(a) Enforcement of chapter

Sections 38 and 39 of this title shall govern the Secretary's authority to enforce this chapter, make rules, regulations, issue orders, hold hearings, and make decisions based upon findings of fact, and take other appropriate action hereunder.

(b) Limitations and regulations allowing variations, tolerances, and exemptions

The Secretary may provide such reasonable limitations and may make such rules and regulations allowing reasonable variation, tolerances, and exemptions to and from any or all provisions of this chapter (other than section 358 of this title), but only in special circumstances where he determines that such limitation, variation, tolerance, or exemption is necessary and proper in the public interest or to avoid the serious impairment of government business, and is in accord with the remedial purpose of this chapter to protect prevailing labor standards.

(c) Predecessor contracts; employees' wages and fringe benefits

No contractor or subcontractor under a contract, which succeeds a contract subject to this chapter and under which substantially the same services are furnished, shall pay any service employee under such contract less than the wages and fringe benefits, including accrued wages and fringe benefits, and any prospective increases in wages and fringe benefits provided for in a collective-bargaining agreement as a result of arm's-length negotiations, to which such service employees would have been entitled if they were employed under the predecessor contract: Provided, That in any of the foregoing circumstances such obligations shall not apply if the Secretary finds after a hearing in accordance with regulations adopted by the Secretary that such wages and fringe benefits are substantially at variance with those which prevail for services of a character similar in the locality.

(d) Duration of contract

Subject to limitations in annual appropriation Acts but notwithstanding any other provision of law, contracts to which this chapter applies may, if authorized by the Secretary, be for any term of years not exceeding five, if each such contract provides for the periodic adjustment of wages and fringe benefits pursuant to future determinations, issued in the manner prescribed in section 351 of this title no less often than once every two years during the term of the contract, covering the various classes of service employees