855773644-LEED-v5-BD-C-Reference-Guide-Launch-Edition - Page 198
Extracted Content
Option 4. Outdoor Water Use (1–3 points)
PATH 1. NO IRRIGATION (3 POINTS)
Show that the landscape does not require a permanent irrigation system beyond a maximum two-year establishment period.
OR
PATH 2. EFFICIENT IRRIGATION (1–3 POINTS)
Reduce the project’s theoretical irrigation requirement (TIR) by at least 50% from the calculated baseline. Points are awarded according to Table 17.
Table 17. Points for reducing outdoor water use
| Percentage reduction | Points |
|---|---|
| 50% | 1 |
| 75% | 2 |
| 100% | 3 |
AND/OR
Option 5. Optimize Process Water Use (1–3 points)
PATH 1. LIMIT COOLING TOWER CYCLES (1–3 POINTS)
For cooling towers and evaporative condensers, conduct a one-time potable water analysis, measuring at least the five control parameters listed in Table 18.
Table 18. Maximum concentrations for parameters in condenser water
| Parameter | Maximum level |
|---|---|
| Ca (as CaCO3) | 600 ppm* |
| Total alkalinity | 500 ppm |
| SiO2 | 150 ppm |
| Cl– | 300 ppm |
| Conductivity | 3300 μS/cm** |
*ppm = parts per million
**µS/cm = micro siemens per centimeter
Calculate the maximum number of cooling tower cycles by dividing the maximum allowed concentration level of each parameter by the actual concentration level of each parameter found in the potable makeup water analysis. Limit cooling tower cycles to avoid exceeding maximum values for any of these parameters.
U.S. Green Building Council LEED v5 Reference Guide for Building Design and Construction, April 2025 Launch Edition 188