v>EPA
United States
Environmental Protection
Agency
Owner and Operator Introduction:
Automated Interstitial Monitoring
Systems for Underground Pressurized
Piping on Emergency Power Generator
UST Systems
EPA-510-K-22-001
May 2022

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Contents
Purpose	1
Background	2
Section 1: General Discussion about using AIM Systems on Pressurized Piping Systems	3
Section 2: Description of AIM Systems	4
Section 3: Examples of AIM Systems	6
Section 4: O&M Testing and Inspection Requirements At-A-Glance	9
Section 5: Required Documentation from UST System Owners and Operators	12
Section 6: AIM Systems Inspection and Testing Checklists	16

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Purpose
This document provides owners and operators of emergency power
generator (EPG) underground storage tank (UST) systems with
information about using automated interstitial monitoring (AIM)
systems on their EPG UST systems. AIM systems monitor
pressure, vacuum, or liquid levels or use liquid-detecting sensors
located in containment sumps that are part of secondarily
contained piping systems to meet federal release detection
requirements for pressurized piping.
This document provides basic information and introduces EPG
UST system owners and operators to AIM systems. It contains
helpful forms and checklists to assist them with verifying AIM
system compliance with their UST implementing agency and
complying with periodic testing requirements for their AIM
system.
The U.S. Environmental Protection Agency (EPA) encourages
owners and operators to work with their UST system installer, fuel
system designer, or other qualified professional, when installing or
modifying their fuel storage system to meet federal UST regulatory
requirements. This document does not address all issues regarding
AIM systems. For a complete discussion about AIM systems, see
EPA's In-Depth Discussion: Automated Interstitial Monitoring
Systems for Underground Pressurized Piping Systems on
Emergency Power Generator UST systems at
https://www.epa gov/system/files/documents/2022-05/aim-
svstems-in-depth-discussion.pdf.

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Background
The 2015 federal UST regulation no longer defers EPG UST
systems from release detection requirements. EPG UST systems
contain unique features that are not characteristic of UST systems
installed at conventional UST facilities, such as retail gas stations
or convenience stores and non-retail facilities. Features unique to
EPG UST systems include return product piping, day tanks, and a
power generator. Prior to 2015, many EPG UST systems were
understandably installed without consideration for meeting federal
UST system release detection requirements.
In addition to compliance with the UST regulations, various fire
code requirements apply to power generator systems which owners
and operators must consider and address. Some EPG UST systems
include relatively long pipe runs that begin at underground
locations, extend through multiple stories, run within walls, and
continue through other building structures. These pipe runs contain
underground and aboveground piping, some without transition
sumps or separation points that more easily allow testing of the
underground piping components, as required by the federal UST
regulation.
Note: This document uses
the terms monthly or
month and annually or
annual These terms in
the context of federal
release detection
requirements mean at
least once every 30 days
and not to exceed 365
days, respectively.
For information on EPG compliance with the federal UST
requirements, reference EPA's Release Detection for Emergency
Power Generator Underground Storage Tank Systems at:
https://www.epa.gov/system/files/documents/2022-05/epg-sy stem-
requirements. pdf

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Section 1: General Discussion about Using
AIM Systems on Pressurized Piping
Systems
The federal UST regulation requires that UST system owners and
operators with underground pressurized piping equip their systems
with an automatic line leak detector that will alert the owner or
operator to the presence of a leak. The alert either restricts or shuts
off the flow of regulated substances through piping or triggers an
audible or visual alarm. In addition to the automatic line leak
detector, UST system owners and operators must have a second
release detection method by meeting one of the two below
requirements, as applicable:
•	Pressurized piping installed on or before April 11, 2016,
must have an annual line tightness test conducted according
to 40 CFR § 280.44(b) or have monthly monitoring
conducted according to 40 CFR § 280.44(c).
•	Pressurized piping installed or replaced after April 11,
2016, must use monthly interstitial monitoring according to
40 CFR § 280.43(g). To comply with Energy Policy Act of
2005 requirements, most state UST implementing agencies
established compliance dates for their secondary
containment and interstitial monitoring requirements that
pre-date the federal compliance date.
For all pressurized piping systems associated with EPG UST
systems, regardless of the date of installation of the piping system,
EPA recognizes the use of an AIM system as an option to meet
both release detection requirements for pressurized piping systems.
3

