Ecology & Environment returned to profitability during its first quarter, but the Lancaster-based environmental services firm’s earnings still tumbled by 80 percent.

The weaker profits stemmed from a 13 percent decline in E&E’s revenues, which was spread evenly between its U.S. and international markets.

E&E said that it did less work during the quarter for the federal government, while its revenues from energy projects also declined. Its Walsh Environmental subsidiary in Colorado was particularly hard-hit, with revenues tumbling by 31 percent, the company said in a filing with the Securities and Exchange Commission.

E&E’s profits plunged to $242,527, or 6 cents per share, from $1.16 million, or 28 cents per share, a year ago, but that still was an improvement over the $946,000 loss that the company reported during the fourth quarter, which ended in July.

E&E’s revenues weakened to $36.8 million during the quarter that ended in October, from $42.3 million a year earlier. Both domestic and international sales declined by 13 percent.