https://www.dodig.mil/Whistleblower-and-DoD-Hotline/Cash-Awards-Program/
https://www.epaoig.gov/cash-awards-program-disclosure-fraud-waste-or-mismanagement
https://www.howtoreportfraud.com/state-and-federal-whistleblower-rewards-for-reporting-fraud/
https://constantinecannon.com/practice/whistleblower/whistleblower-types/whistleblower-reward-laws/
Not all these cover waste, but they already exist.