Drinking Water Treatment Process and Helps Them to Understand Where Their Water Supply Comes From
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Drinking water 5 treatment Inquiry stage 3: Splash around Overview: We need clean safe drinking water to stay healthy. This activity introduces students to the drinking water treatment process and helps them to understand where their water supply comes from. Drinking water treatment Inquiry stage 3: Splash around Key concepts Overview We need clean safe drinking water to stay healthy. This activity introduces students to the drinking water • Water sources treatment process for Wellington and helps them to understand where • The general their water supply water treatment comes from. process LEVELS 2 - 4 YEARS 4 - 8 Curriculum LEARNING Social science links AREAS Social studies Technology Nature of Technology; Characteristics of technology Technological Knowledge: Technological systems LEARNING Learning Intentions OBJECTIVES Students are learning to: • understand where their drinking water comes from and how it is treated • explore the steps in the drinking water process • understand why we need to look after and not waste treated drinking water Example Success Criteria Students can: • describe where their water comes from and how and why it is treated • explain the basic steps in the drinking water treatment process • discuss why it is important to save water Learning Experience ttttttttt 5 Drinking Vocabulary water • drinking • collection treatment water • separating • treatment • distributing • clumping • storing • coagulation • reservoir • filtering, • aquifer. 30 screening Background information: Water treatment is necessary for public health, to make sure the community has healthy water to drink every day. Chemicals, bacteria, bugs, animal waste and other substances in water can make it unsafe to drink. Some diseases can also be carried in water. Water treatment plants can remove these potentially harmful substances. Wellington Water supplies on average We are fortunate in New Zealand to have drinking water provided through pipes and taps in our homes and schools. Some countries do not have that luxury. about 140 million litres Water for all New Zealand cities is thoroughly cleaned, screened and filtered before (ML) of water per day it goes out to homes and schools. Most people in Wellington get their water from the town supply, but some collect their own rainwater to drink. Some people also collect to almost 400,000 water from the artesian water supply bores (in Petone and Lower Hutt). people in Wellington. Drinking water treatment plants in the Wellington Region Treatment plants are used to remove bugs and impurities and ensure water is safe to drink. 1. The Te Marua Water Treatment Plant The Te Marua Treatment Plant supplies Upper Hutt, Manor Park, Stokes Valley, Porirua and the western suburbs of Wellington, as far south as Karori. The Te Marua plant typically produces just over 40% of the region’s total water supply. Left: Te Marua drinking water treatment plant by Wellington Water. 2. The Waterloo Water Treatment Plant This treatment plant is supplied by eight wells from the Waiwhetu aquifer beneath Lower Hutt. Waterloo supplies 40% of the region’s water to Lower Hutt (apart from Manor Park and Stokes Valley) and mixed with water from Wainuiomata, supplies Wellington’s CBD and southern and eastern suburbs. 3. Wainuiomata Water Treatment Plant The Wainuiomata Water Treatment Plant receives water from the Wainuiomata and Orongorongo rivers and three smaller creeks. It usually supplies 20% of the region’s water to Wainuiomata and mixed with treated water from the Waterloo Water Treatment Plant, it also supplies Wellington’s CBD and the city’s southern and Learning eastern suburbs. Experience 5 Left: Wainuiomata drinking water treatment plant (by Drinking Wellington Water). water treatment 4. Gear Island in Petone The Gear Island Treatment Plant is used for emergency and back up for Waterloo Water Treatment Plant. 31 Summary of Stages in the drinking water treatment process This process is an example of how water is made safe to drink. The process varies slightly at different treatment plants. Large screens trap twigs, branches, rocks, and fish before they get to the treatment plant. Collection and Water from rivers has tiny particles of dirt and sediment in it, which makes it look screening cloudy and murky. There may also be bacteria, viruses and chemicals in the water attached to the dirt and sediment which need to be removed. Carbon dioxide and lime are added to make the water the right acidity. Inside the treatment plant Fine particles of dirt and sediment are then removed from the water. A special chemical is added to the water which encourages the suspended particles to Coagulation clump together in a process called coagulation. This makes the big clumped particles (called ‘floc’) easier to remove from the water. Millions of tiny bubbles of air are pumped into the water. The bubbles join onto the floc, floating them to the surface where they form a ‘floc blanket’ which can then be removed and