Air Transportation Element Table of Contents

LIST OF FIGURES

LIST OF TABLES

TABLES

1.0 INTRODUCTION

1.1 PURPOSE AND AUTHORITY

The purpose of the Air Transportation Element of the Sonoma County General Plan is to establish policies that will guide future growth and development of aviation activity and airport facilities in the county through the year 2005 in a manner consistent with the goals and policies established in other elements of the General Plan.

State of California law requires that acquisition or disposal of real property and capital improvements such as construction projects be consistent with and conform to the adopted general plan. The Air Transportation Element will serve to establish direction and standards for judging consistency of proposed actions involving airports with the General Plan. The Air Transportation Element will serve to establish direction and standards for judging consistency of proposed actions involving airports with the General Plan. The Air Transportation Element also includes an implementation program that the County of Sonoma will utilize to effectuate policies and attain conformity with the General Plan.

Inclusion of the Air Transportation Element in the General Plan is optional as defined by Section 65303 of the Government Code. The Element has the same legal status as mandatory elements of the plan, including requirements for internal plan consistency and consistency of public and private development projects.

1.2 RELATIONSHIP TO OTHER ELEMENTS

California Government Code Section 65300.5 requires that the elements of a general plan comprise an integrated, internally consistent, compatible statement of policies for the adopting agency. The Air Transportation Element's policies complement policies expressed in other elements and comply with the requirement for internal consistency in the following manner:

1. The economic-demographic projections and assumptions used in other elements, notably the Land Use, Circulation and Transit, and Noise Elements, are used in the Air Transportation Element.

2. The policies expressed herein are designed to complement and reinforce the policies stated in other elements of the General Plan, in particular those in the Land Use, Circulation and Transit and Noise Elements.

3. The goals and objectives reflect the goals and objectives expressed in other elements of the General Plan.

The Air Transportation Element addresses 1986 and projected future noise levels at the various public use airports in the County, with special emphasis placed on the county-owned Sonoma County Airport. Information about noise levels is also contained in the Noise Element so that all noise sources are evaluated within a single context.

1.3 ORGANIZATION

This element is organized into five major sections:

Background: A section that includes information on past air transportation activity in the county, airport activities, the existing airport system and service levels, and a description of the roles and the level of authority of the many jurisdictions involved in aviation.

Air Transportation Demand And The County Airport System: This section includes the projected air transportation demand for Sonoma County. It is based on demographic and economic forecasts used in the land use and other elements. A future county airport system (including additional facilities) that can serve some or all of the air travel demand is also identified.

Compatibility With The Community: Community compatibility, an important issue addressed by this element, is specifically defined so airport-related activities will be appropriately controlled.

Air Transportation Policies: This section expresses air transportation policies that are detailed enough to allow judgements to be made on airport-related actions of the County of Sonoma and its various agencies.

Implementing Program: This section identifies the specific legislative and administrative actions necessary to effectuate policies and attain conformity of regulations with the plan.

2.0 BACKGROUND

2.1 HISTORICAL OVERVIEW

Aviation activity of varying types -- privately-owned aircraft, commercial aircraft and airline service -- has occurred in Sonoma County for over 60 years. Since 1965, the number of annual aircraft operations at various airports throughout the County has ranged from a low of about 120,000 operations to a high of approximately 460,000 operations in the early 1980's. As can be seen in Figure AT-1 on page 345 the maximum aircraft activity levels occurred in the late 1970's at the Sonoma County Airport. The number of based aircraft at county airports has grown steadily over the years to the present level over 850.

Airline service has varied since loss of scheduled service by a local carrier in the 1970s. At the peak of that service, approximately 50,000 air passengers used the Sonoma County Airport each year. In recent years, commuter-type service has handled about 3,000 annual passengers. As of 1987, recent service affiliated with a major carrier indicated an annual rate of approximately 35,000. Figure AT-2 on page 345 indicates the fluctuations that have occurred in air passenger activity at the Sonoma County Airport.

2.2 DEFINITIONS

Terms used in this element to describe aviation activity are defined as follows:

Annual Operations: Annual operations are the number of takeoffs plus the number of landings occurring during a twelve-month period.

Annual Passengers: Annual passengers are the total number of scheduled and commuter air passengers enplaning and deplaning at an airport during a twelve-month period.

Aviation Easement: An interest in real property frequently obtained by airport owners as a means of safeguarding airport activities. Such an easement may create a right for free and unobstructed passage of aircraft over the property above a specified altitude and a right to subject the property to noise, vibration, fumes, and other effects associated with normal airport activity.

Community Noise Exposure Level (CNEL): CNEL is a measure of the cumulative effect of individual noise events averaged over a 24-hour period and weighted by the time of occurrence.

Commuter Airline: Commuter airlines engage in regularly scheduled air service, carrying persons or property on intrastate routes.

Emergency Service: Emergency services conducted by public agencies or private firms including the following:
- fire services including wildland fire suppression
- police services
- medical services

Federal Aviation Regulation: Regulations published by the Federal Aviation Administration denoting specific federal requirements in the certification and operation of aircraft, airmen and airports.

Flight: Refers to an aircraft operation - either a departure or an arrival.

General Aviation: General aviation includes all aviation activity except activity by airlines and the military. The privately-owned aircraft is the most common type of general aviation aircraft and activities include:
- personal and business travel
- flight instruction and training
- recreational flying
- commercial uses (eg. aerial applicaton fire fighting, photography, mapping, air taxi, charger and emergency services.
General aviation aircraft includes airplanes, helicopters, ultralights and specialty craft (eg. blimps, balloons and hang-gliders).

