Protect all inlets and storm drains if there is a threat of discharge from construction activities. Sediment, oil, and other pollutants that enter the storm system can be washed into creeks and drainage swales during line flushing or the first rains. Inlet protection devices can include filter fabric, sediment traps, gravel bag barriers, and fiber rolls.
Designate a concrete washout area to avoid wash water from entering inlets, drainage swales, or storm drains. Dispose of concrete waste on a regular basis. Contact the solid waste facility for proper disposal or recycling of concrete waste. Concrete is highly toxic and has the potential to bind with soil particles that can be tracked or washed offsite and enter creeks or storm drains.
Trash and Good Housekeeping
Have trash cans and dumpsters available for disposal of trash or other items and empty them when full. Trash, insulation, and other floatable materials can blow around on windy days and end up in drainage swales and creeks.
Locate portable toilets on a vegetated or dirt surface at least 30 feet away from any roads, storm drains, or drainage swales. The potential to discharge highly toxic effluent during routine maintenance or if tipped over poses a threat to storm water quality.
Apply fertilizer and pesticides at a proper rate and avoid spills that can get into the storm drain system as pollutants. Irrigation runoff that enters storm drains or waterways is also a concern. Sweeping up any excess material and avoiding over-watering is recommended.
Provide a stabilized construction access to reduce tracking of sediments and other pollutants onto paved roads. A stabilized access usually consists of a pad of 3-5 inch rock approximately 50 ft. long by 30 ft. wide and can be placed over geotextile fabric for greater longevity. Road sweeping may also be necessary to protect storm drains and prevent airborne dust. An encroachment permit shall be required if the stabilized construction access is within a county right of way.
Use a trailer or shed to store materials such as paints and petroleum products, or cover materials with a tarp when not in use to reduce the potential for pollutants to spill or blow around.
Implement dust control measures such as spraying water, or covering stockpiles on all construction sites where there will be major soil disturbances or heavy equipment activity. Airborne particles pose a dual threat to the environment and human health.
Discharge sediment laden water from de-watering sites or sediment basins in an appropriate manner to prevent sediment from entering waterways or storm drains. Typical methods used to filter sediment include a de-watering tank, or gravity bag filters. De-watering activities should be performed by a qualified person and monitored for effectiveness. (Note: A Low Threat Discharge permit may be required from the State Regional Water Board for de-watering activities.)