In this lesson, we will examine Site and Layout Design Guidance. In particular, we will examine site level considerations and concepts for integrating land use planning, landscape, architecture, site planning, and other strategies to mitigate the Design Basis Threats.

You will gain an understanding of the myriad of options available to enhance site design, taking into account many environmental challenges.

At the completion of this lesson, students will be able to:

1. Identify site planning concerns that can create, reduce, or eliminate vulnerabilities and understand the concept of "layers of defense"
2. Recognize protective issues for suburban site planning
3. Determine the pros and cons of barrier mitigation measures that increase stand-off or promote the need for hardening of buildings at risk
4. State the benefits that can be derived from appropriate security design
5. State the benefits of adopting a creative process to face current design challenges
6. State the benefits of including aesthetic elements compatible with security and architecture characteristics of buildings and their surrounding environment
7. Identify mitigation measures needed to reduce vulnerabilities

Multiple layers of defense provide multiple opportunities to deter and detect potential threat elements.

There is no limit to the layers applied around an asset; however, three layers are generally used, which can include:

• Deter
• Detect
• Engage
• Assess
• Delay
• Respond

The layers of defense is a traditional approach in security engineering and uses concentric circles extending out from an area or site to the building or asset that requires protection. The image on this screen shows the layers of defense, which are described as follows:

• First layer of defense
• Second layer of defense
• Third layer of defense

First Layer of Defense

This involves understanding the characteristics of the surrounding area, including construction type, occupancies, and the nature and intensity of adjacent activities. It is specifically concerned with buildings, installations, and infrastructure outside the site perimeter. For urban areas, it also includes the curb lane and surrounding streets.

The building owner has little or no control outside of working with the city or municipality. The first layer of defense should be designed to prevent large bombs or weapons from entering the site and to control access of personnel.

Second Layer of Defense

This refers to the space that exists between the site perimeter and the assets requiring protection. It involves the placement of buildings and forms in a particular site and understanding which natural or physical resources can provide protection.

The building owner has control of this layer. The second layer controls stand-off from the building, which provides protection from weapons that may slip through the first layer of defense.

Third Layer of Defense

This deals with the protection of the asset itself. It proposes to harden the structures and systems, incorporate effective HVAC systems and surveillance equipment, and wisely design and locate utilities and mechanical systems.

The building owner has control of this layer. Its main mitigation measures are hardening against blast and security sensors/CCTV as final access control.

There are many mitigation techniques available that can be used at one or more layers of defense. This lesson concentrates on site and layout design, thus it looks primarily at the first and second layers of defense.

The table below shows general mitigation considerations for the urban environment and this presentation will follow the flow of these measures from left to right, starting with Survey Surroundings on the left and ending with CBR Issues on the right.

The flow also follows the general assessment approach of looking from outside to inside and going from general information to specific information.

Survey Surroundings - Data Collection

In an urban environment, this action literally considers what may be a threat or vulnerability in all directions.

Understanding the surroundings includes a 360° assessment of any structures above and under the building and site of interest as to their impact on design or assessment.

• Overhead:
• What can fall on the building?
• Underneath:
• Subways
• Roadway tunnels
• Utilities
• Potential vantage points for looking into the building
• Where are different access points to the building?

Survey Surroundings - Data Collection (continued)

GIS can be used to determine:

• Approaches to site/building:
• Personnel
• Vehicles
• Flight paths
• Railways
• Potential collateral damage near facility
• Buildings and infrastructure of concern nearby
• Important geographic and topographic elements

A 5-mile perspective around the COOP building or site of interest is also needed to understand interaction of the building's critical functions and critical infrastructure against utilities, response capability, and other support provided in the local community. Included should be potential targets in the area to determine the potential for collateral damage and choke points that may restrict response or evacuation capability.

GIS applications are excellent resources that enable designers and building owners to analyze various demographic, hazardous areas, transportation networks, underground utilities and structures, etc., in order to identify potential threats, hazards, and vulnerabilities. These applications may depict a truer picture of the surrounding situation, allowing decision makers to take proactive measures to mitigate potential vulnerabilities.

Layout/Site Considerations

The following considerations can have an impact in the site layout design and will be described in more detail in the next several screens:

• Building placement
• Dispersion of facilities
• Building orientation
• Site lines and view relationships
• Landscaping - plant selection and design

The fundamental objective of site planning is to establish the placement of buildings, parking areas, and other necessary structures in such a way as to provide a setting that is functionally effective as well as aesthetically pleasing. The need for security adds another dimension to the range of issues that must be considered.

