What are the elements of equitable estoppel?

The elements of equitable estoppel include: "'(1) the party to be estopped must be apprised of the facts; (2) he must intend that his conduct shall be acted upon, or must so act that the party asserting the estoppel had a right to believe it was so intended; (3) the other party must be ignorant of the true state of facts; and (4) he must rely upon the conduct to his injury.'" (City of Long Beach v. Mansell (1970) 3 Cal.3d 462, 489.)

"It is settled that '[the] doctrine of equitable estoppel may be applied against the government where justice and right require it. [Citation.]' [Citation.] [Citations.] Correlative to this general rule, however, is the well-established proposition that an estoppel will not be applied against the government if to do so would effectively nullify 'a strong rule of policy, adopted for the benefit of the public . . . .' [Citation.] The tension between these twin principles makes up the doctrinal context in which concrete cases are decided." (City of Long Beach v. Mansell, supra, 3 Cal.3d at p. 493.)