ordnance safety

Ordnance Safety

DO NOT TOUCH!DO NOT MOVE!

Note/record location

Call 911 or local law enforcement

Technical ProjectTechnical ProjectPlanning (TPP) Meeting 7Planning (TPP) Meeting 7

Remedial Investigation and Feasibility Study Remedial Investigation and Feasibility Study (RI/FS), Formerly Used Defense Site (FUDS) (RI/FS), Formerly Used Defense Site (FUDS)

Kirtland AFB Precision Bombing Ranges (N-1, Kirtland AFB Precision Bombing Ranges (N-1, N-2, N-3, N-4 and “New” Demolition Area) N-2, N-3, N-4 and “New” Demolition Area)

(A.K.A. West Mesa)(A.K.A. West Mesa)

FUDS ID K06NM044501FUDS ID K06NM044501

AgendaPre-meeting Coffee (optional) – 8:30-9:00•Introductions and Agenda Review•Review results of the follow-up MRS boundary meeting•Explain MRS N-2/NDA split from rest of MRSs•Summary of the RI Report•Summary of the FS Report-Summary of Regulator Comment Resolution•Present MEC HA ResultsBreak -10:00-10:15•Introduction to the RD/RA•USACE Goal•Presentation of Conceptual Site Model•Discussion of Stakeholder values•Development of DQOs

Agenda (continued)

Lunch - 11:45-1:00•Presentation of Recommended RA AlternativeBreak – 2:30 – 2:45 •Presentation of EM61 and MetalMapper Technologies•Presentation of Alternative Geophysical Survey and RA Design Approaches

- UXO Estimator- VSP- Probabilistic Approach

•Discussion and Selection Design Approach for the RD/RA•Presentation of Hazard Assessment Approach•Final DiscussionsMeeting End – 5:00

West Mesa Project Map

MRS N-2/NDA Addressed First• The RI and FS reports address MRSs N-2 and NDA only.

• The primary reason this RI/FS report is focused on N-2 and NDA is because there is a more urgent need to reduce potential hazards at these sites than at the other MRSs.

• The City of Albuquerque intends to develop this land within the next five years.

• Separating these “high priority” sites from the other six MRSs will allow USACE to expedite progress to select a remedial alternative for these two MRSs, and thus mitigate the majority of hazards that would be potentially encountered during future planned land development activities.

• A result of the RI and Technical Project Planning (TPP) discussions is that MRSs N-2 and NDA were combined into one MRS.

• These areas are henceforth designated as MRS N-2/NDA.

MRS N-2/NDA Boundary• Primary Purpose - Develop a systematic defensible approach for defining the West

Mesa MRS boundaries. • DOD and EPA have no formal approach to defining MRS boundaries.• Julie Jacobs (NMED) spoke with a representative of UXOPro.com, who suggested

using a specified distance beyond the furthest MD item to help define the MRS boundary.

• AR 750-10, Range Regulations for Firing Ammunition in Time of Peace, May 1939 – January 1944; AAF Manual 85-0-1, Army Air Forces Gunnery and Bombardment Ranges, June 1945; Army Air Corps Studies and Reports on Bombing Analysis and Bombing Accuracy, 1942. In reference to 100-lb AN-M30 General Purpose bombs this research states:

• From studies completed in WWII, “99 percent of the bombs should be found within 3,000 feet for bombers flying at 25,000 feet or below and at speeds up to 250 mph. The same study implied a 2,000-foot radius should include 95 percent of the bombs under the same conditions.”

Approach for Determining West Mesa MRS Boundaries

• First, establish the 3000-ft radius boundary from each target feature center. • Use dig results from the EE/CA, TCRA and WAA to determine where anomalies

identified as MD fall outside or within 250 ft of the 3000-ft boundary.• Draw boundary to include the MD item plus a buffer of 250-ft beyond the item.• If there is an MD item further away, but within 250 ft of the MD, move the boundary

250 ft beyond that item. • If an MD item is discovered outside of the 250-ft buffer this MD item shall be

considered an isolated incidence and not be included in the MRS boundary. • In an instance where a MEC is discovered within the 250-ft buffer or outside of the

MRS boundary the boundary will be moved to include the location of the MEC item plus the 250-ft buffer.

• All agreed that if during subsequent phases of investigation or remedial action, if MEC and MD items are found adjacent to a boundary, the boundary will be refined.

MRS N-2/NDA Boundary (continued)

• Figures display:

- proposed MRS boundaries 3,000 ft from target centers,

- anomaly density contours,

- colorized anomaly concentrations from heli-mag surveys,

- anomalies identified by the EE/CA,

- likelihood 2 anomalies identified by the WAA,

- dig results from the WAA and EE/CA that were MD items greater than three lbs,

- and TCRA dig results for MD greater than three lbs.

