| name | environmental-due-diligence-expert |
| description | Use when reviewing Phase I/II ESA reports, evaluating contaminated site acquisitions, estimating remediation costs, analyzing MOE regulatory pathways (Tier 1/Tier 2, RSC filing), or allocating environmental liability between buyer and seller. Triggers on RECs, soil/groundwater exceedances, brownfield redevelopment, and contamination-driven price adjustments. |
Environmental Due Diligence Expert
Overview
Environmental Due Diligence = Systematic assessment of environmental risks associated with real property acquisition, including historical contamination, regulatory liabilities, remediation requirements, and acquisition price adjustments.
Purpose:
- Identify and quantify environmental liabilities before acquisition
- Assess contamination risk severity and cleanup requirements
- Estimate remediation costs and timelines
- Determine regulatory pathway and approval requirements
- Develop liability allocation and insurance strategies
- Calculate acquisition price adjustments for environmental risk
- Protect buyer from hidden environmental costs
Key Components:
- Phase I ESA interpretation (RECs, historical uses, data gaps)
- Phase II ESA analysis (soil/groundwater sampling, contaminants)
- Contamination risk scoring (HIGH/MEDIUM/LOW)
- Cleanup cost estimation (risk-adjusted, scenario analysis)
- Regulatory pathway analysis (MOE approval, Record of Site Condition)
- Liability allocation strategies (vendor indemnity, holdback, insurance)
- Acquisition price adjustment recommendations
Phase I vs Phase II vs Phase III Decision Framework
Phase I ESA — Non-Intrusive Desktop & Visual Inspection
Identifies Recognized Environmental Conditions (RECs) through records review, site inspection, and environmental database searches.
- REC: Evidence of release or threat of release of hazardous substances
- HREC (Historical REC): Past contamination evidence, no current threat
- CREC (Controlled REC): Current contamination being addressed through active remediation program
Process: (1) Records review (~80% of value) — historical uses, regulatory filings, prior ESAs; (2) Site inspection — visual observation, interviews, neighboring property assessment; (3) Environmental records — spill reports, Sanborn maps, aerial photos, planning records.
Red flags: manufacturing, service stations, dry cleaners, USTs, spill reports, adjacent contamination.
Decision:
- No REC → Proceed with development, no further action
- HREC only → Verify no current threat; Phase II optional (close data gaps)
- REC identified → Proceed to Phase II
- CREC → Check status of existing remediation program
Phase II ESA — Intrusive Sampling & Lab Analysis
Soil/groundwater sampling to quantify contamination versus MOE Generic Quality Standards (GQS).
Process: Sampling plan → soil borings + monitoring wells → laboratory analysis (PHC, PAHs, VOCs, metals, cyanide) → compare to MOE Tier 1 GQS → identify exceedances and exposure pathways.
Outcomes:
- Non-exceedance → Property clean for intended use (immediate, optional Cleanup Completion Certificate)
- Tier 1 exceedance → Standard cleanup pathway (6-12 month timeline)
- Tier 2 required → Site-specific Risk Assessment + MOE approval (12-24 month timeline)
Triggers for Tier 2: any groundwater exceedance, soil >5× Tier 1, potential third-party migration, potential human exposure.
Phase III — Remediation Implementation
Executes the cleanup plan (excavation/removal, on-site capping, in-situ treatment) and culminates in Record of Site Condition (RSC) filing with MOE for liability protection.
See regulatory-pathway.md for full MOE process, three-outcome decision tree, timeline estimates, RSC requirements, and MOE Tier 1 GQS contaminant tables.
