The Cummings Road Landfill has been the primary municipal waste disposal site for Humboldt County for over 50 years and is currently in the process of a multi-year phased closure. Heavy rainfall during the winter of 2005 caused severe damage to the surface water drainage infrastructure and resulted in reduced water quality in adjacent streams. In order to mitigate on-going infrastructure damage and environmental degradation, it was necessary to conduct a failure analysis of the existing drainage facilities and develop plans to temporarily stabilize the existing infrastructure and redesign the facilities to withstand similar or greater rainfall events to protect water quality and minimize maintenance costs.
Pacific Watershed Associates led a team of geologists, engineers, erosion control specialists, and public officials in addressing: degraded water quality, damaged landfill facilities, re-design of the surface water drainage infrastructure, and facilitated dialogue with regulatory agencies.
During this process Pacific Watershed Associates:
- Designed temporary fixes to damaged surface water drainage infrastructure to minimize on going erosion
- Designed and implemented sediment control BMP’s specifically tailored to the needs and constraints at the job site
- Conducted a failure analysis of the surface water drainage infrastructure
- Reconfigured the surface water drainage infrastructure and grading plan based on the failure analysis
- Trained landfill employees in erosion and sediment control BMP installation and maintenance