Fort Mojave Indian Tribe v. California Department of Health Services (38 Cal. App. 4th 1574, 1995)

Opinion

FUKUTO, J.

This case concerns the California Department of Health Services’ (DHS) approval of an environmental impact report (EIR) and license for the construction and operation of a low-level radioactive waste (LLRW) disposal facility at Ward Valley, San Bernardino County, in the Mojave Desert. Petitioners, the Fort Mojave Indian Tribe (Tribe) and three nonprofit corporations, sought a writ of mandate invalidating DHS’s decisions certifying the EIR and granting the license to real party in interest US Ecology, Inc. (US Ecology). California Radioactive Materials Management Forum (Forum), an organization of institutions that generate LLRW and require its disposal, intervened in opposition. The trial court gave judgment denying the petition on all substantive grounds, but requiring that the approvals be set aside and reconsidered in light of a scientific report, issued after their grant, which discussed the possibility of contamination of the Colorado River from the facility.

All parties have appealed. Petitioners seek broader relief from DHS’s decisions, while respondents seek reversal of the limited grant of the writ and thus denial of the petition. We have concluded that there was insufficient basis to remand the matter for reconsideration, and that petitioners’ other grounds for setting aside DHS’s disposition were correctly determined to be without merit. We therefore reverse with directions to deny the petition.

Statement of the Case

1. The Administrative Proceedings.

The general background of the proceedings under review is described in California Radioactive Materials Management Forum v. Department of Health Services (1993) 15 Cal.App.4th 841, 848-854 [19 Cal.Rptr.2d 357] (CalRad), which also concerned those proceedings. In brief, LLRW is statutorily defined by excluding certain other radioactive material, the responsibility for safe disposal of which generally resides in the federal government. LLRW comprises a variety of radioactive materials, used in or generated by many medical, industrial, research, and other activities and facilities. (See 15 Cal.App.4th at p. 849.) Only six facilities for land disposal of LLRW have previously been established, between 1963 and 1971. Most of them have since been closed. (Id. at pp. 849-850.)

In 1980 and again in 1985, Congress enacted legislation to encourage every state to provide for disposal of its own LLRW, preferably on a regional basis pursuant to interstate compacts. (See CalRad, supra, 15 Cal.App.4th at pp. 850-851.) In response, California enacted a series of amendments to its 1961 Radiation Control Law (Health & Saf. Code, § 25800 et seq. (RCL)). The amendments first required DHS, the agency already responsible for issuing licenses under the RCL (Health & Saf. Code, § 25810), to plan for the disposal of California’s LLRW. (E.g., Health & Saf. Code, §§ 25811.5, 25811.7.) The Legislature then directed the Governor to enter into an interstate compact, and DHS to select a private contractor, for a waste disposal facility. (See CalRad, supra, at pp. 851-852.)

In 1987, California entered into the Southwestern Low-Level Radioactive Waste Disposal Compact (Health & Saf. Code, §§ 25877-25878 (compact)), with Arizona, North Dakota, and South Dakota. The compact provided that this state would be the “host state” for a regional LLRW disposal facility for the first 30 years, the role thereafter to be extended or transferred at California’s option. (Health & Saf. Code, § 25878, art. 2, subd. (G), art. 4, subd. (C)(1).) The compact obligated California to cause the facility to be developed on a timely basis, and to assure, among other things, protection and preservation of public health and safety in its siting, licensing, operation, closure, and long-term care. (Health & Saf. Code, § 25878, art. 4, subds. (E)(1), (2); see CalRad, supra, 15 Cal.App.4th at p. 852.)

Pursuant to its statutory duty, DHS in 1985 selected US Ecology as the contractor, and prospective licensee, for the facility. US Ecology had operated four of the six previous LLRW facilities.

