Diffuse Security Threats: USPS Air Filtration Systems Need More  
Testing and Cost Benefit Analysis before Implementation 	 
(22-AUG-02, GAO-02-838).					 
                                                                 
Following the anthrax attacks of October 2001, the Unites States 
Postal Service (USPS) has started to look at various technologies
that could be implemented in the event of another bioterror	 
attack. The high-efficiency particulate air (HEPA) filtration	 
system is being used as a prototype at two facilities and is	 
planned for implementation throughout the country. HEPA filtering
technology is the state-of-the-art technology for the removal of 
particulate biohazards and other particles of micron-sized range.
USPS has not adequately tested the HEPA filtration system to	 
confirm that it will meet its intended purpose of trapping	 
anthrax spores and its secondary purpose of cleaning the mail	 
processing equipment. USPS's testing has not shown conclusively  
(1) the HEPA filtration system's ability to trap released hazards
and other contaminants, and (2) what level of hazards or	 
contaminants could be released into the mail processing 	 
environment as a result of the air filtration system's design.	 
Furthermore, USPS has not verified through testing that the air  
filtration system will not interfere with the air sampling and	 
detection equipment. Even though HEPA filtration systems could	 
reduce the risk of exposure to biohazards, they may negate the	 
benefits of other technologies being considered by USPS to	 
protect its employees and customers in the event of another	 
anthrax attack. Finally, the design and installation of the HEPA 
filtration system requires custom modification to USPS equipment 
nationwide and will likely cost more than USPS projected in its  
Emergency Preparedness Plan.					 
-------------------------Indexing Terms------------------------- 
REPORTNUM:   GAO-02-838 					        
    ACCNO:   A04500						        
  TITLE:     Diffuse Security Threats: USPS Air Filtration Systems    
Need More Testing and Cost Benefit Analysis before Implementation
     DATE:   08/22/2002 
  SUBJECT:   Air pollution control				 
	     Biological warfare 				 
	     Chemical and biological agents			 
	     Counterterrorism					 
	     Mail delivery problems				 
	     Postal facilities					 
	     Postal service					 
	     Safety						 
	     Strategic planning 				 
	     Terrorism						 
	     National preparedness				 

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GAO-02-838

Report to Congressional Committees

United States General Accounting Office

GAO

August 2002 DIFFUSE SECURITY THREATS

USPS Air Filtration Systems Need More Testing and Cost Benefit Analysis
before Implementation

GAO- 02- 838

Page i GAO- 02- 838 USPS Air Filtration Systems Letter 1

Results in Brief 2 Background 4 USPS Needs to Address HEPA Filtration
System*s Effectiveness

and Design Issues 5 Air Filtration System*s Effects on Air Sampling and
Detection Need

to Be Determined 15 USPS Plans to Deploy Air Filtration Systems Nationwide
Are Not

Justified 16 Conclusions 18 Recommendations 18 Agency Comments and Our
Evaluation 19

Appendix I Comments from the U. S. Postal Service 22

Figures

Figure 1: Tray Showing Items Captured by HEPA Filtration System 9 Figure
2: Design of HEPA Filtration System at Dulles P& DC/ F 10 Figure 3:
Prototype FSX Air Filtration System on the AFCS 11 Figure 4: Prototype
Torit Air Filtration System on the DBCS 12 Figure 5: AFCS Modified with
Metal Hoods 13 Figure 6: DBCS Modified with Plastic Shrouds 14 Figure 7:
DBCS Torit Air Filtration System 15

Abbreviations

AFCS Advanced Facer- Canceller System AFSM Automated Flats Sorting Machine
DAR Decision Analysis Report DBCS Delivery Bar Code Sorter HEPA high-
efficiency particulate air P& DC/ F processing and distribution center/
facility USPS United States Postal Service Contents

Page 1 GAO- 02- 838 USPS Air Filtration Systems

August 22, 2002 The Honorable Henry A. Waxman Ranking Minority Member
Committee on Government Reform House of Representatives

The Honorable Danny K. Davis Ranking Minority Member Subcommittee on Civil
Service, Census, and Agency Organization Committee on Government Reform
House of Representatives

In response to the anthrax attacks of October 2001, the United States
Postal Service (USPS) acknowledged the need for increased protection for
both its employees and customers. In this regard, USPS has started to look
at various technologies that could be implemented in the event of another
bioterror attack. One technology that is being used as a prototype at two
facilities and planned for implementation throughout the country is the
high- efficiency particulate air (HEPA) filtration system. HEPA filtering
technology is the state- of- the- art technology for removal of
particulate biohazards and other particles in the micron- sized range. It
is used in countless facilities around the world for biosafety, electronic
clean room assembly, isolation wards, surgical theaters, bioengineering,
pharmaceutical processing, and any application where the maximum stateof-
the- art reduction or removal of submicron particulate material is
required. USPS expects that the use of HEPA filters will reduce the risk
of exposure to biohazards and prevent cross- contamination of the mail.

