Aquifer Sampling and Assessment Program

Approximately 200 water wells are included in a statewide well grid.  This number varies over time due to owner participation, which is strictly voluntary, and due to operational status of each well.  The water wells are located in fourteen of Louisiana's major aquifers and aquifer systems and are sampled by LDEQ at no cost to the well owner. The sampling process is designed so that the fourteen aquifers and aquifer systems are monitored on a rotating basis, within a three-year period so that each well is monitored every three years.

 

Currently a well density of at least one well per 400 square miles is maintained for each aquifer.  An effort is made to distribute the wells evenly within the areal extent of each aquifer, and various well use types are selected to be included in the ASSET Program.  This distribution and varied use of wells sampled helps to ensure that the data derived from the sampling of each aquifer is representative of the aquifer as a whole.  The following types of wells are monitored:  domestic, public supply, industrial, irrigation, observation, power generation, and monitoring wells.

 

For each well, samples are collected and analyzed for the following parameters:  water quality, metals, nutrients, volatile organic compounds, semi-volatile organic compounds, pesticides, PCB's, and up to 1994, radioactivity.  The following field parameters are also recorded at the time of sampling:  temperature, pH, specific conductance, salinity, and beginning in March of 2003, total dissolved solids or TDS.  In addition to these, the geographic location (latitude and longitude) of each well is determined using real-time differentially corrected GPS. View the Analytical Parameter List for complete information

 

After each aquifer is sampled and all field and analytical data have been received and validated, an aquifer summary is written which reports and interprets the data for the aquifer.  All summaries together are used to complete a triennial report that summarizes the entire three-year monitoring rotation.  The Triennial Report and aquifer summaries are posted to LDEQ's website and all well locations are incorporated into LDEQ's Geographic Information System.  Field and laboratory results from the sampling of each well are mailed to the well owner.  Additionally, the data derived from the ASSET Program is available to interested parties statewide and nationally that are interested in the quality of Louisiana’s freshwater aquifers.