Rutan partner Anna Amarandos was interviewed in a July 5, 2016 article in Construction Dive magazine entitled “Land(fill) of opportunity: Why builders are turning dumps into new developments.” This article addresses issues that arise as California developers are looking to landfills to build new communities, including a landfill in Santa Clara currently being redeveloped by a Rutan client.
A major challenge to repurposing a landfill for a commercial or residential use project, according to Anna Amarandos with Rutan & Tucker in California, is remediation and preparing the site for development. However, she said, if everything is done correctly, there’s no reason a landfill site can’t be used for residential and commercial buildings. “But you can’t just come in and put something down over landfill waste,” Amarandos said.
To mitigate the risk, contractors can install a permeable layer of gravel, which provides a pathway of escape for gas, and then a membrane underneath the slab of a building, Amarandos said. The gas can then be piped out from underneath the building, up the sides and then released at rooftop level. In California, she said, developments within 1,000 feet of a landfill must use some vapor mitigation method.
It’s common for developers to move the waste, consolidate it and then encapsulate it away from where buildings will be constructed, according to Amarandos. If there is no other option than to build directly over waste material, contractors must anchor the foundation into solid ground beneath the waste with, for example, a deep foundation with piles.
Perhaps the biggest obstacle to such a project, though, is the time it takes to get up and running. “I always tell my clients they need to anticipate a very lengthy timeframe for getting the approvals needed,” Amarandos said. This doesn’t discourage many of her clients, however, who have their sights set on landfills in desirable areas for development. “Some of my clients are pretty experienced with complex projects like these, and they don’t scare easily,” she said.
This, is most likely the case with the Santa Clara site. “They wouldn’t be doing this if they hadn’t figured out a way to do it safely and cost-effectively,” she said.
Ironically, Amarandos said, an ideal use of a site like the landfill in Santa Clara is exactly what is there now — a golf course and a dirt BMX bike track. “If you have a little subsidence in a golf course area, what they typically do is regrade those areas from time to time, but you don’t have the gas accumulation that would go into a building’s closed space,” she said. “A golf course or a bike track or any kind of outdoor activity is really the perfect repurposing for a landfill.”