Select this link to learn about new building placement.

For security, the building placement must balance the possibilities for stand-off distances; relationship to adjacent streets and buildings; and utilities siting, driveways, and surface parking areas, as well as access to parking garages and loading areas.

Layout/Site Considerations

Placement and Orientation

Orientation is the building's spatial relationship to the site, its orientation relative to the sun, and its vertical or horizontal aspect relative to the ground.

Good site design, orientation, and building placement have a significant impact on making the building visible or hidden to aggressors. Good designs should allow for enhanced surveillance opportunities of approaches and parking.

The proximity of a vulnerable façade to a parking area, street, adjacent site, or other area that is accessible to vehicles and/or difficult to observe can greatly contribute to its vulnerability. Especially toward blast effects.

Layout/Site Considerations

Clustered Versus Dispersed Facilities

Depending on the site characteristics, the occupancy requirements, and other factors, buildings may be clustered tightly in one area, or dispersed across the site. Both patterns have compelling strengths and weaknesses.

Concentrating people, property, and operations in one place creates a target-rich environment, and the mere proximity of any one building to any other may increase the risk of collateral impacts. Additionally, the potential exists for the establishment of more single-point vulnerabilities in a clustered design than would exist in a more dispersed pattern. However, grouping-high risk activities, concentrations of personnel, and critical functions into a cluster can help maximize stand-off from the perimeter and create a "defensible space."

Layout/Site Considerations

Siting and View Relationships

• Operational security is not a traditional element of landscape/urban design, but managing the threat of hostile surveillance is a significant consideration in protecting people, property, and operations.
• Landscape elements can provide visual screening that protects sensitive operations, gathering areas, and other activities from surveillance without creating concealment for covert activity.
• Topography, relative elevation, walls, fences, and vegetation are design elements that can open and close views.

Select this link for information on counter surveillance.

Countersurveillance is another aspect of line of sight. It involves of finding places where terrorists can survey (easily see without being obvious) your facility and its operations/procedures and watch those locations for potential threats.

When designing a site, it is a design goal to NOT create a location with a line of sight that can be used for surveillance.

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Layout/Site Considerations

Landscaping - Plant Selection and Design

The following are some considerations for the use of planting for security:

• Maintenance - When a living landscape is installed with a security function, it needs to be well-maintained to support its continued health and effectiveness
• Aesthetics - Planting can be effectively used to soften and enhance the sometimes stark appearance of security elements
• Perimeter barriers - Planting can be used as a perimeter barrier in the form of thorny hedges and dense hedge rows
• Site lines/hiding sites - Choice of plant material with the ultimate size and maintenance requirements in mind must ensure that plants do not ultimately block important sight lines or create hiding places
• Underground utilities - Conflicts may occur between planting areas and underground utilities. Below-ground conditions should be accurately identified before landscape design is commenced

Stand-off Distance and Effects of Blast

Increasing the stand-off distance from the detonation to the structure will reduce the intensity of the blast loading, which in turn decreases the cost for protective design. Although the optimum stand-off distance is a function of the weight of the explosive threat and the cost of real estate, the selection of stand-off distance is often limited by site conditions.

A major benefit of the increased stand-off distance is the reduction in hazard to the occupants, shown in this table.

Keep in mind constraints or opportunities provided by the site. For stand-off distances for a typical COOP site, where the building face may be around 10 to 20 feet from the curb, an acceptable minimum distance may be completely unachievable. In this case the identified threat must be addressed by measures such as perimeter barriers, structural hardening, building envelope enhancement, location of valuable functions within or away from the building, operational procedures such as increased surveillance, or acceptance of some higher degree of risk. Some combination of these measures will probably apply.

Determination of stand-off Distances

Determination of the minimum stand-off is specific for each building or other asset. It is based on:

• Prediction of the explosive weight of the weapon (Design Basis Threat provided by the threat assessment)
• Required level of protection: This may be specified in the case of a Federal or other Government building, but for a privately owned building it is a determination of the acceptable risk made during the risk assessment process
• Evaluation of the type of building construction, including the building structure and the nature of the building envelope

Controlled Access Zones

The controlled access zone is one of the key elements when determining an effective placement of a building. Designers may determine if the building to be designed or protected will require an exclusive or non-exclusive access zone.

An exclusive zone is defined as the area surrounding a single building or building complex that is in the exclusive control of the owners or occupants: Anyone entering an exclusive zone must have a purpose related to the building.

