Wastewater in Lyttelton, Governors Bay and Diamond Harbour is currently fully treated at wastewater treatment plants at each of these locations before being discharged through outfall pipelines into the Harbour.
The existing resource consents for the Governors Bay, Diamond Harbour and Lyttelton Wastewater Treatment Plants require that routine treated wastewater discharges into the harbour cease by December 2018, 2021 and 2029 respectively.
In 2009 The Council approved a joint working party's recommendation to achieve this by pumping untreated wastewater from Lyttelton, Governors Bay and Diamond Harbour plants through the Lyttelton road tunnel to the Christchurch Wastewater Treatment Plant in Bromley.
The target is to have all planned discharges of wastewater to the Harbour end by 2021.
Consultation on the scheme took place from 16 September - 12 October 2015 and public drop in sessions were held in Diamond Harbour on 23 September 2015 and in Lyttelton on 24 September 2015 and 3 March 2016.
During the consultation period 44 submissions were received.
Responses have been analysed and public feedback, together with other aspects such as cultural impact, environmental impact, cost, time and ease of construction, were used to support resource consent applications lodged with Environment Canterbury and the Council on 31 March 2016.
The resource consent applications will be reviewed, accepted and then notified. Once notified, there is a twenty working day period for the public to make formal submissions.
Based on consultation feedback, Council intend to bury submarine pipelines approximately one meter under the seabed to transport untreated wastewater from the Diamond Harbour and Governors Bay Wastewater Treatment Plants to Lyttelton. Wastewater will then then be pumped to the Christchurch Wastewater Treatment Plant through the road tunnel via a new pump station at Simeon Quay in Lyttelton.
An overland road option for the Governors Bay pipeline has been discarded as a result of the consultation referred to above.