You requested that we review USPS*s plans to deploy air filtration systems
nationwide at its processing and distribution centers/ facilities (P& DC/
F). Specifically, we reviewed the (1) effectiveness and design of HEPA
filtration systems for implementation on mail processing equipment; (2)
issues associated with HEPA filter interaction with USPS*s proposed air
sampling and detection systems; and (3) costs, benefits, and risks
associated with deploying an air filtration system.

To address these objectives, we reviewed and analyzed USPS*s Emergency
Preparedness Plan and other documents describing the agency*s plans to
deploy and test air filtration systems. To assess the effectiveness of the

United States General Accounting Office Washington, DC 20548

Page 2 GAO- 02- 838 USPS Air Filtration Systems

HEPA design, we reviewed USPS*s test plans and results. We also visited
the Dulles and Merrifield P& DC/ Fs in Virginia to observe USPS*s mail
processing operations and how the HEPA filtration systems were designed,
installed, tested, and used in an operational environment. During the
course of our work we met with USPS officials to discuss the HEPA air
filtration system*s interaction with detection equipment. We also met with
industry personnel to discuss the effectiveness of HEPA filters in
capturing biohazardous materials. Additionally, we interviewed USPS
officials to discuss the objectives, costs, benefits, and risks of
deploying the air filtration system nationwide. We conducted our review at
the USPS Headquarters in Washington, D. C., and P& DC/ Fs in Merrifield
and Dulles, Virginia, from May through July 2002, in accordance with
generally accepted government auditing standards. We requested comments on
a draft of this report from USPS, and these comments are discussed later
in this report and reproduced in appendix I.

USPS has not adequately tested the HEPA air filtration system to confirm
that it will meet its intended purpose of trapping anthrax spores and its
secondary purpose of cleaning the mail processing equipment. USPS*s
testing has not shown conclusively (1) the HEPA air filtration system*s
ability to trap released hazards and other contaminants, and (2) what
level of hazards or contaminants could be released into the mail
processing environment as a result of the air filtration system*s design.
We recognize the challenge that USPS faces in trying to protect its
workers from airborne biohazards while trying to maintain its operations
and control costs. However, without adequate testing USPS has no assurance
that investing in air filtration equipment will provide adequate risk
reduction to its employees.

Furthermore, USPS has not verified through testing that the air filtration
system will not interfere with the air sampling and detection equipment.
Even though HEPA filtration systems could reduce the risk of exposure to
biohazards, they may negate the benefits of other technologies being
considered by USPS to protect its employees and customers in the event of
another anthrax attack. USPS recognizes that it will need additional
technology to detect and identify potential hazardous materials as early
as possible in the mailstream. Therefore, in addition to installing air
filtration equipment, USPS is designing and installing air sampling and
detection equipment to monitor airborne particles released during
automated mail processing. USPS plans to use this sampling in conjunction
with biohazard detection technology to confirm whether anthrax spores are
present. To be most effective in collecting airborne anthrax, the air
sampling Results in Brief

Page 3 GAO- 02- 838 USPS Air Filtration Systems

equipment must be placed directly over the automated mail processing
machines. However, unless designed correctly, HEPA filtration systems
might have a negative impact on the air sampling and detection equipment
because the anthrax spores could become lodged in the filters and render
the air intake ineffective for detection. Although the USPS has requested
funding for both technologies, it has not yet completed any tests to
determine whether the HEPA filtration systems interfere with the
performance of the proposed air sampling and detection equipment, or
whether other alternatives should be assessed.

Finally, the design and installation of the HEPA filtration system
requires custom modification to USPS equipment nationwide and will likely
cost more than USPS projected in its Emergency Preparedness Plan. In
addition, even as USPS is initiating efforts for the full deployment of
HEPA filtration systems at its nearly 300 P& DC/ Fs across the country, it
has not yet performed a comprehensive investment analysis to identify the
costs, benefits, and risks associated with this initiative or any
alternative solutions. While USPS estimates that the total cost of its
HEPA filtration initiative could be over $300 million by the end of fiscal
year 2002, without a complete investment analysis, the agency will not
know whether these costs outweigh the benefits of the technology.
Moreover, we believe that USPS*s $300 million estimate is understated
because it does not include other costs associated with maintenance.
Specifically, the HEPA filtration systems and portable vacuum systems
appear to be less efficient in cleaning the mail processing equipment than
the former process of blowing out the dust with compressed air (i. e.,
pressurized air exiting through nozzles akin to the air nozzles used to
fill up tires). Thus, there is the potential for greater maintenance
costs, and USPS runs the risk that the costs of investing in a HEPA
filtration system nationwide could be more than originally planned.