Figure AT-1

Figure AT-2

Maximum Single-event Noise Level (Lmax): Lmax is a measure that indicates the maximum noise level reached during a single aircraft overflight, expressed in dBA, at a specified point of measurement.

Public-Use Airport: A publicly- or privately-owned airport where public use is invited or allowed without restriction, as defined by the state Division of Aeronautics; such airports must have a California Airport Permit issued by the Division.

Scheduled Airlines: Scheduled airlines engage in regularly scheduled air passenger service, and operate on intrastate and interstate routes.

Single-Event Noise Exposure Level (SENEL): SENEL is a measure of the noise generated by a single aircraft overflight. It includes the loudness of the event during the time interval that the event is above the threshold level.

2.3 EXISTING AIRPORTS AND SERVICE LEVELS

There were seven airports in Sonoma County open for public use as of 1986 (Figure AT-3) on page 349. Three were privately-owned (Sonoma Skypark, Santa Rosa Air Center and Sonoma Valley), three were owned by cities (Cloverdale, Healdsburg and Petaluma airports) and one was owned by the County of Sonoma (Sonoma County Airport). these airports all have general aviation activity consisting of single-engine and twin-engine piston-powered aircraft. Twin-engine turboprop and jet-powered aircraft utilize the Sonoma County Airport and, to a lesser extent, the Petaluma Airport. Sonoma County Airport is the only point for commercial air passenger service. In addition, the airport has been designated as a fire base by the California Department of Forestry which uses aerial tankers and helicopters in forest fire suppression operations. The current activity levels at the seven airports are shown in Table AT-1 on page 351. A general description of the facilities available at public use airports in the county is noted in Table AT-2 on the same page.

2.4 INSTITUTIONAL ROLES

The public and private sectors both plan significant roles in air transportation. Authority and responsibilities are shared by a number of public agencies and the resulting relationships are important to the implementation of County policies.

2.4.1 County of Sonoma

County jurisdiction affects aviation in two principal areas -- as airport owner and as public agency with zoning authority over private lands adjacent to the airports. As airport owner, the County can develop the Sonoma County Airport, maintain and operate it and establish operational rules and regulations. Local airport proprietors are limited by provisions of federal and state laws. Under federal law an airport proprietor may not interfere with interstate commerce or discriminate among airport users. In addition, the California Public

Utilities Code expresses requirements for airport permits, noise regulations and funding grants. An airport owner is also subject to federal requirements for airport security, crash-fire-rescue, facility maintenance and funding grant conditions.

In its land use role the County is responsible, under the California Public Utilities Code, to act in accordance with recommendations of the County Airport Land Use Commission (ALUC) or the County may overrule their recommendation by a two-thirds vote of the Board of Supervisors if findings are made that the proposed action is consistent with the purposes of Article 3.5 of the State Aeronautics Act.

2.4.2 Airport Land Use Commission

Sections 21670-21678 of the California Public Utilities Code require formation, under certain conditions, of an ALUC and an environs plan to achieve compatible land uses in the areas adjacent to airports within an ALUC's

jurisdiction. The Sonoma County ALUC has adopted an Airport Land Use Policy Plan which defines compatible land uses as they relate to noise, airspace and safety.

Each local agency whose general plan includes areas covered by the ALUC plan must submit those plans to the Commission for its review. The Commission must make a determination of consistency or inconsistency with the Commission's plan. The Commission's determination may be overruled by a two-thirds vote of the governing body of a city or county. In addition, the following subsequent actions must be reviewed by the Commission:
- amendment to a general plan or specific plan
- adoption or approval of a zoning ordinance
- adoption or approval of a building regulation

Proposed changes to an airport master plan must also be submitted to the ALUC for a determination of consistency with its policy plan.

2.4.3 Airport Owners

A city airport owner has the same responsibilities as a county airport owner. In some cases, control of the land uses adjacent to a city-owned airport is within the jurisdiction of the county of Sonoma. Privately-owned airports are affected by state and federal regulations to a lesser extent, but they are still required to provide for safe operations. Private airport owners are dependent upon city and county land use actions to protect their compatibility with the community.

2.4.4 Private Sector

Aircraft operated in Sonoma County are, for the most part, privately owned and operated; general aviation and airline owners may operate their aircraft at their discretion, but are subject to the FARs governing aircraft operations and local airport rules and regulations.

2.4.5 Regional Agencies

The Metropolitan Transportation Commission (MTC) is a regional agency established under state law and charged with the tasks of creating a regional transportation plan and allocating federal and state funds in accordance with the plan. All aviation funds from state and federal sources that go to cities and counties must be approved by MTC. MTC prepares aviation forecasts, conducts special planning studies and collects data on airports in the San Francisco Bay Region. The Association of Bay Area Governments (ABAG), in cooperation with MTC, collects demographic and land use planning data and forecasts.

2.4.6 State of California

As previously noted, the State has jurisdiction in areas specified in the Public Utilities Code as noted below:

Airport Permit: An airport permit, issued by Caltrans' Division of Aeronautics, is required at all airports open for public use. Specified safety conditions must be met.

Noise Regulations: Noise regulations require that any airport deemed to have a "noise problem" must develop a noise mitigation plan. None of the airports in Sonoma County have been identified as having a noise problem.

Conditions of Grants: Specific conditions may be imposed if an airport receives grant-in-aid funds under the State program.

