- (a) No onsite wastewater system in existence on the effective date of this part, nor any onsite wastewater system installed after the effective date of this part in a subdivision wherein individual lots have been developed or sold for use with onsite wastewater systems for which a plat has been filed on record prior to the effective date of this part shall be required to conform to more stringent specifications and requirements as to design, construction, density of improvements, lot size, and installation than those standards contained in any applicable duly adopted and published rules in effect at the time of platting of record of such subdivisions.
- (b) No onsite wastewater system to be installed on a residential lot for which the Department of Health or its authorized agent has issued a construction permit on or before the effective date of this part shall be required to conform to the design, construction, and installation provisions of this part.
- (c) In a subdivision for which a master plan has been approved by the department prior to the effective date of this part, or for which the department has otherwise previously issued its written approval for the installation of onsite wastewater systems and where individual lots have been developed or sold in reliance upon such prior written approval, onsite wastewater systems shall not be required to conform to more stringent specifications as to design, construction, and installation than those standards in effect at the time of, or referred to, in such prior written approval.
- (d) However, it is provided that any onsite wastewater system which is determined by the department to be a health hazard or which constitutes a nuisance due to odor or unsightly appearance shall conform to the provisions of this part within thirty (30) working days after notification that such determination has been made.