2007-11-20_REVISION - M1982015 ‎(14)‎

• Permit No: M1982015
• IBM Index Class Name: REVISION
• Doc Date: 11/20/2007
• Doc Name: Addendum 1 to Integrated Corrective Action Plan
• From: E-21 Engineering, Inc.
• To: DRMS
• Type & Sequence: TR3
• Media Type: D
• Archive: No

TABLE OF CONTENTS
t
Cover Letter
' 1.0 Incorporation of CDPHE Email Comments ............................................................... .1

' 2.0
3.0 Emergency Response Activities (Rocky Mountain Pipeline) .....................................
Water Well Search Results ....................................................................................... .1
.1
'

' 4.0 Summary of Soil Excavation and Waste Disposal Activities .....................................
4.1 Slurry Wall Excavation ..................................................................................
4.2 Slurry Holding Trench Excavation .................................................................
4.3 Petroleum Impacted Groundwater Pumping .................................................
4.4 Post Excavation Slurry and Backfill Results .................................................. .2
. 2
.3
. 5
.6

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' 5.0 Surface Water Sampling Results ............................................................................... 6
5.1 Quarry Pond #1 (Sunset Lake) ............................................................................. 7
5.2 Quarry Pond #2 (Big Lake) . • 7
5.3 Quarry Pond West ................................................................................................ 7
5.4 St. Vrain River Sampling ...................................................................................... 7
6.0 Quarry Pond Sparging Activities ................................................................................ 8
' 7.0 Additional Site Characterization Activities .................................................................. 8

'

8.0 7.1 New Well Installations and Sampling Activities .................................................... 8
7.2 Groundwater Flow Regime and Contaminant Fate & Transport .......................... 9
Air Sparge and Soil Vapor Extraction Pilot Testing ....................................................9

'

'

9.0 8.1 Soil Vapor Extraction Pilot Test Results .............................................................
8.2 Air-Sparge Pilot Test Results .............................................................................
Additional Site Characterization and Monitoring Schedule ......................................
9.1 New Wells North of the Slurry Wall ....................................................................
9.2 New Wells South of the Slurry Wall ....................................................................
9.3 Groundwater and Surface Water Monitoring Schedule ...................................... 10
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12
10.0 Groundwater Remediation Plan .............................................................................12
LIST OF FIGURES
' Figure 1 - Site Map
Figure 2 - Water Well Search Map
Figure 3 - Soil Excavation Map
' Figure 4 - Slurry Wall Excavation Map
Figure 5 - Slurry Holding Trench Excavation Map
Figure 6 - Groundwater Laboratory Results (3/14/07)
' Figure 7 - Groundwater Laboratory Results (4/21/07)
Figure 8 - Benzene in Groundwater and Potentiometric Surface Map (4/21/07)
Figure 9 - Air-Sparge/Soil Vapor Extraction System Layout

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