Every two years the board may, and upon petition of 15 percent of the electors of the district shall, employ a qualified expert who shall with all due diligence examine and report upon the following:
(a)
The system of accounts kept by the district.
(b)
All the contracts made and entered into by the board within the two years immediately preceding.
(c)
The management of the utilities of the district, their operation, the service furnished, and the rates charged by the district.
(d)
The properties and investments of the district.
(e)
All official acts of the board relating to acquisition, construction, completion, extension, improvement, and betterment of the public utilities of the district.
(f)
The efficiency and adequacy of each public utility, and of the property used in connection with it or with its operation, the reasonableness of the service and commodities furnished, and of the rates and charges therefor.
(g)
All the business and affairs of the district relating to the ownership, management, and operation of each public utility of the district.