There are specific tests to determine each of the inorganic contaminants. This is dependent on type of toxicity and the degree of toxicity. Generally when its metal poisoning chelation therapy is done not only to neutralize not only toxicity but also to prevent further absorption from taking place. The water suppliers have to follow specific protocols to keep the level of contaminants below MCL and if found to be higher need to follow specific protocols to handle the situation. Drink and cook only with cold water.
Hot water tends to dissolve lead from pipes.
Let the water run for about one minute or until a change in temperature occurs in the morning before drinking water from your tap. For private wells, consider water treatment devices such as calcite filters that reduce acidity and make water less corrosive. Reverse osmosis devices.