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Hyperspectral Imaging Can Be

a Useful Evaluation Tool for 

Office of Inspector General

Reviews Focused on 

Contaminated Land

Report No. 14-N-0360 September 26, 2014

U.S. ENVIRONMENTAL PROTECTION AGENCY

OFFICE OF INSPECTOR GENERAL
Report Contributors: Rick Beusse

Christina Lovingood 

James Hatfield

Kathryn Hess 

Patrick Milligan

Natasha-Ahsaki Henry

Bakari Baker

Kevin Good

Abbreviations

EPA U.S. Environmental Protection Agency

HSI Hyperspectral Imagery

OIG Office of Inspector General 

RCRA Resource Conservation and Recovery Act 

USGS U.S. Geological Survey

UST Underground Storage Tank

Cover photos: From left: Civil Air Patrol’s Airborne Real-Time Cueing Hyperspectral 

Enhanced Reconnaissance (ARCHER) sensor; example of a brownfields site 

where hyperspectral imagery was collected. (USGS photos)

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 14-N-0360

September 26, 2014

Why We Did This Review

We conducted this review to 

determine whether 

hyperspectral imaging (HSI) 

data is a useful tool for the

U.S. Environmental Protection 

Agency (EPA) Office of 

Inspector General (OIG) to 

assess conditions and 

effectiveness of cleanup 

actions at Superfund, 

Brownfields, Resource 

Conservation and Recovery Act

Corrective Action, and 

Underground Storage Tank

sites.

HSI is similar in concept to 

satellite images. HSI is a type 

of remote sensing technology 

used on an airborne

hyperspectral sensor that

records reflected and emitted 

electromagnetic energy in 

hundreds of very narrow 

wavelengths. The data can 

assist in the identification and 

analysis of environmental 

conditions and certain 

contaminants.

This report addresses the 

following OIG goal:

 Contribute to improved 

human health, safety, and 

the environment.

Send all inquiries to our public

affairs office at (202) 566-2391 or 

visit www.epa.gov/oig. 

The full report is at:

www.epa.gov/oig/reports/2014/ 

20140926-14-N-0360.pdf

 

Hyperspectral Imaging Can Be a Useful 

Evaluation Tool for Office of Inspector General

Reviews Focused on Contaminated Land

 What We Found

Starting in December 2007, in coordination with 

the U.S. Geological Survey, the OIG has been 

assessing the feasibility of using remote sensing 

technologies for OIG oversight of the 

effectiveness of EPA cleanup actions. We 

conducted HSI work at 40 sites in seven states.

Our work shows that HSI is useful in identifying vegetative stress on land related 

to the presence of certain heavy metals, such as lead and arsenic. HSI is also 

useful for identifying debris on land. HSI can be useful during the scoping phase

of an audit or evaluation to screen multiple sites and select a smaller, more 

relevant sample of sites for on-site visits and further review. In our work, when 

the HSI indicated little vegetative stress, we also found that sites were generally 

free of any significant residual contamination

HSI is one available evaluation tool for collecting information and designing an 

assignment under the broad objective of assessing, on a case-by-case basis, the 

effectiveness of cleanup actions on land. OIG assignment timeframes, costs and 

objectives must ultimately be factored in when deciding the most appropriate 

evaluation methods.

U.S. Environmental Protection Agency

Office of Inspector General

At a Glance

Hyperspectral imaging is 

an evaluation tool that has 

specialized value in 

designing and conducting 

Office of Inspector General 

assessments of cleanup 

actions.
September 26, 2014

MEMORANDUM

SUBJECT: Hyperspectral Imaging Can Be a Useful Evaluation Tool for Office of Inspector General

Reviews Focused on Contaminated Land

Report No. 14-N-0360

FROM: Carolyn Copper, Assistant Inspector General

Office of Program Evaluation

TO: Charles Sheehan, Deputy Inspector General 

Attached is a report assessing the use of remote sensing technologies in U.S. Environmental Protection 

Agency (EPA) Office of Inspector General oversight of the effectiveness of EPA cleanup actions. This 

report represents the culmination of work that the Office of Program Evaluation began in December 

2007, in coordination with the U.S. Geological Survey. We made observations in determining whether 

hyperspectral imaging data is a useful tool for assessing contamination and cleanup at Superfund, 

Brownfields, Resource Conservation and Recovery Act Corrective Action, and Underground Storage 

Tank sites.

We will post this report to our website at http://www.epa.gov/oig.

