Less Prescriptive Consent Conditions  More Effective

Less Prescriptive Consent Conditions More Effective

Are consent conditions for wastewater discharge becoming too prescriptive? Are they locking the applicant into a specific solution at an early stage and not enabling design development? Can there and should there be a middle ground? I think so.  Let me illustrate with the following story...

Williamson District Council (WDC) is planning to install a wastewater treatment plant, which will discharge treated effluent to the Taylor River.  WDC has undertaken all necessary ecological studies and options assessments to satisfy the McCullum Regional Council (MRC) that the impact of the wastewater discharge on the Taylor River will be less than minor.  An application for a discharge consent is lodged accordingly.

Following the application there is much ‘to and fro’ between MRC and WDC  around the information provided in the application.   

As a result, MRC proposes a set of conditions that WDC must comply with.  WDC is slightly surprised with their prescriptive nature.  The following dialogues occur:

WDC - why have you proposed a condition that we install a membrane bioreactor (MBR) plant?

MRC – To ensure that  your discharge will meet the effluent quality required and that’s what you proposed in the application

WDC – but, the RMA is an ‘effects based’ legislation; therefore as long as the effects of the discharge are less than minor, it shouldn’t matter what technology we provide. We only presented an MBR as an example of how the proposed conditions can be met.

MRC – But we need surety that your discharge does not cause adverse effects and we can ensure this by specifying the conditions, including technology, which, by the way, was part of your options study.

WDC – we agree that MBR was part of our options study and it may be the solution; however we wish to have the flexibility to go to with any technology which provides us the best practical and economical solution.

And it went on......

I can understand both  perspectives.  It’s MRC’s role to regulate the RMA.  And the WDC want to achieve the RMA outcome by minimising the burden on rate payers.

Some consent conditions do specify the technology.  But, I believe that once the effluent quality targets have been agreed,  the process technology should be left to the local council, the applicant.  To satisfy the regional councils, which require an assurance that the applicant will provide the appropriate technology, I think that local councils should state the various technological options, but refrain from stating a preferred technology.  This gives them  the choice of selecting the best option at the time.  In some cases, due to a prolonged consenting process, there might be better and cheaper options available at the time of implementation.  Also, through design development, new ideas (potentially better) and options emerge as the design progresses.

Such an approach  would give WDC the flexibility it requires, and also give MRC assurance that appropriate technology will be implemented. 

In other words, MRC should specify the consent conditions and let WDC decide on how they will satisfy those conditions.  After all, it is an ‘effects based’ assessment.     

Back to our story with a happy ending...

MRC – ok, what nutrient removal processes will you be evaluating?

WDC -  It could be SBR, MLE, Bardenpho or MBR.  All well proven technologies.

MRC – ok, we will amend the condition as follows:

The applicant shall install a biological nutrient removal plant to satisfy the effluent quality conditions specified under Clause 12.

This thought leadership article is by Ash Deshpande, a Lead Process Engineer at Harrison Grierson.

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