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Speaker 1: Welcome to text, a production from I Heart Radio. Hey there,

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Speaker 1: and welcome to tech Stuff. I'm your host, Jonathan Strickland.

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Speaker 1: I'm an executive producer with I Heart Radio, and I

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Speaker 1: love all things tech, and I don't think there is

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Speaker 1: a more trite or obvious way to start an episode

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Speaker 1: this year than by saying, twenty has been a tough year.

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Speaker 1: And I'm not going to go through the list of

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Speaker 1: all the things that have been tough, because all of

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Speaker 1: you listening are aware of most, if not all, of

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Speaker 1: those reasons. However, one of the things, a very localized

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Speaker 1: thing that hit my neighborhood in Atlanta was a massive

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Speaker 1: water main break. It actually happened along the border of

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Speaker 1: the Georgia Tech Campus, which is, by the way, not

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Speaker 1: close to where I live, but it is in the city.

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Speaker 1: And that break meant that thousands of homes, including mine,

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Speaker 1: lost water pressure, and it took quite a while before

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Speaker 1: water pressure was restored, and even then we were all

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Speaker 1: on a boil water advisory for several days. So in

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Speaker 1: this episode, I thought maybe we could talk about the

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Speaker 1: different technologies we use to supply homes with water, from

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Speaker 1: personal or community wells to large municipal systems and why

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Speaker 1: that boil water advisory was necessary in the first place,

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Speaker 1: and we'll get to all of that. It's a lot

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Speaker 1: of interesting tech and and ways that we have come

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Speaker 1: up with clever solutions to the issue of getting water

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Speaker 1: to people. Let's begin with just some basic facts about water.

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Speaker 1: This is like elementary school level stuff. So on our planet,

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Speaker 1: it's the only stuff you can find occurring naturally in

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Speaker 1: three of the four states of matter that would be

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Speaker 1: solid or ice, liquid you know, water and gas or

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Speaker 1: water vapor. You don't tend to find it occurring as plasma,

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Speaker 1: the fourth form. It's more dense as a liquid than

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Speaker 1: it is when it is a solid, which is why

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Speaker 1: ice will float in a glass of water. The Earth

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Speaker 1: has a water cycle that is pretty much self contained.

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Speaker 1: You know, we aren't really losing water out to space

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Speaker 1: beyond some relatively tiny amounts here and there in some

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Speaker 1: very specific circumstances, like if we send water up with

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Speaker 1: astronauts and some of that water gets vented out into space, yeah,

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Speaker 1: that's gone. But the stuff that is here is staying here.

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Speaker 1: The water cycle is one that I'm sure you're all

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Speaker 1: familiar with. Liquid water evaporates into water, vapor, which goes

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Speaker 1: into the atmosphere where it will eventually condense and form

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Speaker 1: into clouds, and at high enough concentrations with seed particles

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Speaker 1: in those clouds, droplets will form until they're big and

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Speaker 1: heavy enough to fall back to Earth as rain or snow.

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Speaker 1: In addition liquid water, it can run across the land.

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Speaker 1: This is called runoff and into the ground. This is

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Speaker 1: called percolation and infiltration, and then eventually through the ground,

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Speaker 1: seeping down through the ground and becoming groundwater. Plants absorb

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Speaker 1: water in the ground through their roots, and then water

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Speaker 1: evaporates from the leaves of plants into the atmosphere, and

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Speaker 1: you get the picture. The water is changing form and

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Speaker 1: it's changing place, but it's not leaving the planet. So

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Speaker 1: when you hear about things like wasting water, well, it's

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Speaker 1: not that the water is going away permanently, but it

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Speaker 1: does mean that you are using up water that is

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Speaker 1: very important, and it takes a lot of treatment to

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Speaker 1: get that water back into a state where people can

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Speaker 1: make safe use of it again, so really it's not

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Speaker 1: so much of that water has gone away, as now

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Speaker 1: we have to do a whole lot of stuff to

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Speaker 1: that water in order to use it. Again, about of

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Speaker 1: all the water on Earth is in the oceans, and

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Speaker 1: that's just plain inconvenient. Ocean water is extremely salty, so

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Speaker 1: you can't drink it, you can't use it for irrigation

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Speaker 1: unless you put it through a desalination process, which essentially

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Speaker 1: means you're pulling the salt out of the water. But

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Speaker 1: we'll get into that in some other episode because that's

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Speaker 1: an entirely separate topic that requires a lot of discussion.

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Speaker 1: Plus I've I've kind of covered it in previous episodes anyway,

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Speaker 1: but only three of the water on Earth is freshwater,

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Speaker 1: and on some parts of the planet it's really hard

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Speaker 1: to come by. Wars are fought over the stuff, which

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Speaker 1: isn't a surprise because news flash, in case you weren't aware,

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Speaker 1: we need fresh water to survive. Generally speaking, the typical

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Speaker 1: human body is six water, and some oregans are much

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Speaker 1: higher in water content than others, like the lungs, which

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Speaker 1: are about water, so we can only go a few

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Speaker 1: days without water before we start to suffer some pretty

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Speaker 1: awful effects like death. Water can also carry with it

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Speaker 1: some dangerous stuff. Toxins can leach into water, so you

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Speaker 1: can have dissolved medals like lead. This has historically been

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Speaker 1: an enormous problem and continues to be a challenge to

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Speaker 1: this very day in the United States, a country that

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Speaker 1: arguably should have solutions in place to deal with this

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Speaker 1: sort of thing all the time. We've seen a crisis

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Speaker 1: that started really in two thousand fourteen in Flint, Michigan.

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Speaker 1: I'll get back to that story at the end of

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Speaker 1: this podcast, because it is an important crisis that should

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Speaker 1: have been handled or should have never happened in the

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Speaker 1: first place, and it's an example of a massive failure

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Speaker 1: in leadership because we do have the technology to deal

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Speaker 1: with this sort of stuff, so it comes down to

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Speaker 1: administration and sadly money. Anyway, water, even fresh water, isn't

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Speaker 1: necessarily inherently safe to drink. Water can carry toxins and pathogens,

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Speaker 1: and those can have a negative effect on us up

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Speaker 1: to and including death depending on the situation, and so

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Speaker 1: much of human history, particularly in the era of civilization,

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Speaker 1: has had a focus on how to gather water, to

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Speaker 1: store it, to distribute it, and how to treat it. Now,

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Speaker 1: early on humans seem to have managed fairly well without

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Speaker 1: massive problems related to water contamination. Now and then it

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Speaker 1: would happen but by and large, humans got pretty good

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Speaker 1: at avoiding water that wasn't safe to drink. Our senses

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Speaker 1: tell us things such as if the water smells bad

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Speaker 1: or tastes bad, that means it probably is bad. And

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Speaker 1: that brings up an interesting series of questions about how

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Speaker 1: we developed those reactions and senses. I mean, when you

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Speaker 1: encounter a bad smell, you know that it's a bad smell.

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Speaker 1: But why do our brains interpret it as bad? Why

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Speaker 1: do we have that negative reaction? What makes one smell

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Speaker 1: a good smell and another one a bad smell. But

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Speaker 1: to be fair, those questions and answers are all outside

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Speaker 1: the realm of tech stuff. I just find them fascinating.

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Speaker 1: In the early eras of human history, we were hunter

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Speaker 1: gatherers and nomads, and once we decided, you know, our

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Speaker 1: feet were done itching, we wanted to set up shop

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Speaker 1: and settle down. New challenges came about, not just regarding

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Speaker 1: access to clean, drinkable water, which got to be more

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Speaker 1: complicated as humans started to create larger and larger settlements,

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Speaker 1: but also what to do with the waste we were generating,

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Speaker 1: like the waste water. Contaminating drinking water with waste is

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Speaker 1: you know, gross, and a terrible problem to have. It

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Speaker 1: leads to awful outbreaks of illness. So humans had to

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Speaker 1: start figure out how to deal with all this once

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Speaker 1: they began to make permanent settlements and populations began to grow.

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Speaker 1: One of the important early techniques for humans, one used

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Speaker 1: to the present day, was all about digging a well.

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Speaker 1: And this was, you know, important if you didn't have

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Speaker 1: access immediately to some body of water like a lake

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Speaker 1: or river or stream. But it's a pretty straightforward process.

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Speaker 1: So I'm gonna be quick about the whole well digging thing.

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Speaker 1: So you got the ground right, and the ground is

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Speaker 1: made up of dirt and rocks and dinosaur bones and

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Speaker 1: zombies and you know that kind of stuff. The ground

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Speaker 1: in most places tends to be porous and permeable to water.

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Speaker 1: So as water falls as precipitation, you know, rain or snow,

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Speaker 1: and then either just goes into the ground or melts

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Speaker 1: and then goes into the ground. It moves down through

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Speaker 1: the soil and rocks. It takes up the space that

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Speaker 1: is in between particles and continues because of gravity, to

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Speaker 1: move downward. Now, some layers in the soil might be impermeable,

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Speaker 1: you know, the rocks are less porous. Maybe there's a

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Speaker 1: level of clay which is not terribly permeable to water,

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Speaker 1: so then water will start to saturate the layers that

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Speaker 1: are higher up from that impermeable one, it can't go lower,

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Speaker 1: so the water just kind of continues to accumulate and

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Speaker 1: saturate the porous ground, and it has nowhere else to go.

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Speaker 1: It can't really seep lower down. So if you were

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Speaker 1: to look at the ground in a cross section, the

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Speaker 1: top layers of dirt and rock would have some water content,

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Speaker 1: but not at a point where the ground is saturated.

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Speaker 1: At that level, water is essentially being held onto particles

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Speaker 1: through molecular attraction, and it's just kind of loosely held

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Speaker 1: to the surfaces of rock particles. But as you go lower,

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Speaker 1: you would find a greater concentration of water as the

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Speaker 1: rocky soil becomes saturated with the stuff, meaning all the

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Speaker 1: porous surfaces are full of groundwater. The top layer of

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Speaker 1: this saturated zone of rock is what we call the

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Speaker 1: water table. It is the top level of the saturated zone.

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Speaker 1: It's the upper layer of groundwater. And if you find

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Speaker 1: an area of groundwater that readily refills a hole, like

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Speaker 1: if you were to dig a hole and you hit groundwater,

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Speaker 1: you take the water out, and more water comes in.

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Speaker 1: You have found an aquifer. Aquifers are store houses for water.

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Speaker 1: Aquifers get refilled or recharged when precipitation hits the ground

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Speaker 1: and water soaks into the soil and gradually makes its

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Speaker 1: way down to this layer again, so it's constantly being refilled,

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Speaker 1: or maybe not constantly regularly being refilled. The water in

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Speaker 1: a well will start at around the same level of

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Speaker 1: the water table in general, So let's say that the

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Speaker 1: water table is ten feet down from the ground surface.

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Speaker 1: That means once you hit ten feet as you're digging

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Speaker 1: your well, you'll start to see water. You typically would

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Speaker 1: dig further down than that so that you would have

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Speaker 1: a reservoir of water, but if you were to remove

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Speaker 1: water from the well, it would continuously refill to that

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Speaker 1: you know, that same level ten feet down from the surface.

