Groundwater conditions at a site are important in both the design and construction of trenchless projects. Structurally, the groundwater level at a site controls the external groundwater pressure that will act on a pipe or installed liner. It also has an important impact on the provisions for face support in microtunneling or tunneling projects. The groundwater also can be tested for the presence of pollutants or other chemical characteristics that may require special provisions either during construction or that may affect longevity of the utility. It can also be important to assess fluctuations of groundwater levels over time (from historical records or by ongoing monitoring of groundwater wells) and to assess any potential long-term trends that may arise from natural or man-made influences (e.g. starting or ceasing industrial pumping in the region).
Depth / Elevation
Structurally, the groundwater level at a site controls the external groundwater pressure that will act on a pipe or installed liner. It also has an important impact on the provisions for face support in microtunneling or tunneling projects.
It can also be important to assess fluctuations of groundwater levels over time (from historical records or by ongoing monitoring of groundwater wells) and to assess any potential long-term trends that may arise from natural or man-made influences (e.g. starting or ceasing industrial pumping in the region).
Quality
Groundwater quality in terms of its chemical and biological constituents can be important to determine both for construction implications and for any impacts on the long-term performance of the installed or rehabilitated utility system. Examples include checking for chemicals that may impact the behavior of drilling fluids used in construction or the presence of chemicals that may increase the long-term corrosion potential for an installed pipe.