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Section 2: Description of AIM Systems
Note: Category 1 and 2
systems will likely also use
containment sumps and
liquid detecting sensors to
meet the piping interstitial
monitoring requirement
associated with secondary
containment areas. Unless all
piping components within a
sump are double walled or
otherwise secondarily
contained, the underlying
sump is the secondary
containment and must be
monitored for releases. This
typically is accomplished
using a liquid detecting
sensor.
AIM systems are secondary containment systems that include
piping and all connected containment sumps, for example
submersible turbine pump, transition, collection, and detection
containment sumps. The piping and connected sumps have been
specifically designed and constructed by the manufacturer and in
accordance with a code of practice (UL or other nationally
recognized association) for containment purposes and are
compatible with fuels stored in the EPG UST system.
There are three categories of AIM systems: category 1, category 2,
and category 3. An audible or visual alarm notifies a breach in any
of these systems.
•	Category 1 is a pressure or vacuum system. This system
monitors for the change of either pressure or vacuum levels
within the interstice. This system continually monitors the
integrity of both the inner and outer walls of double-walled
piping.
•	Category 2 is a liquid-filled system that monitors for
changes in the level of a liquid such as brine or propylene
glycol solutions within the reservoir holding the interstitial
liquid. This system also continually monitors the integrity
of both the inner and outer walls of double-walled piping.
•	Category 3 is a dry interstice system. This system uses
float-based or other type sensors typically located in
containment sumps to monitor dry interstitial spaces that
are used for piping interstitial monitoring. Category 3 AIM
system uses liquid-detecting sensors to monitor for a leak
through the inner wall. A breach of product through the
primary wall is conveyed through the interstice to the
containment sump where it contacts the sensor.
Categories 1, 2, and 3 AIM systems are composed of the same
components, except that category 1 and 2 systems contain a
pressure or vacuum monitor or liquid monitoring reservoir,
respectively, located at various places in the piping run.
List of Key Components of AIM Systems
•	Double-walled piping with full interstitial communication
S Piping that is a secondary contained system. It is a
pipe within a pipe, or pipe encased in an outer
covering, with an interstitial space between the

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outer and inner piping walls. All components must
be compatible with the product stored.
Monitoring points: pressure, vacuum, or liquid reservoirs
(category 1 and 2 systems) or containment sumps
(primarily category 3 systems)
S Dedicated areas used to monitor piping for loss of
product or change in condition of pressure, vacuum,
or liquid level.
Sensors
S Pressure sensors or liquid-detecting sensors
(category 1 or category 2 systems, respectively)
> Sensors designed to respond to changes in
pressure (vacuum) or changes in liquid-
level within monitoring reservoir)
S Liquid-detecting sensors (category 3 systems) using
various operating principles such as float-based,
optical and hydrocarbon polymer sensitive.
Leak detection monitoring console with alarm system
(audible or visual)
S An automatic tank gauging system or other system
controller (i.e., console) that works in conjunction
with the pressure, vacuum, or liquid reservoirs, or
liquid-detecting sensors to determine potential
product loss from the AIM system. They contain an
audible or visual alarm component that is
configured to relay an alarm condition to an
appropriate alarm. The alarm condition must be
conveyed to the attention of specific individuals
such as a designated Class A, B, or C operator or
petroleum or power services contractor within one
hour of the suspected release.

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Section 3: Examples of AIM Systems
Category 1 Systems: Continuous Monitoring using
Pressure or Vacuum-Based Methods
Example 1.1 (Pressure)
Example 1.2 (Vacuum)
6

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Category 2 Systems: Continuous Monitoring using
Liquid-Filled Piping Interstice Methods
Example 2.1
CONTINUOUS
Page 12 of EPA's In-Depth Discussion: A utomated Interstitial
Monitoring Systems for Underground Pressurized Piping Systems
on Emergency Power Generator USTSystems discusses
information presented on the National Work Group on Leak
Detection Evaluation's (NWGLDE) website. NWGLDE identifies
several listings of equipment that have been third-party evaluated.
These equipment evaluations are not specific for use on or as AIM
systems detailed in this document. The equipment identified is
potentially adaptable for use in category 1 and category 2 AIM
systems designed for EPG UST systems.
Category 3 Systems: Liquid-Detecting Sensors - Sump
Monitoring to Sensor Activation Point
A basic category 3 AIM system design depicted below highlights
two key system components of this standard design: double-walled
piping and the sumps being monitored by dry interstitial sensors.
The one-hour period for alarm system notification involves the
combination of the time it takes for the total interstitial volume of
the double-walled piping to fill up from a product leak from a
breach in the primary wall to flow through the piping interstice and
accumulate within the sump to where it activates the sensor at the
sensor threshold.
7

