Rt2d k100 00 Spill Containment

Ras Tanura Integrated Project (RTIP)KBR Project No. A554SPILL CONTAINMENT GUIDELINES

Document No: RT2D-K100-00Revision: 2Issue Purpose: IFD

SUMMARY OF DOCUMENT REVISIONSRev.No.

DateRevised

SectionRevised

0

30-May-08

1

27-July-09

4.1.1, 4.1.1.3,4.1.2.4, 4.1.2.6,4.1.3, 4.1.3.2,4.1.3.3, 4.1.4,4.1.4.1, 4.1.4.2,4.1.4.3, 4.1.4.4,4.1.4.5, 4.1.4.6,4.1.4.7, 4.1.4.8,4.2.1, 4.2.1.2,4.2.1.4, 4.3.6 and4.3.6.7

2

8-Oct-10

General

Revision DescriptionIssued for Design

3.4.1, 4.1.2.9,4.1.3.6, 4.2.1.5,4.2.3.5, 4.3.1.3,4.3.4.1, 4.3.4.5,4.3.4.6, 4.3.4.7,4.3.5.1, 4.3.6.2.2,5, 5.1, 5.1.1,5.1.1.3, 5.1.2,5.1.2.1, 5.1.2.2,5.1.2.3, 5.1.2.4,5.1.2.5, 5.1.2.6,5.1.3, 5.1.3.1,5.1.3.2, 5.1.3.3,5.1.3.4, 5.1.4,5.1.4.1.1, 5.2,5.2.1, 5.2.2,5.2.3, 5.3, 5.3.1,5.3.2

Revised sections to overlay.

Issued per A554-RFV-PRG-649Issued for FEED and EPC ContractorsRevised sections to overlay.

Contains Confidential information of Both Dow and Saudi AramcoPage 2 of 7



PREFACEThis standard or specification is a revision or an overlay to a DOW EMETL, LPP,Engineering Standard, or a Saudi Aramco Materials System Specification, for the scopeof the Ras Tanura Integrated Project (RTIP), unless specifically defined as a Newdocument. A RTIP specification consists of a revision or an overlay and the DOWdocument with the same name. An overlay establishes if there are any required changesto the DOW document and specifically defines the changes. If the DOW document is tobe used without any changes the overlay will state there are no changes required. If thedocument is a new RTIP document, with no reference to a DOW standard, the overlaywill state it.The RTIP Specification Index identifies which RTIP documents are new and the onesthat relate to documents that are unchanged, changed, or deleted.All references to DOW procedures, specifications and standards are to be defined asreferences to RTIP procedures, specifications and standards unless specifically statedotherwise in the overlay.All references to DOW organizations are to be defined as the RTIP Management Team.Interpret the following as specified: Revise A specific revision to a (EMETL or LPP) paragraph or sentence as noted inthis specification. Add Continuation of a (EMETL or LPP) paragraph with an overlay requirement. Substitute Replace the (EMETL or LPP) paragraph in entirety by the overlayrequirement. New New paragraph number in the overlay with no corresponding DOWparagraph. Delete paragraph is deleted by the overlay.REVISIONThis overlay is a revision to Dows Engineering Specification G2D-K100-00, SpillContainment Guidelines 11 Sep 2006.The following sections and paragraph numbers match that of the Dow document of thesame name unless noted as New.ATTACHMENTG2D-K100-00 Spill Containment Guidelines



1.


GENERAL1.1 (Revise) Replace the word Dow with Owner. Replace Electronic Most EffectiveTechnology Library (EMETL) with RTIP Library.1.2 (Revise) Replace G2Z-0001-01 with RT2Z-0001-01

2.

DEFINITIONS2.24 WATERWAY- (Substitute) All plant drainage or water transportation features, notdirected to an impoundment or treatment system capable of handling a release ofprocess fluid in a credible scenario. Examples of waterways include canals, rivers,drainage ditches, etc.

3.

GENERAL REQUIRMENTS3.1

General3.1.1 (Revise) Delete, and modifications to existing facilities3.2.1 (Revise) Delete, in business-specific level 2 MET

3.4 Codes and References3.4.1 (Revise) Replace Dow with RTIP3.4.3 (Revise) RTIP Civil Discipline Level 1 MET:

RT2D-2700-00

Drainage Design Aid

RT2G-3310-05

TPER Control Joint for Slabs

RT2G-3315-42

Partially Solid Grating for Control of Flames Spread

G2Q-K100-10

Containment Structures Inspection Checklist

RT2S-3001-01

Concrete Specification

RT2Z-0001-01

Civil Engineering Design Criteria

3.4.4 (Revise) Change Dow to Owner

4.

DESIGN AND INSTALLATION PRACTICES4.1.1

General

4.1.1.3 (Substitute) Flows from process equipment, such as seal flushes and drains,should be collected and transported in an above grade closed pipe system, rather thanbeing allowed to be discharged directly onto process areas. Underground pipes forconveying potentially contaminated materials shall not be used unless approved by the




Owner. Pipes placed in trenches shall be avoided whenever possible due to high cost indesign, construction and difficulty with cleaning and maintenance activities.4.1.2

Trenches

4.1.2.2 (Substitute) Trenches in plants or process areas where flammable liquids arepresent require special details for grating to prevent propagation of flaming liquidsthrough the trench system. See loss Prevention Principle 2.4 and RT2G-3315-42 forgrating details.4.1.2.4 (Revise) Replace 0.5% with 0.25%.4.1.2.6 (Revise) Replace Level 1 MET with RTIP Library4.1.2.9 (Revise) Delete third bullet listing. Replace G2D-2700-00 with RT2D-2700-00

4.1.3

Sumps and Impoundments

4.1.3.2 (Revise) Delete and buried pipe from first sentence.4.1.3.3 (Delete)4.1.3.6 (Revise) Replace Level 1 MET with RTIP4.1.4 Underground Drain systems4.1.4.1 (Replace) Underground pipes for conveying potentially contaminated materialsshall not be used unless approved by the Owner. Pipes placed in trenches shall beavoided whenever possible due to high cost in design, construction and difficulty withcleaning and maintenance activities.4.1.4.2 (Delete)4.1.4.3 (Delete)4.1.4.4 (Delete)4.1.4.5 (Delete)4.1.4.6 (Delete)4.1.4.7 (Delete)4.1.4.8 (Delete)

4.2.1 General4.2.1.2 (Revise) Replace Dow Engineering with RTIP4.2.1.4 (Delete)4.2.1.5 (Revise) Delete For Germany slopes for environmental concrete slabs andfloors must be 2% according to guideline DAfStb.4.2.2 Pavement Design




4.2.2.1 (Revise) Replace second sentence with: RTIP Civil Engineering SpecificationRT2S-3001-01 has been developed to satisfy these requirements.4.2.3.5 (Revise) Replace G2G-3310-05 with RT2G-3310-054.3.1.1 (Delete)4.3.1.3 Table 4.1 (Revise) Delete 4th row of table Below ground pipes and vessels4.3.2.2 (Substitute) Concrete shall be used for all dikes and impounding basins.4.3.2.3 (Delete)4.3.2.4 (Delete)4.3.3 Drainage from Dikes & Containment Areas4.3.3.4 (Delete)4.3.4 Storage Tanks and Process Equipment4.3.4.1 (Substitute) The minimum volume capacity of dike/bunded areas shall be inaccordance with RT-LPP-7.54.3.4.1 Figure 2 (Revise) Replace Volume Criteria: with Volume Requirementsas per RT-LPP-7.54.3.4.2 (Delete)4.3.4.5 (Revise) Replace G2D-K120-00 with RT2D-K120-004.3.4.6 (New) All diked/bunded areas designed for secondary containment ofhazardous material storage tanks shall be reinforced concrete and shall beprovided with an external, impervious, HDPE liner with minimum thickness of1.5mm (60 mils).4.3.4.7 (New) Leak detection is required for single bottom storage tankscontaining hazardous or corrosive chemicals. For tanks supported on a solidconcrete foundation the leak detection system shall be in accordance to A554-KPRG-CV-SPC-C30-003. For tanks supported on sand by a concrete ringwallfoundation the leak detection system shall be in accordance to RT2G-3340-80 andRT2G-3340-82.4.3.5 Loading and Unloading Stations4.3.5.1 (Substitute) The minimum volume of secondary containment for truck andrailcar loading/unloading stations shall be in accordance with RT-LPP-8.1.4.3.6 Oil Filled Transformers and Electrical Equipment4.3.6.2.2 (Revise) Replace second bullet a 24-hour 100 year rainstorm with a75mm rainstorm height.4.3.6.7 (Revise) Replace G2G-K100-02 with RT2D-K100-024.4.4 (Revise) Replace Project Steering Team with Owner.4.3.4.2 (Delete)



5.


