What Mars says about the Earth

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Mars has much to teach us about running a planet.  What a lovely home we have--with its deep blue sky, sparkling sun, mostly clear air, and clean green landscapes!

In contrast, the dust of Mars is everywhere--turning the sky red, casting the landscape into a reddish gloom.  Dust would fill your vehicle, your spacesuit, and your habitat.  We could live there, but we'd have to manufacture every last resource--even the air to breathe.

Dust to the horizon on Mars.  NASA.

"Chip sealing" of streets generates complaints

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On Madison's west side, City Engineering is in the process of "chip sealing."  This is a maintenance program that extends the life of pavement which is still in good condition.

Steps in the process we observed

• Workers clean out cracks between pavement and curb, and place filters on the stormsewer inlets.
• Asphalt is laid down to seal the cracks in pavement.
• Bottom slag is liberally applied to cover the asphalt, provide traction, and surface protecton.
• A pickup truck drags a rake to make sure the slag is evenly distributed.
• The excess slag is removed in several passes by sweepers.

Complaints are coming from the use of a black, sandy material called "bottom slag."

The loose slag is creating a nuisance for pedestrians and a minor hazard for cyclists.  It's also creating a lot of dust, either when vehicles pass by, or when the contractor drags a rake over the slag--as they are doing in multiple passes (below).

The City claims chip sealing will save millions of dollars over the years.  They also claim that it's environmentally friendly, because it saves natural resources.  In other words, when slag is used on streets, sand doesn't have to be mined.  And, keeping the slag--a waste product--out of landfills saves landfill space.  I don't doubt these assertions.  I just wonder if all the long-term costs of using slag have been accounted for in the "cost-benefit" calculations.

Not sustainable--the construction industry in Madison

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Recently, the American Lung Association named Madison as one of the most polluted cities in the nation from particle pollution--dust and smoke.

There's construction all over downtown Madison.  Dust is being tracked onto streets every day, and is being blown out of construction sites on windy days.

Covering sources of dust

Findorff site before covering, & after. Click to enlarge.