Abandoned Laguna Air Force Basea123.g.akamai.net/7/123/11558/abc123/forestservic... · 2011. 5....

Environmental Assessment

Abandoned Laguna Air Force Base

Descanso Ranger District, Cleveland National Forest

San Diego County, California

For information, contact:

Pete Gomben, NEPA coordinator

10845 Rancho Bernardo Road, Suite 200

San Diego, CA 92127

(858) 674-2901

Kiosk outside former air base office building.

Abandoned Laguna Air Force Base Environmental Assessment, Page 2


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CHAPTER 1

Introduction

1.1 Document Structure

The Cleveland National Forest (“Cleveland NF”) has prepared the Abandoned Laguna Air Force Base

Environmental Assessment in compliance with the National Environmental Policy Act (NEPA) and other

relevant federal laws and regulations. This environmental assessment discloses the direct, indirect, and

cumulative environmental effects that would result from the proposed action and alternatives. The

document is organized into the following parts:

• Chapter 1: Introduction. This chapter includes background information on project area, the purpose and need for the project, and a brief description of the Cleveland NF proposed action. This chapter

also details how the Forest Service informed the public of the proposal and how the public responded.

• Chapter 2: Alternatives. This chapter provides a more detailed description of the Cleveland NF’s proposed action as well as any alternative methods for achieving the stated purpose that may have

been developed based on significant issues raised by the public and other agencies during the scoping

period. This chapter includes possible mitigation measures and design criteria.

• Chapter 3: Environmental Consequences. This chapter describes the affected environment for each resource, as well as the environmental effects of implementing the proposed action and any

other alternatives.

• Chapter 4: Agencies and Persons Consulted. This section provides a list of preparers and agencies consulted during the development of the environmental assessment.

• Appendices. The appendices provide more detailed information to support the analyses presented in the environmental assessment.

Additional documentation, including more detailed analyses of project-area resources, may be found in the

project planning record located at the Cleveland National Forest Supervisor’s Office, 10845 Rancho

Bernardo Road, Suite 200, San Diego, CA 92127.

1.2 Background

In 1981, the United States Air Force unilaterally cancelled the special use permit issued by the USDA-

Forest Service for operation of the radar facility on Laguna Mountain. Since that time, the abandoned

buildings have deteriorated severely due to the effects of exposure to the weather and as a result of a high

level of vandalism. Remaining structures on the site are considered to be a risk to public health and safety

due to the presence of asbestos and the potential for neglected buildings to collapse. In 1990, the

Cleveland NF issued Forest Order No. 90-02-1 to close the site to public access for health and safety

reasons. Enforcement of the order has been difficult due to the proximity of the facility to vehicle traffic

on the Sunrise Highway and foot traffic on the Pacific Crest Trail. Evidence exists that the abandoned

facility may be used in drug-related activities and that transients are living on site. Photographs of

vandalized and damaged buildings at Laguna AFB are shown in Appendix A.



1.3 Purpose and Need

The purpose and need for this project is to bring the landscape in and around the abandoned Laguna Air

Force Base in line with the desired condition for the area as described in the Cleveland NF Land

Management Plan (“LMP”). Goal 3.1 of the Land Management Plan directs the Cleveland NF to

maintain facilities and infrastructure that are safe, and to remove abandoned facilities and to restore sites

to their natural condition (LMP, Part 1, pg. 33). The Land Management Plan recognizes that the presence

of the abandoned Laguna Air Force Base affects the quality of the recreational experience in the Laguna

area because of public safety and environmental hazards (LMP, Part 2, pg. 41). Program emphasis for the

Laguna area includes direction to continue decommissioning of the abandoned facility (LMP, Part 2, pg.

42).

1.4 Proposed Action

In order to address the purpose and need for the project, the Cleveland NF proposes to remove buildings,

hazardous materials, and other components of the abandoned Laguna Air Force Base and to restore the

landscape to a naturally functioning condition. The proposed action, which is described in greater detail

in section 2.2.2, consists of four parts, as summarized below.

1.4.1 Removal of hazardous materials

Confirmation on the presence and extent of hazardous materials at the abandoned facility would be

determined by sampling and testing, including the removal of small amounts of materials from existing

structures. Abatement work would include establishing roll-off bins, emergency shower units, portable

toilets, and other small equipment and safety facilities on the site, and establishing curtained enclosures

for containment purposes and worker safety.

Hazardous materials would be removed from existing facilities and transported to approved sites off

National Forest System lands. Asbestos abatement would be done in curtained enclosures to maximize

containment of airborne contaminants. Where necessary, contaminated soil would be excavated and

removed from the site.

1.4.2 Demolition and removal of abandoned facilities

All debris currently on the site would be removed and disposed of in an approved landfill located off

National Forest System lands. Suitable material that can be salvaged from buildings on the site would be

recycled, if appropriate. Existing buildings, concrete stairways, rails, power pole, above-ground utilities,

and other human-constructed facilities would be destroyed or demolished. Resulting material would be

disposed of in an approved landfill located off National Forest System lands.

1.4.3 Site restoration

All concrete curbs, asphalt, unnecessary retaining walls, and other ground improvements would be

removed and disposed of in an approved location off National Forest System lands. Grading and

contouring for drainage and a naturally appearing landscape would be performed. Seeding and erosion

control measures, revegetation and tree planting, and ripping of compacted soils would be undertaken as

necessary.

1.4.4 Site interpretation/public education

Consider interpretation and education opportunities associated with a facility that existed and was

operated to protect the airspace of the continental United States during the Cold War.



1.5 Decision Framework

Based on the analysis contained in this environmental assessment and in the project record, the deciding

official will select either the proposed action, the no action alternative, or an alternative to the proposed

action for implementation.

