Overall Rating	Gold
Overall Score	75.90
Liaison	Deborah Steinberg
Submission Date	Dec. 6, 2021

STARS v2.2

Carnegie Mellon University
OP-21: Water Use

Status

Score

Responsible Party

4.00 / 4.00

Martin Altschul
Director of Strategic Facilities Initiatives of FMCS
Facilities Management Services

"---" indicates that no data was submitted for this field

Level of ”Physical Risk Quantity” for the institution’s main campus as indicated by the World Resources Institute Aqueduct Water Risk Atlas:

Low

Part 1. Reduction in potable water use per person

Total water withdrawal (potable and non-potable combined):

	Performance Year	Baseline Year
Total water withdrawal	80,666,000 Gallons	123,907,000 Gallons

Potable water use:

	Performance Year	Baseline Year
Potable water use	80,666,000 Gallons	123,907,000 Gallons

Start and end dates of the performance year and baseline year (or three-year periods):

	Start Date	End Date
Performance Period	July 1, 2020	June 30, 2021
Baseline Period	July 1, 2004	June 30, 2005

If end date of the baseline year/period is 2004 or earlier, provide:

A brief description of when and why the water use baseline was adopted:

FY 2005 was selected to be consistent with earlier STARS reporting Baseline year. However, the building gross floor area was re-adjusted using performance year methodology. In 2018 CMU revised its approach to calculating square footage. Historically, CMU included in its square footage rented floor area for which we paid utility bills. We also used to calculate square footage using the the area the federal government calls “Net Usable Area." In an effort to standardize our approach to square footage reporting for various campus reports, we now include only the floor area of the buildings we own. We also have shifted to a gross square footage approach, (similar for USGBC and for AASHE).

Figures needed to determine "Weighted Campus Users":

	Performance Year	Baseline Year
Number of students resident on-site	3,924	3,744
Number of employees resident on-site	0	0
Number of other individuals resident on-site	0	0
Total full-time equivalent student enrollment	12,193.80	8,894
Full-time equivalent of employees	5,192.10	4,032
Full-time equivalent of students enrolled exclusively in distance education	323	106.50
Weighted campus users	13,778.18	10,550.63

Potable water use per weighted campus user:

	Performance Year	Baseline Year
Potable water use per weighted campus user	5,854.62 Gallons	11,744.04 Gallons

Percentage reduction in potable water use per weighted campus user from baseline:

50.15

Part 2. Reduction in potable water use per unit of floor area

Gross floor area of building space:

	Performance Year	Baseline Year
Gross floor area	6,759,150.76 Gross square feet	5,391,617 Gross square feet

Potable water use per unit of floor area:

	Performance Year	Baseline Year
Potable water use per unit of floor area	11.93 Gallons per square foot	22.98 Gallons per square foot

Percentage reduction in potable water use per unit of floor area from baseline:

48.07

Part 3. Reduction in total water withdrawal per unit of vegetated grounds

Area of vegetated grounds:

	Performance Year	Baseline Year
Vegetated grounds	157.20 Acres	120 Acres

Total water withdrawal per unit of vegetated grounds:

	Performance Year	Baseline Year
Total water withdrawal per unit of vegetated grounds	513,142.49 Gallons per acre	1,032,558.33 Gallons per acre

Percentage reduction in total water withdrawal per unit of vegetated grounds from baseline:

50.30

Optional Fields

A brief description of the institution's water-related behavior change initiatives:

To date, the university has focused on widespread installation of presence-sensing devices, flow controllers, and low-flow fixtures and fittings within buildings to reduce water consumption. As an integrated environmental strategy, we have also replaced many standard water fountains with water-refill stations in order to reduce the impact of bottled water use. We have recently updated controls on irrigations systems for our main quadrangle, resulting in irrigation consumption reduction by 37%.

A brief description of the institution's water recovery and reuse initiatives:

In 2016, CMU installed 275,000 gallons of rainwater collection and storage capacity below grade in the center of campus. Downspouts from surrounding buildings (Baker, Porter & Doherty Halls) feed the storage tanks. Collected water can be routed to the chiller plant for cooling tower make-up and can also serve our limited irrigation needs.

Our Gates Hillman Computer Science Complex has a 10,000-gallon rainwater collection tank within the building. That water is used for flushing building toilets. Vegetated swales and tree plantings on hillside where that building is situated slow water flow.

The Collaborative Innovation Center (CIC) has a 6,000-gallon rainwater storage tank to supply toilets & irrigation.

Purnell Center for the Arts has a 10,000-gallon underground baffled stormwater cistern to slow water flow.

The Tepper Quad collects rain water from the building roof and grounds to a 150,000 gallon cistern located in the building for use as the water for toilet flushing.

In addition, Carnegie Mellon has over a dozen buildings with green roofs, (living or vegetated roofs), and several rain gardens. Because of abundant rainfall and old stormwater infrastructure in Pittsburgh, campus design and facilities personnel make considerable effort to preserve permeable area despite the increase in new buildings on campus.

A brief description of the institution's initiatives to replace plumbing fixtures, fittings, appliances, equipment, and systems with water-efficient alternatives:

See above. Low and ultra-low urinals are used for all new construction and renovations. Other high efficiency fixtures such as touchless faucets are also used.

Website URL where information about the institution’s water conservation and efficiency efforts is available:

https://www.cmu.edu/environment/energy-water/stormwater.html

Additional documentation to support the submission:

---

Data source(s) and notes about the submission:

Baseline year building gross floor area was re-adjusted using performance year methodology.

Great efforts have been taken to reduce campus energy uses since our baseline year of 2005. Campus-wide initiatives described above have allowed us to greatly reduce potable energy use.