guidelines for facility siting and layout

The objectives of these guidelines are to provide guidance on the ing points.follow-• Approaching siting and layout from a safety perspective • Assembling a site selection team, compilin

FACILITY SITING AND LAYOUT

Center for Chemical Process Safety

of the

American Institute of Chemical Engineers

3 Park Avenue, New York, New York 10016-5991

Copyright © 2003

American Institute of Chemical Enginers

3 Park Avenue

New York, New York 10016-5991

All rights reserved No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise without the prior permission of the copyright owner AIChE™and CCPS® are trademarks owned by the American Institute of Chemical Engineers These trademarks may not be used without the prior express written consent of the American Institute of Chemical Engineers The use of this product in whole or in part for commercial use is prohibited without prior express written consent of the American Institute of Chemical Engineers To obtain appropriate license and permission for such use contact Scott Berger, 212-591-7237, scotb@AIChE.org.

CCPS Publication Number G-84

Library of Congress Cataloging-in-Publication Data:

Library of Congress Data Applied for

ISBN 0-8169 0899-0

It is sincerely hoped that the information presented in this volume will lead to an even more impressive safety record for the entire industry However, the American Institute of Chemical Engineers, its consultants, CCPS Subcommittee members, their employers, and their employers’ officers and directors and Baker Engineering and Risk Consultants Cheryl A Grounds and Joseph R Natale disclaim making or giving any warranties or representations, express or implied, including with respect to fitness, intended purpose, use or merchantability, and/or correctness or accuracy of the content of the information presented in this document As between (1) American Institute of Chemical Engineers, its consultants, CCPS Subcommittee members, their employers, and their employers’ officers and directors and Baker Engineering and Risk Consultants Cheryl A Grounds and Joseph R Natale (2) the user of this document accepts any legal liability or responsibility whatsoever for the consequences of its use or misuse.

PRINTED IN THE UNITED STATES OF AMERICA

10 9 8 7 6 5 4 3 2 1

This book is available at a special discount when ordered in

bulk quantities For information, contact the Center for

Chemical Process Safety at the address shown above.

vContents

SITE SURVEY AND SELECTION

6.5 Layout and Spacing to Minimize

6.6 Relative Location of Equipment 106

7

OPTIMIZE THE LAYOUT

8

APPENDIX B SITE SELECTION DATA REQUIREMENT LIST 151

The Center for Chemical Process Safety (CCPS) The Center for Chemical cess Safety (CCPS) was established in 1985 by the American Institute ofChemical Engineers for the express purpose of assisting industry in avoiding

Pro-or mitigating catastrophic chemical accidents To achieve this goal, CCPShas focused its work on four areas:

• Establishing and publishing the latest scientific, engineering andmanagement practices for prevention and mitigation of incidentsinvolving toxic, flammable, and/or reactive materials

• Encouraging the use of such information by dissemination throughpublications, seminars, symposia, and continuing education pro-grams for engineers

• Advancing the state of the art in engineering practices and technicalmanagement through research in prevention and mitigation of cata-strophic events

• Developing and encouraging the use of undergraduate engineeringcurricula that will improve the safety knowledge and consciousness ofengineers

This book outlines a process for finding an optimal location for a cal or petroleum processing site and then arranging the units and equip-ment It provides comprehensive guidelines on how to select a site, how torecognize and assess long-term risks, and how to lay out the facilities andequipment within that site A survey guide is provided to aid site selectionteams in obtaining necessary data to select a new site Site layout and equip-ment spacing guidelines are provided based on historical and current dataincluding industry practices and standards Spacing tables are providedwhich can be used as a starting point in laying out a site Case histories andexamples are included to illustrate both the appropriate manner in which toaddress facility siting and layout as well as the consequences when the effort

chemi-is inadequate

ixPreface

The American Institute of Chemical Engineers and the Center for ChemicalProcess Safety express their gratitude to all the members of the FacilitySiting and Layout Subcommittee for their generous efforts and valuabletechnical contributions in the preparation of this Guidelines book.

Chairs:

Ephraim A Scheier BP America, Inc.

Frank Worley, III Rohm & Haas Company

Authors:

Cheryl A Grounds Baker Engineering and Risk Consultants

Joseph R Natale Baker Engineering and Risk Consultants

CCPS Staff Consultant:

John A Davenport

Subcommittee Members:

John A Alderman RRS Engineering

Richard L Alexander, Jr formerly with Solutia

Michael P Broadribb BP America

Chris R Buchwald ExxonMobil

Christopher P Devlin Celanese Chemicals Division

Brian R Dunbobbin Air Products & Chemicals

William Hague Honeywell Specialty Chemicals

Michael D Moosemiller formerly with Det Norske Veritas (DNV)

xiAcknowledgments

Vanessa E Rodriguez US Environmental Protection Agency

William E Thornberg formerly with GE Global Asset

Protection Services

Tracy Whipple formerly with Det Norske Veritas (DNV)

Before publication, all CCPS books are subjected to a through peer reviewprocess CCPS also gratefully acknowledges the thoughtful comments andsuggestions of the peer reviewers

Don Connolley Akzo Nobel Chemicals Inc.

Neil Macnaughton British Petroleum

Orville M Slye, Jr., PE Loss Control Associates

1.1 Objectives

The cost, complexity, and safety of process operation and maintenance ishighly dependent on site location and layout Building inherent safety into asite generally reduces both the cost and complexity Siting and layout areamong the earliest steps in design, and are quite costly to modify once thesite is constructed Optimum siting and layout minimizes material and con-struction costs, but more importantly, minimizes the risk of losses through-out the site’s life cycle

What principles do you use to decide on the location and layout of a new

or expanded site? What information do you need to consider before selecting

a site location? How do you maximize inherently safer design with minimalimpact on cost and schedule? How do you manage siting issues when limitedspace is available? How to you address security concerns in a new site?This book addresses siting and layout in terms of the overall process offinding an optimal location for the site and then arranging the units andequipment It provides comprehensive guidelines on how to select a site,how to recognize and assess long-term risks, and how to lay out the facilitiesand equipment within that site Site layout and equipment spacing guidelinesare provided based on current industry practices and standards

This book is applicable to the following types of facilities

• Large and small

• Petroleum and chemical facilities and other industries using leum or chemical products

petro-• Within and outside of the US

• Grassroots sites, brownfield sites, and expansions within a site

• Open air sites

• Processes enclosed in a building (in terms of siting the building, not interms of process equipment layout inside of the building)

1

1

The objectives of these guidelines are to provide guidance on the ing points.

follow-• Approaching siting and layout from a safety perspective

• Assembling a site selection team, compiling the issues they need toconsider, and determining what data they should collect (This infor-mation is needed for selecting a location for a new grassroots site, abrownfield site, or an expansion within a site.)