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Speaker 1: So if you locate an aquifer and you dig down

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Speaker 1: far enough and you you know, shore up the sides

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Speaker 1: of your hole so that it doesn't collapse in on itself,

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Speaker 1: then you've got yourself a well from which you can

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Speaker 1: draw water. Now, in the olden days, you would do

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Speaker 1: that with like a rope in a bucket, you would

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Speaker 1: lower the bucket down, fill it up in the water

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Speaker 1: than the well, and then pull the bucket back out.

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Speaker 1: And you do that on demand. These days we have

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Speaker 1: pumps and filters and stuff, and I'll get into those

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Speaker 1: more a bit later. And there's another case I should cover,

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Speaker 1: because it is a really cool thing. Some aquifers are confined. Now.

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Speaker 1: That means that these aquafers have layers of less porous

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Speaker 1: or impermeable rocks or soil, both below them and above them. So,

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Speaker 1: in other words, the water you can think of the

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Speaker 1: groundwater is flowing. It's flowing through the rocks and soil,

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Speaker 1: and sometimes this water flows into areas where the layer

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Speaker 1: above is impermeable. So the water didn't just seep straight down.

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Speaker 1: It seeped in from some other place, flowed into an

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Speaker 1: area where it no longer can move in an upward

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Speaker 1: direction as more water is coming in. So this water

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Speaker 1: is actually under pressure, you know, like the song by

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Speaker 1: Queen and David Bowie. But here's the things that water

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Speaker 1: doesn't compress. If you put pressure on water, then that

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Speaker 1: water is going to push outward in all directions. This

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Speaker 1: makes it different from a gas. You know, gas has

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Speaker 1: molecules where you can typically force them closer together, and

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Speaker 1: through pressurization you can compress a gas. You can't do

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Speaker 1: that with water. Applying pressure to water we can do

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Speaker 1: some pretty impressive things. That's what hydraulic systems are all about.

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Speaker 1: But let's get back to confined aquifers. So, because this

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Speaker 1: type of aquifer is under pressure and the water can't

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Speaker 1: escape that confined space due to those non porous rock layers,

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Speaker 1: if you drill a well down into that confined aquifer,

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Speaker 1: it allows the water an escape route and that result

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Speaker 1: in what is called an artesian well. The water in

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Speaker 1: an artesian well will rise above the water table line.

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Speaker 1: Because there's pressure on that water, it's going to start

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Speaker 1: to move up the well. Uh sometimes it will move

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Speaker 1: all the way up the well and come out of

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Speaker 1: the well entirely. So, if you've got yourself a confined

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Speaker 1: aquifer and you dig a well down to it, the

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Speaker 1: water can be under enough pressure underground to create a

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Speaker 1: constant flow up and out of the well. There are

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Speaker 1: a lot of springs that are fed this way. They

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Speaker 1: are pretty nifty, and there are a lot of people

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Speaker 1: who have pipes that extend down into the ground, and

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Speaker 1: there's no electric pump or anything working on those pipes.

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Speaker 1: The pipes actually go down into a confined aquifer. So

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Speaker 1: just opening up a valve allows that water and escape route,

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Speaker 1: and the pressure from the ground itself is pushing the

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Speaker 1: water out. And I also need to explain the difference

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Speaker 1: between a well and a cistern. A cistern a c

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Speaker 1: I s t e r in is a collect system

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Speaker 1: that collects rainwater rather than groundwater. So it's a container,

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Speaker 1: and sometimes it's one that's actually buried in the ground,

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Speaker 1: so that can potentially confuse you if you just were

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Speaker 1: to see one. But it's just there to collect the

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Speaker 1: runoff of rainwater that feeds in through rain showers, so

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Speaker 1: it doesn't pull groundwater up. You're just collecting rainwater before

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Speaker 1: it can go into the ground. So that's pretty straightforward.

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Speaker 1: Now I want to talk about the physics of getting

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Speaker 1: water out of a well and up to us. There

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Speaker 1: are a few ways to do this, and one is

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Speaker 1: one I mentioned already, a purely mechanical method to lower

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Speaker 1: a bucket down into the well and collect water and

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Speaker 1: then pull the bucket back out. A lot of classic

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Speaker 1: wells you know the kind of I think about when

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Speaker 1: I think of the word well. Have a simple pulley

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Speaker 1: system that allows you to lower a bucket down into

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Speaker 1: the well chamber and fill it up and then pull

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Speaker 1: the bucket back out. Pulleys are one of the simplest

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Speaker 1: of machines. A pulley is a wheel around which you

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Speaker 1: wrap a hope or wire, and the pulley just changes

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Speaker 1: the direction of the force you need to use to

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Speaker 1: do work. So instead of pulling straight up, you could

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Speaker 1: pull down. And typically pulling downward is easier to do

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Speaker 1: than pulling straight up, So while you're still lifting the

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Speaker 1: same amount of weight, it's easier work to do because

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Speaker 1: of the direction of the force you're applying. Now, if

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Speaker 1: you add more pulleys to a system, you can actually

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Speaker 1: create a mechanical advantage and that makes work easier. But

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Speaker 1: that is outside this episode. But what about something like handpumps.

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Speaker 1: You've likely seen this in movies or TV shows where

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Speaker 1: there's a hand pump for water. Maybe you've seen pictures

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Speaker 1: of one, maybe you've even used one. They tend to

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Speaker 1: look like a pipe that's sticking out of the ground

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Speaker 1: and it has a spout on one side where the

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Speaker 1: water comes out, and a pump handle on the other

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Speaker 1: that you pump up and down. So you give the

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Speaker 1: handle a few pumps and before long water starts coming

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Speaker 1: out of the spout. How does that work? This all

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Speaker 1: has to do with pressure and using the atmospheric pressure

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Speaker 1: to do work for us. So let's remember again, we're

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Speaker 1: all under pressure. At sea level. We're under an atmosphere

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Speaker 1: of pressure or about fourteen point seven pounds per square inch.

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Speaker 1: That's how much the atmosphere is pressing down on us

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Speaker 1: at sea level. If we can decrease the pressure that's

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Speaker 1: in a tube sticking down into the ground into ground water,

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Speaker 1: if we can reduce the air pressure inside that tube

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Speaker 1: by introducing a vacuum, water will move up that tube

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Speaker 1: because it's an area of lower pressure. It helps if

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Speaker 1: you think about the outside pressure, the atmospheric pressure as

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Speaker 1: pushing down on the water, and the lower pressure is

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Speaker 1: an escape route. So the water moves up the area

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Speaker 1: of lower pressure. So we think of it as you know, sucking,

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Speaker 1: but that's not really the case. Like like when you're

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Speaker 1: drinking from a straw, it's not that you're using suction

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Speaker 1: to draw the water up directly. You're reducing the air

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Speaker 1: pressure inside the straw, and the atmospheric pressure is forcing

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Speaker 1: liquid to go up the straw as a result. So

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Speaker 1: really to do this, all we need is a device

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Speaker 1: that can lower the pressure inside a tube that extends

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Speaker 1: down into the water in order to draw water up somehow.

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Speaker 1: But how do you do that If the tube you

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Speaker 1: have has a spout at the top right, if it's open,

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Speaker 1: then you can't create a vacuum because you have an

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Speaker 1: open path to the atmosphere. In general, the secret is

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Speaker 1: in a pair of valves and a piston that is

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Speaker 1: inside the pump. So if you could use Superman's powers

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Speaker 1: of X ray vision and look through a pump, you

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Speaker 1: would see that the handle connects to a reciprocating piston.

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Speaker 1: So this is a piston that moves up and down

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Speaker 1: inside the pump. But the base of this piston wouldn't

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Speaker 1: be like a solid fixed disc, you know, like the

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Speaker 1: piston you would find in a car engine. Instead, it's

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Speaker 1: a disc that's actually on a hinge. It's a valve.

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Speaker 1: So when you are forcing the piston downward, the disc

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Speaker 1: flips up because the pressure you're you're encountering is pushing

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Speaker 1: the disc up. The valve is open and the piston

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Speaker 1: is allowed to go down the shaft of this pipe.

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Speaker 1: When the piston starts moving up again, the disc flips

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Speaker 1: closed because again the pressure causes this to happen, and

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Speaker 1: that means that it is sealed everything that's underneath the piston.

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Speaker 1: And as the piston draws up, it starts to create

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Speaker 1: a vacuum. It's it's lowering the pressure inside the pipe.

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Speaker 1: So every time the piston comes up to the top

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Speaker 1: of its stroke and starts to move down again, the

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Speaker 1: valve opens and allows are to pass past it, and

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Speaker 1: as it gets to the bottom, it closes and creates suction.

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Speaker 1: It does this over and over and over again as

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Speaker 1: it starts to draw water upward. Now at the other

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Speaker 1: end of the pump leading down into the well, you

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Speaker 1: have a second valve. This is called the foot valve.

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Speaker 1: This one's very important because I just mentioned that when

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Speaker 1: the piston is going down, the piston valve opens. Well,

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Speaker 1: if that were all, if that was the only valve

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Speaker 1: in the system, then the water would just fall away

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Speaker 1: because you've just you know, allowed the air pressure to

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Speaker 1: equalize again. So the air pressure, the atmospheric pressure is

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Speaker 1: no longer pushing water up the pipe. So this foot

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Speaker 1: valve when the piston is coming down, is closed, so

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Speaker 1: it prevents water from going back down the pipe. And

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Speaker 1: when the piston is moving up again, when the piston

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Speaker 1: valve is closed, the foot valve opens, allowing access to

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Speaker 1: the water that's in the well. So it's these two

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Speaker 1: valves working together as the piston is moving up and

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Speaker 1: down that create the ability for the atmospheric pressure to

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00:20:09,640 --> 00:20:13,760
Speaker 1: push water down, pushing it up the pipe. So every

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00:20:13,800 --> 00:20:16,520
Speaker 1: time the piston completes its upward journey and switches direction,

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00:20:16,600 --> 00:20:20,160
Speaker 1: the piston valve opens, the foot valve closes, water moves

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Speaker 1: into the pump. It can't flow back down into the

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Speaker 1: well because then the foot valve closes. It keeps that

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Speaker 1: water steady, maintains the vacuum that's in place below the valve,

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Speaker 1: and then the piston valve opens, allowing the piston to

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Speaker 1: travel back down into the water that has collected inside

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Speaker 1: the pump. Then, as the piston begins to change direction

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Speaker 1: and move upward, the piston valve closes again that traps

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Speaker 1: the water above it. It essentially is like a bucket, right,

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Speaker 1: It has just trapped the water that had already entered

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Speaker 1: into the pump and it lifts it as the piston

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Speaker 1: moves up, So you essentially are using suction the same

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Speaker 1: way you would drink out of a glass, and then

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Speaker 1: at the very very end of it using kind of

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Speaker 1: a bucket method to pull the water up to the spout.

