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15-100378ZIP " Jim Ferrell, Mayor September 10, 2015 Ms. Jennifer Taylor Ryka Consulting 918 South Horton Street, Suite 1002 Seattle, WA 98134 FILE Re: File #15-100378-00-UP; USE PROCESS I APPROVAL AT&T,Mobility — SS64 Lakota; 2629 SW 308th Street, Federal Way Dear Ms. Taylor: The City of Federal Way's Department of Community Development has completed an administrative land use review of the proposed upgrades to an existing Personal Wireless Service Facility (PWSF). Modifications include the addition of antennas and extension of existing utility pole in the public right-of-way, which is located at 2629 SW 308th Street, Federal Way. The proposal also includes the extension of existing equipment on private property. For these upgrades to take place, a height increase of the PWSF pole is also proposed. The Process I application was submitted and determined to be complete on August 19, 2015. Your proposal is found to be consistent with the provisions of Federal Wlay Revised Code (FWRC) Chapter 19.55, "Process I — Director's Approval," and Chapter 19.255, "Personal Wireless Service Facilities." Your Process I proposal is hereby approved based on the following statements of fact: 1. Zoning & Land Use — The zoning designation for the subject property is Single Family Residential (RS 15.0). PWSFs are permitted in the RS zone pursuant to the zoning chart found in FWRC 19.200.190. 2. Review Process — According to submitted materials, the applicant proposes to upgrade an existing wireless facility by adding four panel antennas to a two sector array, two to each array, for a total of six antennas. An expansion to the existing equipment platform is proposed and has been determined to meet the development standards of FWRC 19.255.020(4). The relocation and addition of antennas (which increase the height of the PWSF pole to 76' 11"), enlargement of the equipment pad, and modifications to ancillary equipment on an existing PWSF is subject to Process I Director's Approval pursuant to FWRC 19.15.030, "Review Processes for Improvements and Additions to Developed Sites." 3. Prioritised Locations — The applicant proposes PWSF improvements in the right-of-way, which is the 511, prioritized location. The highest prioritized locations are not feasible as this proposal is an upgrade to an existing facility. Staff finds the applicant has met the burden to utilize the lower prioritized location. The proposed antennas should improve service coverage to the area. 33325 8th Avenue South, Federal Way, WA 98003-6325 (253) 835-7000 www.cityoffederalway.com Ms. Jennifer Taylor Page 2 September 10, 2015 4. Screening Upgrades — The applicant proposes to implement screening techniques compliant with FWRC 19.255.020(3) through the use of a five foot landscaping buffer around the equipment pad on the northern, southern; and western sides in order to shield public views from the right-of-way. 5. Omvlative Effe&-- The city must consider the cumulative visual effects o€PWSFsmounted on existing structures andlor- located on a given permitted site in determining whether additional permits may be granted so as to not adversely affect the visual character of the city. As shown on the site plan, elevations, and photo simulations, the addition of antennas and associated equipment are not a substantial increase to the existing site. The PWSF will not adversely affect the visual character of the city and the planned height increase will meets the development standards of FWRC 19.255.020. 6. Facility — The proposed facility exceeds microcell and minor facility thresholds defined in FWRC 19.05.130, "M definitions." Per FWRC 19.255.020(1)(a)(ii), facilities exceeding such thresholds may be permitted if: (A) adverse visual impacts are not created; (B) equipment cabinets meet adopted development standards; (C) the number of antennas and their size are appropriate for the location, surrounding environment, and potential visual impacts; and (D) the PWSF shall comply with all other applicable standards of the FWRC. The proposal is consistent with this code section. 7. State Environmental Policy Act (SEPA) — The proposed improvements are exempt from State Environmental Policy Act review as the scope of work meets categorical exemption of WAC 197-11- 800(25)(a)(i): the collocation of new equipment; removal of equipment; or replacement of existing equipment on existing or replacement structures that does not substantially change the physical dimensions of such structures. 8. Process I Thresholds— The proposed improvements meet Process I purpose criteria set forth in FWRC 19.55.020 and 19.15.030; including compliance with applicable provisions of FWRC Title 19, "Zoning and Development Code," and health, safety, and welfare standards. RIGHT-OF-WAY PERMIT ISSUANCE REQUIRED The city has not received a right-of-way permit application for the work associated with this approval. No work may begin until a right-of-way permit has been issued. Please contact Engineering Technician Kathy Mathena at 253-835-2725 if you have any questions regarding a right-of-way permit. PERMIT ISSUANCE REQUIRED The city is currently reviewing the associated building permit for the antenna upgrade, File #15-100379-00- CO. No work may begin until the building permit is issued. A separate electrical permit is also required. Please contact the Permit Center at 253-835-2607, or permitcenter@cityoffederalway.com, if you have any questions regarding the building or electrical permits. CLOSING This decision shall not waive compliance with future City of Federal Way codes, policies, and standards relating to this site. This Process I approval does not constitute approval of a building or electrical permit. The effective date of this decision is September 13, 2015, three days from the date of this letter, per FWRC 19.05.360. Pursuant to FWRC 19-55.050, the applicant, any person who submitted written comments or File #1 i-100378-00-UP Doc I.D. 68062 1 Ms. Jennifer Taylor Page 3 September 10, 2015 information, any person who has specifically requested a copy of the decision, or the city may appeal the decision to the Federal Way Hearing Examiner by September 13, 2015. Any appeal must be in the form of a letter delivered to the Department of Community Development with the established fee. The appeal letter