1.6 Public Involvement

The 30-day scoping period for this project began with a legal notice published on April 15, 2009, in the

San Diego Union-Tribune. The legal notice summarized the proposed action and requested public input

on the proposed action. A scoping letter that summarized the proposed action was sent to the Cleveland

National Forest mailing list of approximately 1,000 individuals, agencies, tribes, and organizations. One

comment was received from the public.

1.7 Issues When analyzing scoping comments, the Forest Service typically separates issues into two groups:

significant and non-significant. Significant issues are defined as those directly or indirectly caused by

implementing the proposed action, and may result in formulation of an alternative to the proposed action.

Non-significant issues are identified as those that are (1) outside the scope of the proposed action; (2)

already decided by law, regulation, the Land Management Plan, or other higher level decision; (3)

irrelevant to the decision to be made; or (4) conjectural and not supported by scientific or factual

evidence.

The Council on Environmental Quality NEPA regulations require the Forest Service to identify and

eliminate from detailed study the issues which are not significant or which have been covered by prior

environmental review (Sec. 1506.3).

The only public comment provided during the scoping period requested that the Cleveland NF consider

restoration of the air base facilities as a camp and lodging for the public. The proposal was considered to

be a non-significant issue because it was outside the scope of the proposed action.



CHAPTER 2

Alternatives

2.1 Introduction

This chapter describes and compares the alternatives considered under this environmental analysis. This

chapter presents the alternatives in comparative form, defining the differences between each alternative

and providing a basis for choice by the decision maker and the public. Some information used to compare

the alternatives is based on the design of the alternative and some information is based upon the

environmental and social effects of implementing each alternative.

2.2 Alternatives

Two alternatives were considered in detail for this project. Each alternative is described below.

2.2.1 Alternative 1 (No Action)

Under Alternative 1, current management plans would continue to guide management of the project area.

All structures, debris piles, and hazardous materials would remain at the abandoned facility.

2.2.2 Alternative 2 (Proposed Action)

Under Alternative 2, approximately 27 buildings or structures (see Table 2.1) would be demolished on-

site and removed from the abandoned facility to a suitable. Project activities are described below.

1. Removal of hazardous materials. Confirmation on the presence and extent of hazardous materials at the abandoned facility would be determined by sampling and testing, including the

removal of small amounts of materials from existing structures. This would include soil sampling

and extraction of no more than one cubic yard of material in previously disturbed areas known to

have been storage locations for transformers that contained PCBs. Abatement work would

include establishing roll-off bins, emergency shower units, portable toilets, and other small

equipment and safety facilities on the site, and establishing curtained enclosures for containment

purposes and worker safety.

Hazardous materials would be removed from existing facilities, wrapped first in high-density

plastic sheets and then placed in protective containers. The containers would be loaded onto

vehicles for transportation off National Forest System lands. All asbestos abatement would be

done in curtained enclosures to maximize containment of airborne contaminants. Where

necessary, contaminated soil would be excavated and removed from the site. If additional

underground fuel storage tanks or other abandoned infrastructure or facilities were discovered,

they would be removed from the previously disturbed excavations and transported off National

Forest System lands.

2. Demolition and removal of abandoned facilities. All piled debris currently on the site would be removed and disposed of in an approved landfill located off National Forest System lands. All

suitable material that can be salvaged from buildings on the site would be recycled, if appropriate.



All existing buildings, concrete stairways, rails, power pole, above-ground utilities, and other

human-constructed facilities would be destroyed or demolished. Resulting material would be

disposed of in an approved landfill located off National Forest System lands.

3. Site restoration. All concrete curbs, asphalt, unnecessary retaining walls, and other ground improvements would be removed and disposed of in an approved location off National Forest

System lands. Minor grading and contouring for drainage would be performed. Seeding and

erosion control measures would be undertaken as necessary.

4. Site interpretation/public education. Consider interpretation and education opportunities associated with a facility that existed and was operated to protect the airspace of the continental

United States during the Cold War.

Table 2.1: Laguna Air Force Base buildings or other structures proposed for removal.

Building Use Sq. ft. Stories Year built Primary building material

101 Office 2952 1 1951

103 Crew quarters 7001 2 1951

105 Gymnasium 4545 2 1956

109 Unknown 2 --




115 Mess hall 5508 2 1951

Stick-built, aluminum,

composite shingles

116 Utility—steam plant 1575 -- 1951 N/A

130 Officers club 2158 1 1954 Stick-built, aluminum,

composite shingles

201 Command center 21232 -- 1969 Concrete

202 HQ group—office 1291 -- 1954

203 ACW operations 1421 -- 1963 N/A

204 Water tank 200k gal. -- -- Metal panel, riveted

205 Utility—pump house 633 -- 1951

207 Utility—telecom 859 -- 1951

216 Utility—electric -- -- --

217 Security sentry house -- -- --

220 Storage—chemical 48 -- 1957

N/A

221 Utility—generator 6278 -- 1960 Concrete

223 Dome superstructure 4402 -- 1962 Steel


302 Utility—pump house 28 -- 1960 N/A

403 Housing—quadplex 4197 2 1960 Stick built, stucco siding,

composite shingles



Telco Utility—telephone -- -- --

N/A



2.3 Mitigation Measures and Design Features

As part of the environmental analysis for the proposal that is described in Chapter 3, resource specialists

identified mitigation measures and design features to lessen or eliminate potential resource impacts.

These mitigation measures and design features, which would be applied to Alternative 2, are described

below.

Wildlife Although the open nature of most of the buildings at the site make them suitable only as occasional roost

sites for bat species, replacement roost sites would be constructed on site to mitigate for loss of roost

sites. This could include placement of bat boxes at the site or construction of a bat “shed” that would be

suitable for Townsend’s big-eared bat roosting.

