University snow dump could threaten Madison's aquifer

The University's snow dump is located close to an old dump.


The huge pile of melting snow on University property, near Picnic Point, is a potential threat to Madison's aquifer and water supply.

A portion of the 500-750 tons of salt that the University spreads each winter on roads and parking lots ends up in this pile.  This unrefined road salt is contaminated with trace heavy metals and ferrocyanide.

Update 3/29/11: Samples taken in former years by Madison's Health Department show high levels of salt flowing into Lake Mendota from this site.

In addition, in the 1960s, the University Farms used to dump manure here from the nearby barn.  And, the Ecology Students' Association caught the University Power Plant dumping many truckloads of fly ash here.  Fly ash also contains toxic heavy metals. The students found the University didn't have a permit from the DNR, so the UW was forced to stop.

A pump and a dump

Nevertheless, as the current pile of snow melts and floods the ground with water, it may push that water through the previous deposits of manure and fly ash, pumping contaminants deeper into the aquifer.

The pile of snow is a dump for trash, salt, and heavy metals--but it's also a source for water leaching into the ground.  Most dumps are supposed to be protected by a clay liner that prevents the leachate from reaching the aquifer.

But this dump isn't so protected.  The DNR has required the University to build a berm and some puny stone spillways around it, but these minimal safeguards have been breached by today's pile.  Reaching three stories hight, the pile exceeds the capacity of these protections many fold.   Water that doesn't leach into the ground or flow to the Class of 1918 wetland is pumped right to Lake Mendota. 

Incredible.  Pumping the leachate from a dump into the lake!

Growing contamination of our aquifer

Madison has two aquifers, a shallow and a deep one, separated in most places by a layer of impervious shale. Madison gets most of it's drinking water from the deep aquifer.  But the shale which protects the deep aquifer is absent in some places, especially around the lakes.  So perhaps there is no shale to protect the deep aquifer under the pile of snow.

One of Madison's most active wells, #15 on the east side, is showing increasing levels of salt, proving that salt is a concern for our drinking supply.  Since water moves very slowly through the ground, it takes many decades for groundwater problems to show up.  But once contaminated, it takes even longer to clear.

Out at the Odana Golf Course, MG&E is pumping salty water into the ground.  That project is part of a plan to compensate for the millions of gallons of cooling water that the West Campus Cogeneration Facility withdraws from Lake Mendota.   Yet that project, also, is contaminating Madison's aquifer.  The levels of salt in test wells near the Odana pumping site have already reached actionable levels.  And, MG&E's 5-year permit to pump has expired.*

The University (and MG&E) is playing fast and loose with Madison's water supply.  You can't have a healthy economy, without ample supplies of clean water.  It costs millions to drill and equip new wells for the City.

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Why doesn't the CoGen Facility collect water from the melting snow dump, clean it, and use it instead of water from Lake Mendota?  Sure, it would be expensive to purify that filthy water from the snow pile, but shouldn't the University be cleaning up after itself, rather than using the lake or groundwater to do their cleaning?

*  I'll be writing more about the Odana CoGen pumping project soon.

More photos and details in this previous story.
Salt problems in Wisconsin.
Salt problems in Minneapolis.
History and management of the Class of 1918 Marsh.