The city where I live estimates that we lose somewhere between 25% and 30% of drinkable water to leaky infrastructure.
We've had something close to a drought this summer -- unseasonally long periods without rain. You can see the young trees on the streets and trees in the middle of large parks suffer from it - wilted leaves and leaves dropping earlier than usual. BUT, large old trees seem to be thriving - full canopies, lush, firm leaves.
I've been suspecting the big street trees do so well because they benefit from the dilapidated state of our water delivery infra. It's nice to read of a study that confirms my amateur observations and musings.
Older, bigger plants have roots that go deeper and have access to more water. You can see the same effect in gardens, where new plants wilt sooner than established plants (and the care instructions advise frequent watering for the first couple of weeks).
That’s really high. There’s either a big problem in your city, or they are making generous estimates to justify asking for more capital. 10-15% is more typical.
In my region, the street trees are usually getting sewer water. Residential service in older houses are usually clay pipes with lead solder that the tree infiltrates. It’s not a problem until the clay pops and roots clog it.
It varies a lot by region and jurisdiction. One of the cities near me made the mistake of using riveted pipe from rolled steel to save money 75 years ago, and regularly has catastrophic main breaks as the rivets aren’t as robust as a regular pipe.
OP numbers aren’t only a city problem, IIRC [0] the numbers are close here in France. There’s a startup that try to tackle it : www.leakmited.com/en I applied there 3 month ago and they never responded. Can’t blame them but I’m a bit sad: it’s the dream impact-job.
Here in Germany, we estimate sewer infrastructure to last anywhere from 50-100 years, and water mains around 50-ish years. After that, it needs replacement or, that's the modern thing but it's a one-trick pony, re-lining.
The prudent thing would be to set aside and invest a tiny bit of money every year to fund a replacement, but unfortunately modern economic theory ("run lean") and manufactured income crises (aka, politicians going for lower taxes and utility rates) have led to a lot of infrastructure being utterly dilapidated and no savings left, and now we need to invest untold billions of euros raised from debt to keep it running.
Unfortunately, a lot of the deciders are already dead, and for those that still live, it's fallen out of favor to hold them accountable.
Not only trees in cities do that. A lot of clogged home sewers are caused by trees that wanted more to drink. Once the sewer line is fully blocked, they've arrived in paradise. Now there is a constant supply in the permanently filled sewer line.
Or at least, constant supply for the several hours it will take to call a rooter company and clear the drain line. Ironically, the tree would have better results if it only partly blocked the drain. I wonder if trees might ever evolve to strike that kind of balance, or if there's not enough selection pressure for that to happen.
I wonder how many of the pipes are made of wood. I forget the source, but I heard a decent number of pipes in Montreal are very old and made of wood (which is better than the proliferation of lead pipes that are still being removed)
We had a lemon tree that did this. The irrigation line connector was probably not 100% sealed and the roots grew to it slowly broke it. It enabled the lemon tree to gets lots of water and grow. Meanwhile the trees further down the irrigation line suffered.
Same happened to me with a hackberry I didn't know was wild. Some genius added landscaping to make it look like a choice. You got off easy, I think after all was said and done I paid about the same out of pocket, but also was displaced for a long time due to the damages, and it cost insurance another $80+ grand that I'm sure I'll pay back over time in raised premiums.
> Maple trees need to consume around 50 litres of water per day. Since street trees can’t get much of this from rainwater, which falls on concrete and drains into the city’s sewers, Poirier says the most likely explanation is that it is coming from Montreal’s leaky pipes, which lose 500 million litres of water per day.
>The spelling lede (/ˈliːd/, from Early Modern English) is also used in American English, originally to avoid confusion with the printing press type formerly made from the metal lead or the related typographical term "leading".
Do we really want that? Thousands of people are being killed each year by heat strokes. Keeping those trees alive by its environmental services is much more valuable in terms of lives and also energy saved. Maples have soft big leaves but also reduce the asphalt temperature by 5-10 degrees. If required just plant a tree species that can live with less water.
Why should anything be done to reduce leakage? They take water out of the St Lawrence and, as much isn't diverted by trees, it goes back in (cleaner then when it came out.)
> While the park trees contained lead isotopes normally associated with air pollution, the street trees had isotopes found in lead water pipes, which were made with metal from geologically old deposits in nearby mines.
I don't understand this part. We didn't use different sources of lead to make leaded gas and lead pipes, no?
Tetraethyllead production was very centralized by Ethyl corp/DuPont and required a higher purity lead ore so their isotope ratios are very well known based on the deposits that they mined. More locally sourced lead used for construction will have different isotope ratios.
When you need a lot of lead (enough to build plumbing for a neighborhood), you probably want to source it locally. When "1 part TEL to 1300 parts gasoline by weight is sufficient to suppress detonation",[1] you can source the lead from just about anywhere and ship it with the fuel.
