Farm Dairy Effluent

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Farm Dairy Effluent (FDE) is now more than ever a valuable resource in terms of it’s nutrient value as fertiliser prices continue to rise. Here you will find information on Tasman’s FDE rules and how to comply, and guidance on where to start when you are designing and modifying new and existing FDE systems.

Good effluent management is a combination of having a well-designed effluent system and processes in place to ensure that effluent is applied to pasture in the right amount and at the right time. The overall objective is to minimise the risk of contamination of water bodies from stored and applied FDE.

Farm Dairy Effluent Rules

In the Tasman District, applying effluent to land is a permitted activity that may be undertaken without resource consent if it complies with all conditions contained within Rule 36.1.2.3 of the Tasman Resource Management Plan (TRMP)- Discharge of Bird or Animal Effluent(external link)

If the discharge of Dairy Effluent does not meet the permitted activity rules, resource consent is required (see Related Pages - below)

Good Management Practices and Compliance

Staying compliant is best achieved by putting Good Management Practices (GMPs), clear procedures, and sound day‑to‑day operations into place. If you’re new to GMPs, or didn’t arrive here from our main GMP page, you can click here to go back and learn more about all 21 industry‑agreed practices. GMPs 16–19 focus specifically on the management and operation of farm dairy effluent (FDE) systems, helping minimise the risk of surface and groundwater contamination from stored or applied effluent.

Effluent Management Checklist for Tasman Dairy Farms

The checklist provided on the right was developed by DairyNZ with input from Tasman District Council, Federated Farmers, Westland Milk, and Fonterra. Its purpose is to support farmers in meeting effluent discharge rules every day of the year.

This checklist brings together the requirements of Rule 36.1.2.3 of the Tasman Resource Management Plan (TRMP), along with practical good‑practice tips to help you maintain ongoing compliance. You are encouraged to work through the checklist with your staff, use it to self‑audit your effluent system, and follow up on any areas that need improvement.

Download a pdf of the checklist (pdf 653 KB)

Designing and modifying new and existing effluent systems

Avoiding the loss of nutrients and bacteria from the soil profile into groundwater or surface water is the key environmental outcome of a well-designed effluent irrigation system. Having the capacity to store effluent before it is applied to land means effluent doesn’t have to be applied during wet periods when the risk of surface ponding and runoff is high. This greatly reduces the risk of overflows to surface water, and plant nutrient uptake is maximised. These objectives can be achieved by:

Ensuring your effluent system meets industry-specific Farm Dairy Effluent Design Standards and Code of Practice. This resource gives good management practice advice for the collection, storage, and land application of farm dairy effluent. The main goals of any FDE system are:
- To capture and contain all FDE.
- To spread the FDE at a time that allows uptake by plants.
- To uniformly spread the FDE to the desired depth, and at the desired intensity.
- To control FDE application to within the boundaries of the application area.
- To ensure that FDE systems can be operated safely.
- To comply with all regulatory requirements, including Regional plan rules.

Having your farm’s FDE storage needs calculated. This can be determined by using the Dairy Effluent Pond Storage Calculator (DESC) Your milk supply company’s Sustainable Dairy Advisor or an accredited effluent design practitioner (see Useful Links) can do this for you.
Ensuring equipment for spreading effluent is well maintained and calibrated.
- Spreading equipment is calibrated according to its design specifications.
- The effluent system is self-evaluated at least annually to demonstrate optimal performance, e.g. through an application efficiency test (bucket test); Evaluating your irrigation system - DairyNZ.
Applying effluent to pasture and crops at depths, rates, and times to match plant requirements and minimise risk to water bodies.

Which effluent system should I choose?

Whether you are well underway with establishing a new dairy farm, or investing in a new system, or modifying an existing effluent system you will quickly find that there is no one best FDE system. Just like you, each and every farms’ situation and needs are unique.

This is why Council supports and advocates that farmers align themselves with DairyNZ’s Farm Dairy Effluent Design Standards and Code of Practice. These standards and design codes are your industry’s best practice when it comes to the design of any FDE system and contains good practice advice for the collection, storage, and land application of FDE.

Dairy NZ has important information on designing systems, managing and operating systems, and determining effluent storage volumes available on their website.