• Balancing infrastructure, environmental, security, population, andprocess risk considerations with each other in the site selection pro-cess

• Anticipating outside factors that may affect the project cost andschedule

• Fitting a new expansion within an existing unit and compensating forlimited spacing by taking risk mitigation measures

• Maximizing inherently safer design in siting and layout by gatheringdata and conducting hazard analysis in the conceptual design andlayout stages of the site design

• Maximizing ease of operations and maintenance as well as ing operating and maintenance risks to personnel and the surround-ing site through layout and equipment spacing

minimiz-This book will benefit anyone responsible for making or advising onsiting decisions Project developers will find the information they need tocollect and/or develop in order to select a site Planners and those who eval-uate the economic justification for a site will learn of the potential safety andrisk impacts of siting decisions Designers and engineers will appreciate thetechnical details included in specifics given on plant and equipment layoutand spacing

1.2 How To Use This Book

This book may be considered the starting point for establishing the criterianeeded to make decisions on the location of a grass roots site or new unitwithin an existing site, as well as the basic equipment layout and spacingwithin the site This book discusses the sequential steps taken in this process

as outlined in Figure 1-1

2 Guidelines for Facility Siting and Layout

It is important to use consistent vocabulary when discussing the nents and subcomponents of a process complex Figure 1-2 shows the ter-minology used in this book.

compo-A unit is a collection of process and/or manufacturing equipment that is

focused on a single operation For example, a refrigeration unit supplying afrozen food plant, a crude distillation unit, a water treating unit chlorinatingwaste-water effluent from a waste disposal facility, a polyethylene unit, or abatch reactor train

A plant is a collection of process units with similar process parameters

or related by feeding or taking feed from each other For example, a fuelsplant which produces materials for blending gasoline, a lubricating oil blend-ing plant, a tank farm area supporting a refinery, chemical site or both, awharf receiving raw materials and loading products, a polypropylene pro-cessing and plastic pellet silo storage area, a pipeline pumping station

A site is a collection of plants typically owned by a single entity A site

may have its own support facilities or share them with another site Supportfacilities may include parking, offices, maintenance, and warehousing facili-ties, firehouse, medical, transportation, and security facilities Examples of

Figure 1-1 Guidelines Book Flowchart

a site may include a petroleum refinery, or a manufacturing facility that duces a variety of products such as paints, synthetic rubbers for tire manu-facturing, or petrochemicals.

pro-A complex is a collection of sites that may or may not be owned by the

same business entity A site within a complex may feed or take feed fromanother site within the same complex or be totally independent

This book provides a selection of examples throughout the text and casehistories in Chapter 8 These case histories and examples serve to illustrateboth the appropriate manner in which to address facility siting and layout aswell as the consequences when the effort is inadequate These case historiesinclude actual events, scenarios based on real events but modified toemphasize a point, and purely illustrative examples

1.3 Layers of Safety

Siting and layout provide a fundamental aspect of risk management It rates sources of potential fire, explosion, or toxic incidents from adjacentareas that might become involved in the incident or be harmed by its poten-tial consequences This is also a key component in inherently safer design

sepa-4 Guidelines for Facility Siting and Layout

Figure 1-2 Guidelines Terminology

Inherently safer strategies can impact a potential incident at variousstages The most effective strategy will prevent initiation of the incident.Inherently safer design can also reduce the potential for an incident to esca-late Lastly, an inherently safer strategy can limit the incident sequencebefore there are major impacts on people, property, or the environment.(CCPS, 1996, no 23)

There are many challenges to the ability to site and lay out a plant as will

be discussed in these guidelines Layers of safety are utilized to compensatefor less than desired spacing and to implement additional aspects of inher-ently safer design This use of layers of safety or layers of protection is a tra-ditional risk management approach and is illustrated in Figure 1-3 Theselayers may include the inherently safer strategies of preventing the incident,minimizing escalation, and minimizing impact The layers may include using

a less hazardous process, separation distances, operator supervision, trol systems, alarms, interlocks, physical protection devices, and emergencyresponse systems (CCPS, 2001)

con-Consider layers from inside to outside following inherently safer concepts:

1 Process design

2 Separation distance

3 Safety and process devices, instruments, alarms, and controls

4 Administrative processes and controls

Figure 1-3 Layers of Safety

1.4 References

1.4.1 CCPS Publications

Where appropriate, reference is made to other CCPS books for additionalguidelines and methodology for specific applications The most relevantCCPS Publications are listed here

Guidelines for Evaluating Process Plant Buildings for External Explosions and Fires.

Chapter 5 provides general guidance on locating buildings within the site withrelation to other facilities (CCPS, 1996, no 22)

Guidelines for Chemical Process Quantitative Risk Assessment and Guidelines for Hazard Evaluation Procedures provide additional guidance on conducting risk

assessments Risk assessment may be applied in many siting decisions (CCPS,

2000 and CCPS, 1992)

Inherently Safer Chemical Processes—A Life Cycle Approach discusses inherently

safer design (CCPS, 1996, no 23)

Layer of Protection Analysis: Simplified Process Risk Assessment describes layer of

protection analysis (CCPS, 2001)

Guidelines for Analyzing and Managing Security Vulnerabilities of Fixed Chemical Sites describes security measures and analysis techniques (CCPS, 2002) Guidelines for Fire Protection in Chemical, Petrochemical, and Hydrocarbon Process- ing Facilities describes fire protection measures that may be applied to the site

and the equipment on the site (CCPS, 2003, no.29)

