Advice request on safe use of bore hole water

I am not an expert in water but I need your advice. I am located at Kasoa city in Ghana in the Central region and have Just moved into a new apartment and the the water tastes like sea water. I also notice that after boiling, there is white sediment at the bottom in it, it's fading my clothes and when I mix any colour liquid in the water, it turns to different colour e.g a blue liquid will not be blue but rather lighter green.  The water is from a bole hole and being treated before entry into the 10000liter tank that passes it into the apartment. But the water is still salty like sea water. Please  note that the apartment is rented not owned by me. I have the following questions: 1. How to tell If I can use the water to cook? 2. How to know I can use the water to bath? 3. If I use the water for my laundry how can I stop the fading? 4. What can I do in my little way to resolve it because I don't have big money to do a complete treatment. Thank you for your good advice.