(A) MS4 Stormwater Construction BMP Manual.
(1) Adoption. The city adopts as its MS4 stormwater construction BMP manual(s) the following publication(s), which is incorporated by reference in this chapter as if fully set out herein:
(a) Tennessee Permanent Stormwater Management and Design Guidance Manual (most current edition).
(b) TDEC Erosion and Sediment Control Handbook (most current edition).
(c) A collection of MS4 approved BMPs developed or collected by the MS4 that comply with the goals of the MS4 permit and/or the CGP, such as the Nashville-Davidson County Metro Stormwater Management Manual (BEST MANAGEMENT PRACTICES (BMP) MANUAL - Volume 4); most current edition.
(2) The city has adopted, for use in designing stormwater control measures, construction design storm events. The construction design storm events adopted by the city are as follows:
(a) Water Quality (1-yr 24hr).
(b) Water Quantity (2-yr, 5-yr and 10-yr).
(3) Requirements for design storm for all waters as well as special conditions for unavailable parameters waters or exceptional Tennessee waters must be consistent with those of the current Tennessee Construction General Permit (TNR100000).
(B) The municipality has adopted, for use in designing EPSC measures, the design storm requirements from the current Tennessee Construction General Permit for all waters as well as special conditions for unavailable parameters or Exceptional Tennessee Waters.
(C) Waste control construction site operators are required to minimize the exposure of building materials, building products, construction wastes, trash, landscape materials, fertilizers, pesticides, herbicides, detergents, sanitary waste and other materials present on the site to precipitation and to stormwater.
(D) Priority construction.
(1) Priority in construction shall be, at a minimum, those construction activities discharging directly into, or immediately upstream of, waters the state recognized as unavailable condition for siltation or Exceptional Tennessee Waters.
(2) Requirements for all priority construction activities must include preconstruction meetings with construction site operators for priority construction activities.
(E) Land development.
(1) This section shall be applicable to all land development, including, but not limited to, site plan applications, subdivision applications, land disturbance applications and grading applications. These standards apply to qualifying new development or redevelopment site(s), when required. Every person will be required to obtain a land disturbance permit from the city in the following cases - one acre or more:
(a) New development that involves land development activities of one acre or more;
(b) Redevelopment that involves other land development activity of one acre or more;
(2) Projects of less than one acre of total land disturbance may also be required to obtain authorization under this chapter if:
(a) The city has determined that the stormwater discharge from a site is causing, contributing to, or is likely to contribute to a violation of a state water quality standard; or is likely to be a significant contributor of pollutants to water of the state.
(b) Changes in state or federal rules require sites of less than one acre that are not part of a larger common plan of development or sale to obtain a stormwater permit;
(c) Any new development or redevelopment, regardless of size, that is defined by the city to be a hot spot land use; or any project disturbing more than 4,000 square feet.
(d) The minimum applicability criteria set forth in division (E)(1) above if such activities are part of a larger common plan of development, (see COMMON PLAN OF DEVELOPMENT" definition in § 14-802).
(e) The creation and use of borrow pits, that are not permitted under the Tennessee Multi Sector Permit (TMSP), where material is excavated and relocated offsite, and fill sites where materials or earth is deposited by mechanized methods resulting in an increased elevation or grade.
(f) As determined by the city for single or duplex residential lots of any size, adjoining lakes or streams, slopes exceeding 15%, floodplains or streams to cross, are required to submit an erosion control and stormwater management plan. Depending on site specific conditions the requirement that the plan be developed by a qualified licensed professional engineer or landscape architect may be waived by the city.
(g) Minimal plan requirements shall include pre- and post-stormwater runoff directions, construction access, erosion/sediment control measures, roof downspout direction and termination, swales and temporary and/or permanent soil stabilization.
(h) If unpermitted construction activity is on-going, the city will issue an immediate stop-work order. If, in addition to the city's permit, a TDEC permit was required but was not obtained, the violator will also be reported to TDEC.
(F) Land disturbance/grading/stormwater construction permit. Persons seeking the issuance of any land disturbance permit must provide proof of coverage under the Tennessee Construction General Permit (CGP) (if applicable) when requested; and a copy of the stormwater pollution prevention plan (SWPPP) to the city when requested.
