City of Portland v. Environmental Protection Agency

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued September 25, 2007 Decided November 6, 2007

No. 06-1068

CITY OF PORTLAND, OREGON,
PETITIONER

v.

ENVIRONMENTAL PROTECTION AGENCY,
RESPONDENT

CITY OF NEW YORK, NEW YORK,
INTERVENOR FOR PETITIONER

On Petition for Review of an Order of the
Environmental Protection Agency

John M. Stevens, argued the cause for petitioner. With him
on the briefs was Jonathan M. Ettinger.

Martin F. McDermott, Attorney, U.S. Department of
Justice, argued the cause for respondent. With him on the brief
was Caroline H. Wehling, Assistant General Counsel.

Susan E. Amron, Assistant Corporation Counsel, was on the
brief for intervenor City of New York in support of petitioner.
Christopher G. King, Counsel, entered an appearance.
 2

Diane Curran was on the brief for amici curiae Oregon
Wild, et al. in support of petitioner.

Timothy Donaldson and Charles B. Roe, Jr. were on the
brief for amicus curiae City of Walla Walla, Washington.

Before: GINSBURG, Chief Judge, and SENTELLE and TATEL,
Circuit Judges.

Opinion for the Court filed by Circuit Judge TATEL.

TATEL, Circuit Judge: In this case Portland and New York
City challenge an Environmental Protection Agency rule
regulating microbial contaminants in drinking water. The rule
requires the two cities to take several steps to eliminate the
parasite Cryptosporidium from their drinking water. The cities
challenge the rule on many grounds, arguing that EPA
improperly conducted a required cost-benefit analysis, provided
inadequate notice and opportunity for public comment, ignored
significant comments on the draft rule, failed to use the best
available science, and issued a final rule unsupported by the
record. Because we find the cities’ arguments either meritless,
irrelevant, or both, we deny the petition for review.

I.
Cryptosporidium is a parasite found in human and animal
feces. When ingested, it can cause cryptosporidiosis, which
generally leads to mild flu-like symptoms, but can be deadly in
children, the elderly, and those with weak immune systems (e.g.,
AIDS patients). From 1984 to 2000, the United States
experienced ten reported cryptosporidiosis outbreaks linked to
drinking water. By far the most serious outbreak occurred in
Milwaukee, Wisconsin, in 1993, killing more than fifty people
and sickening hundreds of thousands of others. See National
Primary Drinking Water Regulations: Long Term 2 Enhanced
 3

Surface Water Treatment Rule; Final Rule, 71 Fed. Reg. 654,
659-61 (Jan. 5, 2006) (to be codified at 40 C.F.R. pts. 9, 141,
142).

Most cities try to protect against Cryptosporidium by
running their “source water”—the river or lake from which they
draw water—through high-tech filters. New York and Portland,
however, are two of the rare large cities that do not filter their
water before it reaches consumers. Instead, the two cities seek
to protect public health by carefully controlling the sources from
which their water originates. In particular, they have taken steps
to ensure that their watersheds are entirely off-limits to human
activity and domestic animals. Thus, wild animals represent the
only likely cause of Cryptosporidium in their source waters.

Portland and New York are also unusual in that they use
uncovered reservoirs, rather than covered reservoirs, to store
their “finished water”—water that goes directly to consumers
without further treatment. The cities say they have gone to great
lengths to protect their reservoirs from sources of
Cryptosporidium. Though located in urban areas, the reservoirs
were carefully constructed to prevent runoff from draining into
them, fences and security exclude people and animals from
them, and overhead wires (in New York but not Portland)
discourage flocks of birds from landing on them. According to
EPA, however, Cryptosporidium can still enter these reservoirs
via bird droppings, small animals able to penetrate the fences,
and intentional human contamination.

