CalTrans District 4 - Devil’s Slide Improvement Project - Environmental Engineering Assistance

Placement of Tunnel Spoils and Concrete Waste at the Devil’s Slide On-Site Fill Location
Bridge site inspections for SWPPP compliance and appropriate BMP implementation at a risk level 3 site.
Prime Contractor: 
Period of Performance: 
February, 2008 to March, 2011
Project Goals: 

The goal of this project was to provide inspection services of storm water and non-storm water treatment systems for construction activities at the Devil’s Slide tunneling project which had the potential to impact receiving water quality in respect to the project’s Water Pollution Control Plans and Storm Water Pollution Prevention Plans (SWPPP). Additionally, SWPPP inspection services were provided for bridge and tunnel construction, risk level 3 and 2 sites, respectively, and performance of on-site shotcrete waste monitoring and reporting.

Scope of Services: 


ADH provided the following services on this project:

  • Preparation of a comprehensive punchlist for operations requiring inspection
  • Inspection of storm water conveyances
  • Evaluation of active water treatment systems
  • SWPPP inspections at bridge and tunnel construction sites
  • Monitoring shotcrete waste disposal to determine conformance with regulatory requests
  • Weekly and monthly summary reporting
  • Preparation of annual reports. Preparation of a comprehensive punchlist for operations requiring inspection


A review of all relevant water quality information - including permits and contractor submittals – related to the project was performed and an initial site visit was conducted to gather information needed to develop a comprehensive punchlist for use during field inspections. In consultation with Caltrans, ADH also formulated a mechanism for tracking shotcrete waste quantities in conformance with the San Francisco Regional Water Quality Control Board’s criteria for on-site disposal. 

Field Inspections and Monitoring

Site visits to the bridge and tunnel construction sites were conducted on a weekly basis to inspect storm water best management practices (BMP) controls; to evaluate the monitoring, operation, and maintenance of water treatment systems; and to track the usage and impacts of shotcrete operations. Weather tracking for potential rain events was performed, and special weather-related inspections were conducted for qualified events.


The following reporting tasks were performed for this project:

  • Submittal of weekly inspection Technical Memoranda that summarized on-site activities, concerns and recommendations
  • Brief weather forecast updates
  • Annotated photo-documentation
  • Preparation of annual shotcrete monitoring reports.