Cal. Education Code § 16077

If an apportionment is made for a project which includes a multipurpose room the board shall determine and specify the portion of the apportionment that is allocated to the cost of the multipurpose room. If a district receives an apportionment a portion of which is for a multipurpose room it shall repay the principal amount of such portion of the apportionment as an additional payment as provided by this section. Interest on the total apportionment shall be paid as provided in Section 16083. The repayment is in addition to the repayments required on the total of all apportionments to the district, which shall be repaid as otherwise provided in this chapter. Notwithstanding the provisions of Sections 16083 and 16087 for cancellation of the principal amount of apportionments the Controller shall continue to make the deduction provided by Section 16080 during each fiscal year thereafter until the principal amount of the portion of the apportionment that was allocated to the cost of the multipurpose room and was made and disbursed to the district has been withheld, or for an additional period of 10 years, whichever first occurs. At the expiration of 40 years from the first day of July of the fiscal year next succeeding the fiscal year in which the apportionment became final, the unpaid balance of the principal amount of the portion of the apportionment shall be canceled on the books of the State Controller and the provisions of Section 16083 shall thereupon become applicable thereto and the board shall execute a conveyance to the district as provided in Section 16087.