A non-exclusive zone may be either a public right-of-way, such as plazas, sidewalks, and streets surrounding a downtown building, or an area related to several buildings, such as an industrial park with open access.

Vehicle Approach Speed/Traffic Calming

Access Points

Controlling the angle of approach and the length of straightaways is important to provide protection to high-risk buildings.

Traffic calming strategies seek to use design measures to cue drivers as to the acceptable speed for an area. They can control the angle of approach:

• Turns
• Curves

Or slowdown approach:

• Chicanes
• Speed bumps/tables
• Pavement treatments

In conjunction with traffic calming considerations, appropriate barriers to block moving vehicle attacks should be considered at high-risk buildings.

Vehicle Approach Speed Analysis

The threat of vehicular attack can be reduced significantly by controlling vehicular speed and removing the opportunity for direct collision with the building. If the vehicle is forced to slow down and impact a barrier at a shallow angle, the impact forces are reduced.

Controlled Access Zone/Entry Control and Vehicle Access

The objective of the access point is to prevent unauthorized access, while at the same time controlling the rate of entry for vehicles and pedestrians. An access point is a designated area for authorized building users: employees, visitors, and service providers. Access points along the defended perimeter:

1. Reject vehicles before final barrier

2. Inspection area blast effects:

• Pressure
• Fragments

3. Provide reaction time to activate barriers

It is advisable to design circulation to separate different types of traffic and provide separate routes for staff, for visitors, and for deliveries. With the separation of vehicle types, security can more easily address differing needs for screening, observation, and potential threat mitigation.

Gatehouses and Security Screening

Entry control facility considerations include:

• Gatehouses
• Inspection considerations
• Final denial barrier
• Sally ports (double row of barriers)

Each consideration is discussed in more detail on the next two screens.

Controlled Access Zone

Gatehouses

Gatehouses and screening require manned access control and inspection considerations. Design of the entry control point must accomplish many security-related functions and should consider:

• Gatehouses should be hardened as determined by the expected blast load and should provide protection from the elements.
• If ID checking is also required between the traffic lanes, some measure of protection against hostile activity should be provided for the security guard.
• Gatehouses, lobbies, and guard posts should be provided with clear views of approaching traffic, both pedestrian and vehicular.
• Queuing space for pedestrian visitors to gather as they wait to enter a building is necessary; this may be provided in a screening pavilion for visitors beyond the building entry, which may be at a distance from the main facilities.
• Active vehicle crash barriers are necessary to deny entry and to give entry control personnel adequate time to respond to unauthorized activities. The response time is defined as the time required for complete activation of the active vehicle barrier once a threat (vehicle circumventing access control) is detected. The response time includes the time for security personnel to react to a threat and initiate the activation of the barrier system, and the time for the selected barrier to fully deploy and close the roadway.

Some inspection considerations:

• Pullover lanes at site entry gates should be provided for an initial vehicle check prior to allowing access to a site.
• Inspection areas should be large enough to accommodate a minimum of one vehicle and a pullout lane.

Controlled Access Zone

Final Denial Barriers

For high-security buildings, a final denial barrier after initial screening is necessary to stop unauthorized vehicles from entering the site.

A properly designed final denial barrier will safely stop individuals who have made an honest mistake, but provide a properly designed barrier to stop those with hostile intentions.

Perimeter Security Design

A perimeter security design involves two main elements:

• Perimeter barrier that prevents unauthorized vehicles and pedestrians from entering the site
• Access control points at which vehicles and pedestrians can be screened and, if necessary, inspected before they pass through the barrier

Perimeter Security Design (continued)

Issues to be considered in the design of a barrier system:

• The design should be based directly on the Design Basis Threat assessed for the project, as well as available countermeasures and their ability to mitigate risk.
• The barrier layout at sidewalks should be such that a constant clear path of 8 feet or 50 percent of the sidewalk, whichever is e greater, should be maintained.
• Any security (or other) object placed on the curb should be at least 2 feet from the curb line to allow for door opening and to facilitate passenger vehicle pick-up and drop-offs, if this can be done anywhere along the curb. However, the most effective placement is at a maximum of 2 feet: This allows the barrier to engage the engine block and mass of an approaching vehicle before the tires have impacted the curb and begun to launch it over the barrier.
• Monotonous repetition of a single element should be avoided.
• Use a palette of elements, such as varied bollard types, engineered sculptured forms, hardened street furniture, low walls, and judicious landscaping.

