Tank Monitoring System Services

Tank Monitoring System Services

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CommTank offers complete fuel and equipment monitoring services for tank owners and operators. Since 1994, customers have ranked us the best tank monitoring company serving MA, NH, ME and RI.

Our tank monitoring system service is a preventive maintenance solution for customers who depend on fuel tank monitoring systems to ensure the safe operation of their aboveground and underground storage tanks.

We supply several sizes and price ranges of tanks for storage of products ranging from oil to water.

We also service tanks that power generators, equipment, machinery and vehicles.

Fuel Tank Monitoring ServicesFuel Tank Monitoring Services

Applications for use of fuel tank monitoring equipment include a range of mission-critical industries such as healthcare, education, commercial and municipal facilities.

Our customers are building managers, maintenance managers, industrial and manufacturing facility managers, DPW professionals, gas station owners and those responsible for fuel storage tanks at schools, hospitals, and industrial chemical storage facilities. CommTank is their choice provider for fuel oil tank monitoring service to maintain compliance with local and federal regulations.

Modern tank technology includes fuel storage tank gauges with color touch screens that provide web-enabled access to inventory. These tank monitoring systems power continuous leak detection and visual notifications of overfill conditions or loss of pressure in a fuel line.  They ensure that levels of tank products are instantly accessible, as well.  Generators, equipment, and vehicles require constant levels of fuel products to function properly and serve their intended purposes.

In our article about storage tank management, you’ll learn the key components and maintenance requirements of a typical storage tank management program. The article also provides a brief video of what Class A/B Underground Storage Tank Operators should look for during monthly visual inspections.


Terms People Use to Describe UST Tank Monitoring

    • Automatic Tank Gauge System is in use by typically in the United States
    • Leak Detection System is a term typically used by the Federal government
    • Fuel Management System is a term used in the fuel industry (more commonly for fleet tracking)

Automatic Tank Gauge Services

Levels of CommTank automatic tank gauge services include installation, testing, maintenance/repair and recertification of many brands and models of underground tank monitoring systems.  Applications include water tank and fuel tank monitoring systems.

Automatic Tank Gauge Testing

To maintain optimal performance, automatic tank gauge testing for all types of ATG systems should be performed annually, or in accordance with manufacturer specifications and regulatory requirements.

For example, Veeder-Root recommends performing periodic operability testing (annually at a minimum) on all line leak detection systems by a Veeder Root certified technician.

Veeder Root Services

Certified Veeder Root Service Contractors

As your team of local certified Veeder Root service contractors, CommTank professionals install, program, and service Veeder Root aboveground and underground storage tank monitoring systems and perform comprehensive Veeder Root maintenance.

Veeder Root Certification

Veeder Root Certification

Automatic fuel tank monitoring equipment including the Veeder Root TLS-350, TLS-450, TLS4i/TLS4C, and TLS-450PLUS are the most common systems covered by our Veeder Root certification and training.

CommTank professionals perform these on-site services for each Veeder-Root Tank Monitoring System, including Line Leak Detection:

    • Veeder Root Installation & Startup
    • Programming & Operations Training
    • System Tests
    • Level and Leak Sensor Monitoring Systems Troubleshooting
    • Servicing & Maintenance

CommTank Veeder-Root Certified technicians comply with OSHA and manufacturer safety practices, as well as NFPA 30 and 30A installation requirements and other Federal, State and Local UST regulations.

UST Operator Training for Tank Owners (C Operator)

In most states the primary responsibility of a C operator is to respond to alarms on the fuel monitoring system. CommTank provides tank owners and operators with training on UST setup, use, and alarms. This training support includes underground storage tank design, UST monitoring system layout, product delivery procedures, routine inspections, emergency spill procedures and alarm response protocols. 

Learn more about Operator A&B inspection and reporting services, as well as Operator C Training, in our UST Operator Services overview.  It features a Maintenance Schedule Example for Regulated USTs, including the annual requirement of tank leak detection testing.

