Managing animal effluent

Good effluent management means having a well-designed system with proper processes to ensure the right amount of effluent gets applied to pasture at the right time. Untreated effluent entering surface water bodies or groundwater can negatively affect human health and water quality.

Farm effluent can enter the environment through:

effluent storage overflow
ponding, surface runoff and/or drainage caused by application rates or depths that are excessive for the conditions
effluent storage leaking into groundwater.

Good management practices for farm effluent and wastewater

Industry-agreed Good Management Practices (GMPs) have applied to all Canterbury farms since June 2017 and work in conjunction with consents, regional plans, Farm Environment Plans (FEPs) and land management agreements.

Meet industry standards

GMP: Ensure the effluent system meets industry-specific Code of Practice or equivalent

Farm Dairy Effluent (FDE) systems should:

capture all FDE
spread the FDE at a time that allows uptake by plants
uniformly spread the FDE to the desired depth and at the desired intensity
control FDE application within the boundaries of the application area
ensure that FDE systems can be operated safely
comply with all regulatory requirements, including consent conditions.

All new effluent systems should be designed according to the Farm Dairy Effluent (FDE) design code of practice.

Ensure adequate storage

GMP: Have sufficient, suitable storage available to enable farm effluent and wastewater to be stored when soil conditions are unsuitable for application.

In a Farm Dairy Effluent (FDE) system:

calculate suitable storage using the Dairy Effluent Storage Calculator. This enables FDE to be stored when soil and management conditions are unsuitable for FDE land application
seal all areas where FDE is collected (including feed pads). All new effluent systems should be designed to FDE Design Code of Practice standard
seal and maintain all storage facilities to ensure effluent is contained. Actively manage storage to ensure capacity is available when required.

With a deer enclosure system:

store effluent for later dispersal to land where appropriate
ensure effluent and run-off water does not enter natural waterways untreated
keep solid waste away from waterways
clear faecal/urine surface material annually
ensure paddock enclosure systems do not result in significant or irreparable soil loss or erosion.

Maintain and calibrate equipment

GMP: Ensure equipment for spreading effluent and other organic manures is well maintained and calibrated.

calibrate spreading equipment according to its design specifications specific to the product being spread
apply effluent efficiently. Record effluent applications, including product, rate, date and location
evaluate your effluent system annually to demonstrate optimal performance, e.g. through an application efficiency test (bucket test).

Apply effluent appropriately

GMP: Apply effluent to pasture and crops at depths, rates and times to match plant requirements and minimise risk to water bodies.

apply effluent to pasture and crops at depth, rates and times that best prevent loss and to increase utilisation. Ensure your distribution area complies with your consent conditions (use OverseerFM® to calculate)
take account of nutrients supplied by effluent or manure when calculating fertiliser requirements.
ensure no effluent is spread on an area where pigs are grazed.

Storing farm dairy effluent

Effluent storage design

Effluent storage is a pond, tank or structure used to capture and store the wastewater (effluent) from a dairy shed or other stock holding area.

A well-designed and maintained effluent storage pond has many benefits. These include efficiency (saving you time and money), adequate storage capacity for wetter periods, greater flexibility for irrigation to meet plant and soil needs, and better overall utilisation of nutrients and water for pasture production. It also means measures are in place to protect the environment, helping you meet your compliance and Farm Environment Plan (FEP) audit obligations.

Download guide
PDF file, 2.36MB

Key components of a well-designed storage pond include:

appropriate size for the expected seasonal effluent volume into the future
sealed to avoid effluent leakage to groundwater
compliance with regional and district council rules and building act requirements.

Animal effluent storage facilities need to be designed and constructed in line with the Institution of Professional Engineers New Zealand (IPENZ) practice note 21. More information, including a downloadable guide to building a new effluent storage pond, can be found on the DairyNZ website.

Effluent storage capacity

Effluent storage is calculated based on the size of your farming operation and your seasonal needs. Other factors that may impact include cost, installation conditions, district council regulations and the conditions of your individual Environment Canterbury resource consent. Tools like Dairy NZ’s Dairy Effluent Storage Calculator can help determine your storage capacity needs.

Effluent storage capacity

Effluent is one of the major risk areas on a dairy farm and one where our compliance officers often see issues. Overflow events, leakage and failure of storage can result in effluent entering waterways and groundwater, which can have a serious impact on the health of our environment.

Regardless of liner, age and construction type, all ponds can be subject to damage. This can happen as a result of design faults, poor installation, lack of maintenance or inappropriate operation. Ongoing inspection and testing will help identify whether your pond is storing liquid effluent without seepage or leakage loss of more than 1mm/day.

