Is the objective of a verb 'dump' suitable for a waste(trash) which was thrown by a person?
Solution 1:
As commenters have suggested, it is natural to use the verb 'dump' for disposing of a quantity of unwanted objects in a careless or unceremonious way.
Your example of 'he dumped his garbage on the street' sounds perfectly natural to me.
This is nuanced, but it feels a little unnatural to use 'dump' if you mean 'improperly disposing of a single small object', for example 'he dumped his book in the street' sounds slightly strange to me. But if the single object is large or cumbersome, such as a body, then it is fine.
It would be natural to say 'he dumped his books', (plural) 'he dumped his coffee', (liquids or objects from a container) 'he dumped his french fries', or 'he dumped his couch' (cumbersome/large single object).