[Federal Register: October 19, 2009 (Volume 74, Number 200)]
[Rules and Regulations]
[Page 53589-53625]
[DOCID:fr19oc09-16]

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Part II

Environmental Protection Agency

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40 CFR Part 141

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

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 141

[EPA-HQ-OW-2005-0025; FRL-8967-9]
RIN 2040-AE84

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

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: The Environmental Protection Agency is establishing Federal
drinking water requirements (known as national primary drinking water
regulations or NPDWRs) for aircraft public water systems (hereafter,
aircraft water systems) under the Safe Drinking Water Act (SDWA).
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. This
final rule's requirements are intended to tailor existing health-based
drinking water standards to the unique characteristics of aircraft
water systems for the enhanced protection of public health against
illnesses attributable to microbiological contamination. EPA believes
that this approach 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 disruptions of aircraft flight schedules.

DATES: This rule is effective November 18, 2009. For judicial review
purposes, this final rule is promulgated as of October 19, 2009.

ADDRESSES: EPA has established a docket for this action under Docket ID
No. EPA-HQ-OW-2005-0025. All documents in the docket are listed on the
http://www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, e.g., Confidential Business
Information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, is
not placed on the Internet and will be publicly available only in hard
copy form. Publicly available docket materials are available either
electronically through http://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<PHONE_NUMBER>, and the
telephone number for the Water Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Richard Naylor or Cindy Y. Mack,
Drinking Water Protection Division, Office of Ground Water and Drinking
Water (MC-4606M), Environmental Protection Agency, 1200 Pennsylvania
Ave., NW., Washington, DC 20460; telephone numbers: Richard Naylor
(202) 564-3847 or Cindy Y. Mack<PHONE_NUMBER>; e-mail addresses:
<EMAIL_ADDRESS>or<EMAIL_ADDRESS>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 Aircraft Drinking Water Rule
(ADWR) include air carriers that operate aircraft 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:

------------------------------------------------------------------------
                                                         Examples of
             Category                 NAICS code     regulated entities
------------------------------------------------------------------------
Scheduled passenger air                     481111  Air carriers.
 transportation.
Nonscheduled chartered passenger            481211  Air carriers.
 air transportation.
------------------------------------------------------------------------

    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 Sec.  141.800 of this final rule.
If you 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. Abbreviations Used in This Notice

ADWR: Aircraft Drinking Water Rule
ANSI: American National Standards Institute
AOCs: Administrative Orders 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
NAICS: North American Industrial Classification System
NCWS: non-community water system
NDWAC: National Drinking Water Advisory Committee
NPDWR: national primary drinking water regulation
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 Administration

SDWA: Safe Drinking Water Act
SDWIS: Safe Drinking Water Information System
SWTR: Surface Water Treatment Rule
TC: total coliform
TCR: Total Coliform Rule
TCRDSAC: Total Coliform Rule/Distribution System Advisory Committee
TNCWS: transient non-community water system
TT: treatment technique
UMRA: Unfunded Mandates Reform Act
US: United States
UV: Ultra Violet
WHO: World Health Organization
WSG: Water Supply Guidance
WSP: Water Safety Plan

C. Table of Contents

I. General Information
    A. Does this Action Apply to Me?
    B. Abbreviations Used in This Document
II. Background
    A. Legal Authority
    B. Purpose of the Rule
    C. Scope and Applicability of Rule
    D. Regulatory and Enforcement History
III. Final Rule Development
    A. Stakeholder Involvement
    B. Aircraft Drinking Water Quality
IV. Elements of the Final Aircraft Drinking Water Rule
    A. Definitions (Sec.  141.801)
    B. Sampling Requirements (Sec. Sec.  141.802 and 141.803)
    C. Responses to Sample Results (Sec.  141.803)
    D. Restricted Access to the Water System
    E. Response to Proposed Rule Requests for Comment
    F. Aircraft Water System Operation and Maintenance Plan (Sec.
141.804)
    G. Notification Requirements to Passengers and Crew (Sec.
141.805)
    H. Reporting Requirements (Sec.  141.806)
    I. Recordkeeping Requirements (Sec.  141.807)
    J. Audit and Self-Inspection Requirements (Sec.  141.808)
    K. Violations (Sec.  141.810)
    L. Compliance Date
V. Cost Analysis
    A. National Cost Estimates
    B. Estimated Impacts of Final ADWR to Air Carrier Passengers
    C. Comparison of Costs From Proposed Rule to Final Rule
    D. Non-quantified Costs and Uncertainties
VI. Benefits Analysis
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 Tribal 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
    M. Congressional Review Act
    N. Analysis of the Likely Effect of Compliance With the ADWR on
the Technical, Financial, and Managerial Capacity of Public Water
Systems
VIII. References

II. Background

A. Legal Authority

    EPA is finalizing 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 pipes or other constructed conveyances and that
regularly serves an average of at 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
of 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.
    EPA's NPDWRs establish different requirements based on the
classification of the public water system (water system), including
whether the system is a ``community,'' ``non-transient non-community,''
or ``transient non-community'' system, and whether the system uses
surface water or groundwater. Aircraft water systems are considered
transient non-community water systems (TNCWS) because they are not
community water systems and they do not regularly serve an average of
at least twenty-five 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.

B. Purpose of the Rule

    The primary purpose of the 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 and effective way to
comply with SDWA and the NPDWRs. Due to the unique characteristics of
aircraft water systems and demonstrated implementation challenges, EPA
developed a new NPDWR specifically tailored to aircraft water systems,
the Aircraft Drinking Water Rule (ADWR).
    The ADWR has been developed 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.

C. Scope and Applicability of Rule

    This final rule 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 final rule applies to the onboard water
system only. EPA defers to the United States Food and Drug
Administration (FDA) with respect to regulating watering points such as
water cabinets, carts, trucks, and hoses from which aircraft board
water.
    EPA assumes that only finished water is boarded for human
consumption 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 an FDA requirement that only potable water may be provided for
drinking and culinary purposes on interstate carrier conveyances (ICCs)
(21 CFR 1240.80). However, aircraft water systems that are boarding
water that is not finished water will continue to be subject to
existing NPDWRs.
    FDA requirements cover 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. FDA requirements for watering points
do not entail the individual certification of every potential source,
method, facility, or system; however, ICC selected watering points must
be in accordance with FDA requirements (21 CFR part 1240, subpart E).
    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 regulated under this final ADWR. EPA also
does not regulate under SDWA water systems that only serve water
outside the U.S. On the April 9, 2008, proposed ADWR, EPA received
public comment as to the applicability of the ADWR to aircraft water
systems based on ownership (e.g., foreign carrier, U.S. military). The
final rule clarifies that the applicability of the ADWR is not based on
ownership, but on the determination as to whether the aircraft water
system is operating within the U.S., meets the definition of a public
water system (PWS) under SDWA section 1401, and is not excluded from
regulation under SDWA section 1411. An aircraft is not considered a
public water system if it does not regularly serve an average of at
least twenty-five individuals daily at least 60 days out of the year.
The ADWR applies to aircraft (regardless of ownership) that fly routes
between two or more locations within the U.S., while the aircraft is
within U.S. jurisdiction. For instance, an aircraft flying an
international route that serves only one U.S. location would not
generally be considered a PWS. Another example is an aircraft that is
used solely for military purposes, is not conveying passengers in
interstate commerce, and meets all of the other exclusion criteria
under SDWA section 1411; in this case, the aircraft would also be
excluded from regulation under the NPDWRs and the ADWR.
    An estimated 63 air carriers and 7,327 aircraft water systems are
regulated by this rule.

D. Regulatory and Enforcement History

    SDWA, including the amendments of 1986 and 1996, requires EPA to
promulgate NPDWRs to prevent tap water contamination that may adversely
affect human health. As previously noted, aircraft are subject to
certain NPDWRs specific to TNCWS. 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). Since then,
EPA has determined that a new rule, the ADWR, specifically adapted to
aircraft water systems would provide a clearer and more implementable
regulatory framework for aircraft water systems. EPA suspended WSG 29
in 2003 and is no longer approving operation and maintenance programs
in lieu of monitoring.
    As discussed in the preamble to the proposed rule (73 FR 19323,
April 9, 2008), 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
under 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 water systems. In the interim, EPA placed 45
air carriers under Administrative Orders on Consent (AOCs) that will
remain in effect until 24 months following publication of the final
rule.
    The ADWR adapts to aircraft water systems the applicable
requirements from the Total Coliform Rule (TCR), the suite of surface
water treatment regulations, and the Public Notification 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 fecal coliforms or
E. coli. Fecal coliforms or E. coli indicate more immediate health
risks from sewage or fecal contamination and are used as an indicator
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 five
years for systems that collect fewer than five total coliform samples
per month (those serving 4,100 people or fewer). A TNCWS using surface
water serving less than 1,000 individuals daily would typically be
required to take one total coliform sample per month for routine
sampling requirements.
    Under 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.
    In addition to the EPA 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. For example, such
programs and practices 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 requirements 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. Throughout the rule's development, EPA has worked
closely with FDA and FAA to ensure that the ADWR is integrated with
these programs to avoid unnecessary duplication.

III. Final Rule Development

A. Stakeholder Involvement

    As discussed in the proposed ADWR, EPA announced in 2004 that it
had initiated a rulemaking process to develop regulations for aircraft
water systems. (73 FR 19324, April 9, 2008). The Agency committed to
working collaboratively with other Federal agencies (e.g., FDA and FAA)
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 final ADWR.
    EPA 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. This pre-proposal input greatly
assisted EPA in the rule's development.
    EPA proposed the ADWR on April 9, 2008 (73 FR 19320), and requested
public comment. The 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.
EPA received comments on the proposal and has made revisions to this
final rule that increases regulatory flexibility and adaptability to
the airline industry's operations, while ensuring public health
protection. Section IV of this notice describes how EPA incorporated
public comments into revisions to the final rule. A Response to
Comments Document is available in the docket for today's action.

B. Aircraft Drinking Water Quality

1. Data Collection Efforts
    To better understand aircraft drinking water quality, EPA analyzed
sampling results submitted by air carriers under Administrative Orders
on Consent (AOCs) from 2005-2008. As detailed in the proposed ADWR, EPA
also drew upon the results of the following three studies: (1) A
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 (73 FR 19324).
    The AOCs established interim aircraft water testing and
disinfection protocols. As part of the AOCs' requirements, air carriers
were required to submit two documents for EPA approval, which 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. 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 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                   [check]          [check]
     aircraft's water system no less
     than quarterly...................
    Disinfect and flush watering               [check]          [check]
     points (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 had a pre-AOCs 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.