MRS N-2/NDA Boundary (continued)

MRS N-2/New Demolition Area

• The result of applying these criteria is that Former MRSs N-2 and NDA are combined into one MRS designated as MRS N-2/NDA. This approach:

Serves to encompass all high-density anomaly areas delineated through statistical spatial analysis and indicative of specific impact areas

Provides supporting documentation for boundary selection in the form of DoD studies specific to the munitions used at the site

Provides built-in contingences that allow refinement of the MRS boundary if MD meeting a specified criteria are discovered, outside of the initial MRS boundary in the future; and

It makes the conservative assumption that the two target areas should be treated similarly, and assumes the higher risk of HE bombs cannot be ruled out, given a 100-lb HE bomb was found elsewhere outside the NDA target in 1996.

Summary of the Remedial Investigation

Goals of the RI• Determine nature and extent of MC contamination at each MRS,• Verify the type of MEC items within each MRS,• Determine the density and distribution of MEC items within each

MRS, • Redefine the boundaries of each identified MRS, • Redefine the boundary of the West Mesa MRA, if necessary• Determine the presence or absence and distribution of 100-lb HE

bombs within MRSs N-2 and New Demolition Area,• Assess MEC Hazard with MEC HA, and• Develop a FS to identify and evaluate munitions response

alternatives for each MRS.

Data Gaps and RI ActionsData Gap Identified by the TPP

TeamRI Action Result

Is HE UXO present in the vicinity of the New Demolition Area?

Intrusive investigation of 100 high probability anomalies

No UXO found: still unknown

Is UXO is present in the vicinity of other MRSs (N-2)?

Qualitative Reconnaissance (QR) during incremental sampling (IS) and document MEC, MC or MPPEH

No MEC, MC or MPPEH observed

Are HE MCs present in surface soils at all MRSs?

Systematic random and biased IS for HE MC in areas most likely to have surface soil contamination

No HE MC detected in 0 to 4 -inch soil samples

What impact do physical processes have on transport of MEC, specifically wind and water erosion and frost heave?

Gather physiographic data and present results of this research

Net increase in aeolian sediment deposition, no water transport of MEC, near zero potential for frost heave to being MEC to surface

What is future land use within the MRA?

Obtain future land use plans from the City of Albuquerque.

Airport and commercial development is planned for the area in and around MRS N-2/NDA.

Uncertainty with regard to the existing MRS boundaries.

Use data from previous geophysical investigations, the intrusive investigation at NDA, IS, and QR to define MRS boundaries.

The MRS boundaries and the MRA boundary are delineated based on presence of metallic anomalies associated with MD identified in the EE/CA, WAA, and this RI.

MRSs N-2/NDA MC Sampling• 8 random SUs and 4 biased SUs performed

at N-2 target area

• No HE MC detected

• 8 random SUs and 5 biased SUs performed at NDA target area

• No HE MC detected

Intrusive MEC InvestigationExcavation Results

Investigation

Total Anomalie

s Identified

Total Anomalies

Dug

Percent UXO

Percent Practice

Bomb MD

Percent HE Fragmentati

on

Percent Non

Munitions Scrap

Percent No

Contact

Percent Other

RI/FS - New Demolition

and N-2

236 100 0 77% 19% 2% 0% 2%

EE/CA - New Demolition

and N-2

1,149 755 0 43% 31% 18% 0% 8%

Wide Area Assessment

(WAA)

Tens of Thousands

777 0 73% 0% 0% 19% 8%

Intrusive MEC Investigation

Intrusive MEC InvestigationReacquisition of 100 Anomaly

Locations

EM 61 Anomaly Location Verification

Intrusive MEC InvestigationHE - Bomb Fragmentation M38 Sand-filled Practice

Bomb

Summary of Feasibility Study

Remedial Alternative

EVALUATION CRITERIA

Threshold Criteria Balancing Criteria Modifying Criteria

Overall Protectiveness of Human Health and the Environment

Compliance with ARARs

Short-Term Effectiveness

Long-Term Effectiveness and Permanence

Reduction of Toxicity,

Mobility, and Volume Through

Treatment

Implementability Cost (Present-Worth)

State Acceptance

Community Acceptance

Alternative 1 – No Further Action

Not protective; does not mitigate potentially remaining MEC hazards to surface receptors or intrusive workers

Could be implemented to compliance with ARARs

Not effective in the short term; no MEC hazard reduction

Not effective in the long term; no MEC hazard reduction.

None Likely not administratively feasible

Minimal Unlikely Unlikely

Alternative 2 - Land Use Controls

Protective of construction and maintenance workers; but poses some degree of hazard due to potential MEC to future receptors


Effective in the short term; implementation of LUCs to mitigate MEC hazard to construction and maintenance workers

Required training and construction support would mitigate hazards to construction and maintenance workers until evaluation determines LUCs no longer necessary.

