Coordinating BMP implementation with construction activities is critical in preventing erosion and sediment loss. All construction sites, regardless of size, should have a pre- and post- construction schedule. This allows a connection to the sequence of construction and the installation of erosion and sediment control measures.
Developing a written plan and specified work schedule for implementing BMPs is a key objective of planning.
DEVELOPMENT OF EROSION AND SEDIMENT CONTROL PLAN
Before designing a plan and schedule, gather the project’s background information including soil type, drainage, previous uses, location details and site topography. This information helps determine appropriate BMPs for the site. Once BMPs have been selected, an Erosion and Sediment Control Plan should be developed for the site and updated throughout the duration of the project’s construction. This plan should include a drawing of the construction site with the locations of all BMPs, construction and installation details, and appropriate notes.
BMP IMPLEMENTATION AND SEQUENCING
There are several micro-climates within the Monterey Bay region. As a result, pay close attention to local weather reports when developing the construction schedule. Certain construction activities such as grading, foundation work and paving should not be conducted during the rainy season which typically runs from October to April. If activities like grading continue into the rainy season, the length of time that soils are exposed must be minimized. Additional measures for erosion and sediment control such as rock bags, sediment fences and fiber rolls should always be kept on site in case of immediate need.
Weather forecasts that include rainfall predictions can be found on the National Oceanic and Atmospheric Administration (NOAA) website. This is a helpful tool for larger projects when completing rainfall monitoring in accordance with the Construction General Permit.
EXAMPLE PROJECT PHASING AND IMPLEMENTATION
Maintenance guidelines for all specified BMPs should be provided on the Erosion and Sediment Control Plans. Routine inspections and maintenance ensure that BMPs function properly and help prevent construction site runoff discharges. BMP maintenance training for on-site workers is a critical factor in an effective erosion and sediment control program. Proper training on general erosion and sediment control principles can expedite identification of maintenance issues and repairs.
Projects that disturb over an acre of land must submit a Notice of Intent with the SWRCB and comply with the operation, maintenance and inspection guidelines set forth in the Construction General Permit.
Construction site activities can damage BMPs. Routine inspections are necessary to ensure the integrity and effectiveness of BMPs, and helps protect a site from unexpected weather events. Project owners or contractors should perform daily inspections to identify BMPs in need of maintenance. Upon identifying failures or other maintenance items, contractors should implement repairs or design changes to BMPs within 72 hours of identification and complete the changes as soon as possible.
Prior to the start of any construction activities, it is critical to identify and protect trees and existing vegetation. Trees and vegetation are effective for erosion and sediment control, watershed protection, dust and pollution control, and landscape preservation.
The Erosion and Sediment Control Plan should clearly show the areas of vegetation and trees to be protected. The appropriate fencing or protection barrier will also be identified on these plans. The figures on the next page show two examples of tree protection. The wood impact barrier is appropriate for the more urban sites where space is limited and trees are often located within sidewalk areas. Wrapping tree trunks with straw wattles should help protect existing trees within dense project areas. During contractor supplied erosion and sediment control training, work crews should learn how to install and maintain these protective measures. To further support vegetation protection, the following construction activities should not be conducted or located within and around the barrier of the protected areas:
- Parking, vehicle access areas, stockpiles and storage areas
- Heavy equipment, vehicular traffic, or storage of construction materials
During construction, the limits of disturbance should remain clearly marked at all times. All protective measures must remain in place, and restored immediately if damaged. Once all construction activity has been completed, the measures can be removed, and reused or disposed of properly. In areas that allow it, orange construction fencing should also be placed at the drip line of trees to clearly mark protected areas.