(1) It is contemplated that various applicants may present to the department differing regulatory criteria designed to cope with particular local needs and conditions. For the purposes of determining whether an applicant intends to administer the permit program in accordance with applicable state and federal laws, regulations, and policies, the department shall evaluate proposed regulatory criteria on the basis of whether such criteria, if implemented, would be at least as stringent as state or federal requirements.

(2) All implementing ordinances or resolutions shall contain a proviso requiring that the permit program as administered by any municipality be revised, as necessary and to the satisfaction of the department, to conform with any changes in applicable rules and regulations which may be adopted by the department or the federal government subsequent to the effective date of the grant of authority. All amendments of implementing ordinances or resolutions shall be submitted to the department for approval prior to passage.

(3) Any municipality granted authority hereunder to administer a permit program shall adhere to, as a minimum requirement for commercial and industrial dischargers, the state or federal pretreatment standards and regulations, as now exist or are hereafter amended. If necessary to impose more stringent standards in order to meet the effluent limitations contained in its National Pollutant Discharge Elimination System (NPDES) permit, the municipality shall impose and enforce such stricter pretreatment requirements as necessary to meet these limitations pursuant to the authority preserved to the state by section 510 of the FWPCAA.

(4) Nothing in this grant of authority shall relieve the municipality of its obligation of compliance with the terms and conditions of its NPDES permit or the requirements of state and federal laws and rules pertaining to water pollution control.