evidence: Have a question that's not answered on this page? Contact the Safe Drinking Water Hotline. [...] - the chemistry of the water (acidity and alkalinity) and the types and amounts of minerals in the water, - the amount of lead it comes into contact with, - the temperature of the water, - the amount of wear in the pipes, - how long the water stays in pipes, and - the presence of protective scales or coatings inside the plumbing materials. [...] You can also view and print a fact sheet on testing your home's drinking water.