When a river transports large quantities of sediments it is usually rendered “muddy,” a color somewhat similar to coffee with milk. Major tributaries with headwaters in the Andes are all turbid because of the huge amount of loose material in the high mountain chain that is easily eroded and then carried downstream as far as the Atlantic Ocean. Locally, these rivers are often referred to as whitewater rivers, though the term should not be confused with its English interpretation that can also refer the turbulent waters of rapids. These tributaries include the Madeira, Ucayali, Marañón, Putumayo-Içá and Caquetá-Japurá rivers. There are also several tributaries that do not have headwaters in the Andes but are also considered whitewater rivers because of their relatively high sediment loads, such as the Purus and Juruá. Whitewater rivers have a higher nutrient content than the blackwater and clearwater rivers. The pH of water in turbid rivers is often near or above neutral (7.0). At elevations higher than approximately 2,000 m in the Andes, the pH of river water can be above 8.0.