Loading...
PLN200300184-10457.PDFCITY OF EDMONDS 121 5TH AVENUE NORTH • Edm ds, WA 98020 • (425) 771-0220 • FAX (425) 771-0221 HEARING EXAMINER 'nC.189V FINDINGS, CONCLUSIONS AND DECISION OF THE HEARING EXAMINER CITY OF EDMONDS APPELLANT - CASE NO.: LOCATION: APPEAL: REVIEW PROCESS: MAJOR ISSUES: William Snell for David and Julie Clobes AP-03-184 7425 Olympic View Drive GARY HAAKENSON MAYOR Appeal of staff decision denying the Steep Slope Exemption for the subject property. Hearing Examiner conducts public hearing and makes final decision. Compliance with Edmonds Community Development Code (ECDC) Chapter 20.15B.100.D.2. (CRITICAL AREAS). SUMMARY OF RECOMMENDATION AND DECISION: Staff Recommendation: Approve the appeal Hearing Examiner Decision: Approve the appeal PUBLIC HEARING: After reviewing the official file, which included the Planning Division Staff Advisory Report, and after visiting the site, the Hearing Examiner conducted a public hearing on the application. The hearing on the application was opened at3:00 p.m., February 19, 2004, in the City Hall, Edmonds, Washington, and closed at 3:05 p.m. Participants at the public hearing and the exhibits offered and entered are listed in this report. A verbatim recording of the hearing is available in the Planning Division. HEARING COMMENTS: The following is a summary- of the comments offered at the public hearing. Incorporated August 11, 1890 Sister City - Hekinan, Japan �"TIearing Examiner Decision Case No. AP-03-184 Page 2 From the City: Steve Bullock, Senior Planner, submitted the staff advisory report into the record. From the Appellant: William Snell, Applicant's Attorney, asked staff for clarification of one point in the staff advisory report. Brian Hall, Applicant's Geotechnical Engineer, said he concurred with the staff advisory report. From the Community: No one from the general public spoke at the public hearing. The applicant, William Snell, on behalf of property owners David and Julie Clobes, submitted an appeal of a Staff Decision to deny a Steep Slope Exemption. The Steep Slope Exemption is required for an addition to the Clobes' residence at 7425 Olympic View Drive, because the addition encroaches into a Steep Slope Hazard Area on the property (see Exhibit 1, Attachment Q. Staff initally determined during review of the Steep Slope Exemption application that one of the criteria that must be met in order for a Steep Slope Exemption to be approved, could not be met. The Steep Slope Exemption was denied. A letter of appeal was subsequently submitted to the William Snell, representing David and Julie Clobes. After review of the appeal information, staff determined that the appeal should be approved, with several conditions. FINDINGS OF FACT AND CONCLUSIONS: A. HISTORY 1. Application Chronology: a) Facts: (1) The applicants also applied for an Accessory Dwelling Unit permit since the reason for the proposed addition is to accommodate an Accessory Dwelling Unit. The application for the Accessory Dwelling Unit was approved. (2) During review of the Steep Slope Exemption application it became evident that one of the criteria that must be met in order for a Steep Slope Exemption to be approved could not be met. (3) The Staff Decision to deny the Steep Slope Exemption was issued on November 17, 2003. (4) A letter of appeal was subsequently submitted to the William Snell, representing the applicants, on December 1, 2003, within the allowed time period for an appeal. Hearing Examiner Decision Case No. AP-03-184 Page 3 B. APPEAL ISSUES 1. Issues raised by the Appellant: a) Summary of Statements by the appellant: (See Appeal Letter, Exhibit B) (1) The denial of the Steep Slope Exemption will prevent the applicants from constructing an Accessory Dwelling Unit that was previously approved on October 13, 2003. (2) The application meets the Steep Slope Exemption Criteria and the overall purpose of the code, "which is to provide for stable slopes." (3) This is because the concern over the loose soils is addressed by the HWA Geosciences, Inc. report because the report states that, "by removing the loose fill as part of the construction that the basement excavation will improve slope stability." b) City Staff Responses: (1) The purpose for the proposed addition to the residence is to accommodate an Accessory Dwelling Unit (ADU). The Accessory Dwelling Unit (ADU) application was approved prior to the denial Steep Slope Exemption, while the Steep Slope Exemption application was still pending. However, the ADU permit has a separate review process and a separate set of criteria than the Steep Slope Exemption. Staff is obligated to approve an application for an ADU if the applicant can demonstrate that all the criteria for an ADU may be met. The applicant still has to be able to meet all other relevant code criteria that are related to the addition of the Accessory Dwelling Unit to the residence. (2) Pages 3 through 7 (Section II.B.La.) of the Staff Decision (Exhibit C) addresses the application's compliance with the requirements for a Steep Slope Exemption. The section lists the criteria that must be met in order for a development or alteration within a Steep Slope Hazard Area. The project's compliance with each criterion were considered separately as they were addressed by the Geotechnical Report submitted by the applicant (Exhibit 1, Attachment C-3) as well as the peer review of this report (Exhibit 1, Attachment C-4). (4) As stated on page 4 (Section 11.13. La. l .£) of the Staff Report (Exhibit 1), one of the Steep Slope Exemption criteria is that, "Steep slope areas cannot be altered if the thickness of organics, debris, weathered soils, collovial soils or soils exhibiting loose conditions on or adjacent to the steep slope exceed three feet." (Exhibit 1, Attachment C) (5) Page 6 (Section H.B.I .a.9), of the Staff Decision (Exhibit 1) states that the loose soils criterion, "is addressed on pages 5 and 6 of the report. The report states that loose soils were encountered from 3.5 to 7.5 feet deep in two of the four test pits at the site." (Exhibit 1, Attachment C) I%W Hearing Examiner Decision Case No. AP-03-184 Page 4 (6) Staff had tried to determine, through the Steep Slope Exemption review process, whether or not the fact that the loose soils were of non-native origin meant that the application would satisfy the intent of the criterion. Staff ultimately determined that the origin of the loose soils alone was not of adequate consequence to determine that this criterion may be met. (7) The appeal letter made an issue of a statement in the HWA report that referred to removing the loose fill. (Exhibit 1, Attachment A) Staff considered this as a potential means to satisfy the criterion of concern. However, the ability for the application to potentially meet this criterion by the removal of the loose soil was not sufficiently detailed in the original HWA report. (8) In order for Staff to recommend approval of the appeal, the applicant would need to present additional information to demonstrate that the criterion having to do with loose soils at the site may be met. (9) The applicant's geotechnical engineer submitted an addendum to the original report (Exhibit 1, Attachment A). The information regarding this criterion clarified the origin and location of the loose soils at the site including supplementing the original information with additional test pit locations and more fully addressed the removal of the loose soils during the construction of the addition. (10) The report addendum (Exhibit 1, Attachment A), clarified the origin of the loose soils on the slope as being non-native and originating from un-permitted fill from the original home construction and garden refuse that has been dumped onto the slope. (11) The report also recommends that the fill and garden refuse should be removed during construction of the addition and details how this may be accomplished by the project. (Exhibit 1, Attachment A) (12) The report also documents how, once the un-permitted fill is removed, the slope complies with the loose soil criterion. It also goes on to say how the construction practices used will ultimately result in a more stable condition than currently exists. 2. Conclusions: (1) The application must meet all of the criteria required for a Steep Slope Exemption in order for a Steep Slope Exemption to be granted. (2) Through the review of the Steep Slope Exemption application, it became evident that the site bad loose soils that exceed three feet in depth and thus did not meet one of the criteria. This is what prorated staff to deny the application. (See Exhibit 1, Attachment C) ""llearing Examiner Decision Case No. AP-03-184 Page 5 (3) The applicant was able to demonstrate, through additional information obtained from the geotechnical engineer the loose soils criterion would ultimately be able to be met. (See Exhibit 1, Attachment A) (4) The appeal and the Steep Slope Exemption should be approved. The Steep Slope Exemption decision should have some specific conditions that will ensure that the project will be constructed to meet all the Steep Slope Exemption criteria. DECISION: Based upon the foregoing findings and conclusions, the appeal is approved, subject to the following conditions: A report by a state licensed geotechnical engineer must be submitted, prior to the ultimate approval of any building permit, that evaluates the specific construction plans for the addition to be constructed and any site alterations such as grading or construction of rockeries or retaining walls. 2. This report will need to demonstrate that the proposed development at the site meets the site and development specific criteria for granting a Steep Slope Exemption as required by ECDC 20.15.B.I IO.D2. 3. The report should include the following specific statement by the project geotechnical engineer: that, "the proposed development will not decrease stability on any adjacent property, and the site following the permitted activity will be stable." 4. This report will also need to state that the proposed alterations to and construction at the site meet the recommendations made by HWA Geosciences Inc. in the January 29, 2004, report addendum (Exhibit 1, Attachment A). 4. The construction plans and geotechnical report will need to demonstrate that if any proposed alteration of the slope extends beyond a 35 degree plane extended down from the property lines, structural shoring is utilized. 5. The construction plans and geotechnical report will need to show that the project will not include any rockeries greater than four feet in height that function as retaining structures and that all retaining structures are engineered structures that conform to the State Building Code. NOW "'" Iaring Examiner Decision Case No. AP-03-184 Page 6 Entered this 26th day of February 2004 pursuant to the authority granted the Hearings Examiner under Chapter 20.100 of the Community Development Code of the City of Edmonds. Ron McConnell, FAI Hearing Examiner RECONSIDERATION AND APPEAL: The following is a summary of the deadlines and procedures for filing reconsideration and appeal. Any person wishing to file or respond to a recommendation or appeal should contact the Planning Department for finther procedural information. REQUEST FOR RECONSIDERATION: Section 20.100.010.G allows for the Hearing Examiner to reconsider his decision or recommendation if a written request is filed within ten (10) working days of the date of the initial decision by any person who attends the public hearing and signs the attendance register and/or presents testimony or by any person holding an ownership interest in a tract of land which is the subject of such decision or recommendation. The reconsideration request must cite specific references to the findings and/or the criteria contained in the ordinances governing the type of application being reviewed. APPEALS: Section 20.105.020.A & B describe how appeals of a Hearing Examiner decision or recommendation shall be made. The appeal shall be made in writing, and shall include the decision being appealed along with the name of the project and the date of the decision, the name of the individual or group appealing the decision, their interest in the matter, and reasons why the appellant believes the decision to be wrong. The appeal must be filed with the Community Development Director within ten (10) working days after the date of the decision being appealed. TIME LIMITS FOR RECONSIDERATION AND APPEAL: The time limits for Reconsideration and Appeals run concurrently. If a request for reconsideration is filed before the time limit for filing an appeal has expired, the time clock for filing an appeal is stopped until a decision on the reconsideration request is completed. Once the Hearing Examiner has issued his decision on the reconsideration request, the time clock for filing an appeal continues from the point it was stopped. For example, if a reconsideration request is filed on day 5 of the appeal period, an individual would have 4 more days in which to file an appeal after the Hearing Examiner issues his decision on the reconsideration request. VW LAPSE OF APPROVAL: F"Hearing Examiner Decision Case No. AP-03-184 Page 7 Section 20.05.020.0 states 'Unless the owner obtains a building permit, or if no building is required, substantially commences the use allowed within one year from the date of approval, the conditional use permit shall expire and be null and void, unless the owner files an application for an extension of the time before the expiration date.' NOTICE TO COUNTY ASSESSOR: The property owner may as a result of the decision rendered by the Hearing Examiner request a change in the valuation of the property by the Snohomish County Assessors Office. EXHIBIT: The following exhibit was offered and entered into the record. 