Soil Quality


The land in Warringah has many different uses including residential, industrial and commercial. In some situations some of these uses can contaminate the land. Historically, industrial activities such as disposal and use of chemicals have contaminated land and groundwater. However, contamination of land is not solely limited to previous or current industrial sites.

Warringah Council is required by legislation to consider whether land is contaminated. As part of the Development Application (DA) process, Council requires applicants to provide information about contamination. This information is often provided as part of the Statement of Environmental Effects. The applicant is required to address issues such as previous and current land uses and activities of the site and adjoining sites, any known contamination of the land and details of any contamination investigation reports or remediation works that have occurred on the land.

NSW Government legislative requirements are provided through State Environmental Planning Policy No. 55 Remediation of Land and The Contaminated Land Management Act 1997. The Contaminated Land Management Act 1997 enables the Office of Environment & Heritage (OE&H) to respond to contamination that is causing significant risk of harm to human health or the environment and sets out criteria for determining whether such risk exists.

Contaminated land information on Section 149 Planning Certificates

Warringah Council is required under the Environmental Planning and Assessment Act 1979, Environmental Planning and Assessment Regulation 2000 and the Contaminated Land Management Act 1997 to note on Section 149 (2) Planning Certificates whether the land which the Certificate relates is:

  • within land declared to be an investigation area or remediation site
  • subject to an investigation order or a remediation order
  • the subject of a voluntary investigation proposal or a voluntary remediation proposal
  • the subject of the OE&H's agreement
  • subject to a site audit statement

Acid sulfate soils

Acid sulfate soils are natural soils and sediments that contain iron sulfide. When the sulfide is exposed to air, such as after drainage and excavation, the soils form sulfuric acid.

This acid can leach into the surrounding area and acidify surrounding drains, wetlands, creeks and lagoons, causing severe environmental damage. It can affect industries such as fishing and tourism and can impact on public and private infrastructure by causing serious damage to steel and concrete structures such as the foundations (footings) of a building. It can also corrode drinking water pipes and have negative effects on humans and animals from drinking polluted water.

The Acid Sulfate Soils Risk Maps (under 'documents') for Warringah show the location of possible acid sulfate soils in the Warringah area. Refer to these maps if you are building in an area that might be affected by acid sulfate soils.