There were plenty of hazards and regulatory failures at a contaminated Ground Zero tower where two firefighters died, but that’s no reason to toss out manslaughter charges against three construction-company officials who worked there, a judge ruled yesterday.

The ruling puts the case on course for trial as soon as January. Mitchel Alvo, Salvatore DePaola and Jeffrey Melofchik — the only people criminally charged in the deadly August 2007 blaze at the former Deutsche Bank building — have pleaded not guilty to manslaughter.

Prosecutors say the men knew about, failed to fix and even covered up a break in a water conduit.

Firefighters Robert Beddia and Joseph Graffagnino got trapped on the burning 14th floor and died of smoke inhalation.