1

Filed 9/6/24

CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIRST APPELLATE DISTRICT

DIVISION FIVE

SUNFLOWER ALLIANCE,

Plaintiff and Respondent,

v.

CALIFORNIA DEPARTMENT OF 

CONSERVATION et al.,

Defendants;

REABOLD CALIFORNIA, LLC,

 Real Party in Interest and 

Appellant. 

 

 A167698

 (Contra Costa County Super. Ct. 

No. N221503)

The California Environmental Quality Act’s regulatory 

guidelines provide an exemption from CEQA for minor 

alterations of an existing facility if the project involves only 

“negligible or no expansion” of the facility’s use. (Cal. Code Regs., 

tit. 14, § 15301.)1 The Department of Conservation’s Division of 

Geologic Energy Management (CalGEM) invoked the exemption 

in approving a project to convert an oil well, which formerly 

pumped oil and water from an aquifer, into an injection well, 

which would pump excess water back into the aquifer. The 

project requires only minor alterations of the well. The question 

1 All references to “CEQA” are to the California 

Environmental Quality Act (Pub. Resources Code, § 21000 et 

seq.). All references to “guidelines” are to the state CEQA 

Guidelines (Cal. Code Regs., tit. 14, § 15000 et seq.). 
2

is whether injecting water, rather than pumping it, constitutes a

negligible expansion of the well’s former use. 

We conclude that any expansion of the well’s use is 

negligible because, under the facts here, the environmental risks 

of injecting the water are negligible. The well conversion project 

falls within the exemption. Because the trial court concluded 

otherwise, we reverse.

BACKGROUND

A.

CalGEM oversees California’s underground injection 

program and, more generally, regulates oil and gas extraction in 

the state. (Pub. Resources Code, §§ 3000-3359; Cal. Code Regs., 

tit. 14, §§ 1724.3-1724.13; see Center for Biological Diversity v. 

Department of Conservation (2018) 26 Cal.App.5th 161, 165-169 

(Center for Biological Diversity).) Underground injection projects 

are governed by federal and state law, both of which place strict 

limitations on the type of injection well at issue here. 

The federal Safe Drinking Water Act protects the nation’s 

drinking water supply. (See 42 U.S.C. § 300f et seq.) Federal 

regulations bar injection into an aquifer unless the 

Environmental Protection Agency affirmatively exempts the 

aquifer from the Safe Drinking Water Act. (40 C.F.R. §§ 144.1(g), 

146.4, 144.7(a) (2024).) The agency may only exempt an aquifer 

when, for specified reasons such as poor water quality, it 

determines the aquifer will never serve as a source of drinking 

water. (40 C.F.R. § 146.4(a)-(c) (2024); see also, Pub. Resources 

Code, § 3131, subd. (a)(2).) Aquifers containing significant 

quantities of oil are among those aquifers, making them eligible 

for exemption and injection. (40 C.F.R. § 146.4(b)(1) (2024).)

Oil wells commonly pump several barrels of water (called 

“produced water”) with each barrel of oil. Well operators 

separate the oil from the produced water, but they then must 
3

dispose of the water, which may be very poor quality. One 

common solution is to inject the water back into an exempt oilbearing aquifer, using what both federal and state law deem a 

Class II well. (40 C.F.R. § 144.6(b)(1) (2024); Pub. Resources 

Code, § 3130, subd. (b).) 

CalGEM, in consultation with the State Water Resources 

Control Board and the Regional Water Quality Control Boards,

reviews Class II well applications for compliance with state and 

federal requirements. (Cal. Code Regs., tit. 14, § 1724.6.) An 

applicant must demonstrate that the injected water will be 

confined by the aquifer’s geology and will not escape the exempt 

aquifer through a well, fault, flaw in the well casing, or other 

pathway. (Cal. Code Regs., tit. 14, § 1724.7.) This requires a 

detailed technical review of the aquifer, the proposed injection

well, and the other wells in the area, as well as the plan for 

injection and a monitoring system “to ensure that no damage [to 

the well] is occurring and that the injection fluid is confined to

the approved injection zone.” (Cal. Code Regs., tit. 14, §§ 1724.7, 

subds. (a)-(e), 1724.7.1.) 

