Speaker 1: Welcome to text, a production from I Heart Radio. Hey there,
Speaker 1: and welcome to tech Stuff. I'm your host, Jonathan Strickland.
Speaker 1: I'm an executive producer with I Heart Radio, and I
Speaker 1: love all things tech, and I don't think there is
Speaker 1: a more trite or obvious way to start an episode
Speaker 1: this year than by saying, twenty has been a tough year.
Speaker 1: And I'm not going to go through the list of
Speaker 1: all the things that have been tough, because all of
Speaker 1: you listening are aware of most, if not all, of
Speaker 1: those reasons. However, one of the things, a very localized
Speaker 1: thing that hit my neighborhood in Atlanta was a massive
Speaker 1: water main break. It actually happened along the border of
Speaker 1: the Georgia Tech Campus, which is, by the way, not
Speaker 1: close to where I live, but it is in the city.
Speaker 1: And that break meant that thousands of homes, including mine,
Speaker 1: lost water pressure, and it took quite a while before
Speaker 1: water pressure was restored, and even then we were all
Speaker 1: on a boil water advisory for several days. So in
Speaker 1: this episode, I thought maybe we could talk about the
Speaker 1: different technologies we use to supply homes with water, from
Speaker 1: personal or community wells to large municipal systems and why
Speaker 1: that boil water advisory was necessary in the first place,
Speaker 1: and we'll get to all of that. It's a lot
Speaker 1: of interesting tech and and ways that we have come
Speaker 1: up with clever solutions to the issue of getting water
Speaker 1: to people. Let's begin with just some basic facts about water.
Speaker 1: This is like elementary school level stuff. So on our planet,
Speaker 1: it's the only stuff you can find occurring naturally in
Speaker 1: three of the four states of matter that would be
Speaker 1: solid or ice, liquid you know, water and gas or
Speaker 1: water vapor. You don't tend to find it occurring as plasma,
Speaker 1: the fourth form. It's more dense as a liquid than
Speaker 1: it is when it is a solid, which is why
Speaker 1: ice will float in a glass of water. The Earth
Speaker 1: has a water cycle that is pretty much self contained.
Speaker 1: You know, we aren't really losing water out to space
Speaker 1: beyond some relatively tiny amounts here and there in some
Speaker 1: very specific circumstances, like if we send water up with
Speaker 1: astronauts and some of that water gets vented out into space, yeah,
Speaker 1: that's gone. But the stuff that is here is staying here.
Speaker 1: The water cycle is one that I'm sure you're all
Speaker 1: familiar with. Liquid water evaporates into water, vapor, which goes
Speaker 1: into the atmosphere where it will eventually condense and form
Speaker 1: into clouds, and at high enough concentrations with seed particles
Speaker 1: in those clouds, droplets will form until they're big and
Speaker 1: heavy enough to fall back to Earth as rain or snow.
Speaker 1: In addition liquid water, it can run across the land.
Speaker 1: This is called runoff and into the ground. This is
Speaker 1: called percolation and infiltration, and then eventually through the ground,
Speaker 1: seeping down through the ground and becoming groundwater. Plants absorb
Speaker 1: water in the ground through their roots, and then water
Speaker 1: evaporates from the leaves of plants into the atmosphere, and
Speaker 1: you get the picture. The water is changing form and
Speaker 1: it's changing place, but it's not leaving the planet. So
Speaker 1: when you hear about things like wasting water, well, it's
Speaker 1: not that the water is going away permanently, but it
Speaker 1: does mean that you are using up water that is
Speaker 1: very important, and it takes a lot of treatment to
Speaker 1: get that water back into a state where people can
Speaker 1: make safe use of it again, so really it's not
Speaker 1: so much of that water has gone away, as now
Speaker 1: we have to do a whole lot of stuff to
Speaker 1: that water in order to use it. Again, about of
Speaker 1: all the water on Earth is in the oceans, and
Speaker 1: that's just plain inconvenient. Ocean water is extremely salty, so
Speaker 1: you can't drink it, you can't use it for irrigation
Speaker 1: unless you put it through a desalination process, which essentially
Speaker 1: means you're pulling the salt out of the water. But
Speaker 1: we'll get into that in some other episode because that's
Speaker 1: an entirely separate topic that requires a lot of discussion.
Speaker 1: Plus I've I've kind of covered it in previous episodes anyway,
Speaker 1: but only three of the water on Earth is freshwater,
Speaker 1: and on some parts of the planet it's really hard
Speaker 1: to come by. Wars are fought over the stuff, which
Speaker 1: isn't a surprise because news flash, in case you weren't aware,
Speaker 1: we need fresh water to survive. Generally speaking, the typical
Speaker 1: human body is six water, and some oregans are much
Speaker 1: higher in water content than others, like the lungs, which
Speaker 1: are about water, so we can only go a few
Speaker 1: days without water before we start to suffer some pretty
Speaker 1: awful effects like death. Water can also carry with it
Speaker 1: some dangerous stuff. Toxins can leach into water, so you
Speaker 1: can have dissolved medals like lead. This has historically been
Speaker 1: an enormous problem and continues to be a challenge to
Speaker 1: this very day in the United States, a country that
Speaker 1: arguably should have solutions in place to deal with this
Speaker 1: sort of thing all the time. We've seen a crisis
Speaker 1: that started really in two thousand fourteen in Flint, Michigan.
Speaker 1: I'll get back to that story at the end of
Speaker 1: this podcast, because it is an important crisis that should
Speaker 1: have been handled or should have never happened in the
Speaker 1: first place, and it's an example of a massive failure
Speaker 1: in leadership because we do have the technology to deal
Speaker 1: with this sort of stuff, so it comes down to
Speaker 1: administration and sadly money. Anyway, water, even fresh water, isn't
Speaker 1: necessarily inherently safe to drink. Water can carry toxins and pathogens,
Speaker 1: and those can have a negative effect on us up
Speaker 1: to and including death depending on the situation, and so
Speaker 1: much of human history, particularly in the era of civilization,
Speaker 1: has had a focus on how to gather water, to
Speaker 1: store it, to distribute it, and how to treat it. Now,
Speaker 1: early on humans seem to have managed fairly well without
Speaker 1: massive problems related to water contamination. Now and then it
Speaker 1: would happen but by and large, humans got pretty good
Speaker 1: at avoiding water that wasn't safe to drink. Our senses
Speaker 1: tell us things such as if the water smells bad
Speaker 1: or tastes bad, that means it probably is bad. And
Speaker 1: that brings up an interesting series of questions about how
Speaker 1: we developed those reactions and senses. I mean, when you
Speaker 1: encounter a bad smell, you know that it's a bad smell.
Speaker 1: But why do our brains interpret it as bad? Why
Speaker 1: do we have that negative reaction? What makes one smell
Speaker 1: a good smell and another one a bad smell. But
Speaker 1: to be fair, those questions and answers are all outside
Speaker 1: the realm of tech stuff. I just find them fascinating.
