wetland delineation / determination report cover form · wetland delineation / determination report...

WETLAND DELINEATION / DETERMINATION REPORT COVER FORM This form constitutes a request for a jurisdictional determination by the Department of State Lands. It must be fully completed and signed, and attached to the front of reports submitted to the Department for review and approval.

Wetlands Program Manager/Oregon Department of State Lands 775 Summer Street NE, Suite 100

Salem, OR 97301-1279

Applicant Owner Name, Firm and Address: Riverbend Landfill Company, Inc., attn: George Duvendack 13469 SW Highway 18 McMinnville, OR 97128

Business phone # 503-472-8788 Home phone # (optional) FAX # E-mail:

Authorized Legal Agent, Name and Address: Business phone # FAX # E-mail:

I either own the property described below or I have legal authority to allow access to the property. I authorize the Department to access the property for the purpose of confirming the information in the report, after prior notification to the primary contact. Typed/Printed Name: George Duvendack Signature: Date: Special instructions regarding site access:

Project and Site Information (for latitude & longitude, use centroid of site or start & end points of linear project) Project Name: Riverbend Landfill Expansion Latitude: Longitude: Proposed Use: Expansion of existing landfill and mitigation area, requiring a change in designated land use

Tax Map # 5 5 01, 5 5 02, 5 5 11 Tax Lot (s): 5501-0100, 5501-101, 5501-200, 5501-400, 5501-401, 5501-500, 5501-200, 5502-400, 5502-500, 5511-100, 5511-500, 5511-600

Project Street Address (or other descriptive location): 13469 SW Highway 18 (study area on both sides of Hwy. 18)

Township 5N

Range 5W Section 1, 2, 11 QQ

Waterway: South Yamhill River River Mile: ~mile 21 City: McMinnville County: Yamhill NWI Quad(s): McMinnville, Muddy Valley

Wetland Delineation Information Wetland Consultant Name, Firm and Address: Phone # 503-248-9507 ext. 287 Jones & Stokes, attn. Heather Arndt Anderson 317 SW Alder St., Suite 800 Portland, OR 97204

FAX # 503-228-3820 E-mail address: [email protected]

The information and conclusions on this form and in the attached report are true and correct to the best of my knowledge. Consultant Signature: Date:

Primary Contact for report review and site access is Consultant Applicant/Owner Authorized Agent Wetland/Waters Present? Yes No Total Wetland Acreage: 14.08 Delineation Purpose:

R-F permit application submitted with delineation Sale, purchase, lease etc. Mitigation bank site Partition, re-plat, lot line adjustment Industrial Land Certification Program site Habitat restoration project R-F application will be submitted within 90 days Other: Proposed change to land use designation; land use

approval procedures

Other Information: Y N Has previous delineation/application been made on parcel? If known, previous DSL # 05-0002 (portion on-site)

Does LWI, if any, show wetland on parcel? LWI wetland code: no LWI

For Office Use Only DSL Reviewer: Report Tier: 1 2 3 DSL WD #

Date Delineation Received: / / DSL Project # DSL Site #

Scanned: Final Scan: DSL WN # DSL App.#

Riverbend Landfill Expansion Riverbend Landfill Company, Inc. December 2007

Wetland Delineation Report

Wetland Delineation Report Riverbend Landfill Expansion

Prepared for: Riverbend Landfill Company, Inc.

13469 SW Hwy. 18 McMinnville, OR 97128

Contact: George Duvendack (503) 472-8788 ext. 28

Prepared by:

317 SW Alder Street, Suite 800

Portland, OR 97204 Contact: Heather Arndt Anderson

503/248-9507 ext. 287

December 2007

This document should be cited as: Jones & Stokes. 2007. Wetland Delineation Report. Riverbend Landfill Expansion. December. (J&S 06293.06.) Portland, OR. Prepared for Riverbend Landfill Company, Inc.

December 2007 i

Table of Contents Chapter 1. Introduction .......................................................... 1

1.1. Study Area ............................................................................. 1 1.2. Landscape Setting ................................................................. 2 1.3. Previous and Current Land Uses ........................................... 2

Chapter 2. Methodology ......................................................... 5 2.1. Site-Specific Methodology ...................................................... 5

2.1.1. Wetlands ..................................................................... 5 2.1.2. Other Waters of the State ........................................... 6

2.2. Off-Site Methodology ............................................................. 6 2.2.1. USGS Topographic Maps ........................................... 6 2.2.2. Soil Survey .................................................................. 7 2.2.3. Local Wetlands Inventory and NWI Maps ................... 7 2.2.4. Aerial Photographs ...................................................... 8 2.2.5. Fish Presence or Absence .......................................... 8

2.3. Precipitation ........................................................................... 8

Chapter 3. Wetlands ............................................................. 11 3.1. Delineated Wetlands ............................................................ 13

3.1.1. Wetlands B and C – Herbaceous Wetlands (Creek Overflow) ................................................................... 13

3.1.2. Wetland D – Stormwater Detention Pond.................. 14 3.1.3. Wetlands E, F, and G – Herbaceous Wetlands ......... 14 3.1.4. Wetlands J and K – Seasonally Ponded ................... 15 3.1.5. Wetland N – Emergent with PSS and PFO

Components .............................................................. 16 3.2. Other Waters of the State .................................................... 17

3.2.1. Feature A – South Yamhill River Active Floodplain ... 17 3.2.2. Stream H – Tributary to South Yamhill River ............. 18 3.2.3. Stream I – Tributary to South Yamhill River .............. 18 3.2.4. Ditch L – Ephemeral Hillside Trench ......................... 19 3.2.5. Stream M – Tributary to South Yamhill River ............ 19

Chapter 4. Results and Conclusions .................................. 21 4.1. Required Disclaimer ............................................................. 21


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Chapter 5. References .......................................................... 23

Table of Contents

December 2007 iii

Tables Table 1. Soil Mapping Information for the Riverbend Landfill Study Area .......................... 7

Table 2. Precipitation During the Riverbend Landfill Study Area Site Visits ....................... 9

Table 3. Wetland and Water Resources Delineated in the Study Area ............................ 11

Appendices Appendix A Figures

Figure 1. Vicinity Map

Figure 2. Tax Lot Map

Figure 3. USGS Topographic Map

Figure 4. Soil Survey Map

Figure 5. NWI map

Figures 6a through 6g. Wetland maps

Appendix B Wetland Delineation Data Forms

Appendix C Aerial Photographs

Acronyms 1987 Manual U.S. Army Corps of Engineers Wetlands Delineation Manual

Corps U.S. Army Corps of Engineers

DEQ Department of Environmental Quality

DSL Oregon Department of State Lands

FWS U.S. Fish and Wildlife Service

HGM hydrogeomorphic

HUC hydrologic unit code

MSL mean sea level

NRCS Natural Resources Conservation Service

NWI National Wetland Inventory


Riverbend Landfill Expansion iv

OAR Oregon Administrative Rule

OHW ordinary high water

OR 18 Oregon State Route 18

PEM5 palustrine, emergent, permanently flooded

PEMA palustrine, emergent, temporarily flooded

PEMD palustrine, emergent, seasonally flooded, well-drained

PEMF palustrine, emergent, seasonally flooded/saturated

PFO palustrine, forested

PSS palustrine, scrub-shrub

PSS1 palustrine, scrub-shrub, broad-leaved deciduous

PUB palustrine, unconsolidated bottom

PWS Public Works/Safety

R2SB3 riverine, lower perennial, cobble gravel

R2UBH riverine, lower perennial, unconsolidated bottom, permanently flooded

R2US5D riverine, lower perennial, unconsolidated shore, vegetated, seasonally flooded/well drained

R3UBH riverine, upper perennial, unconsolidated bottom, seasonally flooded

RC Recreation Commercial

RFT riverine, flowthrough

RI riverine

USGS U.S. Geological Survey

December 2007 1

Chapter 1. Introduction Jones & Stokes was retained by Riverbend Landfill Company, Inc. to perform a routine-level wetland delineation for a proposed expansion of the Riverbend Landfill in Yamhill County, Oregon (Appendix A, Figure 1). The purpose of the study was to delineate wetlands and other waters of the State of Oregon/United States within the study area being considered for the landfill expansion. This expansion may require a zoning change to the tax lots that are currently zoned as Recreation Commercial (RC) and Public Works/Safety (PWS).