1. Planning Division Advisory Report, with 3 attachments PARTIES of RECORD: David and Julie Clobes 7425 Olympic View Dr. Edmonds, WA 98026 Paul Stromme 9623 8 " Ave. NE Seattle, WA 98115 William Snell 1111 Third Ave., Suite 220 Seattle, WA 98101-32078 Edmonds Planning Division CITY OF EDMONDS 121 5TH AVENUE NORTH, EDMONDS, WA 98020 PLANNING DIVISION ADVISORY REPORT FINDINGS, CONCLUSIONS, AND RECOMMENDATIONS To: Ron McConnell, Hearing Examiner From: C,! , . - Cp _tat . 0 0 Star Campbell Planner Date: FEBRUARY 11, 2004 File: AP-03-184 Appeal of a Staff Decision by William Snell for David and Julie Clobes Hearing Date, Time, And Place: February 19, At 3:00 PM, 3`d Floor Meeting Room Edmonds City Hall 121 5 b Avenue North TABLE OF Section I. INTRODUCTION................................................................................................................2 A. Application...............................................................................................................................................2 B. Recommendations....................................................................................................................................2 II. FINDINGS OF FACT AND CONCLUSIONS...................................................................3 A. History .....................................................................................................................................................3 B. Appeal Issues...........................................................................................................................................3 III. RECONSIDERATION AND APPEALS............................................................................5 A. Request for Reconsideration....................................................................................................................6 B. Appeals.................................................................................................................................................... 6 IV. APPENDICES.....................................................................................................................6 V. PARTIES OF RECORD......................................................................................................6 AP-03-184sr.doc / Febmary 11, 2004 / Staff Report Clobes Appeal File No. AP-03-184 Page 2 of 6 I. INTRODUCTION The applicant, William Snell, on behalf of property owners David and Julie Clobes, has submitted an appeal of a Staff Decision to deny a Steep Slope Exemption. The Steep Slope Exemption is required for an addition to the Clobes' residence at 7425 Olympic View Drive, because the addition encroaches into a Steep Slope Hazard Area on the property (see Staff Decision — Introduction). However, staff determined during review of the Steep Slope Exemption application that one of the criteria that must be met in order for a Steep Slope Exemption to be approved, could not be met. The Steep Slope Exemption was denied. A letter of appeal was subsequently submitted to the William Snell, representing David and Julie Clobes. The following is the Edmonds Planning Division's analysis and recommendation of this appeal. A. Application 1. Applicant: William Snell for David and Julie Clobes. 2. Site Location: 7425 Olympic View Drive (see Exhibit C, Attachment 1). 3. Request: Appeal of Staff Decision (see Exhibit B). 4. Review Process: Hearing Examiner conducts public hearing and makes final decision. 5. Major Issue: a. Compliance with Edmonds Community Development Code (ECDC) Chapter 20.15B.100.D.2. (CRITICAL AREAS). B. Recommendations Based on statements of Fact, Conclusions, and Attachments in this report we recommend APPROVAL of the appeal with the following conditions: 1. A report by a state licensed geotechnical engineer must be submitted, prior to the ultimate approval of any building permit, that evaluates the specific construction plans for the addition to be constructed and any site alterations such as grading or construction of rockeries or retaining walls. 2. This report will need to demonstrate that the proposed development at the site meets the site and development specific criteria for granting a Steep Slope Exemption as required by ECDC 20.15.B.110.D2. 3. The report should include the following specific statement by the project geotechnical engineer: that, "the proposed development will not decrease stability on any adjacent property, and the site following the permitted activity will be stable." 4. This report will also need to state that the proposed alterations to and construction at the site meet the recommendations made by HWA Geosciences Inc. in the January 29, 2004, report addendum (Exhibit A). AP-03-184sr.dw / February 11, 2004 / Staff Report Clobes Appeal File No. AP-03-184 Page 3 of 6 4. The construction plans and geotechnical report will need to demonstrate that if any proposed alteration of the slope extends beyond a 35 degree plane extended down from the property lines, structural shoring is utilized. 5. The construction plans and geotechnical report will need to show that the project will not include any rockeries greater than four feet in height that function as retaining structures and that all retaining structures are engineered structures that conform to the State Building Code. II. FINDINGS OF FACT AND CONCLUSIONS A. History 1. Application Chronology: a) Facts: (1) The applicants also applied for an Accessory Dwelling Unit permit since the reason for the proposed addition is to accommodate an Accessory Dwelling Unit. The application for the Accessory Dwelling Unit was approved. (2) During review of the Steep Slope Exemption application it became evident that one of the criteria that must be met in order for a Steep Slope Exemption to be approved could not be met. (3) The Staff Decision to deny the Steep Slope Exemption was issued on November 17, 2003. (4) A letter of appeal was subsequently submitted to the William Snell, representing the applicants, on December 1, 2003, within the allowed time period for an appeal. B. Appeal Issues 1. Issues raised by the Appellant: a) Summary of Statements by the aoaellant: (See Appeal Letter, Exhibit B) (1) The denial of the Steep Slope Exemption will prevent the applicants from constructing an Accessory Dwelling Unit that was previously approved on October 13, 2003. (2) The application meets the Steep Slope Exemption Criteria and the overall purpose of the code, "which is to provide for stable slopes." (3) This is because the concern over the loose soils is addressed by the HWA Geosciences, Inc. report because the report states that, "by removing the loose fill as part of the construction that the basement excavation will improve slope stability." AP-03-184sr.doc / February 11, 2004 / Staff Report Clobes Appeal File No. AP-03-184 Page 4 of 6 b) City Staff Responses: (1) The purpose for the proposed addition to the residence is to accommodate an Accessory Dwelling Unit (ADU). The Accessory Dwelling Unit (ADU) application was approved prior to the denial Steep Slope Exemption, while the Steep Slope Exemption application was still pending. However, the ADU permit has a separate review process and a separate set a criteria than the Steep Slope Exemption. Staff is obligated to approve an application for an ADU if the applicant can demonstrate that all the criteria for an ADU may be met.. The applicant still has to be able to meet all other relevant code criteria that are related to the addition of the Accessory Dwelling Unit to the residence. (2) Pages 3 through 7 (Section II.B.l.a.) of the Staff Decision (Exhibit C) addresses the application's compliance with the requirements for a Steep Slope Exemption. The section lists the criteria that must be met in order for a development or alteration within a Steep Slope Hazard Area. The project's compliance with each criterion were considered separately as they were addressed by the Geotechnical Report submitted by the applicant (Exhibit C, Attachment 3) as well as the peer review of this report (Exhibit C, Attachment 4). (3) As stated on page 4 (Section II.B.l.a.l.f.) of the Staff Report, one of the Steep Slope Exemption criteria is that, "Steep slope areas cannot be altered if the thickness of organics, debris, weathered soils, collovial soils or soils exhibiting loose conditions on or adjacent to the steep slope exceed three feet." (Exhibit C) ' (4) Page 6 (Section II.B.l.a.9), of the Staff Decision states that the loose soils criterion, "is addressed on pages 5 and 6 of the report. The report states that loose soils were encountered from 3.5 to 7.5 feet deep in two of the four test pits at the site." (Exhibit C) (5) Staff had tried to determine, through the Steep Slope Exemption review process, whether or not the fact that the loose soils were of non- native origin meant that the application would satisfy the intent of the criterion. Staff ultimately determined that the origin of the loose soils alone was not of adequate consequence to determine that this criterion may be met. (6) The appeal letter made an issue of a statement in the HWA report that referred to removing the loose fill. (Exhibit A) Staff considered this as a potential means to satisfy the criterion of concern. However, the ability for the application to potentially meet this criterion by the removal of the loose soil was not sufficiently detailed in the original HWA report. AP-03-184sr.dw / February 11, 2004 / Staff Report `IN �. Clobes Appeal File No. AP-03-184 Page 5 of 6 (7) In order for Staff to recommend approval of the appeal, the applicant would need to present additional information to demonstrate that the criterion having to do with loose soils at the site may be met. (8) The applicant's geotechnical engineer submitted an addendum to the original report (Exhibit A). The information regarding this criterion clarified the origin and location of the loose soils at the site including supplementing the original information with additional test pit locations and more fully addressed the removal of the loose soils during the construction of the addition. (9) The report addendum (Exhibit A), clarified the origin of the loose soils on the slope as being non-native and originating from on - permitted fill from the original home construction and garden refuse that has been dumped onto the slope. (lo)The report also recommends that the fill and garden refuse should be removed during construction of the addition and details how this may be accomplished by the project. (Exhibit A) (11)The report also documents how, once the un-permitted fill is removed, the slope complies with the loose soil criterion. It also goes on to say how the construction practices used will ultimately result in a more stable condition than currently exists. 