All mobile home parks in existence as of the date this section becomes effective shall maintain their existing safety separation, outdoor hazards and water supply for fire protection systems and/or measures (if applicable). Manufactured home installations, sites and parks in the MHP mobile home park district which are replaced, expanded or enlarged after the effective date of this section shall conform to the requirements of National Fire Protection Association Standard 501A-1997, specifically sections 4.2.1 pertaining to fire safety separation requirements, 4.3.3 pertaining to outdoor hazards and 4.3.5 pertaining to water supplies for fire protection.