To address these concerns, we are recommending that the Postmaster General
take steps to (1) perform additional tests to assess the system*s ability
to capture biohazardous materials and its compatibility with other
proposed technologies before making a decision on whether to deploy the
system nationwide; and (2) evaluate the costs, benefits, and risks
associated with implementing air filtration on mail processing equipment
and other alternative solutions before a large- scale rollout is
initiated.

In commenting on a draft of our report, the USPS generally agreed with our
recommendations and stated that USPS already has actions under way to
address them prior to deploying the filtration systems. While USPS had
concerns that we placed too much emphasis on the secondary benefits of

Page 4 GAO- 02- 838 USPS Air Filtration Systems

the air filtration system*s ability to control dust and its increased
maintenance costs, it agreed with our recommendation to conduct additional
testing to determine the system*s ability to capture biohazards prior to
making a decision on nationwide implementation.

USPS is a vast enterprise that delivers about 680 million pieces of mail
daily to virtually every household and business in the United States
through an array of services. Typical mail items* letters, flats, and
parcels* may be introduced into the mailstream through mailboxes and
collection boxes, thousands of drop points at customer sites, mail
facilities, and other locations across the country. Once mail enters the
USPS mail processing operation, it becomes part of a complex and
diversified system, requiring the coordinated effort of mail processing
plants and delivery units across the country. While much of mail delivery
is labor intensive, most of the effort required to sort the mail for
distribution has been automated by a series of high- volume machines. USPS
has at least 10 different types of automated mail processors totaling more
than 10,000 pieces of equipment in operation. These machines exist at
various points in the mailstream and have mechanical forces that are
likely to cause the release of substantial amounts of anthrax spores from
a piece of mail.

The October 2001 anthrax attacks raised great concerns over the security
of postal employees and customers from exposure to biohazardous materials.
In January 2002, Congress passed Public Law 107- 117 providing USPS $500
million for emergency expenses to buy equipment for sanitizing and
screening mail and to protect postal employees and customers from
biohazardous material with the requirement that they develop an emergency
plan. 1 On March 6, 2002, USPS issued its Emergency Preparedness Plan. The
plan discusses a variety of process changes and technology initiatives
that could be applied to the threat of biohazards in the mail. In
addition, the plan addresses USPS*s goals of protecting postal employees
and customers from exposure to biohazardous material and safeguarding the
mail system from future bioterror attacks, while maintaining current
service levels. USPS plans to achieve this by developing prototypes to
test and evaluate which technologies should be used together with existing
mail processing equipment. To fund its efforts,

1 USPS was also allocated $175 million out of emergency supplemental
appropriations for fiscal year 2001 to be used in part to purchase mail
sanitization equipment, for employee safety measures, and for other
expenses related to the anthrax attacks. Background

Page 5 GAO- 02- 838 USPS Air Filtration Systems

USPS plans to request an additional approximately $1.8 billion for fiscal
years 2002 through 2004.

In response to the anthrax- laden letters that caused widespread
contamination at two postal facilities, USPS began testing HEPA filters to
minimize paper dust, reduce risks to employees from biohazards, and clean
mail processing equipment. The Postal Service plans to deploy this
technology at nearly 300 P& DC/ Fs 2 that handle outgoing mail, but is
specifically testing the prototypes for this technology at its Dulles and
Merrifield, Virginia P& DC/ Fs. 3 These filtration systems have been
implemented to run on two major types of mail processing equipment, the
Delivery Bar Code Sorter (DBCS) and the Advanced Facer- Canceller System
(AFCS) at both sites. The DBCSs are computerized machines that sort
letter- sized mail by using a reader to interpret an imprinted barcode,
while the AFCS is a type of mail processing equipment that automatically
faces letter- sized mail in a uniform orientation and cancels the postage
stamps. However, issues associated with the design and effectiveness of
HEPA filtration systems still need to be addressed. First, USPS has not
completed necessary tests and analysis to confirm the effectiveness of
HEPA filtration systems installed on mail processing equipment and,
therefore, does not know whether this technology will satisfy the agency*s
objectives. Second, the benefits of the HEPA air filtration system*s
ability to reduce dust and clean the mail processing equipment have not
been confirmed. Third, the amount of energy needed to run the HEPA systems
might overwhelm the existing power supply at some P& DC/ Fs and,
therefore, degrade the operation of current mail processing equipment.
Finally, the mail processing equipment will have to be modified in order
for the filtration systems to operate effectively.

