oEPA
             United States
             Environmental Protection
             Agency
          Office of
          Solid Waste and
          Emergency Response
DIRECTIVE NUMBER:
9610.2
              TITLE:  Clarification of the Definition of "Underground
                   Storage Tank"
              APPROVAL DATE:
              EFFECTIVE DATE: <4l?t?
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     &EPA
             United States
             Environmental Protection
             Agency
          Office of
          Solid Waste and
          Emergency Response
DIRECTIVE NUMBER:
9610.2
              TITLE: Clarification of the Definition of "Underground
                  Storage Tank"


              APPROVAL DATE:

              EFFECTIVE DATE:

              ORIGINATING OFFICE: OUST

              Q FINAL

              D DRAFT

               STATUS:



              REFERENCE (other documents):
  OS WER     OS WER      OS WER
VE   DIRECTIVE   DIRECTIVE   Dl

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  x°/EPA
                               United States Environmental Protection Agency
                                       Washington, DC 20460
                       OSWER Directive Initiation Request
                                               Interim Directive Number

                                                9610.2
                                           Originator Information
Name of Contact Person
   Virginia Cummings
                                  Mail Code
                                          WH-562A
                                 Telephone Number
                                   382-7925
Lead Office

   D OERR
   D OSW
                 l±l OUST
                 n OWPE

                 D AA-OSWER
                                                            Approved for Review
Signature of Office Director
                           Date
Title
            Clarification of  the Definition  of "Underground  Storage Tank"
Summary of Directive
                 List of  terms to  clarify  the definition of  "underground
            storage tank"  and related words.   This  list is to be used by
            HQ and  Regional staff  as well  as  State  personnel in answering
            questions from tank owners about  whether they must notify or
            not.  The clarification of these  terms  is badly  needed  to clear
            up confusion  over the  interpretation of what is  an underground
            storage tank.

                 This list of definitions  represents the Agency's policy
            until we propose them  in the Federal Register and take  public
            comment on them.
Type of Directive {Manual. Policy Directive. Announcement, etc.)


            Policy directive
                                                                   Status
                                                                      D Draft
                                                                      El Final
                                                     CU New

                                                     I	I Revision
Does this Directive Supersede Previous Directive(s)?  |  | Yes
If "Yes" to Either Question. What Directive (number, title)
                                                  No   Doe's It Supplement Previous Directive(s)?   |  | Yes   [Jj No
Review Plan
   D AA-OSWER   EE3 OUST

   D OERR       D OWPE

   I	I OSW       I—I Regions
                                  D OECM

                                  D OGC

                                  O OPPE
                 D
Other (Specify)
This Request Meets OSWER Directives System Format
Signature of Lead Office Directives Officer
                                                                                Date
                                                                                      .V
Signatures! OSWER Directives Officer
                                                                                Date
EPA Form 1315-17(10-85)

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 .„--,«.                                              OSWER Directive9610'2
 • ^^
* ^^ \         UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                            WASHINGTON, D.C. 20460
 V" "
                               APR   7
    MEMORANDUM


    SUBJECT:   Clarification of the Definition of
               Jndergro,u^id Storage Tank"
                                                             OFFICE OF
                                                    SOLID WASTE AND EMERGENCY RESPONSE
    FROM:     /P.  Winston Po/ter
              (ssistant Administrator

    TO:        EPA Regional Administrators
         Please  find attached to this memo definitions of key
    terms for  the  purpose of implementing the notification
    process  for  underground storage tanks.  As the May 8 deadline
    for  notification approaches, it has become clear that we need
    consistent answers for the questions frequently asked by the
    States and regulated community.

         Please  forward a copy of this information list to each of
    your states.   I  have provided the list to the RCRA/ Superfund
    hotline.

         Should  you  have any questions concerning these terms,
    or if you  are  aware of remaining definitional issues, please
    contact  Virginia Cummings of my staff (382-7925) or
    Carrie Wehling of the General Counsel's office (475-8067).

