Bluff Hills Dairy Farm

Soils

In accordance with Schedule 21 (2) (e) (iv) of the Otago Regional Plan for Water

Soil Types and Risk Profiles

Click here to access the S - Map for Bluff Hills. The effluent application area consists of flat land Claremont and Darnley Soils which are high risk FDE Category B land due to moderate drainage. According to Dairy NZ industry best practice the maximum effluent irrigation depth allowed is 10mm when a soil water deficit is identified that is greater than the application rate. This is achieved by application using low depth tools, specifically a slurry tanker which can apply a custom amount depending on how fast the tractor is travelling but typically 5mm but as little as 3mm.

Bucket tests are used to verify application rates and soil water deficit is determined a minimum of 24 hours after rain by a hand-held probe at the next location effluent will be applied. The application rate must not result in exceeding Field Capacity (a reading of 40% VWC on the soil moisture meter) by ensuring Soil Water Deficit exceeds planned application depth.

• Clar_1a.1

  • Deep silt loam.

  • Poorly drained.

  • High profile available water (57mm).

  • FDE risk category B
    
    

• Darn_14a.1

  • Shallow silt loam.

  • Moderately well drained.

  • High profile available water (54mm).

  • FDE risk category B

Subsurface Drains

No subsurface drains are known in the effluent area.

Critical Source Areas

Critical source areas are included in the effluent application area as shown on the map above but because effluent is only spread when there is a soil water deficit there is low risk of run off. Maximum application rate in CSA's is 5mm.

Operational Procedures and Maintenance

In accordance with Schedule 21 (2) (f) of the Otago Regional Plan for Water

The effluent pump is maintained monthly as part of the dairy shed inspection. For major issues that can't be repaired in-house contact the irrigation contractor.

Electrical issues are to be referred to an electrician.

All effluent applications, and any maintenance and repairs are recorded in the dairy diary.

ORC Fact sheets provide guidance for staff.

Operational Procedures

1. Check pond level.

2. Check the weather forecast for rain exceeding 10mm.

3. Check Soil Water Deficit exceeds planned application rate.

4. Operate slurry tanker as per the manufacturers operating manual.

5. Don’t apply effluent twice in the same place - there is enough effluent area that you won’t have to come back to that spot for at least a month.

6. Don’t apply within 10 days ahead of grazing.

7. Don’t prioritise application to CSA or swales where grass grows well anyway as this is increases risk of runoff - apply to dry bony areas to improve these instead.

8. Don’t apply to damaged soil until repaired with good grass cover.

9. Record application in dairy diary when complete.

Risks

• • Some paddocks have slopes which can cause potential run-off. 

  • Water troughs to be avoided.

  • Effluent area has been designed to reduce the risk of neighbours experiencing odour.

  • Effluent is not to be discharged within 150m of neighbouring dwellings as per the Effluent Map above.

Solids

• Solids are spread every three months with the slurry tanker, and cannot be spread on the same area more than once every two months, preferably by incorporating into cultivation of land.

• Solids are not spread onto land when the soil moisture exceeds field capacity; or within 20 metres of waterways. 

• Solids are also not spread where previous applications are still visible on the ground, or where soil moisture exceeds field capacity (a reading of 40% VWC on the soil moisture meter).

• Hazardous substances, hazardous waste and human effluent is not to be added to the effluent system.

Inspection, Monitoring and Reporting

In accordance with Schedule 21 (2) (g) of the Otago Regional Plan for Water

Inspections

Inspect the ground for any ponding and run off from the previous pass with the slurry tanker as you travel down the next run.

Inspect the system for leaks, ponding and run off each time the pump is started up and in between shifts. Weak points are at the hydrants and the feeder hose. Check for kinks in the hose, holes, leaks or blowouts. Check that the nozzles are under pressure, the irrigator is operating normally. Ensure the irrigator is not in a swale. Leaks, ponding, run off and flow through drainage can cause the effluent to enter a waterway which must not occur.

As part of the monthly shed inspection check the area below the storage pond for wet patches, areas of grass that are greener than the grass surrounding it or any other signs of leaking from the pond. 

Bucket tests are completed every three years to verify application depth and rate.

Monitoring

In addition to the checks after start up staff are to check the same components while the effluent is running if they are passing the irrigator during the day.

All staff are to report any odour from the system to the farm owner if it reaches the farm boundary, or if any complaints are received about the effluent system including odour.

Reporting

When a leak, ponding or run off are discovered the pump must be turned off immediately and the fault reported to the farm owner within half an hour. Where possible the problem should be fixed immediately and recorded in the dairy diary.

For major issues that can't be repaired in-house contact the irrigation contractor.

Effluent applications are recorded in the dairy diary and reported at audits.

Pond Drop Test Records

In accordance with Schedule 21 (2) (h) of the Otago Regional Plan for Water

The effluent components and storage facility operate under permitted activity

Date of last test: TBC

Date next test is due: TBC

Drop Test Report in progress.
Visual Inspection in progress.
Dairy Effluent Storage Calculator

Contingency Measures

In accordance with Schedule 21 (2) (i) of the Otago Regional Plan for Water

The effluent system has several measures to prevent discharges to water:

• Staff training

• Monitoring

• Low depth application systems.

• Large storage pond. We never know when we will need to pump to storage or when we can empty the storage so we use every opportunity to drain effluent out of storage and apply to the paddocks. If there is effluent in storage and the soil has the appropriate soil water deficit to irrigate then emptying storage is a priority.

Leak Response

In accordance with Schedule 21 (2) (j) of the Otago Regional Plan for Water

• When a leak, ponding or run off are discovered the pump must be turned off immediately and the fault reported to the farm owner within half an hour. Where possible the problem should be fixed immediately and recorded.

• For major issues that can't be repaired in-house contact an irrigation contractor.

• If a leak is detected in the effluent storage pond it must be emptied as soon as possible within the limits of the soil water deficit and the leak found and repaired.

Effluent Complaint Record

A register of effluent complaints must be available to the Otago Regional Council on request. If a complaint is received use this form to collect the following information:

(a) The date, time, location, and nature of the complaint

(b) The name, phone number and address of the complainant – unless the complainant elects not to supply, this information

(c ) Action taken by the consent holder to remedy the situation and any policies or methods put in place to avoid or mitigate the problem occurring again.