2. Conclusions: (1) The application must meet all of the criteria required for a Steep Slope Exemption in order for a Steep Slope Exemption to be granted. (2) Through the review of the Steep Slope Exemption application, it became evident that the site had loose soils that exceed three feet in depth and thus did not meet one of the criteria. This is what prorated staff to deny the application. (See Exhibit Q (3) The applicant was able to demonstrate, through additional information obtained from the geotechnical engineer the loose soils criterion would ultimately be able to be met. (See Exhibit A) (4) The appeal and the Steep Slope Exemption should be approved. The Steep Slope Exemption decision should have some specific conditions that will ensure that the project will be constructed to meet all the Steep Slope Exemption criteria. III. RECONSIDERATION AND APPEALS The following is a summary of the deadlines and procedures for filing reconsideration's and appeals. Any person wishing to file or respond to a recommendation or appeal should contact the Planning Department for further procedural information. AP-03-184sndoc / February 11, 2004 / Staff Report Clobes Appeal File No. AP-03-184 Page 6 of 6 A. Request for Reconsideration Section 20.100.010.G allows for the Hearing Examiner to reconsider his decision or recommendation if a written request is filed within ten (10) working days of the date of the initial decision by any person who attends the public hearing and signs the attendance register and/or presents testimony or by any person holding an ownership interest in a tract of land which is the subject of such decision or recommendation. The reconsideration request must cite specific references to the findings and/or the criteria contained in the ordinances governing the type of application being reviewed. B. Appeals Pursuant to Section 20.105.030.D the Hearing Examiner's decision on the appeal of a staff decision of a project permit application is final and no appeal the City Council is permitted. IV. APPENDICES Exhibits A, B, and C: a. Geotechnical Report — Addendum by HWA Geosciences Inc. dated January 29, 2004. b. Appeal of Staff Decision dated November 26, 2003 c. Staff Decision to deny Steep Slope Exemption dated 7425 Olympic View Dr. with the following attachments: 1. Vicinity and Zoning Map 2. Project Site Plan 3. Geotechnical Report by HWA Geosciences Inc. dated July 3, 2003. 4. Geotechnical Peer Review Addendum by Geo Group Northwest Inc. dated September 26, 2003. V. PARTIES OF RECORD David and Julie Clobes William Snell Paul Stromme 7425 Olympic View Dr. 1111 Third Ave., Suite 220 9623 8' Ave. NE Edmonds, WA 98026 Seattle, WA 98101-32078 Seattle, WA 98115 AP-03-184sr.doc / February 11, 2004 / Staff Report F L _ MAGEOSCIENCES INC. Geotethnital Engineering • Hydrogeology • Geaennronmental Services • Inspection d Testing January 29, 2004 ? rsy st. HWA Project No. 2003082-21 Mr. David Clobes 7425 Olympic View Drive 1 ` Edmonds, Washington 98026 ' Subject: GEOTECHNICALREPORT-ADDENDUM Proposed Extension to Residence ' 7425 Olympic View Drive, Edmonds, Washington Dear Mr. Clobes; ' As requested, HWA GeoSciences Inc. (HWA) met with the City of Edmonds to discuss the steep slope exemption required to construct the proposed extension on the eastern end of your house. We have also had discussions with Stephen Beardsley, of Lovell-Sauerland & Associates, Inc., regarding the slopes at the western side of your house. This letter provides our conclusions and recommendations and should be included as an addendum to our ' geotechnical report dated July 3, 2004. Steep Slope on Eastern Side of House The Critical Areas Chapter of the Edmond Community Development Code (ECDC) 20.15B.I10 (f) state; "Steep slopes cannot be altered if the thickness of organics, debris, ' weathered soils, colluvial soils or soils exhibiting loose conditions (as measured by the Standard Penetration Test (ASTMD1586)) on or adjacent to the portion of the subject property classified as a steep slope exceeds 3 feet ". The original explorations undertaken by HWA (see Figure 2) show that the loose soil thickness is 3 feet at HH-1, 7.5 feet at HH-2, and 3.75 feet at HH-4. Based on these explorations; we concluded that the loose soil, which is mainly located at the foot of the slope, is un-permitted fill that was placed a long time ago, probably at the time of original ' house construction. We understand from Mr. Clobes that some of this fill was placed by the previous owner as part of the septic field construction. The septic field is no longer in use, and the house is connected to the municipal sewer system. ' On January 28, 2004, HWA undertook three Dynamic Cone Penetration (DCP) tests at the locations shown on the attached revised Figure 2. These explorations were undertaken to confirm that the thickness of loose soil directly behind the planned addition is similar to that encountered in the original explorations. The attached DCP plots show the following: 19730 - 64th Avenue W. Suite 200 Lynnwood, WA 98036.5957 ' TeL 425.774.MO6 EXHIBIT A ' C-' t January 29, 2004 HWA Project No. 2003082-21 ' Test Designation Description ' DCP 1 DCP 2 5.3 feet of loose soil over medium dense to dense soil. 3.1 feet of loose soil over medium dense soil. DCP 3 3.8 feet of garden refuse over 1.2 feet of loose soil, over medium dense becoming dense soil. Based on these recent DCP results, we consider that the initial explorations accurately ' represent the soil conditions in the portion of slope directly behind the proposed addition. The presence of garden refuse (mainly shrub trimmings and grass clipping) at the top of the ' slope along the entire north property line, should be noted. In DCP 3, this dumped garden refuse is 3.8 feet, and we estimate it be about 10 feet thick near the northeast comer of the property. We recommend that such garden refuse should be removed because it can become ' saturated and slide off the slope. We understand from our discussion with the City that if the planned construction were to ' remove the loose fill and so bring the slope into compliance with the ECDC, the City would likely be able to grant a steep slope exemption. Therefore, we recommend construction of the extension should consist of the following: 1. Remove all dumped garden refuse from the upper portion of the slope. ' 2. Remove all loose (un-permitted) fill from the foot of the slope along the length of the proposed extension, and sufficiently far beyond the end of the extension to allow safe excavation slopes for the planned construction. Based on the explorations completed as part of the original investigation and on the recent DCP tests, we consider that removal of the loose fill will bring the slope into compliance with the ECDC with regard to the thickness of loose fill. ' 3. Construct a retaining wall generally in line with the existing rockery wall along the north side of the property to form both shoring for the basement excavation, and a permanent retaining wall. Detailed design of the wall/shoring will be undertaken at the ' time of detailed design of the extension, and it should be recognized that the City of Edmonds does not permit a rockery wall to retain fill. However, to match the existing rockery wall, we anticipate that the City would allow a rockery facing to be constructed ' in front of a permanent retaining wall constructed in accordance with Building Code requirements. 4. Excavate material in front of the shoring wall to allow construction of the lower level of the planned house. In order to satisfy the temporary excavation stability requirements of Part N of the Washington Administrative Code 296-155, the unsupported excavation slopes should not exceed 1.5H:1 V. Therefore, any loose native material remaining 20MOn-21 GeoachniW RepM - Addmd= 2 HWA GEOSCMNCES INC. January 29, 2004 HWA Project No. 2003082-21 after excavation of the loose fill, will be excavated because the house foundation must extend down to at least medium dense founding material. 5. The basement wall will be structurally designed to resist earth pressures generated by the fill and slope soils as recommended in the original HWA geotechnical report. Replacement fill will be provided behind the basement wall to match the existing deck grade (El. 313.04 feet). This fill should comprise adequately compacted structural fill. This structural fill will add stability to the slope, by virtue of greater strength and reduced earth pressures. It is reasonable to conclude that any fill placed at this position on the slope (i.e. near the toe of the upper steep section) will, in fact, add to the stability of that section of slope above it. With regard to the slope section below, it will not decrease the level of stability provided that the weight of the fill remaining is less than currently existing, and measures will be implemented to ensure that this is so. Slope on West Side of the House The ECDC 20.15B060(A)(3)(c) defines a steep slope hazard area as "any ground that rises at an inclination of 40 percent or more within a vertical elevation change of at least 20 feet (a vertical rise of 10 feet or more for every 25 feet of horizontal distance). A slope is delineated by establishing its toe and top and measured by averaging the inclination over at least 20 feet of vertical relief'. Based on the cross sections added (SB addition dated January 19, 2004) to the revised topographic survey prepared by Lovell-Sauerland & Associates, Inc., the slope at the east side of the house is less than 20 feet high and is, by ECDC definition, not a steep slope. In addition, because of the existing deck elevation of the existing house (El. 313.04 feet), there is no steep slope along the length of the existing house. ^•O 2003092-21 Geotechnical Report -Addendum 3 HWA GEOSCIENCEs INC. January 29, 2004 O C HWA Project No. 2003082-21 We appreciate the opportunity to be of service. If you have any questions or concerns, please do not hesitate to contact us. Sincerely, HWA GwSmNas INc. � zocv EXPIRES 02f 04 70 61 Brian E. Hall, P.E. Senior Geotechnical Engineer Lome Balanko, P.E. Principal 2003092-21 GeokeMical Report -Addendum 4 HWA GEOScwNCEs INC. 401-. t moll "I 0 Lf) R O 04 cn IT In co r, Go Ps;'41dea v U �A a, Az 9 L SN cif h i O i /o ------------------- F _ f'rP-D3-t 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 BEFORE EDMONDS HEARING EXAMINER APPEAL OF DAVID AND JULIE CLOBES I STATEMENT OF APPEAL On behalf of David and Julie Clobes the staff decision of the Development Services Department ("DSD') denying the Steep Slope Exemption for the property at 7425 Olympic View Dr., File No. SD-2003-115, is hereby appealed. The DSD decision is dated November 17, 2003. David and Julie Clobes are the owners of the property at 7425 Olympic View Dr. They are is directly and adversely impacted by the denial of the Steep Slope Exemption, since it will prevent them from constructing an accessory dwelling unit, which was previously approved by DSD on October 13, K111 ?I The decision of DSD is erroneous, contrary to law and factually inaccurate. The sole basis for the denial is under Section 20.15B.110.D.21, that provides restrictions on the alteration of steep slopes areas "...if the thickness of organics, debris, weathered soils, collovial soils or soils exhibiting loose conditions ... on or adjacent to the portion of the subject property classified as steep slope exceeds three feet." We will show that the Clobes' application meets the Steep Slope Exemption criteria and that the overall purpose of the code is met, which is to provide for stable slopes. The concern of DSD with regard to loose soils is addressed in the report of the geologist. Brain Hall of LAW OFFICES OF STATEMENT OF APPEAL - 1 WILIIAM N. SNELL C:NDocumenfs and Settings0wner\My Docmne WFORMS R I1117HIRD AVENUE ADMINISTRATIVE LAWWd. Law PleadingsWppeal to SEA HE ftniAm SEATTIE, EXHIBIT B j j 1 2 3 4i 5' 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 HWA Geosciences, Inc., stated that by removing the loose fill as part of the construction that the "basement excavation will improve slope stability." The Clobes request that decision of denial of the Steep Slope Exemption be reversed. DATED this day of November, 2003 Respectfiilly submitted, LAW OFFICES OF WILLIAM N. SNELL, P.S. William N. Snell Attorney for David and Julie Clobes STATEMENT OF APPEAL - 2 C:zocmnants and Sefthw\0vmaWy Do=entsTORMS & ADIAMSMAUVE LAW(Ad. Law Pkadings\Appeal to SEA HE Prael.doc LAW OFFICES OF WIL IAM N. SNELL 11117EIDtD AVENUE sunE 2220 SEAT" WASHINGM 98101-32078 TEL (206) 38&7855 CITY OF EDMONDS 121 - 5TH AVENUE NORTH, EDMONDS, WA 98020 PLANNING DIVISION STAFF REPORT FINDINGS, CONCLUSIONS, AND DECISION To: File, SD-2003-115 From: � 16 . C����s nsl Star Campbell Planner Date: NOVEMBER 17, 2003 File: SD-2003-115 7425 OLYMPIC VIEW DRIVE, STEEP SLOPE EXEMPTION Decision Date: NOVEMBER 17, 2003 TABLE OF CONTENTS Section Paee I. INTRODUCTION..............................................................................................................2 A. APPLICATION.....................................................................................................................................2 B. DEciS10N...........................................................................................................................................2 H. FINDINGS OF FACT AND CONCLUSIONS................................................................2 A. SrrE DEscpiPnoN.............................................................................................................................2 B. EDMONDS COMMUNrrY DEVELOPMENT CODE (ECDC) COMPLIANCE .............................................. 