Water Efficiency

Water is generally seen as an endless, plentiful, renewable resource. Unfortunately, this viewpoint is misconceived. In reality, only 2.5 percent of water found on earth is fresh; and two-thirds of this freshwater supply is frozen in earth’s glacial ice caps and is inaccessible to humans. The renewable, usable, freshwater supply is actually only 0.008 percent of the total freshwater supply found on earth. As population size increased by 2.7 billion people from 1950 to 1990, water consumption levels also increased dramatically, placing strain upon the freshwater resources found on earth.[1]

According to David Chris, author of The Natural House, “Decades of waste and exploitation, coupled with unsustainable population growth have brought water shortages to almost every country on the planet.”[2] These issues ultimately affect everything and everyone, including human populations and potable water supplies found in the United States and more specifically, Minnesota.

The Mississippi River is an abundant natural resource which travels through several states before reaching the Gulf of Mexico. The source of the river is found within Itasca State Park, in northern Minnesota. This river ecosystem is impacted immediately as the water leaves the river source. Before the river leaves Minnesota, it is polluted from a variety of point and non-point sources. Point sources include direct sources of pollution, such as waste from industrial buildings or power plants. Non-point sources, which have the most dramatic affect on the river ecosystem, include urban run-off from lawns and sand and salt from roads and agricultural run-off .[iii] Pollutants carried in these run-offs include phosphates found in industrial detergents, nitrogen and phosphorus from lawn fertilizers, petroleum products, sediment, trash, and storm water. Many of these materials contain salts, sediment, and other pollutants that alter water ecosystems. Ultimately, this polluted water ends up in aquifers or other potable water sources, and the water has to be heavily treated before it is safe for human consumption. Alternative building strategies and landscaping techniques can be adopted in order to reduce the negative environmental impacts of run-off.

The state of Minnesota plays a unique role in the region’s and nation’s maintenance of an adequate and safe freshwater supply. The state itself is composed of eight major watershed basins. Within these regions there are approximately 5,000 minor watersheds and 80 major watersheds. [iv] This is attributed to the geology of Minnesota and the abundance of small kettle lakes located throughout the state.[v] In addition to these surface watersheds, the state also contains ground water watersheds, otherwise known as groundwater aquifers. The water found in these aquifers supplies Minnesota with seventy-five percent of its potable or drinkable water. Additionally, ninety percent of water used for irrigation also comes from these potable freshwater sources.[vi] The freshwater supply is more abundant in Minnesota compared to more arid regions of the United States such as Arizona, Nevada, California, and other states found in the southwest. In order to both protect and preserve our precious freshwater resources used for drinking, bathing, and irrigation, alternative building strategies relating to water consumption must be examined and adopted.

CSB and SJU are located within the Upper Mississippi Watershed. While the eight watersheds are close in proximity to one another, they vary slightly. According to data compiled by the Minnesota Department of Natural Resources as well as the Minnesota Pollution Control Agency, the water aquifers in Saint Joseph are more susceptible to contamination or pollution than the aquifers found in Collegeville. CSB is located in a high pollution sensitivity zone, while SJU is located in a moderately high zone.[vii] In order to reduce this sensitivity and be responsible stewards to the land, the institutions have the opportunity to adopt construction , landscaping , or renovation strategies which prevent run-off pollutants from entering the waterways and groundwater supplies.

According to the United States Geological Survey, SJU is located on the minor Platte-Spunk major watershed within the Upper Mississippi Watershed Basin, with an area of 5,030 acres that drain through the university land.[viii] Additionally, SJU treats all of its waste water, also known as black water, on-site and all water is contained and treated without utilizing municipal resources. The effluent produced at CSB is not treated on-site, but instead utilizes municipal treatment facilities. While the practice of treating water on site at SJU is a responsible one, there are still waste water treatment issues which need further consideration.

