National Primary Drinking Water Regulations: Drinking Water Regulations for Aircraft Public Water Systems, 19320-19348 [E8-7035]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 73, Number 69 (Wednesday, April 9, 2008)]
[Proposed Rules]
[Pages 19320-19348]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-7035]



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Part III





Environmental Protection Agency





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40 CFR Part 141



National Primary Drinking Water Regulations: Drinking Water Regulations 
for Aircraft Public Water Systems; Proposed Rule

Federal Register / Vol. 73, No. 69 / Wednesday, April 9, 2008 / 
Proposed Rules

[[Page 19320]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 141

[EPA-HQ-OW-2005-0025; FRL-8551-3]
RIN 2040-AE84


National Primary Drinking Water Regulations: Drinking Water 
Regulations for Aircraft Public Water Systems

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency is proposing to amend and 
consolidate in one place the federal drinking water requirements (known 
as National Primary Drinking Water Regulations or NPDWRs) for aircraft 
public water systems under the Safe Drinking Water Act (SDWA). Aircraft 
public water systems are subject to the requirements of SDWA and the 
NPDWRs. The existing federal drinking water standards were primarily 
designed to regulate water quality in stationary public water systems 
and the application of these requirements to mobile water systems with 
the capability of flying throughout the world has created 
implementation challenges. The proposed requirements are intended to 
tailor existing health-based drinking water standards to the unique 
characteristics of aircraft public water systems for the enhanced 
protection of public health against illnesses attributable to 
microbiological contamination. This is accomplished through multiple-
barrier protection and procedural control measures. EPA believes that 
the combination of these components will better protect public health 
while building upon existing aircraft operations and maintenance 
programs, better coordinate federal programs that regulate aircraft 
water systems, and minimize disruption of aircraft flight schedules.

DATES: Comments must be received on or before July 8, 2008. Under the 
Paperwork Reduction Act, comments on the information collection 
provisions must be received by OMB on or before May 9, 2008.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-OW-
2005-0025, by one of the following methods:
     https://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: ow-docket@epa.gov.
     Mail: Water Docket, Environmental Protection Agency, 
Mailcode: 2822T, 1200 Pennsylvania Ave., NW., Washington, DC 20460. In 
addition, please mail a copy of your comments on the information 
collection provisions to the Office of Information and Regulatory 
Affairs, Office of Management and Budget (OMB), Attn: Desk Officer for 
EPA, 725 17th St., NW., Washington, DC 20503.
     Hand Delivery: EPA Docket Center, Public Reading Room, EPA 
Headquarters West Building, Room 3334, 1301 Constitution Ave., NW., 
Washington, DC 20460. Such deliveries are only accepted during the 
Docket's normal hours of operation, and special arrangements should be 
made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OW-2005-
0025. EPA's policy is that all comments received will be included in 
the public docket without change and may be made available online at 
https://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through https://
www.regulations.gov or e-mail. The https://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through www.regulations.gov your e-mail address will be 
automatically captured and included as part of the comment that is 
placed in the public docket and made available on the Internet. If you 
submit an electronic comment, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses.
    Docket: All documents in the docket are listed in the https://
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in https://www.regulations.gov or in hard copy at the Water Docket, EPA/
DC, EPA West, Room 3334, 1301 Constitution Ave., NW., Washington, DC. 
The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday 
through Friday, excluding legal holidays. The telephone number for the 
Public Reading Room is (202) 566-1744, and the telephone number for the 
Water Docket is (202) 566-2426.

FOR FURTHER INFORMATION CONTACT: Richard Naylor, Drinking Water 
Protection Division, Office of Ground Water and Drinking Water (MC-
4606M), Environmental Protection Agency, 1200 Pennsylvania Ave., NW., 
Washington, DC 20460; telephone number: (202) 564-3847; e-mail address: 
naylor.richard@epa.gov. For general information, contact the Safe 
Drinking Water Hotline, telephone number: (800) 426-4791. The Safe 
Drinking Water Hotline is open Monday through Friday, excluding legal 
holidays, from 10 a.m. to 4 p.m., Eastern time.

SUPPLEMENTARY INFORMATION:

I. General Information

A. Does This Action Apply to Me?

    Entities potentially regulated by the proposed Aircraft Drinking 
Water Rule include air carriers that operate aircraft public water 
systems using finished surface water, finished ground water under the 
direct influence of surface water (GWUDI), or finished ground water. 
Regulated categories and entities include:

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                                                   Examples of regulated
              Category                NAICS code         entities
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Scheduled passenger air                   481111  Air carriers.
 transportation.
Nonscheduled chartered passenger          481211  Air carriers.
 air transportation.
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    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that EPA is now aware 
could potentially be regulated by this action. Other types of entities 
not listed in this table could also be regulated. To determine whether 
your air carrier is regulated by this action, you should carefully 
examine the applicability criteria in section Sec.  141.800 of this 
proposed rule. If you

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have questions regarding the applicability of this action to a 
particular entity, consult the person listed in the preceding section 
entitled FOR FURTHER INFORMATION CONTACT.

B. What Should I Consider as I Prepare My Comments for EPA?

    1. Submitting CBI. Do not submit this information to EPA through 
https://www.regulations.gov or e-mail. Clearly mark the part or all of 
the information that you claim to be CBI. For CBI information in a disk 
or CD-ROM that you mail to EPA, mark the outside of the disk or CD-ROM 
as CBI and then identify electronically within the disk or CD-ROM the 
specific information that is claimed as CBI. In addition to one 
complete version of the comment that includes information claimed as 
CBI, a copy of the comment that does not contain the information 
claimed as CBI must be submitted for inclusion in the public docket. 
Information so marked will not be disclosed except in accordance with 
procedures set forth in 40 CFR part 2.
    2. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree, suggest alternatives, 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible.
     Make sure to submit your comments by the comment period 
deadline identified.

