agricultural water that is used to wash produce postharvest, such as in
packing houses. However, because these antimicrobial products are not
authorized by EPA for use on agricultural fields, they cannot be used
to treat irrigation water that is applied prior to harvest. Also on
this list are certain registered antimicrobial products for use in the
treatment of irrigation water systems or irrigation ponds to control
bacterial and algae growth. However, because these antimicrobial
products are not authorized by EPA for use to control human pathogens
or indicator organisms, they cannot be used to treat irrigation water
to comply with the microbial quality criteria in Sec.  112.44(b).
    We anticipate that the delayed compliance dates for certain water
quality provisions in this rule (see our discussion of compliance dates
in section XIII.K of this document) provide adequate time to address
the current lack of EPA-registered chemical treatments for agricultural
water used in growing activities. We will work with EPA, as
appropriate, regarding registration of pesticide products for treatment
of agricultural water during growing. In response to comments
requesting priority review for registration of irrigation water
chemicals, we note that EPA has statutory timelines under which it must
consider registration applications (i.e., 15 to 21 months for a ``new
food use'' of a compound). Information about EPA's pesticide
registration process is available on its Web site at http://www2.epa.gov/pesticides (Ref. 129), and is also explained in chapters
3.8 and 4.2 of the EIS.
    Section 112.43 also allows for non-chemical suitable methods for
treatment

of agricultural water. Unlike pesticide products, pest control devices
that work by physical means and are classified by EPA as ``pesticide
devices'' do not require registration by EPA under FIFRA. According to
EPA, FIFRA defines a device as any instrument or contrivance (other
than a firearm) that is intended for trapping, destroying, repelling,
or mitigating any pest or any other form of plant or animal life (other
than man and other than bacteria, virus, or other microorganism on or
in living man or other living animals); but not including equipment
used for the application of pesticides when sold separately therefrom
(Ref. 130). (Note that ``pesticide devices'' do not include medical
devices, which are regulated by FDA.) Although not required to be
registered, pesticide devices are regulated by EPA in that false or
misleading claims cannot be made about the effectiveness of the device.
Physical treatment of agricultural water, including using a pesticide
device(s), or by any other suitable treatment method can be employed
provided the method is effective to make the water safe and of adequate
sanitary quality for its intended use and/or meet the relevant
microbial quality criteria in Sec.  112.44, as applicable. In addition,
the treatment must be delivered and monitored in a manner and with a
frequency adequate to ensure that the treated water is consistently
safe and of adequate sanitary quality for its intended use and/or
consistently meets the relevant microbial quality criteria in Sec.
112.44, as applicable, as required under final Sec.  112.43(a)(2) and
(b). Examples of pesticide devices used to treat water include filter
units, ultraviolet light units, and ozonator units. Information about
EPA's regulation of pesticide devices is available on its Web site
(Ref. 130), and we advise you to consult EPA for information about
appropriate use of pesticide devices. Note also that some States
require registration of pesticide devices, and we refer you to the
appropriate State pesticide regulatory agency for more information on a
particular State's requirements related to pest control devices (Ref.
131). Information about EPA's Tribal Pesticide Programs is available on
EPA's Web site at: http://www2.epa.gov/pesticide-advisory-committees-and-regulatory-partners/tribal-pesticide-programs (Ref. 132). In
addition, information regarding current EPA-registered pesticide
products is available on EPA's Web site at: http://iaspub.epa.gov/apex/pesticides/f?p=PPLS:1 (Ref. 133).
    With respect to environmental concerns related to chemical
treatment of agricultural water, we note that environmental and health-
related risk assessments of pesticide products are conducted by EPA
prior to their registration and use (see Comment 194).
    (Comment 197) One comment expresses concern that adding an
antimicrobial treatment to irrigation water would be considered a point
source discharge of a pollutant, requiring farms to obtain a National
Pollution Discharge Elimination System (NPDES) permit, and that
implementation of agricultural water treatment in compliance with Sec.
112.43 would expose farms to liability under the Clean Water Act (CWA),
including a potential citizen suit. The commenter also maintains that
requiring farms to treat surface irrigation water with antimicrobial
pesticides could subject farms to liability under the ESA or potential
increased scrutiny regarding their effects on anadromous (i.e.,
ascending rivers from the sea for breeding) species. The commenter
notes that the 2013 proposed rule did not indicate whether FDA would
conduct ESA consultation, and recommends that we outline our intentions
with respect to ESA compliance and the potential impact of
implementation of the produce safety regulation.
    (Response) We have evaluated the potential effects of the produce
safety regulation on the human environment in the United States. Our
evaluation and conclusions based on that evaluation are described in
the final EIS (Ref. 126). We refer you to that document for a detailed
discussion of the potential environmental effects of the produce safety
regulation, including those associated with the standards for
agricultural water in subpart E of part 112. With respect to the CWA,
only a portion of agricultural facilities are considered point source
dischargers that would require NPDES permits. This form of regulatory
oversight is discussed in Chapter 3.1.2 of the EIS. The provisions of
the produce safety regulation do not authorize covered farms to violate
existing laws and regulations, including the CWA. This rule also does
not affect the status of any farm that is currently subject to NPDES
permits.
    We also considered the effects of the produce safety regulation on
threatened and endangered species. In the supplemental notice, we
proposed a new provision Sec.  112.84 that explicitly states that part
112 does not authorize or require covered farms to take actions that
would constitute the ``taking'' of threatened or endangered species in
violation of the ESA, or require covered farms to take measures to
exclude animals from outdoor growing areas, or destroy animal habitat
or otherwise clear farm borders around outdoor growing areas or
drainages. We are finalizing this provision, as proposed. FDA has
concluded informal consultation with FWS under the ESA. We have also
been involved in conversations with National Marine Fisheries Service
regarding our ESA obligations. See (Ref. 134) (Ref. 135) for additional
information.
    (Comment 198) Several commenters discuss the interface between
proposed Sec.  112.43 and State or regional policies related to water
or water treatment, such as permit requirements. One comment notes
that, in most States, application of pesticides to any surface waters
(including irrigation waters) is subject to permit requirements.
Another comment mentions that, if a farm installs a chlorination
facility in order to comply with the produce safety regulation, then
the applicable State and/or Regional Water Board might issue a permit
to that farm to make sure that any disinfection by-products running out
of the farm's fields do not damage the environment or water quality.
This comment asserts that the issuing of such permits could be a
significant burden on farms and on State and Regional Water Boards. One
comment mentions that water treatment products used in California must
be registered with the California EPA's Department of Pesticide
Regulation (CDPR). This comment speculates that if the produce safety
regulation results in significant increase in use of pesticides to
treat water, that the CDPR's requirement to register treatment products
may result in time delays and antimicrobial products may become less
available.
    (Response) As noted in response to Comment 194, the produce safety
regulation does not require covered farms to consider treating
agricultural water as an immediate first step where the water is not
safe or of adequate sanitary quality for its intended use and/or does
not meet the microbial quality criteria in Sec.  112.44. Rather,
covered farms have a range of viable options to consider based on
practices and conditions specific to the farm, treatment of water being
only one such option. When a covered farm does choose to treat water to
ensure its safety for its intended use, we are providing for the
treatment of water using any effective treatment method (such as
physical treatment, including using a pesticide device as defined by
EPA; EPA-registered antimicrobial pesticide product; or other suitable
method).

Nothing in the regulations in part 112 requires or authorizes farms to
take measures in conflict with existing federal, State, or local
regulations related to water treatment. We also considered the
environmental impacts associated with the standards for agricultural
water, as discussed in the final EIS (Ref. 126).
    When agricultural water is treated to ensure that it is safe and of
adequate sanitary quality for its intended use, we expect any treatment
that is used would be applied in accordance with all applicable
federal, State, tribal, or local regulations. For example, any
pesticide chemicals used in the treatment of water require EPA
registration before they can be lawfully used.
    (Comment 199) Several comments request that we provide additional
clarification, instruction, and/or examples regarding how farms can
treat water in order to comply with proposed Sec.  112.43. One
commenter claims that proposed Sec.  112.43 is vague, in that it
outlines neither the level of microbial reduction that must be achieved
nor the microbial standard that must be met. Several comments request
that FDA clarify which economical water treatments exist that might be
used to bring water into compliance with levels established in the
rule, and ask that we give examples of such treatments, provided that
they do not conflict with other federal or State regulations. Other
commenters maintain that farms need agricultural water treatment
alternatives to chlorine, and request that FDA clarify which water
treatments beyond chlorination are available to comply with proposed
Sec.  112.43. Another comment asks that, if FDA chooses to provide
examples of water treatment methods, that we cite methods, such as
hydrogen peroxide and UV treatment, which minimize the potential for
environmental and public health impacts. Relatedly, another commenter
contends that FDA should explicitly recommend methods of water
treatment that do not involve chemicals. Although supporting the
requirement in proposed Sec.  112.43(c)(2) that any treatment of
agricultural water must be monitored, some comments seek additional
specification, such as a defined interval for monitoring, the resulting
water quality, and the point of monitoring (either at the place where
the treatment is added or at the point of use of water).
    (Response) If a covered farm chooses to treat agricultural water to
make the water safe and of adequate sanitary quality for its intended
use and/or to meet the relevant microbial quality criteria in Sec.
112.44, Sec.  112.43 requires that the treatment that is applied,
regardless of the specific method employed, must be effective to make
the water safe and of adequate sanitary quality for its intended use
and/or meet the relevant microbial quality criteria in Sec.  112.44, as
applicable. The required quality is dependent on the intended use of
the agricultural water, with specific microbial quality criteria
established in Sec.  112.44(a) for certain specified uses; in Sec.
112.44(b) for use during growing of produce (other than sprouts) using
a direct application method; and in Sec.  112.41, generally.
    The specific level and frequency of treatment, the point at which
treatment should be applied, and the intervals for monitoring
treatments required under Sec.  112.43 also vary, and are dependent, in
part, on the method of treatment and the farm's operations, including
its water source, intended use of the water source, and the water
distribution system. As discussed in the 2013 proposed rule, an example
of an effective monitoring program for use of a chemical treatment
method would measure the level of active compound as well as those
factors that may affect its activity, such as pH, temperature, and
contact time. For example, adequate monitoring of water treated with
hypochlorite in an orange postharvest wash must include, at a minimum,
monitoring the level of active antimicrobial (free available chlorine)
and pH, since it is known that hypochlorite activity is reduced both by
organic material (e.g., soil, plant debris) and pH values outside its
effective range (pH 6.0-7.5) (Ref. 136) (Ref. 137) (Ref. 138) (Ref.
139). The concentration of active disinfectant and pH must be adjusted,
as necessary, taking into account variations in water quality in order
to maintain the effectiveness of the treatment. In addition, the
frequency at which you monitor agricultural water treatment must be
adequate to ensure that the conditions for proper treatment are
consistently met and adjusted, as necessary, to result in water that is
safe and of adequate sanitary quality for its intended use and/or meets
the relevant microbial quality criteria in Sec.  112.44, as applicable.
Research has shown that, in other settings, monitoring of physical
parameters, such as temperature, pH and disinfectant concentration, can
be done in real-time and in an inexpensive, automated manner,
facilitating good control of the treatment process (Ref. 136). As a
verification that the treatment process, monitored in accordance with
Sec.  112.43(b), is effective in achieving a certain microbial quality
requirement (e.g., no detectable generic E. coli in 100 mL of water),
you may choose to perform periodic microbiological analysis of the
treated agricultural water. Although not a requirement, we encourage
farms to perform such testing to provide further assurance of the
effectiveness of their treatment under the specific conditions that
exist on their farm. We will consider discussing these issues further
in the Produce Safety Regulation implementation guidance to be issued
in the near term.
    (Comment 200) Several comments focus on the treatment of harvest
and postharvest water. For example, one comment requests clarification
on whether the proposed standard would require water for dump tanks to
have an added disinfectant, whereas another commenter recommends that
farms should use, as appropriate, antimicrobials in fruit and vegetable
wash water for pathogen reduction. Comments also provide other
suggestions, including: (1) That farms with more than $5 million in
gross sales should be required to include a disinfectant in their wash
water, if such farms are immersing in dump tanks either leafy greens or
produce that can take up water through a temperature differential; (2)
that farms should be permitted to continue their current use of a
chlorine-free product to treat water in a dunk or flume, which in the
commenter's view renders the proposed water standards excessive; and
(3) that the provisions should address the use or validation of
compounds authorized for use.
    (Response) As noted in response to Comment 194, the produce safety
regulation does not require covered farms to consider treating
agricultural water as an immediate first step where the water is not
safe or of adequate sanitary quality for its intended use and/or does
not meet the relevant microbial quality criteria in Sec.  112.44, as
applicable. Rather, covered farms have a range of viable options to
consider based on practices and conditions specific to the farm,
treatment of water being only one such option. This includes
agricultural water used during or after harvest. Under Sec.
112.44(a)(2), agricultural water must contain no detectable generic E.
coli per 100 mL when it is applied in any manner that directly contacts
covered produce during or after harvest activities (for example, water
that is applied to covered produce for washing or cooling activities,
and water that is applied to harvested crops to prevent dehydration
before cooling), including when used to make ice that directly contacts
covered produce during or after harvest activities. This microbial
quality criterion, therefore, applies to wash

