Why is it important to conserve water if it gets recycled at the treatment plant anyway?

Question

Just got in an argument with my girlfriend about conserving water. She says "why bother it just gets recycled at the treatment plant." Water bill is included in rent, so she doesn't mind leaving the cold water run forever and I try to say it's wasteful. She says it gets recycled so it doesn't matter. Please help, is she right and I am just being a nag, or is she actually harming the enviroment?

Answer 1

Electricity is used to process the water so the more water used, the more electricity.

Answer 2

Water doesn't  get recycled at the treatment plant.  It gets cleaned up to a certain level of purity which is not drinkable, and then dumped into a river, from which it goes back to the ocean. Then it is recycled by the sun, which evaporates it, and the atmosphere, which carries it back over land, condenses it, and drops it back into the reservoir.  All this takes a lot of time, and if the atmosphere doesn't cooperate by dropping the rain when you need it, it is easy to suck the reservoir dry.  Many cities don't have enough reservoir capacity to hold out through a long drought.  Also, many places in dry areas get their water from underground aquifers (wells), which take very much longer to replenish.

The technology exists to purify wastewater enough to make it drinkable, and a few plants can do this, but they still don't pump the water directly into the reservoir because people don't trust the technology, and the idea of drinking directly recycled waste water is very repugnant.  Besides that, purifying water is expensive and energy consuming.

Even if we did completely recycle all our water, we would still run out at some point because the population of every place is constantly growing, and reservoirs need to be added to the supply.  There is only so much fresh water that can be collected from the atmosphere.  Eventually, we will suck up all the water from all the rivers in the world, and that point is not as far away as you think.  It has already happened to several major rivers, like the Colorado, which no longer reaches the sea.