3 C. TECHNICAL COMMITTEE....................................................................................................................7 I. RECONSIDERATIONS AND APPEALS.......................................................................7 H. APPENDICES ......................................... »......................................................................... 8 III. PARTIES OF RECORD...................................................................................................8 SD-03-115snakethm.doc / Nm mba 17, 2C EXHIBIT C J File No. SD-03-115 ® Page 2 of 7 I. II. INTRODUCTION Paul Stromme, on behalf of the owners, Dave and Julie Clobes has submitted a Steep Slope Exemption application to allow for an addition to the Clobes' residence at 7425 Olympic View Dr. This site contains a "Steep Slope Hazard Area." A "Steep Slope Hazard Area" is defined by the Critical Areas Chapter of the Edmonds Community Development Code (ECDC) as a slope of at least 40% within the broader category of "Geologically Hazardous Areas." The ECDC does not allow for any development or alteration of Steep Slope Hazard Areas unless an exemption has been granted. The procedure for obtaining a Steep Slope Exemption involves the preparation of a geotechnical analysis of the site by a State licensed Geotechnical Engineer. This analysis must demonstrate that the site has certain physical features and that the proposed development meets a specific list of characteristics as specified in the Steep Slope Exemption section of the Critical Areas Ordinance. In addition, the development must not compromise the stability of the site or any adjacent sites. Through the review process for the Steep Slope Exemption, the applicant was unable to demonstrate that the site had all the physical features necessary to allow it to qualify for a Steep Slope Exemption. The following is Staff's review and analysis of the Steep Slope Exemption application: A. Application 1. Applicants: Dave and Julie Clobes. 2. Site Location: 7425 Olympic View Dr. (See Attachment 1). 3. Request: Steep Slope Exemption 4. Review Process: Staff Decision 5. Malor Issue: Compliance with Edmonds Community Development Code (ECDC) Chapter 20.1513.110.D.2. (CRITICAL AREAS) B. Decision Based on statements of Fact, Conclusions, and Attachments in this report the Steep Slope Exemption request does not meet all of the exemption criteria and is therefore DENIED. FINDINGS OF FACT AND CONCLUSIONS A. Site Description 1. Site Development and Zoning: a) Facts: (1) Zoning: The zoning of the subject property is Single Family Residential (RS-12). (See Attachment 1) (2) Current Land Use: The lot is currently developed with a Single -Family Residence. SD-03-115srtakethre Am / November 17, 2003 1 Staff Report MIA Pile No. SD-03-115 Page 3 of 7 (3) Proposed Development: The applicants are proposing to construct an addition to their residence. See Attachment 2. (4) Terrain and Vegetation: The hot rises gently in a general south to north direction over much of the lot and then just to the north of the house rises steeply. See Figure 2 of Attachment 3. Vegetation around the house consists of residential landscaping. The slope has several large evergreens and ivy undergrowth. 2. Neighboring Development and Zoning: a) Fact: The surrounding properties are zoned and developed to the "Single - Family Residential' (RS-12) designation. (See Attachment 1) b) Conclusion: The proposal would allow the continued development of the lot with a single-family residence. This is consistent with the surrounding development. B. Edmonds Community Development Code (ECDC) Compliance 1. Compliance with requirements for a Steep Slope Exemption Section D of ECDC Chapter 20.15B.110 (Development Standards- Geologically Hazardous Areas) addresses development in Steep Slope Hazard Areas. This section states that no development or alteration shall be allowed in steep slope hazard areas unless the property qualifies for an exemption or exception under the provisions of this section. a) Facts: (1) ECDC Section 20.15B.110.D.2 establishes the following list of criteria that must be met in order for a development or alteration to qualify for an exemption: (a) The proposed development will not decrease stability on any adjacent property, and the site following the permitted activity will be stable. (b) The development will occur on steep slope areas that either are mapped as one of the following deposits on the "Geological Map of the Edmonds East and part of the Edmonds West Quadrangles", by James P. Minard: Till, Advance Outwash, and/or Olympia Gravel or on steep slope areas comprised of fill placed under engineered conditions on stable geological deposits of these same soils. The fill must meet the following conditions: all fill was placed under a legal grading permit, the grading and fill were designed by a licensed professional engineer, native soils beneath the fill were prepared in accordance with the engineering design, and compaction testing confirms that uniform compaction to the specified percentage is present throughout the entire fill. (c) All excavations on steep slopes will not extend below a 35-degree plane extended down from the property lines, unless the excavation is retained by structural shoring. The shoring must be designed by a registered professional engineer. SD-03-115srtakethree.doc / November 17, 2003 / Staff Report File No. SD-03-115 Page 4 of 7 (d) All retaining structures on steep slopes shall be engineered structures conforming to the State Building Code and rockeries greater than four feet in height are not permitted. (e) Steep slope areas cannot be altered if one or more of the following conditions are on or adjacent to the steep slope: impermeable soils interbedded with granular soils, springs or groundwater seepage, significant visible evidence of groundwater seepage, previous landsliding or instability, or existing landslide deposits. (f) Steep slope areas cannot be altered if the thickness of organics, debris, weathered soils, collovial soils or soils exhibiting loose conditions on or adjacent to the steep slope exceed three feet. (g) A buffer of 15 feet shall be retained in an undisturbed condition from commercial development to property lines of adjacent residential properties. (2) ECDC Section 20.15B. I 10.17 states the requirement that all applications for development proposals within geologically hazardous areas shall be accompanied by a written site analysis by a geologist or geotechnical engineer licensed by the state of Washington. A peer review of this document is also required. (3) The applicant submitted a geotechnical report by HWA Geosciences Inc. that addresses the Steep Slope Exemption Criteria (See pages 4 through 6 of Attachment 3). (4) The criterion that states that, "The proposed development will not decrease stability on any adjacent property, and the site following the permitted activity will be stable" is addressed on page 4. (a) The report, in specifically addressing this criterion, does not specifically state that the development will not decrease stability on the site or on adjacent sites. (b) This section does state that, "the excavation could impact the 10-foot exception zone shown on Figure 2" and that, "...the short term risk of slope instability on the subject property will be low." (c) A statement is made in another section of the report on page 3 that, the project, "can be safely achieved without impacting the stability of the adjacent, upslope property." (5) The criterion that addresses the types of soil deposits required on the site as stated in the above Section II.B.l.a).(1).(b) of the Staff Report is addressed on pages 4 and 5 of the HWA report (Attachment 3). It states that the site is mapped as one of the allowed types of deposits and that the fill at the site should be removed. (6) The criterion that states that, "All excavations on steep slopes will not extend below a 35-degree plane extended down from the property lines, unless the excavation is retained by structural shoring... designed by a registered professional engineer" is addressed on page 5 of the report. SD-03-115srtakethreeAm / November 17, 2003 / Staff Report I File No. SD-03-115 Page 5 of 7 (a) The report states that the excavation will not extend below a 35 degree plane drawn from the lot line but does extend below a 35 degree plane drawn from the edge of the exception zone. Since this exception zone is actually not part of the property, it appears that the excavation will extend below a 35 degree plane extended down from the north property line. (b) A rockery is referred to (see below Section II.B.l.a).(7).(d) of the Staff Report that apparently would also intersect this 35 degree plane. There is no statement made to indicate whether or not the project design will utilize structural shoring. However, this is a requirement that may be incorporated into the project as a condition of construction. (7) The criterion that states that, "All retaining structures on steep slopes shall be engineered structures conforming to the State Building Code and rockeries greater than four feet in height are not permitted" is addressed on page 5 of the report. (a) The report states that, `retaining structures should be engineered in conformance with the Building Code," and refers to an approximately 8' high rockery that is planned. This rockery is shown in Figure 5 of the report. (b) Rockeries are not considered by the City of Edmonds Building Division to be retaining walls. Rockeries are traditionally used for landscaping and/or erosion control and have less restrictive structural standards than retaining walls. (c) The City of Edmonds Building Division recognizes that retaining walls may be used for soils that are not capable of standing or remaining at the existing slope. Retaining walls must be designed based on standard engineering methods provided by the Uniform Building Code and WSDOT/APWA Standard specifications for Road, Bridge, and Municipal Construction. (d) A rockery is referred to on page 8 of the report. This would be an extension of the existing rockery to the north of the house. It would be located to the north of a deck that would be built behind the addition and a maximum of 8 feet high. The extension of the deck and rockery is not shown on the project site plan (Attachment 2) or the HWA report Figure 2 site plan or Figure 3 cross section. (e) It is not clear whether the proposed rockery functions as a retaining structure. SD-03-115srtakethree.doc / November 17, 2003 / Staff