Plants To return the site to as natural a condition as possible, revegetating areas of bare ground and old road beds

would occur. To maximize the success of revegetation, as much non-native material (e.g., concrete, and

asphalt) as possible would be removed from the site. Non-native trees on the site, including cypress and

fir, would be removed when possible. Recommended species for revegetation are listed in Table 2.2.

Table 2.2: Recommended species for revegetation.

Common name Scientific name

California brome Bromus carinatus

California matchweed Gutierrezia californica

Cup-leaf ceanothus Ceanothus greggii ssp. perplexans

Eastwood manzanita Arctostaphylos glandulosa ssp. adamsii

Flat-top buckwheat Eriogonum fasciculatum var. polifolium

Foothill buckwheat Eriogonum wrightii var. membranaceum

Four-leaf pinyon pine Pinus quadrifolia

Mountain mahogany Cercocarpus betuloides var. betuloides

Palmer’s lilac Ceanothus palmeri

Parish goldenbush Ericameria parishii

Sawtooth goldenbush Hazardia squarrosa

Shiny-leaf yerba santa Eriodictyon tricholcalyx var. lanatum

Air The following measures will help reduce impacts on local air quality.

1. Use ultra-low sulfur diesel fuel. 2. Use clean burning on- and off-road diesel engines. 3. Construction workers will carpool when possible. 4. Restrict vehicle idling time to less than 10 minutes whenever possible. 5. Properly maintain mechanical equipment. 6. Implement feasible fugitive dust control measures. 7. Control or eliminate the release of asbestos into environment from building materials.



Hydrology and Soils

Design features in the proposed action that will reduce the potential for negative effects include the

preparation and implementation of a program to control water pollution effectively during the demolition

and rehabilitation activities on the site. A storm water pollution prevention plan prepared by the

contractor would adhere to California Department of Transportation requirements and would include best

management practices such as:

1. Construction scheduling shall consider the amount and duration of soil exposed to erosion by wind, rainfall, runoff, and vehicle tracking and would seek to minimize disturbed soil area during

the rainy season. A schedule shall be prepared that shows the sequence of construction activities

with the installation and maintenance of soil stabilization and sediment control best management

practices.

2. Preserving existing vegetation to the maximum extent possible and for as long as possible on the site to reduce erosion in these areas. To facilitate this practice, on a year-round basis temporary

fencing shall be provided prior to commencement of clearing and grubbing operations or other

soil-disturbing activities in areas where no construction activity is planned or construction will

occur at a later date.

3. Temporary sediment control practices including practices that intercept and slow or detain the flow of storm water to allow sediment to settle and be trapped. These practices can consist of

installing temporary linear sediment barriers (such as silt fences, sandbag barriers, and straw bale

barriers); providing fiber rolls, gravel bag berms, or check dams to break up slope length or flow;

or constructing a temporary sediment trap.

4. Procedures and practices should be followed to minimize or eliminate the discharge of pollutants to the storm drain systems or watercourses from vehicle and equipment maintenance procedures.

5. Waste management and materials pollution control best management practices should prevent pollution by limiting or reducing potential pollutants at their source before they come in contact

with storm water. Pollutants such as lead based paint should be properly contained to prevent

contaminating soil.

These best management practices would address temporary soil stabilization, temporary sediment control,

wind erosion control, non-storm water management, and waste management and materials pollution

control. Additional mitigation for soil compaction and erosion following the project activity would

include:

1. Soils compact more easily when moist so heavy equipment should be used only when the soil is relatively dry. Heavy equipment should not be used if a handful of soil, when squeezed in the

hand, remains in a ball when the hand is opened.

2. After compacted soils are ripped, waterbreaks should be properly installed on sloped segments. 3. Depending on the anticipated time for vegetation to return to disturbed areas, wood chips or

native vegetation should be added. Vegetation regrowth will vary with slope steepness, and the

degree of soil disturbance. On steeper slopes and areas with a higher degree of soil disturbance,

wood chips should mostly be added (on average less than four inches thick). On areas where

vegetation is more likely to grow, native vegetation should be seeded and wood chips spread

thinly to minimize erosion until vegetation returns.



CHAPTER 3

Environmental Consequences

3.1 Introduction

This chapter describes the affected physical and biological environments of the project area and the direct,

indirect, and cumulative effects to those environments due to project implementation. It also presents the

scientific and analytical basis for comparison of alternatives presented in Chapter 2. This chapter

incorporates analysis contained in resource-specific reports—including the biological evaluation and

biological assessment, the management indicator species report, the hydrology/soils report, the air quality

report, the heritage resource report, and the recreation report—that are found in the project record, which

is kept on file at the Cleveland NF supervisor’s office, 10845 Rancho Bernardo Road, Suite 200, San

Diego, CA 92127.

3.2 Wildlife

3.2.1 Affected Environment

The project area primarily occurs on and is adjacent to the desert escarpment where the dominant

vegetation is disturbed mixed Jeffrey and Coulter pine forest and mixed montane chaparral. Much of the

project area is open and unvegetated due to soil disturbance, buried concrete and asphalt, and crushed

concrete and asphalt mixed with the natural soils.

There are no known locations of, or suitable habitat for, any federally listed animal species at the site.

Potential habitat for six Regional Forester’s sensitive animal species is found in the project area. These

include the Townsend’s big-eared bat, the western red bat, the California spotted owl, the San Diego

horned lizard, the San Diego mountain kingsnake, and the San Diego ringnecked snake.

