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This chapter applies to development areas having new or relocated projects involving highways, underground cables, pipelines, subdivisions, industrial projects, commercial projects, building activities on farms, redevelopment of urban areas and all other land uses not specifically exempted. This ordinance does not apply to:
(a) Land disturbing activities related to producing agricultural crops or Silviculture operations regulated by the Ohio Agricultural Sediment Pollution Abatement Rules (1501: 15-3-01 to 1501: 15-3-09 of the Ohio Administrative Code) and existing at the time of passage of this regulation.
(b) Coal surface mining operations regulated by Chapter 1513 of the Ohio Revised Code and existing at the time of passage of this regulation.
(c) Other surface mining operations regulated by Chapter 1514 of the Ohio Revised Code and existing at the time of passage of this regulation.
(Ord. 2022-17. Passed 3-22-22.)
In implementing these regulations, the Community Engineer or other Community officials may consult with the local county SWCD, state and federal agencies and other technical experts as necessary. Any costs associated with such consultations may be assessed to the applicant or his or her designated representative.
(Ord. 2022-17. Passed 3-22-22.)
In order to control storm water damage and sediment pollution of water resources, wetlands, riparian areas, other natural areas, and public and private lands, the owner of each development area shall be responsible for developing a comprehensive Construction Site Conservation Plan. This plan will address storm water management (volume and peak rate of runoff), soil erosion, sediment and other wastes control. This plan must contain a description of controls appropriate for each construction operation covered by these regulations, and the operator must implement the planned controls in a timely manner. The plan and BMPs used to satisfy the conditions of these regulations shall meet the standards and specifications in the current edition of the Ohio Rain Water and Land Development manual. The plan must make use of the practices that preserve the existing natural condition to the Maximum Extent Practicable. The plan shall identify the subcontractors engaged in activities that could impact storm water runoff. The Construction Site Conservation Plan shall contain signatures from all of the identified subcontractors indicating that they have been informed and understand their roles and responsibilities in complying with the Construction Site Conservation Plan.
(a) Development Sites Under One (1) Acre in Size: Individual development sites that are larger than 8,000 square feet and smaller than one (1) acre (43,560 square feet) in total size of disturbed area, can submit abbreviated soil erosion and sediment control plans with the topography plan for the requested permit(s). The abbreviated plan must cover the following items, in addition to any other items from this chapter that are required by the City Engineer.
(1) Storm Water Issues: A statement as to how the increased storm water runoff that will be caused by the planned development project will be handled. The statement must identify the Best Management Practices (BMP'S) the new construction project will include in order to address storm water runoff.
(2) Redevelopment: Owners of development sites that were created by demolishing an older existing structure can request, in writing, that the City Engineer exempt them from the storm water issues if the total soil surface area being made impermeable is the same or less than the total soil surface area that was impermeable due to the structure(s) being torn down and removed. For a previously developed area, one or a combination of the following two conditions shall be met; (1) a twenty percent (20%) net reduction of the site's volumetric runoff coefficient through impervious area reduction with soil restoration or replacing impervious roof are with green roof area, or (2) treatment of twenty percent (20%) of the WQv (Water Quality Volume) for the previously developed area using a practice meeting table 4a/4b (1315.12(e)) requirements.
Where there is a combination of redeveloped areas and new development, a weighted approached shall be used with the following equation:
WQv = P * A * [(Rv1*0.2) + (Rv2 - Rv1)] / 12 (Equation 3)
where
P = 0.90 inches
A = area draining into the BMP in acres
Rv1 = volumetric runoff coefficient for existing conditions (current site impervious area)
Rv2 = volumetric runoff coefficient for proposed conditions (post- construction site impervious area)
Post-construction practices shall be located to treat impervious areas most likely to generate the highest pollutant load, such as parking lots or roadways, rather than areas predicted to be cleaner such as rooftops.
(3) Riparian and Wetland Setbacks: All riparian and wetland setback areas will be identified in the plan and in the field before construction starts.
(4) Soil Erosion and Sediment Issues: A sketch of the entire development site must be submitted that identifies the location of:
A. All existing and planned impervious areas, storm water inlets, drainage swales, wetlands, streams, conservation easements and other natural features to be saved and protected on the property.
B. All existing and planned temporary and permanent conservation practices for the site. Residential lots shall include at a minimum the following:
1. Soil erosion and sediment control BMPs, and;
2. Construction Entrance, and;
3. Temporary Grass Seeding with two (2) tons per acre of straw mulch, and;
4. Storm Drain Inlet Protection around every storm yard inlet on the site or accepting drainage from the site, and;
5. Silt Fence protection for any stream located on or close to the site and lacking an adequate vegetative buffer, and;
6. Silt Fence to prevent sediment discharge into street storm sewer inlets where no centralized sediment control exists for the drainage area that includes the lot, and;
7. Construction fence to protect any conservation easements, riparian setbacks and wetland setbacks from encroachment by construction activities.
(b) Development Sites One (1) Acre In Size or Larger: All developments that have a larger common plan of development or sale equal to or larger than one (1) acre in size of disturbed area are subject to this ordinance and shall follow all of the requirements set forth in this ordinance.
(1) Description of the Plan of Construction: The following information shall be included in the Construction Site Conservation Plan:
A. Site Description:
1. A description of the prior land uses of the site.
2. A description of the nature and type of construction activity (e.g., low density residential, shopping mall, highway, etc.).
