include placement of multiple firing ranges within the quarry pit area at the future LRC.

In early 2017, TVSC applied for a grading and construction permit through Washington County to develop the multiple firing ranges in the LRC area of the quarry pit. Washington County’s land use decision required a conditional permit approval that states “any future land use application submittal shall include documentation from the Oregon Department of Environmental Quality, Water Quality Division, confirming that no ground water contamination exists at the TVSC site”, in particular, at the of the future LRC. In addition, the DEQ submitted a letter to TVSC in March 2019 requesting the collection of ground water sampling data around quarry pit. In early May 2019, Wood Consultants, on behalf of TVSC, reached out to DEQ to establish what ground water parameters would be necessary for the DEQ to make a determination and provide documentation to Washington County regarding the land use approval condition that no ground water contamination exists. Per email correspondence on May 6, 2019 between Wood and DEQ, the following water quality parameters and analytical testing was agreed to:

• Volatile organic compounds (VOCs); • Polycyclic aromatic hydrocarbons (PAHs); • Resource Conservation and Recovery Act (RCRA) 8 metals as well as copper, zinc; and dissolved lead.

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DEQ requested TVSC screen the anlaytical results against the DEQ’s residential risk based concentrations (RBCs) for ground water ingestion and inhalation from tap water pathway.

3.1 Sample Collection Methods and Rationale Wood Consultants developed the Sampling and Analysis Plan (SAP), which included collecting ground water samples from the existing piezometers PZ-01 through PZ-04 (Figure 3). DEQ and TVSC agreed that an initial ground water sampling event would be performed to determine if additions sampling events were needed. Four ground water samples were collected in May 2019 after the piezometers were developed.

3.1.1 Piezometer Development Piezometers PZ-01 through PZ-04 were installed in 2016 by an Oregon-licensed drilling contractor at locations shown on Figure 3. The piezometers were installed to support future land use, and engineering design of the LRC. They were constructed in accordance with the Oregon Water Resources Department (OWRD), Chapter 690, Division 240 well construction standards. The purpose of the piezometers was to enable measuring ground water level elevations to evaluate how high water levels observed in early 2016 inside the LRC may relate to ground water. The piezometers were developed in 2016 by the drilling subcontractor and Wood Consultants. Additional development was performed by Wood Consultants in May 2019, to improve the ability the piezometers to provide ground water quality data representative of surrounding aquifer conditions. Wood Consultants developed the piezometers using a combination of bailing, surging and pumping. Bailing and surging were performed until the suspended sediment in the bailed water was minimal and the turbidity had decreased. Pumping was performed using an electric submersible pump suspended at five-foot depth intervals within the screen interval. Field parameters were monitored during pumping to establish stability and when to stop development (8).

3.1.2 Ground water Sampling Low flow sampling using bladder pumps was performed to obtain low-turbidity samples and to decrease potential colloidal influence on sample results. A new, clean single-use bladder and dedicated tubing were used at each piezometer. Drawdown of approximately 0.33 feet or less was maintained during pumping and field parameters were measured to evaluate stability. Samples were obtained after a minimum of one system volume (pump bladder and tubing) was removed and after field parameters had stabilized. The samples were collected in laboratory-supplied containers and submitted to the laboratory for analysis following chain-of custody procedures.

3.2 Analytical Methods Sample analysis was performed by Apex Laboratories of Tigard, Oregon. Apex Laboratories has been certified by the Oregon Environmental Laboratory Accreditation Program. The samples were analysed for VOCs using EPA Method 8260C Selected Ion Screening (SIM), PAHs using EPA Method 8270D SIM, and total and dissolved metals using EPA Method 6020A. Apex was able to achieve reporting limits below the DEQ RBCs for all analytes except the following VOCs: acrylonitrile, bromodichloromethane, carbon tetrachloride, 1,2-dibromoethane (EBD), and 1,4-dichlorobenzene.

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Quality control (QC) samples were also collected to evaluate field sampling and laboratory methods. The QC samples consisted of an equipment blank, duplicate, trip blank, and a matrix spike/matrix spike duplicate pair. Analytical results are summarized on Table 1. Analytical reports are included in Appendix C.

3.3 Analytical Results and Risk-Based Screening Detected ground water concentrations were compared to DEQ’s residential RBCs for the ground water ingestion and inhalation from tap water pathway (9). Analytical results are summarized below presented in micrograms per liter (ug/L) and in Table 1.

