Wastewater volumes processed in Christchurch City.
General
Description |
Measure |
% of Christchurch population on a reticulated wastewater system (the remainder in rural areas have septic tanks and other on-site systems or a weekly nightsoil collection) |
99.9% |
Number of households currently serviced by Christchurch Wastewater Treatment Plant |
147,000 (approx) |
Length of time wastewater takes from kitchen sink to Christchurch Wastewater Treatment Plant (amount of time varies from an hour to almost a day depending on distance from Christchurch Wastewater Treatment Plant) |
Maximum 24 hours (gravity systems only) |
Average life of pipes |
94 years |
Gravity sewer system replacement cost (2015) |
$2,458 million |
% wastewater volume domestic (2013) |
30% |
% wastewater volume commercial/industrial (2013) |
20% |
% wastewater volume infiltration |
50% |
Pipework
Description |
Measure |
Length of public pipe reticulation system |
1,814 km |
Longest single stretch of pipe (from furthest point to Christchurch Wastewater Treatment Plant) |
20 km |
Smallest diameter pipe used (gravity sewer) |
90 mm |
Largest diameter pipe used (gravity sewer) |
1.8 m |
Length of gravity sewers |
1615 km |
Length of pressure pipes (gravity system) |
199 km |
Number of manholes |
30,817 |
Pumping
Description |
Measure |
Number of pumping stations |
180 |
Number of lift stations |
56 |
Number of vacuum stations |
3 |
Number of odour control stations |
34 (12 at pump stations, 22 standalone) |
Number of pipelines leading from terminal pumping stations to Christchurch Wastewater Treatment Plant |
5 |
Total capacity of terminal pumping stations to Christchurch Wastewater Treatment Plant |
6,610 l/s (litres per second) |
Number of radio repeater stations |
10 |
Number of monitoring stations |
37 |
Treatment
Description |
Measure |
Average wastewater inflow to Christchurch Wastewater Treatment Plant (includes septic tank sucker trucks) |
172,000,000 L/day |
Rag (screenings) removed from wastewater |
1 tonne/day |
Grit removed from wastewater |
2 tonnes/day |
Dried biosolids produced (includes Christchurch, Akaroa, Wainui, Duvauchelle Bay, Tiako Bay, Wainui, Lyttelton, Diamond Harbour, Governors Bay) |
9 tonnes/day |
Power produced |
35 MWh |
Wastewater treatment plant replacement cost (includes Akaroa, Duvauchelle, Tikao Bay, Wainui, Lyttelton, Diamond Harbour, Governors Bay and Christchurch Wastewater Treatment Plants) (2015 valuation) |
$511 million |