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Speaker 1: It's pretty nifty. Now, when we come back, I'll talk

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Speaker 1: about centrifugal pumps and then we'll move on to more

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Speaker 1: complicated means of getting water to people. But first let's

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Speaker 1: take a quick break. One thing I did not get

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Speaker 1: to when I was talking about handpumps a bit earlier

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Speaker 1: is that since it does work on decreasing the air

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Speaker 1: pressure in a tube and then relying on atmospheric pressure

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Speaker 1: to do some work and push the water up the tube,

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00:21:40,440 --> 00:21:43,399
Speaker 1: there's actually a limit to how far you can pump

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Speaker 1: water vertically. If you're depending on atmospheric pressure to force

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Speaker 1: water up a vertical distance of pipe, you can lift

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Speaker 1: water a maximum of ten point three meters, and that

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Speaker 1: is assuming you've got a perfect vacuum and that your

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Speaker 1: pump is at sea level, and you can ignore some

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Speaker 1: other realities of physics like friction and stuff. In practical terms,

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Speaker 1: it means that ten point three is something you're never

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Speaker 1: going to achieve. It's going to be more like seven

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Speaker 1: to eight meters of vertical space. That's how far you

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Speaker 1: can pump liquid. Because while this air pressure thing does work,

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Speaker 1: you can't just get rid of the concept of gravity.

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Speaker 1: Water has weight to it. So let's say you've dug

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Speaker 1: way down, like fifty feet down, and you finally hit

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Speaker 1: the water table and you install a hand pump, and

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Speaker 1: you pump that hand pump over and over again until

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Speaker 1: you're ready to collapse, but no water is coming out.

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00:22:38,200 --> 00:22:41,640
Speaker 1: So what's actually happening here. Well, while the pump lowers

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Speaker 1: the air pressure in the pipe leading down to the well,

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Speaker 1: and the atmospheric pressure is pushing against the water even

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00:22:48,200 --> 00:22:51,160
Speaker 1: as far down as fifty feet, it does cause water

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Speaker 1: to move up the pipe, but that water still has weight,

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00:22:54,200 --> 00:22:58,119
Speaker 1: and eventually, with enough verticality there, you've got enough water.

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00:22:58,320 --> 00:23:00,879
Speaker 1: The weight of the column of water or ends up

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00:23:00,920 --> 00:23:04,399
Speaker 1: being equal to the force that the air pressure is

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00:23:04,520 --> 00:23:07,240
Speaker 1: applying to that water, and it's not going to go

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00:23:07,320 --> 00:23:11,239
Speaker 1: any higher. Using this pumping method. It's kind of like

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00:23:11,280 --> 00:23:14,679
Speaker 1: a set of scales that achieves balance. Even if you

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00:23:14,680 --> 00:23:17,879
Speaker 1: could create a perfect vacuum, the water would not go

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00:23:18,080 --> 00:23:20,600
Speaker 1: as high as you need if it were fifty ft down.

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00:23:21,359 --> 00:23:25,400
Speaker 1: Centrifugal pumps work in a different way from hand pumps,

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00:23:25,400 --> 00:23:28,919
Speaker 1: but ultimately we'll have to deal with the same limitations

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00:23:28,920 --> 00:23:32,600
Speaker 1: of physics. So with a centrifugal pump, you've got a

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Speaker 1: pipe that leads down into the water. This is where

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00:23:35,680 --> 00:23:38,440
Speaker 1: water will enter the pump from the well, and it's

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00:23:38,480 --> 00:23:43,000
Speaker 1: called an inlet. It's pretty clever, right. There is a

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Speaker 1: valve at the end of that pipe that sits inside

400
00:23:46,400 --> 00:23:49,119
Speaker 1: the well itself, so it's submerged in the well water.

401
00:23:49,600 --> 00:23:52,280
Speaker 1: This is the foot valve. It allows the water to

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00:23:52,400 --> 00:23:55,880
Speaker 1: flow into the pipe, but prevents it from flowing back

403
00:23:55,920 --> 00:23:59,440
Speaker 1: out again. That is going to be important in order

404
00:23:59,520 --> 00:24:02,080
Speaker 1: to make this whole system work. So when the pump

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00:24:02,160 --> 00:24:05,919
Speaker 1: is on, the valve opens and the water can flow

406
00:24:06,160 --> 00:24:09,840
Speaker 1: from the well into the inlet. When the pump is off,

407
00:24:09,840 --> 00:24:13,120
Speaker 1: the valve closes and prevents any water that's already in

408
00:24:13,160 --> 00:24:17,200
Speaker 1: the pipe and the pump from draining back out again.

409
00:24:17,560 --> 00:24:21,399
Speaker 1: There's also a pipe that leads out from the pump.

410
00:24:21,600 --> 00:24:24,360
Speaker 1: This is where the water will flow out while you're

411
00:24:24,400 --> 00:24:27,959
Speaker 1: pumping it. It's the outlet and discharge nozzle. This is

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00:24:28,240 --> 00:24:30,960
Speaker 1: the part of the pump that leads into the plumbing

413
00:24:31,040 --> 00:24:34,280
Speaker 1: system of a house. The heart of the pump is

414
00:24:34,480 --> 00:24:38,840
Speaker 1: a circular or really actually a spiral shaped chamber called

415
00:24:38,880 --> 00:24:42,479
Speaker 1: the volute casing. And a volute is a spiral shape.

416
00:24:42,720 --> 00:24:46,640
Speaker 1: It increases in size as you go around. And so

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00:24:46,880 --> 00:24:49,479
Speaker 1: a volute casing looks a little bit like kind of

418
00:24:49,480 --> 00:24:53,120
Speaker 1: like a conk shell. And there's an electric motor that

419
00:24:53,200 --> 00:24:56,600
Speaker 1: connects to a rotating shaft, and that shaft connects to

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00:24:56,680 --> 00:25:00,240
Speaker 1: a device called an impeller, and that sits inside the

421
00:25:00,280 --> 00:25:04,959
Speaker 1: volute chamber. And impeller is designed to move fluid. And

422
00:25:05,000 --> 00:25:07,560
Speaker 1: it looks kind of like a water wheel in that

423
00:25:07,640 --> 00:25:09,760
Speaker 1: it is sort of wheel shaped, and it has these

424
00:25:09,760 --> 00:25:13,560
Speaker 1: sort of curved fins. They're actually called veins V A,

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00:25:13,960 --> 00:25:18,160
Speaker 1: N E S. And these veins push water. As the

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00:25:18,200 --> 00:25:22,679
Speaker 1: impeller rotates in a single direction, it forces water to

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00:25:22,840 --> 00:25:26,640
Speaker 1: follow the rotating path. As also an interesting note here,

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00:25:26,960 --> 00:25:30,000
Speaker 1: the curve fins look kind of like scoops, so you

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00:25:30,080 --> 00:25:33,760
Speaker 1: might first think they are scooping water, that they're forcing

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00:25:33,760 --> 00:25:36,480
Speaker 1: water out kind of like a paddle and pushing water

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00:25:36,560 --> 00:25:38,760
Speaker 1: that way, but in fact that's not what's happening. The

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00:25:38,880 --> 00:25:43,080
Speaker 1: rotating impeller is creating friction to cause a rotational motion

433
00:25:43,240 --> 00:25:47,000
Speaker 1: with the water, throwing it outward toward the edges of

434
00:25:47,040 --> 00:25:50,639
Speaker 1: the volute chamber. So the water is following the smoothest path,

435
00:25:51,080 --> 00:25:54,440
Speaker 1: and the fins actually curve away from the motion of rotation,

436
00:25:54,520 --> 00:25:57,200
Speaker 1: not towards the motion of rotation, so there's no scooping

437
00:25:57,240 --> 00:25:59,919
Speaker 1: going on with these things. So the water comes in

438
00:26:00,080 --> 00:26:03,320
Speaker 1: through the inlet towards the center of the impeller. It comes,

439
00:26:03,320 --> 00:26:05,679
Speaker 1: you know, kind of head on to the impeller, and

440
00:26:05,720 --> 00:26:08,439
Speaker 1: the motorized impeller pushes the water to the edge of

441
00:26:08,440 --> 00:26:11,960
Speaker 1: the volute casing through centrifugal force. The water in the

442
00:26:12,000 --> 00:26:16,320
Speaker 1: casing follows the curve of the spiral outward, so it

443
00:26:16,400 --> 00:26:19,320
Speaker 1: hits the wall and then just starts to move along

444
00:26:19,359 --> 00:26:23,320
Speaker 1: with the rotational force moving outward. The pressure increases as

445
00:26:23,359 --> 00:26:25,600
Speaker 1: a result of this, will get more into pressure in

446
00:26:25,600 --> 00:26:30,359
Speaker 1: a little bit and that eventually goes to the outlet

447
00:26:30,760 --> 00:26:34,359
Speaker 1: from the far end of the volute casing. There's also

448
00:26:34,440 --> 00:26:37,359
Speaker 1: usually a cut off that prevents the water from just

449
00:26:37,520 --> 00:26:41,520
Speaker 1: circulating in the casing over and over again. The diameter

450
00:26:41,680 --> 00:26:45,160
Speaker 1: of the impeller and the speed of the impeller's rotation

451
00:26:45,240 --> 00:26:47,320
Speaker 1: and the density of the fluid, because you know, these

452
00:26:47,320 --> 00:26:50,160
Speaker 1: centrifugal pumps are used to move all sorts of fluids around,

453
00:26:50,160 --> 00:26:53,720
Speaker 1: not just water. That determines how much force the pump

454
00:26:53,800 --> 00:26:56,920
Speaker 1: is imparting to whatever fluid it happens to be pumping.

