Cal. Educ. Code § 1267

Out of the school maintenance and repair fund the superintendent of schools of the county shall purchase materials, bill the district on supplies and equipment, and employ labor to maintain and repair school premises and property of the school districts, under his or her jurisdiction which have elected to take advantage of the provisions of this article, and shall deliver a memorandum in triplicate of the cost of the service on or about the first of each calendar month to the school district.