Wahlco Environmental Systems: The company said Monday...

Wahlco Environmental Systems: The company said Monday that its Santa Ana-based subsidiary, Wahlco Inc., will install its pollution control system at a large power plant in Webster, Tex. Terms of the contract, awarded by Houston Lighting & Power Co., were not disclosed.

Wahlco said it expects to complete installation of the system--which reduces the emission of nitrous oxide, a component of acid rain--in December, 1995.

Wahlco Environmental Systems, based in Irvine, designs and manufactures air pollution control systems for electric utilities, cogeneration plants, petrochemical refineries and industrial manufacturers.