1970 Physical Environment Conference
The environmental effects of dumps were not officially considered a problem until 1970. A national Physical Environment Conference that year noted that 'controlled tipping' was the main form of solid waste disposal. It was also known as sanitary landfill, but New Zealand’s tips were far from sanitary. It was the cheapest way to dispose of rubbish, and when tips were full they were covered in earth, creating useful land – but standards varied.
The conference recommended that the Board of Health study the problem and its solutions, and recommend policy and practice changes. A Committee on Pollution of the Environment was created. In 1971 the first national survey documented 563 landfills. In 1973 the committee issued New Zealand's first manual on solid waste disposal, for the use of local authorities. It commented that many landfills were 'no better than open dumps which are aesthetically objectionable and dangerous to human and animal health'.1 At the time landfills were known as tips or dumps – they were simply holes in the ground. Unsupervised tipping was common, especially at smaller sites, and so was scavenging of dumped items at the tip face. Many tips were close to waterways, which became polluted by leachate (liquid seeping from the landfill). Little progress was made over the 1970s, although some small illegal tips were closed.
Bigger and more controlled dumps
After the Ministry for the Environment was set up in 1986 and the Resource Management Act was passed in 1991, more attention was paid to solid waste reduction and environmentally safe disposal. The government issued a national waste policy in 1992. The Ministry for the Environment led efforts to reduce waste, and to allocate costs of safe disposal to those who generate waste.
A national landfill census in 1995 found that over 95% of New Zealand's waste was going to landfills, and some of it was causing significant environmental and public health problems. The 2006–7 landfill census found a definite shift towards fewer, larger tips, and good progress in collecting and preventing leachate, but little progress in collecting landfill gas produced by decaying rubbish.
New Zealand was also exporting significant amounts of hazardous waste to Asian countries with poor environmental standards. In 2002 national and local government agreed on a national waste strategy, which set targets for improving waste management, waste minimisation and the efficient use of resources. Attention was also paid to the increasing volume and toxicity of hazardous waste, but an audit of hazardous waste policies and practices in 2005 found many inadequacies.
By the 1980s New Zealand’s landfills were still far from overseas best practice. True sanitary landfills need to have their base lined with an impermeable synthetic or natural material, such as clay. They also need collection systems for leachate (so it can be disposed of in the sewerage system) and for methane generated by decomposing rubbish.
In the 1990s and 2000s major improvements occurred. Green-waste tipping sites and recycling was introduced. Tipping was increasingly controlled. Instead of dumping rubbish at a tip face among screeching gulls while a large compactor moved back and forth, refuse was left at a transfer point, typically a concrete bunker. Workers monitored the waste and reclaimed items for recycling or reuse. The rest was then carted by truck up to the landfill and buried.