Typical Services > Effluent Treatment and Disposal

Effluent Treatment and Disposal

Contact:  Aaron Edwards / Shona Brock (09) 438 9529

Effluent treatment and disposal requires specific design based on soil type and site constraints.  Cook Costello Ltd is experienced in assessment of most suitable options to provide cost-effective solutions that ensure safety for you and your environment.

We have designed effluent treatment and disposal systems since 1976 and understand Northlands soils.  We regularly review new technologies and keep up-to-date with a wide range of systems available.

Cook Costello Ltd understands and is proficient in the use of the following standards and guides:
  • Standard ‘On-Site Domestic Wastewater Management (AS/NZS:1547) and;
  • Technical Publication ‘Onsite Wastewater Management Systems – Design and Management Manual’ (ARC TP58)
  • Whangarei District Council EES 2010
We are experienced in the following restricted sites:
  1. Steep slopes
  2. Low permeability soils
  3. Limited area
  4. Slope instability
  5. Proximity to waterways
  6. At risk groundwater
  7. Perched water tables
  8. Shallow soils above bed-rock
  9. Periodic inundation (flooding)
  10. Overland flow paths
  11. Highly disturbed soil areas or fill
  12. Dispersive or sodic soils
  13. Soil salinization
We are very familiar with the following treatment and disposal options:

Treatment
  • Primary treatment
  • Secondary treatment such as:
  1. Aerated Wastewater Treatment Systems (AWTS)
  2. Activated Sludge (AS-AWTS)
  3. Bio-Filter (BF-AWTS)
  4. Trickling Filter (TF-AWTS)
  • Advanced Secondary Treatment – Packed Bed Reactors:
  1. Intermittent Sand Filters (ISF)
  2. Recirculating Sand Filters (RSF)
  3. Textile Filters
  4. Bottomless Sand Filters
  • Tertiary Treatment:
  1. Chlorine
  2. Ultraviolet (UV)
  3. Ozone
  • Grease traps
  • Use of Treated Wastewater Effluent
  • Consent requirements
  • Modification of existing septic tanks with aeration or outlet filters
  • Alternative Treatment Systems:
  1. Greywater systems
  2. Composting systems
  3. Vermiculture (worm farms)
  4. Peat bed
  5. Constructed wetland
  6. Oxidation ponds
  7. Holding tanks
  • Trade Waste
Disposal:
  • Controlled Dose:
  1. Pump
  2. Siphon
  3. On-Demand
  • Timed
  • Uncontrolled trickle loading
  • Distribution Methods:
  1. Automatic sequencing valves
  2. Distribution manifolds
  3. Distribution boxes
  4. Drop box loading
  5. Serial loading
  6. Pressure Compensating Dripper Irrigation (PCDI)
  7. Low pressure pipe loading (LPP)
  8. Low Pressure Effluent Distribution (LPED) subsurface
  9. Drain coil
  10. Perforated PVC pipe
  • Trench and bed distribution aggregate
  • Gravel-less trench systems
  • Pump chambers
  • Surface trickle irrigation
  • Spray irrigation land disposal
  • Mound disposal
  • Evapo-transpiration systems (ETS)
  • Installation advice
  • Maintenance advice