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Example 3.1
SUBMERSIBLE TURBINE
PUMP (STP) SUMP
SUMP SENSOR
CONTAINMENT SUMPS
INTERSTICE OF DOUBLE-
WALLED PIPING IS OPEN
DOUBLE-WALLED PIPINi
\
'SUMP SENSOR-> |
I
TRANSITION
SUMP
Page 16 of EPA's In-Depth Discussion: A utomated Interstitial
Monitoring Systems for Underground Pressurized Piping Systems
on Emergency Power Generator USTsystems discusses the design
of category 3 systems. It provides:
•	Tables that show maximum lengths of double-walled
piping that can be used in category 3 AIM systems.
•	Tables with examples of commercially available pipe with
their corresponding interstitial volumes and general
reference standards based on set interstitial volumes of
double-walled piping.
•	Step-by-step design of a basic category 3 system.
•	Suggested system improvements to the basic design of
category 3 systems.
•	Several variations of the AIM system design for category 3
systems:
o Use of a small container attached directly to the
piping interstice as a concentrated collection point
instead of a larger containment sump,
o Use of a liquid-detecting cable run within the length
of the piping interstice. This design provides
multiple liquid contact points installed within
secondary containment areas.
8

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Section 4. O&M Testing and Inspection
Requirements at a Glance
Type of AIM System,
Components, and Required
Actions
(As Applicable)
Required
Testing
Frequency
Regulatory
Citation
Comments
Category 1 & 2 Systems
Monitoring console
^ Verify system configuration
S Test alarm
^ Test battery backup
Annual
280.40(a)(3)(i)
This can be an automatic tank gauge (ATG)
or another controller
Sensors
^ Test alarm operability for
communication with controller
Annual
280.40(a)(3)(ii)
For all sensors, pressure/vacuum and liquid
detecting sensors
Sensors
^ Inspect for residual buildup
Annual
280.40(a)(3)(ii)
For liquid detecting sensors
Automatic Line Leak Detector (ALLD)
Test and inspect:
^ Double-wall (DW) piping
¦S Monitoring reservoir(s)
^ Contaimnent sumps at end points
Annual
280.40(a)(3)(iii)
¦	The piping interstitial space and the
pressure, vacuum, or liquid monitoring
reservoir(s) and sensors (pressure,
vacuum, or stand-alone liquid detecting
sensor, as applicable), and containment
sumps at endpoints, comprise the
automatic line leak detector.
¦	Testing of monitoring reservoir and
sensors follows vacuum pumps and
pressure gauge testing, noted on the
table.
¦	Owners and operators must test their DW
piping to verify the tightness of the
interstitial space. This can be done with a
system check.
¦	Verification of the integrity of the
containment sumps at endpoints is
required annually. This could be by
testing of the sump or if the sump is DW,
proving that the interstitial space of the
containment sump has integrity.
¦	Annual integrity testing of contaimnent
sumps at endpoints that varies from that
in 280.35(a)(l)(ii) may be used to test
full area of sumps(s) or area of sump(s)
to the point of each sensor's activation
threshold, if equipped with liquid
detecting sensor(s).
Monitoring Points (reservoirs and sumps)
9

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Type of AIM System,
Components, and Required
Actions
(As Applicable)
Required
Testing
Frequency
Regulatory
Citation
Comments
Monitoring reservoir
¦S Ensure proper communication of
vacuum pumps and pressure
gauges with sensors and
controllers
Annual
280.40(a)(3)(iv)
Verily that the pressure, vacuum, or liquid
detecting sensor triggers the alarm at the
appropriate threshold and communicates that
to the monitoring console.
Contaimnent sumps at end points of
category 1 or 2 systems (see example
1.1, 1.2or2.1)
^ Test contaimnent sumps used for
piping interstitial monitoring.
Note: If DW contaimnent sump with
periodic monitoring of the integrity of
both walls of the sump, sump testing to
comply with 280.35(a)(l)(ii) is not
required.
Every three
years
280.35(a)(l)(ii)
As a component of the ALLD, as noted on
table, integrity/functionality of contaimnent
sumps at end points must be verified
annually. Owners and operators testing
annually using a recognized low-level sump
testing procedure would meet the regulatory
requirement. If the owner and operator use an
annual test that varies from what is allowed
under 280.35 (a)(l)(ii), then once every three
years a test must be completed that complies
with 280.35(a)(l)(ii).
Category 3 System
Monitoring console (e.g., ATG or
another controller)
^ Verify system configuration
S Test alarm
^ Test battery backup
Annual
280.40(a)(3)(i)

