No discussions about development in Hudson, Rigaud and St. Lazare should exclude the impact on the water table supplying our drinking water.
A study released in June 2015 found that precipitation falling on Rigaud Mountain and the Hudson and St. Lazare plateaus represents 41% of the total replenishment of the Vaudreuil-Soulanges aquifer, the water table supplying drinking water to more than 100,000 Vaudreuil-Soulanges residents. (FYI, St. Lazare is the largest municipality in Quebec entirely dependent on well water.)
The chief concern expressed in the Programme d’acquisition de connaissances sur les eaux souterraines (PACES) report is that the zones with the highest replenishment rate — Mont Rigaud, Hudson and St. Lazare — also happen to be the most vulnerable to contamination.
The study was carried out over a two-year period by a multidisciplinary team from the Université du Québec à Montréal, École Polytechnique and GéoMont, the agency mandated to map the Montérégie using satellite data. Their methodology and models are well explained and accessible to anyone with a scientific bent.
Here’s the PACES final report (en français seulement): rapport_final_paces_vaudreuil-soulanges
My English summary:
– About 105,000 Vaudreuil-Soulanges residents living in 18 municipalities get their drinking water from artesian wells. (The other 35,000 get their water from the Ottawa or St. Lawrence rivers.)
– Those 18 municipalities suck 11.2 million cubic metres of water a year from the underground water table, equivalent to a sheet of water 14 millimetres deep covering the entire 814-square-kilometre Vaudreuil-Soulanges MRC.
– St. Lazare is far and away the biggest consumer, averaging 2.8 million cubic metres a year, followed by Vaudreuil-Dorion at 2.1 million (VD draws most of its drinking water from the Ottawa River) and Rigaud, at 1.7 million.
– Hudson’s 5,400 residents come a surprising fourth, consuming 1,123,024 cubic metres a year.
– Our region consumes 20% more water than the Quebec average, with 56% going to residential, 33% for industrial/institutional and 11% for agriculture, most of that to grow sweet corn, a notoriously thirsty crop. (That 33% residential/industrial usage is misleading; this sector draws only 58 percent of its total consumption from public water networks because many have their own wells pulling from the same aquifer.)
– The aquifer is replenished by precipitation averaging just under 1,000 millimetres a year.
Two aspects of the study should be of particular interest to those concerned about water quality and quantity:
The PACES team found total dissolved mineral content in samples from more than 50 testing sites throughout Vaudreuil-Soulanges to be far higher than provincial norms (58.5%). Calcium is 34.8% higher; iron, 31% and sodium, 25%. But it’s the manganese level (30% higher than approved levels) that causes the team the most concern, so much so that it rates a mention in the introduction. The report quotes a 2011 Quebec study which linked higher manganese levels with lower IQs among young children. This was the reason behind Quebec’s decision to approve Hudson’s water filtration plant as part of the 2008 waterworks upgrade — so that manganese could be precipitated out of the water supply. On a positive note, our water has nitrate levels well below provincial norms.
The second aspect of the study deals with the rate at which the aquifer is being replenished, and from where. The aquifer beneath the southern half of the county lies beneath a thick layer of impermeable clay, making it what is classified as captive or semi-captive, relatively protected from contamination but slow to replenish. They get a sizeable percentage of their replenishment from the Glengarry hills of southeastern Ontario.
The researchers discovered the marshes, bogs, swamps and fens found in Hudson, Rigaud and St. Lazare are far more efficient in replenishing the aquifer, with 41 square kilometres of wetland and forested areas supplying 41 per cent of the Vaudreuil-Soulanges aquifer’s total replenishment. But because they’re better connected to the water table, any contamination is also more likely to find its way into the aquifer.
The PACES study went unnoticed when it was released last year, because there is no agency in Quebec with a clear mandate to protect underground water sources. Vaudreuil-Soulanges, like most regions of Quebec, has its Conseil de bassins versants (Rigaud’s Mayor Gruenwald is a former COBAVER-VS president and currently sits on the board) but the COBAVERs have no teeth.
