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The Water-Energy Nexus is the Next Big Thing: Three Case Studies from

By Chris van Daalen, Principal Investigator Code Innovations Database

Whether we’re talking people, ecosystems or the economy, what they say is true:  Water is Life.  From lead-polluted drinking water in Flint Michigan, to a moratorium on building in Whatcom County, Washington, it’s painfully clear how dependent all of us are on water infrastructure for safe clean drinking water, wash water, and yet more water to carry away our wastes.

What is harder to see, is that we also rely on energy infrastructure to deliver an uninterrupted flow of clean water.  For the most part Americans feel secure, but clear signs say we cannot assume future water supplies will be stable in light of a changing climate, evolving technology, and dependency on aging and obsolete infrastructure.

There are many facets to the water-energy nexus, more than can be covered in a short article. To comprehend just part of it in the real world, I want to focus on three case studies published on The Code Innovations Database, an online resource I manage for the Northwest EcoBuilding Guild.

US Department of Energy (DOE)

In 2014, the US DOE issued a report “The Water-Energy Nexus: Challenges and Opportunities” that details the many ways that “energy and water flows are intrinsically interconnected… due to the properties and characteristics of water that make it so useful for producing energy and the energy requirements to treat and distribute water for human use.” (1)

The report identifies six “Strategic Pillars” as the logical structure for their “long-standing” R&D efforts, and which they claim “lays the foundation for future efforts.”  Let’s hope that proves true!

Another seminal report on the Water-Energy Nexus is an extensive literature review published August 2013 by the Water in the West program at Stanford University (2), which I would highly recommend for anyone who wants to gain a handle on this nexus.

Non-traditional water sources and treatment in Bellingham, WA

Most of us aren’t even aware of how much energy it takes to treat and transport water to our taps and toilets. I certainly wasn’t, not until green building innovator Dan Welch of [bundle] design studio opened my eyes with his net-zero energy, net-zero water “Birch Case Study home” in Bellingham, WA. This is the only home I know of within an incorporated city limits that was permitted to not connect to city water and sewer, by proving to code officials they had it covered. Welch and his family use harvested rainwater for drinking water and everything else. He designed an innovative “batch composting” toilet system that uses no water and safely fertilizes the garden. With no toilets to flush, they treat their own wastewater (mostly greywater) in a very small septic system.

His electrified ultra-efficient home produces all its own energy with solar panels. Not only that, but by being off the water grid he is helping the County save additional energy and money that would have been used to transport potable water to, and wastewater from his home to the treatment plant.

Bellingham and Whatcom County code officials approved his non-traditional approach because they’ve adopted State Rules that prescribe such systems.  Yet, most Washington cities don’t have Whatcom County’s water issues, nor it’s forward-thinking policies, and have not adopted these rules.  Which means innovators throughout the State still face significant barriers to non-traditional sources and treatment.  To understand how Welch achieved it, check out our “Birch Home” case studies on the Code Innovations Database.

The California Energy Commission estimates that nationally, it takes roughly 1,200 kWh of electricity per million gallons (kWH/MG) to deliver water to customers. Another 220 kWh/MG or so goes into potable water treatment.  Wastewater treatment is even more energy intensive, though it varies widely by type of treatment and size of plant, ranging from 1,000 to 3,000 kWh/MG water treated.

Alternative Energy for Wastewater Treatment

The Budd Bay Wastewater Treatment Plant in Olympia Washington treats about 12 MG/day, but uses less energy than comparable facilities, because they have a biogas cogeneration system that converts methane from its anaerobic digesters into enough heat and electricity to offset 100% of the facility’s space heating and office power needs. Leftover heat is transferred by underground pipes to the building across the street, a ”district energy” system that heats both buildings!  You can read more about it in the Code Innovations Database case study: Methane CoGen System at LOTT Alliance.

This biogas is a byproduct of the “solids” part of the wastewater, an untapped resource that treatment plants across the US could be using to offset energy needs. The US EPA estimates that biogas energy generation could provide about 50% of the power requirements of an average facility. Yet in 2006, only 7% of biosolids were used in this way, while nearly 40% was landfilled or incinerated (using even more energy) (3).

Commercial Scale Human Waste Treatment and Water Reuse

Developers and City officials in Portland, Oregon have taken solutions like those in the Birch Home to scale. Hassalo on 8th is a mixed-use three-building project that spans four blocks in the City’s vibrant and growing Lloyd EcoDistrict area.  Three buildings share one of the largest natural organic recycling treatment systems in the US, treating all the wastewater (including human waste) which is reused for toilet flushing, mechanical cooling and below surface landscape irrigation in an urban setting.  Excess treated “blackwater” is returned back to the City’s aquifer with two dry injection wells, but only after it’s treated to Class A water standards.

The Water in the West report shows that reclaiming and recycling water for non-potable uses is well-established and accepted in many cities (e.g. industrial use or landscaping).  Recycling of wastewater back into potable water supplies however is much more controversial. The Code Innovations Database case study on this project points out that the district scale of this project, and high profile support from the City made this project possible.

In Conclusion

While the solutions represented by these cases may be nascent, while there are significant barriers to widespread adoption of truly sustainable, resilient and distributed infrastructure, there is a growing body of experience, evolving technology and a sense of urgency at the highest levels helping communities begin to grapple with the challenges posed by the water-energy nexus. For now, projects like those featured in our Database continue to lead the way through innovation. Now we must use this information to educate decision-makers and support action at the local and state levels to keep building momentum.

In Washington, encourage your County to adopt and use Department of Health Rules for rainwater harvesting for potable use, composting toilets and water conserving on-site sewage systems, and push for more research and demonstration projects, and better regulations.  In Oregon, learn about graywater reuse policies for indoor and outdoor use, and follow the work of Recode, a non-profit advocacy group based in Portland.

Meanwhile, check out 20 other related case studies in the Code Innovations Database, or submit a project if you know another we should profile!!

Chris van Daalen is Principal Investigator of the Code Innovations Database, an advocacy research program of the Northwest EcoBuilding Guild.  The Database documents permitting precedents and policy innovations, to provide a platform for public-private collaboration with the goal of accelerating adoption of high-performance green building. vanDaalen is a lifelong environmental activist and for the past 20 years a social enterprise consultant to “green economy” organizations and firms.  He has served the Northwest EcoBuilding Guild and its members for 11 years as volunteer Board Member and Education Coordinator.

References: 1 Bauer, Diana et. al, US Department Energy, The Water-Energy Nexus: Challenges and Opportunities” June 2014, Washington, DC. 2 Water in the West, a joint program of Stanford Woods Institute for the Environment and Bill Lane Center for the American West. “Water and Energy Nexus:  A Literature Review.” August 2013:  Stanford, CA 3 Parsons Corporation. “Emerging Technologies for Biosolids Management.” U.S. Environmental Protection Agency (2006).

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