water in dump tanks, flumes, or wash tanks used to wash covered
produce. Where water does not meet this microbial quality requirement,
farms have different options to ensure the water is safe to use for
this purpose. A covered farm may choose to add an EPA-approved
disinfectant to the wash water in dump tanks to ensure the water
contains no detectable E. coli and is safe and of adequate sanitary
quality for its intended use. However, treatment of water is not the
only option. In addition to treatment, another option available to
farms includes re-inspecting the entire affected system, identifying
conditions that are reasonably likely to introduce hazards, making
changes to the system and re-testing the water successfully (Sec.
112.45(a)(1)) or using water from a different source that does meet the
microbial quality requirement.
    The commenter who suggested a sales-based requirement for use of a
disinfectant in wash water did not provide a rationale for such a
requirement. We are establishing a microbial quality requirement for
such water in Sec.  112.44(a), and options for taking action when water
does not meet that standard in Sec.  112.45(a). We are not requiring
any farms to treat wash water regardless of whether it meets the
quality requirement, nor are we requiring only certain farms to do so
based on their sales or the type of commodity they produce.
    With respect to comments asking us to address the use or validation
of compounds authorized for use, we note that although some
antimicrobial substances are regulated by FDA, most antimicrobial
substances that might be used by covered farms in agricultural water
are regulated by the EPA. A decision tree regarding whether an
antimicrobial substance would be regulated by the EPA or the FDA is
available at: http://www.fda.gov/Food/IngredientsPackagingLabeling/PackagingFCS/RegulatoryAuthorityAntimicrobialSubstances/default.htm
(Ref. 140). See also the discussion of available antimicrobial products
registered with EPA as sterilizers in Comment 194.
    (Comment 201) Several commenters assert that proposed Sec.  112.43
would create a preference for the use of antimicrobial pesticides as an
appropriate water treatment method; these comments point out that the
proposed provision provides only an example of using an EPA-registered
antimicrobial pesticide product to treat water, without offering any
additional examples. Another commenter observes that the proposed
provision appears flexible, but that the related commentary in the
preamble only discusses chemical treatment of water. This commenter
also notes that various non-chemical treatment methods, such as
mechanical or physical methods (e.g., filtration) are currently being
explored.
    (Response) As noted in response to Comment 194, when a covered farm
chooses to treat its agricultural water to ensure it is safe and of
adequate sanitary quality for its intended use and/or meets the
relevant microbial quality criteria in Sec.  112.44, as applicable, we
are providing for the treatment of water using any effective treatment
method (such as physical treatment, including using a pesticide device
as defined by EPA; EPA-registered antimicrobial pesticide product; or
other suitable method). We recognize that methods other than chemical
treatment are either available or being explored for the treatment of
agricultural water, for example, pesticide devices (such as filter
units, ultraviolet light units, and ozonator units), reverse osmosis,
and solar methods (Ref. 141). We also agree that water treatment
options should not be, and are not, limited to chemical methods. As
part of the EIS, FDA has considered a range of management decisions
that a farm might take to be in compliance with the water quality
requirements. These management decisions are outlined in Table 2.1-2 of
the EIS and discussed in further detail in Chapter 4.2 of the EIS (Ref.
126). To make clear that water treatment options are not limited to
chemical methods, we are revising Sec.  112.43(a) to include additional
examples besides chemical treatment methods.
    (Comment 202) Some comments state that, under the NOP standards,
only certain specified substances may be used as disinfectants and
sanitizers in organic crop production (provided that the use of such
substances does not contribute to contamination of crops, soil, or
water), and that currently no pesticide chemicals are allowed under the
NOP that organic farmers would be able to use to treat water.
Similarly, a trade organization comments that they are unaware of any
antimicrobial pesticide that would be effective, allowed for use under
the NOP, and allowed for use according to its label. A State department
of agriculture states that a surface water irrigator treating water
with antimicrobial pesticides could result in organic producers located
downstream to use water that has been treated, which could cause them
to have their organic certifications revoked. Another comment expresses
concern that water treatment chemicals will damage the microbiology of
the soil, thus compromising the ability of organic farmers, who depend
on the soil biology ecosystem, to grow safe and healthy food.
    (Response) Throughout the development of the produce safety
regulation, we have been working with USDA on a number of issues,
including on whether and how this rule affects compliance with the NOP
regulations. Compliance with the provisions of this rule does not
preclude compliance with the requirements for organic certification in
7 CFR part 205. As discussed previously, this rule does not require
covered farms to consider treating agricultural water as an immediate
first step where the water is not safe or of adequate sanitary quality
for its intended use and/or does not meet the relevant microbial
quality criteria in Sec.  112.44, as applicable. Rather, covered farms
have a range of viable options to consider based on practices and
conditions specific to the farm, treatment of water being only one such
option. Thus, this rule does not require organic farms to use a
substance that is prohibited in organic production.
    We understand that substances which are prohibited in organic
production are described in 7 CFR 205.105. We advise you to consult
with the NOP for additional information related to concerns about
downstream effects of chemical treatment of water. In addition, as
discussed previously, current options for EPA-registered pesticide
chemicals for use in agricultural water are limited for all produce
production, including organic produce. However, non-chemical water
treatment options (such as filter units, ultraviolet light units,
ozonator units, reverse osmosis, and solar methods) are either
currently available or being explored, and such treatments may be used
in compliance with Sec.  112.43. In addition, options other than
treating agricultural water are also available under this rule for
organic farms, just as for all other covered farms. See also our
responses to Comment 194 and Comment 196.
    FDA has acknowledged in Chapter 4.2 of the EIS that certified
organic farms are restricted to pesticides approved on the National
List of Allowed and Prohibited Substances. However, FDA has determined
that sustained, long-term water treatment may not be required because
the added flexibility to account for microbial die-off and/or removal
may be as simple as allowing sufficient time between final application
of irrigation water and harvest. Certified organic farms will have
sufficient flexibility to choose management decisions that allow them
to retain their certification, including non-chemical

water treatments, postharvest options with and without chemicals, using
alternative water sources and others as discussed in further detail in
Chapter 4.2 of the EIS. The EIS also considers impacts of water quality
criteria established in this rule on various resources, including soils
(Ref. 126).
    (Comment 203) Some comments discuss the costs associated with
treating water under proposed Sec.  112.43. Comments assert that some
irrigation districts, municipalities, and farms lack the necessary
infrastructure or financial resources to build such infrastructure. An
additional comment states that increased use of antimicrobials in
postharvest water will increase farm operating costs, and could lead to
capital costs to mitigate increased amounts of contaminated waste water
discharges.
    (Response) See our responses to Comment 194, Comment 195, Comment
200, and Comment 201. We also recognize that covered farms will need
time to consider the various options, and may need some adjustments to
their existing practices or operations, to comply with the water
provisions in this rule. Therefore, for covered activities involving
covered produce (except sprouts), we are providing extended compliance
periods for certain water provisions, as explained in section XIII.K of
this document. We also intend to work with our State, tribal, and local
partners and target our education and technical assistance efforts to
smaller farms to help farms meet the requirements of the rule.
    With respect to the comment about increased costs, we estimate
costs of antimicrobial use and related capital investments in our RIA.
See the final RIA for a discussion of costs (Ref. 142).
    (Comment 204) One comment asks that we clarify that agricultural
water should not be treated under Sec.  112.43 if such treatment would
conflict with applicable laws.
    (Response) There is nothing in Sec.  112.43, specifically, or in
part 112, generally, that requires or authorizes violations of other
applicable laws. Should a covered farm choose to treat their
agricultural water to ensure it meets the applicable requirements for
its intended use, we expect any treatment that is used would be applied
in accordance with all applicable federal, State, tribal, and local
regulations.

E. Microbial Quality Criterion for Agricultural Water Used for Certain
Specified Purposes (Sec.  112.44(a)) and Corresponding Corrective
Measures (Sec.  112.45(a))

    (Comment 205) Some comments support the applicability of the
microbial quality criterion in proposed Sec.  112.44(a) (i.e., no
detectable E. coli) for uses of water specified under this provision.
Some comments also state that water used during harvest, packing, and
holding activities should be tested on a more frequent basis than other
water used for agricultural purposes, and request FDA to provide
guidance on the specifics of a sampling plan.
    (Response) We are finalizing proposed Sec.  112.44(a), such that
the no detectable E. coli requirement applies to agricultural water
that is used for purposes specified in that section. We are deleting
proposed Sec.  112.44(a)(3) because we received comments indicating
that this reference to treated agricultural teas in subpart E was
confusing (see Comment 270 and Comment 271). We have amended Sec.
112.51(a) and (b) in subpart F, and the definition of ``agricultural
tea'' in Sec.  112.3(c), to clarify the requirements applicable to
water used to make an agricultural tea.
    We address testing frequency requirements in Comment 224. In
addition, we refer you to the discussion under Comment 180 and Comment
181, where we explain the requirements for corrective measures that
must be taken, and the timing for when such corrective measures must be
taken, in accordance with Sec.  112.45(a), when your agricultural water
does not meet the microbial quality criterion in Sec.  112.44(a) for
those specified purposes.
    In the supplemental notice, we did not propose specific testing
frequency requirements applicable to untreated surface water that is
used for the purposes in Sec.  112.44(a). Instead, we proposed that you
must test the quality of each source of the untreated surface water
with an adequate frequency to provide reasonable assurances that the
water meets the required microbial standard and that you must have
adequate scientific data or information to support your testing
frequency (proposed Sec.  112.45(d)). We also noted that although we
were not restricting use of untreated surface water solely to growing
activities (e.g., irrigation, crop protection sprays), we anticipated
that the primary use of untreated surface water would be during growing
activities. Thus, in the supplemental notice we did not specifically
prohibit a farm from using untreated surface water for any purpose
described in Sec.  112.44(a), provided that the water meets the no
detectable E. coli standard for those purposes. We asked for comment on
the prevalence of use of untreated surface water for the purposes
listed under Sec.  112.44(a), and on an appropriate approach(es) to
sampling and testing of untreated surface water intended for such uses.
We also asked for comment on whether we should require treatment of
surface water sources used for the purposes specified in Sec.
112.44(a), rather than provide for a testing scheme, if the latter is
not practical (79 FR 58434 at 58454).
    Some comments that responded to this request ask for clarification
on what would be an adequate frequency or for guidance on an
appropriate sampling plan. We continue to find it challenging to
establish a generally applicable sampling scheme or frequency that
would provide sufficient confidence that any source of untreated
surface water, given the inherent variability associated with such
sources, will consistently meet the no detectable E. coli microbial
water quality criterion in proposed Sec.  112.44(a). Moreover, none of
the comments explicitly recommended or supported retaining this testing
requirement as a means to allow use of untreated surface water for the
purposes in 112.44(a). Under the Surface Water Treatment Rule (40 CFR
141.70-141.75), EPA requires public water systems to treat surface
water or ground water sources under the direct influence of surface
water to meet the requirements of the Safe Drinking Water Act (SDWA)
(42 U.S.C. 300f et seq.). The intended uses listed in Sec.  112.44(a)
have high potential to serve as a vehicle of fecal contamination
because if fecal contamination is present (along with the corresponding
potential for pathogen presence), it is reasonably likely it could be
transferred directly to covered produce through direct or indirect (via
food-contact surfaces) contact with the agricultural water. Considering
this, as well as the inherent variability of the quality of untreated
surface water sources; the absence of an identifiable, appropriate
testing and sampling scheme to ensure the safe use of such untreated
surface water for the purposes of Sec.  112.44(a); and the lack of
comments persuading us to retain proposed Sec.  112.45(d), we are
eliminating proposed Sec.  112.45(d) from subpart E and adding a
prohibition in Sec.  112.44(a) on using untreated surface water for any
of the purposes identified in that section.
    (Comment 206) One comment recommends that we establish less
protective water quality requirements than those in proposed Sec.
112.44(a) and