The approximately 187.45-acre study area includes Riverbend Landfill and the agricultural land on adjacent lots to the northwest of Oregon State Route 18 (OR 18). Jones & Stokes conducted wetland delineation field work on April 11, 13, 18, and 19, 2006; and on March 28, July 6, August 30, and November 5, 2007. Approximately 14.08 acres of wetlands and other waters were identified, including perennial streams (tributaries to the South Yamhill River), herbaceous, scrub-shrub and forested riparian wetlands, and active floodplain.

1.1. Study Area The study area is located west and southwest of the existing landfill in Township 5 South, Range 5 West, Sections 1, 2, 11 and 12 (Appendix A, Figure 2), approximately 4 miles southwest of the City of McMinnville, Yamhill County, Oregon. As shown in Figure 2, the study area includes the following tax lots:

Tax Map 5 5 01: 100, 101, 400, 401, 500, and a portion of 200

Tax Map 5 5 02: 400, and a portion of 500

Tax Map 5 5 11: 500, 600, and a portion of 100


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The study area lies on both the northwest and southeast sides of OR 18, and is bordered by the South Yamhill River to the south, agricultural land to the west and north, and by the outer boundary of Riverbend Landfill to the east. The study area is located in the South Yamhill River watershed.

The South Yamhill River flows along the southern study area boundary in an easterly direction toward its confluence with the Yamhill River approximately 10 miles to the east. An unnamed perennial stream enters the study area in the northwestern corner and flows in an easterly/southeasterly direction to its confluence with the South Yamhill River in the southeastern corner of the study area.

In the agricultural grassland areas north of OR 18, upland areas are planted in perennial ryegrass (Lolium perenne; FACU) and tall fescue (Festuca arundinacea; FAC-). On the landfill property, tall fescue, common vetch (Vicia sativa; UPL), Canada thistle (Cirsium arvense; FACU), bull thistle (C. vulgare; FACU) and red clover (Trifolium pratense; FACU) dominate the herbaceous layer. Teasel (Dipsacus fullonum; NI), Queen Anne’s lace (Daucus carota; NOL), centaury (Centaurium erythraea; FAC-), English plantain (Plantago lanceolata; FACU+), broadleaf plantain (P. major; FACU+), and dandelion (Taraxacum officinale; FACU) are common throughout the upland areas. Upland areas adjacent to the unnamed tributary to the South Yamhill River are dominated by Himalayan blackberry (Rubus armeniacus; FACU) along the entire study area reach.

1.2. Landscape Setting The study area is located n the Prairie Terraces subregion of the Willamette Valley ecoregion, sitting atop a broad, flat terrace below the western foothills of the Tualatin Mountains (West Hills). It is located in the South Yamhill River watershed (hydrologic unit code [HUC] 1709000804), in the Yamhill subbasin (Willamette Basin).

The study area topography generally slopes gently to the southeast and includes some artificially constructed hills associated with the landfill (e.g., the hill on which the leachate pond is sited). Elevations in the study area vary from 160 feet above mean sea level (MSL) in the northwestern portion to 140 feet MSL at the top-of-bank of the river in the southeastern portion.

1.3. Previous and Current Land Uses Historic aerial photographs (Section 3.3.4) show that the study area was forested until sometime between the 1930s and 1960s, when it was converted to agricultural uses. Northwest of OR 18, land use is still agricultural. This portion of the site is actively maintained as orchard and hay row crops.

Introduction

December 2007 3

On the southeastern side of OR 18, land use is primarily associated with the landfill. This includes a leachate pond in the southeast, an office building and weigh station adjacent to OR 18, and rows of poplar trees that are irrigated with leachate during the summer (as permitted by Oregon Department of Environmental Quality [DEQ] Solid Waste Permit #345) in the south-central portion of the study area. A mobile home court to the west of the leachate pond will be vacated and removed when its lease with Riverbend Landfill Company, Inc. expires in 3 years.

December 2007 5

Chapter 2. Methodology The wetland delineation was conducted in accordance with the 1987 U.S. Army Corps of Engineers Wetlands Delineation Manual (1987 Manual) (Environmental Laboratory 1987) and supporting technical and guidance documents issued by the U.S. Army Corps of Engineers (Corps) and the Oregon Department of State Lands (DSL). The plant species wetland indicators status and scientific names are from the Combined 1988 National List and 1993 Supplement List of Plant Species That Occur in Wetlands (Region 9) (Reed 1988). Wetland delineation data sheets are in Appendix B.

2.1. Site-Specific Methodology

2.1.1. Wetlands Jones & Stokes delineated the study area using the routine determination methodology outlined in the 1987 Manual (Environmental Laboratory 1987). Fieldwork was performed on April 11, 13, 18, and 19, 2006; and on March 28, July 6, August 30, and November 5, 2007, at which time the boundaries of all wetlands and other waters in the study area were identified and flagged. Data plots were established and standard wetland delineation data forms were used to record vegetation, soils, and hydrology observations from each plot (Appendix B). All identified wetlands were classified according to the U.S. Fish and Wildlife Service (FWS) Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al. 1979) and the Oregon hydrogeomorphic (HGM) classification system (Adamus et al. 2001).

Wetland boundaries were generally determined by the plant community transition from upland grass/weedy forb communities to hydrophytic species; examination of



soils and hydrology generally confirmed reasonable expectations based on vegetation. In several wetlands, soils and hydrology data were drastically different across the boundary, even when paired data plots were only a few feet apart.

2.1.2. Other Waters of the State In the streams, OHW was generally determined to be the extent of jurisdictional waters. However, in several areas active floodplains exhibited drift lines and depositions of debris several feet above top-of-bank; in this case the jurisdictional boundary was determined to be along the drift line (if other criteria were also met).

Mapping Methods and Accuracy

The boundary flags of all wetlands and other waters of the State/United States and the wetland data plots were professionally land surveyed by Matt Dunkel and Associates to an approximate accuracy of 0.01 foot and digitally mapped using AutoCAD®.

2.2. Off-Site Methodology Prior to fieldwork, potential wetlands in the study area were identified using U.S. Geological Survey (USGS) Topographic Maps (U.S. Geological Survey 1987) (Appendix A, Figure 3), the United States Department of Agriculture Natural Resources Conservation Service (formerly Soil Conservation Service) Soil Survey of Yamhill County Area, Oregon (Soil Conservation Service 1974) (Appendix A, Figure 4) and USFWS National Wetland Inventory (NWI) Maps (U.S. Fish and Wildlife Service 1976 and 1992) (Appendix A, Figure 5). Aerial photographs obtained from the USGS and Riverbend Landfill Company, Inc. were also examined for historic land usage and the presence of potential wetlands and other waters (Appendix C). In order to provide additional information on the hydrologic conditions at the time of the site visit, precipitation data for the day of, day before, and two weeks prior to each field visit were acquired from the National Weather Service website (2006 and 2007).

2.2.1. USGS Topographic Maps The topographic maps (U.S. Geological Survey 1987) show Streams H, I and M in the same locations as noted during field investigations (Appendix A, Figure 3). The map also shows Wetlands J and K, although it shows them as being an oxbow of open water connected by a channel. Due to historic agricultural activities, this hydrology has been altered and now Wetlands J and K more closely resemble ponds.

Methodology

December 2007 7

2.2.2. Soil Survey The Soil Survey of Yamhill County Area, Oregon (Soil Conservation Service 1974; Sheet 42) maps six soil series in the study area: Amity, Chehalem, Chehalis, Cove, Wapato, and Woodburn (Appendix A, Figure 4). Terrace escarpments are also mapped in the study area. Cove and Wapato are considered to be hydric, and the other soils have hydric inclusions (Natural Resources Conservation Service 1999). Table 1 summarizes soil mapping information for the study area.

The Soil Survey also maps the South Yamhill River and its unnamed tributary in the study area.

Table 1. Soil Mapping Information for the Riverbend Landfill Study Area Mapping Unit Soil Name Slope On Hydric

List? Hydric Inclusions?

Am Amity silt loam -- No Dayton

CeC Chehalem silty clay loam 3-12% No Cove

Ck Chehalis silty clay loam, overflow -- No Wapato

Cs Cove silty clay loam -- Yes n/a

Te Terrace escarpments -- No seep spots

Wc Wapato silty clay loam -- Yes n/a

WuB Woodburn silt loam 0-7% No Dayton

WuC Woodburn silt loam 7-12% No Dayton

WuD Woodburn silt loam 12-20% No Dayton

2.2.3. Local Wetlands Inventory and NWI Maps Because the study area is not located within an urban growth boundary, no Local Wetlands Inventory has been conducted for this site. Yamhill County has inventoried some of their Goal 5 resources; however, natural resources (i.e., wetlands and riparian areas) have not yet been included.