Species accounts are provided in the biological assessment/biological evaluation. Abandoned buildings

on site potentially provide occasional roosting sites for Townsend’s big-eared bat. The western red bat

and California spotted owl have the potential to occur in the denser, undisturbed coniferous forest

adjacent to the project site. The San Diego ringneck snake and the San Diego horned lizard may utilize

the coniferous forest and mixed montane chaparral within and adjacent to the project area. The open,

disturbed and rocky coniferous forest and chaparral areas of the project may support San Diego mountain

kingsnakes.

3.2.2 Alternatives 1 and 2 Direct, Indirect, and Cumulative Effects to Federally Listed Animal Species

Because there are no known locations of, or suitable habitat for, any federally listed animal species in the

project area, Alternative 1 and Alternative 2 would have no direct, indirect, or cumulative effects on any

threatened or endangered species or their critical habitat.



3.2.3 Alternative 1 (No Action) Direct, Indirect, and Cumulative Effects on Sensitive Species

Although potentially suitable habitat for California spotted owls and the western red bats may exist in the

coniferous forest adjacent to the project site, the project area itself is not likely to support these two

species because of the disturbed and open nature of the forest and apparent high level of human activity at

the site. If the project area is left in its current condition, the area would remain unsuitable for these two

species and would therefore have no additional direct, indirect, or cumulative effects on California spotted

owls or western red bats.

The abandoned buildings may provide occasional roosting habitat for Townsend’s big-eared bat, although

bats were only observed in the buildings on initial survey in 1990. Under Alternative 1 the buildings

would remain and therefore there should be no direct, indirect, or cumulative effects to Townsend’s big-

eared bats.

San Diego mountain kingsnakes, San Diego ringneck snakes, and San Diego horned lizards all have the

potential to occur throughout the project area. Because vehicle access is well restricted, there should be

no direct effects by vehicle crushing, but there is the potential for negative direct effects on all three

species if trespassers on the property attempt to capture and keep individuals of these species. No indirect

effects are expected for San Diego mountain kingsnakes, San Diego ringneck snakes, or San Diego

horned lizards. The cumulative effects of Alternative 1 would be extremely minimal considering the

small footprint of the project area and the small number of individuals that may be impacted over time

from collection compared to the total populations of these species.

3.2.4 Alternative 2 (Proposed Action) Direct, Indirect, and Cumulative Effects on Sensitive Species

Because of the pre-existing human activity that makes the site unsuitable for California spotted owls and

western red bats, the immediate direct effects of noise and activity on the site during demolition and clean

up would be minimal. Mid-term direct effects of the site restoration would be discouragement of trespass

and continued human activity at the site, which may improve the suitability for California spotted owl

foraging and western red bat roosting habitat. Long-term indirect effects may be that the portions of

coniferous forest on the site grow denser and result in greater canopy cover, improving habitat conditions

for California spotted owl nesting habitat. The probability of this long-term improvement in owl nesting

is unknown. However the cumulative effect of the increased suitability may be a small scale

improvement of owl habitat on Laguna Mountain.

If Townsend’s big-eared bats are occupying buildings at the time of demolition, they would be directly

impacted and displaced. Scavenging for valuable buildings materials has left many of the buildings very

open and their suitability as roosting habitat is probably minimal so the direct effect would be small. If

suitable structures for Townsend’s big-eared bat roosting are constructed during the project, the long-term

direct effect would be improvement of roosting habitat. Although there are other locations on Laguna

Mountain where Townsend’s big-eared bats have been displaced from cabins and mines, the cumulative

impact of removal of poor quality roosting habitat provided by the abandoned buildings would be

minimal, particularly since the buildings do not serve as long-term or maternal roost sites.

The activities and presence of workers and equipment during demolition could affect San Diego mountain

kingsnakes, San Diego ringneck snakes, and San Diego horned lizards by incidental or intentional killing

of animals and by harassment. These effects would be short-term and direct. Long-term effects to

species both on- and off-site would be the restoration of quality habitat, particularly if revegetation efforts

are successful. Cumulative effects of Alternative 2 are expected to be minimal because only individual

animals present in the disturbed areas have potential to be impacted negatively and the long-term habitat

improvement would likely offset any loss of individuals during construction activities.



3.3 Plants


The project area primarily occurs on and is adjacent to the desert escarpment where the dominant

vegetation is disturbed mixed Jeffrey and Coulter pine forest and mixed montane chaparral. Nearly five

acres of the project area is covered by buildings, old building sites, and roads and is therefore open and

unvegetated.

There are no known locations of, or suitable habitat for, any federally listed plant species at the site.

Potential habitat for two Regional Forester’s sensitive plant species is found in the area. These include

Orcutt’s linanthus (Linanthus orcuttii) and southern jewelflower (Streptanthus campestris). Species

accounts are provided in the biological assessment/biological evaluation. The open, disturbed, and rocky

coniferous forest and chaparral areas of the project may support both of these species.

3.3.2 Alternatives 1 and 2 Direct, Indirect, and Cumulative Effects to Federally Listed Plant Species

Because there are no known locations of, or suitable habitat for, any federally listed plant species in the

project area, Alternative 1 and Alternative 2 would have no direct, indirect, or cumulative effects on any

threatened or endangered species or their critical habitat.

3.3.3 Alternative 1 (No Action) Direct, Indirect, and Cumulative Effects to Sensitive Species

Orcutt’s linanthus and southern jewelflower have the potential to occur in the project area. Alternative 1

may result in impacts to individual plants that may be trampled by persons trespassing on the site, but this

is not expected to result in a trend toward federal listing nor a loss of viability for either of these species.

