By Suchit Kaila,Ahron Nahmias, P.Eng. and Maggie Patterson,MSc.F.
Although waterborne disease
outbreaks are uncommon in
Canadian towns and cities,
the tragic occurrence of
sickness and death due to waterborne
pathogens in Walkerton, Ontario, and
North Battleford, Saskatchewan, have
refocused Canadians on the importance
of our water.
Skid-mounted filtration and UV system, rated for 60 GPM manufactured for the Manorview WTP.
Ontario’s response to these events
has culminated in the current Drinking
Water Systems Regulation (Regulation
170/03). Although this regulation is
currently being revised, its impact has
already had a major effect on small
water systems that use a surface water
source or groundwater source under
the direct influence of surface water.
Because the monitoring and reporting
requirements are difficult for small
sites without full-time trained staff,
pre-packaged treatment, monitoring
and reporting systems offer a solution
to what might otherwise be an intensively
manual water system operation.
Metcon Sales & Engineering
Limited realized the need for effective
water treatment with efficient remote
monitoring. This led to the development
of pre-engineered packaged
water treatment systems which meet
the filtration and disinfection requirements
of the Ministry of Environment
(MOE), monitor and record turbidity,
chlorine residual, pH, UV, distribution
flows and are compatible for remote
site monitoring without needing certified
personnel to visit the site regularly
to collect and record data and prepare
reports.
Pilot studies were conducted at various
sites with varied influent water
quality parameters, including high levels
of iron and manganese, to design a
packaged system that could address all
concerns and provide an efficient,
unmanned and fail-safe solution to
produce safe drinking water.
The Metcon Packaged Filtration
System filters and disinfects water. It
continually monitors treated water turbidity,
free chlorine residual, pH, UV,
distribution flows and tank levels, and
records these values for reporting
requirements. It will shut water flow
off and activate an alarm circuit if it is
not able to treat the water to drinking
water standards.
The system is designed to treat a
surface water source or a groundwater
source under the direct influence of
surface water to the MOE standards. It
is not designed to treat brackish water
or water with unacceptable levels of
chemical or mineral contamination.
The system is designed and engineered
by integrating different equipment
and technologies into a single
package and developing integrated
solutions for control, monitoring and
reporting. The system is made up of
the following equipment:
Chemical feed panel to dose coagulant
for chemically assisted filtration.
Media filters for particulate removal.
Absolute rated one micron filter cartridges.
UV disinfection system.
Online turbidimeter to measure turbidity.
Chemical feed panel for chlorination.
Online chlorine & pH monitor and
controller.
Videographic chart recorder.
Auto alarm dialer.
MRS software for remote monitoring
and reporting.
For sites where high levels of iron
and manganese are present, an additional
chemical feed panel to feed oxidant
is added to the system for oxidation
and precipitation of iron and manganese,
which are then filtered by
macrolite media filters. In some cases
granular activated carbon filter (GAC)
is also required after macrolite filter to
adsorb oxidant, colour, taste, and
odour. Where GAC is used, chlorination
is required before and after the filtration
system.
1. Chemical Feed System for
Coagulant – An engineered chemical
feed system with Surefeed controller
technology and ProMinent metering
pumps for duty standby operation. The
coagulant feed system is flow paced by
a signal from the flowmeter.
2. Macrolite Media Filter – When
fine pre-filtration is critical, this innovative
ceramic media is used to remove
particles as small as three microns. It
normally requires no conventional pre-treatment
such as coagulation or flocculation
to remove particles. This special
media effectively removes particles
such as clay, silt, oxidized iron and
manganese, dead microorganisms and
precipitates from other treatment
processes. The Macrolite Media Filter
System features metered and ondemand
control, adjustable backwash
times to accommodate changing inlet
water characteristics. Effective filtering
capability assures continuous, high
quality, filtered water and the compact
media beds require less water for backwash.
3. Absolute Rated One-Micron
Cartridge Filter – The Harmsco
POLY-PLEAT absolute one-micron
rated filter cartridge meets or exceeds
the three logs (99.9%) removal
requirements described in NSF
Standard 53 for cyst sized particles and
is ideal to control cryptosporidium,
giardia cysts and other harmful
microorganisms to help ensure cystfree
drinking water. These cartridges
are ideal as final filters for municipal
water filtration and provide long filter
life due to their pleated design and
increased surface area. The filter materials
are FDA listed for use in potable
water and the filters themselves are
certified to ANSI/NSF 61 standards
for use in potable water.
