17 Mar Pressure Transducers Save Time and Money, Improve Accuracy in Groundwater Management
A Conceptual Site Model (CSM) allows ESA to better understand the physical, chemical, and biological conditions of a property, particularly in environmental assessments and groundwater management. As part of a CSM, the use of pressure transducers dramatically reduces the amount of time required to perform groundwater level monitoring while at the same time refining the precision of the data collected. This, in turn, provides time and cost savings to our clients while ensuring the scientific accuracy of the results.
The Advent of Pressure Transducers in Groundwater Management
The practice of groundwater monitoring has undergone significant transformation over the years, especially with the advent and adoption of pressure transducers. These advancements have not only streamlined the monitoring process but have also resulted in significant cost savings. The integration of pressure transducers in groundwater monitoring practices has redefined the methodologies used, offering advantages that were not available with traditional monitoring techniques.
In the past, groundwater monitoring was predominantly reliant on labor-intensive manual methods. Traditional approaches included the use of steel tapes, floats, and mechanical devices that required routine maintenance. The potential for human error — be it during measurement or data recording — often led to inconsistencies and inaccuracies in the recorded data.
A relatively recent advancement, pressure transducers have become an essential tool for collecting data on water levels, providing critical information for understanding aquifer behavior, and conducting hydrogeologic studies. In addition to their precision and accuracy, one of the most compelling advantages of pressure transducers is their cost-effectiveness. By significantly reducing the labor needed for manual readings, organizations can allocate resources to other vital areas. Pressure transducers simplify the collection and management of groundwater data, which decreases operational costs associated with frequent field visits.
Key Role of Pressure Transducers in CSM Development
In simple terms, a pressure transducer measures changes in hydraulic pressure, which can be used to infer groundwater levels, groundwater flow, and subsurface interactions. Collectively, these data provide groundwater flow characterization, aquifer and well performance analysis, tidal and barometric effects on groundwater, and hydraulic barriers and preferential groundwater flow paths. Each of these benefits are described below.
Groundwater Flow Characterization: Pressure transducers measure hydraulic head and pressure variations in groundwater, helping to determine flow directions and gradients. Continuous monitoring provides data on seasonal or event-driven changes in groundwater levels. Measurements can be determined from every monitoring point at the same exact time.
During a recent project, ESA used pressure transducers at a property during a three-week period after noticing a change in flow direction from one sampling event to another. It was determined that off-site pumping from a nearby well changed the flow direction at times during the day and/or night when pumping occurred. ESA was able to pinpoint exactly when the off-site pumping started and ended each day.
Aquifer and Well Performance Analysis: Pressure transducers can be used during pumping tests and slug tests to assess aquifer properties such as hydraulic conductivity, transmissivity, and storage coefficients. Additionally, they assist in validating hydrogeologic models by providing accurate drawdown and recovery data.
ESA uses pressure transducers to assist with classification exception area calculations. Specifically, during short-term pump tests and slug tests, pressure transducers determine hydraulic conductivity from on-site wells. They are especially useful in wells that recharge quickly (e.g., sandy soil) because they measure minute changes that may be impossible to detect manually.
Tidal and Barometric Effects on Groundwater: Pressure transducers detect tidal influences and barometric pressure changes on groundwater, which can be crucial in coastal and riverine environments.
In addition to the example referenced above, ESA also used pressure transducers at a contaminated site adjacent to a tidally influenced river to determine the tidal impacts on groundwater movement.
Identification of Hydraulic Barriers and Preferential Flow Paths: Variations in pressure readings indicate impermeable layers, fractures, or conduits that influence groundwater flow.
ESA uses pressure transducers when drilling bedrock monitoring wells. It provides real-time data that detects subsurface fracture interconnections. When fractures are noted in the well being drilled, the time is manually recorded, and thus ESA can determine interconnection between the monitoring wells and fractures within those well.
Pressure Transducers: An Essential Tool
Pressure transducers are an essential tool during groundwater studies. They offer high-resolution, real-time data that enhances the accuracy of site assessments and hydrogeological models. Their ability to continuously monitor water levels and pressure makes them important for environmental investigations. And, best of all, they save our clients untold sums of time and money.