Veeder Root Warranty and Support

Certified Veeder Root TechniciansPartner with CommTank for tank monitoring system installation and maintenance by our certified Veeder Root technicians.  This support ensures that your tanks maintain Veeder Root warranty protection and coverage.

CommTank technicians are certified to perform installation checkout, startup, programming, system tests, troubleshooting, service techniques and operations training on Veeder-Root systems. Veeder Root provides a one-year warranty, beginning on the date of installation, that covers defects in material and workmanship. They will repair or replace the product if it’s determined to be defective under warranty (labor is not included).

Recommended Replacement for TLS-300 Automatic Tank Gauge

Veeder-Root no longer sells parts for the TLS-300 automatic tank gauge. They recommend customers upgrade to the Veeder-Root TLS4 and TLS-450PLUS Series. Below is a table that shows system compatibility for your current model.

Current ModelRecommended Replacement

* For ATEX, TLS4 would replace TLS-300i

** For ATEX, TLSB would replace TLS-300c

Common Error Codes and Alarms for Tank Monitoring Systems

Tank monitoring systems provide error codes and alarms to alert tank owners of potential failures or problems with their UST system. Common causes of Veeder Root beeping – as well as other types of alarm error codes – are listed below by brand.

Pneumercator TMS Console Alarm Conditions & Code Table

Alarm LEDsDisplay Mode LEDs
Leak – In-tank SensorGAL – Gross Volume (Gallons) Net Volume (with degrees F LED on)
SP1 – Product Level is Above 98% (High High)%GAL – Percent of Capacity
SP2 – Product Level is Above 90% (High)ULL – Ullage Volume (Gallons, Default 90%)
SP3 – Product Level is Below 20% (Low)IN – Product Level (Inches) Water Level (with “u” symbol, inches)
Water – Levels Above 2”F – Product Temperature (degrees F)

Veeder-Root Alarms

Alarm or ErrorTrigger ConditionCommon Cause
Tank SumpLiquid is present in sumpSurface water or Groundwater that enters through a leaking cover or boot.
Transition SumpLiquid is present in sumpSurface water or Groundwater that enters through a leaking cover or boot.
Interstitial Space Liquid is present in InterstitialCondensation or water that enters through the tank sump
OverfillProduct level rises above 90%Delivery person not familiar with tank size or incorrect tank is filled.
High WaterWater is present above preset levelTank bottom sludge can interfere with the probe’s float and give a false alarm. Accumulated water will trigger if detection level set low (>2”)
Data warning Device setup data problemA parameter was changed in the device setup that doesn’t match the configuration.
Sensor OutSensor is not accessibleFault in wiring. Typically, corrosion causes this error at a junction box.
Probe OutLevel probe is not accessibleFault in wiring. Typically, corrosion causes this error at a junction box.

Omntec In-Tank Warning and Alarm Levels

ConditionAudible AlarmLED Light
Max Height AlarmXX
High Level AlarmXX
Overfill AlarmXX
Delivery NeededXX
Low Level AlarmXX
High Water AlarmXX
Interstitial XX
Omntec Troubleshooting

Probe Timeout:

  • Check probe wiring and make sure all connections are snug and there are no breaks in the wire.
  • The proper number of floats should be installed on the probe.
  • If there are more than one probe, swap probe inputs and see if problem stays with probe.

Sensor No Reply:

  • Check sensor wiring and make sure all the connections are snug and there are no breaks in the wire.
  • Check the voltage between the red and the black wires at the sensor input. There should be 9-12 volts DC.
  • If one sensor has no reply, try wiring directly at the controller.

System Bus Alarm:

  • Make sure all internal connections are snug.
  • Try powering down the controller and reseating gray communication cables.
  • Press the reset button on the MCU (MCU card in Proteus K & X only) and 416 boards.

RAS Remotes (Proteus K & X only):

  • An RAS remote is used to alert the tank operator of a high-level condition. A red light will come on for a warning condition and the horn will sound for an alarm condition. These can be programmed in setup (See Programming Manual).
  • To silence the horn, press the “Horn Silence Switch”.
  • You can also test this remote by pressing the “Horn Silence Button” for 5 seconds.