3. A description of the total area of the site and the area of the site that is expected to be disturbed (i.e., grubbing, clearing, excavating, filling or grading, including off-site borrow, fill or spoil areas and off-site utility installation areas).
4. An estimate of the impervious area and percent imperviousness created by the construction activity.
5. The types of soils within, or affected by, the development area, and the location of all highly erodible or unstable soils as determined by the most current edition of the soil survey of the county, by the Natural Resources Conservation Service (NRCS),
6. An onsite, detailed Soils Engineering Report if required by the Community Engineer.
7. The name and/or location of the immediate receiving stream or surface water(s) and the first subsequent named receiving water and the major river watersheds in which it is located.
B. A vicinity sketch locating:
1. The larger common plan of development or sale
2. The development area
3. All pertinent surrounding natural features within 200 feet of the development site including, but not limited to:
a. Water resources such as wetlands, springs, lakes, ponds, rivers and streams (including intermittent streams with a defined bed and bank)
b. Conservation Easements
c. Other sensitive natural resources
d. The sensitive areas receiving runoff from the development
4. All off-site borrow or spoil areas
5. All off-site utility installation areas that are related to the planned project
C. The existing and proposed topography shown in the appropriate contour intervals as approved by the Community Engineer (generally one-foot contours are used).
D. The location and description of existing and proposed drainage patterns and facilities, including any allied drainage facilities beyond the development area and the larger common plan of development or sale.
E. Existing and proposed watershed boundary lines, direction of flow and watershed acreage.
F. The person or entity responsible for continued maintenance of all vegetative and/or mechanical BMPs for both the construction and post-construction phases of the development.
G. Long-term maintenance requirements and schedules of all BMPs for both the construction and post-construction phases of the development.
H. Long-term maintenance inspection schedules.
I. The person or entity financially responsible for conducting the inspections of, and the maintenance of, permanent storm water conveyance and storage structures and all other conservation practices.
J. The method of ensuring that funding will be available to conduct the long-term maintenance and inspections of all permanent storm water, soil erosion and sediment control and water quality practices.
K. The location of any existing or planned riparian and/or wetland setback areas on the property.
L. The plan must clearly describe, for each major construction activity, the appropriate BMPs and the general timing (or sequence) during the construction process of when the measures will be implemented; and, who (which contractor) will be responsible for implementation (e.g., Contractor A will clear, grub and install perimeter controls and Contractor B will maintain perimeter controls until final stabilization; Contractor C will conduct and document the scheduled inspections.)
M. Location and description of any storm water discharges associated with dedicated asphalt and concrete plants covered by this regulation and the Best Management Practices to address pollutants in these storm water discharges.
(2) Construction Site Conservation Plan Elements: the Construction Site Conservation Plan shall include, at a minimum, the following information:
A. The Construction Site Conservation Plan shall include a map showing the location of:
1. The limits of earth disturbing activity including excavations, filling, grading or clearing.
2. Drainage patterns during major phases of construction.
3. The location of each proposed soil erosion and sediment control BMP, including:
a. Permanent soil erosion control practices to be left in place after construction operations have been completed (e.g. level spreaders, permanent erosion control matting, gabions, rock lined channels, etc.),
b. Areas likely to require temporary stabilization during the course of site development,
c. Designated construction entrances where vehicles will access the construction site,
d. In-stream activities including stream crossings,
e. Areas designated for the storage or disposal of solid, sanitary and toxic wastes,
f. Dumpsters,
g. Cement truck washout,
h. Fuel tanks
i. BMPs that divert runoff away from disturbed areas and steep slopes where practicable including rock check dams, pipe slope drains, diversions to direct flow away from exposed soils, and protective grading practices,
j. Sediment settling ponds drawn to scale.
4. Existing and proposed locations of buildings, roads, parking facilities and utilities.
5. Boundaries of wetlands and stream channels the owner intends to fill or relocate for which the owner is seeking approval from the US Army Corps of Engineers and/or Ohio EPA.
B. The Construction Site Conservation Plan shall include a list of soil erosion and sediment control BMPs being used and the standards and specifications, including detailed drawings, for each BMPs. This list shall include:
1. Methods of controlling the flow of runoff from disturbed areas so as to prevent or minimize erosion.
2. Identification of the Structural Practices to be used to control erosion and trap sediment from a site remaining disturbed for more than fourteen (14) days. A description shall be included of how each selected control will store runoff so as to let sediments settle out and/or divert flows away from exposed soils or act to limit runoff from exposed areas.
3. Identification for each Structural Practice of its size, detail drawings, maintenance requirements and design calculations.
4. The type and amount of plant seed, live plants, fertilizer, agricultural ground limestone and mulch to be used. Specification of soil testing requirements for fertility and lime requirements will be included. Specification for the use of perennial grass seed will also be included.
5. Settling ponds will be identified with basic dimensions and the calculations for size and volume.
6. Detailed drawings and installation requirements of all other structural control BMPs.
7. Any other soil erosion and sediment control related BMPs and items that are required by the Community Engineer.
8. For developments where the overall plan does not call for centralized sediment control capable of controlling multiple individual lots, a detail drawing of a project specific typical individual lot showing standard individual lot soil erosion and sediment control practices and the sequence and timing of BMP installation for the individual lots. This does not remove or eliminate the responsibility to designate and install specific soil erosion and sediment control practices for the storm water discharges.
