Technolo P" <br />Associates <br />As noted previously, the ability to obtain a variance is questionable. In response to the <br />standard above, provide information about the technological feasibility of <br />undergrounding and consider proposing it an alternative design (alongwith a noise study <br />that addresses an underground design) in the event that a variance is denied. <br />RESPONSE: AT&T requests a variance to the undergrounding requirement based on (1) the <br />technological difficulties and safety issues related to undergrounding ancillary equipment at this <br />site; (2) the proposed, stealth design and landscaping of the equipment enclosure and (3) the <br />planned use of noise baffling within the shelter. <br />AT&T equips certain telecommunication facilities with an emergency power supply in the case of <br />a disaster that cuts off local power supply to the facility. Emergency generators, like the one <br />proposed at this site, use a diesel combustion engine to supply power. Testimony at hearing will <br />demonstrate that undergrounding a combustion engine poses several safety risks, including the <br />risk of explosion and risks to maintenance personnel who would have to service combustible <br />equipment in a confined space. (Maintenance of undergrounded facilities requires at least two <br />maintenance people, so that one can perform safety checks when the other is servicing <br />equipment.) These safety risks make undergrounding prohibitive. Additionally, an <br />undergrounded equipment shelter (compared to an above ground equipment shelter) requires a <br />larger construction footprint, additional belowground impervious surface, and several above <br />ground ventilators and air pumps (which could generate additional noise) to provide cooling far <br />the equipment and resolve air quality issues for maintenance personnel. <br />The proposed design is a fully enclosed equipment shelter, designed to closely resemble the <br />existing church building, with compatible architecture and matching roofing, siding, and paint. <br />The extension is minimal in proportion to the size of the existing building and will be painted and <br />finished to match the existing structure. Applicant also proposes new landscaping around the <br />perimeter of the building extension so the ancillary equipment stored inside it will be completely <br />stealthed and have minimal visual impact. The shelter would be lined with extensive sound <br />baffling to reduce noise produced by the WTF's ancillary equipment below the city's limit of 45 <br />dBA at the adjacent property lines. <br />7117 SW Bevelard Street, Suite 101 <br />Tigard, OR 97223 <br />(323) 559-4103 <br />Email: 'acoh.finney@taec.net <br />www.taec.riet <br />11 <br />