MATERIALS OF CONSTRUCTION AND PRODUCTS

5.1 CONCRETE5.1.1 General5.1.1.3 (Revise) Replace Global with RTIP and G2S-3001-01 with RT2S-300101.5.1.2 Mix Design5.1.2.1 (Substitute) All reinforced concrete shall be in accordance with RT2S-300101, Concrete Specification.5.1.2.2 (Delete)5.1.2.3 (Delete)5.1.2.4 (Delete)5.1.2.5 (Delete)5.1.2.6 (Delete)5.1.3 Reinforcement Requirements & Placement5.1.3.1 (Substitute) All reinforcement requirements and placement shall be inaccordance with RT2S-3001-01, Concrete Specification.5.1.3.2 (Delete)5.1.3.3 (Delete)5.1.3.4 (Delete)5.1.4 Waterstops5.1.4.1.1 (Revise) Replace G2G-3310-05 with RT2G-3310-055.2 POLYMER CONCRETE5.2.1 (Delete)5.2.2 (Delete)5.2.3 (Delete)5.3 LATEX MODIFIED CONCRETE5.3.1 (Delete)5.3.2 (Delete)


THE DOW CHEMICAL COMPANYCIVIL/ARCHITECTURALGLOBALiii

DESIGN AIDG2D-K100-0011-SEP-2006Page 1 of 32

SPILL CONTAINMENT GUIDELINES

TABLE OF CONTENTS1. General2. Definitions3. General Requirements3.1. General3.2. Materials of Construction3.3. QA/QC3.4. Codes & References4. Design & Installation4.1. Drainage From Process Areas4.1.1. General4.1.2. Trenches4.1.3. Sumps and Impoundments4.1.4. Underground Drain Systems4.2. Process Area Pavement4.2.1. General4.2.2. Pavement Design4.2.3. Joints4.3. Secondary containment4.3.1. General4.3.2. Dikes & Containment4.3.3. Drainage From Dikes & Containment4.3.4. Storage Tanks and Process Equipment4.3.5. Loading and Unloading Stations4.3.6. Oil-filled Transformers and Electrical Equipment4.4. Leak Detection Systems4.5. Foundations4.5.1. General4.5.2. Above-Ground Storage Tanks5. Materials of Construction & Products5.1. Concrete5.1.1. General5.1.2. Mix Design5.1.3. Reinforcement Requirements & Placement5.1.4. Waterstops5.1.5. Concrete Curing5.2. Polymer Concrete5.3. Latex Modified Concrete5.4. Coatings & Liners5.5. Sealants5.6. Geomembranes6. Inspection & Testing of Existing Containment Structures6.1. Inspection6.2. Testing

DOW RESTRICTED - For internal use only

THE DOW CHEMICAL COMPANYCIVIL/ARCHITECTURALGLOBAL


1. GENERAL1.1. These guidelines set forth the principles of civil engineeringdesign and construction practices that should be followed toprevent soil and groundwater contamination. These designphilosophies have been developed to meet the requirements ofthe Dow Loss Prevention Principles (LPP's). Specificconstruction details which apply these philosophies may befound in the Civil Discipline of the Electronic Most EffectiveTechnology Library (EMETL).1.2. These practices are not a substitute for good engineeringjudgment and should not rule out other methods or designs whichachieve the stated objectives. Reference should also be made toG2Z-0001-01 "Global Civil Engineering Design Criteria" andlocal variations for additional information.1.3. The provisions of these guidelines apply to process areas inparticular. General principles may also be applicable to otherareas such as maintenance aisles, transformer pads, landfillsetc. where likelihood of process fluid spills exists due tomaintenance and operational requirements.1.4. Refer to Figure 1 "Construction Details for EnvironmentalProtection" which shows traditional construction detailscompared to the current recommended practices for process areapavement and foundations. This Figure illustrates thatsignificant soil and groundwater protection can be achievedwithout major increase in cost.2. DEFINITIONS2.1. CONSTRUCTION JOINTS - Joints which are placed where concreteoperations are concluded for the day and to provide logicalseparation between segments of the structure.2.2. iiiCONTROL JOINTS (EXPANSION/CONTRACTION JOINTS) - Joints whichare intended to control the cracks caused by shrinkage andthermal changes.2.3. CONTROLLED DRAINAGE A strategy to manage drainage from acontainment that prevents the release of process fluids orother contaminants from the containment to the surroundingenvironment. This could include elements such as testing orinspection of contents, valves, pumps, vacuum truck, oil/waterseparators, etc. singularly or in combination as appropriatefor the risk and process fluid contained.2.4. CREDIBLE SCENARIO A single event or chain of eventsconsisting of two events in sequence, or an event that isstipulated by regulation. When considering multiple events, theover-all duration of each event should be considered. Forexample, if combining flows from rainfall and fire-fighting, itwould not be reasonable to use a rainfall duration that islonger than the length of time that the fire-fighting flow is



DESIGN AIDG2D-K100-0011-SEP-2006Page 3 of 32expected to last. When considering events, factors such as therisk of occurrence and consequences of failure of thecontainment, treatment, or drainage system should be discussedwith local Process Safety and Loss Prevention resources, andthen documented in the operating units files. Examples ofcredible scenarios include:

Failure of primary containment plus fire-fighting.

Failure of primary containment plus rainfall.

Rainfall plus fire-fighting.

2.5. CURBED AREA A paved area built around specific equipment tocollect spills and runoff and prevent them from flowing into oraround other equipment.2.6. DIKED AREA A structure built around a storage or productionarea that is designed to prevent the contents of vessels in thearea from escaping to the surrounding environment in the eventof a failure of one or more of the vessels.2.7. EMERGENCY OVERFLOW - Overflow from vessels that are engineeredand instrumented to prevent overflow.2.8. GEOMEMBRANE An impermeable flexible barrier usually made fromsheets of plastic or rubber, or by impregnating a geotextilewith asphalt or elastomer sprays. Polyethylene is the preferredmaterial for geomembranes.2.9. IMPOUNDING BASIN A structure designed to collect and containsurface runoff from process areas. Examples of impoundingbasins include ponds, sumps, etc.2.10. ISOLATION JOINTS - Joints which are intended to isolate twostructural elements such as existing and new foundations toaccommodate differential vertical and horizontal movements.2.11. LEAK DETECTION - Physical and operational management systemsdesigned to indicate failure of either primary containment orsecondary containment systems.2.12. LOCAL IMPOUNDMENT An impounding basin that is located in theimmediate vicinity and is part of the process area that itserves.2.13. MAINTENANCE CONDITION A routine or planned occurrence thatplaces process fluids into plant drainage systems. Examplesinclude start-up, shut-down, preparation for maintenance, etc.The characteristics of flows resulting from this conditionshould be documented by the operating unit.2.14. NORMAL OPERATING CONDITION The amount, composition, andtemperature of flows in or collected by plant drainage systemsthat are present on a routine basis. The description of theseflows in existing plants should be based on actual measurementand sampling of flows in existing plant drainage systems



DESIGN AIDG2D-K100-0011-SEP-2006Page 4 of 32wherever possible. The characteristics of flows resulting fromthis condition should be documented by the operating unit.