No reduction in volume because no further MEC removals would be conducted

Administratively feasible; moderate technical effort required to implement

$1,803,000 May be acceptable because of short- and long-term mitigation actions

May be acceptable; takes short- and long- term mitigation actions

Alternative 3 - MEC removal (100% anomaly excavation for high-density anomaly area only) to 4-feet with LUCs

Protective of construction and maintenance workers; Protective of human health and the environment to future receptors



This alternative would provide long-term effectiveness. The removal action will reduce the potentially remaining MEC hazards. LUCs would be implemented to mitigate the potentially remaining MEC hazards to the future receptors.

May result in MEC reduction if additional MEC is discovered and removed during remediation

Administratively feasible; moderate level of technical effort required to implement

$4,656,000 May be acceptable because of additional remediation and short- and long-term mitigation actions

May be acceptable; takes short- and long-term mitigation actions


EVALUATION CRITERIA

Threshold Criteria Balancing Criteria Modifying CriteriaOverall

Protectiveness of Human Health and the Environment

Compliance with ARARs



Reduction of Toxicity, Mobility,

and Volume Through

Treatment

Implementability Cost (Present-Worth)

State Acceptance

Community Acceptance

Alternative 4 - MEC removal (100% anomaly excavation for high-density anomaly area to 4-feet and surface MEC removal for remaining MRS Area) with LUCs

Protective to construction and maintenance workers; Protective of human health and the environment to future receptors





Administratively feasible; high level of technical effort required to implement



Alternative 5 - MEC removal (100% anomaly excavation for high-density anomaly area and selected anomaly excavation for remaining MRS Area) to 4-feet with LUCs






Administratively feasible; very high level of technical effort required to implement



Alternative 6 - removal (100% anomaly excavation for entire MRS) to 4-feet



May be effective in the short term with existing LUCs

This alternative would provide long-term effectiveness. The removal action will reduce the potentially remaining MEC hazards.


Administratively feasible; very high level of technical effort required to implement

$7,800,000 May be acceptable because of long-term mitigation action

May be acceptable; takes long-term mitigation action

EVALUATION CRITERIA

Remedial Alternative 1 – No Further Action

Threshold Criteria


Not protective; does not mitigate potentially remaining MEC hazards to surface receptors or intrusive workers

Compliance with ARARs Could be implemented to compliance with ARARs

Balancing Criteria


Not effective in the short term; no MEC hazard reduction


Not effective in the long term; no MEC hazard reduction.

Reduction of Toxicity, Mobility, and Volume Through Treatment

None

ImplementabilityLikely not administratively feasible

Cost (Present-Worth)Minimal

Modifying Criteria

State AcceptanceUnlikely

Community AcceptanceUnlikely

EVALUATION CRITERIA

Remedial Alternative 2 – Land Use Controls

Threshold Criteria


Protective of construction and maintenance workers; but poses some degree of hazard due to potential MEC to future receptors


Balancing Criteria




Required training and construction support would mitigate hazards to construction and maintenance workers until evaluation determines LUCs no longer necessary


No reduction in volume because no further MEC removals would be conducted

ImplementabilityAdministratively feasible; moderate technical effort required to implement

Cost (Present-Worth) $1,803,000

Modifying Criteria

State AcceptanceMay be acceptable because of short- and long-term mitigation actions

Community Acceptance May be acceptable; takes short- and long- term mitigation actions

EVALUATION CRITERIA

Remedial Alternative 3 – MEC removal (100% MEC excavation for high-density anomaly area only) to 4-feet with LUCs

Threshold Criteria


Protective of construction and maintenance workers; protective of human health and the environment to future receptors


Balancing Criteria









Modifying Criteria



EVALUATION CRITERIA

Remedial Alternative 4 – MEC removal (100% MEC excavation for high-density anomaly area to 4-feet and surface MEC removal for remaining MRS Area) with LUCs

Threshold Criteria




Balancing Criteria









Modifying Criteria



EVALUATION CRITERIA

Remedial Alternative 5 – MEC removal (100% MEC excavation for high-density anomaly area and selected anomaly excavation for remaining MRS Area) to 4-feet

with LUCs

Threshold Criteria


Protective of construction and maintenance workers; protective of human health and the environment to future receptors


Balancing Criteria









Modifying Criteria



EVALUATION CRITERIA

Remedial Alternative 6 – Removal (100% MEC excavation for entire MRS) to 4-feet

Threshold Criteria




Balancing Criteria









Modifying Criteria




Evaluation Criteria

Alternative 1 - No Further Action

Alternative 2 - Land Use Controls

Alternative 3 - MEC removal (100% anomaly excavation for high-density anomaly area only) to 4-feet with LUCs

