Reading comp PrepTest 158 · Section 1 · Question 4
Passage
A major problem facing industrial societies is their exponentially increasing production of toxic waste. Environmental regulations and expenses for landfills
Remaining source text redacted.
Passage walkthrough
Passage Summary Topic:
Science
Paragraph 1
Main Point:
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.
Key Lines?
Paragraph 1, Sentence 3 (P1, S3) - Problem introduced
P1, S4-6: How deep-well drilling works
P1, S8 - Controversy surrounding problem described
P4, S1 - Author's conclusion
Meta-Structure?
Problem/Solution: The author identifies a problem in the first paragraph, suggesting that this passage utilizes a Problem/Solution Meta-Structure. In the first paragraph, the author defines the problem: industries increasingly use deep-well injection to dispose of hazardous waste (P1, S3). The author also describes the ensuing controversy: people reliant on underground water sources aren't cool with toxic waste being pumped near their drinking water (P1, S8). However, the author doesn't really provide any solutions in this passage. The author uses the second and third paragraphs to describe why deep-well injection is a worrisome problem. The author then recaps their position in the final paragraph. So, this is less a Problem/Solution passage than just a Problem passage. As such, the main point will be the author's opinion on the problem, which is conveniently summarized by the final paragraph. That paragraph asserts that 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.
List: This passage is also organized around a list. Lists are sometimes hard to identify in Reading Comp. However, claims like "there are three serious problems with this method of waste disposal" (P1, S9) provide a strong hint that we're about to get a list of three items. The first two items are enumerated in the second paragraph — the wells may leak due to mechanical failure (P2, S2) or human error (P2, S3-S4). The third item is described in the third paragraph: water flows unpredictably underground, which increases the risk of extensive but unknown contamination (P3, S1-3). When the author organizes part of the passage around items on a list, we'll probably get at least one question about the list. Therefore, it's a good idea to note, remember, or highlight where each item was discussed in each paragraph.
Last Thoughts?
This is a tremendously detail-oriented passage. The first paragraph — the longest — describes deep-well injection in a manner that is ... excuse the pun ... very in-depth. The following two paragraphs enumerate, in detail, three reasons why the author thinks deep-well injection is problematic. Even the author's main point — offered in the last paragraph — just reiterates each item in that list. This passage drills us with details, so we should expect a higher-than-normal amount of Minor Point questions.
Science
Paragraph 1
- Paragraph note
- Background to Problem: Deep-well injection of waste
- Views, minor Meta-Structures, and the author's attitude
- Background info on deep-well injection: Drill hole into rock layer already filled with salt water, inject waste into salt water, typically between 300 and 1800 meters underground (fourth through seventh sentences)
- Author's attitude: "major problem" (first sentence), "serious problems" (last sentence)
- Paragraph note
- Two problems with injection: leaks and human errors
- Views, minor Meta-Structures, and the author's attitude
- List of potential issues, item 1: leak due to mechanical failure (second sentence)
- List of potential issues, item 2: leak due to human error (third sentence)
- Example of leak due to human error: a gap in a 500-meter deep well (fourth and fifth sentences)
- Author's attitude: "best conditions" (first sentence), "significant amount of noxious chemicals" (second sentence), "dangerous levels of water materials for long periods of time before the problem is even discovered" (last sentence)
- Paragraph note
- Third problem with injection: unpredictable water flow
- Views, minor Meta-Structures, and the author's attitude
- List of potential issues, item 3: unpredictable water flow (first sentence)
- Comparison: surface water vs. underground water (second sentence)
- Surface water's flow only affected by gravity, underground water's flow is influenced by other factors, like pressure gradients
- Author's attitude: "nearly impossible" (first sentence)
- Paragraph note
- Author's conclusion
- Views, minor Meta-Structures, and the author's attitude
- Author's conclusion: "The significant uncertainty about where injected wastes will flow, along with the possibilities of mechanical failure and human error, makes deep-well injection a risky means of managing hazardous wastes" (first sentence)
- Author's attitude: "significant uncertainty" (first sentence), "possibilities of mechanical failure and human error" (first sentence), "risky means of managing hazardous wastes" (first sentence), "Unfortunately" (second sentence)
Main Point:
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.
Key Lines?
Paragraph 1, Sentence 3 (P1, S3) - Problem introduced
P1, S4-6: How deep-well drilling works
P1, S8 - Controversy surrounding problem described
P4, S1 - Author's conclusion
Meta-Structure?
Problem/Solution: The author identifies a problem in the first paragraph, suggesting that this passage utilizes a Problem/Solution Meta-Structure. In the first paragraph, the author defines the problem: industries increasingly use deep-well injection to dispose of hazardous waste (P1, S3). The author also describes the ensuing controversy: people reliant on underground water sources aren't cool with toxic waste being pumped near their drinking water (P1, S8). However, the author doesn't really provide any solutions in this passage. The author uses the second and third paragraphs to describe why deep-well injection is a worrisome problem. The author then recaps their position in the final paragraph. So, this is less a Problem/Solution passage than just a Problem passage. As such, the main point will be the author's opinion on the problem, which is conveniently summarized by the final paragraph. That paragraph asserts that 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.
