I am an employee on salary. We work on prevailing wage projects all the time and I do the work of a general laborer and pipelayer yet my hourly salary is less than that of the prevailing wage. Is this legal? Do I have any recourse?

Do you belong to a Union or do you have an empliyment contract?

Otherwise it's employment at will, sort of - you either take or don't take a job based on the pay and other circumstances/conditions. If you don't want to work for the hourly wage paid you, you could quit and find a job that pays what you expect.

I see no violation of anything here as long as you are paid the minimum wage. Now, if it's Government contract work OR the prevailing work/pay language is in the contract, ask Wage and Hour in your State.