Introduction Concern: intrusion into confined aquifer in glacial sediments

Location of study area

Flooding of Retsof salt mine: March 1994 to January 1996 Point out rubble chimneys

Water-level recovery: 1996 to 2006 lower confined aquifer in the collapse area flooded salt mine

Increasing salinity in collapse area: 1996 to 2006 Apparent velocity 12m/year

Halite saturation (Sept 1996) and stratigraphy in the collapse area 3 types of waters: Halite brine Saline water in bedrock @ 30%, Ca, Mg, SO4, Br Confined aquifer @ 10% ~ sea water

Model domain

Saturation profile in collapse area (Sept 1996) Discuss fracture zones, extent and origin: regional vs collapse related Mine filled with brine, 60 billion liters, ~ 30% of aquifer volume Mine cavity squeezing shut -> soda cup analogy

Modeling approach

Model simulations

Recovery period simulations: saturation profiles Observed, 45-layer A&D, 159-layer w/ O/B-FZ

Development of saturation profile: Jan 1996 to Sep 2006 Model B confined aquifer fracture zone Inflow of saline water from bedrock fz Lateral diversion of brine in model B flooded salt mine

Brine migration: Jan 1996 to Sep 2006 Model A Model B Brine moves higher in model B—mixing and lower porosity

Saline water migration: Jan 1996 to Sep 2006 Model A Model B Less saline water inflow in model A

Freshwater migration: Jan 1996 to Sep 2006 Model A Model B Less freshwater remains in chimneys in model A Model A salinity: freshwater and bedrock water at top of chimney Model B salinity: freshwater and brine

Decline in saturation in response to pumping Model B is better match

Sensitivity of simulated pumping Model B w/ 3 fracture zones Important parameters: brine displacement rate, currently ~ 1.6 L/s

Affect of simulated pumping on saturation confined aquifer fracture zone flooded salt mine

Conclusions