The NWI (FWS 1976, 1992) mapping shows the South Yamhill River and the unnamed perennial stream within the study area (Appendix A, Figure 5). The South Yamhill River is mapped as palustrine, forested, broad-leaved deciduous, intermittently flooded. Its unnamed perennial tributary is mapped as palustrine, scrub-shrub, broad-leaved deciduous (PSS1)/palustrine, emergent, permanently flooded (PEM5). This mapping does not completely coincide with the findings of the field visit; a more accurate classification of the South Yamhill River might be riverine, lower perennial, unconsolidated bottom, permanently flooded (R2UBH) and



the unnamed tributary would be classified as riverine, upper perennial, unconsolidated bottom, seasonally flooded (R3UBC). The NWI does not map the active floodplain of the South Yamhill River, which could be classified as riverine, lower perennial, unconsolidated shore, vegetated, seasonally flooded/well drained (R2US5D).

The NWI does not map any of the on-site wetlands, only streams. This is inconsistent with the results of the field investigations.

2.2.4. Aerial Photographs Historic aerial photographs of the entire study area are not available; photographs of the southern and western parts of the study area are not available. However, the aerial photographs from 1936, 1966, and 1973 (Appendix C) do reveal that the South Yamhill River and its unnamed perennial tributary have remained in much the same position over the last 70 years. The 1936 historic photograph shows that the area was largely forested, but the 1966 photograph shows that the study area had been in agricultural use at some time in the prior 30 years. Row crops of poplar trees that were observed during the site visit were present in the 1973 and 1966 aerial photographs, but not in the 1936 photograph. The 1973 photograph shows that the landfill had not yet been constructed, and the site was still in agricultural use.

2.2.5. Fish Presence or Absence StreamNet (2007) lists Stream H (Stream # 1232487451575) as rearing and migration habitat for steelhead and Chinook salmon from river mile 0.00 to river mile 0.61. This stretch is entirely located within the study area, southeast of OR 18. However, Stream H is not mapped as essential salmonid habitat (Oregon Department of State Lands 2001). No other waters in the study area are mapped as fish habitat.

2.3. Precipitation Precipitation data for the day of, day before, and the two weeks prior to the wetland delineation site visits are shown in Table 2. These data were obtained from the National Weather Service, McMinnville Weather Station (#355384). At the time of the April 19, 2006 field investigation, precipitation was at 85.6% of normal levels for the water year (30.73 inches observed; 35.91 inches normal from October 1 to April 19). At the time of the March 28, 2007 field investigation, precipitation was at 94.3% of normal levels for the water year (31.20 inches observed; 33.09 inches normal). At the time of the July 6, 2007 field investigation, precipitation was at 97.1% of normal levels for the water year (38.60 inches observed; 39.77 inches normal). At the time of the August 30, 2007 field investigation, precipitation was at 90.2% of normal levels for the water year (35.62 inches observed; 40.26 inches normal). At the time of the November 5, 2007 field investigation, precipitation was

Methodology

December 2007 9

at 102.8% of normal levels for the water year (4.10 inches observed; 3.99 inches normal).

The growing season at this location begins March 22 (Valley Floor, Yamhill County, OR - 5 in 10 years first date above 28o F) (Soil Conservation Service 1974).

Table 2. Precipitation During the Riverbend Landfill Study Area Site Visits

Date of Site Visit

Actual Precipitation on Day of Visit (inches)*

Actual Precipitation One Day Prior to Visit (inches)*

Actual Precipitation Two Weeks Prior to Visit (inches)*

4/11/2006 0.03 0.04 1.24

4/13/2006 0.22 0.00 1.49

4/18/2006 0.00 0.02 0.90

4/19/2006 0.00 0.00 0.90

3/28/2007 0.00 0.04 0.92

7/6/2007 0.00 0.00 0.28

8/30/2007 0.00 0.04 0.73

11/5/2007 0.00 0.00 0.01

Source: National Weather Service 2006, 2007 (McMinnville Station #355384: Latitude N 45° 11’, Longitude W 123° 8’).

December 2007 11

Chapter 3. Wetlands Nine potentially jurisdictional wetlands and five potentially jurisdictional waters of Oregon State/United States were identified in the study area (Appendix A, Figures 6a through 6g). An ephemeral ditch was also identified in the study area, but may not be considered jurisdictional as it is not connected to any other features, does not meet wetland criteria, and appears to only convey water during high precipitation events. The typical vegetation, soils, and hydrology found in these wetland areas are discussed in the following sections and summarized in Table 3 and on the attached wetland delineation data forms (Appendix B).

Table 3. Wetland and Water Resources Delineated in the Study Area Feature Title

Dominant HGM Class*

Dominant Cowardin Class

Acres Data Plot(s)

DSL JD

Corps JD (Isolated or Connected)

Brief Description of Feature

Feature A

RFT PEMD 5.22 DP-1 –DP-4

Yes Connected “Other waters”; active floodplain of South Yamhill River

Wetland B

RFT PEMA 0.30 Yes Connected Prior delineation (DSL#05-0002)

Wetland C

RFT PEMA 0.25 DP-5 –DP-6

Yes Connected Depressional wetland adjacent/connected to river

Wetland D

Depress-ional

PUB 0.24 No Isolated Stormwater pond, excavated from mapped upland soils



Feature Title

Dominant HGM Class*

Dominant Cowardin Class

Acres Data Plot(s)

DSL JD

Corps JD (Isolated or Connected)

Brief Description of Feature

Wetland E

RFT PEMA 0.07 DP-14 – DP-15

Yes Connected Adjacent to Stream H in depressional area

Wetland F


Yes Connected Adjacent to Stream H; may receive irrigation

Wetland G


Yes Connected Adjacent to Stream H; seasonally inundated

Stream H RFT R2SB3 2.67 Yes Connected Tributary to South Yamhill River

Stream I RFT R2SB3 0.15 Yes Connected Tributary to South Yamhill River

Wetland J

RI PEMF 1.23 DP-16 –DP-17

Yes Connected Pond in former stream channel

Wetland K

RI PEMF 0.92 DP-18 – DP-19

Yes Connected Pond in former stream channel; connected to Stream I

Ditch L -- -- 0.01 No Not connected Trench on slope in fescue field - ephemeral

Stream M

RFT -- 0.59 Yes Connected Swale-like on west side of OR 18

Wetland N

RFT PEMA 0.80 DP-20 –DP-21

Yes Connected PEM w/ PSS and PFO component; connected to riparian corridor

Total 14.08

Abbreviations: HGM= hydrogeomorphic; DSL= Department of State Lands; JD = jurisdiction; Corps: = U.S. Army Corps of Engineers; RFT = riverine, flow-through; RI = riverine ; PEMD = palustrine, emergent, seasonally flooded, well-drained; PEMA = palustrine, emergent, temporarily flooded; PUB = palustrine, unconsolidated bottom; R2SB3 = riverine, lower perennial, cobble gravel; PEMF = palustrine ,emergent, seasonally flooded/saturated; PEM = palustrine, emergent: PFO = palustrine, forested; PSS = palustrine, scrub-shrub.

Wetlands

December 2007 13

3.1. Delineated Wetlands Nine wetlands were identified in the study area (Appendix A, Figures 6a through 6g). Five of the on-site wetlands (Wetlands B, C, E, F and G) are associated with Stream H (perennial tributary to South Yamhill River), and two (Wetlands J and K) are associated with Stream I. Wetland N is associated with an unnamed tributary to the South Yamhill River (this tributary was included in the study area). Wetland D is a cattail-dominated stormwater detention pond and does not appear to be connected to any other wetlands or waters in the study area. Wetlands with similar characteristics are described together.

3.1.1. Wetlands B and C – Herbaceous Wetlands (Creek Overflow)

Wetlands B and C are herbaceous wetlands located along the eastern boundary of the study area (Appendix A, Figure 6d). These depressional areas are contiguous with Stream H. Wetland B had been previously delineated by Jones & Stokes in 2003 as part of a larger delineation for Riverbend Landfill Company, Inc.’s proposed mitigation bank. That delineation has received concurrence from DSL (05-0002). The boundary of Wetland C is documented in sample plots DP-5 and DP-6.

Vegetation – Dense herbaceous vegetation is dominated by reed canarygrass, with sparse Oregon ash (Fraxinus latifolia, FACW) seedlings. As a result, vegetation in these areas meets the hydrophytic vegetation requirement of the 1987 Manual (Environmental Laboratory 1987).

