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A.B.C Consulting Arborists LLC Accurate Balanced Certified Wagner Tree Risk Assessment July 2, 2019 PREPARED FOR: Joe Wagner 451 Nile Ave NE Renton, WA 98059 PREPARED BY: A.B.C. Consulting Arborists LLC Daniel Maple, Consultant Registered Consulting Arborist #627 Tree & Plant Appraisal Qualified (TPAQ) ISA Municipal Specialist # PN-7970BM ISA Tree Risk Assessment Qualified (TRAQ) ISA Board Certified Master Arborist #PN-7970BM Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 2 of 27 TABLE OF CONTENTS CONSULTING ARBORIST .................................................................................................................... 2 ASSIGNMENT .......................................................................................................................................... 3 Limitations .............................................................................................................................................. 3 PURPOSE .................................................................................................................................................. 3 METHODOLOGY ................................................................................................................................... 3 SITE ........................................................................................................................................................... 3 Targets..................................................................................................................................................... 3 TREES ....................................................................................................................................................... 4 Location and ID ...................................................................................................................................... 4 Non-Viable/Hazard Trees ....................................................................................................................... 4 Critical Area / Buffers ............................................................................................................................. 4 Trees to Remove/Habitat/Retain ............................................................................................................. 4 Minimum Tree Density RMC 4-4-130 D, i. ........................................................................................... 4 RECOMMENDATIONS .......................................................................................................................... 5 CERTIFICATION .................................................................................................................................... 5 ATTACHMENTS ..................................................................................................................................... 6 CONSULTING ARBORIST Daniel J. Maple / A.B.C. Consulting Arborists, LLC Westside (425) 999-0867 Daniel@AbcArborist.Com Eastside (509) 953-0293 Certifications ASCA Registered Consulting Arborist (RCA) # 627 ASCA Tree & Plant Appraisal Qualified (TPAQ) December 15, 2024 ISA Board Certified Master Arborist PN-7970BM ISA Certified Arborist Municipal Specialist PN-7970BM ISA Tree Risk Assessment Qualified (TRAQ) May 13, 2025 ATFS Qualified Tree Farm Inspector # 169449 Commercial Applicator # 92432 Commercial UAV Airman Pilot # 4135495 Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 3 of 27 ASSIGNMENT I have been contracted to provide the following: • A Level 2 Risk assessment on 1 Deodar cedar and 1 hemlock in the backyard . Test for internal decay as needed. • Provide recommendations to mitigate any noted risks. • Provide a written report of my observations, analysis and recommendations. Limitations There are limits when testing for internal decay, the test site could go to the side of the decay, or the level of root decay could be enough to cause whole tree failure but not have advanced far enough into the roots/root crown to be detected. We took every reasonable effort to accurately determine the level of risk associated with the trees, however, it is possible that internal decay may exist and not been detected. PURPOSE This report is intended to identify and reduce exposure to tree related risks: • To identify tree(s) defects that pose a risk(s) to the above home(s) and personal property, as well as the owners and their guests. • Provide reasonable mitigation options to reduce risk to acceptable levels. • To document tree hazards for obtaining a tree cutting permit if one is required. METHODOLOGY To evaluate the trees, as well as to prepare this report, I drew upon my 30+ years of experience in the field of arboriculture and my formal education. I followed the protocol of the International Society of Arboriculture (ISA) and I performed my assessment using and/or considering the following Best Management Practices: ANSI A300 Part 1 – Pruning. ANSI A300 Part 3 – Supplemental Support Systems. ANSI A300 Part 9 – Tree Risk Assessment (Second Edition). Best Management Practices were developed to aid in the interpretation of professional standards and guide work practices based upon current science and technology. Using this process, I performed my assessment, which included looking at the overall health of the trees as well as the site conditions. SITE Parcel 1023059219 / 10,890 sq. ft. (0.24-acre) site, Zoned R-6. Renton Maps/Critical Areas notes a wetland 45 to 60-feet west of the trees. Soils were moderate in depth, compaction and moisture. No other relevant site conditions were noted. Targets The primary targets were the home, neighbors’ home, vehicles, patio and the users of the property(s). The targets cannot reasonably be moved or the area restricted. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 4 of 27 TREES Per RMC 4-11-200 a significant tree is a non-hazard tree, 1. that is not on the King County Weed List1 2. is 6” in diameter or greater as measure 4.5 above the ground (DBH) (8” for cottonwood / alder) 3. or planted in the last ten-years. 4. A landmark tree is 30” or greater. Location and ID There were 4 significant trees on-site, non were landmark trees. 2 of the 4 trees had defects of note. They were geo-tagged and referenced as tree 1 & 2. Refer to Attachment 1, Tree Plotter Image for the approximate location of the trees. Non-Viable/Hazard Trees Tree 1 26.5” hemlock with large artist conk at the base. Advanced internal decay was noted2. Tree 2 23” Deodar. Tree previously split, leaving a large crown above the split union. Structural integrity of the union has been compromised. It is unlikely to support the loads above the union. Using the ISA Risk Matrix Tree 1 was rated moderate - high risk. Tree 2 was rated high risk. Critical Area / Buffers The tree 1 was 60-feet and tree 2 was 45-feet east of a wetland. Trees to Remove/Habitat/Retain Removal of the hemlock and deodar is recommended. Retain the fir and cherry tree. Minimum Tree Density RMC 4-4-130 D, i. i. A minimum tree density shall be maintained on each residentially zoned lot, as specified in the table below. The tree density may consist of existing trees, replacement trees, trees required pursuant to RMC 4-4-070F1, Street Frontage Landscaping Required, or a combination. Numbers equal or greater 1/2 shall be rounded up. ii. Property owners are responsible for maintaining trees in a healthy condition. Type of Residential Min. Tree Density Type of Residential Min. Tree Density Multi-Family (attached dwellings) (3) Four (4) significant per 5,000 sq. ft. (1) Single Family ‘ (Detached dwellings) (2) Two (2) significant per 5,000 sq. ft. (1) (1) (2) (3) Or the gross equivalent caliper inches provided By 1 or more trees Lots developed with detached dwellings in the R-10 and R-14 zones are exempt. Development in the RMF zone is exempt. 1 tree is credited for every 6” DBH retained onsite. I.E. Existing 6-inch tree = 1 tree. Existing 12-inch = 2 trees. Existing 9- inch - 15-inch = 4 trees. Planted tree3 = 1 tree. Replanting The site is 10,890 sq. ft. 2 trees are required to be retained. 2 trees will be retained. No replanting is required. 1 Bird cherry, black locust, English holly, English laurel, & European mountain-ash. 2 See Attachment 10-Decay fungi for detailed information on the fungi suspected and/or found on the site. 3 Minimum requirement 2-inch caliper deciduous, 6’ evergreen. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 5 of 27 RECOMMENDATIONS It is my professional recommendation that: ‘ Trees 1 & 2 be removed as soon as reasonably possible to reduce future damages4. Tree retention meets the code requirements, no replanting is required. CERTIFICATION I, Daniel J, Maple, Certify to the best of my knowledge and belief: 1. That the statements of fact contained in this report are true and correct. 2. That the analysis, opinions, and conclusions are limited only by the reported assumptions and limiting conditions, and that they are my personal, unbiased professional analysis, opinions, and conclusions. 3. That I have no present or prospective interest in the property or plants that are the subject of this report, and that I had no personal interest or bias with respect to the parties involved. 4. That my compensation is not contingent upon a predetermined value or direction and that favors the cause of the client, the amount of the value estimate, the attainment of a stipulated results, or the occurrence of any subsequent event. 5. That my analysis, opinions, and conclusions were developed to reflect reasonable conformity with current ANSI A300 Best Management Practices and Industry Standards. 6. The report is based on the information known to me at the time of my assessment. If more information is disclosed, I may have further opinions. 7. The report is based on my analysis at the time of the assessment and covers that time frame only; any additional limitations are addressed in the body of the report and/or in the attachments. 8. That statements of fact in the report are correct to the best of my knowledge and belief, and that they are made in good faith. I further certify that I am a Registered Consulting Arborist / Qualified Tree & Plant Appraiser in good standing with the American Society of Consulting Arborists; ISA Board-Certified Master Arborist; Municipal Arborist; Tree Risk Assessment Qualified in good standing with the ISA; and I am a Qualified Tree Farm Inspector in good standing with the American Forest Foundation. I have been involved full time in the field of arboriculture, urban forestry, and horticulture for over 30-years. . Thank you for contacting A.B.C. Consulting Arborists LLC for your arboricultural needs. Sincerely, Daniel Maple, Consulting Arborist Registered Consulting Arborist #627 Tree & Plant Appraisal Qualified (TPAQ) ISA Municipal Specialist # PN-7970BM ISA Tree Risk Assessment Qualified (TRAQ) ISA Board Certified Master Arborist #PN-7970BM 4 Fill out a Tree Removal Permit & submit along with this report. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 6 of 27 ATTACHMENTS ATTACHMENT 1 - TREE PLOTTER IMAGES ................................................................................. 7 ATTACHMENT 2 - PHOTOS ................................................................................................................ 9 ATTACHMENT 3 - TREE SUMMARY .............................................................................................. 10 ATTACHMENT 4 - HARARDOUS TREE DECLARATION .......................................................... 