Good Management Practices for Effluent and Wastewater

How you can do this:

Farm Dairy Effluent (FDE) design

• Ensure effluent is collected and contained from all sources: farm dairy, yards, barns, feed and stand-off pads, underpasses, and feed storage areas.
• The system design is appropriate for the soil type, topography, and climate.
• For new systems: use an Accredited Effluent Designer. 
• All new effluent systems should be designed to Farm Dairy Effluent (FDE) Design Standards and Code of Practice. 

System Assessment  

• Conduct effluent system checks at least annually, including testing for application depth and rate.
• Perform maintenance as needed to ensure there is no decline in system performance. 

You can show you meet this GMP with:

• Effluent system design plans.
• Confirmation that the designer is certified and/or the effluent design company is accredited.
• Commissioning test report.
• Regular Effluent WOF assessment reports and actioning any fixes that are then captured by time-stamped photographs. You can find a Certified WOF Assessor here.

How you can do this:

• All new effluent systems should be designed to FDE Design Standards and Code of Practice using an accredited effluent designer.
• The effluent storage volume is appropriately sized and meets the 90th percentile as calculated by the Dairy Effluent Storage Calculator (DESC). 
• The design of any new effluent storage is consistent with IPENZ Practice Note 21 "Farm dairy effluent ponds" NOTE: this is a Leading Practice for DairyNZ
• The storage facility meets the requirements of the Building Act.
• Actively manage storage to ensure capacity is available when required.
• Ensure storage facilities are sealed.
• Routinely remove effluent solids that accumulate.
• Have safety barriers, equipment, and signage.
   

You can show you meet this GMP with:

• Dairy Effluent Storage Calculator report
• As-built storage design plans
• Effluent bladder or tank/pond liners: specifications and warranties
• Clay-lined ponds: compaction/seepage tests
• Pond leakage tests (drop-test)  
• A cleaning/maintenance plan with servicing records and invoices.

How you can do this:

• Calibrate spreading equipment according to its design specifications specific to the product being spread.
• Inspect and maintain effluent and pumping equipment routinely.
• Evaluate your effluent system annually to demonstrate optimal performance, e.g. through an application efficiency test (i.e., the 'Bucket Test').

You can show you meet this GMP with:

• Maintenance schedules and records.
• Servicing invoices.
• Effluent calibration results – the Bucket Test.

How you can do this:

Have an effluent management plan that includes: 

• Identify risk areas for effluent application and show these on your farm map along with any waterways, buffer and exclusion zones, high and low-risk soils, and system layout (hydrants and run-lines).
• System operating procedures and maintenance checks.
• Emergency procedures and contacts.
• Application log – recording all applications including effluent form liquids and solids date, location, soil conditions, weather, application amount, depth and rate. 
• Staff training register -  system operation and maintenance. 

System Operation:   

• Adjust effluent application timing and rates based on soil moisture levels. Do not apply effluent when soils are at or above field capacity or when rainfall that would saturate the soil is forecast.
• Spread the nutrient load evenly across the largest practical area.
• Ensure the average application rate does not exceed soil infiltration rates (i.e. avoid ponding on the soil surface). 
• When calculating fertiliser requirements for the effluent disposal area, consider nutrients supplied by effluent or manure. Soil test of these paddocks biennially and adjust fertiliser applications accordingly.   Download this handy tool:  DairyNZ's Farm Dairy Effluent (FDE) Spreading Calculator   to take the guesswork out of determining your effluent nutrient loadings.

• Consider odour impact during application.
• Implement failsafe mechanisms, including:
  • Low-pressure pump cut-of,
  • Irrigator movement pump cut-off, and
  • Pond level sensor.
     

You can show you meet this GMP with:

• Soil test results.
• Nutrient budget ( OverseerFM® – effluent report), ensuring the effluent block is modelled as its own unique management block.
• Effluent application area risk map.
• Rainfall/soil moisture records for effluent application decision-making.
• An effluent log/record  DairyNZ's  Effluent Irrigator Run Sheet is a useful template you could use. 
• Staff training records.
• Operations Manual.
• Council compliance records.