Alternative 4 - MEC removal (100% anomaly excavation for high-density anomaly area to 4-feet and surface MEC removal for remaining MRS Area) with LUCs

Alternative 5 - MEC removal (100% anomaly excavation for high-density anomaly area and selected anomaly excavation for remaining MRS Area) to 4-feet with LUCs

Alternative 6 - MEC removal (100% anomaly excavation for entire MRS) to 4-feet )


□ ◘ ■ ■ ■ ■

Compliance with ARARs■ ■ ■ ■ ■ ■

Short-term Effectiveness□ ■ ■ ■ ■ ◘

Long-term Effectiveness and Permanence

□ ◘ ■ ■ ■ ■

Reduction of Toxicity, Mobility and Volume Through Treatment

□ □ ■ ■ ■ ■

Implementability □ ■ ■ ■ ■ ■

Cost (Present-Worth) << $1,803,000 $4,656,000 $5,880,000 $8,949,000 $7,800,000

State Acceptance TBD TBD TBD TBD TBD TBD

Community Acceptance TBD TBD TBD TBD TBD TBD

Ranking - ■ High ability to meet criteria ◘ Moderate ability to meet the criteria □ Does not meet criteria << - Low cost to implement compared to other criteriaTBD - to be determined. These criteria will be further evaluated following the comment period for the RI/FS report .

Summary of RI /FS Regulator Comment Resolution

New Mexico Environment Department• NMED does nor concur with the RI/FS• Clear definitions / consistency of terminology• Corrections to MRSPP and MEC HA scoring sheets• Horizontal Anomaly Density not explained clearly • “High-Density” Area not mentioned in the RI, but discussed in the evaluation of

alternatives

EPA• Is a 0-4” surface sample sufficient if craters have aeolian deposits in them?• 5-year review clock starts when construction of the remedy starts• 5 -year review cost of $5k is low• Schedule for Proposed Plan

Revised Conceptual Site Models

Revised Conceptual Site ModelsProfile Type Information included in profile

Facility Profile •Site structures and utilities, •Site physical boundaries, •Ordnance activity areas (Precision Bombing Ranges), and •Historical features that indicate potential source areas (Target centers)

Physical Profile •Topography, •Vegetative features, •Surface water features, •Drainage pathways, •Surface and subsurface geology including soil type and properties, •Meteorological data, •Geophysical data, •Hydrogeological data,•Other physical site features

Release Profile •Contaminants and media of potential concern, •Locations and delineation of confirmed releases and observed MEC/MD, •Geophysical modeling results, and•Contaminant fate and transport

Land Use and Exposure Profile

•Types and nature of current and future activities conducted at the site, •Receptors associated with current and future site land use, •Zoning, •Demographics including subpopulation types and locations (schools, hospitals, day care centers, site workers, etc.), and •Resource use locations (water supply wells, hiking trails, grazing lands, etc.)

Ecological Profile •Habitat type(s),• Primary use of the site and degree of disturbance, if any, •Identification of any ecological receptors, and •Relationship of any potential releases to habitat areas

• CSMs visually represent 5 site profiles

Facility ProfilePhysical ProfileRelease ProfileLand Use and Exposure

ProfileEcological Profile

• CSMs incorporate site profiles to provide a visual representation of site hazards and exposure pathways for assessment of remedial alternatives

Profile Information for MRS N-2/NDA (current land use)

Profile Type Profile AspectsFacility Profile • Overhead and underground utility lines present in MRS

• Fencing around some portions of the MRS• Roads• Water retention basin• MRS Boundary (TBD)• 2 Target Features

Physical Profile • Flat to rolling topography, no well defined drainages sandy surface soils with shallow intermittent caliche layer, low precipitation, predominantly grass land.

Release Profile • No HE MC detected • MD consistent with M38A2 practice bombs found in MRS

Land Use and Exposure Profile • Albuquerque Open Space• Utility Maintenance Activities

Ecological Profile • No endangered species habitats or sensitive habitats

Profile Information for MRS N-2/NDA (future land use)

Profile Type Profile AspectsFacility Profile • Commercial, airport facilities and structures are planned for MRS N-

2/NDA• Overhead and underground utility lines present in MRS• Runway• Roads• MRS Boundary (TBD)• 2 Target Features

Physical Profile • Flat to rolling topography, no well defined drainages sandy surface soils with shallow intermittent caliche layer, low precipitation, predominantly grass land

Release Profile • No HE MC detected • MD consistent with M38A2 practice bombs and AN M30 100-lb GP

HE bombs found in MRS

Land Use and Exposure Profile

• Construction• Commercial zoning• Double Eagle II Airport• Albuquerque Open Space• Utility Maintenance Activities

Ecological Profile • No endangered species habitats or sensitive habitats

CSM Pathway Analysis• The pathway analysis determines if there is a

complete pathway for either human or environmental exposure to HTRW or MEC

• Pathway analyses is depicted in a 3D model the draft final RI/FS report

West Mesa MRA Preliminary Pathway Analysis

CSM Pathway Analysis for MRS N-2/NDA (current land use)

Source Release/Exposure Medium or Receptor Complete Pathway?

