On 20 May 2022 the Department for Energy and Mining (DEM) issued a compliance order to Hanson Construction Materials regarding White Rock Quarry.
The compliance order relates to White Rock Quarry’s non-compliance with its mine operations plan in relation to offsite release of sediment-laden stormwater into Third Creek. This non-compliance usually occurs when high rainfall events overwhelm the existing stormwater management controls at the site.
An Environment Protection Authority (EPA) environmental improvement program has been in place at the site since 2017. DEM's compliance order incorporates key elements of this program, particularly regarding actions to improve stormwater quality, reduce offsite sediment discharge and continuously monitor water quality.
The compliance order requires Hanson to undertake the following actions:
- Prepare and implement a plan of action to reduce the amount of sediment-laden (contaminated) stormwater.
- Complete construction of an additional sediment basin, which will allow for the passive treatment of stormwater.
- Commence active treatment using flocculants to accelerate the removal of sediment from water.
These actions will all be completed by the end of 2022.
Sediment basins are already utilised on the site to capture coarse sediment by intercepting stormwater before it reaches waterways. This process slows down water movement to allow the coarse sediment to settle before the runoff is discharged.
Flocculants are not currently utilised in stormwater management at the site, however they will help the fine particles in water to come together as large clusters, or flocs, to make it easier for them to settle out of the water.
DEM has now assumed the lead role in regulating the White Rock Quarry and continues to work closely with the EPA to ensure Hanson addresses these non-compliances as a priority. Although Hanson has been working to improve stormwater management at the site, DEM acknowledges that non-compliances may occur during high rainfall events and expects Hanson to take all reasonable and practicable measures to minimise these events.
The department respects and encourages the role communities play in referring concerns to the department. Communities should report any matters to the department’s customer service number on (08) 8463 3000 or the EPA 24-hour Emergency Response Team on (08) 8204 2004 with dates, times, exact location and photos.