24 CFR Part 51 Subpart C Mitigation Training

24 CFR Part 51 Subpart C Mitigation Training Module Environmental Planning Division Office of Environment and Energy

Training Outline Introduction Limitations/applications Terms and Definitions Mitigation n Principles Analysis Options Designing barriers Questions?

Introduction Purpose n To provide quality data and analytic guidelines for designing and building the required protection against hazards covered under 24 CFR Part 51 Subpart C

Background on 24 CFR Part 51 Subpart C n 24 CFR Part 51 Subpart C covers technical requirements for determining Acceptable Separation Distances (ASD) from HUDassisted projects in close proximity to stationary hazardous operations that have above ground storage stationary containers of more than 100 gallon capacity containing substances of explosive or flammable nature

The guidance contained in this training module can be applied to the following activities: n HUD-assisted projects as defined at 24 CFR 51. 201.

Who will benefit from the guidance contained in this training module? n n n Planners Developers Engineers HUD field and headquarters staff HUD grantees

HUD Standards

Standards There are two standards: Thermal radiation and blast overpressure: 1. Thermal Radiation: Buildings - 10, 000 BTU/Ft. sq Hr People – 450 BTU/Ft. sq Hr. 2. Blast Overpressure: Buildings - 0. 5 PSI

Hazard Identification System used in Industry The NFPA diamond

Example of a Hazard Identification System used in Industry Red The NFPA diamond Symbol established by NFPA for identification of hazardous substances in industry.

Examples of Hazardous Operations Petrochemical plant Bulk fuel storage and distribution facility Propane gas storage and distribution point

Limitations 24 CFR Part 51 Subpart C nor the guidance contained this training module apply to the following: n n n High pressure natural gas transmission pipelines or liquid petroleum pipelines Natural gas holders with floating tops Mobile tanks en route Underground storage tanks Stationary containers of 100 gallons or less capacity Double wall tank interstitial space for Acceptable Separation Distance (ASD) calculation Interstitial spacing not equal to “diked” area

Limitations: Where the HUD Standards and Mitigation do not apply 1. High Pressure Pipelines 3. Mobile tanks en route 4. Double wall tank Interstitial space for ASD calculation 2. Underground Storage Tanks 5. Natural gas holders With Floating Tops

Applications 24 CFR Part 51 Subpart C and the guidance contained in this training module do apply to the following: n HUD-assisted projects in close proximity to stationary hazardous operations that have above ground stationary containers of more than 100 gallon capacity containing substances of explosive or flammable nature

Terms and Definitions Mitigation n Is the scientific process for implementing the required level of protection to a HUD-assisted project site from stationary hazardous operations which store, handle or process materials of explosive or flammable nature. Acceptable Separation Distance (ASD) n Is the distance from a hazard, to where a HUD -assisted project can be located.

What is the ASD? Acceptable Separation Distance (ASD) ASD Distance HUD-assisted project Stationary aboveground storage tank

Thermal Heat Flux n Is the amount of heat being radiated from a source. Heat wave generated from combustion. Combustion n Is a complex sequence of chemical reactions between the mixture of oxygen, a fuel source and an ignition source resulting in the production of heat and light in the form of a glow or flames.

Bleve n Is the type of explosion that occur when a vessel containing a pressurized liquid is ruptured.

Fire Suppression Systems n Is liquid or gas fire extinguishing media distribution system, designed to provide fire protection Diked area n Is the area between the container(s), outside wall and the dike. The dike area provides containment if there is container rupture, causing a spill. Dike n A dike is a continuous wall (built out of soil, asphalt, steel or concrete), constructed as a defense or as a boundary. Built for the purpose of empoldering, or as a boundary for an inundation area.

Tanks with Dikes § The diked area provides spill protection on the tanks shown below § 24 CFR Part 51 Subpart C can be applied for Acceptable Separation Distance (ASD) calculations for above ground storage tanks using dikes Tank Dike

Tanks without Dikes § The interstitial space (space between the walls) provides spill protection system on the tank shown below § 24 CFR Part 51 Subpart C can not be applied for ASD calculation for SCAT tanks (SCAT – Self Contained Above Ground Tank) Self contained Above ground Storage tank“No dike in this Tank”

Container n A structure (words used on subject matter are vessel, container, tank, and enclosure) built to contain material in liquid, gas or solid state of matter, that could be designed to be stationary or for transport purposes.

Examples of Containers 1. Bulk fuel (liquid) storage and distribution facility • Fuel is stored in above ground storage tanks 2. Propane gas storage and distribution point • Propane gas is stored in above ground storage vessels

Blast Overpressure n (also known as peak positive incident pressure) exerted pressure from a compressed liquid inside a container after an incident occurs that prompt a liquid-gas unbalanced reaction and the container explodes with high energy.

