(a) Maintenance During Construction.
(1) The site owner and/or applicant of the land development activity shall at all times properly operate and maintain all facilities and systems of treatment and control (and related appurtenances) which are installed or used by the site owner and/or applicant to achieve compliance with the conditions of this local law. Sediment shall be removed from sediment traps or sediment ponds whenever their design capacity has been reduced by 50 percent.
(2) The site owner and/or applicant or their representative shall be on-site when construction or grading activity takes place and shall inspect and document the effectiveness of all erosion and sediment control practices. Inspection reports shall be completed every seven days and within 24 hours of any storm event producing 0.5 inches of precipitation or more. The reports shall be delivered to the Stormwater Management Officer and copied to the site logbook.
(3) Maintenance easement(s) prior to the issuance of any approval that has a stormwater management facility as one of the requirements, the site owner and/or applicant must execute a maintenance easement agreement that shall be binding on all subsequent landowners served by the stormwater management facility. The easement shall provide for access to the facility at reasonable times for periodic inspection by the Municipality of Grafton to ensure that the facility is maintained in proper working condition to meet design standards and any other provisions established by this local law. The easement shall be recorded by the grantor in the office of the Lorain County Recorder after approval by the legal counsel for the Municipality of Grafton.
(b) Maintenance after Construction.
(1) The site owner and/or applicant, or operator of permanent stormwater management practices installed in accordance with this chapter shall be operated and maintained to achieve the goals of this chapter. Proper operation and maintenance include, as a minimum, the following:
A. A preventive/corrective maintenance program for all critical facilities and systems of treatment and control (or related appurtenances) which are installed or used by the owner or operator to achieve the goals of this law.
B. Written procedures for operation and maintenance and training new maintenance personnel.
C. Discharges from the SMPs shall not exceed design criteria or cause or contribute to water quality standard violations in accordance with the following criteria:
BMPs shall be designed such that the drain time is long enough to provide treatment but short enough to provide storage for successive rainfall events and avoid the creation of nuisance conditions. The outlet structure for the post-construction BMP shall not discharge more than the first half of the WQv in less than one-third of the drain time. The WQv is the volume of storm water runoff that must be detained by a post-construction practice as specified by the most recent edition of the Rainwater and Land Development manual.
Post-construction practices shall be sized to treat 100 percent of the WQv associated with their contributing drainage area. If there is an existing post-construction BMP that treats runoff from the disturbed area and the BMP meets the post-construction requirements of this permit, no additional post-construction BMP will be required. Design information for such facilities such as contributing drainage areas, capacities, elevations, outlet details and drain times shall be included in the SWP3.
Table 4a - Extended Detention Post-Construction Practices with Minimum Drain Times | |
Extended Detention Practices | Minimum Drain Time of WQv |
Table 4a - Extended Detention Post-Construction Practices with Minimum Drain Times | |
Extended Detention Practices | Minimum Drain Time of WQv |
Wet extended detention basin
1, 2 | 24 hours |
Constructed extended detention wetland1, 2 | 24 hours |
Dry extended detention basin1, 3 | 48 hours |
Permeable pavement - extended detention1 | 24 hours |
Underground storage - extended detention1, 4 | 24 hours |
Sand & other media filtration extended detention1, 5 | 24 hours |
Notes: 1. The outlet structure shall not discharge more than the first half of the WQv in less than one-third of the drain time. 2. Provide a permanent pool with a minimum volume equal to the WQv and an extended detention volume above the permanent pool equal to 1.0 x WQv. 3. Dry basins must include a forebay and a micro pool each sized at a minimum of 0.1 x WQv and a protected outlet or include acceptable pretreatment and a protected outlet. 4. Underground storage must have pretreatment for removal of suspended sediments included in the design and documented in the SWP3. This pretreatment shall concentrate sediment in a location where it can be readily removed. For non-infiltrating, underground extended detention systems, pretreatment shall be 50% effective at capturing total suspended solids according to the testing protocol established in the Alternative Post Construction BMP Testing Protocol. 5. The WQv ponding area shall completely empty between 24 and 72 hours. | |
(c) Maintenance Agreements. The Municipality of Grafton shall approve a formal maintenance agreement for stormwater management facilities binding on all subsequent landowners and recorded in the office of the Lorain County Recorder as a deed restriction on the property prior to final plan approval. The maintenance agreement shall be consistent with the terms and conditions of Schedule B of this chapter entitled Stormwater Control Facility Maintenance Agreement. The Municipality of Grafton in lieu of a maintenance agreement, at its sole discretion may accept dedication of any existing or future stormwater management facility, provided such facility meets all the requirements of this chapter and includes adequate and perpetual access and sufficient area, by easement or otherwise, for inspection and regular maintenance.
(Ord. 21-021. Passed 11-16-21.)