Eliminate Water Supply Impact of New Residential Development with Zero Footprint Design

8/14/2019 Eliminate Water Supply Impact of New Residential Development with Zero Footprint Design

1/28

The best solution often lies in the unapparent.

John Olaf Nelson

[email protected]


2/28

Eliminate Water Supply

Impact

of New Residential

Development

withZero FootprintLeague of California Cities

ConferenceSept. 26, 2008

John Olaf Nelson Water Resources Mgt

[email protected]


3/28

What is Zero Footprint?

A. Onsite Reduction of Potable Demand:

Conservation Measures

Recycled Water Use

B. Off-site Offsets of Potable Demand:

Utility Conservation Programs

Utility Recycled Water Projects

A + B = Zero Net Potable Demand


4/28

How Paid For?

Onsite Reductions are cost to

Developer at time of construction.

Off-site Offsets are payments made to

Utility (lump sum or an added

connection fee.

Both reduce profit margin to Developer.


5/28

How are Savings Assured?Onsite

Use of approved devices

Inspection by Utility

Conditions, Covenants & Restrictions

(CC&Rs)

Off-site Factor of Safety in estimating savings

Utility sets/approves Offset Fee

Utility administers off-site cons. programs


6/28


7/28

EPAct Standards

ULFTs 1.6 gpf

Shower heads 2.5 gpm

Faucets/aerators 2.2 gpm


8/28

New Standards - Inside

HE Toilets 1.28 gpf*

HE Shower heads 2.0 gpm

HE Faucets/aerators 1.5gpm**

HE Clothes washers 5.5

gcd HE Dishwashers 0.6 gcd

Submeter MF 21.8 gpd

Structured Plumb./HWD 8.5 gpd


9/28

HE Toilets and Appliances

Dual Flush

Clothes Washer & Dryer


10/28

Structured Plumbing


11/28

in Plan View


12/28

HWD RetrofitHot Cold

Receiver

< Recycle Pump and

Temperature Sensor


13/28

New Standards - Outside

Limit Turf for SF to < 800 sf

No narrow strips of turf (< 8 ft)

Xeriscape plant materials

Smart (ET) Controller

Meet States MAWA requirement *

* 70% ET Adjustment Factor


14/28

XeriscapeTraditional

Xeriscape


15/28

ET Controller


16/28


17/28

B/C of Some Onsite Measures

HE Clothes Washer

4.4

Submetering MF 2.3 HE Dishwasher 1.3

Structured Plumbing 1.2

ET Controllers for SF 0.7


18/28

Added Unit Cost

HE Clothes Washer $238

Submetering MF $273

HE Dishwasher $111 Structured Plumbing $573

ET Controllers for SF $312


19/28

Select Off-site Programs & B/C

Utility Cust.

ET Contr. - Irr. (100%) 2.6 5.1

Submetering MF (100%) 1.9 2.3

ET Contr. - UQ SF (75%) 1.2

1.5

HWD Retrofit (40%) 1.0 1.8

ET Contr. - Typ. SF (50%) 0.6 0.5


20/28

Estd Program Unit Cost to Utility

ET Contr. - Irr. (100%) $1,180

Submetering MF (100%) $473

ET Contr. - UQ SF (75%)

$590

HWD Retrofit (40%) $270

ET Contr. - Typ. SF (50%) $324


21/28

Case Example

Location:

Inland Coastal Valley of North CA

33 inches of annual rainfall (nil in summer)

Description:

300 acres (29% open space)

1,736 DUs (SF = 68%) 250,000 sf of commercial

Total Project Demand = 580 afa (0.518 mgd)


22/28

EDU Relationships

EDU Ratio

SF Detached 1.00

SF Attached 0.70 MF 0.53

Second Units 0.24

Note: 1,736 DUs = 1,330 EDUs


23/28

Onsite Reductions and

Remaining Offset NeedOnsite Reductions:

Conservation 23%

Recycled Water Use 24%

Total 47%

Remainder to offset viaOff-site Programs: 53%


24/28

Measures and Distribution

of Onsite Reductions

`

Recycle 51% EPAct 25%

HE Clothes Washers 9%

Submetering 4%

Commercial and HE Dishwasher 1% eachStructured Plumbing w. HWD 4%

ET Controllers 5%


25/28

Expand Existing 28%

ET - Upper Quart. SF 16%

Increase Clothes

Washer Rebates 6%

HWD Retrofit 8%

Submetering MF

15%

ET - Irr. Only 18%

ET - Typical SF 9%

Note: ET Controller Programs total 43%

Off-site Program Savings and

Distribution


26/28

Case Example Recap

M$ $/DU $/EDU

Onsite Conservation 1.2 684 892

Onsite Recycled 3.2 1,857 2,424Off-site Conservation 2.9* 1,650 2,154**

Total $7.3 $4,191 $5,470

* Includes 22% Safety Factor for est. errors.

** Offset Fee to pay for Off-site Programs


27/28

Build-it-Green Points

Points

Build-It-Green points for SF: 294

Portion in Water category*: 66

Application of New Standards

can capture: 46

* Excluding consideration of Recycled Water Use


28/28

John Olaf Nelson Water Resources Mgt

[email protected]

Eliminate Water Supply Impact of New Residential Development with Zero Footprint Design

Documents

Transcript of Eliminate Water Supply Impact of New Residential Development with Zero Footprint Design