Effluent Management Plan
Reviews
In accordance with 21 (1) (a-c) of the Otago Regional Plan for Water:
This effluent plan was prepared in July 2022 and will be reviewed by July 2023 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.
Reviewed July 2023, no changes.
Location and Ownership
In accordance with 21 (2) (a-e) of the Otago Regional Plan for Water
The physical location of the farm where the effluent system is located is 225 Tilverstowe Road, Island Cliff and the effluent is applied to the same address. Refer to the legal descriptions below for full details.
Land Owner:
Rikon Projects Ltd
RD7C
Island Cliff 9491
Person in Charge:
Brock Hamilton
Ph 021 189 3061
Legal descriptions:
193 Tilverstowe Rd: LOT 1 DP 23464
225 and 295 Tilverstowe Rd: Part Lot C DP 1385
91 Tilverstowe Rd: Lot 2 DP 461559
Existing Consents
Winter Grazing Consent RM23.056
Map
In accordance with Schedule 21 (2) (e) of the Otago Regional Plan for Water.
Effluent Discharge Area: 98ha.
The system features gravity feed from the shed through two weeping walls to a central sump.
There is a storm water diversion to minimise risk of overflow in rain events.
From the sump the effluent can be screened and filtered to inject into one of three pivots at 120psi, or alternatively it can run simultaneously through two pods at 100psi. When conditions do not allow application to pasture it is pumped to storage at 80psi.
Effluent is also used to operate the yard wash.
Safety features include pump control and fault notification via SMS with timer automation. The pump controller also automatically shuts off the pump if loss of pressure or flow occurs.
The pivots have backflow preventers.
The dairy shed makes use of recycled cooler water for wash down to minimise effluent quantity, and has a closed loop chilled water cooling system. Nozzles in the shed are operated at the lowest pressure and flow at which they can be effective
No effluent is to be discharged within:
or across the farm boundary.
20m upwind of the farm boundary to prevent effluent crossing the boundary.
50m of any surface watercourse - particular care to be taken in E17 to keep 50m away from the spring in Gully 2.
50m of any subsurface drainage
100m of any water abstraction point (should any be established).
200m of place of dwelling or assembly not on the property - in particular Ray and Janice Walker's.
Cows: Up to 870 cows milking twice a day and as low as 300 cows per day for winter milking.
Besides the effluent map below there is also a risk map, slope map, critical source area map, and water course map located in the maps folder of the Farm Environment Plan.
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 Avon Glen. The effluent application area consists of both 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, and Brookstead soils which are high risk FDE Category C over 7 degrees of 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 6mm, 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.
Deep silt loam.
Well drained.
High profile available water (166mm).
FDE risk category C (over 7 degrees) and D (under 7 degrees).
Moderately deep silt.
Well drained.
Moderate to low profile available water (69mm).
FDE risk category C.
Subsurface Drains
Known subsurface drains are located on the map above and are not 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. Effluent pods avoid CSA's completely and target dry bony areas to improve instead. Refer to the CSA Management Plan.
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 Johnny Grumball on 027 488 2099.
Electrical issues are to be referred to Calect Electrical on 0800 360 063.
All maintenance and repairs are recorded in the Irrigation Maintenance record or as a photographic record, and the standard methods for operating the system are in the Effluent Operation Procedures.
Risks
All paddocks have slopes which can cause potential run-off. Timers to be used to adjust application depth according to soil moisture.
Water troughs to be avoided by pod.
Storm water divert risks effluent flowing into gully. Have two people responsible for each use of the storm water divert. Use signage at cups on, and put in group message when putting storm water divert on so all staff are aware.
Effluent is not to be applied to gully floors.
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. Weak points are at the manifold, the hydrants and the feeder hose. Check for kinks in the hose, holes, leaks or blowouts. Check that the sprinkler is under pressure and turning normally. Ensure the sprinkler is not located in a swale or in a location lower than the sump in case of siphoning. Leaks, ponding, run off and flow through drainage can cause the effluent to enter a waterway which must not occur. Check that the irrigator is not located near a subsurface drain (refer to map above).
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. Include a check of the stone traps to ensure they aren't becoming blocked.
Bucket tests are completed annually on the irrigators to verify application depth and rate.
Inspections, audits and certificates from North Otago Irrigation Company, Fonterra (QCONZ), and Otago Regional Council are kept on record.
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.
A check on whether the pump is running or not can be done by texting STATUS to the QTech SMS switch. The pump is designed to automatically cut out if the flow increases such as in the case of a blow out.
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 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 or the fix photographed.
For major issues that can't be repaired in-house contact Johnny Grumball on 0274 882 2099.
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: 2nd July 2023
Date next test is due: 2nd July 2028
Storage is a permitted activity.
Visual inspection 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 pressure/high flow automatic pump cut out.
Low rate application systems.
Automated text message timer prevents accidental over watering. It's important not to become complacent and rely on the automation.
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.
Storm water diversion prevents fresh water from unnecessarily occupying capacity in the effluent system during heavy rain.
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 or the fix photographed.
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.