Clean Water for Our School Mission
Your school has a water problem. Investigate three contamination scenarios, test water samples from 3 sites, choose filtration solutions, and build a 2-step treatment chain to make the water safe. Compare quality and cost to find the best solution.
Guided Experiment: Find and Fix the Water Problem
Pick a scenario (Factory Runoff, Farm Fertilizer, or Old Pipes). Before testing, predict which site will have the worst contamination and which treatment you think will work best. Write your prediction.
Write your hypothesis in the Lab Report panel, then click Next.
Controls
Choose a contamination scenario
A factory upstream has been releasing waste into the creek. Three sites near the school have been flagged for testing.
Site A
Site B
Site C
Data Table
(0 rows)| # | Site | Contaminant | Level | Treatment 1 | Treatment 2 | Quality(%) | Cost($) |
|---|
Reference Guide
Water Contaminants
- Heavy Metals. Copper, mercury, and arsenic from factory waste. Can cause serious health problems.
- Chemicals. Solvents and dyes from industrial runoff. Harmful at low concentrations.
- Sediment. Dirt and sand particles that make water cloudy and carry other pollutants.
- Nitrates. From fertilizer runoff. Dangerous for infants at high levels.
- Bacteria. From animal waste. Can cause illness including E. coli infections.
- Lead. Leaches from old pipes. Harmful even at tiny amounts, especially for children.
Filtration Methods
- Sand Filter ($50). Layers of sand and gravel trap sediment and rust particles.
- Charcoal Filter ($80). Activated carbon absorbs chemicals, lead, and taste compounds.
- UV Light ($120). Ultraviolet rays destroy bacteria and algae without chemicals.
- Boiling ($30). High heat kills bacteria and viruses. Cheapest but only works for microbes.
Most real water treatment plants use multiple steps, just like in this lab.
Contamination Levels
Contamination levels tell you how much pollutant is in the water. Higher levels are harder to treat and require more effective or multiple treatments.
- Low. Small amount. A single treatment may be enough.
- Medium. Moderate amount. Usually requires a matched treatment.
- High. Large amount. Almost always needs two targeted treatments.
Quality vs. Cost Trade-offs
In real engineering, you cannot always use the most expensive solution. Engineers must balance performance (quality) with budget (cost).
A treatment that targets the actual contaminant will always work better than one that does not. Matching the treatment to the problem is more important than price alone.
When two treatments work together, the total quality improvement adds up, but the cost also adds up. Find the pair that meets the 70% standard at the lowest possible cost.