Amherst College
OP-3: Water Use

3.1 Potable water use per person

An institution earns 2 points when its annual potable water use per full-time equivalent of students and employees is less than or equal to a benchmark for its peer group. Incremental points are available based on the institution’s performance between a maximum threshold and the benchmark, and earned as outlined in the Technical Manual.

Measurement

Report the most recent annual (fiscal or calendar year) data available from within the previous three years. Use the most recent single year for which data is available or an average from throughout the period.

Report population figures from the same time period as that from which water use data are drawn, e.g., an average from throughout the performance period or a snapshot at a single representative point.

Include all potable water supplied to or by the institution for its use during the performance period. If data on specific water volumes are not available, an institution may work with its facilities department and/or water utility to estimate figures, e.g., based on billing totals. Water that is recycled on-site, e.g., in closed loop systems, may be counted toward water use once (e.g., at initial withdrawal or procurement from a supplier) and excluded at subsequent uses.

3.2 Potable water use per square meter

An institution earns 2 points when its annual potable water use per gross square meter of floor area is less than or equal to a benchmark for its peer group. Incremental points are available based on the institution’s performance between a maximum threshold and the benchmark and earned as outlined in the Technical Manual.

Measurement

Report gross floor area of building space from the same time period as that from which water use data are drawn, e.g., an average from throughout the performance period or a snapshot at a single representative point.

3.3 Systems for water recovery and return

An institution earns 1 point when it has systems on-site to A) harvest rainwater, B) recover water for reuse, and C) collect and return water to surface water or groundwater through on-site green infrastructure (GI). Partial points are available and earned as outlined in the Technical Manual.

Measurement

Report on current practices and existing infrastructure.

3.4 Ratio of water recovered/returned to total water withdrawal 

An institution earns the maximum points available for this indicator when the estimated annual volume of water recovered and/or returned on-site is equal to 100 percent or more of its total water withdrawal. Incremental points are available and earned as outlined in the Technical Manual.

Measurement

Report on current practices and the most recent annual (fiscal or calendar year) data available from within the previous three years.

On-site water recovery and return may be estimated based on measured performance (e.g., metered use or changes in water storage), the design specifications of the systems used, and/or modeling tools such as those listed by the US Environmental Protection Agency (EPA).

Applicable to all institutions.