OPINION

CROSKEY, J.—

Federal law prohibits the possession and distribution of marijuana (21 U.S.C. §§812, 841(a)(1), 844); there is no exception for medical marijuana. (United States v. Oakland Cannabis Buyers' Cooperative (2001) 532 U.S. 483, 490 [149 L.Ed.2d 722, 121 S.Ct. 1711].) Although California criminalizes the possession and cultivation of marijuana generally (Health & Saf. Code, §§ 11357, 11358), it has decriminalized the possession and cultivation of medical marijuana, when done pursuant to a physician's recommendation. (Health & Saf. Code, § 11362.5, subd. (d).) Further, California law decriminalizes the collective or cooperative cultivation of medical marijuana. (Health & Saf. Code, § 11362.775.) Case law has concluded that California's statutes are not preempted by federal law, as they seek only to decriminalize certain conduct for the purposes of state law. (Qualified Patients Assn. v. City of Anaheim (2010) 187 Cal.App.4th 734, 757 [115 Cal.Rptr.3d 89].)

In this case, we are concerned with a city ordinance which goes beyond simple decriminalization. The City of Long Beach (City) has enacted a comprehensive regulatory scheme by which medical marijuana collectives within the City are governed. The City charges application fees (Long Beach Mun. Code, ch. 5.87, § 5.87.030), holds a lottery, and issues a limited number of permits. Permitted collectives, which must then pay an annual fee, are highly regulated, and subject to numerous restrictions on their operation (Long Beach Mun. Code, ch. 5.87, § 5.87.040). The question presented by this case is whether the City's ordinance, which permits and regulates medical marijuana collectives rather than merely decriminalizing specific acts, is preempted by federal law. In this case of first impression, we conclude that, to the extent it permits collectives, it is.

STATUTORY AND REGULATORY BACKGROUND

Before addressing the specific factual and procedural background of this case, we first discuss the contradictory federal and state statutory schemes which govern medical marijuana. This case concerns the interplay between the federal Controlled Substances Act (CSA; 21 U.S.C. § 801 et seq.), and the state Compassionate Use Act of 1996 (CUA; Health & Saf. Code, § 11362.5) and Medical Marijuana Program Act (MMPA).

1. The Federal CSA

"Enacted in 1970 with the main objectives of combating drug abuse and controlling the legitimate and illegitimate traffic in controlled substances, the CSA creates a comprehensive, closed regulatory regime criminalizing the unauthorized manufacture, distribution, dispensing, and possession of substances classified in any of the Act's five schedules." (Gonzales v. Oregon (2006) 546 U.S. 243, 250 [163 L.Ed.2d 748, 126 S.Ct. 904].) Enactment of the federal CSA was part of President Nixon's "`war on drugs.'" (Gonzales v. Raich (2005) 545 U.S. 1, 10 [162 L.Ed.2d 1, 125 S.Ct. 2195].) "Congress was particularly concerned with the need to prevent the diversion of drugs from legitimate to illicit channels." (Id. at pp. 12-13.)

The federal CSA includes marijuana1 on schedule I, the schedule of controlled substances which are subject to the most restrictions. (21 U.S.C. § 812.) Drugs on other schedules may be dispensed and prescribed for medical use; drugs on schedule I may not. (United States v. Oakland Cannabis Buyers' Cooperative, supra, 532 U.S. at p. 491.) The inclusion of marijuana on schedule I reflects a government determination that "marijuana has `no currently accepted medical use' at all." (Ibid.) Therefore, the federal CSA makes it illegal to manufacture, distribute, or possess marijuana. (21 U.S.C. §§ 841, 844.) It is also illegal, under the federal CSA, to maintain any place for the purpose of manufacturing, distributing, or using any controlled substance. (21 U.S.C. § 856(a)(1).) The only exception to these prohibitions is the possession and use of marijuana in federally approved research projects. (United States v. Oakland Cannabis Buyers' Cooperative, supra, 532 U.S. at pp. 489-490.)

The federal CSA contains a provision setting forth the extent to which it preempts other laws. It provides: "No provision of this subchapter shall be construed as indicating an intent on the part of the Congress to occupy the field in which that provision operates, including criminal penalties, to the exclusion of any State law on the same subject matter which would otherwise be within the authority of the State, unless there is a positive conflict between that provision of this subchapter and that State law so that the two cannot consistently stand together." (21 U.S.C. § 903.) The precise scope of this provision is a matter of dispute in this case.

2. The CUA

While the federal government, by classifying marijuana as a schedule I drug, has concluded that marijuana has no currently accepted medical use, there is substantial debate on the issue. (See Conant v. Walters (9th Cir. 2002) 309 F.3d 629, 640-643 (conc. opn. of Kozinski, J.).) In 1996, California voters concluded that marijuana does have valid medical uses, and sought to decriminalize the medical use of marijuana by approving, by initiative measure, the CUA.

