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Managing farm dairy effluent correctly is essential for protecting the environment and meeting regulatory requirements. This page provides information on effluent management rules, compliance inspections, system design and storage, best-practice management, and answers to common questions to help Waikato farmers manage effluent effectively year round.

Rules and regulations

Waikato dairy farmers must operate their dairy effluent systems in accordance with the permitted activity requirements set out in the Waikato Regional Plan, the Resource Management (National Environmental Standards for Freshwater) Regulations 2020 (NES-F), and the Resource Management (Stock Exclusion) Regulations 2020.

These rules and regulations are in place to protect the environment. Dairy effluent systems must comply with them 365 days a year.

Farmers’ guide to environmental rules in the Waikato region

This guide provides a simple summary of the environmental rules and regulations that apply to farm animal effluent and related farming activities in the Waikato region.

Read the Farmers' Guide (PDF, 3.9 MB)

What can you expect from a Waikato Regional Council Farm Compliance Inspection?

We are required to assess compliance with environmental regulations relating to managing dairy effluent, and other relevant farming legislation. These inspections are completed by our Rural Compliance Team, usually working in pairs.

Read our information sheet for more on what's involved.

Considering upgrading your effluent system or just want advice?

Waikato Regional Council recommends the use of accredited dairy industry professionals to provide advice on your effluent system, and to help you design and build a dairy effluent system that can achieve compliance with the relevant rules and regulations at all times.

  • A list of accredited effluent system designers can be found here.
  • A list of certified Dairy Effluent Warrant of Fitness (WoF) assessors can be found here.

The dairy industry has agreed on what constitutes a good effluent system and has set out the required level of design. There are several tools and resources available to help ensure your system meets the requirements.

The Dairy Effluent Storage Calculator (DESC) is one of these tools which is used to determine the volume of storage required for your farm dairy effluent system. This tool is available on the DairyNZ website – this can be found here. Accredited Effluent System Designers and Dairy Effluent WOF assessors can assist in ensuring this calculation is accurate and appropriate for your farming operation. They can also provide suggestions on where system efficiencies can be improved.

Any plan to upgrade or improve your farm effluent system should consider future proofing and fail-safe measures to ensure compliance with current environmental regulation.

Designing or upgrading effluent systems - DairyNZ | DairyNZ

The IPENZ Practice Note 21 provides good practice guidance on the design and construction of Farm Dairy Effluent (FDE) Ponds. Both the IPENZ practice note and further information regarding effluent storage ponds and the required frequency for testing/certifying the pond sealing is available from DairyNZ.

Effluent pond seepage testing | DairyNZ

 

Farm animal (dairy) effluent is a valuable source of nutrients. Good effluent management on your dairy farm not only saves on fertiliser costs and enhances soil health, but also helps prevent animal health problems associated with high potassium levels in the soil.

Good effluent management is also important to ensure compliance with the relevant regional plan rules, which are in place to protect the health of ground water and surface water. Under the Waikato Regional Plan permitted activity rules, the maximum loading rate of effluent cannot exceed 25 millimetres depth per application, and the nitrogen loading rate cannot exceed 150 kilograms per hectare. Effluent must only be applied at a rate suitable for the soil conditions.  Any ponding of effluent on the land surface following application is unlawful. It is important that you know how much your irrigator is applying, adjust application rates according to soil conditions and know how concentrated your effluent is.

The relevant Waikato Regional Plan rule requires effluent storage facilities be sealed to the specified standard of 1 x 10-9 m/s, to prevent the contamination of groundwater. Your effluent storage facility should also be correctly sized for your individual farm system and management. The Dairy Effluent Storage Calculator (DESC) is an excellent tool for determining the volume of storage required for your farm dairy effluent system. Accredited Effluent System Designers and Dairy Effluent WOF assessors can assist in ensuring this calculation is accurate and appropriate for your farming operation. They can also provide suggestions on where system efficiencies can be improved.

Having adequate storage means that you:

  • Can defer irrigation in wet weather when soil conditions are unsuitable to irrigate.
  • Lower the risk of effluent ponding, runoff and leaching to groundwater in wet weather.
  • Have the ability to irrigate effluent when plant uptake is maximised.
  • Can store effluent during mechanical breakdown.
  • Can defer irrigation during busy times e.g. calving.

Increasing your effluent application area means that you:

  • Spread nutrients further, reducing fertiliser requirements and associated costs.
  • Slow the build-up of potassium in effluent paddocks which can lead to animal health problems.
  • Have more flexibility in grazing around effluent applications and safer withholding periods prior to grazing.

Good effluent management

Recommended actions and best management practices

FAQ and Answers