Extract Contamination Evidence From Site Investigation Reports

---
name: extract-contamination-evidence-from-site-investigation-reports
task_id: environmental-esg/extract-contamination-evidence-from-site-investigation-reports
description: Guides preparation of a contamination evidence memorandum by systematically extracting and organizing detected contaminants, concentrations, affected media, and spatial extent across multiple investigation reports spanning different time periods.
activates_for: [planner, solver, checker]
---

# Skill: Extract Contamination Evidence from Site Investigation Reports — Evidence Summary Memorandum

## 1. Subject-matter triage

Where documents span multiple investigation phases and multiple time periods, organize findings chronologically and by investigation phase. Identify the most recent investigation data as the best indicator of current conditions, while using earlier investigations to establish the history of contamination discovery and progression.

If more than one report, sample round, medium, contaminant set, or regulatory letter is present, enumerate them first and then analyze each item consistently. Do not collapse distinct investigations into a single generalized narrative.

Treat the memorandum as evidence synthesis, not advocacy: extract what is measured, where it is measured, what standard applies, and what it means for delineation and risk.

## 2. Failure modes the skill is correcting

- Baseline describes contamination qualitatively without extracting the specific contaminants, concentrations, media, sample locations, and comparisons against applicable cleanup standards
- Baseline does not integrate findings across multiple investigation phases and reports to construct a unified contamination picture
- Baseline omits regulatory correspondence that may establish what standards apply and what actions the agency has already required
- Baseline fails to distinguish between delineated and not-yet-delineated contamination, which is critical for assessing remediation scope and cost uncertainty
- Baseline summarizes exceedances without tying them to the sampled medium, the relevant location, the temporal sequence, and the consequence for further investigation or cleanup
- Baseline leaves severity implicit; the reader cannot tell which findings warrant immediate attention versus routine monitoring
- Baseline omits a recommendation for next-step investigation, leaving the memo diagnostic but not action-oriented

## 3. Legal frameworks / domain conventions that apply

- Site investigation progression: preliminary assessment, site inspection, remedial investigation, and related phases; each stage has defined scope and objectives
- Phase I / Phase II environmental site assessment conventions: Phase I identifies recognized environmental conditions; Phase II characterizes contaminant presence and concentrations
- State voluntary remediation or equivalent cleanup programs: state-specific investigation requirements and cleanup standards that govern what must be characterized and to what level
- Contaminants of concern: identify based on site history, regulatory priority lists, and detection frequency
- Media of concern: soil, groundwater, soil gas / vapor intrusion, sediment, and surface water; each requires separate characterization and separate applicable cleanup standards
- Risk-based cleanup levels: residential, commercial / industrial, construction-worker, or other applicable exposure scenarios; use the relevant generic numeric standards and note when site-specific risk assessment may apply
- Delineation adequacy: whether contamination boundaries have been characterized laterally and vertically with sufficient data density to support reliable remediation scoping
- Regulatory authority and standards: identify the controlling cleanup program, the standard-setting provision, and any agency directive or approval that fixes the applicable comparison baseline
- Vapor intrusion pathway: soil gas investigation findings must be assessed in light of building locations and occupant receptors; an uncharacterized vapor intrusion pathway represents a significant data gap

## 4. Analytical scaffolds

- Compile a master list of all contaminants detected across all investigations, organized by medium
- For each contaminant and medium: extract the highest detected concentration, location of detection, and date of sampling; compare against the applicable cleanup standard
- Assess delineation status: for each contaminant of concern and medium, determine whether the plume boundary has been established or whether additional investigation is needed
- Assess temporal trends: compare concentrations across investigation periods to identify whether contamination is stable, increasing, or decreasing
- Summarize agency correspondence: extract any regulatory determinations about site status, required additional investigation, applicable cleanup program, and cleanup standards
- For each finding: state the contaminant, medium, sample location reference, concentration, applicable cleanup standard, comparison to the standard, and delineation status
- Identify data gaps: media, locations, or contaminants not yet adequately characterized
- For each issue or exceedance, pair the factual finding with the controlling authority or program requirement that makes the comparison meaningful
- Assign a uniform ordinal severity level to each material finding, using a fixed scale defined once at the outset, and apply it consistently across the memo
- Close each material finding with three moves: the scale of the exceedance or data gap, the interaction with other investigations or agency actions, and the practical consequence for remediation scope, risk, or next-step work

## 5. Vertical / structural / temporal relationships

- Investigation chronology: early investigations establish the historical record of contamination; later investigations may show extent of migration or natural attenuation; track both
- Regulatory program enrollment: state cleanup program or analogous program status affects what investigation standards apply and what agency approvals are needed
- Temporal comparison: if results vary across rounds, identify whether differences reflect new sampling locations, changing plume extent, remediation, or natural attenuation
- Medium hierarchy: soil, groundwater, soil gas, sediment, and surface water should be reported separately because contamination in one medium may indicate migration to another
- Vapor intrusion hierarchy: subsurface soil gas findings must be read together with indoor air or sub-slab results, building proximity, and receptor use
- Spatial hierarchy: source area, near-source, mid-plume, and perimeter points should be distinguished so that delineation status is not overstated
- Regulatory chronology: later agency letters or approvals may supersede earlier assumptions about applicable standards or required work scope

## 6. Output structure conventions

- Organize as a contamination evidence memorandum with an executive summary, site background, investigation history, contamination summary by medium, delineation status assessment, regulatory standard comparison, data gaps, and conclusions
- Begin with a short severity legend defining the ordinal scale used in the memo
- Contamination summary tables: one table per medium with columns for contaminant, maximum detected concentration, applicable cleanup standard, exceedance status, delineation status, severity, and source reference
- Include a separate chronology table listing each investigation or correspondence item by date, purpose, medium addressed, and significance
- Risk assessment: flag any exceedances using the defined severity scale based on magnitude of exceedance, receptor proximity, and whether the contamination is bounded or still expanding
- When standards are cited, name the governing program, rule, guidance, or agency directive that supplies the comparison value
- Conclude with a concise recommended actions section that assigns each next step to the responsible party or role and ties it to the next investigation milestone or agency deadline, if available
- Produce the memorandum in the required format and follow any task-specific naming or delivery instructions