C. The Construction Site Conservation Plan shall include the scheduling, phasing, and coordination of construction operations and erosion and sediment control BMPs, including vegetative plantings and mulch.
(3) The Construction Site Conservation Plan shall include a description of the Storm Water Management (SWM) practices to be used on the site. The SWM element of the Plan shall include, at a minimum, the following:
A. A map showing the location, drawn to scale, of permanent SWM conveyance, detention and retention structures, other SWM control structures and the SWM easements.
B. A general description of the SWM strategy proposed to meet this chapter.
C. Design calculations for all permanent SWM conveyance, detention and retention structures, and other SWM control structures.
D. A minimum of one green infrastructure/infiltration stormwater control measure (SCM) to be included on the Construction Site Conservation Plan or any combination of green infrastructure and infiltration practices to be installed on site when feasible. This includes, but is not limited to, bioretention areas/cells, infiltration basins, infiltration trenches, and permeable pavement. Any site exemption to this requirement is to be determined by the Community Engineer pending a review of valid site restrictions provided by the developer. For permeability requirements, refer to Section 1315.12(e) Table 4b - Infiltration Post-Construction Practices with Maximum Drain Times or 1317.09 Table 2.
E. For redevelopment projects/previously developed area requirements, refer to Section 1315.08(a)(2) of this chapter
F. Any other SWM related items required by the Community Engineer.
(Ord. 2022-17. Passed 3-22-22.)
Future access to floodplains, flood control facilities, runoff drainage ditches and channels,
runoff storage facilities, storm sewers and other drainage ways and structures, as required by the Community Engineer, shall be secured by means of easements.
(a) The easements shall be recorded in the name of the Community and, in single-family residential developments, the homeowners association.
(b) Such easements shall be not less than twenty-five (25) feet in width, in addition to the width of the ditch, channel, or other facility it is to serve. Access easements of this type shall be provided on one (1) side of the flood control or storm drainage ditch, channel, or similar type facility.
(c) Access along the initial drainage system shall be by means of easements. Such easements shall be not less than twenty-five (25) feet in width, with a minimum ten (10) foot width on either side of the centerline.
(d) Access adjacent to storage facilities shall consist of a twenty-five (25) foot easement in the case of detention (dry) basins, and a twenty-five (25) foot easement with a twenty-five 25-foot level bench in the case of retention (wet) basins, measured from the top of the bank, and shall include the storage facility itself.
(e) Easements for the emergency flow ways shall be a minimum of twenty-five (25) feet in width, or larger if required by the Community Engineer.
(f) Flood control or storm drainage easements containing underground facilities shall have a minimum width of twenty-five (25) feet.
(g) The easements shall be restricted against the planting within said easement of trees, shrubbery or plantings with woody growth characteristics, and against the construction therein of buildings, accessory buildings, fences, walls or any other obstructions to the free flow of storm water and the movement of inspectors and maintenance equipment and also restricted against the changing of final grade from that described by the grading plan.
(Ord. 2022-17. Passed 3-22-22.)
Any portion of the permanent drainage and soil erosion systems, including on-site and off-site storage facilities that are constructed by the owner, will be continuously maintained into perpetuity.
(a) Maintenance plans shall be provided by the permittee to both the Community Engineer and the post- construction operator of the BMP (including homeowner associations) upon completion of construction activities and prior to the Community Engineer giving final approval for the completed construction.
(b) Single Family and Multi-family Residential Developments: A Homeowners' Association shall be created and placed in title of the affected lands and shall be continuously responsible for post-construction maintenance and inspections into perpetuity unless such maintenance and inspections become officially accepted by the Community.
(c) Apartments, Commercial and Industrial Developments: The plans will clearly state that the owner of the property shall be continuously responsible for post-construction maintenance and inspections into perpetuity unless the Community officially accepts such maintenance and inspections.
(d) Maintenance Design: All temporary and permanent soil erosion and sediment control practices shall be designed and constructed to minimize maintenance requirements. Multi-use facilities incorporating assets such as aesthetics and recreation may be incorporated into the design of the drainage facilities. All permanent drainage, soil erosion, sediment control, water quality management systems and BMPs, including on-site and off-site structures and vegetation that are constructed or planted, must be inspected and maintained into perpetuity by the responsible party designated in the plans. Inspections and maintenance will be incorporated periodically throughout the year to ensure that the facilities are properly operational.
(e) Perpetual Maintenance Inspections: One (1) inspection with a written report will be performed each year. The written report will be given to the Community Engineer by May 1 of each and every year after the Best Management Practice (BMP) has been completed.
(1) Structures that require a permit from the Ohio Division of Water: A written and stamped report from a professional engineer on the status of all structural BMPs that require a permit from the Ohio Department of Natural Resources (ODNR) Division of Water. This applies to all BMPs that require a permit either at the time of construction or fall under the jurisdiction of the ODNR Division of Water at any time after construction is completed.
(2) Easements: A written report from an inspector on the status of all storm water management easements for each project shall be submitted to the Community Engineer by May 1 of each year into perpetuity. These reports will document if restricted plantings, fences and structures are on the easement and will identify the location of the noted easement restriction violations.