• VOCs: Acetone at 15.6 ug/L in PZ-02 • PAHs: Acenahthene at 0.0203 ug/L in PZ-02 Dibenzofuran at 0.0130 ug/L in PZ-02 Fluoranthene at 0.0169 ug/L in PZ-02 Flourene at 0.0205 ug/L in PZ-02 • RCRA 8 metals as well as copper, zinc, and dissolved lead:

Arsenic at 2.07 ug/L in PZ-02 Barium at 47.1ug/L in PZ-01, at 76.7 ug/L in PZ-02, 28.3 ug/L in PZ-03, at 23.8 ug/L in PZ-04 Cadmium at 0.0649J ug/L in PZ-01, at 0.0700J ug/L in PZ-04 Lead at 0.471 ug/L in PZ-02, at 0.128J ug/L in PZ-02, at 0.546 ug/L in PZ-03 Lead (dissolved) at 0.101J ug/L in PZ-01 Copper at 1.27 ug/L in PZ-01, 0.661J ug/L in PZ-02, 0.950J ug/L in PZ-03, 2.11 ug/L in PZ-02 Zinc at 6.11 ug/L in PZ-01, 3.36J ug/L in PZ-02

Ground water analytical results were compared to RBCs for ground water via ingestion and inhalation from tap water. Arsenic exceeded the RBC of 0.052 ug/L in one ground water sample but the concentration is less than the Federal Maximum Contaminant Level (MCL) for drinking water of 10 ug/L.

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4. Ground water Migration Pathway The ground water pathway evaluates the potential for contamination to have migrated to ground water and the potential impact to identified receptors. The target area for the ground water migration pathway is a four-mile radius extending from the quarry source at the TVSC Site. The four-mile site radius is shown on Figure 4.

4.1 Geology The TVSC is located in the Basin. The TVSC is located in the portion of this Basin that is bound by the Tualatin Mountains to the west, the to the north, the foothills of the Cascade Range to the east, and the Willamette River to the south.

The geology within the Tualatin Valley is fine to coarse grained flood sediments. Fine alluvium were deposited by the Missoula Floods approximately 21,000 to 12,000 years ago into the Tualatin Valley at depths from 65 up to 115 feet thick. The fine alluvium overlies the Missoula Flood deposits in the Tualatin River floodplain. The entire area is underlain by the basalts of the Columbia River Basalt Group, which erupted 14 to 16 million years ago from fissure volcanoes near the border of Idaho. Bedrock is exposed at Bull Mountain, north of the site, and Pleasant Hill, south of the site (11).

Basalt outcrops cover a substantial portion of the site. Site soils are mostly mapped as Xerochrepts-Rock outcrop complex with smaller areas of Laurelwood silt loam, Saum silt loam, and Briedwell stony loam. These soils generally have medium acidity (pH of 5.6 to 6.0) and contain 2 to 4 percent organic carbon in their thin upper horizons. Deeper horizons of the Laurelwood soils are strongly acidic (pH 5.4). Soils along the South Rock Creek floodplain and Coffee Lake Creek headwaters are hydric (wetlands) soils, and include Cove clay and Cove silty clay loam, Labish mucky clay, and smaller areas of Wapato silty clay loam. These soils generally have slight to medium acidity (pH 5.5 to 6.2), with 4 to 8 percent organic carbon in their upper horizons. Lower horizons of the Labish soils are very strongly acid (pH 4.6), however. Well logs from both on- and off-site wells indicate that much of the local basalt is fractured (12).

4.2 Hydrogeology & Aquifers Based on local topography and the location relative to the Rock Creek, ground water flow appears to be NW. Well logs on file with the OWRD indicate a shallow ground water aquifer with seasonal variation from 15 to 30 feet below ground surface (bgs) and a deeper aquifer 75 to 200 feet bgs (13). The geomorphology of the South Rock Creek basin near TVSC indicates portions of the area serve as recharge zones for a local basalt aquifer. Well logs from both on- and off-site wells indicate that much of the local basalt is fractured. Copies of the TVSC well and boring logs are included in Appendix C.

The Sherwood Fault, which originates southwest of the site, between Parrett Mountain and the remainder of the Chehalem Mountains, is believed to cross the northwest corner of the site, southwest to northeast. The fault likely causes discontinuities in the local basalt aquifer, although its overall effect on local ground water flow remains unclear (12).