must contain a clear reference to the matter being appealed and a statement of the alleged errors in the Director's decision. No work on the proposal can commence until the end of the appeal period. In that you are the only party of record, your appeal period is waived (assuming you do not wish to appeal this decision). Waiver of the right to appeal does not affect the effective date of this decision. This Process I approval is valid for one year from the effective date of this decision. If no further action is taken within one year, this decision will expire. A one-year extension of time may be granted only if a written request is submitted to the city's Department of Community Development at least 30 days prior to the expiration of the decision. If you have any questions regarding this decision, please contact Planning Intern Cory Darrow at 253-835- 2622, or cony.darrow@cityoffederalway.com. Sincerely, Michael A. Morales Community Development Director c: Cory Darrow, Planning Intern File # 1 5-100378-00-UP Doc I.D. 68062 RYKACON5ULTING 918 South Horton St. Seattle, WA 98134 August 18, 2015 To: City of Federal Way ATTN: Cory Darrow Department of Community Development 33325 8th Ave S Federal Way, WA 98003 RE: AT&T SS64 Lakota Permit Application #15-100378-00-UP Dear Mr. Darrow, On behalf of AT&T, Ryka Consulting is submitting additional materials as requested in the letter from the City of Federal Way dated July 6th, 2015. • Attachment of an aesthetic screen to the structure and/or landscaping accordingly, in order to screed the equipment from Bash Point Road AT&T has redesigned the proposal to include landscaping to screen the equipment from Dash Point Road. The enclosed revised construction plan set includes a landscaping plan on Sheet L- 1. A 5-feet wide buffer will be installed on three sides of the proposed extended equipment platform. The erosion control plan has been updated to include the landscaping as well. • Updated GeoTechnical Report to reflect the latest modification to the proposal. AT&T also submits a geotechnical review letter commenting on the modifications proposed to the equipment platform. Strata performed a literature review of the site and evaluated platform global stability and capacity of the platform piers. Strata's findings in October 2014 were used to complete the structural analysis and design of the platform extension. In August 2015 AT&T requested Strata to review the most recent set of construction plans to ensure the addition of the staircase and landscaping did not affect their previous findings and design parameters. Thank you, RESUBMITTED AUG 19 2015 CITY OF FEDERAL WAY h,.— CDS ' I-) 11') Jennifer Taylor Ryka Consulting, on behalf of AT&T Enclosures: 1. Two sets of construction plans including erosion control plan and landscaping plan 2. Two copies of email correspondence with Strata and the Strata Geotechnical Review from October 2014. i4 STRaTa A PROFESSIOFIAL SERVICES CORPORATION 'r 0c Ms. Tiffany Murray Program Manager Cornerstone Engineering, Inc. 16928 Woodinville Redmond Rd NE Suite B210 Woodinville, Washington 98072 RESUBMITTED AUG 1.9 2015 CITY OF FEDERAL WAY CDS October 3, 2014 File: CORENG SP14177A RE: Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS64) Platform Extension & Cabinet Addition SW Dash Point Way & 30th Avenue Federal Way, Washington Dear Tiffany: Strata, A Professional Services Corporation (STRATA) is pleased to present this letter describing our limited geotechnical services for the Platform Extension and Cabinet Addition project at the existing AT&T Communication Tower located at SW Dash Point Way near 30th Avenue in Federal Way, Washington. Cornerstone Engineering, Inc. (Cornerstone) retained STRATA to assist the project team comprising Cornerstone, AT&T, and WesTower Communication (WesTower) with project structural analyses and design. We provided our services referencing the authorized Task 1 scope of services and proposal dated August 19, 2014. Specifically, STRATA performed a literature review of the site, evaluated platform global stability and capacity of the platform piers, and provided feedback to assist structural design with evaluating the lateral resistance of platform piers. The following paragraphs summarize our scope of service, literature review findings, and associated geotechnical considerations and opinions to assist project planning, design, and construction. PROJECT UNDERSTANDING We base our overall project understanding on our conversations with you, Mr. Jonathan Gibson, P.E. with Cornerstone, Mr. Chris Listoeld with WesTower, and AT&T representatives. We also reviewed current project drawings, site photographs, structural calculations packet, original (2004) project plans and a previous geotechnical engineering evaluation to understand site conditions. We understand Cornerstone was authorized by WesTower, under contract with AT&T to assist structural design and analyses for the platform extension and cabinet addition at the existing communication tower site denoted as "SS64 LAKOTA". The communication tower site consists of an approximately 10020 E Knox Ave, Suite 200 Spokane, Washington 99206 P.509.891.1904 F.509.891.2012 www.stratageotech.com Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS64) File: CORENG SP14177A Page 2 62-foot-tall wood utility pole with adjacent support equipment located on a 6-foot by 8-foot elevated steel platform constructed over steeply sloping terrain. The platform is supported on four, approximate 12 foot long, 12 inch diameter concrete piers embedded approximately 10 feet vertically into the ground, leaving 2 feet of exposed pier above the existing ground surface. Photographic documentation illustrates a 3-foot-deep electric utility trench connecting the platform structure to the utility pole. Another PVC utility sleeve is evident beside the platform, which appears buried below the 2 downhill platform piers. AT&T proposes to install additional cabinets at the site, which requires extending the existing platform 3 feet to the north and south. We understand the site slopes about UH:1V downwards towards the west and is covered with moderate to heavy vegetation and trees. Prior to the original platform construction, the subsurface conditions reported in the June 11, 2004 geotechnical report by LSI Adapt, Inc. (L.SI) consisted of 2 