Reviews

In accordance with 21 (1) (a-c) of the Otago Regional Plan for Water:

This effluent plan was prepared in February 2024 and will be reviewed by February 2025 with the results noted in this section with changes recorded automatically.  The contents of this Effluent Management Plan are available to the regional council on written request.

Location and Ownership

In accordance with 21 (2) (a-e) of the Otago Regional Plan for Water

The physical locations of the farms where the effluent systems are located are 159 Ngapara-Georgetown Rd and 315 Glenn Settlement Rd and the effluent is applied to the same address. Refer to the legal descriptions below for full details.

Land Owner:

M W Farms Ltd
RD 12K,
Oamaru 9494 

Person in Charge:

Blair Hamilton

Legal descriptions:

315 Glenn Settlement Rd
LOTS 1-2 DP 1999 PT SEC 2S GLENN SETTLEMENT PT SECS 11 16 BLK V AWAMOKA SD 

159 Ngapara-Georgetown Rd
LOTS 1-2 DP 463246 SECS 1S GLENN SETTLEMENT 

Existing Consents

Winter Grazing Consent RM23.214

Map

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

Effluent Discharge Area:
Awamoko 90.1ha.
Marchwood 108.9ha
Total 199ha

The system features gravity feed from the shed through a solids settling pond to the large storage pond. There is a third irrigation pond which also serves as an emergency back up storage pond for effluent if necessary.

No effluent is to be discharged:

• across the farm boundary.

• within 20m upwind of the farm boundary to prevent effluent crossing the boundary.

• within 50m of any surface watercourse

• within 50m of any subsurface drainage - none known in effluent discharge area.

• within 100m of any water abstraction point - note bores J041/0490, J041/0503, and J041/0262 no longer exist.

• within 150m upwind of place of dwelling or assembly not on the property. In particular, see map for exclusion zones for the following residences in the following conditions:

  • Brown residence in a southerly wind at Awamoko.

  • Kowhai Dairy cottage in a southerly wind at Marchwood.

Cows:
Awamoko milks up to 900 cows twice a day, including during winter once a day, and Marchwood milks up to 1,100 cows twince a day with up to 900 milked over winter once a day.

Soils

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

Soil Types and Risk Profiles

There are S-Maps for both Awamoko and Marchwood. The effluent application area consists of mostly Ngapara soils which are low risk FDE Category D land less than 7 degrees slope and high risk Category C when over 7 degrees slope. 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 rate tools, specifically centre pivots which apply as little as 1.5mm and up to 10mm, and also through effluent pods which apply at a rate of 8mm per hour and are controlled by automated text message timers at the pump to achieve the correct rate of application between shifts. Bucket tests are used to verify application rates and soil moisture deficit is determined a minimum of 24 hours after rain by a calibrated hand-held probe at the next location effluent will be applied. The application rate must not result in exceeding Field Capacity.

• Ngap_1

  • Deep silt loam.

  • Well drained.

  • High profile available water (166mm).

  • FDE risk category C (over 7 degrees) and D (under 7 degrees).

Subsurface Drains

No known subsurface drains are within the effluent application area.

Critical Source Areas

Lower ends of the CSA's are excluded from the effluent application area as shown on the map above. Higher ends of the CSA's can be irrigated by pivot at low rates. 

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. Major issues are reported to management for repair.

All maintenance and repairs are recorded photographically on a Whatsapp chat, and the standard methods for operating the system are in the Irrigation Operation Procedures.

Risks

• • All paddocks have slopes which can cause potential run-off. Speed of pivots is to be adjusted to match soil water deficit.

Solids

• Solids are spread annually, 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, or the farm boundary. 

• Solids are also not spread where previous applications are still visible on the ground, or where soil moisture exceeds field capacity (a reading of 39% 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 system for leaks, ponding and run off each time the pump is started up and in between shifts. Check that the sprinklers are under pressure and turning normally. 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 ponds for wet patches, areas of grass that are greener than the grass surrounding it or any other signs of leaking from the pond. Include a check of the stone traps to ensure they aren't becoming blocked.

Bucket tests are completed on two pivot irrigators 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 at least once a day.

All staff are to report any odour from the system 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 and water 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 the fix photographed for Whatsapp.

Effluent applications are recorded in the dairy diary and reported at audits for NOIC, ORC and Fonterra.

Pond Drop Test Records

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

Date of last test:
Awamoko - 21st June 2022
Marchwood - 7th June 2022

Date next test is due: 21st and 7th June 2027 respectively.

Storage is a permitted activity.

Drop Test Reports:
Awamoko
Marchwood

Drop Test Graphs:
Awamoko
Marchwood

DESC:
Awamoko
Marchwood

Visual inspection next due 13th June 2028 at both:
Awamoko
Marchwood

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 pressure/high flow automatic pump cut out.

• Low rate application systems.

• Large storage pond. We never know when we will need to pump to storage or when we can reduce  the storage level, so we use every opportunity to pump 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 reducing storage pond level is a priority.

• Low water use creates less effluent with greenwash in the yard and recirculated cooler water for the wash down hoses.

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 the fix photographed for Whatsapp.

• For major issues that can't be repaired in-house contact Johnny Grumball on 027 488 2099. 

• 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.