(A) For major project sites, a project site owner must develop and submit a set of construction plans. Storm water quality measures included in the plan must achieve the minimum project site requirements specified in §§53.025 and 53.027 of this subchapter. The construction plans must include the following components, content, requirements and provisions as hereinafter provided.
(B) Construction plan. The construction plan must include the following 8 major components:
(1) Project narrative and supporting documents; see division (C)(1) below;
(2) Vicinity map; see division (C)(2) below;
(3) Existing project site layout; see division (C)(3) below;
(4) Final project site layout; see division (C)(4) below;
(5) Grading plan or land disturbing activity plan; see division (C)(5) below;
(6) Storm water drainage plan; see division (C)(6) below;
(7) Construction phase storm water pollution prevention plan; see division (C)(7) below; and
(8) Post-construction storm water pollution prevention plan; see division (C)(8) below. A post-construction SWPPP is required for all projects with the exception of:
(a) Land-disturbing activities where there will be no additional impervious surfaces associated with the final completed project, including but not limited to, ditch construction/reconstruction and utility installation/maintenance activities;
(b) Single-family residential strip development offered for sale or lease without land improvements and the project is not part of a larger common plan of development or sale;
(c) Individual residential building lots within a permitted project site;
(d) Residential developments consisting of 4 or fewer lot developments where the proposed impervious surfaces are 10% or less of the project acreage. Impervious is determined by the sum of all infrastructure (roads, paths, parking, and the like) and the average projects hard surfaces associated with all building lots within the project; and
(e) Single family residences and private ponds that are not part of a larger common plan of development or sale.
(C) Components must have sub-components. Each of the 8 major components of the construction plan must consist of the following sub-components and their subdivisions of content:
(1) Project narrative and supporting documents, including the following information:
(a) An index indicating the location, in the construction plan, of all information required by this section;
(b) Description of the nature and purpose of the project;
(c) Legal description of the project site. The description must be to the nearest quarter section, township, and range, and include the civil township;
(d) The latitude and longitude in decimal representation at the approximate entrance to the project site that is obtaining permit coverage if the project is not linear or the beginning of the project site for linear projects;
(e) The size of the project area expressed in acres;
(f) The total expected land disturbance expressed in acres;
(g) Construction support activities that are expected to be part of the project;
(h) Soil properties, characteristics, limitations, and hazards associated with the project site, and the measures that will be integrated into the project to overcome or minimize adverse soil conditions;
(i) General construction sequence of how the project site will be built, including phases of construction;
(j) A plat or project site map showing the boundaries of the project site as represented in the full construction plans and for which the notice of intent will be submitted, the boundaries of each phase, section, or other divisions of the project site associated with the construction activity, and a legend. When applicable, the plat must include lot numbers, lot boundaries, road layout and names. The plat must be legible and submitted on a sheet or sheets no larger than 24 inches by 36 inches and drawn at a maximum scale of 1 inch equals 100 feet for all phases or sections of the project. The Engineer or Storm Water Coordinator will determine the appropriateness of the size and scale of the plat or map;
(k) The identification and location of all wetlands, lakes and water courses on or adjacent to the project site;
(l) The location of any in-stream activities that are planned for the project including, but not limited to stream crossings and pump arounds;
(m) The identification and status of any other state or federal water quality permits or authorizations that are required for construction activities associated with the project site. If the permit or authorization has not been obtained, provide the expected timeline for obtaining the permit or authorization;
(n) The identification of a U.S. EPA approved or established TMDL, including the name of the TMDL and the pollutant(s) for which there is a TMDL; and
(o) The identification of discharges to a water on the current 303(d) list of impaired waters and the pollutant(s) for which it is impaired.
(2) Vicinity map depicting the project site's location in relationship to recognizable local landmarks, cities, towns, major roads, and railways. The applicable portion of a USGS topographical quadrangle map, or county or municipal road map with the project site limits linked in will suffice.