2 USPS P& DC/ Fs are the facilities in which mail is processed and
distributed from its origin to its final destination using computer-
controlled electromechanical sorting equipment and computer data
processing systems. A vast transportation network including trucks,
airplanes, and trains, moves the mail between these centers.

3 Although the automated mail handling machines at the P& DC/ Fs generate
a lot of dust, the mail processing environment has been checked and rated
as an acceptable place to work by regulatory agencies. USPS Needs to

Address HEPA Filtration System*s Effectiveness and Design Issues

Page 6 GAO- 02- 838 USPS Air Filtration Systems

To date, USPS has performed initial tests to determine the effectiveness
of its HEPA system*s (1) airflow velocity and (2) ability to remove dust
in the mail sorting machines. However, USPS has not yet confirmed whether
its HEPA filtration system*s prototypes are designed properly to capture
and contain airborne anthrax within the system and not release it into the
mail processing environment. As a result, USPS does not yet know whether
this technology will meet its intended objectives.

USPS has performed tests to determine its HEPA filtration system*s airflow
velocity, but it has not performed the necessary test to confirm whether
the system can actually capture anthrax spores in a mailprocessing
environment. When installed correctly and in the proper environment, HEPA
filters were designed to effectively capture 99.97 percent of all dust,
pollen, mold spores, and bacteria at the 0.3- micron particle size that
might pass through them. Because biohazard particles typically fall into
the range of 1 to 10 microns, HEPA filtration may significantly reduce the
number of particles that exhaust from the vacuum system into the ambient
air of postal facilities. USPS has designed its air filtration equipment
such that the air flows in accordance with industry standards to capture
particle sizes similar to anthrax. To test the effectiveness of this
design, USPS is working with the National Institute for Occupational
Safety and Health to release smoke and tracer gas 4 to verify that the air
filtration equipment is working as expected. Using tracer gas confirms
that the system is moving air as intended through the filters. Experts
from the Environmental Protection Agency agree with this approach for
testing airflow and capture velocity. However, this procedure does not
test either how much anthrax is trapped in the system or the system*s
effectiveness in not releasing anthrax into the mail processing
environment. Without conducting tests that confirm the system*s ability to
trap anthrax and not release any into the mail processing environment, the
USPS has not proven that its design will meet the intent of protecting its
employees and customers.

4 Sulfur hexa fluoride (SF6). Effectiveness of HEPA

Filtration Systems in Mail Processing Equipment Has Not Been Confirmed

Page 7 GAO- 02- 838 USPS Air Filtration Systems

According to USPS, another benefit of installing HEPA air filtration
systems is that the negative air pressure (i. e., vacuum) generated by the
systems may help clean the mail processing equipment. Until October 2001,
USPS mail processing machines, including rollers, belts, and electronic
card cages, were cleaned with compressed air* pressurized air exiting
through nozzles akin to the air nozzles used to fill up tires* a generally
acceptable way to blow out and clean dusty equipment. USPS maintenance
personnel stated that using compressed air is the best way to clean its
machines because most of the dust collects on the pinch rollers, which are
hard to access using a vacuum nozzle. However, USPS banned compressed air
blowing following the anthrax attacks last fall. As a result, USPS began
installing HEPA systems to permanently vacuum its mail processing
equipment and reduce or eliminate the need to hand vacuum the internal
workings of the machines, which is the current process.

USPS recently performed a test to quantify the amount of dust collected by
the HEPA filtration systems deployed at Dulles, but the results have not
yet been analyzed. USPS gathered data from June 11 through June 25, 2002,
on the amount of dust captured by the HEPA filtration systems installed at
the Dulles facility. The test used data collected from four machines* two
AFCSs and two DBCSs* to determine how much dust the filtration systems are
actually capturing and how much dust remains in the mail processing
equipment. Although one AFCS and one DBCS have a HEPA filtration system
installed, the remaining two did not. The test involved using preweighed
filters on four portable HEPA vacuum cleaners, which are used to clean the
four machines individually. After the 2- week test period, USPS weighed
the portable vacuum filters and canisters to determine how much dust the
mail processing equipment collected with the HEPA filtration system versus
those that did not have the prototype system. These test results are still
being analyzed. While this initial testing is a positive step, we are
concerned that the amount of dust collected by the portable HEPA vacuums
from the mail processing machines with filtration systems will be
understated because the data reflect a 24- hour period of operations
versus the normal operations, which are between 7 and 16 hours depending
on the type of equipment. Accordingly, the test may not provide USPS with
the reliable data necessary to make valid conclusions about the efficiency
of the HEPA filtration system.