The Safe Drinking Water Act (SDWA), 42 U.S.C. §§ 300f
to 300j-26, requires EPA to protect the public from
Cryptosporidium and other drinking water contaminants.
Because the SDWA was the basis for the rule challenged in this
case, we describe the Act’s basic provisions before turning to
the details of the rule at issue here.
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The SDWA regulates public water systems by limiting the
allowable level of contaminants in such systems. It requires
EPA to set a “maximum contaminant level goal” (MCLG) for
each identified contaminant at a level at which no known
adverse health consequences will occur. Id. § 300g-1(b)(4)(A).
It then requires EPA to set a “maximum contaminant level”
(MCL) for each contaminant as close to the MCLG as is
feasible. Id. § 300g-1(b)(4)(B). Under the statute, “feasible”
means “feasible with the use of the best technology, treatment
techniques and other means which the Administrator finds . . .
are available (taking cost into consideration).” Id. § 300g-
1(b)(4)(D). If EPA determines that ascertaining the level of a
contaminant will be either economically or technologically
infeasible—for example, because no adequate testing procedure
exists—the Agency can require a certain “treatment technique”
instead of an MCL. Id. § 300g-1(b)(7)(A). Treatment
techniques must “prevent known or anticipated adverse effects
on the health of persons to the extent feasible.” Id.

Based on these requirements, EPA convened a large group
of stakeholders in 1992 to develop rules to combat microbial
contamination in drinking water, including Cryptosporidium.
The group issued its recommendations in two stages. Acting on
the first set of recommendations, EPA issued a 1998 rule that
did four things relevant to the issue we face here: (1) it
established an MCLG of zero for Cryptosporidium, meaning
there is no safe level of Cryptosporidium in drinking water; (2)
it imposed treatment techniques, rather than an MCL, to control
Cryptosporidium, because EPA had earlier concluded that it
would be infeasible to measure Cryptosporidium at the low
levels at which the parasite can threaten human health; (3) it
required that all finished water reservoirs built after the rule’s
issuance have covers; and (4) it required systems that filter their
water to treat it for Cryptosporidium. See National Primary
Drinking Water Regulations: Interim Enhanced Surface Water
 5

Treatment, 63 Fed. Reg. 69,478, 69,483-84 (Dec. 16, 1998)
(codified at 40 C.F.R. pts. 9, 141, 142). The rule also warned
that EPA was considering requiring that all existing finished
water reservoirs be covered, but explained that the Agency
needed more time to analyze the issue. Id. at 69,494.

Acting on the basis of the stakeholders’ second set of
recommendations, EPA issued a 2003 proposed rule that did
three things: (1) it required all water systems to monitor their
source water for Cryptosporidium; (2) it required systems that
do not filter their water, such as New York and Portland, to treat
their source water for Cryptosporidium; and (3) it imposed new
requirements on existing uncovered reservoirs, giving cities with
such reservoirs three options: covering their reservoirs, treating
the water in them for viruses (but not Cryptosporidium), or
implementing a state-approved risk mitigation plan. See
National Primary Drinking Water Regulations: Long Term 2
Enhanced Surface Water Treatment Rule; Proposed Rule, 68
Fed. Reg. 47,640, 47,644-45 (proposed Aug. 11, 2003) (to be
codified at 40 C.F.R. pts. 141, 142). Unlike most cities,
Portland and New York were affected by all three aspects of this
rule because they had uncovered reservoirs and provided
unfiltered water.

The final rule, which EPA issued in 2006, was identical to
the proposed rule except for two key differences. First, the final
rule eliminated the risk mitigation option, forcing cities with
uncovered reservoirs to cover them or treat the water in them.
Second, rather than requiring treatment of finished water only
for viruses, the final rule required treatment for Cryptosporidium
as well. 71 Fed. Reg. at 657. Thus, under the final rule, New
York and Portland have two choices: they may either treat their
source water for Cryptosporidium and cover their reservoirs, or
they may leave the reservoirs uncovered and treat the water for
Cryptosporidium as it leaves the reservoirs. The basic idea is
 6

that at some point the two cities must treat their water for
Cryptosporidium and, following treatment, protect it from
potential sources of Cryptosporidium.

