Onsite Water Reuse for Homes
By: Nick Sund
Tags: Drought, Housing, Gardening, Water, Sustainability

Last week, we shared what we learned about the growing challenge of drought and water scarcity in the United States, and how water agencies are coping with shrinking water supplies and rising demand. Today, we’ll explore the ways in which homeowners and the housing industry are responding to rising fees and water restrictions, as well as pioneering new approaches to onsite reuse.

Over the course of our study, we interviewed many individual homeowners, small-scale home builders, and large scale housing developers, as well as associated professions like building architects, plumbers, and greywater specialists. With homeowners, we started our conversations with general water-related questions, being careful not to focus on specific solutions (like onsite reuse) too quickly. We wanted to see if our conversations would lead there naturally, or potentially uncover other issues we weren’t aware of.

So we asked homeowners about their water use habits, their monthly water bill, their efforts to conserve water (or not), and their concerns about drought. We weren’t surprised to hear how their water-intensive lifestyles are becoming increasingly threatened by droughts and government water restrictions. The interesting part was what they wanted to do about it.

Homeowner Values: Economics vs. Environment vs. Lifestyle

Saving water and saving money are two sides of the same coin, but not all homeowners are interested in both. Many homeowners are interested in the economic proposition of potentially saving money on their monthly water bill. They are motivated less by the negative environmental impacts of water scarcity, and more by the side effect of their water bill going up.

On the other hand, some homeowners, driven by their environmental values, are more interested in saving water. They are less worried about rising water costs — in fact, they are willing to spend even more for a solution that allows them to live sustainably.

By and large, these two groups of homeowners are interested in adopting some form of conservation, if they haven’t tried something already. Many have already purchased high-efficiency appliances or replaced their lawns with rocks and cacti. Many have started taking shorter showers or tried the old trick of placing a brick in your toilet tank.

At first, it seemed like the market for water reuse might be this simple. People either care about money or the planet, and the challenge for onsite reuse would be to meet those needs. However, as we listened to more and more homeowners, we realized that the real issue for them is not about saving water or money, but rather, their lifestyle.

Whereas many of the financially and sustainability-minded homeowners have already adopted some kind of water-conserving solution, a large majority of lifestyle-oriented homeowners are not satisfied with existing solutions. They want to keep taking long showers. They want to have lush, irrigated lawns. Drought and water costs do not concern them so much as the resulting water restrictions that prevent them from living their preferred lifestyle.

This might be the largest opportunity for onsite reuse in the drought-stricken Southwest. By treating and recycling gently used household greywater into safe reusable water, onsite reuse allows families to maintain their historically high water use while decreasing their overall water consumption and still meet state water usage requirements.

So what’s the holdup?

Retrofitting for Reuse: Hassle and High Costs

Retrofitting existing homes to work with onsite reuse requires separate plumbing for greywater — rerouting any and all existing drains, except the toilet, to a new central drain pipe so it can be treated separately. Not only is retrofitting a huge cost to homeowners, but also a huge hassle. All of those pipes might not be centrally located but scattered throughout the house, requiring the cutting into several walls and areas of the floor. When homeowners are faced with the prospect of remodeling their home to install greywater plumbing, the numerous inconveniences start to outweigh the potential benefits of a reuse system.

We did speak to a handful of homeowners who already have homemade onsite reuse systems. They tended to be sustainability-minded off-grid enthusiasts with a knack for hands-on, do-it-yourself projects. They were comfortable building their own reuse systems simply based on plans they found on the internet. They already had systems and weren’t shopping for new ones. However, most homeowners are not comfortable (or qualified) to be installing their own reuse systems.

Furthermore, the process of permitting an onsite greywater reuse system is not always clear. Requirements vary wildly between jurisdictions, increasing the learning curve for plumbers. Additionally, the various processes for getting rebates from the water utility company are often not very clear and are frequently a missed opportunity for installers.

Reuse in New Construction

If the adoption of onsite reuse in existing homes is blocked by retrofitting costs and permitting headaches, then the other option is new construction. So the next thing we did was talk to homebuilders, who were facing entirely different problems with drought and water restrictions. Many counties in water-stressed regions of the U.S. are requiring separate greywater plumbing in all new homes. However, builders claimed that no one was using the plumbing because there are no treatment systems installed at the point of construction. Architectural and design-build firms reciprocated these claims. Greywater plumbing is included in their designs, but the pipes do not see any use after construction. And without an effective treatment system to use with it, greywater plumbing is simply an added cost without any benefit.

Larger-scale housing developers saw the benefit of reuse to decrease development costs and improve the sustainability and resilience of the communities they help create. The cost of installing water infrastructure for their developments is increasing due to higher tap fees from utility companies. In Colorado, some developers have responded by establishing their own small-scale water districts and utility companies within their developments. This is not a solution for everyone, and it still requires huge investments in new infrastructure. On the other hand, integrating onsite reuse throughout a housing development can reduce the cost of water infrastructure. With a reuse system, each individual home consumes less water and therefore requires smaller (and less expensive) pipes. Scaled across several developments, that savings on pipes alone could save developers significant capital.

Onsite reuse, when integrated into a community as a holistic water management strategy, also reduces the cost of purchasing water from nearby utilities. This reduced demand extends regional water resources, which ultimately increases community sustainability and resilience. Even just from a marketing perspective, this improves the existing local community’s perception of new and upcoming developments, combating the NIMBY effect and decreasing the likelihood of a new development being challenged by neighbors — ultimately reducing legal costs and risk of rejected development permits.

Homebuilders and developers largely respond to the needs and desires of their homebuyers, and as we have learned from our conversations with existing homeowners, people really want to maintain their water-intensive lifestyles. Many in the housing industry recognize this latent demand. One national homebuilder explained how their customers are not interested in individual features like high-performance faucets or weather-sensing irrigation. Instead, they’re interested in the resulting benefits: a healthier home, lower utility costs, and feeling proud of the home they buy. Another homebuilder told us, quite bluntly, that homebuyers really just want more turf.

This alone might be the greatest advantage to homebuilders that adopt onsite reuse: the ability to sell more livable green space to their customers. One builder estimated that a few larger trees and more lawn area (which are banned by current water restrictions) would add $15,000 to a home’s final appraised value.

So it seems the opportunity for onsite reuse is not in retrofitting existing homes, but in new housing construction. Responding to the needs and desires of homebuyers, developers and homebuilders will drive the adoption of onsite reuse. For large-scale developers, this reduces infrastructure costs and increases community resilience to drought. For individual homebuilders, onsite reuse reduces construction and permitting costs and simultaneously decreasing adds value to their finished product. Ultimately, homebuyers get the yards and gardens they’ve always dreamed of, and they get to live more sustainably as well.