1

Filed 9/27/22 Raptors Are The Solution v. Superior Court CA1/2

NOT TO BE PUBLISHED IN OFFICIAL REPORTS

California Rules of Court, rule 8.1115(a), prohibits courts and parties from citing or relying on opinions not certified for 

publication or ordered published, except as specified by rule 8.1115(b). This opinion has not been certified for publication or 

ordered published for purposes of rule 8.1115. 

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIRST APPELLATE DISTRICT

DIVISION TWO

RAPTORS ARE THE 

SOLUTION,

Plaintiff and Appellant,

v.

THE SUPERIOR COURT OF 

ALAMEDA COUNTY,

Defendant and 

Respondent;

LIPHATECH, INC. et al.,

Real Parties in Interest.

 A161787

 (Alameda County

 Super. Ct. No. 

RG18908605)

Plaintiff and appellant Raptors Are The Solution (Raptors) appeals the 

trial court’s order denying its petition for writ of mandate filed against 

California Department of Pesticide Regulation (the Department). The 

petition alleged that the Department abused its discretion and acted contrary 

to the law in its decision not to reevaluate diphacinone, a registered 

rodenticide.

We reverse the trial court’s judgment denying Raptors’ petition for writ 

of mandate.
2

BACKGROUND

Before turning to the factual and procedural history of this case, we 

first summarize the regulations pertaining to the Department’s registration, 

renewal, and reevaluation of pesticides to provide context for Raptors’ 

challenge. 

I. 

Registration of Pesticides

The Department oversees a pesticide registration program that aims 

“[t]o provide for the proper, safe, and efficient use of pesticides essential for 

production of food and fiber and for protection of the public health and safety” 

while protecting the environment “from environmentally harmful pesticides

by prohibiting, regulating, or ensuring proper stewardship of those 

pesticides.” (Food & Agr. Code, § 11501, subds. (a), (b).) 

A pesticide must have a certificate of registration from the Department

before it can be manufactured or sold in California. (Food & Agr. Code, 

§ 12811.) A pesticide must first be registered by the United States 

Environmental Protection Agency (the EPA) in order to be eligible for 

registration in California. (7 U.S.C. § 136a.) The Department then conducts 

“a thorough and timely evaluation” of the pesticide pursuant to Food and 

Agricultural Code section 12824. This includes the review of specific data 

that the registrant was required to submit to the EPA as well as 

supplemental data required by the Department. (Cal. Code Regs., tit. 3,

§ 6159.)1

The Department may refuse to register a pesticide if, among other 

reasons, a pesticide “has demonstrated serious uncontrollable adverse effects 

1 All further statutory references are to title 3 of the California Code of 

Regulations unless otherwise noted. 
3

either within or outside the agricultural environment” or if its use “is of less 

public value or greater detriment to the environment than the benefit 

received by its use.” (Food & Agr. Code, § 12825, subds. (a), (b).) The 

Department may also register a pesticide but place appropriate restrictions 

on its use, including “limitations on quantity, area, and manner of 

application.” (Id., § 12824.)

II. 

The Renewal Process

Pesticide registrations expire on the last day of each year and must be 

renewed annually with the Department. (Food & Agr. Code, § 12817.) As 

part of the renewal application, the registrant must pay a fee and certify that 

he or she has submitted all known “factual or scientific evidence of any 

adverse effect or risk of the pesticide to human health or the environment.” 

(§§ 6210, subd. (a), 6215, subd. (a).)

“Each renewal shall be issued within 60 days after the [Department]

receives an accurate and complete renewal application unless the 

[Department] takes action pursuant to Sections 12816, 12825, or 12827 of the 

Food and Agricultural Code.” (§ 6215, subd. (b).) Those referenced sections

provide that a registration may be cancelled if it fails to satisfy the criteria 

for registration or if the registrant otherwise fails to comply with the Food 

and Agricultural Code. 

Further, the Department shall, “when renewing a pesticide without a 

reevaluation, make a written finding that [it] has not received sufficient 

information necessitating reevaluation pursuant to Sections 6220 and 6221.” 

(§ 6215, subd. (c).) When registering, renewing, or reevaluating a pesticide, 

the Department must post its proposed decision on its official bulletin boards 

for 30 days for public review and comment. (§ 6253, subd. (a).)
4

III. 

The Reevaluation Process

“The [Department] may, at any time, evaluate a registered 

pesticide . . . . The [Department] shall investigate all reported episodes and 

information received by the [Department] that indicate a pesticide may have 

caused, or is likely to cause, a significant adverse impact, or that indicate 

there is an alternative that may significantly reduce an adverse 

environmental impact. If the [Department] finds from the investigation that 

a significant adverse impact has occurred or is likely to occur or that such an 

alternative is available, the pesticide involved shall be reevaluated.”

(§ 6220.) The specific factors that warrant reevaluation include

environmental contamination, pesticide residue overtolerance and fish or 

wildlife hazard. (§ 6221.)

“If information is obtained from an individual or organization 

indicating possible adverse effect from the use of a pesticide, the 

[Department] shall respond in writing to the individual or organization 

indicating the reasons for [its] decision either to reevaluate or not reevaluate 

the pesticide registration based upon the information submitted.” (§ 6222, 

subd. (b).) The Department’s decision to reevaluate a pesticide is not tied to 

the 60-day renewal period for the registration of the pesticide. (Californians 

for Alternatives to Toxics v. Department of Pesticide Regulation (2006) 

136 Cal.App.4th 1049, 1066 (CATS).)

IV. 