  • The Mini-Me is a remote monitor that can be connected to any industry standard ATG to view current inventory and alarms.
  • If you get a no response alarm, check that the baud rate matches the baud rate of the controller

Tank Monitoring System Installations

An appropriate fuel tank monitoring system is an important component of the tank installation process. 

Our Underground Storage Tank Installation Service page details each step of the underground fuel tank installation.

There are many types of UST monitoring systems, ranging from fully electronic inventory control systems with full monitoring and reporting, to hybrid systems that provide minimal electronic reporting and require manual tracking and recording.

Tank Monitoring SystemYou can trust CommTank to recommend the tank monitoring system that best fits your needs.  Our expertise and experience also enable us to integrate tank gauges into your security system, so all alarms can be monitored in one place.

Automatic Tank Gauge Brands that CommTank Installs and Services

CommTank installs several common models of automatic tank gauge systems, including:

Veeder-Root Tank Monitoring System

    • Veeder Root TLS 350
    • Veeder Root TLS 450
    • Veeder Root TLS4i/TLS4C
    • Veeder Root TLS-450PLUS

OMNTEC – Automatic Tank Gauges

    • OMNTEC Proteus-X OEL800III
    • OMNTEC Proteus-K OEL8000IIIK4 and OEL 8000IIIK8
    • OMNTEC Proteus-B OEL8000III-B

OMNTEC – Leak Detection

    • OMNTEC LU1, LU2, LU3, LU4, LU6, LU9

Pneumercator  - Tank Management System

    • Pneumercator TMS 3000
    • Pneumercator TMS2000
    • Pneumercator TMS400
    • Pneumercator TMS1000

Pneumercator - Audible Alarm Controls

    • Pneumercator LC1000, LC2000

Preferred Utilities

    • Fuel Sentry Model TG-EL-D4A
    • Tank Leak Sentry HD-A2-C

Franklin – Automatic Tank Gauges

    • EV0 200, EVO 400, EVO 550, EVO 600, EVO 5000, EVO 6000

Morrison Brothers

    • Electronic Tank Gauge 1218

OPW site sentinel

    • Nano®, Integra 100™, Integra 500™ and iTouch®


    • Tank Gauging System (Bulk Liquid Management)

Visit our products page for detailed descriptions of each automatic tank gauge system, as well as a video that illustrates the technical capabilities and web-enabled features of the Veeder-Root TLS-450.

Fuel Tank Inventory Control

Fuel tank inventory control is vital for several industries.  The transportation industry relies upon retail gas station tank monitoring systems for underground gas tanks, and commercial fuel tank monitoring systems for underground diesel tanks.  Healthcare and technology are other mission-critical industries for which UST monitoring systems ensure accurate, uninterrupted fuel access and measurement.

Fuel Tank Level Monitoring SystemsFuel tank level monitoring systems (ATGs) enable tank owners to:

  • Observe accurate product levels at a glance, without manual measuring of tank volume
  • Maintain continuous fuel availability (sensors indicate low fuel and the need for a new delivery)
  • Reconcile fuel levels nightly, to ensure no unexplained fuel loss due to:
    • Unauthorized use of fuel pumps
    • Leaking tanks
  • Record fuel levels for regulatory compliance
  • Comply with state regulations that require tank and line tightness testing
  • Eliminate manual measurement and calculation of monthly inventory by providing detailed reports of product delivered and product dispensed

Tank Monitoring System CertificationAnnual Tank Monitoring System Certification

Massachusetts and New Hampshire require annual tank monitoring and leak detection system recertification for regulated underground storage tanks. Owners must submit test results to the state.

As part of our UST maintenance program, CommTank annually inspects and certifies each system we service.  We also offer operator training and annual inspection and tank monitoring system certification services for customers whose systems we do not maintain.