feet of topsoil underlain by glacially -deposited sated exhibiting increased soil density with depth. Based on the photographs you provided, it appears most of the upper 2 feet of topsoil was removed during platform construction. Cornerstone retained STRATA to review and reevaluate the previous geotechnical studies and structural calculations for the project to consider whether the as -built conditions (e.g. existing pier embedment depth) provides sufficient vertical and lateral capacity and overall global stability for the increased platform loading from a geotechnical standpoint. Based on STRATA's preliminary analyses and findings as conveyed by electronic mail on September 12, 2014, our opinion is that less lateral soil resistance may be currently available than was assumed for the original platform design. Accordingly, we understand AT&T seeks to retrofit the existing tower to accommodate the increased loading conditions. To support this effort, Cornerstone requested STRATA provide the results from our vertical, lateral and global stability evaluation to assist retrofitting design of the platform piers. SCOPE OF SERVICE Per your direction, we accomplished the proposed Task 1 scope of service, which consisted of a literature review, analyses, and letter stating our findings. We were not authorized and thus did not perform Task 2 activities, which were focused on formally assisting retrofit design. However, per Cornerstone's request, we outlined possible remediation systems and approaches as an initial effort to consider retrofitting options. To provide this letter we completed the following: 1. STRATA secured and reviewed available information to assist our limited geotechnical evaluation including: Sf Recent and construction site photographs provided by Cornerstone; 49 Current construction plans by Cornerstone, dated July 1, 2014; Illy Original construction plans by KDC Architects and Engineers, dated May 25, 2004; 04 www.stratagootmh.com 0 2014 by Strata, A Professional Services Corporation. All rights reserved. Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS64) File: CORENG SP14177A Page 3 '7 Platform details by Newave Tower Components LLC, dated November 3, 2004; 47 Structural calculations by Cornerstone, dated August 15, 2014; and 14 Geotechnical Engineering Evaluation by LSI, dated July 11, 2004. 2. STRATA evaluated global stability of the existing platform extension and existing concrete piers under the increased loading conditions and reflecting the current site configuration. Our initial global stability review did not warrant additional detailed numeric analyses, therefore, STRATA did not perform global stability calculations using computer modeling programs. 3. STRATA evaluated whether the existing concrete piers can accommodate the increased vertical load within typical settlement tolerances. 4. STRATA evaluated site geometry and soil aspects regarding the existing pier embedment depths. We worked with Cornerstone to understand loading conditions and help determine if the piers are sufficiently embedded to accommodate increased platform lateral loads. We briefly reviewed the lateral resistance parameters from the LSI report (2004) and provided revised parameters for reference by structural design. 5. STRATA prepared and provided this letter summarizing our geotechnical evaluation; of the existing concrete piers under the future loading conditions and presenting conceptual options for retrofitting. We provided 3 hard copies and 1 electronic copy of this letter for your use. GEOTECHNICAL FOUNDATION EVALUATION As presented above and referencing our authorized scope of service, STRATA evaluated the following site soil aspects for the platform extension: 6v Vertical bearing capacity of platform piers 1v Overall platform global stability 0 Lateral resistance of platform piers In summary, based on our literature review, geotechnical analyses, and experience with similar soil conditions, our opinion is the vertical bearing capacity and overall global stability of the existing platform remain acceptable for the proposed platform modifications. The lateral capacity of the platform piers and ongoing scope movement appear the controlling factors with respect the new pier loads and existing embedment depth. The following sections summarize our analyses and opinions for each aspect outlined above. Vertical Pier Bearing Capacity STRATA reviewed the as -built pier geometry, post -construction vertical loads, and soil conditions reported in the LSI report. Structural calculations indicate the existing platform piers can accommodate the increased loading conditions from a vertical bearing capacity standpoint. Vertical loads are resisted by both end -bearing and skin friction. As discussed below, the actual available skin friction area along the pier is less than assumed for platform extension design as reported in the 2014 structural calculations. However, even if actual "pier -to -soil" contact area may be less than assumed, it appears sufficient capacity is available for the existing pier geometry based on the LSI parameters www.svatageotech.com 0 2014 by Strata, A Professional Services Corporation. All rights reserved. Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS64) File: CCRENG SP14177A Page 4 reported in the 2004 report. The parameters recommended by LSI appear reasonable from a vertical bearing resistance standpoint. Platform Global Stability Based on our literature review and discussions with Cornerstone, we did not identify evidence of major slope instability, large scale soil movement, vegetative anomalies, or other potential indicators the slope may be unstable with respect to "overall" global stability. The site maintains a slope angle similar to the "angle of repose" for the soil conditions outlined in the 2004 LSI report. Apparent and true soil cohesion also increase the resisting forces in the slope that help maintain global stability. The lack of anecdotal or historical evidence of global slope stability issues encompassing the entire platform suggests future satisfactory slope performance. Notwithstanding the lack of evidence for global platform stability issues, we identified evidence of localized ground movement near the downhill piers as shown in Photographs 1 and 2 below. The existing ground surface immediately downhill from the two western piers appears lower than shown in construction photographs from 2004 and 2005. Our opinion is such movement occurred via a variety of factors including, but not limited to erosion, post 2004/2005 site modifications, and progressive downhill slope creep caused by frost action and seepage forces. Photograph 1— Downslope pier and ground configuration on November 23, 2004. The trees on the downslope side of the platform appear healthy and near -vertical. The gravel woddng pad located between the trees and platform is roughly level and appears stable. No steps, metal grate, or other site features evident in Photograph 2 are present. 