1.4.2 Other References

Where appropriate, this book references pertinent American PetroleumInstitute (API) Practices, National Fire Protection Association (NFPA) Codes,and American Society of Mechanical Engineers (ASME) Codes Referencesare generally made to US codes and practices; recognizing that when the site

is located outside the United States, there may be non-US codes and tions that override the references in this book A complete list of all refer-enced industry practices, including applicable CCPS books, is included in theReferences at the end of this book

regula-6 Guidelines for Facility Siting and Layout

Management Overview

Example

In 1969, the site started to produce the pesticide SEVIN Methyl isocyanate(MIC), an intermediate chemical, was imported from another location Inthe late 1970s, the site added a MIC production unit [Originally] the sitewas located approximately 3–4 miles outside the city center At the time ofthe incident, the site employed 630 people The city had a population of900,000 people with a community of squatters situated immediately out-side of the site boundary Just after midnight there was an accidentalrelease of approximately 40 metric tons of MIC into the atmosphere Thou-sands of people lost their lives, hundreds of thousands were injured, andsignificant damage was done to livestock and crops The plant was located

2.1 Implications of Siting and Layout

Appropriate siting and layout establishes a foundation for a safe and securesite A site that is well laid out will have a lower risk level than a poorly laidout site The potential for toxic impacts, fire escalation, and explosiondamage will be lower The risk to personnel and the surrounding communitywill be reduced Additionally, maintenance will be easier and safer to per-form However, these benefits do not come without associated costs Sepa-ration distances translate to real estate that costs money Tradeoffs betweeninitial capital investment, life cycle costs, and risk reduction are inherent insiting and layout decisions

7

2

2.2 Management of Risks

Consideration of siting and layout is an important aspect of risk ment Managers must address several types of business risks, including therisks from costly potential incidents The approach in this book is to find asite location and layout that will minimize risk to site and community person-nel and property while maximizing the ease of safe operation and mainte-nance This approach may reduce the total life cycle cost The guidance inthis book is aimed at maximizing the use of inherently safer strategies in thedesign to build in safety and risk reduction

manage-Inherently safer design strategies may prevent initiation of an incident,reduce the potential for incident escalation, and limit the incident conse-quence before there are major impacts on people, property, or the environ-ment (CCPS, 1996, no 23) Appropriate siting and layout separates sources

of potential fire, explosion, or toxic incidents from adjacent areas that mightbecome involved in the incident or be harmed by its potential consequences.Thus, siting and layout not only provide for a fundamental aspect of riskmanagement but are also key components in inherently safer design.The many challenges associated with plant siting and layout are dis-cussed in this book Layers of safety are utilized to compensate for less thandesired spacing and to implement additional aspects of inherently saferdesign This use of layers of safety or layers of protection is a traditional riskmanagement approach and is illustrated in Figure 1-3 These layers includethe inherently safer strategies of preventing the incident, minimizing escala-tion, and minimizing impact The layers may include using a less hazardousprocess, separation distances, operator supervision, control systems,alarms, interlocks, physical protection devices, and emergency responsesystems Although safety protective systems are often necessary, they areless reliable and more costly to maintain than the protection afforded byinherently safer design strategies (CCPS, 2001)

2.3 Basis for Facility Siting and Layout

Building a new site or adding equipment to an existing one is often an ing, but daunting, proposition If it is done well, capital is well invested, goalsare met, and the future looks promising If it is done poorly, money may bewasted, goals unachieved, and the future could be unwittingly compromised

excit-8 Guidelines for Facility Siting and Layout

In designing and building a project, the difference between these two comes is greatly influenced by consideration of siting, layout, and otherinherently safer design concepts early in the project evolution If these fun-damental issues are addressed too late, costly changes may be required,opportunities for cost-effective protection may be unrecognized, and thenew site could actually increase company liability The importance of timelyconsideration of inherently safer principles is depicted in Figure 2-1.Application of inherently safer design concepts to the design and layoutcan identify the need for process modifications or alternative site arrange-ments The solution may cost more initially (more infrastructure, more land,longer piping runs, and greater unit spacing); however, life cycle costs will belower Some savings are realized through reduced losses due to potential fires,explosions, or toxic releases In addition there will be savings resulting fromlower costs for managing risk (fewer protection systems requiring mainte-nance, ease of maintenance, ease of operations, and lower insurance costs).

out-Figure 2-1 Safety in Project Development

It is helpful to follow a sequential process to site and lay out a new ject This process is illustrated in Figure 2-2 This book will discuss andfollow this sequential process.

pro-1 First a team should be assembled to determine what issues need to

be considered and what data to collect This may seem obvious andexperience shows that the effort spent in selecting a team with theright credentials for a specific project assures a more thoroughassessment of the sites under evaluation and will pay-off in the end.Environmental, population, and process risk considerations must bebalanced with each other and costs in the site selection process.Also, outside factors that may affect the project cost and scheduleshould be anticipated

2 Once the site is chosen, the various components of the plant can belocated with respect to each other Issues such as topography, winddirection, and process risk come into play Fitting a new expansionwithin an existing unit is often a challenge and may require additionalfire protection or other safeguards due to space limitation

10 Guidelines for Facility Siting and Layout

Figure 2-2 Guidelines Book Flowchart

3 Finally, the individual unit equipment can be laid out Equipmentspacing should maximize ease of operations and maintenancethereby minimizing operating and maintenance risks to personneland the surroundings This spacing will also aid in minimizing con-gestion, which will reduce potential explosion overpressures Sitesecurity should be considered Site layout and typical equipmentspacing guidelines are provided based on current industry practicesand standards.

2.4 Changing World

Societies increasingly demand higher standards for processing sites Thesestandards include cleaner effluents and greater assurances of a safe opera-tion The demands for higher standards will continue resulting in the benefits

of a new or modified site being weighed against the risks to the community.One must also be aware that attitudes to risk change with time Whatmay be acceptable to a neighboring community today may be undesirabletomorrow Periodic review of risk tolerability is necessary as the technologyadvances, the process changes, the site expands, the regulations change,and the surroundings outside the fence change Increased spacing providesbetter flexibility as future demands evolve

A damaging incident lowers the credibility of the engineering that wentinto building the plant It is worth investing a little more time and money upfront to proactively incorporate greater risk reduction measures into thedesign than current regulations, codes, and standards identify, to ensure thelong-term viability of the facility