Contamination Risk Scoring
Four-dimensional risk framework:
| Dimension | HIGH | MEDIUM | LOW |
|---|
| Severity | >10× standard, groundwater hit, multi-contaminant, accessible | 2-10× standard, single contaminant, below-ground | <2× standard, deep soil, no groundwater hit |
| Regulatory | Active enforcement, multi-property, sediment/GW | HREC, single property, partial Risk Assessment | No notices, meets Tier 1, no RA needed |
| Feasibility | In-situ + GW remediation, >$2M, 10+ yr monitoring | Partial remediation + capping, $500K-$2M | Simple excavation, $50K-$500K |
| Financial | Cleanup >10% acquisition price | Cleanup 2-10% acquisition price | Cleanup <2% acquisition price |
Overall scoring:
- HIGH RISK: Multiple HIGH dimensions, cleanup >10% price, timeline >2 yrs → Price reduction 15-30% OR seller remediation pre-closing
- MEDIUM RISK: Mix of HIGH/MEDIUM, cleanup 2-10% price, timeline 1-2 yrs → Price reduction 5-15% + seller indemnity
- LOW RISK: Most LOW, cleanup <2% price, timeline <1 yr → Standard due diligence
Cleanup Cost Estimation (Summary)
Cost = (Investigation) + (Remediation) + (Professional Services) + (Post-Remediation), applied as:
Risk-Adjusted Cost = Expected Cost × (1 + Risk Factor)
Low risk: Risk Factor 0.0-0.25
Medium risk: Risk Factor 0.25-0.50
High risk: Risk Factor 0.50-1.0+
Quick reference unit costs:
- Excavation: $20-$50/cy
- Disposal: $75-$200/cy (contaminant-dependent)
- Backfill: $10-$30/cy
- Phase II ESA: $3K-$10K; Risk Assessment (Tier 2): $10K-$50K
- In-situ treatment: $50K-$1M+ depending on method
- Long-term monitoring: $5K-$30K/yr
See cleanup-cost-estimation.md for full cost component tables (excavation, capping, in-situ treatment, professional services, post-remediation), the six-step estimation process, volume calculations, conservative/expected/optimistic scenario framework, and risk-adjusted formulas with worked examples.
Liability Allocation Framework
Match the structure to the cleanup cost magnitude and timeline:
Cleanup < $100K AND Timeline < 6 months:
→ Buyer absorbs (minimal risk)
Cleanup $100K-$500K AND Timeline 6-12 months:
→ Seller indemnity (3-5 year) + standard holdback (2-3%)
Cleanup $500K-$2M AND Timeline 12-24 months:
→ Seller indemnity + 5-10% holdback + cost-cap insurance
Cleanup > $2M OR Timeline > 24 months:
→ Seller pre-closing remediation OR price reduction 50%+
plus post-closing indemnity + escrow
Toolkit components:
- Seller reps & warranties in PSA (no contamination, no violations, prior ESAs disclosed, no spill history)
- Indemnity — typical survival 3-7 yrs, cap $500K-$2M, threshold $10K-$25K
- Holdback/escrow — 1-2% (clean Phase I) to 10-20% (significant Phase II exceedance), released on RSC filing or phased
- Insurance — seller liability (pre-closing), buyer cost-cap (post-closing $250K-$1M coverage), pollution liability (operational)
See liability-allocation-strategies.md for full PSA representation language, indemnity term sheets, holdback calibration table, and insurance product details.
Canonical Example: Phase II Tier 1 Petroleum Site
Scenario: Buyer acquiring 2,000 cy petroleum-contaminated site, Tier 1 standard applies, Phase II already complete.
Cleanup Estimate:
Excavation/Disposal: $350,000
Professional Services: $20,000
Post-Rem Sampling: $10,000
Expected Cost: $380,000
Risk Factor: 0.95 (low uncertainty, simple excavation)
Risk-Adjusted: $361,000
Discount Rate: 85% (low regulatory complexity)
Environmental Discount: $361,000 × 0.85 = $306,850
→ Reduce price by ~$307K
Negotiation range: Buyer opens $400K, seller opens $200K,
likely settle $300-350K + 3-yr seller indemnity, $25K threshold.
See price-adjustment-examples.md for medium-risk (Tier 2), high-risk (severe contamination requiring seller remediation), service station Phase I review, manufacturing metals Phase II, TCE/chlorinated solvent Tier 2, HREC dry cleaner, and settlement/expropriation integration examples.
Acquisition Price Adjustment Formula
Adjusted Price = Base Price - Environmental Discount - Timing Adjustment
Environmental Discount = Risk-Adjusted Cleanup Cost × Discount Rate
Discount Rate:
85% — low risk, straightforward cleanup
75% — medium risk, some regulatory complexity
65% — high risk, regulatory uncertainty
Timing Adjustment = Delay months × (lost revenue/profit per month)
(discounted to present value at WACC)
Rationale for discount rates: estimates may be overstated, buyer may have operational synergies, buyer can phase cleanup over time, certainty premium has value.
Methodology Summary
- Obtain documents: Phase I/II ESAs, Risk Assessment, RSC, spill reports, regulatory database searches.
- Interpret Phase I: Identify RECs (current, historical, controlled); flag data gaps.
- Analyze Phase II: Contaminants, soil vs. groundwater, concentration vs. Tier 1 GQS, contaminated volume.
- Estimate cleanup cost: Method selection → volume × unit costs + professional + monitoring → risk-adjustment → conservative/expected/optimistic.
