Reading ComprehensionDifficulty: Easy

PT158 S1 P1 Q2 ExplanationDeep Well Injection

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

TopicsInferenceScience

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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

Inference

Anticipate

Inference questions are the "prove it with the text" questions. Think of yourself as a cautious lawyer: if you cannot point to specific language in the passage backing up the answer, it is wrong. No assumptions, no reading between the lines, no "well, that seems reasonable." The passage gives us hard facts about depths, rock types, water movement, and contamination mechanisms. The right answer will stick to those facts like glue.

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

The question
2.

The passage most strongly suggests that which one of the following

Answer choices, explained

  1. Too Strong: no longer considered safe2% picked this

    The use of landfills and incinerators for the disposal of hazardous wastes is no

    We're told that the switch to deep well injections was motivated by money. Because landfills and incinerators were coming up against environmental regulations and increasing expenses, industries turn to deep well injection "to save time and money".

  2. Contradicted4% picked this

    Injection of hazardous wastes at depths of more than 1,800 meters is less expensive but more dangerous than injection of

    Injection deeper than 1800 meters was said to be so expensive that it was cost prohibitive. This says it's "less expensive".

  3. Correct86% picked this

    Deep-well injection of hazardous wastes can contaminate aquifers of drinking water that are great distances

    Why this is right

    This was our author's 3rd problem with deep well injections. The movement over time of underground fluid is unpredictable, but it can travel 1000's of meters per year. Thousands of meters qualifies as "great distances" (it's probably several miles) in the sense of you could look where you're injecting and see no underground aquifers nearby, but 10 miles away there could be one, and the waste you're injecting into your site could seep 10 miles in just a few years.

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

  4. Too Strong: does not involve risk6% picked this

    Disposal of hazardous wastes in landfills involves various risks, but—unlike deep-well injection—it does not involve the

    We only talked about whether deep well injections have the risk of contaminating groundwater. We don't know whether landfills also do or not.

  5. Contradicted2% picked this

    Drinking-water wells are usually deeper than the wells that are drilled for deep-well injection

    We're told that that the deep-well injection is actually shot down between 300-1800m, because we're trying to put the toxic waste a "safe distance below" the aquifer (where a drinking well would be pulling water from).

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