Steve Vanko and I believe these muddy plumes were caused by construction of the Wingra Clinic by the Ghidorzi Companies. This construction site is only 1-3 blocks directly upstream on the stormsewer system. In all cases, we have photographs of the construction site proving deficiencies in erosion control, and showing muddy water exiting the construction site.
#1. July 18, 2012. 1.43 inches
There were two big storms, one during early morning, and the other in late afternoon. A large amount of plastic insulation was flushed to the bay.
This photo from the morning, shows the 10-15% that remained, after a city Vactor truck tried to suck up the debris.
At about 8:19 pm, the blue storm pipe across the street from Steve's house was dumping mud into the bay. More photos.
#2. October 14, 2012, 1.74 inches (and .86 inches the preceding day).
About noon, Steve returned from a weekend trip, and noticed a lot of muddy runoff coming into the bay.
#3. October 16, 2012. Pumping water from construction site.
Photo shows the muddy plume spreading north along the shore. More photos.
#4. October 17, 2012--a storm from mid-afternoon to evening of .62 inches.
Some of this mud may have come from large amounts of dirt spilled on Park St--which we observed on Oct. 16. More photos.
#5. October 22, 2012, .51 inches, starting early afternoon
November 11, 2012, with rainfall of .73 inches.
This was the first time that the discharge in front of Steve's house wasn't highly muddy. It was cloudy (turbid), but not bright brown, as before. More.
A number of improvements back at the construction site have greatly reduced the problem--although sediment in the gutters there shows it's not entirely fixed.
It has taken 115 days and many complaints--from the first massive escape of Styrofoam--to partially fix this problem of muddy plumes in the bay.
There were many other problems from this site--dust, blowing debris, dirt on the streets, and in the gutter. Much of this debris will eventually reach the lakes, although it may take longer to get there, and not be as visible as the muddy plumes.
#6. January 29, 2013. Rainfall all day of 1.84 inches.
The pollution continues, despite winter. Large piles of soil have been moved about the site.
I checked the site twice--once in early morning, and the other in the afternoon. On both occasions, muddy water was seen leaving the north end of the site, both onto Fish Hatchery Rd, and onto Park St, then running down the gutters and into the storm sewers.
At both times, muddy water was entering the Bay, creating a muddy plume. More photos.