Graywater in Austin, TexasDr. Lauren Ross, Ph.D.,P.E., Glenrose Engineering, Inc.

Austin’s Water Supply: Lakeway Park on Lake Travis

Austin’s Water Supply: Lake Buchannan

Austin’s Water Supply: Lake Buchannan and Lake Travis Combined

34%

66%

685,000 acre-feet in storage, enough to fulfill LCRA firm water contracts for 1.3 years

Single-Family Residential Outdoor Water Use in 2013

Potential Gray Water -

5,000

10,000

15,000

20,000

25,000

14,661

23,487

Single-Family and Duplex Outdoor Water Use Compared to Potential Gray Water (acre-feet

per year)

• No more than 400 gallons per day

• Only private residences

• Alternative wastewater system must be available

• Pipe must be purple and labeled

Austin Gray Water Design Requirements

Austin Gray Water Design Requirements

• Must be distributed under at least 2 inches of soil, mulch, or gravel

• A plumbing license for pressure systems or more than 250 gallons per day

• A surge tank

Austin Gray Water Design Prohibitions

• No kitchen sinks, toilets, or diaper laundry water

• No use for toilet flushing

• No discharge to ponds, fountains, waterfalls, or creeks

• No use for vegetable gardens with root crops or where edible portions touch the ground

Austin Gray Water Design Prohibitions

• No ponding or runoff

• Not on slopes exceeding 3:1

• No use over outcrop areas of the Edwards or Georgetown Limestone

Soil and Plant Health

• No chlorine products

• No sodium chloride-softened water

• No powered soaps or detergents

Soil and Plant Health

• Use cautiously: whiteners, softeners, enzymatic products

• Acid-loving plants will struggle

DesignExample

Lauren Ross, Ph. D., P.E.Glenrose Engineering, Inc.lauren@glenrose.com512-326-8880

Robert StefaniCity of Austin Water Utility512-974-9302