Effluent discharge - do you comply?

3 April 2016

The Waikato region has the most dairy herds in New Zealand so it’s no surprise that the rules surrounding effluent discharge have a significant effect on a number of Waikato Farmers.  In the Waikato region, the Waikato Regional Council classifies effluent discharge as a ‘permitted activity’ provided that certain requirements are met.  This means that you may not need a resource consent to apply effluent onto your land.

Permitted activity compliance

The Waikato Regional Council has developed rules for disposal of dairy farm effluent which are aimed at meeting the requirements of the Resource Management Act (often referred to as “the RMA”). The RMA was passed to promote management of natural resources to ensure they are sustained for future generations.

In order for your effluent discharge to fall within what is considered to be a ‘permitted activity’ under the Waikato Regional Council rules, the following requirements and restrictions must be met:

  1. No more than 150 kg of nitrogen can be applied per hectare, per year on grazed pasture (1.5 applications at 25 mm deep and 0.04 percent nitrogen);

  2. You must have contingency measures in place in case there is prolonged wet weather or if a pump breaks down;

  3. Any ponds or effluent holding facilities must be sealed to the required extent to reduce leakage;

  4. You must spread effluent and sludge in a way that reduces odour and spray drift;

  5. Each effluent application must not be more than 25 mm deep (The depth might need to be less than this to comply with the nitrogen application rate or to avoid ponding or run off);

  6. Effluent application must not be within 20 metres of a Significant Geothermal Feature;

  7. Effluent must not run off the land into waterways (Best practice recommends leaving an appropriate buffer alongside streams, drains, lakes and boreholes); and

  8. Effluent must not pond on the land surface or cause overland flow after application (The simplest definition of ponding is when stamping a gumboot in applied effluent causes splashing to occur.)

It is important for you to be vigilant, particularly in the winter season, when damp ground and higher water tables can mean that less effluent will be absorbed increasing the risk of non-compliant ponding. If your effluent discharge does not comply with the above requirements, then you will need to obtain a resource consent.

There are numerous tools and resources available to help you ensure that you do not apply too much effluent or fertiliser to your land - Waikato Regional Council has an online calculator to work out effluent application rates, Dairy NZ has a smart phone app to enable you to apply effluent more efficiently. It is recommended that you make full use of the tools and resources available and, if in doubt, contact the Council and seek specialist advice. The best advice can be gained from independent effluent consultants and designers, dairy supply companies, Dairy NZ and other dairy industry organisations.

Managing effluent and fertiliser

If you apply fertiliser to land that has also had farm animal effluent applied to it within the preceding 12 months you will need to have a nutrient management plan complying with the Rules. Factors such as the farm system, supplements used and time of year can significantly alter the nutrient composition of effluent.  Testing the application depth and nutrient value of your effluent will enable you to make the most of the nutrients and help prevent you from inadvertently exceeding the permitted application rates.

Professional advice to suit your situation

The management of effluent discharge is an unavoidable obligation for dairy farmers. Each farm is managed differently and there is no right or wrong system, so long as it meets the regulations and provides what you need

As every farm is different it is advised that when considering a new or upgraded system you should engage a qualified and experienced professional. When purchasing a dairy farm it is important to ensure that your planned activity will comply with Council requirements. If you are purchasing a dairy farm or if you are unsure whether your farm meets legal requirements we can help you.


Please email me at [email protected] with your ideas for future articles. Keep an eye out for next month's column, where I will discuss another relevant rural legal issue.

Barbara McDermott is a partner of Norris Ward McKinnon, specialising in commercial and rural law. With offices in Hamilton and Huntly, we have friendly, expert legal advisors ready to help you with your business and personal legal matters.