State law bars any injection well that allows injected water 

to escape the exempt aquifer or that will harm people or the 

environment: “An underground injection project shall not cause 

or contribute to the migration of fluid outside the approved 

injection zone, or otherwise have an adverse effect on the 

underground injection project or cause damage to life, health, 

property, or natural resources.” (Cal. Code Regs., tit. 14,

§ 1724.8, subd. (a); see also, Pub. Resources Code, § 3131, subd. 

(a).) 

B.

In 2020, Reabold California LLC filed an application with 

CalGEM to convert a former oil well into a Class II injection well. 

The well is in the Brentwood Oil Field, a large oil and gas field in 

Contra Costa County. The well was drilled in 1963, operated as 
4

an oil well for over 20 years, then plugged. The well is more than 

4,000 feet deep. 

Since 1963, dozens of wells in the Brentwood field have 

together pumped over 33 million barrels of water and 3.6 million 

barrels of oil from the aquifer. In 1982, the Environmental 

Protection Agency exempted the aquifer from the Safe Drinking 

Water Act, making it eligible for Class II injection wells. (See 40 

C.F.R. § 146.4(b)(1) (2024).) Two wells have been injecting 

produced water back into the aquifer—about 9.4 million barrels

so far. 

Reabold operates two nearby oil wells that produce about 

300 barrels of water per day from an adjacent oil-bearing aquifer. 

Currently, Reabold trucks the produced water to a disposal site

32 miles away, 10 times per week. Injecting the water would 

eliminate these trips.

Reabold proposed minor changes to the proposed injection 

site—it would remove the well plug, install injection equipment 

inside the existing well, and use the existing well pad and access 

road. The site is sparsely vegetated.

Reabold’s application includes a technical report from an 

engineer, a geologist, and a hydrogeologist, with supporting 

analyses, data, maps, well logs, lab reports, history, and other 

information required by CalGEM. The report concludes that the 

injected water would be confined to the aquifer by thick layers 

(about 1,000 vertical feet) of shale. In the general area there are 

22 wells that supply water for domestic or agricultural purposes, 

the deepest of which is 500 feet deep. None of them penetrates

the oil aquifer (3,938 feet deep) or the protective layers of shale. 

Three regulatory agencies—CalGEM, the State Water 

Resources Control Board, and the Regional Water Quality 

Control Board—reviewed Reabold’s application. They posed 

detailed questions and requested additional data in several 
5

rounds of discussions. Eventually, the Regional Board confirmed 

that the aquifer is exempt, concluded that all its concerns had

been resolved, and allowed the project to proceed. CalGEM also 

approved the project, with several regulatory conditions. 

Regarding CEQA, CalGEM found that the project fits 

within the Class 1 categorical exemption as a “minor alteration”

of an existing facility involving “negligible or no expansion” of the 

well’s former use. (Guidelines, § 15301.) By regulation, CalGEM 

has determined that minor well conversions and injection 

projects may fall within the Class 1 exemption (Cal. Code Regs.,

tit. 14, § 1684.1). According to CalGEM, the exemption is applied

on a case-by-case basis after a fact-intensive inquiry. 

In this instance, CalGEM observed, in its notice of 

exemption, that Reabold’s injection equipment would be installed 

within the existing well boring and would require no significant 

surface equipment or new wells. The project would eliminate the 

need for routine trucking of the produced water, and it would 

inject water to the aquifer “cleaner than when it was removed.”

C.

Sunflower Alliance filed a petition for writ of mandate 

challenging CalGEM’s use of the categorical exemption. On the 

merits, the trial court said it was inclined to agree with CalGEM 

and Reabold that the physical modifications to the well are minor 

and fit within the exemption. But the court agreed with 

Sunflower that the Class 1 exemption did not apply because—as 

injection is a “significantly different use”—it was “not convinced 

that changing an oil and gas well into a water injection well 

involves negligible or no expansion of use.” 

The court entered judgment in favor of Sunflower and 

issued a peremptory writ of mandate directing CalGEM to set 

aside its notice of exemption and its approval of the project.
6

Reabold appealed; CalGEM complied with the writ and rescinded 

both its notice of exemption and its project approval letter.

