Any request for an out-of-district extension into another water district may not be considered by the Board unless it is accompanied by a written denial of service from the water district where the requesting property or properties are located. Any such out-of-district extension may not be considered unless it is accompanied by an executed inter-municipal agreement in a form acceptable to the Board which includes remedies for nonpayment of any water charges assessed. No out-of-district extension may be constructed unless it is approved in advance by the Board.