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, D.C. 20460

OFFICE OF

INSPECTOR GENERAL
Hyperspectral Imaging Can Be a Useful Tool 14-N-0360

for Office of Inspector General Reviews 

Focused on Contaminated Land

Table of Contents

Purpose...................................................................................................................... 1

Background ............................................................................................................... 1

Scope and Methodology........................................................................................... 1

Results of Review ..................................................................................................... 3

Conclusion ................................................................................................................ 3

Appendices

A USGS Work Products as a Result of Interagency Agreement 

With EPA OIG.................................................................................................... 4

B Example of Hyperspectral Imagery ................................................................. 5

C EPA OIG Distribution........................................................................................ 6
14-N-0360 1

Purpose

This report addresses whether hyperspectral imaging (HSI) is a useful tool for the 

Office of Inspector General (OIG) of the U.S. Environmental Protection Agency 

(EPA) to use in assessing contamination and cleanup at Superfund, Brownfields, 

Resource Conservation and Recovery Act (RCRA) Corrective Action, and 

Underground Storage Tank (UST) sites. Starting in December 2007, in 

coordination with the U.S. Geological Survey (USGS), we have been assessing

the use of remote sensing technologies for OIG oversight of the effectiveness of 

EPA cleanup actions. 

Background

Hyperspectral imaging is a type of remote sensing technology that records 

reflected and emitted electromagnetic energy in hundreds of very narrow 

wavelengths. Data can be captured using an airborne sensor. The data can assist in 

the identification and analysis of environmental conditions and certain 

contaminants.

In 2007, the EPA OIG determined that the EPA had failed to detect hazardous 

waste at the Ringwood, New Jersey, Superfund site, leading to the EPA’s 

insufficient characterization of contamination and, consequently, insufficient 

cleanup at the site. The EPA OIG further concluded that the overlooked 

contamination may have been detected sooner if the EPA had made greater use of 

available aerial photographs.

1 As a result of that work, the OIG initiated a series 

of HSI research projects in December 2007 designed to test the use of HSI for 

OIG oversight of the effectiveness of EPA cleanup actions. 

Scope and Methodology 

We began our work in December 2007, and received our final HSI analyses in 

May 2014. This report evaluates the usefulness of HSI technology to identify 

certain conditions at contaminated sites. The scope of work performed for this 

report does not constitute an audit under generally accepted government auditing 

standards. 

Working with USGS, we conducted our HSI work in three phases which involve 

different types of contaminated sites and different states. Each phase included the 

collection and analysis of hyperspectral imagery, soil sampling and soil analysis. 

The three phases encompassed a total of 40 sites in seven states, as shown in

Table 1. We visited Superfund, Brownfields, RCRA Corrective Action and UST

sites.

 

1 Limited Investigation Led to Missed Contamination at Ringwood Superfund Site, (Report No. 2007-P-00039, 

September 25, 2007), http://www.epa.gov/oig/reports/2007/20070925-2007-P-00039.pdf. 
14-N-0360 2

Table 1: Sites sampled for HSI testing

Phase Number of sites Type of sites States

1 5 Superfund Maryland

Virginia

2 11* Superfund Pennsylvania

3 24**

Brownfields (16) Florida 

South Carolina

Louisiana

Texas

RCRA Corrective Action (6)

UST (2)

Source: OIG analysis.

* Soil samples were not taken at four sites because we did not visit the sites. 

** Soil samples were not collected from three sites because the sites were paved over.

We reviewed site assessment and other site background documents and worked 

with EPA, state officials and site owners to obtain site access. To obtain HSI data, 

the USGS entered into an interagency agreement with the U.S. Air Force Civil 

Air Patrol. For all sites visited we conducted an inspection of general site 

conditions, and soil samples were collected at most sites in cooperation with 

USGS. Whenever possible, we used a portable X-ray fluorescence unit to obtain a 

field scan of the metal composition of the soil prior to taking each soil sample.

Soil samples were analyzed in the USGS laboratory for heavy metal 

contamination and, in some cases, were also analyzed for asbestos. A subset of 

these samples was sent to an independent laboratory for confirmatory testing by 

Inductively Coupled Plasma analysis using EPA methods 3050 and 6010. The 

Inductively Coupled Plasma results were compared to HSI to determine whether 

there was any correlation between vegetation stress and high metals readings.

Since our work began in December 2007, we issued an early warning report to 

EPA2and we provided the EPA with early sampling results to give early notice of 

possible issues at sites. Other reports are in progress.

Further, the USGS has issued four final reports and a draft report as a result of its 

interagency agreement with the EPA OIG (see Appendix A).