Speaker 1: In the early eras of human history, we were hunter
Speaker 1: gatherers and nomads, and once we decided, you know, our
Speaker 1: feet were done itching, we wanted to set up shop
Speaker 1: and settle down. New challenges came about, not just regarding
Speaker 1: access to clean, drinkable water, which got to be more
Speaker 1: complicated as humans started to create larger and larger settlements,
Speaker 1: but also what to do with the waste we were generating,
Speaker 1: like the waste water. Contaminating drinking water with waste is
Speaker 1: you know, gross, and a terrible problem to have. It
Speaker 1: leads to awful outbreaks of illness. So humans had to
Speaker 1: start figure out how to deal with all this once
Speaker 1: they began to make permanent settlements and populations began to grow.
Speaker 1: One of the important early techniques for humans, one used
Speaker 1: to the present day, was all about digging a well.
Speaker 1: And this was, you know, important if you didn't have
Speaker 1: access immediately to some body of water like a lake
Speaker 1: or river or stream. But it's a pretty straightforward process.
Speaker 1: So I'm gonna be quick about the whole well digging thing.
Speaker 1: So you got the ground right, and the ground is
Speaker 1: made up of dirt and rocks and dinosaur bones and
Speaker 1: zombies and you know that kind of stuff. The ground
Speaker 1: in most places tends to be porous and permeable to water.
Speaker 1: So as water falls as precipitation, you know, rain or snow,
Speaker 1: and then either just goes into the ground or melts
Speaker 1: and then goes into the ground. It moves down through
Speaker 1: the soil and rocks. It takes up the space that
Speaker 1: is in between particles and continues because of gravity, to
Speaker 1: move downward. Now, some layers in the soil might be impermeable,
Speaker 1: you know, the rocks are less porous. Maybe there's a
Speaker 1: level of clay which is not terribly permeable to water,
Speaker 1: so then water will start to saturate the layers that
Speaker 1: are higher up from that impermeable one, it can't go lower,
Speaker 1: so the water just kind of continues to accumulate and
Speaker 1: saturate the porous ground, and it has nowhere else to go.
Speaker 1: It can't really seep lower down. So if you were
Speaker 1: to look at the ground in a cross section, the
Speaker 1: top layers of dirt and rock would have some water content,
Speaker 1: but not at a point where the ground is saturated.
Speaker 1: At that level, water is essentially being held onto particles
Speaker 1: through molecular attraction, and it's just kind of loosely held
Speaker 1: to the surfaces of rock particles. But as you go lower,
Speaker 1: you would find a greater concentration of water as the
Speaker 1: rocky soil becomes saturated with the stuff, meaning all the
Speaker 1: porous surfaces are full of groundwater. The top layer of
Speaker 1: this saturated zone of rock is what we call the
Speaker 1: water table. It is the top level of the saturated zone.
Speaker 1: It's the upper layer of groundwater. And if you find
Speaker 1: an area of groundwater that readily refills a hole, like
Speaker 1: if you were to dig a hole and you hit groundwater,
Speaker 1: you take the water out, and more water comes in.
Speaker 1: You have found an aquifer. Aquifers are store houses for water.
Speaker 1: Aquifers get refilled or recharged when precipitation hits the ground
Speaker 1: and water soaks into the soil and gradually makes its
Speaker 1: way down to this layer again, so it's constantly being refilled,
Speaker 1: or maybe not constantly regularly being refilled. The water in
Speaker 1: a well will start at around the same level of
Speaker 1: the water table in general, So let's say that the
Speaker 1: water table is ten feet down from the ground surface.
Speaker 1: That means once you hit ten feet as you're digging
Speaker 1: your well, you'll start to see water. You typically would
Speaker 1: dig further down than that so that you would have
Speaker 1: a reservoir of water, but if you were to remove
Speaker 1: water from the well, it would continuously refill to that
Speaker 1: you know, that same level ten feet down from the surface.
Speaker 1: So if you locate an aquifer and you dig down
Speaker 1: far enough and you you know, shore up the sides
Speaker 1: of your hole so that it doesn't collapse in on itself,
Speaker 1: then you've got yourself a well from which you can
Speaker 1: draw water. Now, in the olden days, you would do
Speaker 1: that with like a rope in a bucket, you would
Speaker 1: lower the bucket down, fill it up in the water
Speaker 1: than the well, and then pull the bucket back out.
Speaker 1: And you do that on demand. These days we have
Speaker 1: pumps and filters and stuff, and I'll get into those
Speaker 1: more a bit later. And there's another case I should cover,
Speaker 1: because it is a really cool thing. Some aquifers are confined. Now.
Speaker 1: That means that these aquafers have layers of less porous
Speaker 1: or impermeable rocks or soil, both below them and above them. So,
Speaker 1: in other words, the water you can think of the
Speaker 1: groundwater is flowing. It's flowing through the rocks and soil,
Speaker 1: and sometimes this water flows into areas where the layer
Speaker 1: above is impermeable. So the water didn't just seep straight down.
Speaker 1: It seeped in from some other place, flowed into an
Speaker 1: area where it no longer can move in an upward
Speaker 1: direction as more water is coming in. So this water
Speaker 1: is actually under pressure, you know, like the song by
Speaker 1: Queen and David Bowie. But here's the things that water
Speaker 1: doesn't compress. If you put pressure on water, then that
Speaker 1: water is going to push outward in all directions. This
Speaker 1: makes it different from a gas. You know, gas has
Speaker 1: molecules where you can typically force them closer together, and
Speaker 1: through pressurization you can compress a gas. You can't do
Speaker 1: that with water. Applying pressure to water we can do
Speaker 1: some pretty impressive things. That's what hydraulic systems are all about.
Speaker 1: But let's get back to confined aquifers. So, because this
Speaker 1: type of aquifer is under pressure and the water can't
Speaker 1: escape that confined space due to those non porous rock layers,
Speaker 1: if you drill a well down into that confined aquifer,
Speaker 1: it allows the water an escape route and that result
Speaker 1: in what is called an artesian well. The water in
Speaker 1: an artesian well will rise above the water table line.
Speaker 1: Because there's pressure on that water, it's going to start
Speaker 1: to move up the well. Uh sometimes it will move
Speaker 1: all the way up the well and come out of
Speaker 1: the well entirely. So, if you've got yourself a confined
Speaker 1: aquifer and you dig a well down to it, the
Speaker 1: water can be under enough pressure underground to create a
Speaker 1: constant flow up and out of the well. There are
Speaker 1: a lot of springs that are fed this way. They
Speaker 1: are pretty nifty, and there are a lot of people
Speaker 1: who have pipes that extend down into the ground, and
Speaker 1: there's no electric pump or anything working on those pipes.
Speaker 1: The pipes actually go down into a confined aquifer. So
Speaker 1: just opening up a valve allows that water and escape route,
Speaker 1: and the pressure from the ground itself is pushing the
Speaker 1: water out. And I also need to explain the difference
Speaker 1: between a well and a cistern. A cistern a c
Speaker 1: I s t e r in is a collect system
Speaker 1: that collects rainwater rather than groundwater. So it's a container,
Speaker 1: and sometimes it's one that's actually buried in the ground,
Speaker 1: so that can potentially confuse you if you just were
Speaker 1: to see one. But it's just there to collect the
Speaker 1: runoff of rainwater that feeds in through rain showers, so
Speaker 1: it doesn't pull groundwater up. You're just collecting rainwater before
Speaker 1: it can go into the ground. So that's pretty straightforward.
