Cal. Health and Safety Code § 44297

(a) The state board, acting within its existing authority, shall, at its first opportunity following January 1, 2005, revise the grant criteria and guidelines adopted pursuant to Section 44287 to incorporate projects described in subdivision (c). (b) The guidelines may define eligible costs to include monitoring and verifying compliance with this article. (c) Notwithstanding any other provision of this chapter, a project that meets either of the following criteria constitutes a heavy-duty fleet modernization project and thus is eligible for funding under the program, if it complies with the guidelines established by the state board pursuant to subdivision (a): (1) Replaces an old engine or vehicle with a newer engine or vehicle certified to more stringent emissions standards than the engine or vehicle being replaced, pursuant to paragraph (2) of subdivision (a) of Section 44281. (2) Provides the equivalent emission reductions as would be gained by a project that combines both of the following: (A) The purchase of a new very low or zero-emission covered vehicle pursuant to paragraph (1) of subdivision (a) of Section 44281. (B) The replacement of an old engine or vehicle with a newer engine or vehicle certified to more stringent standards than the engine or vehicle being replaced, pursuant to paragraph (2) of subdivision (a) of Section 44281. (d) In establishing guidelines pursuant to subdivision (a), the state board shall consider any existing heavy-duty fleet modernization program carried out by a district. The state board shall design a program that, to the extent feasible, includes fleet owners, independent truck owners, heavy-duty vehicle dealers, districts, and other participants it determines appropriate from existing local programs. (e) The grants provided pursuant to this article shall provide moneys to offset the incremental cost of projects that reduce emissions of oxides of nitrogen (NOx) and particulate matter (PM). (f) The state board shall determine an appropriate weighted cost-effectiveness standard for projects intended to reduce particulate matter.