Sec.  112.44(c) that would be applicable to produce commodities that
may be cooked or that are often cooked, and that we establish for such
commodities a labeling requirement similar to ``Safe Handling''
labeling instructions for consumers that appear on meat products.
    (Response) We do not agree that such an approach would
appropriately minimize the risk of serious adverse health consequences
or death from consumption of contaminated produce. We believe the
provisions in Sec. Sec.  112.2(a) and 112.2(b) sufficiently address the
circumstances where produce is either rarely consumed raw or receives
commercial processing to adequately reduce pathogens. For produce that
is not ``rarely consumed raw'' or receives commercial processing to
adequately reduce pathogens, we do not believe that less protective
water requirements along with labeling instructions would be
appropriately protective of public health or fulfill our FSMA mandate
to establish science-based minimum standards for the safe production
and harvesting of produce that minimize the risk of serious adverse
health consequences or death. It is unclear how we could determine
appropriate microbial criteria for such a ``less protective'' set of
microbial water standards. It is also not clear that consumers would
always cook such produce even if it were labeled with instructions that
it should only be consumed after cooking or that consumers would
understand why there were cooking instructions on a product that is
often consumed uncooked.
    (Comment 207) Some comments suggest the microbial quality
requirement in proposed Sec.  112.44(a) should apply to postharvest
activities only.
    (Response) As discussed in the QAR, water used for the purposes
listed in Sec.  112.44(a) has high potential to serve as a vehicle of
fecal contamination because if fecal contamination is present (along
with the corresponding potential for pathogen presence), it is
reasonably likely it could be transferred directly to covered produce
through direct or indirect (via food-contact surfaces) contact with the
agricultural water. We explained our rationale for subjecting the
intended uses of agricultural water listed in Sec.  112.44(a) to the
stringent zero detectable E. coli microbial quality standard in the
2013 proposed rule (see 78 FR 3504 at 3568). Therefore, we disagree
with the commenters' suggestion that the microbial quality criterion in
Sec.  112.44(a) should be limited to postharvest uses only (See also
discussion in section XIV.A.1 of this document).
    (Comment 208) One comment points out that under the proposed
provisions of part 112, on-farm postharvest handling of produce (such
as packing) grown on the farm or other farms under the same ownership
would be required to comply with the proposed Sec.  112.44(a)
requirement to test water used for the listed purposes to ensure there
is no detectable generic E. coli; but that the same activities, when
subject to proposed part 117 (e.g., when the produce is packed off-
farm, or on-farm packing of produce from a farm under separate
ownership) would not be subject to specific provisions requiring
testing of such water.
    (Response) First, we note that there is no requirement to test
water from certain types of public water systems used for the purposes
listed in Sec.  112.44(a), nor is there any requirement to test water
treated in accordance with Sec.  112.43 used for the same purposes (see
Sec.  112.46(a)). See Comment 222. In addition, we are prohibiting use
of untreated surface water for these purposes (see Sec.  112.44(a)),
which means that only untreated ground water must be tested when used
for these purposes (see Sec.  112.46(c)).
    Second, as discussed in section IX.B. and in the supplemental
notice, we have revised the definition of ``farm'' so that farms that
pack or hold produce RACs that are grown on a farm that is under
different ownership would no longer necessarily be ``farm mixed-type
facilities'' subject to the requirements of the PCHF regulation.
Rather, packing or holding others' produce RACs on a covered farm will
be subject to this rule unless the farm or the produce is otherwise
exempt or not covered. Thus, there is no longer a difference in what
requirements will apply to testing water used in on-farm postharvest
handling of produce based on where the produce was grown. Moreover, we
are also revising the definition of ``farm'' to include certain
operations (Secondary Activities Farms) devoted to harvesting, packing,
and/or holding of RACs, provided that the Primary Production Farm(s)
that grow or raise the majority of the RACs harvested, packed, and/or
held by the Secondary Activities Farm own, or jointly own, a majority
interest in the Secondary Activities Farm. Thus, farm-owned cooperative
packing houses, for example, will be considered Secondary Activities
Farms, and water used in their postharvest handling of produce will be
subject to this rule unless the farm or the produce is otherwise exempt
or not covered.
    This rule does not apply to activities of a facility subject to
section 418 of the FD&C Act. Such activities are addressed in the final
human preventive controls rule and the final animal preventive controls
rule (80 FR 55908 and 80 FR 56170, respectively).

F. Microbial Quality Criteria for Agricultural Water Used for Direct
Application During Growing Activities of Produce (Other Than Sprouts)
(Sec.  112.44(b) and Corresponding Corrective Measures (Sec.
112.45(b))

1. Microbial Quality Criteria (Sec.  112.44(b))
    (Comment 209) Several comments assert that the use of EPA's
Recreational Water Quality Criteria (RWQC) is inappropriate or
insufficient for use in setting the microbial quality standard for
agricultural water, as established under proposed Sec.  112.44(c).
Comments express various concerns, including that: (1) FDA has not
established a correlation between the RWQC and food safety and applying
recreational water standards to irrigation water does not meet the
statutory obligation to establish science-based standards for food
safety; (2) the RWQC were developed more than two decades ago and do
not reflect current science; (3) FDA has not provided sufficient
explanation for how the RWQC would serve to minimize risk of known or
reasonably foreseeable hazards, and that FDA, itself, acknowledges the
limitations of using the RWQC; (4) the RWQC are likely appropriate for
some, but not all, crops; and (5) the RWQC may not be achievable in
areas of the country that use surface water for irrigation. These
comments recommend that any microbial quality standard established in a
final rule should be based on data that are specific to produce safety
and agricultural water. In contrast, some comments support the use of
RWQC in developing the microbial quality criteria in proposed Sec.
112.44(c).
    (Response) We disagree with the assertion that the use of the
science underlying the RWQC is inappropriate for informing the
development of microbial quality criteria for agricultural water used
in direct application during growing of produce (other than sprouts),
which are now established in final Sec.  112.44(b). We agree that the
RWQC (which are based on data collected from recreational waters), in
and of themselves, do not sufficiently reflect the circumstances
associated with agricultural water used in produce production. However,
we are not simply applying the RWQC as the safety standard for
agricultural water. Rather,

as discussed in the supplemental notice, we find that the science
underlying the RWQC provides a starting point for quantitative
microbial criteria that are generally applicable to minimize the risk
of known or reasonably foreseeable hazards associated with the use of
agricultural water on produce (other than sprouts) during growing using
a direct water application method. The RWQC, which have been updated in
2012, are based on several recent epidemiological studies and use a
broader definition of illness to recognize that gastrointestinal
symptoms may occur without a fever (Ref. 100). Among other evidence,
EPA considered the latest research and epidemiological data that
demonstrate a link between fecal contamination in recreational waters
and illness, and characterizes the rate of illness based on the
epidemiological data. Using those data, the EPA criteria demonstrate
the microbial threshold at which an exceedance of the threshold
increases illness occurrence to protect primary contact recreation
where immersion and incidental ingestion are likely (Ref. 100). In
addition, the EPA analysis does not distinguish the illness rates
between different bodies of water (i.e., marine or fresh) due to
incidental ingestion. Overall, we find the scientific rigor underlying
the RWQC to be sufficient for us to rely on to inform our thinking on
agricultural water used in produce production, which is also consumed
via incidental ingestion. We described the rationale for our use of the
science underlying the RWQC and our thinking on its relevance to
agricultural water in a reference memorandum that accompanied the
supplemental notice, and we reiterate those conclusions here (Ref. 44).
    In the supplemental notice, we acknowledged that there are
different ways to determine STV, including through sample-based
empirical estimation and model-based calculation, and requested comment
on whether there is a specific statistical method(s) that we should
either require or recommend be used for the derivation of GM and/or STV
values (79 FR 58434 at 58453). We did not receive comments recommending
any specific method(s) for calculation. On further evaluation, we find
a parametric estimation method based on the lognormal distribution to
be appropriate for deriving the STV for purposes of determining the
microbial water quality criteria and any necessary follow-up measures
specified in Sec. Sec.  112.44(b) and 112.45(b)(1), respectively.
Unlike empirical methods, model-based methods of calculating the STV
are more sensitive to the range of extreme values that may be obtained
among the sample outcomes when the STV is being determined based on a
relatively small number of samples. Therefore, we are specifying that
the STV of your water samples calculated to determine whether your
water meets the microbial quality criteria specified in Sec.
112.44(b), must be derived as a model-based calculation based on the
lognormal distribution. (See Comment 229 where we address guidance
related to this issue.)
    Therefore, we are finalizing the microbial quality criteria for
agricultural water used during growing activities for covered produce
(other than sprouts) using a direct water application method of: (1) A
geometric mean (GM) of your agricultural water samples of 126 or less
colony forming units (CFU) of generic E. coli per 100 mL of water (GM
is a measure of the central tendency of your water quality
distribution); and (2) a statistical threshold value (STV) of your
agricultural water samples of 410 or less CFU of generic E. coli per
100 mL of water (STV is a measure of variability of your water quality
distribution, derived as a model-based calculation approximating the
90th percentile using the lognormal distribution).
    Using the RWQC as a starting point, we then considered available
scientific information and recommendations to account for circumstances
that are unique to produce growing (including irrigation), such as
microbial die-off after application of water, which are factors that
were not accounted for in formulating water quality requirements in the
EPA RWQC (Ref. 123) (Ref. 143). We considered the World Health
Organization's (WHO) Guidelines for the Safe Use of Wastewater,
Excreta, and Greywater, Volume II, Wastewater Use in Agriculture, which
were developed with the primary aim of ``maximizing public health
protection and the beneficial use of important resources'' (Ref. 123).
These guidelines are intended to be relevant ``to the intentional use
of wastewater in agriculture and [are] also relevant where faecally
[sic.] contaminated water is used for irrigation unintentionally'' and
provide ``an integrated preventive management framework for safety.''
These guidelines recommend various health protection measures that can
be used alone or in combination to achieve a specific microbial log
reduction, or range of reductions, necessary to meet the desired health
outcome. The health protection measures reflected in the WHO guidelines
are intended to achieve a tolerable disease burden from consumption of
raw food crops irrigated by treated wastewater of 10-6
disability-adjusted life years per person, per year (Ref. 44). The
post-irrigation microbial die-off and/or microbial removal provisions
in final Sec.  112.45(b)(1) were informed by our analysis of these WHO
guidelines.
    (Comment 210) In the supplemental notice, in relation to the
microbial quality criteria in proposed Sec.  112.44(c), we asked for
comment on whether we should establish a single sample maximum level of
E. coli above which the water should not be permitted for use in direct
application (until specific follow-up actions are taken to ensure it
meets the recommended microbial quality requirements) and, if so, what
would be an appropriate maximum level (78 FR 58444). Some comments
oppose a maximum threshold level of E. coli, arguing that it could lead
to discontinuation of water unnecessarily because of the variability in
quality of irrigation water, and one of these comments argues that any
such maximum levels should be included in guidance rather than in
regulation.
    (Response) We are not establishing a single sample maximum
threshold of generic E. coli in relation to the microbial quality
criteria in Sec.  112.44(b). Our approach to developing the standard
for safe use of agricultural water during growing covered produce
(other than sprouts) relies on measures taken by covered farms to know
and respond to the quality of their agricultural water over the long
term. Rather than setting a single sample maximum generic E. coli
standard, we are establishing a STV of 410 CFU or less generic E. coli
per 100 mL of water. The STV is a value that is derived as a model-
based calculation based on the lognormal distribution and approximates
the 90th percentile of the water quality distribution. The use of an
STV rather than a single sample maximum is designed to account for the
variability of water sources, in particular of surface water sources.
    (Comment 211) Several comments recommend FDA set an ``interim''
microbial water quality requirement in proposed Sec.  112.44(c), and
then pursue additional research to inform the development of a final
microbial quality standard that accounts for the diversity in farming
practices and produce commodities. Such comments advise that such an
``interim'' standard should include a mandatory sunset provision, which
they expect would provide an opportunity for stakeholders to work
together to conduct research and develop meaningful commodity- and
situation-specific microbial quality standards for agricultural water.

