A quick start resource guide for schools
Introduction
This resource provides a quick starting point for teachers and educators to introduce the basic concepts of wastewater in their classrooms. It has been developed to help teachers find and use the wealth of resources that are available and provide a framework for approaching this topic.
Wastewater is water that has been used in homes, businesses, or industrial processes and contains waste products. It includes water from domestic activities like bathing and cooking, as well as industrial and agricultural runoff.
Water New Zealand (Water NZ) is a national not-for-profit organisation which promotes the sustainable management and development of Aotearoa New Zealand’s water environment, particularly the three waters (drinking water, wastewater, and stormwater). Water NZ provides leadership and support in the water sector through advocacy, collaboration, and professional development. Its ~3,000 members are drawn from all areas of the water management industry including regional councils and territorial authorities, consultants, suppliers, government agencies, academia, and scientists.
Supplimentary resources
For each concept you can explore additional teaching materials, case studies, and tools via our website. www.waternz.org.nz/UnderstandingWastewater
Key concepts you may like to explore within wastewater include:
1.What is wastewater?
2.Te Mana o te Wai
3.Understanding wastewater and the environment
4.Treating wastewater
5.Reuse and recycling
6.What can you do to help?
What is wastewater 1
The urban water system includes drinking water, wastewater and stormwater. Wastewater is a broad term that includes all water that has been used and contaminated. For example, water from toilets that contains pathogens, or water from a factory that might contain chemicals.
Sewage specifically refers to wastewater from domestic sources like homes and apartments. Sewage can be further divided into black water which contains waste from toilets and is highly contaminated with pathogens, and grey water which comes from sinks, showers, and washing machines and is less contaminated, making it easier to treat and reuse.
Sewers or Sewerage is the system of pipes and infrastructure that transports sewage to treatment facilities. To protect the environment, wastewater is normally treated before it is released back into streams, rivers or the ocean.
2Te Mana o te Wai
We know that all water is connected, the water that we drink comes from streams and rivers which provide environments for fish and other organisms. These are also often the environments that we need to discharge waste into. Thinking of water as one connected system helps us take care of our health and the environment.
Te Mana o te Wai is one framework that helps us think about how to do this. Under Te Mana o te Wai the first priority must be to ensure the life-supporting capacity of water.
It has six principles:
Care and Respect
Understanding wastewater and the environment 3
Wastewater can contain a variety of harmful substances that pose risks to the environment and public health.
These include:
Pathogens: Bacteria, viruses, and parasites from human and animal waste can cause diseases like cholera and dysentery.
Nutrients: Excess nitrogen and phosphorus can lead to algal blooms, which deplete oxygen in water and harm aquatic life.
Chemicals: Industrial wastewater may contain heavy metals, pharmaceuticals, and endocrine disruptors that can be toxic to wildlife and humans.
Proper treatment of wastewater is essential to remove these contaminants and protect the environment.
4Treating wastewater
Before being released into the environment wastewater is “cleaned” to remove pathogens (harmful bacteria and other microorganisms), chemicals and nutrients. Depending on the plant there can be up to four different stages
First, large debris is removed through screening. Then, in primary treatment, solids settle out of the water in a settling tank or similar.
Secondary treatment uses biological processes to break down organic matter. This relies on bacteria that are carefully managed in the plant which compete with and kill other microorganisms and remove chemicals such as nitrogen.
Finally, tertiary treatment such as UV disinfection removes any remaining contaminants, ensuring the water is safe for discharge or reuse.
At the end of treatment there are two waste products – the treated water and biosolids. The water can be discharged to land or water while biosolids might be used for fertiliser or taken to a refuse facility (dump).
5
Reuse and Recycling
Water reuse, also known as water recycling, involves treating and reusing wastewater for various purposes such as irrigation, industrial processes, and even potable (drinking) water supplies.
This practice is important because it helps conserve freshwater resources, reduces pollution in rivers and oceans, and provides a sustainable and reliable water supply, especially during droughts.
By recycling water, we can protect natural ecosystems, support agriculture, and ensure that future generations have access to clean water.
6What can you do to help?
You can help protect and maintain wastewater systems by being mindful of what you flush down toilets and pour down drains.
Avoid disposing of fats, oils, and grease (FOG) in sinks, as these can solidify and combine with other waste to form fatbergs large, rock-like masses that block sewer systems. Instead, collect FOG in a container and dispose of it in the trash.
Additionally, only flush toilet paper and human waste; items like wet wipes, sanitary products, and cotton buds should be thrown in the bin.
By following these practices, you can help prevent blockages, reduce maintenance costs, and protect the environment.
Think before you flush!
Find out how small actions at home and school can prevent fatbergs and protect wastewater systems.
www.waternz.org.nz/UnderstandingStormwater
Finding out more about careers in water
Wastewater experts are justifiably proud of the work they do to protect the health of people and the environment. The field includes people with expertise across a wide range of sectors including environmental sciences, urban planning, infrastructure development, engineering, microbiology, specialist operations, policy development, climate change specialists and many more.
www.inspiringthefuture.org.nz www.waternz.org.nz
Go to our website for more career resources https://www.waternz.org.nz/UnderstandingStormwater
Why work in water?
Whether you ’ re passionate about public and community health and wellbeing, climate change or protecting the environment, a job in the water sector is a great way to make a difference.
The critical role of water treatment, supply, and management in our communities means there is a constant demand for water professionals, making it a secure career choice that means there will always be a need for water professionals.
A job in water is a way to ensure your future job security.
What does the future look like?
The sector is always evolving. In an ever-changing world, water remains at the forefront of our survival.
Here’s some emerging areas in the sector that could provide you with job opportunities
Climate change adaption – drought mitigation, flood management, water quality monitoring
Emerging contaminants – pharmaceuticals, personal care products
Water resource management – water allocation and trading systems, integrated catchment management
Improving water allocation strategies – irrigation, planning, community engagement
Technology advancements – smart water metering, digital twin modelling
Māori engagement and cultural considerations – Te Awa Tupua (River Guardianship) and Co governance models
International public health – water is covered by the UN Strategic Development Goal 6 which supports access to clear water and sanitation in communities around the world
Wastewater Glossary
and contains waste products.
enquiries@waternz.org.nz
waternz.org.nz