California Code
ARTICLE 7.1 - Resolution of Contract Claims
Section 10240.9.

10240.9. A party to the contract may join in the arbitration as a party, any supplier, subcontractor, design professional, surety, or other person who has so agreed and if the joinder is necessary to prevent a substantial risk of the party otherwise being subjected to inconsistent obligations or decisions.

(Added by Stats. 1982, Ch. 466, Sec. 90.)