    (Response) As previously noted, we do not agree that more research
is needed for us to finalize the provisions of this rule relating to
agricultural water. We also disagree that we should establish
requirements with sunset provisions as suggested by these commenters.
As discussed in the 2013 proposed rule, the supplemental notice, and in
this document, there is sufficient scientific information from which we
conclude that the requirements in this rule minimize the risk of
serious adverse health consequences and death, and are reasonably
necessary to prevent the introduction of known or reasonably
foreseeable hazards into produce and to provide reasonable assurances
that produce is not adulterated. However, we do support additional
research as a means of facilitating implementation of the rule and
continuing advancement of scientific knowledge in this area, and we are
pursuing regulatory science and research activities in collaboration
with various partners (see Comment 174).
    (Comment 212) Several comments recommend other approaches for us to
consider in establishing microbial quality requirements for Sec.
112.44(b) uses, including: (1) Using the WHO standard, asserting it may
be easier to implement and more easily understood by foreign producers;
(2) adopting a qualitative standard to require that water must be of
adequate quality for its intended use; and (3) applying the microbial
standard for drinking water to agricultural water for a certain
specified period prior to harvest, and evaluating whether water meets
this standard using a single water test taken at a certain time prior
to harvest. In addition, several other commenters argue that any
agricultural water requirement for this purpose should be no more
restrictive than the WHO standard.
    (Response) See Comment 209. The WHO guidelines present several
illustrations for how to reduce risks associated with consuming raw
crops irrigated by wastewater. However, these are only examples of how
to apply the guidelines to reach the health-based target. They do not
represent specific water quality criteria for particular commodities.
The guidelines recommend several health protection measures, each of
which can be used alone or in combination to achieve a specific
microbial log reduction or range of microbial reductions necessary to
meet the desired (<=10\-6\ disability-adjusted life years) health
outcome. This rule draws upon the WHO water guidelines, but not as a
fixed microbial quality standard, per se. As discussed in the
supplemental notice, the WHO values (i.e., 1,000 CFU per 100 mL and
10,000 CFU per 100 mL for root crops and surface crops, respectively)
are better explained as illustrations of how specific health protection
measures could be used together after waste water treatment to achieve
the additional log reductions recommended for waste water reuse, and
were not intended as absolute end points or maximum permitted levels
for generic E. coli in irrigation water. As explained in (Ref. 44)
regarding the review of water quality standards in development of the
microbial quality criteria in Sec.  112.44(b), the WHO guidelines do
not include any specific criteria for maximum acceptable E. coli levels
in wastewater for agricultural use in the growing of produce. We also
conclude that a quantitative microbial quality requirement that is
enforceable and requires action by industry to ensure the criteria are
met would be both more practicable and more protective of public health
than a qualitative water quality standard alone. The microbial quality
criteria we have established serve as objective measures to be applied
to indicate the quality of agricultural water when used for certain
specified purposes. Note that we are also retaining the general ``safe
and of adequate sanitary quality'' qualitative standard in Sec.
112.41, which applies to all agricultural water regardless of the
specific intended use.
    In response to the comment suggesting requiring agricultural water
to meet the drinking water standard for a specified period of time pre-
harvest and only requiring a single test, we do not believe it is
necessary to require water used in the field to meet the drinking water
standard in light of the die-off of microorganisms that can be expected
to occur after application of agricultural water. As described in
Comment 214, we conclude it is appropriate to account for microbial
die-off between last irrigation and harvest, as well as between harvest
and end of storage, as provided in Sec.  112.45(b)(1).
    (Comment 213) Several comments support the use of the GM and STV as
proposed in the supplemental notice and prefer that approach over the
original approach in the 2013 proposed rule (using a GM and a single
sample maximum). These comments state that the GM and STV approach is
risk-based, appropriately protective, flexible, and does not unduly
burden farmers. However, other comments state the calculations related
to GM and, in particular, STV required under proposed Sec.  112.44(c)
are complicated and are likely to be confusing and challenging for
farmers to implement. Some comments request that FDA provide assistance
to farms regarding the calculation of GM and STV, and the application
of the microbial die-off and/or removal provisions. Comments also ask
FDA to develop guidance and web-based tools to help with these
calculations.
    (Response) We appreciate the comments that recognize the value of
the GM and STV approach as opposed to our original proposed approach
that included a single sample maximum. However, we also recognize the
need for outreach regarding how to calculate the GM and STV, how to use
microbial die-off and/or removal rates, and how to calculate related
time intervals. We intend to provide guidance on these topics in the
Produce Safety Regulation Implementation guidance, which we expect to
issue in the near future. In addition, we are exploring the development
of an on-line tool that you can use to derive the GM and STV values and
appropriate time intervals (in days) between last irrigation and
harvest using the 0.5 log per day die-off rate, based on input of
sample data, such that a farmer would not need to perform the necessary
calculations themselves.
2. Allowance for Microbial Die-Off and/or Removal (Sec.  112.45(b)(1))
and Other Corrective Measures (Sec.  112.45(b)(2) and (b)(3))
    (Comment 214) Several comments support proposed Sec.  112.44(c)(1)
and (c)(2) that would allow farms to account for microbial die-off or
removal between last irrigation and harvest and between harvest and end
of storage, or during activities such as commercial washing. These
comments state these mechanisms provide flexibility; serve as a
reasonable approach to identifying practices that reduce risk; and
minimize the need for chemical water treatment. In addition, several
comments suggest that these provisions should be expanded and applied
to operations where there is no reasonable likelihood of direct water
contact with the harvestable portion within a specified number of days
before harvest.
    (Response) We are retaining the microbial die-off and removal
provisions in final Sec.  112.45(b)(1)(i) and (b)(1)(ii). For the
purposes of this rule, we define agricultural water as water used in
covered activities on covered produce where water is intended to, or is
likely to, contact covered produce or food-contact surfaces, including
water used in growing activities and in harvesting, packing, and
holding activities. Moreover, we use ``covered produce'' to refer to
the harvestable or harvested part of the crop. Therefore,

the provisions in subpart E, including Sec.  112.44(b) and
corresponding Sec.  112.45(b), do not apply to water that is not
intended to or likely to come into contact with covered produce, and we
are not establishing microbial quality criteria (or related microbial
die-off or removal provisions) for such water. See also Comment 179.
    We are also making other revisions within final Sec.  112.45(b) to
consolidate and clarify applicable options for corrective measures when
agricultural water used during growing activities for covered produce
(other than sprouts) using a direct water application method does not
meet the microbial quality criteria in Sec.  112.44(b). That is,
available options include (1) applying a time interval (in days)
between last irrigation and harvest (Sec.  112.45(b)(1)(i)) and/or
between harvest and end of storage and/or applying a (calculated) log
reduction during activities such as commercial washing (Sec.
112.45(b)(1)(i)); (see also Comment 218 discussing certain revisions to
these provisions); (2) re-inspect your entire affected agricultural
water system to the extent it is under your control, and among other
steps, make necessary changes and adequately ensure that your water
meets the criteria in Sec.  112.44(b) (Sec.  112.45(b)(2)); or (3)
treat the water in accordance with Sec.  112.43 (Sec.  112.45(b)(3)).
Consistent with our intent for the microbial quality criteria in Sec.
112.44(b) to serve as a long-term water management tool, we further
clarify in Sec.  112.45(b) that these corrective actions must be taken
as soon as practicable, and no later than the following year. We expect
you to apply these corrective measures as soon as it is practicable,
considering various factors specific to your practices and commodities,
including, for example, the timing when water testing results are
obtained in relation to the current harvest of your commodity or
commodities; whether you have a single or multiple commodities with
different harvest cycles; and whether your commodity is of a nature
such that the time intervals and/or (calculated) log reductions in
Sec.  112.45(b)(1)(i) and/or (b)(1)(ii) can be applied. However, we
require you to implement such corrective measures no later than the
following year. If none of the corrective measures in Sec.
112.45(b)(1)-(3) are used, or if such measures are not effective in
achieving the required criteria, you must discontinue that use of the
water from that source.
    (Comment 215) Several comments express concern that the burden is
placed on covered farms to conduct research and identify appropriate
microbial die-off or removal rate(s) that can be applied between
harvest and end of storage or during activities such as commercial
washing.
    (Response) As noted in the supplemental notice, at this time, we
are not establishing a specific microbial die-off rate(s) between
harvest and end of storage or specific microbial removal rate(s) during
postharvest activities such as commercial washing because we do not
have sufficient information to support the derivation of appropriate,
broadly applicable microbial die-off or reduction rate(s) for these
purposes. Nevertheless, we provide this option in final Sec.
112.45(b)(1)(ii), along with revisions requiring you to use an
accompanying maximum time interval or log reduction. See Comment 218.
We are retaining this option so covered farms may establish and apply
an adequate time interval or calculated log reduction using microbial
die-off or removal rate(s) relevant to the covered produce and
dependent on practices and conditions on the farm, provided the farm
has adequate scientific data or information to support the conclusions.
We are working with our stakeholders to facilitate research into
appropriate die-off and/or removal rates for these activities, and we
intend to disseminate useful scientific information, when available,
such that farmers would be able to consider our recommendations and
apply the new scientific information to their operations, as
appropriate.
    (Comment 216) Several comments ask about the science underlying the
microbial die-off rate in proposed Sec.  112.44(c)(1) that is used to
determine the time interval between last irrigation and harvest.
Comments state that the established rate may not be uniformly
applicable across diverse real-world conditions on farms producing
different commodities across the country.
    (Response) The microbial die-off rate in Sec.  112.45(b)(1)(i) is
based on our review of currently available science. As explained in the
supplemental notice, we determined that a microbial reduction rate of
0.5 log per day provides a reasonable estimate of die-off under a broad
range of variables including microbial characteristics, environmental
conditions, crop type, and watering frequency. (See (Ref. 45) (Ref.
144) for information about the studies we reviewed, our criteria for
study selection, and our conclusions.) We recognize that microbial die-
off rates are dependent on various environmental factors, including
sunlight intensity, moisture level, temperature, pH, the presence of
competitive microbes, and suitable plant substrate. Although our
analysis led us to conclude that a rate of 0.5 log per day provides a
reasonable estimate of microbial die-off under a broad range of
variables, we understand that different microbial die-off rates may
occur between last irrigation and harvest under different circumstances
(Ref. 45) (Ref. 144). For example, higher microbial die-off rates may
occur under conditions of high ultraviolet radiation, high temperature
exposures or low humidity, coupled with little or no precipitation in
comparison to the die-off rates observed under cloudy, cool, and wet
conditions (Ref. 123). Therefore, in final Sec. Sec.
112.45(b)(1)(i)(B), 112.49(b), and 112.12, we are providing for the use
of appropriate alternative microbial die-off rate(s) (as well as an
accompanying maximum time intervals), provided you have adequate
scientific data or information to support a conclusion that the
alternative die-off rate would provide the same level of public health
protection as the 0.5 log per day die-off rate in Sec.
112.45(b)(1)(i)(A), and would not increase the likelihood that your
covered produce will be adulterated under section 402 of the FD&C Act,
in light of your covered produce, practices, and conditions. We expect
that covered farms that rely on an alternative die-off rate under these
provisions to use a rate that is supported by an equally robust and
rigorous scientific analysis applicable to the region and crop for
which the alternative would be used. We would expect such an
alternative rate to be quantitatively demonstrated to be equivalent to
the FDA-established rate under the relevant conditions, thus
``providing the same level of public health protection'' as the FDA-
established rate and ensuring that the alternative rate would not
increase the likelihood that the farm's covered produce will be
adulterated, as required under Sec.  112.12.
    (Comment 217) One comment notes the importance of end-of-season
irrigation water to overall yields, and asks FDA to consider the
detrimental effects of ceasing irrigation in establishing the water
standards.
    (Response) We recognize the importance of irrigation during produce
production, and have provided options in Sec.  112.45(b)(1) that
account for microbial die-off and/or removal post irrigation, as
additional means to achieve the microbial quality criteria for
agricultural water that is used in a direct application method during
growing of produce (other than sprouts). We also note that we have
incorporated flexibility for covered farms to use an alternative
microbial die-off rate in lieu of our established die-off rate, under
certain specified conditions (see