Mitigation Principles If the Acceptable Separation Distance (ASD) has been MET n Mitigation is not Required

If the Acceptable Separation Distance (ASD) has Not been MET n Mitigation is Required

To protect buildings and people When the Acceptable Separation Distance (ASD) cannot be met between the specific stationary hazardous operation to the proposed project site Applies only for HUD-assisted projects in close proximity to stationary hazardous operations that have above ground stationary storage containers of more than 100 gallon capacity containing substances of explosive or flammable nature

Mitigation Analysis The best mitigation is based on site analysis, using the following 10 questions; 1. Has the Acceptable Separation Distance (ASD) been calculated? If yes, and the ASD meets the standard requirement-no further action is required If yes, and the ASD standard has not been met, mitigation may be required If no – calculate ASD

2. Where do you get technical assistance towards the Acceptable Separation Distance (ASD) determination? Technical assistance is available from n n HUD hazards guidebook, HUD field environmental staff

Where to find the HUD Hazard Guidebook-ASD Determination Procedures http: //www. hud. gov/offices/cpd/environment/training/guidebooks/hazfacilities

3. What are the properties of the substances stored at the site deemed hazardous? n n Substances in general are classified as liquids, solids or gases If the substances have flammable or blast overpressure properties and are in stationary aboveground containers, a hazardous analysis is required for the proposed HUDassisted project site

4. Are/or containers diked/undiked ? n If containers are diked: The Acceptable Separation Distance (ASD) calculation will not change by the diked area on pressurized containers (flammable or nonflammable substances). The ASD will be of a smaller numerical value for diked containers vs undiked containers storing flammable liquids. n If containers are undiked: The ASD will be of a larger numerical value for undiked containers vs. diked containers storing flammable liquids

5. What roles does topography have in influencing Acceptable Separation Distance (ASD) calculations? n n If the ASD is not achievable, between the site to be developed and the hazard operation/facility, and there is not a clear line of sight between the proposed HUDassisted project site and the hazard operation, mitigation may not be required. If the ASD is not achievable between the site to be developed and the hazard operation/facility and there is a clear line of sight between the proposed HUDassisted project site and the hazard operation, mitigation is required.

6. Any man-made or natural barriers in between the hazard operation/facility and the proposed HUD-assisted project site? n If the answer is yes, man-made and natural barriers are defined as follow: Man-made barriers are buildings, housing developments and other structures. Natural barriers are hills, mountains, earthen elevations, etc n If the answer is no, there are mitigation options to be considered other than designing a barrier

7. Where can I get maps or other geographic based information? n Sources of information: Maps and related site (topographic) information are available from the United States Geological Survey (USGS), City or County engineer’s or planning office

Sources of information: n Free of cost (web based) for general public use, available electronic sources of information for proposed site analysis, including the usage of digitized topographic maps, are as follows; Yahoo Maps Google Earth Microsoft Map products n HUD does not endorse any of the referenced electronic sources of information

Electronic Source of Information Example GOOGLE EARTH http: //www. google. com For FREE aerial maps (can calculate distances) This is a free download – so simply do the following: Then click “Download”

Example of a Site View using Google Earth’s Digitized Maps

8. Types of geographic based information n Types of information: Scaled maps with site contours (topographic maps) - are highly recommended for the analysis of proposed HUDassisted project sites. Site maps – similar in content to the scaled maps, but without detailed scales or site contours, are recommended as an initial type of geographic based information for analysis of proposed HUD-assisted project sites Site photos – provide actual images of the facilities near proposed HUD-assisted project sites. Recommended to be used with scaled and site maps for the analysis of proposed HUD-assisted project sites

Examples of Types of Geographic based Information: 1. Project site photo 3. Project location map 2. Project layout schematic

Examples of Geographic based Information that can be gathered from a Site Visit

9. If the facility storing these hazards will not release subject information, where can I go for information? n n Fire Department Local Emergency Planning Committee Database

10. Fire suppression systems: n Can they modify or change the analysis to obtain Acceptable Separation Distances (ASDs)? No (not at this time) n Are they an alternative to ASDs? Neither the Regulation nor the HUD hazards guidebook consider the use of fire suppression systems for modification or change the analysis to obtain ASDs or as an alternative to ASDs

What have you learned? n n n Terms and definitions Types of information Sources of information Specific information needed about operations at assessed facilities Site specific data for proposed HUD-assisted project sites Information on how to evaluate natural or man made barriers between the facility been assessed and the proposed HUD-assisted project site

Now What?

If you cannot achieve the ASD, What are the options?

Mitigation Options n n Burying the hazard Modifying the building design to compensate for the Acceptable Separation Distance (ASD) Choose another site Design and implement a barrier

Designing Barriers How does a barrier work/what does it do? n A barrier works as abatement for thermal heat flux and blast overpressure and provides protection to HUD-assisted projects when the Acceptable Separation Distance (ASD) has not been met

Who should design a barrier? n Only a licensed professional (civil or structural engineer) should design and oversee the construction of mitigation barriers

Questions?