USGBC Updated LEED-AP-BD+C Exam Questions and Answers by zackary

Achieving a minimum of 10 cooling tower cycles by increasing the level of make-up water treatment is the way to obtain the maximum number of points for Water Efficiency Credit, Cooling Tower Water Use. This credit aims to conserve water used for cooling tower equipment by encouraging the use of non-potable water sources and increasing the cycles of concentration1. The cycles of concentration are the ratio of the concentration of dissolved solids in the blowdown water to the concentration of dissolved solids in the make-up water2. Increasing the cycles of concentration reduces the amount of make-up water and blowdown water, and thus saves water and energy2. The credit has two options: Option 1. Non-potable Water Source (1 point) and Option 2. Cooling Tower Water Use (2 points). Option 1 requires using at least 50% non-potable water for cooling tower make-up water1. Option 2 requires achieving a minimum number of cooling tower cycles based on the quality of the make-up water, as specified in Table 1 of the credit requirements1. The maximum number of cycles is 10, which can be achieved by increasing the level of make-up water treatment to meet the criteria for conductivity, silica, and alkalinity1. Therefore, Option 2 is the way to obtain the maximum number of points for this credit. References:

Credit: Cooling tower water use | U.S. Green Building Council

Cooling Tower Evaporation Credits | WaterSignal

Private lavatory faucets are eligible for a WaterSense label, provided they meet EPA’s specifications for water efficiency and performance, and are backed by independent, third-party certification. Tankless toilets, waterless urinals, and public lavatory faucets are not eligible for a WaterSense label because they are not included in the product categories that WaterSense covers. WaterSense currently labels products in the following categories: tank-type toilets, water-using urinals, private lavatory faucets, showerheads, irrigation controllers, spray sprinkler bodies, and pre-rinse spray valves. References:

WaterSense Products | US EPA1

The WaterSense Label | US EPA2

Water Sense Labeling | LEEDuser3

Labeled Faucet Questions | WaterSense | US EPA4

What is the WaterSense Label and How Does it Apply?5

Including the material requirements in the project specifications (D) ensures that all project team members are aware of and prioritize materials compliant with the Materials and Resources (MR) Credit: Building Product Disclosure and Optimization. Clearly defined specifications communicate the importance of sustainability criteria, such as environmental product declarations and sourcing. Whole-building life-cycle analysis (C) is part of separate LEED credits and doesn’t directly influence material prioritization by the team.