(a) In general
The Secretary or the transferred works operating entity may carry out, in accordance with subsection (b) and consistent with existing transfer contracts, any extraordinary operation and maintenance work on a project facility that the Secretary determines to be reasonably required to preserve the structural safety of the project facility.

(b) Reimbursement of costs arising from extraordinary operation and maintenance work

(1) Treatment of costs
For reserved works, costs incurred by the Secretary in conducting extraordinary operation and maintenance work will be allocated to the authorized reimbursable purposes of the project and shall be repaid within 50 years, with interest, from the year in which work undertaken pursuant to this subchapter is substantially complete.

(2) Authority of Secretary
For transferred works, the Secretary is authorized to advance the costs incurred by the transferred works operating entity in conducting extraordinary operation and maintenance work and negotiate appropriate 50-year repayment contracts with project beneficiaries providing for the return of reimbursable costs, with interest, under this subsection: Provided, however, That no contract entered into pursuant to this subchapter shall be deemed to be a new or amended contract for the purposes of section 390cc(a) of this title.

(3) Determination of interest rate
The interest rate used for computing interest on work in progress and interest on the unpaid balance of the reimbursable costs of extraordinary operation and maintenance work authorized by this subchapter shall be determined by the Secretary of the Treasury, as of the beginning of the fiscal year in which extraordinary operation and maintenance work is commenced, on the basis of average market yields on outstanding marketable obligations of the United States with the remaining periods of maturity comparable to the applicable reimbursement period of the project, adjusted to the nearest 1/8 of 1 percent on the unamortized balance of any portion of the loan.

(c) Emergency extraordinary operation and maintenance work

(1) In general
The Secretary or the transferred works operating entity shall carry out any emergency extraordinary operation and maintenance work on a project facility that the Secretary determines to be necessary to minimize the risk of imminent harm to public health or safety, or property.

(2) Reimbursement
The Secretary may advance funds for emergency extraordinary operation and maintenance work and shall seek reimbursement from the transferred works operating entity or benefitting entity upon receiving a written assurance from the governing body of such entity that it will negotiate a contract pursuant to this section for repayment of costs incurred by the Secretary in undertaking such work.

(3) Funding
If the Secretary determines that a project facility inspected and maintained pursuant to the guidelines and criteria set forth in section 510a(a) of this title requires extraordinary operation and maintenance pursuant to paragraph (1), the Secretary may provide Federal funds on a nonreimbursable basis sufficient to cover 35 percent of the cost of the extraordinary operation and maintenance allocable to the transferred works operating entity, which is needed to minimize the risk of imminent harm. The remaining share of the Federal funds advanced by the Secretary for such work shall be repaid under subsection (b).