(A) Applicability and exemptions.
(1) The Town will require a SWPPP, which includes erosion and sediment control measures, pollution prevention practices and materials handling procedures, to be submitted as part of the construction plans and specifications. Any project located within the Town that involves land disturbance (with exception of divisions (A)(2) and (A)(3) below) shall comply with this section. Calculation of land disturbance should follow the guidelines contained in division (C) of this section. Land disturbance falls into one (1) of two (2) categories with differing requirements as follows:
(a) Land disturbances which are one (1) or more acres shall obtain coverage under IDEM's CSGP for construction activities and are subject to the requirement of this section. This section also applies to disturbances of less than one (1) acre of land that are part of a larger common plan of development or sale if the larger common plan will ultimately disturb one (1) or more acres of land.
(b) Land disturbances which are less than one (1) acre shall submit a SWPPP that at a minimum includes the following:
1. Installation and maintenance of appropriate perimeter control measures. These measures are to be installed prior to land disturbance and maintained until bare soils are permanently stabilized to at least seventy percent (70%) density of permanent perennial vegetated cover. Maintain existing vegetation when possible.
2. Installation of a temporary construction entrance/drive. Minimize sediment and soil discharge and tracking from the disturbed area. Clean-up sediment that is either tracked or washed on to roads or into stormwater conveyances (sewers, ditches, waterways, storm inlets, and the like). Cleaning surfaces shall not include flushing the area with water. Cleared sediment and soil must be collected and redistributed or disposed of in a manner that is compliant with all applicable statutes and rules.
3. Establish a concrete washout area to contain residual concrete and washout waters. Water collected from washout that does not harden or evaporate must be handled as wastewater.
4. Bare soils are to be stabilized in areas where work is complete, or where bare soils are to be inactive for more than seven (7) days. Utilize soil stabilization measures that are appropriate for the season.
5. Adjacent areas disturbed by an individual lot operator must be repaired and stabilized with temporary or permanent surface stabilization.
6. Install inlet protection at all stormwater inlets that receive runoff from disturbed areas. For inlets within a road or driving lane, inlet protection must be installed below the grate with an overflow or bypass so that ponding water does not cause unsafe driving conditions.
7. Where construction disturbs surfaces greater than 3H:1V slope or in areas of concentrated flow, establish permanent vegetation with erosion control blanket and seeding.
(2) The requirements under this chapter do not apply to the following activities:
(a) Agricultural land-disturbing activities, including tillage, planting, cultivation, or harvesting operations for the production of agricultural or nursery and vegetative crops, pasture renovation and establishment, the construction of agricultural conservation practices, and the installation and maintenance of agricultural drainage tile.
(b) Silvicultural activities associated with nonpoint discharges (40 CFR 122.27).
(c) Stormwater discharges associated with oil and gas exploration, production, processing or treatment operations, or transmission facilities (40 CFR 122.26).
(d) Ditch maintenance for activities performed on a regulated drain by a county drainage board as defined in I.C. 36-9-27.
(e) Single family residential with disturbance of less than five hundred (500) square feet.
(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 and pollution prevention 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.
(c) Municipal solid waste landfills that are accepting waste pursuant to a permit issued by IDEM 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) For an individual lot where land disturbance is expected to be one (1) acre or more, the individual lot owner must complete their own notice of intent (NOI) letter, obtain stormwater management plan approval, and ensure that a SWPPP is completed in accordance with the requirements of this chapter and other relevant ordinances.
(5) An individual lot with land disturbance less than one (1) acre, located within a larger permitted project site, is considered part of the larger permitted project site, and the individual lot operator must comply with the terms and conditions of the stormwater management plan approved for the larger project site. The stormwater management plan for the larger project site must include detailed erosion and sediment control measures for individual lots. The following general requirements apply to all individual building lots, where the individual lot operator/owner is working within a permitted project.
(a) All stormwater measures, including erosion and sediment control measures, necessary to comply with this permit must be implemented in accordance with the overall project construction plan
(b) Provisions for erosion and sediment control and project management on individual building lots regulated under the overall project site permit must ensure:
1. The individual lot operator (contractor/subcontractor), whether owning the property or acting as the agent of the individual lot owner, is responsible for erosion and sediment control requirements associated with activities on individual lots.
2. Installation and maintenance of a stable construction site access unless the site is to be accessed solely from impervious or similar non-erosive areas.
3. Installation and maintenance of appropriate erosion and sediment control measures prior to land disturbance.
4. Temporary stabilization is utilized on the building site, but not required during periods when accessibility to the building site is a necessity.
5. Sediment discharges and tracking from each lot is minimized until permanent stabilization has been achieved.
6. Sediment that is either tracked or discharged onto internal project site roads is removed by the end the same day. Clearing of sediment must not include flushing the area with water, unless authorized by the permittee of the overall project site and the sediment is directed to an appropriate on-site sediment control measure. Cleared sediment must be redistributed or disposed of in a manner that is compliant with all applicable statutes and rules.
