In Varjabedian v. City of Madera (1977) 20 Cal.3d 285, the Supreme Court explained, "'"a statutory sanction cannot be pleaded in justification of acts which by the general rules of law constitute a nuisance, unless the acts complained of are authorized by the express terms of the statute under which the justification is made, or by the plainest and most necessary implication from the powers expressly conferred, so that it can be fairly stated that the Legislature contemplated the doing of the very act which occasions the injury."' ... A requirement of 'express' authorization embodied in the statute itself insures that an unequivocal legislative intent to sanction a nuisance will be effectuated, while avoiding the uncertainty that would result were every generally worded statute a source of undetermined immunity from nuisance liability." (Id. at p. 291.) Applying this standard in the case before it, which involved a nuisance claim based upon odors emitted from the defendant city's operation of a waste water treatment plant, the Supreme Court rejected the city's argument that "the general authorization of municipal construction of sewage plants 'expressly' sanctions the production of any particular level of odors within the meaning of Civil Code section 3482." (Varjabedian, supra, 20 Cal.3d at p. 292.) The court observed: "None of the Government Code statutes under which the city claims to act mentions the possibility of noxious emanations from such facilities. Nor can we find that such odors were authorized by the 'plainest and most necessary implication' from the general powers there conferred, or that it can be fairly said that the Legislature contemplated, to any extent, the creation of a malodorous nuisance when it authorized sewage plant construction. Indeed, one object of such plants is to remove harmful and obnoxious effluents from the environment." (Ibid.)