MC Environmental Contaminants

•Surface Water/Sediments •NO

•Groundwater •NO

•Soils •NO

• Volatilization •NO

• Plant/Animal Uptake •NO

Surface MEC •Utility Maintenance Workers •YES

Subsurface MEC •Utility Maintenance Workers •YES

CSM Pathway Analysis for MRS N-2/NDA (future land use)





•Soils •NO

• Volatilization •NO

• Plant/Animal Uptake •NO

Surface MEC •Construction Workers •YES

• Site Workers (airport, commercial facilities) •YES

• Commercial/Aviation activities (visitors, shoppers and aviators) •YES

Subsurface MEC •Construction Workers •YES

• Site Workers (airport, commercial facilities) •YES

• Commercial/Aviation activities (shoppers and aviators) •NO (no intrusive activity)

CSM Pathway Analysis for MRS New Demolition Area (future land use)





•Soils •NO

•Volatilization •NO

•Plant/Animal Uptake •NO

Surface MEC •Construction Workers •YES

•Site Workers (airport, commercial facilities) •YES

•Commercial/Aviation activities (shoppers and aviators) •YES

Subsurface MEC •Construction Workers •YES

•Site Workers (airport, commercial facilities) •YES

•Commercial/Aviation activities (shoppers and aviators) •NO (no intrusive activity)

MEC Hazard Assessment

MEC Hazard Assessment• MEC Hazard Assessments (MEC HA) according to guidance

provided by EPA Munitions and Explosives of Concern Hazard Assessment Methodology Interim 2008.

• A MEC HA was produced for MRS N-2/NDA

• The MEC HA produces a qualitative hazard level number value based on weighted scoring of:

Physical site conditions, Site land use, Former DoD site usage, and Data collected during the RI and previous investigations

• MEC HA hazard levels range from 4 (low) to 1 (very high)

• MEC HA may be utilized to determine projected future hazard levels as well as current hazard levels

MEC Hazard Assessment Input FactorsInput Factor Description Relevant InformationMEC Energetic Material Type The most hazardous (highest scoring) variety of explosive

material for suspected MEC itemsSpecifications of type of explosive for each MEC item formerly used at the site and suspected to be present after field investigation

Location of Additional Human Receptors

Presence of areas where people might congregate that are within the MRS or within the Explosive Safe Quantity Distance (ESQD) arc for MEC explosions

MRS boundary, location of features orfacilities that attract people to locations potentially on or near MRS boundaries, and the ESQD arc from either the ESS and ESP

Accessibility Ability of persons to enter MEC-contaminated areas MRS boundary, fencing, location of guarded areas, topography, and location of infrastructure

Potential Contact Hours Estimated amount of hours/year that persons may be in contact with MEC-contaminated areas

Types and frequency of site land use activities, average amount of time persons spend on each activity, and number of persons who participate in site activities

Amount of MEC The most hazardous category-level amount of MEC potentially present based on the former DoD use of the site

MRS boundary and nature of former DoD use of the site (e.g. target area)

Minimum MEC Depth Relative to Maximum Intrusive Depth

Potential of intrusive activities normally conducted at the site to excavate beyond minimum depth of suspected MEC

Types of site land use activities, maximum intrusive depths for each activity, nature of former DoD use of the site, and minimum depth at whichMEC is expected to be found (e.g., surface, x feetbelow ground surface)

Migration Potential Likelihood of spatial migration of MEC items (likely vs. unlikely)

MRS boundary, climatic and geologic conditions, types of land cover (vegetative conditions), location of frost line and potential for frost heave, rainfall patterns and amounts, direction of overland flow, and location of areas of erosion activity

MEC Classification The most hazardous (highest scoring) variety of MEC (e.g. UXO, sensitive UXO, Fuzed DMM, Bulk explosives

Specifications of type of explosive for each MEC item formerly used at the site and suspected to be present after field investigation

MEC Size Smallest possible weight of suspected MEC items (either over or under 90 pounds)

Specifications of type of explosive for each MEC item formerly used at the site and suspected to be present after field investigation

MEC Hazard Assessment Results

MRS Category Level Hazard

Driving Input Factors

N-2/NDA (current) 2 (high) Low number of receptor hours, limited accessibility, MEC is suspected to be on ground surface, suspected MEC includes 100-lb HE bombs

