LEED GA Practice Questions: Water Efficiency

Water Efficiency is worth 10 of the 100 questions on the LEED Green Associate exam. It covers outdoor water use, indoor water use, and water performance management. More than any other domain it rewards knowing precise definitions, which makes it the fastest domain to improve in.

If you are short of study time and want the best return, this is where to spend it. Four or five terms — potable, non-potable, graywater, blackwater, process water — account for a large share of the questions, and they are learnable in an evening.

What this domain covers

The exam specification splits Water Efficiency into three areas: outdoor water use, including planting choice, irrigation control and alternative sources; indoor water use, including low-flow and waterless fixtures, efficient appliances and process water; and water performance management, including metering, submetering, leak detection, cooling towers and water quality.

12 Water Efficiency practice questions

Fill in your details, take all 12 questions, and submit once — we'll grade it and email you the score plus a full explanation for every question.

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Welcome to the LEED Green Associate practice quiz. Enter your details, then work through all 12 questions — we'll email you the score and a full explanation for every question.

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1.What is potable water?

A. Any water supplied by the municipal mains

B. Water clean enough for drinking and human contact

C. Water that has been treated on site

D. Water used for irrigation

None

2.Which of these is graywater?

A. Water from toilets and urinals

B. Wastewater from sinks, baths, showers and clothes washers

C. Rainwater collected from a roof

D. Condensate from an air-conditioning system

None

3.A project wants to cut irrigation demand. What is the most effective first move?

A. Choose native and adapted planting suited to the local climate

B. Install a rainwater harvesting tank

C. Install a drip irrigation system

D. Recycle graywater for irrigation

None

4.What is xeriscaping?

A. Removing all planting and replacing it with hard surfacing

B. Irrigating only at night to reduce evaporation

C. Landscaping with drought-tolerant native and adapted species and efficient design to minimise irrigation

D. Using artificial turf instead of grass

None

5.What is the difference between a flush rate and a flow rate?

A. Flush rate applies to taps, flow rate to toilets

B. Flush rate is for potable water, flow rate for non-potable

C. They measure the same thing in different units

D. Flush rate is measured per use, flow rate per minute

None

6.What is process water?

A. Water used by occupants for washing and drinking

B. Water that has been processed for reuse

C. Water used by building systems and equipment, such as cooling towers, boilers and commercial kitchens

D. Water used during construction

None

7.Why do cooling towers consume water?

A. They use water to clean the condenser coils

B. They store chilled water for peak periods

C. They use water as a refrigerant

D. They reject heat by evaporation, so water is continuously lost and must be made up

None

8.Three of these support water performance management. Which one reduces demand instead?

A. Submetering major water end uses

B. Specifying waterless urinals

C. Building a water-end-use profile

D. Leak detection monitoring

None

9.What does a water-end-use profile tell a facility team?

A. The total volume of water the building consumed last year

B. The quality of the incoming water supply

C. Which uses account for the most significant shares of the building's water consumption

D. Whether the building meets local plumbing code

None

10.A hotel installs submeters on its laundry, its kitchen and its cooling plant. What is the main benefit?

A. It reveals which systems consume most and makes abnormal use visible quickly

B. It reduces water consumption automatically

C. It satisfies a Minimum Program Requirement

D. It qualifies the water as non-potable

None

11.Why is saving hot water particularly valuable?

A. Hot water is more expensive to purchase than cold

B. It saves water and the energy and carbon used to heat it

C. Hot water is always potable

D. It reduces the load on the cooling system

None

12.A project proposes to reuse treated graywater for toilet flushing. What is the most important practical constraint?

A. Local codes and regulations govern what non-potable water may be used for, and they vary

B. Graywater cannot legally be reused anywhere

C. Graywater must first be made potable

D. Only rainwater may be used for flushing

None

Time's up

Where candidates lose marks in this domain

• Confusing graywater with blackwater. Toilets are blackwater. Everything else on the clean side is graywater.
• Reversing flush and flow. Flush per use, flow per minute.
• Thinking metering saves water. It creates information. People save water.
• Forgetting process water. Candidates think of taps and toilets and miss the cooling tower entirely.
• Reaching for alternative sources before reducing demand. Efficiency comes first here too.

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