ARTICLE III. - SOIL EROSION, RUNOFF AND SEDIMENT CONTROL PLAN
Part of the Code of Ordinances of Bristol, RI.
The text
Sec. 29-57. - Plan preparation.#
The soil erosion, runoff and sediment control plan shall be prepared by a registered professional engineer, a soil and water conservation society certified professional in erosion and sediment control, or a registered landscape architect as may be appropriate for the specific issues involved with the plan. Five copies of the plan and permit application shall be submitted to the building official.
(Ord. No. 2009-14, 11-28-09)
Sec. 29-58. - Plan contents.#
The soil erosion, runoff and sediment control plan shall include sufficient information about the proposed activities and land parcel(s) to form a clear basis for discussion and review and to assure compliance with all applicable requirements of this chapter. The plan shall be consistent with the data collection, data analysis, land plan preparation guidelines in the current Rhode Island Soil Erosion and Sediment Control Handbook, prepared by the United States Department of Agriculture, Natural Resource Conservation Service, Rhode Island Department of Environmental Management, Rhode Island State Conservation Committee, and at a minimum shall contain: (1)
A narrative describing the proposed land-disturbing activity and the soil erosion, sediment and stormwater management measures to be installed to control erosion that could result from the proposed activity. Supporting documentation, such as a drainage area, existing site, and soil maps shall be provided as required by the building official.
(2)
Construction drawings illustrating in detail existing and proposed contours at least every two feet, drainage features, vegetation, limits of clearing and grading; the location of nearby municipal and/or private drainage structures such as catch basins and detention basins, the location of soil erosion and sediment control and stormwater management measures, stock piles and borrow areas; sequence and staging of land-disturbing activities; and other such information needed for construction.
(3)
Other information, storm drainage computations and/or construction plans and details as deemed necessary by the building official for thorough review of the plan prior to action being taken as prescribed in this chapter. Withholding or delaying submission of such information may be reasons for the building official to judge the application incomplete and grounds for disapproval.
(4)
Best management practices. Identify the type of BMP(s) employed both during and post construction and justification for selection, including any deviation from the Rhode Island Stormwater Design and Installation Standards Manual, as amended, and the potential effect on pollutant removal efficiency. The technical feasibility of BMP's including sizing, location, hydraulic and environmental impacts. Alternatives, which were considered but determined not to be feasible, should also be discussed. Maintenance schedule of BMP's to be used, both during and post-construction including frequency of inspection and maintenance.
(Ord. No. 2009-14, 11-28-09)
Sec. 29-59. - Performance principles.#
The contents of the soil erosion, runoff and sediment control plan shall clearly demonstrate how the principles, outlined below, have been met in the design and are to be accomplished by the proposed development project. (1)
Due regard for natural drainage characteristics, topography and soils shall be indicated.
(2)
To the extent possible, steep slopes (those in excess of ten percent) shall be avoided.
(3)
The grade of slopes created shall be minimized.
(4)
a.
Post-development runoff rates will not exceed pre-development rates for a 25-year storm. Any increase in storm runoff volume should be retained and recharged, as close as feasible, to its place of origin by means of detention ponds or basins, seepage areas, subsurface drains, porous paving, or similar low impact development techniques.
b.
For any properties located within the watershed of the Tanyard Brook (as depicted on the plan titled Tanyard Brook Watershed prepared for the Town of Bristol by Beta Group, Inc.), all increase in stormwater runoff volume, up to and including the ten-year storm event, shall be retained on site to the maximum reasonable extent. This may be achieved through the use of infiltration systems, retention ponds, roof runoff directed to drywells, and driveway runoff directed to grassed areas as opposed to local roadways. Site conditions such as a high groundwater elevation, ledge, poor soils, or the presence of contaminants that limit or prohibit the ability to recharge runoff to the subsurface shall be considered to determine the reasonableness of the applicant's proposal. For increases in runoff volume beyond what is determined can reasonably be retained on site, the applicant may in lieu of compliance with the above requirements be permitted to perform off-site drainage improvements or contribute to a dedicated account to fund drainage improvements within the watershed. Site conditions which limit or prohibit on-site mitigation shall be verified by the town's engineering consultant. The location, scope and relative value of proposed off-site drainage improvements shall be verified by the town's engineering consultant and approved by the director of public works. Payments to the dedicated drainage account shall be calculated at a rate of $2.00 per square foot of new impervious surface created, and may be reduced by the amount of impervious areas for which runoff volumes have been retained on-site.
