7/31/2019 Above Ground and Underground Storage Tanks

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Department Editor:Scott Jenkins

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The ultimate objective o storing liquid,uid and gaseous products, which maybe corrosive, ammable or unstable, is

to store material in an environmentally sae

and economically viable manner. Storagetanks in the chemical process industries(CPI) can be most broadly divided intothose buried underground, and thoseconstructed aboveground. The ollowing isan outline o considerations associated witheach category and positive and negativeaspects o each. Also included are poten-tially applicable regulations and codes romthe U.S. Environmental Protection Agency(EPA), the Occupational Health and SaetyAdministration (OSHA) and others.

UnderGroUnd SToraGe Tank

(UST) advanTaGeSPhysical safety USTs are out o the wayo automobile trafc

Fire safety With a relatively constant un-derground temperature, USTs have superiorvapor suppression and fre protection orammable and volatile contents, as well asa reduced need or fre hazard permits

Security The American Petroleum Institutehas shown that vandalism is a leadingcause o tank ailures. USTs are less subjectto vandalism and easier to protect

Aesthetics USTs are out o sight, which

eliminates a possible public objectionLand use USTs oer a more efcient useo land space and allow more exibility inplacement location

UST diSadvanTaGeS

Leak detection and containment Leak moni-toring, detection and containment is moredifcult and more expensive underground

Installation complexity and cost Excava-tion and special backfll materials add costs

Depreciation Real estate depreciation ispossible due to threat o contamination

aboveGroUnd SToraGe Tank(aST) advanTaGeS

Construction ASTs are simpler and lessexpensive to construct and install. Onesignifcant aspect eliminated is the need orexcavation and special backfll materials

Maintenance Visual inspection is pos-sible, which leads to more reliable leakdetection and easier repair

Insurance Lower pollution insurance pre-miums because o reduced risk o ground-water contamination

Regulatory burden ASTs are subject toless regulatory requirements than USTs

Costs ASTs have lower monitoring andrecord-keeping costs

aST diSadvanTaGeS

Physical safety ASTs are more vulnerableto vandalism, contact with automobiles andexternal damage

Fire safety ASTs have an elevated fre

risk relative to USTsAesthetics ASTs may be objectionable incertain locations

Space use more real estate required tohouse ASTs

Temperature variation ASTs experiencegreater ambient-product-temperature uctua-tions than USTs

MakinG The ChoiCe

When making decisions about whether touse an AST or a UST, consider the ollowing:

Regulatory The local authority in the

area where the tank system will be as-sembled has control o whether a tankpermit will be issued, based on whetherplans or the tank comply with local, state

and ederal requirements. Regulatory rame-works are dierent or AST and UST

Space Space requirements to separate anAST rom trafc, buildings, property lines,present and uture can be signifcant, whilethey are not an issue or USTs. Fire codesgenerally dictate separation distances

Security Protection rom vandalism ismore difcult or ASTs

Cost Several aspects o cost should beconsidered, including: storage tank, tanksystem equipment, initial installation cost,ongoing maintenance cost, security cost,land cost, regulatory cost and secondarycontainment cost

References:

Geyer, W.B. To Bury or Not to Bury: Steel1.Tank Technology Decisions. In: Handbooko Storage Tank Systems, Marcel Dekker,New York, 2000.

Cheremisino, P.N., and Vallamar, O. Aboveg-2. round and Underground Storage Tank Com-parison. In: Storage Tanks. Advances inEnvironmental Control Technology Series,Gul Publishing, Houston, 1996.

RegulAtions And codes potentiAlly ApplicAble to ust And Ast

Regulation name Applicability GoverningBody

Resource Conservation and Recovery Act Subtitle C hazardous waste regulations

AST and UST EPA

Spill Prevention, Control and Countermeasures withinClear Air Act amendments o 1990

AST and UST EPA

Hazardous Waste Operations and Emergency ResponseRegulations 29 CFR 1910.120

AST and UST OSHA

Flammable and Combustible Liquids Standard 29 CFR1910.106

AST and UST OSHA

Hazard Communication Standard 29 CFR 1910.1200 AST and UST OSHA

Confned Space Saety Standard 29 CFR 1910.146 AST and UST OSHA

Oil Pollution Act o o 1990 AST only EPA

National Pollutant Discharge Elimination System AST only EPA

Comprehensive Environmental Response, Compensationand Liability Act (CERCLA)

AST only EPA

Benzene 29 CFR 1910.1028 AST only OSHA

Process Saety Management o Highly Hazardous Chemi-cals, Explosives and Blasting Agents 29 CFR 1910.119

AST only OSHA

Resource Conservation and Recovery Act Subtitle I regulations addressing USTs storing petroleum and haz-ardous substances 40 CFR 280

UST only EPA

Stage II Vapor Recovery Regulations established inClean Air Act Amendments o 1990

UST only EPA

Clean Air Act Tit le V operating permits UST only EPA

Emergency planning and Community Right-to-know Act Title III o Superund Amendments and Reauthorization Act.

UST only EPA

National Fire Protection Association NFPA 30(Flammable and Combustible Liquids Code)

AST and UST NFPA code

International Code Council (ICC) International Fire Code AST and UST ICC code