2. Microbiological Occurrence for the Estimated Baseline
    As of December 31, 2008, EPA has processed drinking water sampling
data from 25 of the 45 air carriers under the AOCs. From these 25 air
carriers, EPA processed a total of 20,156 total coliform samples
(13,872 routine and 6,284 repeat) and 17,267 chlorine residual samples.
These 25 air carriers represent 78 percent of the total estimated AOCs'
fleet size (5,558 aircraft) and 79 percent of the total expected annual
number of routine samples. However, data for air carriers with an EPA-
approved QAPP and CRMP are only available from 2 air carriers in 2005,
5 air carriers in 2006, 8 air carriers in 2007, and 12 air carriers in
2008.
    The following data summaries are from air carriers with an EPA-
approved QAPP and CRMP. As noted above, not all 25 air carriers
provided data collected under an EPA-approved QAPP and CRMP for all
four years. Therefore, insufficient data are currently available to
support statistical evaluation of the data sets. However, the data were
used to provide an observational indication of trends. It should be
noted that total coliform repeat samples by nature have a higher
probability of being positive since repeat samples are taken after a
routine sample is total coliform-positive. Consequently, the occurrence
baseline for total coliform and E. coli/

fecal coliform occurrence was based on routine samples only. Table III-
2 presents data for routine total coliform samples collected under EPA-
approved QAPPs and CRMPs.
    Of the total 20,156 total coliform samples received, 93 percent or
18,724 samples (12,794 routine and 5,930 repeat samples) were from air
carriers with an EPA-approved QAPP and CRMP. Of the 12,794 routine
samples, 3.6 percent (463 samples) were positive for total coliform and
3.9 percent (18 samples) of the total coliform-positive samples were E.
coli/fecal coliform-positive. Of the 463 total coliform-positive
routine samples, 413 were collected in the lavatory, 47 were collected
in the galley, and one was a composite sample of galley and lavatory
sources; the location of the remaining two positive results are
unknown. Although the lavatory samples had a higher total coliform-
positive occurrence rate (5.9 percent, or 413 of 7,027 lavatory
samples) than the galley samples (0.8 percent, or 47 of 5,695 galley
samples), the galley samples had a higher E. coli/fecal coliform
occurrence of 12.8 percent (6 of 47 total coliform-positive samples),
compared to 2.9 percent (12 of 413 total coliform-positive samples) in
the lavatories. More details on the routine coliform data set by
calendar quarter and by sample collection location on the aircraft are
presented in the following table (Table III-2).

   Table III-2--AOCs Occurrence Baseline Data--Routine Total Coliform Samples of Air Carriers With EPA-Approved
                                        QAPPs and CRMPs (Years 2005-2008)
----------------------------------------------------------------------------------------------------------------
                                                                                Total  of TC+     Total  of TC+     samples that      i> of TC
                                                  percent EC+ or      samples     are EC+ or FC+      samples
                                                        FC+
----------------------------------------------------------------------------------------------------------------
                                     Total Coliform Data by Calendar Quarter
----------------------------------------------------------------------------------------------------------------
Calendar Qtr 1..................             3.2             4.0             100               4           3,145
Calendar Qtr 2..................             3.5             3.5             198               7           5,641
Calendar Qtr 3..................             4.1             0.0              79               0           1,930
Calendar Qtr 4..................             4.1             8.1              86               7           2,078
                                 -------------------------------------------------------------------------------
    Total.......................             3.6             3.9             463              18          12,794
----------------------------------------------------------------------------------------------------------------
                                     Total Coliform Data by Sample Location
----------------------------------------------------------------------------------------------------------------
Galley..........................             0.8            12.8              47               6           5,695
Lavatory........................             5.9             2.9             413              12           7,027
Composite*......................            14.3               0               1               0               7
Unknown Sample Site.............             3.1               0               2               0              65
                                 -------------------------------------------------------------------------------
    Total.......................             3.6             3.9             463              18          12,794
----------------------------------------------------------------------------------------------------------------
* Composite sample of Galley and Lavatory sources.
Note: ``TC+'' means total coliform-positive; ``EC+ or FC+'' means E. coli-positive or fecal coliform-positive.
Note: For air carriers with EPA-Approved QAPPs and CRMPs (Years 2005-2008), out of a total number of 12,794
  routine samples, a total of 18 samples (0.14%) were EC+ or FC+.

3. Residual Chlorine Estimated Baseline
    Table III-3 presents data for disinfectant residual samples
collected under EPA-approved QAPPs and CRMPs during routine and repeat
total coliform sampling events. Of the 18,724 routine and repeat total
coliform sample events reported, 16,109 disinfectant residual sample
results were also reported. Results were reported as either ``detect''
with the residual value recorded, or ``non-detect.'' Disinfectant
residual data were not provided for 2,615 coliform sample events.
Disinfectant residual data are presented for the total of routine and
repeat sample collection events because repeat samples have no higher
or lower probability of having a detectable residual than routine
samples.
    For air carriers with approved QAPPs and CRMPs, approximately 18.2
percent (2,927 samples) of the 16,109 disinfectant residual results
processed from 2005 to 2008 had a non-detectable disinfectant residual.
Non-detectable levels were similar in galleys (17.3 percent) and
lavatories (18.9 percent), while 22.4 percent (73 out of 326 samples)
of the composite samples were non-detects. A sample location was not
identified for 13 samples with a detectable residual. While not
statistically significant, the occurrence of non-detectable
disinfectant residuals appeared to increase in months with warmer
weather. Quarter 3 (i.e., July to September) had the highest percentage
of samples with a non-detectable disinfectant residual (30.2%),
although as shown in Table III-2, Quarter 3 routine total coliform
sample results showed no appreciable increase in the percentage of
coliform-positive samples.

   Table III-3--AOCs Occurrence Baseline Data--Disinfectant Residual Routine and Repeat Samples of Air Carriers
                               With EPA-Approved QAPPs and CRMPs (Years 2005-2008)
----------------------------------------------------------------------------------------------------------------
                                                                   Total  of           i> of           i> of
                                                   disinfectant    disinfectant    disinfectant    disinfectant
                                                   residual non-   residual non-     residual        residual
                                                      detect          detect          detect          samples
----------------------------------------------------------------------------------------------------------------
                                 Disinfectant Residual Data by Calendar Quarter
----------------------------------------------------------------------------------------------------------------
Unknown Calendar Qtr............................               0               0               0               0
Calendar Qtr 1..................................            22.8             864           2,933           3,797

Calendar Qtr 2..................................             9.3             632           6,128           6,760
Calendar Qtr 3..................................            30.2             813           1,879           2,692
Calendar Qtr 4..................................            21.6             618           2,242           2,860
                                                 ---------------------------------------------------------------
    Total.......................................            18.2           2,927          13,182          16,109
----------------------------------------------------------------------------------------------------------------
                                  Disinfectant Residual Data by Sample Location
----------------------------------------------------------------------------------------------------------------
Galley..........................................            17.3           1,336           6,386           7,722
Lavatory........................................            18.9           1,518           6,530           8,048
Composite *.....................................            22.4              73             253             326
Unknown Sample Site.............................             0.0               0              13              13
                                                 ---------------------------------------------------------------
    Total.......................................            18.2           2,927          13,182          16,109
----------------------------------------------------------------------------------------------------------------
* Composite sample of Galley and Lavatory sources

    It appears that a non-detectable disinfectant residual is not
associated with an increase in total coliform-positive samples. Of the
801 total routine and repeat samples that were total coliform-positive,
24 did not include any data on a disinfectant residual. Of the
remaining 777 total coliform-positive routine and repeat samples, 584
samples (75 percent) had a detectable disinfectant residual and 193
samples (25 percent) did not have a detectable disinfectant residual.
Twenty-one (3.6 percent) of the 584 total coliform-positive routine and
repeat samples with a detectable residual (the lowest measuring 0.05
mg/L) also tested positive for E. coli/fecal coliforms. Only one (0.5
percent) of the 193 total coliform-positive samples did not have a
detectable residual and tested positive for E. coli/fecal coliforms.
    Seventy-three samples had non-detectable disinfectant residual and
were reported to have carbon filters installed on the water lines to
the sample tap; two of those samples were total coliform-positive. For
comparison, 364 samples with detectable disinfectant residual were
reported to use carbon filters; three of those samples were total
coliform-positive. Aside from charcoal/carbon, and particle removal
filters in some galleys and lavatories, the majority of aircraft do not
provide additional treatment for boarded water.
    For more details on aircraft drinking water sample results under
the AOCs, see Chapter 3 and Appendix B of the Economic and Supporting
Analyses for the Final ADWR.

IV. Elements of the Final Aircraft Drinking Water Rule

    The following sections describe the elements of the final rule as
developed by EPA. EPA specifically designed the rule to allow air
carriers to be consistent with the manufacturer recommen- dations for
disinfecting and flushing aircraft water systems, instead of
prescribing the frequency, chemical type and concentration to be used.
By allowing air carriers to be consistent with the manufacturer
recommendations for disinfection and flushing, the rule requirements
will automatically evolve with technological improvements in aircraft
water tank lining and piping materials, and as new more effective
disinfectants are developed.
    EPA requested comment on all aspects of the rule in its proposal of
April 9, 2008 (73 FR 19320); however, EPA did not request and did 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 the proposed rule. In addition to
rule requirements, EPA identified specific requests for comment on
subject matters pertaining to the proposed rule. The public comment
period for the April 9, 2008, proposed ADWR closed on July 8, 2008. The
following sections of this preamble explain the final rule and present,
when applicable, a summary of the major public comments received. In
addition, EPA has responded to all of the public comments in its
Response to Comment document, which can be found in the docket for this
rule (see ADDRESSES of this notice to obtain information on accessing
the docket).

A. Definitions (Sec.  141.801)

    All definitions included in the proposed rule (73 FR 19343), remain
the same in today's final rule except for the definitions for Aircraft
Water System Operations and Maintenance Plan and Watering Point.
    In the proposed rule, the definition for Aircraft Water System
Operations and Maintenance Plan reads, ``Aircraft Water System
Operations and Maintenance Plan means the schedules and procedures for
operating, monitoring, and maintaining an aircraft water system that is
included in an aircraft operations and maintenance program approved or
accepted by the Federal Aviation Administration (FAA).'' Since the
publication of the proposed rule, the Agency has learned that FAA does
not ``approve'' the air carrier operations and maintenance programs,
and that describing these programs as ``FAA-accepted'' programs is more
accurate. Thus, in the final rule, EPA removes the word ``approved''
from the definition.
    In the proposed rule, the definition for Watering Point reads,
``Watering Point means a facility where finished water is transferred
from a water supply to the aircraft. These facilities may include water
trucks, carts, cabinets, and hoses.'' However, the Agency received
comments concerning selection of watering points in Sec.  141.804. The
commenters (details under Section IV. F of this notice) believed that
EPA intended to alter Food and Drug Administration (FDA) regulations
applicable to watering points. EPA did not intend to alter these
regulations, and clarifies in today's final rule that it is the
Agency's intent to keep the rule consistent with existing FDA
regulations. Thus, the Agency is revising the definition for Watering
Point to read, ``Watering Point means

the water supply, methods, and facilities used for delivery of finished
water to the aircraft. These facilities may include water trucks,
carts, cabinets and hoses.''