C. Abbreviations Used in This Notice

ADWR: Aircraft Drinking Water Rule.
ANSI: American National Standards Institute.
AOC: Administrative Order on Consent.
ATA: Air Transport Association.
BMP: Best Management Practice.
CDC: Centers for Disease Control and Prevention.
CFR: Code of Federal Regulations.
CRMP: Comprehensive Representative Monitoring Plan.
CWS: Community Water System.
DBP: Disinfection Byproducts.
E. Coli: Escherichia coli.
EO: Executive Order.
EPA: United States Environmental Protection Agency.
FAA: United States Federal Aviation Administration.
FDA: United States Food and Drug Administration.
FR: Federal Register.
GWS: Ground Water System.
GWUDI: Ground Water Under the Direct Influence of Surface Water.
HACCP: Hazard Analysis and Critical Control Point.
HHS: Department of Health and Human Services.
HPC: Heterotrophic Plate Count.
ICC: Interstate Carrier Conveyance.
ICR: Information Collection Request.
IESWTR: Interim Enhanced Surface Water Treatment Rule.
LIMS: Laboratory Information Management System.
mL: Milliliters.
MCL: Maximum Contaminant Level.
MCLG: Maximum Contaminant Level Goal.
MDRL: Maximum Disinfectant Residual Level.
mg/L: Milligrams per Liter.
NASA: National Aeronautics and Space Administration.
NCWS: Non-Community Water System.
NDWAC: National Drinking Water Advisory Committee.
NPDWR: National Primary Drinking Water Regulation.
NSF: NSF International.
NTNCWS: Non-Transient Non-Community Water System.
NTTAA: National Technology Transfer and Advancement Act.
PWS: Public Water System.
OMB: Office of Management and Budget.
QAPP: Quality Assurance Project Plan.
RFA: Regulatory Flexibility Act.
SAB: Science Advisory Board.
SBA: Small Business Association.
SDWA: Safe Drinking Water Act.
SDWIS: Safe Drinking Water Information System.
SWTR: Surface Water Treatment Rule.
TC: Total Coliform.
TCR: Total Coliform Rule.
TNCWS: Transient Non-Community Water System.
TT: Treatment Technique.
UMRA: Unfunded Mandates Reform Act.
WHO: World Health Organization.
WSG: Water Supply Guidance.
WSP: Water Safety Plan.

D. Table of Contents

I. General Information
II. Background
    A. Legal Authority
    B. Purpose of the Proposed Rule
    C. Scope of Proposed Rule
    D. Potential Health Concerns Associated With Aircraft Water 
Systems
    E. Regulatory and Enforcement History
III. Proposed Rule Development
    A. Stakeholder Involvement
    B. Data Collection Efforts
    C. Framework for Proposed Rule Development
IV. Elements of the Proposed Aircraft Drinking Water Rule
    A. Sampling Requirements
    B. Responses to Sample Results
    C. Aircraft Water System Operation and Maintenance Plan
    D. Notification Requirements to Passengers and Crew
    E. Reporting Requirements
    F. Recordkeeping Requirements
    G. Audit and Self-Inspection Requirements
    H. Supplemental Treatment
    I. Violations
    J. Compliance Date
V. Cost Analysis
    A. Summary of Regulatory Alternatives Considered
    B. National Cost Estimates
    C. Comparison of Cost of Regulatory Alternatives
    D. Estimated Impacts of Proposed Rule to Air Carrier Passengers
    E. Non-quantified Costs and Uncertainties
VI. Relative Risk Analysis and Benefits
    A. Relative Risks--Qualitative Analysis
    B. Assessment of Potential Quantitative Relative Risk Analyses
    C. Non-quantified Benefits
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations or Low-Income 
Populations
    K. Consultations with the Science Advisory Board, National 
Drinking Water Advisory Council, and the Secretary of Health and 
Human Services
    L. Plain Language
VIII. References

II. Background

A. Legal Authority

    EPA is proposing this regulation under the authority of the Safe 
Drinking Water Act (SDWA), as amended, 42 U.S.C. 300f et seq., 
primarily sections 1401, 1411, 1412 and 1450. Under SDWA, EPA 
establishes minimum requirements for tap water provided to the public, 
known as the National Primary Drinking Water Regulations or NPDWRs; 
these standards are applicable to ``public water systems.'' SDWA 
Section 1401 and EPA's regulations define a ``public water system'' 
(PWS) as a system for providing water for human consumption to the 
public through

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pipes or other constructed conveyances and that regularly serves an 
average of a least twenty-five individuals daily, at least 60 days per 
year. 40 CFR 141.2.
    All public water systems are subject to the NPDWRs unless they are 
excluded from regulatory requirements under SDWA Section 1411. Section 
1411 excludes from regulation any public water system that receives all 
its water from another regulated public water system, does not sell or 
treat the water, and is not a ``carrier which conveys passengers in 
interstate commerce.'' The classes of interstate carrier conveyances 
(ICCs) include aircraft, trains, buses, and water vessels. As a result, 
all ICCs that regularly serve water to an average of at least twenty-
five individuals daily, at least 60 days per year are public water 
systems and are currently subject to existing NPDWRs regardless of 
whether they treat or sell the water. Due to the unique characteristics 
of aircraft water systems and demonstrated implementation challenges, 
EPA has decided that a new NPDWR specifically tailored to aircraft 
water systems is necessary and an Agency priority. EPA may decide to 
tailor existing requirements to other classes of ICCs in the future.

B. Purpose of the Proposed Rule

    The primary purpose of the proposed Aircraft Drinking Water Rule 
(ADWR) is to ensure that safe and reliable drinking water is provided 
to aircraft passengers and crew. This entails providing air carriers 
with a feasible way to comply with SDWA and the NPDWRs. The existing 
NPDWRs were designed primarily with traditional, stationary public 
water systems in mind. Some of these requirements have proven difficult 
to implement when applied to aircraft water systems, which are 
operationally very different. For example, aircraft must maintain 
rigorous operating schedules. They fly to multiple destinations 
throughout the course of any given day and may board drinking water 
from sources at any of these destinations. Aircraft board water from 
airport watering points via temporary connections. Aircraft drinking 
water safety depends on a number of factors including the quality of 
the water that is boarded from these multiple sources, the care used to 
board the water, and the operation and maintenance of the onboard water 
system and the water transfer equipment (such as water cabinets, 
trucks, carts, and hoses). These unique operational characteristics 
present different challenges, which EPA is addressing in this proposal.
    EPA's NPDWRs establish different requirements based on the 
classification of the public water system (water system), including 
whether the system is a ``community,'' ``nontransient noncommunity,'' 
or ``transient noncommunity'' system and whether the system uses 
surface water or groundwater. Aircraft public water systems are 
considered transient noncommunity water systems (TNCWS), because they 
are not community water systems and they do not regularly serve at 
least 25 of the same persons over six months per year (See 40 CFR 
141.2). Also, aircraft are regulated as surface water systems because 
they are likely to board finished drinking water from other public 
water systems that use surface water in whole or in part. EPA considers 
water for human consumption to include water for drinking and food 
preparation as well as water for brushing teeth and hand washing (see 
63 FR 41941 (August 5, 1998)). Therefore, if an aircraft has a sink in 
the lavatory, then the water provided to that sink must be suitable for 
human consumption.