(3) Best Management Practices (BMPs) that do not have a high risk for loss of life, bodily injury, or damage to structures or infrastructure related to imminent failure as determined by the Community Engineer: A written and stamped report from a professional engineer, landscape architect or Certified Professional In Erosion and Sediment Control (CPESC) on the status of permanent soil erosion, sediment control, water quality management systems and the status of the related easements shall be submitted to the Community Engineer by May 1 of each year into perpetuity.
(4) BMPs that have a potential loss of Life: A written and stamped report covering the status of all BMPs that have a potential for loss of life, bodily injury, or damage to structures or infrastructure will be prepared by a professional engineer or other individual possessing a valid state license that authorizes them to design the same type of BMP for construction.
(Ord. 2022-17. Passed 3-22-22.)
In order to control sediment pollution of water resources, the owner or person responsible for the development area shall use conservation planning and practices to maintain the level of conservation established in the following standards.
(a) The plan shall include measures that control the flow of runoff from disturbed areas so as to prevent soil erosion from occurring.
(b) Structural Practices shall be used to control erosion and trap sediment from areas remaining disturbed for more than fourteen (14) days.
(c) Sediment Barriers: Sheet flow runoff from denuded areas shall be intercepted by Silt Fence or Diversions to protect adjacent properties and water resources from sediment. Where intended to provide sediment control, Silt Fence shall be placed on a level contour. The relationship between the maximum drainage areas to Silt Fence for a particular slope is shown in the table below (placing silt fence in a parallel series does not extend the size of the drainage area).
Table 1: Silt Fence Applicability
Maximum drainage area (in acres) to Range of slope for a particular drainage area | |
100 linear feet of Silt Fence | (in percent) |
0.5 | <2% |
0.25 | >2% but <20% |
0.125 | >20% but <50% |
This does not preclude the use of other sediment barriers designed to control sheet flow runoff. The total runoff flow treated by a sediment barrier shall not exceed the design capacity for that sediment barrier. Straw Bale Barriers are not acceptable.
(d) Storm Water Diversion Practices: Storm water diversion practices shall be used to keep runoff away from disturbed areas and steep slopes where practicable. Such practices, which include Swales, Dikes or Berms, Pipe Slope Drains and Diversions, may receive storm water runoff from areas up to ten (10) acres. Storm water diversion practices alone are not considered a sediment control practice unless those are used in conjunction with a sediment settling pond.
(e) All sediment control practices must be capable of ponding runoff in order to be considered functional.
(f) Clearing and Grubbing will be done in two (2) or more phases. The first phase will include only those locations necessary to install the perimeter soil erosion, sediment and storm water control BMPs. After the perimeter controls are in place and functioning, the remaining phase(s) of clearing and grubbing may continue.
(g) Timing of Sediment Trapping Practices: Sediment control practices shall be functional throughout all phases of up slope earth disturbing activity. Settling facilities, perimeter controls and other practices intended to trap sediment shall be implemented prior to grading and within seven (7) days from the start of grubbing. They shall continue to function until the up slope development area is permanently restabilized. As construction progresses and the topography is altered, appropriate controls must be constructed or existing controls altered to address the changing drainage patterns.
(h) Stabilization of Denuded Areas: Disturbed areas must be stabilized as specified in the tables below, or according to the Ohio EPA NPDES Storm Water Permit Rules, whichever is most restrictive:
Table 2: Permanent Stabilization
Area requiring permanent stabilization | Time frame to apply erosion controls |
Any areas that will lie dormant for one year or more | Within seven days of the most recent disturbance |
Any areas within 50 feet of a surface water of the state and at final grade | Within two days of reaching final grade |
Other areas at final grade | Within seven days of reaching final grade within that area |
Table 3: Temporary Stabilization
Area requiring temporary stabilization | Time frame to apply erosion controls |
Any disturbed areas within 50 feet of a surface water of the state and not at final grade | Within two days of the most recent disturbance if the area will remain idle for more than 14 days |
Any disturbed areas that will be dormant for more than 14 days but less than one year, and not within 50 feet of a surface water of the state | Within seven days of the most recent disturbance within the area For residential subdivisions, disturbed areas must be stabilized at least seven days prior to transfer of permit coverage for the individual lot(s). |
Disturbed areas that will be idle over winter | Prior to the onset of winter weather |
(i) Sediment Settling Ponds: A sediment settling pond is required for any one of the following conditions:
Concentrated storm water runoff (e.g., storm sewer or ditch);
Runoff from drainage areas, which exceed the design capacity of silt fence or other sediment barriers;
Runoff from drainage areas that exceed the design capacity of inlet protection;
Runoff from common drainage locations with ten (10) or more acres of disturbed land.
Alternative controls can be used if the owner can show, in writing, that the Ohio EPA approved the use of alternatives that the owner demonstrated to be equivalent in effectiveness to a sediment settling pond.
(1) Where storm sewer drainage areas include ten (10) or more acres disturbed at one time, a temporary (or permanent) sediment settling pond must be provided until final stabilization of the site. In single-family residential construction, final stabilization is after the houses are built and permanent landscaping is done.
A. It is recommended that for drainage locations of less than ten (10) acres, smaller sediment settling basins and/or sediment traps be used.
(2) Each facility's storage capacity shall be no less than 1800 cubic feet of dewatering zone area per acre of total contributing drainage area and 1000 cubic feet per disturbed acre of sediment storage zone area. The storage volume will be measured from the bottom of the basin to the top of the primary (principle) spillway.
