Apply for a wastewater audit

All non-domestic water meters are given an ‘industry type’ based on the main activity on the water meter. Each industry type has a wastewater percentage. This represents the proportion of water that is charged for volumetric wastewater services.
 
View chart of industry types and percentages
 
If you believe that your actual percentage of wastewater discharge varies from the value on the chart, you may wish to apply for a wastewater audit. If the variation is less than 5% from the standard, we may not agree to a change.

• Download and complete the non-domestic wastewater audit form.  

• Email it, with any supporting information, to wastewateraudit@water.co.nz

 
If you have any questions, call us on (09) 442 2222, press 3.
 
When we receive your application, we will contact you to discuss:

• your business operations and how you use water

• the processes where some water does not go to the wastewater network, and how to measure this volume

• a suitable date and time for a site visit, if needed.

The auditor may visit to confirm the amount of discharge and any other information. 
 

In some cases, we may ask you to get a plumber to install a check meter.  This measures any water used in a process not discharging into the wastewater network.
 
We can then compare water use between your Watercare water meter and the check meter. 
 
The flow monitoring using the check meter should continue for 3 to 12 months, depending on the water use. You will supply this data to us at agreed timeframes.
 
In some cases, we may need to monitor wastewater flow, or to install a wastewater meter.
 

New audits

For your first audit, the auditor calculates the volume and percentage of water that does not return to the wastewater network.
 
Gathering this data could continue for up to a year. If it is a long process, we may determine an interim percentage and use this for your monthly charges.
 
When we have all the required information, we will calculate:

• a final percentage once we have all the data

• a final balancing of charges, if required, but only to the date of application.

Reviews

For future reviews of the wastewater percentage, we will continue to use the current audited percentage until we have calculated a reviewed, final percentage.

When we have completed the new audit or wastewater percentage review, we send you the calculations and final wastewater declaration form.
 

If you are satisfied with the proposed percentage, sign and return the final wastewater declaration form.
 
The new reduced wastewater charge will take effect from your next billing cycle and will show, with the audit fee, on your next invoice.
 
If we don't hear back from you within 30 days of receipt of the declaration form, we will revert your wastewater percentage to the standard percentage associated with your industry type.