The CUA added section 11362.5 to the Health and Safety Code. Its purposes include: (1) "[t]o ensure that seriously ill Californians have the right to obtain and use marijuana for medical purposes where that medical use is deemed appropriate and has been recommended by a physician who has determined that the person's health would benefit from the use of marijuana in the treatment of cancer, anorexia, AIDS, chronic pain, spasticity, glaucoma, arthritis, migraine, or any other illness for which marijuana provides relief"; (2) "[t]o ensure that patients and their primary caregivers who obtain and use marijuana for medical purposes upon the recommendation of a physician are not subject to criminal prosecution or sanction"; and (3) "[t]o encourage the federal and state governments to implement a plan to provide for the safe and affordable distribution of marijuana to all patients in medical need of marijuana." (Health & Saf. Code, § 11362.5, subds. (b)(1)(A), (B) & (C).)

To achieve these ends, the CUA provides, "Section 11357, relating to the possession of marijuana,[2] and Section 11358, relating to the cultivation of marijuana, shall not apply to a patient, or to a patient's primary caregiver,3 who possesses or cultivates marijuana for the personal medical purposes of the patient upon the written or oral recommendation or approval of a physician." (Health & Saf. Code, § 11362.5, subd. (d).) As noted above, this statute, which simply decriminalizes for the purposes of state law certain conduct related to medical marijuana, is not preempted by the CSA. (Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 757.)

3. The MMPA

The MMPA was enacted by the Legislature in 2003. The purposes of the MMPA include: (1) to "[p]romote uniform and consistent application of the [CUA] among the counties within the state" and (2) to "[e]nhance the access of patients and caregivers to medical marijuana through collective, cooperative cultivation projects." (Stats. 2003, ch. 875, § 1, subd. (b)(2) & (3), p. 6422.) The MMPA contains several provisions intended to meet these purposes.

First, the MMPA expands the immunities provided by the CUA. While the CUA decriminalizes the cultivation and possession of medical marijuana by patients and their primary caregivers,4 the MMPA extends that decriminalization to possession for sale, transportation, maintaining a place for sale or use, and other offenses. Cultivation or distribution for profit, however, is still prohibited. (Health & Saf. Code, § 11362.765.)

Second, while the CUA provides a defense at trial for those medical marijuana patients and their caregivers charged with the illegal possession or cultivation of marijuana, it provides for no immunity from arrest. (People v. Mower (2002) 28 Cal.4th 457, 469 [122 Cal.Rptr.2d 326, 49 P.3d 1067].) The MMPA provides that immunity by means of a voluntary identification card system. Individuals with physician recommendations for marijuana, and their designated primary caregivers, may obtain identification cards identifying them as such.5 Under the MMPA, no person in possession of a valid identification card shall be subject to arrest for enumerated marijuana offenses. However, a person need not have an identification card to claim the protections from the criminal laws provided by the CUA. (Health & Saf. Code, § 11362.71.)

Third, the MMPA set limits on the amount of medical marijuana which may be possessed. Health & Safety Code section 11362.77 provides that, unless a doctor specifically recommends more6 (Health & Saf. Code, § 11362.77, subd. (b)), a qualified patient or primary caregiver "may possess no more than eight ounces of dried marijuana per qualified patient. In addition, a qualified patient or primary caregiver may also maintain no more than six mature or 12 immature marijuana plants per qualified patient."7 (Health & Saf. Code, § 11362.77, subd. (a).) This provision establishes a "safe harbor" from arrest and prosecution for the possession of no more than these set amounts.8 (Health & Saf. Code, § 11362.77, subd. (f).)

Fourth, the MMPA decriminalizes the collective or cooperative cultivation of marijuana, providing that qualified patients and their primary caregivers "who associate within the State of California in order collectively or cooperatively to cultivate marijuana for medical purposes, shall not solely on the basis of that fact be subject to state criminal sanctions under [the same provisions identifying conduct otherwise decriminalized under the MMPA]." (Health & Saf. Code, § 11362.775.)

Two other provisions of the MMPA are relevant to our analysis. First, the MMPA provides for local regulation, stating, "Nothing in this article shall prevent a city or other local governing body from adopting and enforcing laws consistent with this article."9 (Health & Saf. Code, § 11362.83.) This has been interpreted to permit cities and counties to impose greater restrictions on medical marijuana collectives than those imposed by the MMPA. (County of Los Angeles v. Hill (2011) 192 Cal.App.4th 861, 867-868 [121 Cal.Rptr.3d 722].)