Sensors
^ Test alarm operability for
communication with controller
^ Inspect for residual buildup
Annual
280.40(a)(3)(ii)
For liquid detecting sensors
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Type of AIM System,
Components, and Required
Actions
(As Applicable)
Required
Testing
Frequency
Regulatory
Citation
Comments
Category 3 System (Continued)
ALLD
Test and inspect:
S DW piping
^ Area of containment sump(s) to
the activation point(s) of the
sensor(s)
Note: If DW containment sump with
periodic monitoring of the integrity of
both walls of the sump, sump testing is
not required.
Annual
280.40(a)(3)(iii)
¦	The piping interstitial space and the
area of the sump(s) used for interstitial
monitoring (to the point of each
sensor's activation threshold) and liquid
detecting sensors comprise the
automatic line leak detector.
¦	Owners and operators must test their
DW piping (by air test) to verify
tightness of the interstitial space.
¦	Verification of the integrity of the
containment sump is required annually.
This could be by testing of the sump or
if the sump is DW, proving that the
interstitial space of the containment
sump has integrity.
¦	Annual integrity test of contaimnent
sump that varies from that in
280.35(a)(l)(ii) may be used to test area
of sump(s) to the point of each sensor's
activation point.
Containment sump
^ Test contaimnent sumps used for
interstitial monitoring to ensure
liquid tight using vacuum,
pressure, or liquid testing.
Every three
years
280.35(a)(l)(ii)
¦ As a component of the ALLD,
integrity/functionality of contaimnent
sump(s) must be verified annually.
Owners and operators testing annually
using a recognized low-level sump
testing procedure would meet the
regulatory requirement. If the owner
and operator use an annual test that
varies from 280.35 (a)(l)(ii) then once
every three years a test must be
completed that complies with
280.35(a)(l)(ii).
For more information on low-level sump testing, see EPA's technical compendium.
Section 10 of EPA's "In-Depth Discussion: Automated Interstitial Monitoring Systems for Underground
Pressurized Piping Systems on Emergency Power Generator USTsystems," discusses AIM system testing
more in depth.
11

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Section 5: Required Documentation from
UST System Owners and Operators
Basic Documentation Design and Installation Criteria
40 CFR § 280.40(a)(4) requires that UST system owners and
operators provide a method, or combination of methods, of release
detection that meets the release detection performance
requirements with any performance claims and their manner of
determination described in writing by the equipment manufacturer
or installer.
There are many variations among individual UST site conditions
and system configurations across the United States. This is
especially applicable to EPG UST systems. Because of these
variations a complete AIM system would have to be manufactured
and installed onsite as a unit to meet the release detection method
requirements. AIM systems are comprised of several components.
No one component manufacturer can verify that applicable
regulatory performance requirements can be met for the entire
system.
UST system owners and operators can use the Certification of
Compliance Form on page 14 to verify that their AIM systems
meet design and installation criteria. The equipment installer, a
licensed professional engineer, or other professional required by
the applicable UST implementing agency must sign this form. EPG
UST system owners and operators in Indian Country, where the
federal UST regulation (40 CFR part 280) applies, may submit this
form to the applicable EPA regional office. EPAjs UST website
lists EPA Regional UST contacts.
UST system owners and operators in other jurisdictions should
contact their UST implementing agency to determine whether the
agency allows use of an AIM system to meet its regulatory
requirements and whether this sample form meets the agency's
documentation requirements. Note that many state UST
implementing agencies require UST system installers to be
licensed. EPA's UST website lists state UST contacts .
The checklist below covers testing requirements applicable to AIM
systems. This checklist helps owners and operators identify and
comply with key operation and maintenance testing requirements
associated with AIM systems. This checklist does not include all
testing requirements that owners and operators of EPG UST
systems must meet. For additional information on meeting federal
UST requirements applicable to other equipment and components
12

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of EPG UST systems see EPA's Requirements for Emergency
Power Generator UST Systems at:
https://www.epa.gov/system/files/documents/2022-05/epg-
systein-requirements.pdf.
13

