Wastewater | pūnaha parakāika me te parawai
Services and activities
The 3 Waters – wastewater group includes activities relating to wastewater.
Wastewater is the dirty water discharged from toilets, kitchens, bathrooms and laundries in dwellings and commercial premises. It also includes trade waste discharged from industrial premises into public sewers. The DCC collects domestic and trade wastewater via its systems of sewers and pumping stations, and transfers them to the wastewater treatment plants, where it is treated to a standard acceptable for discharge to the environment.
The DCC protects public health and safety by delivering effective wastewater services to every customer connected to the network with a minimal impact on the environment and at an acceptable financial cost.
Community outcomes
The 3 Waters - wastewater group contributes to the following community outcomes:
- A sustainable city with healthy and treasured natural environments
- A healthy city with reliable and quality water, wastewater and stormwater systems
- A supportive city with caring communities and a great quality of life.
Measuring performance
| Level of service statement | Performance measure | Actual 2023-24 | Target | |||
|---|---|---|---|---|---|---|
| Year 1 2025-26 | Year 2 2026-27 | Year 3 2027-28 | Year 4 - 9 2028-34 | |||
The wastewater service is reliable, and the Council is responsive to customer concerns | Percentage of residents satisfied with the wastewater system | 68% | ≥65% | ≥65% | ≥65% | ≥65% |
Wastewater is managed without adversely affecting the quality of the receiving environment | The number of dry weather wastewater overflows from the wastewater system, expressed per 1000 wastewater connections to that wastewater system | 2.56 overflows per 1,000 connections | 0 | 0 | 0 | 0 |
Compliance with DCC resource consents for discharge from its wastewater system measured by the number of abatement notices, infringement notices, enforcement orders and convictions | 1 | Zero abatement notices, infringement notices, enforcement orders, and convictions | ||||
Service calls related to wastewater are responded to promptly | Median attendance time when the DCC attends to wastewater overflows resulting from a blockage or other fault in the wastewater system (from the time notification is received to the time that service personnel reach the site) | 39 | <60 | <60 | <60 | <60 |
Median resolution time when the DCC attends to wastewater overflows resulting from a blockage or other fault in wastewater system (from the time notification is received to the time that service personnel confirm resolution of the blockage or other fault) | 124 | <240 minutes | <240 minutes | <240 minutes | <240 minutes | |
The wastewater service is reliable, and the Council is responsive to customer concerns | Total number of complaints per 1000 properties received by Council per year about: | 4.67 per 1,000 connections | <5 per 1,000 connections | <5 per 1,000 connections | <5 per 1,000 connections | <5 per 1,000 connections |
ROS = Residents' Opinion Survey
Mandatory = Mandatory performance measures required by the Department of Internal Affairs (DIA).
Significant Negative Effects
| Group/Activity | Significant and potential negative effects | Response |
|---|---|---|
Wastewater The collection treatment and discharge of treated wastewater may have potential negative effects on the community. The 3 Waters Strategic Direction Statement and the system planning approach prioritises and plans the resolution of these issues and recognises that some issues can only be resolved pragmatically over longer periods of time. | Locations of treatment plants close to residential properties can give rise to issues with odour or noise. | Potential negative effects are managed as part of the day-to-day operation of the water supply activity. Preventative maintenance, emergency management planning and operational procedures are in place to limit disruption to wellbeing. Community liaison has been initiated in known areas of community concern, and complex odour and noise mitigation is programmed at treatment plants. |
High trade waste charges may affect industries expanding/relocating to Dunedin or treatment upgrade costs contributing to rating increases that are unviable for those ratepayers on low incomes. | System planning looks at long term strategic investment objectives and outcomes for the optimal cost/benefit ratio. | |
Discharge from the wastewater system from treatment plants and overflows from the network can impact the local community. These discharges to the environment can be planned (e.g., the constant discharge of treated wastewater via an ocean outfall) or unplanned (e.g., a heavy rainfall event, blockage or broken pipe in the network causing an overflow). There is also the potential for wastewater to enter the stormwater system (e.g., in heavy rainfall events). | Potential negative effects are managed as part of the day-to-day operation of the wastewater system. Activities are permitted and regulated by conditions of relevant resource consents, which ensure potential adverse effects are managed at acceptable levels. This includes monitoring of the effluent and sediment/coastal receiving waters and impact assessments. Renewal programmes for the treatment plants and wastewater network are intended to minimise the incidence of asset failures. System planning looks at long term strategic investment objectives and outcomes for the network, treatment plants and sludge treatment and disposal. Mana whenua are engaged as partners in system planning. |