Domestic Water Reuse

Q&A on Graywater

I don’t live in a house that is served by recycled water from EID. Can I reuse water from my home to irrigate plants in my yard?

With some investment and proper permitting by El Dorado County Environmental Health, you may be able to install a graywater system to meet some or potentially all of your irrigation needs.

What is graywater?

Graywater is untreated, non-disinfected wastewater that has not come into contact with toilet waste. Graywater includes wastewater from residential showers, bathtubs, bathroom sinks and washing machines which may be used in landscapes using an onsite collection system and must employ a subsurface irrigation method. Click here for more information on the use of recycled water and graywater in the landscape.

Will a graywater system cut down on my irrigation costs?

The short answer is yes, but there are certain requirements you must follow and other costs that you must consider. Depending on the amount of graywater generated, the costs to construct and maintain a graywater system may outweigh the savings. Click here for a case study of graywater systems including an analysis of the costs and benefits of constructing such a system.

Does EID need to approve my graywater system?

While EID does not need to approve your graywater system, you will want to consult the following links and obtain all appropriate approvals, including those from El Dorado County Environmental Health. Click here for a link to the Environmental County Environmental Health Department liquid waste program webpage. Please be aware that your system will be subject to approval and inspection by the County. Further, graywater systems are restricted in that all irrigation must occur subsurface. As such, a separate irrigation system may be required depending on the configuration of your property (type of irrigation, etc) and the new system may not meet all of your irrigation needs.

How can I make sure that may graywater system does not flow into my drinking water?

Your graywater system must meet specific requirements to ensure it is properly separated from your onsite drinking water system. The County ensures this separation by requiring an air gap or other physical device which prevents graywater from flowing back into your drinking water system, which is known as “backflow”. Click here for more information regarding graywater systems requirements enforced through El Dorado County Environmental Health.

What does EID do to make sure that graywater does not enter the public water system?

State law requires EID to protect the public water system from auxiliary water sources such as graywater. This is accomplished by requiring the customer to install a backflow prevention assembly at the meter prior to operation of the graywater system. The assembly is tested annually to ensure continued protection. Once the backflow prevention assembly is installed you will be assessed a bimonthly fee to cover the EID’s costs for testing and maintenance of internal components. Click here for more information about the EID’s Cross-Connection Control Program.

 

Additional Information


El Dorado County Ordinance - Chapter 15.32 - Private Sewage Disposal

Revised Graywater Standards

Graywater Guide: Using Graywater in Your Home Landscape

Chapter 16A: Nonpotable Water Reuse Systems

EID Cross-Connection Control and Backflow Prevention Program

Backflow Prevention Assembly Testing Services