Health and Safety Code § 6800

Notwithstanding the provisions of any other section of this article, the board may, out of any surplus funds remaining in the bond fund, the running expense fund or the sewer construction fund, purchase in the open market its outstanding unmatured bonds.

No bonds shall be purchased at a price above par and accrued interest plus an allowance of six months interest from the date of purchase. All bonds so purchased shall be canceled.