I've found that nearly all gravel tracking pads in Madison are out of compliance. They are almost universally too short,* and often they are so dirty as to be useless.
Sweeping is another way to reduce muddy tracks that's required at every site, but seldom enforced. Sweeping isn't very effective unless it's combined with water. Even then, the mud adheres to the pavement.
Nevertheless, we should enforce sweeping when the day is done, because it serves as a backup to the gravel pads. The gutters below sites should be thoroughly swept with hand brooms, since what's in the gutters goes directly to the lakes when it rains.
The muddy tracks go for miles, although the quantity drops off rapidly with distance. I believe the most effective kind of sweeping would be intensive sweeping, with water, close to the site. Of course, details have to be adapted to each site.
EPA study I found. Tiny particles of dust are hazardous to health, because they can penetrate deeply into lungs, carrying other toxins which adhere to them. When dirt lies on the roads, traffic moves over it, grinding it down to smaller particles, then wafting it into the air.
The study shows that construction site tracking of mud is a significant contributor to this load of dirt on our streets. Who would have thought that some of that mud on tires--would wind up in our lungs? First it's second-hand smoke. Now it's second-hand mud in our lungs!
Yesterday, I was downtown on State Street, photographing the Rawson and Tri-North sites on W. Gillman St. The whole area within several blocks of these sites was more dirty than usual, and it was easy to see dirt was escaping from the sites largely on tires--day in and day out.
These two companies, through their non-compliance--are not just being sloppy neighbors to nearby businesses. They are not just harming the lakes. They are also harming the health of the people who work and shop downtown.
Entrance to the Rawson and Tri-North sites from State St, 7/27.
A truck with 22 tires visits the Rawson site. You can see this gravel pad at the State St end is too short for this truck. 7/27
No pad at all, lots of traffic, dust and dirt everywhere--wasn't cleaned up at end of day.