Sources of pollution:

1.  A snow pile, created by moving snow from the University of Wisconsin parking lots to the southeast edge of the Class of 1918 Marsh, brings trash, salt, and possibly heavy metals and oil.

2.  Much of the water from the increasingly built-up area around the UW-Hospital complex flows into the marsh after flowing through a settlement pond. In 1975, when only the original UW-Hospital and Clinics buildings were built, Pat McGuire estimated that 63 to 87 percent of the solids were trapped by the settling pond (McGuire, 1975). Despite the many additional buildings built in the hospital area and the large increase in impermeable pavement, this original settling pond has only been slightly enlarged and no new settling ponds have been built.

3.  Runoff including fertilizers and pesticides from the surrounding upland residential areas including parts of Shorewood Hills and Eagle Heights Apartments.

4.  Runoff including fertilizers and pesticides from the playing fields.
 

Potential (partial) solutions:

Goals (Gibson, et. al., 1998):

1.  Reduce turbidity to allow light to penetrate and aid plant growth.

2.  Reduce the fertility (eutrophic levels) by reducing phosphorus and nitrogen inflow to minimize the growth of undesirable algae and waterweeds. 

Standard solutions:

1.  Move the snow pile. (Currently, there is no sufficiently close alternative site.)

2.  Monitor water leaving the settling pond to ensure that most of the solid material still settles out.  Make sure it is large enough to hold storm water long enough so that solid materials settle out.   Make changes or build additional settlement ponds if the pond fails to serve its function.  (Currently, all other possible settlement pond sites are already dedicated to other uses.)

3.  Sweep streets and discourage excessive pesticide and fertilizer use in residential areas.  Try not to increase the amount of impermeable surface.

4.  Create a buffer zone beyond the trail circling the marsh in the playing fields where pesticide and fertilizer will not be used.  Mow this zone infrequently  so that the grass is taller than the surrounding fields. 

Additional Possible Solutions:

1.  Pump eutrophic water out of Marsh onto playing fields.  Replace water with less fertilized University Bay water.  This will fertilize playing fields without extra chemicals and make the Marsh less fertile (Zimmerman, 1972). 

2.  Dredge the marsh to remove excess solids and prevent it from filling up.

3.  Build siltation/filtration ponds planted with marsh plants between the Marsh and the path to hold water so that solids will settle out and nutrients will be absorbed before they arrive in the Marsh (Gibson, et. al., 1998).

Sources:

Gibson, S., B. Krause, C. Leinss. R. Michels, T. Reese, and L. Zelewski.  1998.  Class of  1918 Marsh:  Restoration and Management Plan.  University of Wisconsin – Madison. Group Project.

McGuire, P.  1975.  Class of 1918 Marsh Management Plan.  The University Bay Project. University of Wisconsin – Madison.  MS thesis.

Zimmerman, J.  1972.  Class of 1918 Marsh Signs.  University of Wisconsin Arboretum.  University of Wisconsin  Foundation.

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