C. Scope of Proposed Rule

    The proposed ADWR only addresses aircraft regulated under SDWA. 
SDWA does not regulate aircraft water systems operating outside the 
U.S.; however, EPA is supporting an international effort led by the 
World Health Organization (WHO) to develop international guidelines for 
aircraft drinking water. The proposed ADWR applies to the onboard water 
system only. EPA defers to the Food and Drug Administration (FDA) with 
respect to regulating watering points such as water cabinets, carts, 
trucks, and hoses from which aircraft board water. Aircraft that do not 
provide water for human consumption or those with water systems that do 
not regularly serve an average of at least twenty-five individuals 
daily at least 60 days out of the year do not meet the definition of a 
public water system; these aircraft are not regulated under the NPDWRs 
or covered under the new NPDWR proposed today. An estimated 63 air 
carriers and 7,327 aircraft public water systems are covered by this 
proposal.

D. Potential Health Concerns Associated With Aircraft Water Systems

    The proposed ADWR assumes that only finished water is boarded on 
aircraft. Finished water means water that is introduced into the 
distribution system of a public water system and is intended for 
distribution and consumption without further treatment, except as 
necessary to maintain water quality in the distribution system (e.g., 
supplemental disinfection, addition of corrosion control chemicals) (40 
CFR 141.2). The assumption that only finished water is boarded on 
aircraft is based on a FDA requirement that only potable water may be 
provided for drinking and culinary purposes on interstate carrier 
conveyances (ICCs) (21 CFR 1240.80). Aircraft public water systems that 
are boarding water that is not finished water will continue to be 
subject to existing NPDWRs and will not be subject to the new NPDWR 
proposed today. However, even when the water boarded is finished water, 
the opportunity exists for microbiological organisms to be introduced 
during the act of transferring the water from the supplier truck, 
cabinet, or cart to the aircraft water system, or for biofilm to 
develop within the water system itself.
    The proposed ADWR seeks to protect against disease-causing 
microbiological contaminants or pathogens through the required 
development and implementation of aircraft water system operation and 
maintenance plans that include best management practices, air carrier 
training requirements, and periodic sampling of the onboard drinking 
water. Testing drinking water for each individual pathogen is not 
practical, nor feasible. Instead, water quality and public health 
professionals use total coliform bacteria as an indicator organism. 
Total coliforms are a group of closely related, mostly harmless 
bacteria that live in soil and water as well as in the guts of animals. 
The presence of total coliforms in drinking water suggests that there 
may be disease-causing agents in the water or there has been a breach, 
failure, or other change in the integrity of the drinking water. 
Normally, total coliforms are not harmful to human health. However, if 
Escherichia coli (E. coli), a type of coliform bacteria, is present, it 
can be harmful to human health. Total coliforms are inactivated, or 
made harmless, by treatment or die off naturally in a manner similar to 
most bacterial organisms. However, if total coliforms are found in a 
water system, the system may be vulnerable to disease-causing bacteria 
(i.e., pathogens), whether pathogens are actually present or not. If an 
aircraft water system is not disinfected and/or flushed on a routine 
basis, it may be at risk for biofilm or other bacterial growth.
    Most of the bacteria in drinking water distribution systems are 
associated with biofilms. There are several studies showing that 
pathogenic organisms can survive longer and have greater resistance to 
chlorine when occurring in biofilms than in drinking water (Lehtola et 
al., 2007). Most aircraft water tanks

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are either topped off or drained on a daily basis. However, there are 
occasional situations when the water may become stagnant. Some examples 
are aircraft that are occasionally taken out of service for an extended 
maintenance period, or cold weather conditions that affect the ability 
to drain tanks (due to concerns about the drained water freezing on the 
tarmac). Additionally, aircraft with water in their tanks that 
experience long layovers or overnight stays in high temperature areas 
have a higher potential for rapid growth of organisms. There are no 
data on outbreaks of illness caused by drinking water on aircraft. That 
does not mean there is no illness because there is a high rate of 
underreporting of illnesses caused by drinking water contamination. 
Illness resulting from consuming contaminated aircraft water would be 
no exception to this because the population onboard disperses after a 
flight and even if passengers develop gastrointestinal symptoms within 
hours of deplaning, they are unlikely to associate the illness with the 
aircraft water or to contact the air carrier or any government agency 
to report the illness. The effects of waterborne disease are usually 
acute, resulting from a single or small number of exposures. Most 
waterborne pathogens cause gastrointestinal illness with diarrhea, 
abdominal discomfort, nausea, vomiting, or other symptoms. Most such 
cases involve a sudden onset and generally are of short duration in 
healthy people. Some pathogens (e.g., Giardia and Cryptosporidium), 
however, may cause extended illness, lasting weeks or longer in 
otherwise healthy individuals. Waterborne pathogens are particularly 
harmful to sensitive populations, such as the immuno-compromised, and 
can sometimes prove fatal.