Speaker 1: Now I want to talk about the physics of getting
Speaker 1: water out of a well and up to us. There
Speaker 1: are a few ways to do this, and one is
Speaker 1: one I mentioned already, a purely mechanical method to lower
Speaker 1: a bucket down into the well and collect water and
Speaker 1: then pull the bucket back out. A lot of classic
Speaker 1: wells you know the kind of I think about when
Speaker 1: I think of the word well. Have a simple pulley
Speaker 1: system that allows you to lower a bucket down into
Speaker 1: the well chamber and fill it up and then pull
Speaker 1: the bucket back out. Pulleys are one of the simplest
Speaker 1: of machines. A pulley is a wheel around which you
Speaker 1: wrap a hope or wire, and the pulley just changes
Speaker 1: the direction of the force you need to use to
Speaker 1: do work. So instead of pulling straight up, you could
Speaker 1: pull down. And typically pulling downward is easier to do
Speaker 1: than pulling straight up, So while you're still lifting the
Speaker 1: same amount of weight, it's easier work to do because
Speaker 1: of the direction of the force you're applying. Now, if
Speaker 1: you add more pulleys to a system, you can actually
Speaker 1: create a mechanical advantage and that makes work easier. But
Speaker 1: that is outside this episode. But what about something like handpumps.
Speaker 1: You've likely seen this in movies or TV shows where
Speaker 1: there's a hand pump for water. Maybe you've seen pictures
Speaker 1: of one, maybe you've even used one. They tend to
Speaker 1: look like a pipe that's sticking out of the ground
Speaker 1: and it has a spout on one side where the
Speaker 1: water comes out, and a pump handle on the other
Speaker 1: that you pump up and down. So you give the
Speaker 1: handle a few pumps and before long water starts coming
Speaker 1: out of the spout. How does that work? This all
Speaker 1: has to do with pressure and using the atmospheric pressure
Speaker 1: to do work for us. So let's remember again, we're
Speaker 1: all under pressure. At sea level. We're under an atmosphere
Speaker 1: of pressure or about fourteen point seven pounds per square inch.
Speaker 1: That's how much the atmosphere is pressing down on us
Speaker 1: at sea level. If we can decrease the pressure that's
Speaker 1: in a tube sticking down into the ground into ground water,
Speaker 1: if we can reduce the air pressure inside that tube
Speaker 1: by introducing a vacuum, water will move up that tube
Speaker 1: because it's an area of lower pressure. It helps if
Speaker 1: you think about the outside pressure, the atmospheric pressure as
Speaker 1: pushing down on the water, and the lower pressure is
Speaker 1: an escape route. So the water moves up the area
Speaker 1: of lower pressure. So we think of it as you know, sucking,
Speaker 1: but that's not really the case. Like like when you're
Speaker 1: drinking from a straw, it's not that you're using suction
Speaker 1: to draw the water up directly. You're reducing the air
Speaker 1: pressure inside the straw, and the atmospheric pressure is forcing
Speaker 1: liquid to go up the straw as a result. So
Speaker 1: really to do this, all we need is a device
Speaker 1: that can lower the pressure inside a tube that extends
Speaker 1: down into the water in order to draw water up somehow.
Speaker 1: But how do you do that If the tube you
Speaker 1: have has a spout at the top right, if it's open,
Speaker 1: then you can't create a vacuum because you have an
Speaker 1: open path to the atmosphere. In general, the secret is
Speaker 1: in a pair of valves and a piston that is
Speaker 1: inside the pump. So if you could use Superman's powers
Speaker 1: of X ray vision and look through a pump, you
Speaker 1: would see that the handle connects to a reciprocating piston.
Speaker 1: So this is a piston that moves up and down
Speaker 1: inside the pump. But the base of this piston wouldn't
Speaker 1: be like a solid fixed disc, you know, like the
Speaker 1: piston you would find in a car engine. Instead, it's
Speaker 1: a disc that's actually on a hinge. It's a valve.
Speaker 1: So when you are forcing the piston downward, the disc
Speaker 1: flips up because the pressure you're you're encountering is pushing
Speaker 1: the disc up. The valve is open and the piston
Speaker 1: is allowed to go down the shaft of this pipe.
Speaker 1: When the piston starts moving up again, the disc flips
Speaker 1: closed because again the pressure causes this to happen, and
Speaker 1: that means that it is sealed everything that's underneath the piston.
Speaker 1: And as the piston draws up, it starts to create
Speaker 1: a vacuum. It's it's lowering the pressure inside the pipe.
Speaker 1: So every time the piston comes up to the top
Speaker 1: of its stroke and starts to move down again, the
Speaker 1: valve opens and allows are to pass past it, and
Speaker 1: as it gets to the bottom, it closes and creates suction.
Speaker 1: It does this over and over and over again as
Speaker 1: it starts to draw water upward. Now at the other
Speaker 1: end of the pump leading down into the well, you
Speaker 1: have a second valve. This is called the foot valve.
Speaker 1: This one's very important because I just mentioned that when
Speaker 1: the piston is going down, the piston valve opens. Well,
Speaker 1: if that were all, if that was the only valve
Speaker 1: in the system, then the water would just fall away
Speaker 1: because you've just you know, allowed the air pressure to
Speaker 1: equalize again. So the air pressure, the atmospheric pressure is
Speaker 1: no longer pushing water up the pipe. So this foot
Speaker 1: valve when the piston is coming down, is closed, so
Speaker 1: it prevents water from going back down the pipe. And
Speaker 1: when the piston is moving up again, when the piston
Speaker 1: valve is closed, the foot valve opens, allowing access to
Speaker 1: the water that's in the well. So it's these two
Speaker 1: valves working together as the piston is moving up and
Speaker 1: down that create the ability for the atmospheric pressure to
Speaker 1: push water down, pushing it up the pipe. So every
Speaker 1: time the piston completes its upward journey and switches direction,
Speaker 1: the piston valve opens, the foot valve closes, water moves
Speaker 1: into the pump. It can't flow back down into the
Speaker 1: well because then the foot valve closes. It keeps that
Speaker 1: water steady, maintains the vacuum that's in place below the valve,
Speaker 1: and then the piston valve opens, allowing the piston to
Speaker 1: travel back down into the water that has collected inside
Speaker 1: the pump. Then, as the piston begins to change direction
Speaker 1: and move upward, the piston valve closes again that traps
Speaker 1: the water above it. It essentially is like a bucket, right,
Speaker 1: It has just trapped the water that had already entered
Speaker 1: into the pump and it lifts it as the piston
Speaker 1: moves up, So you essentially are using suction the same
Speaker 1: way you would drink out of a glass, and then
Speaker 1: at the very very end of it using kind of
Speaker 1: a bucket method to pull the water up to the spout.
