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Some documents are in Adobe Acrobat Reader (.PDF) format.
You may download the free software by clicking on the icon below.
DESIGN CONSIDERATIONS FOR NEW PROJECTS
• WQMP- All new projects that results in the addition of new impervious surfaces greater than 1 acre in the Santa Margarita Region must comply with the Water Quality Management Plan (WQMP). All WQMPs must be submitted to the NPDES Coordinator for review and approval. A copy of the final WQMP must be sent to the Transportation NPDES Coordinator along with a digital submission of the WQMP and all drainage facilities. Submissions must include: Digital submission of the drainage facilities including all post construction BMPS(Best Management Practices)
• Treatment BMPs selection - All projects should include site design BMPS(Best Management Practices) and source control BMPS as applicable and practicable such as:
- Control the post-development urban runoff discharge velocities, volumes, durations, and peak rates to maintain or reduce pre-development downstream erosion, and to protect stream habitat.
- Conserve natural areas and protect stream habitat, where feasible.
- Minimize storm water pollutants of concern in urban runoff from the Priority Development Projects(through implementation of source control BMPs). Identification of pollutants of concern shall include, at a minimum, all pollutants for which water bodies receiving the development’s runoff are listed as impaired under CWA section 303(d), all pollutants associated with the land use type of the development, and all pollutants commonly associated with urban runoff.
- Remove Pollutants of Concern from Urban Runoff to the MEP. Be effective at removing or treating the pollutants of concern associated with the project.
- Protect slopes and channels from eroding.
- Require storm drain inlet stenciling and signage.
- Require properly designed outdoor material storage areas.
- Require properly designed trash storage areas.
- Be located as close to pollutant sources, as appropriate and economically/technologically feasible, and before the Urban Runoff is discharged into Receiving Waters.
Santa Margarita Special Provisions:
- Include proof of a mechanism, to be provided by the project proponent or Permittee which will ensure ongoing long-term BMP maintenance.
- Include additional water quality provisions applicable to individual Priority
Development Project categories.
- Be correctly designed so as to remove pollutants to the MEP.
- Ensure that post-development runoff does not contain pollutant loads which cause or contribute to an exceedance of water quality objectives and which have not been reduced to the MEP.
- Minimize directly connected impervious areas when feasible.
Under no circumstances can a BMP be constructed in a receiving water.
TREATMENT BMPS
The following treatment BMPs can be considered for Transportation Department road projects:
- Infiltration
- Bioswale
- Infiltration trenches
- Detention/Retention Basins
- Water Quality inlets only if used in combination with Street Sweeping
- Street Sweeping
The following maintenance programs are available for county maintained roads:
- Catch Basin Inspection and Cleaning for more information
contact Paul Russell
- Landscaping and Lighting Maintenance Districts (LLMDs)
- Street Sweeping funded by the Community Services Area 152 (CSA152)
- Litter Crew
- Code Enforcement Clean Up Crew
The Riverside County Transportation Department will not accept mechanical devices for maintenance on county maintained roads.
INFILTRATION
Infiltration trenches basins shall not cause or contribute to an exceedance of groundwater quality objectives. Evaluate project site conditions to determine if infiltration is feasible:
- Determine soil types and infiltration rates.
- Site hydrology.
- Vertical distance for the base of any infiltration treatment control BMP to the seasonal high groundwater mark shall be at least 10 feet. Where groundwater basins do not support beneficial uses, this vertical distance criteria may be reduced, provided groundwater quality is maintained.
- Infiltration treatment control BMPs shall not be used for areas of industrial or light industrial activity; areas subject to high vehicular traffic(25,000 or greater average daily traffic on a main roadway or 15,000 or more average daily traffic on any intersecting roadway) and other high threat to water quality land uses and activities as designated by each Permittee.
- Infiltration treatment control BMPs shall be located a minimum of 100 feet horizontally from any water supply wells.