Our effluent pond checklist provides guidance on suitable design, construction and maintenance, with reference to applicable industry standards.

In line with the IPENZ practice note 21, we recommend:

an initial Pond Drop Test (iPDT) within three months of pond construction completion
ongoing PDT testing (use the flow chart on page 9 of the practice note to check how often you should test)
undertaking your own simple pond level test
installation of a leak detection system
annual monitoring and inspection of effluent pond and connecting infrastructure.

Spreading effluent for optimal farm management

Good effluent management is not only about a well-designed system. It’s also about having good processes to ensure the right amount of effluent is applied to pasture at the right time to maximise pasture growth and reduce the need for synthetic nitrogen fertiliser.

Apply effluent at the right rate, at the right time: Effluent is best applied to actively growing pastures (ideally straight after grazing) at a rate that can absorb into the soil without ponding or causing run-off, avoids draining below the plant root zone (which can pollute groundwater supplies), and is spread evenly.
Utilise soil moisture tools: The use of soil moisture tools can help you determine when the soil is dry enough to absorb more effluent, preventing unnecessary applications and potential runoff issues by helping you to only apply what is needed.
Keep good records and train staff: For compliance purposes, you will need to maintain records of application. Make sure you are familiar with your consent conditions and what is required for an FEP audit. We also recommend taking the time to train staff to fully understand how and when to operate effluent spreading systems – remember to keep a record of what training has been undertaken.
Keep an eye on your pond level: Maintaining low levels in your effluent pond reduces the risk of having to spread effluent when the soil moisture levels are already at capacity. If your pond is leaking without your knowledge, an emptier pond can also reduce potential leaching to groundwater.
Use precision tools for effluent management: Tools such as the DairyNZ Farm Dairy Effluent Spreading Calculator and Depth Testing Calculator can help you manage the application of effluent nutrients more precisely and ensure your effluent is evenly distributed.

Effluent injection

Effluent injection is when effluent is injected into the base of an irrigator and applied to land through the same line. It can help reduce synthetic nitrogen use on farms, minimising the risk of nutrient loss.

Backflow prevention: Fertigation and effluent injection systems that use irrigators connected directly to a water source (for example, groundwater abstracted from a bore, or water taken straight from a river) need a functioning backflow prevention system. This is a system that prevents backflow from occurring in the case of pressure loss, as this can cause contaminants to enter the water source.

Rules and resource consent requirements

The rules for animal effluent are included in Section 5.29-5.37 of the Canterbury Land and Water Regional Plan (Pages 98-101). Click on the accordions below to read the rules that apply to you.

Permitted activities

If you are able to meet all of the permitted activity thresholds set out in these rules, you do not require resource consent, but you must continue to operate within the rules at all times.

Resource consent required

If you can't meet one of the permitted activity thresholds, you will have to apply for resource consent. In most cases, resource consent is needed for both effluent storage facilities and discharging effluent to land, whether they are new or existing.

Depending on the set-up of the system and what you are proposing to do, modifications to your consent conditions may be required. Sometimes additional consents are needed for associated systems. For example, an effluent storage consent might be modified to include adding silage leachate to the storage facilities. If the silage stack is also near a waterbody or property boundary, a separate consent might be required, even if the leachate is collected in the effluent system.

Non-complying activities:

Activities meeting the definition of a non-complying activity are not permitted and resource consent cannot be granted.

Rules 5.29 and 5.30: discharge of solid animal waste

Rule 5.29

The discharge of solid animal waste (excluding any discharge directly from an animal to land), or vegetative material containing animal excrement or vegetative material, including from an intensive farming process or industrial or trade process, into or onto land, or into or onto land in circumstances where a contaminant may enter water is a permitted activity, provided the following conditions are met:

The material does not contain any hazardous substance; and
The material does not include any waste from a human effluent treatment process; and
The material is not discharged:

(a) onto the same area of land more frequently than once every two months; or

(b) onto land where solid animal waste, or vegetative material containing animal excrement or vegetative material from a previous application is still visible on the land surface; or

(c) onto land when the soil moisture exceeds field capacity; or

(d) within 20 m of a bore used for water abstraction, a surface waterbody not listed in Schedule 17 or the Coastal Marine Area; or

(e) within 50 m of a surface waterbody listed in Schedule 17; or (f) within a Community Drinking-water Protection Zone as set out in Schedule 1.