E. Regulatory and Enforcement History

    SDWA, including the amendments of 1986 and 1996, require EPA to 
promulgate NPDWRs to prevent tap water contamination that may adversely 
affect human health. As TNCWSs, aircraft are subject to certain NPDWRs 
specific to this category of systems. EPA published Water Supply 
Guidance 29 (WSG 29) in October 1986 to assist ICC operators, including 
air carriers, in complying with these standards (USEPA 1986). WSG 29 
described an alternative under which the operator of an ICC water 
system could use an approved operation and maintenance program in lieu 
of monitoring requirements. However, this guidance did not alter the 
regulatory requirements for ICCs. Since then, EPA has determined that a 
new rule specifically adapted to aircraft water systems would provide a 
clearer and more implementable regulatory framework for aircraft water 
systems. EPA suspended the earlier guidance in 2003 and is no longer 
approving operation and maintenance programs in lieu of monitoring 
under WSG 29 while the ICC program is being revised.
    In 2004, EPA found all aircraft water systems to be out of 
compliance with the NPDWRs. According to the air carriers, it is not 
feasible for them to comply with all of the monitoring that is required 
in the existing regulations. Subsequently, EPA tested 327 aircraft of 
which 15 percent tested positive for total coliform. In response to 
these findings, EPA embarked on a process to tailor the existing 
regulations for aircraft public water systems. In the interim, EPA 
placed 45 air carriers under Administrative Orders on Consent (AOC) 
that will remain in effect until tailored aircraft drinking water 
regulations are final. The air carrier AOCs combine sampling, best 
management practices, corrective action, public notification, and 
reporting and recordkeeping to ensure public health protection.
    Many drinking water rules for systems using surface water or ground 
water under the direct influence of surface water (GWUDI) relate to the 
treatment of source water, but because aircraft board finished water, 
the responsibility for treating the water is borne by the water 
supplier from which aircraft obtain their water. This situation is 
comparable to traditional, stationary water systems that are 
consecutive systems (i.e., buy finished water from other PWSs). The 
proposed ADWR adapts to aircraft water systems the applicable 
requirements from the Total Coliform Rule, the suite of surface water 
treatment regulations, and the Public Notification Rule, the relevant 
sections of which are summarized as follows.
1. The 1989 Total Coliform Rule
    The Total Coliform Rule (TCR) (USEPA, 1989) applies to all public 
water systems. Because monitoring water systems for every possible 
pathogenic organism is not feasible, coliform organisms are used as 
indicators of possible source water and distribution system 
contamination. Coliforms are easily detected in water and are used to 
indicate a water system's source and distribution system vulnerability 
to pathogens. In the TCR, EPA sets a Maximum Contaminant Level Goal 
(MCLG) of zero for total coliforms. EPA also sets a monthly Maximum 
Contaminant Level (MCL) for total coliforms and requires testing of 
total coliform-positive cultures for the presence of E. coli or fecal 
coliforms. E. coli and fecal coliforms indicate more immediate health 
risks from sewage or fecal contamination and are used as a trigger of 
acute contamination. In addition, the TCR requires sanitary surveys 
(i.e., onsite review of the water source, facilities, equipment, 
operation and maintenance of a PWS for the purpose of evaluating the 
adequacy of such source, facilities, equipment, operation and 
maintenance for producing and distributing safe drinking water). The 
TCR requires sanitary surveys by the State primacy agency every 5 years 
for systems that collect fewer than 5 total coliform samples per month 
(those serving 4,100 people or fewer). A TNCWS using surface water 
serving less than 1,000 persons daily would typically be required to 
take one total coliform sample per month for routine sampling 
requirements.
2. Surface Water Treatment Regulations
    EPA has promulgated a suite of regulations to address 
microbiological contamination of surface water. These regulations 
include the Surface Water Treatment Rule (SWTR), the Interim Enhanced 
Surface Water Treatment Rule (IESWTR), the Filter Backwash Recycling 
Rule, and the Long Term 1 and Long Term 2 Enhanced Surface Water 
Treatment Rules. These rules apply monitoring and treatment technique 
requirements to protect the public from microbiological pathogens in 
drinking water such as bacteria, viruses, Giardia lamblia, and 
Cryptosporidium. The monitoring and treatment technique requirements 
must be met prior to water entering the distribution system. Aircraft 
which board only finished water are not required to provide source 
water treatment or to perform monitoring of source water because these 
activities are the responsibility of the public water system from which 
the aircraft obtains finished water for boarding. However, the SWTR 
includes provisions for maintaining a detectable distribution system 
disinfectant residual and for monitoring distribution system 
disinfectant residuals at the same time and location as used for total 
coliform monitoring. Because disinfectant residual monitoring is 
required in the distribution system, current regulations require 
aircraft to perform this monitoring. A TNCWS using surface water 
serving less than 1,000 persons daily would typically be required to 
take one disinfectant residual sample per month. Additionally, the 
IESWTR requires primary enforcement agencies to conduct sanitary 
surveys for all

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surface water and GWUDI systems regardless of size, and specifies a 
frequency of every 5 years for noncommunity water systems.
3. The Public Notification Rule
    Public water systems must give notice to persons served by the 
water system for violations of NPDWRs and for other situations posing a 
risk to public health from drinking water. The term ``NPDWR 
Violations'' is used in the public notification regulations to include 
violations of the MCL, Maximum Residual Disinfectant Level (MRDL), 
treatment technique (TT), monitoring, and testing procedure 
requirements. Public notice requirements are divided into three tiers, 
which take into account the seriousness of the violation or situation 
and of any potential adverse health effects that may be involved. Due 
to the transient nature of the public served by TNCWSs, public notice 
is typically provided through posting of the notice at locations where 
the public may access drinking water from the water system.
4. Roles of the FAA and FDA in Regulating Aircraft Drinking Water
    Drinking water safety on air carriers is jointly regulated by the 
EPA, the Food and Drug Administration (FDA), and the Federal Aviation 
Administration (FAA). EPA regulates the parent public water systems 
within the United States that supply water to the airports and the 
drinking water once it is onboard the aircraft. EPA is responsible for 
developing and implementing the NPDWRs for all public water systems, 
including public water systems on aircraft. FAA requires that air 
carrier companies submit operation and maintenance programs (14 CFR 
part 43, 14 CFR part 91, 14 CFR part 121) for all parts of the 
aircraft, including the water system. Under the current Memorandum of 
Understanding between EPA and FDA, the FDA takes the lead in regulating 
culinary water and the watering points where aircraft obtain water at 
the individual airports. FDA is responsible for approving all ICC 
watering points (21 CFR 1240.83(a)), (1) to ensure the water supply 
meets EPA's NPDWRs and (2) to ensure the methods (i.e., water transfer 
process) of and facilities (e.g., water cabinets, carts, trucks, 
containers, and hoses) for delivery of such water to the conveyance and 
the sanitary conditions surrounding such delivery prevent the 
introduction, transmission, or spread of communicable diseases.
    In addition to the EPA and FDA requirements, air carriers have many 
different on-going programs and practices for assessing and correcting 
deficiencies and risks associated with the drinking water supply and 
related safety, security and sanitation issues. Such programs and 
practices may include FAA Airworthiness Standards: Transport Category 
Airplanes (airworthiness maintenance and inspection program) (14 CFR 
part 43, 14 CFR part 91, and 14 CFR part 121); vulnerability 
assessments/security programs; FDA regulations for Interstate 
Conveyance Sanitation (USFDA 2005); FDA sanitary surveys of watering 
points and servicing areas; and FDA certification of aircraft 
sanitation systems including potable (finished) water, sewage, and 
galleys. These programs may contribute valuable information related to 
the condition of the aircraft water system and water quality. EPA has 
worked closely with FDA and FAA to ensure that this proposal for 
aircraft water system regulation is integrated with these programs to 
avoid unnecessary duplication.

