All water-service pipes and their connections to the municipal water system must be inspected and approved in writing by the Superintendent before they are covered, and the Superintendent shall keep a record of such approvals. If the Superintendent refuses to approve the work, the plumber or owner must proceed immediately to correct the work so that it will meet with the Superintendent's approval. Every person who uses or intends to use the municipal water system shall permit the Superintendent or the Superintendent's authorized assistants to enter the premises to inspect and make necessary alterations or repairs at all reasonable hours and on proof of authority.
(Code of Iowa, Sec. 372.13(4))