Automatic Tank Gauges are designed to self-perform a static or statistical test that meets federal tank testing requirements.

  • A static test is performed when the tank is not accepting deliveries or dispensing product. The test monitors the tank for level changes over a 2-hour period.
  • A statistical test is performed while the tank is in service. This test ignores the dispensing cycles and measures levels in between those cycles, to create equivalent data that a static test captures.
    • Monthly test - 50% capacity at .2 gallon/hour detected leak rate
    • Yearly test - 90% capacity at .1 gallon/hour detected leak rate

To ensure that an automatic tank gauge is capable of testing at the proper rate, the monitoring system must be annually calibrated to the manufacturer’s standard and certified. The technician must be manufacturer-certified, and trained to perform the test.

  • The New Hampshire Department of Environmental Services developed an ATG test form to document the required annual testing of ATG equipment.
  • Massachusetts does not provide a test form, so CommTank technicians use a form created in-house to document the tank management system recertification procedure.

Example of a tank monitor inspection report:

Tank Monitoring Systems Report

During the tank management system recertification process, CommTank technicians calibrate the release detection system according to manufacturer specifications.  We also check key UST system components such as thermistors and fuel tank probes in accordance with manufacturer instructions.

CommTank technicians test and inspect a water or fuel tank monitoring system and provide the tank owner with a user-friendly report that details the status of these UST monitoring system components:

  • In-Tank Testing
  • Fuel Tank Probes (Leak Detection and Level Sensing)
  • Interstitial Monitors
  • Containment Sensors
  • Dispenser Sensors

Underground Storage Tank Compliance – Meeting Leak Detection Regulations

A typical underground storage tank system includes the following components; spill buckets, interstitial monitors, double-wall piping, underground storage tank sump, fuel dispenser sump, and a monitoring panel.

Functionality of the leak detection system is confirmed through annual tank management system certification.

Compliance Inspection Requirements

Veeder-Root recommends periodic inspection of each TLS tank level monitoring system to ensure completion of compliance tests in accordance with local underground storage tank regulations.

In order for a tank to pass a leak test, the tank leak detection system must compensate for changes in product level due to varying temperatures within the tank. Therefore, completion and review of periodic tank tests will verify the system’s successful operability and ensure compliance with local regulatory requirements.

Learn more about our storage tank compliance program and how CommTank serves the Massachusetts Water Resources Authority (MWRA) in this case study, which includes an underground storage tank diagram.

EPA Requirements for Automatic Tank Gauge Systems

The underground storage tanks page of the US EPA website provides guidance regarding automatic tank gauge systems, including how to maintain compliance with federal UST regulatory requirements. The EPA also provides tank owners and operators this basic checklist to ensure the effective operation of automatic tank gauging systems. This resource outlines steps designed to help UST operators comply with required tank gauging and leak detection processes to prevent fuel spills and costly remediation.

Learn more about MA laws in our article, How to Stay Compliant with Massachusetts Tank Laws.

How to Choose the Correct Fuel Tank Monitoring Sensor

It’s important for tank owners to know that many companies that test UST systems are not experienced tank installers.  Therefore, it’s vitally important to partner with an experienced, full-service UST services firm such as CommTank, versus a general construction contractor with less familiarity and experience with all the steps of the UST installation process.

It’s also critical to perform annual inspections to detect the warning signs of sensor failure.

Fuel Tank Monitoring SensorThe Top 4 Causes of Fuel Tank Monitor Sensor Failure and How to Prevent Them

The top four causes of sensor failure all stem from improper or inadequate UST installation and maintenance.

Four conditions that commonly lead to fuel tank monitoring sensor failure:

    • Corrosion – Condensation forms naturally at the top of the tank can corrode the sensor wiring if the tank was installed without proper sealants to protect the wiring
    • Tank Sump Failure – A tank sump protects the sensor wiring as it enters the tank.  If the sump is incorrectly designed or installed by an inexperienced contractor, water can infiltrate and cause sensor failure.
    • Clogged Sump Drainage – If not correctly installed and maintained, the pea stone that surrounds a sump can get clogged as surface dirt infiltrates the stone, causing water to rise inside the sump area instead of draining away from the tank
    • Dry or Cracked Seals – The rubber seals in tank manways and sumps can dry out and crack, allowing water infiltration. Flexible boots that seal the pipe and wire connections entering the tank are another source of sump sensor failure.