Rule 5.30

The discharge of solid animal waste, (excluding any discharge directly from an animal to land), or vegetative material containing animal excrement or vegetative material, including from an intensive farming process or industrial or trade process, into or onto land, or into or onto land in circumstances where a contaminant may enter water that does not meet one or more of the conditions in Rule 5.29 is a discretionary activity.

Rules 5.31 and 5.32: use of land for a stockholding area

Rule 5.31

The use of land for a stock holding area is a permitted activity, provided the following
conditions are met:

The stock holding area is not:
(a) within 20 m of a surface water body, a bore used for water abstraction or the
Coastal Marine Area; or
(b) within 100 m of a pre-existing dwelling or place of assembly on another property;
and
1A. The stock holding area is not located within a Community Drinking-water Protection
Zone as set out in Schedule 1; and
All liquid animal effluent, washdown water or stormwater containing animal effluent is
collected and disposed of to an animal effluent collection and storage system
authorised under Rules 5.33 to 5.37 or an existing discharge permit; and
The base of any stock holding area located on land over an unconfined or semi-confined
aquifer shall be sealed such that seepage into land does not exceed one millimetre per
day.

Rule 5.32:

The use of land for a stock holding area that does not meet one or more of the conditions
of Rule 5.31 is a discretionary activity.

Rules 5.33 and 5.34: use of land for the collection, storage and treatment of solid animal waste

Rule 5.33

The use of land for the collection, storage and treatment of animal effluent is a permitted activity, provided the following conditions are met:

The land used for the collection, storage and treatment of animal effluent is not: (a) within 20 m of a surface water body (other than a wetland constructed primarily to treat animal effluent), a bore used for water abstraction or the Coastal Marine Area; or (b) within 50 m of the boundary of the property; or (c) within a Community Drinking-water Protection Zone as set out in Schedule 1; and
The collection, storage and treatment system is sealed, such that seepage into land does not exceed one millimetre per day.

Rule 5.34

The use of land for the collection, storage and treatment of animal effluent that does not meet one or more of the conditions of Rule 5.33 is a discretionary activity.

Rules 5.35-5.37: discharge of animal effluent or water containing animal effluent

Rule 5.35

The discharge of animal effluent or water containing animal effluent and other contaminants originating from a stock truck holding tank onto or into land where a contaminant may enter water is a permitted activity, provided the following conditions are met:

The maximum volume discharged does not exceed 100 m3 per property in any 12 month period; and
The discharge of animal effluent or water containing animal effluent and other contaminants: (a) is not within 20 m of a surface water body (other than a wetland constructed primarily to treat animal effluent); or (b) within 20 m of a bore used for water abstraction, the Coastal Marine Area, or the boundary of the property.

Rule 5.36

The discharge of animal effluent or water containing animal effluent and other contaminants originating from: (a) a stock holding area; or (b) a stock truck holding tank that does not meet one or more of the conditions of Rule 5.35; or (c) an animal effluent storage facility; onto or into land where a contaminant may enter water is a restricted discretionary activity, provided the following conditions are met:

The discharge of animal effluent or water containing animal effluent and other contaminants: (a) is not within 20 m of a surface water body (other than a wetland constructed primarily to treat animal effluent), a bore used for water abstraction or the Coastal Marine Area; and (b) does not occur beyond the boundary of the property on which the animal effluent is generated unless the written approval of the property owner where the discharge occurs has been obtained; and (c) is not within a Community Drinking-water Protection Zone as set out in Schedule 1; and (d) has backflow prevention installed if the animal effluent or water containing animal effluent is applied with irrigation water; and (e) is not to contaminated or potentially contaminated land; and
The discharge is the subject of a Farm Environment Plan that has been prepared in Canterbury Land and Water Regional Plan Page | 101 accordance with Schedule 7 Part A. The exercise of discretion is restricted to the following matters:
Measures to avoid, mitigate or remedy adverse effects on aquatic ecosystems and human or animal drinking-water; and
Effluent and water application rates and nutrient load; and
The effectiveness of methods to store effluent and application rates in times of adverse weather conditions, including frozen or saturated soil, or in cases of equipment failure; and
The proximity of any discharge site to, and actual or potential effects on, any identified site of significant indigenous biodiversity on biodiversity; and
The adequacy of design, construction, systems and management processes to minimise fugitive discharges from the system, including, but not limited to, mitigation in case of equipment failure or breakage; and
The quality of, compliance with, and auditing of the Farm Environment Plan; and
Any adverse effects on Ngāi Tahu values or on sites of significance to Ngāi Tahu, including wāhi tapu and wāhi taonga.