3.3.4 Alternative 2 (Proposed Action) Direct, Indirect and Cumulative Effects to Sensitive Species

Orcutt’s linanthus and southern jewelflower have the potential to occur in the project area. Alternative 2

may result in short-term direct effects to individual plants that may be destroyed by equipment working

on the site during demolition and clean-up activities, but this is not expected to result in a trend toward

federal listing nor a loss of viability for either of these species.

Long-term indirect effects include overall improvement of the habitat and a reduction of human activity at

the site. Alternative 2 would have minimal cumulative effects to the two species because the long-term

benefits should balance any short-term negative effects, particularly considering the fact that both species

are tolerant to most of the disturbances that may impact their populations on Laguna Mountain.

3.4 Management Indicator Species

3.4.1 Introduction

The purpose of this section is to evaluate the effects of the proposed project on management indicator

species (MIS) identified in the Land Management Plan (LMP, Part 1, pg. 45). These species, along with

their indicators of management and relevance to the project area, are listed in Table 3.1.



Table 3.1: Management indicator species

Indicator species Management resource/concern Status in project area

Mountain lion Fragmentation

Mule deer Healthy diverse habitats

Coulter pine Coulter pine forest

California black oak California black oak forest

Occurs

California spotted owl Montane conifer forest May occur

Arroyo toad Aquatic habitat

Song sparrow Riparian habitat

Engelmann oak Oak regeneration

Big cone Douglas-fir Big cone Douglas-fir forest

White fir Montane conifer forest

Does not occur

3.4.2 Alternative 1 (No Action) Direct, Indirect, and Cumulative Effects

Under Alternative 1 the site would be left in its current state with all buildings and debris piles remaining

and likely continued trespass. With the disturbed and open nature of the site, along with the high levels of

human activity, the project area is currently and would continue to be unsuitable habitat for California

spotted owls. While mountain lions and mule deer may pass through the area, it is highly unlikely that

these species regularly use the site. Alternative 1 would not change current conditions and would

therefore have no effect on population trends for California spotted owls, mountain lions or mule deer.

Under Alternative 1 all vegetation and trees adjacent to buildings and debris piles would be left in place.

Coulter pines and California black oaks that are growing on site would not be impacted. Alternative 1

would not change current conditions and would have no effect on population trends for Coulter pines or

California black oaks.

Implementation of Alternative 1 would result in no direct, indirect, or cumulative effects to management

indicator species.

3.4.3 Alternative 2 (Proposed Action) Direct, Indirect, and Cumulative Effects

Under Alternative 2 there would be a short time period of high activity on the site while equipment and

workers were removing hazardous materials and demolishing buildings. Given the disturbed and open

nature of the site, along with the high levels of human activity, the project area is currently unsuitable

habitat for California spotted owls, mountain lions, and mule deer. During site restoration, the area will

continue to be unsuitable. However after debris has been removed from the soil and reseeding efforts

have taken place, there is a greater chance that the site would eventually return to a more natural

condition, providing suitable habitat for California spotted owls, mountain lions, and mule deer. In the

short-term, implementation of Alternative 2 would have no effect on California spotted owls, mountain

lions, or mule deer population trends, but after restoration of the site, there may be a small increase in

local population trends for these three species.

Under Alternative 2 some vegetation and trees adjacent to the buildings that would be demolished may

need to be removed for safety and operability. This would include a number of individual Coulter pines

and California black oaks. Despite the loss of a few individuals, restoration efforts on site after

demolition would return the site to a more natural condition and may improve regeneration.

Implementation of Alternative 2 may impact individual Coulter pines and California black oaks in the

short-term, but would not change population trends for those two species. Restoration efforts on the site



may, in the long-term, result in a slight increasing trend for the local populations of Coulter pine and

California black oak.

Implementation of Alternative 2 would result in slight negative direct effects to management indicator

species during project-related activities, and would result in slight positive indirect and cumulative effects

to management indicator species after the site has been returned to a natural condition.

3.5 Air


San Diego County Air Pollution Control District (“Control District”) includes the entire county. The

climate of the Control District is dominated by a semi-permanent high pressure cell located over the

Pacific Ocean, which influences the direction of prevailing winds and maintains clear skies for much of

the year. The high pressure cell also creates two types of temperature inversions that may act to degrade

local air quality—subsidence inversions and radiation inversions—both of which can trap pollutants

between layers of air. When the pollutants become more concentrated in the atmosphere, photochemical

reactions can produce ozone. The project area currently is in nonattainment of national ambient air

quality standards for ozone and of state ambient air quality standards for ozone.

3.5.2 Analysis

For purposes of meeting federal requirements, impact significance is related to federal conformity with

the Environmental Protection Agency-approved state implementation plan and with national ambient air

quality standards. Air quality impacts would be considered significant if they are expected to cause or

contribute to an air quality violation in a nonattainment or maintenance area. However, if total direct and

indirect project emissions fall below designated applicability threshold levels established under the

Conformity Rule, no adverse change in attainment status is expected. For purposes of meeting state

requirements, San Diego Air Quality Management District thresholds of significance for project

emissions serve the same purpose as the federal applicability thresholds.

Both nitrogen oxides (NOx) and volatile organic compounds (VOCs) are the precursors for the

nonattainment pollutant ozone. Vehicle exhaust and travel on unpaved roads emit particulate matter.

Inhalable coarse particles (PM10) are emitted directly from the source, such as soot from engine exhaust,

windblown dusts from bare soil, and dust from vehicle travel on unpaved roads. Fine particles (PM2.5)

are associated with the products of engine exhaust including the reaction of NOx and sulfur dioxide (SO2)

with ammonia and diesel soot. Inhalable particulate matter poses a serious health hazard because it can

be deposited in the lungs and can cause permanent damage by interfering with the body’s mechanism for

clearing the respiratory tract or by acting as a carrier of a toxic substance. PM2.5 is the major cause of

reduced visibility in Southern California, including in national forest Class I wilderness areas.

