Water Supply Flashcards
1
Q
Three waters integration
A
- strategic planning
- recognises inter-relationships
- integrates financial planning
2
Q
Water Supply Sources
A
- groundwater bores
- reservoirs
- stream/river offtakes
- lakes
- de-salination
- roof water
- process water reuse
source determines level of treatment
3
Q
what determines the level of treatment required
A
the source of the water
4
Q
Water Supply Design Criteria
A
- water quality (must achieve minimum standard)
- hydraulic capacity (adequate for estimated use)
- structural strength of water system components to resist applied loads
- fire supply (must achieve standard)
- “fit for purpose” service life
- seismic resistance
- resistance to internal and external corrosion or degradation
- optimal “whole of life” cost for an asset life of 50 years
- capacity and ability to service future extensions and development
- networking, redundancy and security of supply
5
Q
Water use breakdown inside NZ home
A
- 30% baths and showers
- 30% toilet flushing
- 20% kitchen use
- 20% laundry
6
Q
Design Water Quantity
A
- between 180 and 250 litres per person per day, plus water used outside the house
- Summer can raise the average demand, inside plus outside, to 800 L/day
7
Q
Non-residential water use
A
- commercial (cooling, bathrooms and landscaping)
- industrial (major uses for ‘process’ eg. rinse processes and sanitation)
- institutional (cooling, bathrooms and landscaping)
8
Q
Industrial High Water Users
A
- food processing
- beverages
- textiles (due to dyeing/bleaching)
- semi-conductor manufacturing
- pulp and paper
9
Q
Industrial Low Water Use
A
- warehouses
- electrical goods manufacture
10
Q
Design Flow and Pressures
A
need to calculate:
- minimum water demand (e.g. 250 L/p/day)
- peak flow
- fire water demand
11
Q
Network Design
A
- use models to assess combinations of pipe size, pressure and layouts
- ability to add future connections
- looping to provide flow security
- incorporate values for maintenance/fault isolation
- design pressures
- rate pipes for 1.5 times operating pressure
12
Q
Pipe Materials
A
- ductile iron and steel
- PVC-U
- PE80, PE 100
13
Q
Ductile Iron and Steel pipes
A
- internal lining and external coatings must be undamaged or fully restored after repairs or fabrication work
- potential problems with stray electric currents and bimetallic corrosion
14
Q
PVC-U
A
- UV degradation
- scratching, gauging and impact damage
- proper bedding and installation required
- permeation by contaminants possible
15
Q
PE 80 or PE 100
A
- susceptible to permeation by some hydrocarbon contaminants
- sophisticated equipment and highly skilled workers required
- UV degradation
- bedding support to prevent excessive deformation
- pulling forces for PE not to exceed manufacturer’s reccommendations
- minimum radii
- Poissons effect and end restraint
