Recognizing that groundwater usage is more common than we think, we realized we had figured out a lot out about groundwater and were at a good point to put pieces together!  

We know that the water deep in a well is clean enough to drink, and that the particles of earth above where the well is drilled are so packed together that only water seeps, or infiltrates through. We also recognized that special rocks, called aquifers, are  rocks saturated with water and are actually located all over the US!  The people who responded to us on Twitter mentioned they get their water from the ground, wells, or aquifers are highlighted on the map below.  We realized that there's actually lots of aquifers all over the United States. 

We still didn't really know how the aquifers continue to refill, especially in areas like Oklahoma or Texas that don't get a ton of rain annually.  This video helps us see what infiltration really is, and how water continues to travel deep into the Earth over time, seeping in from bodies of water that may be close by or far away. We also saw how water can runoff surfaces.   Also looking at a breakdown of groundwater vs. surface freshwater, we are seeing that there is WAYYYYYYYYYYYYY more groundwater than surface freshwater on the Earth.  

Here in Chicago, we're fully aware that we have Lake Michigan near us and that we don't get our drinking water from aquifers, like many people across the US (and the world)!  So if we wouldn't drink directly from Lake Michigan, what happens with the water from the lake before it reaches our homes and we use it for so many daily activities?

We're starting to see all these ideas come together and we're so proud of what we've figured out. An elephant can't fit through a hole that's too small for it to step through.  The larger objects we put in our water to make it dirty that didn't dissolve got caught in our strainers.  Mrs. Brinza's "toy" model showed us how empty space/gaps allow some things to get caught and others to pass through--just like the holes or empty spaces in filters.  We're thinking the ground is a filter, too!

We also circled back to our Twitter post from Oklahoma.  She mentioned that the groundwater had to get refilled when they used all the water. We're curious how this happens so we agreed we needed to figure out more about wells.  When we found a well diagram, we were surprised at how different it looks like the "Jack and Jill" nursery rhyme picture many of us envisioned to be a well!  And of course there was so much to notice and wonder about this well system!

While actually going to a well would have been an incredible field trip, we're limited by a couple things. One, everyone in the city uses water from Lake Michigan, so we couldn't really ask anyone here about wells.  And we're still in the middle of a pandemic, so field trips are kind of out of the question.  But we did find a great video resource helping us figure out more about wells, how they're built, and how they get refilled!

Seeing all these groundwater/water in the ground/well water similarities pop up on Twitter made us wonder if we really could get water out of the ground.  We figured the best thing to do was to just dig...and this survivalist helped us see some amazing things!

So many of us had questions about how the water could actually be clean enough for the survivalist to drink (or anyone else that uses groundwater for that matter).  We are focusing on scale, and returned to one of our favorite practices as scientists--modeling.  We did a quick review of what we've figured out about particles and came to this agreement:

We then started thinking about the ground itself.  We know that sand is made of little particles, but we started considering what would happen to those particles as we got deeper and deeper in the ground, like the survivalist.  Through a lengthy discussion that we may have compared to a basket of laundry or a big pile of people wrestling on top of one another, we agreed that the things on the bottom of those piles would be super squished!  This means the sand deep in the hole is super compacted with little space around all the particles!

We then wanted to see a working model--like a model that actually tried to show what happened when water was in the ground, trying to move through the sand particles.  So since we're remote, we came up with some things Mrs. Brinza could use to help us figure this out.  She's teaching from her kids' playroom, so here's what they worked through together with some everyday toys:

We are really trying to make sense of this, as it seems so odd that water deep in the ground (which we think is dirty, right?) can actually help clean water!

With all our figuring out, the class majority agreed that we must get our freshwater from somewhere else besides the ocean, since it's too far, to long of a process, and just way too expensive!  We went back to our evolving model and updated it with the new ideas we figured out!

This naturally led to us thinking where we and others get our freshwater from!  Students were asked to develop models to explain their thinking!

We first agreed research would be okay to figure out where we get our water from here in Chicago.  Both the Chicago River and Lake Michigan were overwhelmingly voted for, but the size of Lake Michigan determined our best claim. Research confirmed this!

So we used Google Maps and looked at places all over the country!  We found some pretty interesting things:

1. There's nothing like Lake Michigan near ANY other part of the country. While places have freshwater, the bodies of water are really small and might not have the volume of water necessary based on what people use.

2. Some places have LITERALLY NO FRESHWATER.  Like what do these folks do?

Mrs. Brinza also turned to Twitter for help--since her account is public and active, people responded to this post and messaged her privately, which was great!

This really got us thinking about where people got their water from and we summarized our findings on this map.  So many ideas focused on water in places we hadn't even considered...like the ground.  That's super weird...maybe we should focus on that next since lots of people in lots of different places mentioned that!

So if boiling salt water to get freshwater works...maybe there was something more we needed to consider.

Like just how far is the ocean from us?  How much water do we use on a given day?  How much would it cost to actually heat the water?  We do have energy bills and we know energy isn't free.  We dug a little deeper into all these questions we had to figure out some important ideas about salt water being turned into freshwater!

We did a lot of figuring out with many tools that are offered to use during remote learning.  With Google Maps, we figured out that the nearest ocean is over 800 miles away...that's really far to get water!!!  With an online water footprint calculator, we determined how much water we use on average and it's a LOT!  And then with some energy cost analysis for the city of Chicago...HOLY COW!  Boiling salt water from the ocean to get our freshwater would be nuts!  That's just way to expensive!  We have to get our water elsewhere...and people that even live near the ocean must get their water elsewhere, too!  This process is just too long and too costly for it to be a reality for the majority of people.  Back to the drawing board...where do people get their freshwater from then???  