Speaker 1: It's pretty nifty. Now, when we come back, I'll talk
Speaker 1: about centrifugal pumps and then we'll move on to more
Speaker 1: complicated means of getting water to people. But first let's
Speaker 1: take a quick break. One thing I did not get
Speaker 1: to when I was talking about handpumps a bit earlier
Speaker 1: is that since it does work on decreasing the air
Speaker 1: pressure in a tube and then relying on atmospheric pressure
Speaker 1: to do some work and push the water up the tube,
Speaker 1: there's actually a limit to how far you can pump
Speaker 1: water vertically. If you're depending on atmospheric pressure to force
Speaker 1: water up a vertical distance of pipe, you can lift
Speaker 1: water a maximum of ten point three meters, and that
Speaker 1: is assuming you've got a perfect vacuum and that your
Speaker 1: pump is at sea level, and you can ignore some
Speaker 1: other realities of physics like friction and stuff. In practical terms,
Speaker 1: it means that ten point three is something you're never
Speaker 1: going to achieve. It's going to be more like seven
Speaker 1: to eight meters of vertical space. That's how far you
Speaker 1: can pump liquid. Because while this air pressure thing does work,
Speaker 1: you can't just get rid of the concept of gravity.
Speaker 1: Water has weight to it. So let's say you've dug
Speaker 1: way down, like fifty feet down, and you finally hit
Speaker 1: the water table and you install a hand pump, and
Speaker 1: you pump that hand pump over and over again until
Speaker 1: you're ready to collapse, but no water is coming out.
Speaker 1: So what's actually happening here. Well, while the pump lowers
Speaker 1: the air pressure in the pipe leading down to the well,
Speaker 1: and the atmospheric pressure is pushing against the water even
Speaker 1: as far down as fifty feet, it does cause water
Speaker 1: to move up the pipe, but that water still has weight,
Speaker 1: and eventually, with enough verticality there, you've got enough water.
Speaker 1: The weight of the column of water or ends up
Speaker 1: being equal to the force that the air pressure is
Speaker 1: applying to that water, and it's not going to go
Speaker 1: any higher. Using this pumping method. It's kind of like
Speaker 1: a set of scales that achieves balance. Even if you
Speaker 1: could create a perfect vacuum, the water would not go
Speaker 1: as high as you need if it were fifty ft down.
Speaker 1: Centrifugal pumps work in a different way from hand pumps,
Speaker 1: but ultimately we'll have to deal with the same limitations
Speaker 1: of physics. So with a centrifugal pump, you've got a
Speaker 1: pipe that leads down into the water. This is where
Speaker 1: water will enter the pump from the well, and it's
Speaker 1: called an inlet. It's pretty clever, right. There is a
Speaker 1: valve at the end of that pipe that sits inside
Speaker 1: the well itself, so it's submerged in the well water.
Speaker 1: This is the foot valve. It allows the water to
Speaker 1: flow into the pipe, but prevents it from flowing back
Speaker 1: out again. That is going to be important in order
Speaker 1: to make this whole system work. So when the pump
Speaker 1: is on, the valve opens and the water can flow
Speaker 1: from the well into the inlet. When the pump is off,
Speaker 1: the valve closes and prevents any water that's already in
Speaker 1: the pipe and the pump from draining back out again.
Speaker 1: There's also a pipe that leads out from the pump.
Speaker 1: This is where the water will flow out while you're
Speaker 1: pumping it. It's the outlet and discharge nozzle. This is
Speaker 1: the part of the pump that leads into the plumbing
Speaker 1: system of a house. The heart of the pump is
Speaker 1: a circular or really actually a spiral shaped chamber called
Speaker 1: the volute casing. And a volute is a spiral shape.
Speaker 1: It increases in size as you go around. And so
Speaker 1: a volute casing looks a little bit like kind of
Speaker 1: like a conk shell. And there's an electric motor that
Speaker 1: connects to a rotating shaft, and that shaft connects to
Speaker 1: a device called an impeller, and that sits inside the
Speaker 1: volute chamber. And impeller is designed to move fluid. And
Speaker 1: it looks kind of like a water wheel in that
Speaker 1: it is sort of wheel shaped, and it has these
Speaker 1: sort of curved fins. They're actually called veins V A,
Speaker 1: N E S. And these veins push water. As the
Speaker 1: impeller rotates in a single direction, it forces water to
Speaker 1: follow the rotating path. As also an interesting note here,
Speaker 1: the curve fins look kind of like scoops, so you
Speaker 1: might first think they are scooping water, that they're forcing
Speaker 1: water out kind of like a paddle and pushing water
Speaker 1: that way, but in fact that's not what's happening. The
Speaker 1: rotating impeller is creating friction to cause a rotational motion
Speaker 1: with the water, throwing it outward toward the edges of
Speaker 1: the volute chamber. So the water is following the smoothest path,
Speaker 1: and the fins actually curve away from the motion of rotation,
Speaker 1: not towards the motion of rotation, so there's no scooping
Speaker 1: going on with these things. So the water comes in
Speaker 1: through the inlet towards the center of the impeller. It comes,
Speaker 1: you know, kind of head on to the impeller, and
Speaker 1: the motorized impeller pushes the water to the edge of
Speaker 1: the volute casing through centrifugal force. The water in the
Speaker 1: casing follows the curve of the spiral outward, so it
Speaker 1: hits the wall and then just starts to move along
Speaker 1: with the rotational force moving outward. The pressure increases as
Speaker 1: a result of this, will get more into pressure in
Speaker 1: a little bit and that eventually goes to the outlet
Speaker 1: from the far end of the volute casing. There's also
Speaker 1: usually a cut off that prevents the water from just
Speaker 1: circulating in the casing over and over again. The diameter
Speaker 1: of the impeller and the speed of the impeller's rotation
Speaker 1: and the density of the fluid, because you know, these
Speaker 1: centrifugal pumps are used to move all sorts of fluids around,
Speaker 1: not just water. That determines how much force the pump
Speaker 1: is imparting to whatever fluid it happens to be pumping.
Speaker 1: This process creates the lower pressure inside the pipe, and
Speaker 1: so while the centrifugal pump looks a lot different from
Speaker 1: a hand pump, it's ultimately relying on the same force
Speaker 1: to do a lot of the work that atmospheric pressure
Speaker 1: on the water that's in the well. But the centrifugal
Speaker 1: pump doesn't have the dual valve system that the hand
Speaker 1: pumps have. So getting one going means that first you
Speaker 1: have to prime the pump, and that means submerging the
Speaker 1: entire system from the pump all the way down into
Speaker 1: the well with water. So you've got to make sure
Speaker 1: that there's water going through the pump all the way
Speaker 1: down the line into the well before the pump can
Speaker 1: start to pull water in. Uh. This is so that
Speaker 1: it can create that vacuum for the lower pressure for
Speaker 1: atmosphere pressure to push water. You know, to continuously feed
Speaker 1: the pump and uh that valve at the foot of
Speaker 1: the inlet pipe is what keeps the water from flowing
Speaker 1: out into the well while you're trying to get this
Speaker 1: to work. And if the supply of water to the
Speaker 1: volut casing begins to diminish, you might introduce air bubbles,
Speaker 1: and that is bad news. The air bubbles that can
Speaker 1: travel to the impeller, they can collapse its speeds faster
Speaker 1: than sound, and those implosions can damage the impeller. This
Speaker 1: is called cavitation. It's really bad news for pumps. Similar
Speaker 1: to the centrifugal pump is the jet pump. The jet
Speaker 1: pump also uses an impeller, but otherwise it's a little
Speaker 1: bit different in design. The impeller moves water called drive
Speaker 1: water through a path in the pump that loops back
Speaker 1: to point at the impeller. So UH, at the end
Speaker 1: of this loop, the path that leads back to the impeller,
Speaker 1: there's a narrow orifice, there's a jet and water can't
Speaker 1: be compressed, right, So if it can't be compressed to
Speaker 1: fit through this narrow path, then in order for the
Speaker 1: water to move through it actually has to pick up speed.
