Chris Langston, SAWS

1. TAGD Meeting
Chris Langston
San Antonio Water System
SAWS Well Mitigation
Program
January 22, 2019

2. January 22, 2019
SAWS Well Mitigation
Page 2
SAWS Mitigation Program
• Mitigation Program Overview
• Mitigation Process
• Results
• The Mitigation Experience

3. January 22, 2019
SAWS Well Mitigation
Page 3
Mitigation Program Overview
• SAWS Aquifer
Storage &
Recovery
(ASR) Project
• Majority of
SAWS
mitigation work
•ASR
•site

4. January 22, 2019
SAWS Well Mitigation
Page 4
ASR Project History
• 3,200 acres purchased
in south Bexar,
Atascosa, and Wilson
counties in 2000 and
2001
• Facility online in 2004
•ASR
•site

5. January 22, 2019
SAWS Well Mitigation
Page 5
ASR Project History

6. January 22, 2019
SAWS Well Mitigation
Page 6
ASR Project History
• Project includes:
– 29 Injection/Recovery
Wells
– 7 Carrizo Production
Wells
– Storage/Recovery
capacity of 64 mgd
•Twin Oaks treatment facility

7. January 22, 2019
SAWS Well Mitigation
Page 7
Mitigation Program Background
• The SAWS Board established policy to
mitigate private wells impacted by the ASR
Facility in February 2002.
• Designed to proactively address adverse
impacts to private wells from the operation
of the SAWS ASR project.
• Mitigation is part of operating agreement
with EUWCD.

8. January 22, 2019
SAWS Well Mitigation
Page 8
• Utilized a hydrologic model to determine
the estimated impact of ASR operation.
• Hydrologic Model
– Established the Estimated Impact Area
– Estimated water level decline for each
location within the Impact area
Mitigation Program Background

9. January 22, 2019
SAWS Well Mitigation
Page 9
WILSON COUNTY
ATASCOSA COUNTY
BEXAR COUNTY
Twin Oaks ASR
I37
FM 536
STATE HWY 97
FM
1303
USHWY281
FM
2579
FM
RD
476
FM
3006
FM RD 536
RANCH
RD
1784
CORGEY RD
STATEHWY16
BYRDRD
PRIEST
RD
FM
541
USHW
Y1
PLEASANTONRD
CAMPBELLTONRD
MATHISRD
RANCH
RD
541
MOGFORD RD
RAMP
OLDPLEASANTRD
HARDY RD
RANCH RD 536
RAMPRAMP
RAMPRAMP

10. January 22, 2019
SAWS Well Mitigation
Page 10
Mitigation Program Background
• Mitigation applies to both domestic and
irrigation wells.

11. January 22, 2019
SAWS Well Mitigation
Page 11
Eligibility Requirements
• Eligible wells must meet specific criteria:
– Located within the defined impact area
– Drilled before operational start date of SAWS project
– Completed in the same formation as SAWS project
– Fully operational & capable of producing water
– Registered with appropriate GCD

12. January 22, 2019
SAWS Well Mitigation
Page 12
Mitigation Process
• INITIAL INVESTIGATION
– Meet with well owner,
explain mitigation
program.
– Verify location and
condition of well.
– Collect well construction
data/records.

13. January 22, 2019
SAWS Well Mitigation
Page 13
Mitigation Process
• DIAGNOSTICS
– Forms the basis for mitigation
actions.
– Data collected includes:
• static water level
• pumping level
• gpm
• pump setting and condition
• total depth of well
• geophysical log
• televised survey

14. January 22, 2019
SAWS Well Mitigation
Page 14
Mitigation Process
• MITIGATION COMMITTEE
– Review data collected during diagnostics
– Determine if mitigation is necessary for the well,
and if so, what type of mitigation based on the
modeled impact for the well location

15. January 22, 2019
SAWS Well Mitigation
Page 15
Mitigation Process
• NO MITIGATION
• LOWER PUMP
• DRILL
REPLACEMENT
WELL
• WATER PURVEYOR
CONNECTION

16. January 22, 2019
SAWS Well Mitigation
Page 16
Mitigation Process
• COMPLETE MITIGATION
– Contractor completes
mitigation action.

17. January 22, 2019
SAWS Well Mitigation
Page 17
Completed Mitigation
• Before Mitigation • After Mitigation

18. January 22, 2019
SAWS Well Mitigation
Page 18
Completed Mitigation
• Before Mitigation • After Mitigation

19. January 22, 2019
SAWS Well Mitigation
Page 19
Completed Mitigation
• Before Mitigation • After Mitigation

20. January 22, 2019
SAWS Well Mitigation
Page 20
Results
Mitigation Stage ASR Mitigation
Properties & Wells Investigated 311
Mitigation To Be Determined 31
Wells Not Eligible for Mitigation 107
Mitigation In Progress 7
Mitigation Completed To Date 166
ASR Mitigation To Date

21. January 22, 2019
SAWS Well Mitigation
Page 21
Results
Type of Mitigation ASR Mitigation
Lowered Pump 53
Water Purveyor 17
Monetary Settlement 0
Drilled New Well 83
No Mitigation Required 13
Mitigation Completed

22. January 22, 2019
SAWS Well Mitigation
Page 22
Mitigation Costs

23. January 22, 2019
SAWS Well Mitigation
Page 23
Domestic Well Mitigation
Average Costs
Mitigation Action Average Cost
Perform Well Diagnostics $2,700.00
Lower Pump $4,000.00
Drill, Outfit, & Connect Replacement Well $58,000.00
Water Purveyor Connection $5,000.00
Plug Existing Well $4,500.00

24. January 22, 2019
SAWS Well Mitigation
Page 24
Irrigation Well Mitigation
Average Costs
Mitigation Action Average Cost
Perform Well Diagnostics $5,508.48
Lower Pump $16,352.43
Drill, Outfit, & Connect Replacement Well $202,059.40
Water Purveyor Connection $0.00
Plug Existing Well $24,433.60

25. January 22, 2019
SAWS Well Mitigation
Page 25
ASR Total Mitigation Costs
2003 - Present
Type of Cost Total %
Well Diagnostics/Investigation $459,126.49 6.88%
Mitigation - Pump Lowering $374,622.28 5.61%
Mitigation - Replacement Well $5,307,294.67 79.49%
Mitigation - SAWS Meter Connection $7,931.67 0.12%
Well Plugging $250,233.00 3.75%
Miscellaneous $277,779.39 4.16%
Total $6,676,987.50 100.00%
ASR Mitigation Costs - Total

26. January 22, 2019
SAWS Well Mitigation
Page 26
The Mitigation Experience
• Problems Encountered
• Program Benefits
• Additional Results
• Lessons Learned

27. January 22, 2019
SAWS Well Mitigation
Page 27
Problems Encountered
• Lack of Well Information
• Substandard Wells
• Complaints

28. January 22, 2019
SAWS Well Mitigation
Page 28
Lack of Well
Information
• The majority
landowners don’t
have info on their
wells.
• Often, what info
they do have is not
accurate

29. January 22, 2019
SAWS Well Mitigation
Page 29
Substandard Wells

30. January 22, 2019
SAWS Well Mitigation
Page 30
No Slab, Casing Height

31. January 22, 2019
SAWS Well Mitigation
Page 31
Insufficient Casing Height

32. January 22, 2019
SAWS Well Mitigation
Page 32
No Sanitary Seal

33. January 22, 2019
SAWS Well Mitigation
Page 33
Top Secret

34. January 22, 2019
SAWS Well Mitigation
Page 34
Top Secret

35. January 22, 2019
SAWS Well Mitigation
Page 35
Top Secret

36. January 22, 2019
SAWS Well Mitigation
Page 36
Top Secret

37. January 22, 2019
SAWS Well Mitigation
Page 37
Complaints – Before & After
Mitigation

38. January 22, 2019
SAWS Well Mitigation
Page 38
Complaint Investigation

39. January 22, 2019
SAWS Well Mitigation
Page 39
Complaint Investigation

40. January 22, 2019
SAWS Well Mitigation
Page 40

41. January 22, 2019
SAWS Well Mitigation
Page 41
Complaint Investigation

42. January 22, 2019
SAWS Well Mitigation
Page 42
Complaint Investigation

43. January 22, 2019
SAWS Well Mitigation
Page 43
Complaint Investigation

44. January 22, 2019
SAWS Well Mitigation
Page 44
Complaint
Investigation

45. January 22, 2019
SAWS Well Mitigation
Page 45

46. January 22, 2019
SAWS Well Mitigation
Page 46
Screens – Drilled Holes

47. January 22, 2019
SAWS Well Mitigation
Page 47

48. January 22, 2019
SAWS Well Mitigation
Page 48
No Gravel Pack

49. January 22, 2019
SAWS Well Mitigation
Page 49

50. January 22, 2019
SAWS Well Mitigation
Page 50
Replacement Well Screens
Mill-slotted PVC
Screen
Stainless Steel Wire
Wrapped Screen

51. January 22, 2019
SAWS Well Mitigation
Page 51
Gravel Pack
8/16 Washed Gravel
• The screen is
gravel packed to
keep formation
sand out while
letting water in.

52. January 22, 2019
SAWS Well Mitigation
Page 52
Gravel Pack

53. January 22, 2019
SAWS Well Mitigation
Page 53
Gravel Pack

54. January 22, 2019
SAWS Well Mitigation
Page 54
Program Benefits
• Improved Water Quality Protection
• Bring Substandard Wells up to State
Standards
• Plug Potential Sources of Aquifer
Contamination
• Replace Substandard Equipment
• Improved Public Relations

55. January 22, 2019
SAWS Well Mitigation
Page 55
Water Quality Protection

56. January 22, 2019
SAWS Well Mitigation
Page 56
Water Quality Protection

57. January 22, 2019
SAWS Well Mitigation
Page 57
Water Quality Protection

58. January 22, 2019
SAWS Well Mitigation
Page 58
Bring Wells up to State
Standards

59. January 22, 2019
SAWS Well Mitigation
Page 59
Lack of Surface Sealing Block

60. January 22, 2019
SAWS Well Mitigation
Page 60
Insufficient Casing Height

61. January 22, 2019
SAWS Well Mitigation
Page 61
Insufficient Sanitary Seal

62. January 22, 2019
SAWS Well Mitigation
Page 62
Insufficient Sanitary Seal

63. January 22, 2019
SAWS Well Mitigation
Page 63
Bring Wells Up to State Standards
BEFORE AFTER
Wellhead vulnerable to
contamination from surface run-off.
Properly sized sealing block protects
well from potential contamination.

64. January 22, 2019
SAWS Well Mitigation
Page 64
Bring Well Up To State Standards
• Before • After

65. January 22, 2019
SAWS Well Mitigation
Page 65
Replace & Plug
Substandard Wells
• Before Mitigation • After Mitigation

66. January 22, 2019
SAWS Well Mitigation
Page 66
Replace & Plug
Substandard Wells
• Before Mitigation • After Mitigation

67. January 22, 2019
SAWS Well Mitigation
Page 67
Replace Worn or Substandard
Equipment

68. January 22, 2019
SAWS Well Mitigation
Page 68
Replace Worn or Substandard
Equipment

69. January 22, 2019
SAWS Well Mitigation
Page 69
Additional Results
• Program has led to development of positive
relationships with initially unreceptive well
owners
• Improved public perception

70. January 22, 2019
SAWS Well Mitigation
Page 70
Additional Results
• During the 2011-2015 drought, we did not
receive a single water level complaint from
the wells that were previously mitigated.
• Only complaints received were from wells
that refused mitigation.

71. January 22, 2019
SAWS Well Mitigation
Page 71
Lessons Learned
Pre Mitigation
• Establish as large a monitoring well
network as possible
• Document pre-pumping water levels
• If utilizing a hydrologic model, make the
pumping scenario as realistic as possible

72. January 22, 2019
SAWS Well Mitigation
Page 72
Lessons Learned
Pre Mitigation
• Document with Pictures & Notes
– Before & After Mitigation
• Can be used as a means to improve
aquifer protection
– Bringing substandard wells up to the state
standards
• Opportunity to register unregistered wells

73. January 22, 2019
SAWS Well Mitigation
Page 73
Lessons Learned
Post Mitigation
• Expect post-mitigation complaints
• Once you work on a well, if anything goes
wrong with the well you are likely to
receive a call, at least for a period time.
• Establish a clear warranty period.

74. January 22, 2019
SAWS Well Mitigation
Page 74

75. January 22, 2019
SAWS Well Mitigation
Page 75

76. January 22, 2019
SAWS Well Mitigation
Page 76

77. January 22, 2019
SAWS Well Mitigation
Page 77
Complaint Investigation

78. January 22, 2019
SAWS Well Mitigation
Page 78

79. January 22, 2019
SAWS Well Mitigation
Page 79
Stainless Steel Screens

80. January 22, 2019
SAWS Well Mitigation
Page 80
Other Benefits of Mitigation
• System improvements/education

81. January 22, 2019
SAWS Well Mitigation
Page 81
Lessons Learned
Mitigation
• Easier to upgrade components on a well
than to go back and fix them during the
warranty period.
• Easier to add extra depth to a well or a
pump setting the first time, than to go back
and re-mitigate