water supply in NZ, potable water process in NZ, household supply of water in NZ, sedimentation of water for supply, coagulation of water for supply, filtration of water for supply, disinfection of water for supply, storage of water for supply, reticulation of water for supply
2. The Resource Management Act 1991 LOCAL AUTHORITIES control & regulate the drinking water supplies , Ensuring safe water is delivered to our homes. The DEPARTMENTS work together closely to provide this . ( Govt NZ, 2008) H 2 O in NZ that is utilised in homes is monitored in accordance with:
3. Ministry of Environment & the Regional Council monitor the source of H 2 O [Rivers & Groundwater] Resource Management Act 1991 stipulates the tools needed to ensure this supply . The ,”Council Officers,” are responsible to the position (Govt NZ, 2008)
4. Ministry of Health H 2 O treated under the law of the: Health Amendment Bill of Drinking Water The ,”Drinking Water Assessors,” are responsible The Building Act Building Inspectors: responsible to the tap (Govt NZ, 2008)
5. Discussion: Outline the Treatment Process of POTABLE H 2 O Includes: sedimentation coagulaton filtration disinfection storage reticulation
6. treatment begins by sedimentation H 2 O is collected in a large tank, the SOILDS in H 2 O settle by gravity
7. Particles smaller than 0.1um remain in motion due to ELECTROSTATIC CHARGE . This charge ALSO causes these small particles to repel each other.
8. A coagulant chemical is added that neutralises the water. The particles then agglomerate & also then settle - these bigger particles are called ,”FLOCS”
9. Often used in smaller plants Mixed gently to prevent molecular breakage FILTER AID POLYMERS, 0.1mg/L , added to lengthen filter run times CHEMICLALS USED Aluminium sulphate Polyaluminium chloride MOST COMMON Usually dosed at >1mg/L Ferric chloride Ferric sulphate
10. H 2 O is THEN filtered, It removes particles – to the size of: 0.035 microns . It catches almost ALL bacteria
11. Often used ,” sand filtering ,” ie: MASTERTON’S TOWN SUPPLY - utilises this process & then the H 2 O is covered in a pond NZ’s newest,“ ultrafiltration ,” plant is located in the WAIKATO REGION. Filters: 75 million litres per day (International NZ, 2008) (Masterton District Council, 2008)
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14. ALSO : extracts hydrogen sulfide, ammonia & nitrogen compounds that cause unpleasant taste. Stops: moulds slime bacteria algae that grow on the walls of pipes & storage tanks
15. A local DAM or TANK : holds MILLIONS of Litres. Household’s are supplied from this, via the use of a reticulation system (network of pipes & junctions)
16. :is a system of PIPES that carries H 2 O to the house/s Treated H 2 O is passed through an extensive network of pipes .
17. 30% saving of supply H 2 O can be achieved with the instalment of tanks (on site) to collect rainwater & GREYWATER (sinks/ laundry& bathroom) SAVING the WATER SUPPLY
18. IN DOING THIS: Residents obtain a more consistant and regular supply as the peak demand can be satisfied THE AIM: less than < 1000L per day (For each house on town supply)
19. Bibliography Masterton District Council. (2008). Water treatment and supply-masterton district council . Retrieved September 15, 2008, from http//: www.mstn . govt.nz/services/ water /index.php International NZ. (2008). Waikato water treatment plant . Retrieved September 15, 2008, from http//: www.ch2m.com/corporate/worldwide/assests/ ProjectPortfolio/australia/ Waikato .pdf New Zealand. Govt NZ. (2008). Resource Management Act [Ministry for the Environment] . Retrieved September 15, 2008, from http ://www.mfe.govt.nz/rma/index.php
