Doherty Smith & Associates have extensive experience providing monitoring well locations for various purposes including mining, contamination investigation and monitoring.The services of a surveyor are required to determine the location and level of monitoring wells. The coordinates of the well are provided in Map Grid of Australia (MGA94) format which is standard statewide. Levels of the well head are provided based on the Australian Height Datum (AHD).
Doherty Smith & Associates have been involved with many monitoring well location projects for contamination investigation in Central West NSW. In addition, wells have been located for mining projects.
Monitoring wells are typically located using Total Station (Infra-red distance measuring) to ensure accuracy of stated levels and coordinates. In more remote areas, GNSS (Global Navigational Satellite System or GPS) is used in combination with Total Station measurements.
The results of a monitoring well location survey are presented as a plan showing the location of the wells in relation to the subject site and a table with the MGA94 coordinates of the well, the level of the lid of the well and the level of the well head. In most cases, the plan will show an aerial image of the site as background information.
Monitoring wells for contamination investigation are installed at facilities with above ground or underground fuel tanks such as fuel depots, service stations and private land. The well head levels are used to determine groundwater levels across a site.The wells are used to check the quality and level of groundwater across a site. The wells are monitored periodically, with a monitoring interval dependent on the type of monitoring being carried out and the severity of the contamination involved. In cases where groundwater is severely contaminated, rehabilitation wells or injections walls can be installed, where chemicals are introduced to the groundwater to break up any contamination present.
Contaminated sites may have a varying number of wells installed, with our largest well location project to date having some 80 wells for groundwater monitoring, testing and rehabilitation, extending over an area of approximately 32 hectares and over a period of seven years.
Groundwater monitoring wells can be installed over a large area to monitor the groundwater levels and are typically used for large scale projects. Groundwater monitoring wells are typically located using GNSS and if necessary total station. Varying GNSS techniques can be used depending on the scale of the project and the location of nearby marks with accurate coordinates and AHD levels.
Often, monitoring wells are installed at the completion of new built service stations and monitored periodically to ensure that any fuel leakage into the groundwater is detected early. In such cases, monitoring wells have more of a preventative role than a remediation role.
Doherty Smith & Associates can provide coordinates and levels for monitoring wells for all purposes to specified accuracy, and present the data in a format that is clear and easy to understand.