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How potable H2O is produced

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.

H2O in NZ that is utilised in homes is monitored in accordance with:

( Govt NZ, 2008)

Ministry of Environment & the

Regional Councilmonitor the source of H2O[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)

Ministry of HealthH2O 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)

Discussion: Outline the Treatment Process of POTABLE H2O

Includes: sedimentation

coagulaton

filtration

disinfection

storage

reticulation

treatment begins by sedimentation

H2O is collected in a large tank,

the SOILDS in H2O settle by gravity

Particles smaller than 0.1um

remain in motion due to

ELECTROSTATIC CHARGE. This

charge ALSO causes these

small particles to repel each

other.

A coagulant chemical is added

that neutralises the water.

The particles then agglomerate

& also then settle - these

bigger

particles are called,”FLOCS”

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

H2O is THEN filtered,

It removes particles – to

the size of: 0.035 microns.

It catches almost ALL

bacteria

Often used,”sand filtering,”

ie: MASTERTON’S TOWN SUPPLY -

utilises this process & then

the H2O 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)

CHLORINE is the most used chemical 98% treated H2O is with chlorine

chlorine dioxide is very strong & effective against crytosporidium

sodium hypochlorite solution solid calcium hypochlorite

Before delivery along: reticulation system H2O is disinfected to remove

the BACTERIA

o Economical

o Reliable

o Straightforward

o Measurable

o Protects H2O from contamination

at treatment to the TAP

Chlorine is:

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

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)

:is a system of PIPES that carries H2O to the house/s

Treated H2O is passed through an extensive network

of pipes.

30% saving of supply H2O can be

achieved with the instalment of

tanks(on site) to collect rainwater

& GREYWATERGREYWATER (sinks/ laundry& bathroom)(sinks/ laundry& bathroom)

SAVING the WATER SUPPLY

IN DOING THIS: Residents obtain

a more consistant and regular

supply

as the peak demand can be

satisfiedTHE AIM: less than < 1000L per

day(For each house on town supply)

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