(A) Applicability and exemptions.
(1) The city requires that a stormwater pollution prevention plan (SWPPP), which includes erosion and sediment control measures and materials handling procedures, to be submitted as part of the construction plans and specifications. Once approved, the developer must comply with the approved plan and abide by all the requirements of the permit. Any project located within the city that includes clearing, grading, excavation, or other land-disturbing activities, resulting in the disturbance of or impact on one acre or more of total land area, is subject to the requirements of this section. This includes both new development and redevelopment. This section also applies to disturbances of less than one acre of land that are part of a larger common plan of development or sale if the larger common plan will ultimately disturb one or more acres of land, within the MS4 area. For sites with a total disturbance less than one acre that are not part of a larger common plan or development, the applicant shall provide an erosion and sediment control plan, as noted in § 54.32. Division (C) provides guidelines for calculating land disturbance.
(2) The requirements under this section do not apply to the following activities:
(a) Agricultural land-disturbing activities; and
(b) Timber harvesting activities.
(3) The requirements under this section do not apply to the following activities, provided other applicable state permits contain provisions requiring immediate implementation of soil erosion control measures:
(a) Landfills that have been issued a certification of closure under 329 IAC 10;
(b) Coal mining activities permitted under I.C. 14-34; and
(c) Municipal solid waste landfills that are accepting waste pursuant to a permit issued by the State Department of Environmental Management under 329 IAC 10 that contains equivalent stormwater requirements, including the expansion of landfill boundaries and construction of new cells either within or outside the original solid waste permit boundary.
(4) The owner or operator of each individual lot where land disturbance is expected to be one acre or more must complete their own notice of intent letter, apply for an improvement location permit (ILP) from the city, and ensure that a sufficient construction and stormwater pollution prevention plan is completed and submitted in accordance with § 54.32, regardless of whether the individual lot is part of a larger permitted project site.
(5) An individual lot with land disturbance or impact less than one acre, located within a larger permitted project site, is considered part of the larger permitted project site and the individual lot operator must, at a minimum, comply with the terms and conditions of the stormwater pollution prevention plan approved for the larger project site. The development plans for the larger project site must include detailed erosion and sediment control and material handling measures for individual lots. In addition, the owner or operator of these individual lots are required to submit as part of their improvement location permit (ILP), a stormwater pollution prevention plan in the form of an individual lot plot plan detailing erosion and sediment control measures and material handling procedures that will be followed for the duration of construction. Details of the permitting process are contained in § 54.32.
(6) An individual lot with land disturbance or impact of greater than 10,000 square feet but less than one acre must include, as part of the improvement location permit (ILP), a stormwater pollution prevention plan in the form of an individual lot plot plan detailing erosion and sediment control and material handling procedures.
(7) It is the responsibility of the project site owner to complete an improvement location permit application and ensure that a sufficient construction plan is completed and submitted to the city in accordance with § 54.32. It is the responsibility of the project site owner and permit holder to ensure compliance with this subchapter during the construction activity and implementation of the construction plan, and in following and implementing all best management practices, and to notify the city with a sufficient notice of termination letter upon completion of the project and stabilization of the site. However, all persons engaging in construction and land-disturbing activities on a permitted project site meeting the applicability requirements must comply with the requirements of this section and this subchapter.
(B) Policy on stormwater pollution prevention. Effective stormwater pollution prevention on construction sites is dependent on a combination of preventing movement of soil from its original position (erosion control), intercepting displaced soil prior to entering a waterbody (sediment control), and proper on-site materials handling. The developer must submit to the city a SWPPP with detailed erosion and sediment control plans as well as a narrative describing materials type and specification, handling and storage, and construction sequencing. The following principles apply to all land-disturbing activities and must be considered in the preparation of a stormwater pollution prevention plan within the city.