Speaker 1: As it picks up speed as velocity increases, pressure decreases.
Speaker 1: This is kind of similar to if you have a
Speaker 1: a hose and you put your thumb over the end
Speaker 1: of the hose. You have UH increased the velocity of
Speaker 1: the water coming out, but you've actually decreased the pressure.
Speaker 1: But this whole process creates a vacuum that helps pull
Speaker 1: more water from the well are As we've pointed out,
Speaker 1: it doesn't really pull the water so much as it
Speaker 1: decreases the pressure, so atmospheric pressure does the job on
Speaker 1: the groundwater on the other side of the jet UH
Speaker 1: is what is called a venturi tube. This is a
Speaker 1: tube that increases in diameter, so it gets bigger on
Speaker 1: the other side, and as diameter increases, the speed of
Speaker 1: the water will decrease, but the pressure of the water
Speaker 1: increases and the drive water and well water end up combining.
Speaker 1: They are at a high enough pressure to pump into
Speaker 1: the plumbing system. And this approach still is reliant on
Speaker 1: that atmospheric pressure, so again it only works down to
Speaker 1: a certain depth. But what happens if the water in
Speaker 1: your area is at a lower level, If the water
Speaker 1: table is further down than what you can achieve by
Speaker 1: relying on atmospheric pressure well to pump water below that
Speaker 1: ten point three meters, and again that's the ideal that
Speaker 1: will never achieve. Engineers had to get really creative. There
Speaker 1: are two pipe systems that do this. One pipe is
Speaker 1: the inlet pipe. This is the one that will ultimately
Speaker 1: draw water from the well and supply it to the
Speaker 1: house or building that you're using. And there is a
Speaker 1: foot valve at the end of this so again it
Speaker 1: prevents water from escaping once it enters the pipe. And
Speaker 1: this pipe goes all the way up to the pump
Speaker 1: that is on the ground. It's it's not buried or anything.
Speaker 1: It's right up there. And joining this pipe through a
Speaker 1: special jet joint is a second pipe. This pipe comes
Speaker 1: from the pump, So the second pipe comes out of
Speaker 1: the pump, extend down into the ground to join the
Speaker 1: inlet pipe through this jet joint a little further up
Speaker 1: the pipe's length, and this joint is constructed so that
Speaker 1: the jet is moving water from this second pipe to
Speaker 1: shoot up the first pipe toward the direction of the pump.
Speaker 1: So the jet is down inside the well in this
Speaker 1: version of the pump, but the impeller is still up
Speaker 1: at the pump on the ground. So what's happening is
Speaker 1: both these pipes and the pump are full of water. Okay,
Speaker 1: you've got a full system of water here. It's almost
Speaker 1: like a closed system. It's not really closed because you know,
Speaker 1: we have an outlet pipe with the pump, but let's
Speaker 1: ignore that for now. When you turn on the pump,
Speaker 1: the motor begins to spend the impeller, and the impeller
Speaker 1: forces water down the second pipe, which then moves through
Speaker 1: this jet before joining up with the first pipe, and
Speaker 1: the water as it moves through the jet picks up
Speaker 1: velocity and it lowers the pressure. This lower pressure draws
Speaker 1: water from the well up the inlet, so this part
Speaker 1: is still using atmospheric pressure, but the whole assembly is
Speaker 1: down inside the well, so it's not lifting the water
Speaker 1: very far. The drive water from the pump and the
Speaker 1: well water then pass through a venturi tube, and that
Speaker 1: increase in diameter decreases the water velocity but increases the
Speaker 1: water pressure. And it's that increase in water pressure that
Speaker 1: drives the water up further than it would go if
Speaker 1: we were just relying on atmospheric pressure to do the job.
Speaker 1: The high water pressure inside the tube moves the water
Speaker 1: up the inlet pipe into the pump and then ultimately
Speaker 1: through the plumbing system. So this pump uses the trick
Speaker 1: of lowering pressure inside the pipe to draw up water
Speaker 1: to a certain elevation. Then, through increasing the water pressure
Speaker 1: inside the pipe, lifts it or pushes it further up
Speaker 1: to the pump. This system can work with wells that
Speaker 1: are much deeper than shallow ones, though the further down
Speaker 1: the water is, the less efficient the system will be. Finally,
Speaker 1: we've got submersible pumps. Now, these are pumps that are
Speaker 1: actually in the water of the well itself, and rather
Speaker 1: than lifting water, they are pushing it up the pipe.
Speaker 1: They're also used for deeper wells. These pumps use a
Speaker 1: series of impellers that are separated by diffusers. Uh just
Speaker 1: like the tubes we're talking about before. These lower the
Speaker 1: speed of the water, but they increase the water pressure
Speaker 1: further up the chain, and they do that by increasing
Speaker 1: the diameter of the pathway that the water is following.
Speaker 1: So the water moves through a series of impellers and
Speaker 1: diffusers over and over again, with the water pressure building
Speaker 1: along the way, and that ends up creating the pressure
Speaker 1: needed to deliver the water up the well and to
Speaker 1: a home's plumbing system. One other common component of well
Speaker 1: systems know well water that is supplying homes is a
Speaker 1: pressure tank. Water from the pump will enter a pressure
Speaker 1: tank first before going through the home's plumbing system, and
Speaker 1: as water fills the tank, the pressure inside the tank increases.
Speaker 1: The pump has a sensor connected to this tank and
Speaker 1: there's a cut off value once a certain level of
Speaker 1: pressure is achieved, and at that point the pump shuts off.
Speaker 1: So when you turn on a faucet in a house
Speaker 1: that's supplied with well water, the water actually first comes
Speaker 1: from the pressure tank and the pump will stay off
Speaker 1: unless the pressure in that tank dips below a certain threshold.
Speaker 1: At that point, the pump will kick on and begin
Speaker 1: to resupply the pressure tank with water. Now, the reason
Speaker 1: for the pressure tank is that it decreases the number
Speaker 1: of times the pump has to cycle on and off,
Speaker 1: which helps cut down on wear and tear. There are
Speaker 1: usually some other components that are part of a well system,
Speaker 1: and these are meant to treat the water to remove
Speaker 1: stuff like minerals and organic material and sediment from your water.
Speaker 1: So a water softener is a type of device that
Speaker 1: does that. It's meant to treat so called hard water.
Speaker 1: Hard water contains high concentrations of minerals like magnesium and calcium.
Speaker 1: These are not toxic or anything like that, but they
Speaker 1: can deposit minerals on stuff like on shower tiles. For example,
Speaker 1: I actually have some issues with hard water at my house,
Speaker 1: so I have to scrub my tubs and sinks and
Speaker 1: showers fairly frequently to prevent build up. Water softeners combine
Speaker 1: a tank filled with resin beads and a brian tank
Speaker 1: that you typically have to fill with potassium chloride pellets
Speaker 1: or salt pellets on occasion. So incoming water moves through
Speaker 1: these resin beads, and the resin beads carry a negative
Speaker 1: charge and attract positively charged minerals that are in the water.
