(A) Stormwater Quality Management. The permittee shall complete a permit application that includes a Post-Construction Stormwater Pollution Prevention Plan (P-SWPPP) to be completed, sealed and signed by a Licensed Professional Engineer and/or land surveyor as appropriate and submitted to the City Representative.
(B) Post-Construction Stormwater Pollution Prevention Plan. A SWQMP Permit requires a review and submittal of a Post-Construction Stormwater Pollution Prevention Plan (SWPPP). The Post-Construction SWPPP shall include the following information:
(1) A description of the proposed land use including amount of impervious area, directly connected impervious area, and nature of the development.
(2) Location, dimensions, detailed specifications, and construction details of all post-construction stormwater quality Best Management Practices (BMPs), as defined in the city guidance documents.
(3) A sequence describing when each post-construction stormwater quality BMP will be installed.
(4) A Long-Term Operation and Maintenance Agreement containing maintenance guidelines for all post-construction stormwater quality measures to facilitate their proper long-term function. This Agreement shall be made available to future parties, including property owners, who will assume responsibility for the operation and maintenance of the postconstruction stormwater quality measures.
(5) The P-SWPPP shall include provisions for buffers.
(a) The Waterway Buffer will be used to define areas where land disturbance activities shall be permitted, but construction of any building or structure shall not be permitted.
(b) A waterway buffer shall be applied to all waterways serving more than 25 acres of tributary area or presented on a United State Geological Survey map as a blue line stream.
(c) The waterway buffer shall be defined as the greater of:
1. Area contained within a boundary established by the floodplain boundary as defined by FEMA or city master planning: or
2. Where a floodplain is not defined or calculated, the buffer will be 25-feet on each side from the top of waterway bank as defined by geomorphic shape (not by the current water surface elevation).
(d) The waterway buffer and floodplain may be used for application of stormwater quality devices. This may only be permitted if erosion prevention and sediment control, water quality, and cut first fill policies are adequately addressed as determined by the city according to the provisions of this chapter.
(e) Exemptions are granted so long as, erosion prevention and sediment control, water quality and cut-fill policies are adequately addressed. Exemptions shall be granted for:
1. Roads and utilities crossing waterways.
2. Pedestrian trails and walkways proximate to waterways.
3. Other exemptions may be made at the discretion of the city representative.
(6) A Licensed Professional Engineer in the Commonwealth of Kentucky shall stamp all construction plans and long-term maintenance documentation. This shall include all proposed improvements or modifications to existing or new stormwater infrastructure and other related improvements or modifications.
(7) The city may require the posting of a maintenance bond to secure the structural integrity of said facilities as well as the functioning of said facilities in accordance with the approved Post- Construction SWPPP for a term of twenty-four (24) months from the date of acceptance of dedication. An irrevocable letter of credit can be used as the financial assurance in lieu of a maintenance bond although the contribution shall be equivalent to the amount that would be estimated for the maintenance bond. The maintenance bond shall be calculated as twenty percent (20%) of the estimated construction cost and may be reduced to ten percent (10%) after twelve (12) months if there are no concerns by the city representative.
(C) BMP design requirements and criteria.
(1) The city reserves the right to develop or adopt other guidance documents to serve as design and implementation standards. Other guidance documents distributed by the city should be reviewed and considered when preparing the Post-Construction SWPPP. These documents may be applied as standards by which designs are to be prepared and controls implemented.
(2) The city shall have authority to implement this chapter by appropriate regulations, guidance or other related materials. In this regard, technical, administrative, or procedural matters may be modified as needed to meet the objectives defined herein, so long as such modifications as to technical, administrative, or procedural matters are not contrary or beyond the intent of the objectives defined above.
(a) Regulations, guidance or other related materials that may be given authority by this chapter may include, but are not limited to: Best Management Practice (BMP) manuals, design regulations and requirements, submittal checklists, review checklists, inspection checklists, certifications, stormwater management manuals and operation and maintenance manuals.
(b) Materials may include information deemed appropriate by the city including guidance and specifications for the preparation of grading plans, selecting environmentally sound practices for managing stormwater, minimum specifications and requirements, more complete definitions and performance standards.
(c) The above referenced documents may restrict or prevent the use of specific products, techniques or management practices (that are to be accepted by the public or are deemed to have a negative impact on public infrastructure or the MS4) that have been identified as unacceptable for performance, maintenance or other technically based reasons.
(d) Documents referenced above may be updated periodically to reflect the most current and effective practices and shall be made available to the public. However, the failure to update the manual shall not relieve any applicant from the obligation to comply with this chapter, and shall not prevent the city from imposing the most current and effective practices.
(3) The P-SWPPP shall include provisions for stormwater quality BMPs functioning independently or in combination. Acceptable stormwater quality BMPs shall be defined by policy and guidance documents as approved by the Stormwater Board.
(4) The P-SWPPP shall include provisions for stormwater quality BMPs that are designed to treat, filter, flocculate, infiltrate, screen, evapotranspirate, harvest, cool, and reuse stormwater runoff, or otherwise manage the quality of stormwater runoff from an 80th percentile precipitation event or 0.61 inches of precipitation.
