Voltas, a Tata group company that offers engineering solutions across a range of industries, hopes to use a major contract it has bagged for a water treatment project in Singapore to expand its activities in that area.Voltas and United Engineers (Singapore) Pte Ltd. have jointly bagged a Singapore $200 million (about Rs. 600 crore) component of the Singapore $2.2 billion Changi water reclamation plant. Voltas' share of that contract is Singapore $116 million (about Rs. 350 crore).