Reading comp PrepTest 158 · Section 1 · Question 3

Does this make the risk of water contamination from deep-well injection more likely? Suppose that almost all the sites for deep-well injection were far away from sources of drinkable water. Wouldn't that make you feel less concerned about the risk of water contamination? Of course, the author notes that the hazardous waste could contaminate groundwater "thousands of meters" away (P3, S3), so this wouldn't guarantee clean drinking water. Still, it would probably reduce the likelihood of contamination, weakening the author's argument.

Does this make the risk of water contamination from deep-well injection more likely? If we haven't tested the hazardous waste for its effect on "nonhuman organisms," we don't know whether it's toxic to these organisms. It could be toxic. It could be safe. So, this answer choice doesn't add any definitive information that makes contamination more or less likely, so this has no effect on the argument.

Further, the author's issues center on how water contamination would affect humans. ("Deep-well injection ... has become a matter of controversy as growing numbers of communities come to rely on underground sources of drinking water" (P1, S8). "This allows waste to escape ... threatening a regional aquifer supplying water to 100,000 people" (P2, S5). "[P]eople may be exposed to dangerous levels of waste materials" (P2, S6).) We assume the author would prefer we didn't poison animals and other organisms, but that position was never explicitly advanced. For that reason, (B) doesn't address the author's position at all.

Does this make the risk of water contamination from deep-well injection more likely? This tells us that the deep-well injection sites aren't close to the industrial facilities, but that doesn't address whether the deep-well injection sites were close to drinkable water sources. Some test-takers assume that moving the waste from the industrial facility to the injection site may increase the chance of mechanical error with the transportation system, but the passage never discusses whether mechanical errors could exist anywhere other than in the well itself. Plus, even if this type of error occurred, we still don't know whether the leakage would pose any risk of contaminating a water source. For these reasons, (C) has no effect on the author's position.

Question Type:
Application/Strengthen

Strategy Overview:
Review the author's position on the risks of deep-well injection of hazardous waste, determine weaknesses in that claim to anticipate how to improve it, and select the answer choice that makes the claim more convincing

Answer Anticipation:
Typically, we'll want to approach Strengthen questions in Reading Comprehension in a very similar manner as we would in Logical Reasoning. That means interrogating the author's position for any weaknesses to anticipate how to fix those weaknesses and make the position more convincing.

However, this question asks us to strengthen the author's view on the risks of deep-well injection of hazardous wastes. The author describes these risks throughout the entire passage. It would probably be too time-consuming to look for weaknesses across all four paragraphs. Instead, we can just review the main point, and check for any immediately apparent weaknesses with that claim.

The main point states the increasing use of deep-well injection of hazardous waste presents a risk of severe water contamination due to mechanical failure, human error, and significant uncertainty about where the injected waste will flow. There aren't any immediately apparent problems with the author's line of reasoning (that we can see, at least) other than the possibility that the author exaggerates the risk of mechanical failure, human error, or uncertain water flow. Therefore, it's challenging to develop a precise anticipation. We can instead assess each answer choice. To do so, we can start with a simple question we’ll ask of each: Does this answer choice make the risk of water contamination from deep-well injection more likely?

Answer Choice Explanation:
Does this make the risk of water contamination from deep-well injection more likely? Yes! The author cautioned that the unpredictable flow of underground water makes it very hard to anticipate where the injected waste will go (P3, S1-3). According to the author, this makes deep-well injection risky. (D) shows the author was not mistaken or overstating that risk! In fact, (D) shows that this unpredictability is even more significant than the author led us to believe. So, the waste mixed with underground salt water in deep-well injection sites can move more unpredictably and more quickly than the author thought, making it even more probable that water sources will be contaminated. 

Key Takeaway:
The most popular wrong answer selection on this question is (A). As discussed above, this weakens the argument. Answer choices that weaken the argument are consistently popular wrong answer choice selections on Strengthen questions in RC and LR. Some test-takers recognize that such answer choices affect the argument, but get mixed up when determining how they affect the argument. When you can't form a strong anticipation, asking a question like, "Does this make the risk of water contamination from deep-well injection more or less likely?" can help you avoid this confusion.

Does this make the risk of water contamination from deep-well injection more likely? The author claimed the unpredictable flow of underground water was one reason why deep-well injection was so risky. This answer choice shows that the author was overstating how unpredictable that flow is. If we are better at anticipating and tracking this flow of water, we might be able to monitor where the waste leakage is headed and halt its progress. This makes the risk of water contamination less likely, which weakens the author's position.