2.15. NORMALLY DRY A system that is not classified as normally wet.Examples of conditions that could exist but would not cause atrench to be rated as normally wet include - emergencyoverflow, floor wash, seal pots (if normally water),preparation for maintenance such as clearing blocked equipmentor pipes or clearing residual material from equipment, a pump,or pipe system that occurs on an infrequent basis and is notspecifically included in the definition of normally wetdrainage systems.2.16. NORMALLY WET A system that collects or conveys a processfluid by design on a continuous or routine basis. Examples offlows that would result in this trench classification includesample stations, seal flush, cell wash (diaphragm wash), cellstart-up, seal pots (if not water), preparation for regularmaintenance of sparkler filters, etc.2.17. PRIMARY CONTAINMENT - The first vessel in contact with thecontained process fluid. It should have the structuralintegrity and chemical compatibility to contain the processfluid for the anticipated operating life of the facility.Examples of primary containment systems include equipment usedin process or storage, process piping, drainage collection andconveyance facilities, etc.2.18. PROCESS AREA - Chemical processing areas of both indoor andoutdoor plants including reactor structures, truck and railcarloading and unloading areas, storage areas of raw materials andfinished products, railcar or truck wash, maintenance areas,etc.2.19. PROCESS FLUID A fluid which if released to the environmentwill have a detrimental effect on the environment, or whoserelease to the environment would result in a reportableincident.2.20. REMOTE IMPOUNDMENT An impounding basin that is located awayfrom the process areas that it serves. A remote impoundmentcould be located on the same process block or on a separateprocess block, and could service more than one process areamodule or type of production facility.2.21. SECONDARY CONTAINMENT - A backup system for containment ofprocess fluids in case the primary containment leaks orotherwise fails for any reason. Examples of secondarycontainment systems include double-walled process equipment,double-walled piping, or double-walled normally wet trenches;process area pavement; dikes or impounding basins associatedwith storage equipment; etc.



DESIGN AIDG2D-K100-0011-SEP-2006Page 5 of 322.22. SUMP A below-grade structure serving as a collector forsurface runoff, groundwater, or process fluids with provisionfor storage and subsequent treatment or removal.

2.23. UPSET CONDITION An unplanned occurrence that places processfluids into plant drainage systems. Examples include emergencyoverflow, emergency shut-down, Loss of Primary Containment,etc. The characteristics of flows resulting from this conditionshould be documented by the operating unit.2.24. WATERWAY All non-Dow drainage or water transportationfeatures, and any Dow drainage or water transportation featurenot directed to an impoundment or treatment system capable ofhandling a release of process fluid in a credible scenario.Examples of waterways include canals, rivers, drainage ditches,etc.3. GENERAL REQUIREMENTS3.1. GENERAL3.1.1. The civil discipline is involved in engineering of newfacilities and modifications to existing facilitiesincluding process areas, secondary containment, sumps,trenches, sewers and drain systems etc. that relate tostorage, dispensing, use and handling of process fluid.These items need special considerations during planning,design and installation stages to prevent soil andgroundwater contamination.3.1.2. It is critical to maintain cost effectiveness throughrational use of design and construction practices, andguard against the temptation to "gold plate" ourfacilities.3.1.3. Each project should be analyzed for existing soilconditions, potential for contamination, materialtoxicity, applicable codes, etc.3.2. MATERIALS OF CONSTRUCTION3.2.1. Compatibility with the materials to be contained is theprimary consideration in selecting materials ofconstruction and products (toppings, coatings, sealant,membranes, etc.). Before such choice is made, verify withthe Materials specialist that the materials are capable ofwithstanding the expected exposure and duration. Unlessspecifically noted otherwise in business-specific Level 2MET, materials of construction for plant drainage systemsshould be selected based on normal operating conditions.3.2.1.1. Local sections of plant drainage systems that could beaffected by maintenance or upset conditions mayrequire special measures to deal with elevatedtemperatures or different chemical concentrationscompared to normal operating conditions. In such



DESIGN AIDG2D-K100-0011-SEP-2006Page 6 of 32instances, it is important to consider the frequencyand durations of anticipated exposures.

3.2.1.2. When determining compatibility for upset conditions,additional considerations include the risk ofoccurrence, the anticipated performance of thematerials under extreme exposure, the potential forinjury or environmental damage, the cost andcomplexity of repair or replacement of damagedsections, and the potential for lost production.3.2.2. Where compatibility tests are required, these shouldsimulate the actual operating conditions, pH, temperature,pressure, etc., as closely as possible. Vendor literatureand past case histories are a good starting point forinformation. Testing can take up to six months tocomplete; therefore, the testing should be initiated asearly in the design process as possible. Acceleratedtesting procedures are available, but exercise caution inutilization and interpretation of the results.3.2.3. It is often more economical and dependable to resistliquid permeation by the use of good quality concrete,proper design of joint details, adequate reinforcement andproper attention to workmanship than by means of animpervious protective barrier or coating.3.3. QUALITY ASSURANCE/QUALITY CONTROL3.3.1. Process area pavement traditionally receives minimalattention in design engineering and construction. In orderto make all concrete structures as watertight as possible,both design and construction must pay added attention totheir respective areas of responsibility.3.3.2. Proper and thorough inspection of all phases ofconstruction helps to ensure good quality final productwhich will provide good long-term performance.3.3.3. Requirements of inspection and testing should be clearlyunderstood by all parties, including the designers,inspectors, contract administrators, and the contractor.3.4. CODES AND REFERENCES3.4.1. These guidelines provide the minimum acceptablerequirements as defined by Dow Loss Prevention Principles.Where local codes, regulations, or laws exist that aremore stringent, they shall govern.3.4.2. Design and construction of concrete structures isgenerally based upon the requirements of ACI 350,"Environmental Engineering Concrete Structures".3.4.3. Dow Civil Discipline Level 1 MET:




G2D-2700-00

Drainage Design Aid

G2G-3310-05

TPER Control Joint for Slabs

G2G-3315-42

Partially Solid Grating for Control of FlameSpread

G2Q-K100-10

Containment Structures Inspection Checklist

G2S-3001-01

Concrete Specification

G2Z-0001-01

Civil Engineering Design Criteria

3.4.4. Dow Loss Prevention Principles:LPP 2.4 Drainage Systems, Sewer and Drain SystemsLPP 7.5 Dikes and ContainmentLPP 8.1 Tank Cars and Tank Trucks4. DESIGN AND INSTALLATION PRACTICES4.1. DRAINAGE FROM PROCESS AREAS4.1.1. GENERAL4.1.1.1. Plant drainage and containment systems will consist ofsome or all of the elements described in Figure 1.

Sump

Drainage Trench

Treatment oroff-blockCurbed Area

Process Area

Diked Area withcontrolled drainage.

Remote Impoundment

Figure 1 Drainage & Containment Components

4.1.1.2. Where possible, drainage systems should be designedand constructed to prevent the release of process



DESIGN AIDG2D-K100-0011-SEP-2006Page 8 of 32fluids beyond the process unit. In all cases, plantdrainage systems should be designed and constructed toprevent the release of process fluids into offsitedrainage systems.

