(1) If the zoning ordinance authorizes the consideration and approval of special land uses or planned unit developments under section 502 or 503 or otherwise provides for discretionary decisions, the regulations and standards upon which those decisions are made shall be specified in the zoning ordinance.

    (2) The standards shall be consistent with and promote the intent and purpose of the zoning ordinance and shall insure that the land use or activity authorized shall be compatible with adjacent uses of land, the natural environment, and the capacities of public services and facilities affected by the land use. The standards shall also insure that the land use or activity is consistent with the public health, safety, and welfare of the local unit of government.

    (3) A request for approval of a land use or activity shall be approved if the request is in compliance with the standards stated in the zoning ordinance, the conditions imposed under the zoning ordinance, other applicable ordinances, and state and federal statutes.

    (4) Reasonable conditions may be required with the approval of a special land use, planned unit development, or other land uses or activities permitted by discretionary decision. The conditions may include conditions necessary to insure that public services and facilities affected by a proposed land use or activity will be capable of accommodating increased service and facility loads caused by the land use or activity, to protect the natural environment and conserve natural resources and energy, to insure compatibility with adjacent uses of land, and to promote the use of land in a socially and economically desirable manner. Conditions imposed shall meet all of the following requirements:

    (a) Be designed to protect natural resources, the health, safety, and welfare, as well as the social and economic well-being, of those who will use the land use or activity under consideration, residents and landowners immediately adjacent to the proposed land use or activity, and the community as a whole.

    (b) Be related to the valid exercise of the police power and purposes which are affected by the proposed use or activity.

    (c) Be necessary to meet the intent and purpose of the zoning requirements, be related to the standards established in the zoning ordinance for the land use or activity under consideration, and be necessary to insure compliance with those standards.

    (5) The conditions imposed with respect to the approval of a land use or activity shall be recorded in the record of the approval action and remain unchanged except upon the mutual consent of the approving authority and the landowner. The approving authority shall maintain a record of conditions which are changed.