(5)
Original boundaries, alignment and slope of watercourses within the project locus shall be preserved to the greatest extent feasible.
(6)
Storm drainage (including driveways) shall be directed away from structures intended for human occupancy, municipal or utility use, or similar purposes. Where the elevation of a building lot is below that of adjacent public roadways, methods such as a bituminous asphalt berm should be employed to prevent roadway stormwater runoff from entering the lot.
(7)
All drainage provisions shall be of such a design and capacity so as to adequately address stormwater runoff, including runoff from tributary upstream areas which may be outside the locus of the project.
(8)
Drainage facilities shall be installed as early as feasible during construction and, if possible prior to site clearing, and must be installed and capable of being operational prior to increase in impervious area.
(9)
Fill located adjacent to watercourses shall be adequately protected from erosion by means of rip-rap, gabions, retaining walls, sediment control fencing, vegetative stabilization, or similar measures.
(10)
Adjacent properties and roadways shall be protected from sediment and changes to runoff rate and location during construction through the use of sediment control fencing or other appropriate barriers and dedicated construction entrances with wheel cleaning stone blankets to prevent sediment from being transported off site. Nearby drainage inlets should also be protected from silt-laden runoff through the use of filter fabric or other appropriate means to prevent silt and sediments from entering existing drainage systems.
(11)
Silt fencing, temporary vegetation and or mulching shall be used to contain bare areas and stockpiles from erosion during construction. The smallest areas feasible shall be exposed at any one time and disturbed areas shall be protected during the non-growing months (November through March).
(12)
Permanent stabilizing vegetation shall be planted immediately following fine grading.
(13)
Trees and other existing vegetation shall be retained whenever feasible. The area within the drip line shall be fenced or roped off to protect trees from construction equipment.
(14)
All areas damaged during construction shall be re-sodded, re-seeded or otherwise restored.
(15)
Elevation of building in relation to abutting town street. The top of foundation for all new buildings will be constructed at or above the existing centerline grade of the abutting street to ensure that surface water runoff from the street will not negatively impact the property. Therefore, in all new construction, the elevation of the top of the foundation shall not be below the elevation of the centerline of the abutting road, unless, either (a) a grading and drainage plan is submitted to address the runoff from the road onto the property and ensures there are no adverse impacts to adjacent property from the proposed site grading; or (b) the property owner records a deed restriction and indemnity agreement that stormwater runoff from the street onto the property is not the responsibility of the town.
(Ord. No. 2009-14, 11-28-09)
Sec. 29-60. - Technical standards.#
All applicants for qualifying development activity must develop and submit a proposed plan as outlined in section 29-58 which must meet all the requirements of this chapter. All such measures shall be consistent with the Rhode Island Stormwater Design and Installation Standards Manual and the Rhode Island Soil Erosion and Sediment Control Handbook, as amended. The plan must include a description of proposed best management practices (BMP's), detailed site plans, and a written narrative, that when implemented, provides protection of receiving waters by reducing pollutant loadings and other negative impacts associated with changes in land use as described below. Structural BMPs are described as structural stormwater devices that temporarily detain and treat stormwater runoff in order to reduce pollutant loadings. Typical BMPs include wet ponds, extended detention ponds, infiltration trenches, created wetlands, grassed swales and the like. (1)
Performance standards. A plan must incorporate best management practices for water quality control, which in combination are demonstrated to reduce the average annual total suspended solids in post development runoff by 80 percent. Development in drinking water supply watersheds or watersheds where impaired waters as defined by the State's 303(d) list exists may be held to higher standards.
(2)
Disallowed stormwater best management practices. The placement of structural BMP's and other stormwater structures within a floodplain shall be avoided. If there is no alternative, the applicant must show what effects, if any, the tail waters created by the floodplain will have on the outflow and effective storage capacity of the detention facility.
(3)
Facilitation of maintenance. Facilities that require maintenance shall be designed to minimize the need for regular maintenance, facilitate required maintenance, and ensure accessibility of components that require maintenance. At a minimum, all Stormwater Management Plans must incorporate structural BMP's with appropriate maintenance design in accordance with the Rhode Island Stormwater Design and Installation Standards Manual, as amended; or the Rhode Island Soil Erosion and Sediment Control Handbook, as amended.