(1) Minimize the potential for soil erosion by designing a development that fits the topography and soils of the site. Deep cuts and fills in areas with steep slopes must be avoided wherever possible, and natural contours must be followed as closely as possible;
(2) Existing natural vegetation must be retained and protected wherever possible. Areas immediately adjacent (within 30 feet of top of bank) to watercourses and lakes also must be left undisturbed wherever possible. Unvegetated or vegetated areas with less than 70% cover that are scheduled or likely to be left inactive for 15 days or more must be temporarily or permanently stabilized with measures appropriate for the season to reduce erosion potential. Alternative measures to site stabilization may be acceptable if the project site owner or their representative can demonstrate they have implemented and maintained erosion and sediment control measures adequate to prevent sediment discharge from the inactive area;
(3) All activities on a site must be conducted in a logical sequence so that the smallest practical area of land will be exposed for the shortest practical period of time during development;
(4) The length and steepness of designed slopes must be minimized to reduce erosion potential. Drainage channels and swales must be designed and adequately protected so that their final gradients and resultant velocities will not cause erosion in the receiving channel or at the outlet. Methods for determining acceptable velocities are included in the “Stormwater Technical Standards Manual”;
(5) Sediment-laden water which otherwise would flow from the project site shall be treated by erosion and sediment control measures appropriate to minimize sedimentation. A stable and erosion resistant construction site access point (i.e., crushed stone, slag, aggregate, and the like) shall be provided at all points of construction traffic ingress and egress to the project site;
(6) Appropriate measures shall be implemented to prevent wastes or unused building materials, including garbage, debris, packaging material, fuels and petroleum products, hazardous materials or wastes, cleaning wastes, wastewater, concrete truck washout, and other substances from being carried from a project site by runoff or wind. Identification of areas where concrete truck washout is permissible must be clearly posted at appropriate areas of the site. Wastes and unused building materials shall be managed and disposed of in accordance with all applicable state statutes and regulations. Proper storage and handling of materials such as fuels or hazardous wastes, and spill prevention and cleanup measures shall be implemented to minimize the potential for pollutants to contaminate surface or ground water or degrade soil quality;
(7) Public or private roadways shall be kept cleared of accumulated sediment that is a result of runoff or tracking. Bulk clearing of accumulated sediment shall not include flushing the area with water. Cleared sediment shall be redistributed or disposed of in a manner that is in accordance with all applicable statutes and regulations;
(8) Collected runoff leaving a project site must be either discharged directly into a well-defined, stable receiving channel, or diffused and released to adjacent property without causing an erosion or pollutant problem to the adjacent property owner; and
(9) Natural features, including wetlands, shall be protected from pollutants associated with stormwater runoff.
(C) Calculations and design standards and specifications.
(1) In calculating the total area of land disturbance, for the purposes of determining applicability of this section to the project, the following guidelines must be used.
(a) Off-site construction activities that provide services (for example, road extensions, sewer, water, 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) Strip developments will be considered as one project site and must comply with this section unless the total combined disturbance on all individual lots is less than one acre and is not part of a larger common plan of development or sale.
(c) To determine if multi-lot project sites are regulated by this rule, 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. Construction of 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. Construction of 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; and
3. To calculate lot disturbance on all other types of projects 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.
(2) The calculation methods as well as the type, sizing, and placement of all stormwater pollution prevention measures for construction sites shall meet the design criteria, standards, and specifications outlined in the latest editions of the state’s “Stormwater Quality Manual” and the city’s “Stormwater Technical Standards Manual”. The methods and procedures included in these two references are in keeping with the above stated policy and meet the requirements of IDEM’s Rule 5. A copy of the state’s “Stormwater Quality Manual” may be obtained through IDEM.
(D) Inspection, maintenance, record keeping, and reporting.
(1) Following approval of the development plan or improvement location permit, the city will have the authority to conduct inspections of the site to ensure full compliance with the provisions of this section, the latest edition of the state’s “Stormwater Quality Manual”, and the terms and conditions of the approved permit.
(2) A self-monitoring program must be implemented by the project site owner or permit holder to ensure the stormwater pollution prevention plan is working effectively. A trained individual, acceptable to the city, shall perform a written evaluation of the project site by the end of the next business day following each measurable storm event. If there are no measurable storm events within a given week, the site must be monitored at least once in that week. Weekly inspections by the trained individual shall continue until the entire site has been stabilized and a notice of termination has been issued. The trained individual must look at the maintenance of existing stormwater pollution prevention measures, including erosion and sediment control measures, drainage structures, and construction materials storage/containment facilities, to ensure they are functioning properly and that they are not dismantled or tampered with by others. The trained individual must also identify additional measures, beyond those originally identified in the stormwater pollution prevention plan, necessary to remain in compliance with all applicable statutes and regulations.
(3) The resulting evaluation reports must include the name of the individual performing the evaluation, the date of the evaluation, problems identified at the project site, and details of maintenance, additional measures, and corrective actions recommended and completed.
(4) The stormwater pollution prevention plan shall serve as a guideline for stormwater quality, but shall not be interpreted to be the only basis for implementation of stormwater quality measures for a project site. The project site owner and permit holder is responsible for implementing, in accordance with this section, all measures necessary to adequately prevent polluted stormwater runoff. Recommendations by the trained individual for modified stormwater quality measures must be implemented.
(5) Although self-monitoring reports do not need to be submitted, the city has the right to request complete records of maintenance and monitoring activities involving stormwater pollution prevention measures. All evaluation reports for the project site must be made available to the city in an organized fashion within 48 hours upon request.
(Ord. 2006-13, passed 10-26-2006; Ord. 2019-25, passed on 5-13-2020)