Raptors’ Challenge to the Renewal of Diphacinone

On December 22, 2017, in response to the Department’s proposed 

decision to renew rodenticide registrations for 2018, Raptors requested that 

the Department initiate reevaluation of three first-generation anticoagulant 
5

rodenticides (FGARs) and four second-generation anticoagulant rodenticides 

(SGARs).2 Raptors argued that the continued use of these rodenticides posed 

a significant risk and/or is likely to have significant cumulative impacts on 

wildlife, and that the Department was therefore required to reevaluate these 

rodenticides pursuant to section 6220. Raptors attached several exhibits to 

its request and provided additional information and data over the course of 

the next several months in support of its request for reevaluation. 

In March 2018, the Department responded to Raptors that it was “in 

the process of reviewing data submitted by the California Department of Fish 

and Wildlife and wildlife organizations” to determine the potential adverse 

impacts of the continued use of FGARs and SGARs on non-target wildlife.

The Department further wrote that it was “proceeding with the renewal of 

[the seven rodenticides] and will not be placing them into reevaluation at this 

time.” On April 18, 2018, the Department published a “Final Decision 

Regarding Renewal or Registration of Pesticide Products for 2018” that 

confirmed its decision to renew the subject rodenticides without reevaluation.

On June 13, 2018, Raptors filed a verified petition for writ of mandate.

The petition alleged two causes of action against the Department for violation 

of the California Environmental Quality Act (CEQA) and violation of the 

Department’s own regulations based on its decision to renew the subject 

rodenticides for 2018 without reevaluation. On October 19, 2018, Raptors 

filed an amended petition that added various agencies and companies as real 

2 The three FGARs are diphacinone, chlorophacinone and warfarin. 

The four SGARs are brodifacoum, bromadiolone, difethialone, and 

difenacoum. Anticoagulant rodenticides generally work by disrupting the 

blood-clotting mechanism in the target animal, which causes hemorrhaging 

and ultimately leads to death.
6

parties in interest. These parties had all received a renewal from the 

Department for one or more of the seven challenged rodenticides for 2018.

On November 16, 2018, the Department wrote to Raptors’ counsel that 

it had completed its investigation of the subject rodenticides in response to

Raptors’ request and that it would begin reevaluation of SGARs, but not 

FGARs. The Department reasoned that its “investigation of the reported 

impacts found that the rate of FGAR exposure among non-target wildlife is 

generally decreasing and is lower than for SGARS.” The letter was 

accompanied by a 35-page report that summarized the Department’s 

investigation of FGARs and SGARs based on the data submitted and its 

reasons for placing SGARs into reevaluation but not FGARs. At the same 

time, the Department published its proposed decision to reevaluate the four 

SGARs.

The Department subsequently filed a demurrer to the first amended 

petition that argued, among other things, that the Department was not 

obligated to place a pesticide into reevaluation during the 60-day renewal 

period based on the holding in CATS, supra, 136 Cal.App.4th at page 1066

(“[r]eevaluation can take place at any time and is not linked in any way to 

annual renewal”). The trial court agreed and sustained the demurrer with 

leave to amend.

On May 24, 2019, Raptors filed a second amended petition that 

narrowed its challenge to the Department’s decision to renew the registration 

of diphacinone (one of the three FGARs) without reevaluation. The second 

amended petition alleged two causes of action: 1) challenge to the 

Department’s April 18, 2018 decision to renew the registration of diphacinone 

without reevaluation and 2) challenge to the Department’s 
7

November 16, 2018 decision not to reevaluate diphacinone.3 The first cause 

of action was dismissed pursuant to the parties’ stipulation. 

On November 17, 2020, following briefing by the parties and real 

parties in interest, the trial court heard and denied Raptors’ second amended 

petition. The trial court held that the Department’s decision not to 

reevaluate diphacinone did not constitute an abuse of discretion because the 

Department’s decision was supported by substantial evidence based on the 

record.

On January 11, 2021, Raptors filed its notice of appeal of the trial 

court’s November 17, 2020 order.

4 On January 14, 2021, the trial court 

entered judgment in favor of the Department. As the Department notes in its 

brief, Raptors’ notice of appeal was filed prematurely prior to the trial court’s 

entry of judgment. The Department does not contend that the appeal should 

be denied on this basis. This court, in its discretion, will treat the notice of 

appeal as having been filed immediately after entry of judgment pursuant to

California Rules of Court, rule 8.104(d)(2), and therefore timely. 

3 The second amended petition erroneously references the 

Department’s two decisions as April 18, 2019, and November 16, 2019. 

4 Raptors’ notice of appeal also included reference to the trial court’s 

May 7, 2019 ruling that sustained the Department’s demurrer to the first 

amended petition and the stipulated dismissal of Raptors’ first cause of action 

in the second amended petition. Raptors’ opening brief states that it is only 

appealing the trial court’s holding as to the second cause of action (whether 

the Department’s decision not to reevaluate diphacinone violated CEQA) and 

that it has elected not to proceed on appeal as to the dismissed first cause of 

action.
8

DISCUSSION

I.

Standard of Review

In a case that involves a public agency’s compliance with CEQA, “the 

appellate court reviews the agency’s action, not the trial court’s decision; in 

that sense appellate judicial review under CEQA is de novo.” (Vineyard Area 

Citizens for Responsible Growth, Inc. v. City of Rancho Cordova (2007) 

40 Cal.4th 412, 427 (Vineyard).) Like the trial court, our review of the 

challenged decision for compliance with CEQA “shall extend only to whether 

there was a prejudicial abuse of discretion.” (Pub. Resources Code, 

§ 21168.5.) “Abuse of discretion is established if [the Department] has not 

proceeded in a manner required by law or if the determination or decision is 

not supported by substantial evidence.” (Ibid.)