(3) Permanent storm water management ponds that are designed to trap sediment during construction shall be designed to provide for a slow release of sediment-laden water. The draw down time must be at least forty-eight (48) hours, or meet the criteria in the Ohio Rainwater and Land Development manual whichever is most stringent.
(4) The design configuration between inlet(s) and the outlet of settling ponds must provide at least two units of length for each one unit of width (> 2:1 length to width ratio); a length to width ratio of 4:1 is recommended.
(5) The depth of the dewatering zone of the sediment settling pond must be less than or equal to five (5) feet.
(6) Sediment must be removed from the sediment settling ponds when the design capacity has been reduced by forty percent (40%).
(7) Public safety, especially as it relates to children, must be considered in the design. Alternative sediment controls must be used where site limitations would preclude a safe design.
(8) Temporary sediment settling ponds will not be constructed in any stream channel.
(j) Storm Sewer Inlet Protection:
(1) All storm sewer inlets that accept water runoff from the development area shall be protected so that sediment-laden water will not enter the storm sewer, unless the storm drain system drains to a Sediment Settling Pond and is exempted in writing by the Community Engineer. In areas where construction will be ongoing, such as subdivisions, the storm sewer protection shall be maintained until all up slope areas reach final stabilization, as determined by the Community Engineer.
(2) All inlets receiving runoff from drainage areas of one or more acres will require a sediment settling pond.
(3) At the end of this period the site owner shall hydraulically clean the storm sewers to the satisfaction of the Community Engineer. All sediments shall be removed from the system and shall not be flushed downstream.
(k) Storm Sewer and Other Drainage Outlets: All storm sewers, footer drains, roof gutter drains and all other drains will be outletted at the bottom of the slope. The slope below the outlet will be able to control the water being drained through the storm sewer or other drains without causing erosion of the stream or channel banks or channel bottom or other areas that the water is outletted on.
(l) Working Near, Or Crossing Streams and Wetlands:
(1) Construction vehicles shall avoid water resources, wetlands, riparian areas, and their setbacks. If construction vehicles must cross these areas during construction, an approved temporary crossing shall be constructed. Streams, including intermittent streams with a defined bed and banks, shall be restabilized immediately after in-channel work is completed, interrupted, or stopped. Erodible materials will not be used in making stream crossings.
(2) No soil, rock, debris, or any other material shall be dumped or placed into a water resource or into such proximity that it may slough, slip, or erode into a water resource unless such dumping or placing is authorized by the approving authority and, when applicable, the US Army Corps Of Engineers and Ohio EPA, for such purposes as, but not limited to, constructing bridges, culverts, and erosion or sediment control structures.
(3) If construction activities disturb areas adjacent to streams, structural practices shall be designed and implemented on site to protect the adjacent streams from the impacts of sediment runoff.
(4) No temporary or permanent sediment controls will be constructed in a stream channel.
(5) Streams and wetland setbacks required by the community will be implemented. As a minimum a setback of twenty-five (25) feet, as measured from the ordinary high water mark of the surface water, will be maintained in its natural state as a permanent buffer.
(m) Construction Entrance:
(1) Measures shall be taken to prevent soil transport onto public roads, or surfaces where runoff is not checked by sediment controls.
(2) Stone with geotextile construction entrance(s) shall be implemented as required by the Community Engineer and the Ohio EPA. These will be planned and installed according to the requirements in the most recent edition of the Ohio Rainwater and Land Development manual.
(3) Where soil is transported onto a public road surface, the roads shall be cleaned thoroughly at the end of each day, or more frequently, in order to ensure public safety. Soil shall be removed from paved surfaces by shoveling or sweeping. Street washing shall be allowed only after shoveling or sweeping has removed most of the sediment and street sewer inlet protection is properly installed unless end of sewer sediment ponds exist and are properly functioning.
(4) Erodible material ramps in streets will not be used to enable equipment to cross curbs. Non-erosive materials (e.g. wood and stone) can be used.
(n) Unstable Soils:
(1) Unstable soils will be as determined by the local county Soil Survey or by a detailed soils report.
(2) The Community Engineer may require detailed soil reports when deemed necessary.
(3) Unstable soils prone to slipping or land sliding shall not be graded, excavated, filled or have loads imposed upon them unless the work is performed in accordance with a qualified professional engineer's recommendations to correct, eliminate, or adequately address the problems.
(o) Cut And Fill Slopes: Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion and slippage. Consideration shall be given to the length and steepness of the slope, soil type, up slope drainage area, groundwater conditions and slope stabilization. The minimum final unreinforced soil slopes will have a horizontal to vertical ratio of 2:1 (the horizontal will be two (2) times the vertical).
(p) Stabilization of Outfalls and Channels: Outfalls and constructed or modified channels shall be designed and constructed to withstand the expected velocity of flow from the planned post-development frequency storm without eroding. The planned post-construction velocity and flow shall include the entire contributing watershed. Velocity dissipation devices shall be placed at discharge locations and along the length of any outfall channel to provide non-erosive velocity from the structure to a water course so that the natural physical and biological characteristics and functions are maintained and protected.
(q) Establishment of Permanent Vegetation: A permanent vegetative cover shall be established on denuded areas not otherwise permanently stabilized. Permanent vegetation shall not be considered established until ground cover is achieved which, in the opinion of the Community Engineer, has eighty percent (80%) vegetative density over the entire disturbed area and provides adequate cover, and is mature enough to satisfactorily control soil erosion and survive adverse weather conditions.
