New South Wales has over 300 active concrete batching plants, producing numerous concrete by-products and waste. NSW legislation requires operators to minimise new resource use, recycle or reuse materials whenever possible, and dispose of unreusable waste appropriately and ethically.
Many concrete by-products can be reused in the batching process without breaching environmental regulations. The CCAA provides guidance on managing the four main concrete by-products:
Types of Concrete By-Product
1. Hardened Returned Concrete
Definition: Concrete returned to a plant that has cured and hardened, largely free of contaminants. It can be safely stored with minimal risk of contaminated water runoff.
Handling & Re-use:
• Can be crushed at licensed facilities to form recovered aggregates
• Reused in batching, as engineering fill, or road base
• Applied to private road construction if:
- Development consent is approved
- Used minimally for road construction
- Provides access to approved development
- Material is tested to ensure minimal environmental risk
Restrictions: Cannot be used for:
• Quarry, mine, or sand dredge rehabilitation
• Dams
• Backfill for voids
• Reshaping land for agricultural purposes
2. Concrete Wash Water
Definition: High pH (~12) water with suspended solids produced from washing pumps, trucks, chutes, mixers, and batch plant areas.
Re-use & Recycle:
• Typically stored in settling ponds on-site
• Recycled into batching, reducing clean water usage
3. Liquid Wash / Slurry
Definition: Washout slurry collected in settling ponds, highly alkaline and difficult to reuse directly in concrete batching.
Handling & Disposal:
• Requires transport by licensed contractors using specialized “sucker trucks”
• If kept in suspension, water can be pumped and reused
• If settled, the material must be pumped out and disposed of at licensed facilities
Transformation:
• Can be converted to solid waste for easier handling and increased disposal options
• Pump slurry into dewatering tubes (geofabric bags) to solidify
4. Solid Wash Out
Definition: Dried, washed concrete with sand, aggregates, and cementitious materials.
Disposal & Re-use:
• Does not require licensed transport but must go to a licensed facility for:
- Re-processing into sand and gravel
- Mixing with other materials for new products
- Road base construction
If you want to optimise concrete by-product handling for efficiency and sustainability, contact a PumperDump expert at 1300 366 668 or via the PumperDump App (App Store / Google Play).
Ref: Extracted from the NSW Government’s Concrete by-product Recycling and Disposal Industry Guidelines