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Certification of Compliance Form: Use of AIM System for EPG UST Facility (Page 1 of 2)
Facility Name
Facility ID #
Physical Address
City
County
State
UST Owner
Installer or PE's Signature
Printed Name of Installer or PE
Description
Line #/
Line #/
Line #/
Line #/ Product

Product
Product
Product

Line Number / Product




Piping Manufacturer




Piping Model




Pipe Diameter / Length of Pipe
/
/
/
/
Approximate Pipe Interstice Volume
(Gallons)




Type of AIM System (Category #)
~ 1 ~ 2 ~ 3
~ 1 ~ 2 ~ 3
~ 1 ~ 2 ~ 3
~ 1 ~ 2 ~ 3
Category 1 or Category 2 Aim Systems
Pressure (P) / Vacuum (V) / Liquid
	Reservoir Manufacturer	
P / V / Liquid Reservoir Model
Note: Some category 1 and 2 systems may also have contaimnent sumps with liquid-detecting sensors like those used in
category 3 systems. These sumps may not be monitored by the pressure, vacuum, or liquid reservoirs. The sumps may be
needed to monitor single-walled piping components inside the sump. As a contaimnent sump used for interstitial monitoring of
piping, the sumps must be tested for integrity once every three years.
Note: Contaimnent sump testing is not required if the contaimnent is double-walled and uses periodic interstitial monitoring
that monitors the integrity of both walls of the sump.
Comments
14

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Certification of Compliance Form: Use of AIM System for EPG UST Facility (Page 2 of 2)
Category 3 Aim Systems
Sump Sensor Manufacturer




Sump Sensor Model




Secondary Pipe Open to Secondary
Contaimnent Sumps or Collection
Point?
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Secondary Containment Sumps
Contaimnent Sump Manufacturer




Contaimnent Sump Model




Automatic Tank Gauge or Monitoring Console
Monitoring Console Manufacturer




Monitoring Console Model




With Alarm
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Alarm
Alarm Manufacturer
Alarm Model
Comments
Attach relevant site diagram, pictures, as-built drawings and other supporting documentation as required by
UST implementing agency.
15

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Section 6:
AIM Systems Inspection and Testing
16

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AIM System Inspection and Testing Checklist: Category 1 or 2 (Page 1 of 2)
UST Facility
Person Completing Checklist
Facility Name
Facility ID #
Name
Physical Address
Company
City County
State
City
State
UST Owner
Signature
Date Completed
Description
Line 1
Line 2
Line 3
Line 4
Type of AIM System (Category #)
~ 1 ~ 2
~ 1 ~ 2
~ 1 ~ 2
~ 1 ~ 2
Attach a copy of the Certification Form for detailed system description.
Walkthrough Inspections [280.36]
Annual
• Visually check contaimnent sumps at
end points for damage and leaks to the
contaimnent area or releases to the
enviromnent. Remove water and
debris.
~
~
~
~
• For double-walled sumps with
interstitial monitoring, check for a
leak in the interstitial area.
~
~
~
~
Every 30 Days
• Check that system is operating with
no alarms or unusual operating
conditions.
~
~
~
~
• Ensure records of system component
testing listed below are reviewed and
current
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Note: The steps below are not required to be performed every 30-days as part of the walkthrough inspection. Most steps
must be performed annually. Use this checklist to verify that each step has been performed within one year (i.e., 365 days)
of the previous test, unless otherwise noted. If No is checked for any of the steps, the AIM system fails. Provide copies of
all relevant test forms upon request to the UST implementing agency.
Testing (Required Annually -
Unless Otherwise Noted)

Monitoring Console 280.40(a)(3)(i)
• Verily system configuration.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Test alarm
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Test battery backup
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Date Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Sensors 280.40(a)(3)(ii)




• Test alarm operability for
communication with
controller/monitoring console.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Inspect for residual buildup.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Date Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
17