Sec.  112.49(b)). We expect that, in most cases, these provisions will
provide sufficient flexibility for covered farms to achieve our
microbial quality criteria, as soon as practicable, and no later than
the following year, without having to cease irrigation. See also
Comment 214 regarding timing of corrective actions and other available
options.
    (Comment 218) Several comments state the microbial die-off and/or
removal provisions in proposed Sec.  112.44(c)(1) and (c)(2) should not
be allowed to be used when agricultural water exceeds a certain level
of generic E. coli. These comments recommend a maximum time interval
between last irrigation and harvest of 4 days, applying a microbial
die[hyphen]off rate of 0.5 log per day. One comment provides the
example that if the water quality is uncontrollable or testing results
are between 410 and 41,000 CFU E. coli/100 mL, a time interval between
last irrigation and harvest at a rate of 0.5 log per day, to a maximum
of 4 days should be permitted, but that such flexibility for microbial
die-off is not appropriate when water testing results indicate a level
of above 41,000 CFU E. coli/100 mL.
    (Response) As discussed in the QAR, the timing of water application
can affect the potential for produce contamination. For example, water
containing elevated generic E. coli used in overhead irrigation shortly
before harvest may increase the likelihood of covered produce being
contaminated at the time of harvest, but the same water could be used
to establish a crop because microbes die-off over time on the surface
of produce. Studies reporting decay constant(s) measured over time have
concluded that microbial die-off rates are highest immediately
following contamination and slow over time (Ref. 45) (Ref. 144). This
phenomenon, known as ``tailing,'' suggests microbial die-off curves are
biphasic, i.e., two decay constants may be needed to accurately
describe microbial die-off over time. Moreover, it suggests the initial
time period immediately following a contamination event via irrigation
is the most important time period in reducing the numbers of microbes
(including pathogens) present on the crop.
    We also reviewed available literature for a maximum time interval
that is appropriate when applying a microbial die-off rate of 0.5 log
per day. The studies we reviewed indicate that greater microbial die-
off or decay rates occur during the early timeframe post-contamination,
and although the die-off rate in these studies was established from
survival data or decay rates for bacterial studies ranging from 2-7
days, the specific timeframe for the biphasic shift in die-off was not
identified (Ref. 45) (Ref. 144). Within this range identified in the
literature, a maximum time interval of 4 days is reasonable because it
serves as a general mid-point in time representing neither end of the
range where microbial die-off was observed in these studies. A maximum
time interval of four consecutive days is also consistent with
recommendations by commenters. Therefore, we are adding a new
limitation in Sec.  112.45(b)(1)(i)(A) that a time interval of no more
than four consecutive days may be applied between last irrigation and
harvest to achieve the microbial quality criteria in Sec.  112.44(b).
In addition, we expect any scientifically-supported die-off rate that a
farm applies as an alternative under Sec.  112.45(b)(1)(i)(B) between
last application and harvest; or to determine the appropriate time
interval between harvest and end of storage, in accordance with Sec.
112.45(b)(1)(ii), to be similarly characterized in a manner that
addresses the likely biphasic nature of microbial die-off (i.e., the
two different decay constants of a rapid short-term die-off and a
gradual long-term die-off). We also expect that if you develop an
alternative to the microbial quality criteria in Sec.  112.44(b) and if
you intend to take advantage of the provision in Sec.  112.45(b)(1)(i)
applying die-off between last application and harvest, then you must
also appropriately characterize a microbial die-off rate between last
irrigation and harvest that relates to your alternative microbial
quality criteria, including consideration of the likely biphasic nature
of microbial die-off.
    (Comment 219) One comment requests flexibility to apply the 0.5 log
per day die-off rate in proposed Sec.  112.44(c)(1) on a per hour,
rather than a per day, basis.
    (Response) We have determined the microbial die-off rate of 0.5 log
per day between last irrigation and harvest in final Sec.
112.45(b)(1)(i)(A) based on our review and analysis of currently
available evidence. There is not enough evidence to support modifying
the die-off rate that is reported in time periods of days in current
literature to microbial die-off per hour. Moreover, decay constants
have been found to vary within the 24 hour cycle, depending on climatic
and other conditions (Ref. 145) (Ref. 146) (Ref. 147) (Ref. 148) (Ref.
149). Therefore, we do not believe it is appropriate to extrapolate the
per day die-off rate to a per hour die-off rate.
    (Comment 220) Some comments question the need to subject water that
is used in the growing of dry bulb onions using a direct water
application method to the testing requirements in proposed Sec.
112.45, particularly in light of the microbial die-off and removal
provisions in proposed Sec.  112.44(c)(1) and (c)(2). These comments
find the testing requirements burdensome and unnecessary for water used
in the growing of dry bulb onions because harvest typically occurs
weeks or months after irrigation. One comment suggests a 6-day time
interval between last irrigation and harvest would be sufficient to
account for a ``worst case scenario of 20,000 CFU generic E. coli/100
mL'' water quality, and that dry bulb onion farms should be allowed to
``opt out'' of testing requirements for untreated surface water in
proposed Sec.  112.45(b), if they allow 6 days to elapse between last
irrigation and harvest.
    (Response) We recognize that covered farms growing dry bulb onions
typically have an extended period between last irrigation and harvest
and between harvest and end of storage, which should help them comply
with the microbial water criteria in final Sec.  112.44(b) for
agricultural water that is used during growing of dry bulb onions using
a direct application method. However, unless untreated surface water
that is used during growing in a direct application method is tested,
there would be no way to determine whether there is a need to apply a
time interval between last irrigation and harvest and, if so, the
appropriate time interval. Therefore, when required under final Sec.
112.46, agricultural water testing and calculation of the GM and STV
must be done to inform and determine the appropriate way(s) in which
the water may be used. To take advantage of the die-off and/or removal
options in Sec.  112.45(b)(1), you must first characterize the water
quality by testing in accordance with Sec.  112.46(b) and calculate a
GM and STV. Moreover, under Sec.  112.45(b)(1)(i), the use of the
microbial die-off rate of 0.5 log per day between last irrigation and
harvest is limited to four consecutive days (see Comment 218). At a
rate of 0.5 log per day and a maximum of four days, the die-off option
provided in Sec.  112.45(b)(1)(i)(A) could not, on its own, effectively
achieve the microbial quality criteria for water containing 20,000 CFU
generic E. coli/100 mL if this value represents the GM, as presented in
the comment. You may instead apply an alternative microbial die-off
rate under Sec. Sec.  112.45(b)(1)(i)(B), 112.49(b), and 112.12. To do
so, you must have adequate scientific data and

information to support your conclusions, as required in those
provisions, and you must determine an accompanying appropriate maximum
time interval associated with your alternative die-off rate, similar to
the 4-day maximum under Sec.  112.45(b)(1)(i)(A). Also, under Sec.
112.45(b)(1)(ii), you may apply a microbial die-off rate between
harvest and end of storage, and/or a microbial removal rate for
activities such as commercial washing, that is relevant to your covered
produce and dependent on practices and conditions on your farm,
provided you have adequate scientific data or information to support
your conclusions (see also corresponding documentation requirement in
Sec.  112.50(b)(5)). As for the die-off or removal rates in Sec.
112.45(b)(1)(ii), you must also determine an accompanying maximum time
interval or log reduction associated with these die-off rates, similar
to the 4 day maximum under Sec.  112.45(b)(1)(i)(A). See Comment 216.
    While these flexible options make it less likely that a dry bulb
onion farm will find that its untreated surface water cannot meet the
Sec.  112.44(b) criteria, the fact that each of these die-off or
removal rates may have a maximum appropriate application limit means
that they cannot be presumed to reduce the GM and STV of the most
contaminated water sources to a level compliant with Sec.  112.44(b).
Testing must be conducted to determine the quality of the water and
determine whether it is usable within the requirements of the rule.
    (Comment 221) In the supplemental notice, we asked for comment on
whether we should require farms to establish and maintain any
documentation in relation to the option to apply a time interval
between last irrigation and harvest. One comment recommends requiring
records to be maintained on the time interval applied, how the time
interval was calculated, and/or the dates of last irrigation and
harvest corresponding to that time interval. The commenter also notes,
however, that such records should be required only in the case where
the agricultural water tested in accordance with proposed Sec.  112.45
does not meet the microbial quality criteria established in proposed
Sec.  112.44(c).
    (Response) We agree that documentation of the time interval
applied, calculation of the time interval based on water testing
results, and the dates of last irrigation and harvest corresponding to
that time interval, must be prepared and maintained, when the provision
in Sec.  112.45(b)(1)(i) is applied to achieve the microbial quality
criteria in Sec.  112.44(b). Likewise, records must be made and kept of
the time interval or calculated log reduction applied, calculation of
the time interval or log reduction based on water testing results, and
the dates of harvest and end of storage or other relevant activities
corresponding to that time interval or log reduction, when the
provision in Sec.  112.45(b)(1)(ii) is applied to achieve the microbial
quality criteria in Sec.  112.44(b). Such records would be required
only when such a time interval or log reduction is applied, in
accordance with Sec.  112.45(b)(1), and not when no such time
interval(s) is applied. We are adding this records requirement in new
Sec.  112.50(b)(6) (corresponding with our elimination of proposed
Sec.  112.161(b)), which requires you to document any actions you take
in accordance with Sec.  112.45. This new section also provides
specifically that you must prepare and maintain documentation of any
time interval or (calculated) log reduction applied in accordance with
Sec.  112.45(b)(1)(i) and/or (b)(1)(ii), including the specific time
interval or log reduction applied, how the time interval or log
reduction was determined, and the dates of corresponding activities
(such as the dates of last irrigation and harvest, the dates of harvest
and end of storage, and/or the dates of activities such as commercial
washing).

G. Testing of Agricultural Water (Sec.  112.46)

1. Testing of Agricultural Water Not Required Under Certain Conditions
(Sec.  112.46(a))
    (Comment 222) Some comments believe proposed Sec.  112.45(a) would
allow farms to draw and hold municipal water with no further
requirement to test that water. These comments state that the
provision, as proposed, is not sufficiently protective of the quality
of water from public water system to forgo testing.
    (Response) In final Sec.  112.46(a), we are retaining proposed
Sec.  112.45(a), which establishes that there is no requirement to test
any agricultural water that is subject to the requirements of Sec.
112.44 when: (1) You receive water from a public water system, under
the conditions specified in that provision (Sec.  112.46(a)(1)); (2)
you receive water from a public water supply that furnishes water that
meets the microbial quality requirement in Sec.  112.44(a), under the
conditions specified in that provision (Sec.  112.46(a)(2)); or you
treat water in accordance with Sec.  112.43 (Sec.  112.46(a)(3)).
    This exception from the testing requirements that follow in Sec.
112.46(b) and (c) applies only when water received from a public water
system (as in Sec.  112.46(a)(1)) or a public water supply (as in Sec.
112.46(a)(2)) is not held under your control in a way that meets the
definitions of ``ground water'' or ``surface water'' before you use it
as agricultural water. See the definitions of ``ground water'' and
``surface water'' in Sec.  112.3(c). If you hold water received from a
public water system or public water supply in either a ground water or
a surface water capacity, the water is exposed to potential
contamination in a manner similar to other ground water or surface
water sources, such that it becomes a ``ground water'' or ``surface
water'' source as applicable, and the testing requirements applicable
to untreated ground water or untreated surface water will apply, as
established in Sec.  112.46(b) and (c).
    We are also revising Sec.  112.46(a)(1) to add a reference to the
relevant EPA definition of a State approved to administer the SDWA
public water supply program by adding a cross reference to the relevant
definition in 40 CFR 141.2. The definition of ``State'' for this
purpose includes, in relevant part, the agency of the State or tribal
government which has jurisdiction over public water systems.
    (Comment 223) One comment asks why a body of water, such as a
river, would need to be tested if it meets the federal water quality
standards.
    (Response) The Water Quality Standards (WQS), issued under the CWA,
define the goals for a waterbody by designating its uses, setting
criteria to protect those uses, and establishing provisions such as
anti-degradation policies to protect waterbodies from pollutants. The
WQS regulation at 40 CFR part 131 describes the requirements and
procedures for States and authorized tribes to develop, adopt, review,
revise, and submit water quality standards. It also establishes the
requirements and procedures for EPA to review, approve, disapprove, and
promulgate water quality standards as authorized by section 303(c) of
the CWA (33 U.S.C. 1313(c)). Water that is determined to be within the
established WQS for the waterbody does not necessarily meet the
agricultural water requirements in this rule, which as discussed
throughout this section, are intended to prevent the introduction of
known and reasonably foreseeable hazards into produce and to provide
reasonable assurances that produce is not adulterated. For example,
many farms rely on ditches to direct water to the field, and these
ditches are normally open to the environment and can cover significant
distances. There are no