B. Sampling Requirements (Sec. Sec.  141.802 and 141.803)

    This section begins with a summary of the major sampling
requirements of the final ADWR, then addresses public comments received
on the proposed ADWR related to changes EPA has made to the final rule
requirements. Finally, EPA provides responses to the ``Request for
Comment'' issues posed in the proposal designed to aid the Agency in
developing requirements under the final ADWR.
    In keeping with the TCR, today's rule reiterates that 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 is not required. In addition, this final rule
specifies that only analytical methodologies approved by EPA are to be
used for sample analysis. For routine total coliform monitoring, each
aircraft water system water sample must be 100 mL. For most systems,
one sample must be collected from a lavatory and one sample from a
galley. Each sample must be analyzed for total coliforms. If total
coliforms are detected, the sample must further be analyzed for E.
coli. Under this rule, E. coli is the indicator that fecal
contamination may have occurred. 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 to
be analyzed for total coliforms. If an aircraft water system has a
removable/portable tank, that is drained at least every day of
passenger service and there is one tap on the aircraft, the air carrier
may collect one 100 mL sample from the available tap (i.e., galley or
lavatory).
1. Coliform Sampling Plan (Sec.  141.802)
    EPA proposed to allow six months for air carriers to develop a
coliform sampling plan for each aircraft following publication of the
rule. However, the Agency received several comments requesting that the
compliance date be extended in order to allow more time for air
carriers to restructure maintenance programs between the AOCs and the
final rule. The comments and the Agency's response are explained in
more detail in section IV. L of this notice. EPA agrees that more time
may be needed for air carriers to develop a coliform sampling plan.
Therefore, today's final rule extends the compliance date for
development of the coliform sampling plan to 18 months after
publication of the final rule.
    Under the proposed and final rules, an air carrier must develop a
coliform sampling plan for each aircraft water system it owns and
operates. The coliform sampling plan must be included in the Aircraft
Water System Operations and Maintenance Plan required in Sec.  141.804.
The air carrier need not develop a separate coliform sampling plan for
each aircraft, but the air carrier must ensure that each aircraft it
owns and operates is covered by a plan. For example, if the air carrier
operates several of the same type of aircraft water system with the
same coliform sampling frequency, procedures, sampling tap locations,
etc., the air carrier may choose to develop one coliform sampling plan
that applies to all aircraft of this type in the air carrier's fleet.
    While most of the sampling plan requirements are the same in the
proposed and final rules, the Agency received comments that the
proposed rule was unclear as to whether and how air carriers could
amend their operations and maintenance plans or their coliform sampling
plans. EPA agrees that the final rule should more clearly state the
requirements for making changes to these plans. Thus, in the final
rule, EPA addresses this concern by clarifying that any subsequent
changes to the coliform sampling plan must also be included in the
Aircraft Water System Operations and Maintenance Plan. Changes to the
coliform sampling plan could include changes to any of the requirements
listed in this section, including changes to the frequency of routine
coliform sample collection. In addition, both the reporting
requirements and the requirements for the operations and maintenance
plan have been revised to respond to these comments.
2. Coliform Sampling Requirements (Sec.  141.803)
    In the proposed rule, all air carriers would be required to collect
the same volume and number of samples regardless of aircraft size:
     For routine samples--collect two 100 mL samples: one from
a lavatory and one from a galley. If only one tap is available--collect
two ``separate'' 100 mL samples.
     For repeat samples--collect four 100 mL samples: one from
the positive tap, one other lavatory, one other galley, and one other
tap. If less than four taps are available--collect four 100 mL samples
from the available taps.
    In the proposed rule, routine sampling frequencies were based on
the routine disinfection and flushing frequency as detailed in the
following table (Table IV-1):

   Table IV-1--Proposed Rule Requirements for Routine Disinfection and
                          Flushing and Sampling
------------------------------------------------------------------------
   Disinfection & flushing frequency per     Coliform sampling frequency
               aircraft PWS                       per aircraft PWS
------------------------------------------------------------------------
Once per Quarter (4 times per year).......  Annually.
Once to 3 times per year..................  Quarterly.
Less than once per year...................  Monthly.
------------------------------------------------------------------------
If not specified by the manufacturer, disinfection and flushing must be
 no less frequent than once per quarter.
------------------------------------------------------------------------

    Public comments on the proposed rule raised several concerns
related to (1) the lavatory as a sampling location site, and (2) the
routine frequencies for disinfection and flushing, and coliform
monitoring. EPA received several public comments regarding the
elimination of lavatory samples. Several commenters stated that
lavatory sampling should be eliminated because it is not representative
of the water actually consumed for drinking purposes on aircraft and,
requiring the sampling of lavatories mischaracterizes risks unless (1)
there are no other sampling locations available on the aircraft; and/or
(2) the airline takes affirmative steps to offer water in the
lavatories for drinking purposes, such as providing drinking cups. EPA
disagrees with these comments. In today's rule, air carriers must
collect a total coliform sample from one galley and one lavatory, when
available. Collection of samples from the lavatory is necessary since
this water may be used for human consumption (e.g., brushing teeth,
hand washing). Additionally, lavatory samples are as representative of
the aircraft drinking water quality as galley samples when proper
collection techniques/procedures are used to minimize the frequency of
positive results due to surface contamination or improper collection
procedures. EPA plans to discuss these issues further in its separate
ADWR technical guidance.
    EPA received the following two major comments regarding routine
disinfection and flushing, and coliform monitoring frequencies: (1)
Reduce the sample collection for small volume aircraft water systems
(e.g., regional jets with 5-gallon removable tanks), and (2)

extend the minimum disinfection intervals to accommodate for less
frequent disinfection based on sampling results.
    With respect to sampling number and volume, commenters expressed
concern that the proposed ADWR was unduly complicated (e.g., number of
total coliform samples collected was too much) for small tanks (e.g.,
regional jets with 5 gallons) that are removable/portable and are
drained daily; and that the rule does not account for varying sizes of
aircraft. EPA agrees with the comments regarding aircraft with small
drinking water tanks and today's rule incorporates the following
changes:
     For aircraft water systems that have a removable/portable
drinking water tank that is drained every day of passenger service, and
the aircraft has only one tap, air carriers may collect one 100 mL
routine sample from the available tap; and
     Collect three 100 mL repeat samples when performing the
corrective action upon the receipt of a total coliform-positive sample.
This reduction in repeat samples also applies to all tank types.
    EPA believes these reductions are appropriate because the
complexity of aircraft water systems with removable/portable tanks and
one tap on the aircraft is low (e.g., few feet of tubing/pipes; few
potential points for cross contamination); and the reductions maintain
consistency with the recommendations of the Federal Advisory
Committee--The Total Coliform Rule/Distribution System Advisory
Committee (TCRDSAC)--to reduce sampling volume and frequency for small
non-community stationary systems (see docket for the TCRDSAC Agreement
in Principle, signed September 18, 2008). EPA also believes that the
economic and logistical burden on air carriers, particularly small
regional jets, will be minimized by taking fewer samples.
    Public comment on the proposed ADWR disinfection and flushing, and
monitoring frequencies centered around two main issues: (1) Extend the
minimum disinfection intervals to accommodate an approach that focuses
on risk and allows for less frequent disinfection based on sampling
results, and (2) set ``reasonable minimum'' disinfection timelines
consistent with the AOCs of some major air carriers to align a semi-
annual disinfection schedule with an annual sampling schedule, thereby
reducing the ``significant'' economic cost to restructure in-place
disinfection programs. EPA agrees that some changes are warranted and
today's rule includes revised requirements to the routine frequencies
as presented in Table IV-2:

    Table IV-2--Final Rule Requirements for Routine Disinfection and
                Flushing and Routine Sampling Frequencies
------------------------------------------------------------------------
Minimum routine disinfection & flushing    Minimum frequency of routine
              per aircraft                     samples per aircraft
------------------------------------------------------------------------
At least 4 times per year = At least     At least 1 time per year = At
 once within every three-month period     least once within every twelve-
 (quarterly).                             month period (annually).
At least 3 times per year = At least     At least 2 times per year = At
 once within every four-month period.     least once within every six-
                                          month period (semi-annually).
At least 2 times per year = At least     At least 4 times per year = At
 once within every six-month period       least once within every three-
 (semi-annually).                         month period (quarterly).
At least 1 time per year or less = At    At least 12 times per year = At
 least once within every twelve-month     least once every month
 period (annually) or less.               (monthly).
------------------------------------------------------------------------
If not specified by the manufacturer, select any frequency that is no
 less stringent than these four disinfection and flushing frequencies
 which meet the aircraft's unique operational needs.
------------------------------------------------------------------------

    EPA considers disinfection and flushing to be a more protective and
pro-active public health measure than monitoring. Therefore, EPA re-
aligned the disinfection and flushing and monitoring frequencies in
order to emphasize the importance of disinfection and flushing in
comparison to monitoring. As a result, those air carriers that conduct
more frequent disinfection and flushing do not have to monitor as
frequently. Today's final rule requires an air carrier that conducts
disinfection and flushing three times per year to perform sampling
twice a year instead of four times per year. And an air carrier that
conducts disinfection and flushing once per year or less must sample
monthly. With respect to the commenter's concern about accommodating a
semi-annual disinfection and flushing frequency with annual sampling
(as allowed under some AOCs), the ADWR continues to accommodate the
semi-annual disinfection and flushing schedule. However, EPA believes
that linking this with annual sampling would be inconsistent with the
importance of disinfection and flushing as the preferred, pro-active
measure. As reflected in Table IV-2, today's rule continues to require
air carriers that conduct disinfection and flushing semi-annually to
conduct monitoring four times per year.
    While the frequencies in Table IV-2 provide air carriers with
enough flexibility to schedule both routine disinfection and flushing
and routine monitoring in a way that avoids disruption to passenger
service, EPA intends for air carriers to schedule routine disinfection
and flushing and routine monitoring at regular intervals throughout the
calendar year. Routine disinfection and flushing should be scheduled so
that the amount of time between each disinfection and flushing event is
approximately equal. EPA believes that this will maximize the
effectiveness of the disinfection and flushing event. Similarly,
routine monitoring should be scheduled so that the amount of time
between each monitoring event is approximately equal. EPA does not
intend for routine disinfection and flushing events to take place back-
to-back such that disinfection and flushing occurs at the end of one
disinfection and flushing period and again at the beginning of the
following period. Nor should air carriers schedule routine monitoring
events to take place back-to-back such that samples are taken at the
end of one monitoring period and again at the beginning of the
following period.
    In addition, the Agency received comment that the requirement to
disinfect and flush quarterly, when no manufacturer recommendations
were available, did not provide flexibility. In today's rule, EPA
removed this requirement (as reflected in Table IV-2) so that when
there is no manufacturer recommendation, air carriers can select any of
the routine frequencies that best