Report i 1 ) File No. SD-03-115 Page 6 of 7 (8) The criterion that states that, "Steep slope areas cannot be altered if one or more of the following conditions are on or adjacent to the steep slope: impermeable soils interbedded with granular soils, springs or groundwater seepage, significant visible evidence of groundwater seepage, previous landsliding or instability, or existing landslide deposits" is addressed on pages 5 of the report. The report states that, "No impermeable soils interbeddd within the advance outwash were encountered; no seepage was encountered, or evidence of previous seepage noted; and no signs of slope instability observed." (9) The criterion that states that, "Steep slope areas cannot be altered if the thickness of organics, debris, weathered soils, collovial soils or soils exhibiting loose conditions on or adjacent to the steep slope exceed three feet" is addressed on pages 5 and 6 of the report. The report states that loose soils were encountered from 3.5 to 7.5 feet deep in two of the four test pits at the site. (10)The criterion that states that, "a buffer of 15 feet shall be retained in an undisturbed condition from commercial development to property lines of adjacent residential properties" is not applicable to this project as the project is not considered to be commercial development. (I I)A peer review document by Geo Group Northwest that addresses the Steep Slope Exemption criteria has been included as Attachment 4. This report concludes, on page 2, that the proposal does not satisfy the Steep Slope Exemption criteria that has to do with the depth of loose soils at the site. b) Conclusions: (1) Staff has reviewed the geotechnical report by HWA Geosciences Inc. (Attachment 3). In addition, Staff has reviewed and taken into consideration the peer review report provided by Geo Group Northwest, Inc. (Attachment 4). (2) The criteria that have to do with the aspects of the development as stated in above Sections II.B.l.a).(1).(a).,(c), and (d) of the staff report may potentially be dealt with as conditions of approval. If further information is required in order to more fully demonstrate that the development will meet these criteria, this can be required with the review of the building permit for the development. (3) For this project, additional information would be needed to ensure that aspects of the development would qualify for a Steep Slope Exemption as follows: a specific statement would need to be made by the project geotechnical engineer that, "the proposed development will not decrease stability on any adjacent property, and the site following the permitted activity will be stable;" if any proposed alteration of the slope extends beyond a 35 degree plane extended down from the property lines, structural shoring would need to be utilized; construction plans would need to show that the project would not include any rockeries greater than four feet in height and that all retaining structures were engineered structures conforming to the State Building Code. SD-03-115srtakethree.doc / November 17, 2003 / Staff Report File No. SD-03-115 Page 7 of 7 (4) hi order for a Steep Slope Exemption to be approved with the conditions that specific aspects of the development will meet the criteria for a Steep Slope Exemption, it must be apparen that the specific site standards required for a Steep Slope Exemption can be et. (5) The criteria that have to do with the specific characteristics of the property as stated in above Sections II.B.l.a).0).(b).,(e), and (f). of the staff report appear to have been met with the exception of the criterion that states that, "steep slope areas cannot be altered if the thickness of organics, debris, weathered soils, collovial soils or soils exhibiting loose conditions on or adjacent to the steep slope exceed three feet." (6) Since this criterion may not be met, the Steep Slope Exemption should be. denied. 2. Compliance with Public Notification Requirements a) Facts: (1) ECDC 20.15B. I I O.D.3 requires Steep Slope Exemptions to be processed as staff decisions with public notification required as regulated by ECDC 20.95.050. (2) A notice of application was posted for public comment on August 22, 2003. There was a two -week public comment period that ended on September 5, 2003. (3) There were no public comments received. b) Conclusion: The City and the Applicant have complied with the requirements for public notification. C. Technical Committee Review by City Departments: The application has been reviewed and evaluated by the Engineering Division and the Fire Department, Public Works Department and Parks and Recreation Department. There were no comments received related to the Steep Slope Exemption proposal. III. RECONSIDERATIONS AND APPEALS A. Reconsideration of Decision A request for reconsideration or clarification of this decision may be made by filing a letter with the Planning Department by December 2. 2003. This is within ten (10) working days of the mailing of this notice (see mailing date below). B. The Right to Appeal This decision may be appealed to the Hearing Examiner. In this case, a written appeal letter must be submitted with the required appeal fee to the Planning Department by December 1.2003. This is within fourteen (14) calendar days of the mailing of this notice (see mailing date below). S1303-115snakethree.doc / November 17, 2003 / Staff Report 4 File No. SD-03-115 Page 8 of 7 City of Edmonds, Attn.: Planning Division 121- 5th Avenue North Edmonds, Washington 98020 DATE MAILED: November 17, 2003 IV. APPENDICES Attachments 1 through 4: 1. Vicinity and Zoning Map 2. Project Site Plan 3. Geotechnicai Report by HWA Geosciences Inc. dated July 3, 2003. 4. Geotechnical Peer Review Addendum by Geo Group Northwest Inc. dated September 26,2003. V. PARTIES OF RECORD Dave and Julie Clobes 7425 Olympic View Dr. Edmonds, WA 98026 Paul Stromme 9623 8"Ave. NE Seattle, WA 98115 SD-03-115sriakethree.doc / November 17, 2003 / Staff Report i802f IM20 n fea¢H R iH028 n 16101 /8103 feo32 -too 18111 yy +p N 18108 18115 18116 Iefa is fella 18125 iezi4 1 12 18203 I8201 fez1H ie I8209 18211 18211 18214 18223 18219 �p ? `3 18222 18228 18320 7001 18311 18105 18225 18220 Z _n 18227 18228 n R 1s= 18303 /8305 18308 IMM 18312 18312 18329 \\III' 18409 18408 18107 18412 BC _- R � 18411 18410 18415 18416 r 18417 18424 18423 18424 10.502 i4 23 18430 /8428 18302 111510 dry h 78129 18504 18503 / M iH530 _ 18510 18509 �' 1&583 - iB51H 18521 'h x x R 18624 18710 h k 18720 =• t ,AJ me ..-C' . 18730 r OK Zoning and Vicinity Map Attachment 1 ^�'�• g0 6ZVM'ONV- V30131 sec-set•sr� ^"�"^`A'M 5OA`�''� SSZb-ZEZ _L 4 S 4008 Ip.�'�.� 2«B11F1 tlVw;^O dtl'NV 3a :a2/ i�00/N-Ja/�AbLL/QQY i✓lLA6q/92� `4 Q '7Opp:+vtLMVi9'W/Ave+A y) "��Hrt l+'!//JVj Try>lnAnH a.'�P A ZWi'IS � �9Y�.WloJ 'bsaw URN noo a3 !�t4 j� a � .•.,u. rue � i ° : i � - ! ; > 3=Fe2= F r` PF YI -11 R� ATTACHMENT 2 July 3, 2003 HWA Project No. 2003082-21 Mr. David Clobes 7425 Olympic View Drive Edmonds, Washington 98026 Subject: GEOTECHNiCALREPORT Proposed Extension to Residence . 7425 Olympic View Drive, Edmonds, Washington Dear Mr. Clobes; HWAGEOSCIEKB INC 29730-64TH AVE. W., SUITE 200 LYNNWOOD, WA 98036-5957 TEL 425-774-0106 FAX. 425-774-2714 E-MAIL hwaQhongwest.mm This report presents the results of a geotechnical investigation, undertaken for a proposed extension to the northeast end of your residence, at 7425 Olympic View Drive in Edmonds, Washington (Figure 1). The proposed extension is located on a slope defined as a Steep Slope Hazard Area in the City of Edmonds Municipal Code (EMC). The purpose of this report is to investigate whether the proposed extension can be safely constructed as planned, and is consistent with the requirements of the EMC. Our work included a site reconnaissance, subsurface explorations, laboratory testing, and engineering analyses to develop our results and conclusions. PROJECT DESCRIPTION We understand that the planned 2-story extension will have footprint dimensions of 22 feet by 30 feet (Figure 2), and floor elevations will match those of your existing house (main ' floor at EI.304.37 feet and upper floor at El. 313.12 feet). Excavation to a maximum depth of about 12 feet below existing ground surface is required. An extension is also planned for the western end of the house, but is not impacted by steep slope requirements. SITE DESCRIPTION AND OBSERVATIONS The lot has approximate dimensions of 160 feet by 90 feet and is located on the northeast side of the intersection of Olympic View Drive and Homeview Drive (Figure 2). Residential lots border the north and east sides of the property. The steep slope area is located along the north property line. The ground surface slopes southwards at about 56%, but is locally as steep as 109% near the northeast property line. The top of the slope is at about El. 330 feet which is 26 feet above the lower floor elevation (El. 304.37 feet). Figure 3 prdol&tc EI V E D section of the slope at the proposed extension. JUL 17 2003 We observed the following: PERMIT COUNTER There are no signs of previous slope instability, or evidence of slope creep inferred from trees with bent bunks. The steepest slope segment of 109% near the northeast corner has been locally steepened as,a result of dumping of garden GEOLOGY GEOENVIRONMENTAL SERVICES HYDROGEOLOGY GEOT&yptu =T 3 July 3, 2003 140) C HWA Project No. 2003082-21 refuse over many years. • Slope vegetation consists mainly of ivy with several large coniferous trees. No vegetation that is typically indicative of seepage or very moist conditions was noted. ' • The slope is undeveloped, but the surface has been disturbed possibly by excavated material dumped during the construction of the original house. A boardwalk provides access across the slope, and a small shed is present at the foot of the slope. A manhole is present a short distance above the toe of the slope. We understand this manhole previously discharged to a now abandoned septic absorption system at the foot of the slope. • We understand that at grade parking is present over a portion of the planned extension area, but this was filled some years previously with sawdust. • A rockery is located about 10 feet from the northern side of the house to provide a private deck. The deck is at El. 313.04 feet and the rockery is about 7 feet high. The rockery shows no signs of instability, or seepage through the wall. SUBSURFACE EXPLORATIONS The site was explored by means of 4 hand auger borings (designated HH-1 through HH-4) supplemented with drop -weight cone penetration (DCP) tests. The DCP test consists of a sliding hammer weighing 17.5 pounds which free -falls through a vertical drop of 22.5 inches. The cone has a %-inch diameter and 600 apex angle. Test results are obtained by recording penetration for each 5 blows. In order to facilitate comparison with Standard Penetration Test (SPT) N-values, the penetration results are converted into equivalent number of blows/foot for the length driven. SPT N-value is approximately equal to the DCP blow count expressed in equivalent blows/foot over the range of 3 to 20 blows/foot. Pertinent information including soil description and engineering characteristics, stratigraphy, and ground water occurrence are recorded on the attached soil logs (Appendix A). The stratigraphic contacts shown on the logs represent the approximate boundaries between soil ' types; actual transitions may be more gradual. It should be noted that the soil and ground water conditions depicted are only for the specific dates and locations reported and, therefore, are not necessarily representative of other locations and times. It is anticipated that ' water conditions will vary depending on seasonal precipitation, local subsurface conditions and other factors. ' SUBSURFACE CONDITIONS The geological map by Minard, J.P (1983), "Geologic Map of the Edmonds East and Part of the Edmonds West Quadrangles", indicates that the slope consists of advance outwash comprising mostly clean, pebbly sand with fine-grained sand and silt common in the lower part of the unit. Glacial till is present at the top of the slope. Undisturbed advance outwash 2003082-21 Geotechnical Repon 2 HWA GEo$c1ENCEs INC. July 