Determination of Barrier Performance Requirements

The security design criteria required for a barrier are largely determined by key information obtained in the following steps in the risk assessment process:

1. Threat analysis should provide the following Design Basis Threat:

• Vehicle size, weight, speed
• Bomb size (weapon yield in pounds of TNT equivalent) and worst-case stand-off distance

2. Vulnerability analysis provides:

• Building envelope and structural information that contribute to the determination of the appropriate stand-off distance and that enable possible tradeoff between alternative building characteristics and stand-off distances to be evaluated and budgeted
• Information on available stand-off distances
• Information on the possible reduction of vehicle speed through the existing or modified characteristics of approach roads using various traffic calming techniques
• Limitations imposed by underground utilities
• Information on the types of soil, which affect barrier standards

3. The risk assessment provides:

• Information to assist the property owner in determining the acceptable risk and the desired level of protection.

These photos show retractable bollards stopping a substantial truck with very little penetration.

An active barrier can be activated in seconds (one to three) and should be either always up (sally port concept) or deployed upon identification that the gate is being crashed (taking into consideration response time, maximum vehicle speed, and activation speed).

Pop-up barriers can create serious damage to vehicles, especially if deployed when a vehicle is above the barrier. Consider manual activation to avoid unnecessary damage (i.e., avoid magnetic vehicle loops to redeploy barriers that may catch tailgating vehicles).

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Barrier Types

There are two basic categories of barriers:

• Passive (fixed)
• Active (operable)

Passive Barriers

Passive barriers are fixed in place, do not allow for vehicle entry, and are used to provide perimeter protection away from vehicle access points. Examples of passive barriers include:

• Walls
• Berms
• Engineered planters
• Fixed bollards
• Heavy objects
• Reinforced street furniture
• Fixtures
• Trees and water obstacles
• Jersey barriers in fixed and anchored installations
• Fences

Passive Barriers - Street Furniture

Streetscape can be used to increase security. It can include hardened versions of parking meters, street lights, benches, planters, and trash receptacles that act as barriers to moving vehicles.

Design of streetscape should take into consideration:

• Scale - appropriate to primary users, less inviting to users with malicious intent
• Scope - adequate for pedestrian circulation and normal use

Passive Barriers - Barriers and Bollards

This chart shows the sizing requirements for the level of protection sought. The bigger the vehicle and the higher its speed, the stronger the barrier must be as shown by this chart.

The greater the barrier mass and reinforcement and the deeper it is connected to the earth, the higher its rating.

Passive Barriers - Jersey Barrier

Jersey barriers are the least desirable of barrier types because they:

• Are difficult to place and move
• Have no vehicle-stopping capability unless tied to pavement with at least four pieces of #4 (1/2-inch diameter) rebar into pavement about 18 inches deep and/or tied together with steel cable (3/4 to 1-inch)
• Can cause sidewalk failure due to concentrated load and the fact that sidewalk may be hollow underneath for storage or utilities
• Add to fragmentation (barrier shatters) if a vehicle bomb explodes next to barrier
• Impede access to pedestrians and first responders:
• Utilities (if placed on top of manholes)
• Emergency access (fire trucks, ambulance, police)
• ADA (Americans With Disabilities Act) access - crosswalks and ramps

Note: Jersey barriers with 4,000 psi (compressive strength) concrete readily fragment when a vehicle bomb nearby explodes, resulting in an incident pressure exceeding 4,000 psi.

Passive Barriers - Architectural

When placed, make sure bollards accomplish their barrier function with an appropriate distance of not more than 4 feet between them.

Placed in long unbroken rows, they present a monotonous appearance and may appear as a wall from some angles.

Pay attention to how bollards or fences:

• Turn the corner
• Intersect with driveways and gates
• Cross pedestrian paths and handicapped ramps

In a COOP environment, bollards and barriers are ideally the first layer of defense to obtain the most stand-off possible.

Active Barriers

Active barriers are used at vehicular access control points within a perimeter barrier system, or at the entry to specific buildings within a site, such as a parking structure or a parking garage within an occupied building, to provide a barrier for vehicle screening or inspection; they can be operated to allow vehicle passage. Examples of active barriers include:

• Rotating drum systems
• Rising-wedge barricades
• Retractable bollards
• Crash beams
• Crash gates
• Surface-mounted wedges and plates

Active devices must be used in conjunction with signage, light signals, gatehouses, and security personnel.

Active Barriers - Barriers and Bollards

As with passive barriers, active barriers also have different levels of kinetic energy stopping power, based upon mass and connection to the earth, as shown in the table below.

