1977—Par. (2). Pub. L. 95–105 inserted “based on estimated calendar year 1976 costs, plus or minus such amounts as may be justified by reason of ordinary fluctuations in operation and maintenance costs involved therein,” after “$25,000”.

1973—Par. (2). Pub. L. 93–126 substituted “$25,000” for “$20,000”.

Amendment by Pub. L. 95–105 effective Oct. 1, 1977, see section 514(d) of Pub. L. 95–105, set out as a note under section 277d–3 of this title.