controls in the CWA that would account for potential contamination in
these ditches.
2. Approach to Testing Untreated Surface Water (Sec.  112.46(b)) and
Untreated Ground Water (Sec.  112.46(b) and (c))
    (Comment 224) Several comments support the revisions we proposed in
the supplemental notice to proposed Sec.  112.45 that we had proposed
in the 2013 proposed rule. These comments state the tiered approach to
testing described in the supplemental notice better reflects current
sources of agricultural water and farmers' practices related to use of
those sources of water. These comments also find the proposed tiered
approach less burdensome than the originally proposed requirements.
Conversely, several other comments state the revisions to proposed
Sec.  112.45 proposed in the supplemental notice result in a testing
scheme that is overly complicated, burdensome, lacks scientific
justification, and does not incorporate sufficient flexibility. These
comments state the proposed requirements would impose significant costs
on farmers, particularly when agricultural water is derived from
multiple water sources and/or when the quality of water from a source
is highly variable.
    (Response) In the 2013 proposed rule, we proposed requirements for
specific frequencies of testing untreated surface water used for the
purposes in proposed Sec.  112.44, ranging from once every 7 days to
once per month during the growing season, depending on certain
specified circumstances related to the source of untreated surface
water. A majority of stakeholder concerns with those proposed testing
frequencies centered on the financial burden imposed on farms, in
particular, under a weekly testing requirement; arguments that FDA did
not provide scientific data in support of the proposed testing
frequencies; and the need for a more flexible approach accounting for
the variability in water quality associated with various water sources
and the particular use of the water during growing, harvesting, or
postharvest activities. Taking into account these comments, in the
supplemental notice, we made the proposed requirements more flexible by
proposing tiered approaches to testing untreated surface water
(proposed Sec.  112.45(b)) and untreated ground water (proposed Sec.
112.45(c)).
    We continue to believe our proposed tiered approaches for testing
untreated surface water and untreated ground water used for certain
purposes will allow farms to make decisions about safe use of available
water sources prior to the beginning of the next growing season; adjust
testing frequencies dependent on long-term test results and
historically derived data; and reduce the required frequency of testing
from the testing requirements of the originally proposed rule. A key
objective of our requirements for water testing in relation to the
microbial quality criteria in Sec.  112.44(b), specifically, is to
establish a testing approach sufficient to adequately characterize the
quality of the agricultural water such that the information can be used
by farms to make informed and appropriate decisions about its use and/
or the need for any appropriate corrective actions, prior to such use
in the future.
    We explained our scientific basis, and underlying statistical
analysis, for these testing frequencies in a reference memo that
accompanied the supplemental notice, which we have updated for the
purposes of this rule (Ref. 99). Our evaluation indicates that minimum
sample sizes of 20 samples for initial survey and of 5 samples for
annual survey, which we are establishing in our testing scheme for
untreated surface water in Sec.  112.46(b), are necessary to provide
sufficient precision of estimation of the microbial quality profile
(which includes GM and STV values for generic E. coli) in order to then
use that information to determine and verify appropriate conditions of
use of that water (Ref. 99). Similarly, for untreated ground water, we
conclude that a minimum sample size of 4 samples for initial survey and
of 1 sample for annual survey is necessary when the previous samples
have met the microbial quality criteria under the testing scheme that
we are establishing in Sec.  112.46(b).
    We have introduced flexibility into the testing requirements to
minimize burden to the extent possible. For example, we provide
flexibility with respect to the timing of sample collection,
recognizing the timing of the use of agricultural water in a direct
application method during growing varies by crop, region, season, and/
or from year to year. This flexibility is intended to permit farms to
tailor their sampling of water to the unique circumstances relevant to
their crop(s) and practices and conditions on their farm. In addition,
in new Sec.  112.49(c) and (d), we are allowing, under certain
specified conditions, the use of an alternative water testing frequency
in lieu of the required minimum number of samples for initial and
annual surveys under Sec.  112.46(b)(1)(i)(A) and (b)(2)(i)(A),
respectively, for testing untreated surface water that is used during
growing activities using a direct application method for produce (other
than sprouts). We are also adding a corresponding provision, in new
Sec.  112.50(b)(8) to require documentation of the scientific data or
information you rely on to support any such alternative to the required
water testing frequencies. In addition, we have also included
provisions to permit data sharing among farms as well as to permit
covered farms to use data collected by third parties, under certain
specified circumstances (see Sec.  112.47(a)). We realize that the
testing requirements may be particularly challenging for farms that
have multiple agricultural water sources and we encourage farms to
provide us with details of their specific situations so that we can
consider flexible approaches to testing multiple sources.
    Moreover, in final Sec.  112.46(b), we apply the same approach to
testing untreated ground water as the approach for testing untreated
surface water used during growing for covered produce (other than
sprouts) using a direct water application method, except that fewer
tests are required at each stage for ground water as compared to
surface water (see Comment 225 and Comment 232). We have combined the
testing frequency provisions for untreated surface and ground water
used for Sec.  112.44(b) purposes into one provision for editorial
reasons and to more clearly demonstrate the differences and
similarities between the testing required for the two types of sources
when the water is used for the same purpose. We note that this retains
the same ground water testing frequency for these purposes as proposed
in the supplemental notice as Sec.  112.45(c).
    In addition, we are revising proposed Sec.  112.45(c) to separately
address the testing of untreated ground water when used for purposes of
Sec.  112.44(a) (see final Sec.  112.46(c)).
    Similarly, in final Sec.  112.46(c), we have retained the general
approach as well as the specific frequency for testing of untreated
ground water when used for purposes of Sec.  112.44(a), as proposed in
the supplemental notice in proposed Sec.  112.45(c).
    (Comment 225) One comment states that it is critical to monitor the
quality of water used during growing of produce, and supports testing
untreated surface water and untreated ground water used during growing
at a greater frequency than the frequency we proposed, to allow earlier
detection of any contamination of the water.
    (Response) The requirements for testing untreated surface water and

untreated ground water used for Sec.  112.44(b) purposes represent
science-based minimum standards for the safe production and harvesting
of covered produce that we have determined minimize the risk of serious
adverse health consequences or death. These testing protocols will
enable farms to make decisions about safe use of available water
sources prior to the beginning of the next growing season, and to
adjust testing frequencies based on long-term test results and
historically-derived data. We specify the required testing frequencies
that we conclude, based on our statistical analysis, are necessary for
sufficient precision of estimation of the microbial quality profile,
considering the average variability in the quality of untreated surface
water and ground water sources. However, these provisions do not
preclude a covered farm from testing at a greater frequency than that
required under Sec.  112.46(b)(1)(i) or 112.46(b)(2)(i), as appropriate
based on your observations, experience, and practices related to your
agricultural water source(s), farming operation, and commodities.
    (Comment 226) One comment suggests that FDA should allow each State
to develop its own testing regime for ensuring water meets the
microbial quality standard in proposed Sec.  112.44(c), subject to FDA
approval. This commenter believes such an approach would allow States
to tailor testing requirements to the unique circumstances farms
encounter in a particular region and suited to growing conditions and
variability of water sources in that region.
    (Response) Under the provisions in subpart P of part 112, a State
(or tribe or foreign country) may request a variance from one or more
of the requirements in part 112. A competent authority in a State that
considers a water testing approach that deviates from the requirements
in Sec.  112.46 to be more appropriate for covered farms within that
State may submit a request for a variance, in accordance with the
provisions in subpart P. The request for a variance in relation to the
testing requirements may include requests for a different testing
scheme for untreated surface water and/or ground water sources (in lieu
of the tiered approaches we have established in Sec.  112.46(b)),
whereas the provisions for alternatives under Sec.  112.49(c) and (d)
are restricted only to the use of alternative testing frequencies in
lieu of the frequencies we identified in Sec.  112.46(b)(1)(i)(A) and
(b)(2)(i)(A) for untreated surface water, and do not extend to the
entire tiered scheme set forth in Sec.  112.46(b) more broadly.
    (Comment 227) Some comments assert that the proposed testing
frequency requirements in proposed Sec.  112.45 significantly favor use
of ground water over surface water, which the commenter believes may be
contrary to regional efforts to prevent overdraft of aquifers.
    (Response) The differences between the testing frequency
requirements for untreated surface water and untreated ground water
sources in Sec.  112.46(b) are based on the difference in the expected
variability in quality between these two types of sources (see Comment
225 and Comment 232). We have evaluated the potential effects of the
produce safety regulation on the human environment in the United
States. Our evaluation and conclusions based on that evaluation are
described in the final EIS (Ref. 126). We refer you to that document
for a detailed discussion of the potential environmental effects of the
produce safety regulation, including those associated with the
standards for agricultural water in subpart E of part 112. This
analysis includes potential impacts related to pesticide use, chemical
treatment of agricultural water, changes in ground water demand, and
existing water quality standards. FDA has considered these potential
impacts when making its decision on the provisions to be finalized
(Ref. 150).
    (Comment 228) Some comments express concern that the testing
approach places burden on covered farms to test water sources,
including water they receive from irrigation districts, over which they
have no control. One commenter believes the responsibility should be on
the government or on the irrigation districts, not the farm. Similarly,
another comment points out it may not be possible for farms to correct
a contamination problem when the source of contamination is not in
their control. Another commenter states that if a farm is receiving
water from an irrigation district, the farm may not know the water
quality and cannot establish the appropriate time interval to account
for microbial die-off.
    (Response) Regardless of the source of water or who supplies it to
the farm, a covered farm is responsible for ensuring the safe and
appropriate use of that water in covered activities. Therefore, whether
or not the irrigation districts provide information about the quality
of water they supply to a farm, the covered farm must take measures to
understand the quality of water under their control that is used as
agricultural water during the growing, harvesting, packing, or holding
of covered produce, including complying with the testing requirements
in Sec.  112.46 when applicable. Test results obtained through such
testing will give farms information about the quality of their water
and how it may be used in compliance with the rule.
    We understand that many covered farms are dependent on irrigation
districts to supply water for use in farming, and some covered farms
have no control over the quality of the water at the time and place at
which they receive the water. We encourage irrigation districts to
conduct sampling and testing around the watershed that they manage and
to share the data on its water quality with farms that receive the
water from that watershed. As described in the supplemental notice, for
example, covered farms sourcing water from an irrigation district may
consider using water testing data from the district sampling program. A
covered farm considering the district sampling program data would need
to determine whether the water source(s) sampled adequately represent
the covered farm's agricultural water. The covered farm would also need
to consider whether the district's data set includes samples collected
during a time period(s) as close as practical to the covered farm's
harvest time; whether the district's data set satisfies the minimum
number of samples the farm is required to have under the rule; and
whether the district's data were obtained using appropriate test
methods, as described in subpart N of part 112 and cross-referenced in
new Sec.  112.47(b). In addition, the covered farm would need to get
and keep records of the district's testing that satisfy the rule's
recordkeeping requirements.
    (Comment 229) Several comments ask for guidance, technical
assistance, and outreach related to water testing requirements,
including sampling methods and procedures, so farms know how to
properly collect samples, process them for testing, and transport them
in a sanitary manner. Some comments state that the GM and STV
calculations and subsequent analysis necessary to test, verify, and
ensure compliant use of agricultural water, are complicated, and that
most farmers do not have the expertise necessary to implement these
provisions.
    (Response) In section XXII of this document, we discuss our plans
to work with various organizations on outreach and education for
effective implementation of the produce safety regulation. We agree
training and outreach will be necessary to ensure covered farms
understand the water testing requirements. Relevant staff will