Both parties then turned to examining possible sites for the facility. Sixteen were considered. After extensive surveys, analyses, consultations and scientific studies, DHS selected as the preferred site among three candidates a location at Ward Valley, situated in a-closed surface basin in the southeastern comer of the state, about 20 miles (including mountains) from the Colorado River. The site is extremely arid, with average annual rainfall of less than 5 inches but average annual evaporation of 80 to 100 inches, and with groundwater about 650 feet below surface, all helpful conditions for secure burial of enclosed waste.

The Ward Valley site was (and still is) owned by the federal government, through the Department of the Interior’s Bureau of Land Management (BLM). Employment of the site therefore required transfer of title to California. The federal transfer in turn required review and an environmental impact statement under the National Environmental Policy Act (42 U.S.C. § 4321 et seq.). DHS’s own licensing of US Ecology also required environmental review, and an EIR, under the California Environmental Quality Act (Pub. Resources Code, § 21000 et seq. (CEQA)). DHS and BLM agreed to prepare the EIR and environmental impact statement as a joint document.

Between 1989 and 1993, the DHS regulatory process proceeded on two overlapping tracks: preparation of the EIR under CEQA, and completion and review of US Ecology’s license application under the RCL. The initial, 11-volume license application was followed by DHS’s propounding and US Ecology’s responding to 4 sets of amplifying and clarifying interrogatories. The application focused on US Ecology’s proposed methods for waste disposal, in compliance with federal regulations, including description of the types, amounts, and sources of waste to be received. The proposed disposal method involved burying the waste, enclosed in sealed containers, in a series of trenches, which would be refilled with earth and planted over. The trenches would be unlined, out of concern for moisture-dispersal, with a view toward prevention of waste migration.

As prepared and augmented, the license application became part of the EIR, physically or by reference. The draft EIR was released for public comment in June 1990. (See Guidelines, § 15084 et seq.) In July 1990, concurrently with BLM’s public hearings on the draft EIR (no such separate hearings being required by CEQA), DHS held public comment hearings on the license application. The final EIR, including responses to comments received on the draft, was issued in April 1991. In the EIR, DHS concluded that the possibility for contamination of the Colorado River by accidental release and long-term migration of radioactive matter from the facility was not realistic, in light of (among other things) the physical and temporal inaccessibility of local groundwater and the separation between the Ward Valley and the river. In July 1991, DHS held recorded hearings on the license application, before an administrative law judge. (See Health & Saf. Code, § 25845, subd. (a).)

The state licensing process, and the federal transfer, then became embroiled in proceedings at other levels of government. In 1992, the state Senate Rules Committee extracted a commitment from DHS to hold an additional, APA-type hearing on the project. That requirement ultimately was ruled to lack basis in law, and DHS was directed to proceed to consider the license application without regard to it. (CalRad, supra, 15 Cal.App.4th 841.) In the meantime, a new administration and Secretary of the Interior had assumed office. Secretary Bruce Babbitt resolved to proceed deliberately with the site transfer, and asked Governor Wilson to hold further hearings to that end.

In February 1993, three United States Geological Survey (USGS) geologists with professional experience in the area—Howard Wilshire, Keith Howard, and David Miller—wrote to Secretary Babbitt, stating that they had not been “consulted in the planning process,” and offering consultation. The Secretary’s special assistant requested their comments. On June 2, 1993, Wilshire, Howard and Miller responded with a three-page memorandum based on their review of the draft EIR of three years earlier (the Wilshire memorandum). The memorandum set forth seven alleged deficiencies in that EIR, devoting a paragraph to each. The three that the authors labeled significant were as follows.

First, the authors concluded, from the persistence of vegetation downslope from flood control levees in the desert, that shallow subsurface water flow persisted; hence, infiltration of the proposed LLRW facility’s trenches by such flow had to be considered. Second, the EIR allegedly gave “[n]o information” about the properties of the unsaturated zone and the potential for groundwater contamination should waste leak. Third, the EIR allegedly lacked information about hydrologic interconnection of the Ward Valley and Colorado River basins, and although the selection of a topographically closed basin was “a first step,” it was not sufficient in view of “our general state of ignorance on hydrologic connections.” The authors stated that groundwater systems elsewhere in the vicinity did cross between topographically separated basins.

