Lake Ferry Wastewater Treatment
At Lake Ferry the wastewater treatment system consists of on-lot septic tanks with effluent filters and a community wastewater treatment plant. At the treatment plant, septic tank effluent flows through a packed bed reactor, a recirculation tank and ultraviolet treatment. Discharge of the treated effluent is managed to either an adjacent block of land by irrigation or to a constructed wetland, depending on the conditions of the Resource Consents.
The plant was granted new consents on 17 June 2005. A change of conditions was granted on 10 January 2011. These consents will expire on 30 September 2025.
In general, the consents allow SWDC:
- to discharge treated wastewater to land via an irrigation system at up to a maximum daily flow rate of 200 cubic meters per day and a maximum weekly flow rate of 700 cubic meters per week.
- to discharge treated wastewater to land at a maximum application rate of 3.0mm/day or up to the field capacity.
- to discharge treated wastewater to water (wetland) when the field capacity of the irrigation field has been exceeded or when a discharge is required for emergency or maintenance purposes.
- to discharge contaminants and odours from the collection, treatment and discharge facilities within the site boundary.
Resource Consents
Plant Performance
Current Status: Compliant, but with risks identified below.
Period: August 2024
Commentary:
Further investment is required to achieve this management plan and consent compliance into the future.
Stantec has been commissioned to prepare and develop a new resource consent application by 30 March 2025.
Early conversations suggest that the current scheme will require capital works because of consenting requirements.
More funding is required for the consent 20204-25 renewal project than currently allocated. The extra funding is required to prepare an adequate application and undertake community consultation.
Items of significance:
Source of current high inflow and infiltration is still not funded for investigation. Peak loads are near the plant's hydraulic capacity.
Septic Tanks cleanouts, filter cleaning, completed. The effect on effluent compliance will be assessed in coming months. The treatment process is being tested and assessed for optimised operation.
Plant valving automation is required to better comply with consent discharge requirements; however it is not funded.
Projects underway:
Sodium Bicarbonate dosing improvements – optioneering
Dripline leaks – some repaired, more require repair