Judge and improve a solution that reduces human impact
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
Table, Power-plant SO2 and scrubbers (EPA), with columns Measure, EPA figure
SO2 from power plants, 2023, 0.65 million tons; Drop from 1995 to 2023, 11.2 million tons (95%); Wet scrubbers remove, 90% to 98% of SO2; Wet scrubber trade-off, more water use and wastewater to treat; Dry scrubber trade-off, no wastewater; What cut SO2 since 1995, controls, lower-emitting fuels and other changes.
A classmate says scrubbers alone caused the 95% fall in power-plant SO2 since 1995. Ari checks the EPA table. Which reply fits?
- Yes: SO2 fell after scrubbers were built, so they caused it
- No: EPA credits controls, fuels and other changes together
- No: scrubbers cannot lower SO2 emissions from any plant
- Yes: scrubbers remove 90% to 98%, so they explain the 95% drop
Card (EPA)
a landfill has a liner, leachate collection, soil cover and monitoring. In 2018, 146.1 of 292.4 million tons of waste were landfilled.
Bo's friend says a lined landfill is safe, so landfilling is the answer to waste. Which reply is strongest?
- A liner cuts groundwater risk, but landfills still need land and care
- Landfilling beats recycling on each criterion we can score here
- Liners make groundwater risk worse, so landfills should end soon
- A liner removes the need for leachate collection once the cell closes
Card (EPA)
1 inch of rain on 1 square foot is 144 cubic inches, about 0.62 gallon. One cubic foot holds 7.48 gallons. A rain garden is a low planted area where runoff soaks in. A 600 square foot roof sheds about 372 gallons in a 1 inch storm.
A classmate says one rain garden solves flooding for a 600 square foot roof. Esme tests the claim. Which reply is strongest?
- Yes: it keeps the runoff out of the street drains in any storm
- No: rain gardens make runoff move off faster than pavement
- Yes: one garden size works for a roof of any size
- No: it holds a limited volume, so a big storm can exceed it
Card (EPA)
1 inch of rain on 1 square foot is 144 cubic inches, about 0.62 gallon. One cubic foot holds 7.48 gallons. A rain garden is a low planted area where runoff soaks in. A 900 square foot roof, a 2 inch storm and a 250 square foot, 6 inch deep garden.
A 900 square foot roof meets a 2 inch storm. Jun has 250 square feet for a 6 inch deep rain garden. Does it hold the runoff?
- No: it holds about 468 gallons, short by about 648
- Yes: it holds about 935 gallons, which is fine since storms are rare
- Yes: it holds about 1,870 gallons, more than enough
- No: it holds about 935 gallons, short by about 181 of the 1,116
Use the table
U.S. waste, 2018 (EPA)
Pathway Million tons Total generated 292.4 (4.9 pounds per person per day) Recycled 69.0 Composted 24.9 Other food management 17.7 Burned with energy recovery 34.6 (11.8%) Landfilled 146.1 (50%) Recycled and composted almost 94 (32.1%) If the extra tons diverted to reach 50% recycling and composting came from landfills, how much would Kira see landfilled?
- About 52 million tons, close to 18% of the waste
- About 198 million tons, close to 68% of the waste
- About 146 million tons, unchanged at 50%
- About 94 million tons, close to 32% of the waste
Card (model data)
Without controls a plant emits 1,000 tons of SO2 a year, and its permit limit is 60 tons a year. EPA: wet scrubbers remove 90% to 98% of SO2. Wet scrubber: 95% removed, $2,000,000 a year. Dry scrubber: 90% removed, $1,500,000 a year.
Model data: a wet scrubber removes 95% of 1,000 tons for $2,000,000 a year; a dry one removes 90% for $1,500,000. With a 60-ton limit, what does Luz pick?
- Wet: about $2,105 a ton, and the 50 tons left meet the limit
- Dry: about $1,667 per ton removed, so dry is the cheapest option
- Wet: about $4,000 per ton, found by dividing by 500 tons
- Dry: it needs no wastewater, so it also meets the 60-ton limit
Note: Weights: runoff counts 3, cost counts 2, upkeep counts 1, habitat counts 1. A town must choose between plans J and L. Milo asks which new fact would change the choice the most.
- A photo of each plan after a storm in a nearby town
- A note that plan L has the highest habitat score of 4
- A cost cap that needs a score of 3 or more, which L fails
- A vote on which plan has the nicest name for the project
Card (EPA)
a rain garden lets runoff soak in, filtering pollutants, and gives wildlife food and shelter. A 1 inch storm puts 0.62 gallon on each square foot of roof.
Pia claims rain gardens help water quality, not just water amount. Which EPA fact supports that claim best?
- EPA: rain gardens cost less than underground tanks
- EPA: rain gardens are planted, so they look green and neat
- EPA: rain gardens let runoff soak in and filter pollutants
- EPA: a roof sheds 0.62 gallon per square foot in a 1 inch storm
Use the table
U.S. waste, 2018 (EPA)
Pathway Million tons Total generated 292.4 (4.9 pounds per person per day) Recycled 69.0 Composted 24.9 Other food management 17.7 Burned with energy recovery 34.6 (11.8%) Landfilled 146.1 (50%) Recycled and composted almost 94 (32.1%) Tala writes one summary of 2018 U.S. waste from the EPA table. Which one fits?
- Of 292.4 million tons, most was burned to make energy
- Of 292.4 million tons, half was recycled and a third was landfilled
- Of 292.4 million tons, half was landfilled and about a third recycled or composted
- Of 292.4 million tons, half was landfilled and about 12% recycled or composted
Note: Weights: runoff counts 3, cost counts 2, upkeep counts 1, habitat counts 1. Zee writes one summary of the stormwater scoring table. Which one fits?
- J wins with these weights, and no change in weights could alter that
- K wins because it has the fewest scores of 1 on the card
- J wins with these weights; a habitat weight of 3 changes it
- L wins because its unweighted sum of 13 is the highest