On June 25, 1993, US Ecology sent Secretary Babbitt a four-page summary response to the Wilshire memorandum, under cover of a letter protesting the authors’ failure to consult with DHS or review the final EIR and license application, which had addressed the stated concerns. With respect to the three significant issues, the response cited studies conducted during the license and EIR approval process which had produced negative conclusions about subsurface flow, the properties and propensities of the unsaturated zone, and the possibility of hydrologic connection between the two basins. DHS included both the Wilshire memorandum and US Ecology’s response in the final EIR.

On August 30, 1993, the Department of the Interior announced a proposed designation of critical habitat for the desert tortoise, a threatened species under the Endangered Species Act (16 U.S.C. § 1531 et seq.). The proposal included the project site among over 6,000,000 acres to be so designated. DHS already had extensively studied the effects of the project on the tortoise and its desert habitat, and had included findings and mitigation measures in the EIR.

On September 16, 1993, Governor Wilson responded to Secretary Babbitt’s request that a hearing be conducted to inform the federal decision, and agreed to do so. Expressing satisfaction with DBS’s performance of its assigned role, and the sufficiency of the administrative record, the Governor further stated that he would direct DHS to act on the license application presently. On the same date, DHS finally certified the EIR (Guidelines, § 15090) and approved US Ecology’s license—the decisions now under review.

2. The Present Litigation.

On October 15, 1993, one month following DHS’s decisions, petitioners filed their petition for writ of mandate, under section 21168 and Code of Civil Procedure section 1094.5, naming DHS as respondent and US Ecology as real party in interest. Petitioners alleged that in certifying the EIR and issuing the license DHS had violated both CEQA and the RCL. The petition alleged several deviations from CEQA, including failure adequately to assess the “waste stream” (types and amounts of waste to be disposed of), and failure to recirculate the EIR following receipt of new information of various types, including the proposed federal designation of tortoise habitat and the Wilshire memorandum. Under the RCL, petitioners claimed a number of procedural deficiencies, and alleged that several of DHS’s findings, including that of US Ecology’s qualifications, were unsupported.

On motion, the Forum was permitted to intervene. The court thereafter granted US Ecology’s motion for summary adjudication (Code Civ. Proc., § 437c, subd. (f)) that, in conformity with CalRad, supra, 15 Cal.App.4th 841, an APA-type hearing had not been required for the license.

Before the hearing on the merits, two extrinsic events occurred. On February 8, 1994, the Department of the Interior published in the Federal Register its final designation of critical habitat for the desert tortoise, including the project site. Petitioner Committee requested that DHS prepare a supplemental or subsequent EIR for the project (§ 21166) in light of this designation, and petitioners requested the court take judicial notice of it. Over DHS’s relevancy objection, the court did so.

Second, on December 2, 1993, the authors of the Wilshire memorandum issued a 39-page report (with appendices), restating and discussing the concerns set forth in that memorandum (the Wilshire Report). Although bearing the authors’ USGS address, the report specifically stated that it represented only the authors’ views, not those of any agency. The report explained that United States Senator Barbara Boxer had asked the authors in September 1993 to respond to US Ecology’s response to the Wilshire memorandum, and USGS had allowed them to respond as individuals. The report indeed was structured as a rebuttal to US Ecology’s critique of the Wilshire memorandum. The Wilshire Report reiterated its authors’ criticisms of the EIR, with particular regard to the three significant issues concerning groundwater infiltration and transport of wastes. It included further discussion of the basis for the authors’ geological hypotheses, including an analysis of five theoretical “pathways” for groundwater from Ward Valley to the Colorado River.