Preparing for the Site Selection Process

There is never any substitute for good planning and preparation when taking

on any complex task Site selection is a very complex process fraught withmany unknowns and concerns that are difficult to resolve From a safety per-spective, choosing a site that is not adequately sized or where the impact onadjacent sensitive neighboring sites has not been determined may result inadditional prevention or mitigation measures being required These mea-sures generally include the need for expensive, maintenance-intensive, andattention-demanding protective systems to counter potential exposurerisks This additional expense may have been avoided by an alternate loca-tion or by a larger site Thinking ahead about potential issues of concern andidentifying the information you need to develop before the site selection pro-cess begins is a very cost effective effort

What are we trying to achieve in the preparation phase of the site tion process?

selec-Our objectives include the following:

• Identify, early on, issues associated with each site under ation that may become a concern later in design or operation;

consider-• Collect critical information necessary to make decisions regarding thelocation, size and layout of a site; and

• Ensure maximum opportunity to incorporate the principles of ently safer design and layout of a new or expanded site with minimalimpact on project cost and schedule

inher-This chapter provides guidance and discussion on a number of issues toconsider in preparing for the site selection process It is presented as a listaddressing the objectives above Guidance is provided on information to col-lect or develop and where to find the information Guidance is also provided

on how the collected information is likely to be used during the permitting,design, construction, and future operation of the site

The content is comprehensive and applicable worldwide Much of theinformation discussed will not necessarily be needed for all types of projects

13

3

The information obtained using these guidelines should be sufficient to allowfeasibility or scoping studies for budget estimates and to anticipate potentialmajor downstream impacts on a project.

This chapter deals with the following steps listed in sequence:

1 Describe the new site and planned uses for the site

2 Define the team of experts needed to assess potential sites

3 Decide on the site size (How much land area do I need?)

4 List information required to assess the location with respect toneighboring sites, e.g., preliminary hazard analysis

5 List information required prior to site surveys

6 Detail environmental considerations at pre-site selection stage

3.1 Project Description

A project description is needed to guide the selection teams This will vide the information that will be needed in evaluating a potential site or sites.This document should include as much information as is known and specifics

pro-on what is desired at the new site The following is a suggested cpro-ontent forthe project description:

• Project scope:

—What is the purpose of the new plant or facility?

—Who and where are key customers for the products?

—Who and where are the key suppliers for feed stocks?

—What is the planned level of staffing for operation and maintenance

of the site? Are specialized outsourced maintenance and/orinspection skills required?

—What are the primary considerations for the anticipated sitesincluding locations, contacts, potential consultants, security con-cerns, permit requirements, and climate conditions?

—Is a future expansion being considered? Should site selection ipate additional land for expansions or future facilities? Could thesame site and equipment be utilized for a new process involvingdifferent chemicals and reactions?

antic-• General site location information:

—Are qualified operations and maintenance staff available in theregion?

—Will the site be shared with another operation? If so, with whom?List other shared or owned operations, staff, and/or facilities onthe new site (office buildings, day care facilities, warehousing, stor-age facilities, utilities, security staff, maintenance staff, site man-agement staff, and emergency response staff and equipment).

—What specific infrastructure is desired at the potential sites (e.g.,are marine facilities required; is it intended that the site will pur-chase power or is power generation a consideration; utilities, rail,and roads)?

—Are there known security risks in the region (adversary ization)?

character-—What is the availability of external firefighting resources andmutual aid?

—Is there land surrounding the site to allow purchase of, or control

of, that land to provide a buffer zone?

—If the new plant is to be built on an existing site, what field data mayalready be available to minimize the data collection effort?

—In what language is the local workforce fluent?

—What languages are used in communication and design tation?

documen-—What standard system of units and measures should be used?

—What is the earthquake zone in the area?

—Is the area subject to hurricanes or typhoons or other severeweather conditions?

• Detailed description of the plant and processes:

—List raw materials used, and intermediates and products made,including any alternative raw materials, catalysts, or additives thatmay be considered

—Identify fundamental hazards of materials and products: e.g.,flammability and toxicity

—Tabulate production rates, expected inventory levels, and mum hazardous material inventory levels

maxi-—List known process technologies that will be employed Are etary technologies planned or under consideration?

propri-—Define the automation level that is envisioned Will the plant be fullyautomated versus manual? (This will affect spacing and layout.)

3 Preparing for the Site Selection Process 15

—Describe the means of feedstock and product transportation (truck,rail, ship, pipeline, by company owned means or contract) Listcargo sizes and frequencies of shipments in and out of the site

—List the design concepts employed in developing the process thatmay affect the layout and spacing of the site, i.e., enclosed loading

vs outside loading

—Identify the turnaround philosophy (shuts down once every two years,

or continued operation with individual process shutdowns as required)

—Identify the expected life of the plant (10 year, 20 year, or other)

—Identify the desired on-stream factor

—Identify requirements for waste disposal

• Points of special interest to include:

—Known process safety hazards associated with the process ing any past incidents from similar facilities

includ-—Regulatory issues associated with the chemicals

—Experience at other similar facilities with community concerns orproductivity issues (e.g., noise, odors, traffic issues, or high per-sonnel turnover)

—Special security or design measures required at the site due to thematerials used or produced (explosives, toxic agents, or precur-sors to either), or to the proprietary nature of the site

—Anticipated permitting concerns or environmental issues related tothe site construction and/or operation

—Community concerns regarding potential site development or expansion

—Activities at neighboring facilities that may impact on the new facility

—Public infrastructure required such as an interstate interchange or

a railway bridge overpass

—Potential environmental liability concerns associated with sion to existing or with former industrial sites

expan-The project description sets the stage for what the site survey team will

be looking for and what level of detail will be needed to select a site

3.2 Assembling a Site Selection Team

Assemble a team to organize, collect and analyze data, develop information,and conduct site surveys in order to form recommendations regarding theselection of potential sites The team make-up should provide the expertise

needed to meet the unique requirements for a specific type of plant as well

as a particular site location The following is the type of expertise that may berequired for a specific site selection task:

• Knowledge of the types of plant and processes under considerationfor the new site

• Knowledge of site layout

• Knowledge of the specific areas where the new site is planned orbeing considered

• Familiarity with the local language

• Familiarity with the local regulations

• Specialists (engineer, scientist, or other person with the appropriateexpertise):

—Marine design specialist who can evaluate potential sites along thecoast for deep water ports such as for Very Large Cargo Carrier(VLCC) crude tanker access

—Environmental specialist who can evaluate wastewater, groundwater, and air issues