4.1.1.3. Flows from process equipment, such as seal flushes anddrains, should be collected and transported in closedpipe systems, rather than being allowed to dischargedirectly onto process areas. Instead of beingunderground, the pipes should be placed in trenchesprovided for surface drainage where available or intrenches installed specifically for this purpose. Thetrench provides secondary containment for the pipes,and keeps pipes from becoming an obstruction inproduction areas. Pipes should be mounted above thebottom of the trench to avoid restricting the flow inthe trench. Note that this design makes it moredifficult to clean the trenches, and could expose theoutside of the pipe, including insulation and heattracing, to process liquids that are conveyed by thetrench. These materials and systems should be checkedfor compatibility with the expected process fluidsbefore implementing this design.4.1.2. TRENCHES4.1.2.1. Surface run-off from process areas should be carriedby trenches and not underground pipes. Trenches permitrelatively quick run-off, and are generally easier tomaintain and repair.4.1.2.2. Trenches in plants or process areas where flammableliquids are present require special details forgrating to prevent propagation of flaming liquidsthrough the trench system. See Loss PreventionPrinciple 2.4 and G2G-3315-42 for grating details.4.1.2.3. Trenches that are normally wet shall be constructedwith secondary containment and leak detectionsystems.4.1.2.3.1. Trenches which are normally dry do not requireadditional secondary containment, unlessspecifically directed otherwise in theTechnology Implementation Plan.4.1.2.3.2. The classification of drainage trenches(normally wet/normally dry) should be documentedin the plants process documents (drainagesystem P&ID, trench list, etc.)4.1.2.4. Trenches which are intended to be normally dry shouldincorporate adequate slope to drain. Minimum slope of0.5% is recommended.



DESIGN AIDG2D-K100-0011-SEP-2006Page 9 of 324.1.2.5. Where secondary containment is required for trenches,commercial double-walled liner systems arerecommended, subject to material compatibility andavailability constraints.4.1.2.6. Construction techniques for trenches include cast-inplace, monolithic construction, and precast. Precastoffers higher quality and faster construction in thefield as well as alternative materials such aspolymer concrete, but joints and lifting requirementsmay be problems. Monolithic construction reduces oreliminates joints, but requires more complicatedformwork. See Figure 3 for examples of recommendedconstruction practices. Current Level 1 MET detailsincorporate these recommendations. Economics shouldusually be the deciding factor in choosing a methodof construction.4.1.2.7. Joints in trenches require waterstops and should beraised above the floor to get them out of anystanding water.4.1.2.8. Keys should not be used for joints. Keys addcomplexity to forming, often resulting in a jointwhich is less watertight. Design reinforcing to carryshear across the joint.4.1.2.9. Drainage trenches shall be designed to carry themaximum flows as defined in G2D-2700-00 from:

Design rainfall event;

Firefighting activities, including flow fromhydrants, deluge, or monitors to knock downflammable or corrosive vapors;

Other criteria as defined in business-specific MET.

4.1.3. SUMPS & IMPOUNDMENTS4.1.3.1. Due to significant potential for ground watercontamination, underground sumps and related pipingshould be avoided whenever possible.4.1.3.2. Sumps and buried pipe that are classified as normallywet shall be constructed with secondary containmentand leak detection.4.1.3.3. Local regulations may require secondary containmentand/or leak detection for buried piping regardless ofservice condition. Check business-specific MET andlocal regulations before starting design.4.1.3.4. Where secondary containment is required for sumps orimpoundments, commercial double-walled liner systems



DESIGN AIDG2D-K100-0011-SEP-2006Page 10 of 32are recommended, subject to material compatibilityand availability constraints.

4.1.3.5. Cooling tower basins are not normally constructedwith secondary containment. However, requirements forspecific projects must be confirmed.4.1.3.6. Construction techniques for sumps include cast-inplace, monolithic construction, and precast. Precastoffers higher quality and faster construction in thefield as well as alternative materials such aspolymer concrete, but joints and lifting requirementsmay be problems. Monolithic construction reduces oreliminates joints, but requires more complicatedformwork. See Figure 3 for examples of recommendedconstruction practices. Current Level 1 MET detailsincorporate these recommendations. Economics shouldusually be the deciding factor in choosing a methodof construction.4.1.3.7. Joints in sumps require waterstops and should beraised above the floor to get them out of anystanding water.4.1.3.8. Keys should not be used for joints. Keys addcomplexity to forming, often resulting in a jointwhich is less watertight. Design reinforcing to carryshear across the joint.4.1.3.9. Below grade sumps should be tested for watertightness before backfilling, and where appropriatethis condition should be considered in structuraldesign. If a hydrotest is required for sumps, theprocedure documented in local codes or ACI 350 shouldbe used.4.1.3.10. Details for pipes entering or leaving concretestructures require special attention to ensure thatthe joint has adequate strength to resist appliedforces and to maintain a liquid-tight seal. Thecomplexity increases with the addition of liningsystems. For these systems the lining manufacturershould be consulted for recommended details.4.1.4. UNDERGROUND DRAIN SYSTEMS4.1.4.1. Underground process drains should be eliminatedwherever possible. Drains should be routed abovegrade or installed in trenches.4.1.4.2. Underground pipe connected to a process area shouldbe designed and constructed using process pipingtechnology. This includes pipes used to collect stormwater run-off from these areas.



DESIGN AIDG2D-K100-0011-SEP-2006Page 11 of 324.1.4.3. Underground pipes which are normally wet should havesecondary containment and leak detection. Check localregulations for requirements for secondarycontainment and leak detection on underground pipesthat are considered normally dry.4.1.4.4. Flanges and screwed fittings on underground pipesshould be avoided. Where these cannot be avoided thenthey should have secondary containment and a leakdetection system.4.1.4.5. Final material selection must be confirmed by theMaterials specialist, and may already be defined inthe Dow Global pipe spec for the service.4.1.4.6. Where underground pipes are joined to a structure,welded connections should be used. This means thatthe pipe should be the same material as the structureor liner to which it will be connected.4.1.4.7. Pipe used for the secondary containment should meetthe same design criteria as the carrier pipe. Doublepiping (pipe inside a pipe) is one way of providingsecondary containment which can also provide a builtin means of leak detection system.4.1.4.8. Pipes may be slip-lined with another pipe, such aspolyethylene inside steel or concrete. Slip-liningwith a resin impregnated fiber sleeve, such asInsituform*, allows pipes up to 500 m (1,800 feet) tobe lined without joints. These systems are good waysto upgrade or rehabilitate existing pipe.4.1.4.9. ivIf sub-soil drainage (SSD) is installed for thepurpose of dewatering during construction and left inplace, it should be plugged off immediately after itis no longer needed. It should be plugged at allcrossing with other underground services and atintervals not exceeding 150 m (500 feet) to minimizethe potential of chemicals migrating to other areas.4.1.4.10. Details at pond penetrations, sumps, and changes ofdirection should be designed to accommodatedifferential expansion and contraction between pipes,or for the substantial anchor forces which can arise.A pipe stress analysis is recommended, so that thesedetails should be properly designed. Differentialsettlement between pipes and structures should alsobe accounted for.

4.2. PROCESS AREA PAVEMENT4.2.1. GENERAL4.2.1.1. Process areas should be paved with concrete to providepositive collection of run-off and conveyance to a



DESIGN AIDG2D-K100-0011-SEP-2006Page 12 of 32treatment or storage facility before discharging tooff-site waterways.

