Yes, it is acceptable to develop validated assessment alternatives to ACWA as long as the alternative complies with the following requirements:
5 CFR 300.103 states that selection procedures must have a rational relationship to job performance, including showing that the selection procedures were "professionally developed."
The phrase "professionally developed" comes from Title VII (Sect. 703h) (http://www.eeoc.gov/laws/statutes/titlevii.cfm). The Uniform Guidelines on Employee Selection Procedures (http://uniformguidelines.com/) interprets "professionally developed" to mean a selection procedure that is validated according to the technical standards in the Uniform Guidelines. The Uniform Guidelines also states that a validity study can be "performed by any person competent to apply the principles of validity research."
There was an unexpected error when performing your action.
Your error has been logged and the appropriate people notified. You may close this message and try your command again, perhaps after refreshing the page. If you continue to experience issues, please notify the site administrator.