Petitioners tendered the Wilshire Report to the trial court. DHS objected to its introduction on grounds it was not new evidence within the meaning of Code of Civil Procedure section 1094.5, subdivision (e), because it comprised not new facts but rather a recapitulation of the authors’ opinions, previously expressed in the Wilshire memorandum, about facts already considered by DHS. Alternatively, DHS offered a copy of its own, 22-page response to the Wilshire Report, which DHS had issued in January 1994. At the brief hearing on the merits, the trial court reserved ruling on the admissibility of the report.

After taking the matter under submission, the court filed an eight-page order stating its decision. The court admitted the Wilshire Report in evidence “for the limited purpose of evaluation on whether to remand the case,” and also admitted DHS’s response “for the same purpose.” It then ruled that, notwithstanding that section 21168 provides that in CEQA cases “. . . the court shall not exercise its independent judgment on the evidence but shall only determine whether the act or decision is supported by substantial evidence in the light of the whole record,” resort to the independent judgment test was required with respect to petitioner Tribe, because of its “unique position and rights”—and hence with respect to the entire case.

The court proceeded to enumerate and reject many of petitioners’ contentions, including the claim that the desert tortoise critical habitat designation required a subsequent EIR. It then turned to the Wilshire Report, observing that its subject matter (i.e., the possibility of pollution of the Colorado River) was “an underlying concern” of petitioners’ remaining contentions. The court stated, “The court agrees with petitioners’ contentions on the limited grounds that the ‘Wilshire’ report is significant new scientific analysis. All other assertions within these contentions are without merit. For the reasons expressed below, this analytical data should be considered.”

The court explained: “Although the outline of this significant new analysis is in the record [i.e., the Wilshire memorandum] and was presumably considered[, t]he full analysis presented by the report is extremely significant. . . . [H Even if the material in the Wilshire Report and response thereto is in the present administrative record in some form, it does not appear that the analysis therein has been placed in a proper perspective, so that an objective person can properly evaluate it ... . The court does not doubt that an evaluative process has been applied to the Wilshire Report by [DHS] (see [DHS’s January 1994 response]); however, the report should be evaluated in a pre-approval setting in order to give CEQA its full reign.”

Restating that “The analysis of the Wilshire Report should be placed side by side, in its complete form, with the counter analysis before any approval,” the court concluded that in light of its rejection of petitioners’ other arguments, “the remand will be for the limited purpose of reconsideration in light of the ‘Wilshire Report.’ Respondents are not required to have an entire renewal of the CEQA or licensing process unless it is necessary to give full exposure and evaluation to the Wilshire Report. The report is significant new ‘analysis,’ not data. It does not change the project, nor does its presence deprive the public of a meaningful opportunity to comment.”

The court further opined that the Wilshire Report was not the type of material to call for a supplement or addendum to the EIR, as provided in Guidelines sections 15163 and 15164, but “is more likely the type to be considered as warranting a ‘subsequent’ EIR pursuant to [Guidelines] section 15162 and Public Resources Code section 21166.” The court concluded: “Inasmuch as the court has determined the report to be evidence, which reasonably could not have been produced at the hearing (Code Civ. Proc., § 1094.5 (e)), the court is remanding the case to respondents to be reconsidered in the light of the report’s analysis. Whether a new hearing or recirculation [sic] of a ‘subsequent’ EIR is required or desirable is to be considered by respondents.”

Petitioners proceeded to lodge a proposed judgment, incorporating much of the language of the order, and directing the issuance of a peremptory writ requiring DHS to set aside its approvals of the EIR and license and reconsider them in light of the Wilshire Report. DHS objected to the judgment, interpreting the court’s order to require interlocutory remand and reconsideration, without a writ or vacation of DHS’s decisions. The court overruled the objection and interpretation, and entered judgment granting the writ. (See Code Civ. Proc., § 1094.5, subds. (e), (f).) The writ directed DHS to set aside its approvals and reconsider the case in light of the Wilshire Report, “in a pre-approval setting.”

