Reading passage Grade 3 English Language Arts
Making Salty Water Fresh at Harkspur Bay
A grade 3 informational passage about a fictional seaside town that takes the salt out of bay water in dry years, with seven questions and an answer key.
Objectives
- Students will answer questions about an informational passage using details the passage states.
- Students will explain in their own words what happens at the membrane.
- Students will give the reason the passage supplies for running the plant only part of the year.
Vocabulary
- Desalination
- Turning salty water, like ocean water, into fresh water people can use. It works, but it takes a lot of energy and leaves behind very salty water that must be handled carefully.
Also: bay, salty, membrane, log book
Teacher overview
Harkspur is a fictional seaside town surrounded by salt water, yet it ran short of drinking water after three dry years. The passage explains why salt water is not a supply until something takes the salt out, then walks through a small plant that does exactly that. It also states plainly why the town runs the plant only in dry months, which gives students a reason to locate rather than guess.
Passage
Making Salty Water Fresh at Harkspur Bay
The town of Harkspur sits on a bay. Salt water stretches out past the end of every street. For a long time, though, no one in Harkspur could drink a drop of it.
Salt water is not safe to drink. It pulls water out of a person's body instead of putting water in. So Harkspur drank from wells. The wells reached down into a bed of sand under the town.
Then came three dry years. Little rain fell, and the wells did not refill. Salt water from the bay crept sideways through the sand. It reached two of the wells. The water from those wells began to taste salty, and the town shut them off.
So Harkspur built a small plant by the shore. The plant takes the salt out of bay water. Desalination is the word for that.
Here is how the plant works. A pipe pulls water in from the bay. A screen keeps fish and weeds out. Sand filters catch grit. Then a strong pump pushes the water hard against a thin sheet. The sheet is called a membrane. Its holes are far too small to see. Water slips through those holes. Salt does not. The salt stays behind.
The fresh water flows on into a tank. The salty leftover goes back to the bay through a long pipe that ends far from shore.
The plant works, but it is not free. Pushing water against the membrane takes a great deal of power, and power costs the town money. The membrane wears out too, and a worn one has to be swapped for a new one. For those reasons, Harkspur does not run the plant all year. In a wet spring, the wells do the work. In a dry August, the plant starts up.
Ines Portillo runs the plant. Twice a day she checks how much salt is left in the water leaving the tank. If that amount starts to climb, a membrane may have a tear in it. She writes every check in a log book, and the town office reads the log each Friday.
Questions
- Where does the town of Harkspur sit?
- What did Harkspur drink from before the three dry years?
- What happened to two of the wells during the dry years?
- What does the word "desalination" mean in this passage?
- What happens at the membrane? Use two details from the passage.
- Why does Harkspur run the plant only in dry months?
- Ines checks the salt in the water twice a day. What might it mean if that amount climbs?
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: On a bay, with salt water past the end of every street. The first sentence of the passage says so.
- Answer: Wells that reached down into a bed of sand under the town. The second paragraph states this.
- Answer: Salt water crept sideways through the sand and reached them, so the water tasted salty and the town shut those wells off.
- Answer: Taking the salt out of salty water. The passage names it right after it says the plant takes the salt out of bay water.
- Answer: A strong pump pushes water hard against the membrane, and water slips through holes too small to see while the salt stays behind. Both details come from the middle of the passage.
- Answer: Because pushing water against the membrane takes a great deal of power that costs money, and the membrane wears out and must be replaced. In a wet spring the wells do the work instead.
- Answer: That a membrane may have a tear in it. The passage says this is what a rising amount can mean, which is why she writes every check in a log book.
Differentiation
Support
Read the passage aloud in two parts, stopping after the dry years to summarize the problem before the plant appears. Give these students a copy with four margin labels already written: the bay, the wells, the plant, the cost. Demonstrate question 5 by pouring water through a coffee filter holding a spoonful of sand. Point out that salt dissolved in water would pass straight through a coffee filter, which is why the plant needs a membrane with far smaller holes.
Extension
Ask students to write the three sentences a sign at the plant gate could carry, telling a visitor what the building does, when it runs, and where the salty leftover goes. Each sentence must rest on a detail from the passage.
ELL supports
Pre-teach "bay," "salty," "membrane," and "leftover" with a sketch of a shoreline and a strainer students can hold. Let students taste plain water and describe it, then describe salt water from memory rather than tasting it. Provide sentence frames for questions 5 and 6: "At the membrane, water ___ and salt ___," and "The town runs the plant only in dry months because ___."
Extensions
Students can list three places in their own town where water is used and mark which ones would still work if the tap water tasted salty. Sorting the list shows that a supply problem reaches past drinking water into cooking, washing, and watering.