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entitled 'Securing Wastewater Facilities; Costs of Vulnerability 
Assessments, Risk Management Plans, and Alternative Disinfection 
Methods Vary Widely' which was released on May 1, 2007. 

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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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To order by Phone: Voice: (202) 512-6000 TDD: (202) 512-2537 Fax: (202) 
512-6061: 

To Report Fraud, Waste, and Abuse in Federal Programs: 

Contact: 

Web site: www.gao.gov/fraudnet/fraudnet.htm E-mail: fraudnet@gao.gov 
Automated answering system: (800) 424-5454 or (202) 512-7470: 

Congressional Relations: 

Gloria Jarmon, Managing Director, JarmonG@gao.gov (202) 512-4400 U.S. 
Government Accountability Office, 441 G Street NW, Room 7125 
Washington, D.C. 20548: 

Public Affairs: 

Paul Anderson, Managing Director, AndersonP1@gao.gov (202) 512-4800 
U.S. Government Accountability Office, 441 G Street NW, Room 7149 
Washington, D.C. 20548: