Risk assessment for environmental management systems in the manufacturing of wastewater transmission and discharge lines

Industrialization and urbanization are leading to an increase in water consumption. With higher water usage comes the challenge of removing used water. Wastewater from industrial facilities and residential areas getting indiscriminately dumped into nature without any treatment causes significant pollution in the environment. Especially, wastewater discharged into sea creates marine pollution. Wastewater transmission and discharge lines help prevent negative environmental effects. In recent years, the number of wastewater collection lines has increased, and there has been a significant rise in treated wastewater getting discharged to the sea in accordance with regulations. However, people still consider environmental investments to be superfluous. But, Turkey is investing a lot in environment. The number of treatment facilities are increasing, wastewater transmission and discharge lines are getting larger, and there are ongoing efforts to prevent uncontrolled discharges (chimney gases outside discharge limits released into atmosphere, illegal discharge of wastewater, solid waste dumped into environment). Wastewater lines are produced using various pipe types and manufacturing methods. There are 5 types of pipes: concrete pipes, glass reinforced plastic pipes, polyethylene pipes, spirally welded steel pipes, and ductile iron pipes. There are 3 manufacturing methods: open excavation, horizontal directional boring, and pipe jacking. Usually, spirally welded steel pipes are preferred for horizontal boring methods while steel pipes are used in open excavations. Deep sea discharge lines, enabling the discharge of wastewater into the sea, are built with spirally welded steel pipes. Marine pollution due to manufacturing and operational errors in the discharge of wastewater into deep sea is a major problem. This pollution has short and long-term impacts on the marine environment. This thesis studies, within the framework of environmental management systems, the advantages and disadvantages of deep sea discharge, a wastewater treatment method to prevent illegal discharging of wastewater, and the manufacturing methods of wastewater transmission lines, and also recommends solutions for problems encountered during manufacturing and operation. In this context, solution recommendations are presented for optimal treatment of wastewater after the deep sea discharge process and seamless production of wastewater transmission lines. Research has shown that the problems in the manufacturing methods of land lines lie with the heavy equipment used in wastewater manufacturing methods, imperfectly connecting pipe joints, not choosing the right pipe type, illegal disposal of excavation waste, and the negative environmental effects due to using backfill materials with incorrect grain diameter; while the problems in the manufacturing for deep sea discharge lie with deep sea discharge applications for water that has not been pre-treated, picking the wrong materials in the manufacturing process, and improper placement of the station point (first discharge point for water). It is necessary to apply deep sea wastewater discharge environmental management systems for right types of water allowed by domestic and international regulations, use corrosion-resistant materials in the manufacturing process, and pay attention to line length and depth while positioning the station point. In order to avoid negative environmental impact, it is key to enable timely maintenance of the heavy equipment used in the manufacturing of wastewater transmission lines and use authorized fuel retailers, deliver the excavation waste to facilities with disposal permissions, put up boards around the construction site, use ballast with the right grain diameter for backfilling, and pick the right pipe type and manufacturing method.