(a) The P-SWPPP shall identify pollutants of concern, based on land use. Post-construction land use examples may include, but are not limited to, single family and multi-family residential properties, gas and refueling stations, truck stops and vehicle service stations, vehicle washing facilities, commercial business, parking facilities, waste transfer stations, industrial sites, uncovered material storage areas, soil stockpile and compost processing facilities, and the like.
(b) The P-SWPPP shall demonstrate that target pollutants have been identified as well as treatment solutions for those pollutants. Target pollutants to be considered based on land use may include heavy metals, polycyclic aromatic hydrocarbons (PAHs), hydrocarbons, nutrients, temperature, pathogens, sediment (TSS), trash, chemicals, organic debris, and other materials on site that could adversely impact water quality.
(c) All runoff generated up to and including the 80th percentile storm event shall be routed through appropriately sized water quality treatment devices, which intercept and collect target pollutants to prevent them from leaving the site.
(d) Stormwater detention/ retention facilities shall be designed to address the rate at which flow is released over the entire runoff discharge period and the volume of discharge over the critical design-storm period if defined by city stormwater master plans. The outlet structure shall be designed as a v-notch weir or other multiple stage configurations capable of controlling the discharge rates for the first flush, two (2)-, ten (10)-, and twenty-five (25)-year design- storm events. The outlet structure shall be designed to safely bypass the one hundred (100)-year storm event.
(e) Additional requirements may be necessary per KYG20000 for discharges to waters with an approved Total Maximum Daily Load (TMDL) or waters on the Section 303(d) list of impaired waters.
(5) Soil bioengineering, "green" and other "soft" slope and stream bank stabilization methods shall receive preference over rip rap, concrete and other hard armoring techniques.
(6) Retention. Supportive data must be submitted to justify the type of facility selected. If the facility is designed to retain (volume control) all or a significant portion of runoff (as opposed to temporarily detain), then appropriate soils analyses findings shall be submitted to the city. This submission shall also discuss the impacts the facility will have on local karst topography as found through a geotechnical investigation of the site. The facility may be designed to infiltrate runoff to groundwater rather than transmit it downstream under conditions up to a ten (10)-year storm event. It must be able to bypass all other storms including one hundred (100)-year event with a discharge rate equivalent to or less than pre-development conditions without negatively impacting the one hundred (100)-year floodplain above or below the site. If data indicates that the facility can not retain a significant portion of the runoff (95%) then the facility must be designed to detain runoff.
(7) If available, each P-SWPPP shall be evaluated for consistency with the stormwater master plan or watershed study for the major watershed or watersheds within which the project site is located. The individual project evaluation will determine if stormwater quantity and quality management practices can adequately serve the property and limit impacts to downstream public and private properties. The presence of a regional facility(s) will be considered in determining the extent to which stormwater quantity and/or quality controls will be necessary.
(8) The city reserves the right to require superseding or additional treatment criteria or objectives for specific pollutant(s) as necessary to meet overall stormwater quality management program objectives or directives under a watershed improvement or Total Maximum Daily Load (TDML) program as administered by the USEPA or Commonwealth of Kentucky.
(9) On-site BMP Coordination with Regional BMPs.
(a) All properties are expected to implement on-site stormwater quality control measures, but the extent of application may bereduced given the availability, proximity and nature of regional stormwater quality BMPs.
(b) The extent and type of on-site stormwater quality management practices implemented shall be proportionate to the land use, and proximity to regional stormwater quality management practices.
(D) BMP ownership and easements.
(1) Any stormwater management facility or BMP which services individual property owners shall be privately owned. General routine maintenance (controlling vegetative growth and removing debris) shall be provided by the owner(s). The owner shall maintain a perpetual, non- exclusive easement that allows for access for inspection and emergency maintenance by the city. The city has the right, but not the duty, to enter premises for emergency repairs.
(2) Any stormwater management facility or BMP which services an individual residential subdivision in which the facility or BMP is within designated open areas or serves as an amenity with an established homeowners association shall be privately owned and maintained consistent with provisions of this chapter. The owner shall maintain a perpetual, nonexclusive easement which allows access for inspection and emergency maintenance by the city. The city has the right, but not the duty, to enter premises for emergency repairs.
(3) Any stormwater management facility or BMP which services commercial and industrial development shall be privately owned and maintained. The owner shall maintain a perpetual, nonexclusive easement which allows access for inspection and emergency maintenance by the city. The city has the right, but not the duty, to enter premises for emergency repairs.
(4) All regional stormwater management control facilities proposed by the owners, if approved and accepted by the city for dedication as a public regional facility, shall be publicly owned and/or maintained. All other stormwater management control facilities and BMPs shall be privately owned and/or maintained unless accepted for maintenance by the city.
(5) The city may require dedication of privately owned stormwater facilities, which discharge to the City stormwater system. This shall be at the approval of the City Council.
(E) Regional facilities management.
(1) The objective of a regional stormwater management facility, pond or other device, is to address the stormwater management concerns in a given watershed with greater economy and efficiency than possible through individual facilities. The intended result is fewer stormwater management facilities to maintain in the affected watershed while sustaining efficiency.
