Madison Engineer Reveals Social Experiment Intent of Alum Application


Proposal Designed to Test Public Acceptance of Treating Rainfall As If It Were Part of Sanitary Sewer System

Weakened Commitment to Promote Rainfall Infiltration Signals Policy Shift

The City of Madison Engineering Division has designed its alum application trial project at Marion Dunn (stormwater) Pond as a social experiment and intends to use it as a test of the public acceptance of treating rainfall the same way it handles sewage in the sanitary sewer system.

This revelation came at a public information meeting on March 3, 2013 at Edgewood College about the City of Madison Engineering Division’s proposed alum application to a storm water pond.    “This is more a social test”, said Greg Fries of the Engineering Division in describing the alum application trial.  Fries went on to explain, “Will Madison accept this (alum chemical application) as a long-term, large-scale strategy.   This is not a chemical test because we know the method works.”

The jaw-dropping admission came up when Alder Sue Ellingson, inquired about the project’s success criteria and asked, “What is the decision process.”  Mr. Fries responded that the trial would be judged on three criteria, “1) successful removal of phosphorous; 2) is it economical; and 3) not controversial.”

Mr. Fries (pronounced “freeze”) elaborated that the City needs to test the effectiveness, economics, and the social acceptability at a small-scale before it decides if larger, long-term applications can be proposed.

Nine people attended the public information meeting conducted by the City of Madison Engineering Division, sponsors of the alum application proposal.  The meeting was held to provide interested citizens with information about a proposed application of alum (aluminum sulfate) to the City’s storm water pond at Glenway and Monroe Streets in the UW-Madison Arboretum.

For more information on Madison’s alum application proposal click here to see a post about the upcoming public information meeting.  Click here to see public documents that provide background information about the alum application.

A Social Engineering Experiment

Those at the meeting did not miss the Engineering Division’s  intent found in Fries’ surprising statement.  One citizen in attendance summed up the social and cultural implications of the City’s alum application proposal by saying that,  “We are really planning to treat our rainfall as if it were a sanitary sewer by applying chemicals (aluminum sulfate) as we do to the sanitary sewer.   Maybe some people don’t want to do that and would rather spend time and money on improvements up in the watershed.”

Federal Requirement for Some Improvement

Fries explained that the City of Madison’s storm water discharges are regulated by the US Environmental Protection Agency (EPA), under the Clean Water Act.   The EPA has listed  the City’s waters “impaired” from too much phosphorous.  To be removed from the “impaired list” the City must write a plan of action that reduces phosphorous discharges.  According to Fries the City of Madison is required to reduce is phosphorous discharges to receiving water bodies (read lakes) by 16,000 pounds or “about a tri-axle dump truck’s worth of phosphorous.” said Fries.

The Test Site

The trial alum application is proposed for the Marion Dunn (storm water) Pond in the UW-Madison Arboretum, in part because there is, according to Fries, a large amount of background data available against which the results of the alum treatment can be judged.  Other possible factors that make the location desirable are that the pond is easily accessible from Monroe Street, that the Arboretum is viewed as malleable, and that the pond (1 acre) and its sub-watershed (230 acres) are relatively small.

The trial application of alum in Marion Dunn Pond is likely to begin in late 2013 and run through 2014 and perhaps into 2015.  After that, according to Fries, next steps are not certain.  The application to Marion Dunn Pond, Fries said,  is not likely to be permanent and a wholesale application to Lake Wingra is not planned.  A more likely next step would be to apply alum to some of the larger storm water ponds in the city, say the West Towne ponds, Fries speculated.

How Was a Treatment Method Chosen?

Although the US EPA, under the Clean Water Act, requires a reduction in phosphorous discharges, it does not specify how this is to be done.  The City may establish selection criteria and choose its preferred method (s).

The City of Madison is, understandably, considering cost-effectiveness among other variables.   For example, according to a slide Fries showed, the alum application is estimated to cost $100 per ton of phosphorous removed.  This is compared to:

Street sweeping        $1,800/ton of phosphorous removed

Rain gardens                  700/ton of phosphorous

Catch basins          600/ton of phosphorous

Detention ponds         350/ton of phosphorous

Fries dismissed rain gardens and catch basins as practical methods of reducing phosphorous because, “infiltration is a slow form of settling out particles.”

Fries repeatedly stated during the evening that achieving the EPA’s goal of 16,000 pound phosphorous reduction is almost impossible.  The City, he said, has about 220 storm water ponds and even if alum were applied to each of them the goal of 16,000 pound reduction could not be met.

Lake Wingra As Storm Water Detention Pond

In explaining the City’s planning for the alum project and the difficulty of meeting the EPA phosphorous reduction goals,  Fries  said that one big constraint was the fact that City has no storm water ponds between Midvale Boulevard and Stoughton Road, except for those in the UW-Madison Arboretum.  Fries was describing a large chunk of the urban area.  His statement prompted one person attending the meeting to ask, “isn’t Lake Wingra then really just a big storm water pond?”   Fries issued the surprising and shocking admission, that yes Lake Wingra is indeed a large storm water detention pond.

Will The Public Have More Opportunities for Input?

At the public info meeting Mr. Fries said his plan for the future was to send out project updates to those who signed up at the meeting plus the “450 or so people” who received notices about the first public meeting.   At the suggestion of Alder Ellingson, she and Fries will discuss how to ask for input as the project moves forward.

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About Steve Glass

The blogger is a restoration ecologist practicing and writing in the Midwestern United States.
This entry was posted in Alum application trial, Dudgeon-Monroe Neighborhood Association, Friends of Lake Wingra, Lake protection, Lake Wingra, Lake Wingra Watershed, Madison/Nakoma Road storm water pond, Marion Dunn Pond, Storm water, Stormwater best management practices and tagged , , , , , , , , , , . Bookmark the permalink.

4 Responses to Madison Engineer Reveals Social Experiment Intent of Alum Application

  1. Pingback: Forward Lookout | Zach Madden: Permissible Pollution

  2. Pingback: Update on Alum Application to Arboretum’s Marion Dunn Pond | WingraSprings

  3. Pingback: Madison Engineering Division Considering Additional Sites for Aluminum Sulfate Application | WingraSprings

  4. Pingback: Study Finds Aluminum Sulfate (Alum) Applications to Control Eutrophication of Lakes May Have Unintended and Untargeted Effects on Ecological Processes | WingraSprings

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