# California Manufacturers etc. v. Off. of Environmental Health etc.

> California Court of Appeal · March 23, 2023

URL: https://www.frixlaw.com/law-library/cases/9381769

## Case

- **Court:** California Court of Appeal
- **Decided:** March 23, 2023
- **Precedential status:** Published
- **Opinion:** Opinion
- **Cited by:** 0 later opinions in the Frix Law Library

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## Opinion text

Filed 3/23/23
CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA
THIRD APPELLATE DISTRICT
(Sacramento)
----

CALIFORNIA MANUFACTURERS & C093351
TECHNOLOGY ASSOCIATION,
(Super. Ct. No. 34-2015-
Plaintiff and Appellant, 80002120-CU-WM-GDS)

v.

OFFICE OF ENVIRONMENTAL HEALTH
HAZARD ASSESSMENT et al.,

Defendants and Respondents.

APPEAL from a judgment of the Superior Court of Sacramento County, Laurie M.
Earl, Judge. Affirmed.

Downey Brand, Jay-Allen Eisen, Annie S. Amaral, and Alexandra K. LaFountain
for Plaintiff and Appellant.

Beveridge & Diamond and Kaitlyn D. Shannon for American Chemistry Council
as Amicus Curiae on behalf of Plaintiff and Appellant

Rob Bonta, Attorney General, Edward H. Ochoa, Senior Assistant Attorney
General, Laura J. Zuckerman, and Elizabeth Song, Deputy Attorneys General, for
Defendants and Respondents.

1
“Every resident of California has the right to pure and safe drinking water.”
(Health & Saf. Code, § 116270, subd. (a).)1 To protect the quality of drinking water in
California, under the California Safe Drinking Water Act (§ 116270 et seq.), defendant
Office of Environmental Health Hazard Assessment (OEHHA) is charged with
conducting a risk assessment for contaminants in drinking water. This process includes
setting a “public health goal” (PHG) for such contaminants, an aspirational “estimate of
the level of the contaminant in drinking water that is not anticipated to cause or
contribute to adverse health effects, or that does not pose any significant risk to health.”
(§ 116365, subd. (c)(1).) After OEHHA sets its PHG, the State Water Resources Control
Board sets a maximum contamination level for that contaminant to be included in the
primary drinking water standard.
At issue here is the 2015 PHG OEHHA set for the contaminant perchlorate, a
chemical found in rocket fuel. After OEHHA set the PHG for perchlorate at 1 part per
billion (ppb), plaintiff California Manufacturers & Technology Association (CMTA)
filed a petition for a writ of mandate ordering OEHHA to withdraw the PHG. The trial
court denied the petition.
On appeal, CMTA raises two primary contentions. It asserts (1) OEHHA violated
the statutory mandate in arriving at the PHG. Specifically, for an “acutely toxic
substance” such as perchlorate, the statute requires the PHG “shall be set at the level at
which no known or anticipated adverse effects on health occur, with an adequate margin
of safety.” (§ 116365, subd. (c)(1)(A).) CMTA asserts OEHHA violated this
requirement by setting the PHG at a level where a nonadverse effect on health occurs.
CMTA also asserts (2) the PHG is void based on the common law conflict of interest
doctrine because its author, Dr. Craig Steinmaus, had a conflict of interest. Steinmaus

1 Undesignated statutory references are to the Health and Safety Code.

2
had previously published three studies on perchlorate, and, according to CMTA, in
determining the PHG, he would at the least be tempted to arrive at a result that would
protect and burnish his professional reputation.
We conclude OEHHA complied with the statutory requirements under section
116365, subdivision (c)(1)(A). We further conclude the common law conflict of interest
doctrine does not apply here. We affirm.
BACKGROUND
The California Safe Drinking Water Act
The Legislature enacted the California Safe Drinking Water Act, among other
things, “to ensure that the water delivered by public water systems of this state shall at all
times be pure, wholesome, and potable.” (§ 116270, subd. (e).) “To effectuate this
purpose, the [California Safe Drinking Water] Act articulates a state policy to ‘reduce to
the lowest level feasible all concentrations of toxic chemicals that, when present in
drinking water, may cause cancer, birth defects, and other chronic diseases.’ ”
(California Manufacturers & Technology Assn. v. State Water Resources Control Bd.
(2021) 64 Cal.App.5th 266, 272 (California Manufacturers), quoting § 116270,
subd. (d).) “The [California Safe Drinking Water] Act also expresses an intent to
establish a safe drinking water program ‘that is more protective of public health than the
minimum federal requirements.’ ” (California Manufacturers, at p. 272, quoting
§ 116270, subd. (f).)
The California Safe Drinking Water Act provides for a two-step process for setting
drinking water contaminant standards. First, OEHHA must “prepare and publish an
assessment of the risks to public health posed by each contaminant for which the state
board proposes a primary drinking water standard.” (§ 116365, subd. (c)(1).) This risk
assessment must include a PHG, which is “an estimate of the level of the contaminant in
drinking water that is not anticipated to cause or contribute to adverse health effects, or
that does not pose any significant risk to health.” (Ibid.) Furthermore, a specific standard

3
applies if the subject contaminant is an “acutely toxic substance.” (§ 116365,
subd. (c)(1)(A).) “If the contaminant is an acutely toxic substance, the public health goal
shall be set at the level at which no known or anticipated adverse effects on health occur,
with an adequate margin of safety.” (Ibid.)
To the extent information is available, the PHG shall take into account, among
other things, “[a]dverse health effects the contaminant has on members of subgroups that
comprise a meaningful portion of the general population, including, but not limited to,
infants, children, [and] pregnant women”; the “relationship between exposure to the
contaminant and increased body burden and the degree to which increased body burden
levels alter physiological function or structure in a manner that may significantly increase
the risk of illness”; and the “additive effect of exposure to the contaminant in media other
than drinking water, including, but not limited to, exposures to the contaminant in food,
and in ambient and indoor air, and the degree to which these exposures may contribute to
the overall body burden of the contaminant.” (§ 116365, subd. (c)(1)(C)(ii)-(iv).)
PHG’s “are aspirational rather than mandatory or enforceable.” (California
Manufacturers, supra, 64 Cal.App.5th at pp. 272-273.) OEHHA is required to review
each PHG “at least once every five years unless the office determines . . . that there has
not been a detection of the corresponding contaminant in the preceding five years.”
(§ 116365, subd. (e)(1).)
As for the second step in the process, after OEHHA sets the PHG for a
contaminant and completes its risk assessment, the State Water Resources Control Board
sets a maximum contaminant level (MCL) for that contaminant. The MCL must be set
“ ‘at a level that is as close as feasible to the corresponding [PHG][,] placing primary
emphasis on the protection of public health, and that, to the extent technologically and
economically feasible’ avoids any significant risk to public health.” (California
Manufacturers, supra, 64 Cal.App.5th at pp. 280-281, quoting § 116365, subd. (a).)
“Unlike MCL[’]s, which are the product of several statutorily enumerated considerations

