Virus transport from drywells under constant head conditions: A modeling study

Area of Science:

• Environmental Science
• Hydrology
• Microbiology

Background:

• Arid regions face water quantity and quality challenges.
• Drywells are crucial for stormwater capture and managed aquifer recharge.
• Virus transport from drywells, especially with subsurface heterogeneity, is understudied.

Purpose of the Study:

• To quantitatively examine virus transport from drywells.
• To assess the impact of subsurface heterogeneity on virus fate.
• To evaluate virus removal efficiency under various scenarios.

Main Methods:

• Axisymmetric numerical experiments simulating virus transport.
• Analysis of homogeneous and stochastically heterogeneous subsurface domains.
• Investigation of varying virus removal rates and subsurface properties (hydraulic conductivity, correlation lengths).

Main Results:

• Virus breakthrough can occur even at 22 m separation.
• 6-log10 virus removal was not achieved with low detachment rates in homogeneous domains.
• Horizontal lenses improved virus distribution, while vertical correlation accelerated downward movement.

Conclusions:

• Standard separation distances for drywells may not guarantee water quality.
• Subsurface heterogeneity significantly influences virus transport and removal.
• Site-specific microbial risk assessments are essential for drywell applications.