Speaker 1: So the minerals deposit to these you know, resin beats.
Speaker 1: They stick to the resin beads, and it allows the
Speaker 1: neutral y charged water to flow through and enter your plumbing. Now,
Speaker 1: eventually the beads attract enough minerals that the software needs
Speaker 1: to be quote unquote regenerated, at which point water flows
Speaker 1: into the brine tank. It creates a brine, and then
Speaker 1: the brine moves through the softener tank. The salty water
Speaker 1: washes the mineral deposits off of the beads. The wastewater
Speaker 1: well then flush down a discharge pipe, and then the
Speaker 1: softerer tank is ready to go again, and you would
Speaker 1: have to occasionally refill the brine tank with pellets on
Speaker 1: a fairly regular basis. How regular would depend on how
Speaker 1: much water you go through. There are other types of
Speaker 1: filtration systems that will remove specific metals and minerals and
Speaker 1: particulates from the water, like iron filtration systems. There's also
Speaker 1: systems that use ultraviolet light to kill off bacteria in
Speaker 1: the water. Actually technically doesn't so much kill off the
Speaker 1: bacteria as it renders the bacteria incapable of replicating. There
Speaker 1: are others that are designed to remove mercury, lead, nickel,
Speaker 1: other metals, as well as those designed to just filter
Speaker 1: out sediment or or getting materials in general. When we
Speaker 1: come back, we'll move away from wells and talk about
Speaker 1: municipal water systems. But first let's take another quick break. Okay,
Speaker 1: so a well might supply a house or a small
Speaker 1: community with water, but what about big cities. These can
Speaker 1: sometimes share some you know, similar elements with well water systems,
Speaker 1: but due to scale, we do require a different approach.
Speaker 1: So you've got to look at the water systems for
Speaker 1: cities as a group of stages and systems. First, you
Speaker 1: have to have a source for your water. Now, that
Speaker 1: could be an aquifer, it could be a lake, It
Speaker 1: could be a river or a stream or some combination
Speaker 1: of these. This water has to go through an extensive
Speaker 1: treatment process to remove anything harmful or unpleasant and make
Speaker 1: the water safe for consumption. More on that in a moment.
Speaker 1: And then the treated water has to go through a
Speaker 1: water distribution system, so pipes and pumps that connect us
Speaker 1: to our water supply, including things like water mains, and
Speaker 1: that provides the water pressure needed to actually move water
Speaker 1: through the system and out our taps and showers and
Speaker 1: washing machines and whatnot. Then you've got a wastewater system.
Speaker 1: I'm not going to really cover those in this episode,
Speaker 1: but the wastewater systems purposes to collect the used water
Speaker 1: and transport it to a wastewater water treatment facility which
Speaker 1: will remove as much contaminants from the wastewater as possible.
Speaker 1: You know, if we think of this a sewer water
Speaker 1: and that water should then be safe to return to
Speaker 1: the environment without contaminating stuff, you know, like your water supply.
Speaker 1: You don't want contaminated water to sink into the ground
Speaker 1: and then become part of the groundwater. You've just major
Speaker 1: drinking water contaminated if you do that. There are also
Speaker 1: stormwater systems that are designed to channel rainwater or snow
Speaker 1: melt away from you know, streets and homes and stuff.
Speaker 1: These systems are integral to prevent flooding, and they move
Speaker 1: water away from the infrastructure of our cities and towns
Speaker 1: and move it back toward the environment like rivers and lakes.
Speaker 1: That can also introduce contaminants. That's another issue, and again
Speaker 1: I'm not really gonna be able to go into that.
Speaker 1: I'm already running fairly along with this episode. So let's
Speaker 1: go through the process of water treatment. You've got your
Speaker 1: water source. So let's say in our example, it's a
Speaker 1: lake and you are transporting water from the lake to
Speaker 1: a water treatment facility. Let's say You've built massive pipes
Speaker 1: and pumps that pump water from the lake into a
Speaker 1: water treatment plant. The first stage is called coagulation and flocculation.
Speaker 1: This is the first stage of removing stuff that we
Speaker 1: don't want in our water, like sediment, bacteria, and you know,
Speaker 1: other stuff that could be floating around in a lake,
Speaker 1: like you know, bits of wood or other organic materials.
Speaker 1: Incoming water from the lake will mix with chemicals like
Speaker 1: ferric chloride or aluminum sulfate, and these chemicals are called coagulants.
Speaker 1: They will congeal with the suspended solids that are in
Speaker 1: the water, and it all comes down to again having
Speaker 1: an opposite charge. The coagulants have the opposite charge of
Speaker 1: the sediments, so they kind of bond to each other.
Speaker 1: They glom onto each other because those opposite charges are
Speaker 1: attracting one another. The mix of coagulants and water then
Speaker 1: moves into what are called flocculation basins, which is what
Speaker 1: a pair of words I mean. Try it, Just say it,
Speaker 1: floculation basin. It's it feels great. Here the water and
Speaker 1: coagulants mixed together. Slowly, the coagulants begin to kind of
Speaker 1: glom onto each other and grow larger. Through this process,
Speaker 1: they form what are called flock particles. Essentially, they're beginning
Speaker 1: to just kind of you know, concentrate, and eventually, once
Speaker 1: a certain quality of water is reached, this mixture will
Speaker 1: move into another section, which could take one of two
Speaker 1: different forms. So one of those forms is as sedimentation basin,
Speaker 1: and in fact, the sedimentation process is kind of what
Speaker 1: we call this part of the whole system. The purpose
Speaker 1: of this basin is to allow those flock particles to
Speaker 1: sink down to the bottom of this vessel, and they
Speaker 1: kind of form a nasty sludge. That sledge is removed
Speaker 1: from the tanks through special pipes near the bottom and
Speaker 1: then dumped in a landfill or something along those lines.
Speaker 1: The water at the top of the sedimentation basin is
Speaker 1: the cleanest, so the closer yard to the surface, the
Speaker 1: cleaner the water, and that water is allowed to move
Speaker 1: over to the next phase. And in this version we
Speaker 1: would take water from the top. Now, the reason I
Speaker 1: say that is to contrast it with the alternative method,
Speaker 1: and that is called a floatation basin, a dissolved air
Speaker 1: floatation basin. So here you pipe air into the bottom
Speaker 1: of the tank. You have like little pipes with holes
Speaker 1: in it, and you shoot air through those pipes and
Speaker 1: the holes allow bubbles to come in through the tank.
Speaker 1: Those bubbles flow up through the tank to go to
Speaker 1: the surface and along the way they push the flock
Speaker 1: particles up to the top of the tank and then
Speaker 1: you can use a sweeping arm to kind of gather
Speaker 1: those flock particles together for collection. So in this version,
Speaker 1: the cleanness water is actually at the bottom of the tank,
Speaker 1: not the top, so we would have a pipe towards
Speaker 1: the bottom of the tank that we would draw water
Speaker 1: from to go into the next part of the system.