4
. . . , [PHG’s] are based exclusively on public health considerations.” (California
Manufacturers, at p. 272, citing § 116365, subd. (c)(1).)
Perchlorate
Perchlorate is a chemical compound used in rocket fuel, slurry explosives, road
flares, and air bag inflation systems. Perchlorate can occur in nature and, through
rainfall, circulate at low levels throughout the environment. Perchlorate is also released
into the environment by human activity. For example, perchlorate can leach into soil and
aquifers through the disposal of rocket fuel. Perchlorate can remain in the ground and in
surface waters for decades. Since 1997, agencies have reported the presence of
perchlorate “in thousands of drinking water sources and wells throughout” California.
When ingested, perchlorate can have the effect in humans of inhibiting the uptake
of iodide in the thyroid gland. This is known as iodide uptake inhibition (IUI). Iodine is
a component of two hormones produced by the thyroid. Transfer of iodide into the
thyroid gland is “an essential step in the synthesis of” these hormones. Thyroid
hormones are necessary to a variety of basic human physiological functions, including
“regulat[ing] the body’s metabolism and physical growth.” Inhibition of iodide transfer
into the thyroid can result in iodide deficiency and, consequently, reduction in the
synthesis of the hormones, a condition known as hypothyroidism. According to the
National Academy of Sciences, hypothyroidism is the first adverse effect on the
“continuum of possible health effects of perchlorate exposure.”2 If thyroid hormone
production falls substantially in a healthy adult, adverse health effects may result. Any
“decrease is potentially more likely to have adverse effects in sensitive populations

2 The National Academy of Sciences “is a private, nonprofit, self-perpetuating
society of distinguished scholars engaged in scientific and engineering research,
dedicated to the furtherance of science and technology and to their use for the general
welfare.”

5
(people with thyroid disorders, pregnant women, fetuses, and infants) . . . .” Ordinarily,
the body maintains concentrations of thyroid hormones within limits through the body’s
own “feedback control mechanisms.” However, “even small decreases in thyroid
hormone levels may be associated with significant adverse effects, including altered
cognitive development in children and increased cardiovascular risk factors in adults.”
OEHHA’s 2004 PHG for Perchlorate
In 2002, a court ordered OEHHA to submit a revised PHG for perchlorate for
public comment and to subject its PHG to peer review. Each of three peer reviewers
agreed with the identification of particularly sensitive subpopulations, specifically
pregnant women, fetuses, and people with compromised thyroid function, arriving at a
PHG sufficient to protect those subpopulations.
The first peer reviewer noted “the potential impact of trace levels of perchlorate
may be nil.” He did not recommend a particular PHG. He noted OEHHA determined
that “iodine uptake per se is an adverse effect and, therefore, suitable for use in risk
assessment and the determination of PHG.” He further concluded the “critical effect,”
which the reviewer equated to the “first adverse effect,” of perchlorate exposure was “not
inhibition of iodine entry, but” rather a decrease in thyroid hormone during pregnancy.
The second reviewer noted that “the calculation of the PHG in the OEHHA
document is based on an effect that is not a direct adverse health event, but rather a
precursor to an adverse health event.” The second reviewer opined that a PHG of 2 ppb
“seems reasonably justified.”3
The third peer reviewer recommended a PHG of 18.6 micrograms per liter.
In 2004, OEHHA announced its PHG of 6 ppb for perchlorate.

3 While the peer reviewers at the time were not identified, OEHHA stipulated the
second peer reviewer in 2002 was Dr. Steinmaus.

6
OEHHA’s 2015 PHG for Perchlorate
OEHHA began the process of reviewing its PHG for perchlorate in 2008. It issued
a draft PHG in January 2011, proposing a PHG of 1 ppb for perchlorate in drinking
water. Dr. Steinmaus authored the draft, which was reviewed by five OEHHA scientists.
The draft stated the “current OEHHA PHG of 6 ppb was set in 2004. The
methods used to develop the proposed PHG described here are similar to those used to
develop the 2004 PHG in that both are based on the same thyroidal [IUI] data . . . .” The
draft further stated the “major difference between the 2004 PHG calculations and the
present proposal is that the 2004 PHG document focused on pregnant women and their
fetuses as the primary susceptible population, whereas the proposed PHG focuses on
infants.” The draft noted new data indicated drinking water intakes per body weight were
higher in infants than previously thought, resulting in the likelihood that infants had
greater perchlorate exposure per body weight from drinking water than estimated in
2004.
The draft further stated: “[T]he identification of the point of departure, prevention
of thyroidal iodide uptake, is a health-protective decision since it is intended to prevent
the very first step of a process that leads to thyroid hormone imbalance and other related
adverse health effects.” The draft continued: “The purpose of the proposed perchlorate
PHG is to help prevent any perchlorate-related reduction in thyroid iodine uptake that
might lead to decreases in thyroid hormone production. As discussed above, recent
evidence suggests that even small decreases in thyroid hormone levels may be associated
with significant adverse effects, including altered cognitive development in children and
increased cardiovascular risk factors in adults. Importantly, these changes have been
seen at thyroid hormone levels that are within what have been traditionally defined as
normal reference ranges, and have occurred in people without any other evidence of overt
thyroid disease. These findings suggest that any change in thyroid hormone levels, no
matter how small, may be associated with at least some increased risk of thyroid-related

7
adverse outcomes.” Among other sources, the draft relied on studies Dr. Steinmaus
coauthored in 2007 and 2010.
Three outside scientists reviewed the draft. One reviewer noted the most
vulnerable subpopulation identified by the PHG was infants, and further noted that, given
“the small thyroidal reserves of neonates and the possible need for an uninterrupted
supply of iodine, this seems to be a reasonable change from the previous PHG’s focus on
pregnant women, whose fetuses may be protected by larger maternal stores.” She further
stated that, given “how little we know about the sensitivity of infants, particularly
neonates, to thyroid hormone disruption or about iodine intake among pregnant women
and breastfed infants it seems reasonable to be cautious about exposing them to thyroid-
hormone disrupting agents.” She stated it was “appropriate and reasonable” to consider
the decrease in iodide uptake, and that “[u]sing inhibition of iodide uptake as the critical
event is appropriate since this is the first step in perchlorate toxicity, and any other effects
would follow subsequently.” She concluded that, until more information was gathered,
“a drinking water concentration of 1 ppb is likely protective to the population.” Another
reviewer concurred infants were more sensitive to the effects of perchlorate. He
recommended a PHG of 2 ppb.
OEHHA circulated a second draft PHG in December 2012. The second draft
adhered to the proposed 1 ppb PHG. OEHHA received several letters offering feedback,
much of it negative.
OEHHA issued the final PHG for perchlorate in February 2015. Dr. Steinmaus
was the author. There were eight OEHHA reviewers of the final PHG. Consistent with
the draft PHG’s, OEHHA set the PHG at 1 ppb. As with the drafts, “OEHHA used
decreased uptake of iodide by the thyroid gland as the key biochemical event for
assessing the risks due to perchlorate toxicity.” “OEHHA considers effects on thyroid
hormone production and subsequent changes to be adverse. [IUI] is the key event that
leads to other possible effects from perchlorate exposure. Prevention of [IUI] prevents