“This statutory language has been interpreted as classifying abuses of 

discretion into two types of agency error—namely, legal error (the failure to 

proceed in the manner required by law) and factual error (making findings 

that are not supported by substantial evidence). [Citation.]” (POET, LLC v. 

State Air Resources Bd. (2013) 218 Cal.App.4th 681, 710-711.) “Judicial 

review of these two types of error differs significantly: while we determine de 

novo whether the agency has employed the correct procedures, ‘scrupulously 

enforc[ing] all legislatively mandated CEQA requirements’ [citation], we 

accord greater deference to the agency’s substantive factual conclusions.”

(Vineyard, supra, 40 Cal.4th at p. 435.) 

Under CEQA, “substantial evidence” means “enough relevant 

information and reasonable inferences from this information that a fair 

argument can be made to support a conclusion, even though other conclusions 
9

might also be reached.” (Cal. Code Regs., tit. 14, § 15384, subd. (a).)5 A 

reviewing court may not set aside an agency’s decision “on the ground that an 

opposite conclusion would have been equally or more reasonable. [Citation.]

A court’s task is not to weigh conflicting evidence and determine who has the 

better argument when the dispute is whether adverse effects have been 

mitigated or could be better mitigated.” (Laurel Heights Improvement Assn. 

v. Regents of University of California (1988) 47 Cal.3d 376, 393 (Laurel 

Heights).) Indeed, a reviewing court has “neither the resources nor scientific 

expertise to engage in such analysis, even if the statutorily prescribed 

standard of review permitted [it] to do so.” (Ibid.)

II.

Compliance with Substantive CEQA Requirements

“CEQA is a comprehensive scheme designed to provide long-term 

protection to the environment. [Citation.] In enacting CEQA, the 

Legislature declared its intention that all public agencies responsible for 

regulating activities affecting the environment give prime consideration to 

preventing environmental damage when carrying out their duties.” 

(Mountain Lion Foundation v. Fish & Game Com. (1997) 16 Cal.4th 105, 112 

(Mountain Lion).) In general, CEQA applies to discretionary projects carried 

out by public agencies (Pub. Resources Code, § 21080, subd. (a).) CEQA 

requires a public agency to either prepare an environmental impact report 

(EIR) where there is substantial evidence that a proposed project will have a 

significant effect on the environment or adopt a negative declaration where 

there is no substantial evidence of a significant effect based on the record. 

(Pub. Resources Code, § 21080, subds. (c), (d).)

5 Title 14, section 15000 et seq. of the California Code of Regulations 

codifies the regulations under CEQA. 
10

“Pursuant to Public Resources Code section 21080.5, state regulatory 

programs which meet certain environmental requirements and are certified 

by the Secretary of the Resources Agency are exempt from some of the usual 

CEQA requirements. [Citation.] There is no mandate for such programs to 

prepare initial studies, negative declarations, and EIRs.” (Pesticide Action 

Network North America v. Department of Pesticide Regulation (2017) 

16 Cal.App.5th 224, 239 (PANNA).)

Instead, these programs submit a “plan or other written 

documentation” in lieu of submitting an EIR in support of certain activities or 

discretionary projects. (Pub. Resources Code, § 21080.5, subd. (a).) Such a 

plan or document “serves as a functional equivalent of an EIR.” (Mountain 

Lion, supra, 16 Cal.4th at p. 113.) However, as this court has held, the 

environmental documents prepared by these programs “remain subject to the 

broad policy goals and substantive standards of CEQA not affected by the 

limited exemption set forth in section 21080.5, subdivision (c).” (PANNA, 

supra, 16 Cal.App.5th at p. 242.) “The same CEQA guideline which confirms 

that certified regulatory programs are ‘exempt from the requirements for 

preparing EIRs, negative declarations, and initial studies’ immediately 

explains, ‘A certified program remains subject to other provisions in CEQA

such as the policy of avoiding significant adverse effects on the environment 

where feasible.’ (Cal. Code [R]egs., tit. 14, § 15250, italics added.)” (PANNA

at p. 241.)

The Department’s pesticide registration program is a certified 

regulatory program under CEQA and governs “[t]he registration, evaluation, 

and classification of pesticides.” (Cal. Code Regs., tit. 14, § 15251, 

subd. (i)(1).) This certified program is exempt from preparing EIRs under 

CEQA, but as its own regulations reflect, CEQA requires it to prepare public 
11

reports that include “a statement of any significant adverse environmental 

effect that can reasonably be expected to occur, directly or indirectly, from 

implementing the proposal, and a statement of any reasonable measures that 

are available to minimize significant adverse environmental impact.”

(§ 6254.) The reports must also “contain a statement and discussion of 

reasonable alternatives which would reduce any significant environmental 

impact.” (Ibid.) The Department’s program remains subject to “CEQA’s 

substantive requirements to thoroughly evaluate specific environmental 

effects before it approves an activity.” (PANNA, supra, 16 Cal.App.5th at 

p. 243.)

III.

