A Consistent and Collaraborative Approach to Trade Waste Consenting and Charging
Annual Conference
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Timaru District Council (TDC) was issued with a new ocean outfall resource consent in February 2011. It has subsequently separated Timaru City’s domestic and industrial wastes and is constructing a new treatment plant for domestic wastewater (WWTP).
Prior to submitting a Resource Consent application, TDC and the city’s major industries jointly decided that each industry would be responsible for their own on-site trade waste treatments. This was agreed as the best method of avoiding a costly centralized industrial WWTP.
To ensure that Resource Consent compliance will still be achieved by this approach TDC decided to develop new conditional trade waste consents for its major industries to improve the quality of trade wastes discharged.
TDC and Cardno BTO developed a mass balance model that has allowed them to assess resource consent compliance in the outfall over a range of possible trade waste limit scenarios for each industry and to utilize all available dilution.
A new charging method has also been proposed. The proposed formula allocates TDC’s fixed and variable trade waste costs against each industry’s fixed consented median flow and variable monthly discharge flow measurements respectively.
Extensive consultation was conducted with all the major industries regarding the imminent changes to the trade waste consents and charging strategy. This has ensured the methodology has been consistent and collaborative.