Second, in 2010, the Legislature amended the MMPA to impose restrictions on the location of medical marijuana collectives. Health & Safety Code section 11362.768, subdivision (b), provides that no "medical marijuana cooperative, collective, dispensary, operator, establishment, or provider who possesses, cultivates, or distributes medical marijuana pursuant to this article shall be located within a 600-foot radius of a school." Subdivision (e) restricts the operation of subdivision (b) to only those providers that have a "storefront or mobile retail outlet which ordinarily requires a local business license."10 In other words, private collectives are immune from this requirement. The section goes on to provide, "Nothing in this section shall prohibit a city, county, or city and county from adopting ordinances or policies that further restrict the location or establishment of a medical marijuana cooperative, collective, dispensary, operator, establishment, or provider." (Health & Saf. Code, § 11362.768, subd. (f).) Moreover, the section provides that it shall not preempt local ordinances adopted prior to January 1, 2011, that regulate the locations or establishments of medical marijuana cooperatives, collectives, dispensaries, operators, establishments, or providers. (Health & Saf. Code, § 11362.768, subd. (g).)

In 2008, the Attorney General issued Guidelines for the Security and Non-Diversion of Marijuana Grown for Medical Use (Guidelines). (<http:// ag.ca.gov/cms_attachments/press/pdfs/n1601_medicalmarijuanaguidelines.pdf> [as of Oct. 4, 2011].) The Guidelines addressed several issues pertaining to medical marijuana, including taxation,11 federal preemption,12 and arrest under federal law.13 The Guidelines also discussed collectives, cooperatives, and dispensaries, indicating that they should acquire medical marijuana only from their members, and distribute it only among their members. (Guidelines, supra, at p. 10.) The Guidelines added the following, regarding dispensaries: "Although medical marijuana `dispensaries' have been operating in California for years, dispensaries, as such, are not recognized under the law. As noted above, the only recognized group entities are cooperatives and collectives.[14] [Citation.] It is the opinion of this Office that a properly organized and operated collective or cooperative that dispenses medical marijuana through a storefront may be lawful under California law, but that dispensaries that do not substantially comply with the guidelines [above] are likely operating outside the protections of [the CUA] and the MMP[A], and that the individuals operating such entities may be subject to arrest and criminal prosecution under California law. For example, dispensaries that merely require patients to complete a form summarily designating the business owner as their primary caregiver—and then offering marijuana in exchange for cash `donations'—are likely unlawful." (Guidelines, supra, at p. 11.)

FACTUAL AND PROCEDURAL BACKGROUND

1. The City's Ordinance

In 2010, the City adopted an ordinance (Long Beach Ord. No. 10-0007) intended to comprehensively regulate medical marijuana collectives within the City. The ordinance defines a collective as an association of four or more qualified patients and their primary caregivers who associate at a location within the City to collectively or cooperatively cultivate medical marijuana. (Long Beach Mun. Code, ch. 5.87, § 5.87.015, subd. J.)

The City's ordinance not only restricts the location of medical marijuana collectives (Long Beach Mun. Code, ch. 5.87, § 5.87.040, subds. A, B & C), but also regulates their operation by means of a permit system (Long Beach Mun. Code, ch. 5.87, § 5.87.020). The City requires all collectives which seek to operate in the City, including those that were in operation at the time the ordinance was adopted,15 to submit applications and a nonrefundable application fee. (Long Beach Mun. Code, ch. 5.87, § 5.87.030.) The City has set this fee at $14,742. The qualified applicants then participate in a lottery for a limited number of permits.16 Only those medical marijuana collectives which have been issued medical marijuana collective permits may operate in the City. (Long Beach Mun. Code, ch. 5.87, § 5.87.020.)

In order to obtain a permit, a collective must demonstrate its compliance, and assure its continued compliance, with certain requirements. (Long Beach Mun. Code, ch. 5.87, § 5.87.040.) These include the installation of sound insulation (id., subd. G), odor absorbing ventilation (id., subd. H), closed-circuit television monitoring17 (§ 5.87.040, subd. I.), and centrally monitored fire and burglar alarm systems (id., subd. J). Collectives must also agree that representative samples of the medical marijuana they distribute will have been analyzed by an independent laboratory to ensure that it is free of pesticides and contaminants. (Id., subd. T.)

Once a permit has been issued, an "Annual Regulatory Permit Fee" is also imposed, based on the size of the collective. That fee is $10,000 for a collective with between four and 500 members, and increases with the size of the collective.

The permitted collective system is the exclusive means of collective cultivation of medical marijuana in Long Beach.18 The ordinance provides that it is "unlawful for any person to cause, permit or engage in the cultivation, possession, distribution, exchange or giving away of marijuana for medical or nonmedical purposes except as provided in this chapter, and pursuant to any and all other applicable local and state law."19 (Long Beach Mun. Code, ch. 5.87, § 5.87.090, subd. A.) The ordinance further provides that no person shall be a member of more than one collective "fully permitted in accordance with this chapter."20 (Id., subd. N.) Violations of the ordinance are misdemeanors, as well as enjoinable nuisances per se. (Long Beach Mun. Code, ch. 5.87, § 5.87.100.)

The City set a timeline for its initial permit lottery. Applications were to be accepted between June 1 and June 18, 2010; the City was to review the applications for compliance from June 21 through September 16, 2010; the lottery would be held on September 20, 2010; and site inspections, public notice and a hearing process would occur between September 21, 2010, and December 15, 2010. However, the City indicated that any collective that did not comply with the ordinance must cease operations by August 29, 2010.

2. Plaintiffs' Complaint and Request for Preliminary Injunction

Plaintiffs Ryan Pack and Anthony Gayle were members of medical marijuana collectives that were directed to cease operations by August 29, 2010, for noncompliance with the ordinance. On August 30, 2010, plaintiffs filed the instant action seeking declaratory relief that the ordinance is invalid as it is preempted by federal law. On September 14, 2010, plaintiffs filed a request for a preliminary injunction. By this time, the City had shut down the collectives of which plaintiffs were members. However, as the lottery had not yet been held, no collectives had been issued permits in accordance with the ordinance. The plaintiffs thus argued that they would be irreparably harmed by the continued enforcement of the ordinance, as there was no collective they could legally join in order to obtain their necessary medical marijuana. As to the probability of success, plaintiffs argued that the City's ordinance went beyond decriminalization and instead permitted conduct prohibited by the federal CSA, and thus was preempted.

3. The City's Opposition to the Preliminary Injunction Request

On September 24, 2010, the City opposed the request for preliminary injunction, arguing that the ordinance was not preempted because it did not affect those responsible for enforcing the federal CSA. The City also raised an unclean hands argument, briefly suggesting that plaintiffs could not complain of any harm because their collectives "opened up for business" in an "unpermitted illegal manner."

4. The Trial Court's Denial of the Request for Preliminary Injunction

After a hearing, the trial court denied the request for a preliminary injunction. Its order issued on November 2, 2010. The court ultimately declined to address the federal preemption argument, on the basis of unclean hands. The court rejected the unclean hands argument raised by the City; however, it concluded that plaintiffs could not be heard to argue that the City ordinance was preempted due to a conflict with federal law (the CSA), when plaintiffs sought this ruling so that they could continue to violate the very same federal law. The court stated, "It is hardly equitable for [p]laintiffs to ask the court to enforce a federal law that they themselves are indisputably violating."21

5. The Plaintiffs' Petition for Writ of Mandate

On November 15, 2010, plaintiffs filed the instant petition for writ of mandate, challenging the trial court's denial of a preliminary injunction. We issued an order to show cause, seeking briefing on the federal preemption issue. We invited amicus curiae briefing from various entities on both sides of the issue, including other cities considering or enacting medical marijuana collective ordinances, the United States Attorneys for California districts, the ACLU, and organizations advocating the legalization of marijuana. We received amicus curiae briefing from (1) the City of Los Angeles; (2) the California State Association of Counties and League of California Cities; and (3) the ACLU, ACLU of Northern California, ACLU of Southern California, ACLU of San Diego and Imperial Counties, Drug Policy Alliance, and Americans for Safe Access. Although the United States Attorneys declined to file amicus curiae briefs, we have taken judicial notice of letters and memoranda which illuminate the federal government's position regarding the enforcement of the CSA with respect to medical marijuana collectives.

6. The Progress of the Lottery and Permitting System

As briefing proceeded in this case, the City's permit lottery was conducted. According to a representation in the City's respondent's brief, the City received 43 applications, and the lottery resulted in 32 applications moving forward in the permit process. By the time briefing was closed, plaintiffs acknowledged that the permit process had resulted in a permit being issued for at least one collective, Herbal Solutions.22

ISSUE PRESENTED

The sole issue presented by this writ proceedings23 is whether the City's ordinance is preempted by the federal CSA. We conclude that it is, in part, and therefore grant the plaintiffs' petition.

DISCUSSION

1. Standard of Review

(1) "Two interrelated factors bear on the issuance of a preliminary injunction—the likelihood of the plaintiff's success on the merits at trial and the balance of harm to the parties in issuing or denying injunctive relief." (County of Los Angeles v. Hill, supra, 192 Cal.App.4th at p. 866.) It is clear, in this case, that if the City's ordinance is invalid as a matter of law, plaintiffs had a 100 percent probability of prevailing, and a preliminary injunction therefore should have been entered.

Whether an ordinance is valid is a question of law. (Zubarau v. City of Palmdale (2011) 192 Cal.App.4th 289, 305 [121 Cal.Rptr.3d 172].) Whether a local ordinance is preempted by federal law is a question of law on undisputed facts.24 (Zubarau v. City of Palmdale, at p. 305.) We therefore review the issue de novo.25 (Zubarau v. City of Palmdale, at p. 305.)