(2) The city encourages regional stormwater quantity and/or quality management practices, serving twenty-five (25) to two hundred and fifty (250) acres of tributary area, which may be consistently and efficiently managed and maintained. These types of practices will be encouraged in order to replace or reduce the implementation of on-site stormwater quantity and/or quality management practices, as determined to be appropriate by the city.
(3) Where a regional stormwater management facility has been established by one (1) or more local governments, or by an authority operating on behalf of one (1) or more local governments, a development or property may participate in said program in lieu of runoff control required by this chapter. This may be permitted provided that:
(a) Runoff from the development drains to an approved existing or proposed public regional stormwater management facility that will be operational within one (1) year.
(b) Participation in the form of contribution of funds, contribution of land, contribution of stormwater management facility construction work, or a combination of these, the total value of which shall be in accordance with a fee schedule adopted by the city.
(c) The city finds that the stormwater quality management plans are in compliance with all other applicable requirements and ordinances.
(d) Each fiscal or in-kind contribution from a development owner participating in a regional stormwater quality management facility shall be used for acquisition, design, construction or maintenance of one (1) or more such facilities in the same watershed in which the development is located.
(4) Detention facilities may, and are encouraged to, be designed to serve multiple purposes. For example, runoff may be detained under wet-weather conditions, but also serve as common or recreational areas during dry weather conditions. Where multi-purpose facilities are provided, or where flat grades or poorly draining soils are encountered, provisions for adequate low-flow stormwater management system may be required. Where the retention/ detention facility is planned to be used as a lake, pond or stormwater quality management practice with a permanent pool, water budget calculations shall be performed and submitted to demonstrate that an adequate permanent pool depth is expected during dry summer months.
(F) Long-term operation and maintenance agreements.
(1) Long-term operation and maintenance agreements shall include a maintenance plan for all stormwater quality BMPs in new development or redevelopment that require more than general maintenance (e.g. periodic mowing).
(a) The plan will be developed to ensure that the stormwater quality BMP(s) is (are) kept functional. The maintenance agreement will specify minimum operation and maintenance requirements and intervals to be performed by the property owner.
(b) The plan shall address schedules for inspections and techniques for operation and maintenance including vegetation clearing or mowing and removing accumulated trash, debris, sediment pollutants and other forms of pollution.
(c) The agreement shall be noted on the final plat with the appropriate notation on the particular lot(s).
(d) The agreement shall be included with property ownership title documents and shall be binding on the owner, its administrators, executors, assigns, heirs, and any other successors in interest.
(e) The format for the Long-Term Operational and Maintenance Agreement shall be provided through example by the city, or through guidance documents.
(f) Stormwater Detention and Retention Maintenance - Care must be taken to ensure that any required facilities do not become nuisances or health hazards. Detention and retention facilities should be designed to require minimal maintenance, and maintenance expectations must be clearly stated in the Long-Term Operation and Maintenance Agreement.
(g) When a stormwater quality BMP serves more than one (1) parcel, a home or property owners’ association or binding contract for the purpose of operation and maintenance is required. The owners association shall be responsible for operation and maintenance as directed by this chapter.
(2) Single entity ownership. Where the permanent stormwater runoff control facilities are designed to manage runoff from property in a single entity ownership, the maintenance responsibility for the stormwater control facilities shall be with the single entity owner.
(a) A single entity shall be defined as an association, public or private corporation, partnership firm, trust, estate or any other legal entity allowed to own real estate exclusive of an individual lot owner.
(b) The stated responsibilities of the entity shall be documented in the Long-Term Operation and Maintenance Agreement. Terms including owning, operating and maintaining the facilities shall be submitted with plans in application for a SWQMP Permit for an adequacy determination. Approval of a SWQMP shall be conditioned upon the approval of these terms. These terms shall be in writing, shall be in recordable form, and shall, in addition to any other terms deemed necessary by the city, contain a provision permitting inspection at any reasonable time by the city of all facilities deemed critical in the public welfare.
(c) Upon approval of the stormwater quality BMPs by the city, the facility owner(s) shall demonstrate the ability to guarantee and apply the financial resources necessary for long-term maintenance requirements. The funding mechanism shall be in a form approved by the city. The city will only approve funding mechanism(s) for long-term maintenance responsibilities that can be demonstrated to be permanent or transferable to another entity with equivalent longevity.
(d) In the event that proposed funding is through an owners association, then it must be demonstrated that the association may not dissolve unless long-term operation and maintenance activities are accepted by another entity with equivalent longevity and adequate funding. Furthermore, the owners association’s responsibility must be stated in the association’s declaration, covenants, or by-laws, as appropriate.
(e) Unless made specifically clear in the preliminary stages of the site design and construction plan review procedure, it will be assumed that all stormwater detention, retention, treatment or storage facilities and/or devices shall be owned, operated and maintained by a single entity as defined above.
(3) City ownership. Where the city has accepted an offer of dedication of the permanent stormwater quality BMPs, the city shall be responsible for operation and maintenance.
(Ord. 08-04, passed 1-14-08; Am. Ord. 12-02, passed 3-12-12)