need to be appropriately trained to properly sample, test, and make the
necessary calculations to determine how best to use their water. We
will consider addressing relevant issues, including appropriate water
sampling methods and procedures, in the Produce Safety Regulation
implementation guidance to be issued in the near term. In addition, we
are exploring the development of an online tool to allow covered farms
to derive their GM and STV values and appropriate time intervals
between last irrigation and harvest using the 0.5 log per day die-off
rate, based on input of sample data, such that farms would not need to
perform the necessary calculations themselves.
    (Comment 230) Several comments ask for clarification on whether and
how testing requirements apply in relation to water used during
different stages of growing or production, particularly in reference to
contact with the ``harvested or harvestable portion'' of the crop. For
example, one comment asks whether and how proposed Sec.  112.45(b)
applies to water used in frost protection sprays, prior to any
flowering or fruit production, in tree crops.
    (Response) The testing requirements in Sec.  112.46(b) require
samples to be collected as close in time as practicable to, but prior
to, harvest. These requirements are intended to provide a true
reflection of the agricultural water that is representative of your use
of the water and near the time of harvest, so the data can then be used
to determine the appropriate use of that water. In Sec.  112.3(c), we
define ``agricultural water'' to mean water used in covered activities
on covered produce, where water is intended to, or is likely to,
contact covered produce or food-contact surfaces, including water used
in growing activities (including irrigation water applied using direct
water application methods, water used for preparing crop sprays, and
water used for growing sprouts) and in harvesting, packing, and holding
activities (including water used for washing or cooling harvested
produce and water used for preventing dehydration of covered produce).
Moreover, we define the term ``covered produce'' in relevant part to
refer to the harvestable or harvested part of the crop. Under these
definitions, water used on a tree crop prior to any flowering or fruit
production does not constitute ``agricultural water'' because it is not
intended to, or likely to, contact covered produce (meaning the
harvestable or harvested part of the crop) or food-contact surfaces.
    (Comment 231) One comment expresses concern about the extent to
which imported produce would be subject to the agricultural water
quality requirements, and recommends that foreign producers be required
to have evidence of water testing and monitoring to ensure that they
are meeting the same requirements as domestic farms.
    (Response) Under the final FSVP rule (published elsewhere in this
issue of the Federal Register), FDA is establishing requirements for
importers to verify that imported food, including produce, is produced
in compliance with applicable FDA food safety regulations, including
this rule, or is produced in accordance with processes and procedures
that ensure the same level of public health protection as is required
under these regulations in the United States. For imported produce,
this will mean that importers must verify that imported produce was
grown, harvested, packed, and held in accordance with the same
agricultural water requirements, or equally protective measures, as
domestic produce. Importers must have documentation of this
verification which, in the case of produce that will not be
manufactured/processed, is likely to be accomplished through an on-site
audit.
    (Comment 232) Several comments support the use of greater minimum
testing frequencies for untreated surface water sources as compared to
untreated ground water sources used for the same purposes. Conversely,
several other comments state that there should be no difference between
minimum testing frequencies for surface water and ground water sources.
This latter set of commenters believe the testing parameters should
instead be consistent across the different water sources but should
still be science-based and reflect risks assessed for each operation.
    (Response) We disagree with comments arguing that water from
surface water and ground water sources should be tested at the same
frequency. The approach we are adopting for water testing in Sec.
112.46 is responsive to comments that requested that we establish a
risk-based, flexible testing approach that accounts for variability in
microbial water quality from different sources, considers the specific
use of water from a particular water source, and contemplates the
reduced likelihood of contamination from well-designed and adequately
maintained water systems. As described in the 2013 proposed rule,
surface watersheds are subject to a great number of external forces
that shape their overall composition, chemistry, and microbial water
quality (e.g., erosion, run-off, dust, suspended sediments). In
contrast, ground water sources typically contain microorganisms,
including pathogens, much less frequently, due to the natural filtering
mechanism of soil (Ref. 118). We recognize, however, that ground water,
which is often believed to be more protected from contamination, can be
contaminated. Ground water can be compromised and its microbial water
quality degraded if wells are improperly constructed, poorly
maintained, improperly located (e.g., near areas of extensive livestock
production or fields where manure is applied) or if the wells are
drawing water from a contaminated aquifer (Ref. 119) (Ref. 151) (Ref.
152) (Ref. 153) (Ref. 154). On the other hand, by their nature, surface
waters are open systems, subject to the influence of various
environmental factors that can impact the safety of the water. For
example, increased precipitation levels, storm events, or run-off may
result in a spike in microbial population of the water due to external
inputs. We conclude that, although there exists significant potential
for contamination of both ground and surface waters, surface water
sources are inherently subject to a greater potential for contamination
than properly designed, constructed, and well-maintained ground water
sources. Therefore, although we require you to test both ground water
and surface water sources used for certain purposes, where both types
of sources may be used for the same purpose under Sec.  112.44(b), we
require a lesser frequency of testing for ground water than for surface
water sources (see Sec.  112.46(b)). We acknowledge that ground water
sources can become contaminated, for example, if they are improperly
maintained. The testing frequencies established in Sec.  112.46 for
such sources, and the requirements in Sec.  112.42 to regularly inspect
and maintain such sources, are designed to address this possibility.
    It is important to note that some water that comes from underground
is subject to direct influence by surface water, and therefore is not
considered ``ground water'' for purposes of this rule. In the 2013
proposed rule, we proposed a definition of ``surface water'' as, ``all
water which is open to the atmosphere and subject to surface runoff,
including water obtained from an underground aquifer that is held or
conveyed in a manner that is open to the atmosphere, such as in canals,
ponds, other surface containment or open conveyances'' to distinguish
such water sources from other water sources that are less likely to
become contaminated, i.e., ``ground water'' sources (see 78 FR 3504 at
3548). We are now establishing a definition of

``ground water'' in Sec.  112.3(c), and revising the definition of
``surface water'' in that section, to clarify the differences between
the two sources for the purposes of this rule. The definition of
``ground water'' is ``the supply of fresh water found beneath the
Earth's surface, usually in aquifers, which supply wells and springs.
Ground water does not include any water that meets the definition of
surface water.'' We are amending the definition of ``surface water'' to
read, ``All water open to the atmosphere (rivers, lakes, reservoirs,
streams, impoundments, seas, estuaries, etc.) and all springs, wells,
or other collectors that are directly influenced by surface water.''
Through inclusion of the phrase, ``all springs, wells, or other
collectors that are directly influenced by surface water,'' the
definition of ``surface water'' includes, for example, water drawn from
an underground aquifer that has been recharged with surface water
(i.e., an aquifer into which humans have injected surface water to
replenish the aquifer). The definition of ``ground water'' also
specifies that ``[g]round water does not include any water that meets
the definition of surface water.'' Thus, where a ground water source is
directly influenced by surface water, it no longer meets the definition
of ``ground water'' and must be considered to be surface water for the
purposes of this rule. ``Directly influenced by surface water''
includes direct influences that are significant, such as a consistent
inflow of surface water. The term ``collectors'' in the definition of
``surface water'' means sources of accumulated water or vessels that
collect and hold accumulated water such that it may be subject to
external influence. See also discussion under Comment 184.
    The specific frequencies for testing that we have established in
Sec.  112.46 are intervals that are reflective of the varying potential
for changes in water quality between ground water sources and surface
water sources. Our analysis suggests that a minimum number of samples
required in ``average'' surface water sources would be 20 samples,
assuming a standard deviation of 0.4 (of log abundance of E. coli). If
you have a discrete surface water source that is minimally impacted by
external forces, such as run-off, such that there is less variation in
its microbial quality than an average surface water source, you may be
able to test the water at frequency lower than that required in Sec.
112.46(b)(1)(i)(A) or Sec.  112.46(b)(2)(i)(A). To account for such
circumstances, we are providing in Sec.  112.49(c) and (d) for the use
of an alternative testing frequency (in lieu of those required in Sec.
112.46(b)(1)(i)(A) or Sec.  112.45(b)(2)(i)(A)), under the conditions
specified in Sec.  112.12. On the other hand, because ground water
sources (as we have defined ``ground water'' in Sec.  112.3(c)) are
generally less variable, the required testing frequency for ground
water in the rule is lower than for surface water when both types of
sources may be used for the same purpose (see Sec.  112.46(b)), and no
alternative option for different testing frequencies is available for
ground water sources.
    (Comment 233) Several comments state the importance of making sure
that water tests are conducted properly by certified and accredited
labs. Some comments ask FDA to establish standards and procedures for
third-party laboratories that perform the tests.
    (Response) We are currently working on a proposed rule to implement
section 202 of FSMA (section 422 of the FD&C Act), which addresses
``Laboratory Accreditation for Analyses of Foods.'' Neither model
laboratory standards nor laboratory accreditation are within the scope
of the produce safety regulation in part 112.
    Water testing required under this rule must be conducted using
certain methods in accordance with Sec.  112.151, as required under
Sec.  112.47(b). In addition, we are specifying in 112.47(b) that
agricultural water samples must be aseptically collected. Aseptic
sampling, often used for product and environmental samples, is a
sampling technique used to assure that the microbial load of a sample
is not affected by the sampling method and/or the sample collector does
not contaminate the source from which the sample is collected. The use
of sterile sampling implements and containers and a prescribed sampling
method defines aseptic sampling (Ref. 155) (Ref. 156) (Ref. 157).
Collecting and delivering samples to the laboratory using an aseptic
technique also helps assure the microbiological findings accurately
reflect the agricultural water at the time of sampling.
3. Timing of Collection of Water Samples for Testing Required Under
Sec.  112.46(b) and (c)
    (Comment 234) Some comments request clarification on the meaning of
the phrases, ``as close to harvest as practical,'' ``during growing
activities,'' and ``as it is used'', which we used in proposed Sec.
112.45(b) and/or Sec.  112.45(c). Some comments point out the time
period for harvesting varies across regions and ranges from a few days
to several months or year round. Other comments support the provision
as proposed, and state that it allows the time frame to be determined
by the farmer based on the wide variation in growing seasons, overlap
of growing seasons for multiple crops, and likelihood of pathogen die-
off prior to harvest.
    (Response) For testing of untreated surface water or untreated
ground water used during growing activities using a direct water
application method, the initial and annual survey samples must be
representative of your use of the water and must be collected as close
in time as practicable to, but prior to, harvest (see Sec.
112.46(b)(1)(ii) and Sec.  112.46(b)(2)(ii)). We recognize the timing
of the use of agricultural water using a direct application method
varies by crop, region, season, and/or from year to year. By revising
the rule to use the term ``representative of your use of the water'' in
lieu of ``as it is used,'' we intend to clarify that agricultural water
should be collected for analysis around the time of harvest so that
samples will be representative of the water that is applied during the
end of the growing season. Samples collected from the source water when
it is not being applied to the crop would not fulfill this requirement.
We intend the wording ``collected as close in time as practicable to,
but prior to, harvest'' to permit farms to tailor their sampling of
water to the unique circumstances relevant to their crop(s) and
practices and conditions on their farm. The agricultural water applied
prior to harvest must be targeted for sampling, recognizing that in
some circumstances such applications may not be preplanned (e.g.,
application of crop protection water due to early frost or unusually
hot, dry weather). Further, sample collection should be designed to
represent events that can reasonably be expected to both impact water
quality (e.g., rainfall wildlife and domesticated animal movement
through upstream water systems) and occur during the end of the growing
season. We expect covered farms to determine the appropriate time for
sampling to meet the requirements that samples be collected during a
time period(s) as close as practicable to harvest, while recognizing
that samples of agricultural water taken more than a few weeks prior to
harvest are less representative of the agricultural water applied at
the end of growing when the risk of produce contamination is greater.
We anticipate seasonal trends in microbial water quality that can be
captured in the long-term microbial water quality profile. In addition,
we do not consider multiple samples collected in a single day to