CEQA’s Application to the Department’s Decision 

Before turning to the merits of the challenged decision, we first address 

the Department’s argument that CEQA does not apply. Public Resources 

Code section 21080, subdivision (5) states that CEQA does not apply to 

“[p]rojects which a public agency rejects or disapproves.” The Department

argues that its decision not to reevaluate diphacinone falls into this 

subdivision since it was a decision not to do something. In response, Raptors 

argues that the “project” at issue was not merely the Department’s decision 

not to reevaluate diphacinone, but more broadly its decision to renew the 

registration for diphacinone without placing it into reevaluation. We find 

that CEQA applies to the challenged decision.

Under CEQA, a “project” is defined as “the whole of an action, which 

has a potential for resulting in either a direct physical change in the 

environment, or a reasonably foreseeable indirect physical change in the 

environment” that is undertaken by a public agency. (Cal. Code Regs., tit. 14, 

§ 15378, subd. (a).) “Courts have considered separate activities as one CEQA 
12

project and required them to be reviewed together where, for example, the 

second activity is a reasonably foreseeable consequence of the first activity 

[citation]; the second activity is a future expansion of the first activity that 

will change the scope of the first activity’s impacts [citation]; or both 

activities are integral parts of the same project [citation].” (Sierra Club v. 

West Side Irrigation Dist. (2005) 128 Cal.App.4th 690, 698 (Sierra).) 

The policy behind CEQA mandates “that environmental considerations 

do not become submerged by chopping a large project into many little ones—

each with a minimal potential impact on the environment—which 

cumulatively may have disastrous consequences.” (Bozung v. Local Agency 

Formation Com. (1975) 13 Cal.3d 263, 283-284.) Indeed, “[a] public agency

may not divide a single project into smaller individual projects in order to 

avoid its responsibility to consider the environmental impacts of the project 

as a whole.” (Sierra, supra, 128 Cal.App.4th at p. 698.)

The Department contends that Raptors waived any challenge to the 

Department’s renewal decision since the only issue raised in Raptors’ opening 

brief was the Department’s November 16, 2018 decision not to reevaluate 

diphacinone challenged in its second cause of action.6 The Department

further argues that even if we were to consider renewal and reevaluation as 

part of one project, “CEQA does not impose separate requirements on the 

annual renewal decisions,” an argument it bases on CATS ̧ supra, 

136 Cal.App.4th 1049. We do not find these arguments persuasive.

6 The second amended petition originally included a first cause of action 

that challenged the Department’s April 18, 2018 decision to renew the 

registration of diphacinone without reevaluation. The parties stipulated to 

dismiss this cause of action based on the holding in CATS, 

supra ̧136 Cal.App.4th 1049, 1066 (that the decision to reevaluate a pesticide

is not tied to the 60-day renewal period) while preserving Raptors’ right to 

appeal the dismissal of this cause of action.
13

First, the record reflects that the Department’s November 16, 2018 

decision not to reevaluate diphacinone was not an isolated activity but

resulted from the Department’s proposed decision to renew its registration 

for 2018 and Raptors’ December 22, 2017 responsive request that the 

Department reevaluate that and other rodenticides. Raptors supplemented 

its request with additional information over the next several months. The 

Department’s own regulations demonstrate the connection between renewal 

and reevaluation, requiring that, “when renewing a pesticide registration 

without a reevaluation, [the Department “shall”] make a written finding that 

[it] has not received sufficient information necessitating reevaluation 

pursuant to Sections 6220 and 6221.” (§ 6215, subd. (c).) The Department 

made such a finding in its April 2018 Final Decision.

The Department’s response to Raptors’ request for reevaluation in 

March 2018 further demonstrates the relationship. It stated it was “in the 

process of reviewing data submitted by the California Department of Fish 

and Wildlife and wildlife organizations” and would be proceeding with 

renewal of the rodenticides without placing them into reevaluation at this

time. The Department confirmed this in its “Final Decision Regarding 

Renewal of Registration of Pesticide Products for 2018” that was published on 

April 18, 2018. (Italics added.) Raptors challenged this decision under its 

now dismissed first cause of action. On November 16, 2018, the Department 

further responded to Raptors that it had completed its investigation in 

response to Raptors’ December 2017 request and would be placing SGARs 

into reevaluation, but not FGARs, which include diphacinone. This decision

was accompanied by a 35-page investigation report.

The foregoing shows that the Department’s ultimate decision not to 

reevaluate diphacinone was connected to its renewal decision. Pursuant to 
14

section 6253, on November 17, 2017, the Department posted its notice of 

proposed decision to renew pesticide registrations for 2018 for at least 

30 days for public review and comment. Raptors submitted its comments 

within this 30-day timeframe that included a request that diphacinone be 

reevaluated based on the significant risk its continued use posed to wildlife.

Pursuant to section 6215, subdivision (b), the Department renewed the

registration for diphacinone within 60 days of receiving a completed renewal 

application. The Department did not and was not required to make a 

decision as to reevaluation within this limited 60-day period and could

instead “initiate reevaluation once it has completed its review of all available 

evidence.” (CATS, supra, 136 Cal.App.4th at p. 1066.) In CATS, the court 

emphasized that the Department was not required to make a rushed decision 

regarding reevaluation but could initiate reevaluation after it had an 

opportunity to review all the scientific evidence before it. (Ibid.) This 

underscores the importance of reevaluation to the Department’s substantive 

assessment of a pesticide’s environmental impact and continued use.

Accordingly, here, following renewal, the Department continued its 

review and investigation pursuant to Raptors’ original request. In 

November 2018, it notified Raptors that it had completed its investigation 

and would not be reevaluating diphacinone. We view this not as a 

disapproval of a project but as the Department’s approval of the continued 

use and sale of this rodenticide. The Department in essence, was affirming 

the earlier finding it made at renewal that it had not received sufficient 

evidence to show it should undertake reevaluation. (§ 6215, subd. (c).) 