2.4.7 Federal Aviation Administration

Federal government preemptions cover aircraft in flight, aircraft engaged in interstate and foreign commerce and discrimination among airport users. Because Sonoma County Airport has airline service, FAR provisions dealing with security and crash-fire-rescue apply. Special conditions that were part of the original quit claim deed which transferred the airport from the federal government to the County are a part of each grant-in-aid program accepted by the County.

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TABLE AT-1: Estimated Existing Aviation Activity Levels at Sonoma County Public Use Airports

* CALTRANS. Annual Airport Inspections. February-August 1985.
** Aviation Planning Services. The Santa Rosa Air Center's Role in The Sonoma County Airport System. June, 1981.
*** 1986 activity levels are substantially reduced.

Source: Walter E. Gillfillan and Associates, from: Federal Aviation Administration. National Plan of Integrated Airport System; 1984-1993.

TABLE AT-2: Existing Facilities at Public Use Airports in Sonoma County

IP - Instrument Procedure
* - Lesser length available for landing

Source: Walter Gillfillan and Associates, from: Federal Aviation Administration, Aeronautical Chart; Form 5010 and Jeppesen, Airways Manual.

3.0 AIR TRANSPORTATION DEMAND AND THE COUNTY AIRPORT SYSTEM

3.1 PROJECTED DEMAND FOR AIR TRANSPORTATION SERVICE

The demand projections used in this element reflect recent trends in the aviation industry as well as forecasted economic and population growth. With respect to general aviation, it is estimated that airport facilities can be improved so the projected demand can be served. Demand for only a part, about 40 percent, of the air passenger travel to and from Sonoma County is projected to be served by commuter and scheduled airline operations at the Sonoma County Airport. The remaining 60 percent of the air travelers are expected to use ground transportation to access other airports in the San Francisco Bay Area - - principally San Francisco International Airport (SFO) and, to a lesser extent, Oakland International Airport (OAK).

3.1.1 General Aviation Activity

The "based-aircraft" projections for Sonoma County through the year 2005 are conservative and reflect the recent significant downward trend in the aviation industry. An annual growth rate of about two percent is assumed, about one-half the rate commonly projected in the late 1970s. Aircraft operation forecasts are also lower compared to projections done in the 1970s; the average used in this element is about 250 annual operations per based aircraft (in the past 500-700 annual operations per based aircraft was used. The types of aircraft are likely to be similar to those in use as of 1986, but there will be an increased use of composite materials and smaller aircraft for personal use. General aviation activity forecasts indicate that by the year 2005, there will be 1,300 based aircraft and 344,000 annual operations at the various public-use airports in Sonoma County.

3.1.2 Commuter Airline Services

According to a state-wide survey (California Division of Aeronautics. The California Aviation System Plan. May, 1981) about 55 percent of the county's commercial air passengers are intrastate. This means that 45 percent of the county's passengers are potential customers for commuter connections to SFO. As of 1986, about ninety percent of the air travelers from Sonoma County used ground access (automobile or the airport buses) to get to SFO. It is estimated that the availability of non-stop airline service to Los Angeles could divert about 20 percent of the commuter passengers to Los Angeles International Airport (LAX) connections. This combination of factors would result in commuter service levels of about 50,000 total annual passengers (about 140 average daily passengers) by the year 2005. Using a 15-passenger aircraft with a 65 percent load factor, this would result in about 14 average daily flights (seven arrivals plus seven departures) by twin-engine, turboprop type aircraft; fewer operations would be necessary if larger aircraft or higher load factors were used. The annual operations generated from these flights would be about 5,000 in the year 2005.

3.1.3 Scheduled Airline Services

The following basic assumptions were used to formulate the projected air passenger demand levels for scheduled commercial air carrier services:
- MTC projections of air passenger demand in the Bay Area reflect the future demand for air travel within the Region.
- In the regional forecast, medium growth scenario, the total air passenger demand in the region in the year 2005 is estimated to be 53.7 Million Annual Passengers (MAP).
- In the 1985 MTC Air Passenger Survey, 2.6 percent of all Bay Area passenger trips began in Sonoma County. Based on that figure, by the year 2005, approximately 1,400,000 annual air passengers would be traveling to and from Sonoma County. By comparison, in 1985, 720,000 air passengers traveled to and from Sonoma County and in 1980 the number stood at 385,000.

The recent availability of aircraft (such as the BAe 146) that suit smaller, short-haul markets provides an opportunity for service between the Los Angeles area and larger, outlying communities in the Bay Area. Surveys reveal that about half of Bay Area air passengers are travelling to Southern California. Dependable service at the Sonoma County Airport could capture about 70 percent of the Sonoma County-Southern California air travel market. In addition, about ten percent of the scheduled airline passengers connecting to interstate and international flights through LAX would also be attracted to service from the Sonoma County Airport.

These factors result in a projection that scheduled airline service at Sonoma County Airport could generate 560,000 total annual passengers by the year 2005 (about 1,500 per day). With a 66 percent load factor, this would require about 15 arrivals and 15 departures per day using an 80-seat aircraft. This service would generate about 10,900 annual operations in the year 2005. Scheduled airline service at Sonoma County Airport has been reduced to about 10,200 annual operations in 2005 due to potential air quality impacts resulting from the projected level of service.

3.2 COUNTY AIRPORT SYSTEM

In the year 2005, the county airport system will be comprised, as it was in 1986, of publicly and privately owned airports open to public use. Even with the anticipated closure of the Santa Rosa Air Center, improvements to existing facilities will accommodate the projected demand without development of new airports. Private airport facilities that serve specific aircraft owners or special uses, such as ultralight aircraft, will continue to function.

