Land Pollution In Nz: Causes And Concerns

Land pollution in New Zealand is caused by a variety of factors, including human activities such as littering, industrial waste, and agricultural practices, as well as natural processes like erosion. While New Zealand boasts relatively good air quality, certain areas experience undesirable levels of air pollution at specific times of the year, largely due to motor vehicles and home wood burning. Water pollution, on the other hand, is a growing concern, with population growth, rural land use, and urban development all contributing to the degradation of freshwater quality.

Human activities and natural processes

Land pollution in New Zealand is caused by a range of human activities and natural processes. Human activities that contribute to land pollution include littering, improper waste disposal, and the release of harmful toxins and hazardous substances. This can occur through the dumping of rubbish and waste, as well as from specific industries such as sewage outlets, oil rigs, and timber treatment mills. For example, the Whakatane Sawmill historically dumped contaminated sawdust, bark, scrap timber, and chemicals, leading to significant pollution in the Kopeopeo Canal.

The storage, use, and disposal of hazardous substances can also lead to land contamination. These substances are encountered in everyday life and have the potential to cause harm to people and the environment. Industries and practices that involve hazardous substances must be adequately managed to prevent land pollution. The Hazardous Activities and Industries List (HAIL) in New Zealand records sites that have been used for activities with the potential to cause contamination.

Natural processes that contribute to land pollution include erosion, which can dislodge contaminated surface soil and encapsulate systems, such as landfill capping. Climate change and extreme weather events, such as heavy rainfall and floods, can exacerbate these issues. Additionally, sediment from the erosion of hills and river banks, as well as organic matter from urban areas, can pollute waterways and impact aquatic ecosystems.

The prevention and mitigation of land pollution require effective management of industries and practices that involve hazardous substances, as well as the implementation of pollution prevention procedures. By focusing on avoiding land contamination, New Zealand can safeguard its land and soil resources, along with the social, economic, and cultural values associated with them.

Littering and waste washed ashore

Littering by individuals is a major issue, and it is important that people dispose of their rubbish responsibly, using bins and recycling facilities where provided. Schools can play a vital role in educating students about the impact of littering and the simple ways they can help combat land pollution, such as by picking up litter and putting it in the bin, or recycling where possible.

Waste washed ashore from boats or ships can also have a significant impact on New Zealand's coastline and land. For example, in 2014, hundreds of packets and bags of food with Japanese writing on them were washed up on the shore at Hengistbury Head, believed to be from a container ship that lost its cargo during storms in the Bay of Biscay. Similarly, in 2018, strange sea creatures were washed up on beaches in the Philippines, attracting curious onlookers and researchers. These incidents highlight how waste and debris can travel great distances and end up polluting shores and land in New Zealand and other parts of the world.

The impact of littering and waste washed ashore is not just unsightly but can also have serious environmental and ecological consequences. It can contaminate soil, harm local wildlife, and introduce toxic substances into the environment. Additionally, the cleanup process can be costly and time-consuming, requiring the dedication of volunteers and the allocation of resources from local authorities and organizations, such as the Dorset Waste Partnership, which collected several tonnes of litter from Chesil Beach following the incident in 2014.

Hazardous substances and industries

The use of hazardous substances and contaminants has become a part of everyday life in New Zealand, with many industries incorporating them for the benefit of people and communities. However, these substances have the potential to cause significant adverse effects on the environment, including human health, if not properly managed.

The Resource Management Act (RMA) defines contaminated land as land with hazardous substances that are reasonably likely to have adverse effects on the environment. The past use of hazardous substances in industry, agriculture, and horticulture has led to soil contamination across the country. This contamination is largely attributed to outdated practices where chemicals were used, stored, and disposed of in ways that are now considered unsafe.

Old industrial sites, such as scrapyards and rail yards, have been identified as sources of contamination. Additionally, the use, storage, or disposal of hazardous substances can lead to issues like accidental fuel leaks, chemical spills, or the release of contaminants through burying or burning rubbish. When water permeates contaminated soil, the underlying groundwater can also become compromised. Contaminants can then spread to other areas of land or nearby water bodies through wind or water movement, causing further environmental damage.

To prevent land contamination, it is crucial to effectively manage potentially contaminating industries and practices. This includes implementing waste minimization strategies, proper disposal of contaminants, and adhering to pollution prevention procedures. By prioritizing the prevention of land contamination, New Zealand can protect its land and soil resources, along with the social, economic, and cultural values associated with them.

Climate change and extreme weather

The National Institute of Water and Atmospheric Research (NIWA) predicts that New Zealand will experience a 40% to 100% increase in hot days by 2040, along with more dry days and severe droughts, particularly in the North and East North Island. These changes in weather patterns will have significant impacts on various aspects of life in the country.

For instance, more hot days will lead to increased health risks such as heatstroke, aggression, and heart disease, especially among vulnerable populations like the elderly, infants, and individuals with chronic health conditions. Additionally, droughts and floods will increase the risk of crop disease, food spoilage, and food contamination, posing challenges to food security.

The impacts of climate change on marine ecosystems also contribute to land pollution. According to a 2012 study, climate change is considered one of the top threats to marine life in New Zealand. Rising sea temperatures, ocean acidification, and extreme weather events disrupt ocean currents, food webs, species distribution, and intertidal habitats. These changes can lead to the contamination of coastal areas and further impact the health and well-being of communities, especially those dependent on marine resources.

To mitigate the impacts of climate change and extreme weather, New Zealand is developing adaptation plans and focusing on reducing greenhouse gas emissions. The DOC Climate Change Adaptation Action Plan aims to outline actions to reduce the effects of climate change across various sectors. Additionally, the restoration of coastal wetlands, known as "blue carbon," is being explored as a tool for carbon sequestration to help combat climate change and protect vulnerable ecosystems.

Industrial, rural, and urban development

Industrial Development

Industries and practices that use, store, or dispose of hazardous substances can contaminate the land. Inadequate management of these activities can lead to soil contamination, rendering the land unsafe for future use or development. An example of this is the Whakatane Sawmill, which, between 1950 and 1989, dumped contaminated sawdust, bark, scrap timber, and chemicals in and around Whakatane and the Rangitaiki Plains, including the Kopeopeo Canal. This canal has been labelled New Zealand's most polluted waterway due to the toxic waste from the timber treatment mill.

Rural Development

Rural land use, particularly agriculture, has been a significant contributor to water pollution in New Zealand. Dairy farming has intensified in the Canterbury region, requiring large amounts of irrigation and contributing to pollution incidents in the Ōpāwaho / Heathcote River. Horticulture, arable farming, and plantation forestry have also impacted water quality, albeit to a lesser extent. Additionally, the use of urea has been linked to increased nitrogen levels in waterways.

Urban Development

Urban areas, with their large paved surfaces, face challenges in managing water contaminated with organic matter. Water run-off from roads and paved areas contains pollutants like zinc, copper, lead, and hydrocarbons from vehicle wear and emissions. This contaminated water can flow directly into streams and rivers, bypassing the natural filtration provided by soils.

Furthermore, urban development and increased population density contribute to water pollution through stormwater runoff. Diffuse pollution from stormwater in towns, carrying nutrients, pathogens, and sediments, remains uncontrolled in many cases.

Frequently asked questions