meet their unique operations and maintenance needs.
    EPA was unable to make a determination on a risk-based approach
that supports a reduced frequency for disinfection and flushing based
on sampling results, because no new data were provided beyond the AOCs'
data. The AOCs' data protocols were not designed to establish risk-
based frequencies. AOCs are interim measures used to aid air carriers
to meet compliance with SDWA and provide an understanding of aircraft
drinking water quality. At this time, EPA believes the final rule
frequencies provide the minimum requirements necessary for public
health protection, while also providing adequate flexibility to meet
the evolving needs of the industry, such as transitioning from the
AOCs' requirements to the ADWR.
3. Analytical Methods (Sec.  141.803(a))
    In the proposed rule, EPA stated that air carriers must use EPA-
approved analytical methodologies for the analysis of coliform
bacteria. Public comment was received regarding the specific use of
concurrent analytical methods that test for total coliforms and E. coli
simultaneously. The commenter named several concurrent methods that
they felt provide ``great benefit'' to the industry, because the
methods are timely and accurate. Although some of these noted methods
are EPA-approved, the final rule reiterates and clarifies that air
carriers must use only the EPA-approved analytical methods for
analyzing total coliforms and/or E. coli in drinking water samples as
specified in Sec.  141.21(f)(3) and Sec.  141.21(f)(6) of the Code of
Federal Regulations, or their equivalent as approved by EPA to
demonstrate compliance with the ADWR sampling requirements. EPA has
approved several methods for use that allow the simultaneous detection
of both total coliforms and E. coli. These methods are also approved
for use under this rule.
    In the proposed rule, EPA required air carriers to use a State- or
EPA-certified laboratory for analysis of drinking water samples. For
compliance with the ADWR, one commenter encouraged EPA to allow the use
of foreign laboratories to conduct analysis on drinking water samples
as permitted under the Administrative Orders on Consent (AOCs). In
addition, the commenter noted that air carriers should be allowed to
conduct disinfection of their aircraft water systems ``at locations
outside the U.S.'' The final rule clarifies and reiterates that
drinking water microbiological samples submitted for compliance with
the ADWR must be analyzed by a certified laboratory to ensure the use
of approved analytical methods and approved quality control procedures
for checking analytical data for completeness and correctness. A
certified laboratory is a laboratory that is certified by EPA or a
State. ``State'' refers to a U.S. State or Tribe that has received
primacy for public water systems (other than aircraft water systems)
under section 1413 of the SDWA. By allowing the use of any laboratory
that is certified by a State or EPA for analysis of drinking water
samples, the ADWR provides air carriers with greater flexibility in
designing their sampling programs while maintaining protection of
public health.
    In one AOC, for a specific set of the fleet (i.e., 47 aircraft) an
air carrier was permitted to use a foreign laboratory, which was
neither EPA- nor State-certified, to perform analysis of drinking water
samples provided that the samples were analyzed using EPA- approved
analytical methods. The commenter incorrectly assumed that this
allowance would fulfill SDWA compliance. In today's notice, the Agency
makes clear that this allowance was not intended for compliance
purposes under the SDWA. The ADWR does not prevent collection of
samples outside the U.S. However, foreign laboratories must be an EPA-
or a State-certified laboratory in order to analyze the drinking water
samples for compliance with the ADWR. EPA plans on addressing these
issues in more detail in its ADWR technical guidance. EPA notes that
the ADWR requirements do not prevent air carriers from performing
disinfection and flushing outside the U.S. for compliance with the
ADWR.

C. Responses to Sampling Results (Sec.  141.803)

    As specified in the proposed rule, air carriers would 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. Under the proposal, upon
receipt of a total coliform-positive result, air carriers would be
required to further analyze the positive sample for the presence of
fecal coliforms, except that the system could test for E. coli in lieu
of fecal coliforms. EPA received public comment requesting the removal
of fecal coliforms as indicators. EPA agrees with this comment and
today's rule eliminates the use of fecal coliforms as indicators of
potential fecal contamination. As a consequence, the final rule
specifies that upon receipt of a total coliform-positive result, air
carriers must further analyze that sample for E. coli only. The fecal
coliform group (also referred to as thermotolerant coliforms) has been
found to sometimes contain environmental bacteria that are not of fecal
origin. Thus, the presence of fecal coliform bacteria in a water sample
is not necessarily indicative of the potential for fecal contaminants
being present. Thus, analyzing for E. coli provides more meaningful
data to protect public health. This change is consistent with the
recommendations of the Federal Advisory Committee--TCRDSAC.
    In the proposed rule, air carriers would be required to perform the
following corrective actions based on a positive coliform result:
    (1) If one routine sample was total coliform-positive and E. coli/
fecal coliform-negative then the air carrier would be required to:
     Within 72 hours of receipt of the positive result from the
laboratory, disinfect and flush the water system, and collect follow-up
samples; or
     Within 24 hours of receipt of the positive result from the
laboratory, collect four repeat samples.
    (2) If two or more routine samples or any repeat samples were total
coliform-positive and E. coli/fecal coliform-negative, or if any sample
was E. coli/fecal coliform-positive then the air carrier was required
to:
     Within 24 hours of receipt of the positive result from the
laboratory, restrict public access. Restrict public access included the
following activities for the aircraft in question: Physically
disconnect or shut-off the water system where feasible; provide public
notification to passengers and crew if the water system could not be
shut-off, but if the system could be shut-off, then provide public
notice to the crew only; and provide alternatives to the use of the
water system such as antiseptic alcohol-based hand gels or wipes and
bottled water (that reduce or eliminate the need to use the water
system during the limited period before access is restored); and
     Within 72 hours of receipt of the positive result from the
laboratory, disinfect and flush the water system and collect follow-up
samples if the system could not be physically disconnected or shut-off.
If the water system could be shut-off to prevent access to passenger
and crew, disinfect and flush when able.
    Public comment on the proposed ADWR noted several concerns related
to the corrective actions upon receipt of a positive coliform result.
Commenters stated that the proposed ADWR lacked flexibility to avoid
passenger and

airspace disruptions that may occur when an aircraft cannot be pulled
out-of-service to disinfect and flush in 72 hours (e.g., if results are
received during an international flight). Commenters recommended EPA
increase the timeframe from 72 hours to 96 or 120 hours to avoid
inconveniencing travelers (due to delays, cost, or loss of service).
Additionally, commenters stated that an aircraft should not be grounded
``solely'' for a problem associated with the aircraft water system. EPA
agrees that some flexibility is warranted to avoid unnecessarily
grounding the aircraft, and for the final rule, better aligned the
corrective actions so that non-fecal microbiological occurrences have
the same corrective actions regardless of the number of samples that
test total coliform-positive and E. coli-negative.
    Generally, most members of the total coliform bacterial group do
not pose a risk to human health. The presence of total coliforms only
(i.e., no E. coli are detected) presents a non-fecal potential health
risk and is an indication of poor water quality that could be caused by
stagnant water, a failure of treatment equipment intended to improve
the aesthetic quality of the water (such as carbon filters) or
inadequate routine maintenance of the water system, among others.
However, EPA considers that an E. coli-positive result is an acute
potential fecal health risk, and it is a necessary public health
measure to ground the plane in 72 hours when the water system cannot be
physically disconnected or the flow of water prevented through the
taps. Therefore, no changes were made to the corrective actions for E.
coli-positive results.
    The final rule reflects corrective action changes to non-fecal
coliform occurrence when an air carrier receives a total coliform-
positive result that is also E. coli-negative. These changes are also
consistent with recommendations of the Federal Advisory Committee--
TCRDSAC for stationary systems under the Total Coliform Rule, whereby
the occurrence of routine total coliform-positive results that are E.
coli-negative should not be considered a maximum contaminant level
(MCL) violation. Therefore, in a set of routine samples, if one or more
are total coliform-positive and E. coli-negative, the air carrier can
select any of the following corrective actions and follow through with
that action until a set of total coliform samples is total coliform-
negative:
    (1) Within 72 hours of receipt of the routine positive result from
the laboratory, the air carrier must disinfect and flush, and collect
follow-up samples prior to providing water for human consumption from
the aircraft water system. From the time follow-up samples are taken
and submitted for analysis to the time of receiving the results, air
carriers may provide water for human consumption from the aircraft
water system to passengers and crew. If any follow-up sample is total
coliform-positive and E. coli-negative, the air carrier must perform
all of the following:
    a. Conduct the Restrict Public Access requirements within 72 hours,
and;
    b. Conduct a second disinfection and flushing, and;
    c. Collect follow-up samples prior to providing water for human
consumption from the aircraft water system. From the time follow-up
samples are taken, as a result of the second disinfection and flushing,
to the time of receiving the results, air carriers must continue all
Restrict Public Access provisions. If the second set of follow-up
results are total coliform-positive and E. coli-negative, then the air
carrier must continue to disinfect and flush the aircraft water system
until a set of total coliform samples is total coliform-negative; or
    (2) Within 24 hours of receipt of the routine positive result from
the laboratory, the air carrier must collect three repeat samples. From
the time repeat samples are taken and submitted for analysis to the
time of receiving the results, air carriers may provide water for human
consumption from the aircraft water system to passengers and crew. If
any repeat sample is total coliform-positive and E. coli-negative, the
air carrier must perform one of the following:
    a. Conduct disinfection and flushing within 72 hours, and collect
follow-up samples prior to providing water for human consumption from
the aircraft water system. From the time follow-up samples are taken
and submitted for analysis to the time of receiving the results, air
carriers may provide water for human consumption from the aircraft
water system to passengers and crew. If any follow-up sample is total
coliform-positive and E. coli-negative, the air carrier must conduct
the Restrict Public Access requirements within 72 hours, and perform a
second disinfection and flushing and collect follow-up samples. From
the time follow-up samples are taken, as a result of the second
disinfection and flushing, to the time of receiving the results, air
carriers must continue all restrict public access provisions. If the
second set of follow-up results are total coliform-positive and E.
coli-negative, then the air carrier must continue to disinfect and
flush the aircraft water system until a set of total coliform samples
is total coliform-negative. Or,
    b. Conduct the Restrict Public Access requirements within 72 hours,
and perform disinfection and flushing and collect follow-up samples
prior to providing water for human consumption from the aircraft water
system. From the time follow-up samples are taken and submitted for
analysis to the time of receiving the results, air carriers may provide
water for human consumption from the aircraft water system to
passengers and crew. If any follow-up sample is total coliform-positive
and E. coli-negative, the air carrier must conduct the Restrict Public
Access requirements within 72 hours, and perform a second disinfection
and flushing and collect follow-up samples. From the time follow-up
samples are taken, as a result of the second disinfection and flushing,
to the time of receiving the results, air carriers must continue all
Restrict Public Access provisions. If the second set of follow-up
results are total coliform-positive and E. coli-negative, then the air
carrier must continue to disinfect and flush the aircraft water system
until a set of total coliform samples is total coliform-negative. Or,
    (3) Within 72 hours of receipt of the routine positive result from
the laboratory, the air carrier must perform the Restrict Public Access
requirements until operationally feasible to disinfect and flush, and
collect follow-up samples. Once disinfection and flushing is performed,
and a set of follow-up samples are taken and submitted for analysis,
then the air carrier may cease the Restrict Public Access provisions
and provide water for human consumption from the aircraft water system
to passengers and crew. If the follow-up sample result from this first
disinfection and flushing is total coliform-positive and E. coli-
negative, the air carrier must perform all of the following:
    a. Conduct the Restrict Public Access requirements within 72 hours,
and
    b. Conduct a second disinfection and flushing and collect follow-up
samples. From the time follow-up samples are taken, as a result of the
second disinfection and flushing, to the time of receiving the results,
air carriers must continue all Restrict Public Access provisions. If
the second set of follow-up results are total coliform-positive and E.
coli-negative, then the air carrier must continue to disinfect and
flush the aircraft water system until a set of total coliform samples
is total coliform-negative.
    As compared to the proposed ADWR, the changes made to the
aforementioned