Each of these failures can be prevented with proper installation or regular inspection and maintenance.

Level and Leak Sensor Monitoring Systems

Level and leak sensor monitoring systems use either discriminating or non-discriminating sensors.

A non-discriminating sensor is a float sensor that measures product levels. This sensor will indicate a level in whatever type of liquid it is installed. A non-discriminating sensor is useful for indicating a leak into an interstitial space, tank or fuel dispenser sump.

Non-discriminating sensors activate the same alarm response for each liquid they detect, and they have a single detection point or element.  Non-discriminating sensors have a quick response and recovery time and are the most common type of sensor installed in leak detection systems.

A discriminating sensor has a poly carbon band on the outside of a set of floats. This poly carbon band expands when it comes in contact with fuel and increases resistance in the band. This increase in resistance, in addition to the float sensor rising allows the ATG to detect the difference between fuel and water.

Discriminating sensors provide a different alarm response for each liquid they encounter and different detection points. Discriminating sensors have slow response and recovery time, and are typically installed in USTs.

Optical SensorAn optical sensor is a type of discriminating sensor. A beam of light is directed at a prism and if no liquid is present then the beam is returned to the sensor.  If a liquid is present on the outside of the prism the beam is then reflected away. This would be a non-discriminating sensor if not for the addition of continuity pins. Continuity pins added to the exterior of the prism allow the ATG to measure for the presence of fuel or water.  If there is continuity between the pins, then water is present, and if there is no continuity, then fuel is present, as water is conductive but fuel is not.

The Veeder-Root Model 420 sensor is commonly used as an annular space alarm. 

Learn more about Veeder Root sensor testing, tank monitor sump sensors, leak detection probes, line leak detectors, in our CommTank article, UST Leak Detection Systems Annual Inspection Requirements.

Types of Interstitial Tank Sensors

The space between the inner and outer walls of a double-wall tank is called the interstitial or annular space. A probe (sensor) placed in a dry interstitial space, checks for fluid that leaves the inner wall or enters from the outer wall.

In some fiberglass underground tanks, the interstitial space is filled with brine or glycol and a sensor is used to measure a drop in fluid level.  A level drop indicates that the interstitial fluid has either left the outer wall of the tank or mixed with the product in the inner wall.

Either occurrence would signal a leak to the automatic tank gauge (ATG) connected to the sensor.

Alternate terms for the space between the inner and outer wall of an underground tank include:

    • Annular space
    • Interstitial space
    • Secondary containment

Learn more about automatic tank gauge sensors in our article about UST Leak Detection Systems.

Tank Monitoring Systems Frequently Asked Questions

Tank Monitoring Systems FAQs

ATGs use probes (sensors) to monitor both fuel and water height.  Most underground tanks will have some water at the bottom and regulations require that less than 1 inch of water is maintained in the tank at all times. Sensors are accurate to 1/1000 of an inch for level measurements. Sensors also measure temperature. It’s important to know the fuel temperature because fuel expands and contracts with temperature changes. The warmer the fuel, the larger the volume change. For example, a rise of one degree Fahrenheit in a 10,000-gallon gasoline tank will increase the volume by 7 gallons.

A sensor placed in the dry interstitial space or annual space of a double-walled underground storage tank checks for fluid that is either leaving the inner wall or entering from the outer wall.  A drop in the fluid level indicates that either the interstitial fluid has left the outer wall of the tank or mixed with the product in the inner wall.  Either situation indicates a leak, which the sensor is designed to detect.

