WITH OUR CONTINUING DROUGHT CONDITIONS and the city urging us to voluntarily reduce water consumption by 20 percent, some people have asked about gray water systems.

I’ve written briefly about gray water before, taking some of my information from a Sunset Design Guide titled “The Green Home.”
Sunset describes gray water as “any water that comes from your bathroom sinks, bathtubs, showers, and clothes washer that can be reused — instead of going down the waste pipe with truly unusable water from the toilet, kitchen sink and dishwasher.”

Sunset quoted architect Peter Pfeiffer, who advised that the effort, cost and smell of installing a gray water system (if allowed) may not be “worth it.” Instead, he advocated for the installation of water-saving fixtures and appliances, drought tolerant planting and drip system irrigation.

It’s my understanding that the city of Benicia doesn’t currently have a gray water ordinance, but recently Benicia’s Climate Action Plan coordinator, Alex Porteshawver, sent me a link to the California Department of Housing and Community Development for the California code on gray water that does allow for reuse in the following situation, per Chapter 16A, Section 1603A.1 System Requirements, 1603A.1.1 Clothes Washer System. Note this is for a Clothes Washer System only and that the system must meet the following requirements. I’ll quote chapter and verse here:

“1603A.1.1 Clothes Washer System. A clothes washer system in compliance with all of the following is exempt from the construction permit specified in Section 108.4.1 and may be installed or altered without a construction permit:

“1. If required, notification has been provided to the Enforcing Agency regarding the proposed location and installation of a gray water irrigation or disposal system.

“Note: A city, county, or city and county or other local government may, after a public hearing and enactment of an ordinance or resolution, further restrict or prohibit the use of gray water systems.

“For additional information, see Health and Safety Code Section 18941.7.

“2. The design shall allow the user to direct the flow to the irrigation or disposal field or the building sewer. The direction control of the gray water shall be clearly labeled and readily accessible to the user.

“3. The installation, change, alteration or repair of the system does not include a potable water connection or a pump and does not affect other building, plumbing, electrical or mechanical components including structural features, egress, fire-life safety, sanitation, potable water supply piping or accessibility.

“Note: The pump in a clothes washer shall not be considered part of the gray water system.

“4. The gray water shall be contained on the site where it is generated.

“5. Gray water shall be directed to and contained within an irrigation or disposal field.

“6. Ponding or runoff is prohibited and shall be considered a nuisance.

“7. Gray water may be released above the ground surface provided at least 2 inches (51 mm) of mulch, rock or soil, or a solid shield covers the release point. Other methods which provide equivalent separation are also acceptable.

“8. Gray water systems shall be designed to minimize contact with humans and domestic pets.

“9. Water used to wash diapers or similarly soiled or infectious garments shall not be used and shall be diverted to the building sewer.

“10. Gray water shall not contain hazardous chemicals derived from activities such as cleaning car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities.

“11. Exemption from construction permit requirements of this code shall not be deemed to grant authorization for any gray water system to be installed in a manner that violates other provisions of this code or any other laws or ordinances of the Enforcing Agency.

“12. An operation and maintenance manual shall be provided. Directions shall indicate the manual is to remain with the building throughout the life of the system and indicate that upon change of ownership or occupancy, the new owner or tenant shall be notified the structure contains a gray water system.”

Gray water clothes washer kits

Naturally, in the world of the Internet of Things, there are kits you can buy, if you meet all the requirements listed above. They range in price from $195 to much less for components — and then either your sweat equity or the assistance of a plumber for the installation.

Landscaping decisions

The city of Pleasanton suggested that 50 percent of residential water usage goes toward landscaping, and they had this interesting information about the typical lawn and the benefits of tackling our landscapes as a way of reducing water usage: “Consider your potential water savings; 1 inch of water applied over a 1,000-square-foot lawn consumes 624 gallons of water (recommended amount of water necessary for turf in mild weather).

“If you watered this amount three times a week, you would consume 97,344 gallons of water a year just to maintain your lawn! This value doesn’t even take into account the hot summer months that may require more frequent watering.”

So, if lawns were replaced with a drought-tolerant landscape, the estimated savings, at minimum, is between 20 to 50 percent. In the example above, the conservative annual 20-percent savings would be 19,467 gallons. If in this example we added the annual gray water produced from a high-efficiency clothes washer — 4,500 gallons — the total reduction would come to almost 25 percent.

The clothes washer

In thinking about architect Peter Pfeiffer’s comments regarding the efforts and costs of installing a gray water system — which in Benicia would only currently apply to washing machines and systems that met the above requirements — I had to wonder about tackling water (and energy) usage via a high-efficiency washing machine as a first step in water conservation.

According to the Energystar.gov website, “The average American family washes about 300 loads of laundry each year.” Standard washing machines, or machines manufactured before 2005, use at least 23 gallons per load. So, 300 x 23 = 6,900 gallons of water annually. The new Energy Star-certified clothes washers use about 15 gallons of water per load, so 300 x 15 = 4,500 gallons of water annually. The difference is 2,400 gallons of water saved, or a 35-percent reduction in water use with the high-efficiency washer! Bingo! For an average family currently living with a washer that is 10 years old or older, converting to a high-efficiency washer is a great step forward in water conservation that also has a nice energy-reduction component of about 20 percent.

Biggest savings

For homeowners, drought-tolerant landscaping is the biggest way to reduce water usage. The next big water savings, inside the home, is upgrading to a high-efficiency toilet that uses 1.28 gallons of water per flush or less.

Water is precious, so whatever we can do to reduce usage, we should — including using only the water needed in washing hands and dishes, filling the clothes washer full of clothes to minimize the number of loads needed and, if you own a pool, making sure to use a pool cover to slow down evaporation.

Learn more

• Benicia Homes Saves: free home water and energy audits — beniciahomeefficiency.org

• California Code — Clothes Washer Gray Water System: hcd.ca.gov/codes/shl/2007CPC_Graywater_Complete_2-2-10.pdf

• Energy Star — Clothes Washers: energystar.gov/certifiedproducts/detail/clothes_washers?fuseaction=find_a_product.showProductGroup&pgw_code=CW

• Greywater Action’s how-to instructions: greywateraction.org/content/laundry-landscape-1

• Cleanwater components: cleanwatercomponents.com/education/greywater/laundry-landscape-greywater-system

• City of Pleasanton utility advisory: http://www.cityofpleasantonca.gov/services/utility/dtl-mainpage.html#sthash.gACeMFoR.dpuf

• Solano County High Efficiency Toilet rebate program replacing toilets that use 3.5 gallons or more per flush: conservationrebates.com/programs/het/SolanoHET.aspx

Constance Beutel is a the chair of Benicia’s Community Sustainability Commission. She is a university professor and videographer and holds a doctorate from the University of San Francisco.