Rule 5.37

Any discharge of animal effluent or water containing animal effluent or other contaminants that does not meet one or more of the conditions in Rule 5.35 or Rule 5.36 or that is directly into water (other than into a wetland constructed primarily to treat animal effluent) is a non-complying activity.

Compliance monitoring for effluent collection and dispersal systems

It's important that you comply with local rules and the conditions of your consent and exercise good management practices for farm effluent and wastewater so you can avoid environmental impacts and get value from the nutrients in the effluent.

If your operation is a permitted activity, you will need to be able to demonstrate how you are farming within those limits.

If you have a Farm Environment Plan (FEP), it will also contain specific objectives and targets relating to effluent management that you will have to demonstrate to an auditor.

Resource consent monitoring: Our Resource Management Officers (RMOs) undertake monitoring inspections on farms to assess compliance with resource consent conditions for many farming activities, including effluent storage and discharge.

During a compliance visit to monitor your consent, you will need to be able to show records relating to the management and maintenance of your effluent storage and spreading. If you are not familiar with these, check your discharge consent conditions on our website to see what’s required.

FEP auditing: For compliance with your FEP targets and objectives, an independent FEP auditor will visit your farm to verify evidence of on-farm management against the expectations set out in the FEP appendix of the resource consent.

An independent assessor looks at your entire effluent system, pointing out areas of risk and suggests practical actions you can take to help meet compliance standards. You can also access the Animal Effluent and Sold Waste FEP Farm auditor guide to understand what an auditor might look at during a visit.

Connected on-farm systems

Depending on the risk to ground or surface water, other point source risk areas may be connected into an existing effluent system or require their own effluent management. If connected, these systems should be captured in your resource consent, and in some cases, could require a separate resource consent.

Silage bunkers

Silage bunkers are often connected to effluent storage systems to enable capture of leachate and to prevent contamination of waterways and groundwater.

Silage leachate is very concentrated and can burn grass when applied direct. Adding leachate into your effluent pond will dilute the concentration of the leachate and enable safer spreading on the paddock with your effluent.

If you have questions about managing silage leachate, view our silage management webpage or get in touch with our Land Management Advisor team.

Farm tracks

Rainwater on farm tracks can create channels that can transport effluent and sediment to waterways. To reduce the risk of this happening, on-farm tracks require good design, construction and management. This is also important for preventing lameness in animals.

Feed pads and yards/stockholding pens

Feedlots and stockholding areas, like feed pads and winter pads, have specific regulations. These rules are based on the age or weight of the cattle, the permeability of the base, how effluent is managed, and the distance from water bodies. View our feedlots and stockholding areas webpage for more information.

Minimising effluent discharge when transporting stock

Effluent spills on our roads and in waterways are an environmental risk and a road safety hazard for drivers.

While stock truck drivers are responsible for managing their effluent tanks and using appropriate disposal facilities, farmers play an important role in keeping effluent off our roads.

Stand stock before transport

As a stock owner, there are simple steps you can take to reduce effluent discharge before the truck even leaves your gate.

Standing stock before being transported is one of the most effective ways to reduce effluent spills.

This practice reduces the volume of effluent produced during the journey, and supports better animal welfare outcomes.

The Ministry for Primary Industries (MPI) recommends farmers:

stand animals off green feed for at least four hours (but no more than 12 hours) before transport
provide animals held off pasture with water and an appropriate alternative feed source (like hay) during their stand off period
use a dry, comfortable base like, woodchip or straw, to keep animals clean and supported, and;
inspect each animal before loading them to ensure they are fit and healthy for transport.

See the MPI Code of Welfare for transporting stock within New Zealand (PDF file, 535KB) for more information.

Work with your transporter

Effluent management is a shared responsibility.

Good communication with your stock agent around loading times and scheduling changes makes sure stock are ready for pick up.

Let your transporter know when you’re taking your stock off feed so they don’t turn up before stock are emptied out.

Truck drivers

Everyone in the supply chain plays an important role in preventing effluent spillage on our roads.

Truck drivers should use effluent disposal facilities as often as possible and keep in close communication with stock agents or farmers about any changes to pick up times.

There are several stock effluent disposal facilities available around the Canterbury region.

Effluent spills are prohibited

Effluent spillage and unauthorised dumping of effluent into the environment is prohibited under Section 15 of the Resource Management Act (RMA 1991).

Under the law, drivers who are found to have let effluent spill into the environment could receive a $750 fine.

For more information, phone us on 0800 765 588 (24/7).

More information

We're here to help. If you have any questions about effluent management or need to talk to your local land management advisor, please contact our advisory team:

0800 324 636

ecinfo@ecan.govt.nz