2. Law of Preemption

(2) "The supremacy clause of the United States Constitution establishes a constitutional choice-of-law rule, makes federal law paramount, and vests Congress with the power to preempt state law." (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc. (2007) 41 Cal.4th 929, 935 [63 Cal.Rptr.3d 50, 162 P.3d 569].)

"There is a presumption against federal preemption in those areas traditionally regulated by the states . . . ." (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at p. 938.) Regulation of medical practices and state criminal sanctions for drug possession are historically matters of state police power. (Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 757.) More importantly, a local government's land use regulation is an area over which local governments traditionally have control. (City of Claremont v. Kruse (2009) 177 Cal.App.4th 1153, 1169 [100 Cal.Rptr.3d 1].) Thus, we assume the presumption against federal preemption applies in this instance. Therefore, "`[w]e start with the assumption that the historic police powers of the States were not to be superseded by the Federal Act unless that was the clear and manifest purpose of Congress.' [Citations.]" (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at p. 938.)

(3) "There are four species of federal preemption: express, conflict, obstacle, and field." (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at p. 935.) "First, express preemption arises when Congress `define[s] explicitly the extent to which its enactments pre-empt state law. [Citation.] Pre-emption fundamentally is a question of congressional intent, [citation], and when Congress has made its intent known through explicit statutory language, the courts' task is an easy one.' [Citations.] Second, conflict preemption will be found when simultaneous compliance with both state and federal directives is impossible. [Citations.] Third, obstacle preemption arises when `"under the circumstances of [a] particular case, [the challenged state law] stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress."' [Citations.] Finally, field preemption, i.e., `Congress' intent to preempt all state law in a particular area,' applies `where the scheme of federal regulation is sufficiently comprehensive to make reasonable the inference that Congress "left no room" for supplementary state regulation.' [Citation.]" (Id. at p. 936.)

(4) "Where a statute `contains an express pre-emption clause, our "task of statutory construction must in the first instance focus on the plain wording of the clause, which necessarily contains the best evidence of Congress' pre-emptive intent."' [Citation.]" (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at p. 941, fn. 6.) (5) In this case, we are concerned with the federal CSA, which contains an express preemption clause: "No provision of this subchapter shall be construed as indicating an intent on the part of the Congress to occupy the field in which that provision operates, including criminal penalties, to the exclusion of any State law on the same subject matter which would otherwise be within the authority of the State, unless there is a positive conflict between that provision of this subchapter and that State law so that the two cannot consistently stand together." (21 U.S.C. § 903.)

It is undisputed that this provision eliminates any possibility of the federal CSA preempting a state statute (or local ordinance) under the principles of field preemption or express preemption (e.g., Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 758). It is also undisputed that, under this provision, the federal CSA would preempt any state or local law which fails the test for conflict preemption. (County of San Diego v. San Diego NORML (2008) 165 Cal.App.4th 798, 823 [81 Cal.Rptr.3d 461].) One California court has concluded that the federal CSA's preemption language bars the consideration of obstacle preemption. (County of San Diego, at pp. 823-825.) Another court, without specifically addressing the conflicting authority, concluded that the federal CSA preempts conflicting laws under both conflict and obstacle preemption. (Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 758.)

We believe this question was resolved by the United States Supreme Court in Wyeth v. Levine (2009) 555 U.S. 555 [173 L.Ed.2d 51, 129 S.Ct. 1187], a case which was decided after the decision in County of San Diego v. San Diego NORML, supra, 165 Cal.App.4th 798. In Wyeth, the Supreme Court was concerned with the preemptive effect of the Federal Food, Drug, and Cosmetic Act (FDCA; 21 U.S.C. § 301 et seq.). The FDCA provided that "a provision of state law would only be invalidated upon a "direct and positive conflict' with the FDCA." (Wyeth v. Levine, supra, 555 U.S. at p. ___ [129 S.Ct at p. 1196].) Given this language, the Supreme Court considered both conflict and obstacle preemption. (Id. at p. ___ [129 S.Ct. at p. 1199].) As there is no distinction between a federal statute which will only preempt those state and local laws which create a "direct and positive conflict" (FDCA) and those which create "a positive conflict . . . so that the two cannot consistently stand together" (CSA), we conclude that the same construction applies here, and the federal CSA can preempt state and local laws under both conflict and obstacle preemption.