Sidewalks and Curbs

Sidewalks serve as the common space for pedestrian interaction, movements, and activity. Sidewalks should be open and accessible to pedestrians to the greatest extent possible, and security elements should not interfere with circulation, particularly in crowded locations.

With exterior walls on the property line, the stand-off distance is the width of the sidewalk in many cases.

Low curbs are not a deterrent in keeping vehicles away from buildings, as shown in the bottom image on this screen.

With little stand-off, increased building security and hardening will be expensive.

Sidewalks and Curbs (continued)

Look at the images on this screen for additional examples of interruptions in sidewalks and closure of streets.

The top image shows bollards that are spaced so far apart that they cannot keep most vehicles out, so a single planter was placed to fill a gap. Also in the top photo, note the restriction to pedestrian traffic caused by the jersey barrier, which would have been equally effective if placed directly behind the bollards or angled with the planter to open up the sidewalk.

The bottom image shows pedestrian traffic being controlled into a closed service street.

Sidewalks and Curbs (continued)

Curbside parking should not be removed unless additional stand-off distance is absolutely necessary for high-risk buildings. Prohibiting on-street parking or closing lanes should only be used as a temporary measure during times of increased alert.

High curbs and other measures may be installed to keep vehicles from departing the roadway in an effort to avoid other security counter-measures.

Site Security Design Guidelines

The collaborative, multidisciplinary approach in defining a security philosophy can represent permanence and encourage citizen participation.

Increased setbacks can become active public spaces, physical restraints can serve as seating areas or landscape features, and new amenities can both increase the safety of Federal employees and integrate our public buildings into their neighborhoods.

Site security design is important, particularly for:

• Parking
• Loading docks and service areas
• Security lighting
• Signage
• Site utilities
• CBR issues

Site Security Design Guidelines

Parking

Parking at the building, at an adjacent building, or in a nearby parking garage have limited stand-off distance in the urban environment.

Hardening considerations come into play for each situation, whether it is the building face, adding bollards to maintain stand-off, or taking access control and column hardening actions in an urban parking garage.

There are three primary types of parking facilities, all of which present security trade-offs:

1. Surface lots can be designed to keep vehicles away from buildings, but they consume large amounts of land and, if constructed of impervious materials, can contribute greatly to storm water runoff volume. They can also be hazardous for pedestrians if dedicated pedestrian pathways are not provided.
2. In contrast, non-street parking is often convenient for users and a source of revenue for local Governments, but this type of parking may provide little or no setback.
3. Finally, garage structures provide revenue and can be convenient for users, but they may require structural measures to ensure blast resistance as well as crime prevention measures to prevent street crime.

Site Security Design Guidelines

Parking (continued)

When designing parking, the following should be taken into consideration:

• Maintain stand-off distance from building
• Restrict parking from the interior of a group of buildings and away from any restricted area
• Avoid having parking near, within, or underneath buildings; consider hardening against
• Locate parking within view of occupied buildings
• If possible, design the parking lot with one-way circulation that restricts straight-on high-speed approaches to buildings
• Provide signage to clearly mark separate entrances for different parking lots
• Keep parking areas well lit; use emergency communications and/or CCTV

Site Security Design Guidelines

Delivery/Loading Docks

Considerations in the design of loading docks and service areas include:

• Since larger vehicles can carry larger weapons, the goal is to screen the vehicles away from the urban area and escort them from the screening to the building.
• Schedule deliveries to avoid queuing. In conjunction with local authorities and building tenants, consider shifting deliveries to time of day when building is not occupied. For example, deliveries are done from 19:00 to 05:00 when the building occupancy is occupied from 06:00 to 18:00.
• Use barriers and gatehouses for access control to allow final approach of vehicles to the loading dock.
• Significant structural damage to the walls and ceiling of the loading dock may be acceptable; however, the areas adjacent to the loading dock should not experience severe structural damage or collapse.

Site Security Design Guidelines

Security Lighting

Security lighting should be provided for overall site and building illumination to allow security personnel to maintain visual assessment during darkness. Lighting is desirable around areas such as entrances, loading docks, parking, etc. At entry points, a recommended minimum surface lighting average of 4 horizontal foot candles will help ensure adequate lighting.

Security lighting has different purposes — to blind, to allow vehicle inspection, to identify credentials, to support CCTV capabilities, etc. Thus, security lighting must be coordinated for all purposes.

