Page 291 - WaterSense at Work

WaterSense at Work: Best Management Practices for Commercial and Institutional Facilities
A.6 Laboratory Eliminates
Single-Pass Cooling
Case Study Highlights
Facility type:
Duluth, Minnesota
Number of occupants:
Building size:
gross square feet
Project overview:
Between 1993 and 2003, the U.S. Environmental Protection
Agency (EPA) Mid-Continent Ecology Division Laboratory (MED) replaced the use
of potable water for single-pass cooling of building and process equipment with
non-potable water from Lake Superior. In addition, MED later replaced a water-
cooled ice machine with an ENERGY STAR® qualified, air-cooled model.
Water savings:
By replacing most single-pass cooling of building and process
equipment, MED reduced the building’s potable water use by 90 percent, or
approximately 7.5 million gallons per year. In addition, the replacement of the
water-cooled ice machine saves MED 283,000 gallons of water per year.
Cost savings:
Approximately $75,000 in water and sewer costs per year from
replacing potable-water single-pass cooling, and $2,800 in water and sewer costs
per year from replacing the ice machine
EPA’s Mid-Continent Ecology Division Laboratory
Project Summary
EPA’s Mid-Continent Ecology Division Laboratory (MED) is located in Duluth,
Minnesota. MED consists of 10 buildings with 88,577 gross square feet of
conditioned space. The laboratory houses both
biology and chemistry laboratories and a large
aquatic culture unit. Significant features include
laboratory rooms, seven constant temperature
rooms, administrative offices, and a library. MED
has used water from Lake Superior to support its
ecotoxicology research since the laboratory opened
in 1970.
Since 1993, MED has been implementing a
comprehensive program to reduce potable water
use. In the late 1980s and early 1990s, MED was
using up to 10 million gallons of potable water per
year, mostly for single-pass cooling of the building
or research equipment. Taking advantage of its