(r) Disposition of Temporary Practices: All temporary soil erosion and sediment control practices shall be disposed of immediately after final site stabilization is achieved or after the temporary practices are no longer needed, unless otherwise required by the Community Engineer. Trapped sediment shall be permanently stabilized to prevent further erosion. The Construction Maintenance Guarantee shall not be released by the Community until all temporary soil erosion and sediment control practices that are no longer needed have been removed, properly disposed of and any trapped sediment has been stabilized.
(s) Underground Utility Construction: The construction of underground utility lines, pipes, etc. shall be subject to the following criteria:
(1) Trenches shall remain open for no more than five (5) days.
(2) There shall be no turbid discharges to surface waters resulting from dewatering activities. If trench or ground water contains sediment, it must pass through a sediment settling pond or other equally effective sediment control device, prior to being discharged from the construction site or to waters of the state.
(3) When discharging clean ground water care must be taken to ensure that it does not become pollutant laden by crossing over disturbed soils or other pollutant sources.
(t) Inspections:
(1) If inspections or other information indicates a control has been used inappropriately or incorrectly or it has failed, it must be replaced or modified for the site conditions.
(2) The owner of the development area shall have the site inspected for soil erosion, sediment control and other environmental concerns every seven (7) calendar days, and within twenty-four (24) hours of a one-half (0.5) inch or greater rainfall event until the Community Engineer certifies the site as being stable. The Community Engineer certification does not relieve the permittee from meeting the Ohio EPA NPDES inspection requirements.
(3) The inspection frequency may be reduced to at least once every month if the entire site is temporarily stabilized or runoff is unlikely due to weather conditions (e.g., the site is covered with snow, ice, or the ground is frozen.) A waiver of inspection requirements is available until one month before thawing conditions are expected to result in a discharge if all of the following conditions are met: the project is located in an area where frozen conditions are anticipated to continue for extended periods of time (i.e., more than one month); land disturbance activities have been suspended; and the beginning and ending dates of the waiver period are documented. Once a definable area has been fully stabilized, you may mark this on your plans and no further inspection requirements apply to that portion of the site.
(4) Following each inspection, a checklist must be completed and signed by the qualified inspection personnel representative. At a minimum, the inspection report must include: i) the inspection date; ii) names, titles, and qualifications of personnel making the inspection; iii) weather information for the period since the last inspection including the timing, duration, and depth of any storms; iv) weather information and a description of any discharges occurring at the time of the inspection; v) location(s) of discharges of sediment or other pollutants from the site; vi) location(s) of BMPs that need to be maintained; vii) location(s) of BMPs that failed to operate as designed or proved inadequate for a particular location; viii) location(s) where additional BMPs are needed that did not exist at the time of the inspection; and, ix) corrective action required including any necessary changes to the Comprehensive Storm Water Management Plan and implementation dates.
(5) The inspection log will include the date and actions taken to correct problems noted in past inspection logs.
(6) If the construction site is subject to Ohio EPA's National Pollutant Discharge Elimination System (NPDES) permit for construction activity, a copy of all of the required inspection sheets will be submitted to the Community Engineer within three (3) working days of the date that the inspection was conducted.
(7) Disturbed areas and areas used for storage of materials that are exposed to precipitation shall be inspected for evidence of, or the potential for, pollutants entering the drainage system.
(8) Erosion and sediment controls identified in the Storm Water Pollution Prevention Plan shall be observed to ensure that they are operating correctly.
(9) Discharge locations shall be inspected to ascertain whether erosion and sediment control measures are effective in preventing significant impacts to the receiving waters.
(10) Locations where vehicles enter or exit the site shall be inspected for evidence of off-site vehicle tracking.
(11) Sensitive areas including riparian and wetland setbacks shall be observed to ensure that they remain well marked and undisturbed.
(12) If the inspection reveals that a control practice is in need of repair or maintenance, with the exception of sediment settling ponds, it must be repaired or maintained within three (3) days of the inspection. Sediment settling ponds must be repaired or maintained within ten (10) days of the inspection.
(13) If any inspection reveals that a control practice fails to perform its intended function and that another, more appropriate control practice is required, the Construction Site Conservation Plan must be amended and the new control practice must be installed within ten (10) days of the inspection.
(14) If the inspection reveals that a control practice has not been implemented in the time required by this chapter it must be installed within ten (10) days from the date of inspection.
(15) If the inspection reveals that a planned control practice is not needed, the record must contain a statement of explanation as to why the control practice is not needed.
(u) Control of Materials and Debris: Site management practices shall be implemented to prevent toxic materials, hazardous materials, or other debris from entering the Community's and state's water resources or wetlands. These practices shall include, but are not limited to, the following:
(1) A covered dumpster shall be made available for the proper disposal of construction site waste materials, garbage, plaster, drywall, grout, gypsum and etc. A second covered dumpster will be provided for the proper disposal of toxic and hazardous wastes.
(2) The washing of excess concrete material into a street, catch basin, or other public facility or natural resource shall not occur. A designated area for concrete washouts shall be made available and used for all concrete washouts.
(3) All fuel tanks and drums shall be stored in a marked storage area. A dike shall be constructed around this storage area with a minimum capacity equal to one hundred ten percent (110%) of the volume of the largest container in the storage area. All additional requirements of the local fire authority must be followed. If the fuel tanks have a self-contained "dike," the plug will be kept in the "dike" tank at all times.
