Abstract: Apparatus and method are provided for sensing the presence of product and/or water in the annular space of a double wall storage tank. The apparatus includes both a product sensing element and a water sensing element that are operatively associated with each other to control the compression of a spring. The spring is operatively connected to a colored marker which is able to move from within an opaque tube to within a transparent tube using the force of the spring. When the product sensing element is contacted by product or the water sensing element is contacted by water so that the respective sensor weakens, the spring force is used to move the colored marker so that it is within the transparent tube. In such a position, the colored marker becomes visible, indicating that product and/or water are present in the annular space of the double wall storage tank.

Abstract: An apparatus and method are provided for detecting solvents, including hydrocarbons. The apparatus includes a hydrocarbon-soluble plastic rod which interconnects a mass or weight and a weighing assembly. The weighing assembly is operatively joined to an alarm indicator, which is utilized to inform the user as to whether hydrocarbons are present. In a preferred arrangement, the weighing assembly is connected to a housing, which is joined to the top of a well casing provided in the ground. The plastic rod may be of any desired length, depending upon the depth of the well casing and where it is desired to check for hydrocarbons. When hydrocarbons are detected the plastic rod dissolves or separates causing movement of the weighing assembly and the alarm indicator so that a visual indication is provided that hydrocarbons are present. The apparatus further includes a mass catch assembly for maintaining connection between the mass and the housing after the plastic rod separates due to the presence of hydrocarbons.

Abstract: An apparatus is provided for gathering monitored data from one or more selected wells of a number of wells and reducing the monitored data in a real time manner to a useful form for analysis by one skilled in ground water evaluation. The apparatus can also be used to control the discharge rate of well water to further assist in the analysis of the characteristics of the selected wells. The apparatus is an integrated system which includes a computer, a number of inter-communicating modules, probes inserted in the wells for sensing water level, and a flow meter for use in measuring water flow rate. A control module directly interfaces with the computer and controls the sending of control and data information to and from the computer. A pump/flow module communicates with the control module and is used in controlling the discharge rate of water from a selected well operatively joined to a pump.