    Attachment

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                                                                  9610.2
                       LIST OF UST DEFINITIONS AND EXEMPTIONS
               I.  Under Section 9001 of the 1984 RCRA Amendments,
                   Underground Storage Tank means "any one or combination
                   of tanks (including underground pipes connected thereto)
                   which is used to contain an accumulation of regulated
                   substances and the volume of which (including the volume
                   of the underground pipes connected thereto) is 10 percent
                   or more beneath the surface of the ground."
Definition
1. tank is a stationary device which is constructed
   primarily of non-earthen materials (e.g., wood, concrete,
   steel, plastic) which provide structural support.
Discussion
   The basis of this definition is the definition of tank
   under Subtitle C of RCRA (40 CFR 260.10).

   Under this definition,  just about every type of container
   (e.g.,  small metal boxes,  underground sumps, and dump
   tanks)  would be considered tanks.  The fact that they are
   small or unusual tanks  may not be of particular relevance
   when the issue is releases to proximate groundwater sources,
Definition
Discussion
2.  used to contain an accumulation of regulated substances,

   An underground storage tank that contains regulated
   substances for any period of time, no matter how small
   the amount,  is within the jurisdiction of Subtitle I.

   For the purposes of UST jurisdiction, there is no
   "de minimus" or small quantities exclusion, although
   such an exclusion is likely to be included in later
   technical regulation of USTs.
Definition
3.  pipes connected thereto

   Connected piping includes all piping connected to a tank
   system through which regulated substances flow.   For the
   purpose of determining how much piping is connected to
   any individual tank, the piping which joins the  two tanks
   should be allocated equally between them.

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                                                                     9610.2
                                       (2)
Discussion
   The definition of connected piping addresses two issues:
   (1) where the connected piping begins, and (2) how the
   connected piping should be allocated between tanks.  To
   be consistent with the RCRA Subtitle C tank rules, the
   starting point of the "connected piping" is the point
   at which the regulated substance is introduced into the
   system.

   This means that if there is an exempt tank between the
   point of introduction and an underground storage tank,
   the connected piping is allocated between them.  Equal
   allocation of piping between tanks is also the basis of
   determining whether the volume of an individual tank is
   10% or more beneath the surface of the ground.
Definition
4.  beneath the surface of the ground

   A tank is 10% or more beneath the surface.of the ground
   if its volume (including the volume of its connected
   piping) is either (1) 10% or more below ground surface
   or grade, or (2) 10% or more beneath ground surface or
   otherwise covered with material so that expeditious
   inspection is precluded.
Discussion
   This definition addresses two situations in which a tank
   would be considered to be underground.   First, a tank
   may be considered an underground storage tank even if
   10% or more of its volume is not covered by ground
   material as for example a tank that is  in a below grade
   containment area (such as a swimming pool or a ditch).

   Second, if 10% or more of the tank volume is covered by
   ground material, either below or above  grade, the tank
   is within UST jurisdiction.  This means that tanks that
   are above ground but mounded over with  dirt (to comply
   with local fire codes) are within UST jurisdiction.
              II.  The definition of underground storage tank exludes
                  nine types of tanks which would otherwise be subject
                  to UST regulation.

              A.   The first group of tanks excluded by the statute is
                  "farm or residential tanks of 1,100 gallons or less
                  capacity used for storing motor fuel for noncommercial
                  purposes."

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                                                                     9610.2
                                      (3)
Definition
Farm tank is a tank located on a tract of land devoted
to the production of crops or raising animals, including
fish, and associated residences and improvements.
Discussion
The definition of farm is based upon that used by the
Internal Revenue Service in connection with tax exclusions
for farmers.  To be exempt from UST jurisdiction, a farm
tank must be located on the farm property.  "Farm" includes
fish hatcheries and rangeland.  "Farm" does not include
laboratories where animals are raised, land used to grow
timber, or pesticide aviation operations.
Definition


Discussion
Residential tank is a tank which is located on property
primarily used for dwelling purposes.