(4) Any toxic or hazardous wastes and/or contaminated soils must be disposed of according to all applicable environmental laws and statutes. Local health districts and Ohio EPA can provide guidance on these issues.
(5) On a site with a prior industrial land use or a site that is contaminated with gasoline, fuel oil, hydrocarbon-based chemicals or other Ohio EPA regulated contaminates, the storm water is considered wastewater. A permit from Ohio EPA is required to address these sites.
(6) Proper permits shall be obtained for development projects on solid waste landfill sites.
(7) Paint, paint washing liquids, excess paints and other paint wastes are considered solid wastes and shall be disposed of in accordance with applicable state regulations. Appropriate handling of these wastes shall occur at the site so as to prevent the discharge of these wastes into surface or ground waters.
A. Water based paint washing liquids and small quantities of excess water based paints may be disposed of by flushing down a connected sanitary sewer but may not be disposed of in an on- lot disposal system.
B. All other paints, paint thinners, and paint cleaning materials will be disposed of in the site's hazardous waste disposal dumpster.
(8) Restroom facilities will be provided for site workers at all times that workers are present on the site and during all phases of the construction.
(9) All required permits from appropriate federal, state, or local agencies are required to develop land with a previous industrial or commercial use or another use that may have led to soil contamination by a regulated pollutant.
(v) Pre-winter Stabilization: If the development area will, or is planned to remain, active through the winter months, the owner of the development area shall hold a Pre-Winter Stabilization Meeting. The meeting will be held before October 1. The owner shall invite the operator, developer, engineer, contractor, Community Engineer and anyone else requested by the Community Engineer to the meeting.
(w) Storm Water Basins:
(1) Pool Geometry: The minimum length-to-width ratio for the pond is 3:1 (the length will be three (3) times the width).
(2) Riser in Embankment: The riser shall be located within the embankment for purposes of maintenance access. Access to the riser will be by manholes.
(3) Water Drains: Each retention basin shall have a drainpipe that can completely drain the pond. The drain shall have an elbow within the pond to prevent sediment deposition from plugging the drain.
(4) Adjustable Gate Valves: Both the storm water management and water quality basin drains shall have adjustable gate valves. Valves shall be located inside the riser at a point where they will remain dry and can be operated in a safe and convenient manner. During the annual inspections the valves shall be fully opened and closed at least once, and the certifying official shall attest to this on the inspection form. To prevent vandalism, the handwheel shall be chained to a ringbolt or manhole step.
(5) Principal Spillway: Each principal spillway shall be designed in accordance with the NRCS standards and specifications for the office serving the county. Each principal spillway shall have the capacity to pass the 100-year design storm flow. The inlet or riser size for the pipe drops shall be designed so that the flow through the structure goes from weir flow control to pipe flow control without going into orifice control in the riser. The crest elevation of the primary spillway shall be no less than one foot below the emergency spillway crest. Premium joint pipe is required and a removable trash rack shall be installed at each location. Anti-seep collars shall be provided for all pipe conduits through an embankment.
(6) Emergency Spillway: An emergency spillway shall be provided on each storm water management basin. Emergency spillways shall convey flood flows safely past the embankment, and shall be designed in accordance with NRCS standards and specifications for the office serving the local county. Emergency spillways shall have a 100-year design storm capacity unless exempted in writing by the Community Engineer.
(7) Embankments: Each dam embankment shall be designed in accordance with the NRCS standards and specifications for the office serving the county that the project is located in. Anti-seep collars shall be provided for all pipe conduits through an embankment.
(8) Safety Features:
A. The primary spillway opening shall not permit access to the public and other non-maintenance personnel.
B. The perimeter of all water pool areas that are deeper than three (3) feet shall be surrounded by benches that meet the following:
1. A safety bench, with a maximum slope of three percent (3%), which extends outward, on dry land, from the shoreline. This bench will be a minimum of twenty-five (25) feet wide to provide for the safety of individuals and maintenance vehicles that are adjacent to the water pool. The safety bench may be landscaped, without the use of structures, to prevent access to the water pool.
2. Side slopes between the safety bench and the aquatic bench shall not be steeper than 3:1 (3 feet horizontal for every 1 foot vertical).
3. An aquatic bench that extends inward from the shoreline far enough to ensure public safety and has a maximum depth of fifteen (15) inches below the normal water surface elevations. The aquatic bench may be landscaped to prevent access to the deeper water pool.
4. Side slopes beyond the aquatic bench and below the permanent water level shall not be steeper than 2:1 (2 feet horizontal for every 1 foot vertical).
5. The contours of the pond will be designed and managed to eliminate drop-offs and other hazards.
6. Side slopes getting to the pond shall not exceed 3:1 and shall terminate on a safety bench.
7. Soil erosion and sediment control practices used to satisfy these standards shall meet the standards and specifications in the current edition of the Ohio Rainwater and Land Development manual, NRCS Field Office Technical Guide for the local county or the Ohio EPA, whichever is most stringent.
(x) These standards are general guidelines and shall not limit the right of the Community Engineer to impose at any time additional, more stringent requirements, nor shall the standards limit the right of the Community Engineer to waive, in writing, individual requirements.
(y) Soil limitations shall be determined by using the current edition of the county soil survey written by the NRCS, USDA.