corrective actions for routine total coliform-positive samples that are
E. coli-negative, include a third action to restrict public access, and
the timeframe for the initial response has been changed from 24 hours
to 72 hours to better align with the other two options for non-fecal
routine occurrences. In addition, under any of the three corrective
action options for non-fecal occurrences, upon completion of the first
disinfection and flushing event, and follow-up samples are taken and
submitted for analysis, the air carrier may provide water for human
consumption to passengers and crew from the aircraft water system until
laboratory results are received. Water is permitted to be served for
human consumption after the first disinfection and flushing and follow-
up samples are taken, because when the air carrier performs
disinfection and flushing routinely and consistently with the
manufacturer recommendations (this includes maintaining the full
contact time of the disinfectant with the distribution system and
affording the complete recommended flushing time) the quality of the
water system should be returned to a total coliform-negative result.
However, after the second or subsequent disinfection and flushing
events occur due to follow-up samples that are total coliform-positive
and E. coli-negative, water is not permitted to be served for human
consumption because the results confirm an on-going microbiological
occurrence problem that warrants further action and investigation until
a set of follow-up samples is total coliform-negative. In the case
where the water system cannot be physically disconnected or shut-off,
or the flow of water prevented through the taps, air carriers are
required to provide public notification to passengers and crew, so that
the public is informed of an on-going non-fecal occurrence with the
water system. EPA believes these changes are appropriate and public
health protection is maintained while providing air carriers with the
flexibility needed to perform corrective actions that meet their
operational challenges.
    In the proposed ADWR, corrective actions for failing to perform a
requirement varied and were the following:
     Failure to perform routine disinfection and flushing would
result in air carriers providing public notification to crew and
passengers within 24 hours after discovery of the failure, until
disinfection and flushing occurred;
     Failure to collect routine samples would result in air
carriers providing public notification to crew and passengers within 24
hours after discovery of the failure, and within 72 hours disinfect and
flush, and collect follow-up samples;
     Failure to collect repeat or follow-up samples would
result in air carriers restricting public access within 24 hours after
discovery of the failure and included: If the aircraft water system
cannot be shut-off, public notification was given to crew and
passengers, but if the aircraft water system could be shut-off, public
notification was given to crew only; and within 72 hours disinfect and
flush, and collect follow-up samples;
     Boarding water from a watering point that is not approved
by FDA would result in air carriers providing public notification to
crew and passengers within 24 hours after boarding the water, and
within 72 hours disinfect and flush, and collect follow-up samples;
     Boarding water that did not meet national primary drinking
water regulations (NPDWRs), would result in air carriers performing all
the corrective actions as applicable to an E. coli/fecal coliform-
positive result; and
     Boarding water under any condition where the water system
was not in compliance with the procedures specified in the aircraft
operation and maintenance plan would result in the air carrier
providing public notification to passengers and crew within 24 hours of
discovery of the failure, and within 72 hours disinfect and flush, and
collect follow-up samples.
    In general, commenters to the proposed ADWR stated that these
corrective actions for performance failures were confusing and ``not
commensurate with the potential health risk,'' they were
administratively and economically burdensome, and that EPA should
instead require the use of ``intermediate and/or diagnostic measures
that allow carriers to determine whether an actual health risk was
presented by the failure to meet the requirement.'' Based on the issues
raised by the commenters, EPA determined that some changes are needed.
The final rule provides more clarity and flexibility to aid in reducing
economic and administrative burden while ensuring public health
protection by aligning the corrective actions based on (1) a fecal
occurrence (i.e., E. coli-positive event) and failing to perform the
applicable required corrective actions (e.g., fails to collect and
submit for analysis the follow-up samples or boards water that that
does not meet the NPDWRs applicable to transient non-community water
systems when there is an E. coli-positive event); and (2) a non-fecal
occurrence (e.g., total coliform-positive and E. coli-negative event,
or boards water that does not meet NPDWRs applicable to transient non-
community water systems) and failing to perform the applicable required
routine and/or corrective actions. Consequently, when the air carrier
becomes aware that it has failed to perform required routine
disinfection and flushing, or collect required routine samples, or
collect the required repeat or follow-up samples for a total coliform-
positive and E. coli-negative result; or boards water from a watering
point not in accordance with FDA regulations; or boards water that does
not meet NPDWRs applicable to transient non-community water systems; or
that is otherwise determined to be unsafe due to non-compliance with
the procedures specified in the operations and maintenance plan, the
air carrier must perform the corrective actions associated with a total
coliform-positive/E. coli-negative result for the Restrict Public
Access provisions:
     Within 72 hours of receipt of discovery of the failure or
after being notified by EPA of the failure, the air carrier must
perform the Restrict Public Access requirements until operationally
feasible to disinfect and flush, and collect follow-up samples. Once
disinfection and flushing is performed, and a set of follow-up samples
are taken and submitted for analysis, then the air carrier may cease
the Restrict Public Access provisions and provide water for human
consumption from the aircraft water system to passengers and crew. If
the follow-up sample result from this first disinfection and flushing
is total coliform-positive and E. coli-negative, the air carrier must
perform all of the following:
    [cir] Conduct the Restrict Public Access requirements within 72
hours, and
    [cir] Conduct a second disinfection and flushing and collect
follow-up samples. From the time follow-up samples are taken, as a
result of the second disinfection and flushing, to the time of
receiving the results, air carriers must continue all Restrict Public
Access provisions. If the second set of follow-up results are total
coliform-positive and E. coli-negative, then the air carrier must
continue to disinfect and flush the aircraft water system until a set
of total coliform samples is total coliform-negative.
    [cir] If any follow-up sample is E. coli-positive, the air carrier
must follow all the corrective actions for an E. coli-positive result.
These actions must continue until a set of follow-up samples is total
coliform-negative.

When the air carrier becomes aware that it has failed to collect the
required follow-up samples due to an E. coli-positive result, or boards
water that does not meet NPDWR applicable to transient non-community
water systems for an E. coli-positive result, then the air carrier must
follow all of the E. coli-positive corrective actions within 24 hours
of discovery of the failure or after being notified by EPA of the
failure. These actions must continue until a set of follow-up samples
is total coliform-negative.
    EPA determined that these corrective actions are appropriate
because the ADWR relies on best management practices (e.g.,
disinfection and flushing, following operations and maintenance plan
procedures, etc.) in lieu of the monthly total coliform sampling as
performed by stationary systems under the Total Coliform Rule. These
best management practices are part of the minimum requirements that
ensure safe and reliable drinking water to aircraft passengers and
crew. If an air carrier fails to perform these minimum requirements,
then either a known problem has not been promptly addressed or the
quality of the aircraft water used for human consumption is in
question.
    In the proposed rule, air carriers were allowed to use water for
hand washing purposes when the water was boarded from a watering point
not approved by FDA or when required routine monitoring or disinfection
and flushing was not conducted. Due to re-aligned corrective actions
(as discussed earlier in this section) that provide air carriers with
more flexibility to reduce the economic and administrative burden of
grounding the plane to disinfect and flush within a set timeframe, the
allowance of hand washing under these conditions no longer apply in the
final ADWR. In addition, corresponding changes were also made to the
applicable public notification sections of the rule (i.e., removed
reference from the health effects language that allowed ``hand
washing'' under these conditions).