The language of the exclusion indicates Congressional
intent to remove from UST jurisdiction small gasoline
tanks located on property used for dwelling purposes
(i.e., residential property).  A private school storing
motor fuel on site for school buses would not be excluded
from UST jurisdiction because the primary use of the
property is not residential.
Definition
Discussion
Noncommercial purposes means where the motor fuel is
not for resale.

The exclusion is limited to motor fuel stored on farmland
or residential property and which is not for resale.
Tanks at gas stations located on "residential" or "farm"
property as defined above are not excluded because the
motor fuel is stored for resale.
             B. The second group of tanks excluded from UST jurisdiction
                by statute is tanks used for storing heating oil for
                consumptive use on the premises where stored.

                (These definitions are forthcoming.)

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                                                                   9610.2
                                   (4)
Definition
C. The third group of excluded tanks covers any "septic
   tank."

   A septic tank is a water-tight covered receptacle designed
   to receive or process, through liquid separation or
   biological digestion, the sewage discharged from a building
   sewer.  The effluent from such receptacle is distributed
   for disposal through the soil.  Settled solids and scum
   are pumped out periodically and hauled to a treatment
   facility for disposal.
Discussion
   The definition of septic tank is based on common and
   technical usage.  There are two issues which have been
   raised with respect to the definition of "septic tank":
   (1) does the septic tank exclusion include all septic
   tanks or only residential ones?  (2) does the exclusion
   refer only to a septic tank or does it refer to the septic
   system?  Based on the history of this provision, the
   "septic tank" exclusion applies to all septic tanks.  In
   addition, the entire septic system which may include other
   types of tanks such as a distribution box, dosing tank, and
   grease trap - is exempt.
Definition
Discussion
D. The fourth exclusion covers any "pipeline facility"
   (including gathering lines) regulated under (1) the Natural
   Gas Pipeline Safety Act of 1968 (49 U.S.C. App. 1671, et
   seq.), (2) the Hazardous Liquid Pipeline Safety Act of
   1979 (49 U.S.C. App. 2001, et seq.), or (3) which is an
   intrastate pipeline facility regulated under State laws
   comparable to the provisions of laws referred to above."

   Pipeline facilities include without limitation, new and
   existing pipe rights-of-way and any equipment, facility, or
   building used in the transportation of gas (or hazardous
   liquids, which includes petroleum and any other liquid
   designated by the Secretary of Transportation) or the
   treatment of gas or designated hazardous liquids during
   the course of transportation.

   This definition was borrowed from the Natural Gas Pipeline
   Safety Act of 1968 and the Hazardous Liquid Pipeline Safety
   Act of 1979.  "Pipeline facility" may also include any
   such facility as defined and regulated under State laws
   comparable to these two federal statutes.

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                                                                   9610.2
                                       (5)
Definition
E. The fifth exclusion covers any "surface impoundment,  pit,
   pond, or lagoon."

   A surface impoundment is a natural topographic depression,
   man-made excavation, or diked area formed primarily of
   earthen materials (although it may be lined with man-made
   materials).
Discussion
   This definition was borrowed from Subtitle C (40 CFR 260.10)
   Because the statute uses the somewhat specialized Subtitle
   C terms "surface impoundment, pit, pond, and lagoon" to
   define this exclusion, it is likely that Congress also
   intended to borrow the meaning of surface impoundment from
   Subtitle C.

   Examples of structures excluded from UST jurisdiction are
   holding, storage, settling, and aeration pits,  ponds, and
   lagoons.
Definition
F. The sixth exclusion covers a "storm water or waste water
   collection system."

   A "stormwater or wastewater collection system" is defined
   as piping, pumps, conduits and any other equipment used to
   receive and convey surface water runoff resulting from
   precipitation or domestic, commercial, and industrial
   wastewater.  The collection of stormwater or wastewater
   must be directed towards conveyance, and does not include
   storage or treatment of stormwater or wastewater
   except where incidental to conveyance.
Discussion
   Excluded from UST jurisdiction under this definition are
   tanks associated with stormwater or wastewater sewer
   systems.  Tanks that are part of wastewater collection
   systems at industrial facilities are also excluded under
   this definition so long as the tanks are primarily used
   for collection and conveyance of wastewater or storm
   water.  Tanks used for storage or treatment of stormwater
   or wastewater not incidental to collection and conveyance,
   such as wastewater treatment tanks at industrial facilities
   or municipal water treatment works, are not excluded under
   this definition.

