1.Where does most of the solid mass of raw sewage end up after being collected at a treatment facility? 2. Why is flushing a toilet with clean water from a municipal supply about as wasteful as...

1.Where does most of the solid mass of raw sewage end up after being collected at a treatment facility? 2. Why is flushing a toilet with clean water from a municipal supply about as wasteful as flushing it with bottled water? 3. Someone argues that he or she doesn’t drink tap water because it contains thousands of molecules of some impurity in each glass. How would you respond in defense of the water’s purity, if it indeed does contain thousands of molecules of some impurity per glass?

(a) Impurities aren’t necessarily bad; in fact, they may be good for you.

(b) The water contains water molecules, and each water molecule is pure. (c) There’s no defense. If the water contains impurities, it should not be drunk.

(d) Compared to the billions and billions of water molecules,

a thousand molecules of something else is practically nothing.