2 

DISCUSSION

A.

We begin with a brief overview of categorical exemptions. 

CEQA embodies a strong public policy of environmental 

protection. (Tomlinson v. County of Alameda (2012) 54 Cal.4th

281, 285 (Tomlinson).) It establishes a three-step process. First, 

the lead agency determines whether a proposed action is a 

“project” within the meaning of the statute. (Id. at p. 286; Pub. 

Resources Code, § 21065.) If so, in the second step, the agency 

determines whether the project is exempt from CEQA. 

(Tomlinson, at p. 286.) If it is exempt, no further environmental 

review is required. (Ibid.) If it is not exempt, the agency 

proceeds to the third step—evaluating the project’s 

environmental impacts, which may include preparing an 

environmental impact report. (Ibid.) 

This case concerns the second step—determining whether 

an exemption applies to the project. Categorical exemptions

define classes of projects that, by regulation, the Secretary of the 

Natural Resources Agency (Secretary) has determined do not 

2 Although CalGEM chose to comply with the writ, Reabold 

is free to pursue an appeal. (See Santa Rita Union School Dist. v. 

City of Salinas (2023) 94 Cal.App.5th 298, 324-325.) CalGEM, 

however, filed a respondent’s brief on the merits and argues that 

the project is exempt. Sunflower asks us to strike the brief on the 

ground that CalGEM is not a proper respondent. Sunflower 

appears to be correct. (See Code Civ. Proc., § 902.) Regardless, 

we accept CalGEM’s brief as an amicus curiae brief. (Cal. Rules 

of Court, rule 8.200(c)(7).)

We deny, as irrelevant to the issues in this appeal, the 

requests for judicial notice filed by Reabold, CalGEM, and 

Sunflower, which relate to an issue we do not reach. 
7

have a significant effect on the environment. (Berkeley Hillside

Preservation v. City of Berkeley (2015) 60 Cal.4th 1086, 1092 

(Berkeley Hillside); Pub. Resources Code, § 21084; guidelines, 

§§ 15300, 15301.) By statute, CEQA does not apply to the 

projects within the exempt categories. (Pub. Resources Code, § 

21080, subd. (b)(9).)

Categorical exemptions provide a measure of certainty and 

predictability in the context of a statute that is famously 

sweeping and imprecise. Our Supreme Court suggested the idea 

in its seminal case Friends of Mammoth v. Board of Supervisors 

(1972) 8 Cal.3d 247, 259 (Friends of Mammoth), disapproved on 

another ground in Kowis v. Howard (1992) 3 Cal.4th 888, 896. In 

Friends of Mammoth, the court interpreted CEQA’s vague terms

expansively to apply to private projects that require government 

approval, contrary to the general belief that it applied only to 

public projects (Berkeley Hillside, supra, 60 Cal.4th at p. 1100), 

and the court warned that the full reach of the statute is “not 

immediately clear.” (Friends of Mammoth, at p. 271.) 

Anticipating an alarmed reaction to its opinion, the court 

reassuringly predicted that “[f]urther legislative or

administrative guidance may be forthcoming” and suggested the 

concept that later became categorical exemptions: “[C]ommon 

sense tells us that the majority of private projects for which a 

government permit or similar entitlement is necessary are minor 

in scope . . . and hence, in the absence of unusual circumstances, 

have little or no effect on the public environment. Such projects, 

accordingly, may be approved exactly as before the enactment of 

[CEQA].” (Friends of Mammoth, supra, 8 Cal.3d at pp. 271-272.) 

The Legislature responded to Friends of Mammoth by 

passing urgency legislation that, among other things, seized on 

the court’s suggestion. The Legislature directed the Secretary to 

adopt regulations (via the guidelines) that establish classes of 

projects that the Secretary has found do not have an effect on the 
8

environment and are therefore exempt from CEQA. (Berkeley 

Hillside, supra, 60 Cal.4th at pp. 1100-1102; see Pub. Resources 

Code, §§ 21083, 21084, subd. (e).) 

