The Greywater Showcase put together by Cool Davis partner Water Wise Davis this past Wednesday July 12, 2017, brought together a diverse group of about 40 participants and sparked some interesting discussion around greywater and water reuse in our community.

Panelists, presenters, honored guests, service providers, participants, and Water Wise Davis members enjoyed a “very pleasant learning experience” according to one happy attendee.

Experts and policy makers weigh in about greywater

Brett Lee, City Council member and Mayor Pro Tem, expressed his appreciation and support for greywater efforts in the community. The opening presentation given by Leslie Crenna of EcoAssistant touched on greywater basics, the potential of greywater for our community, and considerations for the individual homeowner. Panelists represented a range of family types and settings, from rural to in-town, from do-it-yourself to contractor installed.

2017 Greywater Showcase
Participants chatting with service providers and City of Davis officials. Photo credit Johan Verink.

Common questions like whether hot water is okay for laundry systems (yes) and whether established trees do well with the shift in watering regime (generally but keep an eye on them) were asked and answered. While some root damage might occur when digging mulch basins, panelist Robyn Waxman saw no damage to her established citrus trees.

The other panelists were Andrew Clifton, Catherine Brinkley, and Natalya Eagan-Rosenberg. Natural Resources Commissioner from the water subcommittee Steve Westhoff moderated the panel.

2017 Greywater Showcase
2017 Greywater Showcase moderator Steve Westhoff and panelists Natalya Eagan-Rosenbeg, Andrew Clifton, Robyn Waxman, and Catherine Brinkley. Photo credit Johan Verink.

Less common questions specific to Davis brought out some vital information. In particular, the issue was raised about whether installing a greywater system in a home with a water softener was a good idea.

Bernadette Balics of Ecological Landscape Design made the essential point that greywater is only part of the whole on-site water management picture. Other strategies yielding significant results include rainwater capture, landscape transformation, and water conservation.

Water softening unnecessary for homes on surface water

City of Davis Chief Building Officer Grey Mahoney let the group know in no uncertain terms that there is no longer any reason to have a water softener in the City of Davis (due to our new surface water supply). If installed per code, these systems should have a simple by-pass valve. Turning off those softening systems allows Davis homeowners to save money, time, and effort.

Cleaning adjustments and solutions

Another question was raised after the event about whether baking soda was a greywater safe cleaning agent for showers and tubs since its chemical composition is sodium bicarbonate. Sodium is the primary ingredient to avoid with greywater systems and most over the counter liquid detergents and shampoos have high quantities of sodium lauryl and laureth sulfate.

The Skin Deep database developed by the Environmental Working Group was mentioned as a source of information about the chemical composition of cleaning and hygiene products.

The jury may still be out on baking soda because small quantities might not affect the soil significantly depending on how often the surfaces are cleaned and how much is used. However, there is no debate about avoiding powder based laundry detergents which generally contain boron, also harmful to plants.

Fabulous prizes for participants

The City of Davis Public Works department represented by Conservation Coordinator Dawn Calciano generously provided two $100 value laundry to landscape parts kits, as well as two waterless car wash kits, and several soil moisture meters and hose spray nozzles as door prizes. The winners walked away with smiles, some with a mission to transform their waste water into a valuable source of irrigation water supply.

2017 Greywater Showcase
About 40 participants and 14 or so more panelists, organizers, and guests attended the 2017 Greywater Showcase. Photo credit Johan Verink.

Opportunities for DIY learning and cutting edge service providers

A selection of greywater service providers offered up resources and brief introductions to themselves and their work. Traditional provider roles were represented like landscape contractor and landscape designer while professionals with less traditional roles like greywater designer and installer were also on hand. Many of the vendors provided services in all or many of these disciplines.

Greywater provider EcoAssistant is planning both laundry to landscape and branched drain hands-on installation workshops in the next few months. For more information, visit the EcoAssistant website.

Water Wise Davis would like to thank all our panelists, Natalya Eagan-Rosenberg, Andrew Clifton, Robyn Waxman, and Catherine Brinkely, special guests Brett Lee, Steve Westhoff, and John Johnston, and Water Wise members who contributed to this effort: Frances Andrews, Paul Havemann, Larry Fisher, Alan Pryor, Valya Mogilner, Bernadette Balics, and Leslie Crenna. Another huge thanks to Dawn Calciano and Greg Mahoney at the City of Davis for their support and expertise, and the Davis Senior Center for their assistance with setup and tear down.

More Resources

Greywater Showcase program July 12, 2017

EcoAssistant presentation on Residential Greywater in Davis

Cool Davis / Water Wise Greywater Resources list

Cool Davis / Water Wise Greywater Vendors list (and community greywater potential data)

Check out all the fabulous photos taken by Cool Davis volunteer photographer Johan Verink on the Cool Davis Facebook page…and Like us while you’re there!


2017 Greywater Showcase
Mayor Pro Tem Brett Lee makes the case for household greywater. Photo credit Johan Verink.


2017 Greywater Showcase
Bernadette Balics of Ecological Landscape Design talks greywater and integration with the landscape. Photo credit Johan Verink.


2017 Greywater Showcase
MC Paul Havemann of Water Wise Davis and Derek Downey of Whole Systems Design chatting greywater. Photo credit Johan Verink.