WATER DEMAND COMMITTEE
ITEM:		DISCUSSION ITEM
5.	DISCUSS APPROPRIATE HIGH EFFICIENCY APPLIANCE CREDIT FOR FLUSHING RESIDENTIAL TOILETS WITH RAINWATER AND/OR GREYWATER SYSTEM
Meeting Date:			April 23, 2019	Budgeted: N/A
From:			David J. Stoldt,	Program/	N/A
			General Manager	Line Item No.:
Prepared By:			Stephanie Kister	Cost Estimate:	N/A
General Counsel Review: N/A
Committee Recommendation: N/A
CEQA Compliance: This action does not constitute a project as defined by the California Environmental Quality Act Guidelines section 15301

SUMMARY: The 2013 California Plumbing Code allowed for the reuse of treated rainwater and greywater for flushing toilets and clothes washing. New construction of hotels and apartment complexes are best able to incorporate this technology in the building design to reduce their water demand. The Monterey County Health Department requires a backup water supply from a reliable source to augment the rainwater/greywater system. This can be done by installing dual plumbing to the water fixtures or by adding an auto fill valve to the storage tank.

The District has received a request to reduce the Estimated Annual Water Use Capacity for installation of a greywater system to flush toilets in two proposed Multi-Family Dwellings in Monterey. Staff estimates that between 10 and 15 gallons of treated greywater (depending on the flush volume of the toilet) would be needed to meet the toilet demands of an apartment with an average of 2.3 persons per household. This demand would be easily offset with greywater generated from bathing (e.g., one ten minute shower). Design of the system would need to have adequate storage to meet demand for two to three days to ensure that the Potable water backup would not be used. A similar requirement would apply to a rainwater flushing system, which would require significantly more storage to meet demands during the dry months.

Staff is requesting direction from the Water Demand Committee regarding amendment to Rule 24, Table 4: High Efficiency Appliance Credits for greywater (and rainwater) systems for toilet flushing. This table can be amended by Resolution of the Board of Directors. The Committee should discuss whether a complete offset of the toilet fixture count should be available, or whether the fixture count should be reduced for these systems.

In granting a credit for a greywater (or rainwater) toilet flushing system, the District would require metering on both the greywater and the Potable backup to the system and annual reporting. The requirements would be recorded as a permanent requirement on the property title. In addition, the Monterey County Health Department would also permit the system. Roger Van-Horn from the Health Department will be available to respond to questions at the meeting.

RECOMMENDATION: The Committee should discuss the matter and provide direction to staff.

EXHIBITS

5-A Diagram of Rainwater Reuse

5-B Diagram of Greywater Reuse

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