**5. Conclusions**

An important conclusion from the initial concentration data is that the surface soil and subsoil sampled in this study at Smith's Lake and Charles Veryard Reserves is not contaminated with As, Cr, Cu, Ni, Pb, or Zn levels of concern from a human health perspective. There was, however, multiple exceedance of ecological investigation trigger limits (EIL) for Zn in surface soil and Cu, Pb, and Zn in subsoil. The spatial analysis showed that, on the basis of global and local Moran's I, distributions of most elements were not random but showed clustering. In line with the initial hypothesis, this significant clustering of adjacent higher concentrations in surface soil allowed identification of a specific area which, at the scale of sampling design, represented inputs from a point source of As, Cu, Pb, and Zn. At this site, the specific area of surface soil contamination was co-located with the most significant subsoil contamination, but this may not be a general result.

The combination of multivariate geochemical analysis with spatial information allowed both identification of realistic associations of elements, including potential contaminants. In particular, there was a consistent association of the dominant contaminants (Cu, Pb, and Zn) in the south-east of Charles Veryard Reserve which could be deduced from univariate spatial autocorrelation analysis, a composite contamination index (IPI), and multivariate principal components analysis.

In this study, the location and significance of potential contamination in the soil of urban public open space has been assessed thoroughly by measurement of multiple parameters, and rigorous spatial and statistical analysis. It is recommended that any such study uses a similar approach if soil contamination is suspected, especially given the global tendency for urban populations to increase and for redevelopment of, and increased population density in, inner-city precincts.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/2571-878 9/5/3/46/s1. Figure S1: 'Depth profiles of pH, EC, and Fe in soil cores collected from Smith's Lake and Charles Veryard Reserves, City of Vincent, Western Australia'; Table S1: 'Matrix of Spearman correlation coefficients for pH, EC, and elemental composition of soil samples from Smith's Lake and Charles Veryard Reserves. Values in bold type indicate a significant correlation (*p* ≤ 0.05, using Holm's adjusted *p*-values for multiple comparisons)'. Table S2. 'Component Loadings for PC1-PC8'. Table S3. 'Summary of Principal Components'. Table S4. 'Eigenvalues (variances) for the first 8 components'.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The raw data and metadata have been submitted to the PANGAEA repository at https://www.pangaea.de/.

**Acknowledgments:** The City of Vincent, Western Australia, granted permission to sample soil in the reserves. The principal investigator is extremely grateful to the ENVT3361 classes of 2017 and 2018 at The University of Western Australia, who did most of the work to generate the data: collecting samples, conducting the laboratory analyses, and uploading analytical results. Kirsty Brooks and Emielda Yusiharni from the School of Agriculture and Environment at The University of Western Australia made substantial efforts by managing the teaching laboratories, and organising field gear. Michael Smirk conducted the ICP-OES measurements.

**Conflicts of Interest:** The author declares no conflict of interest.