- Regulatory timeline: Non-exceedance (0 mo) / Tier 1 (6-12 mo) / Tier 2 (12-24 mo).
- Calculate price adjustment: Risk-adjusted cost × discount rate + delay PV.
- Allocate liability: Apply decision tree (indemnity / holdback / insurance / seller remediation).
Key Terms & Thresholds
- REC / HREC / CREC: Current / historical / controlled environmental conditions
- MOE GQS: Ontario Generic Quality Standards (Tier 1 generic; Tier 2 site-specific risk-based)
- RSC: Record of Site Condition — MOE certificate granting liability protection once filed
- Tier 2 triggers: Any groundwater exceedance, soil >5× Tier 1, third-party migration, human exposure
- Industrial Tier 1 examples: PHC F2 2,800 mg/kg; Lead 500 mg/kg; Benzene 0.5 mg/kg; Arsenic 100 mg/kg
- Discount magnitude: <$100K (1-2% value) → $100K-$500K (2-5%) → $500K-$2M (5-15%) → >$2M (15%+)
Integration with Slash Commands
Automatically loaded when user mentions environmental due diligence, Phase I/II ESA, contamination, remediation, cleanup cost, environmental risk; or reads files matching *phase*ESA*, *contamination*, *environmental*report*, *risk*assessment*.
Related Commands:
/expropriation-compensation — Compensation adjustments for contaminated properties
/settlement-analysis — Environmental liability settlement scenarios
- Lease-based environmental obligations and compliance reviews are handled by the
lease-compliance-auditor skill in the leasing-commercial plugin
Related Calculators:
${CLAUDE_PLUGIN_ROOT}/skills/environmental-due-diligence-expert/environmental_risk_calculator.py — Automated contamination risk scoring and cleanup cost estimation
JSON Input Schema (environmental_input_schema.json):
{
"site_address": "123 Industrial Ave",
"phase_1_esa": {
"findings": ["AST present", "Historical dry cleaner use"],
"recs": [
{
"description": "Underground storage tank",
"severity": "HIGH",
"location": "Northeast corner"
}
],
"data_gaps": ["Historical chain of title incomplete"]
},
"phase_2_esa": {
"soil_samples": [
{
"sample_id": "SS-01",
"location": "Former UST area",
"depth_m": 2.5,
"contaminants": ["Petroleum hydrocarbons"],
"exceedance": true
}
],
"groundwater_samples": [],
"exceedances": [
{
"contaminant": "Petroleum F2",
"location": "SS-01",
"measured_value": 850,
"standard_limit": 260,
"exceedance_factor": 3.27,
"description": "Tier 1 Table 3 exceedance",
"severity": "HIGH"
}
],
"contaminants": ["Petroleum hydrocarbons", "VOCs"]
},
"cleanup_scenarios": {
"risk_assessment": {
"cost_low": 50000,
"cost_high": 150000,
"description": "Risk assessment only"
},
"remediation": {
"cost_low": 200000,
"cost_high": 500000,
"description": "Full excavation and disposal"
},
"brownfield": {
"cost_low": 500000,
"cost_high": 1000000,
"description": "Comprehensive brownfield redevelopment"
}
}
}
Calculator Output: Risk score (0-100), cleanup cost scenarios, regulatory pathway timeline (0-24 months), acquisition price adjustment recommendation.
Usage:
/environmental-due-diligence path/to/site_data.json
/environmental-due-diligence path/to/site_data.json --output $CLAUDE_PROJECT_DIR/Reports/2025-11-17_environmental_analysis.md
Report Naming: $CLAUDE_PROJECT_DIR/Reports/YYYY-MM-DD_HHMMSS_environmental_risk_{site}.md
Reference Files (Sibling)
- cleanup-cost-estimation.md — Complete cost component tables, six-step estimation process, scenario modeling, risk-adjustment formulas
- regulatory-pathway.md — Full MOE approval process, three outcomes, timeline tables, RSC requirements/benefits/exceptions, Tier 1 GQS contaminant tables
- liability-allocation-strategies.md — PSA representation language, indemnity term sheets, holdback calibration, insurance product details
- price-adjustment-examples.md — Low/medium/high risk worked examples, four extended use cases (service station, manufacturing, TCE solvent, dry cleaner HREC), settlement/expropriation integration
Skill Version: 1.1
Last Updated: May 15, 2026
Related Skills: commercial-lease-expert, lease-compliance-auditor, expropriation-compensation-entitlement-analysis, settlement-analysis-expert
Related Commands: /expropriation-compensation (lease-based environmental compliance is handled by the lease-compliance-auditor skill)