52 States in 8 Months

Wasting water.

Posted in Newark, Stupidities by Ulf on June 10, 2009

A few days ago I had to observe how a water tower was drained (look at the water hose that leads to the street!):
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It took more than a day until the whole thing was empty. I was really feeling sad when I saw this waste of natural resources. But let’s do the math:

a) How much water is thrown away?
From Google Maps I would estimate that the water tower has a diameter of about 13m. Let’s assume it is a sphere, that would give it a capacity of 1,150m3 of water. Let’s take 1,000m3 to keep the calculations simple.
Different sources suggest that the average indoor water usage per person is about 70 gallons/day. What does that mean for our water tower? A single person would need more than 10 years to use all the water that was wasted here! Enough to supply 4,000 Americans for one day. I don’t know about the water prices here in the US. In Magdeburg it currently is at 1.81 Euro/m3. If the price in the US is similar, then about $2,500 where thrown away when this water tower was drained (assuming that the water tower was full when they started the draining).

b) How much energy is thrown away?
Looking at the picture, the structure might be about 30m high. Once again, assuming that the tower was full, then there were 1,000,000 kg of water in there. That gives 294,300,000 J of potential energy, or about 81.75 kWh. That means that with American power prices (roughly $0.12/kWh), it costs about $10 to fill the whole thing (electricity only, I’m not considering the water at this point).
It’s hard to translate that to CO2 because different power plants give different numbers. At 700g CO2/kWh it would be 57kg CO2 for filling this tank.

Edit: A few days after the water was drained I finally saw someone working on the tower. Not the right job for me!!
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