Calculation Trace

LCA Results LCIA Indicators Calculation Trace

Calculation trace

Every quantity line, conversion and factor behind the program total, in audit order · Baseline

Reconciliation

Every line reconciles to quantity × factor

Lines in trace

3,412

all quantity records

Top 10 shown

130,434

tCO2e, 10 largest lines

Remaining lines

54,186

tCO2e, 3,402 lines

Program total

184,620

tCO2e, A1-C4

Line calculations

Quantity × factor, with conversion, recomputed check and stage split

Line by line calculation showing quantity, conversion, factor and stage results
Item ID	Description	Quantity	Conversion applied	Factor	Recomputed	A1-A3	A4-A5	B	C	Total	EPD reference
TU-C-0114	Precast segmental lining, C50/60 Manufacturer EPD	42,180 m3	m3 to declared unit 1 m3, factor 1.0	1.488tCO2e/m3	62,764reconciles	46,840	5,120	8,210	2,610	62,780	EPD-CBE-8841-2
PR-S-0088	Reinforcement bar, grade 500, all packages Manufacturer EPD	39,400,000 kg	kg to declared unit 1,000 kg, factor 0.001	0.762kgCO2e/kg	30,023reconciles	22,410	2,480	3,940	1,190	30,020	EPD-NUCOR-3312-1
ST-S-0119	Structural steel sections, S355 Industry average	4,120,000 kg	kg to declared unit 1,000 kg, factor 0.001	2.31kgCO2e/kg	9,517reconciles	7,180	760	1,180	400	9,520	EPD-AISC-0094-6
ST-C-0031	In-situ concrete, C40/50, base slab Manufacturer EPD	18,470 m3	m3 to declared unit 1 m3, factor 1.0	0.394tCO2e/m3	7,277reconciles	5,410	620	940	310	7,280	EPD-NRMCA-1109-2
EW-E-0007	Bulk excavation, spoil to licensed fill Generic	486,000 m3	Diesel plant model, 2.14 L per m3	0.0134tCO2e/m3	6,512reconciles	0	6,120	0	390	6,510	ECOINVENT-3.9-1120
TU-C-0210	Shotcrete primary lining Industry average	11,620 m3	m3 to kg at 2,350 kg/m3	0.446tCO2e/m3	5,183reconciles	4,680	500	0	0	5,180	EPD-ASTM-4471-1
TU-E-0500	Grid electricity, tunnel ventilation Manufacturer EPD	14,900,000 kWh	Grid factor declining 0.312 to 0.088 by 2075	0.312kgCO2e/kWh	4,649reconciles	0	0	4,650	0	4,650	EGRID-2026-NYUP
UT-P-0402	Ductile iron pipe, DN600 Generic	4,210 m	m to declared unit 1 m, factor 1.0	0.61tCO2e/m	2,568reconciles	1,980	210	310	70	2,570	EPD-USPIPE-7741-3
TR-S-0155	Rail, 60E1 profile Manufacturer EPD	1,240,000 kg	kg to declared unit 1,000 kg, factor 0.001	0.85kgCO2e/kg	1,054reconciles	790	84	140	40	1,054	EPD-SDI-5520-1
ST-A-0210	Bituminous surfacing, station approach Industry average	8,940 t	t to declared unit 1,000 kg, factor 1.0	0.097tCO2e/t	867reconciles	640	78	122	30	870	EPD-COLAS-2214-2
Subtotal, 10 largest lines						89,930	15,972	19,492	5,040	130,434

Showing the 10 largest contributing lines. The full export contains all 3,412 lines with the same columns. Recomputed values apply the declared unit conversion, so a line that drifts from its stated total is visible here rather than only in the export.

Conversion and adjustment rules

Conversion and adjustment rules applied program-wide
Rule	Detail	Lines affected
Density conversion	m3 to kg at declared density where the EPD unit differs	412 lines
Construction wastage	4.5% uplift applied to concrete and steel quantities at A5	1,884 lines
Regional adjustment	1.06 factor where EPD geography is CA-ON and site is US-NY	37 lines
Transport default	82 km road, 32 t articulated, 62% load factor where no route given	2,940 lines
Grid decarbonisation	B6 electricity factor declines 0.312 to 0.088 kgCO2e/kWh by 2075	18 lines
Biogenic split	Biogenic flows reported separately, not netted against fossil GWP	126 lines
Module D exclusion	Benefits beyond boundary reported separately, excluded from total	204 lines

Audit note. Every figure on the LCA, LCIA and report pages derives from these lines and rules. Changing a mapping or a methodology setting regenerates the trace and stamps a new version.

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