Here is one link from Utah. 250 or so people declined saving about $350K
https://www.deseretnews.com/article/765637435/Utah-officials-say-welfare-drug-tests-save-money.html
1600 in Florida
https://drugfree.org/learn/drug-and-alcohol-news/almost-1600-welfare-applicants-in-florida-decline-to-undergo-drug-testing/
There are more out there. I had a big post on it but can’t find it.
Florida
1,597 welfare applicants decline drug test in Florida
http://www.syracuse.com/news/index.ssf/2011/10/1597_welfare_applicants_declin.html
h/t Orlando