(6) Indeed, the Supreme Court has cautioned against drawing a practical distinction between these two types of preemption. "This Court, when describing conflict pre-emption, has spoken of pre-empting state law that `under the circumstances of th[e] particular case . . . stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress'—whether that `obstacle' goes by the name of `conflicting; contrary to; . . . repugnance; difference; irreconcilability; inconsistency; violation; curtailment; . . . interference,' or the like. [Citations.] The Court has not previously driven a legal wedge—only a terminological one—between `conflicts' that prevent or frustrate the accomplishment of a federal objective and `conflicts' that make it `impossible' for private parties to comply with both state and federal law. Rather, it has said that both forms of conflicting state law are `nullified' by the Supremacy Clause, [citations], and it has assumed that Congress would not want either kind of conflict. The Court has thus refused to read general `saving' provisions to tolerate actual conflict both in cases involving impossibility, [citation], and in `frustration-of-purpose' cases, [citations]. We see no grounds, then, for attempting to distinguish among types of federal-state conflict for purposes of analyzing whether such a conflict warrants pre-emption in a particular case. That kind of analysis, moreover, would engender legal uncertainty with its inevitable systemwide costs (e.g., conflicts, delay, and expense) as courts tried sensibly to distinguish among varieties of `conflict' (which often shade, one into the other) when applying this complicated rule to the many federal statutes that contain some form of an express pre-emption provision, a saving provision, or . . . both." (Geier v. American Honda Motor Co. (2000) 529 U.S. 861, 873-874 [146 L.Ed.2d 914, 120 S.Ct. 1913].)

Thus, we turn our analysis to the issue of whether the federal CSA preempts the City's ordinance, under either conflict or obstacle preemption.

a. Conflict Preemption

(7) Conflict or "impossibility" preemption "is a demanding defense." (Wyeth v. Levine, supra, 555 U.S. at p. ___ [129 S.Ct. at p. 1199].) It requires establishing that it is impossible to comply with the requirements of both laws. (Ibid.) At first blush, no impossibility preemption is established by this case. While the federal CSA prohibits manufacture, distribution, and possession of marijuana, the City ordinance does not require any such acts. (See Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 759 [stating that a "claim of positive conflict might gain more traction if the [City] required . . . individuals to possess, cultivate, transport, possess for sale, or sell medical marijuana in a manner that violated federal law"].) Since a person can comply with both the federal CSA and the City ordinance by simply not being involved in the cultivation or possession of medical marijuana at all, there is no conflict preemption. (Cf. Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at p. 944 [no conflict preemption because it is not a physical impossibility to simultaneously comply with both a federal law allowing conduct and a state law prohibiting it].)

We are, however, troubled by one provision of the City's ordinance, the provision requiring that permitted collectives have samples of their medical marijuana analyzed by an independent laboratory to ensure that it is free from pesticides and contaminants. (Long Beach Mun. Code, ch. 5.87, § 5.87.040, subd. T.) We question how an otherwise permitted collective can comply with this provision without violating the federal CSA's prohibition on distributing marijuana.26 In other words, this provision appears to require that certain individuals violate the federal CSA. In an amicus curiae brief in support of the City, the California State Association of Counties and the League of California Cities argue that the only individuals being required to distribute marijuana under this provision are already violating the federal CSA by operating a medical marijuana collective. In other words, these amici curiae argue that this section of the ordinance "does not compel any person who does not desire to possess or distribute marijuana to do so." We find this argument unavailing. That a person desires to possess or distribute marijuana to some degree (by operating a collective) does not necessarily imply that the person is also desirous of committing additional violations of the federal CSA (by delivering the marijuana for testing). The City cannot compel permitted collectives to distribute marijuana for testing any more than it can compel a burglar to commit additional acts of burglary. In this limited respect, conflict preemption applies.27

b. Obstacle Preemption

(8) Obstacle preemption arises when the challenged law stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress. (Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 760.) "As a majority of the current United States Supreme Court has agreed at one time or another, `pre-emption analysis is not "[a] freewheeling judicial inquiry into whether a state statute is in tension with federal objectives," [citation], but an inquiry into whether the ordinary meanings of state and federal law conflict.' [Citations.]" (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at pp. 939-940.) If the federal act's operation would be frustrated and its provisions refused their natural effect by the operation of the state or local law, the latter must yield. (Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 760.)

(9) The United States Supreme Court has already set forth the purposes of the federal CSA. As discussed above, the main objectives of the federal CSA are "combating drug abuse and controlling the legitimate and illegitimate traffic in controlled substances" (Gonzales v. Oregon, supra, 546 U.S. at p. 250), with a particular concern of preventing "the diversion of drugs from legitimate to illicit channels." (Gonzales v. Raich, supra, 545 U.S. at pp. 12-13.)

(10) For this reason, we disagree with our colleagues who, in two other appellate opinions, have implied that medical marijuana laws might not pose an obstacle to the accomplishment of the purposes of the federal CSA because the purpose of the federal CSA is to combat recreational drug use, not regulate a state's medical practices. (Qualified Patients Assn. v. City of Anaheim, supra, 187 Cal.App.4th at p. 760; County of San Diego v. San Diego NORML, supra, 165 Cal.App.4th at p. 826.) While this statement of the purpose of the federal CSA is technically accurate,28 it is inapplicable in the context of medical marijuana. This is because, as far as Congress is concerned, there is no such thing as medical marijuana. Congress has concluded that marijuana has no accepted medical use at all; it would not be on schedule I otherwise. (United States v. Oakland Cannabis Buyers' Cooperative, supra, 532 U.S. at p. 491.) Thus, to Congress, all use of marijuana is recreational drug use, the combating of which is admittedly the core purpose of the federal CSA.29 This case presents the question of whether an ordinance which establishes a permit scheme for medical marijuana collectives stands as an obstacle to the accomplishment of this purpose. We conclude that it does.