(3) An existing project site layout that must include the following information:
(a) Location and name of all wetlands, lakes, streams, waterways, and drains on, or adjacent to, the project site;
(b) Location of all existing structures on the project site;
(c) One hundred year flood plains, floodway fringes, and floodways; (Note if none exists)
(d) Soil map of the predominant soil types, as determined by the USDA, NRCS Soil Survey, or equivalent publication, or as determined by a soil scientist. The soil map must include a soil legend;
(e) Identification and delineation of the pre-development natural buffers and existing vegetative cover such as grass, weeds, brush, crops or crop residue, and trees on the project site;
(f) Land use of all adjacent properties;
(g) Existing topography extending at a minimum of 50 feet beyond the property lines to adequately indicate drainage patterns on and off the project site. The contour intervals shall be appropriate to indicate drainage patterns.
(h) The Town of Chandler Engineer or Storm Water Department Manger reserves the right to determine the appropriateness of the contour intervals and request additional spot elevations to adequately indicate drainage patterns on and off the project site.
(4) Final project site layout, including the following information:
(a) Location of all proposed site improvements including; roads, utilities, lot delineations and identification, proposed structures, and common areas;
(b) One hundred-year flood plains, floodway fringes, and floodways; (Note if none exists)
(c) Proposed final topography extending at a minimum of 50 feet beyond the property lines to adequately indicate drainage patterns on and off the project site. The contour intervals shall be drawn in accordance to the following criteria:
1. Average ground slope between 0 and 2% using 1-foot contour intervals;
2. Average ground slope between 2 and 10% using 2-foot contour intervals; and
3. Average ground slope greater than 10% using 5-foot contour intervals;
(d) The Town of Chandler Engineer or Storm Water Department Manager reserves the right to determine the appropriateness of the contour intervals and request additional spot elevations to adequately indicate drainage patterns on and off the project site;
(e) The boundaries of natural features or unique resource areas that will be left undisturbed or preserved including, but not limited to, wetlands steep slopes, riparian corridors, and natural buffers.
(5) A grading plan, including the following information:
(a) Delineation of all proposed land disturbing activities, including off-site activities that will provide services to the project site;
(b) Location of all soil stockpiles and borrow areas;
(c) Information regarding any off-site borrow, stockpile, or disposal areas that are associated with the project site and under the control of the project site owner; and
(d) Existing and proposed topographic information per divisions (C)(3)(g) and (C)(4)(c) above.
(6) A drainage plan, including the following information:
(a) An estimate of the peak discharge, based on the 10-year storm event; of the project site for both pre-construction conditions and estimates of the peak discharge based on the 10-year, 25-year, and 50-year storm events of the project site for post construction conditions. The calculations to determine these discharges shall be included in the drainage plan;
(b) Location, size and dimensions of all components of the storm water drainage systems such as inlets, culverts, storm sewers, and conveyance channels;
(c) The locations of specific points where concentrated storm water and non-storm water discharges will leave the project site.
(d) Locations where storm water potentially will be directly discharged into ground water, such as abandoned wells or sinkholes; (Note if none exists)
(e) Name of all receiving waters. If a discharge is to a separate municipal storm sewer, identify the name of the municipal operator and the name of the ultimate receiving water; and
(f) Location, size, and dimensions of features such as permanent retention or detention facilities, including existing or manmade wetlands, used for the purpose of storm water management.
(a) Location, dimensions, detailed specifications, and construction details of all temporary and permanent storm water quality measures, ECMs, and BMPs;
(b) Temporary stabilization plans and sequence of implementation;
(c) Permanent stabilization plans and sequence of implementation;
(d) Final stabilization plans;
(e) All stabilization plans shall include the following:
1. Specification and application rates for soil amendments and seed mixtures;
2. The type and application rate for anchored mulch, erosion control blanket, and other appropriate stabilization options; and
3. Other applicable data as may be required by the Town of Chandler Engineer or Storm Water Department Manager;
(f) For each temporary storm water quality measure, ECM, and BMP, a maintenance standard, including a threshold of when each requires corrective action and/or replacement with alternative measures;
(g) Construction sequence describing the relationship between implementation of storm water quality measures, ECMs, and BMPs, and the stages of construction activities;
(h) The provisions for erosion and sediment control on individual building lots regulated under the permit;
(i) A material handling and spill prevent and spill response plan meeting the requirements in 327 I.A.C. 2-6.1, including contact information for local emergency personnel and the IDEM Emergency Spill Line, (888) 237-7745 or (317) 233-7745; and
(j) The material handling and storage procedures associated with construction activity describing the management and disposal of construction products and waste.
