ALS its a decease that attacks the nervous system. The subject with ALS will start having trouble speaking, then gradually his muscles will start losing their function. The person will start having difficulty moving arms and legs. As days and weeks pass , his ability to totally move will be lost. He will be fully paralized. Without speaking and moving the person will be like trapped in a puppet. That will be the worse feeling ever. Then the muscles that helps digestion fail and the person wont be able to eat or drink or to taste the good food ever again. He will be forced to eat and drink surgically , through a tube implanted in the stomach. Then for last ,about 5-7 years, the respiratory muscles will fail and the person will die. Its one of the worse deceases ever. My grandpa died of it.
About the water wasting... yes its true that thats a lot of water going out without a specific use but to compare it with the total consumption of water for a person/day, and for a group of persons or a small city/ day the als water consumption its quite small. Not to forget that water is the only element that can circle in a small amount of time , 1-2 days. You pour the water in the ground. The plants will get the water or the sun will vaporize it. After a few days it will come back as rain or snow and join up with seas or rivers from witch thanks to the modern filtering system it gets pourified and turned into drinkable water, and so the process goes on.
Water never goes wasted , but it turns from one matter to another. Same as energy.