3.2.1 Likely Service Levels

The forecasted demand for general aviation in the County is contemplated to be accommodated within the next five to ten years at the seven airports that were open to the public as of 1986, except for the Santa Rosa Air Center, which is expected to be closed to aviation in the short term. If the Santa Rosa Air Center (privately-owned airport) were to close, demand could be accommodated at the remaining six airports as shown in Table AT-3 on page 349.

The types of aircraft used in the future at airports in the county are likely to be similar to the types that were in use as of 1986. Tanker operations are contemplated to continue through 1990 and the present equipment will continue to be used. Beyond that time, there may not be parts and engines available for the piston-engine equipment that is currently being used. Inexpensive, surplus aircraft with high load capabilities and the ability to maneuver slowly at low altitudes may not be available. Replacement aircraft will probably be two-engine turboprop or C-130 type aircraft.

3.2.2 Facility Requirements

Airport improvements at the four non-county owned airports needed to accommodate future aircraft activity will be modest and consist mostly of aircraft parking and storage. Individual airport master plans will denote specific requirements.

Facility requirements at Sonoma County Airport will be more comprehensive and will be detailed in the airport master plan. The following planning guidelines indicate the general scope of the improvements:

Facility requirements at Sonoma County Airport will be more comprehensive and will be detailed in the airport master plan. The following planning guidelines indicate the general scope of the improvements:

TABLE AT-3: Projected Aviation Activity Levels at Sonoma County Public Use Airports - 2005

*2005 - General Aviation 240,000; commuter airline 5,000; scheduled airline 10,200
+Sonoma Skypark projections are included in those for Sonoma County Airport

Source: Walter Gillfillan and Associates

4.0 COMPATIBILITY WITH THE COMMUNITY

Airports provide county residents with the benefits of air transportation. At the same time, it is important that aircraft operations be compatible with adjacent community areas. Noise, safe airspace and safety to those on the ground are issues of particular interest and importance. The issue of noise is a major concern for residents near airports, particularly where large aircraft are operating. Figure AT-4 on page 357 provides information about the 1986 level of noise exposure for areas surrounding the Sonoma County Airport.

4.1 PROJECTED NOISE EXPOSURE

Most of the aircraft noise in Sonoma County is generated by general aviation aircraft. Noise contours at each airport are established by large numbers of relatively quiet single-engine aircraft. Some jet aircraft generate a high single-event noise, but jet operations are infrequent so they do not significantly contribute to the annualized cumulative noise impact measured on the CNEL index. One exception to this finding is at Sonoma County Airport where aerial tankers contribute to the cumulative impact on the north end of the airport in the primary approach corridor. A map depicting the future noise exposure at the Sonoma County Airport is shown in Figure AT-5 on page 358. This diagram represents the noise exposure that would occur if the airport were to reach its ultimate capacity of 550,000 annual operations. It is the intent that the capacity of the airport would be protected to this level of activity.

The Sonoma County ALUC has established a noise/land use compatibility matrix which identifies the acceptable range of noise levels for various types of land uses. Generally, under ALUC policies, new residential land uses are acceptable if exterior noise levels are at or below 60 dB CNEL: this is at least 5 dB more restrictive than California's Airport Noise Regulations. The lower limit is based on the quiet rural environment found in Sonoma County. The projected future contours for the other airports in the county are taken from the ALUC Policy Plan and are shown in Figures AT-6 through AT-11 on pages 359 through 364.

The ALUC has also established an interior single-even noise limit for residential land uses to ensure that homes built near airports in areas with acceptable exterior noise levels are adequately designed to protect interior spaces from high single-even noise. The limits were established to prevent speech interference during the day and sleep interference at night.

Analyses of future airport operations, with and without air carrier operations, indicate that air carrier activity could be accommodated at Sonoma County Airport without unacceptable environmental impacts, provided the type of aircraft and number of aircraft operations are appropriately limited. With overlapping and unclear jurisdictional boundaries between State, Federal and local agencies, future regulation of airport noise is a complex task. Development of airport noise policy by the county has included consideration of federal preemptions including the FARS, the Airline Deregulation Act, prohibitions against interference with interstate commerce, and prohibitions against discriminating among airport users.

4.2 AIRSPACE

Criteria used by the FAA to determine which structures are or could be a hazard to air navigation are contained in FAR, Part 77. These standards have been adopted by the Sonoma County ALUC and are also indicated in Figures AT-6 through AT-11. As of 1986, there were no obstructions that restricted the use of any of the airports in Sonoma County.

4.3 SAFETY ON THE GROUND

The FAA provides for clear zones off of the ends of each runway to protect aircraft in flight and people on the ground from aircraft accidents. Clear zones are identified by the FAA as the highest risk areas. For six of the general aviation airports in the county, the trapezoidal clear zone extends outward 1,200' from the end of the runway. At the Sonoma County Airport the area extends 2,700' out from the end of the runway because of the Instrument Landing System (ILS). For facilities like Sonoma County Airport, the FAA will fund property acquisitions in an area up to 5,000' to achieve overall compatibility with the community.

In Sonoma County, the ALUC has increased the safety provisions by setting building coverage restrictions and requirements limiting the intensity of building occupancy in runway approach areas.

