www.wwtonline.co.uk | WWT | APRIL 2014 | 17
Top: Installed at new location
Bottom: Specialised equipment for dosing PAC
R
ecently, a key water treatment
works (WTW) in the north of
England was facing closure
due to a spike in the pesticide
concentration found in the raw water
supply entering the water treatment
works. Due to tough constraints on
allowable pesticide concentrations,
which have to be below 0.1μg/l, the
site was forced to shut down.
The utility then had to divert
water from another regional plant to
maintain the local residents' supply
of clean drinking water until the
Emergency dosing
installation
Mobile system
saves site from
closure
problem could be resolved. Water
treatment specialist Transvac had
originally supplied a TransPAC
mobile carbon dosing system to back
up another of the utility's WTPs, but
when the pesticide concentration
spike was detected, a recovery
project was put together to relocate
the TransPAC system to the failed
site.
Pesticide removal
Adding powder activated carbon
(PAC) into treatment works is one of
Project focus
● Pesticide concentration spike detected
● Same-day relocation of mobile plant
● Innovative system to dose PAC
LILLY SMITH
TECHNICAL SALES ENGINEER,
TRANSVAC
● Regularly problem with
chemical contamination
to the raw water sup-
plies from agricultural
pesticides that that get
washed into water sources
by heavy rainfall
● The Drinking Water
Inspectorate monitors and
inspects water quality to
ensure levels of contami-
nates are within allowable
limits and when these lim-
its are breached they issue
notice to a water company
to take action.
● Some pesticides can be
very difficult to remove
from water, requiring high
levels of processing and
additional treatments,
which uses extra energy
and resources
• Drivers
System being
collected from
original site