(1) Copies of additional applicable local, state or federal permits (i.e.: ARAP, approved hydrologic determination, etc.) must also be provided to the city.
(2) The city has the authority to withhold local permits prior to receiving copies of the aforementioned permits.
(3) In circumstances where no such permits have been required, the city may still require a SWPPP as part of the land disturbance permit application.
(G) Building permit. No building permit shall be issued until the applicant has first obtained a land disturbance permit where required by this chapter.
(H) Construction site operators are required to implement appropriate erosion prevention and sediment control measures and best management practices. EPSC requirements shall meet the Tennessee's CGP design storm(s), be consistent with the TDEC ESC Handbook best management practices and with the requirements of this chapter.
(I) Where site assessments are required by the CGP, the operator shall provide a copy of the assessment to the city.
(J) Twice-weekly inspections of the site and the BMP's/SCM's must be performed by an individual who has either received certification under the Level I Fundamentals of Erosion Prevention and Sediment Control course or has other credentials identified as equivalent within this chapter.
(K) Landscaping and stabilization requirements.
(1) Any area of land from which the natural vegetative cover has been either partially or wholly cleared by development activities shall be stabilized. Stabilization measures shall be initiated as soon as possible in portions of the site where construction activities have temporarily or permanently ceased. Temporary or permanent soil stabilization at the construction site (or a phase of the project) must be completed not later than 14 days after the construction activity in that portion of the site has temporarily or permanently ceased. In the following situations, temporary stabilization measures are not required:
(a) Where the initiation of stabilization measures is precluded by snow cover or frozen ground conditions or adverse soggy ground conditions, stabilization measures shall be initiated as soon as practicable; or
(b) Where construction activity on a portion of the site is temporarily ceased, and earth disturbing activities will be resumed within 14 days.
(2) For steep slopes of 35% or more, stabilization measures shall be initiated within seven days.
(3) Construction buffer zones. Construction buffer zones shall be those water quality buffers and buffer zones as defined in § 14-802 and shall meet the requirements in this chapter and, where appropriate in the TN CGP. The criteria for the width of the construction buffer zone can be established on an average width basis at a project, as long as the minimum width of the buffer zone is more than the required minimum width at any measured location. If the new development or redevelopment site encompasses both sides of a stream, buffer averaging can be applied to both sides, but must be applied independently. Water quality riparian buffer widths are measured from the top of bank also referred to as the "ordinary high-water mark." Construction buffers are not primary sediment control measures and shall not be relied on as such. Stormwater discharges must enter the water quality riparian buffer zone as sheet flow, not as concentrated flow, where site conditions allow. The designer/operator must comply with the vegetation requirements and the permissible land uses set forth for buffers in the TN CGP. Where it is not practicable to maintain a construction water quality riparian buffer, BMPs providing equivalent protection to a receiving stream as a natural water quality riparian buffer must be used.
(4) In arid, semiarid, and drought-stricken areas where initiating vegetative stabilization measures immediately is infeasible, alternative stabilization measures such as properly anchored mulch, soil binders or matting must be employed.
(L) Notice of termination (NOT). The operator shall provide the city with a copy of the NOT when it is issued by TDEC.
(M) As built plans (record drawings). All applicants are required to submit actual as built plans certified by the design engineer for any structures located on-site after final construction is completed. The plan must show the final design specifications for all stormwater management facilities and must be sealed by a registered professional engineer licensed to practice in Tennessee. A certification by the design engineer certifying that SCM's will function within original design parameters as constructed shall be included. A final inspection by the city is required before any performance security or performance bond will be released. The city shall have the discretion to adopt provisions for a partial pro-rata release of the performance security or performance bond on the completion of various stages of development. In addition, occupation permits shall not be granted until corrections to all BMP's/SCM's have been made and accepted by the city. No bonds or securities shall be released by the city until the (stormwater manger) has accepted the as built plans. The warranty period for any infrastructure to be accepted by the city for maintenance shall not commence until the city has accepted the as built plans.
(N) Equipment manufacturer startups. No bonds or securities shall be released until any equipment to be maintained by the city passes any specified manufacturer startup procedure. The warranty period shall not commence prior to the equipment passing any specified manufacturer startup procedure.
(Ord. 1722, passed 8-13-2024)