III. Proposed Rule Development

A. Stakeholder Involvement

    In November 2004, when EPA announced that it had initiated a 
rulemaking process to develop regulations for aircraft public water 
systems, the Agency committed to working collaboratively with other 
federal agencies overseeing the air carrier industry, industry 
representatives, and interested stakeholders to identify appropriate 
requirements to ensure safe drinking water onboard aircraft. This 
collaborative rule development process has allowed EPA an opportunity 
to obtain information from, and hear the concerns and questions of 
stakeholders who would be affected by this rule in an organized and 
formal process prior to development of this proposed rule.
    EPA has held three public meetings; these were held in June 2005, 
January 2006, and March 2007. All three events were well-attended by 
stakeholders representing a diverse group of interests including: Air 
carriers, airports, flight attendants, pilots, passengers, public 
health officials, environmental groups, states, public water systems, 
water treatment and equipment vendors, laboratories, foreign government 
agencies, and other federal agencies (e.g., FDA, FAA, and CDC).
    EPA used a third-party skilled in conflict resolution to help 
facilitate the process and to involve the full range of interests. 
Given the number and complexity of issues associated with aircraft 
drinking water, EPA began with an assessment process to identify 
options to support and engage the full range of stakeholders in the 
regulatory development process.
    In June 2005, EPA held a public information meeting to kick-off the 
rulemaking process. The meeting was followed by the development of a 
stakeholder assessment report, produced by the third-party facilitator, 
which is available in the docket for this rule. This report included 
recommendations for a series of joint education workshops to bring 
diverse stakeholders together to identify and understand the issues and 
to provide input and comment on regulatory approaches and options.
    The first workshop was held on January 18-19, 2006. This workshop 
provided an opportunity for stakeholders to learn about aircraft water 
systems and watering points, current regulations, and other information 
relevant to the rulemaking. The stakeholders were encouraged to share 
their initial ideas about the issues that should be addressed in 
developing the proposed rule. EPA also presented for consideration by 
the stakeholders a conceptual approach for the rule, which draws on the 
principles of the Hazard Analysis and Critical Control Point (HACCP) 
and multiple barrier approaches. This systematic approach, known as the 
Water Safety Plan (WSP) approach, is described in greater detail in 
section III. C. Framework for Proposed Rule Development.
    The second workshop was conducted on March 28-29, 2007. At this 
workshop, EPA presented for comment examples of the application of the 
Water Safety Plan approach to aircraft water systems. Also, EPA 
presented the preliminary monitoring data collected under the air 
carrier Administrative Orders on Consent. The majority of the workshop 
time was spent soliciting stakeholder input on topics critical to the 
development of the ADWR including monitoring, best management 
practices, public and crew notification, reporting and recordkeeping 
requirements, and program oversight and verification.

B. Data Collection Efforts

    In developing the ADWR proposal, EPA analyzed preliminary 
monitoring results submitted under the Administrative Orders on Consent 
(AOCs) from 2005-2007. In addition, to gain a better understanding of 
the drinking water quality on domestic aircraft as indicated by total 
coliform, E.coli/fecal coliform, and chlorine residual, EPA drew upon 
the results of the following three studies: (1) A

[[Page 19325]]

voluntary monitoring study completed by the Air Transport Association 
(ATA) in Fall 2003; (2) an EPA study of aircraft NPDWR compliance 
completed in 2004; and (3) the Canadian Inspection Program monitoring 
results completed in 2006
    The EPA data summaries presented here should not be used to draw 
any definitive conclusions. The AOC dataset is incomplete and therefore 
considered preliminary since it represents 15 out of 45 domestic air 
carriers under AOCs with EPA. The 45 domestic air carriers were placed 
under AOCs to resolve non-compliance with the Safe Drinking Water Act 
and the National Primary Drinking Water Regulations. The AOCs 
established interim aircraft water testing and disinfection protocols. 
Each of the air carriers, at a minimum, was required to implement the 
following regular monitoring and disinfection protocols for its entire 
fleet: Regular monitoring of aircraft water systems for coliforms and 
disinfectant residuals; regular disinfection of aircraft water systems 
and water transfer equipment; corrective action for total coliform-
positive sample(s); analysis of any total coliform-positive culture 
media for the presence of fecal coliforms or E. coli; provision of 
public notice or restriction of water service when there is a total 
coliform-positive sample result; performance of a study of possible 
sources of contamination that exist outside of the aircraft; and 
inclusion of information regarding various aspects of its domestic and 
foreign water practices.
    Specific to the AOC sampling data, air carriers were required to 
submit two documents for EPA approval that set the stage for monitoring 
and disinfection protocols/procedures: A Comprehensive Representative 
Monitoring Plan (CRMP) and a Quality Assurance Project Plan (QAPP). The 
CRMP describes the air carrier's sampling and disinfection processes 
and protocols for collecting samples within a 12-month period. The QAPP 
describes the air carrier's Quality Assurance/Quality Control processes 
to ensure good quality data and the methods for collecting and 
assessing data, such as use of State- or EPA-certified laboratories and 
EPA-approved analytical methods for analyzing drinking water samples. 
Once the plans were approved, air carriers were required to collect and 
submit their aircraft water system sampling data to EPA. As reflected 
in Table III-1, air carriers followed slightly different monitoring and 
disinfection protocols based on their fleet size.

  Table III-1.--Monitoring and Disinfection Protocols as Required Under
                                the AOCs
------------------------------------------------------------------------
                                          Air carriers     Air carriers
                                          with greater    with less than
                                            than 20       or equal to 20
                                            aircraft         aircraft
------------------------------------------------------------------------
MONITORING \1\
For each sample event, collect at              [check]          [check]
 least one sample from a galley and
 one from a lavatory for Total
 Coliform (TC) and Disinfectant
 Residual (total residual chlorine)...
Sample 25% of fleet quarterly.........         [check]   ...............
Sample all fleet quarterly............  ...............         [check]
DISINFECTING AND FLUSHING \2\
Disinfect and flush each aircraft's            [check]          [check]
 water system no less than quarterly..
Disinfect and flush watering points            [check]          [check]
 (e.g., water trucks, carts, cabinets,
 hoses) no less than monthly..........
------------------------------------------------------------------------
\1\ The air carrier was required to use State- or EPA-certified
  laboratories and EPA-approved analytical methods for analyzing
  drinking water samples.
\2\ If the air carrier has a pre-AOC monitoring and disinfecting program
  requiring a higher frequency, the air carrier was required to continue
  in accordance with their program, unless modification was requested
  and approved by EPA.