(Ord. No. 2009-14, 11-28-09)
Sec. 29-61. - Maintenance requirements for best management practices.#
(a)
Routine maintenance and repair procedures. Preventative maintenance procedures are required to maintain the intended operation and safe condition of the structural BMP's by greatly reducing the occurrence of problems and malfunctions. To be effective, preventative maintenance shall be performed on a regular basis and include such routine procedures as training staff, periodic inspections, grass cutting elimination of mosquito breeding habitats, and pond maintenance. Disposal of sediment and debris must occur on a regular basis (unless otherwise specified within an approved plan), at suitable disposal sites or recycling sites and comply with applicable local, state and federal regulations. Corrective maintenance procedures are required to correct a problem or malfunction at a stormwater management facility and to restore the facility's intended operation and safe condition. Based on the severity of the problem, corrective maintenance must be performed on an as-needed or emergency basis and include such procedures as structural repairs, removal of debris, sediment and trash removal which threaten discharge capacity, erosion repair, snow and ice removal, fence repair, mosquito extermination, and restoration of vegetated and nonvegetated linings.
(b)
General maintenance standards for stormwater best management practices. Maintenance design and maintenance procedures for all structural BMP's shall be in accordance with Rhode Island Stormwater Design and Installation Standards Manual, as amended; or the Rhode Island Soil Erosion and Sediment Control Handbook, as amended. Maintenance plans shall demonstrate appropriate maintenance design and procedures for each proposed best management practice. A maintenance schedule for each type of structural BMP must be included in the plan. These schedules shall list the frequency and type of maintenance operations necessary along with the legally responsible party's name, address and telephone number. If the stormwater drainage system is to be deeded to the local municipality the applicant must obtain a letter from the municipality acknowledging maintenance responsibility and intent of ownership.
(Ord. No. 2009-14, 11-28-09)
Sec. 29-62. - Maintenance agreements.#
Maintenance agreements between the landowners and the town shall provide written, contractual documentation, which demonstrates compliance with this article and legal arrangements for the upkeep of the structural BMP's to assure their functionality and safety in accordance with this article. Maintenance agreements shall be approved by the director of public works and the town solicitor and recorded in the land evidence records. Maintenance agreements, which describe all maintenance schedules and requirements, must be developed for each structural BMP unless the facility is dedicated to and accepted by the town. (1)
Recognition of municipal inspection requirements. Maintenance agreements shall require landowners to conduct on-site inspections and maintenance of the structural BMPs on a reasonable and regular schedule. Maintenance agreements shall also allow the town to conduct on-site inspections of the functionality and safety of the structural BMPs when, at the discretion of town officials, inspections are not undertaken in accordance with the schedule, inspections are incomplete, or a problem with maintenance is suspected. Inspection schedules shall be based on the complexity and frequency of maintenance needs and shall be subject to the approval of the town in conjunction with the maintenance agreement. At a minimum, maintenance frequency should be in accordance with the Rhode Island Stormwater Design and Installation Standards Manual, as amended.
(2)
Recordkeeping for maintenance activities. Maintenance agreements shall include provisions for maintenance recordkeeping by the landowners. All activities conducted in accordance with a maintenance agreement must be recorded in a work order and inspection log. Timely updates of the log shall be the responsibility of the structural BMP's owner or other responsible party pursuant to this article. A maintenance and inspection report shall be filed annually with the director of public works. Review of the maintenance and inspection log shall be completed by the town to determine the effectiveness of the operation, maintenance and safety activities. Additional reports shall be made as deemed appropriate by the town.
(3)
Responsibility for maintenance to assure functionality and safety. Appropriate maintenance to assure functionality and safety of the structural BMP's shall be the responsibility of the landowners or may be assumed by another party via a written contractual arrangement in accordance. Any arrangement with a third party shall be subject to the review and approval of the director of public works.
(4)
Alterations to maintenance agreements. Any alterations in maintenance responsibility or alterations to maintenance agreements must be reviewed and approved by the director of public works. If portions of the land serviced by a structural BMP are to be sold, written contractual arrangements shall be made to pass all responsibility of the maintenance agreement to the purchaser and shall be subject to review and approval of the director of public works. All alterations to maintenance agreements shall be recorded in accordance with this article.
(5)
Recordation of maintenance agreements. All maintenance agreements and alterations to maintenance agreements shall be recorded in the land evidence records of the town. Copies of all maintenance agreements and alterations to maintenance agreements shall be included with the maintenance plan. Recordation of maintenance agreements in accordance with this article shall be the responsibility of the landowner.
(Ord. No. 2009-14, 11-28-09)