In Tunnel Data

Disclaimer - The data on this page comes directly from the in-tunnel air quality monitoring stations. This data is considered preliminary and may be adjusted at a later time after quality assurance checks have been performed and accounted for such incidences as instrument errors, power interruptions and the like.

For more information relating to the terms used in this table and a short explanation of the values currently shown click on the link below:
In Tunnel Data Explanation

Ambient

Validated monthly summaries of CO, NO₂ ,PM_2.5 and PM₁₀ are also available up to August 2008. Hard copies of monthly validated reports (containing ambient and in-tunnel data) are available from the Customs House Branch of the City of Sydney Council Library.

Ambient Air Quality Goals

DIPNR placed conditions of approval on the Cross City Tunnel such that stack emissions do not result in ambient air quality readings at the monitoring stations exceeding:

• CO - 8 hour rolling average of 9.0 ppm;
• NO₂ - one hour average of 245µg/m³ (12.0 pphm);
• PM₁₀ - 24 hour average of 50µg/m³.

In-Tunnel

CO data for a given hour will be available at 30 minutes after the following hour. For example, data for 09:00 to 10:00 is available at 10:30.

Monthly summaries of CO are also available on this site. To view the most recent data go to the In Tunnel Data.

Historical data is available in tabular form for the following time periods:

• Previous months

Hard copies of monthly validated reports (containing ambient and in-tunnel data) are available from the Customs House Branch of the City of Sydney Council Library.

In-Tunnel Limits

DIPNR placed conditions of approval on the Cross City Tunnel such that the in-tunnel CO air quality does not exceed the following exposure and single point limits:

  Exposure

• CO 1305ppmm rolling 15min average (87ppm multiplied by 15 minutes)
• CO 1500ppmm rolling 30min average (50ppm multiplied by 30 minutes)

• CO 200ppm rolling 3min average

Glossary and Abbreviations