3, 2003 (' HWA Project No. 2003082-21 is typically dense to very dense. Slopes in glacial outwash, typically slough to the angle of repose of the sand of around 300 to 330. When slope instability occurs in glacial outwash, it is mainly confined to loose surficial layers, but deep'seated slides can occur near the contact with less permeable glacial silts and clay near the base of the deposit. The explorations encountered a thin organic topsoil layer, over very loose to loose, fine to medium sand with a trace to some silt and occasional gravel, over medium dense, slightly gravelly fine to medium sand, and occasional gravel layers. The depth of loose sand on the slope was 3 feet at HH-1, 7.5 feet at HH-2, and 3.75 feet at HH-4. Because the holes kept collapsing, the conditions at depth were interpreted from the DCP penetration rates. A profile drawn through the eastern side of the proposed extension is shown in Figure 3. Our interpretation of the soil profile and observation of the site topography indicates that the deep pocket of loose material encountered at HH-2 (and absent at HH4) is likely dumped material from the original house construction. No indication of seepage was encountered in any of the holes or DCP soundings. CONCLUSIONS AND RECOMMENDATIONS GENERAL ' The investigation shows the slope consists mainly of advance outwash, but pockets of loose to very loose surficial material occur which are likely deposits of dumped fill resulting from the original basement and rear yard deck excavation. Exploration HH-2 shows that these ' pockets can be of 7.5 feet deep. In addition, a large amount of garden refuse has been dumped on the slope producing the over -steepened slope near the northeast property corner. We consider that the planned basement excavation into the slope can be safely achieved without impacting the stability of the adjacent, upslope property. In addition, provided that the design and construction of the extension takes account of the loose material blanketing the slope, the basement excavation will improve the stability of the slope. An important factor in achieving a safe excavation is providing adequate temporary excavation slopes or using shoring during excavation and construction of the basement walls. The basement wall ' must be designed to carry the lateral loads imposed by the loose sand. . 1 We did not observe seepage in the explorations, and understand that no seepage has been encountered in the existing basement. Despite this, we recommend that footing drains (Figure 4) be installed around the perimeter of exterior walls and at the toe of retaining walls because the presence of some silt could result in the'outwash being somewhat less than free - draining during very wet periods. EDMONDS MUNICIPAL CODE REQUIREMENTS FOR STEEP SLOPES In this section, extracts from the Edmonds Municipal Code (EMC) relating to steep slopes are summarized with responses pertaining to the subject property following in italics. 2003092-21 Gew cdmkW Report HWA GEOSCIENCES INC. July 3, 2003 HWA Project No. 2003082-21 Steep Slope Hazard Area 1 The EMC defines Landslide Hazard Areas as "those areas of the City of Edmonds which, by reason of excessively steep slopes, unsatisfactory foundation support, stability or topography, have a risk of earth subsidence and landslide hazard in excess of normal allowances". We understand that the slope occurring on the subject property is classified as a Steep Slope Hazard Area "because the ground rises at an inclination of 40% or more within a vertical elevation change of at least 20 feet'. The EMC indicates that a slope is delineated by establishing its toe and top and measured by averaging the inclination over at least 20 feet of vertical relief. The subject property is classified as a Steep Slope Hazard Area because the average slope angle through the building extension is 46% (about 25 degrees). Localized sections with " vertical relief of about 10 feet occur where the slope angle is steeper, e.g. 56% and 57% above the extension, and 109% at the northeast corner. Development in Steep Slope Areas According to the EMC, no development or alteration is allowed in Steep Slope Hazard areas unless the property is exempt, a reasonable use exception has been granted, or a variance has been granted. A development may be exempted if it meets the following criteria summarized ' from Clause 20.15B.110: 1. The proposed development will not decrease stability on any adjacent property, and the site following the permitted activity will, be stable as demonstrated by engineering analysis meeting requirements of the Building Code. Temporary excavation for the basement will extend close to a line drawn at 350 from the north Lot Line (Figure 2) as shown on Figure 3 and so would have no impact on the adjacent property. However, the excavation could impact the I0-foot Exception shown ' on Figure 2. Further, provided the excavation is sloped, benched, or shored in accordance with Part N of Washington Administrative Code (WAQ 296-155, the short- term risk ofslope instability on the subject property will be low. The excavation should be undertaken in dry weather and the slope should be adequately protected 2. The development is located on steep slope areas that are either mapped as till, advance outwash or Olympia gravel, or are composed of engineered fill placed under engineered conditions on stable geologic deposits. All fill should have been placed under a legal grading permit, with the grading and fill designed by a licensed professional engineer, native soils beneath the fill prepared in accordance with the engineering design, and compaction testing confirms that uniform compaction to the specified percentage is present throughout the entire fill. I 1 2003082.21 Geotedmical Report 4 HWA GEOSCIENCES INC. July 3, 2003 HWA Project No. 2003082-21 The geological map and our explorations show that the general area is underlain by advance outwash. Pockets of very loose fill of up to 7.5 feet deep are present near the foot of the slope. The excavation to accommodate the basement should be extended as required to remove this loose material, and so enhance long-term stability of the slope. Buildingfoundations will be established on advance outwash. 3. All excavations on steep slopes shall not extend below a 350 plane extended down from the property lines, unless the excavation is retained by.structural shoring. The shoring must be designed by a registered professional engineer. ' Figure 3 shows the excavation will not extend below a 350 plane drawn from the Lot line, but does extend below a 35°plane drawn from the edge of the Exception zone. 4. All retaining structures on steep slopes shall be engineered structures confomring to the Building Code; rockeries are not permitted greater than four feet in height. It is agreed that retaining structures should be engineered in conformance with the Building Code. The existing rockery appears to be performing adequately. Details of a a rockery designed to support a 10 foot high slope along the outside of the deck are shown in Figure 5. 5. Steep slopes cannot be altered if one or more of the following conditions are present on or adjacent to the portion of the subject property classified as a steep slope; I impermeable soils interbedded with granular soils, springs or groundwater seepage, significant visible evidence of groundwater seepage, previous landsliding or instability, or existing landslide deposits. "On or adjacent to" includes those areas upslope and downslope of the steep slope, within a horizontal distance from the toe onop of the slope equal to two times the vertical height of the steep slope. ' No impermeable soils interbedded within the advance outwash were encountered; no seepage was encountered, or evidence ofprevious seepage noted; and no signs ofslope ' instability observed 6. Steep slopes cannot be altered if the thickness of organics, debris, weathered soils, ' colluvial soils or soils exhibiting loose conditions (as measured by the Standard Penetration Test (ASTM D1586)) on or adjacent to the portion of the subject property classified as a steep slope exceeds 3 feet. The explorations show that the loose soil thickness is 3 feet tit HH-1, 7.5 feet at HH-1, and 3.75 feet at HH-4. However, based on our explorations, we consider that much of the loose soil is fill dumped near the base of the slope during original house 1 2003092.21 Geotechnical Repon 5 HWA GEoSCIENCES INC. July 3, 2003 HWA Project No. 2003082-21 construction. We are convinced that basement excavation will improve slope stability by removing most of the loose fill. EXCAVATIONS Temporary Excavation Slopes Maintenance of safe working conditions, including temporary excavation stability, should- be the responsibility of the contractor. All temporary cuts in excess of 4 feet in height should be sloped, benched, or shored in accordance with Part N of Washington Administrative Code (WAC) 296-155. The loose sandy material classifies as Type C soil. Temporary unsupported excavations in Type C soils should be sloped no steeper than 1%H:1V (approximately 340). The recommended maximum inclinations for temporary slopes assumes that the ground surface behind the cut slope is level and surface loads from equipment and materials are kept a sufficient distance away from the top of the slope. As evident from Figure 3, steeper slopes than permitted by WAC regulations will likely be necessary to facilitate construction of the back wall of the proposed extension. ' With time and the presence of seepage and/or precipitation, the stability of temporary unsupported cut slopes can be significantly reduced. Therefore, temporary slopes should be protected from erosion by covering the cut face with well -anchored plastic sheeting. The 1 contractor should monitor the stability of temporary cut slopes and adjust the construction schedule and slope inclination accordingly. Temporary Shoring I Due to the required excavation depth and the loose sandy soils, temporary braced shoring would likely be preferred to reduce the volume of excavation required to accommodate temporary unsupported slopes. Various cantilevered shoring systems consisting of sheet piles, or soldier piles and lagging could be considered, as well as alternative systems using steel plates and bracing, or trench boxes. The temporary shoring system should be designed and constructed to support lateral loads exerted by the retained soil mass and any surcharge at the ground surface. Lateral earth ' pressures for design of temporary shoring can be provided when the shoring system is selected. I I STRUCTURAL FILL MATERIALS AND COMPACTION For the purposes of this report, material used to raise grades or placed under structures is classified as structural fill. Imported stmctural fill should consist of clean, free -draining, granular soils that are free from organic matter or other deleterious materials. Such materials should comprise particles of less than 4-inch maximum dimension, with less than 7% fines 2003082.21 fxotechnieal Report 6 - - - HWA GEOSCIENCES INC. ' July 3, 2003 V HWA Project No. 2003082-21 (portion passing the U. S. Standard No. 200 sieve), as specified for "Gravel Borrow" in Section 9-03.14(1) of the WSDOT Standard Specications (WSDOT, 2000). The fine- , . grained portion of structural fill soils should be non -plastic. ' Structural fill soils should be moisture conditioned, placed in loose horizontal lifts less than 8-inches thick, and compacted to at least 95% of the maximum dry density as determined using test method ASTM D1557 (Modified Proctor). Achievement of proper density of a ' compacted fill depends on the size and type of compaction equipment, the number of passes,. thickness of the layer being compacted, and soil moisture -density properties. In areas where limited space restricts the use of heavy equipment, smaller equipment can be used, but the soil must be placed in thin enough layers to achieve the required relative compaction. Generally, loosely compacted soils result from poor construction technique or improper ' moisture content. Soils with high fines contents are particularly susceptible to becoming too wet, and coarse -grained materials easily