4.2.1.2. Process area pavement is considered to be secondarycontainment. Where process area pavement has beendesigned and constructed according to therequirements in this guideline and Dow EngineeringSpecifications and drainage from these areas isdirected to a properly designed impounding basin, noadditional secondary containment is required exceptfor those trenches and sumps that are defined asnormally wet.4.2.1.3. Curbed areas should be built around pumps and otherequipment with high likelihood of splash or spill dueto operation or maintenance activities.4.2.1.3.1. In order to reduce tripping hazards considerbuilding curbed areas with a minimum slope of150 mm (6) between high point and low point ofpaving instead of vertical curbs. Provideadequate slope on the outside of the curbed areato match with surrounding grade, recommendedmaximum slope is 10%.4.2.1.3.2. The size of the curbed area should considercontainment of spray from flanges or leaks,access to equipment for maintenance, etc.4.2.1.4. Unless otherwise required by local regulations,provide each separate drainage area with a collectionsump sized to retain a volume equal to 12.5 mm (1/2inch) of rainfall over the drainage area where thesump is located. Discharge excess volume through acontrol device which will retain any process liquidsor solids which have been collected. This localizesthe collection of any residual chemical which may bepresent on the pavement to a manageable volume.Drainage areas may be as small as a curbed area or aslarge as an entire production block.4.2.1.5. For effective run-off of chemical spills, a minimumslab slope of 1 percent is required. Where possible,a slope of 2 percent is preferred. For Germany slopesfor environmental concrete slabs and floors must be2% according to guideline DAfStb.4.2.1.6. Penetrations through pavement slabs, such asfoundation pedestals, electrical grounding testwells, cathodic protection wells, etc., should beavoided wherever possible to eliminate the cost ofsealing and maintenance of joints. All penetrationsmust be designed and constructed to prevent surfacedrainage from passing through the joint. This



DESIGN AIDG2D-K100-0011-SEP-2006Page 13 of 32includes proper consideration for differentialmovement, proper sealant selection, and accenting theslope around slab penetrations so that spills will bediverted away from joints.

4.2.2. PAVEMENT DESIGN4.2.2.1. Concrete should satisfy the usual structuralrequirements, be extremely dense and impermeable toprevent contamination of the environment and providemaximum resistance to processing chemicals. DowGlobal Civil Engineering Specification G2S-3001-01has been developed to satisfy these requirements.4.2.2.2. Process area pavement should have a minimum thicknessof 150 mm (6 inches). Slab thickness of 200 mm (8inches) or more may be required for areas subjectedto heavy construction loads, forklift trucks andother maintenance equipment loads.4.2.2.3. Where sand subbase is required for uniform supportand/or mitigation of frost heaving, the sand shouldbe blocked off at intervals not exceeding 150 m (500feet) to minimize the potential of chemicalsmigrating to soil and groundwater.4.2.2.4. Reinforcing steel in a single mat should be locatedso as to provide minimum 50 mm (2 inches) of cover orone-third of the thickness from the top.4.2.2.5. For crack control, it is preferable to use a largenumber of small diameter bars, rather than equal areaof large bars. Minimum bar diameter is 12 mm (1/2inch) and the maximum bar spacing should not exceed300 mm (12 inches). The actual bar size and spacingwill vary depending upon pavement thickness, jointspacing, etc. If using bar spacing other than 300 mm(12 inches), consider reducing the spacing to no morethan 175 mm (7) to provide a mat that is safe forworkers to walk on while placing reinforcing orconcrete.4.2.2.6. Due to difficulties in maintaining proper locationwithin the mat, do not use rolled welded wire mesh.4.2.3. JOINTS4.2.3.1. Since all joints have to be properly sealedconstruction joints should be avoided whereverpractical. Design and construction techniques whichencourage the use of monolithic pours or reduceconstruction joints should be used. Where joints arerequired they should be located so as to minimizepotential for adverse exposure.



DESIGN AIDG2D-K100-0011-SEP-2006Page 14 of 324.2.3.2. All joints for process area pavement should be shownon the design drawings and the contractor should notbe allowed to construct joints except where shown anddetailed on drawings. Any revision or addition of thejoints shown on the drawings must be approved by theDesign Engineer.4.2.3.3. Control joints should be located at a maximum nominalspacing of 12 m (40 feet) in each direction. Wherestructural columns or process equipment are set onindependent foundations the control joints should belocated to coincide with the foundation locations.Where the foundations are integral with the pavingslab, the joints should be moved to midway betweenthe foundations. In general, panels should be assquare as possible.4.2.3.4. Joints should be located at high points of pavement,at reentrant corners, at stress concentration pointsand where the pavement is likely to crack. Avoidlocating joints at low points and avoid sharpcorners. Figure 2 shows some suggested location ofjoints.4.2.3.5. Maintenance of the field-poured sealant in controljoints is very difficult and expensive. The preferredjoint seal system is the pre-formed TPER expansionboard cap seal, see practice G2G-3310-05.4.2.3.6. Slab reinforcement should be discontinued at thejoint so that the joint is free to move. Transfer ofshear across joint is through dowels where one end ofdowel is free to move. The dowel must be in thehorizontal position and not disturbed when concreteis poured. Even a slight angle causes cracking this is especially critical if using flexible metaljoint materials.

4.3. SECONDARY CONTAINMENT4.3.1. GENERAL4.3.1.1. It is the responsibility of the Project Steering Teamto determine when secondary containment and leakdetection are required. This should occur at GPM steps8.03 and 8.10. Some businesses have developed specificcriteria for secondary containment and leak detectionsystems. Check the business-specific sections of EMETLand review with the Project Steering Team beforestarting design.4.3.1.2. The requirements for secondary containment and leakdetection should be documented in the facility P&ID'sand the project's Technology Implementation plan.



DESIGN AIDG2D-K100-0011-SEP-2006Page 15 of 324.3.1.3. Recommendation for secondary containment and leakdetection systems are summarized in Table 4.1Process or PlantSecondaryLeak detection SystemSystemcontainment SystemStorage TanksDouble-bottom tankDiked Area

Concrete ringand geomembrane

Grooved foundation matVisual inspectionInstrumented ports (eglevel indicator,conductivity probe, gasdetection, etc.)

Trenches, sumps,and surfaceimpoundments

Double-wallconstruction

Visual inspectionInstrumented ports (eglevel indicator,conductivity probe, gasdetection, etc.)

Above-ground pipesand processvessels

Process AreaVisual inspectionpavingInstrumented ports (egLocal orlevel indicator,remoteconductivity probe, gasimpounding basindetection, etc.)Conductive liner

Below-ground pipesand vessels

Double-wallconstruction

Truck and railcarloading/unloadingstations

Visual inspectionProcess AreapavingInstrumented ports (egLocal orlevel indicator,remoteconductivity probe, gasimpounding basindetection, etc.)

Oil-filledtransformers andelectricalequipment

Process AreapavingLocal orremoteimpounding basin

Visual inspectionInstrumented ports (eglevel indicator,conductivity probe, gasdetection, etc.)

