Securing Wastewater Facilities
Costs of Vulnerability Assessments, Risk Management Plans, and Alternative Disinfection Methods Vary Widely Gao ID: GAO-07-480 March 30, 2007In 2006, GAO reported that many large wastewater facilities have responded to this risk by voluntarily conducting vulnerability assessments and converting from chlorine gas to other disinfection methods. The Clean Air Act requires all wastewater facilities that use threshold quantities of chlorine gas to prepare and implement risk management plans to prevent accidental releases and reduce the severity of any releases. In this study, GAO was asked to provide information on (1) the range of costs large wastewater treatment facilities incurred in preparing vulnerability assessments and risk management plans, and (2) the costs large wastewater treatment facilities incurred in converting from chlorine gas to alternative disinfection processes. To answer these questions, GAO conducted structured telephone interviews with a number of facilities surveyed for the 2006 report. The Environmental Protection Agency (EPA) agreed with the report and provided several technical changes and clarifications.
Among the large wastewater facilities GAO examined, the costs reported to prepare vulnerability assessments ranged from $1,000 to $175,000, while costs to prepare risk management plans ranged from less than $1,000 to over $31,000. Whether the documents were prepared in-house or contracted to third parties such as engineering firms was a factor in cost differences. Despite higher costs, some facilities preferred to use contractors due to their expertise and independence. According to one wastewater security official, these attributes can give contractor findings and recommendations greater credibility with utility governing boards that determine spending priorities. One facility that used a contractor to complete a vulnerability assessment in 2002 did so because, at the time, vulnerability assessment software and training were not widely available. Since that time, EPA has increased funding for the development and dissemination of risk assessment software and related training. Overall, cost estimates for vulnerability assessments and risk management plans did not relate to facility size, as measured by millions of gallons of wastewater treated per day. For the large wastewater facilities GAO examined, reports of actual and projected capital costs to convert from chlorine gas to alternative disinfection methods range from about $650,000 to just over $13 million. Most facilities converted, or planned to convert, to delivered sodium hypochlorite (essentially a concentrated form of household bleach shipped in bulk to the facility). Managers of these facilities told GAO they considered other options, but chose delivered sodium hypochlorite because its capital conversion costs were lower than those associated with other alternatives, such as generating sodium hypochlorite on-site or using ultraviolet light. Overall, the primary factors associated with facilities' conversion costs included the type of alternative disinfection method chosen and the size of the facility. Other cost factors facility managers cited included (1) whether existing buildings and related infrastructure could be used in the conversion, (2) labor and building supply costs, which varied considerably among locations, (3) the cost of sodium hypochlorite relative to chlorine gas, and (4) the extent to which training, labor, and regulatory compliance costs were reduced for utilities that no longer had to rely on chlorine gas.
GAO-07-480, Securing Wastewater Facilities: Costs of Vulnerability Assessments, Risk Management Plans, and Alternative Disinfection Methods Vary Widely
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Report to the Chairman, Committee on Environment and Public Works, U.S.
Senate:
United States Government Accountability Office:
GAO:
March 2007:
Securing Wastewater Facilities:
Costs of Vulnerability Assessments, Risk Management Plans, and
Alternative Disinfection Methods Vary Widely:
GAO-07-480:
GAO Highlights:
Highlights of GAO-07-480, a report to the Chairman, Committee on
Environment and Public Works, U.S. Senate
Why GAO Did This Study:
Wastewater facilities provide the essential service of collecting and
treating wastewater, and discharging treated effluent into receiving
waters. Since September 11, 2001, the nation‘s water infrastructure has
received greater attention, including the risk of terrorist attacks at
wastewater facilities that store hazardous chlorine gas for
disinfection.
In 2006, GAO reported that many large wastewater facilities have
responded to this risk by voluntarily conducting vulnerability
assessments and converting from chlorine gas to other disinfection
methods. The Clean Air Act requires all wastewater facilities that use
threshold quantities of chlorine gas to prepare and implement risk
management plans to prevent accidental releases and reduce the severity
of any releases.
In this study, GAO was asked to provide information on (1) the range of
costs large wastewater treatment facilities incurred in preparing
vulnerability assessments and risk management plans, and (2) the costs
large wastewater treatment facilities incurred in converting from
chlorine gas to alternative disinfection processes. To answer these
questions, GAO conducted structured telephone interviews with a number
of facilities surveyed for the 2006 report. The Environmental
Protection Agency (EPA) agreed with the report and provided several
technical changes and clarifications
What GAO Found:
Among the large wastewater facilities GAO examined, the costs reported
to prepare vulnerability assessments ranged from $1,000 to $175,000,
while costs to prepare risk management plans ranged from less than
$1,000 to over $31,000. Whether the documents were prepared in-house or
contracted to third parties such as engineering firms was a factor in
cost differences. Despite higher costs, some facilities preferred to
use contractors due to their expertise and independence. According to
one wastewater security official, these attributes can give contractor
findings and recommendations greater credibility with utility governing
boards that determine spending priorities. One facility that used a
contractor to complete a vulnerability assessment in 2002 did so
because, at the time, vulnerability assessment software and training
were not widely available. Since that time, EPA has increased funding
for the development and dissemination of risk assessment software and
related training. Overall, cost estimates for vulnerability assessments
and risk management plans did not relate to facility size, as measured
by millions of gallons of wastewater treated per day.
For the large wastewater facilities GAO examined, reports of actual and
projected capital costs to convert from chlorine gas to alternative
disinfection methods range from about $650,000 to just over $13
million. Most facilities converted, or planned to convert, to delivered
sodium hypochlorite (essentially a concentrated form of household
bleach shipped in bulk to the facility). Managers of these facilities
told GAO they considered other options, but chose delivered sodium
hypochlorite because its capital conversion costs were lower than those
associated with other alternatives, such as generating sodium
hypochlorite on-site or using ultraviolet light. Overall, the primary
factors associated with facilities‘ conversion costs included the type
of alternative disinfection method chosen and the size of the facility.
Other cost factors facility managers cited included (1) whether
existing buildings and related infrastructure could be used in the
conversion, (2) labor and building supply costs, which varied
considerably among locations, (3) the cost of sodium hypochlorite
relative to chlorine gas, and (4) the extent to which training, labor,
and regulatory compliance costs were reduced for utilities that no
longer had to rely on chlorine gas.
[Hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-07-480].
To view the full product, including the scope and methodology, click on
the link above. For more information, contact John Stephenson at (202)
512-3841 or stephensonj@gao.gov.