—Civil specialist to evaluate sites with complex topography and soilconditions

—Process safety or risk specialist who can assist with process safetyissues, on-site risk concerns, and off-site risk concerns

—Security specialist who can assist in physical security ations

consider-This expertise may be from in-house resources or a third party tant firm The following example demonstrates the team selection process

consul-Example

You are building a process site in an area where you have limited or no ations at present Your team make-up includes a project engineer withexperience in the process operations, process safety engineer, securityexpert, and a local manager with several years experience in the same statebut not with new construction No one on the team has any experience withlocal building officials or new construction regulations in the region wherethe site is being evaluated Your team needs local contacts and expertise.Find someone within the company or hire a consultant that can help collectand interpret the local regulations, and assist in preparing informationrequired for permitting This expertise concerning the area, local govern-

oper-3 Preparing for the Site Selection Process 17

ment, concerns that may exist regarding other industrial sites, and possiblyknowledge of useful contacts can save you much time and assure a fasterand more complete assessment of the site.

The new process site will require access to marine facilities for bothraw material import and product transfer The new site will therefore be verydependent on access to reliable marine facilities that meet the capacityrequirement for the new site Your company has extensive marine facilityoperating experience; however, there is no in-house expertise in marinefacility design or knowledge of the marine facilities in the area of the pro-posed site Utilize a marine engineering specialist to survey and evaluateexisting marine facilities for the team

Lesson

Selecting a site involves consideration and analysis in many specializedareas Assure that the site selection team has the appropriate expertise toevaluate the specialized needs required for that site

Tasks like those described in the example may require hiring consultantswith specialized expertise Two things to consider when identifying outsideresources:

• It is important to set aside adequate time to evaluate contractorand/or consultant capabilities to assure your selection is a good fit forthe project

• It is equally important to prepare a project description in sufficient detail

to assure the consultant understands the basis for his involvement andexactly what his mission is in support of the site selection process.This may seem obvious, but experience shows that the effort spent inselecting a team with the right credentials for a specific project assures a morethorough assessment of the sites under evaluation and will pay off in the end.The site selection team should work to a schedule that allows enough time

to collect all data needed for the selection analysis However, it is often notpossible to gather all the information desired in the time available at the site

In this case, the team should develop a plan for acquiring the remaining data

at a later date This follow-up plan needs to be considered in setting the timeschedule for the overall site selection process In the case where a new plant

or facility is being located within an existing site, it may be beneficial to assign

a local company representative to forward information obtained at a laterdate to the site selection team, or possibly have a local person on the team

3.3 Preliminary Site Size Determination

Once the project description is written, a preliminary estimate can be madefor the size of the site to accommodate the facilities desired Process plotsizes may be based on similar existing process sites However, when basing

a new design on an existing facility, one must consider the existing comings in order to prevent repeating old mistakes Many existing plants donot have a layout to make them inherently safer Preliminary plot sizes can

short-be estimated by the process licensor, engineering contractors, or in-houseengineering specialists that have experience in building similar processes

An engineering and/or construction contractor can also estimate plotsizes for other types of facilities, e.g., parking lots, buildings, warehouses,storage tanks, and utility areas, if the task cannot be done in-house Guide-lines in Chapter 5 offer information regarding the typical spacing betweenfacilities and property lines

As an example, if your site needs to contain one process area, offices,and utilities, then a preliminary site size determination may result in a plotarea that looks like Figure 3-1

3 Preparing for the Site Selection Process 19

Figure 3-1 Preliminary Plot Area (1 ft equals 0.348 m; 1 acre equals 4074 m 2 or 43,560 ft 2 )

This preliminary estimate provides an idea of the land area required tofit all the facilities required on the site Greater separation distances may beemployed to provide security clearances either inside or outside of the siteperimeter or to limit access to critical site areas.

3.4 Preliminary Hazard Screening

Identify and consider all potential exposures that may affect the location of anew plant during the site selection phase As stated in the last section, thesepotential exposures may be to the new plant from an adjacent plant or fromthe new plant to neighboring areas The latter may include potential hazards

to community areas, other industrial sites, and/or environmentally sensitiveareas Make an effort to ensure the location and land area chosen for the newsite is adequate to anticipate permitting, design, and layout concerns thatcan arise later in the project

A useful process for identifying the potential exposures to a new plantfrom an adjacent hazard, or from the new plant to the surrounding area, is apreliminary hazard screening Early in the site selection process, it is notnecessary to conduct a detailed, costly risk assessment A hazard screeninganalysis will provide the information needed to determine if the site providesadequate separation distance from neighboring areas The preliminaryhazard screening analysis is based on the process data developed to-dateand the preliminary plot area

In the preliminary hazard screening, focus on those events with thepotential for off-site consequences The consequence analysis will identifyboth on-site impacts and off-site impacts The on-site events tend to drivethe spacing within units and plants The off-site events tend to drive overalllayout and site selection With the preliminary hazard screening as a basis,the results will address the question at hand, which is whether the prelimi-nary plot area is appropriately sized

This preliminary hazard screening could show that the preliminary plotarea was a good estimate and only minor modifications are needed How-ever, the preliminary hazard screening could also show that the impact area

is larger than desired in which case increasing the plot area to add buffer tance could be an appropriate mitigation measure

dis-A toxic release, fire, or explosion may also be due to sabotage or a rorist action The impact of these events should be considered in the prelimi-nary hazard analysis and a security vulnerability analysis

ter-3.4.1 Preliminary Hazard Analysis

A preliminary hazard analysis is used to identify the main concerns associatedwith a specific type of plant and does not require detailed design drawings(CCPS, 1992) A preliminary hazard analysis is usually done during the earlystage of a project when the plant location and layout is being considered andprior to development of any process design details The information used in theanalysis is in the project description discussed in Section 3.1 The typical haz-ards of concern include: toxic releases and flammable releases leading to fires

or explosions with potential consequences on people, property, and the ment These typical hazards may also address potential security threat scenar-ios involving explosions or release of toxic materials Typical team compositionand analysis methods for preliminary hazard analyses are described in the

environ-CCPS Guidelines for Hazard Evaluation Procedures (environ-CCPS, 1992).