This case is distinguishable from Main San Gabriel Basin Watermaster 

v. State Water Resources Control. Bd. (1993) 12 Cal.App.4th 1371 (San 

Gabriel), the main case cited by the Department to support its position that 
15

CEQA does not apply to project disapprovals. In San Gabriel, the court held 

that CEQA review did not apply to a public agency’s disapproval of a landfill 

expansion project. The court reasoned that the Legislature “evidently 

concluded that public agencies should not be forced to commit their resources 

to the costly and time-consuming environmental review process for proposed 

private development projects slated for rejection, whatever the reason for 

agency disapproval.” (San Gabriel, at p. 1384.) Here, by contrast, the project 

at issue is not development or construction proposed by a private individual, 

but a request for the Department, a public agency, to reevaluate a rodenticide 

that it originally approved for sale and use in California. Again, the 

Department’s own regulations acknowledge its obligations to scrupulously 

evaluate pesticides before they are registered and then to continuously 

monitor whether reevaluation is warranted in response to new information. 

Based on the foregoing, we interpret the project or “the whole of [the]

action” to encompass both the Department’s decision to renew the 

registration of diphacinone and its decision not to reevaluate diphacinone in 

response to Raptors’ request. These are related decisions that ultimately 

resolve one question: whether the continued, unrestricted use of diphacinone 

is warranted given its potential adverse impact on the environment. This 

interpretation furthers CEQA’s substantive policy that certified regulatory 

programs must avoid “significant adverse effects on the environment where 

feasible.” (Cal. Code Regs., tit. 14, § 15250.) To hold otherwise would mean 

that only the Department’s decision to re-evaluate a pesticide could be 

challenged while a decision declining re-evaluation would be insulated from 

CEQA, despite the greater potential for significant adverse environmental 

effects from a decision of the latter kind.
16

The Department argues that CEQA does not apply to its annual 

renewal decisions based on the holding in CATS, supra, 136 Cal.App.4th

1049. There, the court held that the Department was not required “to make a 

hasty decision regarding possible reevaluation of a pesticide by tying 

reevaluation to the 60-day time frame of annual renewal. Revaluation can 

take place at any time and is not linked in any way to annual renewal.” 

(CATS, at p. 1066.) As discussed above, we view the decision in CATS as 

highlighting the importance of reevaluation by not limiting it to the 60-day

time frame for renewal. 

In PANNA, supra, 16 Cal.App.5th 224, the Department made a similar

argument before this court—that its pesticide registration program was 

exempt from CEQA’s substantive requirements based on the holding in 

CATS. This court disagreed and held that “[CATS] concerned a CEQA

challenge related to the Department’s procedure for annually reviewing 

registered pesticides and whether the Department had to annually reopen 

the review for public comment as part of the renewal process.” (PANNA, at 

p. 242.) The CATS court did not address CEQA’s substantive requirements

governing the substance of the Department’s environmental review and does 

not stand for the proposition that the Department is exempt from those

requirements. (PANNA, at p. 242.)

As in PANNA, here, the challenge does not involve the timing or 

procedure governing the Department’s renewal and reevaluation process;

instead, it raises the question whether the Department’s environmental 

review of diphacinone satisfies CEQA’s substantive mandate. PANNA, not 

CATS, governs the applicability of CEQA here.
17

IV.

There Was Prejudicial Abuse of Discretion by the Department.

We now turn to Raptors’ substantive arguments that there was a 

prejudicial abuse of discretion by the Department. “Abuse of discretion is 

established if the [Department] has not proceeded in a manner required by 

law or if the determination or decision is not supported by substantial 

evidence.” (Pub. Resources Code, § 21168.5.) Raptors contends that the 

Department committed the following legal errors in its decision not to 

reevaluate diphacinone: 1) the Department failed to perform a cumulative 

impacts analysis under CEQA; and 2) the Department’s investigation report 

failed to disclose accurate and complete information. These claimed legal 

errors are reviewed de novo. (Vineyard, supra, 40 Cal.4th at p. 435.) 

A. Cumulative Impacts Analysis 

“A substantive CEQA requirement is the assessment of a project’s 

cumulative impacts on the environment. This concept considers the 

incremental effect a proposed approval may have when viewed in connection 

with past, current or future approved projects.” (PANNA, supra,

16 Cal.App.5th at p. 248.) “Cumulative impacts” is defined as “two or more 

individual effects which, when considered together, are considerable or which 

compound or increase other environmental impacts.” (Cal. Code Regs., 

tit. 14, § 15355.)

In every case, a public agency is required “to make at least a 

preliminary search for potential cumulative environmental effects, and, if any 

such effect were perceived, at least a preliminary assessment of its 

significance.” (Laupheimer v. State of California (1988) 200 Cal.App.3d 440, 

462-463 (Laupheimer).) While “ ‘technical perfection’ ” is not required, “the 

cumulative impact analysis must be substantively meaningful.” (Joy Road 

Area Forest & Watershed Assn. v. California Dept. of Forestry & Fire 
18

Protection (2006) 142 Cal.App.4th 656, 676.) This includes “adequacy, 

completeness, and a good faith effort at full disclosure.” (Cal. Code Regs., 

tit. 14, § 15151.) A public agency’s failure to consider cumulative impacts 

constitutes a prejudicial abuse of discretion. (Environmental Protection 

Information Center, Inc. v. Johnson (1985) 170 Cal.App.3d 604, 625.)