The Veeder Root console provides different key information for tank owners, depending on the model of Veeder Root automatic tank gauge system.  For example, the TLS-450 PLUS console provides access to a printer, status lights and a touch screen console. A green status light means ‘all functions normal’, yellow means there is a warning indication and red if there is an alarm. The touch screen console shows the number of tanks you have in service, the gallons of fuel in each tank, and the type of product in each.

During a gross test, the pump turns on and the console records the pressure (Pon). Then, the pump turns off and two additional pressure readings (P1 and P2) are recorded. If the pressure drops below 12 psi, the gross line test fails, and an alarm will be displayed.

  • Check for visible leaks – STP sump and under all dispensers.
  • Verify the tank is not out of fuel. An empty tank will prevent a line from properly pressurizing.
  • Check for other alarms on the console. Depending on console programming, other alarms might prevent a manual gross line test from running.
  • Check the line’s pressure

A UST monitoring system is a release detection system that tracks fuel levels within an underground or aboveground storage tank over a period of time to see if the tank is leaking. It will also provide measurements of the fuel level, volume and temperature, water level and volume, and high and low fuel level warnings.  Many systems are capable of monitoring double-wall tanks and lines, pressurized piping and providing remote communication. UST monitoring systems are also referred to as fuel management systems, automatic tank gauge, and leak detection systems.

A Veeder Root system is an automatic tank gauge (ATG) that can be programmed to monitor several aspects of the use, compliance, and performance of an aboveground or underground storage tank.

Veeder-Root is the world-leading designer and manufacturer of a full line of ATGs. The wide range of available Veeder Root tank gauge systems may be configured to support the various above ground and underground storage tank monitoring needs of petroleum sites.  Optional configurability includes printed documentation and remote monitoring flexibility. Web-enabled connectivity of a remote tank level monitor delivers continuous access via web-enabled devices. This allows tank owners to monitor site performance, and provides real-time alerts, compliance reports, and variance analysis. Visit our products page for details about the many Veeder Root systems that CommTank installs and maintains

The Veeder Root TLS-350 is a proven automatic tank gauging system designed to provide retail and commercial tank operators the flexibility to choose fuel tank management system features that best support their individual needs. Widely used in throughout the world, the Veeder Root TLS 350 offers tank operators key features such as continuous in-tank inventory level tracking, leak detection technology, compliance assurance and reporting tools, and available upgrades such as additional connectivity for optimum flexibility.

An Automatic Tank Gauge system (ATG) is designed to perform a static or statistical test that meets federal tank testing requirements.  Key benefits of an automatic tank gauge system (ATG) for tank owners include compliance with state UST regulations; automatic monitoring of product levels to determine accurate fuel inventories; and easy reconciliation of product use or sales.

Temperature Compensated Volume is also called TC Volume.  Due to seasonal temperature changes, the product in a tank will expand and contract.  For example, colder temperatures cause product to contract, while increasingly warmer temperatures cause incremental increases in product expansion.  Unless a system was otherwise programmed for a different temperature value, Temperature Compensated Volume is set at 60 degrees Fahrenheit.   Also, if the TCV was set to “Disable” during  setup of the system, this will also disable the printing of the TCV value on the system report.

Ultrasonic Tank Monitors are more accurate than gauge readers. The typical gauge reader is accurate to plus/minus 11% while an ultrasonic monitor is accurate to plus/minus 1%.

Choosing the best automatic tank gauge for your application largely depends on the number of tanks that you need to monitor. The Veeder Root TLS-4c is capable of monitoring 2 tanks and TLS-4i is capable of monitoring 4 tanks. This limitation is based on the number of sensor inputs available to each tank. At a minimum, each tank requires a level probe, sump sensor and interstitial space monitor. The Veeder Root 450PLUS is capable of monitoring up to 64 tanks and can track 99 sensors of any one type.

The three main reasons why tank owner or operator would require a UST monitoring system are: 

  • to efficiently and cost-effectively manage product in a tank
  • to comply with local, state and federal regulatory requirements
  • to ensure safe, efficient operation via continuous leak detection.