Given the importance of USPS*s initiative, it is imperative that reliable
tests be performed to confirm whether the use of air filtration systems to
clean mail processing equipment is effective. According to our preliminary
observations, the HEPA filtration systems installed at the Dulles P& DC/ F
are collecting relatively few dust particles and may be causing the dust
to Secondary Benefit of

Reducing Dust and Cleaning Machines Also Not Confirmed

Page 8 GAO- 02- 838 USPS Air Filtration Systems

settle inside the mail processing equipment. When we visited the Dulles P&
DC/ F, we were shown the trays where some of the dust could settle. The
trays contained only rubber bands, paper clips, loose bits of paper, and
mail. See figure 1 for the contents of HEPA filtration system*s tray at
the Dulles P& DC/ F. The Dulles P& DC/ F maintenance manager stated that
when maintenance personnel blew air back through the filters to purge any
dust that may be trapped in them, there was no dust dislodged and the
filters appeared to be clean. The bulk of the dust may be lodged in the
innards of the machines and electronic equipment and not in the filters.
Therefore, USPS maintenance officials are concerned that mail processing
equipment, such as the DBCS, is not being cleaned as thoroughly as it was
previously with the dry sweeping and compressed air blowing methods.
Without an effective mechanism to clean the equipment, 5 the dust lodged
in the machines will manifest itself relatively quickly and may result in
burned out pinch rollers, equipment breakdowns, and generally higher
repair costs and downtime. Hence, USPS may incur additional costs for
repairing equipment in the AFCS and the DBCS, and the additional
maintenance may possibly affect its operations.

5 Although USPS P& DC/ F officials are also attempting to clean the
machines with the HEPA filtered portable vacuum cleaners recently
acquired, the nozzles are not small enough to allow the staff to clean the
intricate portions of the equipment, including bearings and electronic
card cages.

Page 9 GAO- 02- 838 USPS Air Filtration Systems

Figure 1: Tray Showing Items Captured by HEPA Filtration System

USPS believes that installing HEPA filtration systems will minimize the
risks of airborne biohazards in the event of another anthrax attack,
reduce dust levels, and lessen workers* allergy- like symptoms. Therefore,
USPS is proposing the use of HEPA filtration technology as a final
filtering stage to remove smaller particles that constitute airborne
biohazards. However, the design and configuration of the HEPA filtration
system calls for additional requirements.

First, USPS has identified that the HEPA filtration systems installed at
the Dulles P& DC/ F require additional power to avoid affecting current
mail processing equipment. At the Dulles facility, two air filtration
systems* the Torit and FSX* have been installed. The Torit system is being
tested on the DBCS. The FSX system is being tested on the AFCS. See figure
2 for a picture of the HEPA filtration system design at the Dulles P& DC/
F and figures 3 and 4 are pictures of the FSX and Torit HEPA air
filtration systems being tested at the Dulles P& DC/ F. Both the FSX and
Torit systems have been installed with the ductwork covering the entire
AFCS USPS HEPA Design Calls

for Additional Requirements

Page 10 GAO- 02- 838 USPS Air Filtration Systems

and the DBCS units. The front of the DBCS is covered with plastic, and the
back of the cabinet doors have channels cut into them to allow the air to
flow up into the ductwork along the entire length of the machine.

Figure 2: Design of HEPA Filtration System at Dulles P& DC/ F

Page 11 GAO- 02- 838 USPS Air Filtration Systems

Figure 3: Prototype FSX Air Filtration System on the AFCS

Page 12 GAO- 02- 838 USPS Air Filtration Systems

Figure 4: Prototype Torit Air Filtration System on the DBCS

According to USPS officials, this design, as it is configured, presumably
collects dust from all of the rollers and belts along the length of the
machine and directs airborne dust to the ductwork. However, this design
requires a large amount of power to generate enough airflow to move the
dust through the machines. As a result, the Vice President of Engineering
is concerned that the amount of energy required to run the HEPA filtration
systems might overwhelm the power supply at the P& DC/ F and may result in
an outage if additional power is not provided. He added that the HEPA
filtration system*s impact on the power supply is a serious concern, which
the agency plans to address by performing site surveys to determine how
much additional power is required for HEPA air filtration to operate
effectively and to avoid degrading the performance of mail processing
equipment.

Page 13 GAO- 02- 838 USPS Air Filtration Systems

Another concern with USPS*s design of the HEPA filtration system on the
mail processing equipment is that modifications must be made to each type
of machine to ensure that it is automatically and continuously vacuumed
and minimal dust escapes. For instance, the air from inside these machines
will be filtered using HEPA filters before it is discharged back into the
mail processing environment. The continuous flow of air into the equipment
and the discharge of air through multistage vacuum filtration (to
initially filter out larger particles to prevent their plugging the finer
filters), with a final filtration through a HEPA filter, is expected to
reduce the release of airborne hazards from processing equipment into the
facility by several orders of magnitude. To ensure that air is routed to
the HEPA filters, the AFCS and the DBCS have to be closed up with metal
and plastic hoods, respectively. See figures 5 and 6 for examples of the
AFCS metal hoods and DBCS plastic shrouds and figure 7 for the DBCS Torit
air filtration system.