(8) The post-construction Storm Water Pollution Prevention Plan (SWPPP). The post-construction SWPPP must include the following information:
(a) A description of potential pollutant sources from the project site's proposed land use, which sources may reasonably be expected to add a significant amount of pollutants to storm water discharges from the post-construction project site;
(b) Location, dimensions, detailed specifications, and construction details of all post-construction storm water quality measures and BMPsset forth in § 53.031;
(c) A description of control measures and BMPs that will be installed to control pollutants in storm water discharges that will occur after construction activities have been completed. The measures and practices include infiltration of storm water runoff; flow reduction by use of open vegetated swales and natural depressions; installation of filter strips, buffer strips, parking lot tree islands, and riparian zones; minimization of land disturbance and surface imperviousness; maximum of open space; and storm water retention and detention ponds;
(d) A sequence describing when each post-construction storm water quality measure and BMP will be installed;
(e) Storm water quality measures and BMPs that will remove or minimize pollution from storm water runoff within or from the project site associated with its final land use;
(f) Storm water quality measures and BMPs that will be implemented to prevent or minimize adverse impacts to aquatic resources including, but not limited to, streams, wetlands, karst features, and riparian habitat;
(g) Storm water management measures that will address the potential impacts of increased runoff from the project. Measures must be designed and approved according to this permit or, where applicable, local requirements and drainage ordinances. A trained individual must approve that the design meets the applicable requirement(s);
(h) Measures, including structural and those based on low impact development principles, selected to address the pollutant(s) of concern, reduction of peak flows, and ability to infiltrate;
(i) Protective measures that will be implemented during active construction when the type of post-construction measure(s) planned are susceptible to pollutants, specifically sediment that may be generated during land-disturbing activities;
(j) A narrative description of the maintenance guidelines for all post-construction storm water quality measures and BMPs to facilitate their proper long-term function;
(k) A verifiable procedure, such as recorded plat notices and covenants, by which the narrative description of water quality measure and BMP maintenance guidelines will be made available to future parties who will assume responsibility for the operation and maintenance of the post-construction storm water quality measures and BMPs; and
(l) When known at the time of plan submittal, the entity that will be responsible for the operation and maintenance of the post-construction storm water quality measures and BMPs.
(D) Illustrations. Plan and profile sheets, project site layouts, plats, and vicinity maps, must be drawn to a standard engineering scale as indicated on each sheet, plat, or map, and be oriented north as indicated by a north arrow on each sheet, plat, or map. All dimensions must be accurately scaled, drawn, and labeled with dimensions given in feet and tenths of a foot.
(E) Revision of approved construction plans. The requirements for construction plan content enumerated in this section are qualified by the following statements:
(1) The Town of Chandler Engineer or Storm Water Department Manager may require, upon finding reasonable cause, the revision of a construction plan if it is determined that a modification or modifications are necessary to accomplish adequate control the quantity or quality of storm water runoff, in accordance with this subchapter or with applicable federal, state, and local rules, from a project site due to site conditions or project specification changes identified, effected, or extant during or after plan review an approval.
(2) If the Town of Chandler Engineer, Storm Water Management Board or Storm Water Department Manager requests a revised construction plan under this division, the project site owner must submit the revised plan to the appropriate entity or entities within 21 calendar days of a request for plan revision.
(Ord. 2006-6, passed - -; Am. Ord. 2008-10, passed 11-17-2008; Am. Ord. 2024-15, passed 6-17-2024)