Soils – Soil samples collected had matrix chromas of 10YR 3/2 (very dark grayish brown) with mottles of 10YR 4/6 (dark yellowish brown) and 2.5YR 4/6 (red). Samples were typically silty clay loam. Overall, the soils in the drainages satisfy the hydric soil requirements of the 1987 Manual (Environmental Laboratory 1987).

Hydrology – Wetland hydrology was confirmed by local soil survey mapping, the FAC-neutral test, and landscape position (e.g., the site is a topographically low spot immediately adjacent to a stream). Hydrology most likely is seasonally flooded and recharged by overflow and subsurface flow from the adjacent Stream H. These conditions are indicative of wetland hydrology and meet the hydrology criteria set forth in the 1987 Manual (Environmental Laboratory 1987).

Boundary Determination – The boundaries of Wetlands B and C were determined by topography, presence of hydrophytic vegetation, and redoximorphic features in the soils. Adjacent upland plots had similar vegetation but lacked soil mottles.



3.1.2. Wetland D – Stormwater Detention Pond Wetland D is a constructed stormwater detention pond located northwest of the leachate pond, below a gravel road at the base of the landfill (Appendix A, Figure 6d). It has been excavated from upland (Woodburn series) soils and is not likely to be considered jurisdictional unless it is hydrologically connected to Stream H. During the site visit, evidence of hydrologic connection to the stream was not located. Hydrology may be supported by upslope leachate drainage channels.

No data were taken at this pond due to its artificial nature. However, it has been included in this discussion because it appears on aerial photographs. The boundary was determined and flagged according to level of inundation and obvious topographic characteristics (e.g., swale-like in the southeastern portion). Vegetation was dominated by common cattail (Typha latifolia; OBL) and willow (Salix sp.), with meadow foxtail (Alopecurus pratensis, FACW) dominating the perimeter in the southeast and Himalayan blackberry and Canadian thistle dominating the slopes surrounding the pond on all other sides.

3.1.3. Wetlands E, F, and G – Herbaceous Wetlands Wetlands E, F and G are herbaceous wetlands that are located along Stream H in the central portion of the study area, west of the leachate pond and east of OR 18 (Appendix A, Figure 6c). These wetlands greatly resemble Wetlands B and C, but do not appear to receive their sole hydrologic inputs from Stream H. They are slightly less depressional than Wetlands B and C, and have a very slightly different vegetative composition. Also, these wetlands were inundated at the time of the site visit. Wetlands E, F, and G are documented in sample plots DP-14 and DP-15, DP-8 and 9, and DP-10 through DP-13, respectively.

Vegetation – The herbaceous layer is dominated by meadow foxtail, tall fescue, teasel, and reed canarygrass. In Wetland G, soft rush (Juncus effusus, FACW) was also common. Vegetation in these areas met the hydrophytic vegetation requirement of the 1987 Manual (Environmental Laboratory 1987).

Soils – Soil plots typically had matrix chromas of 10YR 3/3 (dark brown; in the top 8 inches) and 10YR 3/1 (very dark gray) silt loams and silty clay loams with common-to-many mottles of 10YR 3/4 (dark yellowish brown) and 7.5YR 3/4 (dark brown). Overall, the soils within these wetlands satisfy the hydric soil requirements of the 1987 Manual (Environmental Laboratory 1987).

Hydrology – Wetland hydrology was confirmed by the presence of inundation, saturation in the upper 12 inches of the soil profile and free water within 12 inches. Hydrology in this large area is most likely seasonally flooded, recharged by overflow and subsurface flow from the South Yamhill River. These conditions are indicative

Wetlands

December 2007 15

of wetland hydrology and meet the hydrology criteria set forth in the 1987 Manual (Environmental Laboratory 1987).

Boundary Determination – The boundaries of Wetlands E, F, and G were determined by topography, presence of hydrophytic vegetation, and hydric soils. Primary indicators of wetland hydrology such as saturation within top 12 inches of soil profile, high water table, and inundation were also readily observed.

3.1.4. Wetlands J and K – Seasonally Ponded Wetlands J and K were documented during the March 28, 2007 field visit. Wetlands J and K are depressional, herbaceous wetlands located along Stream I in the western portion of the study area, west of the South Yamhill River (Appendix A, Figure 6f). Based on aerial photographs and direct observations, these wetlands appear to be seasonally ponded. They are located in topographically low areas of a managed fescue field, and had been previously flagged (presumably by the farmer) as a “no work” zone (likely due to ponding and/or deep mud). Wetland J was not inundated at the time of the field visit but was unvegetated and muddy. Wetland K contained shallow inundation in the lowest portion and appears to have a seasonal surface water connection with Stream I. Based on the soil survey (Soil Conservation Service 1974) and topographic maps (United States Geologic Survey 1987) Wetland K appears to have historically been part of the oxbow of which Stream I is a remnant. Wetlands J and K are documented in sample plots DP-17 and DP-19, respectively.

Vegetation – Wetlands J and K were mostly unvegetated during the field visit, especially along the wetland boundaries. Best professional judgment was used to make a wetland determination in the absence of vegetation. Queen Anne’s lace (Daucus carota) sprouts were noted in Wetland K but constituted only 10% of the plot’s vegetation; therefore, it was not considered dominant. Wetland K was vegetated in lower portions close to the study area boundary with needle spikerush (Eleocharis acicularis, OBL) and slender rush (Juncus tenuis, FACW-), and evidence of the previous growing season’s curly dock (Rumex crispus, FAC+) and prostrate knotweed (Polygonum aviculare, FACW-) was also apparent. Vegetation in these areas met the hydrophytic vegetation requirement of the 1987 Manual (Environmental Laboratory 1987).

Soils – Soils were markedly reduced immediately below the surface. Footprints in the mud revealed very dark gray colors (10YR 3/1), whereas the surface appeared dark brown (10YR 3/3). Soil plots typically corroborated these preliminary observations, with matrix chromas of 10YR 3/3 (in the top 8 inches) and 10YR 3/1 silt loams and silty clay loams with common-to-many mottles of 10YR 3/4 (dark yellowish brown) and 7.5YR 3/4 (dark brown). Overall, the soils in these wetlands satisfy the hydric soil requirements of the 1987 Manual (Environmental Laboratory 1987).



Hydrology – Wetland hydrology was confirmed by the presence of inundation, saturation in the upper 12 inches of the soil profile, and free water within 12 inches. Hydrology in this large area is most likely seasonally flooded, recharged by overflow and subsurface flow from the South Yamhill River. Saturation is also apparent in aerial photographs. These conditions are indicative of wetland hydrology and meet the hydrology criteria set forth in the 1987 Manual (Environmental Laboratory 1987).

Boundary Determination – The boundaries of Wetlands J and K were determined by topography and an abrupt change in vegetation from managed fescue to bare mud. Primary indicators of wetland hydrology such as saturation within the top 12 inches of soil profile, high water table, and inundation were also observed.

3.1.5. Wetland N – Emergent with PSS and PFO Components Wetland N is located in the northeastern corner of the study area (Appendix A, Figure 6e). It has emergent, palustrine scrub-shrub (PSS) and palustrine forested (PFO) components, with woody vegetation generally increasing toward the riparian corridor of an unnamed tributary to the South Yamhill River. The boundary of Wetland N is documented in sample plots DP-20 and DP-21.

Vegetation – Herbaceous vegetation is dominated by reed canarygrass and soft rush, with thickets of Nootka rose (Rosa nootkana, FAC) and spirea (Spiraea douglasii, FACW) increasing toward the Oregon ash-dominated forested portion of the wetland. Adjacent riparian areas are dominated by Oregon ash and redosier dogwood (Cornus sericea). As a result, vegetation in these areas meets the hydrophytic vegetation requirement of the 1987 Manual (Environmental Laboratory 1987).

Soils – Soil samples collected had matrix chromas of 10YR 3/2 (very dark grayish brown) with and 10YR 3/1 (very dark gray). Samples were typically silt loam. Overall, the soils in the drainages satisfy the hydric soil requirements of the 1987 Manual (Environmental Laboratory 1987) by exhibiting low matrix chromas.

Hydrology – Wetland hydrology was confirmed by local soil survey mapping, the FAC-neutral test, and the presence of oxidized rhizospheres with living roots. Hydrology most likely is seasonally flooded and recharged by overflow and subsurface flow from the adjacent stream. These conditions are indicative of wetland hydrology and meet the hydrology criteria set forth in the 1987 Manual (Environmental Laboratory 1987).

Boundary Determination – The boundary of Wetland N was determined by topography, the presence of hydrophytic vegetation, and redoximorphic features in the soils. Adjacent upland plots had a preponderance of upland vegetation dominated by Canada thistle.