Tailpipe emissions from motorized equipment produce criteria pollutants such as carbon monoxide, as

well as the precursor gases for ozone.


Because implementation of Alternative 1 would not involve any activities, this alternative would result in

no direct, indirect, or cumulative effects to the air resource in the project area.




Criteria pollutant emissions from vehicles and demolition equipment are expected to increase for the short

term. Total emissions estimated for the project are 5.5 tons per year of VOC and 8.2 tons per year of

NOx. Rehabilitation activities include road “ripping” with heavy equipment, and revegetation,. The use

of heavy equipment and worker vehicles would produce exhaust emissions, while travel on unpaved roads

would produce fugitive dust. Small increases in short-term, localized emissions would occur.

Actions analyzed for potential cumulative effects include all proposed activities occurring to forest roads

and trails. The project is expected to have limited short-term cumulative effects to air quality. However,

after the rehabilitation and demolition projects are complete, fugitive dust from vehicle travel on

unauthorized routes and windblown dust would decrease, as would exhaust emissions. The project also

demonstrates conformity with the state implementation plan under the federal Clean Air Act, and does not

exceed the Control District daily project emissions significance thresholds.

3.5.5 Conclusions

Project-related activities would create minor, temporary increases in local fugitive dust emissions and

emissions from motorized equipment in both the San Diego County Air Pollution Control District.

However, after project-related activities are completed, emissions from windblown fugitive dust and dust

from travel on unpaved roads and trails may be expected to decrease. No adverse change in attainment

status is expected to occur as a result of this project.

3.6 Hydrology and Soils 3.6.1 Affected Environment

The project area has a low (1.5 percent of the area involved) incidence of landslides. No evidence of

landslides was observed near the project area during field review. Steeper slopes on the eastern side of

Stephenson Peak showed some evidence of surficial slippage, but proposed activities should not have any

significant impacts on slope movement.

The Sheephead rocky fine sandy loam map unit covers approximately 18 percent of the project area,

while the Crouch coarse sandy loam map unit covers approximately 45 percent of the project area.

Metamorphic rock outcrop covers the remaining 36 percent and consists of continuous bare bedrock and

less than 15 percent inclusions of soil capable of supporting plants. Runoff is medium to very rapid on

both the Sheephead and Crouch soils and varies with grain size, depth to bedrock, and slope. Crouch

soils are generally deep, commonly 50 to 80 inches to bedrock with a moderate erosion hazard rating.

Sheephead soils are shallow, commonly with approximately 50 inches to bedrock, and have a severe

erosion hazard rating due primarily to the steeper slopes.

Based on field review, evidence of significant erosion on native surface roads exists in the project area.

Rill and gully erosion is currently visible on most segments of native surface road having a slope greater

than approximately 5 percent. In total, nearly 0.3 mile of road in the project area has large rills and

shallow gullies indicating accelerated erosion is occurring. Using the Water Erosion Prediction Project

(WEPP) erosion prediction model, sediment yield was calculated for these segments of outsloped, rutted

road. The mean annual volume of eroded sediment leaving these road segments was calculated at 8.6

tons and is roughly equal to 5.5 cubic yards.

Based on prior measurements of sediment volumes in debris basins at the mouths of the canyons,

background erosion rates are 3.3 cubic yards per acre in the Pine Valley Creek watershed. The WEPP



erosion prediction values are at best within plus or minus 50 percent of the true value. In comparing these

values to background erosion rates, erosion likely is accelerated in the vicinity of the abandoned offices

and residences due to deteriorated roads.

The project area is located in three eight-level subwatersheds: Upper Portrero Canyon north, Upper

Portrero Canyon south, and Upper Escondido Ravine Canyon. The project area covers less than eight

percent of each subwatershed. The upper Potrero drainages flow north and east into Vallecito Creek.

Vallecito Creek dissipates or flows underground as it reaches Carrizo Valley. The Escondido Ravine

drainage flows west into Big Laguna Lake which is drained by Pine Valley Creek. No perennial or

intermittent streams exist in the project area. There are no documented wetlands, springs, or seeps in or

immediately downstream of the project area.

Infiltration is the process by which water passes through the soil surface and is a critical process in

hydrology. Infiltration can fail on roads and trails, and building roofs act as an impervious surface

thereby increasing storm flow. Nearly five acres of the project area is covered by buildings, old building

sites, and roads. Rill and gully erosion is visible on most segments of native surface roads with greater

than approximately five percent slope where runoff has increased due to compaction and poor drainage.

Approximately 30 percent of the roads in the project area lack sufficient waterbreaks and drainage

control, resulting in accelerated erosion. Depending on slope steepness, the erosion hazard is moderate to

severe on soils in the project area. Buildings likely are contributing to an increase in runoff yet building

site drainage appears to be effective in limiting accelerated erosion. Stream hydrography in the project

area is unaffected by runoff from impervious surfaces due to the very small area of coverage in the

watershed.


Under Alternative 1, soil productivity would remain very low on approximately five acres due to

compaction and erosion on roads and building sites. Accelerated soil erosion would continue on native

surface roads and rates of erosion for the subwatershed would remain above normal. Although sediment

is currently buffered by adequate vegetation and does not reach a stream channel, increased channeling of

water in gullies could affect stream quality in the future.

Soil was compacted during road construction, building site grading activities displaced top soil, and

vegetation was likely removed in areas where heavy machinery was used when the Laguna AFB was

initially constructed. As described above, these past activities still cause elevated erosion and continue to

affect soil productivity. In the time since the Laguna AFB was abandoned, vegetation has returned

around buildings but has not returned to native surface roads.