List: This passage is also organized around a list. Lists are sometimes hard to identify in Reading Comp. However, claims like "there are three serious problems with this method of waste disposal" (P1, S9) provide a strong hint that we're about to get a list of three items. The first two items are enumerated in the second paragraph — the wells may leak due to mechanical failure (P2, S2) or human error (P2, S3-S4). The third item is described in the third paragraph: water flows unpredictably underground, which increases the risk of extensive but unknown contamination (P3, S1-3). When the author organizes part of the passage around items on a list, we'll probably get at least one question about the list. Therefore, it's a good idea to note, remember, or highlight where each item was discussed in each paragraph.
Last Thoughts?
This is a tremendously detail-oriented passage. The first paragraph — the longest — describes deep-well injection in a manner that is ... excuse the pun ... very in-depth. The following two paragraphs enumerate, in detail, three reasons why the author thinks deep-well injection is problematic. Even the author's main point — offered in the last paragraph — just reiterates each item in that list. This passage drills us with details, so we should expect a higher-than-normal amount of Minor Point questions.
Question prompt
According to the passage,
Remaining source text redacted.
Why the credited answer is right
Credited answer: E
The notes below walk through why it fits the stem and how to eliminate the rest.
Question Type
Science
Answer choices
-
AIt can be suitable Remaining source text redacted.
Why choice A is not credited
Do you recall reading about how "low levels of deep-well-injected wastes" in drinking water is safe? Probably not. In fact, this conflicts with the author's main point, which was all about the dangers of deep-well-injected wastes. An experienced test-taker would probably eliminate this answer choice outright since it contravenes the main point.
If we decided we needed to review the passage, we'd realize that the author never brings up "low levels" of hazardous waste. The author only discusses "significant" (P2, S2) or "dangerous" (P2, S6) levels. So, the author never clarifies whether a small amount of hazardous waste is safe, so this answer choice is unsupported. -
BIt can seldom be Remaining source text redacted.
Why choice B is not credited
Do you recall reading about how underground water is rarely found less than 200 meters deep? Possibly. The author mentions this depth in the second paragraph. However, an efficient test-taker would probably not check the passage if they didn't remember what was said about this depth. Instead, they'd punt on this answer choice and move on to the next one.
If you did review the second paragraph for the reference to 200 meters (either by scanning the text for the number or using CTRL/Command+F), you'd find it near the middle of the second paragraph. There, the author explains that leakage from a well escaped at a "depth of only 200 meters," which threatened "a regional aquifer supplying water to 100,000 people" (P2, S5). So the passage tells us there's at least one water source around 200 meters deep. Plus, in the first paragraph, the author claimed that deep-well injection sites are generally lower than 300 meters to put the sites beneath "any aquifer" (P1, S6). Both imply the existence of underground water sources less than 200 meters deep. -
CIt can seldom be Remaining source text redacted.
Why choice C is not credited
Do you recall reading about using underground water for industrial processes? If not, it’s probably not worth it to check the passage. Instead, table this answer choice and move on to the next one.
If you did review the passage, you wouldn't find anything explicitly discussing the water used for "industrial processes." However, the first paragraph reveals that deep-well injection involves the injection of waste into "rock strata that are already saturated with salt water" (P1, S4). So, apparently, water is used for one industrial process: deep-well injection of industrial waste. That means this answer choice is provably false. -
DIt can contain a Remaining source text redacted.
Why choice D is not credited
Do you recall reading about concentrations of salt? Probably not. Decisive test-takers would probably not check the passage if they didn't remember reading about this. Instead, they'd defer on selecting this answer choice and move on to the next one, or they'd eliminate it.
If you did review the passage, you wouldn't find any support for the claim that underground water contains a lot of salt due to contamination from deep-well-injection waste. In fact, the only references to salt in the passage assert that the water in deep-well injection sites is already salty, not made saltier by the wastes. So, this answer choice is not necessarily true. -
EIt can move from Remaining source text redacted.
Why choice E matches the stem
Question Type:
Minor Point/Must Be True
Strategy Overview:
Refer to notes or what you highlighted/underlined to locate where the passage discusses underground water, and refer to the relevant part of the passage as needed to find that answer choice that must be true
Answer Anticipation:
For these questions that ask us to identify a specific piece of information, quickly finding that piece of information is paramount. This is why we make brief notes describing the role of each paragraph and highlight or underline the minor Meta-Structures — doing so helps us find the salient information efficiently and reliably.
Here, the question asks about underground water. Where did that show up in the passage? Our notes should reveal that the third paragraph discussed the flow of underground water at length. We also should have highlighted, underlined, or noted the comparison drawn between underground and surface water (since comparisons are one of our minor Meta-Structures), making this discussion very easy to locate. The correct answer might relate to the claim that the flow of water underground is very unpredictable, as moves through geological faults, porous rocks, and other geological formations due to factors other than gravity (P3, S1-3).
Of course, underground water was discussed elsewhere in the passage — since deep-well injection involves pumping hazardous wastes into underground salt water, underground water is very closely related to the primary subject of this passage. So, we can look for an answer choice that discusses the unpredictable movement of underground water, but we should also keep an open mind. If we see an answer choice discussing a topic we recall reading that’s consistent with the author's main point, it may be worth seeing if we can find textual support for that answer choice.
Answer Choice Explanation:
We predicted that the correct answer would say that the flow of water underground isn't just affected by gravity, so it flows through geological formations unpredictably. And this answer choice says exactly that. This answer choice is explicitly supported by the third paragraph, and it is correct.
Key Takeaway:
Comparisons — particularly distinctions drawn between two things — are frequent fodder for Minor Point/Must Be True questions. Highlighting the contrast between surface and underground water would have helped us quickly and accurately anticipate the answer to this question.
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