LSAT 158 | Section 1 | Reading Comprehension: Q4

RC Question 4 Explanation

DISCUSSION: This question is asking for you to go back into the passage and search for a small detail. It asks about underground water: paragraph 3 most directly talks about underground water: it discusses how it moves. So, you should go back and read/skim over that paragraph before checking the answers. This makes it much quicker to find the right one.

This is the second question where the right answer relies on knowledge of paragraph 3. That is a key paragraph for this passage.

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1. No, this wasn’t supported by the passage: wastewater is presented as a risk to drinking water. Common sense also says no. Who would argue we should drink wells contaminated by wastewater?!
2. We know very little about areas less deep than 300m. We know aquifers are up there, but we don’t know if they are closer to 300m or closer to the surface. It’s possible there are many aquifers less than 200m deep!
    
   In fact, use some common sense: humans drilled down to wells long before we had drilling machines, so there has to be a fair bit of water close to the surface.
3. The passage doesn’t talk about water use in industrial processes at all.
4. This bungles a section of paragraph 1. The middle of that paragraph says that when selecting a wastewater site, you should look for areas “saturated with salt water”. The salt is already there! Then you inject the waste. It isn’t the waste that causes the salt.
5. CORRECT. Paragraph 3 says that water in the underground strata doesn’t “flow entirely under the influence of gravity” and is influenced by subterranean pressure gradients.