Categorial exemptions provide certainty for projects that 

occupy a precarious position—just outside of CEQA’s hazy 

border—by clarifying that CEQA does not apply to them

notwithstanding their potential effect on the environment. (See 

Berkeley Hillside, supra, 60 Cal.4th at p. 1102.) For each exempt 

class, “the Secretary has determined that the environmental 

changes typically associated with projects in that class are not 

significant effects within the meaning of CEQA, even though an 

argument might be made that they are potentially significant.” 

(Id. at pp. 1104-1105.) The guidelines designate more than 30 

categorically exempt classes of projects. (Guidelines, §§ 15301-

15333.) 

The guidelines also include exceptions to the exemptions.

(Guidelines, § 15300.2; Berkeley Hillside, supra, 60 Cal.4th at pp. 

1100-1101, 1104-1105.) When an agency determines that a 

project is categorically exempt, it impliedly finds that none of the 

exceptions applies. (San Francisco Beautiful v. City and County 

of San Francisco (2014) 226 Cal.App.4th 1012, 1022-1023 (San 

Francisco Beautiful).) An objecting party bears the burden of 

producing evidence that an exception does apply. (Berkeley 

Hillside, at p. 1105.) 

Here, Sunflower contends that the well conversion project

does not fit within the class of projects covered by the Class 1 

exemption. Sunflower does not argue that any exceptions apply. 

B.

1.

We must decide whether CalGEM abused its discretion 

when it determined that Reabold’s well conversion project falls 

within the Class 1 categorical exemption. (Pub. Resources Code, 
9

§ 21168.5; see Vineyard Area Citizens for Responsible Growth, 

Inc. v. City of Rancho Cordova (2007) 40 Cal.4th 412, 427 

[appellate court reviews agency’s decision, not trial court’s].) An 

abuse of discretion occurs if the agency failed to proceed in a 

manner required by law or its decision is not supported by 

substantial evidence. (Pub. Resources Code, § 21168.5) 

We apply the de novo standard to CalGEM’s interpretation 

of CEQA and the guidelines. (Walters v. City of Redondo Beach 

(2016) 1 Cal.App.5th 809, 816-817 (Walters).) We treat the 

guidelines as regulations and interpret them in the same manner 

that we interpret statutes, using the traditional rules of statutory 

construction. (Berkeley Hillside, supra, 60 Cal.4th at p. 1097.) 

To the extent that CalGEM’s decision turns on evidence in the 

administrative record, we apply the substantial evidence 

standard. (Walters, at p. 817.)

When interpreting a categorical exemption, moreover, we 

must stay within the reasonable scope of the exemption’s 

language (World Business Academy v. State Lands Com. (2018) 

24 Cal.App.5th 476, 495; Pub. Resources Code, § 21083.1) and 

bear in mind its commonsense purpose. (See Friends of 

Mammoth, supra, 8 Cal.3d at p. 272; Save the Plastic Bag 

Coalition v. City of Manhattan Beach (2011) 52 Cal.4th 155, 175 

[emphasizing importance of common sense “at all levels of CEQA 

review”]; see generally, Berkeley Hillside, supra, 60 Cal.4th at pp. 

1100-1102, 1107-1108.) 

2.

Sunflower’s main argument is that CalGEM misinterpreted 

the Class 1 exemption because well conversion projects, as a 

group, are outside the exemption’s scope. (See Don’t Cell Our 

Parks v. City of San Diego (2018) 21 Cal.App.5th 338, 360-361.)

Class 1 categorical exemptions are aimed at projects 

involving minor alterations of existing structures: “Class 1 
10

consists of the operation . . . permitting . . . or minor alteration of 

existing . . . private structures, facilities, [or] mechanical 

equipment . . . involving negligible or no expansion of existing or 

former use.” (Guidelines, § 15301.) The guidelines emphasize 

that “[t]he key consideration is whether the project involves 

negligible or no expansion of use.” (Ibid.) 

The parties disagree about whether converting an oil well

to an injection well can ever involve “negligible or no expansion” 

of its former use. (Guidelines, § 15301.) Sunflower argues that 

any new use of a modified well is an impermissible expansion.

