Long-Term Stewardship of Three Evapotranspirative Covers ......2018 Long-Term Stewardship Conference...
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2018 Long-Term Stewardship Conference August 20–23, 2018 Grand Junction, Colorado Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. Long-Term Stewardship of Three Evapotranspirative Covers, 15 years Sue Collins, Long-Term Stewardship Program Lead Sandia National Laboratories Track 2.2: Understanding the Post-Closure Changes of Engineered Disposal Cell Covers, Part 1
Transcript of Long-Term Stewardship of Three Evapotranspirative Covers ......2018 Long-Term Stewardship Conference...
2018 Long-Term Stewardship Conference
August 20–23, 2018
Grand Junction, Colorado
Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Long-Term Stewardship of Three
Evapotranspirative Covers, 15 years
Sue Collins, Long-Term Stewardship Program Lead
Sandia National Laboratories
Track 2.2: Understanding the Post-Closure Changes of Engineered Disposal Cell Covers, Part 1
Other Contributors
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Michael M. Mitchell
GRAM, Inc.
Robert Ziock
Sandia National Laboratories
2018 LTS Conference
Dedication:
To Mike and Robert who have remained with all 3 covers since design and construction
To their invaluable knowledge and earnest stewardship
Acknowledgement:
NNSA 533: Richard Dasher and Tom Longo (retired)
NNSA Sandia Field Office: Steve Black and David Rast
Cover Tour Video SAND2018-8211V by John Sandlin, Sandia National Laboratories
Environmental Geographic Information System Intern
Presentation SAND2018-6824C
Cover Tour
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TIMELINE FOR 3 EVAPO-TRANSPIRATIVE COVERS AT SANDIA NATIONAL LABORATORIES
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018
CWL Vapor Extraction
CWL Backfill Phase 1
CWL ET Cover Construction
CWL Landfill Excavation
CWL Backfill Phase 2
MWL Subgrade Construction
MWL ET Cover Construction
MWL Inspection and Maintenance
CAMU Excavate the Fill Area
Corrective Action Management Unit (CAMU) Chemical Waste Landfill (CWL) Mixed Waste Landfill (MWL)
Treated CWL Waste Soils Into CAMU
CAMU ET Cover Construction
CAMU Inspection and Maintenance
CWL Inspection and Maintenance
ET Cover Maintenance since 2003
2003 Corrective Action Management Unit (CAMU)
2005 Chemical Waste Landfill (CWL)
2009 Mixed Waste Landfill (MWL)
Size Range: 2.2 – 4.1 acres
Top Soil: 0.7-1.5ft
Native Soil: 2.5 - 3ft
Local Soils from <1.5 miles away
Soils Prepared/Screened/Tested on Site
ET Design: ~9x ABQ’s Average Annual
Precipitation
Bio-intrusion
Layer
1.25 ft
Filter Sand
Pea Gravel
0.7 ft
Backfill of
Clean Fill
Soil
Replaceable
Soil Subgrade
Bedding Sand
Original
unexcavated
Landfill
Treated Soils
Stored in
Lined RCRA C
MWL CAMU CWL
ET Cover Layers Custom Seed Mix
Biointrustion Crushed Rock 1 – 6 inch, no organics or friable fragments
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ET Cover Construction at Chemical Waste Landfill
Seed Mix Changes and Gravel Mulch
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Seeds for CWL Mix Rate
Indian Rice Grass 39% 7.8 lbs/acre
Galleta 19.5% 3.9 lbs/acre
Blue Grama Grass 29.5% 5.9 lbs/acre
Sand Dropseed 6% 1.2 lbs/acre
Alkai Sacaton 6% 1.2 lbs/acre
Corrective Action Management
Unit, 2005
Minor seed mix adjustments for MWL and Increased the Seed Rate.
Chemical Waste Landfill
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Seed
mix
Seed
ing
Mu
lch
ing,
Cri
mp
ing
Pre
ven
t W
ind
Ero
sio
n
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Supplemental Watering was needed for
2 of the 3 covers
Achieve Vegetation Specification within 5 years
Mixed Waste Landfill
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1-2 years Heavy Weed Coverage
Mixed Waste Landfill
Inspection and Maintenance
Permits Requirements
Quarterly Inspections
Maintenance within 60 calendar days
Maintenance Summary Reports
Operations
Sandia LTS staff perform Inspections
Maintenance Subcontract Lesson Learned: Standard ‘Facilities’ services and practices, not a fit
Ordering Agreement: Small Business – Environmental (NAICS 562910)
Satisfies Grass Maintenance Needs
Satisfies Reporting Needs
Satisfies Compliance Timeliness
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Chemical Waste Landfill December 2016
Mature Covers Primary Maintenance: • Clearing Fences of Wind-
Blown Weeds
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Buffer Area: Herbicide 3 ft outside Perimeter Only
1 Pre-emergent Herbicide Application at CWL
Scheduling Preventive
Maintenance
Chemical Waste Landfill
Corrective Action Management Unit
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Mixed Waste Landfill: June 2016
Chemical Waste Landfill: July 2017
Mature Cover: Still Hand-Pulling Weeds, But Fewer Weeds
Hand-Raking Grass Clumps
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Best Practices Erosion Controls
Mixed Waste Landfill 2018
Mixed Waste Landfill 2016
