Worksheet Grade 6 Careers & CTE

Northsedge Nutrient Recovery Technician: A Shift Log

A grade 6 careers worksheet where students read a nutrient recovery technician's shift log, finding phosphorus removal percents, a production rate, and a permit check.

Grade: Grade 6
Subject: Careers & CTE
Material: Worksheet
Time: 40 min
Prep: No prep
Materials: None

Standards

6.RP.A.3 Common Core Math

Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations, including finding a percent of a quantity and converting measurement units.

How this material aligns: Items 1, 2, and 7 find percent removal of phosphorus and the percent of plant flow the recovery unit treats.

All materials for 6.RP.A.3 →

6.RP.A.2 Common Core Math

Understand the concept of a unit rate a/b associated with a ratio a:b with b not equal to 0, and use rate language in the context of a ratio relationship.

How this material aligns: Item 4 turns 240 pounds of pellets made over 8 days into a pounds-per-day unit rate the technician reports.

All materials for 6.RP.A.2 →

D2.Eco.2.6-8 C3 Framework

Evaluate alternative approaches or solutions to current economic issues in terms of benefits and costs for different groups and society as a whole.

How this material aligns: Item 9 asks students to weigh selling recovered phosphorus as fertilizer against treating it only as a waste to remove.

All materials for D2.Eco.2.6-8 →

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This material is in the public domain (CC0) and may be copied, edited, and shared freely, without attribution. Updated 2026-07-23.

Objectives

Students will calculate percent removal of phosphorus from a treatment log.
Students will find a pounds-per-day production rate and extend it to a month.
Students will check a reported result against a stated permit limit.

Vocabulary

Key words: nutrient recovery, phosphorus, removal efficiency, pellet, permit limit

Teacher overview

Students read two days from the shift log of a nutrient recovery technician at the fictional Northsedge Water Reclamation Facility and complete the calculations that technician files each day. Phosphorus is treated here as two things at once, a pollutant that feeds algae in rivers and a raw material that farms buy as fertilizer. The misconception to head off is that a higher removal percent always means more material recovered. Percent removal depends on what came in, so a day with weaker incoming water can post a high percent while producing fewer pellets.

Northsedge Nutrient Recovery Technician: A Shift Log — Grade 6 Careers & CTE

Name: ____________________________ Date: ______________

Student Worksheet

Your job this week. You are a nutrient recovery technician at the fictional Northsedge Water Reclamation Facility, which cleans wastewater for the town of Littlemoor. Part of the plant pulls phosphorus out of the water and packs it into hard fertilizer pellets that farms buy. You sample the water going into that unit and the water coming out, run the numbers, and write them in the shift log. Most technicians in this job start with a high school diploma, train on the job, and pass a state wastewater operator exam. Many add a two-year college degree in environmental technology, and the engineers who design the recovery units hold four-year degrees.

To find how much of something a unit removed, use this formula: removal percent equals the amount in, minus the amount out, divided by the amount in, times 100.

Northsedge shift log

Day	Phosphorus in (mg/L)	Phosphorus out (mg/L)
Monday	6	0.6
Tuesday	5	1

Answer every item. Show the numbers you used.

On Monday the water going in held 6 mg/L of phosphorus and the water coming out held 0.6 mg/L. What percent of the phosphorus was removed?
On Tuesday the water going in held 5 mg/L and the water coming out held 1 mg/L. What percent of the phosphorus was removed?
Using your answers to items 1 and 2, which day removed a greater percent of the phosphorus that came in?
Over 8 days the recovery unit packed 240 pounds of fertilizer pellets. How many pounds per day is that?
At that same daily rate, how many pounds of pellets would the unit pack in 30 days?
The plant sells the pellets for $0.40 a pound. What would 900 pounds of pellets sell for?
The whole plant treats 2 million gallons a day, and the recovery unit treats 0.5 million gallons a day of that flow. What percent of the plant's flow goes through the recovery unit?
The rules for secondary treatment set a monthly average limit of 30 mg/L for BOD, a measure of how much organic material is left in the water a plant releases. Northsedge reported 12 mg/L for the month. Did the plant meet the limit?
Northsedge could simply remove phosphorus and send it to a landfill with the rest of the solids. Instead the plant packs it into pellets and sells it. Give one benefit and one cost of the plant's choice.
Name two different education paths a person could follow into this job, using the information at the top of this worksheet.

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: 90 percent.
6 minus 0.6 equals 5.4. Then 5.4 divided by 6 equals 0.9, and 0.9 times 100 is 90 percent.
Answer: 80 percent.
5 minus 1 equals 4. Then 4 divided by 5 equals 0.8, and 0.8 times 100 is 80 percent.
Answer: Monday.
Monday removed 90 percent and Tuesday removed 80 percent, so Monday removed the greater percent of what came in.
Answer: 30 pounds per day.
240 pounds divided by 8 days equals 30 pounds each day.
Answer: 900 pounds.
30 pounds per day times 30 days equals 900 pounds.
Answer: $360.
900 pounds times $0.40 a pound equals $360.
Answer: 25 percent.
0.5 divided by 2 equals 0.25, and 0.25 written as a percent is 25 percent.
Answer: Yes.
The reported 12 mg/L is lower than the 30 mg/L monthly average limit, so the plant met the standard with room to spare.
Answer: Any one benefit and one cost.
Benefits include income from selling the pellets, less phosphorus reaching the river where it would feed algae, less material hauled to a landfill, and a fertilizer supply that does not have to be mined. Costs include the money to build and run the recovery unit, the electricity and chemicals it uses, the technician's time, and the risk that pellet prices fall and the sales do not cover the cost.
Answer: Any two of these paths.
A high school diploma with on-the-job training and a state wastewater operator exam, a two-year college degree in environmental technology, or a four-year engineering degree for the people who design the recovery units.

Differentiation

Support

Give these students a copy with the subtraction step already completed for items 1 and 2, so only the division and the percent conversion remain. Provide a simple bar drawing for each day, one bar for the phosphorus going in and a shorter bar for the phosphorus coming out, and have students shade the part that was removed before calculating. Assign items 1 through 5 and item 10 only.

Extension

Give students a third day at the fictional Northsedge Water Reclamation Facility: phosphorus in at 4 mg/L and out at 0.8 mg/L, with 22 pounds of pellets packed. Ask them to find the removal percent, compare it with Monday and Tuesday, and then write a short paragraph explaining why the pounds of pellets packed depend on how much phosphorus arrived at the unit and not on the removal percent alone.

ELL supports

Pre-teach "nutrient," "phosphorus," "removal," and "permit limit" with a labeled drawing of water entering a tank, pellets leaving the bottom, and cleaner water leaving the top. Write the removal formula on a card in words rather than symbols for students to keep beside the worksheet. Allow items 3, 9, and 10 to be answered in short phrases.

Extensions

Have students find out whether the wastewater plant serving their own community recovers nutrients or removes them as solids, using the plant's public reports or a phone call to the utility. Students then write a one-paragraph note to a plant manager naming one question they would want answered before the town spent money on a recovery unit.