Reading Comprehension

PT158 · S1 · P1 · Q4 Deep Well Injection

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A major problem facing industrial societies is their exponentially increasing production of toxic waste.

Topic

The risks and problems associated with deep-well injection as a method for hazardous waste disposal in industrial societies.

Framework

Problem / Solution

Main Point

Although deep-well injection is increasingly used to dispose of hazardous waste due to cost and regulatory pressures, it poses significant risks—including mechanical failure, human error, and unpredictable underground movement of waste—that make it a problematic and potentially dangerous solution. Most Valuable Sentence: Last paragraph:

P1: Introduction to Deep-Well Injection and Its Controversy

This paragraph introduces the growing problem of toxic waste in industrial societies, describes how regulations and costs have led to the increased use of deep-well injection for hazardous-waste disposal, and notes that this method is controversial, especially as more people depend on underground water sources. It ends by foreshadowing that there are three key problems with this method.

P2: Mechanical Failures and Human Error

Here, the passage explains the first two major problems: wells can leak, allowing dangerous chemicals into drinking water sources, and human error (like faulty well construction) can have dire consequences. Example: a well with a casing gap almost contaminated water for 100,000 people, and such issues might go unnoticed for a long time.

P3: Unpredictable Movement of Underground Waste

This paragraph details the third problem: it’s extremely difficult to predict how wastes will move underground due to complex, variable pressure gradients. Wastewater can travel in any direction, sometimes over great distances, making containment unpredictable.

4.

According to the passage, which one of the following is true of underground water?

  1. It can be suitable as

    Opposite, if anything

    Nothing in our Support Window about underground water says anything about whether it is suitable as a source of drinking water, but the gist of the passage suggests the opposite. Our author is alarmed by the possibility of waste contaminating the aquifers from which humans get their drinking water.

    1% picked this

  2. It can seldom be found

    Waste, not Water

    The waste is usually not going to be found less than 200 meters from surface, because those wells are usually drilled at least 300 meters deep. We don't know how high underground water goes. We're told of an incident in the 2nd paragraph involving a well leak at 200 feet that threatened local water, but this answer is saying that underground water usually doesn't rise above 200 m and we have no support for that. We definitely don't have any facts about minimum depth of water in our Support Window for underground water.

    4% picked this

  3. It can seldom be used

    Outside the Support Window

    There's nothing in the two sentences we have available about underground water to talk about whether underground water is seldomly or commonly used as a source of water for industrial processes.

    1% picked this

  4. It can contain a high

    Unsupported Causal Relationship

    The only mention of salt we're given is at the beginning of the 2nd paragraph (far from our Support Window), and it's just saying that waste is often injected into rocks that are saturated with salt water. It speaks about injection wells possibly leaking "significant amounts of noxious chemicals" into drinking water underground, but it never talks about wastes from the well causing the underground water to have lots of salt in it.

    7% picked this

  5. Correct

    It can move from one

    Why this is right

    This answer can be derived from our Support Window, the two sentences the passage gave us about underground water. We were told in the middle of the 3rd paragraph that the water in underground rock strata does not flow entirely under the influence of gravity. We can restate that claim by saying, "At least one other thing besides gravity is partially influencing the flow of underground water". And that's what this answer choice is saying. The rephrasing is difficult. The part of the process we need to make easy is locking in "underground water" from the question stem with the one sentence in the passage that says the words "water" and "underground". If we're anchored to this sentence as the most likely support for the correct answer, then it will be easier to fight for the legitimacy of this weird sounding answer. How do we know that it's moving from one formation to another? The following sentence, the last one in the 3rd paragraph, says "[underground water] can flow in any direction and, in some cases, can be transported thousands of meters through faults, porous rock, or other geologic formations.

    Skill tested: Locate Detail · how this choice captures the passage's function is the move to repeat next time.

    87% picked this

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