Innovators tap the value of wastewater

Water supply photo by artzenter via Shutterstock

The prolonged California drought is forcing businesses and farms across the state to rethink the risks associated with existing water-sourcing strategies, including how to make better use of wastewater.

Just this week, more than 140 companies from Apple to Levi Strauss backed a new Climate Declaration urging for state and federal legislators to consider the economic consequences of climate change and to address the phenomenon more actively. "What made America great was taking a stand. Doing the things that are hard. And seizing opportunities," they write in the declaration.

“We see the dire impacts of climate change happening now,” said Hans Cole, environmental campaigns and advocacy manager for Patagonia, explaining why his company backs this pledge. “California’s decreased snow pack in the mountains and corresponding water scarcity will affect everyone. But there is an opportunity to spur innovation, shift policy and steer a different course. We will continue to support this movement and effective solutions at the state and federal levels.”

Of course, very few companies are naïve enough to sit around waiting for lawmakers to show leadership on this issue. They are seeking commercial approaches to the water crisis, the sooner the better.

In that vein, over the past month, I spoke with two startups tapping into California's water challenges to test approaches that make better use of wastewater without a corresponding spike in fossil fuels consumption — the dreaded energy-water nexus. One company, San Francisco-based WaterFX, is leveraging solar power to desalinate drainage water from farms in the Central Valley; the other, Boston-based Cambrian Innovation, is using bioelectric technology to clean water and generate energy for a small craft brewery based in Cloverdale, Calif.

"There is this giant problem of wastewater — billions of gallons from industrial, agricultural and other sources," said Matthew Silver, co-founder and CEO of Cambrian Innovation. "The issue of management is large and growing, and there needs to be a new paradigm to approach these things."

Brewing up savings

The beverage industry is especially dependent on a reliable and cost-effective clean water supply. We've heard plenty about the efforts of brewing companies Anheuser-Busch InBev and MillerCoors to reduce the water footprint associated with their beer. Bear Republic is taking things a step farther: In January, it was the first brewery to buy Cambrian's EcoVolt system, which uses electrically active organisms to clean wastewater for reuse while creating a high-quality biogas that helps offset the heat and electricity needed for Bear's production process. 

"Sustainable production practices have been a cornerstone of Bear Republic's business since we started in 1996," said Richard Norgrove, chief operating officer and brew master for Bear Republic, explaining the investment. "Cambrian's innovative technology not only fulfills this mission, but also has proven to be a valuable asset for our business, especially as California is in the midst of a drought. By removing barriers to production expansion due to water resource limitations, we can fulfill a family dream of expanding our business within Sonoma County and creating a true destination brewery."

Bear Republic runs its production processes at a 3.5-to-1 production ratio (meaning it takes 3.5 units of water to produce one unit of beer). The EcoVolt will be able to recycle and supply about 10 percent of the facility's water requirements: Each reactor can handle 20,000 gallons daily, Silver said.

Cambrian's technology can help cut water-related costs in several ways:

• It helps reduce current treatment costs or sewer charges. In the case of Bear Republic, the brewery previously was forced to send tanker trucks down the road for treatment.

• It cuts the company's water sourcing expenses and improves operational security, because it won't have to buy as much from the utility.

• It cuts electricity costs: EcoVolt actually will cover more than 50 percent of the site's baseload power requirements.

Each EcoVolt is the size of a shipping container and includes the treatment system and reactors, as well as a system for combined heat and power. They are modular, so that more than one unit can be used at a site, up to about 40,000 gallons per day. Volumes beyond that would require a custom-designed system, Silver said.

Renewable approach to desalination

Making better use of agricultural drainage water is the focus for a 6,500-square-foot test facility in California's Panoche Water district that uses WaterFX solar desalination technology.

The pilot in Firebaugh, being funded by the state's Department of Water Resources Prop. 50, currently can produce up to 8 gallons per minute of pure water from saline discharge drainage that originates from irrigating the farms across the region.

The district serves more than 44,000 acres of almond, tomato, melon, asparagus, pistachio and alfalfa farms. The idea is to take irrigated water, which has higher levels of salt content than seawater, and recycle it through solar desalination. This will help reduce the amount of water that the farms need to draw from the local water utility, reducing their reliance on an increasingly precious (and expensive) supply. "The farmers get to reuse their water, and it frees up water for other municipal and industrial purposes," said Aaron Mandell, chairman and founder of WaterFX.

The pilot, running since July, is being expanded this year to produce up to 2,200 acre-feet of water annually. The WaterFX Aqua4 system uses a solar thermal collector, an absorption heat pump and multi-stage distillation system and storage unit to treat the water. It can be used to recover clean water from drainage water, wastewater, produced water and seawater. Aside from the salts, it also can reclaim extracted metals. Incidentally, those by-products can be sold, which creates another source of revenue for utilities adopting this approach. 

WaterFX doesn't expect utilities or agricultural operations to invest in all this equipment on their own. Instead, it plans to use an approach similar to SolarCity, under which it owns the equipment and leases it back over time to organizations that are buying the desalinated water, Mandell said. In addition, WaterFX said its approach to desalination costs approximately $450 per acre-foot, about 50 percent lower than the costs for traditional approaches because of the fuel costs.

The biggest hurdle to adoption is intellectual. "We are dealing with an agricultural industry that for hundreds of years has gotten their technology in a certain way. Our hurdle is to get people to accept a new approach, new notions of desalination," Mandell said.

WaterFX intends to provide its technology design to other entrepreneurs interested in creating processing sites of their own. "We will allow other groups to put together their own systems using our building blocks," he said.

Water supply photo by artzenter via Shutterstock