N-2/NDA (future) 1 (very high) Very high number of receptor hours, full accessibility, MEC is suspected to be on ground surface, suspected MEC includes 100-lb HE bombs

MEC HA Hazard Level DeterminationMEC HA Hazard Level Determination

Site ID:MRS N-2/NDA

Hazard Level Category Score

Date: 3/10/2011

a. Current Use Activities 1 850

b. Future Use Activities 1 980

c. Response Alternative 1: NDAI 1 980

d. Response Alternative 2: Institutional Controls/ Land Use Controls 1 980

e. Response Alternative 3: Surface Clearance with Institutional Controls 2 800

f. Response Alternative 4: Subsurface clearance with Institutional Controls 3 595

g. Response Alternative 5:

h. Response Alternative 6:

Characteristics of the MRS

Is critical infrastructure located within the MRS or within the ESQD arc? Yes

Are cultural resources located within the MRS or within the ESQD arc? Yes

Are significant ecological resources located within the MRS or within the ESQD arc? No

Introduction to the RD/RA

USACE Goal for MRS N-2/NDA

• RD/RA work will result in sufficient site clearance to support a decision for no further RA (i.e. MEC removal) with LUCs)

RD/RA Starting Point

NDA/N2 Remedial Design Planning

Aug18, 2011

Background• Historical investigations of the MRS that comprises

NDA/N2 and surrounding area have characterized the density of anomalies and established that extensive debris from 100# practice bombs is present throughout the area, while less extensive fragments from 100# HE bombs is restricted to an area around the NDA.

• No MEC has been found in this area despite extensive efforts to investigate anomalies that were considered the most likely to represent MEC.

• A single 100# HE bomb was encountered E or SE of the NDA during construction of roadside drainage ditches in 1996.

Conceptual Site Model (CSM)and Key Assumptions

• Intact spotting charges can separate at a very low frequency, conservatively, probably less than 5% of practice bombs dropped. • None have been observed at the site to date after

thousands of excavations and surface MD observations.

• Separation would occur on impact with the ground; bouncing might occur

• Likely to remain on the surface

Conceptual Site Model (CSM)and Key Assumptions

• Primary future land use in the MRS is industrial (e.g., airport expansion)

• Exposure scenarios might include:– Construction workers including backhoe and bulldozer operators– Industrial (airport) workers

• Consequences of encounter– 100 # HE – death or serious injury– 100# Practice bomb w/intact spotting charge or separated

spotting charge– injury, possible death for unprotected personnel handling (much smaller radius of impact)

Factors to take into account in design– Anomaly density– Pattern of observed craters– Flight path– Wind Direction– Soil characteristics (caliche impact on

penetration depth)– Practice bombing might have similar but less

precise pattern of “misses” as HE bombing– Larger number of practice bombs dropped

Additional Design Factors• Evidence suggests that the number of HE

bombs can be fairly accurately determined from the air photo evidence for the following reasons. – RI intrusive investigation results suggest a low number of bombs

based on the scarcity of frag observed on the surface and found in the subsurface at the center of the site.

– WAA helimag survey data support low amounts of frag at the site.

– A conclusion in the WAA report suggested that the target was either cleaned up at some point or was used sparingly.

– Helimag data for other HE bomb targets that were used more and the helimag data showed significantly more anomalies, more like what we see at N-2.

Data Quality Objectives• Identify the Goals of the Remedial Action

– For the Target Centers/high anomaly density areas:• Perform a surface clearance of all metallic debris on the

surface found through visual observations assisted by a hand held magnetometer.

• Determine the location, and intrusively investigate, all subsurface anomalies that are suspected of being targets of Interest (TOI).

• Remove and destroy any MEC.• Confirm that the probability of MEC remaining below the

surface is adequately low to conclude no further remedial action is needed, beyond continued land use controls.

Data Quality Objectives• Identify the Goals of the Study

– For the medium anomaly density areas:• Perform a surface clearance of all metallic debris on the

surface found through visual observations assisted by a hand held magnetometer.

• Confirm that the probability of MEC remaining below the surface is adequately low to conclude no further remedial action beyond continued land use controls is needed.

Data Quality Objectives• Identify the Goals of the Study

– For the low anomaly density portions of the MRS:• Confirm that the probability of MEC remaining below the

surface is adequately low to conclude no further remedial action beyond continued land use controls is needed.

Information and Data Needs• Historical data including location of craters, anomalies, digs• Target Center:

– Results of surface clearance efforts

– Results of 100% EM-61 survey of the target center/high anomaly density areas.