D. Restricted Access to the Water System

    EPA proposed that in any situation where there is an affirmative
indicator of actual or potential fecal contamination occurrence (e.g.,
a single E. coli-positive sample, water that has been boarded from a
known contaminated source or not in accordance with FDA regulations,
etc.), the carrier would be required to restrict access to the water
system as expeditiously as possible, but in no case more than 24 hours
after the event triggering the requirement (e.g., receipt of an E.
coli-positive sample result). Ideally, under these conditions, access
to all taps used to provide water for human consumption (e.g., galleys,
lavatories, water fountains, built in coffee/tea makers, etc.) should
be physically disconnected or shut-off to prevent exposure. In the
proposed rule, restrict public access included: (1) Physically
disconnect or shut-off the water system; (2) provide public
notification to passengers and crew if the water system cannot be
physically disconnected or shut-off, and if the water system can be
shut-off, then public notification must be provided to crew only; and
(3) provide alternatives to the restricted use of the aircraft water
system, such as bottled water for drinking and coffee preparation and
alcohol-based antiseptic gels and wipes in the galleys and lavatories,
and other feasible measures that reduce or eliminate the need to use
the aircraft water system.
    Public comments on the proposed ADWR raised concerns over
physically disconnecting the water system and the use of alcohol-based
antiseptic gels and wipes. With respect to physically disconnecting the
water system, commenters stated the provision was in conflict with
FDA's requirement to provide food handlers with hand washing
facilities, and the provision did not account for situations where the
water system cannot be physically disconnected or shut-off but other
means can be used to prevent the flow of water through taps. In
response to these comments, the final rule clarifies the Agency's
intent to prevent passenger and crew exposure to the water. Therefore,
EPA has adjusted the final rule language by adding another option to
the Restrict Public Access requirements. In the final rule, as part of
the Restrict Public Access requirements, air carriers can use other
means to prevent the flow of water through the taps in addition to
physically disconnecting or shutting-off the water system. EPA believes
this change is a necessary step towards public health protection in the
event of an actual or potential fecal contamination occurrence. If the
event is due to a fecal occurrence, public access restrictions must
remain in-place until the water system is disinfected and flushed and a
complete set of follow-up samples is total coliform-negative. If the
event is due to a non-fecal occurrence, public access restrictions must
remain in-place until the water system is disinfected and flushed and a
set of follow-up samples is collected and submitted for analysis. After
this initial disinfection and flushing is performed, if any subsequent
ones are needed, public access restrictions must remain in-place until
a complete set of follow-up samples is total coliform-negative. FDA
requirements permit air carriers to temporarily suspend the use of the
aircraft drinking water system during emergencies. The ADWR provisions
that restrict public access to the aircraft water system would be
considered an emergency situation and, therefore, do not conflict with
FDA regulations to provide food handlers with hand washing facilities.
    In addition, due to the corrective action changes made to better
align corrective actions based on non-fecal and fecal occurrences, EPA
adjusted the 24-hour timeframe to initiate the Restrict Public Access
requirements to 72 hours for non-fecal events. Therefore, if an air
carrier fails to perform a requirement in the case of a non-fecal
occurrence (e.g., fails to perform a routine disinfection and
flushing), the air carrier has 72 hours to initiate the Restrict Public
Access requirements from discovery of the failure, or EPA's
notification of the failure, or receipt of the non-fecal positive
result. However, in the event of any failure to perform a requirement
in the case of a fecal-occurrence (e.g., fails to collect the follow-up
samples, or boarding water that that does not meet NPDWRs for E. coli),
EPA did not change the timeframe and the air carrier has 24 hours to
initiate Restrict Public Access requirements from discovery of the
failure, or EPA's notification of the failure, or receipt of the fecal
positive result.
    In determining whether it is ``feasible'' to physically disconnect
or shut off the water system, EPA recognizes that in some cases
carriers may need to consider binding operational constraints. For
example, if the water system cannot be shut off without also shutting
off water to the toilets, a carrier may determine that shutting off the
water is not feasible and use the alternative Restrict Public Access
provisions instead. EPA intends to provide further guidance on this
issue in its ADWR technical guidance.
    Regarding the requirement to provide alcohol-based antiseptic hand
gels or wipes, commenters stated that it was too limiting and did not
allow for the use of other alternative products as specified in FDA's
monograph governing ``Topical Antimicrobial Drug Products for Over-the-
Counter Human Use; Tentative Final Monograph (TFM) for Health-Care
Antiseptic Drug

Products.'' In the final rule, EPA has changed the Restrict Public
Access provision to include any antiseptic hand gels or wipes in
accordance with FDA regulations under 21 CFR part 333--``Topical
Antimicrobial Drug Products for Over-the-Counter Human Use.'' In this
way, the provision evolves with technology and new products, and
maintains consistency with FDA regulations regarding these products.

E. Response to Proposed Rule Requests for Comment

1. Microbiological Indicators
    In the proposed ADWR, EPA requested specific comment on whether
bacterial presence measured by heterotrophic plate count (HPC) should
be allowed, required, or not considered as an indicator of water
quality in addition to total coliform monitoring. One commenter
responded that HPC should be allowed as an indicator of water quality
in addition to total coliform monitoring. However, several commenters
responded that HPC is not a reliable indicator in aircraft water
systems, that the sample holding time between collection and analysis
of six hours if the sample is unrefrigerated is impractical, and that
it provides no additional benefit justifying the regulatory burden of
conducting HPC sampling. EPA agrees with commenters that the use of HPC
in the ADWR is impractical due to the restrictions on sample holding
times and the limitations of the information the HPC test results would
provide. Therefore, today's rule does not require HPC monitoring.
Additionally, HPC testing is used as a surrogate for disinfectant
residual testing for stationary systems and since disinfectant residual
testing is not an ADWR requirement, HPC testing is unnecessary under
the ADWR.
2. Potential for Bacterial Growth
    EPA requested specific comment on whether the final rule should
include provisions to address extended periods during which the
aircraft water would remain stagnant, experience high water
temperatures, or other situations that may contribute to concern
regarding bacterial growth. Although most aircraft water tanks are
either topped off or drained on an almost daily basis, occasional
situations occur when the water may sit stagnant for an extended period
of time or otherwise not be turned over, and thus could be at risk for
biofilm development or other bacterial growth. EPA received several
public comments both in favor of and opposed to regulatory requirements
for dealing with extended stagnant periods, or other situations that
may be of concern regarding bacterial growth. Commenters in favor of
such provisions, in general, agreed with EPA's analysis of the
potential for bacterial growth. The comments ranged from stating that
the provisions should be data-driven to ``The Agency should confirm the
effectiveness of disinfection and flushing in eliminating contaminants
and biofilm by evaluating all aspects of closed circulation, airline
water systems.'' Commenters opposed to the requirements raised two main
concerns: (1) Aircraft do not have the current means to measure the
temperature of the water in the storage tank and retro-fitting the
aircraft to do this would be an immense project, economically and
logistically, for air carriers and manufacturers; and (2) Air carriers
already implement procedures that guard against the risk of bacterial
growth such as draining, disinfecting, and flushing the water tanks if
the aircraft has been out-of-service for extended lengths of time.
Based on these collective comments, the final rule does not include
provisions to address extended stagnant periods, high water
temperatures, or other situations that may augment concern for
bacterial growth. Instead, EPA plans on addressing these issues in its
ADWR technical guidance.
3. Temperature of Water From Sample Taps
    EPA requested specific comment on whether sampling should only be
limited to cold water taps when they are available. EPA also requested
comment on whether or not, in the event that a sample is taken from a
hot water tap, the temperature should also be measured to provide some
indication of whether the temperature achieved is high enough to alter
the microbiological results. EPA received several comments both in
favor of and opposed to sampling only from cold water taps and
measuring the temperature of water collected from hot water taps. The
comments ranged from (1) the ADWR should include collecting samples
from both cold water as well as hot water taps, and taking the
temperature of water from hot water taps does not provide an accurate
measurement of microbiological safeness, to (2) sampling should be from
taps that are most representative of the water consumed by passengers
which, in many cases, comes from galleys that are only equipped with
hot water taps. Also, a commenter indicated that it would be
impractical to set ``minimum temperature'' requirements that apply to
``all hot water taps not only because of the variety of aircraft in
service, but also the effect that altitude has on [water] temperatures.
On the ground, where sampling will occur, a tap would register a
different temperature than it would at an aircraft's cruising altitude,
which is when that tap is most likely to be used to serve coffee/tea.''
    EPA agrees that sample locations should be those most
representative of water used for human consumption by passengers and
crew. However, since there is a potential for the temperature in the
hot water taps to kill existing microorganisms, and this might mask
whether there is a microbiological problem in the aircraft system,
samples should be taken from cold water taps when they are available,
except e.g., in the case when only a hot water tap is available in the
galley. In this case, the galley sample should be taken from the hot
water tap. In addition, EPA plans to further discuss tap sampling in
its ADWR technical guidance.
4. Statistical Sampling of an Air Carrier Fleet
    EPA requested specific comment on the use of statistical sampling
methodologies, specifically on what type of monitoring scheme would
allow a statistical sample to be representative of an entire air
carrier fleet. EPA was especially interested in receiving input on
whether such methodologies, if allowed, should only be used in
conjunction with onboard or other supplemental treatment, such as
adding a chemical disinfectant or ultraviolet light. EPA also requested
input regarding the support for such an option, given the cost and
logistical implications a positive coliform result would have on the
statistical sample by triggering follow-up action in the entire fleet.
The majority of the public comments were in favor of statistical
sampling, but they did not provide any examples of a statistical method
or data to support their position. In opposition to statistical
sampling, a commenter expressed concern over the use of statistical
sampling because of the variability of the quality of the water that
could be boarded from various sources, and because, ``when blended, all
of the chemical and microbiological parameters would change and data
generated would become inaccurate.'' One commenter in favor of
statistical sampling stated that EPA should allow the use of
statistical sampling because there was substantive evidence that
aircraft in a fleet, or a subset of a fleet, behaved similarly with
respect to avoiding positive tests for total coliforms. However, new
data beyond the AOCs' data was not provided to support this statement,
and the AOCs'

