Chris Hill Quarry is located approximately 20 km west from Toodyay, contained within the Avon Valley National Park. The site is a decommissioned quarry that was operational between 1964 and 1992.

Initial rehabilitation of the quarry pit was conducted between 1992 and 1998 by the PTA (then Westrail). Backfilling was carried out using shredded and whole tyres in combination with compacted layers of backfill material including quarry sand and gravel supplied by Western Quarries. This backfill was covered with a layer of topsoil and seeded.

Only sparse vegetation has established since initial rehabilitation works as the backfill material is highly unstable and nutrient deficient. Significant erosion has occurred at the site and deep gullies and cavities have formed, exposing tyres in some areas and forming a public hazard which led to the Avon Valley Environmental Protection Society submitting formal requests for further information and regularly requesting rehabilitation status updates.

Successful rehabilitation of the site is necessary to primarily enable the PTA to formally hand back management of the site to the Department of Parks and Wildlife (DPaW) for re-inclusion into the Avon Valley National Park which will also satisfy the Avon Valley Environmental Protection Society. The total area of the Chris Hill Quarry is approximately 1.6 hectares.

The purpose of the project is to successfully rehabilitate the Chris Hill Quarry to create a safe and stable environment for public and ecological uses within the Avon Valley National Park. The rehabilitation objectives have been identified in consultation with DPaW for the successful inclusion of Chris Hill Quarry into the Avon Valley National Park as follows:

* Create a stable and safe environment for the use of the site within the Avon Valley National Park with the exception of rock fall hazards which will remain after the rehabilitation of the site;
* Rehabilitate the surface to not show signs of excessive erosion;
* Rehabilitate the site to support vegetation compatible with surrounding vegetation;
* Create a self-sustaining ecosystem at the site which will not be infested by weeds or become a source of infestation to the surrounding environment; and
* Rehabilitate the site to encourage the return of native fauna species.

A full Scope of Works is included in Book 4 of the tender documentation.