5.0 AIR TRANSPORTATION POLICIES OF THE COUNTY OF SONOMA

Sonoma County's air transportation policies are designed to support existing air transportation services and provide for a level of growth commensurate with projected population and economic change in the County and its eight cities. There is a specific concern for compatibility of airports with adjacent community areas and for the safety of air travelers and people and property on the ground. Compatible aircraft operations is another major issue addressed by these policies.

5.1 LAND USE COMPATIBILITY IN THE VICINITY OF AIRPORTS

A key issue in the provision of existing and future air transportation services is the maintenance of compatible land uses adjacent to existing airports in the County.

GOAL AT-1: It is the goal of the County of Sonoma to assure that land use types and densities in areas adjacent to public use airports are compatible with airport activity so existing and future capabilities of the airports can be preserved.

Objective AT-1.1: It is the County's objective that its land-use plans, regulations and other actions adhere, to the extent reasonable or practicable, to the land-use compatibility criteria of the Sonoma County Airport Land Use Commission, unless it is determined that an override is appropriate.

Objective AT-1.2: It is the County's objective that ALUC's airport noise land-use compatibility policies and criteria be the principal determinant of the compatibility and acceptability of proposed land-use projects with respect to the activities, noise, and other impacts of a nearby airport, but that any special circumstances also be taken into account in making such determinations.

Objective AT-1.3: The maximum noise exposure which shall be considered normally acceptable for development of new residential uses in areas surrounding a public-use airport is the 60 dB CNEL noise contour as shown in Figures AT-5 through AT-11 on pages 358 - 364.

The following policies shall be utilized to accomplish the foregoing objectives:

AT-1a: When a proposed project will involve a land use which is "marginally acceptable" or "normally unacceptable" within a noise environment in excess of 60 dBA CNEL, an acoustical analysis shall be required in order to show that the structure has been designed to limit intruding noise to the prescribed allowable levels. Such analysis shall be done in the manner indicated in the California Noise Insulation Standards.

AT-1b: When applying the noise compatibility criteria to a given location, the basis for evaluation shall be the maximum CNEL to which the location is or is forecast to be exposed. For the Sonoma County Airport, the contour based on airport capacity shown in Figure AT-5 shall be used. For the Cloverdale, Healdsburg, Petaluma, Santa Rosa Air Center, Sonoma Valley, and Sonoma Skypark airports, the ALUC forecast of future noise exposures shown in Figures AT-6 through AT-11 shall be used.

AT-1c: Aviation use of Santa Rosa Air Center is incompatible with existing and planned land uses in adjacent off-site areas. The County encourages closure of this airport and the termination of its aviation and related uses.

AT-1d: No object or structure shall be permitted to be erected which, because of height or other factors, would result in an increase in the minimum ceiling or visibility criteria for an existing or proposed instrument approach procedure.

AT-1e: An object or structure which would penetrate a horizontal or conical surface as defined by the ALUC, and would be 35 feet or less in height above the ground (ie. is within the height limits prescribed for most Sonoma County zoning districts) shall be considered conditionally acceptable even if it exceeds the prescribed height limit. Appropriate marking and lighting may be conditions for acceptability.

AT-1f: Specific Plans of the County of Sonoma shall be prepared or revised in a manner which will conform to the ALUC's Policy Plan, except where the board of Supervisors determines that special circumstances justify overruling the Commission and finds that the proposed action is consistent with the purposes expressed in Section 21670 of the Public Utilities Code (State Aeronautics Act).

AT-1g: The County and its various agencies shall refer proposed projects which include requests for general or specific plan amendment, changes to the zoning ordinance, and changes to local building regulations to the ALUC for determination of consistency with its policy plan prior to review by the appropriate County decision-making body.

AT-1h: An approach protection plan for identification of appropriate means of protecting approach zones at the Sonoma County Airport, as identified in Figure AT-12 shall be prepared by the Aviation Department. The appropriate method of protection shall be consistent with the level of protection needed based upon the impact from operations anticipated in this element. The plan shall provide for protection of the area anticipated to be impacted by the airport's ultimate capacity of 550,000 annual operations.

AT-1i: When allowed by law, avigation easements may be required as a condition of approval of discretionary planning permits for parcels within the ALUC referral area shown in Figure AT-12 on page 366.

AT-1j: The county of Sonoma or other appropriate agency may acquire by negotiated purchase fee title interest or partial interests, such as conservation or avigation easements, in real property in order to protect the approach zone at the Sonoma County Airport.

AT-1k: Prior to initiation of commuter service to Petaluma Airport, a detailed noise study shall be conducted.

5.2 PROTECTION OF THE AIRSPACE

Safety of aircraft in flight is a major concern and control of tall structures and buildings is a means of protecting aircraft operations as well as people and property on the ground.

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GOAL AT-2: It is a goal of the County of Sonoma to provide appropriate conditions which will permit the safe passage of aircraft operating to and from airports in the County.

Objective AT-2.1: It is the County's objective that the height and type of structures adjacent to airports be restricted or marked so they will not constitute hazards to air navigation as per FAR Part 77.

The following policy shall be utilized to accomplish this objective:

AT-2a: The County of Sonoma and its various agencies shall comply with ALUC policies regarding height, location, marking and lighting of structures, unless it's determined that an override by appropriate government body is appropriate.

5.3 PROTECTION OF ADJACENT COMMUNITY AREAS

Airport activity can, through changes in types of aircraft and/or increased activity, adversely impact surrounding communities. The following directives express policies regarding limitations on airport operations at the Sonoma County Airport which are intended to either prevent or otherwise mitigate these adverse effects.

