What are the current and emerging technologies for detecting and quantifying groundwater contaminants?

1 Sampling methods

One of the most common and traditional ways of detecting and quantifying groundwater contaminants is to collect water samples from wells, boreholes, or springs, and analyze them in a laboratory. However, this method has some limitations, such as high costs, time delays, spatial variability, and potential errors in sampling and handling. To overcome these challenges, some new technologies have been developed, such as passive samplers, which can be left in the groundwater for long periods and capture contaminants over time, or direct push samplers, which can collect discrete samples at different depths using a hydraulic or pneumatic device.

2 On-site analysis

Another way of improving the detection and quantification of groundwater contaminants is to perform the analysis on-site, rather than sending the samples to a laboratory. This can reduce the costs, time, and errors associated with sample transport and storage, and provide more immediate and accurate results. Some of the on-site analysis technologies include portable or handheld instruments, such as colorimeters, spectrometers, or sensors, that can measure various parameters, such as pH, conductivity, metals, or organic compounds, or field kits, such as immunoassays, biosensors, or strips, that can detect specific contaminants, such as pesticides, bacteria, or hormones.

3 Remote sensing

Remote sensing is the use of aerial or satellite imagery, radar, or other electromagnetic signals to observe and measure the surface or subsurface features of the earth. Remote sensing can be useful for detecting and quantifying groundwater contaminants in large or inaccessible areas, or for monitoring the temporal and spatial changes in groundwater quality. Some of the remote sensing technologies include thermal infrared imaging, which can identify groundwater discharge zones or temperature anomalies caused by contaminants, or hyperspectral imaging, which can detect the spectral signatures of different contaminants or vegetation stress.

5 Isotopic methods

Isotopic methods are the use of the stable or radioactive isotopes of different elements to trace the origin, age, or fate of groundwater or contaminants. Isotopes are atoms of the same element that have different numbers of neutrons, and therefore different masses and decay rates. Isotopic methods can be useful for detecting and quantifying groundwater contaminants by measuring the ratios or concentrations of different isotopes in the groundwater or contaminants, and comparing them with the background or source values. Some of the isotopic methods include carbon-14 dating, which can estimate the age of groundwater or organic contaminants, or chlorine-36 tracing, which can track the migration of chlorinated solvents.

6 Molecular methods

Molecular methods are the use of the genetic or biochemical information of microorganisms or contaminants to identify, characterize, or quantify them. Molecular methods can be useful for detecting and quantifying groundwater contaminants by analyzing the DNA, RNA, or proteins of the microorganisms or contaminants in the groundwater, and using specific markers, probes, or enzymes to detect or amplify them. Some of the molecular methods include polymerase chain reaction (PCR), which can amplify and quantify the DNA of specific microorganisms or contaminants, or enzyme-linked immunosorbent assay (ELISA), which can measure the antibodies or antigens of specific contaminants.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?