Speaker 1: Either way, the water coming out of this part of
Speaker 1: the phase will then go through a series of weirs
Speaker 1: or w e I R s. That's a type of
Speaker 1: low dam and it's really just meant to change the
Speaker 1: flow characteristics of water. The water then moves on to filtration.
Speaker 1: Here the water will enter into a basin that has
Speaker 1: a sand filter in it. And the sand filter is
Speaker 1: exactly what it sounds like. It's a filter that's made
Speaker 1: up of different grades of sand. You have very fine sand,
Speaker 1: then you have medium, and you have really coarse sand.
Speaker 1: And wherever the water is coming in from, it's going
Speaker 1: to hit the course sand first and then move through
Speaker 1: progressively finer grains of sand. You can have versions where
Speaker 1: the sand filter is fed through the bottom, so you're
Speaker 1: forcing water in through the bottom, it hits the coarse sand,
Speaker 1: and then the continuing force of water is pushing water
Speaker 1: further up through the filter. Or you can do it
Speaker 1: the other way, where water is coming in through the top,
Speaker 1: hits the coarse sand, and then filters down through it.
Speaker 1: Most sand filters tend to take the bottom up approach,
Speaker 1: so we would just keep forcing water in and the
Speaker 1: water would move up through these different grains of sand.
Speaker 1: So how does it work. Well, it gets super technical,
Speaker 1: so stick with me. The particulates, the particles they're in
Speaker 1: the water, get caught on the sand as they encounter
Speaker 1: spaces where water can squeeze through, but the particles can't see.
Speaker 1: I told you super technical. So yeah, the water continuously
Speaker 1: moves through areas of sand that are more and more
Speaker 1: densely packed together, and more and more of those particles
Speaker 1: are kept behind. Some water treatment plants will then pass
Speaker 1: that filtered water through a second filtration system where they'll
Speaker 1: use something like activated carbon, and the carbon particles are
Speaker 1: porous and they can capture smaller particles and bacteria and
Speaker 1: remove that from the water. So if your fridge as
Speaker 1: a water filter built into it, it's likely using activated
Speaker 1: carbon to do the trick, the carbon grabs onto the
Speaker 1: particles and the water is free to go about its business.
Speaker 1: Then the water moves on to the next phase of
Speaker 1: the treatment system, which is disinfection. This is the phase
Speaker 1: that is intended to remove any remaining bacteria to make
Speaker 1: certain that the water is safe for human consumption. There
Speaker 1: are a few different methods in order to do this.
Speaker 1: One of them is used a chlorine based compound. This
Speaker 1: is a really common approach in the United States. One
Speaker 1: is to use an ozone treatment, and then the third
Speaker 1: is to use UV light treatment, and some facilities use
Speaker 1: a combination of these. All three have different pros and
Speaker 1: cons Chlorine, for example, can continue to kill bacteria even
Speaker 1: after it's moved out of the water treatment facility because
Speaker 1: there's still some chlorine in the water. So that means
Speaker 1: that this particular type of treated water can kill bacteria
Speaker 1: that gets introduced to the system after water has left
Speaker 1: the treatment plant. So if there's any point in the
Speaker 1: system where water from the outside environment can seep in,
Speaker 1: that chlorine can help take care of any bacteria that's
Speaker 1: in that water. The other two versions of of disinfection
Speaker 1: don't allow for treatment of water once it's left the
Speaker 1: treatment plant, but they have their own os and cons.
Speaker 1: Now at this stage the water should be safe to drink,
Speaker 1: assuming everything at the water plant is working properly, so
Speaker 1: you've now reached drinkable water. Once it's gone through all
Speaker 1: these phases, then it gets pumped into the city's water system,
Speaker 1: which is a network of pipes that feed out to
Speaker 1: the various homes and buildings in the city, with other
Speaker 1: pumps along the way to keep the water pressure going.
Speaker 1: And the water pressure leaves the planted around a pressure
Speaker 1: of for d P s I, and that is to
Speaker 1: make sure of a few things. One that the water
Speaker 1: has enough pressure so it can be pumped up to
Speaker 1: areas of higher elevation. And two there has to be
Speaker 1: a positive water pressure in the pipes. In other words,
Speaker 1: the water pressure in the pipes has to be strong
Speaker 1: enough so that the water is pressing outward on the
Speaker 1: pipes at all times, because that prevents any other water
Speaker 1: from outside from seeping into the pipes. If there are
Speaker 1: any gaps or cracks along the way, the internal water
Speaker 1: pressure is strong enough to push that water out so
Speaker 1: it's not gonna it's not able to get in, and
Speaker 1: that's important because if water could get in while that
Speaker 1: water would be untreated, and you would have all the
Speaker 1: dangers that are associated with contaminated water sources all over again.
Speaker 1: It would have been as if the whole process you
Speaker 1: just went through at the treatment facility didn't matter. So
Speaker 1: if there's an indication that's somewhere along the water system
Speaker 1: from the treatment plant to the homes or buildings where
Speaker 1: the water is being delivered, that pressure has dropped somewhere
Speaker 1: along that pathway, that's when you tend to get boil
Speaker 1: water advisories. The concern is that if water pressure is
Speaker 1: low enough, then external water might have entered the pipe
Speaker 1: system and so it could be untreated water and it
Speaker 1: would be unsafe to drink. That's why you're told to
Speaker 1: boil your water. It's really to kill off any potential pathogens. Now,
Speaker 1: boiling water won't remove everything, so you might end up
Speaker 1: with water that has higher concentrations of stuff like iron.
Speaker 1: But the primary concern, the first line of concern, is
Speaker 1: about potentially deadly bacteria like E. Coli. One of the
Speaker 1: most common municipal water system components is the water tower.
Speaker 1: Now you've likely seen lots of these. They are tall
Speaker 1: containers giant, giant containers that can hold a lot of water.
Speaker 1: So like your typical swimming pool holds something around the
Speaker 1: line of twenty tho gallons of water, the typical water
Speaker 1: tower can hold a million gallons. But usually a water
Speaker 1: tower is designed so it holds about a day's worth
Speaker 1: of water supply for the area that water tower services.
Speaker 1: So these water towers are really tall. They often are
Speaker 1: put in places of higher elevation because they depend on
Speaker 1: gravity to do a lot of work. Each additional foot
Speaker 1: of height that you have a container of water at
Speaker 1: increases the water pressure by point four three pounds per
Speaker 1: square inch. So the taller the tower, the higher the
Speaker 1: water pressure. Lifting a volume of water to a high
Speaker 1: point builds up a lot of potential in gy and
Speaker 1: releasing the water and letting it fall converts that potential
Speaker 1: energy into kinetic energy. But in a plumbing system in
Speaker 1: which you've got water filling up the system of pipes,
Speaker 1: the potential energy converts over into water pressure. So let's
Speaker 1: imagine you've got a water system in place for an
Speaker 1: unoccupied city. No one lives in the city, but you've
Speaker 1: got the water system set up, You've got the water
Speaker 1: tower filled up all the taps in the city are
Speaker 1: turned off. It's a sealed system. Right now, the weight
Speaker 1: of the water in the water tower is creating some
Speaker 1: water pressure throughout the system even if the pumps aren't on.