GOAL AT-3: It is a goal of the County of Sonoma to maintain compatibility of airport operations with preservation of environmental quality in areas adjacent to Sonoma County Airport.

Objective AT-3.1: It is the County's objective to utilize the CNEL as the measure of cumulative noise impacts and that the boundary of the 60 dB CNEL noise contour projected for year 2005, as shown in Figure AT-13 on page 369, not be extended to encompass a larger area prior to year 2005.

Objective AT-3.2: It is the County's objective to utilize the maximum noise level as defined in the FAR Part 36 Advisory Circular for take off as the metric for single-event noise impacts and to limit such events at the Sonoma County Airport to 83.2 dBA (Lmax) during daytime hours and to 75 dBA (Lmax) during nighttime hours. As of January 1, 1992, the limit shall be 72 dBA (Lmax) for nighttime hours. Exemptions shall be provided for aircraft operating on emergency missions, including their support functions, and for aircraft of the United States Government and its various agencies and for daytime operations by existing aircraft based at Sonoma County Airport.

Objective AT-3.3: It is the County's objective to move toward use of quieter new technology aircraft at Sonoma County Airport. To implement this objective, the 83.2 dBA limit established by this element is the noise level established in the FAR Part 36 Advisory Circular for the MD-80, the loudest Stage 3, new technology aircraft.

The County shall utilize the following policies with regard to operations at the Sonoma County Airport:

AT-3a: Operations at the Sonoma County Airport shall be regulated so as not to extend the land area encompassed within the 60 CNEL noise contour projected for year 2005, as shown in Figure AT-13, prior to year 2005.

AT-3b: Daytime aircraft operations at Sonoma County Airport by general aviation users and by commercial air carriers shall be restricted to those types of aircraft that have a departure single-event noise level of 83.2 dBA (Lmax) or less, as specified in the most recently published FAR Part 36 Advisory Circular (AC 36-3D, take-off chart). Nighttime operations shall be similarly limited to aircraft not exceeding 75 dBA (Lmax). Daytime hours shall be defined at 6:00 a.m. to 10:00 p.m., and nighttime hours as 10:00 p.m. to 6:00 a.m.

The exemption for aircraft operating on emergency missions, including their support functions and for aircraft of the United States and its various agencies shall continue until this element is amended to the contrary. The exemption for existing aircraft based at Sonoma County Airport shall terminate at the conclusion of a depreciation schedule which amortizes out the economic value of the aircraft over a period of time which is calculated to take into account the useful life of the aircraft and the owner's investment in it.

AT-3c: After January 1, 1992, nighttime operations at Sonoma County Airport shall be restricted to those types of aircraft that have a departure single-event noise level of 72dBA (Lmax) or less, as specified in the most recently published FAR Part 36 Advisory Circular.

AT-3d: It is the County's intent to move towards a quieter single-event noise standard in the future as the aircraft fleet shifts to newer, quieter aircraft. The Aviation Director shall annually provide a report to the Board of Supervisors on noise complaints received at the Sonoma County Airport. If the Board determines that a noise problem exists, the County may establish a more sophisticated measure, standard and monitoring system for single noise events which shall be capable of measuring noise produced by any aircraft arriving or departing the Sonoma County Airport.

AT-3e: The County of Sonoma shall require that, prior to initiation or expansion at Sonoma County Airport of any regularly scheduled commercial passenger service, the applicable air carrier shall enter into an appropriate lease or operating agreement with the County. Such leases or agreements shall conform to all applicable policy directives of the Air Transportation Element, including those pertaining to restrictions on permissible aircraft noise levels. The County shall, in negotiating leases or agreements, encourage that aircraft types with quieter noise levels be utilized. To the extent allowed by law, the County shall require that new leases or other operating agreements with commercial air carriers be limited solely to quieter "Stage 3" aircraft. Prior to its execution, any proposed lease or operating agreement shall be reviewed for consistency with the Air Transportation Element and shall be reviewed pursuant to the California Environmental Quality Act and the implementing ordinance of the County of Sonoma to determine whether the project is exempt from CEQA, is covered by the EIR accompanying this element, or requires the adoption or certification of an additional environmental document.

AT-3f: A noise monitoring program shall be established for the Sonoma County Airport; monitoring shall conform to state standards and include both periodic ambient measurement of single-event noise and computer modeling of CNEL contours based on logs of aircraft operations. The noise monitoring program shall include a 24 hour directory listing and answering machine for receiving complaints. Complaints shall be recorded, investigated, and where possible correlated with aircraft operations. The Airport Director and County counsel shall submit to the Board specific options for the monitoring of noise and a summary of techniques used by other jurisdictions. Reports summarizing the findings and any recommendations for improvements of noise policies and/or standards shall be submitted to the Board of Supervisors by the Aviation Director. The first such report shall be submitted within one year of adoption of this plan and subsequent reports whenever there are significant changes in aviation activity, but at least biannually.

AT-3g: Standards for interior noise levels for existing residences shall be established as part of the Approach Protection Plan. The Approach Protection Plan shall identify appropriate mitigations to be undertaken in the event noise standards are exceeded. These mitigations may include purchase assurance, acoustical treatment, and purchase of easements.

5.4 GENERAL AVIATION

Continuation of existing general aviation activity and provision for future growth are an important part of air transportation in the County.

GOAL AT-4: The County shall encourage the maintenance of an airport system which is capable of accommodating projected growth in aviation demand.

