Swanbank Landfill – Odour Forecast

Odorous Waste Acceptance Risk Assessment · working-face odour screening

Friday 30 October 2026

Next-day forecast · operating hours 06:00–18:00

Odorous waste receival

Receivable all day 06:00–18:00

No HIGH-risk hours forecast

Peak odour at a receptor

0.15 OU

06:00 · guideline 2.5 OU (1-h, 99.5th %ile)

Risk hours

0 / 0 / 12

HIGH / MODERATE / LOW

Expected weather

14–28°C

Wind 6–15 km/h, SSW → E → ENE

Hour by hour – can odorous waste be received?

06:00LOW

RECEIVE

SSW 6 km/h

07:00LOW

RECEIVE

S 5 km/h

08:00LOW

RECEIVE

SE 4 km/h

09:00LOW

RECEIVE

E 6 km/h

10:00LOW

RECEIVE

E 7 km/h

11:00LOW

RECEIVE

ENE 8 km/h

12:00LOW

RECEIVE

ENE 9 km/h

13:00LOW

RECEIVE

ENE 10 km/h

14:00LOW

RECEIVE

ENE 12 km/h

15:00LOW

RECEIVE

ENE 14 km/h

16:00LOW

RECEIVE

ENE 14 km/h

17:00LOW

RECEIVE

ENE 13 km/h

Arrows show the direction the wind blows towards. LOW and MODERATE hours: odorous waste can be received. HIGH hours: do not receive odorous waste.

Maximum 1-hour odour, 06:00–18:00

0.1–0.25 OU0.25–0.5 OU0.5–1 OU1–2.5 OU2.5–5 OU5–10 OU>10 OUSensitive receptorReceptor downwind in a HIGH hourWorking faceLandfill boundaryGround contour 20 m2.5 OU guideline contour

Drainage case (plume follows the ground) – the basis of the risk rating. 100 m grid, highest value in any operating hour. The guideline applies at sensitive receptors, not within the landfill site.

Odour at the most affected receptor, by hour

Hour starting (AEST). Bars coloured by risk rating; drainage case. Log scale.

Expected weather – BOM Amberley

BOM Amberley detailed 3-hourly forecast, issued (page time) 5:40 am AEST 29.10.2026. Dashed line: hourly wind used by the model. Stability class A (unstable) to F (very stable); E and F give the poorest dispersion.

Hourly odour plumes

06:00SSW 6 · 0.15 OU

07:00S 5 · 0.03 OU

08:00SE 4 · 0.01 OU

09:00E 6 · 0.01 OU

10:00E 7 · 0.01 OU

11:00ENE 8 · 0.01 OU

12:00ENE 9 · 0.01 OU

13:00ENE 10 · 0.01 OU

14:00ENE 12 · 0.02 OU

15:00ENE 14 · 0.05 OU

16:00ENE 14 · 0.05 OU

17:00ENE 13 · 0.05 OU

Forecast 1-hour average odour for each operating hour, drainage case. Panel border shows the hour's risk rating. Colours as in the legend above.

Risk schedule

Hour	Wind km/h	Stab.	Mix m	Terrain OU	Drainage OU	Light wind OU	Bounding OU	Risk	Receive
06:00–07:00	SSW 6	D	733	0.14	0.15	0.15	0.44	LOW	YES
07:00–08:00	S 5	C	1,083	0.03	0.03	0.05	0.17	LOW	YES
08:00–09:00	SE 4	C	1,502	0.01	0.01	0.03	0.07	LOW	YES
09:00–10:00	E 6	B	1,921	0.01	0.01	0.02	0.02	LOW	YES
10:00–11:00	E 7	B	2,210	0.01	0.01	0.01	0.02	LOW	YES
11:00–12:00	ENE 8	B	2,372	0.01	0.01	0.01	0.01	LOW	YES
12:00–13:00	ENE 9	B	2,532	0.01	0.01	0.01	0.01	LOW	YES
13:00–14:00	ENE 10	B	2,552	0.01	0.01	0.01	0.01	LOW	YES
14:00–15:00	ENE 12	C	2,431	0.02	0.02	0.02	0.02	LOW	YES
15:00–16:00	ENE 14	D	2,310	0.05	0.05	0.05	0.06	LOW	YES
16:00–17:00	ENE 14	D	2,047	0.04	0.05	0.05	0.06	LOW	YES
17:00–18:00	ENE 13	D	1,644	0.05	0.05	0.05	0.07	LOW	YES

Odour values are the maximum 1-hour average at any of the 140 sensitive receptors (AE 2023). Terrain = plume partly holds release level (face 104 m AHD); Drainage = plume follows the ground; Light wind = drainage case with morning winds halved; Bounding = steady plume to the nearest downwind receptor.
Risk: HIGH if drainage or light-wind ≥ 1.5 OU or bounding ≥ 2.5 OU; MODERATE if ≥ 0.75 OU or bounding ≥ 1.25 OU; otherwise LOW. A HIGH hour followed by stable air (E/F) stays HIGH.

About this forecast

Scenario: Assumes odorous waste is received and covers half (450 m²) of the 30 x 30 m working face (450 m² odorous waste at 15.4 OU/m²/s + 450 m² general waste at 7.0 OU/m²/s = 10,080 OU/s).
This is a screening forecast, not formal or compliance dispersion modelling. Gaussian puff model driven by the BOM Amberley 3-hourly forecast; wind field not terrain-steered; other site sources not included.
Emission rates: odorous waste 15.4 OU/m²/s (digested sewage sludge cake, Scottish Govt), general waste face 7.0 OU/m²/s and covered face 1.97 OU/m²/s (AECOM 2016). Terrain: Ipswich 2023 LiDAR (10 m) + Stage 1 survey 02.10.2026. Coordinates GDA94 MGA56.
Recommended practice in MODERATE hours: keep the exposed area of odorous waste small and cover it immediately.