Visual inspection

Table 4.1 - RECOMMENDED SYSTEMS FOR SECONDARY CONTAINMENT AND LEAKDETECTION




4.3.2. DIKES & CONTAINMENT4.3.2.1. The function of dikes and impounding basins is tocollect and hold the contents of a storage tank,electrical equipment or process vessel in the eventof spills or catastrophic failure and prevent therelease of process liquids to the environment.4.3.2.2. Where loss of primary containment would result indirect and immediate impact on neighboring waterwaysor groundwater additional provisions may be requiredto ensure protection of these systems. Such provisionsmay include additional containment volume, higher dikewalls or curbs, etc.4.3.2.3. For large spill containment areas concrete pavementand walls may not be cost effective. Clay dikes andclay liner or geomembrane with the option to clean upthe soil in the unlikely event of a tank rupture maybe used, where permitted by local regulations. Theliner could be the existing in-place soil if it isacceptable clay. Check business-specific MET toconfirm if clay is acceptable for construction ofcontainment areas. Curbed areas should be builtaround pumps and other equipment with high likelihoodof splash or spill due to operation or maintenanceactivities.4.3.2.4. Clay for earthen dikes and liners should have aplasticity index of 15 or more and a plastic limit of30 or more and should be compacted to form anengineered fill with a permeability of less than orequal to 1x10-6 cm/sec or as specified by Localrequirements whichever is the more stringent. Slopesshould normally be no steeper than 2 horizontal to 1vertical and should be protected from erosion anddesiccation cracking by some method such asvegetation or stones. Steeper slopes can be achievedby use of soil reinforcement.4.3.2.5. Pipe penetrations through dikes and floors should beavoided. If required, they must be properly sealed,accounting for potential differential settlementbetween the pipe and the structure, potential fireexposure to sealant, potential chemical exposure tosealant, etc., and should be inspected at leastannually for deterioration of sealant or damage tothe surrounding structure that could result in a lossof containment.



DESIGN AIDG2D-K100-0011-SEP-2006Page 17 of 324.3.2.6. Joints in pavement slab should be carried through thedike walls and be fitted with waterstops in both theslab and wall.4.3.2.7. When using geomembranes in hydrocarbon service (PO,EO, etc.) special details may be required to mitigatestatic electricity build-up. Confirm requirementswith the Manufacturing Representative.

4.3.3. Drainage From Dikes & Containment Areas4.3.3.1. Drainage from impoundments shall be managed toprevent the release of process fluids or othercontaminants from the containment to the surroundingenvironment. This could include elements such astesting or inspection of contents, valves, pumps,vacuum truck, oil/water separators, etc. singularly orin combination as appropriate for the risk and processfluid contained.

Pumping to site drainage system or removal byvacuum truck provides the most positive method ofcontainment but relies on operating discipline toinspect, test contents, and operate pumps.Automated controls are not permitted on pumps,other than low-level shutdown.

Connection to site drainage system by drain pipe ortrench with a manually-operated valve also relieson operating discipline for inspection, testing,and operation, but is not fail-safe. Where a manualvalve is installed to control flow from acontainment area, the valve shall be located sothat it can be safely operated in the event of afire.

4.3.3.2. Drainage from curbed areas may be by free-flow totrenches or other drainage systems provided:

The drainage system goes to a remote impoundment ortreatment system;

Provisions are made for separating process liquids(such as oil) from water at the exit from thecurbed area; and

Partially covered trench grating is used tosuppress of fire in open trenches and sumps wherethe risk of fire exists.

4.3.3.3. Design oil/water separators based on the greater offlow from 25-year rainstorm or fire-fightingactivities at the containment area.



DESIGN AIDG2D-K100-0011-SEP-2006Page 18 of 324.3.3.4. Separators installed in locations where freeze-thawconditions might exist must include provisions toprevent ice from forming and blocking the separator.Examples include heating the separator to preventfreezing, installation of the separator below thefrost penetration depth, high-level alarms to alertto blocked flow conditions, etc.4.3.3.5. Management systems for impoundments shall includeprovisions for inspection, testing of contents, andoperation of drainage control equipment. Consideralarm systems that are linked to process controlpanels for remote areas.




4.3.4. Storage Tanks and Process Equipment4.3.4.1. Unless specifically directed otherwise in localregulations, Dow Loss Prevention Principles, orbusiness-specific MET, the minimum volume of dikedareas shall be as follows:

100% of the largest tank in the diked area plus thegreater of:

10% of the tank volume; or

30 minutes flow of fire-fighting equipment.

See Figure 2.G2D-K120-00: Minimum height above floor 300 mm or depth of 25-year, 24-hourrainfall + 150 mm

Volume Criteria: 100% full tank + larger of 10% tank volume or 30 minutes fire-fighting

Minimum separation 5m LPP 7.5

Storage Tank

150 mm Freeboard

Tank Foundation

150 mm

Rainfall

Figure 2 Basic Containment Criteria

4.3.4.2. Some businesses and functions have developed specificrequirements for sizing diked areas that consider therisk of injury, environmental damage, and propertydamage. Check the business-specific sections of EMETLand review with the Project Team before startingdesign.4.3.4.3. Provide a minimum freeboard of 150 mm (6) above thedesign liquid level to the top of the dike walls.Additional wall height to protect against over-toppingof the dike due to catastrophic failure of storagetanks is not required, unless over-topping the wallwould result in direct and immediate impact onneighboring waterways or groundwater.4.3.4.4. Provide adequate separation between the dike wall andstorage tank or increase the dike height as required



DESIGN AIDG2D-K100-0011-SEP-2006Page 20 of 32by the procedure described in LPP 7.5. Dike wallsshould be at least 5 m (16) from tank foundations toprovide good access for maintenance.

4.3.4.5. Storage tank bottoms shall be set at an elevation thatensures they are above the design rainfall. See G2DK120-00 Tank Foundation Guidelines.4.3.5. Loading and Unloading Stations4.3.5.1. Unless specifically directed otherwise in localregulations, Dow Loss Prevention Principles, orbusiness-specific MET, the minimum volume ofsecondary containment for truck and railcarloading/unloading stations shall be as follows:

100% of the largest container handled plus thegreater of:

10% of the container volume; or

30 minutes flow of fire-fighting equipment.

4.3.6. vOil-Filled Transformers and Electrical Equipment4.3.6.1. Area containment consisting of concrete curb andpaving shall be provided for all new installations.These are considered to be curbed areas as defined inthis guideline for the purposes of designing drainagemanagement systems.4.3.6.2. Unless specifically directed otherwise in localregulations or business-specific MET the minimumvolume of secondary containment for in-service oilfilled transformers and electrical equipment shall be110% of the oil volume of the largest equipment inthe containment.4.3.6.2.1. Oil-filled transformers that are not in service,but are considered to be in storage, shall beplaced in areas where drainage can be controlledto prevent contamination of surroundingwaterways or groundwater.4.3.6.2.2. Where loss of primary containment would result indirect and immediate impact on neighboringwaterways or groundwater, free-flow with an oilwater separator is not permitted, and the minimumvolume of secondary containment shall be thegreater of:

110% of the oil volume of the largestequipment in the containment; or



DESIGN AIDG2D-K100-0011-SEP-2006Page 21 of 32The volume of water from a 24-hour 100-yearrainstorm plus a minimum of 150 mm (6)freeboard.

4.3.6.3. Drainage trenches and sumps that are part of thecontainment for oil-filled electrical equipment shallinclude provision for fire suppression.

Stones shall not be used as fire-suppression insumps or trenches of new containments for oilfilled electrical equipment. Problems have beenexperienced in some installations includingcorrosion of metal liners, collection of silt withresulting vegetation growth and decrease incontainment volume and fire-suppressioneffectiveness, disposal of contaminated stones inthe event of a leak, difficulties of inspection ofcovered liners, and difficulties with accessbecause stones are difficult to walk on.

