California Code, Health and Safety Code - HSC § 25269.8

(a) Review all current outstanding receivables and make an appropriate adjustment for estimated uncollectible amounts, consistent with current accounting practices and recognizing the present value of future collection. The department may, if warranted, write off or write down those receivable amounts.

(b) Maintain and report an analysis of outstanding receivables and other control analyses.

(c) Consider whether to enter into a contract with a private collection agency to collect substantially past-due accounts and, for longer term receivables, consider whether credit arrangements should be made with banks or other institutions willing to assist in financing a potentially responsible party's obligation for remediation.