[End of section]
Contents:
Letter:
Results in Brief:
Background:
Costs of Preparing Vulnerability Assessments and Risk Management Plans
among Large Wastewater Facilities Vary Widely:
Costs of Converting to Alternative Disinfection Methods at Large
Wastewater Facilities Depend on the Method Used and Other Factors:
Agency Comments and Our Evaluation:
Appendix I: Scope and Methodology:
Appendix II: Comments from the Environmental Protection Agency:
Appendix III: GAO Contact and Staff Acknowledgments:
Table:
Table 1: Reported and Planned Disinfection Conversion Costs for Large
Wastewater Treatment Facilities:
Abbreviations:
AWWARF: American Water Works Association Research Foundation:
DHS: Department of Homeland Security:
EPA: Environmental Protection Agency:
NACWA: National Association of Clean Water Agencies:
OSHA: Occupational Safety and Health Administration:
POTW: publicly owned treatment works:
RAM-W: Risk Assessment Methodology for Water Utilities:
VSAT: Vulnerability Self Assessment Tool:
WEF: Water Environment Federation:
United States Government Accountability Office:
Washington, DC 20548:
March 30, 2007:
The Honorable Barbara Boxer:
Chairman:
Committee on Environment and Public Works:
United States Senate:
Dear Madam Chairman:
Wastewater facilities in the United States provide essential services
to residential, commercial, and industrial users by collecting and
treating wastewater and discharging treated effluent into receiving
waters. The Centers for Disease Control and Prevention cited sewage
disposal and water treatment as important contributors to the control
of infectious diseases, which it considers 1 of the 10 greatest
achievements in public health of the 20th century. Wastewater
disinfection, a key component of the wastewater treatment process,
reduces the risk that disease will be transmitted through wastewater
effluents. Historically, chlorination has been the most commonly used
method of wastewater disinfection because it destroys a variety of
pathogens and microorganisms.
Since the events of September 11, 2001, the security of the nation's
water infrastructure against terrorist threats has received greater
attention, including the potential for terrorist attacks at wastewater
facilities that store large amounts of chlorine gas. If released,
chlorine gas may threaten utility employees and the public near the
affected facilities. The gas can be deadly if inhaled and, at lower
doses, can burn the eyes and skin and inflame the lungs. In a 2004
report, the White House Homeland Security Council determined that a
terrorist attack on an urban chemical facility that resulted in the
rupture of a chlorine gas rail car could kill up to 17,500 individuals
and hospitalize as many as 100,000.
While federal law does not require wastewater systems to take security
measures to protect specifically against a terrorist attack, it does
require certain wastewater facilities to take security precautions that
could mitigate the consequences of such an attack. For example, the
Clean Air Act[Footnote 1] requires wastewater facilities that use
threshold quantities of certain hazardous substances, such as chlorine
gas, to prepare and implement a risk management plan designed to
prevent accidental releases of regulated substances and reduce the
severity of those releases that do occur.[Footnote 2]
As we reported in March 2006,[Footnote 3] many of the nation's large
wastewater facilities have improved security since September 11, 2001.
For instance, a substantial number of facilities reported improving
security fences, increasing security lighting, and implementing
improved employee and visitor identification systems, among other
security enhancements. In addition, though not required, many large
wastewater facilities reported that they conducted vulnerability
assessments[Footnote 4] to identify risks to key process components
such as the use, storage, and handling of chlorine gas. Finally, many
facilities reported that they recently stopped or plan to stop using
chlorine gas in favor of alternate disinfection methods. Commonly used
alternatives include sodium hypochlorite, essentially a concentrated
form of household bleach, and ultraviolet light, which breaks down
disease-causing microorganisms.
For wastewater facility managers, the costs of preparing vulnerability
assessments and risk management plans and converting to alternate
disinfection methods must compete for available resources with other
infrastructure needs. For instance, in 2003, in its most recent Clean
Water Needs Survey, the Environmental Protection Agency (EPA) estimated
that, nationwide, wastewater systems faced $181.2 billion in costs to
upgrade treatment systems and sewer lines, reduce the incidences of
combined sewer overflows, which result in the discharge of untreated
wastewater into receiving waters, and meet other pollution control
requirements. Major U.S. cities, including Washington, D.C., and
Cincinnati, Ohio, are facing costs between $1 billion and $2 billion to
implement necessary capital improvements.
This report provides information on (1) the range of costs large
wastewater treatment facilities incurred in preparing vulnerability
assessments and risk management plans, and (2) the costs large
wastewater treatment facilities incurred in converting from chlorine
gas to alternative disinfection processes.
To identify the costs of preparing vulnerability assessments and risk
management plans, we conducted structured telephone interviews with a
select sample of large wastewater facilities identified as having
completed these assessments in our March 2006 report.[Footnote 5] Our
March report identified 106 large facilities that prepared
vulnerability assessments or had one underway and 85 facilities that
were required to prepare risk management plans because they currently
used chlorine gas as a disinfectant. From this universe, we chose a
nonprobability sample of facilities based largely on geographic
representation and size.[Footnote 6]
To identify the costs incurred by wastewater treatment facilities in
converting from gaseous chlorine to alternative disinfection processes,
we conducted structured telephone interviews with most of the 38 large
facilities identified in the March report as having converted recently
from chlorine gas or indicating that they planned to do so. We also
conducted site visits with some of the facilities. Where available, we
gathered documentation, such as capital plans, from these facilities in
order to document conversion costs. We supplemented the cost
information we gathered at individual wastewater facilities with
information obtained at EPA, the Department of Homeland Security (DHS),
and nongovernmental organizations. Reported costs for preparing
vulnerability assessments, risk management plans, and conversion from
gaseous chlorine include both actual and estimated costs. For estimated
costs, we asked facility managers to explain how they arrived at these
estimates. Reported costs were not adjusted for inflation. We
determined that reported cost data were sufficiently reliable to
provide useful information about the costs for preparing vulnerability
assessments, risk management plans, and conversion from gaseous
chlorine and the factors that affect these costs. We conducted our work
between August 2006 and March 2007 in accordance with generally
accepted government auditing standards. A more detailed discussion of
our scope and methodology is included in appendix I.
Results in Brief:
The expenses large wastewater facilities reported to prepare
vulnerability assessments and risk management plans varied widely among
the facilities we interviewed, costing less than $1,000 in some cases
to $175,000 in others. The cost differences were related to whether the
documents were prepared in-house or contracted to third parties such as
engineering firms. Despite higher costs, some facilities preferred to
use contractors due to their expertise and independence. According to
one wastewater security official, these attributes can give contractor
findings and recommendations greater credibility with utility governing
boards that determine spending priorities. Overall, cost estimates of
the facilities we interviewed did not relate to facility size, as
measured by millions of gallons of wastewater treated per day.
Large wastewater facilities that converted or plan to convert from
chlorine gas disinfection to alternative disinfection processes also
report widely varying costs, ranging from about $650,000 to just over
$13 million. Key factors associated with these costs included the type
of alternative disinfection method chosen and the size of the facility.
The majority of the facilities we examined converted or plan to convert
to sodium hypochlorite (either delivered in bulk to the facility or
generated on-site), which has lower capital costs than converting to
ultraviolet light. For example, managers of a treatment facility in
Virginia told us they spent about $1.2 million in 2004 converting to
bulk sodium hypochlorite disinfection, while managers of a comparably
sized facility in Maryland told us they plan to spend an estimated $4
million converting to ultraviolet light disinfection by the end of this
year. Managers of the Maryland facility indicated that one reason they
chose the more expensive ultraviolet treatment option over bulk
deliveries of sodium hypochlorite was to reduce risk to local traffic
that could result from additional deliveries to the plant. In addition,
using ultraviolet light eliminates the need for wastewater treatment
plants to handle and store significant amounts of hazardous or
corrosive chemicals. Other than the disinfection method and facility
size, key cost factors wastewater facilities cited included (1) whether
existing buildings could be used in the conversion, (2) building costs,
which varied considerably from location to location, (3) the higher
cost of sodium hypochlorite relative to chlorine gas, and (4) the
extent to which training, labor, and regulatory compliance costs were
lower at plants that no longer had to rely on chlorine gas.