Speaker 1: So you open up a tap that creates an escape
Speaker 1: for the water and the water will come out of
Speaker 1: the pipe. The water towers are really there to act
Speaker 1: in a way kind of similar to the way a
Speaker 1: pressure tank works. With a house that has a well
Speaker 1: as its source of water, the water tower helps reduce
Speaker 1: the workload that the pumps in the system have to do.
Speaker 1: If we didn't have water towers in times where people
Speaker 1: were using a lot of water where demand is really high,
Speaker 1: then pumps would need to power up more. They would
Speaker 1: have to work harder to deliver water to meet that
Speaker 1: demand and to keep the system working. That requires more energy.
Speaker 1: It also results in more wear and tear on the pumps.
Speaker 1: But by storing water and water tanks and water towers,
Speaker 1: then we can use that to help supplement the water
Speaker 1: that's being supplied by pumps. We can keep running the
Speaker 1: pumps at a consistent level, which reduces wear and tear
Speaker 1: and is more energy efficient, and then we supplement that
Speaker 1: with the water from the water towers, and at night,
Speaker 1: when water demand is usually pretty low, then special pumps
Speaker 1: can pump water back up into the water tanks to
Speaker 1: refill them so that we again have a full day
Speaker 1: supply raid to go. At the beginning of this episode,
Speaker 1: I mentioned Flint, Michigan, and that the crisis that went
Speaker 1: on in the city's water supply. So what happened. Well
Speaker 1: back in two thousand eleven, Flint, Michigan was in a
Speaker 1: really tough spot financially. The city had been largely built
Speaker 1: around the automotive industry in the United States. In the
Speaker 1: nineteen sixties, the population of the city was around two
Speaker 1: hundred thousand people, but the automotive industry in the United
Speaker 1: States went through a total tumultuous time. Foreign car companies
Speaker 1: were able to really compete fiercely in the market in
Speaker 1: the United States, and American companies ended up having some
Speaker 1: massive problems as a result, and a lot of that
Speaker 1: meant that businesses started to move out of certain areas
Speaker 1: like Flint. So by two thousand eleven, with the automotive
Speaker 1: industry largely absent from the city, Flint's population was less
Speaker 1: than half of what it had been in the nineteen sixties. Now,
Speaker 1: that also meant that the city was taking in less
Speaker 1: money in the form of taxes. Not only was the
Speaker 1: local economy suffering because of the failure of the automotive
Speaker 1: industry there, the city's coffers were empty, and the city
Speaker 1: was actually in debt. In an effort to deal with
Speaker 1: this financial emergency, the city appointed managers who could make
Speaker 1: drastic cost cutting measures without going through the typical political processes,
Speaker 1: so they didn't have to seek after approvals, which sped
Speaker 1: things up considerably. The idea being that it was important
Speaker 1: to be expedient here. So one of the expenses that
Speaker 1: they identified was the water supply. Flint had been buying
Speaker 1: water service from Detroit. Detroit was processing the water and
Speaker 1: then sending it on to Flint, Michigan. So instead Flint wood,
Speaker 1: for at least a short time, starting in two thousand fourteen,
Speaker 1: draw water from the Flint River while building out its
Speaker 1: own regional water system with the goal of pulling water
Speaker 1: from Lake Huron, which was the same source as what
Speaker 1: Detroit was using. But the water coming out the Flint
Speaker 1: River was really contaminated, and the treatment system that Flint
Speaker 1: was using was not capable of treating the water properly.
Speaker 1: And here's where we got a tragic dilemma, because people
Speaker 1: need water, but the water that was coming out of
Speaker 1: the Flints system was unsafe to drink, and that unsafe
Speaker 1: water got pumped into the city's system and to people's homes,
Speaker 1: and some regions got worse water than others, and it
Speaker 1: was all pretty nasty stuff. You can actually watch videos
Speaker 1: of people turning on faucets filling up a clear glass,
Speaker 1: and you can see that the water is discolored. But
Speaker 1: apart from looking and reportedly smelling bad, it carried with
Speaker 1: it lots of contaminants, including dissolved lead. Lead is incredibly toxic.
Speaker 1: There is no level of lead that is considered safe,
Speaker 1: and consuming lead can lead to lifelong health problems. For
Speaker 1: a year, the city denied that there were elevated levels
Speaker 1: of lead in city water, claiming that any specific cases
Speaker 1: where people detected higher levels of lead, we're just restricted
Speaker 1: to the plumbing of those specific buildings or houses, saying, oh,
Speaker 1: it's not a it's not a systemic problem. It's a
Speaker 1: problem with your plumbing. And it took an outside investigation
Speaker 1: that proved otherwise. It said, no, this is a city
Speaker 1: level problem, and it means that people have been relying
Speaker 1: on a water system that was contaminated for a full year. Now,
Speaker 1: in two thousand fifteen, under immense pressure, Flint switched back
Speaker 1: to using water from Detroit, but by then a lot
Speaker 1: of damage had already been done. Now you'll occasionally see
Speaker 1: the message of Flint, Michigan still doesn't have safe drinking water,
Speaker 1: but that's actually not true. The water in Flint, Michigan,
Speaker 1: is now as safe or safer than other cities in
Speaker 1: the United States. However, the amount of damage that was
Speaker 1: done during the switch to the Flint River remains a problem,
Speaker 1: and for many residents it could be a problem that
Speaker 1: they have to manage for the rest of their lives.
Speaker 1: So that explains the challenges associated with delivering water to
Speaker 1: people now in our civilized age, is still a massive
Speaker 1: undertaking and obviously if something goes wrong, it could have
Speaker 1: dire consequences. And it reminds us that we have to
Speaker 1: be very careful with our water supplies. Even with the
Speaker 1: water treatment systems that we have, we need to be careful.
Speaker 1: It is easy to contaminate a water supply, whether that
Speaker 1: is a river or a lake or even groundwater. If
Speaker 1: you have poor wastewater treatment plans, then that wastewater can
Speaker 1: seep into the ground and then you've got very dangerous
Speaker 1: bacteria and other contaminants in the water system that could
Speaker 1: then be consumed later on. And that's why this is
Speaker 1: so important, and the technology involved is pretty interesting stuff.
Speaker 1: I highly recommend watching videos. I know that trying to
Speaker 1: visualize something like a centrifugal pump as a little tricky,
Speaker 1: but there's some great videos on YouTube that really show
Speaker 1: you how it works in case you want to get
Speaker 1: a visual on it. These things are really super cool,
Speaker 1: and again, the harnessing of physics is something I always
Speaker 1: find really fascinating. If you guys have any suggestions for
Speaker 1: future topics of tech stuff, whether it's a technology or
Speaker 1: a trend, into or a company or whatever something related
Speaker 1: to tech, send me a message and tell me about it.
Speaker 1: You can send it on Twitter. The handle for the
Speaker 1: show is tech Stuff H s W and I'll talk
Speaker 1: to you again really soon. Text Stuff is an I
Speaker 1: Heart Radio production. For more podcasts from I Heart Radio,
Speaker 1: visit the I Heart Radio app, Apple Podcasts, or wherever
Speaker 1: you listen to your favorite shows.