“A cumulative analysis which understates information concerning the 

severity and significance of cumulative impacts impedes meaningful public 

discussion and skews the decisionmaker’s perspective concerning the 

environmental consequences of the project, the necessity for mitigation 

measures, and the appropriateness of project approval.” (Citizens to Preserve 

the Ojai v. County of Ventura (1985) 176 Cal.App.3d 421, 431.) For example, 

in Laupheimer, supra, 200 Cal.App.3d 440, the court found that the 

Department of Forestry failed to perform a sufficient analysis of the 

cumulative impacts of a timber harvesting plan, including the increased risks 

of causing landslides and runoff damage in areas beyond the logging site. 

The court criticized the Department of Forestry’s “approach” as “minimiz[ing]

the adverse effects of logging operations on the 28 Plan site itself, and . . .

assum[ing] that such minimization would sufficiently mitigate offsite impacts 

of whatever kind. Such an approach was expressly rejected as ‘at odds with 

the concept of cumulative effect, which assesses cumulative damage as a 

whole greater than the sum of its parts.’ ” (Id. at p. 466.) 

Here, Raptors argues that the Department’s decision improperly relied 

on a comparative analysis of the effects of FGARs versus SGARs, instead of a 

cumulative analysis that considers the incremental effect of diphacinone

when used in addition to other anticoagulant rodenticides over time. Raptors 

contends that this lack of a cumulative impacts analysis constitutes an abuse 

of discretion by the Department. We agree.
19

Although Raptors’ original request for reevaluation included seven 

rodenticide products (three FGARs and four SGARs), the Department was

obligated under CEQA to perform a cumulative impacts analysis as to each of 

these rodenticides, including diphacinone. (PANNA, supra, 16 Cal.App.5th at

pp. 249-250.) This includes an analysis of each rodenticide’s prevalence, 

toxicity, effect on non-target wildlife, and the effect of its interaction with 

other rodenticides (like brodifacoum) on non-target wildlife. The 

Department’s 35-page report contains no discussion of the cumulative 

impacts resulting from the combination of diphacinone with other 

rodenticides present in the environment, but instead focuses on the relative

toxicity and effects of FGARs compared to those of SGARs.

7 This is so despite 

the fact that, with respect to mammals, diphacinone was shown to have a 

toxicity value only second to brodifacoum (an SGAR). In the Department’s 

letter notifying Raptors of its decision, the Department states that it “has 

decided not to reevaluate FGARs at this time” because its “investigation of 

the reported impacts found that the rate of FGAR exposure among non-target 

wildlife is generally decreasing and is lower than for SGARs.”

After discussing the various data and studies that were submitted by 

Raptors’ counsel, the Department stated in its investigation report that it 

found FGARs to be less toxic, less persistent, and less bioaccumulative than 

SGARs. Based on this, the Department concluded that “current uses of 

FGARs are unlikely to have a significant adverse impact to non-target 

wildlife.” Put differently, the Department concluded that because FGARs as 

a class posed less risk than SGARs as a class, FGARs were unlikely to have a 

significant adverse impact. What is lacking is any consideration of the effects 

7 The investigation report makes no mention of “cumulative impacts” 

at all. 
20

of diphacinone in particular, including any cumulative or incremental 

impacts resulting from its continued use in addition to the use and effects of

other approved rodenticides in the environment. The Department thus failed 

to consider the cumulative impacts it was required to consider under CEQA.

The importance of a cumulative impacts analysis stems from the fact 

that damage to the environment often occurs incrementally from various

small projects. In Kings County Farm Bureau v. City of Hanford (1990) 

221 Cal.App.3d 692, 720, the court found that an EIR that focused on “the 

ratio between the project’s impacts and the overall problem” did not 

adequately assess the project’s cumulative impacts. The court held that “the 

standard for a cumulative impacts analysis is defined by the use of the term 

‘collectively significant’ in Guidelines section 15355 and the analysis must 

assess the collective or combined effect of energy development. The EIR 

improperly focused upon the individual project’s relative effects and omitted 

facts relevant to an analysis of the collective effect this and other sources will 

have upon air quality.” (Kings County, at p. 721.)

Similarly, here, the Department did not assess diphacinone’s 

cumulative or incremental effect on non-target wildlife in conjunction with 

the effects of other anticoagulant rodenticides over time. (See PANNA, 

supra, 224 Cal.App.5th at p. 248.) Instead, it concluded that reevaluation of 

FGARs was not warranted since FGARs were found to be less toxic and 

persistent than SGARs. However, in exercising its regulatory functions, the 

Department was required to consider each rodenticide “in its full 

environmental context and not in a vacuum.” (Laupheimer, supra, 

200 Cal.App.3d at p. 462.) 

The Department’s report focuses on FGARs and SGARs as two broad 

categories of rodenticides, and seemingly minimizes the adverse effects of 
21

FGARs as a whole by comparing them to the more severe effects of SGARs. 

This ignores the unique attributes and risks of diphacinone and more 

importantly does not inform the reader of the potential adverse effects of 

continued diphacinone use when considered in addition to the other 

rodenticides circulating in the environment. This is precisely what CEQA 

was designed to guard against; small projects or decisions that cumulatively 

could have significant consequences on the environment.

The studies submitted to the Department discussed the use and 

prevalence of diphacinone. For example, as summarized in the investigation 

report, in a 16-year study of urban bobcats in Los Angeles, diphacinone was 

detected in approximately 30% of the blood samples tested and 40% of the

liver samples tested. It was the most frequently detected FGAR, despite 

having a shorter half-life than any of the SGARs. The report further found 

that, with the exception of bromadiolone, more diphacinone was sold and 

used than any other rodenticide in 2016. 

