•Designs systems to safely, efficiently, and effectively treat wastewater, remove harmful substances, and return water to the ecosystem; creates domestic or industrial treatment plants for water or wastewater.•Reviews and analyzes drainage systems for storm water or floodplains to ensure safety of the ecosystem; designs necessary structures such as bridges to safeguard the area.•Assesses the need for wastewater treatment systems based on current and projected future residences; conducts feasibility studies for the construction of water treatment facilities in the area.•Analyzes various wastewater treatment methods used to prepare water for industrial and domestic use; recommends the most effective method.•Analyzes disposal methods or treatments for sludge; recommends and develops sludge tre