04 www.sbutmgeotech.com © 2014 by Strata, A Professional Services Cofpmag m. All rights reserved. Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS 4y File: CORENG SP14177A Page 5 Photograph 2 -- Downslope pier and slope configuration on May 29, 2014. The trees appear to be a different species and appear leaning, possibly due to surficial downslope ground movement The gravel working pad is not evident and has been replaced by a steel grate stabilized by an additional concrete pier. The ground surface appears to be 2 to 3 feet lower in 2014 than in 2004, suggesting lateral movement, erosion, and/or localized slope distress. The PVC sleeve evident in both photos may have been painted after 2004 and Photograph 2 suggests the ground has moved since it was painted. New concrete block steps are evident below the access ladder. The electrical conduit utilities appear to have been exposed due to site alterations or slope erosiordmovement. The small pier supporting the metal grate in the foreground shows sign of downslope movement and rotation. In summary, our opinion is overall global stability appears satisfactory with respect to catastrophic platform movement potential. However, the ground surface below the platform appears to have moved downslope, been eroded, or otherwise exhibits localized slope movement. Although this movement does not appear to have impacted the structure to date, it has reduced the amount of western pier embedment. Furthermore, our opinion is the slope below the platform may continue to move or be subject to erosion if not stabilized via a retaining stricture, re -vegetation, buttressing, or other measures. Continued downslope movement may over -steepen the slope and create future platform stability issues. Such loss of slope support can manifest as global platform failure, pier deflection, or other project distress. Finally, the loss of soil near the metal grate shown in Photograph 2 impacts lateral pier resistance as discussed below. 4�0 www.stmtogeotech.com 0 2014 by Strata, A Profeisabna! Services Co►poratfon. att rr9ms reserved. Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS64) File: CORENG SP14177A Page 6 Lateral Capacity STRATA's project review regarding lateral pier capacity identified two primary concerns; reduced embedment depths than assumed in the structural calculations, and; equivalent fluid pressure (EFP) values presented in the 2004 LSI report. Regarding reduced embedment depths, we recommend structural design assume an actual, as -built embedment of 7.5 feet to reflect the conditions shown in Photograph 2 above. We suspect this actual embedment configuration does not provide sufficient lateral resistance to meet pier stability requirements. Also, the ground surface slopes steeply below the pier, thus requiring an adjustment to lateral earth pressure parameters based on the slope's presence. Although LSI provided EFP recommendations that purportedly incorporate the slope, STRATA estimated lower EFP values referencing the boring data from the 2004 LSI report. Our estimated lateral support properties are outlined in Table 1 below. Due to the relatively steep slope, passive earth pressure coefficients are substantially and non -linearly reduced. Continued slope erosion/movement could further reduce available passive resistance derived from pier embedment. Finally, the presence of at least one utility trench below western piers creates soil backfill properties that may be different than the native soil used as a basis for our evaluation. Our experience suggests that compacting trench backfill along steep slopes is nearly impractical, and our opinion is the utility backfill was not placed in a similar or better condition than the surrounding native soils. The future performance of such backfill relative to lateral pier resistance is unknown, but suspected to further reduce available passive resistance for the piers. The backfill is presumably present directly downslope of western piers and within the primary zone where lateral resistance is generated. Foundation Evaluation Summary The existing platform appears to be stable under the current loading conditions, assuming continued localized slope movement does not progress. Our opinion is the current platform system can accommodate the increased vertical loads with negligible vertical deflection. However, although the existing platform may not be in imminent risk of failure, the anticipated future platform loads are likely to cause additional lateral deflection. The additional deflection may not occur during the first year, however, prolonged existence of the additional platform loads coupled with seasonal slope movement may cause unacceptable lateral pier deflection over time. STRATA cannot predict whether such deflection would be due to reduced lateral soil resistance or progressive downhill slope creep/movement that impacts the supporting piers. Regardless, our resulting opinion is that retrofitting the platform system, including the supporting piers may be necessary to support the current proposed loading conditions. 