Organic and particulate removal, desalination, and disinfection are the major classifications of produced wastewater treatment technologies. This chapter presents a qualitative comparison of produced wastewater technologies to provide an assessment of the benefits and limitations of each technology for produced water applications. Oil and water separation at onshore sites generally involves some form of oil/water separator or free water knockout vessel. Hydrocyclones have been used for surface treatment of produced wastewater for several decades. Hydrocyclones can be used to remove particulates and oil from produced wastewater. Hydrocyclones have been used extensively to treat produced wastewater and are marketed by numerous companies for produced wastewater. The primary goals of produced wastewater ponds focus on simplicity and flexibility of operation, protection of the water environment, and protection of public health. Ponds are relatively easy to build and manage, they accommodate large fluctuations in flow, and they can also provide treatment that approaches conventional systems at much lower cost.