The next step, then, is to identify the potential consequences These sequences include potential toxic exposures, fires, or explosions

con-Methodologies for estimating the potential consequence of both toxicand flammable vapor releases can be found in a variety of resources The

CCPS book, Guidelines for Consequence Analysis of Chemical Releases,

pro-vides information regarding how to evaluate the consequences from varioushazards including explosions, flash fires, and toxic releases (CCPS, 1999).Computer-based models are available that estimate vapor cloud dispersion,heat radiation from fires, overpressure from explosions, and toxic concen-tration downwind of toxic releases Many simple models overestimate theconsequence; however, these models provide adequate consequence esti-mates for the site selection process

A preliminary hazard analysis may also identify potential environmentalconcerns to consider when choosing a plant site and deciding on the amount

of land area required for the plant facilities Environmental control issuesare discussed later in this chapter

In some locations, specific regulatory requirements may govern levels

of risk, as opposed to hazard, on the site and its surroundings In thesecases, not only consequences but also likelihood must be evaluated

3.4.2 Toxic Release Scenarios

Toxic releases, whether originally liquid or vapor phase, usually have theirmost significant impact as a vapor cloud The extent of the hazard depends onthe vapor properties and conditions at the time of the release Large releaseincidents for materials like anhydrous ammonia or chlorine can be lethal forgreat distances downwind, particularly if initially released as a liquid

3 Preparing for the Site Selection Process 21

Established design and operation guidelines help minimize the hazard oflarge releases (for example, safe handling and transport) However, the siteselection team may not know at this point in time what safeguards will bebuilt into the plant to compensate for these toxic hazards So what do youneed to consider in terms of siting when evaluating the hazards associatedwith toxic releases?

Chemical and petroleum industry accident data show that most releasesinvolve equipment failures and occur from:

• Pump seal leaks

• Piping or hose leaks

• Piping or hose failures

• Sample points, vents, drains, plugs left open or broken off

During the preliminary hazard analysis, consider those more severeincidents that may pose off-site exposure concerns to neighboring sites Atthis stage in the screening analysis, a range of scenarios can be selectedfrom the above list to provide insight on the adequacy of the plot area or thesize of buffer zone required These potential exposures may affect the per-mitting process and result in future costly prevention or mitigation systems

to compensate for separation distance

The following examples illustrate how the potential consequences ofincidents are used to determine site land requirements

Site B

A new site uses pressurized ammonia gas for making fertilizer The site islocated in an area where a housing community is located 1968 feet (600 m)away A credible incident identified during the preliminary hazard analysis is

a vent line failure on the charge line to the process The company uses

Emer-gency Response Planning Guideline (ERPG) 3 as a screening criterion TheERPG 3 value for ammonia is used as a toxic endpoint exposure maximum atthe property boundary for the site The potential consequence estimate forthe vent line release showed that the ERPG 3 level goes as far as 3300 feet(1000 m) downwind based on total loss of the content of the tank when atnormal operating level Risk reduction options are considered includingreduction of on-site inventory of ammonia and storage in smaller vessels.These options however are not favorable from a processing viewpoint.

As a result of the consequence analyses, the owners of both sites maywant to consider the following:

1 Can an inherently safer chemical (e.g., using sodium hypochloriteinstead of chlorine in the first example) be used instead? If the originalchemical is the only choice, can smaller containers be used to store it?Can the operation take place inside a containment area (buildingenclosure) where releases can be mitigated more effectively?

2 Can good separation be achieved if the operation is located withinthe site at the furthest point from the neighboring sites?

3 Can additional land area be acquired to provide a greater buffer areabetween the facility and the neighboring sites?

4 Consider future land use around the new site Will there be furtherdevelopment around the site that will cause future off-site exposureconcerns?

5 Can a separate site be considered which is more remote to sensitiveneighboring sites?

Lesson

The release of toxic chemicals may have impacts on people and the ronment beyond the fence line A preliminary hazard analysis and conse-quence analysis may be used to determine the potential impact, site thematerial handling appropriately, and prompt the consideration of hazardreduction measures There may be a number of possible reduction mea-sures for a hazard Consider inherently safer options first Evaluate theeffectiveness and feasibility of all options

envi-3.4.3 Fire Scenarios

Fire is an example of a credible incident resulting in off-site exposures fromhigh radiant heat (thermal flux) levels Scenarios for consideration mayinclude radiant heat from:

3 Preparing for the Site Selection Process 23

• A process unit fire.

• A truck or rail car loading rack fire resulting from hose failure

• A pool fire in a dike or impoundment area resulting from the overflow

of a storage tank

• The flare during maximum flare system loads due to a power failure,loss of cooling water, or an emergency shutdown

• A full surface area fire in flammable or combustible storage tanks

A potential consequence estimate for a heat radiation (thermal flux)exposure to a neighboring facility or community area can be estimatedquickly using typical process conditions and equipment sizes Guidelines inthis book include spacing distances between equipment and facilities fromproperty lines These spacing guidelines are generally sufficient to minimizeheat radiation exposures from tanks and process area fires

With regard to exposures to other facilities on a shared site, this bookcontains typical spacing and layout that will provide separation to minimizeexposure to the plant from most typical industrial site hazards However,consider severe hazard exposures identified in the preliminary hazard analy-sis to determine if additional separation is required Consider the potentialfor business interruption as well as damage to equipment and exposures topersonnel in the determination of additional separation needs

A methodology for estimating pool, flash, and jet fire heat radiation

levels is included in the CCPS Guidelines for Consequence Analysis of cal Releases (CCPS, 1999) Criteria for safe heat radiation exposure levels

Chemi-that can be used as criteria to estimate a safe distance to adjacent plants orfacilities may be found in API RP 521

3.4.4 Explosion Scenarios

Damage from an explosion is caused by the resulting blast wave, thermalradiation, flying debris, or toxic release There are many different types ofexplosions including a vessel rupture explosion and a vapor cloud explosion

(VCE) Explosion phenomena are discussed in the CCPS Guidelines for uating the Characteristics of Vapor Cloud Explosions, Flash Fires, and BLEVEs (CCPS, 1994) and Understanding Explosions (CCPS, 2003, no 30).