become too dry, for proper compaction. I I I I [I I SEISMIC CONSIDERATIONS The project site lies within Seismic Zone 3 as defined in the 1997 Uniform Building Code (UBC). Zone 3 includes the western portion of Washington and represents an area of relatively high seismic risk. We recommend that a soil profile type So be used for design. The absence of ground water or seepage means that the slope materials are not susceptible to liquefaction during a design level (1:475 year recurrence interval) earthquake. FOUNDATIONS Design Considerations Spread and strip footings may be used for the building extension and should extend through all loose material onto medium dense (or better) undisturbed advance outwash. All exterior footings should be founded at least 18 inches below the lowest adjacent finished grade; interior footings should be founded a minimum of 12 inches below the top of adjacent slabs or floors. The footings should designed for a maximum allowable bearing pressure of 2,000 psf, subject to minimum footing widths of 18 and 24 inches for continuous strip and isolated column footings, respectively. The recommended maximum allowable bearing pressure may be increased by 1/3 for short-term transient conditions such as wind and seismic loading. Provided construction is accomplished as recommended herein, and for the foundation loads anticipated, we estimate differential settlements between adjacent load -bearing structures to be less than I - inch. 2003082-21 GwwcMicei Report HWA GEoSciENCEs INC. July 3, 2003 �W C HWA Project No. 2003082-21 Construction Considerations t. All footing excavations should be trimmed neat and the excavation bottoms should be carefully prepared such that over -excavation of native soils is avoided. All loose or softened soil should be removed from the footing excavation prior to placing reinforcing steel. We recommend that HWA observe footing excavations prior to pouring concrete to verify that the recommendations of this report have been followed and that an appropriate bearing ' stratum has been exposed. If footing excavations are open during the winter or periods of wet weather, we recommend that a lean concrete mat or mud -slab, be placed to help preserve the subgrade until the footings are poured. ' BASEMENT WALLS AND RETAINING WALLS I Although, concrete basement retaining walls will be utilized for the building extension, we understand a rockery matching the existing would be preferred along the outside of the deck area. Maximum rockery height would be about 8 feet, and exceeds the maximum height. of,4 feet allowed for rockeries in the EMC. We believe that a rockery with the details shown in Figure 5 would be suitable, but if the City does not accept a matching rockery, we recommend either a reinforced concrete cantilever or segmental block retaining wall. Alternatively, consideration should be given to extending the basement wall to existing ground surface, and not providing a flat deck behind the new extension. We recommend that for areas of level backfill (i.e. basement wall if deck provided), an at - rest equivalent fluid density of 55 pounds per cubic foot (pcf) be used to determine design lateral earth pressures. This value assumes that backfill behind the walls is horizontal and is placed and compacted in accordance with our recommendations. For walls with sloping backfill, the equivalent fluid density should be increased by 1 pcf for each degree of backslope up to a maximum of 80 pcf for a wall with a backslope of 250 (existing ground slope at location of building extension). Fill within a distance of about 3 feet of the walls should be compacted with lightweight equipment. Care must be taken to avoid over -compaction near the walls, or excessive lateral pressures may develop. Positive drainage should be provided behind the base of all subgrade and retaining walls to prevent the buildup of hydrostatic pressures (see Figure 4). Wind, earthquakes, and unbalanced earth loads will subject the walls to lateral forces, which may be resisted by a combination of sliding resistance of the footing on the underlying soil and passive earth pressure against the buried portions of the wall and footing. For design purposes, a coefficient of friction of 0.4 may be assumed between the base of the footing and advance outwash. An allowable passive earth pressure equivalent to a fluid weighing 260 1 2003082-21 GeoucMical Report 8 - HWA GEOSCIENCES INC. ' July 3, 2003 HWA Project No. 2003082-21 ' pcf may be assumed for properly compacted fill placed against the sides of the foundations. These recommended values assume drained conditions that will prevent the build-up of hydrostatic pressure in the compacted fill. The passive resistance provided by the upper 2 feet of soils should be neglected in design computations unless protection against excavation is provided by pavement or a concrete slab. The recommended allowable passive earth pressure value includes a factor of safety of about 1.5 for static conditions. ' SITE DRAINAGE Roof drains should carry all runoff via a tightline to a storm drain or other appropriate outlet. ' Perimeter footing drains should be provided behind all subgrade and retaining walls as shown in Figures 4 and 5. Roof downspouts and footing drains should not be connected to ' reduce the potential for clogging and back flooding of the perimeter drains. EROSION CONSIDERATIONS Erosion during construction can be minimized by careful grading practices, the appropriate use of silt fences and/or straw bales. The excavated slope should be seeded and growth of ' vegetation should be encouraged as soon as possible after grading. Surface runoff control during construction should be the responsibility of the contractor. All collected water should be directed under control to a positive and permanent discharge system. Permanent control of surface water should be incorporated in the final grading design. Water should not be allowed to pond immediately adjacent to foundations or paved areas. Grading measures, slope protection, ditching, sumps, dewatering, and other measures should be employed as necessary to permit proper completion of the work. CONDmoNS AND LIMITATIONS We have prepared this letter report for use by David Clobes and his designated agents for use in the design of an extension on the east side of the existing single-family residence on the property. This report should be provided to prospective contractors for their bidding or ' estimating purposes, but conclusions and interpretations included in this letter report should not be construed as our warranty of the subsurface conditions. Experience has shown that soil and ground water conditions can vary significantly over small distances. Inconsistent conditions can occur between explorations and may not be detected by. a geotechnical study. . If, during future site operations, subsurface conditions are encountered which vary appreciably from those described herein, HWA should be notified for review of the recommendations of this letter report, and revision of such if necessary. This report is issued with the understanding that it is the responsibility of the owner to ensure that the information and recommendations contained herein are brought to the attention of the appropriate design team personnel and incorporated into the project plans and 1 2003082-2I Geaechnied Report - 9 - HWA GEOSCtENCEs INC. I u E I ICI I [J July 3, 2003 HWA Project No. 2003082-21 6� specifications. It is also the owner's responsibility to see that the necessary steps are taken to verify that the contractor and subcontractors carry out these recommendations in the field. In this regard, we recommend that HWA be retained to review the plans and specifications. We also recommend that HWA be retained to monitor the geotechnical aspects of construction. The scope of work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or ground water at this site. This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations and we cannot be responsible for the safety of personnel other than our own on the site; the safety of others is the responsibility of the contractor. The contractor should notify the owner if any of the recommended actions presented herein are considered unsafe. O.O We appreciate the opportunity to be of service. If you have any questions or concerns, please do not hesitate to contact us. Sincerely, HWA GEOSCIEN ;TJ I1 -151 Brian E. Hall, P.E. s r a ExPfREs 02 / Senior Geotechnical Engineer Enclosures: Figure 1 Figure 2 Figure 3. Figure 4 Figure 5 Appendix A: ' Figure Al Figures A-2 - A-5 Vicinity Map Site and Exploration Map Geological Cross Section Footing Drainage Requirements Typical Rockery Details Lome Balanko, P.E. Principal Legend of Terms and Symbols used on the Boring Logs Logs of Explorations HH-I through HH4 2003082.21 Geotechnieal Report 10 1 HWA GEoSc1ENCEs INC. u 11 1 I I F f Uol I I HWAGEosmaslNC VICINITY MAP CLOBES RESIDENCE 7.425 OLYMPIC VIEW DRIVE EDMONDS, WASHINGTON NOT TO SCALE BY s CKED BY j 7.01.03 1 2003-082 's 0 _ N i m I i =M$ N Q :.........:.........:..... ... s 1 ................................... ....: Z O _ 61 i £L 13Sdd0) £-1 IH : W Q N i ..................:Ns... g� o 3Z( �tWK N� LL w . IL W Z N N O . . . . . V 0 1 : : : •r� W hZr p = (SL 13Sdd0) l HH o o W U ............ / a / g vi 0 F wo gw : ° ^ W i................. � ...:.. �.. i iSL'13SfJOi L H!F / ................. 3NIl-J.213d021d :L� ........................... r •' Il NOIld30X3 i 1 0 0 0 C lO M M M M U33d) NOUVATS I PAVEMENT OR a - IMPERVIOUS SOIL STABLE EXCAVATION SLOPE (Contractor s Responsibility) SLOPED TO DRAIN AWAY FROM STRUCTURE 01 Uo GRANULAR BACKFILL t PEA GRAVEL SUBDRAIN NOT TO SCALE MATEBIAI.S Gravel Backfill for Drains shall meet the gradation requirements specified in section 9-03.12(4) of the WSDOT Standard Specifications. Granular Backfill shall meet the gradation requirements specified in section 9-03.14(1) of the WSDOT Standard Specifications. 4' minimum diameter slotted plastic pipe; sloped to drain (6 /100' min. slope); provide clean —outs. Slotted pipe to have 1/80 maximum width slots. Cleanoute should be included to allow periodic maintenance and inspection. e IMGESMICH M WALL GRAVEL BACKFILL FOR DRAINS DAMP PROOFING 1. Wall backtill should consist of well — graded granular soil with no more than 5% (by weight based on the minus 3/4— inch portion passing the' No. 200 sieve (by wet sieving), with no plastic fines. 2. Backfill behind the wall should be compacted with hand —operated equipment. Heavy equipment should not be used as such equipment operated near the wall could increase lateral earth pressures and possibly damage the wall. 3. Backfill should be placed in to era not exceeding 8" loose thickness, and should be compacted to at least 95X of the Modified Proctor maximum dry density (ASTM D1557, Method C or D). 4. Drainage gravel beneath floor stab should be hydraulically connected to a drainage system. Use of 1' dia. weep holes located of the downslope side of the structure is one method. WALL DRAINAGE AND BACKFILLING CLOBES RESIDENCE 7425 OLYMPIC VIEW DRIVE EDMONDS, WASHINGTON 7.01.03 1 2003-082 i PORTION OF WALL BELOW 6 ft., 2400 lb. (6—MAN) ROCK PORTION OF WALL ABOVE 6 ft., 16DO lb. (4—MAN) ROCK SLOPED TO MAXIMUM STABLE EXCAVATION SLOPE --� (CONTRACTOR'S RESPONSIBILITY) COMPACT IN 60 UFTS WITH MINIMUM OF 4 PASSES BY HAND —OPERATED TAMPER. COMPACT TO AT LEAST 92% OF MODIFIED PROCTOR MAXIMUM DRY DENSITY (ASTM D-1557). BACKFILL SHOULD BE PLACED AND COMPACTED AS ROCKS ARE PLACED. 4• DIAMETER PERFORATED PLASTIC PIPE---' ALL LOOSE SOIL AT ROCKERY FOUNDATION SHOULD BY OVEREXCAVATED AND REPLACED WITH COMPACTED BACKFILL AS DESCRIBED ABOVE. THE EXCAVATION SHALL BE KEPT FREE OF WATER. THE PREPARED ROCKERY FOUNDATION .SHOULD BE EVALUATED BY A SOILS ENGINEER PRIOR TO PLACEMENT OF ROCK. LEGEND 4 H=10' MAX 12' MIN H/3 MIN WIDTH FOR BASE ROCK NOT TO SCALE [FOR ILLUSTRATION ONLY, NOT INTENDED FOR CONSTRUCTION] IMPERVIOUS SURFACE LAYER: 8 TO 12 COMPACTED SOIL BACKFILL: CLEAN, CRUSHED LEDGE ROCK, 20 MAXIMUM SIZE, 40 TO 60% GRAVEL, LESS THAN 5% FINES (PASSING 1200 SIEVE). FINES SHALL BE NON —PLASTIC. ROCKERY RETAINING WALL am .Y Jii °icune "o. " t = HM�MNaSM GLOBES RESIDENCE XCKE° °T 1 M. 7425 OLYMPIC VIEW DRIVE °AT '"0"" M. EDMONDS, WASHINGTON 7.01.03 1 2003-082 RELATIVE DENSITY OR 41STENCY VERSUS SPT N-VALUE CONESIONLESS SOILS COHESIVE SOILS Drnly N mwe ffi) ApprUnnate RMaeva Derally(%) Coniulerlr/ N (dawsllg Approxmide IkibWned Shear Shen Very Lone 0 b 4 0- f5 Very Son 0 to 2 42W Los" 4 to 10 15 - 33 Solt 2 to 4 250 - 500 Madwn Dues 10 to 30 35 - 65 Medan SW 4 b 6 i d00 - 1000 Owes, 30 b 50 65 - s still S b 1s 1ooD 2000 Very Derss ~ 60 65 . 