Industry self monitoring

Read the requirements you need to know if you wish to implement self-monitoring processes in your business.

What is self monitoring?

We carry out regular sampling of wastewater from large industrial customers to characterise the chargeable loading discharged to sewer. Under a self-monitoring protocol you, as the customer, are responsible for sampling of trade waste effluent, rather than Water Corporation performing this function. You may do the sampling yourself, or use an approved contractor. Analysis of samples must be carried out at a National Association of Testing Authorities (NATA) & accredited commercial laboratory acceptable to Water Corporation. Results are then submitted to us, usually on a formatted spreadsheet where they are used to determine the quality and quantity trade waste loadings and charges.

What are the advantages of self-monitoring?

  • Sampling can be done more frequently. This means that less chargeable loading is determined from any one sample, and reduces the impact of a stronger than typical sample on trade waste charges. Extra samples can be taken if a high atypical result is obtained and found to be non-representative.
  • Accruing trade waste charges can be tracked, using the spreadsheet supplied. The availability of more frequent wastewater quality data should also help optimise process performance, which may enable wastewater strength to be reduced or product loss to the waste stream minimised. This could result in more efficient use of resources and provide cost savings.

What sampling procedures are involved?

The sampling procedure would be the same as the one we follow. That is flow-proportional composite sampling using an auto sampler. Meter readings would also be required to determine the volume of the discharge.

Sampling of trade waste

How often must sampling be done?

Customers may choose how often samples are taken, as long as this is not less frequently than we would sample.

Sampling frequency is a balance between increasing cost of sampling and increasing precision in determination of waste strength. We will provide guidance on the optimum sampling frequency. For most large customers, the cost-effective optimum is somewhere between fortnightly and quarterly sampling.

What are the customer's responsibilities?

Customers must:

  • take samples and have analysis performed in the same manner as we do –this will be defined in a protocol when self-monitoring is set up
  • take samples on prearranged dates
  • seek agreement from our Commercial and Industrial Services section before making changes to sampling dates or any other aspects of the self-monitoring procedures
  • report the data to Commercial and Industrial Services in the protocol format, usually as soon as results are received. Results that are outside the trade waste acceptance criteria are to be reported immediately they are detected.

What happens if the results are unusual?

Results which appear non-typical will be subject to the same review that we apply to our own samples. Depending on the situation, the sample result may be discarded, applied for a limited time, or may stand.

Who pays for the cost of self-monitoring?

The customer bears the cost of sampling and analysis under a self-monitoring arrangement. However self-monitoring customers are not subject to our trade waste sampling and meter reading fees. 

Will Water Corporation still take samples?

Staff from Commercial and Industrial Services will continue to visit the site to inspect waste treatment facilities, as is presently the case. We will also audit self-monitoring activities, and may take check samples occasionally. However, the customer’s own samples will be those normally used for charging purposes.

Is self-monitoring available to all customers?

Generally yes. However, it is most cost effective for customers with relatively large volume, high-strength, variable wastes. For smaller dischargers, the value from self-monitoring is limited, as the cost of frequent sampling becomes significant in comparison to total trade waste charges. Self-monitoring is also of lesser value for customers where volume is the largest component of the trade waste charge.

Commercial and Industrial Services will provide advice on the worth of a self-monitoring program for the business.

What steps are required to set up self-monitoring?

If your business is interested in self-monitoring, you should contact us for further advice. A self-monitoring protocol will be setup, documenting the way in which sampling, analysis and data reporting will be carried out. It can be amended by negotiation at any time. 

Once a self-monitoring protocol has been established the terms of the protocol will become part of the permit conditions whereby a breach of the protocol will be considered a breach of the permit. A business may withdraw from self-monitoring at a future time. If this happens, we will carry out sampling to determine compliance and quality/quantity charges at a frequency to fit our sampling programmes and the permit will be amended accordingly.

More information

Our Trade Waste Officers are happy to assist with any queries you may have in relation to your trade waste discharge. You can contact us on 13 13 95 or email