Recognizing that freshwater from the Chicago River eventually reaches the Mississippi River and dumps into the Gulf of Mexico, we were starting to wonder not only why this was the case (because all that fresh water would become salt water like our model showed us), but we also quickly realized just how much more salt water there was than freshwater!

Like we really thought the Chicago River was big and that Lake Michigan was big, but compared to the size of all the oceans, the river system was super tiny and the Great Lakes small compared to the size of the oceans on the Earth!  This visual REALLY got us thinking...

There's so much salt water, and very little freshwater...but how much of each is there?  Doing some research and math, we figured out the following:  

Whoah!  If 98% of the Earth's water is salt water, and the other 2% is freshwater, how can we really see what this looks like?  Fifth graders were asked to represent this mathematically, and we got some really cool ideas!

So if there is so much salt water, is this the water we use to drink?  How exactly do they get the salt out?  We turned to research again, and apparently  you can boil the water to get the water out of the salt water...

We've had questions where we get our drinking water from (as this was how we launched our unit when we all washed some dirty dishes) and it seems like this can't possibly be the way knowing it takes so long.  But maybe it is???

With Mrs. Brinza's help, we built out a landscape with some garbage bags and some toys she had laying around in her remote learning workspace (her kids' playroom)!  We added water to it to see what would happen. Here's what we noticed:

1.  Water always goes down to the lowest point. 
2.  It seems to pool where there's no slant.
3.  Water droplets join other droplets and kind of make rivers downwards at they flow.

While we initially thought wind got water flowing (and it might), Mrs. Brinza had no wind in her playroom, so we're thinking that it's just the slope that gets water flowing.

We decided the best way to figure out how the water flows in Chicago (like which direction) was to see if the land was sloped, and we're thinking it's not since Chicago is so incredibly flat.  But with some elevation data for Chicago and surrounding areas, we're seeing that the land is actually sloped, which means the water does have to flow!

With all the data, we see how the water is flowing towards the Gulf of Mexico, and using Google Maps, we confirmed this!  But now we're thinking...what does this really mean?  Doesn't all our treated water, that's 99% clean from our wastewater treatment facilities end up in a body of water that has salt in it?  What does this possibly mean?

Now that we agree what it means for a substance to dissolve, we returned to the wastewater treatment facility to realize we really didn't know how they could get out all the dissolved solids (and harmful bacteria from waste)!  So as we revisited our investigation ideas, we realized that our local wastewater treatment facility has made a virtual tour due to it being closed for tours due to the pandemic!  So we got a glimpse to go inside ours! 

After discussing what went on there, we realized we didn't understand a lot of the process, and did some more research and breaking down of some words that stumped us!

From here, we revisited our consensus model only to realize we absolutely knew how they treated the wastewater, but we had no clue what they did with it!  So we turned to Google Maps to help us locate the nearest waterways to the three wastewater treatment facilities here in Chicago!

We narrowed it down that each facility dumps the treated water into a river.  We've got some questions about this as:

1. Why would they work so hard to treat the water if it's still not safe to drink?
2.  Why do they dump it into a river?  Rivers are not safe to drink! 
3.  Is there another place that cleans the water we drink?
4.  Where does the river lead to? Does it go to the place we get our drinking water from?

SO MANY QUESTIONS!

With all this discussion around particles and dissolving, we're starting to see some patterns!  We've noticed that our dirty water looks so dirty because there are probably LOTS of solids that have dissolved in them!  We continued to focus this week on what it means for a substance to dissolve, practicing with salt, sugar, and a favorite this time of year--citric acid (it's found on the outside of Sour-Patch-Kids).  We tasted samples of water with salt dissolved in it and even used a scale to prove that the salt was still there!

With all this focus on dissolved solids, we're going back to where we had a lot of questions--what exactly happens at the wastewater treatment facility to get out everything from the dirty water?  If there are so many tiny, tiny particles in the water, how exactly do they get them out?

With our big AHA! moment coming in regards to the evidence showing us that water must be made of particles (and even smaller ones than the dirty stuff in the water), we reflected upon the models some students developed:  

We then went back to the drawing board to realize that all the models we've developed before could be improved with the evidence we've figured out regarding particles.  One of our investigation ideas was also to use a microscope to help us nail down what, if anything was still in our water, and by reaching out to the scientific teaching community on Twitter, Mrs. Brinza found a teacher with a microscope willing to help!

This got us thinking about how we could represent water, and anything that might be added to water in a new, improved way.  So we worked through a discussion determining:
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From here, students were asked to try and model their dirty water again!  We're really trying to figure out what's in our dirty water so we can better determine just how they clean it at the wastewater treatment facility.  

Knowing that many of the particles can't be seen, we're starting to think of what's actually happening to these particles in the water, especially since they can be seen at first and then seem to disappear over time.  We've got lots of ideas about what's happening to these substances made of particles, which include:

1. They're melting.
2. They're dissolving.
3. They're disintegrating.
4. They're disappearing.
5.  They're turning into something new!

Check out all the ways these students have modeled this:
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And by watching a microscope video, doing a taste test, and using a scale, we're figured out the following about what happens when a substance, like salt, enters the water and disappears.

We've got some consensus-making to do!!!  So exciting!