Figure 5: AFCS Modified with Metal Hoods

Installation of HEPA Air Filtration Systems Requires Equipment
Modifications

Page 14 GAO- 02- 838 USPS Air Filtration Systems

Figure 6: DBCS Modified with Plastic Shrouds

Page 15 GAO- 02- 838 USPS Air Filtration Systems

Figure 7: DBCS Torit Air Filtration System

USPS has not yet performed any tests to determine whether the HEPA air
filtration system will impede the performance of the proposed air sampling
and detection system. While HEPA filtration systems might reduce the risk
of exposure to biohazards, USPS will need additional technologies to
detect and identify potential hazardous materials as early as possible in
the mailstream. Therefore, in addition to installing air filtration
equipment, USPS is designing and installing air sampling and detection
equipment to monitor airborne particles released during automated mail
processing. USPS plans to use this sampling in conjunction with biohazard
detection technology to confirm whether anthrax spores are present.
According to USPS officials, to be most effective in collecting airborne
anthrax, the air sampling and detection system must be placed directly
over the automated mail processing machines, including the AFCS and the
DBCS, where the anthrax dispersion is most likely to occur. The efficacy
of the air sampling detection equipment, however, might be hindered since
the AFCS and Air Filtration System*s

Effects on Air Sampling and Detection Need to Be Determined

Page 16 GAO- 02- 838 USPS Air Filtration Systems

DBCS will have to be closed up with metal and plastic hoods, respectively,
in order for the HEPA filtration equipment to function effectively. Refer
to figures 5 and 6 for pictures of AFCS and DBCS with the metal and
plastic hoods installed. Therefore, any HEPA filtration equipment that is
installed in the P& DC/ F would have to be designed so that it does not
interfere with anthrax air sampling and detection system. USPS engineers
recognize this requirement and stated that they would design a *dead
zone,* or an area free of any negative air pressure, in the location where
singular pieces of mail are processed through pinch rollers so that a
proper sample can be taken by the air sampling and detection system.
Consequently, until USPS tests this requirement, it will not know whether
the *dead zone* design will be sufficient to ensure that an adequate
sample can be collected for detection.

According to industry best practices, investment analysis is a critical
process required to select and fund technology investments that will
result in cost- effective solutions focused on measurable and specific
missionrelated benefits. This process involves examining the fundamental
cost, benefit, schedule, and risk characteristics of each investment
before it is funded. USPS has not completed an investment analysis of its
HEPA air filtration systems currently deployed at the Dulles P& DC/ F and,
thus, has not justified investing in HEPA filtration systems for
deployment in its approximately 300 P& DC/ Fs across the country.

Even though the USPS has prepared cost estimates to develop and implement
HEPA filtration systems at its nearly 300 P& DC/ Fs across the nation,
these estimates are incomplete and, therefore, are understated. USPS plans
to implement the HEPA air filtration systems nationwide, at a cost of $245
million, by the end of fiscal year 2002 for air filtration on the Loose
Mail system, AFCS, DBCS, and the Automated Flats Sorting Machine 100
(AFSM). A supplemental funding request of $61 million is also being
considered for fiscal year 2002 to acquire additional air filtration
systems on the regular and outgoing DBCS machines. When added to the $245
million already being considered for near- term purchase, the total cost
of HEPA air filtration systems could increase to $306 million by September
2002. However, these amounts do not include USPS*s recurring costs
including the air filtration estimate of more than $125 million annually
for regular activities such as equipment maintenance, purchase of new
filters, training, and updates to air filtration manuals for more than
10,000 HEPA filtration systems nationwide. Furthermore, USPS may also
incur additional costs. For instance, preliminary data show that the HEPA
filtration systems require more USPS Plans to Deploy

Air Filtration Systems Nationwide Are Not Justified

Page 17 GAO- 02- 838 USPS Air Filtration Systems

power, which results in additional costs to run these systems. According
to our analysis of the initial implementation of air filtration on the
Loose Mail systems, an annual cost of about $8 million will be required to
power these systems. When this amount is added to expenditures associated
with providing more power to support the 6,300 AFCS and DBCS units on
which HEPA filtering technology will be installed, the annual cost for the
extra energy required could be as high as $42 million. 6