Site Security Design Guidelines

Security Lighting (continued)

Types of lighting include:

• Lighting zones:
• Concentrate light - Site lighting can be separated into zones in order to concentrate light where it is needed most.
• Prioritize - Prioritizing will allow for the most efficient use of lighting while keeping within a reasonable budget.
• Scalable:
• Provide different levels of lighting - It is also important to consider operational factors when designing an appropriate lighting situation.
• Operational issues:
• Costs - Estimate and evaluate the lifecycle costs for energy and maintenance.
• Sustainability - Evaluate the impact on project sustainability.

In addition, site lighting can be helpful as a response to different levels of alert, by designing it to be increased in times of high security alert. Provision of additional light is a common technique to discourage unwanted activities on sites and within buildings and to enhance desirable activities.

Site Security Design Guidelines

Signage

Building owners should determine how visible the project should be and the corresponding implications for site signage. For some projects, a degree of anonymity may be part of the security strategy. Signage considerations:

• Unless required, signs should not identify sensitive areas.
• Minimize signs identifying critical utility complexes, such as power plants and water treatment plants.
• Warning signs should be posted at all entrances to limited, controlled, and exclusion areas.
• The wording on the signs should denote warning of a restricted area.
• Signs should be posted at intervals of no more than 100 feet or at entrance points only.
• Signage may be mounted on other elements, such as walls, to reduce the number of posts along the street or perimeter.
• Signposts may be hardened and included as part of the perimeter barrier.
• The lighting of signage may also enhance nighttime safety to those who come to the site during evening or early morning hours.
• Warning signs must use language commonly spoken.

Site Security Design Guidelines

Site Utilities

Utility considerations:

• Concealed or underground utilities are easier to protect than exposed or aboveground constructions. Fortunately, in the urban environment utilities are primarily underground.
• Access to utilities should be protected or secure, allowing only authorized personnel access to perform maintenance and repair.
• The location and accessibility of site utilities directly impacts the vulnerability of systems to disruption and failure.
• Incoming utility systems should have two entry points to the building for redundancy as required by criticality.
• Looped versus radial distribution of utilities to the building allows for higher system reliability and faster repair by avoiding utility loss by a single incident.
• If possible, surveillance of critical utility points should be conducted.

Site Security Design Guidelines

CBR Issues

A major concern is the vulnerability of buildings to CBR threats.

The following information presented is limited to those aspects of protection against CBR threats that concern site design and building placement. Further detail is provided in Lesson 10.

The main site and layout protective measures against CBR are:

• Avoid low-lying sites
• Evacuation areas
• Areas designated for decontamination, entry, and exit
• Location of air intakes - relative to ground level and prevailing winds
• Placement and orientation of a new building should take into account prevailing winds, although the actual wind direction and speed at the time of an outdoor release will directly affect the building
• The surrounding terrain may result in channeling a CBR release toward the site and building

Select this link for a description of the incident that occurred in the image on this screen.

About 11:15 am Central Daylight Time on October 27, 2004, an 8-inch-diameter pipeline owned by Magellan Midstream Partners, L.P., (Magellan) and operated by Enterprise Products Operating L.P. (Enterprise) ruptured near Kingman, Kan., and released approximately 4,858 barrels (204,000 gallons) of anhydrous ammonia. Nobody was killed or injured due to the release. The anhydrous ammonia leaked into a creek and killed more than 25,000 fish, including some from threatened species. The cost of the accident was $680,715, including $459,415 for environmental remediation.

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To summarize:

• A broad spectrum of mitigation actions can be taken - with a wide range of cost, protection provided, and level of effort required by the asset owner
• The nominal ranking of mitigation measures on page 2-30 (FEMA 430) provides a framework for the identification of short-term and long-term measures that can be taken

Note: Page 2-30 of FEMA 430 provides a comprehensive list of security/protection measures that can be taken — increasing in protection, cost, and level of effort - that complements this graphic on Site Mitigation Measures.

Now that you have completed this lesson, you should be able to:

1. Identify site planning concerns that can create, reduce, or eliminate vulnerabilities and understand the concept of "layers of defense"
2. Recognize protective issues for suburban site planning
3. Determine the pros and cons of barrier mitigation measures that increase stand-off or promote the need for hardening of buildings at risk
4. State the benefits that can be derived from appropriate security design
5. State the benefits of adopting a creative process to face current design challenges
6. State the benefits of including aesthetic elements compatible with security and architecture characteristics of buildings and their surrounding environment
7. Identify mitigation measures needed to reduce vulnerabilities