Answer:
It contains a negative connotation because when something is contaminated, it contains a harmful substance.
Step-by-step explanation:
Connotation is the feeling a word or phrase inspires in the person reading a statement. This is apart from its literal meaning.
In the given scenario the statement - There are strict laws in place regarding the dumping of waste, in part to avoid the possibility that drinking water supplies will become contaminated.
Implies that wastes being dumped leads to poisoning or introducing harmful substance into the drinking water.
Contaminated has a negative connotation because it implies something that can bring harm.