7. Adjacent lots disturbed by an individual lot operator are required to be repaired and stabilized with permanent surface stabilization.
8. Construction and domestic waste must be managed to prevent the discharge of pollutants and windblown debris. When disposed of in waste containers (trash receptacles) the receptacle must be covered when not in use and at the end of the day. Waste that is not disposed of in trash receptacles must be removed at the end of the day from the site and disposed of properly.
9. Demolition waste must be managed to prevent windblown debris and to protect water quality.
10. Concrete washout areas provided by the permittee of the overall project site are utilized unless a leak-proof containment system is operated on the building lot, or special arrangements are made to properly dispose of the wash water. Concrete washout systems on individual lots must be properly installed and maintained. Wash water must be disposed of by the individual lot operator and is not allowed to discharge.
(c) For an individual residential lot to be considered stabilized according to the criteria in § 151.28, the individual lot operator must:
1. Complete final stabilization taking into account weather and season;
2. Initiate permanent seeding with appropriately crimped or tackified mulch cover, erosion control blanket, sod; or
3. Install appropriate and/or ensure functional erosion and sediment control measures are in place on the individual lot. Upon issuance of the certificate of occupancy and concurrence of the homeowner, the homeowner is responsible to maintain the sediment control measures until final stabilization has occurred.
(6) It will be the responsibility of the project site owner to obtain stormwater management plan approval and ensure that a sufficient construction plan is completed and submitted to the Town in accordance with the requirements of this section and other relevant ordinances. It will be the responsibility of the project site owner to ensure compliance with this section during the construction activity and implementation of the construction plan, and to notify the Town with a sufficient NOT letter upon completion of the project and stabilization of the site. However, all persons engaging in construction and land disturbing activities must comply with the requirements of this section.
(7) For land disturbing projects owned or operated by the Town, construction plans must be submitted to the Development Services Department and County SWCD for review and approval.
(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 and pollution prevention practices. The developer must submit to the Town a SWPPP with detailed erosion and sediment control plans as well as a narrative describing materials handling and storage, and construction sequencing. The following principles apply to all land-disturbing activities and should be considered in the preparation of a stormwater pollution prevention plan within the Town.
(1) Minimize the potential for erosion by designing a development that fits the topography and soils of the site. Deep cuts and fills in areas with steep slopes should be avoided whenever possible, and natural contours should be followed as closely as possible.
(2) Existing natural buffers that are adjacent to waters of the state to promote infiltration and provide protection of the water resource shall be preserved, unless infeasible. Activities performed by a county drainage board under I.C. 36-9-27 are excluded.
(3) Natural buffers must be preserved, including the entire buffer bordering and/or surrounding the water resource. Buffers:
(a) Fifty (50) feet or more in width must be preserved to a minimum of fifty (50) feet.
(b) Less than fifty (50) feet in width must be preserved in their entirety.
(c) May be enhanced with vegetation that is native and promotes ecological improvement and sustainability.
(d) Runoff directed to the natural buffer must be:
1. Treated with appropriate erosion and sediment control measures prior to discharging to the buffer.
2. Managed with appropriate runoff control measures to prevent erosion from occurring within the buffer area.
(e) Further information regarding buffer requirements is contained in IDEM's "Implementation of Buffers" guidance document.
(4) Unvegetated or vegetated areas with less than seventy percent (70%) cover that are scheduled or likely to be left inactive for seven (7) 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. Vegetated areas with a density of less than seventy percent (70%) shall be restabilized using appropriate methods to minimize the erosion potential.
(5) All practices on a site should be conducted in a logical sequence so that the smallest practical area of land will be exposed for the shortest practical period during land disturbing activities.
(6) The length and steepness of designed slopes should 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. Guidance for determining acceptable velocities and energy dissipation is provided in HEC-14.
(7) Sediment basins, where feasible, must withdraw water from the surface of the water column.
(8) Basin slopes must be stabilized upon achieving design grades to eliminate sediment inflow from the measure itself.
(9) The outfall of a basin must be stabilized and non-erosive within twenty-four (24) hours of installation of the basin outlet.
(10) Pipe outlets discharging from the project site must be provided with temporary or permanent energy dissipation within twenty-four (24) hours of discharging runoff.
(11) Sediment-laden water which otherwise would flow from the project site shall be treated by erosion and sediment control measures appropriate to minimize sedimentation.
(12) A stable construction site access shall be provided at all points of construction traffic ingress and egress to the project site.
(13) Stormwater runoff leaving a project site must be discharged in a manner that is consistent with applicable state or federal law.
(14) 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, port-a-let waste, 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 groundwater or degrade soil quality.