455
00:26:57,840 --> 00:27:03,119
Speaker 1: This process creates the lower pressure inside the pipe, and

456
00:27:03,160 --> 00:27:05,920
Speaker 1: so while the centrifugal pump looks a lot different from

457
00:27:05,920 --> 00:27:09,040
Speaker 1: a hand pump, it's ultimately relying on the same force

458
00:27:09,119 --> 00:27:12,040
Speaker 1: to do a lot of the work that atmospheric pressure

459
00:27:12,080 --> 00:27:15,040
Speaker 1: on the water that's in the well. But the centrifugal

460
00:27:15,119 --> 00:27:18,440
Speaker 1: pump doesn't have the dual valve system that the hand

461
00:27:18,480 --> 00:27:22,480
Speaker 1: pumps have. So getting one going means that first you

462
00:27:22,520 --> 00:27:27,040
Speaker 1: have to prime the pump, and that means submerging the

463
00:27:27,240 --> 00:27:30,240
Speaker 1: entire system from the pump all the way down into

464
00:27:30,240 --> 00:27:32,480
Speaker 1: the well with water. So you've got to make sure

465
00:27:32,520 --> 00:27:35,800
Speaker 1: that there's water going through the pump all the way

466
00:27:35,840 --> 00:27:39,560
Speaker 1: down the line into the well before the pump can

467
00:27:39,600 --> 00:27:42,600
Speaker 1: start to pull water in. Uh. This is so that

468
00:27:42,800 --> 00:27:46,840
Speaker 1: it can create that vacuum for the lower pressure for

469
00:27:47,000 --> 00:27:50,159
Speaker 1: atmosphere pressure to push water. You know, to continuously feed

470
00:27:50,200 --> 00:27:54,439
Speaker 1: the pump and uh that valve at the foot of

471
00:27:54,480 --> 00:27:57,440
Speaker 1: the inlet pipe is what keeps the water from flowing

472
00:27:57,520 --> 00:28:00,199
Speaker 1: out into the well while you're trying to get this

473
00:28:00,280 --> 00:28:02,879
Speaker 1: to work. And if the supply of water to the

474
00:28:02,920 --> 00:28:07,440
Speaker 1: volut casing begins to diminish, you might introduce air bubbles,

475
00:28:07,480 --> 00:28:10,560
Speaker 1: and that is bad news. The air bubbles that can

476
00:28:10,600 --> 00:28:13,399
Speaker 1: travel to the impeller, they can collapse its speeds faster

477
00:28:13,520 --> 00:28:17,560
Speaker 1: than sound, and those implosions can damage the impeller. This

478
00:28:17,640 --> 00:28:21,640
Speaker 1: is called cavitation. It's really bad news for pumps. Similar

479
00:28:21,680 --> 00:28:24,880
Speaker 1: to the centrifugal pump is the jet pump. The jet

480
00:28:24,880 --> 00:28:28,440
Speaker 1: pump also uses an impeller, but otherwise it's a little

481
00:28:28,440 --> 00:28:33,119
Speaker 1: bit different in design. The impeller moves water called drive

482
00:28:33,359 --> 00:28:36,800
Speaker 1: water through a path in the pump that loops back

483
00:28:37,400 --> 00:28:40,800
Speaker 1: to point at the impeller. So UH, at the end

484
00:28:40,840 --> 00:28:44,800
Speaker 1: of this loop, the path that leads back to the impeller,

485
00:28:44,840 --> 00:28:49,040
Speaker 1: there's a narrow orifice, there's a jet and water can't

486
00:28:49,080 --> 00:28:52,360
Speaker 1: be compressed, right, So if it can't be compressed to

487
00:28:52,440 --> 00:28:55,600
Speaker 1: fit through this narrow path, then in order for the

488
00:28:55,600 --> 00:28:58,040
Speaker 1: water to move through it actually has to pick up speed.

489
00:28:59,080 --> 00:29:03,040
Speaker 1: As it picks up speed as velocity increases, pressure decreases.

490
00:29:04,000 --> 00:29:05,960
Speaker 1: This is kind of similar to if you have a

491
00:29:05,960 --> 00:29:08,160
Speaker 1: a hose and you put your thumb over the end

492
00:29:08,160 --> 00:29:12,160
Speaker 1: of the hose. You have UH increased the velocity of

493
00:29:12,200 --> 00:29:15,080
Speaker 1: the water coming out, but you've actually decreased the pressure.

494
00:29:16,000 --> 00:29:19,720
Speaker 1: But this whole process creates a vacuum that helps pull

495
00:29:19,880 --> 00:29:23,360
Speaker 1: more water from the well are As we've pointed out,

496
00:29:23,400 --> 00:29:25,520
Speaker 1: it doesn't really pull the water so much as it

497
00:29:25,840 --> 00:29:29,239
Speaker 1: decreases the pressure, so atmospheric pressure does the job on

498
00:29:29,320 --> 00:29:32,600
Speaker 1: the groundwater on the other side of the jet UH

499
00:29:32,880 --> 00:29:35,400
Speaker 1: is what is called a venturi tube. This is a

500
00:29:35,400 --> 00:29:39,040
Speaker 1: tube that increases in diameter, so it gets bigger on

501
00:29:39,080 --> 00:29:42,600
Speaker 1: the other side, and as diameter increases, the speed of

502
00:29:42,640 --> 00:29:45,240
Speaker 1: the water will decrease, but the pressure of the water

503
00:29:45,360 --> 00:29:49,240
Speaker 1: increases and the drive water and well water end up combining.

504
00:29:49,320 --> 00:29:51,920
Speaker 1: They are at a high enough pressure to pump into

505
00:29:51,960 --> 00:29:56,080
Speaker 1: the plumbing system. And this approach still is reliant on

506
00:29:56,200 --> 00:29:58,840
Speaker 1: that atmospheric pressure, so again it only works down to

507
00:29:58,880 --> 00:30:02,680
Speaker 1: a certain depth. But what happens if the water in

508
00:30:02,720 --> 00:30:05,560
Speaker 1: your area is at a lower level, If the water

509
00:30:05,640 --> 00:30:10,360
Speaker 1: table is further down than what you can achieve by

510
00:30:10,360 --> 00:30:14,640
Speaker 1: relying on atmospheric pressure well to pump water below that

511
00:30:14,800 --> 00:30:18,000
Speaker 1: ten point three meters, and again that's the ideal that

512
00:30:18,040 --> 00:30:21,320
Speaker 1: will never achieve. Engineers had to get really creative. There

513
00:30:21,360 --> 00:30:25,000
Speaker 1: are two pipe systems that do this. One pipe is

514
00:30:25,040 --> 00:30:28,280
Speaker 1: the inlet pipe. This is the one that will ultimately

515
00:30:28,360 --> 00:30:31,400
Speaker 1: draw water from the well and supply it to the

516
00:30:31,440 --> 00:30:34,240
Speaker 1: house or building that you're using. And there is a

517
00:30:34,240 --> 00:30:36,280
Speaker 1: foot valve at the end of this so again it

518
00:30:36,360 --> 00:30:41,040
Speaker 1: prevents water from escaping once it enters the pipe. And

519
00:30:41,080 --> 00:30:43,080
Speaker 1: this pipe goes all the way up to the pump

520
00:30:43,320 --> 00:30:46,640
Speaker 1: that is on the ground. It's it's not buried or anything.

521
00:30:46,640 --> 00:30:51,840
Speaker 1: It's right up there. And joining this pipe through a

522
00:30:51,880 --> 00:30:56,360
Speaker 1: special jet joint is a second pipe. This pipe comes

523
00:30:56,520 --> 00:30:59,240
Speaker 1: from the pump, So the second pipe comes out of

524
00:30:59,240 --> 00:31:02,040
Speaker 1: the pump, extend down into the ground to join the

525
00:31:02,080 --> 00:31:06,520
Speaker 1: inlet pipe through this jet joint a little further up

526
00:31:06,600 --> 00:31:11,440
Speaker 1: the pipe's length, and this joint is constructed so that

527
00:31:11,480 --> 00:31:14,960
Speaker 1: the jet is moving water from this second pipe to

528
00:31:15,160 --> 00:31:19,000
Speaker 1: shoot up the first pipe toward the direction of the pump.

529
00:31:19,120 --> 00:31:21,760
Speaker 1: So the jet is down inside the well in this

530
00:31:21,840 --> 00:31:24,240
Speaker 1: version of the pump, but the impeller is still up

531
00:31:24,240 --> 00:31:27,880
Speaker 1: at the pump on the ground. So what's happening is

532
00:31:28,080 --> 00:31:31,000
Speaker 1: both these pipes and the pump are full of water. Okay,

533
00:31:31,040 --> 00:31:34,479
Speaker 1: you've got a full system of water here. It's almost

534
00:31:34,560 --> 00:31:37,840
Speaker 1: like a closed system. It's not really closed because you know,

535
00:31:37,880 --> 00:31:39,840
Speaker 1: we have an outlet pipe with the pump, but let's

536
00:31:39,840 --> 00:31:43,160
Speaker 1: ignore that for now. When you turn on the pump,

537
00:31:43,640 --> 00:31:46,880
Speaker 1: the motor begins to spend the impeller, and the impeller

538
00:31:47,000 --> 00:31:51,840
Speaker 1: forces water down the second pipe, which then moves through

539
00:31:51,920 --> 00:31:55,720
Speaker 1: this jet before joining up with the first pipe, and

540
00:31:55,840 --> 00:31:58,080
Speaker 1: the water as it moves through the jet picks up

541
00:31:58,160 --> 00:32:02,520
Speaker 1: velocity and it lowers the pressure. This lower pressure draws

542
00:32:02,600 --> 00:32:05,680
Speaker 1: water from the well up the inlet, so this part

543
00:32:05,760 --> 00:32:08,840
Speaker 1: is still using atmospheric pressure, but the whole assembly is

544
00:32:09,040 --> 00:32:12,320
Speaker 1: down inside the well, so it's not lifting the water

545
00:32:12,480 --> 00:32:15,800
Speaker 1: very far. The drive water from the pump and the

546
00:32:15,840 --> 00:32:19,800
Speaker 1: well water then pass through a venturi tube, and that

547
00:32:20,000 --> 00:32:23,920
Speaker 1: increase in diameter decreases the water velocity but increases the

548
00:32:23,960 --> 00:32:27,840
Speaker 1: water pressure. And it's that increase in water pressure that

549
00:32:28,000 --> 00:32:31,160
Speaker 1: drives the water up further than it would go if

550
00:32:31,160 --> 00:32:34,360
Speaker 1: we were just relying on atmospheric pressure to do the job.

551
00:32:34,800 --> 00:32:38,880
Speaker 1: The high water pressure inside the tube moves the water

552
00:32:39,160 --> 00:32:42,680
Speaker 1: up the inlet pipe into the pump and then ultimately

553
00:32:42,840 --> 00:32:45,880
Speaker 1: through the plumbing system. So this pump uses the trick

554
00:32:45,920 --> 00:32:48,880
Speaker 1: of lowering pressure inside the pipe to draw up water

555
00:32:49,160 --> 00:32:53,480
Speaker 1: to a certain elevation. Then, through increasing the water pressure

556
00:32:53,520 --> 00:32:57,840
Speaker 1: inside the pipe, lifts it or pushes it further up

557
00:32:58,000 --> 00:33:01,240
Speaker 1: to the pump. This system can work with wells that

558
00:33:01,280 --> 00:33:04,200
Speaker 1: are much deeper than shallow ones, though the further down

559
00:33:04,240 --> 00:33:07,680
Speaker 1: the water is, the less efficient the system will be. Finally,

560
00:33:07,760 --> 00:33:10,640
Speaker 1: we've got submersible pumps. Now, these are pumps that are

561
00:33:10,680 --> 00:33:13,520
Speaker 1: actually in the water of the well itself, and rather

562
00:33:13,560 --> 00:33:16,760
Speaker 1: than lifting water, they are pushing it up the pipe.

563
00:33:16,960 --> 00:33:19,960
Speaker 1: They're also used for deeper wells. These pumps use a

564
00:33:20,000 --> 00:33:23,360
Speaker 1: series of impellers that are separated by diffusers. Uh just

565
00:33:23,480 --> 00:33:26,080
Speaker 1: like the tubes we're talking about before. These lower the

566
00:33:26,080 --> 00:33:28,640
Speaker 1: speed of the water, but they increase the water pressure

567
00:33:29,200 --> 00:33:32,000
Speaker 1: further up the chain, and they do that by increasing

568
00:33:32,000 --> 00:33:34,680
Speaker 1: the diameter of the pathway that the water is following.

