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Reading passage Grade 4 Careers & CTE

Testing Willow Creek: A Day in the Work of a Water Quality Lab Analyst

An original grade 4 passage following a water quality lab analyst through a morning of field testing at a creek and an afternoon of lab work, with comprehension items.

Objectives

  1. Students will identify the steps a water quality lab analyst follows in the field and in the lab.
  2. Students will draw inferences about why careful testing and record-keeping matter.
  3. Students will describe one education path that leads to a water-testing career.

Vocabulary

Turbidity
Turbidity is a measure of how cloudy or murky water looks because of tiny particles floating in it. Clear water has low turbidity, and muddy water has high turbidity.

Teacher overview

This original passage follows Elena Cho, a water quality lab analyst, through one morning of fieldwork at a creek and one afternoon of lab testing, showing that the job happens both outdoors and in the lab. The passage introduces the career concretely, including the schooling that prepares someone for it, and the comprehension questions move from locating stated details to drawing inferences about why careful, repeated testing matters even when nothing seems wrong.

Testing Willow Creek: A Day in the Work of a Water Quality Lab Analyst — Grade 4 Careers & CTE
Name: ____________________________ Date: ______________

Passage

Testing Willow Creek

Twice a month, Elena Cho puts on tall rubber boots. She wades into Willow Creek before most of the town wakes up. Elena is a water quality lab analyst. Part of her job happens right in the water, not at a desk.

Standing in the creek, Elena checks three things. First, she dips a thermometer in the water. It tells her the water's temperature. Fish need water that is not too hot and not too cold. Second, she looks at how clear the water is. This is called turbidity. Cloudy water can mean that dirt or pollution is getting into the creek. Third, she turns over a few smooth rocks. She looks for tiny bugs living underneath them. Some bugs can only live in clean water with plenty of oxygen. Finding these bugs is a good sign that the creek is healthy.

Elena also fills small bottles with creek water. She labels each bottle with the date, the time, and the exact spot. "If I mix up a bottle," she says, "the whole test becomes useless. It will not matter how careful I was after that."

Back at the lab, Elena's work looks very different. She wears gloves and safety goggles. She works at a counter full of careful, precise tools. These tools test the water for things she cannot see out at the creek, such as bacteria and certain chemicals. Elena follows an exact set of written steps for every test. She also runs extra "check" samples next to the real ones. This proves that her tools are working the right way.

Late in the afternoon, Elena writes up her results. She enters them into the town's water records. Most days, everything sits in the healthy range Elena expects. Her report simply says that Willow Creek is doing fine. On a rare day, something looks unusual. Elena's careful labels let her trace exactly where and when that sample was taken. That helps the town figure out what might be happening.

Elena studied biology in college before she started this job. That is one path into water-testing work. Other people begin with a two-year degree in lab science instead. "I liked biology class because it felt like solving a mystery," Elena says. "This job still feels that way."

Questions

  1. What is Elena's job? How often does she visit Willow Creek?

  2. According to the passage, what three things does Elena check while she is standing in the creek?

  3. Why does Elena look for tiny bugs under the rocks? Use a detail from the passage in your answer.

  4. According to the passage, how is Elena's testing at the lab different from her testing at the creek?

  5. Why do you think Elena labels every sample bottle so carefully, even though it takes extra time? Use a detail from the passage to support your answer.

  6. Based on the passage, what education helped prepare Elena for her job? Is it the only path the passage mentions?

  7. Suppose Elena's temperature reading at Willow Creek came back much higher than usual one week. What do you think she would do next? Use details from the passage to support your idea.

From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.

Answer Key

  1. Answer: Elena is a water quality lab analyst, and she visits Willow Creek twice a month.
    Both details are stated in the passage's first paragraph.

  2. Answer: She checks the water's temperature, how clear the water is (turbidity), and whether certain small bugs are living on the creek bottom. All three are listed in order in the second paragraph.

  3. Answer: Certain bugs can only survive in clean, oxygen-rich water, so finding them is a good sign that the creek is healthy. This reasoning is stated directly at the end of the second paragraph.

  4. Answer: At the creek, Elena makes quick field observations using simple tools like a thermometer and her own eyes. At the lab, she uses precise instruments to test for things that are invisible in the field, such as bacteria and certain chemicals, following an exact written procedure. Both settings should be described for full credit.

  5. Answer: Careful labeling lets Elena know exactly where and when each sample came from, which matters if a result ever looks unusual and she needs to trace the problem back to its source. Accept any answer connecting careful labels to trustworthy or useful results, supported by Elena's own quoted explanation.

  6. Answer: Elena studied biology in college, but the passage also mentions that some people enter water-testing work through a two-year degree in laboratory science instead. Both paths should be named for full credit.

  7. Answer: Answers will vary. A strong answer proposes that Elena would record the unusual reading carefully, retest to confirm it, and use her records to figure out where and when the change started, since the passage states that her labels and records help her retrace exactly where and when a sample was taken.

Differentiation

Support (below grade level)

Read the passage aloud in two parts, at the creek and at the lab, pausing after each to summarize together before continuing. Reduce the question set to 1, 2, 3, and 6, saving the inference questions for a guided class discussion.

Extension (above grade level)

Ask students to research (using only the passage and one teacher-provided source, not open internet searches) one other tool or method water quality analysts use to test for bacteria or chemicals beyond what the passage describes, and to write two sentences explaining what they learned.

ELL supports

Pre-teach analyst, sample, turbidity, and procedure using pictures of a thermometer, a labeled sample bottle, and cloudy versus clear water side by side. Allow students to answer questions 1 through 4 with short phrases pointing to the exact sentence in the passage.

Extensions

Have students design their own simple sample-bottle label, including at minimum a location, a date, and a time, and explain in one sentence why each piece of information on the label matters to someone testing the water later.