11 ATTACHMENT 5 - PLANTING PLAN .............................................................................................. 12 ATTACHMENT 6 - MULCHING ........................................................................................................ 15 ATTACHMENT 7 - LIST OF TREES THAT GENERALLY PERFORM WELL IN THE PNW 17 ATTACHMENT 8 - RISK ASSESMENT DEFINITIONS & PROCESS ......................................... 21 ATTACHMENT 9 - DECAY FUNGI ................................................................................................... 24 ATTACHMENT 10 - ASSUMPTIONS & LIMITING CONDITIONS ............................................ 26 ATTACHMENT 11 - REFERENCES .................................................................................................. 27 Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 7 of 27 ATTACHMENT 1 - TREE PLOTTER IMAGES Site Map North 1 2 Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 8 of 27 Renton Map W/Critical Area Layers North 1 2 Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 9 of 27 ATTACHMENT 2 - PHOTOS Photo 1 Tree 1 Hemlock Photo 2 Ganoderma Conk on hemlock Photo 3 Tree 2: Fork torn out Photo 4 large canopy above failure point Photograph Authenticity The photographs depicted in this report, to the best of my knowledge are an accurate representation of the site and its conditions. The photographs have been resized to fit the formatting of this report, in no other way have they been enhanced, or altered. The photographs accurately represent the site as I saw it on my site visit. 1 2 Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 10 of 27 ATTACHMENT 3 - TREE SUMMARY ID Species Scientific Name DBH Height Spread Defect/Decay/LCR/PT/Other Risk Recommend 1 Hemlock Tsuga heterophylla 26.5 50 30 Advanced decay in root collar / large 7” artist conk Decay in crown from previous topping M-H Remove 1 Deodar Cedrus deodar 23 55 30 Large crown above failed trunk. Cant top to mitigate risk M-H Remove ISA RISK MATRIX Matrix I. Likelihood matrix. Matrix 2. Risk rating matrix. Likelihood of Failure & Impact Consequences of Failure Negligible Minor Significant Severe Very likely Low Moderate High Extreme Likely Low Moderate High High Somewhat likely Low Low Moderate Moderate Unlikely Low Low Low Low TARGETS: 1) Home 2) Neighbors Home 3) Vehicles 4) Pedestrians 5) Outbuildings 6) Pets 7) Other: Transmission lines TREE NUMBER Tree part Condition of concern Size of Part Fall Distance Target Number Target protection Likelihood Consequences Risk rating of part (from Matrix) Failure Impact Failure & Impact (from Matrix 1) Improbable Possible Probable Immanent Very Low Low Medium High Unlikely Somewhat Likely Very Likely Negligible Minor Significant Severe 1 Whole Cavity and decay. 26 50 1, 4, 5 N X X X X X M-H 2 Whole Heavy weight above failure point 23 55 1, 4, 5` N X X X X X M-H likelihood of Failure Likelihood of Impacting Target Very low Low Medium High Imminent Unlikely Somewhat likely Likely Very likely Probable Unlikely Unlikely Somewhat likely Likely Possible Unlikely Unlikely Unlikely Somewhat likely Improbable Unlikely Unlikely Unlikely Unlikely Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 11 of 27 ATTACHMENT 4 - HARARDOUS TREE DECLARATION All the statements below are attested to by an International Society of Arboriculture CERTIFIED ARBORIST prior to the removal of any tree(s) in the areas listed above. The tree(s) proposed for removal have been certified as hazardous / Not Viable. The potential target(s) cannot be moved. Pruning, partial removal of parts of the tree(s) or other risk mitigation measures will not alleviate the hazard or are not feasible. (Explain what measures were considered and why they were not feasible.) A COPY OF A COMPLETED INTERNATIONAL SOCIETY OF ARBORICULTURE “TREE HAZARD EVALUATION FORM” OR AN EQUIVALENT TREE RISK ASSESSMENT MUST BE INCLUDED WITH THIS FORM. ONE TREE HAZARD EVALUATION OR ASSESSMENT MUST BE COMPLETED PER TREE. Comments: The Data collected contains all the elements from the ISA Risk Form it is uploaded in Tree Plotter our Tree Management Program. The Risk Ratings are auto computed using an electronic version of the ISA RISK Matrix within our program. Arborist Contact Information: Name(Print): Daniel J Maple ISA Board Certified Master Arborist # PN-7970 BM Company: A.B.C. Consulting Arborists LLC Registered Consulting Arborist #627 Phone #: (509) 953-0293 (425)999-0867 ISA Municipal Specialist # PN-7970BM ISA Tree Risk Assessment Qualified (TRAQ) June 2025 ASCA Tree & Plant Appraisal Qualified (TPAQ) December 2024 Signature of Arborist:_______________________________ Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 12 of 27 ATTACHMENT 5 - PLANTING PLAN Planting Plan NOT Required Applicant Name________________________________________________________________ 1. Street Address_________________________________________________________________ 2. Tax Parcel Number_____________________________________________________________ 3. Approx. location & dimensions of property. __________________________________________ 4. Approx. location & dimensions of buildings, driveways and septic________________________ 5. Approximate location of any ECA or ECA Buffer areas (e.g. wetlands, streams, steep slopes). _____________________________________________________________________________ 6. Approximate location of required replacement trees. 7. Scale of the drawing (e.g. 1 inch = 20 feet) Site Plan N Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 13 of 27 Planting Plan North Planting can be done October – March 15th. Fall plantings are preferred. For 2 years May – September monitor plants/soil for moisture weekly, supplemental water as needed. For 3-years monitor and weed as needed to control weeds (proper mulching should reduce the need to weed). Symbol Name Size Spacing Qty. Symbol Name Size Spacing Qty. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 14 of 27 TREE And SHRUB Planting Detail TREE And SHRUB Planting SEQUENCE 1) Remove all invasive(s) from the site. Spraying with glyphosate in spring during active growth is recommended, remove ivy from the site and plant in the fall. 2) Evaluate the soil conditions. If the soil is too compacted to easily dig, consider options for uncompacting and amending the soil with compost. Amend the entire area when possible. 3) Lay out plants or use flags to mark the location of each plant. 4) Dig a pit for each plant that is twice the size of the root ball or plant container. 5) Remove large rocks and other debris from the pit. 6) soak the pit with water by filling it at least half-way. Allow the water to drain before installing plant. Note that some pits may not fill if the soil is very sandy. 7) Remove soil as needed to expose the root flare, remove adventitious roots. 8) “Rough up” the roots of the plants, pruning or straightening circling roots. Roots that circle the bottom and sides of the root ball can later girdle the tree as the trunk attempts to grow outward. 9) Install the plant in the pit, backfilling as necessary such that soil surface matches the surrounding ground level. Make sure the root flare is at or slightly above surrounding ground level. 10) Form a basin to hold water around the plant using remaining soil. 11) Mulch each plant with 4 inches of coarse wood chip mulch (preferred) or raked leaves. Do not bury the stem in mulch – mulch should be kept a few inches away from the stem. Attachment-8 Mulch 12) Water the plant again, filling up the small basin formed in step 8. NOTES: Planting pit TO BE AT LEAST Twice THE width OF ROOTBALL LOOSEN ROOTS OF ROOT-Bound plants BEFORE Planting SOAK Planting pit BEFORE and AFTER Planting SET TRUNK vertical LAYER, BUT do NOT pile MUCH Around THE BASE OF THE TRUNK/STEM SOAK Planting pit, LOOSEN Edges OF pit, Compact SOIL TO prevent SETTLING BACKFILL Planting pit with Native Leave BOTTOM OF HOLE INTACT, 2 TIMES ROOTBALL width Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 15 of 27 ATTACHMENT 6 - MULCHING Mulching is one of the easiest and most effective ways to improve urban soil quality entry health. Mulching is the application materials to the soil surface to improve or protect the tree and/or soil. Most materials can be organic or inorganic. When selecting mulch, organic materials are usually preferred over inorganic materials. Organic mulches moderate soil temperatures reduce soil compaction and erosion and increase soil organic matter; thereby stimulating microbial activity, soil aggregation, and nutrient availability. Inorganic mulches may be fire resistant, do not decompose, reflect, or transfer heat more readily into the soil, and tend to be more stable when exposed to high wind or flooding. Table 2) Potential uses and limitations of typical mulches for urban trees. *Arborist woodchips are less costly and hold up better, they are the preferred mulch, in moderate to high traffic areas. Mulch Uses Limitations Prevent compaction Prevent erosion Limit evaporation Deter past Control weeds Promote aggregation Increase organic matter Increase nutrients Expensive or limited availability Crusting or matting Unstable Anaerobic soils Salts or contaminants Potential N immobilization Temporary or unknown effects Grass clippings X X X X X X X Fresh leaves X X X X X X Needles X X X X X Hay/straw X X X X X X *Arborist woodchips X X X X X X X X Bark X X X X X X X X X Eucalyptus X X X X X X X Cypress X X X X X X X Pecan shells X X X X X X Leaf mold X X X X X X Compost X X X X X X Fabrics X X X X Recycled rubber X X X X X X Stone/gravel X X X X Black plastic X X X X X Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 16 of 27 Mulching guidelines for urban landscapes 1. Depth of mulch application is dependent upon mulch texture, density, material decomposition rate, and climate. Wooden chip mulch should be applied and maintained at depths of 3-6 inches for trees. Materials that are finer, denser, and slower to decompose should be applied at lesser depths. thicker mulch layers should be applied in arid regions to retain more water in the soil. 2. Apply a sufficiently thick layer of mulch, usually 2-4 inches, to kill existing weeds and prevent new weed seeds from germinating or reaching the soil surface. If thinner layers are applied, kill or remove weeds prior to installing mulch. 3. Do not place impervious plastic sheeting or fabric barriers under mulch. Impervious barriers stop water movement and limit incorporation of organic matter into the soil. 4. The mulch area should cover as much of the tree root zone as possible, from near the trunk to the dripline, is considered ideal. 5. For recent transplants, mulch beyond the root ball. The minimum recommended radius is 3 feet. Maintain mulch for at least three years to facilitate root growth and protect trees from mechanical damage. 6. For larger existing trees, the minimum radius for mulch is at least three times the trunk diameter. 7. Mulch applied as a continuous bed around multiple trees is more effective than single rings around individual trees. 8. Average chip size of most organic mulches should be 1-2 inch. 9. Avoid woodchips from trees that are known to have allelopathic affects (e.g., Juglans nigra) and from individual trees that may have soil transmittable diseases (e.g., Verticillium wilt). On wet sites, soil drying can be promoted by removing organic mulches. Be aware of some other potential negative impacts of mulches, including: toxicity (allelopathy and “sour” anaerobic mulches with pH of <2.5), slime molds (unsightly, but mostly harmless), matting (hydrophobic layers from fungal mats and mulches), flammability, and some fungus problems (e.g., Sphaerobolus, Mutinuscaninu, and M. elegans). Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 17 of 27 ATTACHMENT 7 - LIST OF TREES THAT GENERALLY PERFORM WELL IN THE PNW Evergreen Trees Trees Evergreen Arbutus menziesii Madrone Height/Width (in ft)** Drought Tolerant Tolerates Wet Soil Sun Partial Sun Shade Developed Areas Native Species **Approximate size in 20 years. Actual size will vary. 50/30 ● ● ● Difficult to transplant. Very susceptible to overwatering. Hard to find. Prefers sandy, dry, and sunny locations. Calocedrus decurrens Incense Cedar 40/15 ● ● Narrow and columnar. Very drought tolerant; native to Oregon. Cedrus deodara Deodar Cedar 50/45 ● ● ● A true "Cedar" with needles. Compare with Libani and Atlas Cedars. Trees vary from wide to very wide and need lots of room. Chamaecyparis obtusa Hinoki Cypress 25/15 ● ● ● Small and slow-growing. Attractive layered branching. Chamaecyparis lawsoniana Port Orford Cypress 60/25 ● ● ● Native to Oregon; looks similar to Western Red Cedar. Subject to root fungus problems. Chamaecyparis nootkatensis Alaskan Yellow Cedar 60/25 ● ● ● Narrow, graceful; often pendulous and irregular form Cupressocyparis X. leylandii Leyland False Cypress 45/20 ● ● ● Subject to phytothera root rot. Fast growing; dull green color. Juniperus virginiana Eastern Red Cedar 40/20 ● ● ● Although named Red Cedar, it is actually a narrow Juniper. Magnolia grandiflora St. Mary's Southern Magnolia 40/25 ● ● Small and narrow. Large glossy leaves and fragrant flowers. Pinus nigra Austrian Black Pine 40/20 ● ● ● Massive and dark. Susceptible to the Pine Shoot Moth. Pinus sylvestris Scotch Pine 50/25 ● ● The world's most common Pine. Orange to red-tinged bark. Pinus thunbergiana Japanese Black Pine 40/25 ● ● Graceful, informal shape. Pseudotsuga menziesii Douglas Fir 80+/25 ● ● ● Our most common native tree. It can grow rapidly to heights over 100'. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 18 of 27 Trees Evergreen Juniperus virginiana Eastern Red Cedar Height/Width (in ft)** Drought Tolerant Tolerates Wet Soil Sun Partial Sun Shade Developed Areas Native Species **Approximate size in 20 years. Actual size will vary. 40/20 ● ● ● Although named Red Cedar, it is actually a narrow Juniper. Magnolia grandiflora St. Mary's Southern Magnolia 40/25 ● ● Small and narrow. Large glossy leaves and fragrant flowers. Pinus nigra Austrian Black Pine 40/20 ● ● ● Massive and dark. Susceptible to the Pine Shoot Moth. Pinus sylvestris Scotch Pine 50/25 ● ● The world's most common Pine. Orange to red-tinged bark. Pinus thunbergiana Japanese Black Pine 40/25 ● ● Graceful, informal shape. Pseudotsuga menziesii Douglas Fir 80+/25 ● ● ● Our most common native tree. It can grow rapidly to heights over 100'. Sequoia sempervirens Coast Redwood 100+/40 ● ● ● Requires moist soil in a large grove area; not for use as a solitary tree. Sequoiadendron gigantea Giant Sequoia 100+/45 ● With ample room, this tree will form a giant cone pyramid. Thuja plicata Western Red Cedar 80+/25 ● ● The largest member of the Cypress family. Great for screening; grows 80- 200 feet in height and retains its lower branches. Prefers moist soils. Tsuga heterophylla Western Hemlock 60+/20 ● ● ● This native is harder to use than Douglas Fir or Western Red Cedar. Intolerant of full sun. Tsuga mertensiana Mountain Hemlock 30/18 ● ● ● ● Slow-growing and narrow. Prefers sun. Umbellularia californica Bay Laurel 30/25 ● ● ● Native to Oregon and California. Leaves from this tree are used in cooking. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 19 of 27 Deciduous Trees Trees Deciduous Cercidiphyllum japonicum Katsura Tree Height/Width (in ft)** Drought Tolerant Tolerates Wet Soil Sun Partial Sun Shade Developed Areas Native Species ** Approximate size in 20 years. Actual size will vary. 40/40 ● ● ● With graceful branding and heart-shaped leaves, this tree prefers rich moist (not wet) soil. Cercis canadensis Eastern Redbud 35/25 ● ● ● ● This small horizontal-branched tree has purple-pink flowers and yellow fall foliage. Cornus kousa Japanese Dogwood 20/20 ● ● ● Best in well-drained soils, this dogwood grows horizontally and has large white flowers. Cornus mas Cornelian Cherry 25/20 ● ● ● A little taller and oval shaped, this yellow flowering dogwood is adaptable to all soils. Cornus nuttallii Pacific Dogwood 35/20 ● ● ● Our prized native dogwood is subject to disease and harder to grow. Crataegus phaenopyrum Washington Thorn 25/20 ● ● ● A popular tree because of its white blooms, red fruit, and orange/red fall color. Crataegus x lavallei Lavalle Hawthorne 28/20 ● ● ● ● Has an irregular vase shape, dark green leaves, and orange fruit that hold on during early winter. Fraxinus pennsylvanica Seedless Ash varies ● ● ● ● Forms vary from narrow (Summit Ash) to broadly oval (Marshall Seedless Ash). Good yellow fall color. Ginkgo biloba Maiden Hair Tree 40/15 ● ● ● The Princeton Sentry variety is best as it is seedless and has better form. Gleditsia triacanthos Honey Locust 45/35 ● ● ● ● Shademaster variety has a vase shape and open upright branching; very small leaflets; yellow in fall. Liquidambar styraciflua Sweet Gum 55/45 ● ● ● Great fall color with red, orange, and purple leaves that hold until December. Palo Alto variety is preferred. Liriodendron tulipifera Tulip Tree 60/30 ● ● Very different from the Magnolias, this Tulip Tree has smaller yellow flowers. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 20 of 27 Trees Deciduous Malus spp. Flowering Crabapple Height/Width (in ft)** Drought Tolerant Tolerates Wet Soil Sun Partial Sun Shade Developed Areas Native Species ** Approximate size in 20 years. Actual size will vary. 20/20 ● ● ● ● ● Crabapples are now grown for their resistance to disease and improved form. Among several good varieties are Robinson and Snowdrift. Prunus spp. Flowering Cherry varies ● ● ● Sargent and Mount Fuji cherries are tougher and more disease resistant. Narrow to rounded forms; most have aggessive roots Prunus cerasifera Purple Leaf Plum 20/20 ● ● ● Variety Thundercloud is drought tolerant; others with purple leaves and pink flowers include Mt. Saint Helens and Newport. Pyrus calleryana Ornamental Pear 35/15 ● ● ● ● Common varieties include Capital, Chanticleer, and Redspire. No fruit; white flowers and orange/red fall color. Quercus rubra Red Oak 50/45 ● ● Fast-growing and wide, this tree needs space and deep, well-drained soils. Red fall color. Stewartia pseudocamellia Japanese Stewartia 30/20 ● ● ● ● Unusual attractive peeling bark, white flowers, and yellow/red/purple fall colors make this a good garden tree. Styrax japonicus Japanese Snowbell 25/25 ● ● ● ● Fragrant flowers; often low-branched. Has a rounded form. Tilia cordata Little-Leaf Linden 40/30 ● ● ● Varieties have different shapes, most with yellow fall color. Leaves drop during dry Septembers. Zelkova serrata Sawleaf Zelkova 40/38 ● ● Variety Village Green has a nice vase shape and better orange/red fall color. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 21 of 27 ATTACHMENT 8 - RISK ASSESMENT DEFINITIONS & PROCESS Level 1 Limited Visual Assessment: Involves a visual assessment of an individual tree or group of trees near specified targets, conducted from a specified perspective in order to identify obvious defects or specified conditions. A limited visual assessment typically focuses on identifying trees with imminent and/or probable likelihood of failure. Level 1 assessments do not always meet the criteria for a "risk assessment" if they do not include analysis and evaluation of individual trees. Limited visual assessments are the fastest, but least thorough, means of assessment and are intended primarily for managing large populations of trees when time and resources are limited. The assessments may be done as walk-by, drive-by, aerial patrol, or LiDAR as requested by the tree owner or manager. The assessment is often done on a specified schedule and/or immediately after storms to rapidly assess a tree population. A limited Visual Assessment, performed from one side or by an aerial flyover, typically looks for obvious defects such as dead trees, large cavity openings, cracks, and severe or uncorrected leans. In addition, the client may specify certain conditions of concern, such as lethal pests or symptoms associated with root decay. Level 2 Basic Assessment: This is a detailed visual inspection of a tree and its surrounding site, and a synthesis of the information collected. It requires that a tree risk assessor inspect completely around the tree - looking at the site, and visible buttress roots, trunk, and branches. This is the level of assessment that is commonly performed by arborists in response to clients’ requests for individual tree risk assessments. A level 2 basic assessment may include the use of simple tools to gain additional information about the tree or defects. The use of simple tools maybe used to measure the tree and acquire more information about it or any potential defects, however, the use of these tools is not mandatory unless specified in the scope of work. Simple tools may include diameter tape, clinometer or hypsometer, level/plumb bob, binoculars, mallet, probe, and digging tools. The primary limitation of a basic assessment is that it includes only conditions that are detected from a ground-based inspection on the day of the assessment. Internal, belowground, or upper-crown conditions, as well as certain types of decay, may be impossible to see or difficult to assess and may remain undetected. Level 3 Advanced Assessment: Advanced assessments are performed to provide detailed information about specific tree parts, defects, targets or site conditions. They usually are conducted in conjunction with or after a basic assessment if the assessor needs additional information and the client approves the service. Specialized equipment, data collection and analysis, and/or expertise are usually required for advanced assessments. These assessments are therefore generally more time intensive and more expensive. Procedures and methodologies should be selected and applied as appropriate, with consideration for what is reasonable and proportionate to the specific conditions and situations. The risk manager/property owner should consider the value of the tree to the owner and community, the possible consequences of failure, the time and expense needed to provide the advanced assessment. The tree risk assessor should identify what additional information is needed and recommend the appropriate technique(s). Many techniques can be considered for advanced tree risk assessment. Some situations may be assessed with several techniques. Advanced assessment techniques may include but are not limited to: aerial inspection and evaluation of structural defects in high stems and branches, detailed target analysis, detailed site evaluation, decay testing, health evaluation, root inspection and evaluation, storm/wind load analysis, measuring and assessing the change in trunk lean, and load testing. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 22 of 27 Risk Assessment In qualitative tree risk assessment, assessors can use a matrix to help categorize risk. When categorizing tree risk, the factors to be considered are the likelihood of a tree failure impacting a target and the consequences of the failure. The likelihood of a tree failure impacting a target determined by considering the two factors: 1. The likelihood of a tree failure occurring within a specified time frame5. The likelihood of tree failure is determined by examining structural conditions, defects, response growth, and anticipated loads. 