8
progression to the adverse health effects of perchlorate.” The PHG noted the National
Academy of Sciences “deemed ‘inhibition of iodide uptake by the thyroid as the basis of
the perchlorate risk assessment to be the most health-protective and scientifically valid
approach.’ OEHHA agrees with this approach and used it in developing its original 2004
PHG for perchlorate.” Thus, the PHG stated that the value of 1 ppb “is intended to help
prevent any perchlorate-related decrease in iodide uptake by the thyroid that could lead to
decreased thyroid hormone production and that could disrupt the important functions of
this hormone.”
CMTA’s Writ Petition
Pursuant to Code of Civil Procedure section 1085, CMTA filed a petition for a
writ of mandate ordering OEHHA “to withdraw the current revised PHG for perchlorate
and to identify a new revised PHG for perchlorate in compliance with legal
requirements.”
CMTA asserted section 116365 requires that the PHG “shall be set at the level at
which no known or anticipated adverse effects on health occur, with an adequate margin
of safety.” (§ 116365, subd. (c)(1)(A).) According to CMTA, in its determination of the
PHG, OEHHA violated this statutory mandate.
CMTA also asserted that, as both “principal author of the PHG technical support
document on which the PHG is based, and the author of the key studies on which the
technical support document relies,” Dr. Steinmaus had a conflict of interest which
“should have resulted in his recusal . . . .” According to CMTA, “OEHHA’s decision to
have Dr. Steinmaus conduct the required assessment and author the corresponding report
created a conflict of interest which compromised the PHG process and violated
OEHHA’s obligations under both the Health and Safety Code and common law conflict
of interest principles.”
The trial court denied CMTA’s writ petition and entered judgment in OEHHA’s
favor.

9
DISCUSSION
I
Compliance with Section 116365 in Setting the PHG
A. Standard of Review
“Code of Civil Procedure section 1085 permits judicial review of ministerial
duties as well as quasi-legislative and legislative acts.” (County of Los Angeles v. City of
Los Angeles (2013) 214 Cal.App.4th 643, 653.) Here, we address OEHHA’s
interpretation of a statute, specifically section 116365, subdivision (c)(1). In reviewing
the trial court’s denial of a writ of mandate pursuant to Code of Civil Procedure section
1085, “[w]here the facts are undisputed and the issue is one of statutory interpretation, we
review the trial court’s ruling de novo.” (Asian Americans Advancing Justice—Los
Angeles v. Padilla (2019) 41 Cal.App.5th 850, 863, fn. omitted; accord, Lopez v.
Ledesma (2022) 12 Cal.5th 848, 857 [generally appellate court reviews questions of
statutory interpretation de novo].)
However, “ ‘[i]n determining whether an agency has incorrectly interpreted the
statute it purports to implement, a court gives weight to the agency’s construction.’
[Citation.] ‘How much weight to accord an agency’s construction is “situational,” and
greater weight may be appropriate when an agency has a “ ‘comparative interpretative
advantage over the courts,’ ” as when “ ‘the legal text to be interpreted is technical,
obscure, complex, open-ended, or entwined with issues of fact, policy, and discretion.’ ”
[Citation.] Moreover, a court may find that “the Legislature has delegated the task of
interpreting or elaborating on a statute to an administrative agency,” for example, when
the Legislature “employs open-ended statutory language that an agency is authorized to
apply or ‘when an issue of interpretation is heavily freighted with policy choices which
the agency is empowered to make.’ ” [Citations.] In other words, the delegation of
legislative authority to an administrative agency sometimes “includes the power to
elaborate the meaning of key statutory terms.” [Citation.] Nevertheless, the proper

10
interpretation of a statute is ultimately the court’s responsibility.’ ” (California
Manufacturers, supra, 64 Cal.App.5th at pp. 279-280.)
B. Principles of Statutory Interpretation
“ ‘ “Under settled canons of statutory construction, in construing a statute we
ascertain the Legislature’s intent in order to effectuate the law’s purpose. [Citation.] We
must look to the statute’s words and give them their usual and ordinary meaning.
[Citation.] The statute’s plain meaning controls the court’s interpretation unless its words
are ambiguous.” [Citations.] If the words in the statute do not, by themselves, provide a
reliable indicator of legislative intent, “[s]tatutory ambiguities often may be resolved by
examining the context in which the language appears and adopting the construction
which best serves to harmonize the statute internally and with related statutes.
[Citation.]” [Citation.] . . . If the statute is ambiguous, we may consider a variety of
extrinsic aids, including legislative history, the statute’s purpose, and public policy.’ ”
(People v. Lucero (2019) 41 Cal.App.5th 370, 394-395; accord, Union of Medical
Marijuana Patients, Inc. v. City of San Diego (2019) 7 Cal.5th 1171, 1183-1184.)
C. CMTA’s Contentions
As stated, in setting the PHG, “OEHHA used decreased uptake of iodide by the
thyroid gland,” or IUI, “as the key biochemical event for assessing the risks due to
perchlorate toxicity.” CMTA maintains this violated the statutory mandate because the
PHG must be set at a level to prevent adverse health effects, not nonadverse health
effects, and IUI is not an adverse health effect.4
CMTA notes, correctly, that the National Academy of Sciences has explicitly
stated IUI is a “nonadverse effect rather than an adverse effect.” That body nonetheless
recommended use of IUI “as the point of departure for the perchlorate risk assessment”

4 The California Safe Drinking Water Act does not specifically define the terms
“adverse” or “adverse effects on health.” (See § 116275.)

11
because using “a nonadverse effect that is upstream of the adverse effects is a
conservative, health-protective approach to the perchlorate risk assessment.” CMTA also
cites OEHHA’s “Questions and Answers” published in connection with the 2004 PHG.
In it, OEHHA noted: “The perchlorate health effect of primary concern is the reduction
of the uptake of iodide, an essential nutrient, by the thyroid gland . . . . While not harmful
by itself, inadequate iodide uptake may lead to the harmful disruption of proper thyroid
function.” (Italics added.) In the same document, OEHHA further noted that its 2004
perchlorate PHG, like the current PHG and like the National Academy of Sciences
approach, “focused on the reduction of iodide uptake as the critical health effect.”
Additionally, OEHHA acknowledged in the 2015 PHG that IUI was “the key event that
leads to other possible effects from perchlorate exposure” and that prevention of IUI
“prevents progression to the adverse health effects of perchlorate.” Similarly, in its 2015
publication responding to public comments, OEHHA stated it treated IUI “as it would an
adverse event because it is in the direct causal pathway between perchlorate exposure and
several important adverse events.” (Italics added.)
Thus, according to CMTA, IUI is not an adverse health effect, and OEHHA has
explicitly acknowledged as much. By regulating to prevent it, OEHHA violated section
116365, expanding the scope of that section and exceeding the authority granted to it
thereunder.
D. Analysis
There is no dispute among the parties that perchlorate is an acutely toxic substance
within the meaning of section 116365, subdivision (c)(1)(A). Accepting the premise that
perchlorate is indeed an acutely toxic substance, we consider whether OEHHA acted
within its authority in identifying IUI as the effect on health to prevent such that, in
avoiding it, the PHG would be “set at the level at which no known or anticipated adverse
effects on health occur, with an adequate margin of safety.” (§ 116365, subd. (c)(1)(A).)
In other words, as a corollary, we essentially consider whether IUI gives rise to a “known

