In many cases, reuse of treated wastewater is not feasible or may cause high health risks. Consequently, treated wastewater is disposed off to nearby water bodies such as rivers, lakes, reservoirs, seas and oceans. Special care should be given in order to avoid pollution as a result of wastewater disposal. This implies choosing the suitable level of both treatment and disposal means. Long and deep sea outfall systems are used to discharge treated or partially treated wastewater far from the surf zone of the beach. This in turn reduces the pollution level by dilution process.