DHS then moved for a new trial, on two grounds. First, it argued there had been insufficient basis for admission of the Wilshire Report under Code of Civil Procedure section 1094.5, subdivision (e) (see fn. 8, ante), and indeed that the court’s order, characterizing the Wilshire Report as “new analysis, not data,” established that. Second, DHS urged that denial of the writ was appropriate because DHS and its EIR consultant had now performed further analyses of the Wilshire Report—in reaction to the court’s decisional order —which confirmed that the report did not require a subsequent EIR or other modifications. Concurrently, DHS filed a “response” to the court’s original order, containing its consultant’s voluminous analysis of the Wilshire Report and supplemental findings by DHS. US Ecology and the Forum noticed parallel motions.

The trial court denied all motions for new trial or modification of the judgment, specifically noting that DHS’s “response” had not, by its terms, been filed as a return to the writ. These appeals followed.

Respondents’ Appeals

All three respondents contest the propriety of the trial court’s judgment remanding the case to DHS for reconsideration in light of the Wilshire Report. In addition, US Ecology raises a preliminary issue as to the court’s election of the “independent judgment” standard of review.

1. “Independent Judgment. ”

US Ecology contends that the trial court should not have used the independent judgment test rather than the substantial evidence test in considering whether the evidence supported DHS’s findings. (See Code Civ. Proc., § 1094.5, subd. (c).) At this stage, the issue is effectively academic. Although it afforded petitioners the stricter, weight-of-the-evidence review of the independent judgment test, the court ultimately decided all issues subject to that test adversely to petitioners. Were we to agree with the court’s choice of the independent judgment test, the standard for our review of the court’s determinations under it would be whether they are supported by substantial evidence found in the administrative record. (Eisenberg et al., Cal. Practice Guide: Civil Appeals and Writs 1 (The Rutter Group 1994) ^[8:128.1, p. 8-43.) On the other hand, if the court should have employed the alternative, substantial evidence test, its determinations would be subject to review by applying that same test, de novo, to the administrative record. {Id., 18:128.2, p. 8-43.) The scope of review being effectively the same (see id., 18:128, p. 8-43), it thus is difficult to see how US Ecology is presently aggrieved by the trial court’s decision to apply the independent judgment test.

Nevertheless, we briefly address the merits of the issue. The independent judgment test, as opposed to the substantial evidence test, applies when the administrative decision subject to review substantially affects a party’s fundamental vested right. (Bixby v. Pierno (1971) 4 Cal.3d 130, 143-144 [93 Cal.Rptr. 234, 481 P.2d 242].) Recognizing that none of the other petitioners could assert such rights as involved in DHS’s decisions, the trial court nonetheless applied the independent judgment test based on what it termed the Tribe’s “unique position and rights.” The rights in question are the Tribe’s long-established rights to water in and from the Colorado River. (See Arizona v. California (1963) 373 U.S. 546, 595-602 [10 L.Ed.2d 542, 575-579, 83 S.Ct. 1468].) These rights indeed are fundamental and vested. (See id. at pp. 598-600 [10 L.Ed.2d at pp. 576-578].) However, it cannot be said that they have been or will be substantially affected by the licensing of the project. DHS has not acted, directly or indirectly, to displace, abridge, or otherwise interfere with the Tribe’s water rights. To contend otherwise involves total speculation about the long-term fate of the project, well beyond even the scientific skepticism of the Wilshire Report. Because DHS’s decisions did not substantially affect the Tribe’s fundamental vested rights, this case was not subject to the independent judgment test.

2. The Remand for Consideration of the Wilshire Report.

The trial court’s judgment granting the writ and remanding the case for reconsideration turned upon the Wilshire Report, which had been issued two and one-half months after DHS’s decisions, and hence naturally was not a part of the voluminous administrative record. The court relied on Code of Civil Procedure section 1094.5, subdivision (e) (quoted ante, fn. 8), which accords the court in an administrative mandamus proceeding discretion to remand the case for reconsideration if the court finds “there is relevant evidence which, in the exercise of reasonable diligence, could not have been produced” at the administrative hearing (or which was improperly excluded therefrom). We consider first respondents’ preemptive contention that the statute’s provision for remand in light of evidence outside the record does not contemplate or allow resort to evidence which, like the Wilshire Report, did not come into existence until after the administrative decision. Respondents rely on a recent decision of the Supreme Court that announced just that restriction with respect to extra-record evidence in quasi-legislative mandamus cases.