12
or anticipated adverse effect[ ] on health.” (Ibid.) We conclude that, in setting the PHG,
OEHHA properly identified IUI as a “known or anticipated adverse effect[ ] on health,”
and therefore it complied with section 116365, subdivision (c)(1)(A) in setting the PHG.
If the statute specifically required OEHHA to set the PHG at a level at which no
known adverse effects on health occur, we might find CMTA’s position—that IUI is not
an adverse effect on health and therefore should not be used in setting the PHG—to be
more persuasive. However, the statute also requires OEHHA to set the PHG at a level “at
which no . . . anticipated adverse effects on health occur, with an adequate margin of
safety.” (§ 116365, subd. (c)(1)(A).) In other words, the statute requires OEHHA to set
the PHG at a level that will prevent the occurrence of anticipated adverse health effects.
CMTA accuses OEHHA of effectively reading the word “adverse” out of the statute.
However, we conclude CMTA’s interpretation essentially reads the words “or
anticipated” out of the statute.
Based on our reading of the plain language of the statute, we conclude OEHHA
acted within its statutory authority in concluding that the onset of IUI results in
“anticipated adverse effects on health,” and that therefore the PHG must be set at a level
so as to prevent IUI. (§ 116365, subd. (c)(1)(A).) The California Safe Drinking Water
Act does not define “anticipated” in its definitions (§ 116275), and we find it helpful to
resort to dictionary definitions for this term and others (see Wasatch Property
Management v. Degrate (2005) 35 Cal.4th 1111, 1121-1122 [when ascertaining ordinary,
usual meaning of a word, courts appropriately refer to dictionary definition]). Dictionary
definitions of “anticipate” include: “to give advance thought, discussion, or treatment
to,” “to meet (an obligation) before a due date,” “to foresee and deal with in advance,”
“to act before (another) often so as to check or counter,” and “to look forward to as
certain.” (Merriam-Webster’s Collegiate Dict. (11th ed. 2006) p. 54.) Synonyms include
“foresee” and “prevent.” (Ibid., capitalization omitted.) Employing these definitions,
OEHHA could conclude, for example, the onset of IUI resulted in foreseeable adverse

13
health effects to be dealt with in advance. Thus, in setting the PHG to avoid IUI,
OEHHA set the PHG “at the level at which no known or anticipated adverse effects on
health occur, with an adequate margin of safety.” (§ 116365, subd. (c)(1)(A), italics
added.)
The record fully supports the conclusion that, with the onset of IUI, adverse
effects on health are anticipated. OEHHA stated in the 2015 PHG that IUI was “the key
event that leads to other possible effects from perchlorate exposure” and that prevention
of IUI “prevents progression to the adverse health effects of perchlorate.” In its 2015
publication responding to public comments, OEHHA stated IUI “is in the direct causal
pathway between perchlorate exposure and several important adverse events.” OEHHA
stated the use of IUI in establishing the PHG was a “health-protective decision since it is
intended to prevent the very first step of a process that leads to thyroid hormone
imbalance and other related adverse health effects.” It further stated, “OEHHA considers
effects on thyroid hormone production and subsequent changes to be adverse. [IUI] is
the key event that leads to other possible effects from perchlorate exposure. Prevention
of [IUI] prevents progression to the adverse health effects of perchlorate.”
We reach this conclusion notwithstanding the fact, as stated by the National
Academy of Sciences, that “outcomes at the end of the continuum” of health effects
caused by perchlorate exposure may not be “inevitable consequences” of that exposure.
Based on our interpretation of the statutory language, OEHHA could set the PHG at a
level where there exist foreseeable, if not inevitable, adverse health effects. Indeed, if
there were a condition, such as IUI, the onset of which always and inevitably resulted in
adverse health effects, it is not difficult to imagine characterizing such condition itself as
a known adverse effect on health.
Further reinforcing our determination is the statutory language stating that the
PHG shall be set at the specified level, “with an adequate margin of safety.” (§ 116365,
subd. (c)(1)(A).) We conclude this language builds into the PHG determination a degree

14
of latitude, particularly where the precise point at which known adverse effects on health
may occur, or the precise volume of exposure to a contaminant that will cause such
effects, is uncertain. In other words, we read this qualifier as building into the process
reasonable room—a margin—to account for uncertainty so as to ensure public health.
In its grammatical and lexical interpretation, CMTA asserts the phrase, “with an
adequate margin of safety” modifies the sentence’s main subject, the level at which the
PHG shall be set. CMTA further asserts that the words “level” and “margin” are metrics,
and thus the phrase effectively calls for the further refining of a numerical value of the
PHG. Essentially, CMTA’s reading of the statute would call for the setting of the initial
PHG at a specified value and then adjusting that numerical value by the additional
numerical value of a margin of safety.
We read the phrase “with an adequate margin of safety” in a more general way.
We read this language as providing latitude for OEHHA to ensure public health,
particularly where the level at which known adverse effects on health may arise, or the
amount of exposure that will cause such effects, is not entirely clear. CMTA is correct
that one definition of the word “margin” is a “spare amount or measure or degree allowed
or given for contingencies or special situations.” (Merriam-Webster’s Collegiate Dict.
(11th ed. 2006) p. 759.) However, contrary to CMTA’s suggestion, this does not
necessarily mandate a precise numerical value for a margin of safety. For example, the
word “amount,” in addition to meaning “the total number or quantity” can also mean,
among other things, “the whole effect, significance, or import.” (Merriam-Webster’s
Collegiate Dict. (11th ed. 2006) p. 42.) “Measure” can mean, among other things, “an
adequate or due portion,” “a moderate degree,” “a measured quantity,” and “a step
planned or taken as a means to an end.” (Merriam-Webster’s Collegiate Dict. (11th ed.
2006) p. 769.) And “degree” can mean, among many other things, “the extent, measure,
or scope of an action, condition, or relation.” (Merriam-Webster’s Collegiate Dict. (11th
ed. 2006) p. 328.) In our view, these definitions do not mandate the employment of