provide adequate variation as the distribution estimates resulting from
such a sampling plan would defeat the purpose of the microbial water
quality profile. We also do not consider samples collected after the
final harvest of the crop (for a single crop farm) to be representative
of the agricultural water applied to that crop.
    In addition, we intend the wording ``representative of your use of
the water'' and the requirement that samples must be ``collected as
close in time as practicable to, but prior to, harvest'' to ensure
that, when testing water used for growing activities of produce (other
than sprouts) using a direct application method, the samples for
initial and annual surveys are collected prior to harvest and at a time
that can be reasonably expected to represent the quality of the water
when it is being applied to the crop. Collection before harvest is
necessary in order for the samples and the microbial water quality
profile to represent the water used for the purposes in Sec.
112.44(b). Collection close to harvest is necessary because there are
certain seasonal variations in water quality that may be relevant to
the microbial water quality profile, such as harvesting during a time
of heavy, seasonal rains or harvesting of commodities at the end of the
summer when water temperatures may be elevated compared to the
beginning of the summer. The microbial water quality profile is
intended to capture long-term trends related to quality of water as it
is used close to harvest, and sample collection must be done with the
understanding that recurring patterns of water quality variations are
often seen on an annual basis. See also a discussion of the definition
of ``direct water application method'' in section IX.B of this
document.
    On the other hand, for untreated ground water used for purposes of
Sec.  112.44(a), considering the nature of different uses spanning
across different covered activities specified in that provision, we
require that samples be taken at least four times either during the
growing season or over a period of one year, as applicable, using a
minimum total of four samples collected to be representative of the
intended use(s) (see Sec.  112.46(c)). See Comment 229.
4. Clarification of Terms Used in Sec.  112.46
    (Comment 235) Some comments oppose the use of the term ``water
quality profile,'' stating the concept is not clearly explained and/or
not necessary.
    (Response) As used in this rule, ``microbial water quality
profile'' generally refers to the set of data that provides information
about the microbial quality of water from a specific water source,
based on which a covered farm can determine whether the water meets the
microbial quality criteria in Sec.  112.44(b) and make a decision
regarding corrective measures, as necessary, under Sec.  112.45(b). The
microbial water quality profile consists of two numerical values of
generic E. coli in the water: The GM and the STV. The GM and STV values
are initially calculated using data obtained in an initial survey and
updated annually thereafter. The GM and STV values are initially
derived based on the initial survey data set (described in Sec.
112.46(b)(1)), which consists of a minimum total of 20 samples for
untreated surface water sources (taken over at least 2 and no more than
4 years) and 4 samples for untreated ground water sources (taken during
the growing season or over a period of one year). The GM and STV values
are then revised annually based on annual survey data (described in
Sec.  112.46(b)(2)). For untreated surface water sources this entails
taking at least 5 new samples, and for untreated ground water this
entails taking at least one new sample. The new samples are then
combined with your most recent data from within the previous 4 years,
to make up a rolling dataset of 20 samples for untreated surface water
and 4 samples for untreated ground water, and the GM and STV values are
recalculated using this updated data set to update the microbial water
quality profile.
    (Comment 236) Some comments request clarification on the meaning of
``statistical threshold value.''
    (Response) The ``statistical threshold value'' is a value that
approximates a specified percentile of a distribution, which depends
upon the inherent variability of the observations in a sample set as
well as their central tendency. For purposes of the testing
requirements in Sec.  112.46(b) and (d), STV is a value that is derived
as a model-based calculation based on the lognormal distribution and
approximates the 90th percentile of the water quality distribution. For
clarity, we are specifying in Sec.  112.44(b) that ``STV is a measure
of variability of your water quality distribution, derived as a model-
based calculation approximating the 90th percentile using the lognormal
distribution.'' See also our discussion in the supplemental notice at
79 FR 58434 at 58444 for additional information. We note that we are
exploring the development of an on-line tool that you can use to derive
STVs and certain other values (such as GM values and appropriate time
intervals (in days) between last irrigation and harvest using the 0.5
log per day die-off rate) based on input of sample data, such that a
farmer would not need to perform the necessary calculations themselves.
    (Comment 237) Several comments request clarification on the meaning
of the term ``water source,'' as it relates to the water testing
requirements in proposed Sec.  112.45(b), (c), and (d). One comment
recommends that FDA broadly define ``water source'' as ``any reasonable
portion of a watershed where a sanitation survey identifies no
reasonably foreseeable point or nonpoint source of microbial discharge
between agricultural water and withdrawal points.'' Another comment
provides an example of an open irrigation ditch and questions whether
water samples would be required for each irrigation district, at each
pump site or water box, for each block or branch of the irrigation
system, or for each sprinkler head. This commenter also asks whether a
farm using multiple sources of water for irrigation would need to
conduct a baseline survey of 20 samples over two years for each source.
Comments ask whether a single source can be used for multiple
commodities or to irrigate noncontiguous fields. Another comment notes
testing agricultural water stored in holding containers (such as
barrels) would be impractical and expensive.
    (Response) We consider each agricultural water source in your
operation to be a discrete body of water that is representative of the
microbial quality of agricultural water from that source used in your
growing, harvesting, packing, or holding activities. For example, if
you have a surface water impoundment on your farm that stores water to
be used as agricultural water, but you also source water from a river
that you use for the same purpose, you would need to consider these two
be two different water sources, as each delivers water that is
distinctly different in origin and likely to differ in overall
composition and characteristics. Or if, for example, you source some
water directly from a properly constructed well on your property, and
you also draw water from the same source and hold it in a holding pond
on your property that is open to environmental influences before you
use it, you would need consider the well and the holding pond to be two
separate water sources (the well would be a ground water source, and
the holding pond would be a surface water source). Where water testing
requirements apply, they apply

to each water source individually. There is no difference in testing
requirements based on whether the water is used for multiple
commodities, or applied over non-contiguous fields. We realize that the
testing requirements may be particularly challenging for farms that
have multiple agricultural water sources and we encourage farms to
provide us with details of their specific situations so that we can
consider flexible approaches to testing multiple sources.
    Section 112.42(a) requires you to inspect your water distribution
systems to the extent that they are under your control, including
considering different factors identified in (a)(1) through (a)(5).
Therefore, for example, provided you have inspected your water
distribution systems in compliance with Sec.  112.42 and you have
determined there is no additional exposure to potential contamination
along your distribution system from your ground water to the sprinkler
heads, collecting water samples from the ground water would
sufficiently represent your water source such that you would not need
to additionally collect water samples at the sprinkler head(s). This
rule is not prescriptive about the exact point of collection of water
samples when testing is required, but it requires that all water
samples must be representative of your use of the water (see Sec.
112.46(b) and (c)).
5. Minimum Number of Samples for Initial Survey (Sec.
112.46(b)(1)(i)(A)) and/or Annual Survey (Sec.  112.46(b)(2)(i)(A))
Related To Testing of Untreated Surface Water Used in a Direct Water
Application Method During Growing Activities
    (Comment 238) Some comments oppose the proposed minimum number of
samples required for the proposed baseline and annual surveys for
untreated surface water used in a direct water application method
during growing activities for covered produce other than sprouts. These
comments ask that we align the testing frequency requirements with the
guidelines in USDA GAPs, which according to these comments recommend
testing three water samples during the growing season.
    (Response) The testing frequency we proposed, and are now
finalizing in Sec.  112.46(b) for untreated surface water used for
Sec.  112.44(b) purposes, is based on the minimum number of samples
needed to do the relevant calculations to characterize the untreated
surface water source used as agricultural water for purposes of Sec.
112.44(b), given certain expectations about the variability of that
source. For untreated surface water sources, where measurements of
log10 abundance of generic E. coli are expected to exhibit
an average (population) standard deviation of 0.4, our evaluation
indicates that when water quality is stable, neither deteriorating nor
improving over time, a sample size of 20 for initial or for a moving
window of most recent observations from initial and/or annual surveys
would provide sufficient precision of estimation of the microbial water
quality profile (GM and STV of indicator bacteria) to determine
appropriate conditions of use. In the absence of detailed information
concerning how frequently changes occur in water quality of surface
water sources, and what patterns and magnitude of changes are most
likely, it is not possible to determine a best or optimal frequency by
which prior data should be replaced by more current survey data within
a moving window of observations collected over multiple years. However,
based on an assessment of the magnitude of bias in estimates of
log10 GM and log10 STV for hypothetical changes
in population log10 GM, a minimum sample size of 5 for
annual surveys, being 25 percent of the minimum of 20 samples found to
be sufficient to determine appropriate conditions of use, provides a
reasonable degree of compromise between the competing objectives of
having estimates of the microbial water quality profile sensitive to
sudden and substantive changes in water quality and minimizing the
number of samples collected annually when water quality is relatively
stable and unchanging (Ref. 99). Therefore, we are establishing the
minimum testing frequencies as 20 samples for the initial survey
required under Sec.  112.46(b)(1)(i) and 5 samples for the annual
survey required under Sec.  112.46(b)(2)(i). To provide flexibility and
account for sources of water that have less variability in their
quality than that assumed in our calculations, we are providing for the
use of an alternative testing frequency in lieu of the required minimum
number of samples, in Sec.  112.49(c) and (d), provided the conditions
in Sec.  112.12 are met. With respect to comments about USDA's GAP
guidelines, we plan to work with USDA as they update their GAPs audit
program to align with the requirements of the produce safety
regulation.
    (Comment 239) Several comments state that the proposed minimum
number of 20 samples for the proposed baseline survey, under proposed
Sec.  112.45(b)(1)(ii), is excessive, too stringent, and/or does not
take into consideration critical site-specific variables of surface
waters. Comments also point out that the 20-sample minimum requirement
is a statistical construct, and argue that it was not selected as an
indicator of food safety, arguing that the time and location of
sampling are far more important than the number of samples. Others
contend that 20 samples over two years would be burdensome or
impracticable for certain commodities or in certain regions. For
example, one comment states that the proposed frequency is not
practicable in the mid-Atlantic States, where the commenter notes
overhead irrigation is often used fewer than ten times per year,
depending on the crop. This commenter also points out strawberry farms
often only apply overhead irrigation as frost control one to three
times per season, and crops are often rotated and farms may change
water sources every three to four years. Similarly, another comment
argues that the proposed 20-sample minimum would be impracticable for
certain crops, such as cherries and berries, which have a harvest
period of approximately 20 days. Another comment recommends that
baseline characterization should be done once a month during the
growing season with a minimum of three times per season, but that the
required testing frequency should never be greater than the frequency
of irrigation. Still other comments that suggest aligning the frequency
for baseline characterization for untreated surface water with that for
untreated ground water, recommend requiring testing at least four times
during the growing season or over a period of 1 year, using a minimum
total of four samples. These comments argue that four tests for
untreated surface water, particularly when based on effective sample
collection (e.g., time of day, depth, and at high or low flow of
water), provide an appropriate range for farms to use in establishing
the profile of their water quality.
    (Response) As previously explained, a sample size of 20 for the
initial survey for untreated surface water used in a direct application
method is the minimum necessary to provide sufficient precision of
estimation of the microbial water quality profile to determine and
verify appropriate conditions of use of the water based on certain
expectations about the average variability of log10 E. coli
abundance (Ref. 99). Therefore, we are retaining the requirement for a
minimum sample size of 20 samples in Sec.  112.46(b)(1)(i)(A). However,
we acknowledge the concerns commenters raised about the
impracticability of collecting 20 samples

in 2 years, as the water is used during growing activities using a
direct water application method and collected as close in time as
practicable to, but prior to, harvest, particularly for certain
commodities or irrigation practices where the time period of direct
application of agricultural water is short or variable. The minimum 20
samples for the initial survey are required to be collected over a
minimum (not maximum) of 2 years such that, in the circumstances where
direct application periods are short, you may collect your samples over
more than 2 years. We believe a minimum period of 2 years is necessary
to provide an adequate representation of the microbial quality of
agricultural water to enable informed decisions about its use in a
direct application method. However, we are also adding a requirement
that the 20 samples for the initial survey must be collected within a
time period not greater than 4 years. This limitation on the use of
older data is intended to ensure that the data used adequately
represent the current microbial quality of your untreated water source.
Therefore, you may collect your water samples for the initial survey
over a period of four years to make up the minimum sample size of 20
samples to then establish your microbial water quality profile. We
expect that farms will use this option to collect initial survey
samples over more than 2 years and up to 4 years in circumstances with
short timeframes for direct application of agricultural water, for
example.
    (Comment 240) One comment recommends the necessary number of
samples for the proposed baseline survey should be based on a study of
available historical data on quality of that water source.
    (Response) As previously explained, we conclude a minimum sample
size of 20 samples is necessary for the initial survey, assuming a
standard deviation of 0.4 (of log abundance of E. coli). If you have
evidence the microbial quality of your untreated surface water source
is less variable than that assumed in our calculations, including based
on your historical data (provided such data are representative of the
current quality of your water and were gathered within the previous
four years), you may be able to use a testing frequency that is lower