CA AB1738

Defines "dark graywater" as untreated wastewater from kitchen sinks and dishwashers that meets safety standards and has not been contaminated by toilet discharge or unhealthy bodily wastes

Requires the Department of Housing and Community Development to develop and submit building standards for construction, installation, and alteration of dark graywater systems for indoor and outdoor uses at the next triennial building standards rulemaking cycle

Mandates the department consult with a stakeholder group including experts in public health, water quality, geology, plumbing, home building, and environmental stewardship when developing the standards

Requires consultation with the State Water Resources Control Board when developing dark graywater building standards to ensure protection of water quality

Terminates the Department of Water Resources' authority to adopt graywater system standards for residential buildings once the California Building Standards Commission approves the new standards