Objective AT-4.1: It is the County's objective to maintain the functions and level of service at Sonoma County Airport to accommodate the projections of aviation activity shown in Table AT-3 on page 354.

Objective AT-4.2: It is the County's objective to provide adequate runway, taxiway, aircraft parking, aircraft storage and attendant facilities to meet demand projected at Sonoma County Airport.

Objective AT-4.3: The County may accommodate general aviation activity at private restricted-use airports when compatible with surrounding land uses.

Figure AT-13

View full size Figure AT-13

The County shall utilize the following policies to achieve the objectives noted above:

AT-4a: The County shall revise, update and maintain a current airport master plan for Sonoma County Airport which conforms to the policy direction established in the Air Transportation Element.

AT-4b: The Airport Department shall limit proposed projects to those consistent with the policy directives of this element, including construction of permanent facilities and land acquisition.

AT-4c: The airport capital improvement program and budget shall be prepared and administered in a manner which is consistent with the directives of the Air Transportation Element.

AT-4d: Any airport projects shall be required to be justified based on the need resulting from projected aviation activity or current use levels.

5.5 COMMERCIAL AIR PASSENGER SERVICES

Commercial air passenger services are defined to consist of two components, commuter airlines and scheduled airline services. These services are contemplated to be provided exclusively at the Sonoma County Airport and to reach total annual passenger levels of 573,000 by year 2005.

Commuter airlines provide Sonoma County passengers with convenient connections to major airline service points in the Bay Area. This service is an important component in accommodating the future demand for air travel to and from the county, and provides a time-saving alternative to utilization of ground transportation along the Highway 101 corridor to San Francisco International Airport. Annual passenger levels are projected to reach 50,000 by 2005.

Scheduled airline service would consist of passenger service to one or more of the major air passenger markets outside the Bay Area. The most likely points for such service are located in Southern California. Passenger levels are projected to reach 523,000 by 2005.

GOAL AT-5: It is a goal of the County of Sonoma to encourage establishment and maintenance of commuter and scheduled airline services at the Sonoma County Airport and to provide for the production of adequate airport facilities to serve passengers in a manner which is safe, efficient, and compatible with the surrounding community.

Objective AT-5.1: It is the County's objective to provide commercial air services including commuter and scheduled aircraft at the Sonoma County Airport not to exceed 573,000 annual passengers or 15,200 annual operations by 2005.

Objective AT-5.2: It is the County's objective to provide a balance of commercial air carrier services at the Sonoma County Airport not to exceed a total of 21 departures per day. Each of the 21 departures shall constitute a departure slot. The 21 departure slots shall be allocated between commuter and scheduled air carriers as follows:

Slots 1-8: Reserved for scheduled air carriers; may be used by commuter air carriers, but use is revocable and subject to reallocation upon application by a scheduled air carrier to initiate or increase service.

Slots 9-14: Reserved for commuter air carriers; may be used by scheduled air carriers.

Slots 15-21: Reserved exclusively for commuter air carriers.

At no time shall scheduled air carriers utilize more than 14 of the 21 departure slots.

Objective AT-5.3: It is the County's objective that when the above commercial air passenger services reach 650 enplaned passengers per day averaged over a one year period (474,500 annual passengers), a review by the Board of Supervisors shall occur prior to any increase in annual passenger or operations levels. The review anticipated by this section and policy AT-5e is not intended to require an amendment to the Air Transportation Element nor is it intended to require review of this element in its entirety; rather it is intended to trigger Board consideration of the impacts and infrastructure of the Sonoma County Airport as it relates to its immediate environs.

Objective AT-5.4: It is the County's objective to plan terminal, access, parking, other passenger service facilities and airport facilities consistent with the levels of service in Objective AT-5.1.

Objective AT-5.5: It is the County's objective to provide airport facilities which would allow appropriate separation of dissimilar air traffic to allow for the safe operation of general aviation, commuter airlines and scheduled airlines at the Sonoma County Airport.

The County shall utilize the following policies to achieve the objectives noted above:

AT-5a: The Aviation Department shall revise, update and maintain the Sonoma County Airport Master Plan to accommodate 15,200 annual operations by commuter and scheduled airlines by 2005. The Master Plan shall provide for commercial air carrier services not to exceed a total of 21 departures per day with scheduled air carriers utilizing no more than 14 of the 21 departures.

AT-5b: Commercial air carrier services at the Sonoma County Airport shall not exceed a total of 21 departures per day. Each of the 21 departures shall constitute a departure slot. The 21 departure slots shall be allocated between commuter and scheduled air carriers as follows:

Slots 1-8: Reserved for scheduled air carriers; may be used by commuter air carriers, but use is revocable and subject to reallocation upon application by a scheduled air carrier to initiate or increase service.

Slots 9-14: Reserved for commuter carriers; may be used by scheduled air carriers.

Slots 15-21: Reserved exclusively for commuter air carriers.

At no time shall scheduled air carriers utilize more than 14 of the 21 departure slots.

AT-5c: Runway length at the Sonoma County Airport for the existing and any new runway which may be constructed shall be limited to no longer than the present length of approximately 5,000 feet. Existing runways will not be substantially strengthened except as needed to perform necessary or routine maintenance. Operations by commercial air carriers shall be limited to those aircraft types that may safely and efficiently operate within this facility constraint and which do not exceed an operating weight of 95,000 pounds.

