The water that was used for the morning washing is forbidden to be used for any purpose, as this water is forbidden in benefit due to the impurity that resides on it. Therefore one may not leave the water lying in his house and he may not spill the water on the ground, or any other place where people pass by, as perhaps a person will touch the water and get injured.
A Segula for Yiras Shamayim:
It is a Segula for fear of heaven to discard the washing water outside of one’s home. It suffices to spill the water down the sink or toilet in order to fulfill this Segula.
Where is one to discard the water?
It suffices to spill the water down the sink or toilet. However one must take great heed not to spill the water over food vessels. If one did so he is to wash the vessels very well afterwards.
May one give this water to another person if requested?
If someone requests the washing water it is forbidden to give it to him as they are certainly asking for it in order to perform sorcery.
May one water plants with this water?
What is one to do if the water spills on the floor?
One is to pour pure water over it hence nullifying the impurity.
If someone touched the impure water must he re-wash his hands?
He is to clean his hands. He is not required to rewash his hands three times in-consecutively.
 Kama 4/9 based on Zohar brought in Kaf Hachaim 31-32
 One can be injured through leaving the water in the home. [Oar Tzaddikim 4/9]
 Dvar Yitzchak 112 in name of Sar Shalom of Belz
 Beir Moshe 8/39
 Beir Moshe 8/39; Salmas Chaim 17
 Ashel Avraham Butchach 4
 Bach in name of Zohar; Peri Megadim 4 A.A. 7; Levushei Serud brought in Kaf Hachaim 4/29
 Kaf Hachaim 4/31
 Rambam Hilchos Rotzeiach 11/15 regarding revealed waters
 Kaf Hachaim [Falagi] 8/7 based on Chida in Moreh Batezba
 Ben Ish Chaiy Toldos 8; Kaf Hachaim 4/32
 Artzos Hachaim 4/51 as the hands do not become impure again through touching the water. Nevertheless the hands must be cleaned as it is similar to having feces on the hands.