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WHAT'S THE STORY ON LEAD
IN YOUR DRINKING WATER?
INTRODUCTION
As
part of the City of Portage la Prairie’s ongoing drinking water review
program and the continuing effort to ensure the City’s treated water
meets current treatment standards, the City undertook testing of tap
water at a few homes. Based on the test results of these few samples
taken in September and November, 1999 and February, 2000, it has been
determined that lead concentrations in tap water at homes with lead
service connections is higher than the Canadian Drinking Water
Guidelines maximum acceptable concentration (MAC) of 0.010 mg/l
(10ppb), after extended periods of non-use.
Lead is a common element found throughout the environment. The primary
concern of health scientists related to low level exposure to lead is
its potential impact on children, possibly resulting in small changes
in intelligence, behavior and performance. Over the years lead levels
can build up in the human body with continued exposure and this is
considered unhealthy. Drinking water is a minor source of lead which
contributes 5-10% of a person’s total lead intake. Major sources of
lead include discharges to air which affect food, dust, and soil; lead
based paints; and certain types of glazes used on porcelain and
pottery.
LEAD IN DRINKING WATER
Portage la Prairie’s raw water supply originates from the Assiniboine
River which contains very low, nearly undetectable levels of lead. The
treated water leaving the water treatment plant also has extremely low
concentrations of lead. Lead dissolves into drinking water after it
comes in contact with plumbing materials having lead in them. The
longer the water stands in the plumbing system, the more lead that can
dissolve into it.
Materials contributing to lead in water from water plumbing systems
are:
WHAT'S BEEN DONE?
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Health Canada reduced the National
Guideline for lead in drinking water from 30 to 10 parts per billion
based on a flushed sample.
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The Province of Manitoba banned the use
of lead solder for drinking water plumbing systems in 1989 and follows
the new National Guideline.
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The City of Portage la Prairie has
initiated testing and studies on lead in drinking water.
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As a result of the testing, the City
notified Manitoba Health officials and is working on developing plans
to deal with the issue of lead in water from lead service connections.
THE PORTAGE LA PRAIRIE SITUATION
LEAD WATER CONDITIONS
Water connections are the pipes that carry water from watermains to
individual residences. In the City of Portage la Prairie, there could
be up to 1000 lead water connections in older parts of the city. This
is about 15% of the total number of connections in the city. Your
residence will likely not have a lead water connection if it was built
in the 1950’s or later. You can check your service line on the
incoming side of the water meter. Lead service lines are grey in
color. Newer service lines are copper. If the line is painted, the
paint can be removed with a knife. Scratched lead will appear silver
in color.
ACCEPTABLE LEAD LEVELS
Lead above 10 parts per billion is normally found in water which has
been standing for some time in the plumbing system of homes with lead
water service connections. Once the lines in a home and the service
line have been flushed by opening a tap, the level of lead decreases
significantly.
For the homes with lead water service connections, flushing for two to
five minutes will lower the lead levels in drinking water but levels
might remain above the maximum acceptable guideline limits of 10 parts
per billion, especially during warmer months of the year.
COPPER SERVICE LINES
From preliminary testing in Portage la Prairie, lead solder in copper
water pipes does not appear to result in significant levels of lead in
tap water. Flushing the system for a short period of about 30 seconds
(4 to10 liters) after extended periods of non-use will reduce lead
concentrations to very low levels, well within the Canadian Drinking
Water Guidelines. If your home was constructed after 1989, it should
not contain lead based solder.
Lead in drinking water is not unique to Portage la Prairie. Many
cities in North America and Manitoba, including Winnipeg, also
experience lead in their drinking water.
HEALTH EFFECTS
Customers need not be unduly concerned about lead in their water,
since precautions can be taken to minimize the risk. Manitoba Health
Officials have been advised of the test results and have reviewed the
Portage la Prairie situation regarding lead in drinking water and the
potential effect on health. For most homes, average lead levels found
in drinking water after letting the water run will not have adverse
health effects. However, for those homes with lead water service
connections, there may be some concern about the health effects on
small children. The City and Manitoba Health advise consumers wishing
to minimize lead intake to not drink tap water that has been standing
in the plumbing system for a long time.
TIPS FOR REDUCE LEAD CONSUMPTIONS AND CONSERVE WATER
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Avoid drinking water that has been
standing in the water plumbing system for long periods of time, such
as overnight or the workday.
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"Flush" your tap water before drinking
or cooking by letting it run until it is cold. A practical way of
flushing the water plumbing system without wasting water is by using
the toilet or taking a shower first.
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Once the water piping has been flushed,
fill a container with drinking water and keep it in the fridge. Water
flushed from the water plumbing system should not be wasted – collect
it and use it for washing dishes or watering plants.
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Avoid drinking or cooking with water
from the hot-water tap. If you need hot water for drinking, use water
from the cold tap and heat it.
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Do not use lead solder (commonly
displayed as 60/40 or 50/50 solder) on plumbing systems for drinking
water.
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If you have a lead service connection,
consider the use of a commercially available in-line or jug-type
carbon filter for drinking water. When used properly, these filters
will reduce lead concentration to acceptable levels.
WHAT IS PORTAGE LA PRAIRIE DOING?
The City is continuing to investigate the various possible control
measures for reducing lead in drinking water.
The City of Portage la Prairie currently monitors the
"stability" of its treated water and makes treatment adjustments to
minimize the corrosiveness, or tendency to dissolve lead into the
water. However, due to the nature of the City’s water, it is slightly
corrosive at certain times of the year.
Another possibility to reduce lead is the replacement
of the lead water service connection. If you have a lead water service
connection, you may choose to have it replaced. The City is
responsible for the water connection between the watermain and the
curb stop valve at the property line. The property owner is
responsible for the water connection from that point to the house. If
the City is making an excavated water pipe repair, the City will
replace the lead connection for which it is responsible. You will be
advised when this work is being done. You may save some money by
having your portion of the connection replaced at the same time. To do
this work, you must hire a plumbing contractor licensed by the City.
Alternate chemical treatment strategies can be used
which are costly but there are a number of potential benefits that may
balance out the costs. The City of Portage la Prairie is currently
continuing with research and evaluation of these control methods. More
information on the results of the City’s research will be available by
November, 2000.
For more information, contact the City of Portage la
Prairie Operations Department at 239-8346.
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