Get right advice to design, build and manage dairy effluent

Article Details

16 Dec, 2019

Dairy News

New Zealand

"It’s important to customise each effluent system to match the unique conditions of a dairy farm"

Designing an effluent system to meet the unique needs of each dairy farm requires careful planning, as our Dairy Effluent Specialist, Samantha Bull explains.

Climate conditions, contour of the land, cow numbers, soil composition and farm management practice are just some of the points to consider when designing a new effluent system.

All vary from property to property, which is why it’s important to customise each effluent system to match the unique conditions of a dairy farm.

That was the case when we designed three separate effluent systems for Tainui Group Holdings (TGH) in the Waikato in 2019.

Each property had unique conditions and we had to consider design, construction, location, operation, storage and maintenance of the effluent system.

For example, at TGH’s Hukanui Dairy, improvements there included relocating and upgrading the pump and stirrer system, installing a new stone trap and extending the area which can be irrigated, using a new irrigator.

Not far away at TGH’s Punawai Dairy, we had to come up with a new plan for effluent storage. The farm there is on rolling country so we opted for a storage pond, cut into the side of a hill below the milking shed.

The neighbouring Tainui Rd Dairy had different geographical conditions too and there we upgraded with a new sump and stone trap, new pump and stirrer with a new, large, lined effluent pond.

Farm Management

Farm management regimes can also have an impact on the type of effluent system needed.

You have to look at how the farm dairy is managed. Some farmers may stand cows on a feedpad, other farmers may have storm water diversion systems they can use.

Reducing or recycling water can also be a way to reduce effluent storage requirements.

Some farmers are a bit surprised when you show them how much water they are using, and how big their storage needs to be to accommodate for their water use.

Farms that are in high rainfall areas will need more storage but this is where farmers can use stormwater diversion. That will reduce the amount of storage required.

You can use stormwater diversion when the cows are dried off or some farmers use it throughout the season, it just requires more management of the system, doing it that way.

Storage pressure

One of the pressure points around dairy effluent management is storage.

Farmers should double check to make sure their current storage is sufficient to manage the amount of effluent their cows are producing. Or it should be set up to future proof the farm, to account for projected herd increases.

It’s also important to make sure effluent storage meets compliance rules.

Upgrading or retrofitting existing dairies with new effluent solutions will need careful planning. There are many factors to consider but the most crucial is how the landscape and climate affects effluent management.

Soil Types

This leads on to the need to understanding the types of soils on the farm.

It’ll provide a picture of the soil moisture deficits, soil drainage characteristics and infiltration rates along with the type of land contours on farm.

This is one of the most important elements in upgrading an effluent system.

Soils that are classified as high risk will increase storage requirements as there are fewer days available to irrigate. Application of dairy effluent can only take place when a soil water deficit exists.

This is compared to low risk soils where the application of dairy effluent can generally occur 24 hours post saturation, therefore there will be more days available for irrigation in any one year.

Options and Regulations

We took part in the Effluent and Environment Expo at Mystery Creek near Hamilton in 2019.

It’s a great chance for farmers to get some expert advice from people working in the industry but I also understand how it can be confusing for some.

There’s a lot of options, a lot of machinery to look at and comprehend, and many system configurations confronting you when you walk around the expo hall.

Sometimes it can be overwhelming trying to understand what’s best for your unique farming conditions.

The capital investment to upgrade an effluent system can also stand as a barrier for many looking to make sure they’re farm is compliant.

There is a high focus now on dairy effluent discharge to land. There are lots of different rules and regulations depending on where you are farming.

In the Waikato region, operating a dairy farm effluent system is a permitted activity, which means it does not require a resource consent, but farmers are required to meet key conditions.

In the Taranaki region, for example, all discharges of farm dairy and feed pad effluent require a resource consent. The consent is approved for a certain length of time and needs to be renewed when it expires.

Both permitted activity and resource consent compliance are monitored but those with consents seem to be monitored a lot more closely.

Ask For Advice

The best way to ensure you’re investing in the right system for your farm is to get advice from the experts.

Farmers should contact their local regional council if they’re unsure what their dairy effluent systems needs to be complaint.

People can also speak to Dairy NZ, there are discussion groups they can join to find out more. You may find there are many other farmers in the same situation.

Farmers can also talk to specialist staff, like our team at Waikato Milking Systems, who have Farm Dairy Effluent System Design Accreditation.

It means we can visit farms and design a system that takes into account the rules and regulations set out by regional councils.

The reports that I produce, when designing a new effluent system, can be used as part of the application to regional councils for resource consents to operate a dairy effluent system.

Education The Key

There’s no doubt that the keen public focus on the environment is fuelling demand for better effluent management solutions.

Consumers of dairy products also want assurance the land and animals are being looked after on dairy farms.

An educational approach, rather than being heavy handed towards farmers, is the key to meeting those challenges.

Learning about careful use and management of effluent can increase pasture production and also reduce the amount of chemical fertiliser needed on the land.

New technology is helping savvy dairy farmers meet some of those challenges but there are some who are reluctant to adopt new practices.

That’s where education and a bit of team work comes in.

If you look at the good work from regional councils, industry leaders like Dairy NZ and accredited designers, we’re trying to educate people around the nutrient value and benefit of effluent and how to manage it correctly.

Regional councils are focused on ensuring each farm has a plan to effectively manage effluent and mitigate the risk of effluent escaping and impacting on the environment.

It may include fail-safe systems to detect burst irrigation pipes or even measures to trace where and when effluent is being applied.

There are solutions available that can help take care of those decisions on behalf of the farmer.


-This story appeared in Getting The Basics Right, a feature by Dairy News, NZ.