Counterclaim: While volunteering to clean litter in a community might save that community money, it does not solve the problem that litter cleanup is a huge, expensive problem in the entire country.

What is the best rebuttal for this counterclaim?

When communities see how much money is saved by cleaning and preventing more litter, they will join the effort. Making a big difference often starts by making a small difference.
It is important to remember that litter costs the United States over $11 billion every year. Businesses and governments pay most of this cost.
Volunteering is free for the community. Anyone who volunteers saves the community money that they would have spent cleaning up the litter.