This standard provides a code of practice for the planning, design, installation, operation, and maintenance of blackwater treatment systems. It outlines various technologies and sets performance requirements for treated effluent to ensure it is safe for non-potable reuse applications like toilet flushing and landscape irrigation, promoting water sustainability.
Provides guidelines for the design, installation, operation, and maintenance of blackwater treatment systems for reuse or safe disposal.
Quick Reference Values
Target pH for reuse6.5 to 8.5
Max BOD for toilet flushing (mg/L)< 10
Max Turbidity for toilet flushing (NTU)< 2
Max Total Suspended Solids (TSS) for flushing (mg/L)< 10
Max Faecal Coliform for flushing/irrigation (MPN/100ml)< 100
Minimum Residual Chlorine for disinfection (mg/L)0.5
Practical Notes
A clear distinction must be made between blackwater (toilet waste) and greywater (from sinks, showers); this code is exclusively for blackwater.
The success of a blackwater treatment system is critically dependent on consistent and proper Operation & Maintenance (O&M). Under-resourcing O&M is a common cause of system failure.
A dual plumbing (pipe) system is mandatory to keep treated non-potable water completely separate from the fresh potable water supply, preventing any risk of cross-contamination.