4.3 Ground water Targets

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A search of the OWRD’s well log query database was completed for a 4 mile radius of the Site in order to identify the location of domestic or community water wells. In addition, the Oregon Department of Human Services’ (ODHS) Drinking Water Program (DWP) database was searched for information on community water systems (15). The radial distance of domestic, community, and municipal wells from the Site are presented on Table 2. This table also includes the secondary target population data for people served by wells at various distances from the Site. The 4 mile radial distance of the Site is shown on Figure 4.

4.3.1 Community Water Systems Information Two community water systems utilizing ground water were identified within a 4 mile radius of the site. Community water systems located in Oregon are regulated by the Oregon Health Authority Drinking Water Program and must have 15 or more service connections used by year-round residents or regularly supply drinking water to 25 or more year-round residents. The nearest designated Public Water Supply well is a City of Sherwood municipal well, located about 2 miles east of the site. The next closest community well is a City of Wilsonville municipal well located approximately 4 miles south of the site.

4.3.2 Domestic Well Information The nearest active domestic water supply well is a 320 foot deep well located on the TVSC site (Appendix E). This well is cased to 20 feet bgs. There are 5 other water wells located at the site according to the OWRD well database, however, only one is listed as being used by the site according to Wood Consultants (6).

4.3.3 Ground water Resources In addition to its apparent use for drinking-water purposes, ground water is used for industrial and irrigation purposes within the 4 mile radius (10).

4.4 Ground water Conclusions Shallow ground water was encountered at 15 feet bgs during a 2019 site investigation. Deeper ground water has a beneficial use as drinking water. Ground water from the site likely poses a low risk to current ground water targets. Ground water may recharge Rock Creek (3500 feet west of the Site) or wetlands within 1000 feet north and east of the Site. The on-site domestic well is up-gradient from the quarry pit. DEQ did not identify any primary targets. The limited ground water investigation concluded there are currently no impacts to ground water at the site.

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5. Surface Water Pathway The surface water pathway evaluates the potential for contamination to have migrated to surface water and the potential impacts to identified receptors. The quarry pit, contains surface water which was artificially created due to the mining operation breaching the water table. Therefore, the site does not have any natural surface water bodies on the property and the surface water pathway was not evaluated.

5.1 Area Setting The quarry pit contains approximately 4 to16 acres of water depending on the season. The quarry pit is currently being filled with soil for the development of the LRC (6). Because the banks of the quarry pit are steep due, surface water does not leave the quarry pit via overland flow or storm water. The nearest surface water is Rock Creek located 3500 feet to the east, and the Tualatin River approximately 4 miles to the North.

The Site is located in the South Rock Creek Watershed Basin (SRCWB) which supports a variety of land uses and fish and wildlife habitats. The SRCWB is part of the Tualatin River watershed basin which drains 712 square miles and includes both agricultural, urban, industrial, and natural areas (11). The area immediately surrounding the Site includes a mix of industrial properties mixed with natural spaces. Tualatin River National Wildlife Refuge is 2 miles to the northeast of the Site.

The area is temperate, receiving approximately 42.54 inches of precipitation annually. The average temperature is 63 degrees Fahrenheit (14). The 2-year, 24 hour precipitation event is 2.87 inches. The Site is located outside the 500-year flood plain (Zone X) and the 100-year flood plain (11).

5.2 Surface Water Conclusions Because no natural surface water bodies exist, the quarry pit does not pose a surface water pathway risk to surface water targets. The quarry pit is an artificially created surface water body that is currently being filled with soil for future redevelopment.

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6. Soil Exposure Pathway The soil exposure pathway evaluates the potential for contamination located in surface and subsurface soils onsite the quarry pit and the potential to impact identified receptors. There is no evidence that suggested that soil was impacted at the quarry pit.

6.1 Physical Conditions The TVSC property is covered by a variety of surfaces including soil, asphalt, natural areas (grass, vegetation, trees), and shooting range structures. Site photographs are included in Appendix A. The Site is an active shooting range which primarily is an open space with facilities to support training activities. Approximately 10% of the land area is covered by shooting ranges, 15% covers the quarry pit, with the rest of the property being undeveloped and natural land.