100 Very Nor 1S to 30 2000 - 4000 Herd ovr30 a4000 USCS SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS Caeraa Gravel and Clan Gravel GW Weeynded GRAVEL Soh GP Pwnyyradso GRAVEL �Gravely Ptile r roc anes) e Q Mon man 50%of Core Gravel VA h a GM Say GRAVEL Fn:tbn Retained Finaa (appredada n No4sleve amerce altos) GC Clsyay GRAVEL Sand and Clan swhd • : SW walFgredse SANG Sandy so" pm. rm has) Mon inn SP Paorggreded SAND 50% Retained Sertl wish . SM SkySAND n No. CC Moran 20D Sieve FMs (ap vadable Fraction Pesaro Sol No. 4 stew a1 o,at of Ones) SC I CW M SAND PAL SILT Wed CL Len CLAY Gressel U@ed time en led Gala Clay Lass tlrn Smi OL organic su iDor: CLAY MF( Eleatic SILT Smarm" llgsa limit Passing 50%orMors CFI Fr CLAY Camay OH I OngeMc SILTNgenl: CLAY Na. 200 Stow Boca Mlgtay Orders: Solo v' PT PEAT COMPONENT DEFINITIONS COMPONENT SIZE RANGE seJaera. tagrmn llh Cobbles 3in1012h Gravel 3In b No 4 (4.6mm) Corse gravel Sin to 3I4 in Fla Pawl 3N h b No 4 (4JYrn) Sand No. 4(4.5 mm) to Na 2D0(4074 can) Corse sand No. 4 (4.5 mm) b NO. 10 (2.0 mm) Medan anti Ne 10 G.0 mm) to No. 40(0.42 mm) Fine send No. 40 (0.42 rem) b No. 200 (0.074 mm) Sit red Cary -- Smaller than No. 2D0 (0.07amm) V TEST SYMBOLS %F Pow Fines . AL Aderbeg UIMs: PL-Plastic LNNt LL a Lkpad LimIt CBR California Bearing Rath ON Consolidation DD Dry Density (pc) DS Direct Sher GS Grain Size Distribution K Permeabift MD Molstum/Density Relationship (Proctor) MR Resilient Modulus PID Photolohizadon Device Reading PP Pocket Penetrometer Approx. Compressive Strength (tare SG Specific Gravity TC Trisxiat Compreubn TV Tor Approc Shear Smegm hard UC Unconfined Comprusion SAMPLE TYPE SYMBOLS ®2.0' OD Split Spore (SPT) (140 m. hemmer with 30 in, drop) I Shelby Tube 0 3-1I4 OD Split Spoon with Bnu Rings OSmall Bag Sample Large Bag (Bulk) Sample Con Run Non-standard Peneballn Teo (3.0.013 split spoon) GROUNDWATER SYMBOLS F Groundwater Level (measured at tens of drilling) Groundwater Level (meuund In well or open as after under level stabilized) COMPONENT PROPORTIONS PROPORTION RANGE DESCRIPTNE TERMS .5% Cban 5 -12% Slightly (Clayey, Silly, Sandy) 12 -30% Clayey, Silty, Sandy, Gravely 30.50% Very (Clayey. Silty. Sandy. Gravelly) COmponenb are arranged m order of increasing quraitbs. NOTES: Soo dassi0cations presented On exploration logs sit based on visual and laboratory observation. Sol descr irld" sit presened in the following general order. Densyconsislancy, Polar, modifier IN my) GROUP NAME, malbo a to lyeup name IN my), mdswn conies. PmopwbM gradation, and WVWerfy of naneftwes, moduef carrrneres (GEOLOGIC INTERPRETATION) Please refer to me diaaulon in me repo tow as well IN; the exploration logs for a more mnpMte description Of wbMafam conditions. ' u tnlLi HMGEOSQENCEs INC Clobes Residence 7425 Olympic View Drive Edmonds, Washington MOISTURE CONTENT DRY Absence of mde5ew, dotal. dry bins Muth. . MOIST Derry but no vleale wwNr. WET Visible arm water uxsay MR Is below valet Able. LEGEND OF TERMS AND SYMBOLS USED ON EXPLORATION LOGS 'PROJECT NO.: 2003082 FIGURE' A-1 LEGEND 2003032.GPJ TMA13 SM Very loon to loose. dark brown, silty, fire SAND, moist. Abundant rootlets and organics. [TOPSOILJDUFFJ . SP Loose, light blown, slightly silly, slightly fine to me= SM gravely, fire SAND, mold Rootlets noted. :.. SP .................................................................... Medium dens, brown, slightly fine to coarse gravely, fine to medlum SAND, moisL Total depth with hand auger was 4 feet due to soil caving I below this depth. � BORING: ' WE n Clobes Residence HH ORING:=1 a, 7425 Olympic View Drive HMGE0saENCES INC Edmonds, Washington PACE t of i PROJECT NO.: 2003082 FIGURE: A-2 BORING WITH OTHER PENETRATION TESTS 2D030%2.GPJ 7/3n3 BORING: ' IT Clobes Residence HH-2/DCP-2 V 7425 Olympic View Drive I- IWAGEOSCIENCES INC Edmonds, Washin&n PAGE: 1 of 7 'PRoJECT No.: 2003082 FIGURE: A-3 BORING WITH OTHER PENETRATION TESTS 2003082.GPJ 7rA3 ILSM Loose, brown, silty, fine SAND, moist Organioshcotlets rated• UOPSOILIDUFF11 SP Loose, brown, Slightly fine to comae 9mvelty, fine SAND, moist. Rootlets noted. a GP Loose, Sandy. Me to coarse GRAVEL, mast Total hand Super depth was 2 feet due to 9mvei uvkV BORING: '17`I(j%1 Clobes Residence HH-3/DCP-3 L! �1v1 7425 Olympic View Drive IMGEMENCESINC Edmonds, Washington PAGE.' of 1 PROJECTNo.: 200.3082 FIGURE: A-4 BORING WITH OTHER PENETRATION TESTS 10a3M.GPJ 7$W3 BORING: ' R Clobes Residence HH-4/DCP-4 LJ 1 7425 Olympic View Drive HmaosCImu iNG Edmonds, Washington PAGE:' °" PROJECTNo.: 2003082 FIGURE: A-5 BORING MTH OTHER PENETRATION TESTS 2W3063.GPJ 7=3 monsoon mossonsmon MEMMEMMEN mmmmmmmmmm ONE ME= 0 ONE U. z Ln �z V (40 Geotechnical Engineers, Geologists t'�1 Groun Northwest, Inc. QEnvirenmentalScientists September 25, 2003 Ms. Star Campbell Development Services Department Planning Division 121 - 5th Avenue North Edmonds, Washington 98020 Subject: Geotechnical Peer Review Addendum Clobes Residence Addition 7425 Olympic View Drive Edmonds, Washington Reference: HWA Geosciences, Inc. Project No. 2003082-21 Geotechnical Report dated July 3, 2003 Dear Ms. Campbell: eCP,1VZ1) G-1697 Sf p 2 6 20p3 �'LANr1iPd� pEpT We had reviewed the referenced HWA Geosciences, Inc. (HWA) report and prepared peer review comments in a letter dated September, 9, 2003 for the Clobes residence addition. At your request, we are providing additional comments regarding the steep slope exemption information contained in the HWA report. Steep Slope Hazard Areas The slopes at the project site as defined by the Edmonds Community Development Code (ECDC) are classified as steep slopes hazard areas, since the slopes average 46 percent for a total elevation change of approximately 25 feet. Steep Slope Exemption Criteria A. Site Standards 1) The site will be stable after the permitted activity. 2) The slope is mapped as advance outwash. 3) Fill placement recommendations are, contained in the HWA report. 13240 NE 20th Street, Suite 12 • Belleuve, Washington 98005 Phone 4251649-8757 • FAX 425/649.8758 ATTACHMENT 4 September 25, 2003 Peer Review - Steep Slope Exemption G-1697 Page 2 4) Impermeable soils interbedded with granular soils, springs, groundwater seepage, previous landsliding or slide debris are not present at the site. 5) Depth of loose soils on the slope is 1 to 7 feet, which exceeds the 3 foot site standard criteria. B. Development Characteristics 1) The HWA report Figure 3 - Cross Section A -A' shows the 35 percent slope excavation line extending from the edge of the exception zone. 2) Retaining structures on the slope or rockeries have been addressed in the HWA report. 3) A buffer of 15 feet can be kept free from commercial development to property lines of adjacent residential properties, however, this buffer has been previously disturbed, and it will be disturbed again by following the 35 percent excavation line recommended in the ECDC. 4) The proposed development will not decrease the stability of any adjacent property. From the above review, we conclude that the HWA report generally satisfies the City of Edmonds Steep Slope Exemption criteria for the subject project, with the following exceptions: a) Depth of loose soils on the slope. b) The proposed 35 percent excavation line extends into the Exception zone. c) The 15 foot buffer has been disturbed in the past and will be disturbed again. It is our professional opinion that the above exceptions do not decrease the stability of the proposed development or the adjacent property if the project is developed under proper engineering supervision. We conclude that the HWA report addresses the steep slope exemption criteria although it is not done in an explicit manner for all of the items listed in the Steep Slope Exemption Handout. Geo Group Northwest, Inc. September 25, 2003 G-1697 Peer Review - Steep Slope Exemption Page 3 If you have any questions regarding this addendum letter, please call. Sincerely, Geo Group Northwest, Inc. William Chang, P.E. Principal Geo Group Northwest, Inc. L i .E x qCT C) •L N 3�: d K/ L M o Ui a C Q U v *k .a Q 0 U- Q Z o Q O O Z Mea E E Cgz LL! Z 0 = c c c ° d.� �- Q Q a 7 to a u. c p o 0 0 0 0 0U. d C C c W .�+" M ; 3 c N CDQ c E 2 E O a m E �+ cr`o w °' > w e o. a-0i Q _ N E O U U 0 m L G Q w m a a o = d d= d d V •s o O. t 0 FL C W O vs 0 N O 0 o v 'iv o M E Gda NP IL m N N Do G i _ N P00 O o d C a d Co � E d E o a= NNE E = ^� c °3 b b a �•� d d N q G C G n a aut� N 0 0 0 0 0 � cw o� o o i �z aCL y o Q n 2i c lL " f0 a m c. f6 O a> a� c) N - ,--� cq za oa �U a a`0 q ww_�dvm Mark Yeadon Edward Mcmackin lack &Sharon Miller '7505184th PI SW 18328 Homeview Dr 18404 Homeview Dr Edmonds, WA 98026 Edmonds, WA 98026 Edmonds, WA 98026 Samuel Lee Jeffrey Butler Samuel & Cynthia Lee 7512184th PI SW 19119 N Creek Pkwy #113 7512184th PI SW Edmonds, WA 98026 Bothell, WA 98011 Edmonds, WA 98026 Vernon Edwin Williams George Jensen Paul & Amy Tomlin 7520184th PI SW 7517 Olympic View Dr 7530184th PI SW Edmonds, WA 98026 Edmonds, WA 98026 Edmonds, WA 98026 Scott & Karen Hibbert Gary & Terrie Gerber Donald Johnson 18420 Homeview Dr 18421 Homeview Dr 18427 Homeview Dr Edmonds, WA 98026 Edmonds, WA 98026 Edmonds, WA 98026 Mary Lou Vigil Marvin & BrenAa Jones Matthew & Susan Wood 18428 74th PI W 7333 Olympic View Dr 1 3 t Edmonds, WA 98026 98026 Edmonds, WA 98026 Andre & Carolyn Belyea Charles Taylor Snohomish Cc Property Mgmt 7327 Olympic View Dr 18429 74th PI W 3000 Rockefeller Ave #M 40 Edmonds, WA 98026 Edmonds, WA 98026 Everett, WA 98201 Keith & Sherrelle Collingridge Rudolph & Barbara Julian i Richard & Jeanne Sherwood 18423 74th PI W 18417 74th PI W 18411 74th PI W Edmonds, WA 98M6 Edmonds, WA 98026 Edmonds, WA 98026 Donald & Lois Schatz Jong Chung Charles & Marlene Belt 18403 74th PI W 18325 Homeview Dr 18401 Homeview Dr Edmonds, WA 98026 Edmonds, WA 98026 Edmonds, WA 98026 City Of Lynnw Lynnwood City Of William & Kathleen Massey PO Box 5 PO Box 5008 PO Box 399 Lyn WA 98046 Lynnwood, WA 98046 Oak Harbor, WA 98277 William Snell Paul Stromme Dave & Julie Clobes 1111 Third Ave., Suite 220 9623 8th Ave. NE 7425 Olympic View Dr, Seattle, WA 98101-32078 Seattle, WA 98115 Edmonds, WA 98026 ADJACENT PROPERTY OWNERS LIST r. Attach this notarized declaration to the adjacent property owners list. On my oath, I certify that the names and addresses provided represent all properties located within 300 feet of the subject property. Signature of Applicant or Applicant's I Subscribed and sworn to before me this j/day of and for the State of Washington Residing at C/l S` 1 9 C. .� S tiFCCY" Ir1/ o S0TAR 5) Zi PUBLIC 71,9 � WASHY APO.docV_:\TemP\foTm STATE OF WASHINGTON, COUNTY OFSNOHOMISH RECEIVED Affidavit of Publication S.S. The undersigned, being first duly sworn on oath deposes and says that she is Principal Clerk of THE HERALD, a daily newspaper printed and published in the City of Everett, County of Snohomish, and State of Washington; that said newspaper is a newspaper of general circulation in said County and State; that said uewspaper has been approved as a legal newspaper by order of the Superior Court of Snohomish County and that the notice Notice of Development Application & Notice of Hearing Pkaminer Hearing David and Julie Clobes; V-03.184 a printed copy of which is hereunto attached, was published in said newspaper proper and not in supplement form, in the regular and entire edition of said paper on the following days and times, namely: February 04, 2004 and that said newspaper was regularly distributed to its subscribers during all of said period. Subscribed and swom to before me this 4th day of Notary Public in and for the County. NOTAygy 328-07, '�O? OF WASNCa N� Account Name: Oay of Edmonds Accat" Number: 101416 Order Number: 00011310M