While spaying is traditionally recommended for kitties between 4 and 6 months of age, spaying as young as 8 weeks old is considered safe, according to Cat Channel.
The national drinking water standards state that the maximum residual amount of chlorine is 4 mg/L. Untill recently the USA used chlorine gas extensively for wastewater treatment. Today, the use of chlorine has been forced back.
Most household chlorine bleaches have 4-6% available chlorine, in which case you should add 1/8 teaspoon (8 drops) of regular, unscented, liquid household bleach for each gallon of water (2 drops per quart/liter), stir it well, cover, and let it stand for 30 minutes before you use it.