Final Landfill Cover

City of Portola Landfill

Portola, CA

The Portola Class III landfill is located approximately 1.5 miles northeast of the City of Portola. The landfill was an unlined landfill with highly erosive soils on site causing long-term maintenance issues and ground water contamination problems.

When the city began the closure process, they began looking at options outside of the traditional Subtitle D vegetative cap. When introduced to ClosureTurf®, one of the biggest benefits they considered was the major reduction of maintenance activities and cost.

“Prior to ClosureTurf becoming available we had looked at the traditional Subtitle D vegetative cap however one of the biggest advantages of ClosureTurf is the avoidance of long-term maintenance costs,” stated the City of Portola’s solid waste consultant, Tom Valentino P.E., President of the for TGV Solid Waste Inc. “Another one of the advantages of going with the ClosureTurf system was the ease of installation as we were under a tight time schedule to get the project completed and coincidentally enough there was a storm the night the project was completed, and we got the project done on time. We went with a tan color to blend in with the surroundings. From a short-term stability and a long-term post closure maintenance cost, the ClosureTurf® system was the absolute right decision to make for the Portola Landfill.”

After a thorough process of approval from the City Council and public, ClosureTurf was submitted to the State of California for permit modification and approved. The scope of work included removing the interim cover, making drainage improvements and installing the ClosureTurf system.

“From a quality construction assurance perspective, installation of a ClosureTurf cover system required less field personnel during construction than a traditional prescriptive cover system. This resulted in cost savings to the city,” stated Jake Russell, P.E., of the City of Portola’s CQA consulting firm Geo-Logic Associates. “The installation of the ClosureTurf cover was completed in significantly less time than other similarly sized perspective Subtitle D vegetative cap landfill cover systems with which I have been involved. By removing the soil components of the cover system, construction issues associated with the variability and availability of soil materials were eliminated.”

Specified aggregate infill is brushed into the engineered turf.

With a residential neighborhood 1,500 feet South West of the landfill, contaminated water was also a concern. Many of the residents receive water through individual domestic supply wells. Because the specified aggregate infill and engineered turf act as a natural filter, ClosureTurf can provide clean runoff with very low turbidity. In addition, no chemicals, fertilizers or pesticides are required to maintain vegetation.

Clean groundwater post ClosureTurf installation.
Clean groundwater post ClosureTurf installation.
Project Type MSW Landfill
Owner City of Portola
Engineer TM Engineering
Contractor Cal Valley Construction D&E Construction
Size 10 Acres
Date Completed 2014