Whenever you create a new file in GoldSim while the Contaminant Transport Module is enabled (or if you enable the Contaminant Transport Module in an existing file), you will find a Container An element that acts like a "box" or a "folder" into which other elements can be placed. It can be used to create hierarchical models. named "Material" in the Model Root The top-level Container in a GoldSim model..
This Container contains two elements: the Species The chemical (or non-chemical, such as bacterial or viral) constituents that are stored and transported through an environmental system in a contaminant transport model. In GoldSim, the Species element defines all of the contaminant species being simulated (and their properties). element, and the Reference Fluid A special type of Fluid element that provides a basis for defining partition coefficients between media for the various species in the model (i.e., the ratio of the species’ concentration in the medium to its concentration in the Reference Fluid at equilibrium). (named "Water"):
This Container is created only for your convenience. If you want to, you can move these elements out of the Material Container to some other location, and you could then delete the Container. You can also rename the Reference Fluid "Water" to something else (e.g., Blood, Air). Note, however, that GoldSim will not allow you to delete either of these elements.