04 www.stratsgeotech.com 0 2014 by Strata, A Professional Services Corporation. All rights reserved. Limited Geotechnical Engineering Sere€ees Lakota AT&T Communication Tower (SS64) File: CCRENG SP14177A Page 7 The structural engineer can reference the lateral earth pressure parameters presented herein to evaluate embedment depth requirements for new, existing, or retrofitted pier configurations. If lateral earth pressures parameters are necessary to complete retrofit design or to perform additional structural analyses, we present the following estimated lateral resistance properties referencing LSI's 2004 exploratory data: Table 1. Lateral Earth Pressure Parameters Soil Unit PassitlO Earth Prenwe Coefficient Passive EFP' Upper Sand Medium dense to dense 0.8 77 pcP 0 to 5 feet BGS2 (2 to 7 feet on LSI log) Soil Friction Angle — 34- Soil Moist Unit Weight — 120 Lower Sand Very dense 5 to 10 feet BGS (7 to 12 feet on LSl log) 0.8 86 pcf Soil Friction Angle — 37" Soil Moist Unrl Weight — 134 pcf 1. EFPs reported in pcf and are based on moist unit weights. EFP's derived from NAWAC OM7.02, Ftgure 6 assuring an mterfaee friction angle (6) value of 22 degrees. Passive soil resistance has been prorated for 0-5 inches of tt}terai movement and sto ng terrain below the piers- 2_ Below gmund surface (BGS)- The upper 2 feet of the LSI log was accounted fa based on reported topsoil shipping during anginal construction in 2004. 3- Pounds per cubic foot (pd). Lateral surcharge pressures due to equipment, storage loads, etc. have not been included in the above lateral earth pressure recommendations. Although not anticipated, if a perched, seasonal groundwater table develops within the pier passive resistance zone, buoyant soil conditions may develop, which will substantially reduce the EFP values presented above. Furthermore, based on anticipated freeze -thaw conditions, and reduced lateral capacity in the upper 12 to 24 inches of the soil profile, we recommend the upper 2 vertical feet of soil passive resistance be neglected by structural design. Neglecting the upper 2 feet in stability calculations also helps account for potentially loose utility backfill directly downslope from western piers. FOUNDATION SYSTEM RETROFITTING CONSIDERATIONS As presented above, it appears retrofitting is necessary from a lateral capacity standpoint to accommodate the increased platform loads. STRATA did not propose to provide detailed retrofitting recommendations under our Task 1 scope of services; Task 2 was intended for final design services after a retrofitting option is selected by the structural design team. However, to assist the project team, we introduce the following 3 retrofitting options we feel are viable; others may be appropriate: 'v New Piers 'v Soil Anchor Tiebacks is Buttress Fill 04 www.shatagootech.com 0 2014 by Strata, A Professional Services Corporation. All rights reserved. Limited Geotechnical Engineering Services Lakota AT&T Communication Tower (SS64) File: CORENG SP14177A Page 8 Option 9 — New piers New pier systems comprise relatively inexpensive, conventional construction practices familiar to local contractors. However, it may be difficult to access the site with equipment necessary for new pier installation, which could warrant a different retrofit system. Although new piers can rely, in part, upon the parameters outlined herein, the overall pier configuration, long-term soil performance, as - built conditions, and many other factors should be carefully considered given the site conditions that could impact the performance of improvements. If new piers are designed to replace or augment existing piers, we anticipate Cornerstone will require vertical bearing pressures, lateral equivalent fluid pressures, pier arching width, and side shaft friction recommendations. Option 2 — Soil Anchor Tiebacks This option comprises a retrofit approach that would include installing near -horizontal tiebacks to provide lateral resistance and connecting the anchors to existing piers or to the platform. Tieback options include helical piers, soil nails, and many other anchorage systems. For any tieback system, we recommend the plans specify the location and design loading required for the system and specify that the selected contractor shall procure tieback design. Our opinion is that it is in the Owner's interest to avoid specifying a specific tieback system, rather allow bidding contractors flexibility to design and install the system commensurate with their capabilities, experience, and overall construction approach. Our preliminary opinion is helical piers can provide the necessary tieback resistance and are relatively easy and cost-effective system to install. If helical piers are considered, we recommend STRATA document installation torque, overall length and other system aspects to confirm the contractor's design and ensure the required tieback resistance is achieved. Via retrofitting design, the project team would specify the load and require the anchor be installed to at least the specified load as determined by the termination depth torque measurements. Helical piers can typically accommodate up to 55 kip design loads for typical pier configurations. Thus, this system may require only 1 or 2 additional anchors if the structural engineer incorporates an I-beam or other bracing into the existing platform/pier system. Furthemwre, this system may provide sufficient resistance with anchors tied to western piers only, thus eliminating work access to uphill platform and pier areas. Depending on the contractor's approach, several helical piers can be installed in a single workday and the system does not require grout curing delays. Limitations include the presence of existing utilities near the piers and any helical pier tieback length may be unknown until installed. However, the selected contractor can provide estimated pier lengths and unit pricing as a basis for bidding, or the system can be bid on a "lump sum" basis to provide Owner pricing regardless of the as -built length. 