This is an introductory chapter to provide prospective on wastewater treatment objectives and regulations, basic design considerations, and processes used for wastewater treatment. The topics covered in this chapter are: wastewater treatment objectives and regulations; basic design considerations to include current and future trends in population growth, design period, wastewater characteristics and degree of treatment, treatment processes selection and combination, and other design factors; service area, treatment plant site selection, regulatory requirements and effluent discharge limitations; residuals production, handling and processing technology selection and combinations, and final disposal and reuse of biosolids; plant layout, plant hydraulics, flow through conduits, pumping, and flow measurement; energy and resource requirements, plant economics, and environmental impact assessment; general considerations in plant planning, design, and construction management. Also, discussed in Chapter 6, are the objectives of a wastewater treatment plant, which are to meet the federal, state, and regulatory authority standards in addition to preventing adverse environmental conditions.