New water recycling
facilities have been commissioned in Alice Springs this week and will undergo
three months of testing before the water is supplied to businesses and
institutions south of Heavitree Gap.
As part of the Alice Water
Smart Reuse Project, the new treatment processes at the Alice Springs
wastewater plant will improve the quality of recycled water available.
Around ten large businesses
and institutions south of The Gap will use the water for irrigation and
horticultural purposes, such as watering gardens at caravan parks and the
cemetery, as well as road and civil construction works.
“It will save around 220
million litres of the drinking water that is currently used for these purposes
each year. That’s equivalent to 100 Olympic sized swimming pools”, says Alice
Water Smart Project Manager Les Seddon.
The new facilities include an
architecturally designed building to house gravity filters and UV reactors, as
well as 3.5km of new network distribution pipe and an additional 2.5 Megalitre
storage tank.
As part of the three-month
testing period, Power and Water Corporation and the Department of Health will
carry out a series of validation checks to ensure the system is robust.
"Along with water quality
testing, we’ll be monitoring how the system works under various operational
conditions, such as when there is peak demand or low water levels in the
tanks.”
“We are currently in
discussions with businesses and institutions south of the Gap about how they
can access the scheme and we look forward to that first turn of the tap.”
95 tonnes of special sand
media has been brought in from NSW for use in the system’s new gravity filters;
which has some irony for a place that is surrounded by sand.”
"The certified sand has a
high quartz content, so it is quite strong and won’t
break down into powder form to clog the system. The sand grains are uniform in
size to allow wastewater to filter through, and small enough to pick up tiny
solid particles along the way.”
After the sewerage has
travelled through several wastewater ponds over a 70-day period, the recycling
process takes about one hour, which includes the following five steps:
Acid and coagulant is added
to a reactor tank to modfy pH and bind fine solids together
Waste water enters a
Dissolved Air Flotation (DAF) tank to inject air and allow solid particles to
float to the top (which are scraped off and sent to waste)
Partially treated water
enters the new gravity media (sand) filters to remove more solid particles and
further improve quality
Pumps push the water through
80 high intensity UV lamps to disinfect pathogens (disease forming bacteria)
Recycled water is then injected with
chlorine and stored in two 2.5 megalitre storage tanks, from where it is
accessed by the end user.
Testing is expected to be
complete by mid December and will be available for customers straight away.
Alice Water Smart is
supported by the Australian Government.