data are not sufficiently robust to support such an analysis. Another
commenter suggested that statistical sampling could be used to minimize
the sample collection volumes and frequency; however, no sampling
scheme or data was provided. Yet another commenter suggested EPA
incorporate into the rule the allowance of a procedure whereby an
individual carrier could propose a statistical sampling method, present
a proposed program for doing so along with technical analyses
demonstrating its representativeness and efficacy, and request EPA to
review and approve the plan.
    Today's rule does not include provisions for statistical sampling
because EPA did not receive data to change its opinion that sampling a
fraction of aircraft water systems does not identify all of the
aircraft that may be operating with a contaminated water system.
Therefore, the potential still exists that the un-sampled aircraft may
be operating with a contaminated water system, possibly for years,
until it is randomly selected and tested. EPA considers that its
approach is appropriate, because each aircraft water system is a unique
system that may board water from a potentially large number and variety
of sources and distribution systems, and the volume of water that is
boarded may vary on a daily basis or more often. Under current
practices, the sources of water for an individual aircraft are so
varied, in addition to variability in the quality of operation and
maintenance practices, it would be difficult for a statistical sample
to provide an accurate representation of all water being served on an
air carrier's fleet. In addition, the majority of the committee members
of EPA's Science Advisory Board (SAB) were not in favor of statistical
sampling of aircraft drinking water because the available data is too
sparse to interpret results for the whole fleet. As a result, the final
rule does not allow for statistical sampling.
5. Option for Repeat Sampling
    EPA requested specific comment on whether to disallow the option
for repeat sampling in response to a routine total coliform-positive
sample if the aircraft has boarded water since the routine sample was
taken. EPA noted that the repeat samples may not be providing an
accurate picture of the water quality since it is not characterizing
the same water as the routine sample. EPA received comments that were
both in favor of and opposed to disallowing the option for repeat
sampling in response to a routine total coliform-positive sample.
Commenters in favor of repeat sampling noted that it was a reliable
method of investigating the extent of bacterial problems in the water
system, and another commenter stated that it allows an air carrier to
pinpoint a source of contamination and should be permitted. In
opposition to repeat sampling, a commenter noted that it should not be
allowed because the process takes several days, which extends the time
period for passengers and crew to be exposed to a potential health
risk. In today's rule, EPA maintains the option to collect repeat
samples as a corrective action to a total coliform-positive routine
sample that is E. coli-negative. EPA believes repeat sampling is a
valuable option because it can indicate whether the problem reflected
by the routine sample result is no longer present, or whether the
problem has persisted and requires further corrective action;
therefore, EPA is allowing the option for repeat sampling in response
to a routine total coliform-positive sample that is E. coli- negative
in this ADWR.
6. Disinfectant Residual Monitoring
    EPA requested specific comment on whether it is appropriate to
require monitoring of routine disinfectant residuals and if so, the
frequency for monitoring and the corrective action required if
sufficient disinfectant residuals are not detected. EPA received
approximately the same number of comments in favor of and opposed to
adding a requirement for routine monitoring of a disinfectant residual.
In favor of monitoring for disinfectant residuals, a commenter stated
that flight attendants should be trained in the use of chlorine
residual testing equipment, and that the rule should maintain the AOCs'
disinfectant residual monitoring requirements, because having a
detectable residual is effective against bacterial growth. Commenters
who opposed routine monitoring of a disinfectant residual thought that
(1) it was unnecessary and does not provide a meaningful representation
of risks or system integrity; (2) since air carriers receive finished
water from PWSs, the level of disinfectant residual in the water supply
is outside of the control of the air carriers; meaning, there is no
benefit to requiring the carriers to monitor for disinfectant residual
since the air carriers cannot take action to increase it on a system-
wide basis; and (3) since water turns over very quickly in aircraft
water systems, monitoring of residual disinfectant provides no added
benefit.
    The final rule does not require monitoring of a disinfectant
residual for several reasons. First, the Surface Water Treatment Rule
requires public water systems using surface water as a source to
maintain a detectable disinfectant residual in the distribution system
to ensure that disinfection is maintained throughout the water system.
If a stationary system has a non-detectable disinfectant residual it
may increase the amount of disinfectant added at the treatment
facility, routinely flush water from dead-end or low water use areas of
the distribution system, or add additional disinfection to a specific
area of the system by installing booster-disinfection equipment to
increase the disinfectant residual. Adding disinfectant booster
equipment is not practicable or feasible for aircraft water systems due
to tank design challenges. In addition, any corrective action requiring
manual addition of water with a disinfectant residual would result in
major disruptions to flight schedules (e.g., to drain and refill or
flush and disinfect the aircraft water tank). Second, since aircraft
may board water more than once per day from a variety of sources, some
of which may be groundwater that is not disinfected, EPA is uncertain
whether monthly (or less frequent) disinfectant residual monitoring
would provide useful information for aircraft water systems. At the
same time, EPA believes that more frequent flushing and disinfection of
the entire aircraft water system as a treatment technique combined with
other barriers incorporated into the ADWR (e.g., operations and
maintenance plans, etc.) will ensure that microbiologically safe tap
water is provided on the aircraft even without the residual
disinfectant requirements applicable to stationary public water
systems. Finally, the rule specifies that aircraft water systems are to
board only finished water (i.e., drinking water intended for
distribution and consumption without further treatment). Therefore, it
is the responsibility of the PWS from which the aircraft receives water
to provide finished water that meets all the NPDWRs. Under the NPDWRs,
if that PWS uses groundwater as its ambient source, then the finished
water is not required to have a detectable disinfectant residual.
Trying to determine if boarded water is required to have a disinfectant
residual, and then trying to correct it if monitoring yields a non-
detectable disinfectant residual result, would be an economic and
operational burden for the air carrier.

7. Timeframe for Disinfection and Flushing
    EPA requested specific comment on the appropriateness of the 72-
hour timeframe to disinfect and flush, upon receipt of two total-
coliform-positive sample results or a single fecal coliform- or E.
coli-positive result, since disinfection and flushing requires taking
the aircraft out-of-service to a designated maintenance facility. The
majority of the public comments received favored the 72-hour timeframe
with some concerns. For example, one commenter expressed that the
timeframe is a ``sensible'' and necessary response, but such
unscheduled activities will be costly and burdensome to the air
carriers and create an unfavorable reaction from passengers to the
restricted access to the water and flight delays. On the same note,
another commenter stated that the 72-hour timeframe is appropriate
under normal conditions; however, in situations where weather or other
airspace system delays renders compliance with the 72-hour timeframe
impractical, the Agency should provide an extension to 96 hours.
Another commenter noted ``while in the abstract'' the timeframe appears
to be achievable, the Agency needs to provide ``reasonable
accommodation for scheduling'' in cases where the air carrier may
receive sample results while the aircraft is overseas and is unable to
return to the U.S. and to the maintenance facility in 72 hours. EPA
recognizes that its proposed timeframe of 72 hours has the potential to
disrupt some passenger services, and may cause logistical challenges
such as receiving results while on an international route. Therefore,
the final rule includes an optional corrective action intended to
provide air carriers with more disinfection and flushing flexibility
when routine and/or repeat coliform samples are total-coliform-positive
but E. coli-negative. The option in the final rule allows the air
carrier to perform the Restrict Public Access requirements within 72
hours of learning of the total coliform-positive result(s) that is E.
coli-negative and conduct disinfection and flushing when it is
operationally feasible. If the air carrier performs the Restrict Public
Access Requirements, it does not have to disinfect and flush the
aircraft in 72 hours, even if the aircraft water system cannot be
physically disconnected or shut off, or the flow of water prevented
through the taps. This option allows an air carrier to avoid service
disruptions. The air carrier must collect follow-up samples prior to
providing water for human consumption from the aircraft water system.
    The presence of total coliforms only (when no E. coli is detected)
presents a non-fecal potential health risk and is an indication of poor
water quality. Since the water is of poor quality, the passengers and
crew have a right-to-know. Hence, public notification is an emphasized
component of this option. However, EPA considers an E. coli-positive
result to be an acute potential fecal health risk, and it is a
necessary public health measure to ground the plane in 72 hours when
the water system cannot be physically disconnected or shut-off, or the
flow of water prevented through the taps. Therefore, no changes were
made in the final rule to the corrective actions for E. coli-positive
results.
8. Supplemental Treatment
    EPA requested specific comment on whether to require supplemental
disinfection of water boarded onto aircraft, and whether to require
monitoring for disinfectant residuals either in addition to or in lieu
of supplemental disinfection. In addition, EPA requested comment on the
feasibility of using other types of supplemental disinfection, such as
UV treatment onboard aircraft, including providing incentives such as
reduced routine monitoring or routine disinfection and flushing if an
air carrier provides supplemental treatment. EPA received public
comments both for and against the required use of supplemental
treatment. Concern was expressed that supplemental treatment would
increase costs for installation, extra weight, maintenance, and
revision of aircraft operation and maintenance programs to accommodate
a system that was not a part of the aircraft manufacturer's final
product. Comments in support of supplemental treatment indicated that
it may be viewed as the ultimate barrier against the risk of illness
due to contaminated drinking water, and that there could be economic
savings associated with reduced monitoring, reduced routine
disinfection and flushing of aircraft water systems, and reduced
remedial activity due to fewer positive test results. In addition, the
commenter expressed that supplemental treatment could possibly reduce
or eliminate the need for bottled water.
    In the final ADWR, supplemental treatment is not required to be
used with finished water that has been boarded on the aircraft. EPA
believes it has prescribed the minimum requirements necessary to
provide safe drinking water to passengers and crew onboard aircraft,
including the requirement to board finished water. However,
supplemental treatment can provide an additional barrier of protection
in the event of a failure in any of the basic protection barriers
required under this rule (e.g., boarding finished water in accordance
with FDA requirements; transferring the water from the watering point
to the aircraft in a manner that ensures it will not become
contaminated during the transfer; appropriate training of personnel;
implementation of a water system operation and maintenance plan; etc.).
    EPA believes the basic requirements of the ADWR, when performed
consistently and diligently by the air carriers and their agents,
provide assurance that drinking water onboard aircraft is safe for
passengers and crew. Based on the information that EPA has at the time
of this rulemaking, there is not sufficient information or data to
support a requirement of supplemental treatment for aircraft water
systems or for reducing any of the minimum requirements based on the
installation of supplemental treatment. However, EPA plans to revisit
this issue as part of the Six-Year review of this rule under SDWA
section 1412(b)(9) and as more data become available. EPA also plans to
address supplemental treatment issues in its ADWR technical guidance.
9. Recording the Boarding of Water
    EPA requested specific comment on whether the potential benefit of
recording information of where, how much, and when water is boarded
outweighs the information collection burden. The boarding of water is
usually done on an as-needed and as-requested basis, and EPA is not
aware of any current requirements for capturing this type of
information. EPA received public comments both for and against
recording the information (e.g., where, how much, and when water is
boarded). One commenter stated that this information may be helpful in
determining the cause of contamination events. Another commenter noted
that requiring carriers to record this information would increase
delays and costs. EPA has not received sufficient information or data
that show a benefit to recording information on the boarding of water
that would justify the additional recordkeeping burden on the air
carrier. A single aircraft may board water several times a day from
multiple airports. During the boarding of water, water from more than
one source is usually commingled in the aircraft water system since the
tanks may not be completely drained between fillings. Maintaining a log
of this information

may not necessarily help in identifying the source of contamination of
an aircraft water system because there could be multiple causes for
contamination of such systems. Requiring a log would generate multiple
daily records for each aircraft without a known health benefit.
Consequently, the final rule does not require recording information of
where, how much, and when water is boarded.
10. Follow-Up Sampling To Confirm the Effectiveness of Routine
Disinfection and Flushing
    EPA requested specific comment on whether follow-up sampling should
be required to confirm the effectiveness of routine disinfection and
flushing, and if so, the frequency/number of samples by which this
monitoring should occur. EPA received comment in favor of and against
requiring follow-up sampling after routine disinfection and flushing. A
comment in favor of a requirement specifically noted, ``follow-up
sampling should be required to confirm the effectiveness of routine
disinfection and flushing, at least until a body of evidence can be
established that clearly indicates that routine disinfection and
flushing is reliably effective in removing biofilm from the aircraft
water system.'' Another commenter believed, ``Once the aircraft has
been disinfected and flushed, it may be necessary to test the water
(again) to be sure that the disinfection has been successful and any
problem of bacterial contamination has been solved. Sampling
immediately after the disinfection and flushing may not show any hidden
contamination problems. Hence, it is very important to wait a minimum
time requirement (7-10 days) after disinfecting in order to re-commence
the regular water testing regime.'' A commenter against such follow-up
sampling as a regulatory requirement noted the following concerns: (1)
It would be ``inconsistent with and undermine the [routine]
disinfection and monitoring frequency schedules''; (2) ``Inasmuch as
routine disinfection does not involve evidence of a system problem, but
is simply a preventative measure, there is no risk-based benefit to
post-disinfection routine sampling''; (3) it would ``impose significant
logistical and cost burdens on the airlines and unduly delay the return
of aircraft to service while sampling results were processed''; and (4)
``Imposing additional sampling costs would be arbitrary and
unreasonable in situations that do not suggest any compromise of system
integrity, but rather are routine measures.''
    As discussed in the proposed rule, EPA established that, to ensure
the results of routine samples are not inadvertently skewed by sampling
too close to a disinfection event, routine coliform samples must not be
collected within 72 hours after completing routine disinfection and
flushing procedures. Collecting a coliform sample within 72 hours of
routine disinfection and flushing is not representative of the general
conditions of the aircraft water system. This required 72-hour time
interval has not been changed in the final rule. However, EPA does
agree that such follow-up samples do aid in determining the success of
disinfection and flushing, and encourages additional or special
coliform sampling. Today's rule does not require follow-up sampling to
confirm the effectiveness of routine disinfection and flushing. EPA has
not received sufficient information or data that show that such
monitoring is necessary, and believes spacing routine samples evenly
across monitoring periods is more representative of aircraft drinking
water quality and normal aircraft water system operations.

