The assemblation of the filter parts and applying filter sand in a traditional monitoring well system is time spending, while storage and transportation of filter sand causes dirt and spoiling. The traditional use of bentonite in a auger hole around a well pipe often results in an insufficient sealing, as bentonite swells slowly, allowing sand to penetrate until the bore is completely sealed. An unsufficiently centred filter system often causes unsatisfactory filtering and bentonite sealing. A traditional monitoring pipe system requires more cleaning as necessary, while the amount of water flowing through is affected also. Our program consists of a series of products for application in a standard auger hole that help to reduce the complexity and the time of installation, avoid the necessity for cleaning, and improve the efficiency and the quality of the monitoring well system.
The quality monitoring well consists of three components: a ready-to-use all-in-one filter pipe, plain pipes with bentonite collar and a sand catcher and is also available in a longer version.
The prefab filter consists of a filter pipe with filter sand around the perforated pipe (outside diam. max. 60 mm), fixed by a filter gauze. After installation of the filter in the auger hole, only larger soil particles are stopped by the gauze, while smaller particles are stopped by the prepacked filtering sand. The function of the pipe slits is to stop the pre-packed filter sand only. The resulting filter is efficient, while the filter gauze with filter sand causes perfect centration of the filter, in a auger hole as well as in a casing.
The HDPE pipes with screwthread connection, having a diameter of 32x25 mm, and a length of 1 m, are provided with a bentonite collar. Installation of the monitoring well consists of applying a casing tube in the auger hole first, while secondly the well pipes and the prefab filter are to be fixed in a vertical position, sinking the fixed pipes down into the casing tube. As soon as the prefab filter has been sunk down to the right depth, the casing tube can be removed. The room around the well pipes in the auger hole at an impermeable soil layer is sealed by applying the plain pipe with the fixed bentonite collar. The well pipes are supplied in packages of 5 pieces.
The synthetic Sand/Bentonite catchers will keep backfill material, liquid sand and bentonite products in place along well material. Thus preventing these materials from moving to unswollen bentonite sections or to filter sections. The high quality prefab monitoring pipe components are suited for application in casing tubes with a diameter between 70 and 100 mm. High quality prefab monitoring pipe systems are characterized by the following advantages: