An effective alternative process for treating low temperature groundwater
By Dan Hogan and Hans Peterson
The Yellow Quill First Nation bio-membrane water treatment plant in
Saskatchewan is the first of its kind in Canada.
Associated Engineering and
WateResearch Corp. of
Saskatoon have developed,
piloted and implemented a
new, full-scale water treatment
process based on biological purification,
integrated with reverse osmosis
membranes. The Yellow Quill First
Nation bio-membrane water treatment
plant in Saskatchewan is the first of its
kind in Canada.
Yellow Quill is a native community
of approximately 600 people in eastern
Saskatchewan. Due to its poor surface
water source and ineffective water
treatment process, a boil-water advisory
was established in 1995. A search
for better quality source waters found
good quality water 100 kilometres
from the community. The potential for
local groundwater to supply the community
was positive; however,
although the quantity of groundwater
supply was sufficient, quality was
extremely poor. Despite concerns with
iron, manganese, arsenic, dissolved
organic carbon, manganese, ammonium,
and high total dissolved solids
(TDS) levels, Yellow Quill decided to
proceed with piloting treatment
processes which could treat the source
water to drinking water quality.
Conventional technologies, such as
manganese greensand filtration, were
ineffective. While some other technologies,
such as ozonation, were
promising, the floc generated by
ozonation resulted in short filter runs.
The biological filtration was attractive;
however, the low temperature of the
well water, only 6°C, would impact
treatment efficiency. However, the
integrated biological reverse osmosis
treatment system offered promise for
removing iron, arsenic, biologically
available carbon, and transforming
ammonium to nitrate.
Pilot testing showed that, despite
low temperatures, the biological activity
in the filters was very high. The
biologically stable water produced
generated low biological and low
organic fouling of the membranes in
the final treatment of the water.
The bio-membrane process has a
number of advantages. No chemicals
are used for the biological process,
which takes advantage of naturally
occurring microorganisms to remove
contaminants from the water. A small
amount of chemicals is required for the
membrane process. The process
accommodates long filter runs before
backwashing is required and uses 15-
20 times less water compared to manganese
greensand filtration. The biological
material can withstand large
variations in pressure. The process
delivers high quality water, which
allows the membranes to run 24 hours
per day, 7 days a week without membrane
“relaxation” and membrane
cleaning. Higher membrane recoveries
are also possible using this process.
Thus, treatment can be relatively inexpensive
as the filtration material will
last for more than 10 years and there is
no need for coagulation or pre-oxidation
chemicals.
Commissioned in the Fall of 2003,
the plant meets both current and future
Canadian Drinking Water Quality
Guidelines. Operation of the bio-membrane
treatment process is stable and
robust.
The success of bio-membrane filtration
in treating this low temperature
groundwater bodes well for applying
biological treatment to poor quality
groundwater sources elsewhere. Currently,
Associated Engineering and
WateResearch Corp. are applying this
process technology at a water treatment
plant retrofit for the Pasqua First
Nation in Saskatchewan.
The Consulting Engineers of
Saskatchewan recently presented the
project team with Awards of
Excellence for technology innovation
and infrastructure for their work on the
Yellow Quill plant.
Dan Hogan, P.Eng. is a Senior Civil
Engineer with Associated Engineering.
Contact e-mail: Hogan@ae.ca.
Hans Peterson, Ph.D. is President of
WateResearch.
Contact e-mail: hanspeterson@sasktel.net.
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