15
strictly numerical values to adjust the initial numerical PHG value as asserted by CMTA.
Putting aside these definitions, we are of the opinion the term “margin of safety” has a
more commonly understood meaning, employed here as a reasonable degree of latitude to
ensure the health of all populations.
We further note we afford deference to OEHHA’s interpretation of the statute it is
tasked with implementing. While “ ‘the proper interpretation of a statute is ultimately the
court’s responsibility,’ ” we nevertheless give due weight to OEHHA’s construction.
(California Manufacturers, supra, 64 Cal.App.5th at p. 280.) The Legislature enacted the
California Safe Drinking Water Act, among other things, “to ensure that the water
delivered by public water systems of this state shall at all times be pure, wholesome, and
potable.” (§ 116270, subd. (e).) As the Legislature stated: “Every resident of California
has the right to pure and safe drinking water.” (§ 116270, subd. (a).) We conclude the
Legislature has delegated interpretation of the statute to OEHHA, as the interpretation of
section 116365 involves “ ‘ “ ‘an issue of interpretation [that] is heavily freighted with
policy choices which the agency is empowered to make.’ ” ’ ” (California
Manufacturers, supra, 64 Cal.App.5th at p. 280.) Safeguarding the right of every
Californian to pure and safe drinking water, and, in so doing interpreting section 116365,
is a charge “ ‘ “ ‘heavily freighted with policy choices which [OEHHA] is empowered to
make.’ ” ’ ” (California Manufacturers, at p. 280.) As such, we afford deference to its
interpretation.
Additionally, as stated, the National Academy of Sciences (or a committee
thereof) employed the same method as OEHHA here in identifying IUI as the basis for its
risk assessment: “[T]he committee recommends that inhibition of iodide uptake by the
thyroid in humans, which is the key biochemical event and not an adverse effect, should
be used as the basis of the risk assessment. Inhibition of iodide uptake is a more reliable
and valid measure, it has been unequivocally demonstrated in humans exposed to
perchlorate, and it is the key event that precedes all thyroid-mediated effects of

16
perchlorate exposure.” It is true, as asserted by CMTA, that, unlike OEHHA, the
National Academy of Sciences does not operate under the mandates of section 116365.
However, that this “society of distinguished scholars” advocated the method employed by
OEHHA here further supports OEHHA’s determinations.
We conclude OEHHA properly considered IUI and established its PHG “at the
level at which no known or anticipated adverse effects on health occur, with an adequate
margin of safety.” (§ 116365, subd. (c)(1)(A).) OEHHA did not exceed its authority
under the statute.
II
Conflict of Interest
A. Additional Background, CMTA’s Contentions, and Standard of Review
In 2005, OEHHA hired Dr. Steinmaus in the capacity of Public Health Medical
Officer II. In 2007, 2010, and 2013, Steinmaus coauthored and published three studies
involving perchlorate. The studies specified the views expressed therein were those of
the authors and did not necessarily represent those of OEHHA.
CMTA asserts the PHG is void due to Dr. Steinmaus’s conflict of interest. It
asserts the record establishes Steinmaus’s conflict under the common law conflict of
interest doctrine based on circumstances in which he would be tempted to serve his own
interests. According to CMTA, through his publications, Steinmaus had already taken
public positions on issues OEHHA was deciding in setting the PHG for perchlorate and
his positions conflicted with other opinions in the scientific community. Therefore,
according to CMTA, Steinmaus could not objectively participate in setting the PHG
because he had the conflicting interest in protecting his reputation and the propriety of his
prior studies and positions he had publicly taken. CMTA contends that these
circumstances demanded Steinmaus’s recusal from setting the PHG.
“We assess the court’s factual findings under the substantial evidence standard,
but exercise independent judgment on legal issues. [Citations.] Legal issues include the

17
interpretation of the governing statute or regulation and whether the agency took into
account the relevant factors and acted ‘consistent with applicable law.’ ” (Manderson-
Saleh v. Regents of University of California (2021) 60 Cal.App.5th 674, 693, quoting
Associated Builders & Contractors, Inc. v. San Francisco Airports Com. (1999)
21 Cal.4th 352, 361.) Thus we exercise our independent judgment in determining
whether the “ ‘common law doctrine against conflicts of interest’ ” (Clark v. City of
Hermosa Beach (1996) 48 Cal.App.4th 1152, 1171 (Clark)) applies, and, if so, whether
OEHHA acted “consistent with applicable law” (Associated Builders & Contractors,
Inc., at p. 361).
B. The Common Law Conflict of Interest Doctrine
“ ‘[T]he common law doctrine against conflicts of interest . . . prohibits public
officials from placing themselves in a position where their private, personal interests may
conflict with their official duties.’ ” (Clark, supra, 48 Cal.App.4th at p. 1171.) This
doctrine extends to noneconomic conflicts of interest. (Id. at p. 1171, fn. 18.) “ ‘Actual
injury is not the principle the law proceeds on. Fidelity in the agent is what is aimed at,
and as a means of securing it the law will not permit him to place himself in a position in
which he may be tempted by his own private interests to disregard those of his
principal.’ ” (Id. at p. 1171.) A finding of self-interest sufficient to set aside a challenged
action “ ‘need not be based upon actual proof of dishonesty, but may be warranted
whenever a public official, by reason of personal interest in a matter, is placed in a
situation of temptation to serve his or her own purposes, to the prejudice of those for
whom the law authorizes that official to act. . . . [A]n individual member ordinarily
cannot vote on a matter in which that member . . . is interested. If the member does, the
action taken by the body of which he or she is a member is invalidated. . . . Where the
vote of a member interested is necessary to pass an ordinance or bylaw, such ordinance or
bylaw is void, irrespective of how beneficial the ordinance may be.’ ” (Ibid., italics
omitted.)

18
C. Analysis
The cases CMTA relies upon as applying the common law doctrine against
conflicts of interest are factually distinguishable. However, of far greater importance,
almost all involve quasi-judicial acts and challenges to them by writ petitions for
administrative mandate pursuant to Code of Civil Procedure section 1094.5.5 (Petrovich
Development Co., LLC v. City of Sacramento (2020) 48 Cal.App.5th 963; Fisher v. State
Personnel Bd. (2018) 25 Cal.App.5th 1; Nasha v. City of Los Angeles (2004)
125 Cal.App.4th 470 (Nasha); Clark, supra, 48 Cal.App.4th 1152.)
“ ‘[T]he terms “quasi-legislative” and “quasi-judicial” are used to denote . . .
differing types of action. Quasi-legislative acts involve the adoption of rules of general
application on the basis of broad public policy, while quasi-judicial acts involve the
determination and application of facts peculiar to an individual case. [Citations.] Quasi-
legislative acts are not subject to procedural due process requirements while those
requirements apply to quasi-judicial acts regardless of the guise they may take. . . .’ ”
(Save Civita Because Sudberry Won’t v. City of San Diego (2021) 72 Cal.App.5th 957,
983 (Save Civita), fn. omitted, quoting Beck Development Co. v. Southern Pacific
Transportation Co. (1996) 44 Cal.App.4th 1160, 1188 (Beck Development Co.).) “The
principle that procedural due process protections do not apply to quasi-legislative action
is well established. [Citations.] ‘ “Legislative action generally is not governed by these
procedural due process requirements because it is not practical that everyone should have
a direct voice in legislative decisions; elections provide the check there.” ’ ” (Save
Civita, at pp. 983-984, citing Western Oil & Gas Assn. v. Air Resources Board (1984) 37

5 One of the cases on which CMTA principally relies is Noble v. Palo Alto (1928)
89 Cal.App. 47. While Noble did not involve administrative mandamus, it also did not
involve a quasi-legislative matter and, to our knowledge, it has not been applied in such a
case.

