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Reading passage Grade 10 English Language Arts

Camas Bluff's Water Reuse and Recharge: A Reading Passage

A grade 10 informational passage on how a fictional dry town recycles wastewater and banks it underground, with a treatment-failure exception and comprehension questions.

Objectives

  1. Students will identify the sequential treatment steps in an indirect potable reuse system.
  2. Students will explain the multiple-barrier idea using evidence from an informational text.
  3. Students will make inferences about why the system stores water underground before reuse.

Vocabulary

Potable reuse
Cleaning used water so thoroughly that it becomes safe drinking water again. Special plants use several layers of treatment and constant testing to make sure it is safe.
Reverse osmosis
Reverse osmosis cleans water by pushing it through a membrane with holes so tiny that salt and most other dissolved things cannot fit through. It can even turn seawater into fresh water.

Also: aquifer recharge, multiple barrier, recovery well

Teacher overview

In dry regions, a community's used water is too valuable to send away only once. This passage describes indirect potable reuse, a process that cleans treated wastewater to a very high standard, stores it underground, and later draws it back up as drinking water. The setting is a fictional town so students can follow the sequence of treatment barriers without tying the numbers to a real system, though the passage names a real example for scale. Students trace a multistep process and a built-in exception for treatment failure, reading technical writing for both order and special cases.

Camas Bluff's Water Reuse and Recharge: A Reading Passage — Grade 10 English Language Arts
Name: ____________________________ Date: ______________

Passage

The fictional town of Camas Bluff sits in a dry valley where rain is scarce and the nearest river is already fully spoken for. For years the town sent its treated wastewater down a canal and out of the valley. During a long drought, Camas Bluff decided it could no longer afford to use that water only once. The town built a water reuse system that takes water leaving the wastewater plant and cleans it far beyond ordinary standards, so it can become drinking water again. Systems like this already run at large scale elsewhere. Orange County, California, operates the world's largest indirect potable reuse facility, which produces about 130 million gallons of water each day.

The idea behind the system is called the multiple barrier approach. No single treatment step is trusted on its own. Instead, the water passes through several independent steps in order, and each one removes a different kind of contaminant. If any one step underperforms, the others still stand between the water and the public. Understanding the order of these barriers is the key to understanding why the recycled water is safe to drink.

The water begins as effluent from the town's wastewater plant, already treated to normal standards. First, it passes through microfiltration. These filters have pores so small that they strain out suspended solids, most bacteria, and other particles. Second, the water flows through reverse osmosis. Here it is pushed under high pressure against a membrane so tight that it blocks dissolved salts, many chemicals, and viruses, letting nearly pure water pass through. Third, the water receives an advanced oxidation step. Ultraviolet light combined with a small dose of hydrogen peroxide breaks apart trace compounds that slipped through the earlier barriers. After these three steps, the water is extremely clean, cleaner than much of the water people ordinarily drink.

The system then adds one more stage before the water is used. Rather than piping this clean water straight to homes, Camas Bluff pumps it underground into the aquifer beneath the valley. There it mixes with the natural groundwater and is stored. This underground stage is a barrier of its own. The water spends months in the ground before it is used, which adds time and natural filtration, and it reassures residents who are uneasy about drinking recycled water that goes directly from the plant to the tap. Later, the town's recovery wells draw the blended water back to the surface, where it receives standard drinking water treatment one more time before entering the distribution system. Because the recycled water passes through the environment before reuse, the process is called indirect potable reuse.

The system is designed for normal operation, but its most important rule is what happens when a step fails. Sensors watch each barrier continuously. If the reverse osmosis membranes or the ultraviolet step ever fall below their required performance, the system does not send that water toward the aquifer. Instead, it automatically diverts the substandard water back to the start of the process or out of the drinking water path entirely. This exception matters because the whole promise of the multiple barrier approach depends on every barrier actually working. Allowing water past a failed step, even briefly, would defeat the layered protection the design is built to guarantee. Operators would rather lose a batch of water than let an unverified batch move toward people's taps.

Questions

  1. Why did Camas Bluff decide to build a water reuse system?
  2. List, in order, the three main treatment steps the water passes through before it is sent underground, and state what each one removes or does.
  3. What is the multiple barrier approach, and why does the passage say no single step is trusted on its own?
  4. What does the system do when a treatment step falls below its required performance, and why is this exception so important?
  5. Why does Camas Bluff store the cleaned water underground instead of piping it straight to homes? Give two reasons from the passage.
  6. Based on the passage, why is this process called "indirect" potable reuse rather than "direct"?
  7. Explain how the multiple barrier approach keeps the recycled water safe, using details about at least two of the treatment steps.

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: During a long drought, with scarce rain and no available river water, the town decided it could no longer afford to use its treated wastewater only once. The passage states this in its first paragraph.
  2. Answer: (1) Microfiltration strains out suspended solids, most bacteria, and particles; (2) reverse osmosis blocks dissolved salts, many chemicals, and viruses; (3) advanced oxidation with ultraviolet light and hydrogen peroxide breaks apart trace compounds that slipped through. The passage lists these three steps in order.
  3. Answer: The multiple barrier approach uses several independent treatment steps in order, each removing a different contaminant, so that if one step underperforms the others still protect the public. No single step is trusted alone because relying on one leaves no protection if it fails. The passage explains this in its second paragraph.
  4. Answer: The system diverts the substandard water back to the start or out of the drinking water path instead of sending it toward the aquifer. It is important because the multiple barrier promise depends on every barrier working, so letting water past a failed step would defeat the layered protection. The passage explains this in its final paragraph.
  5. Answer: Any two of: the underground stage acts as another barrier; the water spends months in the ground, adding time and natural filtration; and it reassures residents uneasy about water going straight from plant to tap. The passage gives these reasons in its fourth paragraph.
  6. Answer: It is called indirect because the recycled water passes through the environment, the aquifer, before being drawn back and reused, rather than going straight from the treatment plant to the tap. The passage defines the term in its fourth paragraph.
  7. Answer: Answers will vary but should explain that each barrier removes a different contaminant, and that even if one step underperforms the others still stand between the water and the public. A strong response names at least two steps, such as reverse osmosis blocking dissolved salts and viruses and advanced oxidation breaking apart trace compounds. The passage's second and third paragraphs support this.

Differentiation

Support

Provide a labeled flow diagram showing microfiltration, reverse osmosis, advanced oxidation, aquifer storage, and recovery wells for students to annotate while reading, and allow question 7 to be answered with a labeled sketch plus one or two sentences.

Extension

Ask students to write a short paragraph, using only the passage, addressing a resident who says recycled water "sounds unsafe," explaining how the multiple barriers and the underground storage stage respond to that concern.

ELL supports

Pre-teach potable reuse, aquifer recharge, reverse osmosis, multiple barrier, and recovery well with simple definitions and a labeled diagram before reading. Allow questions 1, 2, and 6 to be answered with short phrases rather than full sentences.