Background:
A majority of the nation's wastewater is treated by publicly owned
treatment works that serve a variety of customers, including private
homes, businesses, hospitals, and industry. These publicly owned
treatment works are regulated by the Clean Water Act. Wastewater
treatment includes a collection system (the underground network of
sewers) and a treatment facility. Wastewater enters the treatment
facility through the collection system, where it undergoes an initial
stage called primary treatment, during which screens remove coarse
solids, and grit chambers and sedimentation tanks allow solids to
gradually sink. Next, wastewater enters secondary treatment, where
bacteria consume most of the organic matter in the wastewater. After
these processes, wastewater is disinfected to eliminate remaining
pathogens and other harmful microorganisms.
Wastewater facilities typically use both chemical and physical
disinfection methods, including the following:
* Chlorine gas. Injecting chlorine gas into a waste stream has been the
traditional method of disinfecting wastewater. Chlorine gas is a
powerful oxidizing agent, is relatively inexpensive, and can be stored
for an extended period of time as a liquefied gas under high pressure.
Also, the residual chlorine that remains in the wastewater effluent can
prolong disinfection after initial treatment. However, chlorine gas is
extremely volatile and hazardous, and it requires specific precautions
for its safe transport, storage, and use. Because it is stored and
transported as a liquefied gas under pressure, if accidentally
released, chlorine gas can quickly turn into a potentially lethal gas.
EPA requires, among other things, that any facility storing at least
2,500 pounds of chlorine gas prepare a risk management plan that lays
out accident prevention and emergency response activities. At certain
concentrations, the residual chlorine that remains in wastewater
effluent is toxic to aquatic life, so wastewater facilities that use
chlorine compounds may also need to dechlorinate the treatment stream
before discharging it to receiving waters.[Footnote 7] Chlorine can
also oxidize certain types of organic matter in wastewater, creating
hazardous chemical byproducts, such as trihalomethanes. Our March 2006
report found that many large wastewater facilities have discontinued,
or are planning to discontinue using chlorine gas as a disinfectant in
favor of alternative disinfection methods such as sodium hypochlorite
delivered in bulk to the facility. Of the 206 large wastewater
facilities responding to our survey, only 85 facilities indicated they
currently use chlorine gas, and 20 of these facilities plan to switch
from the gas to another disinfectant.
* Sodium hypochlorite. Injecting sodium hypochlorite--essentially a
concentrated form of household bleach--into a waste stream is another
chlorination method of disinfecting wastewater. Sodium hypochlorite is
safer than chlorine gas because, if spilled, it remains liquid and can
be contained and recovered. For this reason, it is not subject to EPA's
risk management planning requirements. However, sodium hypochlorite is
more expensive than chlorine gas, and it degrades quickly if it is
exposed to sunlight or is not kept at proper temperatures. For this
reason, properly storing delivered sodium hypochlorite in the
concentration necessary to disinfect wastewater may require an on-site
building with environmental controls. Sodium hypochlorite can also be
generated on-site at a wastewater facility using an
"electrochlorination system" that produces sodium hypochlorite through
an electrical reaction with high-purity salt and softened water.
Facilities choosing this method of disinfection reduce chemical costs,
but face increased electrical costs from the generation equipment.
Because it is a chlorine compound, wastewater facilities using sodium
hypochlorite must also be concerned with residual chlorine and
hazardous chemical byproducts, such as trihalomethanes.
* Ultraviolet light. This disinfection method uses ultraviolet lamps to
break down disease-causing microorganisms in wastewater. Wastewater
passes through an open channel with lamps submerged below the water
level. The lamps transfer electromagnetic energy to an organism's
genetic material destroying the ability of its cells to reproduce.
Because ultraviolet light is a physical process rather than a chemical
disinfectant, it eliminates the need to generate, handle, transport, or
store hazardous and corrosive chemicals. In addition, there are no
harmful residual effects to humans or aquatic life. However,
ultraviolet light disinfection may not be effective given the turbidity
of some wastewater streams. Wastewater facilities using ultraviolet
instead of chlorine gas or delivered sodium hypochlorite for
disinfection will face additional costs to maintain lamps and increased
electrical costs.
* Ozone. This disinfection method feeds ozone generated on-site from
oxygen exposed to a high-voltage current into a contact chamber
containing wastewater. According to EPA, ozone is very effective at
destroying viruses and bacteria, but it is the least used disinfection
method in the United States largely because of its high capital and
maintenance costs compared to available alternatives.
According to EPA, vulnerability assessments help water systems evaluate
susceptibility to potential threats such as vandalism or terrorism and
identify corrective actions that can reduce or mitigate the risk of
serious consequences. The Public Health Security and Bioterrorism
Preparedness and Response Act of 2002 (the Bioterrorism Act)[Footnote
8] required drinking water utilities serving populations greater than
3,300 to complete vulnerability assessments by June 2004.[Footnote 9]
Wastewater facilities are not required by law to complete vulnerability
assessments. Congress has considered bills that would have encouraged
or required wastewater treatment plants to assess vulnerabilities, but
no such requirement has become law.
In our March 2006 report on wastewater facility security efforts, we
found that many large wastewater facilities have either completed a
vulnerability assessment or had one underway. Of the 206 large
wastewater facilities that responded to our survey, 106 facilities--or
51 percent--reported that they had completed a vulnerability assessment
or were currently conducting one. Several other facilities indicated
they had conducted or planned to conduct other types of security
assessments. Facilities cited several reasons for completing a
vulnerability assessment or some other type of security assessment, but
most--roughly 77 percent--reported doing so on their own initiative.
Many facilities indicated they were combined systems--facilities that
manage both drinking water and wastewater treatment. As such, 37
percent of facilities reported that they did some type of security
assessment in conjunction with the required assessment for their
drinking water facility.
The Clean Air Act requires wastewater facilities that use or store more
than 2,500 pounds of chlorine gas to submit to EPA a risk management
plan that lays out accident prevention and emergency response
activities. Under this act, EPA requires that about 15,000 facilities-
-including chemical, water, energy, and other sector facilities--that
produce, use, or store more than threshold amounts of chemicals posing
the greatest risk to human health and the environment take a number of
steps to prevent and prepare for an accidental chemical release. EPA
regulations implementing the Clean Air Act require that the owners and
operators of chemical facilities include a facility hazard assessment,
an accident prevention program, and an emergency response program as
part of their risk management plans. The regulations required that a
summary of each facility's risk management plan be submitted to EPA by
June 21, 1999. The plans are to be revised and resubmitted to EPA at
least every 5 years, and EPA is to review them and require revisions,
if necessary.
Costs of Preparing Vulnerability Assessments and Risk Management Plans
among Large Wastewater Facilities Vary Widely:
Although accurate information on the costs of vulnerability assessments
and risk management plans is limited, available estimates suggest that
their costs vary considerably. A factor contributing to the cost
differential was whether they were contracted to third parties (such as
engineering consulting firms) or prepared in-house with existing staff.