4. UV Disinfection Systems – The
UV reactor meets the minimum 40
mJ/cm2 (40,000 µwsec/cm2) treatment
requirement, in addition to being a
NSF/ANSI Standard 55–Class A system
which is designed to disinfect
and/or remove microorganisms from
contaminated water, including bacteria
and viruses, to a safe level.
5. Online Turbidity Monitor – The
H.F. Scientific MicroToL on-line turbidity
monitor meets USEPA method
180.1 and ISO 7027 design and performance
criteria. It has a fast response
time and inexpensive calibration due
to low sample volume. The unit has
removable sample cuvettes to allow for
easy cleaning and calibrating.
6. Chemical Feed System for
Chlorine – An engineered chemical
feed system with Surefeed controller
technology and ProMinent metering
pumps for duty standby operation. The
chlorine feed system is proportionally
paced by both flow and chlorine residual
(using the chlorine analyser/controller),
allowing tight control over the
chlorine residual which has the added advantage of minimizing chemical
usage for operational cost savings. The
system incorporates a pause contact, to
freeze the control signal when the well
pump is off.
7. Online Chlorine Monitor and
Controller – The ProMinent Dulcometer
Chlorine Residual Analyser is an amperometric
type analyser with a membrane-covered
probe. It has many features,
which makes it the most preferred instrument in the industry. The measuring
probe is reagent less and buffer less, thus
there are no operational costs associated
with chemicals usage. The only consumables
are the electrolyte and cap which
are replaced approximately every 9-12
months. The chlorine measurement is
both pH and temperature compensated to
ensure the chlorine residual is as accurate
as possible.
8. Videographic Chart Recorder –
Monitors and records treated water
parameters like free chlorine residual,
pH, treated water turbidity, UV intensity
distribution flows, and tank levels.
An optional Ethernet modem can be
added as built in with the data logger
so that all data can be remotely monitored
and downloaded to generate
reports through MRS software from a
remote location.
9. Auto Alarm Dialer –The Metcon
EchoDial is an automatic alarm dialer,
which notifies personnel in the event
of a process alarm. The EchoDial
allows for up to 96 analog or dry contact
inputs and 16 different phone
numbers to be programmed. The user
recordable alarm message allows
instant identification of the location
and cause of an alarm. The EchoDial
has a sophisticated lightning and surge protection system, containing three
levels of protection. The unit also has a
line seizure feature, which will interrupt
a phone conversation, or an off the
hook phone in order to call out, ensuring
that you always know the potential
problems in your system.
10. Automatic Reporting Software –
MRS (Metcon Reporting System)
Software is the solution for remote
data collection and report generation of data collected from the videographic
chart recorder. MRS simplifies the
repetitive tasks of data collection,
archiving and report formatting. It
contains a set of reports tailored to
solve the large reporting requirements
for the water industry.
The software is installed on the
user’s computer and is configured to
collect data for field recorders either
by modem or manual upload via card
reader. MRS uses a secure, robust and
structured SQL database format. This
allows Crystal Reports to present data
in a professional and meaningful manner.
The base software is supplied with
a selection of reports for chlorine, turbidity,
and flow. MRS generates suitable
graphical and tabular reports for
flow, chlorine, turbidity, and UV monitoring.
Summary details and summary
reports are available to the user.
Reports generated by MRS can be
exported for further analysis with
Microsoft Excel and other spreadsheet
programs.
In Ontario, for those water systems
that have no history of problems with
their groundwater, and are not under
the influence of surface water, it is
expected that the treatment and reporting
requirements may be more relaxed
under the upcoming Regulation 170.
However, the risk associated with
drinking untreated water that has not
been adequately filtered through the
ground, means that for those sites that
use surface water or groundwater
under the direct influence of surface water, full treatment and reporting will
likely remain part of the regime. Hence
the demand for a user-friendly prepackaged
solution for small water systems
is here to stay.
Suchit Kaila, Ahron Nahmias and
Maggie Patterson
are with Metcon Sales &
Engineering Limited.
Contact: ahron@metconeng.com
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