569
00:33:34,960 --> 00:33:38,600
Speaker 1: So the water moves through a series of impellers and

570
00:33:38,680 --> 00:33:42,160
Speaker 1: diffusers over and over again, with the water pressure building

571
00:33:42,280 --> 00:33:45,240
Speaker 1: along the way, and that ends up creating the pressure

572
00:33:45,280 --> 00:33:48,760
Speaker 1: needed to deliver the water up the well and to

573
00:33:49,120 --> 00:33:54,440
Speaker 1: a home's plumbing system. One other common component of well

574
00:33:54,800 --> 00:33:58,800
Speaker 1: systems know well water that is supplying homes is a

575
00:33:58,840 --> 00:34:03,320
Speaker 1: pressure tank. Water from the pump will enter a pressure

576
00:34:03,360 --> 00:34:07,400
Speaker 1: tank first before going through the home's plumbing system, and

577
00:34:07,440 --> 00:34:11,399
Speaker 1: as water fills the tank, the pressure inside the tank increases.

578
00:34:11,719 --> 00:34:14,880
Speaker 1: The pump has a sensor connected to this tank and

579
00:34:14,920 --> 00:34:17,560
Speaker 1: there's a cut off value once a certain level of

580
00:34:17,560 --> 00:34:21,520
Speaker 1: pressure is achieved, and at that point the pump shuts off.

581
00:34:22,000 --> 00:34:24,080
Speaker 1: So when you turn on a faucet in a house

582
00:34:24,120 --> 00:34:27,640
Speaker 1: that's supplied with well water, the water actually first comes

583
00:34:27,680 --> 00:34:31,240
Speaker 1: from the pressure tank and the pump will stay off

584
00:34:31,560 --> 00:34:35,440
Speaker 1: unless the pressure in that tank dips below a certain threshold.

585
00:34:35,840 --> 00:34:38,880
Speaker 1: At that point, the pump will kick on and begin

586
00:34:39,000 --> 00:34:42,000
Speaker 1: to resupply the pressure tank with water. Now, the reason

587
00:34:42,040 --> 00:34:45,080
Speaker 1: for the pressure tank is that it decreases the number

588
00:34:45,080 --> 00:34:47,600
Speaker 1: of times the pump has to cycle on and off,

589
00:34:47,640 --> 00:34:50,359
Speaker 1: which helps cut down on wear and tear. There are

590
00:34:50,440 --> 00:34:53,800
Speaker 1: usually some other components that are part of a well system,

591
00:34:53,920 --> 00:34:56,200
Speaker 1: and these are meant to treat the water to remove

592
00:34:56,239 --> 00:35:00,800
Speaker 1: stuff like minerals and organic material and sediment from your water.

593
00:35:01,160 --> 00:35:04,000
Speaker 1: So a water softener is a type of device that

594
00:35:04,080 --> 00:35:07,320
Speaker 1: does that. It's meant to treat so called hard water.

595
00:35:07,640 --> 00:35:12,920
Speaker 1: Hard water contains high concentrations of minerals like magnesium and calcium.

596
00:35:12,960 --> 00:35:15,879
Speaker 1: These are not toxic or anything like that, but they

597
00:35:15,880 --> 00:35:20,800
Speaker 1: can deposit minerals on stuff like on shower tiles. For example,

598
00:35:20,960 --> 00:35:23,480
Speaker 1: I actually have some issues with hard water at my house,

599
00:35:23,520 --> 00:35:26,040
Speaker 1: so I have to scrub my tubs and sinks and

600
00:35:26,080 --> 00:35:31,600
Speaker 1: showers fairly frequently to prevent build up. Water softeners combine

601
00:35:31,640 --> 00:35:34,640
Speaker 1: a tank filled with resin beads and a brian tank

602
00:35:34,640 --> 00:35:37,560
Speaker 1: that you typically have to fill with potassium chloride pellets

603
00:35:37,640 --> 00:35:41,160
Speaker 1: or salt pellets on occasion. So incoming water moves through

604
00:35:41,200 --> 00:35:44,320
Speaker 1: these resin beads, and the resin beads carry a negative

605
00:35:44,400 --> 00:35:48,200
Speaker 1: charge and attract positively charged minerals that are in the water.

606
00:35:48,719 --> 00:35:53,200
Speaker 1: So the minerals deposit to these you know, resin beats.

607
00:35:53,200 --> 00:35:55,799
Speaker 1: They stick to the resin beads, and it allows the

608
00:35:55,920 --> 00:36:00,560
Speaker 1: neutral y charged water to flow through and enter your plumbing. Now,

609
00:36:00,560 --> 00:36:04,640
Speaker 1: eventually the beads attract enough minerals that the software needs

610
00:36:04,680 --> 00:36:08,240
Speaker 1: to be quote unquote regenerated, at which point water flows

611
00:36:08,280 --> 00:36:11,120
Speaker 1: into the brine tank. It creates a brine, and then

612
00:36:11,120 --> 00:36:15,080
Speaker 1: the brine moves through the softener tank. The salty water

613
00:36:15,520 --> 00:36:19,680
Speaker 1: washes the mineral deposits off of the beads. The wastewater

614
00:36:20,080 --> 00:36:23,120
Speaker 1: well then flush down a discharge pipe, and then the

615
00:36:23,120 --> 00:36:25,480
Speaker 1: softerer tank is ready to go again, and you would

616
00:36:25,480 --> 00:36:29,080
Speaker 1: have to occasionally refill the brine tank with pellets on

617
00:36:29,120 --> 00:36:31,799
Speaker 1: a fairly regular basis. How regular would depend on how

618
00:36:31,880 --> 00:36:34,960
Speaker 1: much water you go through. There are other types of

619
00:36:35,000 --> 00:36:38,400
Speaker 1: filtration systems that will remove specific metals and minerals and

620
00:36:38,440 --> 00:36:42,759
Speaker 1: particulates from the water, like iron filtration systems. There's also

621
00:36:42,840 --> 00:36:45,920
Speaker 1: systems that use ultraviolet light to kill off bacteria in

622
00:36:45,960 --> 00:36:48,719
Speaker 1: the water. Actually technically doesn't so much kill off the

623
00:36:48,760 --> 00:36:53,839
Speaker 1: bacteria as it renders the bacteria incapable of replicating. There

624
00:36:53,840 --> 00:36:57,520
Speaker 1: are others that are designed to remove mercury, lead, nickel,

625
00:36:57,840 --> 00:37:00,280
Speaker 1: other metals, as well as those designed to just filter

626
00:37:00,320 --> 00:37:03,319
Speaker 1: out sediment or or getting materials in general. When we

627
00:37:03,360 --> 00:37:05,879
Speaker 1: come back, we'll move away from wells and talk about

628
00:37:06,000 --> 00:37:17,080
Speaker 1: municipal water systems. But first let's take another quick break. Okay,

629
00:37:17,120 --> 00:37:20,120
Speaker 1: so a well might supply a house or a small

630
00:37:20,160 --> 00:37:23,440
Speaker 1: community with water, but what about big cities. These can

631
00:37:23,520 --> 00:37:26,880
Speaker 1: sometimes share some you know, similar elements with well water systems,

632
00:37:26,920 --> 00:37:30,760
Speaker 1: but due to scale, we do require a different approach.

633
00:37:30,880 --> 00:37:33,840
Speaker 1: So you've got to look at the water systems for

634
00:37:33,920 --> 00:37:38,640
Speaker 1: cities as a group of stages and systems. First, you

635
00:37:38,640 --> 00:37:41,080
Speaker 1: have to have a source for your water. Now, that

636
00:37:41,160 --> 00:37:44,200
Speaker 1: could be an aquifer, it could be a lake, It

637
00:37:44,200 --> 00:37:46,880
Speaker 1: could be a river or a stream or some combination

638
00:37:46,920 --> 00:37:50,160
Speaker 1: of these. This water has to go through an extensive

639
00:37:50,200 --> 00:37:54,200
Speaker 1: treatment process to remove anything harmful or unpleasant and make

640
00:37:54,200 --> 00:37:57,400
Speaker 1: the water safe for consumption. More on that in a moment.

641
00:37:57,719 --> 00:37:59,799
Speaker 1: And then the treated water has to go through a

642
00:37:59,840 --> 00:38:03,920
Speaker 1: water distribution system, so pipes and pumps that connect us

643
00:38:03,920 --> 00:38:07,200
Speaker 1: to our water supply, including things like water mains, and

644
00:38:07,280 --> 00:38:10,480
Speaker 1: that provides the water pressure needed to actually move water

645
00:38:10,560 --> 00:38:13,920
Speaker 1: through the system and out our taps and showers and

646
00:38:14,040 --> 00:38:17,680
Speaker 1: washing machines and whatnot. Then you've got a wastewater system.

647
00:38:17,719 --> 00:38:19,920
Speaker 1: I'm not going to really cover those in this episode,

648
00:38:19,920 --> 00:38:23,280
Speaker 1: but the wastewater systems purposes to collect the used water

649
00:38:23,440 --> 00:38:27,120
Speaker 1: and transport it to a wastewater water treatment facility which

650
00:38:27,120 --> 00:38:30,000
Speaker 1: will remove as much contaminants from the wastewater as possible.

651
00:38:30,280 --> 00:38:31,960
Speaker 1: You know, if we think of this a sewer water

652
00:38:32,719 --> 00:38:36,000
Speaker 1: and that water should then be safe to return to

653
00:38:36,040 --> 00:38:40,400
Speaker 1: the environment without contaminating stuff, you know, like your water supply.

654
00:38:40,520 --> 00:38:43,880
Speaker 1: You don't want contaminated water to sink into the ground

655
00:38:44,320 --> 00:38:47,239
Speaker 1: and then become part of the groundwater. You've just major

656
00:38:47,760 --> 00:38:51,560
Speaker 1: drinking water contaminated if you do that. There are also

657
00:38:51,640 --> 00:38:55,520
Speaker 1: stormwater systems that are designed to channel rainwater or snow

658
00:38:55,560 --> 00:38:58,800
Speaker 1: melt away from you know, streets and homes and stuff.

659
00:38:59,440 --> 00:39:02,439
Speaker 1: These systems are integral to prevent flooding, and they move

660
00:39:02,480 --> 00:39:05,840
Speaker 1: water away from the infrastructure of our cities and towns

661
00:39:06,120 --> 00:39:09,759
Speaker 1: and move it back toward the environment like rivers and lakes.

662
00:39:09,800 --> 00:39:13,239
Speaker 1: That can also introduce contaminants. That's another issue, and again

663
00:39:13,280 --> 00:39:14,759
Speaker 1: I'm not really gonna be able to go into that.