In Western States Petroleum Assn. v. Superior Court (1995) 9 Cal.4th 559 [38 Cal.Rptr.2d 139, 888 P.2d 1268] (Western States), the court held that evidence from outside the administrative record is generally not admissible in traditional mandamus cases reviewing quasi-legislative action, including those brought under CEQA. (Code Civ. Proc., § 1085; Pub. Resources Code, § 21168.5.) At issue was the admissibility of scientific, extra-record evidence in a proceeding challenging the promulgation of regulations. After reconfirming for CEQA cases the traditional quasi-legislative/quasi-judicial distinction between action subject to traditional and administrative mandamus remedies, the court first held that in the former type of cases review of the agency’s decision for substantial evidence must be confined to evidence in the administrative record. This holding was based on the language of section 21168.5, traditional notions of judicial deference to legislative action, and the propriety of such deference to agency expertise as well. (Western States, supra, 9 Cal.4th at pp. 570-574.) Second, again stressing the deferential nature of judicial review of quasi-legislative action, the court held that dehors the record evidence also could not be used to show that the quasi-legislative agency had not proceeded in the manner required by law. (Id. at pp. 574-575.) Third, the court rejected two proposed exceptions to these rules, which would have allowed new evidence—there, conflicting scientific opinions—to be admitted to show that the agency had not considered “all relevant factors” or that the evidence on which it relied lacked substance to support its decision. (Id. at pp. 576-578.) The court characterized these proposals as “nothing more than a thinly veiled attempt to introduce conflicting expert testimony to question the wisdom and scientific accuracy of the [agency’s] decision.” (Id. at p. 578.)

However, the Western States court did acknowledge an exception for the admission of evidence “that could not be produced at the administrative level ‘in the exercise of reasonable diligence’ ....’’ (Western States, supra, 9 Cal.4th at p. 578.) Citing Code of Civil Procedure section 1094.5, subdivision (e), the court stated, “Extra-record evidence is admissible in administrative mandamus proceedings under such circumstances (Code Civ. Proc., § 1094.5, subd. (e)) and we see no reason to apply a different rule in traditional mandamus proceedings.” (Western States, supra, at p. 578.) But the court further ruled that this exception could not be extended to expert testimony and reports prepared after the agency decision, under the premise that, not having existed then, they could not have been discovered with reasonable diligence. Such a range of admissibility, the court explained, “would seriously undermine the finality of quasi-legislative administrative decisions”: a dissatisfied party could produce the report of “an expert who is likewise dissatisfied,” obtain a judicial remand, and thereafter repeat the same process. (Ibid..)

The court concluded, “Therefore, although we agree that there is such an exception in traditional mandamus proceedings challenging quasi-legislative administrative decisions, this exception is to be very narrowly construed. Extra-record evidence is admissible under this exception only in those rare instances in which (1) the evidence in question existed before the agency made its decision, and (2) it was not possible in the exercise of reasonable diligence to present this evidence to the agency before the decision was made so that it could be considered and included in the administrative record.” (Western States, supra, 9 Cal.4th at p. 578.) And although there might yet be further exceptions for extra-record evidence, “under unusual circumstances or for very limited purposes not presented in the case now before us” (ibid.), “extra-record evidence can never be admitted merely to contradict the evidence the administrative agency relied on in making a quasi-legislative decision or to raise a question regarding the wisdom of that decision.” (Id. at p. 579.)

