(1) In lieu of a cash deposit required by these rules, a utility shall accept the written guarantee of a responsible party as surety for a customer service account. For the purpose of this rule, a "responsible party" shall mean:

(a) Any individual or business entity which has maintained service with the utility in question for the previous 24 months, and who has not had service disconnected for failure to pay, and has received no more than two delinquency notices.

(b) Any special fund approved by the commission.