Furthermore, there is the potential risk for greater maintenance costs
because the HEPA filtration systems and portable vacuum systems appear to
be less efficient in cleaning the mail processing equipment and may result
in burned out bearings and equipment parts. USPS maintenance and
engineering personnel at Dulles and Merrifield informed us that there is
significant potential for equipment maintenance costs to rise. For
example, we analyzed the potential cost impact of bearing replacement for
the DBCS machines and found that, depending on the cost of the bearing, an
additional $26 to $46 million could be spent on maintenance each year.
According to USPS officials, the DBCS is the largest fleet of machines the
USPS owns, and they run all secondary mail. If these machines break down
more often because the bearings need replacing, this could affect both
costs and operations. In addition, USPS will also have to consider the
risks of increased maintenance costs associated with other equipment such
as the AFCS, Loose Mail, and AFSM 100, which also contain bearings.
However, until USPS completes a risk assessment to determine if the
bearings are wearing out faster using the new maintenance procedures, it
cannot know the extent of the additional maintenance costs that will be
required.

With respect to benefits, USPS officials stated that the agency is
reluctant to quantify benefits because it is committed to spend whatever
is necessary to protect its employees from future biohazard attacks.
Therefore, the officials noted that it is difficult to quantify the
benefits of this technology and its ability to safeguard human life.
Nevertheless, without completing required tests to confirm that the HEPA
filtration systems are able to contain airborne anthrax in a mail
processing environment, USPS will not know whether it is making a
worthwhile investment.

6 These cost estimates assume that the air filtration systems are running
at the same time the machines are processing the mail.

Page 18 GAO- 02- 838 USPS Air Filtration Systems

We recognize the challenge that USPS faces in trying to protect its
workers from airborne biohazards while trying to maintain its operations
and control costs. By designing and testing air filtration systems on its
mail processing machines, USPS has taken steps to reduce risk of exposure
from biohazards to its employees. However, the USPS HEPA air filtration
system design has not yet been proven to contain anthrax spores or reduce
the levels of dust in a mail processing environment and in mail processing
equipment. In addition, the HEPA filtration system*s design and
installation require additional energy and modifications to the mail
processing equipment in order to work properly. Furthermore, USPS has not
verified through testing that the HEPA air filtration system will not
interfere with the air sampling and detection system. Finally, even though
USPS has identified initial cost estimates, it has not yet completed
investment analyses to identify the costs, benefits, and risks associated
with alternative deployment scenarios for HEPA filtration systems. As a
result, USPS has no assurance that investing in HEPA air filtration
systems will provide adequate risk reduction to its employees.

Given the magnitude of this investment and its impact on maintaining the
mail processing equipment, as well as potential effects on its operations
and proposed biohazard detection capabilities, it is important that the
USPS show the specific performance gains attributable to this initiative
before full deployment is pursued.

To ensure that USPS is making a sound investment, we recommend that the
Postmaster General direct the Vice President of Engineering to complete
the following actions before determining whether to proceed with a large-
scale rollout of air filtration systems at 300 USPS P& DC/ Fs:

 Perform tests to determine (1) the HEPA air filtration system*s ability
to trap released hazards and other contaminants and (2) what level of
hazards or contaminants could be released into the mail processing
environment as a result of the air filtration system*s design.  Perform
integrated tests with HEPA air filtration system and detection

technologies being considered to determine whether the *dead zone* will
impede the detection technology*s performance.  Identify the effects of
the HEPA filtration system*s energy consumption on

mail processing equipment performance and what could be done to mitigate
this risk.  Complete an investment analysis to prioritize USPS*s plans to
spend

approximately $300 million to deploy the HEPA air filtration systems
nationwide. Conclusions

Recommendations

Page 19 GAO- 02- 838 USPS Air Filtration Systems

 Analyze alternative solutions, including whether maintenance costs can
be reduced by using compressed air for cleaning mail processing equipment
after implementing a suitable detection technology.

USPS provided comments on a draft of this report in a letter dated August
9, 2002. These comments are summarized below and reproduced in appendix I.
In commenting on a draft of our report, USPS shared overall concerns that
(1) our report placed too much emphasis on the supposed secondary benefits
of the air filtration systems, (2) their cost estimates in its Emergency
Preparedness Plan are low, and (3) increased maintenance costs are not
anticipated.

On the other hand, USPS generally agreed with our recommendations to
continue testing the system to confirm its ability to trap anthrax spores
and to test for interaction between the air filtration and detection
systems. Furthermore, the Service noted that detailed site surveys would
be performed at each P& DC/ F as part of the deployment planning process
to ensure that operation of these systems will not adversely affect the P&
DC/ F*s power supply. USPS also commented that a Decision Analysis Report
(DAR) is being prepared that will address both start- up costs to procure
and deploy the equipment, as well as recurring costs such as increased
electrical usage, maintenance support, spare parts, and training costs for
HEPA air filtration systems. In its comments, the Service stated that it
plans to submit a DAR that must be reviewed and approved by senior
management and voted on by USPS*s Board of Governors prior to deployment.
Finally, USPS agreed with our recommendation that it review the
prohibition on using compressed air to clean mail processing equipment
after effective biohazard detection systems are in place.

With regard to the concern about too much emphasis on secondary benefits,
USPS noted that the main purpose of adding air filtration systems to the
mail processing equipment is to minimize the potential exposure risk to
postal employees and customers in the event of another anthrax attack.
Further, the Service stated that it does not expect the air filtration
systems to eliminate the need for daily cleaning of the mail processing
equipment, and that no cost reductions for reducing nuisance dust were
used to justify the deployment of these systems. We modified our report to
address USPS*s concern that the draft report placed too much emphasis on
the secondary effects of air filtration systems.

The reason we also focused on the HEPA air filtration system*s ability to
clean mail processing equipment is because an additional maintenance
Agency Comments

and Our Evaluation

Page 20 GAO- 02- 838 USPS Air Filtration Systems

cost of up to $46 million annually could result from installing these HEPA
air filtration systems and changing maintenance practices from compressed
air blowing to hand vacuuming. Furthermore, USPS*s Emergency Preparedness
Plan discusses the HEPA air filtration system*s ability to clean equipment
and also states that such designs for reducing nuisance dust were under
way prior to the anthrax attacks.

USPS*s comments additionally stated that the cost for deploying HEPA air
filtration systems nationwide was based on the best information available
at the time. The Service anticipates that as it moves further into testing
and manufacturing, it may run into unanticipated complications that will
require revisions to the cost estimates. We agree that unanticipated
complications may arise and, as a result, additional funding may be
required to reengineer and resolve these issues, which will most likely
increase the cost to develop, deploy, and maintain the HEPA air filtration
systems. Furthermore, we are concerned that the costs are understated due
to the potential for increased operational costs to power the equipment.
This potentially could add up to $42 million annually.

The Service also had concerns relating to our finding on increased
maintenance costs. The comments stated that USPS has not seen any increase
in the number of machine repairs and parts replacements that were required
because of dust buildup in bearings and other components and, therefore,
does not foresee any increased maintenance costs. Our audit work and
evidence provided to us by USPS engineers shows that bearing replacement
rates have changed in the last 6 months. USPS may need to conduct more
studies and analysis before it will know for sure whether the cost of the
new maintenance procedures is higher or lower.

With regard to USPS*s concurrence with our other recommendations, these
planned actions are the appropriate steps to take. USPS plans to conduct
additional testing at the Dulles P& DC/ F to determine the system's
effectiveness in capturing biohazards and to determine the amount of
biohazards that might be released into the mail processing environment.
Testing in an P& DC/ F environment with particles in the 2 to 6 micron
range can be used by the USPS to confirm that the system operates as
designed and will provide the USPS with objective data to make appropriate
modifications, if necessary, to improve the design.

Finally, once the additional testing is completed, USPS plans to complete
the DAR for the HEPA air filtration system and present it for management
review. This should ensure that USPS management has accurate and

Page 21 GAO- 02- 838 USPS Air Filtration Systems

complete information on the capabilities and cost of the air filtration
system prior to making a decision on nationwide implementation.

As agreed with your offices, unless you publicly announce the contents of
this report earlier, we plan no further distribution until 30 days from
the date of this letter. At that time, we will provide copies to
interested congressional committees, the Postmaster General, and Chief
Executive Officer of USPS. We also will make copies available to others
upon request. In addition, the report will be available at no charge on
the GAO Web site at http:// www. gao. gov.

If you have any questions on matters discussed in this report, please
contact me at (202) 512- 6412 or Madhav Panwar, Director, at (202) 512-
6228. We can also be reached by E- mail at rhodesk@ gao. gov and panwarm@
gao. gov, respectively. Individuals making key contributions to this
report were Karen A. Richey, Yvette R. Banks, Teresa Anderson, Teea Kim,
and Sushil Sharma.

Keith A. Rhodes Chief Technologist, Applied Research and Methods

Appendix I: Comments from the U. S. Postal Service

Page 22 GAO- 02- 838 USPS Air Filtration Systems

Appendix I: Comments from the U. S. Postal Service

Appendix I: Comments from the U. S. Postal Service

Page 23 GAO- 02- 838 USPS Air Filtration Systems

Appendix I: Comments from the U. S. Postal Service

Page 24 GAO- 02- 838 USPS Air Filtration Systems (460532)

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