## ORVR Compatibility and Vapor Recovery Monitoring

9/14/2004

## Overview

1990 revisions to the Clean Air Act required regions that were in
nonattainment to the 1 hr (120 ppb) standard for ground level ozone
install Stage II vapor recovery systems on all gasoline-dispensing
facilities (GDF). An uncontrolled station has the potential to emit 8.5
lb of hydrocarbon per 1,000 gallons of fuel dispensed. The average GDF
dispenses 1,300,000 gallons of fuel each year, which means the average
uncontrolled station has the potential to emit approximately 1,500
gallons of liquid gasoline into the atmosphere annually. Stage II vapor
recovery systems were designed to capture and contain at least 90% of
the gasoline vapors emitted from the fuel tank of a vehicle during the
refueling process. As components on the vapor recovery system wear out,
drift out of calibration or fail, the ability of the system to capture
and control vapor loss into the atmosphere is adversely affected and the
collection efficiency at the vehicle may be reduced. For example, a
station operating at 60 % efficiency instead of the required 90% has the
potential to emit an additional 450 gallons of liquid gasoline per year
into the environment. Most failures of vapor recovery equipment that
result in excess emissions are difficult to detect and typically go
uncorrected until the next inspection which in most regions is only
required annually. Failed, worn or loosened stage I components such as
riser caps and fill adaptors can result in containment leaks in the
underground storage system resulting in vapor losses at the GDF.

**In-Station Diagnostics (ISD)**

In an effort to further reduce the amount of VOC's in the atmosphere,
the State of California has recently passed new legislation requiring
that Stage II vapor recovery systems be continuously monitored by a
system that is capable of detecting the failure of collection and
containment equipment that could and most likely will result in excess
emissions. As a result In-Station Diagnostic (ISD) systems have been
developed and make technology available to monitor the operation and
efficiency of a vapor recovery system installed at a GDF. These systems
provide warnings and alarms when the vapor recovery equipment installed
at the GDF falls below required operating levels. The ISD system will
prompt operators to make necessary repairs when the equipment drifts out
of compliance or fails. Adherence to these warnings and alarms can help
station owners avoid losses resulting from loss of inventory,
environmental contamination and costly equipment repairs.

Veeder-Root has developed an ISD system that is capable of monitoring
the operation and efficiency of a vapor recovery system. This system
utilizes ISD software installed in an existing TLS 350 console that is
widely used throughout the US and Canada for monitoring underground
tanks and lines. The TLS console is connected to an inventory probe in
each tank used to gather tank level and delivery information, a
Dispenser Interface Module (DIM) used to gather dispenser transaction
data (liquid flow), a Vapor Flow Meter installed in each dispenser (one
per dispenser) used to measure the amount of vapor returning (vapor
Flow) to the underground storage tank and a Vapor Pressure Sensor
installed in the vapor return line (one per station) that monitors the
pressure of the ullage space of the underground tanks.

Once installed the TLS 350 continuously monitors and collects data from
the various sensors. Once a day the data is processed, reports are
generated and warnings and alarms are issued if required. The test
results are also stored for up to one year in the memory of the TLS
system and can be retrieved upon demand. Multiple tests are conducted to
monitor the collection efficiency of the stage II system and the
containment integrity of the underground storage tank system. The tests
utilize differing amounts of historical sensor data ranging from 24
hours to 30 days depending on the individual test being conducted.
Failure of a particular test will result in an ISD warning being issued
(both visual and audible) on the TLS 350 console and if uncorrected will
result in a failure 1 to 30 days later depending on the test and
severity of the problem.

If used properly, an ISD monitoring system can assist a GDF owner and/or
operator in keeping his vapor recovery equipment in proper repair and
operation.

# ORVR Compatibility

The requirement for automakers to equip passenger vehicles and light
trucks with an On-Board Refueling Vapor Recovery (ORVR) system has
further complicated the stage II vapor recovery situation when an assist
pump is used to meter the vapor collected at the vehicles fill spout.
When an ORVR car is fueled at a GDF equipped with an assist style stage
II system, saturated vapors are not available at the fill spout;
consequently, fresh air is collected and returned to the underground
storage tank resulting in increased evaporation and vapor pressure
growth. When the pressure in an underground storage tank rises to 3
inches of water column, a pressure relief valve will open allowing the
excess vapor to be released to the atmosphere.

Several ORVR compatible systems are under development including one that
will be supplied by Gilbarco/Veeder-Root. These systems will allow ORVR
compatibility to be added to a new or existing GDF that is equipped with
an assist style stage II vapor recovery system. These systems detect the
presence of an ORVR vehicle and limit the amount of air that returns to
the underground storage tan during the refueling process. When properly
maintained these ORVR compatible systems will help limit vapor losses
due to over pressurization.

# Recommendation

Since it will likely be quite some time before the population of ORVR
cars reaches the point where Stage II vapor recovery equipment in no
longer needed and since current vapor recovery systems that are not ORVR
compatible and are not continuously monitored for proper operation are
at risk of releasing excess gasoline vapors (VOC's) into the atmosphere
resulting in further environmental damage and loss of inventory. We
would like to see incentives put in place to encourage and assist GDF
owners and operators to install ORVR compatible stage II systems and
Vapor Recovery Monitoring Equipment that can help insure that the stage
II vapor recovery systems are operating at or above the levels they were
originally designed to meet.

Kent Reid

Veeder Root

Director of Strategic Development

125 Powder Forest Drive

Simsbury, CT 06070

\(860\) 651 2710 office

\(860\) 651 2719 fax

\(860\) 985 3485 cell

<kreid@veeder.com>

www.veeder.com