Despite higher costs, some facilities preferred using contractors
because their expertise and independence lent credibility to their
assessments, which may be useful in obtaining support for security-
related upgrades. Costs generally did not relate to facility size, as
measured by million of gallons of wastewater treated per day.[Footnote
10]
Vulnerability Assessment Costs Depend Primarily on Whether a Contractor
Is Used:
The reported cost of preparing vulnerability assessments at the 20
large wastewater facilities where we interviewed officials ranged from
$1,000 to $175,000. Whether the assessment was done in-house with
existing staff or contracted to a third party was a factor contributing
to the cost differences. Officials from several facilities told us they
used contractors to complete vulnerability assessments in 2002. For
example, staff at the Denver Metro Wastewater Reclamation District
reported that a contractor completed a vulnerability assessment in
November 2002 for its Central Treatment Plant, which treats 130 million
gallons of wastewater per day, at an estimated cost of $175,000. Of
this cost, $100,000 was for the contractor, and $75,000 was estimated
for in-house staff time.
Other large wastewater facilities that reported completing
vulnerability assessments in 2002 were part of combined systems that
provide both drinking water and wastewater services. These systemwide
vulnerability assessments were done before the 2002 Bioterrorism Act
required drinking water utilities serving populations greater than
3,300 to complete vulnerability assessments by June 2004. The combined
systems that conducted systemwide vulnerability assessments include the
following:
* San Antonio Water System (San Antonio, Texas). According to system
staff, a contractor completed a systemwide vulnerability assessment for
all its drinking water, wastewater, and related infrastructure in
August 2002 for $112,000. Staff did not provide an estimate of in-house
costs related to the assessment, but prorated the wastewater treatment
plants costs related to this contract at $37,000: $25,000 for its Dos
Rios plant, which treats 70 million gallons per day; $5,000 each for
its Leon Creek and Salado Creek plants, which treat 33 million gallons
per day; and $2,000 for its Medio Creek plant, which treats 5 million
gallons per day.
* The Phoenix Water Services Department (Phoenix, Arizona). According
to department staff, a contractor completed a systemwide vulnerability
assessment for its five drinking water plants, three wastewater plants,
and related infrastructure in November 2002 for $479,725. Staff did not
provide an estimate of in-house cost related to the assessment, but
estimated the contract costs related to its largest wastewater
treatment plant, the 91st Avenue Sewage Treatment Plant, which treats
140 million gallons per day, to be $100,000.
* Fort Worth Water Department (Fort Worth, Texas). According to
department staff, a contractor completed a systemwide vulnerability
assessment for its four drinking water plants and one wastewater
treatment plant in December 2002 at a cost of $292,300. Staff did not
provide an estimate of in-house cost related to the assessment, but
estimated the contract costs related to its Village Creek Wastewater
Treatment Plant, which treats 96 million gallons per day, at $73,075.
Wastewater facility managers cited several reasons for using
contractors to complete vulnerability assessments. Staff with the
Phoenix Water Services Department told us they used contractors for
their vulnerability assessment because a citywide policy required that
contract services be used whenever possible. Staff at other wastewater
facilities told us that, despite the higher costs, they preferred to
use contractors because of their expertise. According to a wastewater
security official, contractor expertise and independence can give
contractor findings and recommendations greater credibility with
utility governing boards that determine spending priorities.
One manager told us that he used a contractor for a 2002 vulnerability
assessment because risk management software and tools were not yet
available. After the events of September 11, 2001, EPA provided funding
to the Association of Metropolitan Sewerage Agencies[Footnote 11] to
develop software, called the Vulnerability Self Assessment Tool (VSAT),
for water utilities to use to develop vulnerability assessments.
According to a Water Environment Federation (WEF) official, VSAT became
available in June 2002. This official also said that EPA provided
funding to WEF to provide training workshops to wastewater utilities on
how to use VSAT to conduct vulnerability assessments beginning October
2002.[Footnote 12]
According to interviews with wastewater facility managers, large
wastewater facilities that prepared vulnerability assessments in-house
with existing staff reported lower costs for preparing the document.
These include the following:
* City of Ventura Public Works Department (Ventura, California).
According to facility staff, in-house staff completed a vulnerability
assessment in March 2003 for the Ventura Water Reclamation Facility,
which treats 9 million gallons per day, at a cost of roughly $1,000 in
staff time. Facility staff participated in VSAT training sponsored by
EPA and completed the assessment using this tool.
* City of Fort Wayne Utilities Division (Fort Wayne, Indiana).
According to facility staff, in-house staff completed a vulnerability
assessment in November 2005 for the Fort Wayne Water Pollution Control
Plant, which treats 43 million gallons per day, at undetermined staff
time. Facility staff participated in VSAT training and updated a
previous risk assessment prepared for the facility by a contractor in
2000 at a contracted cost of $10,000.
* City of Eugene Wastewater Division (Eugene, Oregon). According to
facility staff, in-house staff completed a vulnerability assessment in
October 2005 for the Eugene/Springfield Regional Water Pollution
Control Facility, which treats 38 million gallons per day, for about
$2,000 in staff time.
* City of Cedar Rapids Department of Water Pollution Control (Cedar
Rapids, Iowa). According to facility staff, in-house staff completed a
vulnerability assessment in January 2007 for the Cedar Rapids
Wastewater Treatment Plant, which treats 35 million gallons per day,
for about $5,000 in staff time.
* Detroit Water and Sewerage Department (Detroit, Michigan). According
to department staff, in-house staff completed a vulnerability
assessment in January 2005 for the Detroit Wastewater Treatment Plant,
which treats 700 million gallons per day, for about $20,000 in staff
time.
Risk Management Plan Costs Also Influenced by Use of Contractors:
Costs to prepare risk management plans ranged from less than $1,000 for
facilities that completed the plan in-house to over $31,000 for
facilities that used contractors. Costs to update risk management plans
were generally less, ranging from less than $1,000 to $20,000 depending
upon whether facilities used in-house staff or contractors.
Costs were generally higher at facilities that used contractors. These
include the following:
* The Phoenix Water Services Department (Phoenix, Arizona). According
to department staff, a contractor completed risk management plans for
all the system's drinking and wastewater facilities in 1999 for
$230,086. Costs for the 91st Avenue Sewage Treatment Plant were
prorated at $28,761. Department staff said a contractor updated the
91st Avenue plant's risk management plan in 2004 for $20,000.
* Fort Worth Water Department (Fort Worth, Texas). According to
department staff, a contractor completed risk management plans for all
of the department's drinking water and wastewater facilities in 1999
for $124,718. Costs related to the Village Creek Wastewater Treatment
Plant's risk management plan were prorated at $31,100. Department staff
reported that the contractor later updated these risk management plans
for $18,040 in 2004, $4,510 of which was for the Village Creek plant.
* City of Fort Wayne Utilities Division (Fort Wayne, Indiana).
According to facility staff, a contractor completed a risk management
plan in 2001 for the Fort Wayne Water Pollution Control Plant for
$16,000. Facility staff reported a contractor updated the plan in 2005
for $6,000.
* South Central Regional Wastewater Treatment and Disposal Board
(Delray Beach, Florida). According to facility staff, a contractor
completed a risk management plan in 1999 for the South Central Regional
Wastewater Treatment and Disposal Plant, which treats 18 million
gallons per day, for $10,000. Facility staff reported a contractor
updated it in 2006 for $2,000.
* City of Portland Bureau of Environmental Services (Portland, Oregon).
According to bureau staff, a contractor completed a risk management
plan in 1999 for its Columbia Boulevard Wastewater Treatment Plant,
which treats 143 million gallons per day, for $30,000. Bureau staff
reported they updated the plan using in-house staff in 2004 for $10,000
in staff time.