Wetlands

December 2007 17

3.2. Other Waters of the State Five areas of other waters of the State/United States were identified in the study area. These are the active floodplain of the South Yamhill River (Feature A), three perennial tributaries to the South Yamhill River (Streams H, I, and Ditch M) and an ephemeral ditch (Ditch L).

3.2.1. Feature A – South Yamhill River Active Floodplain In the southeastern portion of the study area, the active floodplain (Appendix A, Figure 6d) on the top of the north bank of the South Yamhill River exhibited many wetland characteristics, including abundant evidence of primary hydrology and a vegetation community dominated by hydrophytic species. However, evidence of hydric soils was largely absent from this area. Therefore, the active floodplain does not meet the three required criteria of “wetland” and is mapped as “other waters.” Its Cowardin classification is riverine, lower perennial, unconsolidated shore, vegetated, seasonally flooded well drained (R2US5D), and its HGM classification is riverine, flowthrough (RFT). Sample plots SP-1 through SP-6 document conditions in the active floodplain.

Vegetation – Throughout the floodplain, vegetation is dominated by reed canarygrass (Phalaris arundinacea; FACW), with meadow foxtail (Alopecurus pratensis; FACW) becoming more common in the eastern portion of the floodplain. Oregon ash and Douglas’ hawthorn (Crataegus douglasii; FAC) saplings are common as the floodplain transitions to a teasel- and Himalayan blackberry-dominated upland area. Near the confluence of the South Yamhill River and its unnamed perennial tributary, stinging nettle (Urtica dioica; FAC+) is common in topographically low places. Cow parsnip (Heracleum lanatum; FAC) becomes more common as the floodplain curves to the west. Riparian vegetation on the top of the banks was dominated by various willow species (Salix spp.; FAC to FACW), redosier dogwood and Oregon ash.

Soils – Soils in the active floodplain are typically 10YR 3/2 to 10YR 3/3 (dark grayish brown to dark brown) and 10YR 4/3 (brown) silt loams and silty clay loams with or without redoximorphic features. Where present, mottles were 7.5YR 3/4, 4/4 (dark brown and brown) or 10YR 3/6 (dark yellowish brown) and common. Soils in this area were compared to those immediately adjacent to the wetted edge of the river and exhibited chromas very similar to streambed soils; however soils in the floodplain above the top-of-bank lacked the organic streaking observed in the slightly sandier soils of the river. Due to light soil matrix chromas, the fluvium deposited by annual flooding of the South Yamhill River does not meet the hydric soils criterion; however, due to the nature of active floodplains, this portion of the site may qualify as an “atypical situation” according to the definition presented in the 1987 Manual and the soil criterion may be construed as inconclusive.



Hydrology – Primary indicators of hydrology such as drift lines and sediment deposits were abundant in the active floodplain. Debris carried by flood waters was observed as high as 15 feet up in the trees on the top of the banks, and large amounts of woody debris have been deposited throughout the riparian area along the river and its unnamed perennial tributary (Stream H). These indicators were observed to reach as far as the base of the leachate pond.

Boundary Determination – The boundaries of this feature were determined based on the limits of the primary hydrologic indicators of OHW, which mainly consisted of debris and sediment deposits on vegetation. The OHW line was much further away and higher upslope from the South Yamhill River than expected, but conversations with employees of the landfill revealed that floodwaters reach such high levels on an annual basis.

3.2.2. Stream H – Tributary to South Yamhill River Stream H is an unnamed perennial tributary to the South Yamhill River (Appendix A, Figures 6b and 6c). It enters the study area from the northwest (on the northwest side of Highway 18) and flows in a southeasterly direction to its confluence with the South Yamhill River in the southeastern portion of the study area. The limits of jurisdictional “other waters” was flagged according to the OHW, and the stream is hydrologically connected to adjacent wetlands.

Water depths in Stream H ranged from approximately 12 inches to 24 inches at the time of the site visits. Substrate was cobbles and gravels, with portions having silty or organic substrates. The stream flowed through a deeply incised, v-shaped channel, with steep banks along much of the on-site reaches.

Boundary Determination – Stream H was flagged according to the OHW. Indicators of OHW included scour, sediment deposits, and debris caught in riparian vegetation. In some reaches it was unsafe to access the stream due to very high and steep banks and 10 feet tall/50 feet thick patches of Himalayan blackberry and sweetbriar rose (Rosa eglanteria). In these areas, which were primarily restricted to the road north of the leachate pond, OHW was estimated based on obvious topography (Appendix A, Figure 6b).

3.2.3. Stream I – Tributary to South Yamhill River Stream I is an unnamed perennial tributary to the South Yamhill River (Appendix A, Figure 6f), and based on aerial photographs, appears to be a remnant oxbow of the river. It enters the study area in the south (in the southeastern corner of tax lot 5 5 11 600) and flows in a northeasterly direction to its confluence with the South Yamhill River in the southern portion of the study area. The limits of jurisdictional “other waters” were flagged according to the OHW, which was approximately 5 to 8 feet wide. Stream K appears to be seasonally connected via surface water to Wetland K.

Wetlands

December 2007 19

Water depths in Stream I ranged from approximately 3 inches to 10 inches at the time of the site visits. Substrate was primarily mud and silt. The stream flowed through a deeply incised, v-shaped channel, with steep banks along much of the on-site reaches.

Boundary Determination – Stream I was flagged according to evidence of the OHW mark. Indicators of OHW were scour and sediment deposits. Riparian vegetation was dominated by Himalayan blackberry, redosier dogwood, bigleaf maple (Acer macrophyllum), ninebark (Physocarpus capitatus), and snowberry (Symphoricarpos albus).

3.2.4. Ditch L – Ephemeral Hillside Trench Ditch L appears to be a hillside trench that likely conveys flow to Pond J during high precipitation events. No surface water was observed during field visits, but soil erosion and rilling were noted. Ditch L was unvegetated during field visits on March 28 and August 30, 2007.

Boundary Determination – Ditch L was flagged according to top-of-bank, although this feature will not likely be considered jurisdictional due its lack of wetland characteristics and hydrologic connection to other features.

3.2.5. Stream M – Tributary to South Yamhill River Stream M is another unnamed perennial tributary to the South Yamhill River (Appendix A, Figure 6g). It enters the study area from the west (west of tax lot 5 5 11 100) and flows in a southeasterly direction through a culvert beneath OR 18. On the east side of the highway the stream is more swale-like, picking up flow and becoming more channelized as it moves east. On the east side of the highway Stream M is highly degraded due to grazing. It is likely that this feature was a natural stream at one time, but has been ditched since at least the 1930s.

Vegetation was dominated by common cattail, hardstem bulrush (Scirpus acutus), teasel, and reed canarygrass, making the feature easily noticed in a mowed field of orchard grass (Dactylis glomerata). Himalayan blackberry was dominant along the edges closer to the culvert. On the east side of OR 18, the stream is dominated by common cattail and barnyard grass (Echinochloa crus-galli, FACW) with some spirea along the edges.

Boundary Determination –Stream M was flagged according to the hydrophytic vegetation that grew only within the wetted edges of the swale. Bed and bank were not very discernable on either side of the highway, and this was a more reliable indicator of the boundaries of jurisdictional waters of the State/United States.

December 2007 21

Chapter 4. Results and Conclusions Jones & Stokes delineated nine wetlands and five other waters in the Riverbend Landfill study area between April 2006 and November 2007. Included in the approximately 14.08 acres of potentially jurisdictional wetlands and waters are 4.4 acres of emergent wetlands, 0.80 acre of emergent/scrub-shrub/forested wetland, and 0.24 acre of stormwater treatment pond. The remaining 8.64 acres of “other waters” consist of 5.22 acres of active floodplain and 3.42 acres of waters of the state/United States. The extent of each of these areas is shown on Figures 6a through 6g (Appendix A) and summarized in Table 3.

4.1. Required Disclaimer This report documents the investigation, best professional judgment, and conclusions of Jones & Stokes. It is correct and complete to the best of our knowledge. It should be considered a Preliminary Jurisdictional Determination of wetlands and other waters and used at your own risk, unless it has been reviewed and approved in writing by DSL in accordance with Oregon Administrative Rules (OAR) 141-090-0005 through 141-090-0055. If impacts on wetlands and other waters on this property are proposed, this report will also need to be reviewed and approved in writing by the Corps, Portland District, in conjunction with the submittal of a Joint Section 404/Removal-Fill Permit Application.