In the mid-1990s the Air Force demolished some of the abandoned buildings and left debris in

approximately four piles on the site. These demolished building sites have only about 20 percent

vegetative cover, and although the ground surface is relatively flat, some accelerated soil erosion is

occurring. Building materials including concrete, lead-based paint, and asbestos may have entered the

soil. Although some of these materials can be hazardous to human health, they do not have a significant

effect on soil productivity.

Under Alternative 1 accelerated soil erosion from roads would continue and soil productivity would

remain low under debris piles and on previously demolished building sites.




The analysis of potential effects of Alternative 2 was conducted by evaluating proposed activities and the

climate, soil, watersheds, and vegetation in the project area. Demolition of buildings would result in a

short-term increase of soil disturbance on small areas of soil surrounding buildings and along the

perimeter of the project area where some holes for fence posts may need to be dug. Heavy machinery

needed for building demolition and material removal activities should be able to use existing roads, but

additional soil disturbance could occur on areas of soil that are not currently compacted. Mitigation

measures, including ripping of compacted soil and revegetation, would increase soil productivity on

disturbed soils. Proper containment and disposal of hazardous materials from existing facilities would

minimize soil contamination.

Removal of piled debris currently on site should not increase soil compaction and disturbance. Debris

piles are currently located near old building sites that have previously been compacted and disturbed.

Removal of resulting material from demolished buildings, concrete stairways, rails, power pole, and

above-ground utilities may result in a small direct increase in soil disturbance and compaction. By

temporarily fencing existing vegetation in close proximity to planned demolition sites, and by using

existing roads and disturbed areas, there should only be a minimal increase of disturbed soil.

Soil sampling is proposed in previously disturbed areas known to have been storage locations for

transformers that contained polychlorinated biphenyls (PCBs). If these soil contaminants are found, the

contaminated soil would be removed. This could have a significant direct effect on soil productivity yet

should affect a very small area. Removal of the soil surface layer would decrease the productivity of the

soil yet limit effects to water quality and surrounding areas of soil. Restoration activities including

grading and revegetation would help improve soil quality in areas where soil was excavated.

Following demolition and material removal activities, site restoration activities including ripping

compacted soil, grading, contouring, revegetation, and the addition of wood chips would result in overall

decreased erosion during the short and long term. Erosion would be limited to sloped bare areas of soil

that are not revegetated or covered with wood chips.

Cumulative effects to soil and hydrology from the Laguna Air Force base construction in 1940, and

demolition activities occurring between 1994 and 1995 are described in section 3.6.3. If design features

and best management practices are used, effects from this alternative would be minor and last less than

five years. By effectively decommissioning roads and restoring vegetative cover, this alternative would

decrease the magnitude and extent of past construction and demolition activities.

3.6.4 Compliance with the Land Management Plan and Other Direction

Alternative 1 may not comply with the Pollution Prevention Act of 1990. Pollution, including lead-based

paint and asbestos, may be present in deteriorated buildings and in debris piles. To comply with the act,

any lead-based paint or asbestos should be removed. If potential water pollutants, including PCBs or

lead, are found in soil, Alternative 1 may not comply with the Clean Water Act because it would not

control these sources of pollution. Alternative 1 would not comply with the Land Management Plan

because it would not decommission the abandoned Laguna AFB and restore it to natural conditions.

Alternative 2 complies with the Land Management Plan because it would maintain or restore soil

properties and productivity to ensure ecosystem health, soil hydrologic function, and biological buffering

capacity, as well as restore, maintain and improve watershed conditions.



3.7 Heritage Resources 3.7.1 Affected Environment

The Laguna AFB was one of over 200 air defense and long-range radar facilities that monitored the skies

over the continental United States during the Cold War. The Laguna AFB included extensive technical

equipment complexes, offices, bomb shelters, living quarters, infrastructure and support facilities

distributed over a 140-acre compound. Up to 400 military personnel, family members, and support staff

lived permanently at the Laguna AFB at the height of its operations in the 1960s.

The Forest Service has no past or current involvement with the facility, other than permitting its use on

National Forest System lands when it was operated by the Air Force under a special use permit. The Air

Force terminated the permit, abandoned the site, and ceased all staffing and upkeep of the facility in 1981.

Although unstaffed, the electronic radar equipment at the southern portion of the site remains in use by

the Federal Aviation Administration for flight safety and air-traffic control, and by the Air Force for

peacetime air surveillance. The site has been closed to public access for health and safety reasons since

1990.

3.7.2 Summary of Previous Section 106 Activities Conducted

A cultural resources survey and analysis of the potential for adverse effects to historic properties

associated with the site was performed in compliance with Section 106 of the National Historic

Preservation Act (“NHPA”) in 1984 in support of a proposal to turn the facility over to the Bureau of

Prisons for use as a correctional facility. No prehistoric sites were located as a result of the

archaeological survey at that time. No buildings were recommended eligible for nomination to the

National Register of Historic Places (“NRHP”) because none were evaluated. That was sufficient at the

time because no structures were 50 years old, and therefore none met the requirements of NRHP Criteria

Consideration G “Properties that have Achieved Significance within the Past 50 Years,” and the Cold

War era historical period (1945 to 1989) had not yet been identified as a potentially significant historic

context because the Cold War was still in progress. The state historic preservation officer concurred with

the recommendation in the evaluation report that the site did not contain potentially eligible properties

with a finding of “does not involve National Register or historic properties.”

The transfer of the facility to the Bureau of Prisons did not occur due to public concerns over the location.