F. Aircraft Water System Operations and Maintenance Plan (Sec.
141.804)

    Both the proposed rule and today's final rule require each air
carrier to develop and implement an aircraft water system operations
and maintenance plan for each aircraft water system operated by the air
carrier. The air carrier need not develop a separate plan for each
aircraft, but the air carrier must ensure that each aircraft it owns
and operates is covered by a plan. For example, if the air carrier
operates several of the same type of aircraft with the same type of
water system, the air carrier may choose to develop one operations and
maintenance plan that applies to aircraft of this type in its fleet.
    In the proposed rule, air carriers would be required to include the
aircraft water system operations and maintenance plans in a Federal
Aviation Administration (FAA)-approved or -accepted air carrier
operations and maintenance program. The Agency received several public
comments against including this requirement in the final rule.
Commenters expressed concern that this cast FAA in an inappropriate
regulatory role, and that inclusion of the aircraft water system
operations and maintenance plans in a FAA-approved or -accepted air
carrier operations and maintenance program could cause significant
reworking of existing maintenance program documents and may cause a
duplication of effort in terms of regulatory oversight.
    EPA disagrees with these comments and continues to believe that
including the aircraft water system operations and maintenance plans in
a FAA-accepted air carrier operations and maintenance program is a
critical element of the final rule. FAA views proper operation and
maintenance of the water system as an operational safety issue and
agrees with EPA that it is appropriate to have the water system
operations and maintenance plans included in the FAA-accepted
operations and maintenance program. FAA requires all maintenance and
operational procedures to be formally documented for each aircraft, and
a failure by an air carrier to perform the prescribed program
requirements may result in forfeiture of air carrier operating
certificates and/or fines. In addition, properly integrating aircraft
water system operations and maintenance procedures with other FAA-
accepted operations and maintenance procedures is the most reliable way
to ensure effective implementation of the plan and maximize effective
oversight by EPA and FAA. This will help to minimize duplication of
effort by the two agencies.
    Though this requirement remains in the final rule, the Agency made
one minor change to the language in this paragraph. Since the
publication of the proposed rule, the Agency has learned that FAA does
not ``approve'' the air carrier operations and maintenance programs,
and that describing these programs as ``FAA-accepted'' programs is more
accurate. Thus, the final rule requires that air carriers include the
aircraft water system operations and maintenance plan in an FAA-
accepted operations and maintenance program.
    In the proposed rule, EPA proposed to allow air carriers only six
months to develop an aircraft water system operations and maintenance
plan for each existing aircraft. However, the Agency received several
comments requesting that the compliance date be extended in order to
allow for more time for air carriers to restructure maintenance
programs between the AOCs and the final rule. The comments and the
Agency's response are explained in more detail in section IV.L of this
notice. EPA agrees that more time may be needed for air carriers to
develop aircraft water system operations and maintenance plans for
existing aircraft. Therefore, today's final rule extends the compliance
date for development of the aircraft water system operations and
maintenance plan for existing aircraft from six months to 18 months
after publication of the final rule.
    The Agency also received comments that the proposed rule was
unclear as to

whether and how air carriers could amend their operations and
maintenance plans or their coliform sampling plans. EPA agrees that the
final rule should more clearly state the requirements for making
changes to these plans. Thus, in the final rule, EPA addresses this
concern by clarifying that any subsequent changes to the aircraft water
system operations and maintenance plan must also be included in the
FAA-accepted air carrier operations and maintenance program. For
example, changes to the aircraft water system operations and
maintenance plan could include, but are not limited to, changes to the
procedures for disinfecting and flushing, including changes to the
routine disinfection and flushing frequency, changes to training
requirements, changes to self-inspection procedures, or changes to
procedures for boarding water. The reporting requirements and the
requirements for the coliform sampling plan have also been revised to
respond to these comments.
    The following is a discussion of elements of the aircraft water
system operations and maintenance plan for which EPA received comment
and/or made changes to the final rule.
    The proposed rule would require that the operations and maintenance
plan ensure all water boarded within the United States is from an FDA-
approved watering point as required under 21 CFR 1240.80. The Agency
received several comments on this requirement. Some commenters believed
that EPA intended this requirement to alter FDA regulations applicable
to watering points. The commenters also pointed out a possible
inconsistency with this requirement and existing FDA regulations for
watering points.
    The Agency continues to acknowledge the joint oversight role of EPA
and FDA in ensuring safe drinking water on aircraft. Therefore, this
requirement does not seek to change any of FDA's regulations regarding
watering points. Rather, EPA continues to defer to FDA with respect to
regulating watering points. FDA will continue to ensure that the water
supply meets the standards prescribed in EPA's NPDWRs, and ensure the
methods of delivery, facilities for delivery, and the sanitary
conditions surrounding the delivery of water to the aircraft in order
to prevent the introduction, transmission, or spread of communicable
diseases. Therefore, EPA revised the final rule to clearly communicate
the Agency's intent. The final rule requires that all watering points
must be selected in accordance with FDA regulations (21 CFR part 1240,
subpart E). Today's final rule also requires that the operations and
maintenance plan include procedures for ensuring that the air carrier
board water from a watering point in accordance with FDA regulations
(21 CFR part 1240, subpart E). These changes remove any inconsistency
between the final rule and existing FDA regulations. It also ensures
that all FDA regulations regarding watering points, including those
applicable to watering points permitted for temporary use, are
referenced in the final rule.
    The proposed rule stated that in no event must air carriers
knowingly serve water that violates the NPDWRs. It also provided that
if it was necessary to board water that violated the NPDWRs, the air
carrier must perform the corrective action requirements applicable to
E. coli-positive coliform sample results. Today's final rule clarifies
that in no event must air carriers knowingly provide water for human
consumption that violates the NPDWRs applicable to transient non-
community water systems. The Agency understands that sometimes unsafe
water must be boarded in order to operate other essential systems, but
at no time are air carriers to provide such water to passengers and
crew in the form of beverages (e.g., coffee, tea, etc.); nor may
passengers and crew be allowed access to the water system (i.e., the
water system must be shut-off or the flow of water prevented through
the taps); nor may the water be used for food preparation or any other
consumptive use.
    The proposed rule would require that the operations and maintenance
plan describe emergency procedures to be used in the event that water
is boarded to operate essential systems, such as toilets, but is not
boarded from an FDA-approved or otherwise safe watering point. In the
final rule, EPA continues to require that the operations and
maintenance plan include a description of emergency procedures to be
used in the event that unsafe water is boarded to operate essential
systems. In today's final rule, the operations and maintenance plan
must include a description of emergency procedures used when the air
carrier becomes aware that unsafe water is boarded. Unsafe water
includes:
     Water boarded from a watering point not in accordance with
FDA regulations;
     Water that does not meet NPDWRs applicable to transient
non-community water systems; or
     Water that is otherwise determined to be unsafe due to
non-compliance with the procedures for boarding water specified in the
operations and maintenance plan.

G. Notification Requirements to Passengers and Crew (Sec.  141.805)

1. Situations Requiring Public Notification
    In EPA's proposed rule, public notification would be required in
the following situations: (1) Where access to the aircraft water system
is required to be restricted (e.g., fecal coliform/E. coli-positive
sample result); (2) where there was a failure to collect required
samples; (3) when the quality of the water cannot be assured, for
example, when water has been boarded from a watering point not approved
by FDA, or in a manner that does not otherwise comply with the air
carrier's procedures for ensuring safe water outside the United States;
or (4) in any other situation where the Administrator, air carrier, or
crew determines that notification is necessary to protect public
health.
    The Agency received several comments that prompted EPA to make
changes to the situations described in the proposed rule. Some of the
changes were a result of comments directly related to the public
notification requirements of this section, while other changes were a
result of comments applicable to other sections of the rule which
subsequently affected these public notification requirements.
    First, in the final rule, the Agency restructured the corrective
action requirements in Sec.  141.803 in response to comments discussed
previously. Under the final corrective action provisions, public
notification not only applies to an E. coli-positive sample result, but
also when an air carrier chooses to restrict public access in response
to a sample result that is total coliform-positive and E. coli-
negative, and failure to perform required ADWR provisions.
    Second, the Agency received comments stating that the situations
requiring notification listed in the proposed rule in Sec.  141.810
(i.e., Violations) conflict with the situations listed in proposed
Sec.  141.805 (i.e., Notification of passengers and crew). The comments
suggested that to avoid confusion and inconsistency, EPA should delete
the public notification requirements in Sec.  141.810 or make
conforming changes to the two sections. EPA agrees that the reference
to public notification requirements in Sec.  141.805 is confusing and
inconsistent with Sec.  141.810. Therefore, EPA removed all references
to public notification from Sec.  141.810 and made conforming changes

to Sec.  141.805 of the final rule. As a result, air carriers are now
required to give public notification when there has been a failure to
perform required routine disinfection and flushing; or failure to
collect routine, repeat or follow-up samples; or a failure to perform a
corrective action associated with a fecal occurrence event.
    Third, the Agency received several comments on the watering point
selection requirement and the requirement to board water from FDA-
approved watering points in Sec.  141.804. These comments and EPA's
response are discussed elsewhere in today's notice. As a result, the
Agency clarified both of these requirements in Sec.  141.804 of the
final rule, and made the following changes under which air carriers
must provide public notification when the air carrier becomes aware
that the quality of water cannot be assured:
     Where water has been boarded from a watering point not in
accordance with FDA regulations;
     Where water that has been boarded does not meet NPDWRs
applicable to transient non-community water systems; and
     Where water is otherwise determined to be unsafe due to
non-compliance with the procedures specified in Sec.  141.804(b)(6).
2. Method of Notification Delivery
    Both the proposed rule and today's final rule require that air
carriers provide notification in a form and manner reasonably
calculated to reach all passengers and crew. Using a variety of
delivery methods for these notifications will help ensure that all
passengers, including those with visual or hearing impairments, or non-
English speakers, will have access to relevant public health
information.
3. Cessation of Public Notification
    The proposed rule would require that all public notification
continue until all follow-up samples are total coliform-negative. As a
result of clarifications made to the corrective action requirements in
Sec.  141.803 of the final rule, EPA also clarifies that an air carrier
must continue to provide public notification until the aircraft water