(11) There is a distinction, in law, between not making an activity unlawful and making the activity lawful. An activity may be prohibited, neither prohibited nor authorized, or authorized. (Viva! Internat. Voice for Animals v. Adidas Promotional Retail Operations, Inc., supra, 41 Cal.4th at p. 952.) When an act is prohibited by federal law, but neither prohibited nor authorized by state law, there is no obstacle preemption. The state law does not present an obstacle to Congress's purposes simply by not criminalizing conduct that Congress has criminalized. For this reason, the CUA is not preempted under obstacle preemption.30 (City of Garden Grove v. Superior Court, supra, 157 Cal.App.4th at pp. 384-385.) The CUA simply decriminalizes (under state law) the possession and cultivation of medical marijuana (People v. Mower, supra, 28 Cal.4th at p. 472); it does not attempt to authorize the possession and cultivation of the drug (Ross v. RagingWire Telecommunications, Inc. (2008) 42 Cal.4th 920, 926 [70 Cal.Rptr.3d 382, 174 P.3d 200]).

(12) The City's ordinance, however, goes beyond decriminalization into authorization. Upon payment of a fee, and successful participation in a lottery, it provides permits to operate medical marijuana collectives. It then imposes an annual fee for their continued operation in the City. In other words, the City determines which collectives are permissible and which collectives are not, and collects fees as a condition of continued operation by the permitted collectives. A law which "authorizes [individuals] to engage in conduct that the federal Act forbids . . . `stands as an obstacle to the accomplishment and execution of the full purposes and objectives of Congress'" and is therefore preempted. (Michigan Canners & Freezers v. Agricultural Bd. (1984) 467 U.S. 461, 478 [81 L.Ed.2d 399, 104 S.Ct. 2518].)

The same conclusion was reached by the Oregon Supreme Court in Emerald Steel Fabricators, Inc. v. Bureau of Labor and Industries (2010) 348 Or. 159 [230 P.3d 518]. Oregon had enacted a medical marijuana statute which both affirmatively authorized the use of medical marijuana and exempted its use from state criminal liability. (Id., 230 P.3d at p. 525.) The court concluded that the law was preempted by the federal CSA, under obstacle preemption, to the extent that it authorized the use of medical marijuana rather than merely decriminalizing its use under state law. (230 P.3d at pp. 529-531.) We agree with that analysis.

Additionally, we have taken judicial notice of letters which set forth the position of the United States Attorney General on the purposes of the CSA and the issue of obstacle preemption. While we do not simply defer to its position, we place "some weight" on it. (See Geier v. American Honda Motor Co., supra, 529 U.S. at p. 883 [placing "some weight" on Department of Transportation's interpretation of its own regulations and whether obstacle preemption would apply].) On February 1, 2011, the United States Attorney for the Northern District of California sent a letter to the Oakland City Attorney relating to that city's consideration of a licensing scheme for medical marijuana cultivation and manufacturing. The letter explained, "Congress placed marijuana in Schedule I of the Controlled Substances Act (CSA) and, as such, growing, distributing, and possessing marijuana in any capacity, other than as part of a federally authorized research program, is a violation of federal law regardless of state laws permitting such activities." (U.S. Attorney Melinda Haag, letter to Oakland City Attorney John A. Russo, Feb. 1, 2011.) It further stated, "The Department is concerned about the Oakland Ordinance's creation of a licensing scheme that permits large-scale industrial marijuana cultivation and manufacturing as it authorizes conduct contrary to federal law and threatens the federal government's efforts to regulate the possession, manufacturing, and trafficking of controlled substances." (Ibid.)

(13) On June 29, 2011, the Deputy Attorney General issued a memorandum to all United States Attorneys confirming the position taken in this letter and confirming that prosecution of significant traffickers of illegal drugs, including marijuana, "remains a core priority." (Deputy Attorney General James M. Cole, memorandum for all U.S. Attorneys, June 29, 2011.) The memorandum noted that several jurisdictions "have considered or enacted legislation to authorize multiple large-scale, privately-operated industrial marijuana cultivation centers," and noted that these activities are not shielded from federal enforcement action and prosecution. (Ibid.) In short, the federal government has adopted the position that state and local laws which license the large-scale cultivation and manufacture of marijuana stand as an obstacle to federal enforcement efforts.31 We agree.