664
00:39:14,840 --> 00:39:18,680
Speaker 1: I'm already running fairly along with this episode. So let's

665
00:39:18,760 --> 00:39:22,000
Speaker 1: go through the process of water treatment. You've got your

666
00:39:22,000 --> 00:39:24,560
Speaker 1: water source. So let's say in our example, it's a

667
00:39:24,640 --> 00:39:28,279
Speaker 1: lake and you are transporting water from the lake to

668
00:39:28,320 --> 00:39:31,960
Speaker 1: a water treatment facility. Let's say You've built massive pipes

669
00:39:32,000 --> 00:39:35,440
Speaker 1: and pumps that pump water from the lake into a

670
00:39:35,440 --> 00:39:40,840
Speaker 1: water treatment plant. The first stage is called coagulation and flocculation.

671
00:39:41,560 --> 00:39:44,239
Speaker 1: This is the first stage of removing stuff that we

672
00:39:44,320 --> 00:39:48,359
Speaker 1: don't want in our water, like sediment, bacteria, and you know,

673
00:39:48,480 --> 00:39:50,239
Speaker 1: other stuff that could be floating around in a lake,

674
00:39:50,320 --> 00:39:53,080
Speaker 1: like you know, bits of wood or other organic materials.

675
00:39:54,080 --> 00:39:57,400
Speaker 1: Incoming water from the lake will mix with chemicals like

676
00:39:57,520 --> 00:40:02,200
Speaker 1: ferric chloride or aluminum sulfate, and these chemicals are called coagulants.

677
00:40:02,200 --> 00:40:05,520
Speaker 1: They will congeal with the suspended solids that are in

678
00:40:05,560 --> 00:40:08,719
Speaker 1: the water, and it all comes down to again having

679
00:40:08,719 --> 00:40:12,279
Speaker 1: an opposite charge. The coagulants have the opposite charge of

680
00:40:12,440 --> 00:40:16,520
Speaker 1: the sediments, so they kind of bond to each other.

681
00:40:16,560 --> 00:40:19,720
Speaker 1: They glom onto each other because those opposite charges are

682
00:40:19,760 --> 00:40:25,080
Speaker 1: attracting one another. The mix of coagulants and water then

683
00:40:25,320 --> 00:40:30,560
Speaker 1: moves into what are called flocculation basins, which is what

684
00:40:30,719 --> 00:40:33,160
Speaker 1: a pair of words I mean. Try it, Just say it,

685
00:40:33,239 --> 00:40:38,160
Speaker 1: floculation basin. It's it feels great. Here the water and

686
00:40:38,239 --> 00:40:43,520
Speaker 1: coagulants mixed together. Slowly, the coagulants begin to kind of

687
00:40:43,520 --> 00:40:46,840
Speaker 1: glom onto each other and grow larger. Through this process,

688
00:40:46,880 --> 00:40:52,000
Speaker 1: they form what are called flock particles. Essentially, they're beginning

689
00:40:52,000 --> 00:40:55,160
Speaker 1: to just kind of you know, concentrate, and eventually, once

690
00:40:55,239 --> 00:40:59,719
Speaker 1: a certain quality of water is reached, this mixture will

691
00:40:59,760 --> 00:41:03,800
Speaker 1: move into another section, which could take one of two

692
00:41:04,200 --> 00:41:09,120
Speaker 1: different forms. So one of those forms is as sedimentation basin,

693
00:41:09,200 --> 00:41:11,839
Speaker 1: and in fact, the sedimentation process is kind of what

694
00:41:11,880 --> 00:41:15,400
Speaker 1: we call this part of the whole system. The purpose

695
00:41:15,480 --> 00:41:18,400
Speaker 1: of this basin is to allow those flock particles to

696
00:41:18,560 --> 00:41:22,839
Speaker 1: sink down to the bottom of this vessel, and they

697
00:41:22,920 --> 00:41:27,560
Speaker 1: kind of form a nasty sludge. That sledge is removed

698
00:41:27,600 --> 00:41:30,080
Speaker 1: from the tanks through special pipes near the bottom and

699
00:41:30,120 --> 00:41:32,760
Speaker 1: then dumped in a landfill or something along those lines.

700
00:41:33,160 --> 00:41:36,200
Speaker 1: The water at the top of the sedimentation basin is

701
00:41:36,200 --> 00:41:39,239
Speaker 1: the cleanest, so the closer yard to the surface, the

702
00:41:39,239 --> 00:41:42,359
Speaker 1: cleaner the water, and that water is allowed to move

703
00:41:42,400 --> 00:41:45,800
Speaker 1: over to the next phase. And in this version we

704
00:41:45,840 --> 00:41:49,840
Speaker 1: would take water from the top. Now, the reason I

705
00:41:49,880 --> 00:41:52,960
Speaker 1: say that is to contrast it with the alternative method,

706
00:41:53,560 --> 00:41:58,479
Speaker 1: and that is called a floatation basin, a dissolved air

707
00:41:58,760 --> 00:42:04,280
Speaker 1: floatation basin. So here you pipe air into the bottom

708
00:42:04,480 --> 00:42:06,480
Speaker 1: of the tank. You have like little pipes with holes

709
00:42:06,480 --> 00:42:09,680
Speaker 1: in it, and you shoot air through those pipes and

710
00:42:09,719 --> 00:42:12,160
Speaker 1: the holes allow bubbles to come in through the tank.

711
00:42:12,560 --> 00:42:15,520
Speaker 1: Those bubbles flow up through the tank to go to

712
00:42:15,560 --> 00:42:18,120
Speaker 1: the surface and along the way they push the flock

713
00:42:18,280 --> 00:42:21,279
Speaker 1: particles up to the top of the tank and then

714
00:42:21,560 --> 00:42:25,240
Speaker 1: you can use a sweeping arm to kind of gather

715
00:42:25,360 --> 00:42:29,080
Speaker 1: those flock particles together for collection. So in this version,

716
00:42:29,320 --> 00:42:32,440
Speaker 1: the cleanness water is actually at the bottom of the tank,

717
00:42:32,640 --> 00:42:35,960
Speaker 1: not the top, so we would have a pipe towards

718
00:42:36,000 --> 00:42:38,400
Speaker 1: the bottom of the tank that we would draw water

719
00:42:38,560 --> 00:42:41,120
Speaker 1: from to go into the next part of the system.

720
00:42:41,160 --> 00:42:43,640
Speaker 1: Either way, the water coming out of this part of

721
00:42:43,640 --> 00:42:47,120
Speaker 1: the phase will then go through a series of weirs

722
00:42:47,280 --> 00:42:50,319
Speaker 1: or w e I R s. That's a type of

723
00:42:50,400 --> 00:42:53,840
Speaker 1: low dam and it's really just meant to change the

724
00:42:53,880 --> 00:42:57,919
Speaker 1: flow characteristics of water. The water then moves on to filtration.

725
00:42:58,200 --> 00:43:01,120
Speaker 1: Here the water will enter into a basin that has

726
00:43:01,160 --> 00:43:03,960
Speaker 1: a sand filter in it. And the sand filter is

727
00:43:03,960 --> 00:43:06,439
Speaker 1: exactly what it sounds like. It's a filter that's made

728
00:43:06,480 --> 00:43:09,760
Speaker 1: up of different grades of sand. You have very fine sand,

729
00:43:10,080 --> 00:43:12,960
Speaker 1: then you have medium, and you have really coarse sand.

730
00:43:13,560 --> 00:43:16,279
Speaker 1: And wherever the water is coming in from, it's going

731
00:43:16,320 --> 00:43:18,759
Speaker 1: to hit the course sand first and then move through

732
00:43:18,800 --> 00:43:23,719
Speaker 1: progressively finer grains of sand. You can have versions where

733
00:43:23,719 --> 00:43:27,080
Speaker 1: the sand filter is fed through the bottom, so you're

734
00:43:27,120 --> 00:43:29,680
Speaker 1: forcing water in through the bottom, it hits the coarse sand,

735
00:43:29,680 --> 00:43:33,520
Speaker 1: and then the continuing force of water is pushing water

736
00:43:33,680 --> 00:43:35,960
Speaker 1: further up through the filter. Or you can do it

737
00:43:36,040 --> 00:43:38,600
Speaker 1: the other way, where water is coming in through the top,

738
00:43:38,840 --> 00:43:41,600
Speaker 1: hits the coarse sand, and then filters down through it.

739
00:43:41,920 --> 00:43:46,719
Speaker 1: Most sand filters tend to take the bottom up approach,

740
00:43:47,320 --> 00:43:50,799
Speaker 1: so we would just keep forcing water in and the

741
00:43:50,800 --> 00:43:53,800
Speaker 1: water would move up through these different grains of sand.

742
00:43:54,840 --> 00:43:58,040
Speaker 1: So how does it work. Well, it gets super technical,

743
00:43:58,239 --> 00:44:02,960
Speaker 1: so stick with me. The particulates, the particles they're in

744
00:44:03,000 --> 00:44:06,600
Speaker 1: the water, get caught on the sand as they encounter

745
00:44:06,719 --> 00:44:09,560
Speaker 1: spaces where water can squeeze through, but the particles can't see.

746
00:44:09,640 --> 00:44:13,239
Speaker 1: I told you super technical. So yeah, the water continuously

747
00:44:13,320 --> 00:44:16,040
Speaker 1: moves through areas of sand that are more and more

748
00:44:16,080 --> 00:44:19,080
Speaker 1: densely packed together, and more and more of those particles

749
00:44:19,280 --> 00:44:23,520
Speaker 1: are kept behind. Some water treatment plants will then pass

750
00:44:23,680 --> 00:44:27,399
Speaker 1: that filtered water through a second filtration system where they'll

751
00:44:27,480 --> 00:44:31,080
Speaker 1: use something like activated carbon, and the carbon particles are

752
00:44:31,120 --> 00:44:35,279
Speaker 1: porous and they can capture smaller particles and bacteria and

753
00:44:35,320 --> 00:44:38,680
Speaker 1: remove that from the water. So if your fridge as

754
00:44:38,719 --> 00:44:42,080
Speaker 1: a water filter built into it, it's likely using activated

755
00:44:42,120 --> 00:44:44,960
Speaker 1: carbon to do the trick, the carbon grabs onto the

756
00:44:44,960 --> 00:44:47,960
Speaker 1: particles and the water is free to go about its business.

757
00:44:48,280 --> 00:44:50,960
Speaker 1: Then the water moves on to the next phase of

758
00:44:51,000 --> 00:44:54,920
Speaker 1: the treatment system, which is disinfection. This is the phase

759
00:44:54,960 --> 00:44:57,960
Speaker 1: that is intended to remove any remaining bacteria to make

760
00:44:58,000 --> 00:45:00,960
Speaker 1: certain that the water is safe for human consumption. There

761
00:45:00,960 --> 00:45:03,520
Speaker 1: are a few different methods in order to do this.

