Water Damage Restoration: Scope 3 Emissions Mapping and Calculation Guide

This guide is the working document for calculating Scope 3 greenhouse gas emissions from water damage mitigation jobs under the Restoration Carbon Protocol. It contains the actual emission factors, the calculation methodology for each Scope 3 category, and a complete worked example from a real job type. A contractor who follows this guide will produce a per-job carbon figure that is defensible in a third-party ESG audit.

Job Classification: Why It Matters Before You Calculate

Your emissions total will vary by a factor of 10 or more depending on water category and drying class. Before calculating, classify the job correctly using IICRC S500 definitions:

Category 4: Transportation Emissions

Transportation is typically the largest or second-largest emission source on water damage jobs. Calculate every vehicle separately.

Emission Factors (EPA Mobile Combustion, 2024)

Calculation formula: Vehicle miles × emission factor = kg CO2e. Convert to tCO2e by dividing by 1,000.

What counts as “vehicle miles”: Round-trip distance from your facility or previous job to the loss site, multiplied by the number of trips. Include equipment pickup trips, progress check visits, and equipment retrieval trips. Do not include the vehicle miles of subcontractors — their emissions are captured in their own RCP calculation.

Category 1: Materials Emissions

Emission Factors for Common Water Damage Materials

Note on antimicrobial volumes: If you don’t track liters applied per job, use these application rate proxies: Cat 2 jobs — 0.015 liters per sq ft of affected area. Cat 3 jobs — 0.025 liters per sq ft (double application typically required).

Category 5: Waste Emissions

Emission Factors by Waste Type and Disposal Method

Estimating waste weight when you don’t have disposal receipts: Use 2.5 lbs per sq ft of demolished drywall (standard 1/2″ drywall), 3.0 lbs per sq ft of demolished flooring (carpet + pad), 0.8 lbs per sq ft of demolished wood subfloor. For Cat 3 contaminated water: estimate from extractor tank fill cycles × tank capacity.

Category 12: Demolished Building Materials

Important: Negative values for wood-based materials reflect carbon storage credits under EPA WARM methodology — lumber and hardwood store carbon that is not immediately released when landfilled. Apply these credits only if the material is being landfilled rather than incinerated.

Complete Worked Example: Category 2, Class 3 Commercial Water Loss

Job profile: Washing machine supply line failure, 2,400 sq ft commercial office, second floor. Affected area includes cubicle space and server room (contents moved). Required demolition: 800 sq ft drywall, 600 sq ft carpet. Crew: 2 technicians, 3-day mitigation. Your facility is 24 miles from the job site.

Category 4 — Transportation

2 light trucks × 48 miles round trip × 4 trips (initial, day 2, day 3, equipment pickup) = 384 vehicle-miles
384 × 0.503 kg CO2e/mile = 193 kg CO2e

1 equipment trailer (dehumidifiers, air movers) × 48 miles × 2 trips (drop-off + pickup) = 96 vehicle-miles
96 × 1.084 kg CO2e/mile = 104 kg CO2e

1 dump truck for debris × 14 miles to transfer station × 1 trip = 14 vehicle-miles
14 × 2.25 kg CO2e/mile = 32 kg CO2e

Equipment power source: building electrical supply (Scope 2 — property owner, not included here)

Category 4 total: 329 kg CO2e = 0.33 tCO2e

Category 1 — Materials

Quaternary ammonium antimicrobial: 2,400 sq ft × 0.015 L/sq ft = 36 liters × 2.8 kg CO2e/L = 101 kg CO2e

PPE: 2 technicians × 3 days × 2 Tyvek suits/day = 12 suits × 1.2 kg = 14 kg; 2 × 3 × 4 glove pairs = 24 pairs × 0.3 kg = 7 kg; 2 × 3 × 2 N95 = 12 respirators × 0.4 kg = 5 kg. PPE total: 26 kg CO2e

HEPA filter replacement (2 air scrubbers, 1 filter change each): 2 × 3.2 kg = 6 kg CO2e

Category 1 total: 133 kg CO2e = 0.13 tCO2e

Category 5 — Waste

C&D debris (wet materials, Cat 2 contaminated): estimated 1.2 tons (800 sq ft drywall at 2.5 lbs/sq ft = 1,000 lbs; carpet remnants ~400 lbs)
1.2 tons × 0.18 tCO2e/ton = 0.22 tCO2e

Disposable PPE and consumables: ~0.05 tons × 0.25 tCO2e/ton = 0.01 tCO2e

Category 5 total: 0.23 tCO2e

Category 12 — Demolished Building Materials

800 sq ft drywall demolished: 800 × 2.5 lbs = 2,000 lbs = 0.91 tons × 0.16 tCO2e/ton = 0.15 tCO2e

600 sq ft carpet + pad: 600 × 3.0 lbs = 1,800 lbs = 0.82 tons × 0.33 tCO2e/ton = 0.27 tCO2e

Category 12 total: 0.42 tCO2e

Job Total

This figure — 1.11 tCO2e — is what goes in the Category 4, 1, 5, and 12 rows of the RCP Job Carbon Report delivered to the property manager. The spend-based estimate for a $28,000 job like this (using EPA Services to Buildings factor of approximately 0.10 kg CO2e per dollar) would produce 2.8 tCO2e — more than 2.5x the actual calculated figure. This is why primary data matters.