December 2007 23

Chapter 5. References Adamus, P.R. 2001. Guidebook for Hydrogeomorphic (HGM) – Based Assessment

of Oregon Wetland and Riparian Sites: Statewide Classification and Profiles. Oregon Division of State Lands, Salem, OR.

Cowardin, L.M., Carter, V., Golet, F.C., and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Government Printing Office, Washington D.C.

Environmental Laboratory. 1987. U.S. Army Corps of Engineers Wetland Delineation Manual. Technical Report Y087-1, Environmental Laboratory, Department of the Army, Waterways Experiment Station, Vicksburg, Mississippi.

National Weather Service website. 2006 URL: <http://www.weather.gov/climate/index.php?wfo=pqr>. Accessed: April 19, 2006.

National Weather Service website. 2007 URL: <http://www.weather.gov/climate/index.php?wfo=pqr>. Accessed: November 6, 2007.

Natural Resources Conservation Service (NRCS). 1999. Hydric Soils List – Yamhill County, Oregon: Detailed Soil Map Legend. Natural Resources Conservation Service. U.S. Department of Agriculture. 33 pp.

Oregon Department of State Lands (DSL). 2001. Essential salmonid habitat. Yamhill County. URL: <http://www.oregon.gov/DSL/PERMITS/docs/maps/yamhill.pdf>. Accessed November 5, 2007.



Reed, P.B., Jr. 1988. National List of Plant Species that Occur in Wetlands Northwest (Region 9). U.S. Fish and Wildlife Service Biological Report 88, and 1993 supplement.

Soil Conservation Service. 1974. Soil Survey of Yamhill Area. Soil Conservation Service. United States Department of Agriculture. 130pp + maps and tables.

StreamNet. 2007. Fish Distribution Data Query URL: <http://query.streamnet.org/Request.cfm?cmd=BuildQuery&NewQuery=BuildCriteria&Required=Run,State,County,Stream&State=4&County=136&ID=1231445452258&DataCategory=23&_Count=1>. Accessed November 5, 2007

StreamNet. 2007 Fish Distribution Map. UPL: <http://map.streamnet.org/website/fishdist/viewer.htm?Layers=0000000000000001&ActiveLayer=15&Query=LocationID%20%3D%20%271231445452258%27&QueryZoom=Yes>. Accessed November 5, 2007.

U.S. Fish and Wildlife Service (FWS) National Wetlands Inventory (NWI). 1992. McMinnville, OR. United States Fish and Wildlife Service. National Wetlands Inventory.

U.S. Fish and Wildlife Service (FWS) National Wetlands Inventory (NWI). 1976. Muddy Valley, OR. United States Fish and Wildlife Service. National Wetlands Inventory.

U.S. Geological Survey. 1987. Microsoft TerraServer. <http://terraserver-usa.com/ImageInfo.aspx?T=2&S=12&Z=10&X=599&Y=6250&W=3&qs=%7cmcminnville%7cor%7c>. Accessed December 1, 2007.

Appendix A Figures

Appendix B Wetland Delineation Forms

Date:Client/Owner: State:

County:NoYes Plant Community:No Sample Plot:

VEGETATION

Stratum Raw %

Rel % Cover

Dom. Indicator status

Stratum Raw %

Rel % Cover


H 25 28 X FACW H T FAC+H 20 22 X FACW S/S T FACH 20 22 X FACH 10 11 NOL

Cirsium arvense H 10 11 FACU+Allium vineale H 5 6 NIRubus discolor S/S 5 33 X FACUSalix lasiandra S/S 10 67 X FACW+

% of dominant species that are OBL, FACW, or FAC (excluding FAC-): 4 of 5 =

Yes

80%

Includes trace amounts of Rumex crispus and Crataegus douglasii.Criterion met?

Hypericum perforatum

Crataegus douglasiiAgrostis capillaris

Phalaris arundinacea Rumex crispusAlopecurus pratensis

Is it an atypical situation?Is the area a potential problem area?

Plot location: Approximately 100' north of South Yamhill River on small hill; near dirt road at edge of floodplain.

Species Species

HerbaceousDP-1

Investigators: H. Arndt Anderson/G. MurdoffDo normal circumstances exist on the site?

YamhillT5S R5W Section 12Township, Range, Section:

Project #: 06293.06Waste Management/Riverbend Landfill

4/13/2006Oregon

Routine Onsite Wetland Determination Form

Comments:

SOILSChehalis silty clay loam, overflow Mapped Hydric? NoCumulic Ultic Haploxerolls Drainage Class: Well drained

0-17

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor Redoximorphic features in upper 10" Organic pan (in sandy soils)Low matrix chroma Concretions (w/in 3", >2mm) On hydric soils list

No

HYDROLOGY

none>18" Water-stained leaves>18" Local soil survey data

Within growing season? Yes X FAC neutral testX Recorded Data

Stream, Lake or Tide GaugeX Aerial Photographs

OtherNo recorded data available

Yes

WETLAND DETERMINATIONSoil criterion not met. Active floodplain, but not wetland.

Depth to free water in pit:Depth to saturated soil:

Drift lines

Soils appear to be overlain by fluvium from South Yamhill River. Matrix color and soil texture similar to riverbank soils.

Primary Indicators: Secondary Indicators:Depth of surface water: Inundated Oxidized rhizospheres upper 12"

Taxonomy:Mapped Unit Name:

Redoximorphic features

10YR 4/3 silt loamAbundance/size/contrast

Comments:Criterion met?

Water marks

Depth (inches) Matrix Color

Saturated in upper 12 in.

ColorSoil Texture

UplandDetermination:

Criterion met?Comments:

Other Wetland drainage pattern

Drift lines in adjacent vegetation. Plot located ~10' higher than surrounding floodplain.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 20 17 X FACH 40 35 X NOLH 10 9 FACWH 10 9 FACW

Lotus corniculatus H 10 9 FACAllium vineale H 10 9 NIRumex crispus H 5 4 FAC+Cirsium arvense H 10 9 FACU+

H T OBL


No


Comments:


4/13/2006Oregon

HerbaceousDP-2



Agrostis capillarisDaucus carota


Plot location: Approximately 100' north of South Yamhill River on small hill; near dirt road at edge of floodplain.

Species Species

Alopecurus pratensisPhalaris arundinacea

Carex obnupta

Criterion met?Includes trace amounts of Carex obnupta.

50%


0-1515-17


No

HYDROLOGY


Within growing season? Yes FAC neutral testX Recorded Data



No

WETLAND DETERMINATIONNone of the criteria met.

Sediment deposits




Plot taken ~10' higher than surrounding floodplain.

Rationale:


Water marks



Abundance/size/contrast


Redoximorphic featuresColor

Soil Texture

10YR 3/2.5 silt loam10YR 3/3 silt loam

Soils overlain by fluvium from South Yamhill River. Matrix color and soil texture matches riverbank soils.



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 90 86 X FACWH 10 10 FAC+H 5 4 FAC+


Yes


Comments:

Plot location: Pit paired to SP-4 in SW portion of wetland area, approximately 10' W of boundary. Active floodplain.

Species


4/13/2006Oregon




HerbaceousDP-3

Species

Heracleum lanatum

Phalaris arundinaceaUrtica dioica

Criterion met?Plot 5% bare ground.

100%


0-88-10

10-16


No

HYDROLOGY


Within growing season? Yes X X FAC neutral testX Recorded Data X



Yes

WETLAND DETERMINATIONActive floodplain; within OHW level. Soils receive fluvium from annual flooding of South Yamhill River.

Sediment deposits




Debris caught in adjacent vegetation approximately 36-48" above ground level.

Rationale:


Water marks






Soil Texture

10YR 3/2.5 silty clay loam

silty clay loam10YR 3/2.5 common/fine/prominent silty clay loam10YR 3/6

Soils highly disturbed, overlain by South Yamhill River fluvium.



Drift lines

10YR 3/3



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 25 14 X FACWH 30 16 X NOLH 60 32 X FACUH 15 8 FACW

Carex deweyana H 15 8 FACUDipsacus fullonum H 20 11 FACCirsium arvense H 5 3 FACU+Unidentified herb H 15 8 NOL

S/S 35 100 X FACU


No

25%

Unidentified herb assumed to be a composite based on last year's persistent inflorescence, and is estimated to have an indicator status of FAC- to NOL.

Rubus discolor

Criterion met?

Alopecurus pratensisDactylis glomerata

Phalaris arundinaceaHypericum perforatum


Plot location: Plot taken approximately 3 feet up from wetland boundary.