In 2014 the provincial government adopted its Reglement sur le prélevement des eaux et leur protection, setting threshold levels for the risks of contamination of underground water sources, but there’s no indication the Ministry of Sustainable Development, Environment and the Battle Against Climate Change (I kid you not) is making our most precious resource a protection priority.
Call me madcap, but I’m thinking the three municipalities in Vaudreuil-Soulanges with the most to lose from contaminated water should make it a factor.
thousandlashesdotca 
We need a long term water plan to support our growth plans. Band-aid patches to our wells aren’t a solid plan. I agree we probably should start pumping from the Lake as part of that plan.
Water in Canada is generally treated as an almost free right. I’m shocked at Hudson’s total consumption for such a small population. I wonder how much is lost to leaks, I’ve heard the city of Montreal loses something like 40% to leaking mains and per km of road Hudson’s infrastructure is far older than St. Lazare’s for example.
There is much to be said about meters and charging for water as a way of conservation, but the capital and bureaucracy costs aren’t favourable for a small spread out town like Hudson. Many cities link sewer fees to water use as well.
As to manganese lowering IQ’s of children, I doubt there’s any solid evidence of that in Hudson and St. Lazare. We regularly turn out brilliant kids, a much higher than average percentage of doctors from some classes at the school formerly known as Hudson High as just one example. Early availability of pot probably does far more intellectual damage here than the manganese that used to be too high in our water.
I am happy to report that the Hudson water treatment changes have worked very well, no longer requires changes to hot water heater anodes and no smelly hot water if you don’t. We don’t run a water softener any more and change our whole house filters less frequently.
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Oh Peter, no more water softeners or filters, better smelly water, OH I”M SO ENVIOUS!!!!
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Peter, I believe I was told Hudson’s leakage loss is somewhere about 5% which is considered pretty low. I would agree to the use of the Jack Layton Park for a river supplied water filtration plant I’m just not sure there’ll be room with the new $12 million world class performing arts center slated for there by the strategic plan . Maybe dual purpose the center. Time for some brain storming. Let’s start a committee.
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Blessed are they who bring their sense of humour to every discussion. David, Brian, I apologize for having mislaid mine far too often.
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If you are a resident of Quebec a sense of humour is mandatory. As evidenced by some of your posts yours is still there just exercise it more often. Nice to see you back.
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$!2 Million world class performing arts center just doesn’t flow off the tongue.
Perhaps just call it Zamfir Hall? Boy did Zamfir stick his pan flute in the fan way back when?
5% leakage is low, if it’s correct we Hudsonites sure consume a lot of water per capita. Do the golf courses use town water for irrigation? Or do they have wells of their own?
We could surely fit the pumps into the basement of Zamfir Hall for an extra million or two, but perhaps we could go swim upstream, say Thomson Park area and kill the supply problems to that end of town once and for all and also pump up the hill into the existing network. Put a meter at the border of Rigaud and sell them water they’ll need.
In any case, Jim is correct that we will need lake water sooner or later.
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None of the golf courses are hooked into the Town water lines for irrigation. For the clubhouses , maybe. I think the Falcon is the biggest water user of all . I remember chatting with the construction manager when it was being built . Everything was molded into its final shape. I asked when they would put topsoil down. He laughed and said all we do is seed on the sand , throw down plenty of chemicals, and water the shit out of it from now to eternity. All sand up there. They made this gigantic lake on the 12th . They fill it all day from wells and empty it every night on the course. Without water that course would not survive one hot summer week. Basically it’s a desert underneath………………….I sure hope they can book Zamfir at the formerly named $12 million world class Hudson performing arts center in the Jack Layton Park. It’s been too long since I heard Strangers in the Night on the pan flute.
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Brian, implicit in your statements but maybe not obvious to everyone is that the water that fills that lake every day is in all likelihood coming from the same aquifer as town water. Same can be said for those people who decide to dig their own wells despite being on town water in order to circumvent restrictions about lawn watering during midsummer shortages. In both cases the vast majority of that water is probably lost to evaporation. The Tragedy of the Commons.
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Reblogged this on thousandlashesdotca and commented:
This was first published last February. I’m hoping Hudson residents will develop a sense of urgency on this issue. Maybe when their toilets no longer flush…
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