toxic waste site vs toxic dumpsite

toxic waste site and toxic dumpsite both are nouns.

Word	Noun	Adjective	Verb	Adverb
toxic waste site	Yes	No	No	No
toxic dumpsite	Yes	No	No	No

As nouns, toxic waste site and toxic dumpsite are synonyms defined as:

toxic waste site and toxic dumpsite: a location where toxic wastes can be or have been disposed of (often illegally)

Other synonyms of toxic waste site include toxic waste dump.

toxic waste site (noun)	toxic dumpsite (noun)
a location where toxic wastes can be or have been disposed of (often illegally)	a location where toxic wastes can be or have been disposed of (often illegally)