Preliminary Site Investigations for Proposed Childcare Centres in NSW
When a site is proposed for a childcare centre, understanding its contamination history can be particularly important.
Children are considered a sensitive receptor in contaminated land assessment because of their age, behaviour and potential for frequent contact with soil and dust. Outdoor play areas, gardens, landscaped areas and unsealed ground can all create opportunities for children to come into contact with soil, while contaminants beneath a building may also present risks through vapour intrusion.
For this reason, a Preliminary Site Investigation for a proposed childcare centre needs to do more than simply identify what the land was previously used for. It should establish whether the available information provides sufficient confidence that the site is suitable for the proposed use, or whether further investigation is required.
In NSW, contamination is considered through the planning process under Chapter 4 of the State Environmental Planning Policy (Resilience and Hazards) 2021. The NSW Child Care Planning Guideline also requires site selection to consider environmental, health and safety hazards when assessing proposed childcare facilities.
Why are childcare centres considered a sensitive land use?
The way people interact with land is central to contaminated land assessment.
A warehouse employee working primarily inside a concrete building has a very different potential exposure profile to a child spending time playing on grass, digging in garden beds or sitting directly on the ground.
Under the National Environment Protection (Assessment of Site Contamination) Measure, or ASC NEPM, childcare centres, kindergartens and preschools are included within the HIL A land-use scenario for preliminary assessment of human-health risks. HIL A represents one of the more sensitive standard land-use scenarios because it considers circumstances where young children may have regular access to soil.
This does not mean that every childcare site is contaminated, nor does it mean that development on previously commercial or industrial land is necessarily inappropriate. It does mean that uncertainty about contamination generally deserves careful consideration before a site is relied upon for a sensitive use.
How can children be exposed to contamination?
One of the most important parts of a PSI is the development of a conceptual site model. Rather than simply listing contaminants that might be present, the conceptual site model asks whether there is a credible connection between a contamination source, an exposure pathway and a receptor.
For a childcare centre, several exposure pathways can be particularly relevant.
Soil and dust ingestion can be important because young children regularly place their hands and objects in their mouths. Soil and dust can accumulate on hands, underneath fingernails, on toys and on outdoor play equipment before being unintentionally ingested. NSW Health specifically identifies crawling, hand-to-mouth behaviour and mouthing contaminated objects as potential pathways for childhood lead exposure.
Inhalation of dust or fibres may also be relevant. Contaminated fill, deteriorated building materials or asbestos-containing material within soil may present an inhalation risk where material is disturbed and respirable dust or fibres become airborne.
Vapour intrusion is another pathway that can sometimes be overlooked. Volatile contaminants associated with former fuel storage, service stations, workshops, dry-cleaning activities or some industrial processes may migrate through soil gas and enter buildings. Where a proposed childcare centre contains enclosed indoor areas, the potential for petroleum hydrocarbons or other volatile compounds to migrate into those spaces may need to be considered.
Direct skin contact may also form part of the exposure assessment for some contaminants, although its significance depends on the contaminant involved. For lead, for example, ingestion and inhalation are generally much more important pathways than absorption through intact skin.
The significance of each pathway therefore depends on the site, the contaminants involved and the proposed design of the childcare centre.
What contamination issues can affect a proposed childcare centre?
A PSI considers the historical and current use of the site and surrounding land to identify activities that may have caused contamination.
Issues that commonly warrant closer consideration include:
imported fill of unknown origin;
former workshops, service stations, depots or industrial activities;
underground or above-ground fuel storage;
demolition waste or historical structures containing asbestos or lead-based paint;
historical orchards, market gardens or agricultural activities where pesticides may have been used;
waste disposal, uncontrolled filling or buried materials;
potentially contaminated groundwater or soil vapour migrating from neighbouring properties; and
gaps in the historical record that prevent potentially contaminating activities from being confidently ruled out.
Contaminants associated with these activities can include lead and other metals, petroleum hydrocarbons, BTEX compounds including benzene, polycyclic aromatic hydrocarbons such as benzo(a)pyrene, pesticides, asbestos and volatile organic compounds.
The contaminant profile is not assumed simply because a particular land use occurred. Instead, the PSI uses the site's history, physical setting, site inspection and conceptual site model to determine which contaminants and exposure pathways are reasonably plausible.
Why lead can be particularly important for childcare developments
Lead is a good example of why the proposed land use matters.
Historical industrial activities, lead-based paints, contaminated fill and other legacy sources can result in lead being present in soil or dust.
Young children can ingest contaminated soil or dust through normal hand-to-mouth behaviour, and developing children are more sensitive to the effects of lead exposure than adults. NSW Health advises that even relatively low levels of lead exposure can affect children's physical and neurological development.