Species Species

HerbaceousDP-4




4/13/2006Oregon


Comments:


0-44-17


No

HYDROLOGY





No



Drift lines

Soils overlain by fluvium from South Yamhill River. Matrix color and soil texture matches riverbank soils.




10YR 3/3 silt loam

indicator status of FAC to NOL.

10YR 3/2 silt loamAbundance/size/contrast


Water marks



ColorSoil Texture




Drift lines in adjacent vegetation.

Rationale:

Sediment deposits


County:YesNo Plant Community:No Sample Plot:

VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 70 70 X FACWH 20 20 X FACH 10 10 FACU+

S/S 30 86 X FACWRubus discolor S/S 5 14 FACU


Yes


Comments:


4/13/2006Oregon

HerbaceousDP-5



Phalaris arundinaceaDipsacus fullonum


Plot location: Plot located at Wetland C edge in low spot on NE side of creek, east of leachate pond, approximately 50' south of gravel road.

Species Species

Fraxinus latifoliaCirsium arvense

Criterion met?Ash are saplings.

100%

SOILSWapato silty clay loam Mapped Hydric? YesFluvaquentic Haplaquolls Drainage Class: Poorly drained

0-44-10

10-18

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor X Redoximorphic features in upper 10" Organic pan (in sandy soils)Low matrix chroma Concretions (w/in 3", >2mm) X On hydric soils list

Yes

HYDROLOGY

none>18" Water-stained leaves>18" X Local soil survey data

Within growing season? Yes X FAC neutral testX Recorded Data X



Yes

WETLAND DETERMINATIONAll three criteria met.

Sediment deposits

WetlandDetermination:


Other: Landscape positionWetland drainage pattern

Low spot between creek top-of-bank and road.

Rationale:


Water marks






Soil Texture

10YR 3/2 common/medium/faint silty clay loam10YR 3/4

silty clay 10YR 3/310YR 3/2&4/2 many/coarse/distinct silty clay loam10YR 3/4

Platy/blocky soil structure.



Drift lines

10YR 3/2 common/coarse/faint



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 50 56 X FACWH 5 6 FACUH 30 33 X FACU+H 5 6 FAC+

Fraxinus latifolia S/S 10 100 X FACW


Yes

67%

Plot is 10% bare ground. Ash saplingsCriterion met?

Rumex crispusCirsium arvense

Phalaris arundinaceaTaraxacum officinale


Plot location: Upland plot paired to SP-7, located approximately 10' east of gravel road.

Species Species

HerbaceousDP-6




4/13/2006Oregon


Comments:


0-55-18


No

HYDROLOGY





Yes

WETLAND DETERMINATIONSoil criterion not met.


Drift lines




10YR 3/3 silty clay loam10YR 3/2 silty clay loam



Water marks



ColorSoil Texture




Located ~1.5' higher than SP-7.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 60 92 X FACUH 5 8 FACU


No


Comments:


4/18/2006Oregon

HerbaceousDP-7



Lolium perenneDactylis glomerata


Plot location: Northwest side of Highway 18 on Schmidt Farm in large, uniform ryegrass field.

Species Species

Criterion met?Plot is 40% bare ground. Agricultural field planted in perennial ryegrass.

0%

SOILSWoodburn silt loam Mapped Hydric? NoTypic Palehumults Drainage Class: Well drained

0-88-16

16-18

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor X Redoximorphic features in upper 10" Organic pan (in sandy soils)Low matrix chroma Concretions (w/in 3", >2mm) On hydric soils list

Yes

HYDROLOGY





No

WETLAND DETERMINATIONVegetation and hydrology criteria not met. Plot documents upland conditions in lowest topographic spot in field.

Sediment deposits




Plot located at lowest topographic position in agricultural field.

Rationale:


Water marks






Soil Texture

10YR 3/2 silty clay loam

silty clay loam10YR 3/2 common/coarse/distinct silty clay loam7.5YR 3/3



Drift lines

10YR 3/1



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 40 40 X FACW+H 50 50 X FAC-H 10 10 FAC+


Yes*

50%

Plot taken on wetland edge. More hydrophytic vegetation inside boundary. *Fescue false-negative.Criterion met?

Rumex crispus

Glyceria elataFestuca arundinacea


Plot location: West of recycling center, northwest of leachate pond. Approximately 25' north of creek on edge of Wetland F.

Species Species

HerbaceousDP-8




4/18/2006Oregon


Comments:


0-77-15

15-18

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor X Redoximorphic features in upper 10" Organic pan (in sandy soils)

X Low matrix chroma Concretions (w/in 3", >2mm) X On hydric soils list

Yes

HYDROLOGY



Stream, Lake or Tide Gauge XX Aerial Photographs


Yes

WETLAND DETERMINATIONBPJ used on vegetation criterion - tall fescue false-negative.


Drift lines

10YR 3/2&3/1

Mixed matrix from 7-15".




silty clay loam10YR 3/1 many/medium/faint silty clay loam10YR 3/310YR 3/1 common/fine/distinct silty clay loam10YR 3/4



Water marks



ColorSoil Texture




Approximately 2' away from 2-6" inundation.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 80 73 X FAC-H 10 9 FACUH 5 5 FACH 5 5 FACU

Phalaris arundinacea H 10 9 FACWSalix sitchensis S/S 30 67 X FACWRosa nutkana S/S 10 22 X FACCrataegus douglasii S/S 5 11 FAC


Yes


Comments:


4/18/2006Oregon

HerbaceousDP-9



Festuca arundinaceaDactylis glomerata


Plot location: Near edge of top of bank; upland plot paired to SP-10.

Species Species

Taraxacum officinaleHolcus lanatus

Criterion met?Plot includes adjacent riparian vegetation due to proximity to creek.

67%


0-16

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor Redoximorphic features in upper 10" Organic pan (in sandy soils)Low matrix chroma Concretions (w/in 3", >2mm) X On hydric soils list

No

HYDROLOGY





Yes


Sediment deposits




Rationale:


Water marks






Soil Texture

10YR 3/2 silty clay loam



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 20 20 X FAC-H 20 20 X FACWH 25 25 X FACH 20 20 X FACU

Festuca rubra H 15 15 FAC+


Yes*

50%

Vegetation very marginal, but less hydrophytic outside boundary and foxtail increases further inside wetland boundary. Plottaken on edge. *Tall fescue false-negative.

Criterion met?

Dactylis glomerataPoa annua

Festuca arundinaceaAlopecurus pratensis


Plot location: Eastern edge of Wetland G near fence. At southern end of poplar grove.

Species Species

HerbaceousDP-10




4/18/2006Oregon


Comments:


0-88-18



Yes

HYDROLOGY

none10" X Water-stained leaves5" X Local soil survey data




Yes

WETLAND DETERMINATIONBPJ used for vegetation. Vegetation very marginal but other indicators strong.


Drift lines

Between upper and lower horizon is a 1/4"-thich layer of white substance. Soils very moist and disturbed. Potential




10YR 2/1 many/medium/distinct silty clay loam7.5YR 3/3

taken on edge. Tall fescue false negative.

10YR 3/3 common/medium/distinct silty clay loam7.5YR 3/4Abundance/size/contrast


previously filled wetland.

Water marks



ColorSoil Texture




At base of slope - receives summer leachate irrigation. 1-2" inundation observed in other portions of wetland.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 30 30 X FAC-H 60 60 X FACUH 10 10 FAC


No


Comments:


4/18/2006Oregon

HerbaceousDP-11



Festuca arundinaceaDactylis glomerata


Plot location: Eastern edge of Wetland G near fence. At southern end of poplar grove. Paired upland plot to SP-12.

Species Species

Poa annua

Criterion met?

0%


0-66-16


No

HYDROLOGY





Yes

WETLAND DETERMINATIONSoils and vegetation criteria not met.

Sediment deposits




At base of slope - receives summer leachate irrigation.

Rationale:


previously filled wetland.

Water marks






Soil Texture

10YR 3/3 silty clay loam10YR 2/2 silty clay loam

Between upper and lower horizon is a 1/4"-thich layer of white mold. Soils very moist and disturbed. Potential



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 65 65 X FACWH 15 15 FACH 10 10 FACUH 10 10 FAC

Fraxinus latifolia S/S 20 50 X FACWPopulus balsamifera S/S 20 50 X FACPopulus balsamifera T 75 100 X FAC


Yes

100%

Criterion met?

Dipsacus fullonumTaraxacum officinale

Alopecurus pratensisRumex obtusifolius


Plot location: Northern edge of Wetland G, near house in northwest portion of landfill property. In patch of cottonwood trees near gravel

road.