Other large wastewater facilities that prepared risk management plans
in-house with existing staff reported lower costs for preparing the
documents. These include the following:
* San Antonio Water System (San Antonio, Texas). According to system
staff, in-house staff completed a risk management plan in 1999 for the
Dos Rios Wastewater Treatment Plant for between $5,000 and $10,000 in
staff time. In-house staff updated the plan in 2004 for less than
$1,000 in staff time.
* City of Cedar Rapids Department of Water Pollution Control (Cedar
Rapids, Iowa). According to facility staff, in-house staff completed a
risk management plan in January 2000 for the Cedar Rapids Wastewater
Treatment Plant for $5,000 in staff time. In-house staff updated the
plan in 2004 for about $250 in staff time.
* Denver Metro Wastewater Reclamation District (Denver, Colorado).
According to district staff, in-house staff completed a risk management
plan in 1999 for $10,000 in staff time. In-house staff updated the plan
in 2006 for about $1,000 in staff time.
* City of Savannah Water and Sewer Bureau (Savannah, Georgia).
According to facility staff, in-house staff completed a risk management
plan in 1999 for the President Street Water Pollution Control Plant,
which treats 17 million gallons per day, at a cost of only $150 in
staff time. In-house staff updated the plan in 2006 for about $130 in
staff time.
Costs of Converting to Alternative Disinfection Methods at Large
Wastewater Facilities Depend on the Method Used and Other Factors:
Large wastewater facilities that convert from chlorine gas disinfection
to alternative disinfection processes incur widely varying capital
costs, which generally depend on the alternative treatment chosen and
facility size. Other factors that affect capital costs include the
characteristics of individual facilities, such as whether existing
structures can be used, and local factors, such as building costs.
Alternative disinfection processes may also pose higher annual
operating costs than chlorine gas. However, these costs may be offset,
at least somewhat, by savings in training and labor costs, and
regulatory burdens associated with the handling of chlorine gas. Some
facilities even reported or projected net annual cost savings related
to wastewater disinfection.
Disinfection Method Chosen, Facility Size and Characteristics, and
Other Factors Determine Capital Conversion Costs:
The 23 large wastewater facilities that we interviewed reported capital
costs for chlorine conversion ranging from $646,922 to just over $13
million. Table 1 identifies the 23 large wastewater facilities that
recently converted or plan to convert from chlorine gas to another
disinfection method and their reported and planned capital conversion
cost.
Table 1: Reported and Planned Disinfection Conversion Costs for Large
Wastewater Treatment Facilities:
Facilities that have completed conversion from chlorine gas:
Facility name: Chambers Creek;
Facility location: University Place, Wash;
Conversion year: 2002;
Facility size (in millions of gallons treated per day)[A]: 19;
Disinfection method: Ultraviolet light;
Reported or planned conversion cost[B] (in dollars): $3,900,608.
Facility name: Blue Plains;
Facility location: Washington, D.C;
Conversion year: 2003;
Facility size (in millions of gallons treated per day)[A]: 307;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 12,980,726.
Facility name: Northeast;
Facility location: Philadelphia, Pa;
Conversion year: 2003;
Facility size (in millions of gallons treated per day)[A]: 190;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 2,600,000.
Facility name: Back River;
Facility location: Baltimore, Md;
Conversion year: 2004;
Facility size (in millions of gallons treated per day)[A]: 150;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 3,300,000.
Facility name: Essex and Union;
Facility location: Elizabeth, N.J;
Conversion year: 2004;
Facility size (in millions of gallons treated per day)[A]: 65;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 775,000.
Facility name: Chesapeake-Elizabeth;
Facility location: Virginia Beach, Va;
Conversion year: 2004;
Facility size (in millions of gallons treated per day)[A]: 21;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 1,225,000.
Facility name: Nansemond;
Facility location: Suffolk, Va;
Conversion year: 2004;
Facility size (in millions of gallons treated per day)[A]: 17;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 1,650,740.
Facility name: Columbia Boulevard;
Facility location: Portland, Ore;
Conversion year: 2005;
Facility size (in millions of gallons treated per day)[A]: 143;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 4,660,490.
Facility name: Valley Creek;
Facility location: Bessemer, Ala;
Conversion year: 2005;
Facility size (in millions of gallons treated per day)[A]: 46;
Disinfection method: Ultraviolet light;
Reported or planned conversion cost[B] (in dollars): 3,561,272.
Facility name: Dry Creek;
Facility location: Fort Wright, Ky;
Conversion year: 2005;
Facility size (in millions of gallons treated per day)[A]: 36;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 646,922.
Facility name: Southern Regional;
Facility location: Boynton Beach, Fla;
Conversion year: 2005;
Facility size (in millions of gallons treated per day)[A]: 22;
Disinfection method: Sodium hypochlorite[C];
Reported or planned conversion cost[B] (in dollars): 2,592,800.
Facility name: Burbank;
Facility location: Burbank, Calif;
Conversion year: 2005;
Facility size (in millions of gallons treated per day)[A]: 9;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 2,500,000.
Facility name: Southeast;
Facility location: Philadelphia, Pa;
Conversion year: 2006;
Facility size (in millions of gallons treated per day)[A]: 90;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 1,920,000.
Facility name: Papillon;
Facility location: Omaha, Neb;
Conversion year: 2006;
Facility size (in millions of gallons treated per day)[A]: 62;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 3,000,000.
Facilities that plan to convert from chlorine gas:
Facility name: Metro Central;
Facility location: Denver, Colo;
Conversion year: 2007;
Facility size (in millions of gallons treated per day)[A]: 130;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 13,135,000.
Facility name: Fort Wayne;
Facility location: Fort Wayne, Ind;
Conversion year: 2007;
Facility size (in millions of gallons treated per day)[A]: 43;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 1,791,417.
Facility name: Everett;
Facility location: Everett, Wash;
Conversion year: 2007;
Facility size (in millions of gallons treated per day)[A]: 18;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 2,562,460.
Facility name: South Central;
Facility location: Delray Beach, Fla;
Conversion year: 2007;
Facility size (in millions of gallons treated per day)[A]: 18;
Disinfection method: Sodium hypochlorite[C];
Reported or planned conversion cost[B] (in dollars): 2,454,700.
Facility name: Mill Creek;
Facility location: Cincinnati, Ohio;
Conversion year: 2008;
Facility size (in millions of gallons treated per day)[A]: 120;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 3,085,000.
Facility name: Western Branch;
Facility location: Laurel, Md;
Conversion year: 2008;
Facility size (in millions of gallons treated per day)[A]: 20;
Disinfection method: Ultraviolet light;
Reported or planned conversion cost[B] (in dollars): 4,000,000.
Facility name: South Treatment Plant;
Facility location: Renton, Wash;
Conversion year: 2009;
Facility size (in millions of gallons treated per day)[A]: 75;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 2,575,000.
Facility name: Hartford;
Facility location: Hartford, Conn;
Conversion year: 2009;
Facility size (in millions of gallons treated per day)[A]: 51;
Disinfection method: Ultraviolet light;
Reported or planned conversion cost[B] (in dollars): 10,892,000.
Facility name: Eugene-Springfield;
Facility location: Eugene, Ore;
Conversion year: 2009;
Facility size (in millions of gallons treated per day)[A]: 38;
Disinfection method: Sodium hypochlorite;
Reported or planned conversion cost[B] (in dollars): 4,498,000.
