Walk onto any piece of land in America, and you're standing on a complex environmental story. The soil beneath your feet holds clues to its past uses and potential contamination. Uncovering these stories requires precise scientific methods. Two major players in this detective work are the U.S. Environmental Protection Agency (EPA) and the Oak Ridge Institute for Science and Education (ORISE), each bringing specialized approaches to environmental sampling that protect public health and restore contaminated lands.
The Science of Environmental Sampling: More Than Just Dirt
At its core, environmental sampling is a systematic process of collecting soil, water, air, and other environmental materials to analyze their chemical composition. This isn't simply grabbing a handful of dirt—it's a rigorous scientific procedure designed to yield accurate, defensible data that can guide critical decisions about land use, cleanup, and public safety.
EPA's ESAM Program
The EPA's Environmental Sampling and Analytical Methods (ESAM) program serves as a comprehensive toolkit for contamination response. This coordinated approach provides everything needed to characterize and remediate sites, from field sampling procedures to laboratory analysis and data management 2 .
ORISE Verification
Meanwhile, ORISE specializes in independent verification of environmental cleanup, particularly for radiologically contaminated sites. For over four decades, their health physicists and field technicians have used specialized equipment and rigorous methodologies to ensure facilities and land can be safely released for public use 3 .
A Tale of Two Approaches: When to Use Which Method
While both organizations employ rigorous scientific methods, their specialties complement rather than duplicate each other:
EPA's Broad-Spectrum Environmental Protection
The EPA typically employs methods designed to detect chemical and metal contaminants across diverse environmental settings.
- EPA Method 6010D uses inductively coupled plasma-atomic emission spectrometry to detect metals in groundwater, wastes, soils, and sediments .
- EPA Method 200.8 utilizes inductively coupled plasma-mass spectrometry for trace metal analysis in waters and solid wastes 8 .
- Various PFAS testing methods (533, 537.1, and 1633) target "forever chemicals" in different matrices 4 .
ORISE's Radiological Expertise
ORISE focuses particularly on radiological assessment, with specialized methods.
- ORISE Method AP11: A sophisticated technique for sequential determination of actinides in environmental samples using total sample dissolution and extraction chromatography. This method is particularly valuable for confirmatory analysis when samples exist in refractory form or when matrix interference problems occur 6 .
The choice between these approaches depends entirely on the nature of the suspected contamination—chemical versus radiological—and whether the goal is initial assessment or independent verification of cleanup.
Science in Action: The Henry County Soil Investigation
A recent investigation in Henry County, Missouri, demonstrates EPA's field sampling procedures in action. When questions arose about potential soil contamination, EPA conducted environmental sampling at the Davis R-12 school district to assess metals of concern including arsenic, cobalt, chromium, and lead 1 .
The Step-by-Step Scientific Process
Site Assessment and Sample Planning
Scientists first examined historical land use and potential contamination sources to determine optimal sampling locations across the school property.
Systematic Sample Collection
Using standardized procedures from EPA's ESAM program, technicians collected soil samples from multiple locations (C-1 through C-13), including a blind duplicate (DUP) for quality control 1 2 .
Chain of Custody and Documentation
Each sample was carefully labeled, documented, and tracked to maintain legal defensibility and scientific integrity throughout the process.
Laboratory Analysis
Samples underwent rigorous testing using EPA methods including inductively coupled plasma spectrometry for metal detection.
Data Validation and Interpretation
Results were compared against EPA's Removal Management Levels (RMLs) - the thresholds determining when soil removal is necessary - and Background Threshold Values (BTVs) representing naturally occurring metal levels in local soils 1 .
Revealing Results: The Data Story
The sampling revealed a scientifically significant story about the school's environmental conditions:
| Sample ID | Arsenic (mg/kg) | Total Chromium (mg/kg) | Hexavalent Chromium (mg/kg) | Lead (mg/kg) |
|---|---|---|---|---|
| C-3 | 2.61 | 12.4 | 1.0 | 10.7 |
| C-8 | 2.83 | 16.0 | ND (0.96) | 18.3 |
| C-9 | 3.61 | 12.0 | ND (0.88) | 27.2 |
| C-12 | 2.17 | 12.2 | 0.21 | 11.8 |
| EPA RML | 35 | N.E. | 70 | 200 |
| Local BTV | 19 | 100 | N.E. | 37 |
Notes: ND = Not Detected above laboratory reporting limit; N.E. = Not Established 1
The power of this environmental detective work emerged not from individual numbers, but from their careful comparison to regulatory and natural benchmarks. As shown in Table 2, the scientific conclusion was clear: despite detecting various metals, none required immediate cleanup action.
| Parameter | Arsenic | Cobalt | Total Chromium | Hexavalent Chromium | Lead |
|---|---|---|---|---|---|
| EPA RML | 35 mg/kg | 23 mg/kg | N.E. | 70 mg/kg | 200 mg/kg |
| Local BTV | 19 mg/kg | 30 mg/kg | 100 mg/kg | N.E. | 37 mg/kg |
Source: EPA Regional Screening Levels and Background Threshold Values from Henry County assessment 1
The Scientist's Toolkit: Essential Methods for Environmental Analysis
Environmental investigators rely on sophisticated analytical methods tailored to specific contamination concerns:
| Method | Organization | Best For | Key Applications |
|---|---|---|---|
| ICP-OES (6010D) | EPA | Determining metals in waters, soils, sludges | Groundwater assessment, industrial waste characterization |
| ICP-MS (200.8) | EPA | Trace metal analysis in waters and wastes | Drinking water monitoring, compliance with Clean Water Act |
| ORISE AP11 | ORISE | Sequential determination of actinides | Radiological site cleanup verification, nuclear facility decommissioning |
| EPA 533/537.1 | EPA | PFAS compounds in drinking water | Compliance with Unregulated Contaminant Monitoring Rule |
| EPA 1633 | EPA | PFAS in multiple matrices | Comprehensive site investigation for "forever chemicals" |
This methodological diversity allows environmental scientists to address everything from legacy metal contamination to emerging concerns like PFAS "forever chemicals" 4 and radiological issues 6 .
Beyond the Science: The Human Impact
The rigorous procedures employed by EPA and ORISE represent more than technical exercises—they directly impact human health and community wellbeing. The Henry County case study demonstrates how systematic sampling can reassure communities about their local environments 1 .
Safe Learning Environments
Environmental assessments ensure that schools and playgrounds are free from harmful contaminants, protecting our most vulnerable populations.
Redevelopment Confidence
ORISE's independent verification work provides crucial confidence that previously contaminated lands can be safely returned to public use 3 .
"In both cases, the methodical, transparent approach to environmental assessment helps build trust between scientific institutions and the communities they serve."
The Future of Environmental Field Science
As contamination challenges evolve, so too must sampling methodologies. Emerging concerns like PFAS "forever chemicals" have driven development of specialized methods such as EPA 533, 537.1, and 1633 4 . Meanwhile, the potential restructuring of environmental science under initiatives like Project 2025 could significantly impact how these scientific methods are deployed and prioritized 7 .
The next time you walk through a park or watch children play on a school field, remember the sophisticated scientific work that may have occurred to confirm these spaces are safe. The invisible work of environmental sampling and assessment makes our visible world safer for all who inhabit it.