Q12 - Leachate is a solution

[ManhattanPrepLSAT1]

There are three claims in this stimulus.

1. If, and only, if the landfill's capacity to hold liquids is exceeded does the leachate escape into the environment.
2. Most landfill leachate is sent directly to sewage treatment plants.
3. Not all sewage plants are capable of handling the highly contaminated water.

We need to find an answer that we can infer from one or more of these statements.

(A) may be true and seems to make sense, but is an unsupported prediction. It may not help solve the problem, however.
(B) contradicts the stimulus. The first claim says that leachate will escape into the environment if, and only if, the landfill's capacity is exceeded - not if leachate permeates a landfill.
(C) is not necessarily true. We know that not all sewage plants are capable of handling the highly contaminated water. That does not mean that no sewage plants are capable of handling leachate.
(D) attempts to combine the second and third statement. However, no inference can be made from combining a SOME statement in the third claim and a MOST statement in the second claim. According to these two claims, it's possible that all leachate is sent directly to only those sewage treatment plants that are capable of handling the contaminated water.
(E) must be true. This is part of what can be inferred from the contrapositive of the first statement.

[economienda]

Would (D) be credited if it had said: "Landfill leachate is sent to AT LEAST ONE sewage treatment plant that is incapable of handling it."

This seems to be consistent with the last sentence--namely, "...but not all sewage plants are capable of handling the highly contaminated [leachate-laden] water"

Not all = some are