Hydrology
Hydrology is the study of the distribution and movement of water as it pertains to the earth and its impact on human activity. Deuterium oxide (heavy water or D2O) can provide insights into the movement of water within an aquifer when injected into the water table. Deuterium can be detected in small amounts, informing researchers where and how much water is passing through a specific area. There are many advantages of using deuterium as a tracer, including:
1H2O and D2O are chemically equal. Therefore, the injected tracer is not affected by changes due to various processes (e.g., physical, chemical, and biological).
Oftentimes, the use of D2O does not need authorization by regulatory agencies.
By enriching groundwater with D2O, the natural deuterium content is increased (ranging from 10-100%). In most cases, deuterium contents in groundwater with added D2O are in the range of naturally occurring waters.
D2O leads to no perceivable changes to water. This is of primary importance in most tracer studies, like tracing groundwater in direct proximity of mineral water production wells.
Fracking
Hydrology and using deuterium as a tracer is applied in environmental studies, water mapping, and in the monitoring of hydraulic fracturing, otherwise known as “fracking.” Deuterium oxide is used in fracking to explore natural gas by oilfield services and applications, as a tracer in drilling fluids, and in geological research. There are no harmful chemicals associated with deuterium oxide, and it is a stable isotope, so its hydrological applications do not cause environmental hazards.