There is little doubt that the merger of the Hartley-family business with the Simon Engineering Group of companies provided the right sort of ingredients for a successful and viable enterprise. The interaction of Hartley's long established experience in sewage purification plant and machinery manufacture and Simon's technical resources in the environmental field soon made rapid impact on development of new and better techniques in machinery being manufactured and the range of services being offered. National and international awakening of the dangers of pollution has also created an added impetus to Simon-Hartley's expansion.

The plant for mechanical handling and purification of sewage and industrial effluents, designed and manufactured by Simon-Hartley includes an impressive range of automated machinery suitable to equip a complete treatment works: mechanical screens, grit-removal plants, scraping machines for settling tanks, percolating filter distributors, aeration plants, sludge-digestion equipment, sludge-thickening and -dewatering machines, sand filters for tertiary treatment of treated effluents, and a variety of ancillary equipment like penstocks (sluice gates), valves and screw pumps. Much of the equipment has been supplied to major sewage works in Britain and many other countries.

Apart from the very necessary array of ironmongery, Simon-Hartley carries out process design, plant design, procurement, construction and commissioning of complete turnkey plants for industrial effluent treatment. Over 250 effluent plants for industrial effluent treatment have already been installed and are working on a variety of trades, notably metal-plating works, gas works, dye works, textile-finishing mills, paper mills, coking and carbonisation plants, slaughterhouses, as well as fruit and vegetable processing, brewing, canning, fat-processing and general chemical- and pharmaceutical-processing industries.

In 1972 Simon-Hartley acquired Coplastix Limited of Redditch, Worcestershire, as a fully owned subsidiary. The Coplastix Division is now a valuable member of the Simon-Hartley organisation, manufacturing a range of penstocks, valves and other fluid control equipment in exciting new plastic materials which usefully supplement similar Simon-Hartley products made in metal-based materials. Since joining the Simon-Hartley organisation, Coplastix Division has trebled its turnover and was able to double its space for production activities.

In 1976 Simon-Hartley purchased the whole of the share capital of Ashbrook Corporation of Houston, Texas, U.S.A. This company is already well established in the water pollution business with their own range of high speed and low speed aerators and floating spray coolers for the reduction of thermal pollution in water.

Simon-Hartley's comprehensive range of mechanical equipment and extensive expertise in the treatment of industrial effluents and sewage is founded on continual research and development work carried out in its own workshops and research laboratories. The company is well able to provide a comprehensive service to meet the needs of industry, municipalities, water companies, etc., in most aspects concerning problems of water pollution, effluent treatment and disposal. This service can be both advisory and contracting. It embraces on-site investigations, laboratory analyses, reporting to clients on methods of treatment, design, construction and commissioning of plant, and training of client's operators. Visits to client's premises can be arranged by members of the Simon-Hartley sales force or project engineers, whether for exploratory talks or fact-finding, discussions. In the field of effluent treatment, the combination of advisory, laboratory, manufacturing and contracting by a single organisation is indeed rare, if not unique."