California Code, Government Code - GOV § 54223

(a) After the disposing agency has received a notice of interest from the entity desiring to purchase or lease the surplus land on terms that comply with this article, the disposing agency and the entity shall enter into good faith negotiations to determine a mutually satisfactory sales price and terms or lease terms.  If the price or terms cannot be agreed upon after a good faith negotiation period of not less than 90 days, the local agency may dispose of the surplus land without further regard to this article, except that Section 54233 shall apply.

(b) Residential use shall be deemed an acceptable use for the surplus land for the purposes of good faith negotiations with a local agency conducted pursuant to this article.  Nothing in this subdivision shall restrict a local jurisdiction's authority or discretion to approve land use, zoning, or entitlement decisions in connection with the surplus land.  Except as provided in subdivision (c), terms agreed to pursuant to the negotiations shall not do any of the following:

(c) Terms agreed to pursuant to the negotiations required by subdivision (a) may include limitations on residential use or density if, without the limitations, the residential use or density would have a specific, adverse impact, supported by written findings, upon the public health or safety or upon the operation or facilities of a local agency, and there is no feasible method to satisfactorily mitigate the impact.