6.2 Soil Targets Land use in the vicinity of the site is zoned industrial but large swaths of natural open space surround the area. There are no residences, schools, or daycares within 4000 feet of the site. The closest residence is located 0.7 miles east of the quarry pit. There are no daycares or schools within 0.25 mile to 0.5 mile, no daycares or schools within 0.5 mile and 1.0 mile, 6 daycares and 5 schools are present within 1.0 mile to 2.0 miles, 10 daycares and 13 schools are present within 2.0 to 3.0 miles, and 11 daycares and 30 schools are present within 3.0 to 4.0 miles of the site. The nearest day care facility is located 1.3 miles to the west. The nearest school is located 1.5 miles to the west. The population located in the vicinity of the quarry pit is provided on Table 3. Approximately 3500 feet east of the site, the industrial zone is separated from the residential area by a riparian zone for Rock Creek which runs northwest to southeast.

There are 236 people living within a 1-mile radius of the quarry pit (Table 3). DEQ utilized the Circular Area Profile population tool at the Missouri State Data Center (16) to determine the estimated radial population. The Circular Area Profile population tool uses the population data from the 2010 U.S. Census (17). There are no commercial agriculture, silviculture, and livestock on the property. No terrestrial sensitive environments were identified on the property. The direct exposure scenario is the potential for workers to be exposed to contaminated soil on the property.

6.3 Soil Exposure Pathway Conclusions

Based on the site conditions and the lack of sign or conditions suggesting soil contamination in the quarry pit, the soil pathway is not a concern.

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7. Air Migration Pathway The air migration pathway evaluates the potential that contamination released to the air could be detected and impact nearby receptors.

7.1 Likelihood of a Release The quarry pit does not release contaminants to the air. Operations at the quarry pit include development of the quarry pit for the lower range complex. If heavy equipment is used during construction, there is potential for diesel exhaust to be released into the air column. Based on current site conditions a release to the air pathway from heavy equipment exhaust is not a potential concern.

7.2 Air Targets The site is a large 220-acre property with shooting range complexes surrounded by natural areas. The closest residence is located 0.7 miles east of the Site. There is no daycares or schools within 0.25 mile to 0.5 mile, no daycares or schools within 0.5 mile and 1.0 mile, 6 daycares and 5 schools located within 1.0 mile to 2.0 miles, 10 daycares and 13 schools located within 2.0 to 3.0 miles, and 11 daycares and 30 schools located within 3.0 to 4.0 miles of the Site. The nearest day care facility is located 1.3 miles to the west. The nearest school is located 1.5 miles to the west. The population located in the vicinity of the Site is provided on Table 5. Approximately 3500 feet east of the site, the industrial zone is separated from the residential area by a riparian zone for Rock Creek that which runs northwest to southeast.

There are 84,397 people living within a 4-mile radius of the Site (Table 3). DEQ utilized the Circular Area Profile population tool at the Missouri State Data Center (16) to determine the estimated radial population. The Circular Area Profile population tool uses the population data from the 2010 U.S. Census (16).

There are numerous wetlands, primarily freshwater emergent, located along Rock Creek and the Tualatin River within 4 miles of the site (Table 5).

There are no commercial agriculture, silviculture, and livestock on the property. No terrestrial sensitive environments were identified on the property or within 0.5 miles of the site.

Eight occurrences of rare, threatened or endangered species were recorded with the US Fish and Wildlife Resources IPAC Resources List within a 4-mile radius (17). Species encountered include the Northern Spotted Owl, Streaked Horned Lark, Fender's Blue Butterfly, Bradshaw's Desert-Parsley, Kincaid's Lupine, Nelson's Checker-mallow, Water Howellia, and Willamette Daisy are shown in Table 7.

7.3 Air Migration Pathway Conclusions Based on current quarry pit conditions at the site, there are no significant air migration pathways.

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8. Summary and Conclusions The TVSC quarry pit is located at 13050 SW Tonquin Road in Sherwood, Oregon. The site has been and is currently used as a shooting range since1944. Past activities included mining operations and current activities include the development of future gun firing ranges. When TVSC began filling the quarry pit with imported soil, concern was raised whether contaminated fill would cause ground water contamination at the site.

A limited sampling investigation evaluated ground water at the quarry pit and analyzed for Metals, PAHs and VOCs. There were several detections of COIs, in ground water samples, including acetone, acenahthene, dibenzofuran, fluoranthene, flourene, arsenic, barium, cadmium, lead and dissolved lead, copper and zinc. The COIS were primarily detected in the ground water sample collected from piezometer PZ-02. Piezometer PZ-02 is the sole piezometer placed in the fill material. All samples, other than arsenic, did not exceed RBCs for residential RBCs for ground water. Arsenic exceeds the RBC for ingestion and inhalation from tap water (0.052 ug/L) in one sample, but did not exceed the MCL for drinking water of 10 ug/L.