Treatment of wastewater is an extremely important issue associated with water efficiency and water consumption. In 2001, the Minnesota Pollution Control Agency estimated the state would need to spend 2.28 billion dollars over the next five years on sewage treatment projects.[ix] SJU is currently involved in a renovation of the Waste Water Sewage Treatment Plant. The plant was not able to accept the increased effluent load that resulted from the construction of the Placid and Mauer apartment buildings. The plant needed to be expanded in order to accommodate the additional sewage treatment need. This expensive renovation may have been avoided if the institution had chosen to implement water efficient alternatives campus-wide to reduce the effluent that needed treatment.

In a study conducted by the Saint John’s Arboretum the water quality of all seven bodies of water found on the watershed was assessed based upon phosphorus load (µg/L), chlorophyll content (µg/L), and water clarity (m).[x] The water bodies were then graded based upon a system developed by the Metropolitan Council staff which tested for water quality on lakes in the Twin Cities area. East Gemini Lake, which directly receives treated waste water, received the lowest grade. Lakes were graded on an A-F scale, based upon phosphorus levels, chlorophyll levels, and water clarity. Phosphorus levels were significantly higher in East Gemini Lake compared to the other lakes on campus which do not come in direct contact with treated water emitted from the plant. Phosphorus loading to East Gemini Lake from October 2001 through September 2002 was estimated to equal 2,369 pounds. Ninety percent of this total is attributed to the waste water treatment plant. The remaining ten percent is attributed to internal loading; the lake has become so concentrated in phosphorus that the lake sediment itself is a source of phosphorus loading.[xi]

The East Gemini Lake System also impacts the newly rehabilitated wetland system. The wetland systems are extremely important ecosystems as both a habitat for plant and animal life and as a system retaining water quality. Significant nutrient loading is detrimental to these ecosystems, decreasing habitat diversity and water quality.[xii] There are several steps that can be taken both inside and outside of a building to reduce potable water consumption. For example, the use of natural vegetation for landscaping purposes helps to conserve and protect the potable water supply by reducing polluted run-off from entering freshwater aquifers. Both institutions have the ability to make a change in consumption patterns by establishing a commitment to better practice. Green building construction must consider water efficiency and water use issues in order to preserve and protect groundwater supply.

We have adopted the following CSB and SJU specific goals addressing water efficiency in order to address freshwater resource depletion and to be increasingly responsible stewards to our environment . CSB and SJU are located in a freshwater abundant zone, and thus have a responsibility to set an example on a local , regional and national scale regarding water efficiency and freshwater conservation.


[1] Postel, Sandra. “Dividing the Waters” MIT’s Technology Review.100 (1997): 55-56.

[2] Chiras, Daniel D. The Natural House: A Complete Guide to Healthy, Energy Efficient, Environmental Homes. New York: Chelsea Green Publishing, 2000.

[iii]Hendel, Erin and Alyssa Hawkins. “Life in a Watershed.” The Twin Cities Green Guide. Minneapolis: The Twin Cities Green Guide, 2001.

[iv] Minnesota Department of Natural Resources. 2004. Water. <http://www.dnr.state.mn.us/water/index.html> (14 April 2004).

[v] Minnesota Department of Natural Resources. 2004. Water. <http://www.dnr.state.mn.us/water/index.html>. (14 April 2004).

[vi] Minnesota Department of Natural Resources. 2004. Water. <http://www.dnr.state.mn.us/water/index.html. (14 April 2004).

[vii] Thurnblad, Timothy. 2003. Minnesota Ground Water Information Resources: A Guide to Minnesota Ground Water Information-Emphasizing Internet Available Resources. Minnesota: Minnesota Pollution Control Agency.( 14 April 2003).< http://www.geo.umn.edu/mgs/gwig/gwig.pdf.>(13 April 2003).

[ix] Minnesota Pollution Control Agency and the Department of Trade and Economic Development. 2002. Future Costs of Wastewater Treatment: A Report to the House Environment and Natural Resources Finance Committee and the Senate Environment and Agriculture Budget Division. <http://www.pca.state.mn.us/hot/legislature/reports/2002/futurecostsww-02.pdf.> (14 April 2004).

[x] SJU : Watershed Characterization. pp.11-12.

[xi] SJU : Watershed Characterization. pp. 15.

[xii] SJU : Watershed Characterization. pp. 19.