(14) The California State Association of Counties and the League of California Cities suggest that, although the City's ordinance is phrased in the language of what it will "permit," it is, in truth, merely an identification of those collectives against which it will not bring violation proceedings, and is therefore akin to the CUA as a limited decriminalization. The ordinance cannot be read in that manner. First and foremost, it is the possession of the permit itself, not any particular conduct, which exempts a collective from violation proceedings. That is to say, the ordinance does not indicate that collectives complying with a list of requirements are allowed (or, perhaps, "not disallowed") to operate in the City, which then simply issues permits to identify the collectives in compliance. In this regard, the City's permit scheme is distinguishable from the voluntary identification card scheme set forth in the MMPA. A voluntary identification card identifies the holder as someone California has elected to exempt from California's sanctions for marijuana possession. (County of San Diego v. San Diego NORML, supra, 165 Cal.App.4th at pp. 825-826.) One not possessing an identification card, but nonetheless meeting the requirements of the CUA, is also immune from those criminal sanctions. The City's permit system, however, provides that collectives with permits may collectively cultivate marijuana within the City and those without permits may not. The City's permit is nothing less than an authorization to collectively cultivate.

(15) Second, the City charges substantial application and renewal fees, and has chosen to hold a lottery among all qualified collective applicants (who pay the application fee) in order to determine those lucky few who will be granted permits. The City has created a system by which (1) of all collectives which follow its rules, only those which pay a substantial fee may be considered for a permit and (2) of all those which follow its rules and pay the substantial fee, only a randomly selected few will be granted the right to operate. The conclusion is inescapable: the City's permits are more than simply an easy way to identify those collectives against whom the City has chosen not to enforce its prohibition against collectives; the permits instead authorize the operation of collectives by those which hold them. As such, the permit provisions, including the substantial application fees and renewal fees, and the lottery system, are federally preempted.

c. Severability

Having concluded that the permit provisions of the City's ordinance are federally preempted, we turn to the issue of severability. The City's ordinance provides, "If any provision of this chapter, or the application thereof to any person or circumstance, is held invalid, that invalidity shall not affect any other provision or application of this chapter that can be given effect without the invalid provision or application; and to this end, the provisions or applications of this chapter are severable." (Long Beach Mun. Code, ch. 5.87, § 5.87.130.)

(16) This case is before us on a writ petition from the denial of a preliminary injunction. As we have concluded the permit provisions of the City's ordinance are preempted under federal law, the operation of those provisions should have been enjoined. The parties did not brief the issue of which, if any, of the other provisions of the ordinance must also be enjoined, and which can be severed and given independent effect.32 Under the circumstances, we believe it is appropriate for the trial court to consider this issue in the first instance. However, we make the following observations: Several provisions of the City's ordinance simply identify prohibited conduct without regard to the issuance of permits. For example, the ordinance includes provisions (1) prohibiting a medical marijuana collective from providing medical marijuana to its members between the hours of 8:00 p.m. and 10:00 a.m. (Long Beach Mun. Code, ch. 5.87, § 5.87.090, subd. H); (2) prohibiting a person under the age of 18 from being on the premises of a medical marijuana collective unless that person is a qualified patient accompanied by his or her physician, parent or guardian (id. subd. I); and (3) prohibiting the collective from permitting the consumption of alcohol on the property or in its parking area (id., subd. K). These provisions impose further limitations on medical marijuana collectives beyond those imposed under the MMPA, and do not, in any way, permit or authorize activity prohibited by the federal CSA. As such, they cannot be federally preempted, and appear to be easily severable.

Other provisions of the ordinance could be interpreted to simply impose further limitations, although they are found in sections relating to the issuance of permits. For example, in order to obtain a medical marijuana collective permit, an applicant must establish that the property is not located in an exclusive residential zone (Long Beach Mun. Code, ch. 5.87, § 5.87.040, subd. A), and not within a 1,500 foot radius of a high school or 1,000 foot radius of a kindergarten, elementary, middle, or junior high school (id., subd. B). These restrictions, if imposed strictly as a limitation on the operation of medical marijuana collectives in the City, would not be federally preempted. However, the restrictions, as currently phrased, appear to be a part of the preempted permit process. We leave it to the trial court to determine, in the first instance, whether these and other restrictions can be interpreted to stand alone in the absence of the City's permit system, and therefore not conflict with the federal CSA.33 It is also for the trial court to consider whether any provisions of the City's ordinance that are not federally preempted impermissibly conflict with state law, to the extent plaintiffs have appropriately pleaded (or can so plead) the issue.

DISPOSITION

The petition for writ of mandate is granted. The matter is remanded to the trial court for further proceedings consistent with the views expressed in this opinion. The petitioners shall recover their costs in this proceeding.

Klein, P. J., and Aldrich, J., concurred.