Septic Tank Specialists in Invercargill

Septic system costs in New Zealand range from $10,000 to $30,000 for a new installation. A basic septic tank with a soakage field costs $10,000 to $18,000. A modern aerated wastewater treatment system (AWTS) costs $15,000 to $25,000. A full advanced treatment system with UV disinfection costs $20,000 to $35,000. Septic tank pumping and maintenance costs $300 to $600 per pump-out. Council consent fees for new systems add $1,500 to $5,000.

Septic systems in New Zealand include conventional septic tanks (a concrete or plastic tank with a soakage field — the simplest and most common system), aerated wastewater treatment systems or AWTS (use aeration to treat wastewater to a higher standard, required in many areas), advanced treatment systems (produce near-drinking-water quality effluent, required for sensitive environments), and composting toilet systems (waterless systems for remote locations). Your regional council determines which system type is required for your property based on soil type, groundwater levels, and proximity to waterways.

Proper maintenance is essential for a healthy septic system. Pump out the tank every three to five years (more frequently for smaller tanks or larger households). Do not put cooking oils, paints, chemicals, or non-biodegradable items down the drain. Limit water use where possible (fix leaking taps and toilets). Do not park vehicles over the soakage field. Keep trees with invasive roots away from the tank and field. AWTS systems need annual servicing of the aeration unit and filters.

Septic system installation requires a building consent and, in most regions, a discharge consent from the regional council. The system must comply with AS/NZS 1547 (on-site domestic wastewater management). Installation must be done by a PGDB-registered drainlayer. Regional councils have specific rules about setback distances from waterways, boundaries, and bores. Some councils are requiring older septic systems to be upgraded to AWTS or advanced systems to reduce environmental impact.