Respondents contend that Western States' requirement that “the evidence in question existed before the agency made its decision” (Western States, supra, 9 Cal.4th at p. 578) must be read to apply not only to traditional mandamus proceedings involving quasi-legislative action, but also to the provisions of Code of Civil Procedure section 1094.5, subdivision (e), regarding administrative mandamus proceedings. Respondents base their argument on (1) the high court’s statement, when expounding its limited exception to nonadmissibility, that “we see no reason to apply a different rule [than that provided by Code of Civil Procedure section 1094.5, subdivision (e)] in traditional mandamus proceedings,” as well as (2) the court’s explanation that to allow postdecision expert reports could lead to spiraling review and nonfinality of administrative decisions (Western States, supra, at p. 578)—a prospect respondents suggest the trial court’s decision regarding the Wilshire Report portends.

These points are not without appeal. But ultimately, we cannot construe Western States as fixing the meaning of Code of Civil Procedure section 1094.5, subdivision (e) as well as the common law relating to traditional mandamus brought to review quasi-legislative action. From beginning to end Western States was concerned with the latter type of proceedings. In rendering the very holding on which respondents rely, the court once again expressly addressed such proceedings. Moreover, had the court also intended to construe and qualify Code of Civil Procedure section 1094, subdivision (e)—a construction that would have been obiter dictum—it presumably would have been conscious that its interpretation conflicted with a substantial line of Court of Appeal decisions approving the use, under that subdivision, of evidence that did not exist when the administrative decision was rendered. (E.g., Elizabeth D. v. Zolin (1993) 21 Cal.App.4th 347, 356 [25 Cal.Rptr.2d 852]; Toyota of Visalia, Inc. v. New Motor Vehicle Bd. (1987) 188 Cal.App.3d 872, 881-882 [233 Cal.Rptr. 708]; Curtis v. Board of Retirement (1986) 177 Cal.App.3d 293, 298-299 [223 Cal.Rptr. 123]; Windigo Mills v. Unemployment Ins. Appeals Bd. (1979) 92 Cal.App.3d 586, 594-597 [155 Cal.Rptr. 63].) The Western States court had no difficulty disapproving numerous Court of Appeal cases that had postulated a more generous rule of admissibility of extra-record evidence in quasi-legislative mandamus than the court was approving. (Western States, supra, 9 Cal.4th at pp. 570, fn. 2, 576, fn. 6.) Had the court intended to overrule the cases interpreting Code of Civil Procedure section 1094.5, subdivision (e) too, it surely would have done so explicitly. We therefore are unable to conclude that Western States prohibits the use, under Code of Civil Procedure section 1094.5, subdivision (e), of evidence which did not come into existence until after the administrative hearing or decision.

But even if remand in light of such evidence is not prohibited under Code of Civil Procedure section 1094.5, subdivision (e), we agree with respondents that the concerns that underlay Western States' barring post-decision evidence in quasi-legislative mandamus cases also bear on the proper application of that statute, in administrative mandamus cases. In such cases too, the writ is also made available to “inquir[e] into the validity of [a] final administrative decision,” rendered on the basis of “evidence taken” (Code Civ. Proc., § 1094.5, subd. (a)), that is, evidence in the administrative record. Subdivision (e) opens a narrow, discretionary window for additional evidence, newly discovered after the hearing (or improperly excluded at it). Routine allowance thereunder of conflicting scientific opinions created after the decision would pose for quasi-judicial decisions at least as great a threat of repeated rounds of litigation, and uncertain, attenuated finality, as it would for quasi-legislative actions, as observed in Western States, supra, 9 Cal.4th at page 578 (fn. 14, ante).