Because the well has never been used to inject water, it says, the 

exemption does not apply. Reabold argues that the question is 

not whether the use would change but, instead, the degree of 

change. Formerly, the well pumped oil and water from an 

aquifer. As modified, it will inject water back into the aquifer, 

minus the oil. The modified well basically just reverses the 

process. Similarly, CalGEM equates “use” with “purpose”—

whether the well is pumping or injecting, there is no change in 

the well’s purpose to “transport fluid between the surface and 

subsurface.” 

We are not altogether sold on any of these approaches. In a 

sense, both sides are right: injection is a new use of the well, but

it may not be a significant change. The cases cited by the parties 

do not address this particular situation, nor do they identify a 

principle or rule for resolving it. (See, e.g., Turlock Irrigation 

Dist. v. Zanker (2006) 140 Cal.App.4th 1047, 1066 [installation of 

water meters was not water system expansion]; Santa Monica 

Chamber of Commerce v. City of Santa Monica (2002) 101 

Cal.App.4th 786, 793-794 [requiring permits for existing parking 

spaces was not parking expansion]; County of Amador v. El 

Dorado County Water Agency (1999) 76 Cal.App.4th 931, 960, 967 

[diverting large amount of water from stream for municipal use 

was expansion of hydro station’s existing use that left water in 
11

stream]; Azusa Land Reclamation Co. v. Main San Gabriel Basin

Watermaster (1997) 52 Cal.App.4th 1165, 1193-1196 (Azusa)

[landfill was not a “facility” within Class 1, and use of landfill 

was not a “minor” alteration].) 

To find the applicable rule, we begin with the Class 1 

guideline’s language. If we assume (as Sunflower asserts) that 

injection is an “expansion” of the well’s use, the key term becomes

“negligible.” The guideline uses this term to describe the outer 

limits of a permissible expansion: only a negligible expansion of 

use is exempt. (Guidelines, § 15301.) To determine the 

guideline’s intent, we focus on the plain meaning of its language, 

viewed in the context of the statutory scheme. (Berkeley Hillside, 

supra, 60 Cal.4th at p. 1097; Tuolumne Jobs & Small Business 

Alliance v. Superior Court (2014) 59 Cal.4th 1029, 1037.) The 

plain meaning of “negligible” is small, unimportant, or 

inconsequential. (Merriam-Webster Dict. Online (2024)

<https://www.merriam-webster.com/dictionary/negligible> [as of 

Sept. 6, 2024].) We cannot construe “negligible” to mean that any

new use, or change in use, is disqualifying. Such an 

interpretation would read “negligible” out of the guideline. (See 

Taxpayers for Accountable School Bond Spending v. San Diego 

Unified School Dist. (2013) 215 Cal.App.4th 1013, 1026

[“ ‘[c]ourts should interpret statutes or written instruments so as 

to give force and effect to every provision’ ”].)

Focusing instead on the consequences of a change in use is 

a better approach. CEQA’s objective, of course, is protecting the 

environment. (Tomlinson, supra, 54 Cal.4th at p. 285.) In this 

context, then, it makes sense that the term negligible is intended 

to allow changes or expansions in use that are inconsequential 

and to exclude changes in use that threaten environmental harm. 

In other words, when a modified project is put to a new use, the 

change in use is unimportant, as far as CEQA goes, if the risk of 

environmental harm from the new use is negligible. 
12

Our interpretation finds support in the guidelines, in which 

the Secretary provides examples of Class 1 projects to which the 

exemption would apply. For instance, the Secretary states that 

the exemption applies to a project to modify an existing street by

adding new bicycle or transit lanes, but it does not apply to new

car lanes. (Guidelines, § 15301, subd. (c).) In this example, the 

exemption’s application does not turn on whether the additional 

lanes—for bikes, transit, or cars—constitute a new use of the 

street. More likely the Secretary drew the line based on the 

degree of environmental risk produced by the change: bikes and 

transit do not harm air quality, but cars do.

3 (See also id. at 

subd. (n) [conversion of single family residence into office use], 

and id. at subd. (o) [installation of steam sterilization unit in 

existing medical waste generation facility].) 

By focusing on environmental risks, our interpretation 

serves the purpose of categorical exemptions—to exempt from 

CEQA classes of projects that the Secretary has determined 

typically do not have a significant environmental effect. 

