Sentence improvement

From=20exercises (7a-7i) in "The Random House Handbook," 5th Ed. by Frederick Crews:

Each of the following sentences needs improvement on grounds of insufficiently distinct expression.. rewrite the sentence to align main features of meaning with main grammatical units.. use fewer words to convey the idea...

C. The tar sand oil is so heavy that it cannot be pumped and instead must be strip-mined with the sand and then subjected to a process of treatment whereby the oil and sand are separated by hot water, steam, and air.

E. A choice must be made between goals of oil production to be maintained if the world is not to run out of vital energy supplies and the understandable reluctance felt by many people to permit the devastating if perhaps temporary damage caused by strip mining. --

My attempt at revision:

The tar sand oil, unpumpable due to its heaviness, must instead be strip-mined with the sand and then treated by hot water, steam, and air to separate the oil from the sand.

(Have I altered the original meaning too much? Any better suggestions at rewriting it?)

A choice must be made between maintaining oil production to prevent the exhaustion of vital energy supplies and permitting the devastating albeit temporary damage caused by strip mining.

(But still, what remains to be the "main grammatical units" is "choice must be made," giving scanty information, besides being a passive voice. Also I have ruthlessly stripped away "many people"s feelings. So I think my revision is still not good. Any suggestions?)

Many thanks in advance.

-- P.S.

I'm posting this message on alt.usage.german too, because several habitu=1B.A=8E=E9=*** there have excellent English skills, who, I think, c= an help my English problems as well as my German ones as they did.