Remand under Code of Civil Procedure section 1094.5, subdivision (e) for consideration of postdecision evidence generally has been limited to truly new evidence, of emergent facts. The leading case endorsing the use of newly created evidence under the statute adverted to mandamus’s traditional function of achieving justice, and then concluded that by the enactment of subdivision (e), “. . . it reasonably may be inferred that [the Legislature] meant to authorize the receipt of evidence of events which took place after the administrative hearing.” (Windigo Mills v. Unemployment Ins. Appeals Bd., supra, 92 Cal.App.3d at pp. 596-597.) Subsequent cases, following Windigo Mills, generally have involved that type of newly developed evidence. Thus, in Elizabeth D. v. Zolin, supra, 21 Cal.App.4th at page 356, the court granted the trial court discretion to admit a doctor’s report of the petitioner’s posthearing medical condition, for determination of whether her condition justified the suspension of her driver’s license. Similarly, in Curtis v. Board of Retirement, supra, 177 Cal.App.3d at pages 298-299, the court ordered remand of a disability retirement case for consideration of new medical reports of the petitioner’s condition following the administrative hearing. And in Toyota of Visalia, Inc. v. New Motor Vehicle Bd., supra, 188 Cal.App.3d at page 882, the court approved the admission of evidence of the petitioner’s posthearing restitution to defrauded customers, as relevant to the issue of mitigation in a second penalty hearing. (See also Department of Parks & Recreation v. State Personnel Bd. (1991) 233 Cal.App.3d 813, 836-838 [284 Cal.Rptr. 839], in which the court, while holding certain postdecision evidence relevant and admissible, further held that the trial court had not abused its discretion in declining to remand for reconsideration in light of that evidence.)

The trial court’s present decision to require DHS to reconsider its decision in light of the Wilshire Report differs markedly from these traditional invocations of Code of Civil Procedure section 1094.5, subdivision (e). To begin with, the administrative proceeding here was not a conventional disciplinary or entitlement decision; it was a wide-ranging scientific inquiry not unlike the proceedings at issue in Western States, supra, 9 Cal.4th 559. As analyzed by the Third District, DHS’s role was “hardly a classic quasi-judicial function. ... In the implementation of this project some of [DHS’s] functions are in fact quasi-judicial, but in other respects, such as site selection and regulation, [DHS] is exercising executive and quasi-legislative functions.” (CalRad, supra, 15 Cal.App.4th at p. 862.)

Second, other than its publication the Wilshire Report did not truly constitute “evidence of events which took place after the administrative [decision].” (Windigo Mills v. Unemployment Ins. Appeals Bd., supra, 92 Cal.App.3d at p. 597.) The report was a restatement and elaboration of its authors’ opinions about possible features of the site which they had previously discussed in the Wilshire memorandum, and which, along with that memorandum, DHS had already taken into account. The Wilshire Report was highly cumulative, in light of, among other things, its own “outline” in the Wilshire memorandum (as the trial court put it). (See ante, p. 1588.) In context, requiring renewed reconsideration of DHS’s decisions in light of the authors’ renewed exposition of their opinions bore the earmarks of a revolving rehearing, certain to undermine the prospect of a final decision of this matter so long as scientists are able to advance conflicting views.

As noted above, the trial court yet opined that the Wilshire Report constituted the type of new information that would call for a supplemental EIR, under section 21166 and Guidelines section 15162. Similarly, petitioners had cited the Wilshire memorandum below chiefly in urging that it had required either such a supplemental EIR or recirculation of the original EIR, under section 21092.1 and Guidelines section 15088.5. But in truth, neither the Wilshire Report nor the Wilshire memorandum warranted any such further action under CEQA.

As here relevant, section 21166 allows for the preparation of a subsequent or supplemental EIR, after the original one, if “[n]ew information, which was not known and could not have been known at the time the [EIR] was certified as complete, becomes available.” (§21166, subd. (c).) Guidelines section 15162 elaborates that the “new information” requiring such a further EIR must be “of substantial importance”; that it “was not known and could not have been known with the exercise of reasonable diligence at the time the previous EIR was certified”; and that it show one of the following: “(A) The project will have one or more significant effects not discussed in the previous EIR . . . ; HQ (B) Significant effects previously examined will be substantially more severe than shown in the previous EIR; [U (C) Mitigation measures or alternatives previously found not to be feasible would in fact be feasible and would substantially reduce one or more significant effects of the project, but [its] proponents decline to adopt [them]; or [