    As of May 31, 2007, of the 45 air carriers under AOCs, EPA has 
analyzed preliminary drinking water sampling data from 15 air carriers 
consisting of 2,316 aircraft out of an estimated total fleet size of 
5,558. The total number of samples (routine and repeat) was 12,099. Of 
these samples, 3.1 percent (378 samples) were total coliform-positive. 
Of the 378 total coliform-positive samples, 2.4 percent (9 samples) 
were E. coli/fecal coliform-positive. Of a total of 7,489 routine 
chlorine residual samples taken, 26.1 percent (1,957) resulted in a 
non-detect. However, in relating the preliminary AOC sampling data to 
other aircraft water quality studies only the routine samples were 
used. Repeat samples were not used because they by nature have a higher 
probability of being total coliform-positive since repeats are taken 
after a routine sample is total coliform-positive. In addition, the 
other studies did not take repeat samples, therefore, the routine 
samples are most analogous to the data collected under the other 
studies.
    Therefore, in determining an estimated baseline of domestic air 
carrier drinking water quality the following was observed in the 
preliminary AOC data: Out of 7,812 routine samples, 2.8 percent (222 
samples) were total coliform-positive. Of the 222 total coliform-
positive samples, 2.3 percent (5 samples) were E. coli/fecal coliform-
positive. Of the 3,952 routine chlorine residual samples taken, 21.5 
percent (848) resulted in a non-detect.
    Under a voluntary study coordinated with EPA, ATA sampled 265 
passenger aircraft operated by eight ATA-member U.S. air carriers. As 
noted by ATA, these eight air carriers represent the majority of the 
U.S. commercial passenger fleet, and serve both domestic and 
international routes. The aircraft were randomly selected and samples 
were generally collected from the galley, except in some cases where 
the galley faucets were equipped with filters, efforts were made to 
collect residual disinfectant samples from the lavatory. The samples 
were analyzed for total coliform (and in the case of a total coliform-
positive result, the sample was tested for E. coli/fecal coliform), 
total residual chlorine, turbidity, total nitrate, and nitrite. 
Regarding microbiological testing, of the 265 aircraft sampled, 2.6 
percent (7 aircraft) were total coliform-positive; there were no fecal 
coliform or E. coli-positive samples. Water samples from forty-one 
percent of the aircraft had non-detectable chlorine residuals (ATA 
2003).
    In the 2004 EPA NPDWR Compliance study, 327 passenger aircraft 
belonging to ATA and non-ATA members were randomly tested at 12 U.S. 
airports that served both domestic and international routes. EPA 
analyzed the drinking water samples from galleys and lavatories for 
total coliform (and in the case of a total coliform-positive result, 
the sample was tested for E. coli/fecal coliform), total

[[Page 19326]]

residual chlorine, heterotrophic plate count, total nitrate, and 
nitrite. In regard to microbiological presence, 15 percent (49/327) of 
the aircraft tested positive for total coliform, and 4.1 percent (2/49 
aircraft) of these total coliform positive aircraft also tested 
positive for E. coli/fecal coliform. Twenty-one percent (69/327) of the 
aircraft tested had a non-detectable chlorine residual.
    Under the Canadian Inspection Program, Health Canada randomly 
inspected 431 aircraft for microbiological presence in drinking water. 
Of the 431 aircraft tested, 15.1 percent (65 aircraft) were total 
coliform-positive, and 7.7 percent (5/65 aircraft) of these total 
coliform positive aircraft were also E. coli positive. Most of the 
contamination (4 samples) was found in water from the lavatory faucets. 
The Canadian study did not test for chlorine residual (Canada 2007a and 
2007b).
    It is important to note that the intended purpose and use of the 
preliminary AOC and the other aircraft sampling results were to protect 
public health by providing an understanding of the quality of airline 
drinking water. Although they were not collected to drive the ADWR 
rulemaking process, these datasets provide important information for an 
estimated baseline of aircraft drinking water quality for total 
coliform, E. coli/fecal coliform, and residual chlorine.
    Although it is difficult to complete a one-to-one comparison of the 
sampling results among the studies, observed differences may be 
attributed to several factors. For instance, best management practices 
and protocols (such as systematic sampling, disinfecting, and flushing 
procedures) established under the AOCs may have played a part in the 
varying results. These systematic protocols may have created a greater 
chance of consistency and effectiveness among the air carriers in 
implementing the operational and maintenance procedures of an aircraft 
water system. In addition, these findings suggest that best management 
practices are important for public health protection.
    EPA will continue to collect and analyze the aircraft sampling data 
for the 45 air carriers under the AOCs. EPA will use the data to 
improve the Agency's understanding of aircraft drinking water quality 
relevant to microbiological controls. A summary of the final results 
will be released along with available sampling data from the 45 air 
carriers under AOCs. Docket ID No. EPA-HQ-OW-2005-0025.

