How to determine the key opportunities for customers to be more efficient are reviewed in this Section.
6.2.1 Developing a list of alternative evaluation measures
As part of the evaluation of appropriate measures, compile a list of potential demand management measures that may be appropriate for the area. This process generally yields over 100 potential efficiency measures in the following typical customer categories: (a) domestic; (b) commercial; (c) industrial; (d) public (institutional); and (e) irrigation.
A measure is distinguished from a device that saves water or an overall programme by using the definitions listed below.
(a) Device
This is a physical item of hardware, such as a new showerhead or toilet, or specific action taken by individuals, such as commercial audits, that save water if the recommendations are implemented or carried out by a water utility or other group.
(b) Measure
This is a device plus a implementation method and possibly an incentive, such as a rebate or ordinance (regulation), targeted at a particular type of end user that, when implemented, will save water.
(c) Programme
This is a set of one or more measures targeted at one or more customer categories, and managed by a water utility as a separate project.
(d) Plan
A plan is a set of one or more programmes together with an estimated budget, schedule and staffing plan. In addition, planners can create a strategy or programme for a measure that puts devices or messages into the hands of customers and allows them to take action.
6.2.2 Water efficient devices, fixtures and fittings
(a) Codes and standardsThere are various approaches to making existing and new buildings more water efficient. One method is to incorporate requirements for efficient plumbing fixtures and appliances into building codes. Efforts to develop an international code for energy efficiency led to the development of the International Plumbing Code as one of many standardized codes. A number of countries are at various stages of adopting the International Plumbing Code. Copies are available from the International Code Council at web site:
http://www.iccsafe.org/Pages/default.aspx (last accessed April 18, 2013)
In the United States and in other countries local jurisdictions often adopt the plumbing and mechanical codes developed by the International Association of Plumbing and Mechanical Officials (IAPMO).
Information is available at http://www.iapmo.org/pages/default.aspx (last accessed on June 2, 2013). In 2012 they published a Green Code Plumbing and Mechanical Code Supplement available at http://
iapmomembership.org/index.php?page=shop.product_details&flypage=flypage_iapmo.tpl&product_id=
4&category_id=6&option=com_virtuemart&Itemid=3 (last accessed on June 2, 2013).
This supplement incorporates many sustainability concepts including more aggressive water conservation than required by most local codes.
In the United States, most regulations on water efficiency that pertain to buildings are the result of efforts to make buildings more energy efficient. When the Federal Energy Policy Act was passed in 1992, the water-related provisions of the Act consolidated a patchwork of individual state regulations on water efficient fixtures and appliances. By requiring standard flow tariffs and flush volumes for manufacturing plumbing units, the Act controlled not only fixtures in new construction but also those in the replacement market. The specific requirements for manufactured fixtures are summarized in the Case Study at the end of this chapter. These provisions of the United States Energy Policy Act are available at http://www1.eere.energy.gov/buildings/appliance_standards (last accessed on April 18, 2013)
(b) Available devices and appliances
Available water efficient fittings and fixtures (together with other devices) have been researched and evaluated for cost, possible water efficiency value, and legal status if appropriate. Sources of information on devices and appliances include: (a) the Handbook of Water Use and Conservation by A. Vickers, published in 2001; (b) the Memorandum of Understanding Regarding Urban Water Conservation in Californiapublished by the California Urban Water Conservation Council in 2008, which contains a list
of best management practices; and (c) Best Management Practice (BMP) Cost and Savings Study (Chestnutt, 2005).
Table 6.3 provides a summary of devices. Demand reductions and costs shown need to be checked against local water-use patterns and costs; however, an approximation should be given of the level of savings and costs that can be expected. Actual savings vary with household size, current devices or technology in use, portion of water used in the landscape area and so on.
Table 6.3 Example list of water efficient devices by category.
Device Flow ratinga Estimated cost in the United States (US$) Device life (years)a
Ultra low-flow showerhead 6.8 L/min 10–90 5–10 40c
Low-flow showerhead 9.5 L/min 10–90 5–10 20c
High efficiency faucet 6 L/min 30–90 50 15–20 15
Flow flow control device 8.3 L/min 2 10 20
Low flow faucet aerator 8.3 L/min 5–10 5 5
Ultra low flow faucet aerator 1.9 L/min 5–10 5 20
Toilets
Squat-pour toilets 1 L/flush 50 100 30–40 150d
Ultra high efficiency toilet 3 L/flush 150–300 200 30–40 125d
High efficiency toilet 5 L/flush 200–600 200 30–40 100d
Six-litre toilets 6 L/flush 100–300 200 30–40 90d
Dual flush toilets 6/3 L/flush 200–400 200 30–40 105d
Water dam devices 1 L/flush 5 5 10d
Composting toilets 0 L/flush 2000 500 200 20+ 160d
Kitchen
Kitchen faucet 6.8 L/min 40–300 50 10–15 10
Faucet aerator 8.3 L/min 5–10 5 3
Dishwasher (domestic) 18 L/wash 300–900 200 10–15 20
Laundry
Faucet aerators 8.3 L/min 5–10 5 2
Efficient washing machines 56 L/wash 750–1100 100 10–15 60
General household On-demand or point-of-use hot water systems
24–35 L/min 900–1300 200–400 20+ 15
Household pressure reducing device
414 kPa 50 200 20+ 10
Greywater systems .3000 .400 15–25 80
(Continued)
Several conservation survey type measures are illustrated in Figures 6.5–6.7.
Table 6.3 Example list of water efficient devices by category (Continued).
Device Flow ratinga Estimated cost in the United States (US$) Device life (years)a
Demand reduction (L/////conn/////d)b Purchase
cost ($)
Installation cost ($)
Additional annual costa($) Landscaping
Drip systems 50–100 10–50 10 20
Micro-spray systems 50–100 10 10
Faucet timers 20–50 0–100 5–10 20
Rainwater tanks 1000f 4000 20+ 40
Trigger shut-off valves on hoses 10–15 5 5
General commercial equipment (other than above measures)
Waterless urinals 0 L 500 300 150–200e 20+ 80g,h
Ultra high efficiency urinal 0.5 L/flush 300–500 100–400 20+ 70g,h
Efficient urinal 1.9 L/flush 200–450 100–400 20+ 60g,h
High efficiency flush valve toilet 5 L/flush 450–700 100–400 20+ 800g
Dual flush toilets 6/3 L/flush 300–400 200–400 20+ 100g
aWhere applicable.
bDemand reduction is given in units litre per connection per day (Litre/conn/day). Assumed 2.5 persons per connection.
cBased on comparison with 11 litre/minute shower.
dBased on comparison with 13 litre flush.
eBased on 3–4 cartridges/year (at US$50/cartridge).
fA 550-litre tank with small elevated stand.
gPer device.
hReplacing 8-litre urinals & 13 litre toilets, assume10 flushes/day.
Figure 6.5 Conducting a residential audit and checking shower flow rate. Source: Maddaus Water Management (1995).
Figure 6.6 Conducting a commercial water audit and checking toilet flush volume.Source: Maddaus Water Management (2005).
Figure 6.7 Recording data from a landscape water survey (catch can test) and entering data into a tablet computer to save time and increase accuracy.Source: Maddaus Water Management (2013).