TVSC began filling the quarry pit with imported soil, and a small amount of solid waste material in the soil was believed to be a source of potential contamination to ground water at the site. Based on the results of the limited ground water sampling performed at the site, groundwater is not a pathway of concern at the site. Visual inspection from the site visit did not observe any significant signs of buried solid waste, odors, dying vegetation, leaching or gas formation.

Based on well logs, a shallow ground water aquifer is present between 15 to 30 feet bgs and a deeper aquifer is present between 75 to 200 feet bgs with many basaltic fracture zones in between. Ground water flow from the quarry pit is interpreted to be west to northwest and no domestic or community wells are within a quarter mile of the anticipated migration direction of ground water from the site. Based on the results of the ground water sampling, groundwater has not been impacted from the quarry pit.

Eight occurrences of rare, threatened or endangered species are located at or near the site. Wetlands and Rock Creek are within a half-mile from the site, however no surface water pathways for impacting ecological receptors appears to exist.

Soil contamination at the quarry pit is unlikely and no visual observations support a soil pathway. However, additional soil assessment will be necessary to fully determine the impacts from soil at the site.

Based on current site conditions a release to the air pathway is not a potential concern.

Further investigation of TVSC and the site conditions in not recommended.

9. References [1] Tri-County Gun Club. https://tcgc.org/the-club/, Accessed online March 26, 2020.

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[2] Washington County. http://gisims.co.washington.or.us/InterMap/. Accessed online March 22, 2020. [3] DEQ Complaint, Filed February 24, 2018 to DEQ Water Quality, Mr. Robert Barton.

[4] Oregon Secretary of State, Corporate Division. https://bit.ly/2WrLXIf. Accessed online February 8, 2019. [5] Oregon Department of Environmental Quality, 2002. Strategy Recommendation, Tualatin Valley Sportsmen’s Club, ECSI 3050, Steve Fortuna.

[6] Wood Environment & Infrastructure Solutions, Inc. Telephone interview with consultant, May 29, 2002.

[7] AMEC Earth and Environmental, Inc. July 8, 2003. Expanded Preliminary Assessment Report for the Tualatin Valley Sportsmen’s Club at 13050 SW Tonquin Road in Sherwood, OR.

[8] Groundwater Sampling Results, Tualatin Valley Sportsmen’s Club, Sherwood, Oregon. July 15, 2019. Wood Environment & Infrastructure Solutions, Inc.

[9] Oregon Department of Environmental Quality. Environmental Cleanup Program Risk-Based Concentrations for Individual Chemicals Revision: May 2018. https://www.oregon.gov/deq/FilterDocs/RBDMTable.pdf.

[10] Oregon Water Resources Department. Water Rights Information Query database and mapping. https://bit.ly/2IW29K7. Accessed online June 20, 2020.

[11] Tualatin Basin Information, http://trwc.org/tualatin-basin-information/. Accessed online June 19, 2020.

[12] Supplemental Remedial Investigation Report – Final, Former Frontier Leather Tannery Property, 1210 SW Oregon Street – Sherwood, Oregon, Cooperative Agreement BF-00J93201, AMEC, June 17, 2016

[13] Oregon Water Resources Department. Water Rights Information Query database and mapping. https://bit.ly/2IW29K7. Accessed online April 4, 2020.

[14] Oregon Climate Service. www.wrcc.dri.edu/summary/climsmor.html. Accessed online April 4, 2020.

[15] Oregon Department of Human Services. Drinking Water Program. Drinking Water Program Data. https://yourwater.oregon.gov/. Accessed online April 20, 2020.

[16] Missouri Census Data Center. Circular Area Profiles. Accessed online May 3, 2019. [17] U.S. Census 2010. American Fact Finder. https://www.census.gov/. Accessed online May 6, 2020. [18] U.S. Fish & Wildlife Service. Information, Planning, and Conservation System. https://ecos.fws.gov/ipac/. Accessed online June 21, 2020.

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[19] U.S. Fish & Wildlife Service, National Wetlands Inventory Data by State, Accessed June 29, 2020. [20] University of Oregon. GIS Library, Aerial Imagery, Accessed June 30, 2020.

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