What’s been going on with corruption in Hawaii government these days? Way, way too much — and not nearly enough.

The excess has been in the cases themselves, two of which are linked to the same corporate interest, all of which reveal greed and the unwillingness to adhere to rules that apply to everyone in public service.

What’s lacking is regular oversight. Nobody seems to be watching the hands that hold the purse strings, until a whistleblower speaks up and, more likely than not, the federal prosecutors descend to clean up Hawaii’s mess.

The most recent scandal was also the most politically explosive for this campaign season on Maui. In a case originating from an informant’s tip, the FBI announced last week it has charged Stewart Olani Stant, the former director of the Maui County Department of Environmental Management, with taking $2 million in cash, gambling trips and casino chips from a Honolulu wastewater company owner. Stant pleaded guilty on Monday, and faces up to 20 years in prison.

In return for the undisclosed gifts over six years, federal officials charged, Stant directed $19 million in no-bid contracts to Milton J. Choy, owner and manager of H20 Processes LLC and Central Pacific Controls LLC. This is a classic example demonstrating the corrupting influence of such “sole-source” contracts, which don’t get the level of back-checking and reviews needed to keep county dealings honest.

Choy is the same executive who was at the center of the bribery case earlier this year that tarred the careers of former state lawmakers J. Kalani English and Ty Cullen. English and Cullen pleaded guilty to accepting bribes from Choy in exchange for doing his bidding on introducing and then killing legislative measures affecting his companies.

In another, unrelated investigation that surfaced in July, four alleged co-conspirators on Hawaii island were charged in a housing fraud scheme that diverted more than $10 million in affordable housing funds to them. The scheme involves Alan Scott Rudo, a Hawaii County housing specialist, who pleaded guilty to taking nearly $2 million in kickbacks and bribes to divert public funds.

The public should feel outraged by each of these scandals. The Stant case leaves Maui County governance under a cloud, certainly. That’s why Maui Mayor Michael Victorino, who is seeking reelection, was prompt in issuing a statement clarifying that the incident occurred during the administration of former Mayor Alan Arakawa.

In any event, Victorino’s statement on Friday that he had ordered an audit of no-bid contracts awarded to Choy’s companies is a logical one. It is important to know the extent of Choy’s interactions with state and county governments: There could be more shoes to drop, news of other participants in these illicit deals.

The question is: Why isn’t this kind of due-diligence review simply part of the regular routine?

Stant clearly needed someone else assigned to also sign off on the issuance of these contracts. Stant’s excuse, according to an interview with Politics on Maui, was that he had a blue-collar background and should have considered more carefully before taking the director’s job because he didn’t “speak political.” Choy, he said, is “one of my best friends.”

None of that flies, of course. Simple ethics, not a college degree, is enough to know that steering contracts to someone who is plying you with money is wrong.

This should be zero-tolerance territory, and the elected officials above these Cabinet members and other public servants need to hold them accountable.

The loss — beyond the millions of taxpayer funds that get funneled away — is the public trust that government officials act in the interest of anyone other than themselves.