Mixed-use development planned atop closed Silicon Valley landfill

California-based Related Cos., plans to build a $6.7 billion mixed-use complex with up to 1,680 units of housing in what is considered the largest housing project ever proposed atop a landfill in the Bay Area, and possibly the entire state of California.

An article in the Mercury-News states the Santa Clara All Purpose Landfill contains an estimated 5.5 million tons of municipal waste. In addition to housing, the proposed project includes include 5.7 million square feet of offices, 1.1 million square feet of retail space and 700 hotel rooms on the 240 acres of former landfill where a BMX bike track and golf course currently sit.

To mitigate risks, the development calls for a 1-foot-thick concrete barrier covering more than 30 central acres of landfill where housing would be built. Another foot-thick clay cap topped by the foot-thick concrete slab. The entire inter-connected platform for the project’s center will be anchored by hundreds of piers driven up to 150 feet into the ground.

Other measures to protect the area include sensor and alarm systems, as well as another system to monitor, collect and dispose of gases underground.

Santa Clara County Department of Environmental Health, California Department of Resources Recycling and Recovery (CalRecycle) and the San Francisco Bay Regional Water Quality Control Board all have approved the plan, the report says.

Santa Clara City Council approved the City Place plans last summer after conducting its own environmental review. Core elements of the development could take five to seven years to complete, while the entire project could take as much as two decades to complete, according to the article.

Litigation is pending regarding the site, however, which has stalled the start of the project. The city of San Jose brought the suit claiming the imbalance between the project’s jobs and housing demand (23,000 jobs and 1,680 housing units) will increase housing demand in San Jose and overstretch its services and infrastructure.

The next court date is set for late August, but both sides said they hope for an out-of-court resolution, according to the Mercury-News article.