Source: GAO.
[A] Plant size figures are figures for existing flow (a measure of
average daily flow) reported by wastewater facilities in our survey.
[B] Conversion costs were not adjusted for inflation. Figures do not
reflect changes in annual costs, but are reported costs for
construction, labor, and materials related to the disinfection
conversion. Reported conversion costs include actual costs and
estimates from facility managers. As such, these cost figures do not
represent the present value of the life-cycle cost of conversion.
Conversion costs include reported temporary and permanent conversion
costs.
[C] These facilities will generate sodium hypochlorite on-site. All
other facilities listed as converted or planning to convert to sodium
hypochlorite are having the chemical delivered in bulk to the facility.
[End of table]
As shown in the table, 17 of the 23 facilities converted or plan to
convert to sodium hypochlorite delivered in bulk to the facility.
Officials with several of these facilities told us they considered
ultraviolet disinfection, but chose delivered sodium hypochlorite
because of its lower capital conversion costs. The remainder converted
or plan to convert to sodium hypochlorite generated on-site or
ultraviolet light. None of the facilities we contacted adopted ozone.
Interview responses indicate that several factors affect the cost of
conversion; among these are disinfection method chosen, facility size,
key facility characteristics such as available buildings, and whether
the conversion was permanent or temporary, as follows.
Disinfection Method:
Generally, conversion to delivered sodium hypochlorite has the lowest
capital costs, followed by sodium hypochlorite generated on-site, and
followed again by ultraviolet light.[Footnote 13] This observation is
supported by cost estimates in the Chlorine Gas Decision Tool, a
software program released by DHS in March 2006. The decision tool was
designed to provide water and wastewater utilities with the means to
conduct assessments of alternatives to chlorine gas disinfection. DHS
cautions that the final costs of the disinfection systems will depend
on project design details, actual labor and material costs, competitive
market conditions, actual site conditions, final project scope,
implementation schedule, continuity of personnel and engineering, and
other variable factors.[Footnote 14] With these caveats, the decision
tool estimates that for a wastewater facility with an average
disinfection flow of 10 million gallons per day and a peak disinfection
flow of 20 million gallons per day, capital costs for conversion to
delivered sodium hypochlorite would amount to $533,000, on-site
generation of sodium hypochlorite would total $1,238,000, and
ultraviolet disinfection would reach $1,526,000.[Footnote 15]
Our interviews with wastewater facilities provide specific examples of
conversion costs. For example, managers of the Chesapeake-Elizabeth
Treatment Plant, which treats 21 million gallons per day and serves
customers in Virginia Beach, Virginia, reported spending an estimated
$1,225,000 in 2004 converting to bulk sodium hypochlorite disinfection.
Managers of the comparably sized Western Branch Wastewater Treatment
Plant, which treats 20 million gallons per day and serves customers in
Laurel, Maryland, estimated that they will spend $4 million converting
to ultraviolet light disinfection by January 1, 2008. Managers of the
Western Branch plant indicated that one reason they chose the more
expensive ultraviolet treatment option over bulk deliveries of sodium
hypochlorite was to avoid the risk to local traffic that could result
from additional deliveries to the plant. Plant managers indicated that
because sodium hypochlorite degrades more quickly than chlorine gas,
truck deliveries would increase under a disinfection system using
sodium hypochlorite. They also noted that ultraviolet light
disinfection would eliminate the need for the facility to handle and
store significant amounts of hazardous and corrosive chemicals.
Facility Size:
In addition to disinfection method chosen, facility size can also
influence capital conversion costs. In general, larger facilities spend
more converting to alternative disinfection methods. For example,
because larger facilities process a greater flow of wastewater,
converting to delivered sodium hypochlorite would require a larger
sodium hypochlorite storage building or buildings relative to a smaller
facility. It may also require additional pumps, instrumentation, and
piping to deliver treatment chemicals to a greater number of contact
tanks. Importantly, the largest facilities also tend to serve high-cost
urban areas, and their conversion costs reflect the higher costs for
construction materials and contract labor in these markets.
For example, the Blue Plains Wastewater Treatment Plant, which treats
307 million gallons per day and serves over 2 million customers in the
Washington, D.C., metropolitan area, converted from chlorine gas to
delivered sodium hypochlorite in 2003 at a cost of almost $13 million.
According to facility managers, the facility temporarily converted from
chlorine gas to delivered sodium hypochlorite in April 2002 at a cost
of $500,000, primarily for storage tanks, pumps, piping, and related
instrumentation. It completed the permanent conversion in October 2003
at an added cost of about $12.5 million, which included the purchase of
additional storage tanks, related pumps, piping and instrumentation,
and the construction of storage facilities for sodium hypochlorite and
sodium bisulfate (used for dechlorination).
Other Key Facility Characteristics:
In addition to facility size, other physical characteristics related to
individual facilities also play a large role in conversion costs. For
instance, the availability of usable buildings on facility grounds will
determine whether a facility needs to construct, expand, or update a
building to properly house sodium hypochlorite and its associated
metering equipment. In addition, the distance between the storage
building and treatment tanks will determine the amount of piping needed
to deliver stored sodium hypochlorite to the treatment tanks. An
example comes from the Hampton Roads Sanitation District which provides
wastewater treatment to approximately 1.6 million people in 17 cities
and counties in southeast Virginia, including the cities of Newport
News, Norfolk, Suffolk, Virginia Beach, and Williamsburg. In 2004, the
sanitation district converted from chlorine gas to bulk sodium
hypochlorite disinfection at two of its plants--the Nansemond Treatment
Plant, which treats 17 million gallons per day for the city of Suffolk,
and the previously mentioned Chesapeake-Elizabeth plant, which treats
21 million gallons per day. The Nansemond plant conversion cost an
estimated $1.65 million, while the slightly larger Chesapeake-Elizabeth
plant conversion cost about $1.2 million. Costs were higher at the
Nansemond plant because a building needed to be constructed for sodium
hypochlorite storage, while the Chesapeake-Elizabeth plant had an
existing building that only needed to be upgraded to properly store the
chemical.
Federal discharge permit requirements related to individual treatment
facilities can also influence conversion costs. Certain wastewater
facilities may be allowed higher chlorine residuals in treated effluent
because they discharge into less sensitive waters. Often, these
facilities do not have to dechlorinate wastewater, saving the facility
the cost of dechlorination chemicals, equipment, and storage. For
example, the Philadelphia-area Southeast and Northeast Wastewater
Treatment Plants, which treat 90 and 190 million gallons per day,
respectively, need only to chlorinate water prior to discharging into
the Delaware River. Both plants were converted to delivered sodium
hypochlorite--the Southeast plant in 2006 at an estimated cost of $1.9
million and the Northeast plant in 2003 at an estimated cost of $2.6
million. In contrast, the Baltimore-area Back River Wastewater
Treatment Plant, which treats 150 million gallons per day and
discharges into the ecologically sensitive Chesapeake Bay, must
chlorinate and dechlorinate its wastewater before discharge. This
facility converted to delivered sodium hypochlorite in 2004 at a
reported cost of $3.3 million.