2. The likelihood of the failed tree or parts impacting the specified target. Impact may be the tree directly striking the target, or it may be a disruption of activities due to the failure. These two factors are evaluated and categorized using a matrix to estimate the likelihood of the combined event; a tree failure occurring and the tree impacting the specified target = likelihood of an event occurring. The likelihood of an event occurring is then compared with the expected consequences of a failure impacting the target to determine the level of risk. Likelihood of Failure The likelihood of failure is the chance of a tree or tree part failure occurring within the specified timeframe is primarily determined by site factors, response growth, tree health, tree species, load, defects and conditions. The likelihood of failure is classified in one of four categories; 1. Imminent; failure has started or is most likely to occur in the near future, even if there is no significant wind or increased load. The eminent category overrides the stated timeframe. 2. Probable; failure may be expected under normal weather conditions6 within the specified timeframe. 3. Possible; failure may be expected in extreme weather conditions7, but it is unlikely during normal weather conditions within the specified timeframe. 4. Improbable; the tree or tree part is not likely to fail during normal weather conditions and may not fail in extreme weather conditions within the specified timeframe. Likelihood of Impact The likelihood of impact is the chance of a tree failure impacting a target during the specified timeframe it is determined by considering 1) occupancy rates, 2) location within the target zone, 3) protection factors, 4) direction of fall. The likelihood of impact is classified in one of four categories; 1. High; the failed tree or tree part is likely to impact the target. 2. Medium; the failed tree or tree part could impact the target but is not expected to do so. 3. Low; there’s a slight chance that the failed tree or tree part will impact the target. 4. Very low; the chance of the failed three or tree part impact in the specified target is remote. 5 In the weather events common to the region; based on 30-year weather history – minus the extreme events = “common” per TRAQ, ANSI. 6 Historical data shows common winds for the region are 0 - 25 mph 7 Based on historical data winds 47-55 mph would be considered extreme for the region. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 23 of 27 Likelihood of Failure and Impact Using the likelihood of failure, the likelihood of impacting a target, and the likelihood matrix the likelihood of an event happening is categorized. Consequences of Failure The consequences of failure; personal injury, property damage, or disruption of activities due to the failure of a tree or tree part are affected; by tree or tree part size, fall distance of tree or tree part, protection factors, target value/damage. Consequences of failure are classified into one of four categories; 1. Severe; serious personal injury or death, high value property damage, or major disruption of important activities. 2. Significant; substantial personal injury, moderate to high value property damage, or considerable disruption of activities. 3. Minor; minor personal property, low to moderate value property damage, or small disruption of activities. 4. Negligible; no personal injury, low value property damage, or disruptions I can be replaced or repaired. Risk Rating Using the likelihood of an event happening (steps 1-3), the consequences of failure, and the risk rating matrix, a risk rating is assigned to the tree or tree parts. Matrix 1 & Matrix 2 as used in the risk assessment process. Matrix I. Likelihood matrix. Matrix 2. Risk rating matrix. Likelihood of Failure & Impact Consequences of Failure Negligible Minor Significant Severe Very likely Low Moderate High Extreme Likely Low Moderate High High Somewhat likely Low Low Moderate Moderate Unlikely Low Low Low Low likelihood of Failure Likelihood of Impacting Target Very low Low Medium High Imminent Unlikely Somewhat likely Likely Very likely Probable Unlikely Unlikely Somewhat likely Likely Possible Unlikely Unlikely Unlikely Somewhat likely Improbable Unlikely Unlikely Unlikely Unlikely Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 24 of 27 ATTACHMENT 9 - DECAY FUNGI Ganoderma Latin name Ganoderma applanatum Typical Host tree in the Pacific Northwest Region Deciduous and coniferous trees. Form of fruiting body Perennial Annual Polypore Gilled Type of decay White rot Brown rot Soft rot White rot - preferential loss of lignin, some break down lignin & cellulose. Brown rot - preferential loss of cellulose. Soft rot - breaks down cellulose. Typically attacks: Live wood Dead wood Both Typical location of decay Root rot Butt rot Sap rot Heart rot Comments: Leathery to woody conk, flat, plate-like bracket, upper surface light brown, ridged. Lower surface is white when fresh and active, brown when old. Conk may persist for many years. The bracket form is always horizontal in layout. Downed trees with horizontal brackets suggest the brackets developed after failure. If the brackets are vertical, then they were present prior to failure. Infected trees may show reduced growth rates and smaller than usual leaf size. Early stages may be a white polypore with no defined upper and lower surface. Early decay stage bleaches the wood, circled by a dark brown stain. Advanced decay turns the wood white, mottled, and spongy. Expect to see decay above and below the conk. If multiple conks are present expect extensive decay. New infections spread by spores. When actively reproducing, there may be an area of fine brown powder (the spores) below and near to the conk. Ganoderma brackets may sometimes look similar to Fomitopsis pinicola conks. The simple test is to scratch the underside area. Ganoderma applanatum conks will retain an etched line. Fomitopsis conks do not show any discoloration when scratched. Ganoderma decays dead wood but can enter live trees through wound areas, and may cause extensive decay. There is no control for Ganoderma applanatum. Infected trees may decline slowly, and if in good health, some species may be able to wall off and contain the decay pockets for many years. Oaks generally appear to be better able to compartmentalize an infection than the maples. On western hemlock decay is likely to be present for about 3 meters above and below a fruiting body. Risk assessment and management implications Examine age, overall health, and growth rate of tree and conk. It may be necessary to perform a Level 3 Advanced Risk Assessment to map the extent of the decay using sonic tomography and resistance drilling. The presence of multiple conks may be enough justification for removal of the tree. