Christ Church Playing Fields

The site of the new Christ Church Playing Fields located on Stephenson Avenue, Mount Claremont, operated as the Brockway Landfill site until 1991. The western end of the site was redeveloped as 8 ha of playing fields, with serviced change room facilities and associated bus set down and car parking areas.

The site was classified by the Department of Environment Regulation (DER) under the contaminated Sites Act 2003, as “Contaminated – Remediation Required” owing to its use as a former land fill. An extensive approvals process was undertaken with the relevant authorities before the site could be prepared, with extensive testing and monitoring of groundwater and landfill gas generation along with a suite of environmental management plans guiding the requirements for the development.

Following closure of the tip, where up to 17m of landfill had been placed; the site was capped with a minimum of 1m of fill sand. In excess of 50,000m³ of sand fill was imported to the site to supplement the sand cap where in some areas, settlement of the order of 2m had occurred. Development of the playing fields did not commence until annual settlements had reduced to, of the order of 20mm per year, which will still require minor level maintenance in coming years.

To remove any deleterious materials including ACM from the sand cap, the whole site was remediated by screening approximately 40,000m³ of the sand cap to a depth of 0.5m; the screenings were then buried below this level, a geo fabric placed as a separating “warning” layer and the clean screened sand placed on top of the geo fabric. The area was then overlain with a further 100mm of clean imported sand cap prior to the turf planting.

With the site being located in an area of over allocated ground water, bore water was not an option for irrigation. CCGS and their consultants successfully negotiated with Water Corporation to provide secondary treated waste water from the Subiaco Waste Water Treatment Plant (SWWTP). A 900m long, DN250 pressure main was constructed from the SWWTP to the site to provide the required treated waste water suitable for irrigation purposes.

In addition to the recycled water supply, a ground water bore was established in the NW corner of the site, placing it outside the groundwater contamination plume from the old rubbish tip, but strictly for maintenance purposes only.