4.3.6.4. Drainage trenches and sumps associated with oilfilled electrical equipment shall include provisionsto prevent the spread of burning oil such as oilwater separators, partially-solid trench covering,etc. singly or in combination.4.3.6.5. Where a sump or local impoundment is locatedimmediately adjacent to oil-filled electricalequipment, check with Process Safety to determine ifa fire wall is also required to separate the sump andthe equipment.4.3.6.6. A sump that is part of the containment for oil-filledelectrical equipment may require Class 1, Division 1electrical classification, which would impact thedesign of electrical power and control. Confirmrequirements with the Electrical and Process Safetyleads.4.3.6.7. See G2D~K100-02 for requirements for containment ofoil-filled transformers and electrical equipment.4.4. LEAK DETECTION SYSTEMS4.4.1. The function of a leak detection system is to provideadequate notice to operations that the primarycontainment has failed and a leak has developed to allowactions to be taken to minimize the risk of injury,negative impact on the environment, or property damage.4.4.2. Where the primary containment is pipe or equipment in adefined process area, additional leak detection is notnormally required provided the pipes are not buried.Visual observation for leaks is acceptable, provided amanagement system is in place to ensure regular



DESIGN AIDG2D-K100-0011-SEP-2006Page 22 of 32inspection with a documented action plan to deal with anydiscovered leaks.

4.4.3. The most widely used and least expensive leak detectionsystems are those that rely on visual inspection of thesystem and/or gravity flow of the leakage. There arealso a variety of leak detection systems on the marketwhich use instruments to detect and sometimes pinpointthe location of leaks. These range from gas monitors tosingle probes or installed grid systems which measurethermal or electric conductivity and/or electricalresistivity.4.4.3.1. Where a leak detection system is required, theminimum is inspection ports that are located at thefollowing locations:

Low points in the system;

Sumps or manholes;

Boundaries of defined process areas;

Intervals not greater than 150 m (500) on trenchesor underground pipes.

4.4.3.2. Where leak detection ports are installed onintersecting drainage systems, locate the ports sothat it is possible to determine which leg of theintersecting system has developed the leak.4.4.3.3. The minimum diameter of a leak detection port is 150mm (6) to facilitate inspection, sampling, andremoval of liquids from the system.4.4.3.4. Slope leak detection system to a low point forcollection of potential leakage. Slopes on leakdetection systems should be designed to take intoaccount the anticipated differential settlements inthe foundation system. This may be especiallysignificant in the case of tanks where edgesettlements are usually less than center settlements,often by as much as one-third to one-half. A minimumof 2 percent should be used for earthen surfaces, and1 percent on concrete or other similar surfaces.4.4.3.5. Leak detection system drainage media must becompatible with the process fluids to which it willbe exposed. Where coarse graded sands or pea stonedrainage media are used perforated collection pipesshould be used if leaked material has to travel morethan 15 m (50 feet) to a collection point.4.4.3.6. Leak detection and collection system for flat-bottomstorage tanks are usually incorporated into the



DESIGN AIDG2D-K100-0011-SEP-2006Page 23 of 32foundation. The details of the systems will varydepending upon the size of tank, style of foundation,and contents in the tank.

4.4.3.7. Leak detection systems should be selected, designedand installed carefully to not affect the design ofany related cathodic protection system.4.4.4. The Project Steering Team shall define the minimuminspection frequency for each leak detection system,considering factors such as:

Potential for personal injury;

Potential for environmental impact;

Location of facility;

Effect of maintenance conditions or upset conditions onthe primary containment system;

Local regulations;

Anticipated life span of the primary containmentsystem.

4.4.5. The maximum recommended time between inspections of leakdetection systems is once per quarter.4.4.6. The Project Steering Team shall ensure that the requiredinspection frequency, with the rationale for setting thefrequency, and the required response from operations inthe event of a leak is documented in the plantsoperating discipline.4.4.7. Where maintenance or upset conditions create a severeexposure that could damage the primary or secondarycontainment systems, the drainage system should beinspected for damage or leaks before being put back intoservice. This includes any leak detection system that ispart of the overall drainage system.4.4.8. Where instrumented leak detection systems are to be used,the Instrumentation discipline must be involved to ensuresystems are adequately designed.4.4.9. Instrumentation for leak detection systems should beincluded in the plants regular preventative maintenanceprogram.4.4.10. Notwithstanding the presence of instrumentation, leakdetection systems should be inspected by operationspersonnel at least annually to ensure proper operation ofall components.4.5. FOUNDATIONS4.5.1. GENERAL



DESIGN AIDG2D-K100-0011-SEP-2006Page 24 of 324.5.1.1. The use of thickened slab footings or pilecapsintegral with paving is preferred in order tominimize slab penetrations.4.5.1.2. Where excessive settlement or heave is expected andmat foundations are inappropriate, foundations shouldbe separated from the pavement by properly designedand constructed isolation joints.

4.5.2. ABOVE-GROUND STORAGE TANKS4.5.2.1. Foundations for flat-bottomed storage tanks requirespecial attention to detail in order to properlyaddress the issues of secondary containment, leakdetection, corrosion of the tank bottom andeconomics.4.5.2.2. Tank foundations must be constructed with appropriatejoints between the foundation and the surroundingsurface. Foundations which are integral with the areapaving provide the best spill containment but may notbe suitable where large settlements are expected.Gravel bases are not recommended for tanks which willbe installed in paved containment areas.5. MATERIALS OF CONSTRUCTION AND PRODUCTS5.1. CONCRETE5.1.1. GENERAL5.1.1.1. Important characteristics of concrete used for spillcontainment include low permeability, highdurability, minimum cracks (preferably no visiblecracks) and increased chemical resistance.5.1.1.2. More than any other single factor, the water/cementratio will have the greatest impact on all of thesecharacteristics. Lowering this ratio will result inreduced shrinkage and cracking, higher strengths forthe same cement content, and generally produceconcrete which has lower permeability and betterdurability.5.1.1.3. In the following sections, requirements marked with(M) have been incorporated into the Global CivilEngineering Specification G2S-3001-01 Concrete orrelated standard details.5.1.2. MIX DESIGN5.1.2.1. The minimum compressive strength shall be 30 MPa(4000 psi) @ 28 days. (M)5.1.2.2. The maximum water-cement ratios shall be 0.40, exceptfor Europe where the water-cement ratio is specified



DESIGN AIDG2D-K100-0011-SEP-2006Page 25 of 32at 0.45 0.50 due to higher strength concrete andother quality control requirements. (M)

5.1.2.3. Air-entraining admixtures increase workability, andimprove durability. Concrete should include entrainedair at 4.5% to 7% except where coatings are used.Consult with the coating manufacturer regarding theused of entrained air. (M)5.1.2.4. Pozzolans or fly-ash may be used to reduce the costof concrete by replacing a portion of the cementvolume. Proper use of fly-ash will result in improvedworkability, lower water-cement ratio and improvedcorrosion resistance. Their use is recommended wherelocally available at reasonable cost.5.1.2.5. Microsilica improves concrete through two mechanisms.The extremely fine microsilica particles are able tofill the microscopic voids between the cementparticles, creating a less permeable structure. Inaddition, microsilica reacts with the free calciumhydroxide within the concrete to form additionalcalcium silicate hydrate (binder), producing atighter paste-to-aggregate bond. This generallyresults in lower permeability, especially againstchlorides. Microsilica is an expensive admixture, andis only recommended where other less expensiveoptions will not work.5.1.2.6. Other admixtures such as water reducing agents may beused when their addition to a mix will result in theimprovement of the desired concrete properties.5.1.3. REINFORCEMENT REQUIREMENTS & PLACEMENT5.1.3.1. The minimum amount of shrinkage and temperaturereinforcement shall be provided as per Figure 2.5,ACI 350.5.1.3.2. Minimum concrete cover for reinforcement shall beprovided as per Table 2.5, ACI 350.5.1.3.3. For very harsh environmental conditions, includinghigh temperature exposure, cover on reinforcing barsshould be increased to a maximum of 75 mm (3").5.1.3.4. Coated reinforcing or corrosion inhibitors may beconsidered in very corrosive chemical applications.5.1.4. WATERSTOPS5.1.4.1. Waterstops shall be used for all joints in trenches,sumps, containment areas, and process area paving.(M)



DESIGN AIDG2D-K100-0011-SEP-2006Page 26 of 325.1.4.1.1. For trenches, dikes, containment areas, andprocess area paving, the waterstop in detail G2G-3310-05shall be used.

