Reading ComprehensionDifficulty: Easy

PT158 S1 P1 Q1 ExplanationDeep Well Injection

A free, expert breakdown of this official LSAT Reading Comprehension question.

TopicsMain PointScience

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Passage

A major problem facing industrial societies is their exponentially increasing production of toxic waste. Environmental regulations and expenses for landfills and incinerators have increased significantly in recent years. In an effort to save time and money, many industries have turned to alternative methods of hazardous-waste disposal, including increased use of deep-well injection. water. The controversy arises because there are three serious problems with this method of waste disposal.

Under the best conditions, wastes are injected into rock strata saturated with salt water and separated by impermeable rock strata from aquifers containing drinkable water. However, injection wells may leak, allowing significant amounts of noxious chemicals to mix with supplies of drinking water. In other cases, mistakes by personnel working on the dangerous levels of waste materials for long periods of time before the problem is even discovered.

The third problem associated with deep-well injection arises from the fact that it is nearly impossible to predict how the injected wastes will be acted on by the geological features of the injection area. Unlike surface water, the water in underground rock strata does not flow entirely under the influence of gravity. of meters per year through geologic faults, porous rock, or other geologic formations.

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. Unfortunately, as societies produce more toxic this relatively cheap, efficient means of disposal.

What this question is testing

Main Point

Anticipate

Main Point = This author spent several paragraphs ringing alarm bells about pumping toxic waste underground. The passage is a "you should be worried" essay, not a neutral explainer and not a call to arms.

Goal

Find the answer that matches the author's thesis: deep-well injection is a growing threat to underground drinking water. Eliminate answers that are too narrow (focusing on one detail), too mild (presenting it as safe), or too extreme (demanding it be banned). The author is a worried scientist, not a neutral reporter and not an activist with a megaphone.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
1.

Which one of the following most accurately states the main point of

Answer choices, explained

  1. Too Narrow2% picked this

    Deep-well injection of hazardous wastes is unsafe when expensive precautionary measures

    The passage argues deep-well injection carries inherent risks — mechanical failure, human error, unpredictable water movement — not only when precautions are absent. This misses the broader concern.

  2. Opposite Tone4% picked this

    Although deep-well injection of hazardous wastes can be unsafe, it is generally safe when proper procedures are followed

    The passage argues the opposite: even with proper procedures and careful site selection, underground water movement is so unpredictable that deep-well injection remains risky.

  3. Wrong Focus6% picked this

    Because of the high costs and extensive regulations associated with other methods, deep-well injection has wholly supplanted alternative

    The passage says deep-well injection is an "alternative method" being increasingly used, not that it has "wholly supplanted" other methods. The author never claims other methods have been replaced.

  4. Correct86% picked this

    The increasing use of deep-well injection as a method of hazardous-waste disposal

    Why this is right

    This is supported across all four paragraphs, which detail how mechanical failures, human error, and unpredictable geology make the increasing use of deep-well injection problematic.

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

  5. Too Narrow2% picked this

    Careful design and location of deep-well-injection facilities is important because communities commonly rely on

    This captures one concern (protecting drinking water) but misses the broader point that deep-well injection is problematic due to multiple risks, not just siting considerations.

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