   This definition excludes sumps when they are part of
   stormwater/wastewater overflow or conveyance.

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                                                                     9610.2
                                       (6)
Definition
G. The seventh exclusion covers any "flow-through process
   tank."

   A flow through process tank is a tank which forms an
   integral part of a manufacturing process and through which
   there is a steady or uninterrupted flow of materials
   during operation of the manufacturing process.  The term
   "flow through process tank" does not include tanks used to
   store regulated substances prior to their introduction
   into the manufacturing operation, or to store regulated
   substances as products or by-products from the manufacturing
   process.
Discussion
   There are two key concepts associated with this term: (1)
   "flow-through" means steady or regular flow.  That is, the
   fluid level is subject to constant change during operation
   of the process.  (2) "process" means integral to manufacturing
   process (as opposed to a process in the tank).

   Concerning the first concept, defining "flow through" as
   including regularly occurring flows as well as continuous
   flows the use of a retention-time limitation was rejected
   on the grounds that this would be too complicated.  The
   dividing line between "flow through" and storage would be
   very difficult to determine.

   Concerning the concept of "process", the only tanks that
   are excluded as flow-through process tanks are those tanks
   that are integral to the manufacturing process.  This means
   that tanks that hold raw materials prior to processing and
   tanks holding products,  byproducts, or wastes after the
   processing may be subject to UST jurisdiction.
             H. The eighth exclusion covers "liquid trap or associated
                gathering lines directly related to oil or gas production
                and gathering operations."
Definition
   The liquid trap exclusion refers to tanks used for the
   purpose of the collection and removal of water and other
   liquid impurities from oil and gas during oil and gas
   production operations and their attendant production lines,

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                                                                    9610.2
                                      (7)
Discussion
   Although liquid traps are often used in activities other
   than oil and gas production, the only type of liquid trap
   excluded from UST jurisdiction under the statute is a
   liquid trap used for the purpose of separating unused oil
   and gas liquids from water at oil and gas producing
   facilities.

   However, not all tanks at oil and gas producing facilities
   will qualify for this exclusion.  For example, after removal
   of oil in a liquid trap, the water (containing some oil
   residue) may be stored prior to discharge.  This oily water
   would be subject to UST jurisdiction if stored in an under-
   ground storage tank.  Tanks associated with gas delivery
   lines that connect the liquid trap to an underground storage
   tank may be subject to the pipeline facilities exclusion.
   (See definition of "pipeline facilities" above.)

   "Liquid traps" such as grease and oil traps at gas stations
   as well as methane gas produced at landfills are not within
   this exclusion and would be subject to UST jurisdiction.
Definition
I.  The ninth exclusion covers "storage tanks situated in an
   underground area (such as a basement, cellar, mine working,
   drift,  shaft or tunnel) if the storage tank is situated
   upon or above the surface of the floor."

   Underground area means an underground room, such as a base-
   ment, cellar, shaft or vault, providing enough space for
   external physical inspection of the tank situated on or
   above the surface of the floor.
Discussion
   This exclusion applies to "underground rooms" where tanks
   are located on or above the floor surface.   The purpose of
   this exclusion is to remove from UST jurisdiction tanks
   which are technically underground but which are in a
   practical sense no different from above ground tanks.  They
   are situated so that, to the same extent as tanks above
   ground,  physical inspection for leakage is  possible.  Thus,
   the requirement to be able to physically inspect the tank
   for leakage is consistent with the purpose  of this exclusion,

   Tanks located in a below grade structural vault, cellar,
   basement, mine or other underground room would be subject
   to the UST exclusion as long as the tank sits on or above
   the surface of the floor and there is sufficient space
   to enable physical inspection of the tank.

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