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Worksheet Grade 6 Social Studies & Civics

Norwood Vale's Well Test Letter: Reading the Results

A grade 6 document-analysis worksheet on a county letter reporting private well test results, covering what each result means and why private wells are the owner's job.

Objectives

  1. Students will locate stated results and instructions in a county well test letter.
  2. Students will explain why private wells fall outside the federal drinking water rules.
  3. Students will use the letter to correct the assumption that taste shows whether water is safe.

Vocabulary

Aquifer
An aquifer is an underground layer of rock, sand, or gravel that holds water in the tiny spaces between its grains. Wells reach down into aquifers to bring water up to the surface.
Coliform bacteria
Coliform bacteria are common bacteria found in soil, on plants, and in the guts of animals. Most are harmless, but finding them in drinking water warns that germs may be getting in.
Action level
A trigger number in lead and copper testing. If too many homes test above this level, the utility must take steps like improving treatment and telling the public.
Well casing
Well casing is the pipe that lines the inside of a drilled well, keeping the hole from collapsing and stopping dirty water near the surface from leaking into the clean water below. It is one of the most important parts of keeping a well safe.

Also: private well, shock chlorination

Teacher overview

Households on a private well are outside the federal drinking water rules, which means no agency tests their water unless the owner asks for it. That gap is a useful entry point into what a public policy does and does not cover. This worksheet uses a results letter written for a fictional household in Norwood Vale County. Students read the letter, sort the results into those that need attention and those that do not, and work out why the county offers testing at all when the law does not require it. Question 9 is the one to watch, since the argument that water tasting fine must be safe is a common one, and the letter supplies the evidence needed to answer it.

Norwood Vale's Well Test Letter: Reading the Results — Grade 6 Social Studies & Civics
Name: ____________________________ Date: ______________

Student Worksheet

Read the letter from the fictional Norwood Vale County Health Department, then answer the questions below it.

NORWOOD VALE COUNTY HEALTH DEPARTMENT: PRIVATE WELL TEST RESULTS

Date: April 9

To: The household at 14 Crandall Road

Why you received this letter: You asked the county to test your well, and our lab has finished the work. The county tests a private well when the owner requests it. Federal drinking water rules cover public water systems, which must test on a set schedule and report the results. Those rules do not cover private wells. On a private well, testing and treatment are the owner's responsibility.

Your results:

What we tested for Your result What we compare it to Our note
Total coliform bacteria Present Should be absent Needs attention
Lead 12 ppb The federal action level for public systems: 15 ppb now, dropping to 10 ppb in 2027 Needs attention
pH 7.2 The secondary standard range of 6.5 to 8.5 Within range
Iron Enough to stain sinks and laundry No health standard for iron Not a health concern

What the coliform result means: Coliform bacteria live in soil and in animal waste. Finding them means surface water is reaching your well, usually through a cracked cap, a loose seal, or ground that slopes toward the casing instead of away from it. Boil all water for drinking and cooking for one minute, or use bottled water, until a new sample comes back clean. Have the well shock chlorinated, then retested. Check the cap and the slope of the ground around the casing.

What the lead result means: Lead in well water usually comes from the plumbing in the house or from brass parts in the pump, not from the rock the water sits in. Run the cold tap for a minute before drinking after the water has sat overnight. Use cold water for cooking, since hot water carries more lead. Ask a plumber to look for lead solder and older brass fittings. A filter certified for lead will also lower the amount. Boiling does not remove lead.

What the iron result means: Iron stains fixtures and laundry and can taste like metal. It is not a health concern at this level. Many households treat it anyway for the staining.

Retesting: Send a new sample after the well is treated. We recommend testing every year for coliform bacteria whether or not anything is wrong.

Questions: Call the Environmental Health office at the number on the county website.

  1. Which department sent this letter, and on what date?
  2. According to the letter, why was this well tested at all?
  3. The letter says federal drinking water rules do not cover private wells. What does that mean for who arranges testing on this property?
  4. Which two results did the department mark as needing attention?
  5. Which result did the department say was within range?
  6. The letter says the iron result is not a health concern. Why did the department report it anyway?
  7. According to the letter, how are coliform bacteria most likely getting into this well?
  8. Where does the letter say the lead is most likely coming from, and what does it tell the household to do first?
  9. A neighbor says, "Our well water has always tasted fine, so it must be safe." Use evidence from the letter to explain why that reasoning does not hold.
  10. The law does not require the county to test private wells. Give one reason the county offers the service anyway.

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: The Norwood Vale County Health Department, on April 9. Both appear at the top of the letter.
  2. Answer: The owner asked the county to test it. The letter states that the county tests a private well when the owner requests it.
  3. Answer: Testing and treatment are the owner's responsibility, so no agency will test the well unless the household arranges it.
  4. Answer: Total coliform bacteria and lead. Both carry the note "needs attention" in the results table.
  5. Answer: The pH result, at 7.2, which falls inside the secondary standard range of 6.5 to 8.5.
  6. Answer: Because iron stains sinks and laundry and can give the water a metal taste, and many households choose to treat it for that reason even though it is not a health concern.
  7. Answer: Surface water is reaching the well, most likely through a cracked cap, a loose seal, or ground that slopes toward the casing instead of away from it.
  8. Answer: From the plumbing in the house or from brass parts in the pump rather than from the rock. The first step the letter gives is to run the cold tap for a minute before drinking when the water has sat overnight.
  9. Answer: Coliform bacteria and lead cannot be tasted, and the letter reports both by laboratory test rather than by taste. Accept any answer noting that the only result tied to taste in the letter, iron, is the one the department calls harmless.
  10. Answer: Answers vary. Accept any reasonable reason, such as protecting public health when illness would spread beyond one household, helping owners who cannot judge the water themselves, or catching problems like a cracked well cap early, when they are cheaper to fix.

Differentiation

Support

Read the letter aloud once while students follow, then have them highlight the four rows of the results table in two colors, one for needs attention and one for the rest. Allow questions 1 through 7 to be answered by copying the sentence from the letter before restating it. Save questions 9 and 10 for a partner conversation before writing.

Extension

Have students write the county's follow-up letter after a second sample comes back clean for coliform but still shows lead. It must state what changed, what did not, what the household should do next, and when to test again. Students then explain in two sentences why the two results call for different kinds of fixes.

ELL supports

Pre-teach "well," "sample," "bacteria," "attention," and "action level" with a labeled cross-section drawing of a well casing, a cap, and the ground sloping away from it. Provide a two-column chart labeled "Needs attention" and "No action needed" for questions 4 and 5. Allow short phrases throughout, and give the frame "The county tested this well because ___."

Extensions

Ask students to find out whether their own home or school is on a public water system or a private well, and if it is on a public system, to locate the annual water quality report. Students can compare how often that system must test with the yearly coliform test the county recommends for a private well, then write one sentence on what accounts for the difference.