19
Cal.3d 502, 525 & Horn v. County of Ventura (1979) 24 Cal.3d 605, 612-613.) This
matter, involving OEHHA’s setting of the PHG for perchlorate in drinking water, is a
quasi-legislative act.
“Quasi-legislative actions are generally reviewed by a proceeding in ordinary or
traditional mandate (Code Civ. Proc., § 1085), in which judicial review is confined to the
question whether the classification is arbitrary, capricious, or without reasonable or
rational basis.” (Save Civita, supra, 72 Cal.App.5th at p. 984.) “Administrative
mandamus (Code Civ. Proc., § 1094.5) is available only when ‘by law a hearing is
required to be given, evidence is required to be taken, and discretion in the determination
of facts is vested in the inferior tribunal, corporation, board, or officer . . . .’ ” (Ibid.; see
also Beach & Bluff Conservancy v. City of Solana Beach (2018) 28 Cal.App.5th 244, 259
[determination whether Code of Civ. Proc., §§ 1094.5 or 1085 applies does not depend on
whether agency is required to hold evidentiary hearing, but instead turns on nature of
challenged action; traditional mandamus under § 1085 applies to quasi-legislative
decisions defined as those involving formulation of a rule to be applied to all future cases
while administrative mandamus under § 1094.5 applies to quasi-judicial decisions which
involve actual application of a rule to a specific set of facts].)
As stated, the majority of cases on which CMTA relies for applicability of the
common law conflict of interest doctrine are cases addressing petitions for writs of
administrative mandate involving quasi-judicial acts. (Petrovich Development Co.,
LLC v. City of Sacramento, supra, 48 Cal.App.5th 963; Fisher v. State Personnel Bd.,
supra, 25 Cal.App.5th 1; Nasha, supra, 125 Cal.App.4th 470; Clark, supra,
48 Cal.App.4th 1152.) And, as stated, in such cases, rules of procedural due process
apply. These include, among other things, hearings “ ‘ “ ‘before a reasonably impartial,
noninvolved reviewer.’ ” ’ ” (Nasha, at p. 483.) In quasi-legislative matters, such as this,
these procedural due process rules do not apply. (Save Civita, supra, 72 Cal.App.5th at
p. 983; Beck Development Co., supra, 44 Cal.App.4th at p. 1188.) Regardless of the

20
merits of CMTA’s contention that Dr. Steinmaus was conflicted, in the absence of the
procedural due process safeguards applicable to quasi-judicial matters, we conclude the
common law conflict of interest doctrine does not apply to these quasi-legislative
proceedings.
CMTA offers no direct authority standing for the proposition that, despite the
inapplicability of procedural due process protections, the common law conflict of interest
doctrine should nevertheless apply to circumstances such as these. While CMTA in its
reply brief faults OEHHA for failing to cite any cases stating the common law conflict of
interest doctrine applies only to quasi-judicial matters, what we find more significant is
the lack of any case law we have found applying the doctrine to quasi-legislative matters
such as this.
Among other things, in rejecting CMTA’s conflict of interest contention, the trial
court relied on Friends of La Vina v. County of Los Angeles (1991) 232 Cal.App.3d 1446
(Friends of La Vina), disapproved on another ground in Western States Petroleum
Assn. v. Superior Court (1995) 9 Cal.4th 559, 569-570 and footnote 2. Friends of La
Vina was an appeal from a judgment granting a writ of mandate challenging the approval
of a project and seeking a proper environmental impact report in compliance with the
California Environmental Quality Act (CEQA). (Friends of La Vina, at p. 1450.) Insofar
as relevant here, the court in Friends of La Vina stated: “The trial court’s ruling derived
in large measure from what the court termed ‘general principles of conflict of interest,’ as
applicable to applicants and their consultants. In so ruling, the court assumed an
unwarranted role. The issue in this case is compliance with CEQA. To the extent
policing of specific conflicts of interest might accurately be perceived as a legislative
provision or purpose of CEQA, it could be pursued. But not otherwise. Except where the
law clearly provides rules for identification and rectification of what might be termed
conflicts of interest, that is a legislative not a judicial function.” (Id. at p. 1456, italics
added.)

21
CMTA distinguishes Friends of La Vina on the ground that it was a CEQA case
and the trial court’s employment of “general principles of conflict of interest” in its ruling
was inappropriate given there was a statutory authorization for the challenged action.
(Friends of La Vina, supra, 232 Cal.App.3d at pp. 1452-1453, 1456.) This is true, as far
as it goes. However, the case nevertheless articulates a principle with which we agree:
that we are not to identify and rectify purported conflicts of interest in areas where such
has not previously been done, where there do not exist procedural due process
protections, and where the choice to do so is more appropriately left to the Legislature.
(See id. at p. 1456.)
CMTA also notes that the same appellate district that decided Friends of La Vina
decided Clark approximately five years later, when it “directly applied Noble’s common
law principles and found a conflict of interest.” CMTA argues this suggests Friends of
La Vina is strictly limited to its facts. Clark and Friends of La Vina were indeed both
decided by the Second Appellate District, although the cases were decided by different
divisions. (Clark, supra, 48 Cal.App.4th 1152; Friends of La Vina,
supra, 232 Cal.App.3d 1446.) What is more pertinent, however, is the fact, discussed
ante, that Clark was an administrative mandate case implicating procedural due process
protections.
Ultimately, here, we will not invoke the common law conflict of interest doctrine
in circumstances in which, to our knowledge, it has never been applied. We are not
persuaded it is appropriate to apply that doctrine here, where we are addressing a quasi-
legislative matter, as opposed to a quasi-judicial matter with its attendant procedural due
process safeguards. We conclude the common law conflict of interest doctrine does not
apply here. Accordingly, the PHG is not invalid as a result of any conflict of interest
involving Dr. Steinmaus.

22
DISPOSITION
The judgment is affirmed. Respondents shall recover their costs on appeal. (Cal.
Rules of Court, rule 8.278(a)(1), (2).)

/s/
HOCH, J.*

I concur:

/s/
RENNER, J.

* Retired Associate Justice of the Court of Appeal, Third Appellate District, assigned by
the Chief Justice pursuant to article VI, section 6 of the California Constitution.

23
DUARTE, Acting P. J., Dissenting.
The California Safe Drinking Water Act (Health & Saf. Code § 116270 et seq.)
(Act)1 directs that the Office of Environmental Health Hazard Assessment (OEHHA)
protect the right to safe drinking water by setting aspirational public health goals (PHG)
for acutely toxic substances, such as perchlorate, “at the level at which no known or
anticipated adverse effects on health occur, with an adequate margin of safety.”
(§ 116365, subd. (c)(1)(A).) Because OEHHA clearly did not do so in this case, and
declined to do so in a manner that signals future noncompliance with the statute, I am
compelled to dissent.
I do not dispute that the Act protects the quality of drinking water, and, in my
view, PHGs and drinking water standards set by the State Water Resources Control
Board are a welcome presence. But OEHHA’s power to set PHGs is not unrestricted;
OEHHA must comply with plain language of the Act as it goes about the critical business
of safeguarding the right to pure and safe drinking water for every Californian.
Relying on an overly expansive definition of “anticipate,” the majority concludes
that OEHHA complied with the Act’s requirements in this case because, “with the onset
of IUI, adverse effects on health are anticipated.” (Maj. opn., ante, p. 14.) According to
the majority, OEHHA is authorized to set the PHG to avoid a nonadverse health effect--
here iodide uptake inhibition (IUI)--so long as there exist “foreseeable, if not inevitable,
adverse health effects.” (Maj. opn., ante, p. 14.) But the plain language of the Act
requires OEHHA to set the PHG based on the level at which it expects the target
substance to “cause or contribute to adverse health effects.” (§ 116365, subd. (c)(1),
(c)(1)(A).) Here, rather than setting the PHG at the level at which OEHHA did not
expect perchlorate exposure to cause or contribute to adverse health effects, OEHHA
treated IUI as if it were an adverse health effect and set the PHG to avoid a 5 percent

