Evaluate Impact Solutions Practice Test

A town wants to reduce energy used for lighting in a public library. The library replaced old bulbs with LED bulbs.

Evidence:

• Before: the library used 1,000 kWh per month for lighting.
• After: the library used 720 kWh per month for lighting.
• Total library hours stayed the same.

Success criteria: reduce lighting energy use by at least 25% over three months. Solutions vary in effectiveness.

Does switching to LED bulbs meet the success criteria based on the evidence?

A river near a construction site has increased sediment (muddy water). The site added silt fences to keep soil from washing into the river.

Evidence (sediment concentration in mg/L):

• Upstream (not affected by site): stayed near 20 mg/L before and after.
• Downstream before fences: 80 mg/L
• Downstream after fences (1 month): 55 mg/L

Success criteria: downstream sediment should be no more than 40 mg/L. Solutions vary in effectiveness.

Which claim is unsupported by the evidence?