Sara is working on making her house more eco-friendly. She has a number of upgrades she wants to make such as replacing her toilet that uses 5 gallons per flush with a new toilet that uses 1.2 gallons per flush. She also wants to replace a leaky faucet in her kitchen. Finally, she would like to replace her old washing machine that uses 35 gallons of water per load with a new high-efficiency model that only uses 10 gallons per load.

Question

Sara is working on making her house more eco-friendly. She has a number of upgrades she wants to make such as replacing her toilet that uses 5 gallons per flush with a new toilet that uses 1.2 gallons per flush. She also wants to replace a leaky faucet in her kitchen. Finally, she would like to replace her old washing machine that uses 35 gallons of water per load with a new high-efficiency model that only uses 10 gallons per load.
Which item should Sara replace first and why? Support your answer with evidence and reasoning.

GPT-4o mini · Answer

To determine which item Sara should replace first for the greatest environmental impact, we can evaluate the water savings from each upgrade.

Toilet Replacement: The current toilet uses 5 gallons per flush, and the new toilet uses 1.2 gallons per flush. Assuming an average household flushes the toilet about 5 times a day, the annual water usage can be estimated as follows:
- Current Toilet: \( 5 \text{ gallons/flush} \times 5 \text{ flushes/day} \times 365 \text{ days} = 9,125 \text{ gallons/year} \)
- New Toilet: \( 1.2 \text{ gallons/flush} \times 5 \text{ flushes/day} \times 365 \text{ days} = 2,190 \text{ gallons/year} \)
- Water Savings: \( 9,125 - 2,190 = 6,935 \text{ gallons/year} \)
Faucet Replacement: The water savings from replacing a leaky faucet varies based on the leak. A small drip can waste around 3,000 gallons a year, while a more significant leak can waste much more. For the sake of this analysis, we'll estimate a typical leaky faucet might waste about 1,000 gallons annually, and a new faucet, if used properly, could save that entire amount. Let's assume that replacing the faucet saves 1,000 gallons/year.
Washing Machine Replacement: The current washing machine uses 35 gallons per load, and the new high-efficiency one uses 10 gallons per load. If we assume an average of 5 loads of laundry per week, the water usage calculation is:
- Current Washing Machine: \( 35 \text{ gallons/load} \times 5 \text{ loads/week} \times 52 \text{ weeks} = 9,100 \text{ gallons/year} \)
- New Washing Machine: \( 10 \text{ gallons/load} \times 5 \text{ loads/week} \times 52 \text{ weeks} = 2,600 \text{ gallons/year} \)
- Water Savings: \( 9,100 - 2,600 = 6,500 \text{ gallons/year} \)

Comparison of Savings:

Toilet: 6,935 gallons/year
Faucet: 1,000 gallons/year
Washing Machine: 6,500 gallons/year

Conclusion:

Based on the water savings calculated, Sara should replace the toilet first. This upgrade offers the highest potential for water conservation at 6,935 gallons per year, compared to the faucet at 1,000 gallons and the washing machine at 6,500 gallons. By prioritizing the toilet, Sara maximizes her impact on reducing water consumption and enhancing her home's eco-friendliness.