I can not find any guildence on if a ER can use a Simple IRA for any EE's that they do not provide benefits for under the Davis-Bacon Pervailing Wage Act. That is, are they prohibited from using a Simple IRA if they must give specific benefits to certian EE's under Fed regs. Any help on this is greatly appreciated. Thanks

A simple plan may be maintained for non union ee/s even though contributions are being made for unionized employees in a separate plan (see IRC Section 408(p)(2)(D)). As you point out, the simple would not be useable in a Davis-Bacon situation.