AT-5d: Any air carrier initiating or expanding commuter or scheduled airline passenger service or commercial freight service at the Sonoma county Airport shall be required to enter into a license, lease, or operating agreement with the County of Sonoma. Licenses, leases and operating agreements shall implement and be required to conform to the policy directives of the general plan. Licenses, leases and operation agreements shall include provisions for slot reallocation.

AT-5e: Any proposed improvement projects to accommodate air passenger services shall be consistent with the year 2005 projections of 15,200 annual operations and 573,000 annual passengers.

AT-5f: A review by the Board of Supervisors shall occur at such a time that the "review threshold" of 650 enplaned passengers per day averaged over a one year period (474,500 annual passengers) is reached. The review anticipated by this section is not intended to require an amendment to the Air Transportation Element nor is it intended to require review of this element in its entirety; rather it is intended to trigger Board consideration of the impacts and infrastructure of the Sonoma County Airport as it relates to its immediate environs.

5.6 NON-AVIATION AND ACCESSORY USES AT SONOMA COUNTY AIRPORT

In addition to the facilities at the Sonoma county Airport that are required to serve aviation activities directly, the County leases other airport property for non-aviation accessory activities or uses that benefit from an airport location. These leases are an important source of the airport revenue.

GOAL AT-6: It is the goal of the County of Sonoma to utilize airport properties not needed for aviation activity to enhance airport revenues and operations and to do so in a manner compatible with adjacent community areas.

Objective AT-6.l: It is the County's objective that the lands shown on the revised Airport Master Plan as non-aviation lands be used in an economic manner.

The County shall utilize the following policies pertaining to accessory uses and non-aviation facilities at Sonoma County Airport:

AT-6a: The Aviation Department shall revise, update and maintain the Airport Master Plan consistent with this element to indicate those land areas which may be used for non-aviation purposes.

AT-6b: Permissible non-aviation and accessory uses on county-owned lands include commercial and industrial uses, except that transient lodging and similar uses shall not be allowed.

AT-6c: Lands designated or acquired for approach protection purposes shall not be utilized for commercial or industrial purposes and shall not be extensively developed with structures of any type.

AT-6d: Appropriate uses of lands designated an/or acquired for approach protection include agriculture, outdoor recreation, and similar low-intensity uses, including spray irrigation with treated effluent, provided that such uses do not result in a significant increase in bird populations at a level which would give rise to a safety problem.

6.0 AIR TRANSPORTATION IMPLEMENTATION PROGRAM: 1987-1992

A number of separate actions will be required to implement the Air Transportation Element following its adoption. These actions involve short-term and medium-term programs that, when completed, will assure the achievement of the objectives expressed in this element. With the exception of the program to prepare standard language for incorporation into leases or operating agreements with airlines, completion of the programs identified is not a pre-condition for expansion of commercial air passenger services or of airport facilities.

Program 1: SONOMA COUNTY AIRPORT MASTER PLAN

The Airport Department will be responsible for updating the Sonoma County Airport Master Plan to be consistent with this element. This should be done in the short-term. Airport operations and projects consistent with this element and, unless exempt from CEQA, accompanied by appropriate environmental documentation may occur prior to adoption of the Master Plan. The specific areas requiring review and update are as follows:
- The demand/capacity analysis particularly with respect to the separation of dissimilar traffic.
- Facility requirements (size and location) to accommodate passenger services and aircraft for commuter and scheduled airline service.
- An Airport Layout Plan (ALP) depicting aviation and non-aviation land and location requirements.
- Review and update of the more detailed on-Airport Land Use Plan.
- A Financial Plan to assure economic feasibility under the enterprise account program.
- A study of infrastructure and service needs, including sewer, water, roads, and drainage.
- Implementation of the Burke's Goldfields preservation program.

The draft revisions to the Airport Master Plan shall be submitted for review and adoption by the Board of Supervisors.

Program 2: APPROACH PROTECTION PLAN

The Airport Department will be responsible for review and revision of the Draft Approach Protection Plan to assure that the policies of the Air Transportation Element are reflected. The impact, approach protection methods and recommendations sections will need to be reviewed for consistency with the Air Transportation Element. The plan shall provide for historical or archaeological assessments and resulting site mitigation where appropriate prior to demolition of any structure or construction of permanent airport facilities.

Program 3: STANDARD AIRLINE LEASE AND OPERATING AGREEMENT

The Airport Department, in association with County Counsel, shall be responsible for preparing a standard section or sections for incorporating into all leases or operating agreements with air carriers proposing to utilize the Sonoma County Airport for new or expanded commercial passenger or freight service. These standard sections shall include language which expresses the conditions and limitations upon such services as have been determined to be appropriate in the policy directives of the Air Transportation Element.

Program 4: AMENDMENTS TO THE AIRPORT LAND USE POLICY PLAN

The ALUC would be responsible for reviewing its Policy Plan in light of the Air Transportation Element, Master Plan, and Noise Monitoring Program. The Planning Agency staff would provide staff support for this effort. Funding would come from the Agency budget and the work would be done in the short-term. The specific area requiring review would be:
- A maximum interior single-event level
- Air Transportation Element compliance with the ALUC Land Use Plan.

Program 5: NOISE MONITORING PROGRAM AT SONOMA COUNTY AIRPORT

The Airport Department will be responsible for developing and implementing a noise monitoring program that complies with state guidelines. The program shall include both monitoring of ambient single-event noise levels and computer modeling of CNEL contours based upon logs of aircraft operations. The Airport Director and County Counsel will also submit for the Board's consideration options for monitoring of noise and a summary of techniques used by other jurisdictions.