This means that an elevated lead concentration that might be considered differently under a commercial or industrial exposure scenario can become considerably more important when the proposed receptor is a young child with routine access to outdoor soils.
The same principle applies across contaminated land assessment: site suitability depends not only on what contamination is present, but on who may be exposed to it and how that exposure could occur.
Should soil sampling be undertaken as part of a childcare PSI?
Not every Preliminary Site Investigation requires soil sampling.
A PSI is primarily intended to understand the site's history, identify potentially contaminating activities, establish Areas of Environmental Concern and develop a conceptual site model. In some cases, a strong historical record and site inspection may provide sufficient evidence that contamination is unlikely.
For a proposed childcare centre, however, there can be good reasons to consider targeted soil sampling during the preliminary investigation where it can resolve an important uncertainty.
For example, sampling may help assess shallow fill within a proposed outdoor play area, investigate soil around an older building where lead-based paint may have deteriorated, or provide preliminary information about an area where historical filling has been identified.
Because childcare is a sensitive land use, this additional information may provide greater confidence in determining whether the site is likely to be suitable or whether a more comprehensive investigation is required.
There is an important distinction, however.
Limited PSI sampling should not be used as a substitute for a Detailed Site Investigation where the site history indicates a credible contamination risk.
If the PSI identifies potentially contaminating activities, significant filling, former industrial uses, fuel infrastructure or other material data gaps, a Detailed Site Investigation may be required to properly characterise the nature and extent of contamination.
Does historical industrial use mean a childcare centre cannot be developed?
No.
A former industrial use, imported fill or another potential contamination source does not automatically mean that a site is unsuitable for childcare.
Instead, it may mean that suitability has not yet been demonstrated.
This distinction is important.
A PSI may conclude that there is insufficient information to determine whether the land is suitable for the proposed childcare use and recommend a DSI. The DSI can then determine whether contamination is actually present, its extent and whether it presents an unacceptable risk under the proposed development.
Where contamination is identified, remediation or management measures may allow the land to be made suitable for childcare.
These measures can range from the removal of localised contaminated soil through to validation of imported fill, installation of clean soil cover systems, management of asbestos-affected soils or, where required, controls for soil vapour.
The objective is not necessarily to find a site with absolutely no contaminants present. It is to demonstrate that the land is, or can be made, suitable for the proposed use without unacceptable risks to human health or the environment.
What happens if the PSI identifies a data gap?
For sensitive developments such as childcare centres, unresolved data gaps can be important.
A consultant may be unable to confidently assess suitability where historical records indicate a potentially contaminating activity but there is no evidence showing where it occurred, whether infrastructure was removed, or whether previous remediation was appropriately validated.
Examples might include a former underground petroleum storage system with no validation records, extensive fill of unknown origin or historical industrial buildings that have since been demolished.
In these circumstances, the appropriate conclusion is generally not that the site is unsuitable forever. Rather, further investigation is required before suitability can be demonstrated.
The investigation can then progress through the appropriate contaminated land assessment process, which may include a DSI, remediation action plan and ultimately validation of any remediation works.
Preliminary Site Investigations during the DA or planning proposal stage
Undertaking the contamination assessment early can help avoid delays later in the planning process.
For development applications, Chapter 4 of the Resilience and Hazards SEPP 2021 requires consent authorities to consider whether land is contaminated and whether it is suitable, or can be made suitable, for its proposed use. Certain changes of use also trigger consideration of a preliminary investigation undertaken in accordance with the contaminated land planning guidelines.
For planning proposals involving rezoning, contamination is also considered through NSW's strategic planning framework, including Ministerial Direction 4.4 – Remediation of Contaminated Land.
Addressing these questions early provides an opportunity to identify potential contamination constraints before detailed design progresses and can help establish whether further investigation, remediation or development controls need to be incorporated into the project.
Preparing a PSI for a proposed childcare centre
A well-prepared childcare PSI should give the consent authority, developer and project team a clear understanding of the site's contamination risk.
That means identifying credible contamination sources, understanding how children and other site users could be exposed, documenting the important uncertainties and making clear recommendations about whether further investigation is required.
Where the history is straightforward, the outcome may be relatively simple.
Where historical filling, industrial activities, fuel storage, asbestos, lead or other potential contamination sources are identified, further investigation may be necessary before the site can be demonstrated to be suitable for childcare.
Confluence Environmental prepares Preliminary Site Investigations for contaminated land to support development applications and planning proposals throughout NSW. Our assessments are prepared with consideration of the NSW contaminated land planning framework, NSW EPA guidance and the ASC NEPM, with investigation strategies tailored to the proposed land use and the actual risks identified at the site.
If you are planning a childcare development and need to understand whether a PSI, soil sampling or a Detailed Site Investigation may be required, contact Confluence Environmental to discuss the site and proposed development.