Potty Time - Saving Water

1. Take a look at the graphic below. What do see, what do you wonder?

2. How many gallons of water does this urinal save per flush compared to a standard urinal? How many gallons of water does a standard urinal use per flush? This urinal uses 16 oz. of water per flush.

According to the sign, a standard urinal uses 1 gallon of water per flush.

3. Here is a picture and details of a standard urinal. The 1.0 GPF means 1 gallon per flush. 128 ounces is equivalent to one gallon. Verify that the high efficiency urinal actually saves 88% more water than a standard urinal.

Since there are128 ounces of water in one gallon, this urinal saves 128 − 16 = 112 ������ per flush.

!!" !"#$%& ∗ 100% = ������� �� 87.5% per !"# !"#$%& flush.

It doesn’t stop with the urinals, there are water saving toilets too! See the info on toilets on the next page.

Toilet water use can vary significantly. Older toilets can use 3.5, 5, or even up to 7 gallons water with every flush. Federal plumbing standards now specify that new toilets can only use up to 1.6 gallons per flush (GPF), and there are high efficiency toilets that use up to 1.28 GPF

4. Based on the info, does a new high efficiency toilet or a urinal save a greater percent of water compared to older models? Explain or show your reasoning.

A high efficiency toilet that uses 1.28 gallons per flush will save:

3.5 gallons - 1.28 gallons = 2.22 GPF savings

2.22 ������� ∗ 100% ≈ 63% ������� 3.5 �������

5 gallons - 1.28 gallons = 3.72 GPF savings

3.72 ������� ∗ 100% ≈ 74% ������� 5 �������

7 gallons - 1.28 gallons = 5.72 GPF savings

5.72 ������� ∗ 100% ≈ 82% ������� 7 ������� We only looked at one kind of urinal savings and found that we could save 87.5% of water usage by using that sort of urinal.

With toilets, we have several toilets to compare. We found 63% savings, a 74% savings, and an 82% savings. None of those savings were as great as the urinal savings.

5. If every toilet and urinal in the world were switched to high efficiency models, how much water could be saved per year? You might have to conduct some research to estimate the answer to this question. Tricky question.

Does everyone in the world use toilets?

According to the World Health Organization (WHO), in 2017, only 27% of the global population used private sanitation facilities connected to sewers from which wastewater was treated.

If the world population is about 7 million people than 27% of that population would be 0.27 ∗ 7,000,000 = 1,890,000 people that have access to flushable toilets.

Toilets use between 1 and 7 gallons per flush. People, on average, flush 6 to 8 times per day.

So the range of water used word-wide from flushing is between: 1,890,000 x 1 GPF x 6 flushes/day and 1,890,000 x 7 GPF x 8 flushes/day = Between 11,340,000 gallons per day and 105,840,000 gallons per day.

105,840,000 gallons per day - 11,340,000 gallons per day = 94,500,000 gallons that could be saved in the world (per day) if all toilets were water-saving toilets.

Per year = 94,500,000 gallons x 365 = 34,492,500,000 gallons

Sources: http://www.who.int/mediacentre/factsheets/fs392/en/ https://www.quora.com/How-many-flush-toilets-are-there-in-the-world

Brought to you by YummyMath.com Pictures taken in a bathroom and/or from Google.com