La. Stat. tit. 45 § 801
In implementing systems pursuant to this Chapter, all public agencies in a single system shall annually enter into a joint powers agreement or any other form of written cooperative agreement which is applicable when need arises on a day to day basis. In addition, such agreements shall be entered into between public agencies and public safety agencies which are part of different systems but whose jurisdictional boundaries are contiguous. The agreements shall provide that, once an emergency unit is dispatched in response to a request through the system, such unit shall render its services to the requesting party without regard to whether the unit is operating outside its normal jurisdictional boundaries. Copies of the annual agreement shall be filed with the department of public safety. Commencing with the year 1978, all such agreements shall be so filed prior to the 31st day of January. The department of public safety shall commence judicial proceedings to enforce compliance with the provisions of this section where a public agency or public safety agency has failed to timely enter into such agreement or file copies thereof.
La. R.S. § 45:801