1 Further undesignated statutory references are to the Health and Safety Code.

1
reduction in iodide uptake. This methodology is not in compliance with the statute,
because it is undisputed that a 5 percent reduction in iodide uptake does not cause or
contribute to any adverse health effects.
The majority also concludes that OEHHA is entitled to set the PHG below the
level expressly required by the statute because the Act requires it to set the PHG “with an
adequate margin of safety.” (Maj. opn., ante, pp. 15-16.) It reasons that “margin”
provides OEHHA with “a reasonable degree of latitude” to set the PHG as OEHHA feels
is necessary. (Maj. opn., ante, p. 16.) As I will explain, I disagree with the majority’s
formulation of the phrase “with an adequate margin of safety,” and I view that
formulation as at odds with OEHHA’s methodology in this case. I conclude instead that
the statute requires OEHHA to first determine the level at which the target substance is
anticipated to cause or contribute to adverse health effects--which OEHHA failed to do
here--and then to apply an adequate margin of safety.
Accordingly, I disagree with Part 1 of the majority opinion and dissent from its
disposition affirming the trial court’s order.
DISCUSSION
I
Anticipated Adverse Effects on Health
There is no dispute but that IUI is not an adverse health effect. In its 2005 study,
the National Academy of Sciences recognized when recommending that IUI be used as
the point of departure for the perchlorate risk assessment that it was “recommending
using a nonadverse effect [IUI] rather than an adverse effect.” OEHHA acknowledged
this fact at various places throughout the record. For example, following the 2005
National Academy of Sciences study, OEHHA recognized that IUI was “not harmful by
itself” but “may lead to the harmful disruption of proper thyroid function.” In the
technical support document accompanying the 2015 PHG, OEHHA observed that IUI “is
the key event that leads to other possible effects from perchlorate exposure,” and that

2
“[p]revention of iodide uptake inhibition prevents progression to the adverse health
effects of perchlorate.” (Italics added.) Thus, rather than asserting that IUI is an adverse
health effect, OEHHA acknowledged that it “treat[ed] [IUI] as it would an adverse event
because it is in the direct causal pathway between perchlorate exposure and several
important adverse events.” (Italics added.)
OEHHA considered effects on thyroid hormone production--not IUI--to be an
adverse health effect. It considered effects on thyroid hormone production to be adverse
because “[a]ny downward shift in the mean level of the thyroid hormone T4 in a
population could increase the number of people who fall into the range of T4 values that
are associated with high risks of either subtle or overt thyroid-related disease and
toxicity.” (Italics added.) But in setting the PHG to avoid a 5 percent reduction in iodide
uptake, OEHHA did not conclude that a 5 percent reduction in iodide uptake was
expected to cause the adverse health effect it had identified, reduced thyroid hormone
production. Instead, OEHHA acknowledged that IUI “can lead to reduced thyroid
hormone production” only if it were “severe enough.” (Italics added.) Indeed, the 2005
National Academy of Sciences study recognized that IUI can cause reduction in thyroid
hormone production “if iodide intake is very low.”
The majority agrees that OEHHA set the PHG to avoid the onset of IUI. (Maj.
opn., ante, p. 13.) In approving this practice, the majority considers the meaning of the
word “anticipated,” settles on the synonym “foreseeable,” and then observes that
“OEHHA could conclude, for example, the onset of IUI resulted in foreseeable adverse
health effects to be dealt with in advance.” (Maj. opn., ante, pp. 13-14.) In other words,
the majority appears to conclude that OEHHA may set a PHG below the level at which
the target substance would be expected to cause or contribute to an adverse health effect,
for the purpose of heading off those adverse health effects that might occur at higher
concentrations of the substance. (Maj. opn., ante, p. 14.) But this reading of the statute
authorizes OEHHA to set the PHG at any level below the level at which adverse health

3
effects might be expected to actually occur for the purpose of heading off adverse health
effects that are only foreseeable at concentrations of the target substance greater than the
level set as the PHG. As one comment in opposition to the January 2011 draft PHG
observed: “In essence, OEHHA seems to imply that any initiating events that have even
the slightest potential to pose a downstream adverse physiological effect should be
considered adverse. This is a critically important science policy change that has
ramifications for future PHG risk assessments.”
Indeed, under the majority’s reading, OEHHA could set the PHG at “zero” in
order to head off adverse health effects that are foreseeable at greater concentrations of
perchlorate. Were OEHHA authorized to set the PHG based on any precursor effect that
was within the causal pathway between exposure to a contaminant and subsequent
adverse health effects, the requirement that the PHG be set at the level at which no
anticipated adverse health effects occur would be meaningless. (See State Farm General
Insurance Co. v. Lara (2021) 71 Cal.App.5th 148, 179 [statutory interpretation aims to
avoid rendering any words meaningless].)
I interpret the term “anticipated” differently. “Dictionaries define ‘anticipated’ as
meaning ‘to look forward to as certain’ [citation] and ‘[a]pprehended beforehand, looked
for, expected’ [citation]. ‘The plain and ordinary meaning of “expect,” as reflected in
dictionary definitions, is to anticipate, to consider probable or certain.’ ” (SN Sands
Corp. v. City and County of San Francisco (2008) 167 Cal.App.4th 185, 193.) These
definitions indicate that an “anticipated adverse health effect” is an adverse health effect
that is at least probable or expected, if not necessarily certain. As relevant here, the word
“level” is defined as “a position in a scale or rank (as of achievement, significance, or
value)” or “a concentration of a constituent especially of a body fluid (such as blood).”
(Merriam-Webster Collegiate Dict. (11th ed. 2003) p. 714, col. 2.) Applying these
definitions, “level” clearly refers to a numerical value of the concentration of perchlorate
in drinking water. Accordingly, the requirement that OEHHA set the PHG at “the level