762
00:45:03,640 --> 00:45:07,000
Speaker 1: One of them is used a chlorine based compound. This

763
00:45:07,080 --> 00:45:09,919
Speaker 1: is a really common approach in the United States. One

764
00:45:10,120 --> 00:45:13,160
Speaker 1: is to use an ozone treatment, and then the third

765
00:45:13,360 --> 00:45:16,520
Speaker 1: is to use UV light treatment, and some facilities use

766
00:45:16,560 --> 00:45:21,040
Speaker 1: a combination of these. All three have different pros and

767
00:45:21,120 --> 00:45:26,680
Speaker 1: cons Chlorine, for example, can continue to kill bacteria even

768
00:45:26,800 --> 00:45:29,680
Speaker 1: after it's moved out of the water treatment facility because

769
00:45:29,680 --> 00:45:33,240
Speaker 1: there's still some chlorine in the water. So that means

770
00:45:33,560 --> 00:45:37,319
Speaker 1: that this particular type of treated water can kill bacteria

771
00:45:37,440 --> 00:45:40,480
Speaker 1: that gets introduced to the system after water has left

772
00:45:40,480 --> 00:45:42,759
Speaker 1: the treatment plant. So if there's any point in the

773
00:45:42,800 --> 00:45:46,239
Speaker 1: system where water from the outside environment can seep in,

774
00:45:46,719 --> 00:45:49,480
Speaker 1: that chlorine can help take care of any bacteria that's

775
00:45:49,480 --> 00:45:54,279
Speaker 1: in that water. The other two versions of of disinfection

776
00:45:54,480 --> 00:45:57,440
Speaker 1: don't allow for treatment of water once it's left the

777
00:45:57,440 --> 00:46:00,880
Speaker 1: treatment plant, but they have their own os and cons.

778
00:46:01,200 --> 00:46:04,280
Speaker 1: Now at this stage the water should be safe to drink,

779
00:46:04,280 --> 00:46:07,239
Speaker 1: assuming everything at the water plant is working properly, so

780
00:46:07,320 --> 00:46:10,239
Speaker 1: you've now reached drinkable water. Once it's gone through all

781
00:46:10,280 --> 00:46:13,760
Speaker 1: these phases, then it gets pumped into the city's water system,

782
00:46:14,000 --> 00:46:16,000
Speaker 1: which is a network of pipes that feed out to

783
00:46:16,080 --> 00:46:18,279
Speaker 1: the various homes and buildings in the city, with other

784
00:46:18,320 --> 00:46:20,399
Speaker 1: pumps along the way to keep the water pressure going.

785
00:46:20,880 --> 00:46:24,000
Speaker 1: And the water pressure leaves the planted around a pressure

786
00:46:24,000 --> 00:46:26,440
Speaker 1: of for d P s I, and that is to

787
00:46:26,600 --> 00:46:29,440
Speaker 1: make sure of a few things. One that the water

788
00:46:29,560 --> 00:46:31,360
Speaker 1: has enough pressure so it can be pumped up to

789
00:46:31,480 --> 00:46:34,880
Speaker 1: areas of higher elevation. And two there has to be

790
00:46:35,000 --> 00:46:37,520
Speaker 1: a positive water pressure in the pipes. In other words,

791
00:46:37,680 --> 00:46:39,360
Speaker 1: the water pressure in the pipes has to be strong

792
00:46:39,480 --> 00:46:42,040
Speaker 1: enough so that the water is pressing outward on the

793
00:46:42,080 --> 00:46:45,680
Speaker 1: pipes at all times, because that prevents any other water

794
00:46:45,880 --> 00:46:50,400
Speaker 1: from outside from seeping into the pipes. If there are

795
00:46:50,400 --> 00:46:54,440
Speaker 1: any gaps or cracks along the way, the internal water

796
00:46:54,480 --> 00:46:58,120
Speaker 1: pressure is strong enough to push that water out so

797
00:46:58,200 --> 00:47:01,360
Speaker 1: it's not gonna it's not able to get in, and

798
00:47:02,080 --> 00:47:04,840
Speaker 1: that's important because if water could get in while that

799
00:47:04,880 --> 00:47:07,719
Speaker 1: water would be untreated, and you would have all the

800
00:47:07,800 --> 00:47:11,960
Speaker 1: dangers that are associated with contaminated water sources all over again.

801
00:47:12,040 --> 00:47:14,440
Speaker 1: It would have been as if the whole process you

802
00:47:14,520 --> 00:47:17,960
Speaker 1: just went through at the treatment facility didn't matter. So

803
00:47:18,000 --> 00:47:21,719
Speaker 1: if there's an indication that's somewhere along the water system

804
00:47:21,760 --> 00:47:24,560
Speaker 1: from the treatment plant to the homes or buildings where

805
00:47:24,560 --> 00:47:28,160
Speaker 1: the water is being delivered, that pressure has dropped somewhere

806
00:47:28,200 --> 00:47:31,000
Speaker 1: along that pathway, that's when you tend to get boil

807
00:47:31,080 --> 00:47:35,080
Speaker 1: water advisories. The concern is that if water pressure is

808
00:47:35,160 --> 00:47:38,680
Speaker 1: low enough, then external water might have entered the pipe

809
00:47:38,719 --> 00:47:41,680
Speaker 1: system and so it could be untreated water and it

810
00:47:41,680 --> 00:47:44,239
Speaker 1: would be unsafe to drink. That's why you're told to

811
00:47:44,280 --> 00:47:47,560
Speaker 1: boil your water. It's really to kill off any potential pathogens. Now,

812
00:47:47,600 --> 00:47:50,440
Speaker 1: boiling water won't remove everything, so you might end up

813
00:47:50,480 --> 00:47:53,520
Speaker 1: with water that has higher concentrations of stuff like iron.

814
00:47:53,600 --> 00:47:58,040
Speaker 1: But the primary concern, the first line of concern, is

815
00:47:58,120 --> 00:48:02,640
Speaker 1: about potentially deadly bacteria like E. Coli. One of the

816
00:48:02,640 --> 00:48:06,880
Speaker 1: most common municipal water system components is the water tower.

817
00:48:07,320 --> 00:48:10,200
Speaker 1: Now you've likely seen lots of these. They are tall

818
00:48:10,320 --> 00:48:13,880
Speaker 1: containers giant, giant containers that can hold a lot of water.

819
00:48:14,239 --> 00:48:17,239
Speaker 1: So like your typical swimming pool holds something around the

820
00:48:17,280 --> 00:48:20,360
Speaker 1: line of twenty tho gallons of water, the typical water

821
00:48:20,440 --> 00:48:24,359
Speaker 1: tower can hold a million gallons. But usually a water

822
00:48:24,400 --> 00:48:28,120
Speaker 1: tower is designed so it holds about a day's worth

823
00:48:28,239 --> 00:48:33,120
Speaker 1: of water supply for the area that water tower services.

824
00:48:33,160 --> 00:48:36,000
Speaker 1: So these water towers are really tall. They often are

825
00:48:36,040 --> 00:48:39,000
Speaker 1: put in places of higher elevation because they depend on

826
00:48:39,080 --> 00:48:42,760
Speaker 1: gravity to do a lot of work. Each additional foot

827
00:48:42,840 --> 00:48:47,080
Speaker 1: of height that you have a container of water at

828
00:48:47,440 --> 00:48:50,640
Speaker 1: increases the water pressure by point four three pounds per

829
00:48:50,680 --> 00:48:54,279
Speaker 1: square inch. So the taller the tower, the higher the

830
00:48:54,280 --> 00:48:57,759
Speaker 1: water pressure. Lifting a volume of water to a high

831
00:48:57,760 --> 00:49:00,680
Speaker 1: point builds up a lot of potential in gy and

832
00:49:00,760 --> 00:49:03,480
Speaker 1: releasing the water and letting it fall converts that potential

833
00:49:03,560 --> 00:49:06,160
Speaker 1: energy into kinetic energy. But in a plumbing system in

834
00:49:06,160 --> 00:49:08,440
Speaker 1: which you've got water filling up the system of pipes,

835
00:49:08,760 --> 00:49:12,120
Speaker 1: the potential energy converts over into water pressure. So let's

836
00:49:12,120 --> 00:49:14,759
Speaker 1: imagine you've got a water system in place for an

837
00:49:14,880 --> 00:49:18,120
Speaker 1: unoccupied city. No one lives in the city, but you've

838
00:49:18,120 --> 00:49:20,200
Speaker 1: got the water system set up, You've got the water

839
00:49:20,280 --> 00:49:22,759
Speaker 1: tower filled up all the taps in the city are

840
00:49:22,800 --> 00:49:25,960
Speaker 1: turned off. It's a sealed system. Right now, the weight

841
00:49:26,080 --> 00:49:28,080
Speaker 1: of the water in the water tower is creating some

842
00:49:28,120 --> 00:49:31,440
Speaker 1: water pressure throughout the system even if the pumps aren't on.

843
00:49:31,640 --> 00:49:34,160
Speaker 1: So you open up a tap that creates an escape

844
00:49:34,160 --> 00:49:36,120
Speaker 1: for the water and the water will come out of

845
00:49:36,120 --> 00:49:38,480
Speaker 1: the pipe. The water towers are really there to act

846
00:49:38,520 --> 00:49:40,719
Speaker 1: in a way kind of similar to the way a

847
00:49:40,800 --> 00:49:44,080
Speaker 1: pressure tank works. With a house that has a well

848
00:49:44,560 --> 00:49:48,040
Speaker 1: as its source of water, the water tower helps reduce

849
00:49:48,160 --> 00:49:51,120
Speaker 1: the workload that the pumps in the system have to do.

850
00:49:51,560 --> 00:49:55,839
Speaker 1: If we didn't have water towers in times where people

851
00:49:55,880 --> 00:49:58,120
Speaker 1: were using a lot of water where demand is really high,

852
00:49:58,120 --> 00:50:00,680
Speaker 1: then pumps would need to power up more. They would

853
00:50:00,680 --> 00:50:04,200
Speaker 1: have to work harder to deliver water to meet that

854
00:50:04,320 --> 00:50:08,000
Speaker 1: demand and to keep the system working. That requires more energy.

855
00:50:08,080 --> 00:50:10,640
Speaker 1: It also results in more wear and tear on the pumps.