Species Species

Herbaceous/Scrub-shrubDP-12




4/18/2006Oregon


Comments:


0-18

Histosol Reducing conditions (test) X GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)

X Sulfidic odor X Redoximorphic features in upper 10" Organic pan (in sandy soils)Low matrix chroma Concretions (w/in 3", >2mm) On hydric soils list

Yes

HYDROLOGY

none8" X Water-stained leaves0" Local soil survey data




Yes



Drift lines

few/coarse/prominent

Three types of redox.




10YR 3/4many/fine/prominent7.5YR 3/4

N 3/0 many/coarse/prominent silty clay loam7.5YR 2.5/2Abundance/size/contrast


Water marks



ColorSoil Texture




At edge of inundated area.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 20 25 X FACH 25 31 X FACUH 15 19 FACWH 10 13 FACU

Festuca arundinacea H 10 13 FAC-Populus balsamifera S/S 10 100 X FACPopulus balsamifera T 70 100 X FAC


Yes


Comments:


4/18/2006Oregon




Dipsacus fullonumDactylis glomerata


Plot location: Approximately 20' E of SP-14, ~6" higher.

Species Species

Carex deweyanaAlopecurus pratensis

Criterion met?Bare ground 20%.

75%


0-1313-16


X Low matrix chroma Concretions (w/in 3", >2mm) On hydric soils list

Yes

HYDROLOGY





No

WETLAND DETERMINATIONHydrology criterion not met.

Sediment deposits




Approximately 6" higher than SP-14.

Rationale:


Water marks






Soil Texture

10YR 3/1 silty clay loam10YR 3/1 many/medium/distinct silty clay loam7.5YR 3/4

Very gravelly. Many large roots.



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 85 68 X FACWH 20 16 FACWH 20 16 FACU

S/S 15 100 X FAC


Yes

100%

More Juncus effusus outside plot area in wetland. Criterion met?

Rosa pisocarpaDactylis glomerata

Phalaris arundinaceaJuncus effusus


Plot location: Wetland E, near gravel road on southern side of creek.

Species Species





4/19/2006Oregon


Comments:


0-1414-19



Yes

HYDROLOGY





Yes



Drift lines

7.5YR 4/6





10YR 3/1 many/coarse/prominent silty clay loam10YR 3/2 many/coarse/prominent silty clay loam7.5YR 4/6


Water marks



ColorSoil Texture




Plot located in concave topographic feature.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


S/S 40 100 X FACUH 50 62 X FACH 30 37 X FACU


No


Comments:


4/19/2006Oregon




Rubus discolorDipsacus fullonum


Plot location: Wetland E, near gravel road on southern side of creek. Approximately 10' south of SP-16 on road slope.

Species Species

Dactylis glomerata

Criterion met?Plot is 20% moss/bare ground.

33%


0-16



Yes

HYDROLOGY





No

WETLAND DETERMINATIONVegetation and hydrology criteria not met.

Sediment deposits




Approximately 1' higher than SP-16.

Rationale:


Water marks






Soil Texture

10YR 3/2 common/coarse/prominent silty clay loam7.5YR 3/4

Mixed matrix; likely disturbed from road embankment.



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 50 91 X FAC-H 5 9 FACW-


No

0%

Plot is 50% bare ground. Polygonum is sprout.Criterion met?

Festuca arundinaceaPolygonum aviculare


Plot location: Wetland J, in low portion of managed fescue field. Area has been in agriculture for >70 years.

Species Species

Herbaceous (Agricultural)DP-16




3/28/2007Oregon


Comments:


0-16


No

HYDROLOGY





No



Drift lines





7.5YR 3/2 silty clay loam


Water marks



ColorSoil Texture




Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H T T FAC-


Yes


Comments:


3/28/2007Oregon




Festuca arundinacea


Plot location: Wetland J, ~ 10' west of SP-18

Species Species

Criterion met?BPJ used. Plot is 100% bare ground. Early growing season; area had been ponded in winter.

100%


0-16

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor X Redoximorphic features in upper 10" Organic pan (in sandy soils)Low matrix chroma Concretions (w/in 3", >2mm) X On hydric soils list

Yes

HYDROLOGY


Within growing season? Yes X FAC neutral testX Recorded Data X



Yes

WETLAND DETERMINATIONAll three criteria met. BPJ used for vegetation due to plot being unvegetated.

Sediment deposits




Shallow inundation further inside wetland boundary.

Rationale:


Water marks






Soil Texture

10YR 3/2 many/medium/distinct silty clay loam7.5YR 3/4

Depleted rhizospheres observed.



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 25 56 X FAC+H 20 44 X FACW-


Yes

100%

Plot is 55% bare ground. Early growing season; area had been ponded in winter. Criterion met?

Rumex crispusPolygonum aviculare


Plot location: Wetland K , at edge of pond.

Species Species





3/28/2007Oregon


Comments:


0-1515-18


No

HYDROLOGY

none>16" Water-stained leaves16" X Local soil survey data

Within growing season? Yes X X FAC neutral testX Recorded Data X



Yes



Drift lines

10YR 3/3





10YR 3/1 many/medium/distinct silty clay loam7.5YR 3/3 silt loam


Water marks



ColorSoil Texture




Plot taken at edge of pond. Shallow inundation further inside wetland boundary.

Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 10 100 NOLFACU#N/A


Yes


Comments:


3/28/2007Oregon




Daucus carota (sprout)Anthemis cotula


Plot location: Wetland K , at edge of pond.

Species Species

Criterion met?Plot is 90% bare ground. Early growing season. 10% sprout cover not considered dominant. Water-plantain and spikerushes

observed growing further in wetland, ~15-20' from boundary.

100%


0-77-18



Yes

HYDROLOGY





Yes

WETLAND DETERMINATION

Sediment deposits




All three criteria met. Site re-visit on 8-30-07 showed margins of wetland dominated by Anthemis cotula (FACU) and wetland vegetation dominated by Myosotis arvensis (FAC) and Echinochloa crus-galli (FACW).Rationale:


Water marks






Soil Texture

7.5YR 3/2 silty clay loam10YR 3/1 many/medium/distinct silty clay loam10YR 3/3



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 65 76 X FACH 20 24 X FACU+

S/S 15 100 X FACU


No

33%

Canada thistle more dominant further outside wetland.Criterion met?

Rubus discolor

Agrostis capillarisCirsium arvense


Plot location: Wetland N , on dirt road.

Species Species

Herbaceous uplandDP-20

Investigators: H. Arndt AndersonDo normal circumstances exist on the site?



11/5/2007Oregon


Comments:

SOILSCove silty clay loam Mapped Hydric? YesAquic Palexeralfs Drainage Class: Somewhat poorly drained

0-16


No

HYDROLOGY





No



Drift lines





10YR 3/2 silt loam


Water marks



ColorSoil Texture




Rationale:

Sediment deposits



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 85 85 X FACH 15 15 X FACW


Yes


Comments:


11/5/2007Oregon

Emergent wetlandDP-21



Agrostis capillarisJuncus patens


Plot location: Wetland N , on dirt road.

Species Species

Criterion met?

100%

SOILSCove silty clay loam Mapped Hydric? YesAquic Palexeralfs Drainage Class: Somewhat poorly drained

0-1010-16

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor Redoximorphic features in upper 10" Organic pan (in sandy soils)


Yes

HYDROLOGY

none X>16" Water-stained leaves>16" X Local soil survey data




Yes


Sediment deposits




Rationale:


Water marks






Soil Texture

10YR 3/2 silt loam10YR 3/1 silt loam



Drift lines



VEGETATION

Stratum Raw %

Rel % Cover


Stratum Raw %

Rel % Cover


H 80 80 X FAC-H 20 20 X FAC


No

50%

Criterion met?

Festuca arundinaceaDipsacus fullonum


Plot location: At bottom of slope below turkey pens.

Species Species

Herbaceous uplandDP-22




11/5/2007Oregon


Comments:


0-16

Histosol Reducing conditions (test) GleyedHistic epipedon High organic content surface layer Organic streaking (in sandy soils)Sulfidic odor Redoximorphic features in upper 10" Organic pan (in sandy soils)

X Low matrix chroma Concretions (w/in 3", >2mm) On hydric soils list

Yes

HYDROLOGY





No

WETLAND DETERMINATIONNone of the criteria met. Plot documents upland conditions in topographically low spot below Landfill office and barns.


Drift lines





10YR 2/2 silt loam


Water marks



ColorSoil Texture




Rationale:

Sediment deposits

Appendix C Aerial Photographs

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