Groundwater Flow Field Distortion by Monitoring Wells and Passive Flux Meters

Area of Science:

• Hydrogeology
• Environmental Engineering
• Geoscience

Background:

• Groundwater lateral flow in monitoring wells often deviates from aquifer flow due to hydraulic conductivity and well construction.
• Accurate understanding of these flow differences is essential for passive measuring techniques like passive flux meters (PFMs).
• PFMs are used to measure groundwater and contaminant mass fluxes.

Purpose of the Study:

• To evaluate the impact of well screens, filter packs, and PFMs on groundwater flow within monitoring wells.
• To compare experimental flow field distortion with analytical calculations based on potential theory.
• To provide insights for designing monitoring wells optimized for PFM applications.

Main Methods:

• Laboratory flow tank experiments were conducted.
• The study investigated the influences of well screen, filter pack, and PFM presence.
• Results were compared against analytical flow field distortion calculations (Drost et al., 1968).

Main Results:

• Measured well flow field distortion factors were lower than calculated values.
• Measured PFM flow field distortion factors were generally comparable to calculated factors.
• Well screen geometry complicates analytical calculations when flow fields deviate from uniform flow.

Conclusions:

• The study quantifies flow field distortions in monitoring wells, essential for PFM accuracy.
• Analytical models provide a useful baseline, but experimental validation is key.
• Design plots enable optimization of well construction for effective PFM deployment in groundwater monitoring.