(Berkeley Hillside, supra, 60 Cal.4th at pp. 1104-1105; Pub. 

Resources Code, §§ 21083, 21084.) It also appeals to common 

sense for the Secretary to exempt minor modifications to existing 

3 Similarly, the modifications themselves can also cause 

environmental impacts when they are not “minor.” (Guidelines,

§ 15301; see, e.g., id., subd. (e) [exempting minor additions to 

existing structures, based on size and nature of the 

modifications]; Azusa, supra, 52 Cal.App.4th at p. 1194 [“a 

‘minor’ alteration cannot be an activity that creates a reasonable 

possibility of a significant environmental effect”].) Interestingly, 

the exemption applies to the demolition of three or fewer 

residences in urban areas—which might seem like a major 

alteration to the residences but presumably is minor in the sense 

that it poses few environmental risks. (Guidelines, § 15301, 

subd. (l)(1).) Together, the limits on modifications and use 

generally constrain the exempt class to modest, low-risk

modification projects. 
13

projects that pose a negligible threat to the environment. (See 

Friends of Mammoth, supra, 8 Cal.3d at p. 272 [as a matter of 

“common sense,” CEQA does not apply to most projects because 

they “are minor in scope . . . and . . . have little or no effect on the 

public environment”].) No purpose is served by myopically 

focusing on whether a use is new, thereby excluding from the 

exemption many projects that would cause no environmental 

harm— precisely the type of borderline projects for which 

categorical exemptions are useful.

4

The question remains whether converting a former oil well 

to an injection well falls within the scope of the exemption. As 

explained, we reject Sunflower’s blanket argument that the 

exemption never applies to this kind of project because the 

change in use (injecting rather than pumping) is new. We 

conclude that the exemption is appropriate for the relatively 

modest type of conversion project at issue here. 

First, with respect to the physical modifications to the well 

itself, Sunflower does not dispute (and the trial court agreed) that 

the project fits within the Class 1 guideline because it only 

includes “minor alteration[s]” to “existing . . . equipment.” 

(Guidelines, § 15301.) We agree as well. The conversion entails

only modest alterations to the existing well. The project makes

no significant changes to existing roads, the well pad, or 

surrounding vegetation, nor does it entail complicated 

modifications, deepening, or reconstruction of the well.

4 We also note that agencies routinely evaluate potential 

environmental impacts at this early stage of the CEQA process. 

Before invoking a categorical exemption, for example, agencies 

have a duty to consider a project’s environmental impacts when 

evidence in their records suggests the possibility that it may 

trigger an exception to the exemption. (Berkeley Hillside, supra, 

60 Cal.4th at p. 1103; guidelines, § 15300.2, subds. (b), (c).)
14

Second, the change in the well’s use is negligible. The well 

formerly pumped oil and water from an exempt aquifer. Once 

converted to a Class II injection well, it would inject water into 

the same aquifer. The new use is limited to the disposal of 

produced water. It will not involve any other uses, such as 

fracking, that may pose significant environmental risks. (See 

Pub. Resources Code, §§ 3152, 3160.) Part and parcel of the 

project’s approval as a Class II well is a regulatory determination 

that the injected water cannot escape the aquifer and harm 

people, property, or the environment because the injected water

will be geologically confined within the aquifer. (Cal. Code Regs.,

tit. 14, § 1724.8, subd. (a); see also, Pub. Resources Code, § 3131, 

subd. (a).) The environmental risks of the conversion are 

negligible.

Accordingly, we cannot say that this type of well conversion 

is categorically outside the scope of the Class I exemption.

3.

Next, we reject Sunflower’s argument that substantial 

evidence does not support CalGEM’s use of the Class 1 exemption 

for this project.

Sunflower baldly says that “no evidence in the record 

supports a conclusion that this change in use was negligible.”