Several buildings were demolished for health and safety reasons in 1994. Complete cleanup and

demolition of the facility was not accomplished due to budgetary constraints associated with the cleanup

and disposal of hazardous materials, specifically the presence of large amounts of asbestos associated

with the above-ground steam pipe system. Remaining buildings and structures are gutted, open shells that

are in an advanced state of disrepair due to exposure to the elements for nearly three decades.

3.7.3 Recommended Section 106 Compliance Activities

Due to the fact that most of the remaining buildings are over 50 years in age, the facility type, the fact it

was association with the Cold War period (1945 to 1989), and the fact that the proposed action is now

demolition and not re-use, the state historic preservation officer requires complete Section 106 National

Register evaluation of the station for potential eligibility for nomination to the National Register of

Historic Places under the four established National Register eligibility Criteria (A – D), and that

additional consultation be conducted with the state historic preservation officer prior to any demolition or

hazardous material removal that would compromise the structural or visual integrity of the remaining

buildings or the site as a whole.



Although some buildings are less than 50 years old, according to NRHP Criteria Consideration G, “a

property achieving significance within the last fifty years is eligible if it is of exceptional importance."

The NPS guidelines state that potentially eligible military aviation facilities include supply depots, ports

of embarkation, and other defense installations that may be located away from air terminals. In addition,

because the installation was established over 50 years ago during the Cold War era, all buildings on the

site require individual evaluation as potential contributing elements to the potential National Register

eligibility of the installation as a district, whether or not they appear to be potentially eligible individually.

Full documentation, evaluation, investigation, and analysis of the potential historical significance of the

facility would need to be conducted by a qualified architectural historian, in accordance with the

Secretary of Interior standards (36 CFR part 61), and “Archeology and Historic Preservation: Secretary of

the Interior's Standards and Guidelines” (Federal Register, September 29, 1983 (48 FR 44716)) prior to

implementation of the proposed action.

3.7.4 Summary and Conclusion

After the evaluation and all associated documentation is complete, it would be submitted to the heritage

resources program manager. A consultation request for concurrence would be developed and submitted

to the state historic preservation officer with the results and recommendations (e.g., potential for National

Register eligibility). If the buildings are recommended as eligible for nomination to the National Register

of Historic Places, the heritage resources program manager would request that the state historic

preservation officer accept completion and submission of a Historic American Building Survey package

for the installation to the National Park Service as mitigation for the adverse effect to historic properties

of the proposed demolition.

If recommended as not eligible, the state historic preservation officer would be asked to concur that

demolition does not represent an adverse effect to historic properties, and the project may proceed without

further consultation. Communication of the suggested intention of the Cleveland NF to the state historic

preservation officer to develop and install an interactive display for the purpose of informing the public of

the historic importance of the installation, regardless of its potential National Register eligibility, was

supported by the officer and would further the positive relationship between the Cleveland NF and the

state historic preservation officer.

3.8 Recreation


The abandoned Laguna AFB is located in the Laguna Mountain Recreation Area, which comprises

approximately 8,500 acres on Laguna Mountain and features many recreation facilities, including two

large family campgrounds, three group campgrounds, two picnic areas, over 20 miles of multi-user trails,

the Pacific Crest National Scenic Trail, several trailheads, two mountain resorts, 200 recreation cabins, a

visitor center and other recreational amenities. The abandoned base is located on the northeastern

escarpment of Laguna Mountain and possesses a dramatic and panoramic view of the Anza-Borrego

Desert thousands of feet below. The Laguna Mountain Recreation Area, which is the most highly visited

area on the Cleveland NF, is within a one-hour drive for 3.5 million people in San Diego County. The

abandoned base has become an attractive nuisance within the recreation area and is frequently visited by

the recreating public in violation of the Forest Order closing the site to public access for health and safety

reasons.




Under Alternative 1 the current undesirable conditions would continue at the abandoned base and the

associated health and safety hazards would persist within the recreation area. If not for the existence of

the abandoned base, the area would be open for dispersed recreation and scenic viewing. The Pacific

Crest National Scenic Trail was constructed downslope of the abandoned base in order to avoid the

associated health and safety hazards, rather than along the edge of the escarpment, which would have

been the preferred alignment based on the scenic viewshed.

Alternative 1 would have the direct effect of continued negative impact to the quality and magnitude of

available recreation opportunities within the recreation area. Associated threats to public health and

safety would continue. No indirect or cumulative effects to recreation are known.


Removal of all buildings, structures, road surfaces, and health and safety hazards at the abandoned base

would have a beneficial impact to the recreation area and increase available recreation opportunities for

the public. If the restored site were open to the public, it would likely become popular for dispersed

recreation and for scenic viewing of the desert escarpment. With removal of the buildings and hazards,

the Pacific Crest National Scenic Trail would be considered for realignment to a more scenic location.

An interpretive display may be developed at the site to inform the public of the historical role of the

former base during the Cold War.

Alternative 2 would have the direct effect on increasing recreation opportunities in the recreation area by

opening the area to public entry, possible realignment of the Pacific Crest National Scenic Trail, and

possible development of an interpretive display. No indirect or cumulative effects to recreation are

known.



CHAPTER 4

Consultation and Coordination

4.1 Forest Service Interdisciplinary Team

The interdisciplinary team for this project consisted of:

Name Role/responsibilities

Cardoza, Tim Recreation

Cornejo, Anabele Website liaison, bilingual advisor

Gomben, Pete Team leader, writer/editor, GIS

Graham-Wakoski, Noelle Engineering

Harris, Brian Public affairs officer

Harvey, Steve Heritage resources

Hunner, Nikos Hydrology and soils

Jennings, Megan Wildlife, plants, and management indicator species

McCorison, Mike Air resource

4.2 Federal, State, and Local Agencies

4.3 Tribes

4.4 Others

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