After EPA issued its final rule, Portland filed a petition for
review pursuant to 42 U.S.C. § 300j-7(a), which gives this court
jurisdiction over challenges to final EPA rules promulgated
under the SDWA. We granted New York’s motion to intervene.
The cities challenge two of the final rule’s requirements: that
they either cover their reservoirs or treat the water leaving them
for Cryptosporidium (the “cover or treat” requirement), and that
they treat their source water for Cryptosporidium (the “source
water treatment” requirement). The cities allege that EPA
improperly conducted a cost-benefit analysis required by the
SDWA, provided insufficient opportunity for notice and
comment, and failed to use the best available science. They also
argue that the rule is arbitrary and capricious because EPA failed
to respond adequately to significant public comments and
because the rule lacks support in the record and relies on a
mistaken estimate of Cryptosporidium’s infectivity (the amount
of Cryptosporidium necessary to infect a person).

Before considering these arguments, we observe that
amicus Walla Walla raises an entirely different issue, arguing
that EPA improperly chose to use treatment techniques, rather
than an MCL, to regulate Cryptosporidium. Because neither
Walla Walla nor any other party raised this argument before the
Agency during the rulemaking process, however, it is waived,
and we will not consider it. See, e.g., Military Toxics Project v.
EPA, 146 F.3d 948, 956 (D.C. Cir. 1998).

II.
Portland and New York first attack the rule by claiming
EPA bungled the cost-benefit analysis required by the SDWA.
Section 300g-1(b)(3)(C) requires EPA to conduct a cost-benefit
 7

analysis when proposing a treatment technique or MCL. With
respect to treatment techniques, the statute says:

When proposing a national primary drinking
water regulation that includes a treatment
technique . . . , the Administrator shall publish
and seek public comment on an analysis of the
health risk reduction benefits and costs likely to
be experienced as the result of compliance with
the treatment technique and alternative treatment
techniques that are being considered . . . .

Id. § 300g-1(b)(3)(C)(ii). If, based on this cost-benefit analysis,
EPA concludes that the costs of an MCL outweigh its benefits,
the Agency may set a less stringent MCL. Id. § 300g-
1(b)(6)(A).

Central to the issue before us, however, is whether the
SDWA bars EPA from using cost-benefit analysis to establish
a treatment technique for Cryptosporidium less stringent than
the most stringent feasible. Section 300g-1(b)(6)(C), enacted in
the wake of the Milwaukee outbreak, provides: “The
Administrator may not use the authority of this paragraph . . . to
establish a maximum contaminant level or treatment technique
requirement for the control of Cryptosporidium.” “[T]he
authority of this paragraph” refers to section 300g-1(b)(6)(A),
which says: “if [EPA] determines . . . that the benefits of [an
MCL] . . . would not justify the costs of complying with the
[MCL], [EPA] may . . . promulgate [an MCL] for the
contaminant that maximizes health risk reduction benefits at a
cost that is justified by the benefits.” Put another way,
paragraphs 6(A) and 6(C) together provide that if EPA
determines that an MCL is not cost effective, the Agency may
select a cost-effective MCL—unless the MCL relates to
Cryptosporidium. Paragraph 6 contains an undeniable oddity:
 8

6(C) says clearly that the power of 6(A) cannot be used to
establish a treatment technique for Cryptosporidium, but 6(A)
addresses only the establishment of MCLs, not treatment
techniques. We conclude that the power granted by 6(A) must
be understood to apply to establishing treatment techniques, lest
the phrase “or treatment technique requirement” in 6(C) be
surplusage. See TRW Inc. v. Andrews, 534 U.S. 19, 31 (2001)
(“It is ‘a cardinal principle of statutory construction’ that ‘a
statute ought, upon the whole, to be so construed that, if it can
be prevented, no clause, sentence, or word shall be superfluous,
void, or insignificant.’” (quoting Duncan v. Walker, 533 U.S.
167, 174 (2001))). In summary, then, the statute prohibits EPA
from using cost-benefit analysis to choose a Cryptosporidium
treatment technique less stringent than the most stringent
feasible.