0�0 www.aftategootech.com com 0 2014 by Strata, A Proftsional Services Corporation. All rights reserved. Limited Geotechnical Engineering SeMces La€ ota AT&T Communication Tower (SS64) File: CORENG SP14177A Page 9 Option 3 — Buttress Fill Adding a buttress fill to the downhill slope can increase the lateral pier resistance by placing granular structural fill in the passive resistance zone, thereby improving pier embedment. A buttress fill option may be inexpensive but challenging site grades and a small work footprint may not allow substantially increasing site grades between the existing tower pole and platform. A retaining structure may be necessary at the downhill buttress toe to protect existing improvements, stay within the leased area, and allow sufficient grade increase via the buttress fill. EVALUATION LIMITATIONS Our services were limited to conducting a literature review, performing analyses, and providing this letter. We cannot provide final geotechnical recommendations to assist retrofit design at this time. As discussed in our proposal, retrofit option selection and final design will require interaction with the project team. We recommend the design team consider the above retrofit options and contact us if you have any questions, or require additional feedback. If retrofit design progresses, we recommend you authorize STRATKs proposed Task 2 services so we may continue supporting the project team. Our services consist of professional opinions and considerations provided in general conformance with our understanding of geotechnical engineering principles and practices as they exist at this time and in the project area. We are not assuming the role of geotechnical engineer -of -record for any structure at this time. Our services were not intended for final design, rather to assist the project team in initially evaluating the platform foundation system. STRATA provided no direct exploration, we did not perform laboratory testing, and we have not reviewed site conditions in person. If the lateral earth pressure considerations presented herein are used for design, we respectfully require Cornerstone provide STRATA the opportunity to review retrofitting design and confirm the soil parameters during construction. This acknowledgement is in lieu of any express or implied warranties. We appreciate the opportunity to worts with you on this project and to assist the design and ownership team. If you have any questions, feel free to contact us. Chris M. Comstock, P.E. Senior Engineer RML/CMC/cc Sincerely, STRATA Ryan M. Lewis, E.I.T Staff Engineer 04 vwvw.stategeotech.com © 2014 by Strata, A Professional Services Corporation. All rights reserved. Jim Ferrell, Mayor July 6, 2015 Ms. Jennifer Taylor Ryka Consulting 918 South Horton Street, Suite 1002 Seattle, WA 98134 Re: File #15-100378-00-UP; DISCUSSION FOLLOW-UP AT&T Mobility - SS64 Lakota; 2629 SW 308th Street, Federal Way Dear Ms. Taylor: FILE Planning Manager Conlen asked me to follow up on the discussion that he had with you regarding the PWSF site adjacent to 2629 SW 308th Street. The discussion focused on the following two points. • Attachment of an aesthetic screen to the structure and/or landscaping accordingly, in order to screen the equipment from Dash Point Road. ■ Updated GeoTechnical Report to reflect the latest modification to the proposal. Please submit two copies of requested resubmittal items along with the enclosed resubmittal form. Also note, I will be taking over as your point of contact for this project. If you have any questions regarding this decision, please contact me at coi... arrow citvoffederalway.co , or 253-835-2622. Sincerely, 6w__ Cory Darrow Planning Intern enclosure Doq I.D. 69957 33325 8th Avenue South, Federal Way, WA 98003-6325 (253) 835-7000 www.cityoffederalway.com CITY OF FEDERAL WAY DEPARTMENT OF COMMUNITY DEVELOPMENT DEVELOPMENT REVIEW COMMITTEE TRANSMITTAL DATE: 1/29/15 TO: Ann Dower, Senior Engineering Plans Reviewer Kathy Mathena, Public Works - Streets Division Scott Sproul, Assistant Building Official Vince Faranda, South King Fire & Rescue FROM: Kalon Thomas FOR DRC MTG. ON: No Meeting - Please email any comments FILE NUMBER(s): 15-100378-00-UP RELATED FILE NOS.: 15-100379-00-CO 12-103388-00-UP PROJECT NAME: AT&T MOBILITY - SS64 LAKOTA PROJECT ADDRESS: 2629 SW 308TH ST ZONING DISTRICT: RS 15.0 PROJECT DESCRIPTION: Modification of existing PWSF including replacemnet and addition of antennas and extension of existing utility pole in public ROW. Also includes extension of existing equipment on private property. LAND USE PERMITS: Use Process I PROJECT CONTACT: RYKA CONSULTING JENNIFER TAYLOR 918 HORTON ST Suite 1002 Seattle, WA MATERIALS SUBMITTED: Master Land Use Application PWSF Development Requirements Use Process III Project Approval, dated 9/18/2012 Project Narrative Vicinity Map Site Lease Addendum Existing/Proposed Elevations Exhibit Option and Lease Agreement Site Plan and Elevations July 2, 2015 RYKA CONSULTING JENNIFER TAYLOR 918 S HORTON STSuite 1002 SEATTLE, WA 98134 RE: Permit #15-100378-00-UP; AT&T MOBILITY - SS64 LAKOTA 2629 SW 308TH ST Dear Ms. Taylor: Planning Manager Conlen asked me to follow up on the discussion that he had with you regarding the PWSF site adjacent to 2629 SW 3081h Street. The discussion focused on the following two points. • Attachment of an aesthetic screen to the structure and/ or landscaping accordingly, in order to screen the equipment from Dash Point Road. • Updated GeoTechnical Report to reflect the latest modification to the proposal. Please submit two copies of resubmitted items along with the enclosed resubmittal form. Also note, I will be taking over as your point of contact for this project. If you have any questions regarding this decision, please contact me at cory.darrow@cityoffederalway.com Sincerely, Cory Darrow Planning Intern Attachments. Resubmittal Form enclosure Doc. I.D. RYKA CONSULTING 918 South Horton St. Seattle, WA 98134 RECEIVED 8Y COMMUNITY & ECONOMIC DEVELOPMENT DEPARTMENT MAY 12 2015 May 8, 2015 To: City of Federal Way ATTN: Community Development Director Department of Community Development 33325 8th Ave S Federal Way, WA 98043 RE: AT&T SS64 Lakota Permit Application #15-100378-00-UP Dear Director, On behalf of AT&T, Ryka Consulting is submitting this response to the comments received from the City of Federal Way on February 12, 2015. Community Development - Planning comments stated: "Pursuant to Federal Way Revised Code (FWRC) 19.225.040(4)(b) "Equipment enclosures shall be designed, located, and screened to minimize adverse visual impacts from the public right-of-way and adjacent properties." Although smaller in total area than the previously approved equipment platform, there is still a substantial increase in the total footprint that will need to be screened from the public right of way. Consistent with the previous approval, a five (5) foot landscape buffer will be required. Please provide a landscape plan that depicts these screening requirements." AT&T is requesting a modification to the required landscaping requirements per FWRC 19.125.100 Modification options. This particular project includes unique circumstances and we believe a reduction of disturbed areas around the project site will