Tetra Tech Inc. announced late Thursday that it has acquired an Ohio provider of solid waste management services and a Canadian pipeline services company.

After the markets closed, the Pasadena engineering and professional services company said that the first acquisition, American Environmental Group Ltd. of Richfield serves clients in the solid and hazardous waste, environmental, energy, utility industries. The company has more than 500 employees and annual revenue of about $95 million.

Terms of the deal were not disclosed. Tetra Tech said that it expects the new unit will contribute about $50 million to net revenue and add 1 to 2 cents to adjusted earnings per share in the current fiscal year.

In the second deal, Tetra Tech acquired Parkland Pipeline, an Alberta company that serves the oil and gas industry in Western Canada. Financial terms also were not disclosed.

Parkland Pipeline provides technical support and construction services for pipelines and oilfields. The company has about 900 employees and generates annual revenue of about $140 million. Tetra Tech said that it will release that acquisition’s impact on its financials after the deal closes.

Tetra Tech shares earlier closed down 1 cent, or less than 1 percent, to $26.87 on the Nasdaq.