The Department argues that the urban bobcat study is not significant

since it did not find a positive association between diphacinone exposure and 

mange in bobcats. However, in the comments by one of the study’s authors 

that was submitted to the Department, the author notes that FGARs are not 

detected “as frequently in liver samples because they have much shorter halflives than the second-generation compounds.” The author goes on to conclude 

that “[o]ne of our significant findings using this method is that we learned we 

have been underestimating wildlife (or at least bobcat) exposure to firstgeneration anticoagulants by relying solely on liver samples to do the 

testing.” Although this does not mean that there is in fact a positive 

association between diphacinone exposure and mange, it obligated the 
22

Department to at least meaningfully consider the cumulative effects of 

diphacinone given its prevalence and bioaccumulation in non-target wildlife. 

Finally, even if the Department deemed concerns over the cumulative 

effect of continued use of diphacinone to be “too remote and speculative to be 

significant,” at the very least it should have “made the administrative record 

show the requisite consideration.” (Laupheimer, supra, 200 Cal.App.3d at 

p. 467.) The Department was obligated “to make at least a preliminary 

search for potential cumulative environmental effects, and, if any such effect 

were perceived, at least a preliminary assessment of its significance.” (Id. at 

pp. 462-463.) Even if the cumulative impacts of diphacinone were not readily 

apparent from the information the Department received, it still had to state

this conclusion and explain how it was reached. (See PANNA, supra, 

16 Cal.App.5th at p. 250.) The Department did not do either but instead 

concluded that diphacinone did not warrant reevaluation because FGARs as 

a class are less problematic than SGARs.

B. Inaccurate Disclosure of Information 

Raptors next argues that the Department committed separate legal 

errors under CEQA by failing to disclose accurate and complete information

in various portions of its decision and investigation report. 

1. The Department’s Discussion of Diphacinone with Other 

FGARs and Conclusion of a “General Downward Trend

in FGAR Exposure Rates” Constituted Informational 

Deficiencies.

Raptors argues that the Department’s investigation report “failed as a 

CEQA informational document” because 1) it discussed diphacinone together 

with other less harmful FGARs rather than by itself; and 2) its statement 

concerning “ ‘a general downward trend in FGAR exposure rates’ ” was 

misleading. The Department argues that Raptors did not raise these 

arguments before the trial court. Although Raptors did not raise these exact 
23

arguments below, it did argue that it was an error for the Department to

compare the relative effects of FGARs and SGARs because such an approach 

disregards the impact of diphacinone as an individual rodenticide and as a 

contributing factor affecting the environment. This argument is adequately 

related to the informational deficiency issues Raptors now raises, as they all 

stem from the Department’s failure to evaluate the effects of diphacinone 

individually.

Even if Raptors did not adequately raise these issues below, we 

exercise our discretion and decide these questions of law on appeal, especially 

since they involve issues of public interest. (POET, LLC v. State Air 

Resources Bd., supra, 218 Cal.App.4th 681, 750-751.) We find that based on 

the Department’s failure to perform a cumulative impacts analysis, its 

investigation report also fails as an accurate informational document 

because, by grouping diphacinone together with other FCARS, it fails to 

provide “for intelligent weighing of the environmental consequences of the 

project.” (City of Santee v. County of San Diego (1989) 214 Cal.App.3d 1438,

1455.) 

The issue here was not whether the Department should reevaluate 

FGARs as a group of rodenticides, but whether it should reevaluate any of 

the individual rodenticides, including diphacinone, as requested by Raptors. 

By discussing the effects and trends surrounding FGARs as a group, the 

Department did not accurately inform the public of the “significant adverse 

environmental effect that can reasonably be expected to occur, directly or 

indirectly” from continuing to allow diphacinone to circulate in the 

environment. (§ 6254.) As discussed above, diphacinone was the most 

frequently detected FGAR in liver and blood samples collected from the 

urban bobcat study and has a higher toxicity than three of the four SGARs. 
24

Although the Department’s statement that “there is a general downward 

trend in FGAR exposure rates” may be supported by the data, it missed the 

mark because it failed to inform the public as to the effects of diphacinone. 

Based on its prevalence and toxicity, diphacinone is more akin to an SGAR 

and its adverse effects were obscured by the Department’s grouping of it with 

other less prevalent and toxic FGARs.

8

2. The 1980 Owl Study

Raptors contends that the Department’s discussion of a 1980 owl study 

was misinformative and undermined CEQA’s basic information disclosure 

purposes. This study was one of several studies summarized in a 2004 

document by the EPA that assessed rodenticide risks in birds and non-target 

mammals. The principal study examined the effects of several FGARs and 

SGARs on 36 barn owls. The EPA wrote in its 2004 document that “[s]ix of 

the 18 owls exposed to second-generation anticoagulants died, whereas none 

of the 6 owls offered first-generation anticoagulant-poisoned rats exhibited 

any signs of intoxication.” The Department summarized this 2004 EPA 

document in its investigation report and stated, with respect to this study, 

that “[t]here were no mortalities and no observed sublethal effects in any of 

the owls fed rats exposed to FGARs.”