better serve the intention of the landscaping requirements than implementing a five foot landscaping buffer. The project site is located on a slope so the platform extension was designed to minimize impacts and soil disturbance to the slope. A five foot buffer encircling the platform would significantly increase the amount of ground disturbance. Our Erosion Control Plan indicates that the proposed project would involve 86.5 square feet of disturbed land area while a 5 foot landscaping buffer will require an additional 425 square feet of disturbed land area. Additionally, the site is located along a winding road in what is somewhat of a ravine type area. The land on either side of the Dash Point Road rises steeply on undeveloped properties. There are no developed properties that have views of the project area. Therefore the visual buffer of landscaping would be for the benefit of vehicle passengers. As the road includes many turns, the site is not easily visible from the road and there are no sidewalks so pedestrians are unlikely to pass nearby. Lastly, the area contains heavy natural vegetation. Allowing the natural vegetation to remain and continue to grow will better buffer the wireless facility from view compared to landscaping that will stand out in an otherwise undisturbed wooded area. To support our request we have included a copy of the photo simulations of the site demonstrating the equipment platform is not easily seen and the erosion and soil control plan which includes calculations of the significant increase of soil disturbance that landscaping would result in. Section 19.125.100 of the Federal Way Revised Code allows for requests to modifications of the landscaping requirements if meeting the criteria of subsection 2: (2) Modifications to the landscape standards may be granted by the director of community development if: (a) The proposed modification represents a superior result than that which could be achieved by strictly following the requirements of this title; and Due to the natural heavy vegetation of the area, we believe landscaped type plants will stand out rather than obscure the platform. Allowing native plants already onsite to continue to grow will result in better visual balance with the surrounding native plants. (b) The proposed modification complies with the stated purpose of this title and any applicable subsections of this title; and The purpose of landscaping code explicitly states that retaining natural vegetation is to be encouraged and providing an appropriate amount of landscaping is also a purpose of the code. In an otherwise heavily vegetated area, we believe causing otherwise unneeded soil disturbance on a slope does not fit with other purposes of the code that promote low -impact techniques, existing vegetation retention and flexibility. (c) If the proposed modification will not violate any city of Federal Way Revised Codes or ordinances. In particular, a modification shall not be a substitute for any zoning variance; and The code allows for the request of landscaping modifications. If this was granted there would be no violation of codes or ordinances. (d) Where applicable, the proposed modification would result in an increased retention of sigrtuficant trees and/or naturally occurring vegetation on the site; and AT&T's request specifically would allow for natural occurring vegetation to remain and continue to grow in the area surrounding the expanded platform. (e) The proposed modification also satisfies the criteria listed in subsection (2), (3), (4), (5), or (6) of this section. (3) The width of the perimeter landscaping may be reduced up to 25 percent when the proposed landscaped area incorporates a combination of plant materials, berms a minimum of three feet in height, and architectural elements of appropriate height and scale sufficient to act as an efficient substitute for the three- foot berm. Berms and architectural features are not feasible on the side of the slope such as this site is located. (4) The landscaping requirement may be modified when necessary, because of special circumstances relating to the size, shape, topography, vegetation, location or surroundings of the subject property, to provide it with use rights and privileges permitted to other properties in the vicinity and zone in which it is located, or if strict application would result in scenic view obstruction. The slope of the project area, the small size of the facility, the existence of natural vegetation around the facility, and the location of the project in an area without developed properties with views of the site are special circumstances to this specific project. (5) Perimeter landscape strips may be averaged, provided the minimum width shall not be less than 50 percent of the underlying width requirement. Not applicable as there are no developed sites around the area with landscaping. (6) If the property abutting the subject property is in the same or a more intensive land use zoning district than the subject property, the landscaping required along that common interior property line may be reduced by 25 percent in area. In addition, the remaining 75 percent of the required landscaping may be relocated upon approval of the community development director, consistent with the standards of this title. This is a large parcel with heavy vegetation. No abutting properties are developed and no landscaping was required along the property lines which are heavily vegetated already. We request consideration of a landscaping code modification to allow for retention of existing vegetation in place of a new landscaping buffer. Sincerely, Aennifer Taylor Ryka Consulting, Agent on behalf of AT&T _ - '�� •1 rid' :..�_•.• i. .. 