Temporary Conversions:
Finally, some facilities have reduced conversion costs in the short
term through temporary conversions. For example, the Metropolitan Sewer
District of Greater Cincinnati decided to convert its Mill Creek
Wastewater Treatment Plant, which treats 120 million gallons per day,
from chlorine gas to sodium hypochlorite disinfection soon after
September 11, 2001. According to the plant manager, by mid-October
2001, the facility had begun disinfecting with sodium hypochlorite by
hooking up a rented sodium hypochlorite trailer to its disinfection
system at a cost of $25,000. By May 2002, the facility had completed an
interim conversion to sodium hypochlorite by purchasing and installing
two 8,000 gallon outdoor storage tanks for sodium hypochlorite at a
cost of $60,000. According to the plant manager, this interim
disinfection system is still in use today, though the plant intends to
permanently convert to delivered sodium hypochlorite in 2008 or 2009 at
an estimated cost of $3 million. The plant manager said the permanent
conversion would include an unloading station for sodium hypochlorite
deliveries and a new storage building for the chemical and related
instrumentation. The plant manager said the new storage building was
needed to reduce the decay of stored sodium hypochlorite. The plant
manager added that the storage building and additional piping would
improve plant safety because it would allow for central storage and
delivery of sodium hypochlorite. Currently, sodium hypochlorite
deliveries are made at several plant locations for odor control which,
according to the plant manager, increase the odds the chemical may be
mishandled and accidentally mixed with other reactant chemicals used at
the plant, such as ammonia.
Similarly, the Eastern Water Reclamation Facility, which treats 16
million gallons per day and provides service to Orange County, Florida,
converted from chlorine gas to sodium hypochlorite disinfection at a
cost of $60,000 in November 2001 through the addition of outdoor
storage tanks and related pumps. According to the plant manager, the
facility may consider additional changes in the future, such as
permanent sodium hypochlorite storage or on-site generation.
Changes in Annual Costs Vary Widely, with Some Facilities Reporting
Savings:
Changes in annual costs related to disinfection treatment conversions
were hard to measure due to lack of data. Many facilities we
interviewed were unable to provide complete information on annual costs
related to disinfection before and after converting from chlorine gas.
Available data show that annual chemical costs related to disinfection
increased for facilities that converted to delivered sodium
hypochlorite, because sodium hypochlorite costs more than chlorine
gas.[Footnote 16] Available data also show that electrical costs
related to disinfection increased for facilities that converted to on-
site generation of sodium hypochlorite or ultraviolet light treatment,
however these facilities also saw large reductions in chemical costs.
Available data also show that increases in annual costs related to
disinfection were offset somewhat by savings in training and regulatory
requirements, as several facilities that converted reported a reduced
need for staff time devoted to complying with the EPA risk management
planning that was required when the plant used chlorine gas.
A few facilities were even able to report or project annual savings due
to the disinfection conversion. For example, the wastewater treatment
manager of the Columbia Boulevard Treatment Plant, which treats 143
million gallons per day and provides wastewater service to Portland,
Oregon, estimated that annual costs related to disinfection fell by
over $100,000 after the plant completed a 2005 conversion from chlorine
gas to delivered sodium hypochlorite disinfection.[Footnote 17]
According to the wastewater treatment manager, increases in
disinfection chemical costs for the plant were more than offset by
reductions in electrical, labor, and training costs. Electrical power
costs fell because the plant no longer had to power chlorine gas
evaporators, which heat and help convert the pressurized liquid into
gas before it is injected into the waste stream. In contrast, sodium
hypochlorite is fed into the waste stream via less energy-intensive
pumps. Labor and training costs also fell because the plant no longer
had to meet the Occupational Safety and Health Administration's (OSHA)
Process Safety Management of Highly Hazardous Chemicals
standard,[Footnote 18] and risk management and emergency response
planning costs associated with the use of chlorine gas were eliminated.
In another example, the South Central Regional Wastewater Treatment and
Disposal Plant, which treats 18 million gallons per day for customers
in the cities of Delray Beach and Boynton Beach, Florida, predicts that
it too will achieve annual savings once it converts from chlorine gas
to sodium hypochlorite generated on-site, which it anticipates
completing in September 2007. According to the Executive Director of
the South Central Regional Wastewater Treatment and Disposal Board,
potential disruptions of sodium hypochlorite delivery during hurricane
seasons motivated them to begin generating their disinfection chemicals
on-site. The plant's most recent fiscal year operating and maintenance
budget for disinfection is estimated to be roughly $307,000 for
chlorine gas and associated costs including equipment and maintenance,
labor, and risk management planning. Postconversion annual operating
and maintenance costs for disinfection are estimated to fall to
$205,000 in the 2008 calendar year, primarily due to the suspension of
chlorine gas purchases.
Agency Comments and Our Evaluation:
We provided a draft of this report to EPA for review and comment. In
its letter, reproduced in appendix II, EPA concurred with the results
of the report. EPA's Water Security Division in the Office of Ground
Water and Drinking Water provided technical comments and clarifications
that were incorporated, as appropriate.
As agreed with your office, unless you publicly release the contents of
this report earlier, we plan no further distribution until 30 days from
the report date. At that time, we will send copies of this report to
the appropriate congressional committees; interested Members of
Congress; the Administrator, EPA; and other interested parties. We will
also make copies available to others on request. In addition, the
report will be available at no charge on the GAO Web site at
http://www.gao.gov.
Should you or your staff need further information, please contact me at
(202) 512-3841 or stephensonj@gao.gov. Contact points for our Offices
of Congressional Relations and Public Affairs may be found on the last
page of this report. GAO staff who made major contributions to this
report are listed in appendix III.
Sincerely yours,
Signed by;
John B. Stephenson:
Director, Natural Resources and Environment:
[End of section]
Appendix I: Scope and Methodology:
To identify the costs of preparing vulnerability assessments and risk
management plans, we conducted structured telephone interviews with a
select sample of large wastewater facilities identified as having
completed these documents in our March 2006 report.[Footnote 19] Our
March report identified 106 large facilities that reported they had
prepared vulnerability assessments or had one underway, and 85
facilities that were required to prepare risk management plans because
they currently used chlorine gas as a disinfectant. From these two
groups, we identified 47 facilities that reported that they had
prepared vulnerability assessments and currently use chlorine. Of this
universe, we chose a nonprobability sample of 25 facilities to assure
geographic dispersion and adequate variation in size, since these
factors were likely to influence their costs.[Footnote 20] We completed
structured interviews with 20 of the remaining 25 facilities. We sent
an interview schedule in advance of each of the interviews. We
completed the structured interviews between November 2006 and February
2007. Reported costs included both actual and estimated costs. For
estimated costs, we asked facility managers to explain how they arrived
at these estimates. Reported costs were not adjusted for inflation.
To identify the costs incurred by wastewater facilities in converting
from gaseous chlorine to an alternative disinfection process, we
conducted structured telephone interviews with a nonprobability sample
of 26 of the 38 large facilities identified in the March report as
having recently converted or planning to convert from chlorine gas to
an alternative disinfection process. We sent an interview schedule in
advance of each of the interviews. We completed the structured
interviews between October 2006 and February 2007. Reported costs
included both actual and estimated costs. For estimated costs, we asked
facility managers to explain how they arrived at these estimates.
Reported costs were not adjusted for inflation. We also conducted site
visits with some of the facilities. Where available, we gathered
documentation, such as capital plans, from these facilities in order to
document conversion costs. We supplemented the cost information we
gathered at individual wastewater facilities with information obtained
at the Environmental Protection Agency, the Department of Homeland
Security, nongovernmental organizations, and industry representatives.