Eval-Those facilities handling flammable vapors and reactive chemicals mustconsider the impact of potential explosions on the site and surrounding com-munity Additionally, exposures from surrounding facilities impacting the newsite should be considered VCE overpressures may be influenced by the size ofthe vapor cloud and aspects of plant layout such as the openness of the area

and amount of equipment within the cloud Explosion hazards may be gated by redesigning the process chemistry, relocating exposures, designingblast resistant structures, and providing greater separation distances.

miti-An explosion may also be due to sabotage or a terrorist action Theimpact on the surrounding community or the economic system should beconsidered in the siting and layout

For combustible solids handling operations it is common practice toprovide explosion venting on equipment operating with potentially ignitableatmospheres Since the fireball from these vents can extend large distances,horizontally arranged vents should be arranged to minimize exposure toadjacent areas In some cases it may be necessary to move equipment, such

as large silos, to a remote corner of the operational block to make explosionventing a viable option for explosion protection Another option may be tolocate equipment outdoors if explosion venting is not feasible

Typical explosion scenarios may include (CCPS, 1994):

• A physical explosion such as a vessel rupture or a BLEVE

• A chemical explosion caused by a decomposition or rapid exothermicreaction of reactive chemicals

• A deflagration or detonation of a flammable vapor cloud

Example

A new $100 MM specialty chemicals plant is being considered on a sharedsite with another chemical company that produces ethylene The existingchemical plant has ethylene cracking and separation facilities The separa-tion distance between the new plant site and the existing ethylene facilityproperty line is 250 feet (76 m) A preliminary hazard analysis of the newplant identifies a potential for incidents involving fires due to release of flam-mable liquids and tank fires From an insurance perspective, the physicaldamage loss for the new plant from these fires is estimated to be $10 MM.The exposure hazard to the new plant from the ethylene cracking facility

is also considered in determining the amount of insurance required for thenew plant The potential hazard and consequence associated with the ethyl-ene facility is identified as an ethylene release and subsequent vapor cloudexplosion The consequence of the explosion is destruction of the new spe-cialty chemicals plant The loss is determined to be the cost of a replacementplant The additional cost of the premium may provide justification to allowmore separation distance or consideration of an alternate site

3 Preparing for the Site Selection Process 25

Hazards may be posed either from a site onto its neighbors or from theneighbors onto the site In some cases, cost benefit analysis may show thatthe benefit of greater separation distances to minimize the hazard is worththe increased real estate cost

3.4.5 Refinement of Preliminary Plot Area

With the potential consequence estimates completed, preliminary hazardsfor off-site toxic, fire, and explosion consequences may be compiled Withthis data, the preliminary plot area size can be evaluated The data may showthat the hazards meet the regulatory or corporate guidelines and therefore,the preliminary plot area is appropriate However, the hazards could be out-side of the guidelines and measures to reduce the hazard may be warranted.These measures could include reconsidering inherently safer strategies:eliminating the problem by substituting chemicals, mitigating the potentialconsequences by reducing storage quantities or changing storage location,

or mitigating the impact on the surrounding community by, adding a bufferzone or choosing a different site entirely When the hazards impact sensitivepopulations, the latter is a very appropriate solution

3.5 Guidelines for the Survey and Data Collection Effort

To make this book appropriate for a broad range of projects, each sectionincludes a variety of related topics that may or may not be applicable to aspecific project The intent is to provide enough information to permit a goodsurvey and data collection effort for any type of new site or plant anticipated.The reader will need to pick and choose those topics that apply to the specificproject of interest In the end, the site survey effort should produce sufficientinformation to permit development of a scoping level study based on a spe-cific site for budget estimate

The site selection team can develop a project-specific checklist for datacollection during the site survey The checklist is used during the site survey

as a guideline to assure that data is complete and organized The Site SurveyData Requirement List in Appendix B and discussed further in Chapter 4 canprovide the foundation for developing a project-specific checklist

The project-specific checklist should include the purpose of the project,

a process description, and a design philosophy as it relates to future sions and reliability of operation This information will be available from theproject description discussed in Section 3.1

expan-3.5.1 Codes, Standards, and Local Requirements

The site selection and data collection effort will include acquiring copies ofcodes, standards, and local requirements that pertain to various equipmentand design criteria Codes and standards must be considered on the federal,state, and local level The federal codes and standards may not be the moststringent Of specific interest are those codes and standards for pressurevessels, tanks, boilers and related equipment, piping, electrical design,buildings (including architectural design), storage, plumbing and sanitaryfacilities, structural steel, reinforced concrete, fire protection, and safety.Where engineering is being performed in a country other than where thesite will be constructed, there may be different codes and standards It may behelpful to make a list that cross-references the applicable local codes andstandards between the countries The list can then be used to identify the dif-ferences between the codes and standards and any associated impact on cost

of compliance Where there are differences in regulations, or if regulations donot exist for a specific topic, determine what regulations are acceptable foruse in place of corresponding regulations If not, which regulations must beused? Is the local code more stringent? What is the impact on project qualityand cost? Is it possible to get a variance? How does one apply for a variance?Other issues to consider include:

• Qualification requirements for specific crafts For example, welders

in the United States must qualify based on specific codes Can ers at the site location be qualified for the relevant codes?

weld-• Local restrictions on import of foreign construction materials such as

a steel design code that may not permit the use of foreign steel

• Specific local requirements regarding inspections, quality assurance,hardness, and corrosion allowance

• Specific local codes or standards regarding spacing of equipment anddistance to property lines

• Fire protection requirements that are greater or more stringent thanin-house company or local codes and standards

In addition to codes and standards, there may be local regulations, tocols, and procedures required to assure timely approvals and acceptance

pro-at various stages of the design, construction, and operpro-ation of a new site orplant Ask the following questions regarding local requirements:

• Is there a requirement for approval by a local professional engineerfor buildings, structures, foundations, and/or other designs? What isthe approval schedule and specifics regarding the information thatneeds to be reviewed?

3 Preparing for the Site Selection Process 27

• Is there a requirement for governmental approval of drawings and fications, risk assessment, inspection of construction site activities,and/or inspection of equipment before startup approval is granted?

speci-• Are there zoning regulations that limit the use of property? This mayhave an impact on future intentions for the site For example, arethere limitations on temporary use of the site for stock piling wastematerial during the construction of the new site? Is part of the site notusable because of future local government plans to expand commu-nity housing in the surrounding area?

• Are there limitations regarding the maximum height of structuressuch as buildings, flares, and towers? Are there local requirementsfor limiting the visibility of the site for community housing and/or thesite property line? Are there limitations regarding the visibility of flareluminescence or nighttime site lighting?