8 For example, mammals are more sensitive to diphacinone (or in other 

words, it is more toxic for them) than either of the other FGARs and any of 

the four SGARs except brodifacoum. The absorption rate for diphacinone is 

also higher than either of the other FGARs and is the same as one of the 

three SGARs. The same is true for exposure rates among non-target wildlife; 

diphacinone’s exposure rate is higher than that of either of the other two 

FGARs and higher than one of the SGARs. Finally, the data available 

indicates there is higher usage of diphacinone than of any other FGAR or 

SGAR, and the second highest usage is of an SGAR (bromadiolone). 
25

Raptors argues that the Department’s above statement was inaccurate

because the 1980 study had also included a preliminary trial in which four 

owls were fed diphacinone-killed mice. All four owls “displayed anticoagulant 

poisoning, and 3 died from massive hemorrhaging.”

9 We do not find that the 

Department erred in its summary. Both the EPA and the Department 

accurately summarized the study’s principal experiment, and both discussed 

the study’s findings as to barn owls—the subjects of the principal experiment.

Raptors does not contend that the summary of this principal study was

incorrect, only that the Department failed to reference the outcome of the

study’s preliminary trial. The EPA’s 2004 document itself does not reference 

the preliminary trial, and Raptors does not provide any support that the 

omitting reference to such preliminary trials constitutes a violation of CEQA. 

Lastly, Raptors argues that the Department’s use of this old owl study 

was misleading because it dismissed current science. We do not find this 

argument persuasive. As the Department states in its brief, it discussed this 

study in its report to further support its position that SGARs generally posed 

greater risks than FGARs. However, the Department also considered and 

discussed numerous other more recent data and studies, including 2015 and 

2018 studies on bobcats and a 2015 study on coyotes. 

3. The 2015 Bobcat Study

Raptors next argues that the Department’s discussion of the 2015 

bobcat study was misinformative and did not comport with CEQA. This was 

a 16-year study of anticoagulant rodenticide exposure in urban bobcats. In 

discussing the study’s findings in an email to the National Park Service, one 

of the study’s authors noted that among the liver samples tested, they “most 

frequently detected second-generation compounds brodifacoum and 

9 The four owls used in the preliminary trial were not barn owls.
26

bromadiolone.” The study’s author also stated that they “have not found an 

association between mange and [FGARs].” However, the author explains 

that “because we underestimate first-generation anticoagulant exposure 

when we test liver samples, a lack of association between mange and firstgeneration anticoagulants could potentially be driven by a bias in the shorter 

tissue half-life of first-generation compounds compared to second-generation 

compounds.” 

In its report, the Department discussed this study in detail and then 

later stated that this study “found statistically significant associations 

between SGARs and mange, but not between FGARs and mange.” The 

Department included this statement to support its conclusion that SGARs 

were more toxic than FGARs. Raptors argues that this conclusory statement

effectively “dismissed the significant diphacinone implications” from this 

study. This includes the study’s findings that diphacinone was the third 

most prevalent anticoagulant compound detected in liver samples and was 

detected in blood samples three times more frequently compared to SGARs. 

The Department’s focus on a comparative analysis of FGARs and 

SGARs undoubtably influenced what it chose to highlight from the 2015 

study’s findings. As we discussed above, the Department erred in not 

performing a cumulative impacts analysis. Had it done so, perhaps it would 

have focused more on the study’s findings as to diphacinone and its exposure 

rate in bobcats. However, we do not find that the Department’s statement 

constituted a legal error, as the study’s author herself stated it did not find

an association found between mange and FGARs. She hypothesized that the 

lack of association “could potentially be driven by a bias in the shorter tissue

half-life” of FGARs compared to SGARs. Raptors argues that because 

diphacinone was commonly detected in the samples tested, it must have 
27

cumulatively contributed to mange along with the SGARs that were detected. 

This finding was not made in the study. Given this, we do not find the 

Department’s statement to be incorrect or misleading.

C. Substantial Evidence

Lastly, Raptors argues that even under the substantial evidence 

standard, which Raptors argues should not be applied here, the challenged 

decision still constitutes a violation of CEQA. The substantial evidence 

standard is a more deferential standard where all reasonable doubts are 

resolved in favor of the agency’s decision. (Laurel Heights, supra, 47 Cal.3d 

at p. 393.)

Raptors contends that there was no substantial evidence to support the 

Department’s decision based on the same arguments it had made to support 

the contention that the Department committed legal error. Since we were 

asked to determine whether there was a prejudicial abuse of discretion based 

on legal error and did find legal error in the Department’s lack of a 

cumulative impacts analysis, we need not analyze the Department’s decision 

under the substantial evidence standard. 

DISPOSITION

The judgment denying Raptors’ petition for writ of mandate is reversed. 

The judgment is remanded to the superior court with instructions to issue a 

writ of mandate directing the Department to reconsider its decision not to 

place diphacinone into reevaluation after it performs a cumulative impacts 

analysis. On remand, the Department should analyze the particular 

characteristics of diphacinone that are relevant to assessing its impact on the 

environment. This includes a discussion, to the extent there is available 

information or data, on diphacinone’s prevalence, toxicity, effect on nontarget wildlife, and the effect of its interaction with other rodenticides on 
28

non-target wildlife. The Department’s analysis should not minimize any 

adverse effects of diphacinone by grouping it with FGARs in general or by

comparing the relative effects of FGARs versus SGARs. Raptors shall 

recover its costs on appeal.
29

STEWART, J.

We concur.

RICHMAN, Acting P.J.

MAYFIELD, J. *

Raptors Are the Solution v. Cal. Dept. of Pesticide Regulation (A161787)

* Judge of the Mendocino Superior Court assigned by the Chief Justice 

pursuant to article VI, section 6 of the California Constitution.