49 CFR §655.5

1. (a)An employer subject to this part may petition the FTA for a waiver allowing the employer to stand down, per 49 CFR Part 40, an employee following a report of a laboratory confirmed positive drug test or refusal, pending the outcome of the verification process.
2. (b)Each petition for a waiver must be in writing and include facts and justification to support the waiver. Each petition must satisfy the requirements for obtaining a waiver, as provided in 49 CFR 40.21.
3. (c)Each petition for a waiver must be submitted to the Office of Safety and Security, Federal Transit Administration, U.S. Department of Transportation, 1200 New Jersey Ave., SE, Washington, DC 20590.
4. (d)The Administrator may grant a waiver subject to 49 CFR 40.21(d).