C. Framework for Proposed Rule Development

    For today's proposal, EPA has considered both the existing NPDWRs 
applicable to aircraft water systems--the Total Coliform Rule, the 
Surface Water Treatment Regulations and the Public Notification Rule--
and a systematic risk management approach used for food and water 
safety by other agencies, which EPA believes can be particularly 
effective when dealing with mobile sources of drinking water. The 
resulting proposed rule is intended to consolidate the three existing 
NPDWRs into one new NPDWR and modify them, based on the Water Safety 
Plan approach described as follows, so that the drinking water 
standards can be more effectively implemented for aircraft water 
systems and better integrated with FDA and FAA programs and 
requirements.
1. HACCP and Water Safety Plan Approaches
    EPA believes that an effective means of assuring safe drinking 
water onboard aircraft is through the application of a systematic risk 
management approach referred to as the Water Safety Plan (WSP) 
approach. The Water Safety Plan concept was developed by the World 
Health Organization (WHO) as part of the 3rd edition of its drinking 
water guidelines (WHO 2004). It is based on the Hazard Analysis and 
Critical Control Point (HACCP) concepts and the multiple barrier 
approach to protecting public health.
    The basic HACCP concepts were originally developed in 1959 by the 
Pillsbury Company with cooperation and participation from the National 
Aeronautics and Space Administration (NASA), the Natick Laboratories of 
the U.S. Army, and the U.S. Air Force Space Laboratory Project Group. 
The purpose was to ensure food and beverage safety from microbiological 
hazards for the first NASA manned space missions. Since the 1980s, the 
HACCP system has been adopted by food and beverage industries world-
wide, where it forms an important part of their ``food safety plans.'' 
For example, the FDA has adopted the HACCP system as an effective 
approach for its food safety program. FDA utilized the HACCP approach 
in the final rules for the seafood and juice industries. HACCP 
guidelines developed by WHO, known as Codex Alimentarius, have been 
adopted internationally as the primary recognized food safety 
methodology for risk management. The current HACCP guideline (WHO, 
1997) was developed by the Codex Alimentarius Commission.
    In the multiple barrier approach, technical and managerial barriers 
help prevent contamination at the source, treatment, distribution, and 
tap to provide a safe supply of drinking water for consumers. The 
barriers include risk prevention, risk management, monitoring and 
compliance, and individual action. As an enhancement of the HACCP 
approach, the Water Safety Plan approach identifies control measures 
not only at critical control points, as is done for HACCP, but also at 
the point of contamination where the hazardous event occurs as well as 
downstream of the potential contamination point. The intent is to 
enable the effect of the multiple barriers to be assessed together 
(Davison et al., 2005). The Water Safety Plan approach continues to 
evolve as the water industry gains experience by developing and 
implementing Water Safety Plans.
2. Proposed Rule Approach
    The proposed approach for this rulemaking effort includes elements 
of the HACCP approach and WHO's Water Safety Plan approach and builds 
on the foundation of the controls established under the existing NPDWRs 
applicable to aircraft water systems. This proposed regulation does not 
require each air carrier to develop its own Water Safety Plan (WSP). 
Instead, the WSP approach was used to outline the priority hazards and 
the control measures that could be implemented to control these hazards 
in the entire aircraft water supply and transfer chain. By looking 
holistically at the entire process, EPA ensured a collaborative working 
relationship with other federal agencies overseeing the air carrier 
industry. This holistic approach will minimize duplication of effort 
and regulation by multiple federal agencies over the same segment of 
the process. It also helps minimize concerns of over-regulation in one 
segment of a process to address an issue that could be more effectively 
handled in another segment of the process. Once the hazards and 
potential control measures were identified, EPA could then focus on the 
specific area of its jurisdiction, the onboard water system.
3. Identified Hazard Events and Potential Control Measures
    The following are examples of the primary hazard events and 
potential control measures for aircraft water systems identified 
through the WSP approach.
     Water to be boarded does not meet NPDWRs applicable to 
TNCWSs. The potential control measure is to prevent boarding of water, 
if operational needs (e.g., flushing of toilets) can be met

[[Page 19327]]

without boarding additional water. If water must be boarded, 
appropriate control measures are to: Restrict public access, provide 
public notification, including posting notices at lavatory and galley 
taps stating that the water is not for consumption; provide bottled 
water for coffee making and drinking; providing antiseptic alcohol-
based hand gels or wipes for handwashing; disinfecting and flushing the 
aircraft water system as soon as possible; and demonstrating 
satisfactory aircraft water quality through follow-up sampling before 
resumption of unrestricted public access to the aircraft water system.
     Air carrier or aircraft crew is notified that water 
already boarded does not meet NPDWRs applicable to TNCWSs. The 
potential control measures are to: Restrict public access, provide 
public notification, including posting notices at lavatory and galley 
taps stating that the water is not for consumption; providing bottled 
water for coffee making and drinking; providing antiseptic alcohol-
based hand gels or wipes for handwashing; disinfecting and flushing the 
aircraft water system as soon as possible; and demonstrating 
satisfactory aircraft water quality through follow-up sampling before 
resumption of unrestricted public access to the aircraft water system.
     Use of a watering point, including transfer and delivery 
systems, not approved by FDA. The potential control measure is for the 
air carrier to obtain approval from FDA for new watering points or when 
changing watering points.
     Contamination or cross contamination due to unsanitary 
practices. The potential control measures are to: Clean and disinfect 
hoses, transfer pumps, water trucks, and other equipment; develop 
written standard operating procedures (SOPs) and provide training for 
sanitary water transfer practices and aircraft cleaning; conduct total 
coliform monitoring; restrict public access, provide public 
notification, including posting notices at lavatory and galley taps 
stating that the water is not for consumption; providing bottled water 
for coffee making and drinking; providing antiseptic alcohol-based hand 
gels or wipes for handwashing; disinfecting and flushing the aircraft 
water system as soon as possible; and demonstrating satisfactory 
aircraft water quality through follow-up sampling before resumption of 
unrestricted public access to the aircraft water system; and conducting 
audits or inspections.
     Backflow from unprotected cross connection, failure of 
backflow prevention devices, or cross contamination from water line 
break. The potential control measures are to: Identify possible cross 
connections and install backflow prevention devices as warranted; 
repair failed backflow prevention devices; repair water line breaks; 
disinfect and flush the aircraft water system as soon as possible; and 
resample aircraft water quality before returning to service.
     Improperly designed aircraft water system. The potential 
control measure is to obtain FDA review and approval of plans and 
specifications (Certificate of Sanitary Construction) for new aircraft 
water systems.
     Bacterial growth in aircraft water system. The potential 
control measures are to: Conduct routine total coliform monitoring; and 
routinely disinfect and flush the aircraft water system.

IV. Elements of the Proposed Aircraft Drinking Water Rule

    The following sections describe the elements of the aircraft 
drinking water rule as proposed by EPA. The proposed rule has 
significant operational advantages over the other more prescriptive 
alternatives, which are described in section V. EPA specifically 
designed the proposed rule to allow air carriers to follow the 
manufacturer recommendations for disinfecting and flushing aircraft 
water systems, instead of prescribing the frequency, chemical type and 
concentration to be used. Another advantage of the proposed rule over 
the approaches described in the alternatives is that by utilizing the 
manufacturer recommendations for disinfection and flushing, the rule 
requirements will automatically evolve (another stakeholder 
recommendation) with technological improvements in aircraft water tank 
lining and piping materials and as new more effective disinfectants are 
developed.
    EPA requests comment on all aspects of this rule. Please note, 
however, that EPA is not requesting, and will not consider, comments on 
any aspect of the TCR, surface water treatment regulations, Public 
Notification Rule or any other NPDWR other than as applied to aircraft 
water systems in this proposal. In addition to rule requirements, EPA 
identifies specific requests for comment on subject matters pertaining 
to the proposed rule.

