How are freshwater and sewage organised and priced in Malaga Spain.
Are all city houses connected to public water and sewage?
Who owns the infrastucture, water source, sewage plants? public or private?
What are the prices for private households? separete water and sewage?
Can anyone own all different parts in the infrastructure of water and
sewage? e.g can a private company deliver water and another company
own the infrastucture?

Emasa (www.emasa.es) Empresa Municipal de Aguas de Málaga is the
public company who owns the infrastructure and supplies the water.
They bring the water to the homes by their pipes and guaratize the
quality of the water. Yes, they also manage sewage and they have
sewage plants.
They supply these services exclusively. 
You have one fee for having the water and the sewage and then you pay
for the water you use.