In their opening briefs, the cities dispute none of this. In
fact, they never even mention section 300g-1(b)(6)(C)’s ban on
using cost-benefit analysis to choose a Cryptosporidium
treatment technique. Instead, they argue that section 300g-
1(b)(3)(C)(ii)—“When proposing . . . a treatment technique . . . ,
the Administrator shall publish . . . an analysis of the . . .
benefits and costs likely to be experienced as the result of
compliance with the treatment technique”—means EPA has to
analyze separately the costs and benefits of each treatment
technique it imposes. They then argue that EPA violated this
requirement by performing only one aggregated cost-benefit
analysis for the rule’s two treatment techniques—the cover or
treat and source water treatment requirements.

As EPA points out in its brief, however, the cities’
argument ignores key sections of the statute. In particular,
section 300g-1(b)(7)(A) requires EPA to choose treatment
techniques that “prevent known or anticipated adverse effects on
the health of persons to the extent feasible,” and section 300g-
 9

1(b)(6)(C) prohibits it from choosing less stringent treatment
techniques for Cryptosporidium based on cost-benefit analysis.
Thus, even if, as the cities insist, the statute requires EPA to
perform separate cost-benefit analyses for each treatment
technique and EPA failed to do so, the Agency’s error was
harmless. See 5 U.S.C. § 706 (“[D]ue account shall be taken of
the rule of prejudicial error.”); PDK Labs. Inc. v. DEA, 362 F.3d
786, 799 (D.C. Cir. 2004) (“If the agency’s mistake did not
affect the outcome, if it did not prejudice the petitioner, it would
be senseless to vacate and remand for reconsideration.”). Cost-
benefit analysis could have affected this rulemaking only if it
showed that the treatment techniques EPA proposed were
infeasible—something neither city claims. Indeed, EPA’s cost-
benefit analysis shows that the rule will cost the vast majority of
households less than $12 per year. 71 Fed. Reg. at 743.

In their reply briefs, the cities finally acknowledge section
300g-1(b)(6)(C)’s ban on using cost-benefit analysis to choose
a less stringent Cryptosporidium treatment technique, but insist
that EPA must still conduct the cost-benefit analysis properly for
three reasons, none of which has merit. First, the cities argue
that EPA can use the cost-benefit analysis for purposes of
section 300g-1(b)(4), which requires the Agency to determine
whether an MCL’s benefits justify its costs, or section 300g-
1(b)(5), which allows EPA to set a less stringent MCL if the
most stringent feasible MCL would interfere with other
treatment techniques. Nothing in section 300g-1(b)(4),
however, allows EPA to choose a treatment technique other than
the most stringent feasible, and although section 300g-1(b)(5)
allows the Agency to set a less stringent MCL in the rare
instance when a strict MCL would actually interfere with other
treatment techniques, the cities never said this was the case here.
Second, the cities claim that the cost-benefit analysis must be
done properly in order to inform the public and allow EPA to
make a reasoned decision. This argument fails because the
 10