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AIM System Inspection and Testing Checklist: Category 1 or 2 (Page 2 of 2)
Testing (Continued)
Description
Line 1
Line 2
Line 3
Line 4
ALLD 280.40(a)(3)(iii)
• DW piping.
Verify integrity of interstitial space by air
testing piping. Ensure vacuum pumps and
pressure gauges are operating within
manufacturer's specifications.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Monitoring reservoir.
Note: Testing of this component covered
below. Listed to show as part of ALLD.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Contaimnent sumps at endpoints.
Note: Verification of integrity could be by
testing of the sump or if the sump is DW,
proving that the interstitial space of the
contaimnent sump has integrity. Annual
integrity testing of contaimnent sumps at
endpoints that varies from that in
280.35(a)(l)(ii) may be used to test full
area of sumps(s) or area of sump(s) to the
point of each sensor's activation threshold,
if equipped with liquid detecting sensor(s).
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Date Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Monitoring Points 280.40(a)(3)(iv)
• Monitoring Reservoir (P / V / Liquid)
¦S Ensure proper communication of
vacuum pumps and pressure gauges
with sensors and controllers, as
applicable. Verify that the pressure,
vacuum, or liquid detecting sensor
triggers the alarm at the appropriate
threshold and communicate that to the
monitoring console.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
S P / V System Calibrated Per
Manufacturer's Instructions.
280.40(a)(2)
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Describe calibration completed and frequency:
Containment Sumps At End Points 280.35(a)(l)(ii) - Required Once Every Three Years
• Test contaimnent sumps used for
piping interstitial monitoring to ensure
liquid tight by using vacuum,
pressure, or liquid testing.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Notes: If DW contaimnent sump with periodic monitoring of both walls of the sump, sump testing to comply with
280.35(a)(l)(ii) is not required.
Owners and operators testing annually using a recognized low-level sump testing procedure would meet the regulatory
requirement. If the owners and operators use an annual test that varies from what is allowed under 280.35 (a)(l)(ii), then a
test that complies with 280.35(a)(l)(ii) must be completed once every three years.
Date Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Comments
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AIM System Inspection and Testing Checklist: Category 3 (Page 1 of 2)

UST Facility

Person Completing Checklist
Facility Name
Facility ID #
Name
Physical Address
Company
City
County
State
City
State
UST Owner
Signature
Date Completed
Description
Line 1
Line 2 Line 3
Line 4
I Attach a copy of the Certification Form for detailed system description.	
Walkthrough Inspections [280.36]
Annual
• Visually check contaimnent sumps at
end points for damage, leaks to the
contaimnent area, or releases to the
enviromnent. Remove water and
debris.
~
~
~
~
• For double-walled sumps with
interstitial monitoring, check for a
leak in the interstitial area.
~
~
~
~
Every 30 Days
• Check that system is operating with
no alarms or unusual operating
conditions.
~
~
~
~
• Ensure records of system component
testing listed below are reviewed and
current - Date of last test is not
beyond 1-year (i.e., 365 days) from
previous test.
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Note: If any of the items below are marked as No. then the AIM system fails. Provide copies of all relevant test forms upon
request to the UST implementing agency.
Testing (Required Annually -
Unless Otherwise Noted)

Monitoring Console 280.40(a)(3)(i)
• Verily system configuration.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Test alarm
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Test battery backup
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Date of Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Sensors 280.40(a)(3)(ii)




• Test alarm operability for
communication with
controller/monitoring console.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Inspect for residual buildup.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Date of Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
19

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AIM System Inspection and Testing Checklist: Category 3 (Page 2 of 2)
Description
Line 1
Line 2
Line 3
Line 4
Testing (Continued)
ALLD 280.40(a)(3)(iii)
• DW piping.
Test by air test to prove tightness of the
interstitial space.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
• Area of containment sump(s) to the
activation point of the sensor.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Note: Integrity could be verified by
testing the sump or if the sump is DW, by
proving that the interstitial space of the
contaimnent sump has integrity. Annual
integrity testing of contaimnent sumps at
end points that varies from that in
280.35(a)(l)(ii) may be used to test full
area of sumps(s) or area of sump(s) to the
point of each sensor's activation
threshold, if equipped with liquid
detecting sensor(s).




Date Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Monitoring Points 280.40(a)(3)(iv)
Containment Sumps used for Piping Interstitial Monitoring
280.35(a)(l)(ii) - Required Once Every Three Years
• Test contaimnent sumps used for
piping interstitial monitoring to
ensure liquid tight by using vacuum,
pressure, or liquid testing.
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
~ Yes ~ No
Notes: If DW contaimnent sump with periodic monitoring of both walls of the sump, sump testing to comply with
280.35(a)(l)(ii) is not required.
Owners and operators testing annually using a recognized low-level sump testing procedure would meet the regulatory
requirement. If the owner and operator use an annual test that varies from what is allowed under 280.35 (a)(l)(ii), then once
every three years a test must be completed that complies with 280.35(a)(l)(ii).
Date Last Test




Test Results
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
~	Pass
~	Fail
Comments
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