A. Sampling Requirements

1. Coliform Sampling Plan
    As discussed above, the existing TCR requires testing for total 
coliforms in water systems. Under this proposal, EPA is requiring each 
air carrier to develop a coliform sampling plan (within six months 
after the final rule is published in the Federal Register) for each 
aircraft that identifies the following: (1) Coliform sample collection 
procedures, (2) sample tap location(s) representative of the aircraft 
water system, including both galley and lavatory taps when available, 
(3) frequency and number of routine coliform samples to be collected 
(4) frequency of routine disinfection and flushing as specified in the 
operation and maintenance plan, and (5) procedures for communicating 
sample results promptly so that any required actions including repeat 
and follow-up sampling, corrective action, and notification of 
passengers and crew may be conducted in a timely manner. The 
development of a sampling plan will assist the air carrier in tracking 
regulatory requirements, identifying coliform detection trends, if any 
exist, and in maintaining compliance.
2. Coliform Sampling Requirements
    In keeping with the current TCR, air carriers need only determine 
the presence or absence of total coliforms in water samples collected 
from aircraft water systems; a determination of total coliform density 
would not be required. EPA believes this aids in making the sampling 
process more efficient and avoids unnecessary analysis. In addition, 
this proposed rule specifies that only analytical methodologies 
approved by EPA are to be used for sampling. For routine monitoring, 
each aircraft water system water sample must be 100 mL. One sample must 
be taken from a lavatory and one sample from a galley; each must be 
analyzed for total coliform. EPA believes the selection of sample taps 
from both the lavatory and the galley is necessary since tap options 
throughout these types of water systems is limited. If only one water 
tap is located in the aircraft water system due to aircraft model type 
and construction, then a single tap may be used to collect two separate 
100 mL samples.
    Routine coliform sampling should be representative of the general 
conditions of the aircraft water system. To ensure that results of 
routine samples are not inadvertently skewed by sampling too soon after 
a disinfection event, routine coliform samples must not be collected 
within 72 hours after completing disinfection and flushing procedures. 
EPA believes that spacing routine samples evenly across monitoring 
periods will help. This is necessary in order to capture a 
representative sample from normal aircraft water system operations. 
Additional, or special, coliform sampling is always encouraged and 
recommended by EPA.

[[Page 19328]]

    Routine coliform monitoring frequencies are as follows:
     If the air carrier disinfects and flushes the entire water 
system at least quarterly, then coliform monitoring must occur at least 
annually;
     If the air carrier disinfects and flushes the entire water 
system one to three times per year, then coliform monitoring must occur 
at least quarterly; or
     If the air carrier disinfects and flushes the entire water 
system less than once per year, then coliform monitoring must occur at 
least monthly.
    It should be noted that this is the first NPDWR that requires 
disinfection and flushing as a required extra barrier for the 
protection of public health. EPA understands that most of the air 
carrier maintenance programs employ water system disinfection and 
flushing; however, EPA believes that making three sampling frequency 
options available to air carriers for the aircraft water systems that 
they operate provides the flexibility to meet the evolving needs of the 
industry while still providing adequate barriers of protection.
    This proposal uses calendar-based monitoring and reporting 
frequencies. This basis is also consistent with EPA's current methods 
of oversight and is compatible with the Agency's current data systems. 
EPA is aware that the air carrier industry typically schedules 
maintenance or other activities based on aircraft flight hours or 
flight days. Scheduling activities on a calendar basis could lead to 
incompatibility and challenges in creating regular maintenance 
schedules. On the other hand, if an aircraft is not in frequent 
operation, basing aircraft water system activities on a flight time 
basis could lead to an extended calendar period before any actions are 
taken, which would not be protective of public health. EPA requests 
comment on whether the proposed calendar basis could reasonably be 
integrated with the air carrier industry's flight time basis, or if 
not, how the Agency should transpose the proposed requirements to an 
equivalent standard on a flight time basis.

B. Response to Sampling Results

    1. All routine coliform samples are negative. If all routine 
samples are total coliform-negative in a monitoring period, then the 
air carrier must continue to maintain its routine monitoring for 
coliform based on the frequency required under the rule.
    2. The sample yields a positive result for total coliform. If any 
routine or repeat coliform sample is total coliform-positive, then that 
total coliform-positive culture medium must be analyzed to determine if 
fecal coliforms or E. coli are present.
    3. One of two routine water samples test positive for total 
coliform, but negative for E. coli or fecal coliforms. In response to a 
single total coliform-positive sample result that is fecal/E. coli 
negative, the air carrier must perform at least one of the following:
     Disinfection and flushing no later than 72 hours after the 
laboratory notifies the air carrier of the positive result. Follow-up 
samples must be collected after disinfection and flushing is performed 
to ensure the effectiveness of the process. A complete set of post 
disinfection and flushing follow-up sample results (i.e., one from the 
lavatories and one from the galleys) must be total coliform-negative 
before the air carrier provides water from the aircraft water system to 
passengers and crew and returns to the routine monitoring frequency for 
coliform; or
     Repeat Sampling. Collect four 100 mL repeat samples within 
24 hours of being notified of the positive result. Repeat samples must 
be collected and analyzed from four taps within the aircraft water 
system: the tap which resulted in the total coliform-positive sample, 
one other lavatory tap, one other galley tap, and one other tap; if 
less than four taps exist, then a total of four 100 mL samples must be 
collected and analyzed from the available taps within the aircraft 
water system. If no repeat sample is total coliform-positive, the 
system returns to its routine monitoring schedule and no further 
follow-up is required.
    4. Any sample test result is fecal coliform positive or E. coli-
positive. Since fecal coliform or E. coli bacteria indicate the 
potential presence of contaminants that can cause acute health risks, 
EPA believes it is necessary to take immediate corrective action for 
the protection of public health. The aircraft water system is not a 
traditional water system and the air carrier must therefore take 
additional measures to prevent any disease or illness. If any routine 
or repeat sample is fecal coliform-positive or E. coli-positive, then 
the air carrier must perform all of the following:
     Restrict public access to the aircraft water system which 
includes providing notification to passengers and crew as soon as 
possible but no later than 24 hours after being notified of the 
positive result.
     Conduct disinfection and flushing prior to resumption of 
unrestricted public access to the aircraft water system or no later 
than 72 hours if the aircraft water system cannot be physically 
disconnected/shut off to the crew and passengers.
     Collect follow-up samples after disinfection and flushing 
is performed to ensure the effectiveness of the process. A complete set 
of post disinfection and flushing follow-up sample results must be 
total coliform-negative before the air carrier provides water from the 
aircraft water system to passengers