Central Impact Area UXO Removal Update

Central Impact Area UXO Removal Update

JBCC CT Briefing March 24, 2021Mr. Ben Gregson

Impact Area Groundwater StudyProgram

Overview

Source Area Removal at the Central Impact Area Operable Unit

Groundwater remedy in place: Three extraction wells operating at 750 gallons perminute 2.38 billion gallons treated to date

EPA Decision Document requires source removal Remove 75 – 95% of UXO

93 total acres completed

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CIA – Phase I, II & III Source Removal Areas

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Metal Mapper

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Results so Far….

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* A total of 4,716 anomalies were investigated as identified by TEMTADS and Metal Mapper. Metal Mapper identified 1,954 targets and TEMTADS identified 2,762 Targets.

Summary of Field Operations 2013 – 2017

Work AreaAnomalies

Investigated by Metal Mapper

Anomalies Excavated

UXO Items Recovered

UXO-like Items Recovered

Pounds ofExplosivesRecovered

Phase I (2013 – 2015) - Completed6-Acre ESTCP Area* 4,716 4,716 79 208 2998-Acre Removal Area 15,230 7,023 159 445 43116-Acre Removal Area 27,702 11,179 408 2,203 1,098Phase I Totals (30 Acres) 47,648 22,918 646 2,856 1,828

Phase II (2014 – 2017) - CompletedArea 1 (10 Acres) 24,411 8,883 266 1,241 898Area 2 (10 Acres) 20,912 10,013 323 2,070 736Area 3 (8 Acres) 14,009 6,156 174 891 482Phase II Totals (28 Acres) 59,332 25,002 763 4,202 2,116

Results so Far (Continued)….

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Summary of Field Operations 2017 - 2020

Work AreaAnomalies

Investigated by Metal Mapper

Anomalies Excavated

UXO Items Recovered

UXO-like Items Recovered

Pounds ofExplosivesRecovered

Phase III (Ongoing)Area 1 (10 Acres) 2017 0 0 13 260 29Area 1 (10 Acres) 2018 24,208 8,167 197 1,729 533Area 2 (15 Acres) 2019 26,820 9,323 232 1,467 469Area 3 (10 Acres) 2020** 23,239 5,292 162 691 338Phase III Totals 74,267 22,794 604 4,448 1,369Phase I, II and III Totals 181,247 70,714 2,013 11,206 5,313

**Phase III Area 3 intrusive investigation ongoing.

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Actual UXO Recovered Per Grid

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Explosive Weight Per Quarter-Acre Grid

Current Status/Path Forward

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Draft 2020 Annual Report was submitted in February Under review by EPA and MassDEP

Parsons contract completed; on track to finish in April Demolition operations, scrap management and field cleanup prior

to their final de-mob Includes demolition of items in CDC bunker; may require

coordination with Army EOD team if unstable items are found Community notifications will be made if a detonation-in-place is

required

New UXO contractor IE Weston is mobilizing April 12 Will begin with remaining Phase III Area 3 digs

Begin Phase IV Area 1 investigation (10-15 acres)

Phase IV Area 1 Removal Areas

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Look Ahead – Other IAGWSP Projects

Continue with Former E Range Munitions and Explosives of Concern (MEC) investigation Anticipated to resume March 2021 and continue through June

Draft Demonstration of Compliance Report for Northwest Corner being reviewed by the agencies

PFAS sampling follow-up As needed based on results Additional sampling at J-3 Range

Long-term monitoring and sampling Operations & Maintenance

O&M duties, monthly sampling, and any maintenance and repairs at all treatment facilities continue

Community Involvement Updates to IAGWSP website

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