statute requires EPA to choose the most stringent feasible
treatment technique for Cryptosporidium regardless of its own
or the public’s views about whether the benefits justify the costs;
Congress already made this determination in section 300g-
1(b)(6)(C). Third, the cities insist that the analysis must be done
properly because a treatment technique is only “feasible” if its
benefits outweigh its costs. But if “feasible” meant that the
technique’s benefits justified its costs, section 300g-
1(b)(6)(A)—which allows EPA to use cost-benefit analysis to
set less stringent standards than the most stringent
feasible—would be surplusage. See TRW, 534 U.S. at 31.
Moreover, when Congress wanted EPA to undertake cost-
benefit analysis, it said so expressly. See, e.g., 42 U.S.C.
§ 300g-1(b)(4)(C) (directing EPA to “publish a determination as
to whether the benefits of the [MCL] justify . . . the costs”).
Thus, “feasible” must mean what EPA says it does: technically
possible and affordable. Cf. Am. Textile Mfr.’s Inst., Inc. v.
Donovan, 452 U.S. 490, 509-12 (1981) (“[C]ost-benefit analysis
. . . is not required by the [Occupational Safety and Health Act]
because feasibility analysis is. . . . When Congress has intended
that an agency engage in cost-benefit analysis, it has clearly
indicated such intent on the face of the statute. . . . Certainly in
light of its ordinary meaning, the word ‘feasible’ cannot be
construed to articulate such congressional intent.” (footnotes and
citations omitted)).

Next, the cities argue that EPA’s interpretation of the statute
leads to an absurd result, namely that the Agency is required to
conduct cost-benefit analysis when issuing Cryptosporidium
regulations but prohibited from using that analysis to choose a
less stringent treatment technique. We see nothing absurd about
this result. Although Congress forbade EPA from using cost-
benefit analysis to choose a less stringent technique, the analysis
could still serve some purpose. For example, if the analysis
showed that a proposed treatment technique was infeasible or
 11

would have no effect on Cryptosporidium levels, it would
influence what technique EPA imposed. Moreover, Congress’s
unwillingness to allow a broader role for cost-benefit analysis in
setting Cryptosporidium standards is hardly surprising, given
that it added section 300g-1(b)(6)(C)’s prohibition on using
cost-benefit analysis to the SDWA largely in response to the
deadly Milwaukee outbreak.

In rejecting the cities’ challenge to EPA’s cost-benefit
analysis, we emphasize that nothing we say in this opinion
implies either that agencies may ignore statutorily required
procedures or that we will tolerate rules based on arbitrary and
capricious cost-benefit analyses. In the narrow context of this
case, however, where the SDWA largely prohibits EPA from
using the very cost-benefit analysis the same statute requires it
to prepare, remanding this rule to the Agency based on flaws in
its cost-benefit analysis would be pointless. Even were EPA to
redress its alleged errors, the final rule would remain unchanged,
making this the epitome of harmless error.

III.
The cities next argue that the rule is arbitrary and capricious
because it lacks support in the record, because it rests on a
mistaken estimate of Cryptosporidium’s infectivity, and because
EPA failed to respond adequately to significant public
comments. Highly deferential, “[t]he arbitrary and capricious
standard . . . ‘presumes the validity of agency action.’” Nat’l
Ass’n of Clean Air Agencies v. EPA, 489 F.3d 1221, 1228 (D.C.
Cir. 2007) (quoting AT&T Corp. v. FCC, 349 F.3d 692, 698
(D.C. Cir. 2003)). “We must uphold an agency’s action where
it ‘has considered the relevant factors and articulated a rational
connection between the facts found and the choice made.’” Id.
(quoting Allied Local & Reg’l Mfrs. Caucus v. EPA, 215 F.3d
61, 68 (D.C. Cir. 2000)). “The requirement that agency action
not be arbitrary or capricious includes a requirement that the
 12

agency . . . respond to ‘relevant’ and ‘significant’ public
comments.” Public Citizen, Inc. v. FAA, 988 F.2d 186, 197
(D.C. Cir. 1993) (citations omitted). Measured by these
standards, the challenged rule easily survives.