But it ignores the regulatory agencies’ conclusions and the 

substantial evidence that supports them. (See Save the El Dorado 

Canal v. El Dorado Irrigation Dist. (2022) 75 Cal.App.5th 239, 

263 [CEQA petitioner forfeits argument based on substantial 

evidence if it fails to lay out evidence favorable to agency

finding].) Sunflower does not dispute that almost 1,000 vertical 

feet of shale would confine the injected water to the aquifer. It 

does not argue that the agencies made a mistake. Moreover, it

has expressly waived any challenge to CalGEM’s factual finding 

that there is nothing unusual about this particular Class II well, 

or the aquifer’s geology, that may cause significant 
15

environmental impacts. (See guidelines, § 15300.2, subd. (c)

[unusual circumstances exception]; San Francisco Beautiful, 

supra, 226 Cal.App.4th at p. 1022 [agency’s adoption of 

categorical exemption constitutes implied finding that no 

exception exists].) 

Instead, at most, Sunflower briefly raises concerns that

there “may” be significant adverse impacts although it is 

“unclear.” Even if Sunflower had not forfeited the issue, we are 

not persuaded.

First, Sunflower questions whether the injected water will 

harm the aquifer’s water quality. It asserts that the injected 

water is somewhat more saline than the aquifer, but it does not 

explain why any difference in the injected water’s salinity 

matters.

5 Similarly, Sunflower speculates the aquifer may be 

harmed by a corrosion inhibitor added to the injected water. This 

is pure conjecture—the record simply has no details on the 

nature or amount of the additive, much less any effect (good, bad, 

or immaterial) on the already poor-quality water in the aquifer.

(See Walters, supra, 1 Cal.App.5th at p. 819.) Adding a corrosion 

inhibitor is presumably intended to prevent the well from 

leaking. (See Cal. Code Regs., tit. 14, § 1724.7, subd. (a)(3)(G).) 

The administrative record does not support Sunflower’s 

speculation about harm to the aquifer.

5 In any case, the record does not appear to support

Sunflower’s assertion. Sunflower points to a reviewer’s comment

that the produced (injected) water “appears” to have higher total 

dissolved solids (2,600 parts per million, or ppm) than the aquifer

(1,712 ppm). But the reviewer seems to have mixed up two 

different measurements of salinity. The 1,712 ppm figure is for 

sodium chloride. Sodium and chloride are merely components of 

the total dissolved solids. We were unable to find a measurement 

of the aquifer’s total dissolved solids for comparison. 
16

Second, Sunflower notes that, in CalGEM’s initial review of 

the application, it requested more details on how “fluids would be 

prevented from migrating upwards through [a] non-sealing 

fault.” This is one of many questions the regulatory agencies

raised on a variety of technical issues early in their review. 

Later, based on additional analysis, CalGEM was satisfied that 

“the fault is sealing.” The Regional Board also looked at the 

issue, and it requested, and received, a requirement to conduct a

pressure test to confirm the analysis. The board then stated that 

all its concerns had been resolved. Sunflower presents no basis 

to disregard the technical conclusions of these expert agencies. 

We conclude that substantial evidence—including the 

detailed technical review by CalGEM and the water boards—

supports CalGEM’s determination that the project fits within the 

Class 1 exemption.

C.

Lastly, we reject Sunflower’s argument that CalGEM 

improperly imposed mitigation measures to eliminate the 

project’s (alleged) environmental impacts. 

CalGEM adopted a number of conditions as part of its 

approval of the Class II well. (See Cal. Code Regs., tit. 14, § 

1724.6, sub. (b).) Sunflower asserts vaguely that “numerous 

conditions” are, in reality, mitigation measures that CalGEM 

adopted so that the project would qualify for a categorical 

exemption. In its brief, Sunflower does not discuss any particular 

condition. At oral argument, it identified a condition (mentioned 

above) that the Regional Board had requested—a pressure test

related to a fault.

An agency may not evade CEQA by adopting mitigation 

measures simply to qualify a project for a categorical exemption. 

(Salmon Protection & Watershed Network v. County of Marin

(2004) 125 Cal.App.4th 1098, 1102 (Salmon Protection).) In 
17

Salmon Protection, a county acknowledged a residential 

construction project may have potential adverse impacts on

adjacent stream habitat. It then adopted numerous conditions 

expressly to mitigate the impacts and thereby qualify the project 

for a categorial exemption. (Id. at p. 1104.) The court of appeal 

pointed out that mitigation measures, under CEQA, are only 

proper at later stages of the process, which the county evaded by 

prematurely adopting mitigation measures. (Id. at pp. 1107-

1108; see also Azusa, supra, 52 Cal.App.4th at pp. 1200-1202.)

