Abstract ........................................................ 1
Introduction .................................................... 2
Hydrogeologic Setting ........................................... 6
Mine Flooding and Aftermath ..................................... 7
Flooding and Formation of Rubble Chimneys .................... 7
Water-Level Recovery and Migration of Brine ................. 10
Interception of Brine and Saline Water ...................... 10
Geochemical Modeling ........................................... 13
Inverse Models .............................................. 15
Forward Models .............................................. 19
Discussion of Results from Geochemical Modeling ............. 21
Simulated Migration of Brine and Saline Water During Water-
Level Recovery ................................................. 23
One-Dimensional Flow ........................................ 24
Three-Dimensional Flow ...................................... 24
Model Design ............................................. 26
Model Calibration ........................................ 29
Model Results ............................................ 30
Discussion of Results ....................................... 37
Simulated Pumping of Brine and Saline Water .................... 37
Model Design ................................................ 37
Model Results ............................................... 38
Model Sensitivity ........................................... 42
Discussion of Results ....................................... 42
Implications for Future Mitigation Efforts ..................... 44
Current Conditions in the Collapse Area ..................... 44
Considerations for Future Mitigation ........................ 46
Summary ........................................................ 46
References Cited ............................................... 49
Appendix. Wells and Boreholes in and near the Collapse Area
above the Flooded Retsof Salt Mine ................... 51
Figures
1. Map showing location of aquifer system and Retsof salt
mine in Livingston County, N.Y. ............................. 3
2. Stratigraphic section A-A' depicting rubble chimney above
collapsed room in saltmine, Livingston County, N.Y. ......... 5
3. Graph showing solubility of anhydrite (CaSO4) at 10°C as
a function of halite content (NaCl) in solution ............. 6
4. Topographic map showing location of sinkholes, and pumped
and monitoring wells in the collapse area above the
flooded salt mine, Livingston County, N.Y. .................. 8
5. Geophysical logs conducted in well Lv309 in April 1994 and
March 2004 .................................................. 9
6. Graphs showing drawdown and recovery of (A) water level
in well Lv368 (lower confined aquifer) near the collapse
area, and (B) brine level in wells Lv301 and Lv396
(flooded salt mine) ........................................ 11
7. Stratigraphic section B-B' showing rubble chimneys and
deformation zone in the collapse area above the flooded
salt mine and direction of flow during water-level
recovery, January 1996 through August 2006 ................. 12
8. Graph showing chloride concentrations observed within
the collapse area in well Lv309 (elevation 0 m) and well
Lv322 (lower confined aquifer) after inundation of
the salt mine, January 1996 through August 2006 ............ 13
9. Vertical profile of halite saturation with depth
measured in wells Lv309 and Lv322 in September 2006,
showing stratigraphy and sample depths of final waters
used in inverse geochemical models ......................... 14
10. Vertical profiles of halite saturation with depth in well
Lv309 measured in August 2004 and September 2006, showing
transition zone between brine and saline water in
the Bertie Limestone ....................................... 15
11. Stratigraphic section B-B' depicting screened intervals
of pumped and monitoring wells, and the distribution of
halite saturation within the rubble chimneys and
deformation zone in September 2006 ......................... 16
12. Graphs showing relation between halite saturation and (A)
chloride concentration in samples of saline water and
brine near the collapse area above the flooded salt mine,
and (B) specific gravity of halite brine ................... 20
13. Ternary diagrams showing water-rock reactions for
different mixtures of waters in the collapse area without
and with ion exchange ...................................... 22
14. Ternary diagrams showing subsidence rates resulting from
water-rock reactions for different mixtures of waters in
the collapse area: (A) without ion exchange, (B) with ion
exchange ................................................... 23
15. Graph showing comparison of vertical profiles of halite
saturations observed in wells Lv309 and Lv322 with those
simulated in one-dimensional simulations with different
layer spacings ............................................. 25
16. Diagram showing boundaries of three-dimensional model
showing extent of flooded salt mine, and locations of
rubble chimneys, deformation zone, and wells ............... 27
17. Section C-C showing boundary conditions specified in
three-dimensional model, and depths and extents of
fracture zones ............................................. 28
18. Graph showing comparison of vertical profiles of halite
saturations observed in wells Lv309 and Lv322 with those
simulated by one-dimensional simulation and by three-
dimensional simulations with models A and В ................ 30
19. Graphs showing changes in water compositions in wells
Lv309 (elevation -23 m) and Lv322 from January 1996
through August 2006 in four-solute simulations with: (A)
model A and (B) model В .................................... 32
20. Block diagrams along section C-C in the collapse area
showing simulation results from January 1998 through
September 2006 with model A and model B: (A) changes in
spatial distribution of halite saturation, and (B)
changing directions of groundwater flow .................... 33
21. Block diagrams along section C-C showing changes in
the composition of water in the collapse area from
January 1996 through September 2006 in simulations with
model A .................................................... 35
22. Block diagrams along section C-C showing changes in
the composition of water in the collapse area from
January 1996 through August 2006 in simulations with
model В .................................................... 36
23. Section D-D' showing changes in halite saturations
simulated by models A and В in response to pumping from
the collapse area: (A) initial conditions, September
2006; ДО February 2008; and ДО September 2011 .............. 39
24. Graphs showing changes in halite saturation in
the collapse area during pumping from September 2006
through February 2008, and those simulated by models A
and В from September 2006 through September 2011:
(A) well Lv526, (B) well Lv529, (C) well Lv527,
(D) well 530, (E) well Lv309, and (F) well Lv322 ........... 40
25. Graphs showing changes in water levels in the collapse
area during pumping from September 2006 through February
2008, and those simulated by models A and В from
September 2006 through September 2011: (A) well Lv526,
(B) well Lv529, (C) well Lv527, (D) well 530, (E) well
Lv309, and (F) well Lv322 .................................. 41
26. Graphs showing halite saturations simulated by model В at
well Lv530 from September 2006 through September 2011
with different values of (A) hydraulic conductivity, (B)
porosity, (C) brine-displacement rates, and (D) pumping
rates ...................................................... 43
27. Diagrams showing simulated halite saturations in 2011 and
2016 following shutdown of brine-mitigation project after
2 years of pumping from September 2006 through August
2008: (A) along section C-C through the collapse area,
ДО in plan view of fracture zone at Onondaga / Bertie
contact (O/B-FZ), and (C) in plan view of lower confined
aquifer (LCA) .............................................. 45
Tables
1. Chemical composition of brine and groundwater in November
2005 near collapse area above flooded Retsof mine,
Livingston County, N.Y. .................................... 17
2. Inverse models of waters in the collapse area showing
calculated percentages of initial waters and mole
transfers for water-rock reactions ......................... 18
3. Saturation indices calculated with the Pitzer aqueous
model for sampled waters in the collapse area .............. 21
4. Values of hydraulic and transport properties used in one-
dimensional simulations .................................... 25
5. Values of hydraulic and transport properties used in
three-dimensional simulations of saline water and brine
migration during recovery of aquifer system ................ 29
6. Average halite saturation in water pumped by brine-
mitigation project in February 2008, and simulated
saturation and composition of pumped water with models A
and В ...................................................... 38
7. Sensitivity of simulated concentrations in February 2008
and mass of halite produced from September 2006 through
February 2008 in models A and В to changes in rates of
brine displacement (Qbrine) and pumping (Qpumping) ............ 44
|
