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Kevin Svitaga & Nicholas Grisso. “Temperature Measurements as a simple Method for evaluating Groundwater Flow through Fractured Rock.” AIPG ORG (2018): 24-29.
The understanding of the flow undercurrents in fractured rock aquifers has for a long time experienced a lot of challenges. Many people do not fully comprehend the mechanisms involved due to the numerous challenges involved like for instance the need for complicated equipment. However, in the article, Temperature Measurements as a Simple Method for Evaluating Groundwater Flow through Fractured Rock, authors describe a simplified approach of measuring temperatures to evaluate the flow of groundwater via fractured rocks. They use cheap Hobo temperature loggers to capture the involved changes in temperature in the fissured aquifer when the groundwater pumping is cycling normally. They also use an in situ data logger that records the level of water as well as the temperature to evaluate the relationship between the pumping of water and the treated water injection cycles with the changes in temperature. The central idea of using the two loggers is to investigate whether the Hobo loggers used were reliable methods of evaluating fluctuations in temperature linked to fracture flow.
The study followed Darcy’s law which involves making the assumption that in a constant flow of groundwater, the movement of groundwater is primarily through pores of the matrix. However, the researchers were aware that there could be a drift from the expected and the real clean up time due to the characteristic features of harmful wastes, the dense non-aqueous phase liquids (DNAPL) as well as their interaction with the aquifer material.

Similarly, when the flow is predominantly on the fractures, the flow then becomes irregular with high concentrations of contaminants. These compounds since they are denser than water, do not dissolve in the water. So they are only removed through pumping and then treating which involves the recovering of groundwater and then treating it and discharging the effluent DNAPLs to treatment works. Therefore, the procedures employed in the valuation and determination of the dynamic flow of groundwater in aquifers are important in determining whether the groundwater is predisposed to any contaminants that rebound after the cessation of the pumping process. Most of the methods used in mapping hydrological features of a subsurface are expensive hence the use of temperature variations provides an easy alternative that can detect any anomalies in the subsurface. The temperatures associated with fractures flow, help show that a site is predisposed to contaminations when the speed of flow decreases after pumping ends.
The study is a follow-up study uses only groundwater temperature changes ascribed to compare from regarded intrusion water temperatures as an intermediary to evaluate variable groundwater movements inside monitoring wells introduced in a non-homogenous aquifer and measures the fluctuations using the low-cost data loggers. The site area being Eastern Maryland, the region uses the pump and treat remediation to contain contaminated groundwater. Two zones were used which were the shallow zones between 493-500 feet mean sea level (MSL) and intermediate underlying zones of between 350-425 feet MSL since they were in communication with each other but had varying flow properties. Both the injecting and recovery wells were 6 cm in diameter and the treatment of the water was carried out in batches. The study employed air stripping in the treatment of groundwater and then injecting it in an aquifer since this creates a difference in temperatures that can be used to evaluate any possibilities of fracture flow conditions. The temperature only data loggers were then strategically placed in the monitoring wells of both treated and untreated water to capture the difference in temperatures so as to get the difference involved in treating water three times a day at an interval of one minute. The collected data showed significant changes in temperature.
In conclusion, it is clear that there are temperature fluctuations in the monitoring wells. These fluctuations coincide with the on and off pumping cycles. Therefore, this is an indication that the fracture flow directs the movement of groundwater in drenched zones.