treated. This floc waste is called ‘sludge’. It is taken to the Separating landfill. The water that is left under the floc blanket flows through sand filters at the and filtering bottom of the tank. Water passes through layers of fine sand in the filters, which trap and remove any remaining particles in the water. The remaining filtered water moves down to the bottom of the filters. This is similar to the natural process of water seeping through the earth into underground aquifers. Preparing for Chlorine is added to the water to ensure there are no remaining bugs. Fluoride the journey: is also added for dental health. The water is checked throughout the treatment disinfecting process to make sure it meets New Zealand’s drinking water standards. Water from the water treatment plant is stored in big tanks called reservoirs Distributing which are located all around Wellington. Water travels underground through and storing water pipes. Treated water is then available from the reservoirs to use in homes, businesses Using and schools. All water that is delivered to your home is treated, drinkable water, including the water used for garden hoses, toilet flushing and kitchen taps. Learning Experience 5 Drinking water treatment 32 Learning Experience 5: Drinking water treatment These are suggestions only and are intended to be altered to suit your students and their needs. Inquiry stage 3: Splash around PHASES TEACHER GUIDE TEACHING RESOURCES Introducing drinking water Equipment: glasses of water, classroom tap or water • Show physical examples of drinking bottle. Introduce topic water: turn on a tap, fill glasses of water or drink bottles. Ask students if they know where this water comes from. Discuss their ideas. • Explain that water from the tap originally comes from local collection areas. Brainstorm possible water sources and what people use these water sources for. Visiting a water treatment plant LEARNZ video: Experiencing • If possible, visit a local water Wellington water field trip: from treatment plant. For information C source to tap https://vimeo. drinking water and group bookings to Wellington com/218612085 treatment treatment plants, please email: info@ wellingtonwater.co.nz • If not able to visit, complete a virtual visit with the LEARNZ trip: Wellington Water Field Trip: • https://www.wellingtonwater. co.nz/education-2/learnz-people- and-water-looking-at-our-water- networks/ • If you live outside of Wellington, visit your local drinking water filtration plant or local water source or contact your local council to find out more about the drinking water treatment process in your area. These can vary according to your location and water sources. The drinking water treatment process Drinking Water Treatment C Slideshow (Google Slides) https:// Learning • To learn more about water treatment docs.google.com/presentation/d/ Experience Explore stages in and the steps in this process, view 1vYUC4qDuNbRAmXRo03TMs water treatment the slideshow: Google Slideshow: xRTH7gUn5N2iqWpQpcjRHU/ 5 process Drinking Water Treatment (right) edit?usp=sharing Drinking water • After viewing the slideshow, students Steps in water treatment, Google treatment can then describe the steps in the J Doc: Stages in water treatment drinking water treatment process Student activity: using the Google Doc: Steps in water water treatment treatment- see right. 33 Making decisions about how water can be LEARNZ video: Sources of used. C Wellington’s water Video about where Wellington Dive deep: water • Discuss why is it important to use gets its water from and future to our homes and water carefully. water needs https://vimeo. schools com/218690499 • View the LEARNZ video: Sources of Wellington’s water. Review where LEARNZ: Piping water to your home water comes from in Wellington. How Keith from Wellington Water talks do we make decisions about how we about how they distribute all the use water? water Wellington needs each day and how they make sure the water • If we think about kaitiakitanga and is safe to drink (suitable for Year guardianship, we need to protect 8+). https://vimeo.com/218689599 and look after our precious water. How can we express kaitiakitanga to LEARNZ videos are from http:// protect our water? www.learnz.org.nz People and Water field trip (2017). • Discuss what needs to be considered when making decisions about taking water from the environment, e.g. the needs of animals in the stream, maintaining a healthy habitat for the animals, the quantity of water taken, and where it is taken from. Reflection Extending learning • Discuss why drinking water needs to be treated. What • See the pipe network and are the methods of water trace the path of water from treatment which make it source to tap for your school safe to drink? at GIS Wellington viewer for the water network: https:// • Revise the stages of the gis.wcc.govt.nz/LocalMaps/ Action ideas: drinking water treatment Viewer/?map=57fb534c- process and discuss how 2174471ca485132112088afc save precious water is transformed by the drinking water process. Use the legend tab to see what each colour in the map represents.