What happens to the dirt in the sewage plant that gets cleaned" out of the water?

Question

Why don't they make a sewage plant for drains too? It's like whats the pt. of it, since our rivers and oceans, lakes, are beign ruined by debris from the streets.

Answer 1

It depends. Some WWTPs package some of the sludge as a soil amendment (Millorganite, Philorganic -- from Milwaukee and Philadelphia). The rest goes to a sanitary landfill. In some of the old systems. runoff and sanitary sewage are combined and go thru the WWTP together. The result is that a heavy storm, especially if combined with snowmelt, will overload the plant and raw sewage gets discharged into the streams. More modern cities or ones that have modernized their infrastructure have separate systems. The runoff gets only primary treatment -- removal of the big stuff. If that sounds bad to you, there are still places where sanitary sewage gets no more treatment than that.

Answer 2

Actually, what goes down storm drains often get treated at least a little bit in most cities.  It either runs to the treatment plant just like what you flush does (older systems, old parts of large cities) or might run into at least a tank where the heavy stuff (particles) will settle out.  Now, just a basic sedimentation isn't going to get oily stuff and chemicals. . . but there's a cost/benefit involved, and usually controls on industrial facilities to minimize what's in runoff.  What you put on your lawn or accidentally spill on your driveway, however, is a different matter.

As far as what happens to the sludge (your "dirt") from wastewater treatment plants. . . disposal tends to include becoming fertilizer (after treatment to make sure any diseases should be gone -- takes a fair amount of permitting), burning it, or putting it in a landfill.

Answer 3

It depends on the water treatment plant.  Any soils that enter the sewage treatment plant would end up as sludge when the water is "purified".  Then the sludge needs to be disposed of and in many cities and states that means dumping it on Corporate farms for fertilizer.  The reason so many of our rivers and streams are being destroyed by runoff is that many sewage treatment systems have overflows.  They cannot take the combined input of storm water run-off and waste from buildings, so when the facility begins to overflow, the waste is literally diverted down pipes that send it directly in the rivers, streams, lakes or the ocean.  And yes unfortunately it is raw un-treated waste.  The reason they don't make new plants in these cities for storm-water runoff is price.  People have to vote on how to pay for it and normally they don't want to see their taxes go up.  It's a complicated problem and does not have an easy solution, but your right, it is ruining our water bodies and something should be done about it.

Answer 4

It's probably used as fertilizer.

Answer 5

Just how does dirt get into a waste treatment plant? Unless you flush dirt down the toilet it won't. Storm drains go directly into a tributary. But i guess  there are some that enter a water treatment facility so it, the dirt, becomes part of the waste sludge and is disposed.