To begin with, the source water treatment requirement finds
ample support in the record. EPA provided abundant evidence
that Cryptosporidium is present in the source water of most
water systems. 71 Fed. Reg. at 662-63. Indeed, in its own
submissions to EPA, Portland acknowledged that tests had
discovered Cryptosporidium in its source water. White Paper
from Portland to EPA 5-6 (June 2005). The record also contains
evidence that the newly required treatment techniques for such
source water will reduce Cryptosporidium levels substantially.
71 Fed. Reg. at 662-63. Given this, the SDWA required EPA to
impose these treatment techniques unless they were
infeasible—something neither city claims.

Challenging the cover or treat provision, Portland argues
that “[t]he Rule’s requirement that finished water stored in open
reservoirs be treated for Cryptosporidium . . . bears no rational
relationship to the evidence in the record.” Pet’r’s Opening Br.
18. According to Portland, the only study in the record
demonstrating the presence of Cryptosporidium in uncovered
reservoirs, by Professor Mark LeChevallier, looked at reservoirs
that were less protected than Portland’s. New York attacks the
same study, claiming it showed no Cryptosporidium threat from
uncovered reservoirs.

In truth, however, EPA relied on multiple relevant studies
in promulgating the rule. It cited studies showing that birds
often visit uncovered reservoirs and that bird feces can be a
source of Cryptosporidium. 71 Fed. Reg. at 713. EPA also
documented human contamination of reservoirs in urban areas
via illegal swimming or throwing things into reservoirs. Id.
 13

Moreover, the LeChevallier study the cities attack is more
relevant than they claim. It examined six reservoirs, some of
which were quite similar to New York’s and Portland’s. For
example, the Stanley Levine reservoir was fenced, protected
from runoff, and could be contaminated only by birds and small
animals—just like New York’s and Portland’s reservoirs. See
Mark W. LeChevallier et al., Protozoa in Open Reservoirs, J.
AM. WATER WORKS ASSOC., Sept. 1997, at 84, 88. Yet water
leaving the reservoir contained more Cryptosporidium than it
had when it entered, id. at 91, “most likely caused by wastes
from indigenous animals or birds,” id. at 94.

To be sure, the LeChevallier study never said whether the
Cryptosporidium found was viable, and concluded that the
public health risk from the level of Cryptosporidium present was
likely low. See id. at 92-93. In its 1998 rulemaking, however,
EPA determined that there was no safe level of Cryptosporidium
in drinking water, a determination unchallenged by the cities.
Thus, section 300g-1(b)(7)(A) required EPA to choose treatment
techniques that would reduce Cryptosporidium levels as close to
zero as feasible. Though New York and Portland may be right
that the amount of Cryptosporidium entering their reservoirs
poses a minimal threat, neither city denies that covering or
treating the reservoirs will reduce the amount of
Cryptosporidium in them. Thus, record evidence amply
supports the rule.

Next, the cities argue that the rule relies on a mistaken
estimate of Cryptosporidium’s infectivity. But EPA provided a
detailed explanation of its infectivity estimate and based the
estimate on advice from its expert Science Advisory Board. 71
Fed. Reg. at 662. Given this, EPA’s estimate easily satisfies our
highly deferential standard of review. Nat’l Wildlife Fed’n v.
EPA, 286 F.3d 554, 565 (D.C. Cir. 2002) (“We may reject an
 14

agency’s choice of a scientific model ‘only when the model
bears no rational relationship to the characteristics of the data to
which it is applied.’” (quoting Appalachian Power Co. v. EPA,
135 F.3d 791, 802 (D.C. Cir. 1998))).

In any event, the cities’ criticism of the infectivity estimate
is beside the point. As explained above, the SDWA requires
EPA to impose the most stringent feasible treatment technique
for Cryptosporidium regardless of cost-benefit analysis. Thus,
even if EPA’s infectivity estimate was mistaken, the error was
harmless. Although the alleged mistake could have caused the
Agency to overstate the rule’s benefits, it could not have
affected the final rule because it had no impact on the feasibility
of the prescribed treatment techniques.