4
at which no . . . anticipated adverse effects on health occur” compels OEHHA to set the
PHG at the concentration of the target substance (the level) at which OEHHA determines
it is probable or expected that adverse health effects will occur. Thus, I agree with the
majority’s observation that “OEHHA could set the PHG at a level where there exist
foreseeable, if not inevitable, adverse health effects.” (Maj. opn., ante, p. 14.)
My disagreement stems from the indisputable reality that there are no foreseeable
adverse health effects associated with a 5 percent reduction in iodide uptake. OEHHA
set the PHG at a level that avoids IUI, a nonadverse precursor effect, well below the level
at which it was even arguably foreseeable that this precursor effect would lead to adverse
health effects. Rather than attempting to determine the concentration of perchlorate that
would be expected to cause or contribute to adverse health effects, as the statute requires,
OEHHA simply treated IUI as if it were an adverse health effect.
To summarize my points thus far: it is undisputed that the Act provides that
OEHHA “shall” set the PHG “at the level at which no known or anticipated adverse
effects on health occur, with an adequate margin of safety.” (§ 116365, subd. (c)(1)(A);
italics added.) It is also undisputed that IUI is not an adverse health effect. Finally, it is
undisputed that a 5 percent reduction in iodide uptake is not expected to cause or
contribute to adverse health effects. The statute does not authorize OEHHA to set the
PHG to avoid a precursor health effect below the level at which the precursor effect
would be expected to cause or contribute to adverse health effects.
I next discuss the majority’s reliance on what it deems the “qualifier,” the phrase
“with an adequate margin of safety,” and explain why I find it unconvincing. (Maj. opn.,
ante, p. 15.)
II
Adequate Margin of Safety
The majority concludes that OEHHA was entitled to set the PHG to avoid a
nonadverse precursor health effect because section 116365, subdivision (c)(1)(A)

5
requires OEHHA to set the PHG “with an adequate margin of safety,” which it interprets
as generally providing OEHHA with a “reasonable degree of latitude” in setting the PHG.
(Maj. opn., ante, pp. 15-16.) Although I do not disagree that OEHHA has some latitude,
I read the statute to require that OEHHA establish a margin of safety from the level at
which no known or anticipated adverse health effects occur. Indeed, that is what OEHHA
purported to do here, as I will explain.
To ascertain the meaning of section 116365, subdivision (c)(1)(A) and its
requirement that “[i]f the contaminant is an acutely toxic substance, the [PHG] shall be
set at the level at which no known or anticipated adverse effects occur, with an adequate
margin of safety,” I begin with its grammar. In interpreting the meaning of the provision,
“[w]e must presume that the Legislature intended ‘every word, phrase and provision . . .
in a statute . . . to have meaning and to perform a useful function.’ ” (Garcia v.
McCutchen (1997) 16 Cal.4th 469, 476.) The provision begins with a triggering clause:
“If the contaminant is an acutely toxic substance.” (See Chicago Manual of Style (17th
ed. 2017) § 6.24.) The sentence then includes a subject (the PHG), a modal verb (shall
be), the main verb (set), and an adverbial prepositional phrase (“at the level”), which is
two or more words that function together as an adverb to modify a verb. (Id., § 5.161.)
Here, “at the level” tells us where the PHG shall be set (at the level). The sentence
concludes with two adjectival prepositional phrases modifying “the level.” These
prepositional phrases inform that the level at which the PHG is to be set is the one “at
which no known or anticipated adverse effects on health occur,” and “with an adequate
margin of safety.” Although each of these phrases consists of its own grammatical
subparts, each phrase modifies “the level.”
As I discussed ante, the Act requires OEHHA to set the PHG at the numerical
value of the concentration of perchlorate in drinking water (the level) at which OEHHA
does not expect that adverse health effects will occur. From that numerical value, the Act
requires OEHHA to establish “an adequate margin of safety.” As a modification of a

6
numerical value, the most natural reading of the word “margin” is “a spare amount or
measure or degree allowed or given for contingencies or special situations,” or “measure
or degree of difference.” (Merriam-Webster Collegiate Dict. (11th ed. 2003) p. 759, cols.
1-2.) In other words, the “adequate margin of safety” is a numerical reduction of the
level as previously defined as necessary to ensure public safety.
The majority concludes that the statute’s reference to the term “margin” authorizes
OEHHA to set the PHG to avoid a nonadverse health effect because it provides a general
degree of latitude “to account for uncertainty so as to ensure public health.” (Maj. opn.,
ante, p. 15.) I disagree with that conclusion. First, as stated, “margin” modifies the level
at which the PHG is set (a numerical value), not the nature of the health effect--whether
adverse or nonadverse--used as the basis for determining the level. In other words, the
statute would authorize OEHHA to set the PHG to avoid a nonadverse health effect only
if “adequate margin of safety” modified “no known or anticipated adverse health effects,”
rather than “the level.”
Second, OEHHA’s methodology indicates that it did not treat IUI as an adverse
effect for purposes of establishing a margin of safety, but instead acted to establish the
permissible margin after determining a level, as contemplated by the statute. In setting
the PHG, OEHHA first determined the level at which perchlorate exposure would cause a
5 percent reduction in iodide uptake, which it justified by recognizing that it “treat[ed]
[IUI] as it would an adverse effect.” In other words, OEHHA first determined the level at
which it expected perchlorate exposure to cause a (non)adverse health effect. After
establishing the level of perchlorate estimated to cause a 5 percent decrease in iodide
uptake, OEHHA applied two separate margins of safety. It applied an uncertainty factor
of 10 to “calculate a dose that would address inter-individual variability among humans
and be protective of those who are likely to be sensitive to the effects of perchlorate,”
including infants, which it noted “are particularly susceptible to perchlorate.” It also
calculated the PHG using the 95th percentile of infant water intake per kilogram of

7
bodyweight, based on data indicating that infants drink more water on a body weight
basis than other sensitive groups. Thus, OEHHA expressly acknowledged that it was
treating IUI as it would an adverse effect, and then it separately and subsequently applied
margins of safety to ensure public health.
Based on the grammatical structure of the Act and OEHHA’s methodology in
establishing the PHG, I cannot agree that the Act authorized OEHHA to proceed directly
to establishing an adequate margin of safety by setting the PHG based on avoidance of a
nonadverse health effect, as the majority now holds. Indeed, without first ascertaining
the level at which no known or anticipated adverse health effects occur, from which the
margin of safety is then applied, there is no way to determine whether the margin is
“adequate.”
III
Conclusion
Although the majority concludes that we should defer to OEHHA’s interpretation
of the Act, it also correctly notes that this court ultimately decides what the statute
requires. (Maj. opn., ante, p. 16.) And although the majority observes that the National
Academy of Sciences has embraced OEHHA’s approach, specifically recommending that
IUI, while admittedly “not an adverse effect,” should nonetheless “be used as the basis of
the risk assessment” (maj. opn., ante, p. 16), this recommendation is not relevant to our
analysis of the relevant statutory requirements and whether OEHHA complied with them
here. Further, although the majority correctly states several times that the statute
establishes the right of all Californians to safe drinking water, an observation with which
I readily agree, the existence of that right is not at issue here. At issue is the manner in
which the Act requires that right be ensured.
Based on the foregoing, I would conclude the 2015 PHG does not conform to the
Act’s requirements. I would reverse the trial court’s October 7, 2020, order denying the
Association’s petition for writ of mandate and direct the issuance of a peremptory writ of

8
mandate directing OEHHA to vacate the 2015 PHG and to establish a new PHG that
complies with the requirements of section 116365. Because the majority instead affirms
the trial court’s order, I respectfully dissent.

/s/
DUARTE, Acting P. J.

9

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Source: Frix Law Library, https://www.frixlaw.com/law-library/cases/9381769. Public record. Not legal advice.