If you have recently driven along Interstate 5 (I-5) you may have seen fiber rolls lining the hillside, or a green colored spray (a biodegradable material called Bonded Fiber Matrix) on bare highway slopes. What you are seeing is storm water pollution prevention.
San Diego County has already seen a substantial amount of early rain this winter. Stormwater runoff is the natural occurrence of rain or snowmelt that flows over land and does not absorb into the soil. Depending on the intensity of a storm, runoff can cause erosion, can pick up trash, contaminants, or other debris. If not appropriately contained, it can then travel directly into large bodies of water, or into storm drains that lead to the ocean, bringing silt or pollutants along with it.
Build NCC construction crews prepare well in advance of these major rainstorms. Detailed, prepared Storm Water Pollution Prevention Plans (SWPPP) are executed to prevent and capture stormwater runoff from leaving the construction site. A SWPPP is required by the United States Environmental Protection Agency (EPA) in order to comply with the Clean Water Act and help prevent stormwater contamination and control sediment and erosion.
As part of the Build NCC SWPPP, construction crews installed fiber rolls and sprayed Bonded Fiber Matrix on bare highway slopes to reduce erosion and runoff. Crews also install temporary check dams, small dams built across a drainage ditch, which lessens the speed of runoff and reduces erosion as well. In addition, silt fencing is placed within the San Elijo Lagoon which too helps control sediment and water quality.
As we move through the winter months keep on the lookout for some these prevention efforts used by Build NCC construction crews. And remember, for your safety and the safety of your fellow drivers, reduce speed and “Wipers on, Lights on” when driving in the rain.
About Build NCC
Build NCC is a collaborative effort between the San Diego Association of Governments (SANDAG), Caltrans, and the United States Department of Transportation. The first phase of construction is in the cities of Solana Beach, Encinitas, and Carlsbad as part of the North Coast Corridor Program. Build NCC includes extending the existing carpool lane on I-5 in each direction from Lomas Santa Fe Drive to State Route 78, double tracking the rail line and replacing the highway and rail bridges at the San Elijo Lagoon, restoring the San Elijo Lagoon, and constructing nearly seven miles of new bike and pedestrian trails. Construction on Build NCC began in early 2017 and will be complete by 2022.