LEED - Leadership in Energy and Environmental Design Water Efficiency Concepts Questions and Answers — Questions and Answers
Question 1: A project team is designing a new office building and wants to earn points for Outdoor Water Use Reduction. Which of the following strategies is required to be prioritized before accounting for alternative water sources or smart irrigation technology?
- Installing artificial turf on 50% of the landscaped area.
- Using only potable water from the municipal supply for all irrigation needs.
- Plant species selection and irrigation system efficiency. (Correct answer)
- Achieving a 10% reduction from the baseline peak watering month demand.
Correct answer: Plant species selection and irrigation system efficiency.
For the LEED WE credit Outdoor Water Use Reduction, reductions must first be achieved through the efficiency of the landscape itself—selecting appropriate plants and designing an efficient irrigation system. After these 'efficiency first' measures are accounted for using the EPA WaterSense Water Budget Tool, projects can then claim additional savings from alternative water sources and smart irrigation controllers.
Question 2: To comply with the Indoor Water Use Reduction prerequisite in LEED v4.1, which of the following fixture types, when newly installed, MUST be WaterSense labeled?
- Public lavatory faucets
- Tankless toilets
- Residential (tank-type) toilets (Correct answer)
- Kitchen faucets
Correct answer: Residential (tank-type) toilets
The LEED v4.1 prerequisite for Indoor Water Use Reduction mandates that all newly installed fixtures that are eligible for the WaterSense label must have it. As of the development of LEED v4, this specifically included tank-type toilets, water-using urinals, private lavatory faucets, and showerheads. Public faucets and tankless (flushometer) toilets were not required to be labeled, although using efficient versions is encouraged.
Question 3: A project's cooling tower operates with high 'cycles of concentration'. What is the primary water efficiency benefit of this strategy?
- It increases the rate of evaporation, cooling the water faster.
- It reduces the amount of makeup water needed by minimizing blowdown. (Correct answer)
- It eliminates the need for chemical treatment of the tower water.
- It increases the total dissolved solids (TDS) to improve heat transfer.
Correct answer: It reduces the amount of makeup water needed by minimizing blowdown.
Cycles of concentration (COC) refers to how many times the minerals in the makeup water are concentrated in the cooling tower water before being removed via blowdown. Higher cycles of concentration mean that water is being used more efficiently, as less water is being drained (blowdown) and therefore less fresh makeup water is required to replace it.
Question 4: A project team is calculating the Full-Time Equivalent (FTE) occupants for the indoor water use calculations. A part-time employee works 20 hours per week in a standard 40-hour work week. What is the FTE value for this employee?
- 1.0
- 0.75
- 0.5 (Correct answer)
- 0.25
Correct answer: 0.5
A Full-Time Equivalent (FTE) of 1.0 represents a person who works a standard 40-hour week. The FTE value is calculated based on the hours worked. For a part-time employee working 20 hours, the calculation is 20 hours / 40 hours = 0.5 FTE.
Question 5: Which of the following is an example of 'process water' in the context of the LEED Water Efficiency category?
- Water used for landscape irrigation.
- Water used in kitchen dishwashers and sinks.
- Water used for flushing toilets and urinals.
- Water used in a building's cooling towers and boilers. (Correct answer)
Correct answer: Water used in a building's cooling towers and boilers.
Process water is water used for industrial processes and building systems, such as cooling towers, boilers, and humidification systems, rather than for plumbing fixtures (indoor water) or irrigation (outdoor water).
Question 6: To meet the prerequisite for Indoor Water Use Reduction, a project must demonstrate an aggregate reduction in water consumption from a calculated baseline. What is the minimum percentage reduction required?
- 10%
- 20% (Correct answer)
- 30%
- 40%
Correct answer: 20%
The LEED prerequisite for Indoor Water Use Reduction requires projects to reduce the aggregate water consumption from fixtures and fittings by at least 20% from the baseline case. Achieving higher percentage reductions can earn points under the associated credit.
A project team is designing a new office building and wants to earn points for Outdoor Water Use Reduction.
Which of the following strategies is required to be prioritized before accounting for alternative water sources or smart irrigation technology?