Finally, the cities argue that EPA ignored a comment that
questioned the Agency’s rejection of an infectivity estimate
developed by one of its scientists in a 2001 study. They also
argue that in estimating the occurrence of cryptosporidiosis,
EPA ignored their public health data. We disagree on both
counts. In the final rule, EPA explained that more recent studies
led it to believe that Cryptosporidium was more infective than
the Agency previously thought. 71 Fed. Reg. at 662. EPA also
explained that based on evidence from the Milwaukee outbreak
and various studies, it believed that underreporting of
cryptosporidiosis was severe. Id. at 660-61. Though New York
and Portland cogently attack the merits of EPA’s responses, the
Agency clearly thought about the cities’ objections and provided
reasoned replies—all the APA requires. See Public Citizen, 988
F.2d at 197 (“[T]he agency’s response to public comments need
only ‘enable us to see what major issues of policy were
ventilated . . . and why the agency reacted to them as it did.’”
(quoting Auto. Parts & Accessories Ass’n v. Boyd, 407 F.2d 330,
338 (D.C. Cir. 1968))).
 15

Moreover, whether EPA adequately responded to these
comments makes no difference because the Agency had no
obligation to respond to them in the first place. “‘EPA is
required to give reasoned responses to all significant comments
in a rulemaking proceeding.’” Int’l Fabricare Inst. v. EPA, 972
F.2d 384, 389 (D.C. Cir. 1992) (quoting PPG Indus., Inc. v.
Costle, 630 F.2d 462, 466 (6th Cir. 1980)) (emphasis added).
Significant comments are those “which, if true, raise points
relevant to the agency’s decision and which, if adopted, would
require a change in an agency’s proposed rule.” Home Box
Office, Inc. v. FCC, 567 F.2d 9, 35 n.58 (D.C. Cir. 1977)
(emphasis added). Measured by this standard, the comments
Portland and New York point to are insignificant. Because the
SDWA requires EPA to impose the most stringent feasible
treatment technique for Cryptosporidium, and because neither
comment showed the techniques imposed here to be infeasible,
the comments were incapable of affecting the final rule, and
EPA could disregard them.

IV.
Portland and New York next argue that EPA provided
inadequate opportunity for notice and comment. They say they
were unaware that they needed to comment on the safety of
uncovered reservoirs because the proposed rule, which included
the risk mitigation option and did not require treating finished
water for Cryptosporidium, represented a consensus of the
stakeholders’ committee. They also argue that EPA’s request
for comments on this issue was too vague. Again, we disagree.

“[A]n agency may issue rules that do not exactly coincide
with the proposed rule so long as the final rule is the ‘logical
outgrowth’ of the proposed rule.” Fertilizer Inst. v. EPA, 935
F.2d 1303, 1311 (D.C. Cir. 1991). “Under the ‘logical
outgrowth’ test . . . , the key question is whether commenters
‘should have anticipated’ that EPA might” issue the final rule it
 16

did. City of Waukesha v. EPA, 320 F.3d 228, 245 (D.C. Cir.
2003) (quoting Small Refiner Lead Phase-Down Task Force v.
EPA, 705 F.2d 506, 549 (D.C. Cir. 1983)). In the proposed rule,
EPA made clear that it “continue[d] to be concerned about
contamination occurring in uncovered finished water storage
facilities.” 68 Fed. Reg. at 47,719. And EPA’s first two
questions in the “Request for Comments” section of that portion
of the proposed rule asked: “Is it appropriate to allow systems
with uncovered finished water storage facilities to implement a
risk management plan or treat the effluent to inactivate viruses
instead of covering the facility?” and “If systems treat the
effluent of an uncovered finished water storage facility instead
of covering it, should systems be required to inactivate
Cryptosporidium . . . [since it has] been found to increase in
uncovered storage facilities?” Id. From this, the cities should
have known not only that EPA still had concerns about
uncovered reservoirs, but also that the final rule might require
covering open reservoirs or treating them for Cryptosporidium.