5.1.4.2. The resistance of waterstop material to the chemicalsand exposure temperature must be verified. TypicalPVC waterstops have limited application in chemicalexposures. Polyethylene or TPER provide the best allaround resistance in most applications. Verifywaterstop material selection with the Materialsspecialist.5.1.4.3. Proper splicing of waterstops is extremely important.Splices should be avoided if possible. Factory-madefittings should be used for all corners, tees, andintersections. Only straight butt joint splicesshould be performed in the field. The procedure forsplicing will vary with the type of material.Manufacturer's recommendations for proper splicingmust be followed. (M)5.1.4.4. Improperly installed waterstops can result in leakyjoints. The waterstops must be located accuratelyand should be braced or lashed firmly to reinforcingat approximately 300 mm (12 inch) centers to preventmovement during placing of the concrete. (M)5.1.5. CONCRETE CURING5.1.5.1. Without proper curing, the best designed concretestructures are likely to crack. Curing should startas soon as placing and finishing is completed. Allmaterials and equipment needed for protection fromearly drying and for curing should be available andready for use before the concrete arrives.5.1.5.2. The concrete should be cured for minimum 7 days. Uponthe prior approval by the Design Engineer, thisperiod may be reduced to not less than 3 days byusing high early strength cement. (M)5.1.5.3. Concrete must be kept continuously moist duringcuring to avoid crazing and cracking.5.1.5.4. Ponding, or covering the concrete with water, is thepreferred method of curing concrete. Other methodsfor wet curing are described in the concretespecification.5.1.5.5. Curing compounds do not provide the degree ofprotection which is required for these types ofstructures and should not be used.5.2. POLYMER CONCRETE



DESIGN AIDG2D-K100-0011-SEP-2006Page 27 of 325.2.1. Polymer concrete is a composite material consisting of amix of polymerized monomer and fine/coarse aggregate. Itis similar to regular Portland cement concrete exceptthat it uses a polymer material as the binder instead ofPortland cement. The most common polymers in use todayare polyesters or vinyl-esters. Other polymers may beused for special applications.5.2.2. Some products such as trenches and small sumps areavailable commercially. It is also possible to castcustom shapes. Polymer concrete toppings of variousthickness provide long lasting, long wearing, chemicallyresistant surface for restoration of degraded concrete oroverlays of new concrete.5.2.3. In general, polymer concrete is very expensive, and mayhave limited availability in some areas. Its use shouldbe very selective.

5.3. LATEX-MODIFIED CONCRETE5.3.1. Latex-modified concrete is produced by adding 10 - 15percent styrene/butadiene latex (by weight of cement) tothe fresh concrete mix.5.3.2. The primary benefit is a reduction in permeabilitycompared to regular concrete, and the main application isas a topping in areas with greater risk of exposure tosplash and spill of chlorides.5.4. COATINGS & LINERS5.4.1. Concrete structures and pavements may require additionalcoatings or liners depending upon service conditions andrequirements for environmental protection. Table 5.1describes the conditions under which coatings or linerswill be required.5.4.2. When a coating or liner is required, consult theMaterials Engineer for selection of appropriate products.5.4.3. Refer to the Civil AM/SL for listings of approved vendorsfor double-wall containment systems.Service Condition

Coating or Liner Requirements

Concrete attacked chemically

Coating or liner required

Concrete not attackedchemically

Coating or liner not required,but provisions of ACI 350 mustbe followed to provide liquidtight structure.

Environmental rules requiredouble liner and leakdetection.

Provide double liner systemwith leak detection.




Table 5.1 Liner & Coating Requirements5.5. SEALANTS5.5.1. Sealants may be classified into two main groups - fieldmolded and preformed. Field-molded sealants are thoseapplied in liquid or semi-liquid form, and are thusformed into the required shape within the mold providedat the joint opening. Preformed sealants are usually arigid or semi-rigid material which is set into theconcrete directly or into a frame which is set into theconcrete.5.5.2. Where field-molded sealants must be used, polysulfides orsilicone are preferred. In all cases, the manufacturer'swritten instructions must be followed. This includesrecommendations for joint design, substrate preparation,and curing. The use of primers is generally required,even if the manufacturer states that this is optional.5.5.3. Field-molded sealants are extremely difficult to installcorrectly, and require regular maintenance. For thesereasons, TPER expansion board cap seal is the preferredjoint sealant system.5.6. GEOMEMBRANES5.6.1. The compatibility between the material to be containedand the geomembrane material should be ascertained priorto selection. Any actual testing should simulate expectedfield and operational conditions as closely as possible.5.6.2. Geomembranes typically have a coefficient of expansionwhich is much different than that of concrete or earthenmaterials. This may warrant additional design andinstallation considerations.5.6.3. Groundwater level fluctuations can create excessivepressures on the geomembrane and cause failures. Wherethis possibility exists an underlying drainage systemshould be considered.5.6.4. Gas generated by organic decay in the underlying soils oracid attack of limestone formations may become trappedbeneath the geomembrane, possibly resulting in excessivestresses being applied. In such cases a venting systemmay be needed.5.6.5. All geomembranes are combustible. Do not use geomembraneson exposed surfaces for transformer containment or whereother high flammability potential exists.6. viINSPECTION AND TESTING OF EXISTING CONTAINMENT STRUCTURES6.1. INSPECTION



DESIGN AIDG2D-K100-0011-SEP-2006Page 29 of 326.1.1. Existing containment structures should be inspected atregular intervals to ensure that they have not beendamaged and will remain serviceable in the event of aspill from a tank or pipe within the containment area.6.1.2. The minimum frequency of inspection will be set by localregulatory requirements or the Dow Loss PreventionPrinciples. Each plant is responsible for documenting theminimum requirements for their facilities.6.1.3. Inspection results shall be documented in the plantmaintenance records. Checklist G2Q-K100-10 may be used inthe absence of other forms.

6.2. TESTING6.2.1. Flood testing of containment areas may be required tosatisfy regulatory requirements. Results of flood testsshall be documented in the plant maintenance records.6.2.2. There are several risks associated with flood testing,including but not limited to:-

Introduction of moisture to the underside of tanks, withpotential for increased corrosion;

-

Soaking of pipe or tank insulation;

-

Damage to operating equipment;

-

Damage to surrounding environment or facilities in the eventof a failure of the containment structure.

6.2.3. A Civil Engineering specialist should be consulted beforeundertaking any proposed flood test.




FIGURE 2CONSTRUCTION DETAILS FOR ENVIRONMENTAL PROTECTION




FIGURE 3PAVEMENT JOINTS LAYOUT

i

12/18/2004, MOC2004_02421/02425, By: Darryl Baron, Supercedes Issue Date:16-DEC-2004, Major Revisions to entire document.


THE DOW CHEMICAL COMPANYCIVIL/ARCHITECTURALGLOBALii


07/19/06, MOC2006_03738, By: Darryl Baron, Supercedes Issue Date: 01-APR2005, Revisions throughout document.iii12/16/03, By D. Baron; added EXPANSION in paragraph 2.5iv6/26/01, By: A Arnoudse, Supercedes Issue Date: 27-JUL-99, Revisedparagraph 4.4.9v09/11/06, MOC2006-04135, By: Darryl Baron, Supercedes Issue Date: 19-JUL2006, Removed reference detail G2D~2600~05.vi12/16/03 By: D. Baron; add section 6 per request


Rt2d k100 00 Spill Containment

Documents

Transcript of Rt2d k100 00 Spill Containment