• What are the aircraft regulations regarding height limitations of tures and/or provision of warning lights at the site? Is the site within

struc-an airport glide path?

• Are there specific language requirements that need to be consideredregarding the communication of documents and information to vari-ous local authorities and inspectors?

• Are there other quantitative or qualitative risk standards that willhave to be met? Conducting an abbreviated risk assessment may beprudent to assure the ultimate acceptability of the site

• Do local regulations require any special security measures for ings, roadways, and fencing?

build-• Are there building codes that address earthquakes, fires, or canes or typhoons?

hurri-3.5.2 Maps and Surveys

Acquire maps and surveys of potential sites prior to visiting the sites ing the following:

includ-• A large, overall map of the surrounding area showing adjacent towns,highways, railroads, airports, and harbors

• Detailed maps of the site area, including a topographical map with 1

to 2 foot (0.3 to 0.6 m) contours to provide good definition

• If available, maps showing the location of streams, ponds, marshes,steep slopes, buildings, or other structures on-site, and any present

or future right-of-way requirements, underground sewers, pipelines,and old foundations.

• Survey information that identifies foundations, monuments, marks, and elevations related to standard base points and land eleva-tions, and related to marine elevations if pertinent

bench-• Aerial photographs of the entire site showing the following:

—Surrounding community areas, town centers, malls and shoppingcenters

—Sensitive populations such as schools, hospitals, day care facilities

—Nearby industrial sites and transportation centers

—Farms and agricultural centers

—Environmentally sensitive areas

—Location of services that may be subject to interference from a newsite or may interfere with the communication or operation of yoursite These may include radio, television, or microwave communi-cation equipment

3.6 Environmental Control Issues

Once sites to be evaluated are chosen, acquire information concerning ronmental regulations before site surveys are actually conducted This infor-mation can provide the survey team with guidance on what to look for andwhat additional data to collect while at the site(s) This section outlines thespecific information of interest prior to the site selection process

envi-As discussed previously, a preliminary hazard analysis may also identifypotential environmental concerns to consider when choosing a site and theland area required If there are environmentally sensitive sites on the pro-posed plot or in the area around the site, it may be prudent to relocate the site

to avoid costly environmental controls and permitting difficulties or increasethe size of the site to permit more rigorous environmental control facilities

Example

A site is under consideration at a location where there is a known aquiferbeneath the site An environmental survey identified the need for additionalwastewater treatment land area to accommodate more extensive treatingand retention facilities The topography is also an issue The area is very hilly

3 Preparing for the Site Selection Process 29

and will require costly civil work to control run off and retention of site water Based on this information, the site area must be expanded to accom-modate the additional wastewater treating facilities and the additional landarea required to allow good civil engineering design to prevent flooding.This same site has been found to contain Native American burialgrounds Although located on the purchased land, the burial grounds must

rain-be secured with a buffer area around them as required by local regulation.Since the burial grounds cannot be built upon, additional land area isrequired to accommodate the facilities needed for the new site

All these issues may not have been identified if the siting team had notincluded an environmental specialist that investigated local regulationsregarding the burial grounds and aquifer

Lesson

This example may seem overly simplified; however, there have been caseswhere projects were never built due to unanticipated limitations on how aselected site could be used

Basic information is required at the site selection stage that may weighinto the decision to choose one site over another The first step is to obtaincopies of the federal, state, and local regulations Determine if there is arequirement to have environmental system design plans approved byauthorities Determine if permits are required to operate the environmentalsystems and what the requirements are for acquiring a permit Identifyagencies that enforce the regulations The enforcement agency can often behelpful in providing clarification of various requirements in the regulation.Acquire regulations on:

• Air quality control

• Wastewater volume limitations and quality of industrial discharge

• Solid waste disposal

• Noise level limitations

• Flood levels

• Luminosity levels

3.6.1 Air Quality Control

In the United States, the Code of Federal Regulations (CFR Title 40) and theEnvironmental Protection Agency publications are resources concerning air

quality regulations Local consultants may be necessary to acquire codesand regulations and provide interpretation of the requirements in foreignlocations In foreign locations, it is also useful to investigate if there are anynational technical groups with an interest in air quality control, similar to APIfor example, that may publish helpful data.

The information that is needed during the planning stage of the siteselection process regarding air quality control regulations follows:

• Determine what materials are regulated regarding discharge to theatmosphere, specifically, the maximum discharge rates and quantities.Following is a list of materials that are regulated in the United States:

—Particulate matter

—Hydrocarbon vapors

—Carbon monoxide (CO)

—Nitrogen oxides (NOX)

—Sulfur oxides (SOX)

3 Preparing for the Site Selection Process 31

• Do the regulations specifying analytical methods to be used in mining the level of specific impurities in the effluent include hydrocar-bon or toxic materials content? This is an operating cost issue.

deter-3.6.3 Solid Waste Disposal

In the United States, solid waste disposal is regulated by the Resource servation and Recovery Act (RCRA) Through RCRA, EPA has the framework

Con-to develop regulaCon-tory programs Con-to manage solid waste, hazardous waste,and underground storage tanks RCRA includes a system for controlling haz-ardous waste from its point of generation to its final disposal, encouragesstates to develop comprehensive waste management plans, and regulatescertain underground storage tanks This Act also establishes performancestandards for new tanks and requires leak detection, prevention, and correc-tive action at underground storage tank sites

Clearly understanding the implications of RCRA or other applicablewaste disposal regulations is important to site planning Solid waste dis-posal handling needs may require additional facilities at one site comparedwith trucking only to an existing disposal facility at another site

3.6.4 Noise Control

Consideration of noise regulations at this stage is focused on the communitysound level limits that may be exceeded due to noise from the site as well asnoise due to increased truck traffic associated with the new site Acquireexisting and pending specific regulations and ordinances to determine ifthere are any community noise level limitations

3.6.5 Flood Levels

Many states and local areas have zoning restrictions designed to minimizepotential damage from flooding These regulations may limit the ability toconstruct a facility in a flood prone area or may restrict the type of equip-ment installed at certain elevations

3.6.6 Luminosity Levels

Light levels are also regulated by many states and localities This may impactthe size, height, and design of flare selected for a site