Landfills in New Zealand
Wikipedia describes the modern transformation from tip to 'sanitary landfill':
Waste Not, Want Not
A landfill is a place to dispose of residual waste or rubbish. However, from a zero waste point of view a landfill is a waste of potential resources, and is also the cause of leachate, landfill gas and a potential source of health problems.
Environmental effects of landfills
Leachate is formed as rainwater runs through the accumulated waste.
Landfill gas is a mixture of gases created through the decomposition of waste.
The composition of New Zealand’s waste shows top three categories: organics (23%), paper (15%) and timber (14%) adding up to 52% of the total.
By 2011 New Zealand was sending 2.461 million tonnes of solid waste to municipal landfills and more again to private landfills. The amount reaching landfills falls as diversion for reuse and recycling increases.
To encourage waste reduction, the Waste Minimisation Act 2008 placed a $10 levy on each tonne of waste disposed of at municipal landfills. in 2018 there is discussion about raising this levy.
Benefits of landfills
Energy from gas
Redvale Landfill, owned by Waste Management NZ Ltd, has nine generators to produce electricity from the landfill gas it produces. Enough energy is produced to power the equivalent of 7,500 homes.
Protection of the environment
Modern, sanitary landfills are highly engineered sites with layers of storm water collection systems, clay and synthetic landfill liners with leachate collection systems to provide environmental protection from the effects of landfills. In information about Hampden Downs Landfill, Envirowaste outlines environmental management and monitoring, stormwater and groundwater monitoring and leachate control. A diagram depicts the layers of a landfill (PDF download).
Many landfills are owned by local councils, while some are commercially owned and operated by companies, such as:
The number of landfills is reducing, with more than 300 in 1995 reduced to less than 100 today. Resource consents for landfills are difficult and expensive to secure, and modern sanitary landfills with suitable protection for the environment are expensive to build and manage. Also, no-one really wants a landfill close to their homes because of traffic noise and smells. This objection is often referred to as NIMBY: Not In My Back Yard.
The Circular Economy
The circular economy may reduce waste to landfill as material flows are of two types, biological nutrients and technical nutrients.
In contrast to a traditional linear economy (of make, use, dispose) a circular economy aims to keep resources in use for as long as possible (make, use, reuse, recycle)