We didn't put elemental lead in gasoline, it was a very different molecule with a single lead atom. Given how dense lead is, you want to source it from as physically close as you can. A foundry making pipes in a city with a lead mine nearby will obviously use the local lead.
For gasoline, all production had to be centralized in a few refineries. The lead would have been shipped in, and would have been largely the same quality and age, likely coming from the same mine, or geographically close mines. Plus the absolute quantity of lead added to gasoline is relatively small. In the 60 years the US used TEL, we processed about 8 million tons of lead. Averaged out, it's 133 thousand tons a year. It would only take a few mines to provide that much. Probably not more than five or ten, but I can't immediately find good data on this.
One would expect that the lead used in gasoline is pretty homogeneous across time, and that intensive lead use (as in casting into solid metal object like pipes) would use the nearest available source, and use that source for as long as possible.
Heh. Yesterday, we had a plumber over who told us we have to rebore our sewage pipes because roots got in. It is an old house with cast iron pipes and they still got in.
I've never heard it called "reboring" - wonder if there is a different procedure for when it gets really bad, but I'd have thought problems (backup) would happen pretty quickly, so wouldn't be too bad as long as you take care of it.
They basically use something like a weed whacker fed down the pipe, except it uses a short bit of chain instead of trimmer line, and will pulverise any intruding roots.
there is a new to me datum in that trees along residential streets are experiencing less water stress than trees in parks, due to city water leakage that was demonstrated by doing core samples on the trees to show how lead isotopes differed in the two populations of trees.
it highlights a growing concern with water in general and how carefull water monitering and management is becoming, and how what was primarily interesting to civil engineering types, has a wider audience
Readit News
We've had something close to a drought this summer -- unseasonally long periods without rain. You can see the young trees on the streets and trees in the middle of large parks suffer from it - wilted leaves and leaves dropping earlier than usual. BUT, large old trees seem to be thriving - full canopies, lush, firm leaves.
I've been suspecting the big street trees do so well because they benefit from the dilapidated state of our water delivery infra. It's nice to read of a study that confirms my amateur observations and musings.
In my region, the street trees are usually getting sewer water. Residential service in older houses are usually clay pipes with lead solder that the tree infiltrates. It’s not a problem until the clay pops and roots clog it.
It varies a lot by region and jurisdiction. One of the cities near me made the mistake of using riveted pipe from rolled steel to save money 75 years ago, and regularly has catastrophic main breaks as the rivets aren’t as robust as a regular pipe.
[0] 20% apparently https://www.eaufrance.fr/repere-rendement-des-reseaux-deau-p...
I believe some of the plumbing was wood pipes in select very busy parts of the city until somewhat recently, as it was a nightmare to replace.
https://www.marketplace.org/story/2024/05/27/mexico-city-wat...
The prudent thing would be to set aside and invest a tiny bit of money every year to fund a replacement, but unfortunately modern economic theory ("run lean") and manufactured income crises (aka, politicians going for lower taxes and utility rates) have led to a lot of infrastructure being utterly dilapidated and no savings left, and now we need to invest untold billions of euros raised from debt to keep it running.
Unfortunately, a lot of the deciders are already dead, and for those that still live, it's fallen out of favor to hold them accountable.
Fun!
I feel like this is burying the lede.
What can be done to reduce leakage?
>The spelling lede (/ˈliːd/, from Early Modern English) is also used in American English, originally to avoid confusion with the printing press type formerly made from the metal lead or the related typographical term "leading".
https://en.wikipedia.org/wiki/News_style#Lead
Do we really want that? Thousands of people are being killed each year by heat strokes. Keeping those trees alive by its environmental services is much more valuable in terms of lives and also energy saved. Maples have soft big leaves but also reduce the asphalt temperature by 5-10 degrees. If required just plant a tree species that can live with less water.
I don't understand this part. We didn't use different sources of lead to make leaded gas and lead pipes, no?
1: https://en.m.wikipedia.org/wiki/Tetraethyllead
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For gasoline, all production had to be centralized in a few refineries. The lead would have been shipped in, and would have been largely the same quality and age, likely coming from the same mine, or geographically close mines. Plus the absolute quantity of lead added to gasoline is relatively small. In the 60 years the US used TEL, we processed about 8 million tons of lead. Averaged out, it's 133 thousand tons a year. It would only take a few mines to provide that much. Probably not more than five or ten, but I can't immediately find good data on this.
One would expect that the lead used in gasoline is pretty homogeneous across time, and that intensive lead use (as in casting into solid metal object like pipes) would use the nearest available source, and use that source for as long as possible.
Plastic either is impervious or completely fucked.
They basically use something like a weed whacker fed down the pipe, except it uses a short bit of chain instead of trimmer line, and will pulverise any intruding roots.
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