In calculating the total area of land disturbance, for the purposes of determining applicability of this subchapter to a project, the following guidelines should be used:
(A) Off-site construction activities that provide services (for example, road extensions, sewer, water, offsite stockpiles, and other utilities) to a land disturbing project site must be considered as a part of the total land disturbance calculation for the project site when the activity is under the control of the project site owner.
(B) To determine if multi-lot project sites are regulated by this subchapter, the area of land disturbance shall be calculated by adding the total area of land disturbance for improvements, such as, roads, utilities, or common areas, and the expected total disturbance on each individual lot, as determined by the following:
(1) For a single-family residential project site where the lots are one-half acre or more, one-half acre of land disturbance must be used as the expected lot disturbance.
(2) For a single-family residential project site where the lots are less than one-half acre in size, the total lot must be calculated as being disturbed.
(3) To calculate lot disturbance on all other types of project sites, such as industrial and commercial projects project sites, a minimum of one acre of land disturbance must be used as the expected lot disturbance, unless the lots are less than one acre in size, in which case the total lot must be calculated as being disturbed.
(C) The calculation methods as well as the type, sizing, and placement of all storm water pollution prevention measures for construction sites shall meet the design criteria, standards, and specifications outlined in the Indiana Storm Water Quality Manual, the City of Decatur Storm Water Technical Standards Manual, and the product guidance/specifications of the manufacturer. The methods and procedures included in these two references are in keeping with the above stated policy and meet the requirements of the IDEM's CSGP. A copy of the Indiana Storm Water Quality Manual may be obtained online through IDEM.
(D) The design requirements that would apply to all land-disturbing activities and shall be considered in the selection, design, and implementation of all storm water quality and management measures contained in the SWPPP are contained in the City of Decatur Storm Water Technical Standards Manual.
(Ord. 2023-11, passed 8-1-2023)