856
00:50:10,640 --> 00:50:14,400
Speaker 1: But by storing water and water tanks and water towers,

857
00:50:15,040 --> 00:50:18,040
Speaker 1: then we can use that to help supplement the water

858
00:50:18,120 --> 00:50:20,400
Speaker 1: that's being supplied by pumps. We can keep running the

859
00:50:20,400 --> 00:50:24,200
Speaker 1: pumps at a consistent level, which reduces wear and tear

860
00:50:24,280 --> 00:50:28,000
Speaker 1: and is more energy efficient, and then we supplement that

861
00:50:28,080 --> 00:50:29,960
Speaker 1: with the water from the water towers, and at night,

862
00:50:30,040 --> 00:50:33,800
Speaker 1: when water demand is usually pretty low, then special pumps

863
00:50:33,800 --> 00:50:36,279
Speaker 1: can pump water back up into the water tanks to

864
00:50:36,400 --> 00:50:39,560
Speaker 1: refill them so that we again have a full day

865
00:50:39,600 --> 00:50:42,560
Speaker 1: supply raid to go. At the beginning of this episode,

866
00:50:42,719 --> 00:50:46,640
Speaker 1: I mentioned Flint, Michigan, and that the crisis that went

867
00:50:46,680 --> 00:50:50,200
Speaker 1: on in the city's water supply. So what happened. Well

868
00:50:50,200 --> 00:50:53,160
Speaker 1: back in two thousand eleven, Flint, Michigan was in a

869
00:50:53,320 --> 00:50:57,560
Speaker 1: really tough spot financially. The city had been largely built

870
00:50:57,600 --> 00:51:00,480
Speaker 1: around the automotive industry in the United States. In the

871
00:51:00,520 --> 00:51:03,759
Speaker 1: nineteen sixties, the population of the city was around two

872
00:51:03,800 --> 00:51:07,080
Speaker 1: hundred thousand people, but the automotive industry in the United

873
00:51:07,120 --> 00:51:11,480
Speaker 1: States went through a total tumultuous time. Foreign car companies

874
00:51:11,719 --> 00:51:15,160
Speaker 1: were able to really compete fiercely in the market in

875
00:51:15,200 --> 00:51:18,680
Speaker 1: the United States, and American companies ended up having some

876
00:51:19,440 --> 00:51:22,520
Speaker 1: massive problems as a result, and a lot of that

877
00:51:22,560 --> 00:51:26,040
Speaker 1: meant that businesses started to move out of certain areas

878
00:51:26,160 --> 00:51:29,560
Speaker 1: like Flint. So by two thousand eleven, with the automotive

879
00:51:29,560 --> 00:51:34,120
Speaker 1: industry largely absent from the city, Flint's population was less

880
00:51:34,120 --> 00:51:37,560
Speaker 1: than half of what it had been in the nineteen sixties. Now,

881
00:51:37,600 --> 00:51:40,640
Speaker 1: that also meant that the city was taking in less

882
00:51:40,680 --> 00:51:43,520
Speaker 1: money in the form of taxes. Not only was the

883
00:51:43,560 --> 00:51:46,560
Speaker 1: local economy suffering because of the failure of the automotive

884
00:51:46,560 --> 00:51:49,560
Speaker 1: industry there, the city's coffers were empty, and the city

885
00:51:49,640 --> 00:51:52,839
Speaker 1: was actually in debt. In an effort to deal with

886
00:51:52,880 --> 00:51:56,879
Speaker 1: this financial emergency, the city appointed managers who could make

887
00:51:57,000 --> 00:52:01,279
Speaker 1: drastic cost cutting measures without going through the typical political processes,

888
00:52:01,920 --> 00:52:05,360
Speaker 1: so they didn't have to seek after approvals, which sped

889
00:52:05,440 --> 00:52:08,600
Speaker 1: things up considerably. The idea being that it was important

890
00:52:08,640 --> 00:52:12,799
Speaker 1: to be expedient here. So one of the expenses that

891
00:52:12,880 --> 00:52:17,440
Speaker 1: they identified was the water supply. Flint had been buying

892
00:52:17,880 --> 00:52:22,440
Speaker 1: water service from Detroit. Detroit was processing the water and

893
00:52:22,440 --> 00:52:25,920
Speaker 1: then sending it on to Flint, Michigan. So instead Flint wood,

894
00:52:25,960 --> 00:52:28,800
Speaker 1: for at least a short time, starting in two thousand fourteen,

895
00:52:29,440 --> 00:52:33,160
Speaker 1: draw water from the Flint River while building out its

896
00:52:33,200 --> 00:52:36,399
Speaker 1: own regional water system with the goal of pulling water

897
00:52:36,480 --> 00:52:39,200
Speaker 1: from Lake Huron, which was the same source as what

898
00:52:39,280 --> 00:52:42,280
Speaker 1: Detroit was using. But the water coming out the Flint

899
00:52:42,360 --> 00:52:47,120
Speaker 1: River was really contaminated, and the treatment system that Flint

900
00:52:47,160 --> 00:52:50,759
Speaker 1: was using was not capable of treating the water properly.

901
00:52:51,080 --> 00:52:54,520
Speaker 1: And here's where we got a tragic dilemma, because people

902
00:52:54,560 --> 00:52:57,160
Speaker 1: need water, but the water that was coming out of

903
00:52:57,160 --> 00:53:01,120
Speaker 1: the Flints system was unsafe to drink, and that unsafe

904
00:53:01,120 --> 00:53:05,120
Speaker 1: water got pumped into the city's system and to people's homes,

905
00:53:05,120 --> 00:53:08,239
Speaker 1: and some regions got worse water than others, and it

906
00:53:08,280 --> 00:53:11,360
Speaker 1: was all pretty nasty stuff. You can actually watch videos

907
00:53:11,360 --> 00:53:14,720
Speaker 1: of people turning on faucets filling up a clear glass,

908
00:53:14,760 --> 00:53:17,759
Speaker 1: and you can see that the water is discolored. But

909
00:53:17,840 --> 00:53:22,799
Speaker 1: apart from looking and reportedly smelling bad, it carried with

910
00:53:22,880 --> 00:53:28,640
Speaker 1: it lots of contaminants, including dissolved lead. Lead is incredibly toxic.

911
00:53:28,719 --> 00:53:31,960
Speaker 1: There is no level of lead that is considered safe,

912
00:53:32,400 --> 00:53:36,279
Speaker 1: and consuming lead can lead to lifelong health problems. For

913
00:53:36,440 --> 00:53:40,480
Speaker 1: a year, the city denied that there were elevated levels

914
00:53:40,520 --> 00:53:44,800
Speaker 1: of lead in city water, claiming that any specific cases

915
00:53:44,840 --> 00:53:49,520
Speaker 1: where people detected higher levels of lead, we're just restricted

916
00:53:49,560 --> 00:53:53,239
Speaker 1: to the plumbing of those specific buildings or houses, saying, oh,

917
00:53:53,239 --> 00:53:55,360
Speaker 1: it's not a it's not a systemic problem. It's a

918
00:53:55,360 --> 00:53:58,839
Speaker 1: problem with your plumbing. And it took an outside investigation

919
00:53:58,920 --> 00:54:02,040
Speaker 1: that proved otherwise. It said, no, this is a city

920
00:54:02,160 --> 00:54:05,120
Speaker 1: level problem, and it means that people have been relying

921
00:54:05,160 --> 00:54:09,120
Speaker 1: on a water system that was contaminated for a full year. Now,

922
00:54:09,120 --> 00:54:13,160
Speaker 1: in two thousand fifteen, under immense pressure, Flint switched back

923
00:54:13,239 --> 00:54:17,239
Speaker 1: to using water from Detroit, but by then a lot

924
00:54:17,280 --> 00:54:20,480
Speaker 1: of damage had already been done. Now you'll occasionally see

925
00:54:20,520 --> 00:54:23,560
Speaker 1: the message of Flint, Michigan still doesn't have safe drinking water,

926
00:54:23,640 --> 00:54:27,240
Speaker 1: but that's actually not true. The water in Flint, Michigan,

927
00:54:27,280 --> 00:54:30,160
Speaker 1: is now as safe or safer than other cities in

928
00:54:30,200 --> 00:54:33,560
Speaker 1: the United States. However, the amount of damage that was

929
00:54:33,719 --> 00:54:37,920
Speaker 1: done during the switch to the Flint River remains a problem,

930
00:54:37,960 --> 00:54:40,440
Speaker 1: and for many residents it could be a problem that

931
00:54:40,520 --> 00:54:42,440
Speaker 1: they have to manage for the rest of their lives.

932
00:54:42,800 --> 00:54:48,120
Speaker 1: So that explains the challenges associated with delivering water to

933
00:54:48,239 --> 00:54:52,760
Speaker 1: people now in our civilized age, is still a massive

934
00:54:52,960 --> 00:54:55,799
Speaker 1: undertaking and obviously if something goes wrong, it could have

935
00:54:56,080 --> 00:54:59,200
Speaker 1: dire consequences. And it reminds us that we have to

936
00:54:59,200 --> 00:55:01,360
Speaker 1: be very careful with our water supplies. Even with the

937
00:55:01,360 --> 00:55:04,080
Speaker 1: water treatment systems that we have, we need to be careful.

938
00:55:04,640 --> 00:55:08,040
Speaker 1: It is easy to contaminate a water supply, whether that

939
00:55:08,280 --> 00:55:12,359
Speaker 1: is a river or a lake or even groundwater. If

940
00:55:12,400 --> 00:55:17,920
Speaker 1: you have poor wastewater treatment plans, then that wastewater can

941
00:55:17,920 --> 00:55:21,400
Speaker 1: seep into the ground and then you've got very dangerous

942
00:55:21,400 --> 00:55:25,239
Speaker 1: bacteria and other contaminants in the water system that could

943
00:55:25,239 --> 00:55:29,480
Speaker 1: then be consumed later on. And that's why this is

944
00:55:29,520 --> 00:55:33,680
Speaker 1: so important, and the technology involved is pretty interesting stuff.

945
00:55:33,719 --> 00:55:37,120
Speaker 1: I highly recommend watching videos. I know that trying to

946
00:55:37,280 --> 00:55:40,200
Speaker 1: visualize something like a centrifugal pump as a little tricky,

947
00:55:40,440 --> 00:55:42,959
Speaker 1: but there's some great videos on YouTube that really show

948
00:55:43,000 --> 00:55:45,600
Speaker 1: you how it works in case you want to get

949
00:55:45,600 --> 00:55:48,719
Speaker 1: a visual on it. These things are really super cool,

950
00:55:48,760 --> 00:55:52,720
Speaker 1: and again, the harnessing of physics is something I always

951
00:55:52,760 --> 00:55:56,319
Speaker 1: find really fascinating. If you guys have any suggestions for

952
00:55:56,440 --> 00:55:59,480
Speaker 1: future topics of tech stuff, whether it's a technology or

953
00:55:59,520 --> 00:56:02,560
Speaker 1: a trend, into or a company or whatever something related

954
00:56:02,600 --> 00:56:05,920
Speaker 1: to tech, send me a message and tell me about it.

955
00:56:06,200 --> 00:56:08,440
Speaker 1: You can send it on Twitter. The handle for the

956
00:56:08,480 --> 00:56:11,879
Speaker 1: show is tech Stuff H s W and I'll talk

957
00:56:11,880 --> 00:56:20,080
Speaker 1: to you again really soon. Text Stuff is an I

958
00:56:20,200 --> 00:56:23,680
Speaker 1: Heart Radio production. For more podcasts from I Heart Radio,

959
00:56:24,000 --> 00:56:27,200
Speaker 1: visit the I Heart Radio app, Apple Podcasts, or wherever

960
00:56:27,280 --> 00:56:28,800
Speaker 1: you listen to your favorite shows.