Trade waste

Wastewater generated from businesses (or ‘industrial and trade activities’), is not necessarily toxic but can be harmful or cause damage to the wastewater system if it is not managed properly. The DCC manages trade waste via the Trade Waste Bylaw.

The Trade Waste Bylaw 2008 has been reviewed and replaced with the Trade Waste Bylaw 2020. The Bylaw was adopted by the Council on 8 December 2020 and came into effect on 1 February 2021. The Bylaw regulates the discharge of trade wastes to the  wastewater system.

The Trade Waste Bylaw 2020 is applied to any discharge or proposed discharge into the wastewater system, other than domestic wastewater discharged directly from a building or self-contained vehicle.

Under the bylaw relevant trade waste dischargers are required to obtain a trade waste consent. The bylaw sets limits for substances acceptable for discharge, pre-treatment required for some discharges, and also lists prohibited substances.

The DCC recovers some drainage rate costs via trade waste charges.

The classifications of trade waste customer:

Those classifications reflect how a customer’s flow and contaminant loading compare against baseline limits set out in the Bylaw.  There is also a separate classification for waste from vehicle sources (tankered waste or discharges from mobile cleaning services). For more information about trade waste discharges or consents, contact the DCC Senior Education and Compliance Officer, phone 477 4000.

Conditional (Category A)

Significant industry and major discharges

These are customers whose trade waste flows and/or contaminant loads exceed the baseline limits set out in the Bylaw (either after or without pre-treatment). A trade waste consent is required, and the customer’s discharge will be subject to intensive regular monitoring and monthly trade waste charges.

Conditional (Category B)

Minor discharge with pre-treatment

These are customers whose trade waste requires pre-treatment before discharge, in order to meet the baseline limits for flows and contaminant loads set out in the Bylaw. A trade waste consent is required, and the customer’s discharge may be subject to inspections/regular monitoring and an annual inspection fee.

Tankered waste

These are customers that transport waste by vehicle for disposal at a treatment plant or other agreed location in the wastewater system (e.g. tanker operators or mobile cleaning services). A trade waste consent is required. The customer will be subject to volumetric charging.

Permitted

These are customers whose trade waste flows and contaminant loads are below the baseline limits set out in the Bylaw, without any form of pre-treatment before discharge. Permitted customers will not require a trade waste consent and will not be subject to any trade waste charges or annual inspection fees, however they are required to register their discharge with DCC and be granted approval for the discharge.

Grease traps and your food business

Fats, oils and greases (FOGs) are an essential part of almost all food businesses. They are used as ingredients and for cooking purposes. FOGs residue is also left on plates and cooking utensils which, when cleaned, transfer into the sewage (public wastewater) system.

Proper disposal of FOG's is important, otherwise problems will be experienced later on as fats solidify and block sewers – these are sometimes known as ‘fatbergs’. This can occur at any point on its way to the Wastewater Treatment Plant (WWTP), including at the WWTP itself, resulting in a lower quality of wastewater treatment. Treated wastewater is discharged into the environment, so quality of treatment is important.

To prevent blockages and WWTP problems, the DCC requires all food businesses/premises engaged in the cooking, preparation or sale of food (e.g. restaurants, takeaways, hospitals, hotels, bakeries, butcheries and supermarkets) to install and regularly maintain a system that removes FOGs from the wastewater discharged from that business.

Grease traps are one type of system. There are three types of grease trap: passive grease traps, grease converters and mechanical grease separators.

If your business or premise is engaged in the cooking, preparation or sale of food you must obtain a trade waste consent from the DCC before you discharge your wastewater to the sewer. This consent establishes the conditions under which food outlets and services can discharge waste to the sewer.

To apply for a trade waste consent use the application form in the related information section and return to the DCC Senior Education and Compliance Officer, who will contact you on receipt of the application form and if further information is required. Garbage grinders or macerators shall not be used to dispose of solid waste from trade premises to the sewage system unless approved by the DCC as a conditional trade waste consent. Fees are applicable for trade waste consent applications and a building consent will be required for new grease traps or modifications to existing ones.

The brochure, Waste Fats and Oils and Your Food Business, explains the different types of grease traps available, and can be downloaded from the related information section.

Current trade waste charges

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