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TRILITY news
Newsletter for TRILITY Group and Joint Venture clients
Broughton Pass flooding event
In recent years, weather patterns have changed in Sydney, whereby East
Coast low-pressure systems regularly produce concentrated rainfall events,
which usually last for three to four days at a time. When these occur, the
catchment that supplies water to the Macarthur Water Filtration Plant (WFP);
Broughton Pass raw water supply intake becomes flooded with high colour and
organically loaded raw water. Following these events, raw water colour
can increase to extreme levels, and it can take several weeks before the raw
water returns to pre-rainfall levels. For example, in late February 2022,
a rainfall flooding event occurred, and concurrent rainfall events, high raw
water colour, and organic levels continued into August.
As a result of the repeated heavy rainfall, a landslide occurred, which
deposited rock and soil into the weir at Broughton Pass. Thankfully there were
no personnel at the location at the time; however, access to our pump station
and infrastructure was blocked by boulders, and a large amount of silt blocked
the inlet structure, which needed to be removed. Rectification works required
coordination between TRILITY, Sydney Water, and Water NSW, and
all stakeholders worked together to ensure that the works progressed
safely and effectively.
Following the $20M upgrade of the facility in 2020, mechanisms are now in
place to hold undesirable water in storage so that it can be further treated
through the filtration process. At the flood’s peak, some state-of-the-art online
monitoring equipment installed at Broughton Pass as part of the plant upgrade
was washed away. The Macarthur team’s knowledge and experience ensured
that the filtration process continued to supply the required quality treated
water to over 300,000 customers in Western Sydney throughout
the event.
Flood water abated cable tray missing
Broughton Pass pre flood
Flood water abated with debris
Floodwater above Cable Tray
Due to the raw water’s extreme colour and organic load, high volumes of filter
residue sludge are being produced, which requires dewatering, drying, and,
ultimately, removal from the site. The Macarthur team has worked around the
clock to ensure this occurs effectively, and the Macarthur Management team
is working closely with Sydney Water to ensure that the situation can continue
to be managed long-term.
This is a personal note to pass on my congratulations and job well done for the
Macarthur Plant team in recent months.
I say thanks to Greg, Pat and the team but that can be a bit yeh yeh sometimes, as
success is often just taken for granted. It was an amazing effort given the extreme
wet weather conditions the plant has had to deal with this calendar year, let alone
the last two.
For my last 10 years there were always questions leading with “what’s happening
at Macarthur” It’s now noticeably not asked. In fact it’s nice to say upfront that
Macarthur is performing well despite treating severely deteriorated raw water
quality, atrocious weather and being a bit tired.
It’s really nice to say the improvements the team have been working on for a
long time are working well. We are not out of the woods, as the impacts of recent
floods will be felt for a number of years. But I know the Macarthur team have
done a lot of work, and I’m a bit proud of our successful operational teams here at
Sydney. Well done and thanks.
Ben Blayney - Head of Water Supply and Production