(z) Methods for controlling increases in storm water runoff peaks and volumes may include, but are not limited to:
(1) Retarding flow velocities by increasing friction; for example, grassed road ditches rather than paved street gutters where practical, discharging roof water to vegetated areas, or grass and rock- lined drainage channels.
(2) Grading and use of grade control structures to provide a level of control in flow paths and stream gradients.
(3) Induced infiltration of increased storm water runoff into soil, where practical; for example, constructing special infiltration areas where soils are suitable, retaining topsoil for all areas to be vegetated, or providing good infiltration areas with proper emergency overflow facilities.
(4) Provisions for detention and retention, for example, permanent retention ponds and lakes, dry detention basins, and subsurface detention tanks.
(Ord. 2022-17. Passed 3-22-22.)
(a) Runoff Rate: The peak runoff rate from the development area shall not be greater after development than it was before development. The applicant shall provide calculations proving no increase in the runoff rates from the one (1), two (2), five (5), ten (10), twenty-five (25), fifty (50) and one hundred (100) year storms.
(b) Runoff Volume: Increases in the runoff volume shall be offset by further restricting runoff rates. Based on the increase in runoff volume, the applicant shall determine the critical storm for the development area. The runoff rate from the critical storm shall be restricted to the one (1) year pre- development storm runoff rate. The critical storm shall be calculated as follows:
(1) Determine the total volume of runoff from a one-year frequency, twenty-four hour storm, occurring on the development area before and after development.
(2) From the volumes in paragraph (1) determine the percent of increase in volume of runoff due to development according to the equation (Q after divided by the Q before) X 100 and, using this percentage, select the critical storm from this table:
Table 4: Critical Storm Selection
The Percentage Increase in Volume Of Runoff is: | ||
Equal To Or Greater Than | And Less Than | The 24-hour "Critical Storm" For Discharge Will Be |
0 | 10 | 1 Year |
10 | 20 | 2 Years |
20 | 50 | 5 Years |
50 | 100 | 10 Years |
100 | 250 | 25 Years |
250 | 500 | 50 Years |
500 | --- | 100 Years |
(c) Detention Or Retention Basin Exemption For Redevelopment Or For Expansion Of Existing Facilities:
(1) For any development regulated by this ordinance, the construction of a detention or retention basin may not be required for the development if the post-development peak discharge for a 100 year frequency twenty-four (24) hour storm increases the existing peak discharge by one (1) cubic foot per second or less using the TR-55 method of calculation or other method approved by the Community Engineer. The Community Engineer can waive this requirement if existing storm sewers and drainage structures can safely handle the expected increase in flow.
(2) Only one (1) exemption will be allowed per parcel. Any subsequent expansion must provide for detention or retention and must include the previously exempted area.
(d) Where the Community Engineer determines that site constraints exist in a manner that compromises the intent of this ordinance to improve the management of storm water runoff as established in this section, practical alternatives may be used to result in an improvement of water quality and/or a reduction of storm water runoff. Such alternatives must be in keeping with the intent and likely cost of those measures that would otherwise be required to meet the objectives of this section. When possible, all practical alternatives shall be implemented within the drainage area of the proposed development project. Practical alternatives can include, but are not limited to:
(1) Fees shall be paid in an amount specified by the Community Engineer. These fees shall be applied by the Community to storm water management practices that reduce existing storm water runoff.
(2) Implementation of off-site storm water management practices.
(3) Watershed or stream restoration.
(4) Retrofitting of an existing storm water management practice.
(5) Other practices approved by the Community Engineer in keeping with the intent of this section.
(e) Table 4b: Infiltration Post Construction Practices with Maximum Drain Times
Table 4b Infiltration Post-Construction Practices with Maximum Drain Times
Infiltration Practices | Maximum Drain Time of WQv |
Bioretention Area/Cell 1,2 | 24 hours |
Infiltration Basin 2 | 24 hours |
Infiltration Trench 3 | 48 hours |
Permeable Pavement - Infiltration 3 | 48 hours |
Underground Storage - Infiltration 3,4 | 48 hours |
1. Bioretention soil media shall have a permeability of approximately 1 - 4 in/hr. Meeting the soil media specifications in the Rainwater and Land Development manual is considered complaint with this requirement. Bioretention cells must have underdrains unless in-situ condition allow for the WQv (surface ponding) plus the bioretention soil (to a depth of 24 inches) to drain completely within 48 hours.
2. Infiltrating practices with the WQv stored aboveground (bioretention, infiltration basin) shall fully drain the WQv within 24 hours to minimize nuisance effects to standing water and to promote vigorous communities of appropriate vegetation.
3. Subsurface practices designed to fully infiltrate the WQv (infiltration trench, permeable pavement with infiltration, underground storage with infiltration) shall empty within 48 hours to recover storage for subsequent storm events.
4. Underground storage systems with infiltration must have adequate pretreatment of suspended sediments included in the design and documented in the SWP3 in order to minimize clogging of the infiltrating surface. Pretreatment shall concentrate sediment in a location where it can be readily removed. Examples include media filters situated upstream of the storage or other suitable alternative approved by Ohio EPA. For infiltrating underground systems, pretreatment shall be eighty percent (80%) effective at capturing total suspended solids according to the testing protocol established in the Alternative Post-Construction BMP Testing Protocol.
(Ord. 2022-17. Passed 3-22-22.)
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