An agency may, however, impose conditions on a project

that address environmental issues for legitimate reasons without 

running afoul of CEQA. (See Protect Telegraph Hill v. City and 

County of San Francisco (2017) 16 Cal.App.5th 261, 267-268; San 

Francisco Beautiful, supra, 226 Cal.App.4th at pp. 1032-1033.) 

In Walters, supra, 1 Cal.App.5th at pp. 823-824, the court held 

that a city properly adopted conditions requiring a carwash to 

ensure noise levels meet existing regulatory standards, to 

conduct tests to verify that the standards are met, and to make 

any necessary modifications prior to commencing operations. By 

requiring the project to meet the standards, the city simply took a 

“ ‘belt and suspenders’ approach” to ensure that the project would 

cause no significant impacts. (Id. at p. 824.) 

This case is like Walters. The pressure test, like the noise 

test in Walters, ensures that the project meets the existing 

regulatory standards for Class II wells. Those standards require

a Class II well to be operated so that injected water remains

within a specified zone in the aquifer and cannot escape through 

any pathway, such as a fault. (Cal. Code Regs., tit. 14, § 1724.7, 

subds. (a), (a)(2)(A), (a)(2)(C).) There is no significant impact to 

mitigate. 

Indeed, Sunflower fundamentally misconstrues the nature 

of the conditions and the regulations. CalGEM cannot issue a 

permit for a Class II well that violates these standards, nor can 
18

Reabold operate one. (Cal. Code Regs., tit. 14, §§ 1724.6, sub. (b),

1724.7, sub. (a).) Compliance with the standards is a legally 

mandated element of the project, not a CEQA measure to lessen 

the project’s environmental impacts and shoehorn it into a 

categorical exemption. 

In sum, Sunflower has not shown that CalGEM failed to 

proceed in a manner required by law or that its decision is 

unsupported by substantial evidence. (Pub. Resources Code, § 

21168.5.) The trial court erred by concluding otherwise. We have 

no need to reach the parties’ other arguments, including 

Reabold’s contention that the court should defer to CalGEM’s 

regulation for Class 1 exemptions. (Cal. Code Regs., tit. 14, § 

1684.1.) 

DISPOSITION

The judgment granting Sunflower’s petition for writ of 

mandate is reversed. The matter is remanded to the superior 

court with directions to enter a new judgment that (1) denies

Sunflower’s petition for writ of mandate; (2) recalls the court’s 

peremptory writ of mandate requiring CalGEM to set aside its 

notice of exemption and approval of the project; and (3) orders 

CalGEM to reinstate its project approval and notice of exemption. 

Reabold is awarded its costs on appeal. (Cal. Rules of Court, rule 

8.278(a)(1), (a)(2).)

BURNS, J. 

WE CONCUR:

SIMONS, ACTING P.J.

CHOU, J.

Sunflower Alliance v. Reabold California LLC (A167698)
19

Contra Costa County Superior Court, No. N221503, Hon. Edward 

G. Weil. 

Aqua Terra Aeris Law Group, Jason R. Flanders and Theresa M. 

Trillo for Plaintiff and Respondent. 

Environmental Law Clinic, Deborah A. Sivas, Amanda Zerbe, 

Luke Norquist, and Kevin K. Wang for Center for Biological 

Diversity as Amicus Curiae on behalf of Plaintiff and 

Respondent.

Rob Bonta, Attorney General, Daniel A. Olivas, Senior Assistant 

Attorney General, Christina Bull Arndt, Supervising Deputy 

Attorney General, and Leena M. Sheet and Jackie K. Vu, Deputy 

Attorneys General, for Defendants.

Paul Hastings LLP, Navi Singh Dhillon, Christopher J. Carr, and 

Dylan J. Crosby for Real Party in Interest and Appellant.

Alston & Bird LLP, Jeffrey D. Dintzer, Jeffrey P. Carlin, and 

Ytran L. Hoang for Western States Petroleum Association as 

Amicus Curiae on behalf of Real Party in Interest and Appellant.