Effluent Management Plan
Contents
Reviews
In accordance with 21 (1) (a-c) of the Otago Regional Plan for Water:
This effluent plan was prepared in November 2023 and will be reviewed by November 2024 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
Physical Location:
Twin Terraces Farm
732 Papakaio Rd
Papakaio 9494
Stoneyhurst Farm
995 Ferry Rd
Papakaio 9494
Land Owner:
Twin Terraces Ltd
2 K.R.D.
Oamaru 9494
Person in Charge:
Morgan Easton
0211836997
Legal descriptions:
Twin Terraces:
SECS 1-2 SO 360320 SECS 30A 31A STEWARD SETTLEMENT BLK VI PAPAKAIO SD SECS 1-3 SO 24137
Stoneyhurst:
SEC 4-5 7-8 SO 24137 LOTS 1 3 DP 474132 SEC 36A STEWARD SETT BLK VII PAPAKAIO SD
Existing Consents
RM19.108.01 To discharge treated domestic wastewater to land for the purpose of disposal of wastewater from two residential dwellings.
RM17.332.01 To construct a bore for the purpose of accessing ground water.
RM11.021.01 To take and use groundwater from the Lower Waitaki Plains Aquifer for the purpose of dairy shed and stock water supply.
RM11.214.01 To discharge contaminants, namely sediment and silt, to unnamed tributaries of the Waitaki River and Welcome Creek for the purpose of constructing and operating 13 crossings for a centre pivot.
RM11.214.02 To place gravel and disturb the beds of unnamed tributaries of the Waitaki River and Welcome Creek for the purpose of constructing and operating 13 centre pivot crossings.
Cows:
Twin Terraces: 1,380 cows milked twice a day.
Stoneyhurst: 530 cows milked twice a day.
Map
In accordance with Schedule 21 (2) (e) of the Otago Regional Plan for Water.
Effluent Discharge Area
Twin Terraces: 124ha
Effluent is collected in a settling pond before the storage pond from where it is pumped diluted to three pivots but with the ability to spread straight effluent.
Solids are cleaned out and spread on the paddocks.
Stoneyhurst: 69ha
Effluent solids are separated and the liquid is stored in a Kliptank from where it is pumped to either a pivot or to a travelling irrigator.
No effluent is to be discharged:
Outside the farm boundary.
Within 50m of any surface watercourse. Travelling irrigator is not to be run within the exclusion zone, and the pivot overhang is to be turned off within the exclusion zones.
Within 50m of any subsurface drainange.
Within 50m of any water abstraction point. Particularly the Dyster bore near the Ferry Rd intersection with McPherson Rd. The overhang of the pivot is to be turned off within the exclusion zone pictured below when applying effluent.
Within 200m upwind of place of dwelling or assembly not on the property - do not apply effluent when wind conditions will carry odour to neighbours.
Unblocking the pivot is also to be performed outside the 50m radius of the bore and outside the Dyster bore effluent exclusion zone.
Twin Terrace Maps
Stoneyhurst Maps
Soils
In accordance with Schedule 21 (2) (e) (iv) of the Otago Regional Plan for Water
Soil Types and Risk Profiles
Twin Terrace soils on the southern block are all Steward which according to industry best practice are well-drained flat-land FDE Low Risk Category D with a maximum application depth of 25mmm when a soil water deficit is identified that is greater than the application rate.
Soils under the effluent area on the northern block are mainly Rakaia and Waimakariri which are also well drained flat-land FDE Low Risk Category D with a maximum application depth of 25mmm when a soil water deficit is identified that is greater than the application rate.
This is achieved by soil moisture testing to determine the soil water deficit and adjusting the low-rate pivot application between 1.5mm and 9mm accordingly and verified by bucket testing. The application must not result in exceeding Field Capacity.
Shallow loam
Well drained
Moderate Profile Available Water (38mm to 300mm rooting depth).
Shallow silt
Well drained
Moderate Profile Available Water (47mm to 300mm rooting depth).
Moderately deep loam
Well drained
High profile available water (65mm to 300mm rooting depth).
Stoneyhurst soils are low risk Rakaia soils under the pivot which according to industry best practice are well-drained flat-land FDE Risk Category D with a maximum application depth of 25mmm when a soil water deficit is identified that is greater than the application rate.
Under the travelling irrigator are low risk Rangitata soils which are well-drained flat-land FDE Risk Category E with a maximum application depth of 10mm under pivot when a soil water deficit is identified that is greater than the application rate.
This is achieved by soil moisture testing to determine the soil water deficit and adjusting the low-rate pivot application between 1.5mm and 9mm accordingly and verified by bucket testing. The application must not result in exceeding Field Capacity.
Shallow sandy
Well drained
Moderate Profile Available Water (32mm to 300mm rooting depth).
Shallow loam
Well drained
Moderate Profile Available Water (38mm to 300mm rooting depth).
Subsurface Drains
No subsurface drains are known in the effluent area.
Critical Source Areas
Critical source areas are excluded from the effluent application area as shown on the map above. Primarily achieved by not applying effluent within 100m of the bore and by avoiding applying effluent when the pivot is over the waterway.
Operational Procedures and Maintenance
In accordance with Schedule 21 (2) (f) of the Otago Regional Plan for Water
Maintenance
The effluent pump is maintained monthly as part of the dairy shed inspection. For major issues that can't be repaired in-house contact Morgan to arrange tradespeople.
All maintenance and repairs are recorded in the Irrigation Maintenance record.
Training
ORC Fact sheets provide guidance for staff in addition to training in accordance with this template. Only trained staff are to operate the effluent system, however all staff are responsible for reporting any issues.
Risks
Water troughs to be avoided by travelling irrigator to mitigate risk of contaminating stock drinking water.
Effluent infrastructure has been designed to reduce the risk of neighbours experiencing odour.
The pivot near the Twin Terraces shed crosses a waterway. Effluent is not to be pumped to this pivot when it is within 50m of the waterway, or over the waterway. The pivot is to be programmed to avoid this area as an automated measure to prevent applying effluent within 50m of the waterway. Only Morgan is to operate this pivot with effluent.
Procedures
Stoneyhurst Irrigation Operations and Maintenance Manual
Stoneyhurst Effluent Operations and Maintenance Manual
Twin Terraces Irrigation Operations and Maintenance Manual
Twin Terraces Effluent Operations and Maintenance Manual
Minimisation of Effluent
Limit flow on D gate to minimum.
Pre-wet concrete ahead of milking to speed up hose down at the end.
Cooler water used for washdown.
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. 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 not blocked and are under pressure, the irrigator is moving and operating normally. The travelling irrigator has a wire rope which is prone to tangling or breaking. Ensure the irrigator is not finishing 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. Check for cracks in concrete or other signs of deterioration that may lead to leaks.
Bucket tests are completed on the irrigators at least once every three years to verify application depth and rate. Application rate can be adjusted on the centre pivots between 1.5mm and 9mm. The travelling irrigator applies 10mm which is the maximum application depth on these soils.
Bucket Tests
Stoneyhurst
Twin Terraces
All pivots are achieving either acceptable or high uniformity and applying similar actual application depth to their settings.
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.
Effluent applications are recorded 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: 9th June 2023
Date next test is due: 9th June 2028
Storage meets permitted activity criteria.
Pond Drop Test Report for Twin Terraces Pond
Visual Inspection Stoneyhurst and Twin Terraces next due 13th June 2028.
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:
Monitoring
Low rate 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.
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 recorded.
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.