• Locations of all TOI (anomalies that could be reflective of MEC) and should be further characterized

• Results of MetalMapper characterization of the TOI identified using EM-61• Results of intrusive investigations of all TOI that the MetalMapper identifies

as having characteristics consistent with MEC

• TOI includes 100# practice bombs w/associated spotting charge, ~3# separated spotting charge, and 100# HE bombs

Information and Data Needs• Medium anomaly density/crater area

– Results of surface clearance efforts– Results of EM-61 investigation of transects taken to

adequately represent the area• Locations of all anomalies that should be further

characterized with MetalMapper• Results of MetalMapper characterization • Results of intrusive investigations of all TOI that the

MetalMapper identifies as having characteristics consistent with MEC

Information and Data Needs• Low anomaly density areas

– Results of EM-61 investigation of transects taken to adequately represent the area

• Locations of all anomalies that should be further characterized with MetalMapper

• Results of MetalMapper characterization • Results of intrusive investigations of all TOI that the

MetalMapper identifies as having characteristics consistent with MEC.

Boundaries• Geographic boundaries of the 20 acres surrounding the NDA target center

and 40 acres surrounding the N2 target center

• Geographic boundaries of the area containing anomaly densities greater than background (medium density, 25-100 anomalies per acre) and areas where craters were observed in historical aerial photographs outside the target centers.

– Based on spatial statistical contours developed using the historical geophysical surveys.

• MRS boundaries developed from the RI based on a 3000 ft radius area surrounding target centers, and incorporating all anomaly density contours greater than background and the majority of debris identified as MD.

• 4 acre (127 m2) (or other size) grid over the area, width of transect and max length of a transect

• The subsurface area of interest includes the top 4 feet of soil.

Analytic Approach (VSP Option)• If after completing an adequate survey and investigating

all anomalies of interest no MEC has been found in the investigation area, conclude that no further remedial action is required in the area.– Notes:

• “Investigation” involve reacquiring the EM-61 anomaly and characterization using MetalMapper, and subsequent intrusive investigation of all anomalies having characteristics consistent with MEC

• “Adequate” survey involves investigating the random number and location of transects required by VSP to achieve a desired confidence level.

– Adaptive approach: If MEC is uncovered in any 4 acre cell investigated, resurvey this cell to determine if the cell is now MEC free.

Performance Criteria• For the target center/high anomaly density areas,

establish using the proposed technology that the area is free of MEC.

• For the medium and low anomaly density areas, determine with 99% confidence that 99.375% of all transects within the area are free of MEC.– NOTE:

• Assumes the geophysical detectors reliably detect and locate all MEC. QC requirements for the proposed system will be established and tested during the study.

• Careful attention needs to be paid to the inputs to understand what % of the transects would yield a comparable requirement as UXO estimator (e.g., .1 per acre).

Notion of Probabilistic Risk-Based Sampling Design

• Suppose that you can afford to sample exactly X acres, which sample design will lead to the greatest confidence that no MEC is there (if you find none)?– Sampling X acres where you think there’s a low

chance of MEC– Random sampling of X acres– Sampling X acres where you think there’s a high

chance of MEC

Probabilistic Risk-Based Sampling Design

• Prioritize locations that have highest risk• Risk depends on potentially many factors

– Density (i.e. prevalence rate) of MEC– Accessibility (e.g. depth, public access)– MEC stability (e.g. sensitivity, degradation)– Individual behavior of finder (difficult to model)

• Typically considered identical across a site, but could vary with respect to different MEC

– MEC danger (i.e., result of explosion)

Evidence of MEC Density

• Historical use indicates decreasing density moving away from target areas

• Crater record shows evidence of target hit/miss behavior of HE bombs

• Previous sampling efforts show location of high densities of anomalies– Evidence of behavior of combination of HE

and practice bombs

Transects vs Grids• Transects

– Can get small amount of information about a large number of areas

– Effort (cost) associated with locating the transects

– Large number of edge effects

• Grids– Limited number of locations can be examined

– Effort of locating grids low

– Fewer edge effects

• Cost-Benefit?

Probabilistic, Risk-Based Sample Designs

• Utilize crater information only– Focuses on 100-lb HE bombs

• Utilize anomaly density only– More emphasis on 100-lb practice bombs and

associated spotting charges, but includes HE frag

• Utilize both– Apply risk considerations to decide on balance

between

• Transect and grid designs

Example Designs• VSP

• Probabilistic allocation

• UXO Estimator

Example VSP DesignsArea Acres

Grid Size (m) Grid Area (ac) Confidence % transects % coverage

Acres surveyed

Total Acres Surveyed

Acreage of transect

% transects eqiv to .1/ac

Low 988 127 4 99 99.375 4.59% 45.3 0.062 99.375Med + Crater 203 127 4 99 99.375 20.85% 42.3 87.7

Low 988 127 4 95 99.375 3.05% 30.1Med + Crater 203 127 4 95 99.375 14.05% 28.5 58.7

Risk-Based Probabilistic Design Based on Anomaly and Crater Density (Grid)

Risk-Based Probabilistic Design Based on Anomaly and Crater Density (Transects)

VSP and Probabilistic Design

UXO Estimator• Ordnance is assumed to occur homogeneously within

the AOI.– “This does not mean the ordnance is uniformly distributed; it only

means the occurrence of ordnance items follows a Poisson statistical distribution.”

– “Therefore, there may be certain areas of high density and low density ordnance, as long as it is not “clustered.” (defined as non-clustered poison distribution)”

– We interpret this to mean that MEC could show up anywhere but will not be clustered to the point of failing Poisson distribution assumptions

UXO Estimator

• Does not provide a map – assumes random placement of transects or grids w/in sample area

• Requires you to specify the acceptable number per acre you might leave behind

• Requires a separate software package to develop maps of transect/grid placement

• Does acknowledge and deal directly with what to do if an item is found

UXO Estimator OutputArea Acres

Target Density Confidence

Acres surveyed

Total Acres Surveyed

Transect length (km) Note

Low 988 0.1 99 44.6 90 1 in 10 ac

Med + Crater 203 0.1 99 39.5 84.1 80

.

Low 988 0.1 95 29.2 59

Med + Crater 203 0.1 95 26.6 55.8 54

Low 988 0.05 99 86.3 174 1 in 20 ac

Med + Crater 203 0.05 99 68.7 155.0 139

.

Low 988 0.05 95 57.0 115

Med + Crater 203 0.05 95 48.0 105.0 97

Accessibility-Based Risk

• Highly accessible locations– If MEC present, increased likelihood of public encounter– If highly accessible in the past, likely to have already been found

if there

• Less accessible locations– The reverse

• For West Mesa, primary accessibility difference across the site may be depth – presence of gullies/depressions where high deposition is likely

MEC stability• If MEC is present, why?

– Complete dud (degraded explosive material, low danger)– Failed firing mechanism (danger if can be triggered another way)– Landed unusually (still fully armed?)

• Some MEC more likely than others to be set off upon encounter

• Some MEC degrades in environment more quickly than others

• MEC danger – consequence of explosion much higher for HE bomb than spotting charge

West Mesa Digital Geophysical Mapping

(DGM) Investigation

MRS N-2 / NDA

• Two Fold DGM Survey– Geonics EM 61 MK2 Towed Array and Man

Portable Surveys– Metal Mapper Surveys (MM)

Classification ObjectiveTargets of Interest (TOI) •100-lb practice bombs with M1A1 spotting charges, •100-lb HE bombs, •Separate M1A1 spotting charges

To identify those anomalies that are definitely clutter (they cannot possibly be UXO) at the site

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• Pre DGM work

– Surveying

– Surface Clearance,

– Vegetation Removal

– Instrument Verification Strip (IVS)

– Create MM Calibration/Library Pit

– 10 acre test site in high density area

EM61 MK2 Towed ArrayDGM Survey Coverage

•High density N-2 / NDA - 100% mapping of targets•Medium and low density areas – sampling approach to be determined

Process EM61 data and select targets

EM61 MK2 Surveys

• Testing MM over TOI in Test Pit for Target Library

• Reacquire EM61 targets with Metal Mapper (MM)

• Collect Static data set over EM61 targets

MetalMapper● 3 orthogonal transmitters & 7 three-axis receivers

Park over location estimated by previous surveyFire transmitter 1, record on all 21 receiversFire transmitter 2, record on all receiversFire transmitter 3, record on all receivers

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Metal Mapper Channel 1 – Horizontal 81 mm

MM: Horizontal UXOMM: Horizontal UXO

Transmit x Transmit y Transmit z

Receive x

Receive y

Receive z

Am

plit

ud

e

Time

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Am

plit

ud

e

Time

Receive x

Receive y

Receive z

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Am

plit

ud

e

Time

Receive x

Receive y

Receive z

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• Process MM Data– Invert data using UXO_Analyze (Geosoft)– Inversion compared to TOI Library

• Dig or no Dig decision on each EM-61 targets

• Create prioritized dig list

• MM targets dug by UXO teams

Polarizability Match

Example of Library Match

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Prioritized Dig ListThe Classification Product

Rank based on the probability that the anomaly is clutter

Once prioritized, establishing the dig threshold is critical

Summary

Classify TOI for digging

Using Metal Mapper, project costs are reduced by identifying those anomalies that are definitely clutter (they cannot possibly be UXO) at the site

Open Discussion

Ordnance Safety

DO NOT TOUCH!DO NOT MOVE!

Note/record location

Call 911 or local law enforcement

ordnance safety

Documents

west mesa project mapmrs

fs reports address mrss

ft boundary

west mesa mrs boundariesfirst

nda split

ft radius boundary

draw boundary

nda boundaryprimary