 

2 Observed Conditions at Five Deleted Superfund Sites (Report No. 11-P-0433), August 3, 2011.
14-N-0360 3

Results of Review

Based upon the scope of the work performed and the sites OIG evaluated, remote 

sensing technology can be useful to inform on the status of site conditions and 

further detection of site anomalies. We determined that the current state of HSI

technology is useful in identifying vegetative stress related to the presence of

certain heavy metals. Three of the sites we sampled had areas that showed high 

concentrations of arsenic and/or lead in the soil. Some of the same areas on the 

hyperspectral images also showed vegetative stress. See Appendix B for an 

example of a hyperspectral image.

We determined that HSI technology is useful in identifying debris, and for 

screening out sites for further OIG work. HSI can also be useful during the 

scoping phase of an evaluation to screen multiple sites and select a smaller, most 

relevant sample of sites for on-site visits and further review. When the HSI 

indicated little vegetative stress, our review found that the site was generally free 

of any significant residual contamination. For example, HSI imagery showed little 

indication of vegetative stress or anomalies at eight of the 11 sites tested and 

visited in Pennsylvania. On-site observations confirmed that these sites were 

generally free of significant residual debris that would be detected by the anomaly 

detection routine used to process the hyperspectral images. Further, soil sample 

results indicated that these sites contained low levels of metal concentrations that 

were below the appropriate EPA risk-based screening levels. We believe this is an 

indicator that HSI could be a cost-effective means to periodically screen sites 

designated as ‘cleaned-up’ for new contamination or changed conditions.

In addition, the anomaly detection routine also reliably detected hard surface 

debris left at the site, as well as other site anomalies, such as surface areas that are 

different from the surrounding areas. For example, at one site in Virginia, HSI 

identified anomalies that proved to be scrap auto bumpers, empty metal containers 

and other materials. Thus, if HSI were collected for several sites, those that did 

not have indications of vegetative stress or anomalies might be eliminated from 

further review.

Conclusion 

HSI is one evaluation tool that OIG staff have available when designing an 

assignment under the broad objective of assessing, on a case-by-case basis, the 

effectiveness of cleanup actions at contaminated, previously contaminated or 

potentially contaminated sites, depending on timeframes, costs and assignment 

objectives.
14-N-0360 4

Appendix A

USGS Work Products as a Result of 

Interagency Agreement With EPA OIG

Slonecker, E.T., and Fisher, G.B. 2009. Research Implementation and Quality Assurance Project 

Plan: An Evaluation of Hyperspectral Remote Sensing Technologies for the Detection of 

Fugitive Contamination at Selected Superfund Hazardous Waste Sites. USGS Open-File Report 

2009–1048, http://pubs.usgs.gov/of/2009/1048/.

Slonecker, E.T., and Fisher, G.B. 2011. An Evaluation of Traditional and Emerging Remote Sensing 

Technologies for the Detection of Fugitive Contamination at Selected Superfund Hazardous Waste 

Sites. USGS Open-File Report 2011–1050, http://pubs.usgs.gov/of/2011/1050/.

Slonecker, E.T., and Fisher, G.B. 2011. Graphic Products Used in the Evaluation of Traditional 

and Emerging Remote Sensing Technologies for the Detection of Fugitive Contamination at 

Selected Superfund Hazardous Waste Sites. USGS Open-File Report 2011–1068, 

http://pubs.usgs.gov/of/2011/1068/.

Slonecker, E.T., and Fisher, G.B. 2014. An Evaluation of Remote Sensing Technologies for the 

Detection of Fugitive Contamination at Selected Superfund Hazardous Waste Sites in 

Pennsylvania. USGS Open-File Report 2014–1081, http://dx.doi.org/10.3133/ofr20141081.

Slonecker, E.T., and Fisher, G.B. An Evaluation of Remote Sensing Technologies for the 

Detection of Fugitive Contamination at Selected Sites under the EPA Cross-Program 

Revitalization Measures Program. (In Progress – Draft Report) 
14-N-0360 5

Appendix B

Example of Hyperspectral Imagery 

Hyperspectral Image Processing Results for the Clearwater Automotive Site, Clearwater, Florida. 

Left: USGS color image with field sampling points. Right: Image showing the agricultural stress composite 

index based on the hyperspectral imaging. In the stressed image, red and black indicate vegetative stress. 

Black also indicates paved areas. 
14-N-0360 6

Appendix C

EPA OIG Distribution

Inspector General 

Deputy Inspector General 

Counsel to the Inspector General 

Chief of Staff, Office of Inspector General 

Assistant Inspector General for Audit

Deputy Assistant Inspector General for Program Evaluation

Deputy Assistant Inspector General for Audit

Deputy Assistant Inspector General for Congressional and Public Affairs