During drilling activities, temporary or permanent monitoring wells can be installed to assess the quality of groundwater on a job site. An Aztech geologist will log the geotechnical data associated with the site soil and identify the position of the water table during advancement of the borehole. Based on the observations made during drilling, the geologist will develop specifications for and oversee the construction of the monitoring well. Typically, soil borings are converted into monitoring wells that are constructed in a manner that is consistent with industry standards.
After completing the monitoring well installation, the top of the well casing elevation is determined at each location and is generally tied to a site datum of 100.00 feet. The purpose of establishing the top of casing elevations to the site datum is to collect subsequent depth to water measurements from each monitoring well so that groundwater elevations at each location can be determined and the direction of groundwater flow beneath the site can be evaluated. After the depth to water measurements are obtained, groundwater samples are collected from the newly installed monitoring wells, using disposable bailers, in order to evaluate the groundwater quality beneath the site. The groundwater samples are analyzed for contaminants of concern suspected at the site in accordance with state and federal regulations.
The data obtained during the field activities is compiled into a comprehensive Phase II Environmental Site Assessment (ESA) report that summarizes the field methods, observations, and analytical results for soil and groundwater sampling. The Phase II ESA report will also provide recommendations regarding future work at the site. This can include recommendations for additional soil borings and/or monitoring wells and can establish a frequency for subsequent groundwater sampling events. These recommendations can also be used to develop remedial alternatives for a site, if warranted.