We determined that reported cost data were sufficiently reliable to
provide useful information about the costs for preparing vulnerability
assessments, risk management plans, and conversions from gaseous
chlorine and the factors that affect these costs.
We conducted our work between August 2006 and March 2007 in accordance
with generally accepted government auditing standards.
[End of section]
Appendix II: Comments from the Environmental Protection Agency:
United States Environmental Protection Agency:
Office Of Water:
Washington, D.C. 20460:
Mar 2 0 2007:
Mr. John B. Stephenson:
Director, Natural Resources and the Environment:
Government Accountability Office:
Washington, DC 20548:
Dear Mr. Stephenson:
Thank you for the opportunity to review the draft Government
Accountability Office (GAO) Report Securing Wastewater Facilities.
Costs of Vulnerability Assessments, Risk Management Plans, and
Alternative Disinfection Methods Vary Widely. We appreciate the
information in the report. This draft report is useful, well thought
out, and demonstrates a well conceived and executed project. Our review
did not identify any issues of concern for the Agency and my staff has
provided GAO with technical comments on the draft under a separate
cover.
We all rely on clean, safe, and secure water. Therefore, from a public
health and economic perspective, it is critical that we protect our
nation's wastewater infrastructure. Although there are no federal
statutory requirements for wastewater utilities to conduct risk
assessments, the Environmental Protection Agency (EPA) continues to
develop tools and provide training to assist those water sector
utilities that choose to perform these assessments on a voluntary
basis. As your report notes, many wastewater utilities have elected to
conduct these assessments or are planning to do so in the future.
The Agency is also interested in working with the water sector to
identify disinfectants that are appropriate for their needs to meet
water quality standards and to protect human health and the
environment. Although the conversion from gaseous chlorine to an
alternate disinfectant would eliminate the impacts of a hazardous
gaseous chemical release, it is important to recognize that water
sector utility owners and operators need to make the choice of
disinfectant that is best for their utility. Therefore, many water
sector utilities may continue to use chlorine gas as a disinfectant.
I appreciated the opportunity to coordinate with your staff on this
project. Should you need additional information or have further
questions, please contact me or Cynthia C. Dougherty, Director of the
Office of Ground Water and Drinking Water at (202) 564-3750.
sincerely,
Signed by:
Benjamin H. Grumbles:
Assistant Administrator:
Internet Address (URL) http://www.epa.gov:
Recycled/Recyclable Printed with Vegetable Oil Based Inks on 100%
Postconsumer, Process Chlorine Free Recycled Paper:
[End of section]
Appendix III: GAO Contact and Staff Acknowledgments:
GAO Contact:
John B. Stephenson, (202) 512-3841 or stephensonj@gao.gov:
Acknowledgments:
In addition to the contact named above, Jenny Chanley, Steve Elstein,
Nicole Harris, Greg Marchand, Tim Minelli, Alison O'Neill, Daniel
Semick, and Monica Wolford made key contributions to this report.
FOOTNOTES
[1] Pub. L. No. 101-549 (1990).
[2] EPA requires that any facility storing at least 2,500 pounds of
chlorine gas submit a risk management plan.
[3] GAO, Securing Wastewater Facilities: Utilities Have Made Important
Upgrades but Further Improvements to Key System Components May Be
Limited by Costs and Other Constraints, GAO-06-390 (Washington, D.C.:
Mar. 31, 2006).
[4] According to the Environmental Protection Agency (EPA),
vulnerability assessments performed by water sector utilities address
not only utility vulnerabilities, but also utility threats and
consequences.
[5] We defined large wastewater facilities as those publicly owned
treatment works (POTW) that serve residential populations of 100,000 or
greater.
[6] Results from nonprobability samples cannot be used to make
inferences about a population, because in a nonprobability sample some
elements of the population being studied have no chance or an unknown
chance of being selected as part of the sample.
[7] Sulfur dioxide, often used for dechlorination by wastewater
facilities, is also covered by risk management plan rules when used or
stored in threshold amounts.
[8] Pub. L. No. 107-188 (2002).
[9] The Bioterrorism Act required the assessments to include, but not
be limited to, a review of six components: (1) pipes and constructed
conveyances; (2) physical barriers; (3) water collection, pretreatment,
treatment, storage, and distribution facilities; (4) electronic,
computer, or other automated systems that are utilized by the water
system; (5) the use, storage, or handling of various chemicals; and (6)
the operation and maintenance of such systems. The act further required
systems to prepare or revise an emergency response plan incorporating
the results of the vulnerability assessment within 6 months after
completing the assessment.
[10] In our structured interviews we asked facility managers to provide
estimates of their treatment facility's "existing flow" in millions of
gallons per day. "Existing flow" refers to the calculated average flow
for a recent 12-month period, as defined by EPA in its Clean Water
Needs Survey, and is a common measure of treatment facility size. When
we note how many gallons per day a facility treats, we are referring to
its reported "existing flow."
[11] Now the National Association of Clean Water Agencies (NACWA).
[12] Prior to September 11, 2001, EPA worked to develop and disseminate
risk assessment methodologies for water utilities. In 2000, EPA funded
an initiative with the American Water Works Association Research
Foundation (AWWARF) and the Sandia National Laboratories to apply risk
assessment methodologies developed by the laboratories to water
utilities. The methodology, called the Risk Assessment Methodology for
Water Utilities (RAM-W), was designed to assist large water utilities
and security professionals in assessing the risks from malevolent
threats. Through an interagency agreement with EPA, Sandia National
Laboratories provided training to selected firms in the RAM-W
methodology so that these firms could then provide training and
technical assistance to water utilities.
[13] Conversion to disinfection methods such as ozone and
ultrafiltration can have higher capital costs than ultraviolet light.
[14] The decision tool provides cost estimates for disinfection
conversion alternatives where there is limited site-specific
engineering data. DHS notes that cost estimates were based on cost
curves that were developed from a combination of the actual
construction costs of different-sized disinfection systems and cost
estimates based on conceptual designs.
[15] DHS notes that it is normally expected that an estimate of this
type would be accurate within +50 percent to -30 percent.
[16] In addition, sodium bisulfate, the dechlorination chemical often
used with sodium hypochlorite, costs more than sulfur dioxide, the
dechlorination chemical often used with chlorine gas.
[17] According to the wastewater treatment manager, annual costs
related to disinfection fell from $411,531 for the operating year
covering July 1, 2004, to June 30, 2005, to $302,998 for the operating
year covering July 1, 2005, to June 30, 2006. The wastewater treatment
manager reported the plant's annual operations and maintenance budget
at $12.4 million for the most recently completed operating year.
[18] OSHA's Process Safety Management of Highly Hazardous Chemicals
standard (29 CFR 1910.119) contains requirements for the management of
hazards associated with processes using highly hazardous chemicals.
[19] GAO, Securing Wastewater Facilities: Utilities Have Made Important
Upgrades but Further Improvements to Key System Components May Be
Limited by Costs and Other Constraints, GAO-06-390 (Washington, D.C.:
Mar. 31, 2006). We defined large wastewater facilities as those
publicly owned treatment works (POTW) that serve residential
populations of 100,000 or greater.
[20] Results from nonprobability samples cannot be used to make
inferences about a population, because in a nonprobability sample some
elements of the population being studied have no chance or an unknown
chance of being selected as part of the sample.
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