The cities claim that because the proposed rule flowed from
a negotiated rulemaking and exactly mirrored the stakeholders’
suggestions, EPA should have given clearer notice that the rule
might be revised. This argument, however, ignores that the
Agreement in Principle EPA executed with the stakeholders in
this rulemaking expressly reserved the Agency’s right to modify
the final rule in response to comments. See Stage 2 Microbial
and Disinfection Byproducts Federal Advisory Committee
Agreement in Principle, 65 Fed. Reg. 83,015, 83,017 (Dec. 29,
2000). Moreover, neither the Negotiated Rulemaking Act, 5
U.S.C. §§ 561-570a, nor any other statute we know of requires
an agency to provide more detailed notice of possible changes
in its draft rules just because they evolve from negotiated
rulemaking. Indeed, adopting the cities’ suggestion would make
it easier for disappointed parties to overturn negotiated rules
than non-negotiated rules, thus discouraging agencies from
 17

engaging in negotiated rulemaking—exactly the opposite of
what Congress intended. See id. § 569 (encouraging negotiated
rulemaking).

V.
This brings us to the cities’ final attack on the rule—that
EPA failed to use the best available science. The SDWA
provides: “to the degree that an agency action is based on
science, the Administrator shall use—(i) the best available, peer-
reviewed science . . . ; and (ii) data collected by accepted
methods or best available methods.” 42 U.S.C. § 300g-
1(b)(3)(A). Portland and New York claim that EPA violated
this provision by using outdated science in several parts of its
cost-benefit analysis.

The cities first claim that EPA should have reduced
estimated tap water consumption in sensitive subpopulations
(e.g., AIDS patients) because such populations tend to drink
more bottled water than normal. EPA, however, rationally
declined to do so because it lacked data to support this claim or
estimate its impact. See Public Comment and Response
Document for the Long Term 2 Enhanced Surface Water
Treatment Rule § 20.2.2 (Dec. 2005).

The cities next argue that EPA used old data to estimate the
amount of Cryptosporidium in unfiltered drinking water. Again,
however, EPA explained that none of the newer available data
relates to unfiltered sources, the ones covered by the source
water treatment requirement. See 71 Fed. Reg. at 662. Thus,
EPA’s use of the older data was perfectly rational.

Finally, the cities argue that EPA ignored its own scientist’s
Cryptosporidium infectivity estimate and instead adopted one
that was exceptionally high. But EPA explained that its higher
estimate rested on studies done after its expert’s study, and was
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developed using advice from its Science Advisory Board, 71
Fed. Reg. at 662, which we have treated as an acceptable form
of peer review, see City of Waukesha, 320 F.3d at 250. Thus,
although EPA’s new estimate was much higher than its previous
one, the Agency provided a plausible explanation for choosing
it, and it represented the best available, peer-reviewed science at
the time.

Moreover, even if EPA did rely on inadequate science, its
mistake—like many of the mistakes alleged by Portland and
New York—was harmless. Although the mistakes the cities
allege, if true, might mean that EPA’s cost-benefit analysis
overstated the rule’s benefits, they could not have affected the
final rule because the SDWA required EPA to choose the most
stringent feasible treatment technique for Cryptosporidium
regardless of cost-benefit analysis. Had EPA used outdated or
unreliable science to determine that the rule was feasible, the
cities might have a valid complaint, but none of the science the
cities challenge relates to the feasibility of the required treatment
techniques.

VI.
In conclusion, Portland’s and New York’s attacks on this
rulemaking are all either inaccurate, irrelevant, or both. EPA
used the best available science and provided ample evidence to
support the rule, clear notice to the public about what it was
considering, and adequate responses to comments. Even if
EPA’s cost-benefit analysis, use of science, and responses to
comments were as flawed as the cities insist, these errors had no
effect on the final rule and were thus harmless. We therefore
deny the petition for review.

So ordered.