(15) 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.
(16) Natural features, including wetlands and sinkholes, shall be protected from pollutants associated with stormwater runoff.
(17) Ground water from the dewatering of excavations, trenches, foundations, etc. must not be discharged when:
(a) Sediment and ground water is not first directed to an appropriate stormwater quality measure or a series of control measures that minimize the discharge of the sediment.
(b) A visible sheen and/or pollutants are present at a level that requires additional treatment and/or an individual permit from IDEM.
(18) Fertilizer applications associated with the stabilization plan for the project must meet the following requirements:
(a) Apply fertilizer at a rate and amount as determined by a soil analysis or in accordance with the Indiana Stormwater Quality Manual or similar guidance documents.
(b) Apply fertilizer at an appropriate time of year for the project location, taking into consideration proximity to a waterbody, and preferably timed to coincide with the period of maximum vegetative uptake and growth.
(c) Avoid applying fertilizer before rainfall events that could result in the discharge of nutrients.
(19) Soil compaction is to be minimized, especially in areas where permanent vegetation will be re-established and/or areas that are designated to infiltrate stormwater for the post-construction phase.
(20) Topsoil is to be preserved, unless infeasible.
(21) Generation of dust shall be minimized through dust suppression techniques to prevent deposition into waters of the state.
(22) The use of anionic polymers (cationic polymers are not authorized for use) on the project site are authorized for sediment control provided their use is in conformance with current State of Indiana standards and specifications. The use of the polymers requires notification to IDEM and the Town.
(23) Required postings.
(a) The project site owner shall post a notice near the main entrance of the project site. For linear projects sites, such as a pipeline or highway, the notice must be placed in a publicly accessible location near the project field office. The notice must be maintained in a legible condition and contain the following information:
1. Copy of the completed IDEM NOI and the CSGP number issued by IDEM, where applicable.
2. Name, company name, telephone number, e-mail address (if available), and address of the project site owner or a local contact person.
3. Location of the construction plan.
(b) This permit and posting of the notice does not provide the public with any right to trespass on a project site for any reason, nor does it require that the project site owner allow members of the public access to the project site.
(24) All stormwater quality measures must be designed and installed under the guidance of a trained individual (refer to definitions section or according to the requirements of the CSGP).
(25) Certified professionals shall be utilized for activities associated with the development and design of the SWPPP, stormwater measure implementation, and stormwater project management.
(26) Personnel associated with the project must be informed of the terms and conditions of this permit and the requirements within the SWPPP. The permittee is required to document this process. Information must be provided through training, preconstruction meetings, written notification, contracts, or other means that effectively communicates the provisions and requirements of the permit and SWPPP. Personnel include, but are not limited to:
(a) General contractors, construction management firms, grading or excavating contractors, trade industry representatives (i.e., concrete industry), and utility contractors associated with the overall project.
(b) Contractors or individual lot operators that have primary oversight on individual building lots.
(c) Those responsible for the implementation of the SWPPP, and the installation, repair, and maintenance of stormwater measures.
(d) Those responsible for the application and storage of treatment chemicals.
(e) Those responsible for administering inspections.
(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 should 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 (1) project site and must comply with this chapter unless the total combined disturbance on all individual lots is less than one (1) 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 chapter, 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. A single-family residential project site where the lot(s) is one-half (0.5) acre or more in total size, as one-half (0.5) acre of land disturbance.
2. A single-family residential project site where the lot(s) is less than one-half (0.5) acre in size, as the actual lot size.
3. All other types of project sites, such as industrial and commercial project sites, as a minimum of one (1) acre for all lots regardless of size.
(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 Indiana Stormwater Quality Manual and the Town of Brownsburg Construction Standards.
(D) Submittal requirements. For those projects meeting the requirements of this section, a construction stormwater pollution prevention plan is required in addition to the submittal requirements listed in § 151.20. This plan must include the following information:
(1) IDEM NOI form along with the information required by the NOI form.
(2) Proof of publication in a newspaper of general circulation, in the affected area, that notified the public that a construction activity is to commence. The publication must include language required by the CSGP.
(3) Construction plans and SWPPP shall contain the information required by the CSGP. SWPPP figures shall also contain the following:
(a) Contour lines with maximum one (1) foot contour interval.
(b) Stormwater infrastructure and facilities.
(c) Open conveyances.
(d) Flood routing path and ponding locations in accordance with § 151.21(I).
(4) SWPPP sequencing shall consider various phases of construction activities and may require more than one (1) SWPPP plan sheet. Possible phases of construction include initial clearing, earth moving activities, hauling of borrow or fill soils, current site conditions, installation of infrastructure, final stabilization, off-site work associated with the project, etc.
(Ord. 2017-28, passed 10-12-17; Am. Ord. 2024- 04, passed 4-25-24)