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 25 of 27 Ganoderma applanatum Ganoderma applanatum on Big leaf maple in conjunction with Kretzschmaria deusta. Expect to see extensive internal decay. Ganoderma applanatum on Douglas-fir Multiple conks suggest extensive internal decay. Ganoderma applanatum on Chestnut This young active conk is in its first year Ganoderma applanatum on Purple leaf plum that is over 100-year-old. This is an old conk that is no longer active. Tests suggested that the decay is reasonably well contained at the site of the conk Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 26 of 27 ATTACHMENT 10 - ASSUMPTIONS & LIMITING CONDITIONS 1. A field examination of the site was made for this report (date referenced in report). Reasonable care has been taken to obtain information from reliable sources, however, the certified/consulting arborist cannot guarantee the accuracy or validity of information provided by any outside sources. 2. Information provided in this report covers only tree’s that were indicated for examination in the assignment and reflects the apparent condition of those tree(s) at the time of inspection. This inspection is limited to a visual method of the trees in question, excluding any core sampling, probing, dissection, aerial inspection, or excavation unless noted in writing and is contingent upon the appropriate fee for such services having been authorized in writing. There is no guarantee nor warranty, expressed or implied that any problems with any trees may not arise in the future. 3. All drawings, sketches, and photographs submitted with this report, are intended as visual aids only, and are not exact to scale. They should not be construed as engineering or architectural report or surveys unless noted and specified. 4. The certified/consulting arborist is not required to give any testimony or to attend meetings or dispute resolution proceedings relating this report unless subsequent contractual arrangements and fee agreements are made. 5. Any alterations made to this report automatically invalidates this report. 6.This document is protected by copy right laws©. Unless otherwise required by law, possession of this report or a copy of this report does not imply a right of publication or use for any purpose by anyone other than the person for whom it was created without prior expressed written permission and verbal consent of the certified/consulting arborist. 7. The report and values/opinions expressed, represent the work of the certified/consulting arborist, and the arborist’s fees are in no way contingent upon the reporting of any specified values, stipulated results, or occurrence of a subsequent event. Wagner-Tree Risk Assessment, Renton, WA. By, A.B.C. Consulting Arborists LLC February 19, 2021 Page 27 of 27 ATTACHMENT 11 - REFERENCES 1. Arno, Stephen F. and Hammerly, Ramona P. Northwest Trees. Anniversary Ed. Seattle, Washington: The Mountaineer Books, 2007. 2. Brockman, C. Frank, Trees of North America, A Guide to Field Identification. New York: Golden Press, 1979. 3. Dunster, Dr. Julian A., R.P.F., M.C.I.P. Documenting Evidence, Practical Guidance for Arborists, First Choice Books, Victoria, BC, Canada. 2014. 4. Dunster, Dr. Julian A., R.P.F., M.C.I.P. Interpreting Resistograph Readings, A Manual for Users of the Resistograph Decay Detection Instrument. Bowen Island, Canada: Dunster & Associates, 2000. 5. Eric Allen, et al. Common Tree Diseases of British Columbia. Victoria: Canadian Forest Service, 1996. 6. Harris, Richard W, James Clark, and Nelda Matheny. Arboriculture, Integrated Management of Landscape Trees, Shrubs, and Vines. 4th ed. Upper Saddle River: Prentice Hall, 2004. 7. Jacobson, Arthur Lee. Trees of Seattle. 2nd ed. Seattle, Washington: Arthur Lee Jacobson, 2006. 8. Johnson, Warren T. and Lyon, Howard H. Insects That Feed on Trees and Shrubs. Ithaca: Comstock Publishing Associates, 1991. 9. Matheny, Nelda P. and Clark, James R. Evaluation of Hazard Trees. 2nd ed. Savoy: The International Society of Arboriculture Press, 1994. 10. Matheny, Nelda P. and Clark, James R. Trees & Development, A Technical Guide to Preservation of Trees During Land Development. Savoy: The International Society of Arboriculture Press, 1998. 11. Mattheck, Claus and Breloer, Helge. The Body Language of Trees, A Handbook for Failure Analysis. London: HMSO, 1994. 12. Pacific Northwest Chapter-ISA. Tree Risk Assessment in Urban Areas and the Urban/Rural Interface. Course Manual. Release 1.5. PNW-ISA: Silverton, Oregon, 2011. 13. Scharpf, Robert F. Diseases of Pacific Coast Conifers. Albany, California: USDA Forest Service, Agriculture Handbook 521, rev. June 1993. 14. Smiley, E. Thomas, Nelda Matheny, and Sharon Lilly, Tree Risk Assessment Best Management Practices, ANSI A300 Part 9: Tree, Shrub, and Other Woody Plant Management—Standard Practices (Tree Risk Assessment a. Tree Structure Assessment). The International Society of Arboriculture Press. Champaign. IL. 2011.