Making the most of every drop is not rocket science
The thunderclap epiphany around water, growth and the sustainability of my local industry was provided by Doug Pushard, Santa Fe’s own national water expert. He said NASA stopped hauling water to the International Space Station a long time ago. In other words, they learned how to recycle water. Boom!
At a meeting a few years ago in Washington, D.C., with the smartest green builders in America, I was explaining what a Water Efficiency Rating Score meant for Santa Fe builders and others in the Southwest.
I said it was a metric that could predict net-zero water usage in a home, that there were builders in my market building to that level with only 14 inches of annual rain and that someday every builder in the Southwest would be doing the same.
A savvy energy expert from Maryland asked how we thought we could convince buyers to spend thousands of dollars to chase a low score to maximize conservation. With the low cost of water, the payback would take decades, he said. Nobody would do it.
He was right, of course, but I said it was the wrong question. The better question was to ask builders, with mortgages to pay and kids to raise, how much the next new-home building permit was worth to them. If you had to build to net-zero water usage in order to build at all, would you figure it out? You bet you would.
Building a home with net-zero water usage connected to a municipal system pushes the sustainability failure point — i.e., that date in time when a jurisdiction shuts the spigot and says, “No new building permits” — much further out. Maybe even seven generations.
Another Pushard-learned lesson was his frustration with silos of water. There’s only one definition of water, but within that definition is rainwater, stormwater, greywater and black water. All are just various levels of treated water, with the exception of rainwater. That’s the purest and best. It has no leached arsenic and solids from aquifer mines. No dissolved pharmaceuticals from upstream dumpers. Just life, free and pure from the heavens.
Unfortunately, when that beautiful rainwater hits the ground, it becomes stormwater. That’s bad. It scours our river and arroyos. It picks up parking-lot poisons, plastic bags and dog poop. If the stuff hitting our roofs, rainwater, is captured, filtered and treated and never mingles with nasty stormwater, it can flush toilets, wash clothes and bathe our bodies.
We just broke down a silo or two. If we take that harvested rainwater and make it greywater, from bathroom sinks, showers and clothes washers, we can irrigate the heck out of plants no longer getting water from our canales and downspouts. And then, another silo crashes.
What about that harvested rainwater being used in the toilets? That’s not black water to managers of the wastewater treatment plant; that’s gold. They need every drop. Aggregate superefficiency challenges their business model based on dilution. Taking away greywater from our sewer pipes to water your plants? That’s a problem because less water means less dilution.
If black water is made from rainwater, and not from city water delivered through its pipes, that’s a good thing. But it only offsets what was already going to the treatment plant anyway.
That’s why we need to figure out how to mix harvested and treated stormwater into the wastewater supply at the treatment plant. It’s not rocket science.
Kim Shanahan has been a Santa Fe green builder since 1986 and a sustainability consultant since 2019. Contact him at shanafe@aol.com.