4ik SPCITY OF � Federal Way APPLICATION NO(S) Project Name MASTER LAND USE APPLICATION DEPARTMENT of COMMInvrry DEVELOPMENT SERvIcEs 33325 8'" Avenue South Federal Way, WA 98003-6325 253-835-2607;Fax 253-835-2609 WWw.cit ff i s I n o 37S ' 00 u-rl AT&T - SS64 Lakota JAN 2 6 2015 Date Y CDS l lI. ■■ i■ i a ■ e • ■ : 1i Parcel Numbers) Right-of-way and Parcel 122103-9116 Project Description Modification of existing PWSF including replacement and addition of antennas and extension ore -xi -sting utility pole in the public right-of-way. Also includes extension of existing equipment on private 12ropeKbL. jwa,R�JJ Type of Permit Required Annexation Binding Site Plan Boundary Line Adjustment Comp Plan/Rezone Land Surface Modification Lot Line Elimination Preapplication Conference Process I (Director's Approval) Process H (Site Plan Review) Process III (Project Approval) Process IV (Hearing Examiner's Decision) Process V (Quasi -Judicial Rezone) Process VI SEPA w/Project SEPA Only Shoreline: Variance/Conditional Use Short Subdivision Subdivision Variance: Commercial/Residential Required Information RS1�ing Family Zoning Designation SF - Medium Comprehensive Plan Designation 40,000 Value of Existing Improvements 32,000 Value of Proposed Improvements International Building Code (IBC): unoccupied Occupancy Type telecom Construction Type Applicant Name: New Cingular Wireless PCS LLC (AT&T) Address: 16221 NE 72nd Way RTC 3 City/State: Redmond, WA Zip: 98052 Phone: Fax: Email: Signature: I Agent (if � rent than pplicant) Nan1e: Jennifer Taylor with Ryka Consulting Address: 918 S Horton St #1002 City/State: Seattle WA Zip: 98134 Phone: 206-228-2127 Fax: 206-260-7930 Email: - ylorC@ kaconsulting.com Signature: Owner Name: Antenna location -City of Federal Way / PSE pole Address: owner. Ground space owner Steve Hopkins City/State: Zip: Phone: Fax: Email: Signature: See current lease agreement enclosed with Application Bulletin ii O3 —January 1. 2011 Page 1 of 1 k:lHandoutsl:�iaster Land Use Application r L U 4f, To 10 L �D I A S t- T o; �� p um Yy NWS T T 6 (3-� 0 K 6 N S�Tf N a N a .. o to co co c T-4 , :1 a o a 0 ate' gip_ 0 0 9"'4J 0 c 0_ cu 2 v u f0 a 4a c 0 u OA C .� N, a � SS64 LAKOTA at&t EXISTING NORTH ELEVATION IE "i,., 14 1 • � S F �'�:- {{ - �y it •.i- Ar 16 VIA ..0 R imf;�EIWWAM61 141, THIS IS NOT A SURVEY \ 1 "' �' `� 'l 1 1 VICINITY MAP ALL INFORMATION AND TRUE NORTH HAVE BEEN OBTAINED FROM EXISTING DRAWINGS AND ARE APPROXIMATE. 1[ kCALL O WORM! DrA DAYS 1 \ \ ' % 1 I I ` 1 I 4 y ` 1 - s, P, N t 9EFORE YOU DIGI ll 1 - .. r1 TL#122163-81 1$ 51TE LOGAT(QN =811 � � \ \ t 151,153 R FT 1 1 1 I 1 `"- � \ (3.47 ACRES) � 4 NATIONAL UTILITIES UNDERGROUND LOCATE' �` 1 1 f 1 .,vrrt�iurnwmaLLee i.n+rnnommm.e,nw,�i.0 \ \ � 1 - _ mevawo r,rmm.reom.nnanam,«mAxer es r: .ac.,v.w•rw wmwmmnF waa.a� G - - -. 1 �,y 1 1 TedardW�r l fi I I ly i 1 .� -, l S+s131DIh Si , � ST `', 1^I • EXTENDED 1 1 1 wo \ a aYIT 315111�1 - . RAILROAD TIE WALL a 0�_ ` • ■I' \\ \ — \ \' 1 PROPOSEDLRATTS l `• N 3 1 • P'"l CLFARN�Ci LMHTS - ��' r 1 ' .• 11 ��1���.�-• ,' 11'. 1�1 1 1 1 1 1 ` 1 � 1 l 1 (E] ELECTRICAL 1 SERVICE METER p it � l 1 PROPOSED CONCRETE PIERS (TYP) _ (E) LOCKED 1 ACCESS LADDER � ,I PROPOSED 4 -O* \3 WIDE TIMBER ACCESS STAIRS LM 1TY POOL E�—_�_ 1 1 L lip tO PROPOSED 1 2 SILT FENCE 1 'pO 1� EDGE OF PAVEMENT (E) FOG LINE � 1 � EROSION & SEDIMENT CONTROL PLAN 22x34 SCALE: 114• = 114' Ii1xlT SCALE: 113' =1'-0• N 1 p' j } 1 I (E) DECIDUOUS TREE (fYP) APPLICANT INFORMATION NEW CINGULAR WIRELESS MASTEC 16221 NE 72ND WAY, RTC 3 1203114TH AVE SE P.O. BOX97081 BELLEVUE, WA98004 REDMOND, WA SSW (425) 214-7000 SITE INFORMATION TAX LOT NUMBERS: CITY OF FEDERAL WAY R.O.W. (POLE) 12210"116 (PLATFORM) SITE ADDRESS: SW DASH POINT WAY & 30TH AVE FEDERAL WAY, WA 98023 ZONING: R.O.W.(POLE) RS15.0(PLATFORM) TOTAL LOT AREA R.O.W. (POLE) 3.47 ACRES (PLATFORM) DISTURBED LAND AREA. 76 SO. FT. (ACCESS STAIRS) 10.5 SO. FT. (CONCRETE PERS) 425 SQ. FT. (LANDSCAPING) PROPOSED IMPERVIOUS AREA, c 100 SQ. FT. LEGEND CLEARING LIMBS . • ^ ....... ! . FILTER FABRIC FENCE SHEET FLOW EXCAVATING LIMITS ^ — — — — — — — LEGAL DESCRIPTIONS • \ \ \ \ s `' \ \ l ` CITY OF FEDERAL WAY RIGHT OF WAY (POLE) c1 1 • •\ (E)EQUIPMENT \ ' \ POR OF SE 114 OF NW 114 LY ELY OF CO RD LESS E 285 FT & LESS S 1055 PLATFORM FT TGW N 255 FT OF SD S 1055 FT LESS E 370 FT THOF (PLATFORM) PROPOSED S41' \ \ \ \ \ 1 LANDSCAPE BUFFER 5, `vo, \ CRITICAL AREAS 11 _ \ TT ' 1q E13 EQUIP PLATFORM EXPANSION \ ,fp �� \ ` ALL CONSTRUCTION TAKES PLACE ON STEEP SLOPE (>1.5H:1.m t BOTH ENDS y PROPOSlf7 /YAT1T E 10'-0" MAX SPACING ('TYPO t \ \ � 1 PLAN NORTH PROJECT SCOPE TO MODIFY AN (E) TELECOMMUNICATION FACILITY WHICH INCLUDES THE FOLLOWING: REMOVAL & REPLACEMENT OF AN EXISTING UTILITY POLE WITH A 76-11' TALL POLE IN THE RIGHT -OF -WAY. ADDING (2) 5'$• PLATFORM EXTENSION AT EACH SIDE OF THE (E) STEEL PLATFORM WI(4) NEW CONCRETE PIERS. EXTEND (E) RAILROAD TIE WALL & A Tor LANDSCAPE BUFFER. PERMANENT ACCESS TO THE LEASE AREA BY TELECOM STAFF (ESTIMATED TO BE 1 TIME PER MONTH) WILL BE PROVIDED BY AN EXISTING PAVED ROAD. LITTLE SITE IMPACT IS ANTICIPATED AND THEREFORE MINIMAL T.E.S.C. MEASURES ARE REQUIRED. PROJECT CONTRACTOR SHALL EVALUATE SITE CONDITIONS AS WEATHER CHANGES OCCUR AND THE PROIJECT PROGRESSES TO COMPLETION, COMPLETE FAMILIARITY WITH THE NOTES CONTAINED IN THIS PLAN SET IS REQUIRED PRIOR TO BEGINNING WORK, IT IS ANTICIPATED THAT THE MINIMAL DEVELOPED DRAINAGE THAT RESULTS FROM THE PROJECT WILL SAFELY SHEET FLOW AND DISPERSE INTO THE NATIVE VEGETATION THAT SURROUND THE PROJECT WE NO IMPACT ON EXISTING CONDITIONS OR ADVERSE AFFECTS TO THE LOCAL SOIL AND I OR SURFACE WATER CONDITIONS IS ANTICIPATED_ ALL EARTHWORK SPOILS SHALL BE REMOVED FROM THE SITE ALL WORKMANSHIP AND MATERIALS SHALL BE IN ACCORDANCE WITH CTTYICOUNTY STANDARDS AND THE MOST CURRENT COPY OF THE STATE OF WASHINGTON STANDARD SPECIFICATIONS FOR ROAD. BRIDGE AND MUNICIPAL CONSTRUCTION (WSDOTIAPW4 SPECIAL NOTE TO CONTRACTOR ANY SITE DEVELOPMENT OTHER THAN THE CONSTRUCTION OF THE CELLULAR COMMUNICATIONS PROJECT SHALL BE ADDRESSED BY OTHERS. THIS ESC PLAN ADDRESSES THE CONSTRUCTION WORK AND ACTIVITIES ASSOCIATED WITH THE CELLULAR COMMUNICATIONS PROJECT ONLY. a sTe c =PLANS PREPARED BY: co— -I!-- 19M W'C00" ILLS- REMAIO&D RD NE. SUITE 219 WOODWI.I.E, WA9=2 PHONE: 425-49T.1732 EAWI nl�eOnwalon•Mplmm W"ZORNFA9TONE-ENMCOM =PROJECT INFO: =ISSUED FOR CONSTRUCTION =RkV.Z OATE:—ISSUED FOR BY: :,DRAWN SY:=CMi[; APV.: -- - AJB I JMM MWO =CURRENT ISSUE DATE. 04-29-15 =L IOENI5URE: =PROPRIETARY INFORMATION, DO NOT SCALE DRAWUIGS_ CONTRACTOR MUST VERIFY ALL DaK4 S10NS AND ADVISE CONSULTANTS OF ANY ERRORS A D OMISSIONS- ALL PRENOIA ISSI OF THIS DRAWING ARE SUPERSEDED BY THE LATEST REVOM THE 9dCRMATWNCONTAINED IN THIS SET OF DOCIIDENM ISPROPFIETARYSYNATURE. ANYUSEORDSCLOSURE OTI93i THAN WHICH IS RELATED TD WAEDCUB:f IS STRICTLY PROHISBED. =DRAWING TITLE: EROSION & SEDIMENT CONTROL PLAN ESC-1 O CEI JOB NUMBER NAOD 14.13115