NMCN (formerly North Midland Construction) has agreed to pay up to £3.76m, subject to a three-year earn-out.
LCS specialises in the design, manufacture and maintenance of water and wastewater treatment systems.
Under the deal, NMCN will pay just £1 initially and then staged payments based on performance over the next three years.
Norwich-based LCS made a pre-tax loss of £998,000 in 2018 on revenue of £8.5m.
Former shareholders David Owen and Jamie Thums will remain directors of both acquired businesses when NMCN tales over, with Mark Davy assuming the role of operational lead for LCS.
NMCN chief executive John Homer said: “The strong cash position we've been able to build in recent years has enabled us to take the next step in broadening our offering to the water sector. The acquisition of Lintott Environmental Technologies and Lintott Control Systems is an extremely exciting opportunity and a commercially viable deal. This acquisition offers an excellent opportunity for NMCN to strengthen and expand our already established offering to the UK water industry and potentially other markets in the future in providing off-site build, chemical dosing systems, motor control centres and control systems.
“The acquisition complements our full asset lifecycle management offering to the water sector in offsite manufacture, production and maintenance of assets. We look forward to progressing our product offering combining our own experience with the newly acquired colleagues, skills and expertise to reinforce our market leading position in this sector.”
LCS managing director David Owen said: "We were attracted by the market opportunity and business development opportunities presented by joining NMCN. We look forward to supporting the wider business in achieving its growth objectives and in delivering exceptional customer service."