Sutro Tower Modification
Sutro Tower is a privately-owned, 977-foot tall communications tower used primarily for television and AM/FM radio broadcasts serving much of the San Francisco Bay Area.
The proposed modifications would relocate existing antennas and add 50 antennas, microwave dishes and camera mounts to the tower. In addition a ground mounted satellite dish and improvements to existing access roads and landscaping are proposed.
The Planning Code requires changes such as these to be reviewed by the Planning Commission as a Mandatory Discretionary Review hearing.
The Discretionary Review hearing was held on March 19, 2015 at San Francisco City Hall, 1 Dr. Carlton B. Goodlett Place, Room 400.
Materials for Download
- Photo Simulation 1: Looking West from Twin Peaks
- Photo Simulation 2: Looking South from Johnstone Drive
- Department of Public Health Approval (compliance with radio-frequency emission standards)
- Environmental Review Document (2014 Addendum to the 2008 Final Environmental Impact Report)
- 2008 Draft Environmental Impact Report
- Radio-Frequency Exposure Study
A notice was mailed by the Planning Department 20 days before the hearing to all owners within 1,000 feet of Sutro Tower, and to all nearby neighborhood groups registered with the Planning Department.
A separate notice was mailed, by Sutro Tower Incorporated, inviting community members and neighborhood groups (within 1,000 feet of Sutro Tower) to a community meeting. The community meeting was held on January 7, 2015 at 7 PM at the Saint John Armenian Church at 275 Olympia Way.
Building permit submittals for changes such as those proposed by pending building permits (2013.04.12.4452 & 2013.04.12.4453) require a mandatory Discretionary Review hearing by the Planning Commission. The Planning Commission held a public hearing on March 19, 2015 at City Hall, Room 400, where members of the public provided testimony on the proposed project.
Based on the scope of work, the Planning Department's Environmental Review Officer required that the Project Sponsor prepare an addendum to the previous 2008 Final Environmental Impact Report.
In addition, a licensed engineer, prepared a report to demonstrate compliance with radio-frequency (and other) emissions associated with the proposed antenna additions and relocations. The report is intended to demonstrate compliance with public and occupational exposure standards set by the Federal Communications Commission. That report was reviewed and approved the San Francisco Department of Public Health.
- Will This Proposal Add Cellular Antennas?
No new antennas are proposed for use by Personal Communication Services (also known as cellular or mobile coverage). Sutro Tower features existing antennas for Clearwire, which was acquired by Sprint. No other major wireless carriers (e.g. AT&T Mobility, T-Mobile, or Verizon Wireless) broadcast from the tower.
- Does the City Own the Tower or Antennas on Sutro Tower?
The City of San Francisco does not have an ownership stake in Sutro Tower. Sutro Tower is owned by a consortium of broadcasters (e.g. television). The City and other government agencies do have antennas currently on the tower. The proposed modification would add microwave dishes and antennas to be used by the Department of Technology's Community Broadband Network (CBN). The CBN antennas would provide backhaul (connecting individual sites to the main internet switch) capacity to provide CBN coverage at different locations in the City. Examples include, but are not limited, to Wi-Fi coverage at City parks (especially for parks or buildings that don't currently have fiber optic cable running to them), and affordable housing sites. The CBN antennas proposed on Sutro Tower would not provide direct Wi-Fi service to nearby residences, but are instead used as backhaul to connect larger data streams to off-site locations.
- Will the Proposed Modifications Result in Traffic or Noise Increases?
The proposed modifications would result in intermittent construction-related traffic and noise increases;however, long-term, the modification will result in reduced noise since the existing generator (used for backup power in the event of a power outage) is being replaced with a quieter version.
- Will the Proposed Modifications Include Changes to Lighting at the Tower?
No changes are proposed to existing tower lighting. Tower lighting is required by the Federal Aviation Administration.
- Will the Proposed Modifications Increase Radiation or Radio-Frequency Emissions (RFR) from the Tower?
The project sponsor's consultant, Hammett and Edison, Inc., conducted a supplemental analysis to determine RFR exposure of the modified project.
RFR Impacts During Normal Operation
During normal operation, the modified project would result in a conservatively estimated RFR exposure level of 6.2 percent of the public maximum permitted exposure (MPE) level for any publicly accessible location, well within acceptable FCC exposure limits.
RFR Impacts During Construction Phase
During construction of the tower improvements for the modified project, the project sponsor would limit the operation of the tower's auxiliary antennas such that the total ground‐level RFR exposure, as conservatively estimated, would be less than or equal to 15 percent of the public maximum permitted exposure level (MPE) for any publicly accessible location.
SF Planning Department