Antimicrobial and Chemical Emission Factors: Updated Methodology

The EPA EEIO chemical manufacturing factor used in the Category 1 table above is an economic input-output proxy — useful for estimation but not sourced to the actual chemistry. The following replaces or supplements those values where peer-reviewed lifecycle data now exists.

Hydrogen Peroxide-Based Antimicrobials

H₂O₂ is the only restoration antimicrobial with published lifecycle assessment data. The anthraquinone auto-oxidation production process yields 1.33 kg CO₂e per kg of active H₂O₂ (ACS Omega, 2025); the ecoinvent European market average is 1.79 kg CO₂e per kg based on eight producers. For diluted restoration products (typically 3–7.5% concentration), the per-liter emission scales proportionally. A gallon of 7.5% H₂O₂ antimicrobial contains approximately 0.28 kg of active ingredient, yielding roughly 0.37–0.50 kg CO₂e per gallon of diluted product — substantially lower than the EPA EEIO proxy of 1.9 kg CO₂e/liter previously used. Update your calculations accordingly.

Quaternary Ammonium Compounds (QACs)

No cradle-to-gate lifecycle assessment has been published for quaternary ammonium compound production as of April 2026. QACs are petrochemical-derived surfactants manufactured via chloromethane reactions with tertiary amines. The EPA EEIO factor of 2.8 kg CO₂e/liter remains the only available proxy. Flag all QAC calculations as EPA EEIO estimated in the data_quality section of any RCP Job Carbon Report delivered to clients facing SBTi or CSRD verification requirements. The RCP will update this factor when manufacturer-specific LCA data becomes available.

Botanical Antimicrobials (Thymol-Based Products)

Products such as Benefect Decon 30 (thymol active ingredient) carry USDA BioPreferred certification and UL EcoLogo status but no published LCA emission factor as of April 2026. Essential oil distillation is energy-intensive with extremely low extraction yields (1–2% from plant material). The RCP treats botanical antimicrobials as a data gap requiring manufacturer EPD documentation. In the absence of manufacturer data, apply the QAC proxy (2.8 kg CO₂e/liter) and flag as estimated.

Truck-Mounted Extraction Unit: Fuel Consumption Reference Data

Truck-mounted extraction units operate on dedicated gasoline or diesel engines separate from the vehicle drivetrain. The fuel consumed during extraction operations is a direct Domain 2 Category 4 emission source. Manufacturer specifications and field-reported consumption rates:

RCP proxy for truck mount extraction: 1.0 gallon gasoline per hour of extraction unit operation (8.9 kg CO₂ per hour). A 4-hour extraction job on a standard truckmount generates approximately 35.5 kg CO₂ from the unit alone — independent of the vehicle transportation emissions calculated in Domain 2. Log extraction start/stop times in the job record.

Capture actual fuel consumption from fuel receipts where possible. Where runtime-only is documented, apply the proxy. Flag as proxy in the data_quality section.

Refrigerant Considerations: LGR Dehumidifiers and Fugitive Emissions

Commercial LGR dehumidifiers contain refrigerant charges that are potential Scope 3 emission sources if units are serviced, recharged, or have fugitive leaks. This is not a required RCP data point in v1.0 but is disclosed here for methodological completeness and for contractors with SBTi-committed clients.

Refrigerant Charge Data by Unit Type

The Dri-Eaz LGR 6000i is the first major restoration dehumidifier using R-32, a refrigerant with a GWP of 771 under IPCC AR6 — representing a 63–67% reduction in refrigerant climate impact compared to R-410A units. This is relevant for the RCP Carbon Reduction Playbook: equipment replacement cycles that prioritize R-32 or R-454B (GWP ~530) units over R-410A materially reduce the fugitive emission exposure of a restoration fleet.

Fugitive emission screening: The EPA default annual leak rate for sealed hermetic refrigeration equipment (residential/commercial A/C) is 10% of charge capacity. For a Dri-Eaz Revolution LGR with 0.60 kg R-410A at the 10% screening rate, the annual fugitive contribution would be 0.06 kg × 2,256 GWP = 135 kg CO₂e per unit per year. Actual leak rates for sealed hermetic dehumidifier compressors are likely 1–5% annually. Contractors are not required to calculate refrigerant emissions under RCP v1.0 but should document unit refrigerant type for RCP v1.1 compliance.

Wastewater Extraction: Methodological Note

Extracted water discharged to municipal sanitary sewer generates indirect emissions at the wastewater treatment facility. Based on Metropolitan Water Reclamation District energy intensity data (Elevate Energy, 2018), the national average wastewater treatment energy intensity is approximately 1,978 kWh per million gallons treated, yielding 0.00074 kg CO₂e per gallon discharged at the national grid emission factor. A typical water damage extraction of 500–2,000 gallons produces only 0.37–1.48 kg CO₂e for wastewater treatment — under 0.5% of total job emissions on most jobs. The RCP excludes this source from required calculation in v1.0 but acknowledges it here for methodological completeness and CSRD-grade reporting contexts.