ITEM:

CONSENT CALENDAR

 

3.

CONSIDER ADOPTION OF RESOLUTION 2020-01 AMENDING RULE 25.5, TABLE 4: HIGH EFFICIENCY APPLIANCE CREDITS, TO ALLOW RAINWATER/GRAYWATER SYSTEMS IN ALL RESIDENTIAL APPLICATIONS

 

Meeting Date:

January 23, 2020

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: The Water Demand Committee reviewed this item on January 16, 2020.  A recommendation was not available for the Board’s packet.

CEQA Compliance:  Exempt per CEQA § 15061-b-3

 

SUMMARY:  On July 15, 2019, the MPWMD Board of Directors adopted Resolution 2019-09, Amending Rule 25.5, Table 4: High Efficiency Appliance Credits for Graywater and Rainwater Reuse Systems.  That resolution established a High Efficiency Appliance Credit (Rule 25.5) for the installation of rainwater/Graywater reuse systems for toilet flushing and clothes washing in Multi-Family Dwellings. Resolution 2020-01 (Exhibit 3-A) modifies Rule 25.5, Table 4, to allow rainwater/Graywater credit for any Residential application where the applicant can provide evidence that there is sufficient Alternative Water Sources and storage to meet the needs of the project.

 

BACKGROUND: As of 2013, the California Plumbing Code allows for the reuse of treated rainwater and Graywater for toilet flushing and clothes washing. The Monterey County Health Department requires a backup water supply from a reliable source to augment the rainwater/Graywater system if needed. New construction and remodel projects are best able to incorporate this technology in the building design to reduce water demand. This can be done by installing dual plumbing to the water fixtures or by adding an auto fill valve to the storage tank (the latter is the preferred method for MPWMD and California American Water).

 

District staff has reviewed the Estimated Annual Water Use Capacity for a Graywater system to flush toilets in a Residential Dwelling Unit.  Staff estimates that between 10-15 gallons of treated Graywater (depending on the flush volume of the toilet) would be needed to meet the toilet demand in a Household with an average of 2.3 persons (local average).  This demand could be easily offset with Graywater generated from bathing (i.e., one ten-minute shower).  Design of the system requires adequate storage to meet annual demand plus three days to ensure that the Potable water backup would not be used.  A similar requirement applies to a rainwater system, which would require significantly more storage to have water available to meet demands during the dry months.

 

Resolution 2019-09, amends Rule 25.5, Table 4: High Efficiency Appliance Credits, to allow credit for Graywater and Rainwater Reuse Systems.  The credit is a 75% reduction to the fixture unit count for toilets and/or Clothes Washers supplied by rainwater/Graywater.  Requirements to grant the credit include the following:

 

·         The rainwater/Graywater system capacity shall meet 100 percent of projected annual demand plus three days.

 

·         Meters are required on rainwater/Graywater outflow and on the Potable back-up connection to the system, with an annual District reporting requirement.

 

·         A Notice and Deed Restriction Regarding Limitation on Use of Water on a Property will be recorded on the property title.

 

DISCUSSION:  Affordable Graywater recycling technology is now available for Single-Family/small scale Residential use. New space-efficient products are entering the market-place, making small scale water recycling easier to do. Rainwater harvesting systems are already readily available for properties of all sizes. Most Single-Family Dwellings have the same capacity to utilize these technologies as Multi-Family Dwellings.

 

RECOMMENDATION:  Staff recommends the Board adopt Resolution 2020-01 amend Rule 25.5, Table 4, to allow credit for Residential rainwater/Graywater reuse systems that utilize these Alternative Water Sources to flush toilets and wash clothes.  The resolution will be adopted upon approval of this item in the Consent Calendar.

 

EXHIBIT

3-A      Draft Resolution No. 2020-01

 

 

U:\staff\Boardpacket\2020\20200123\ConsentCalendar\03\Item-3.docx