(inspiring music) - Good day from WTVP.

I'm H. Wayne Wilson with "At Issue."

And there's been a lot of news recently about droughts.

Droughts in Europe, droughts in the Southwest, droughts in California.

We don't have a drought in Illinois, but we should be concerned about the quantity of water we have, the sources that we find our water and the quality of that water.

And to have that conversation, we have Steve Wilson with us.

Steve is with the Illinois State Water Survey where he is a groundwater hydrologist.

And just for the record, he is no relation to me.

- (chuckles) Not that we know of.

- Maybe back in West Virginia, a long time ago.

- [Steve] Yeah.

- So with all the talk of the droughts, is there any concern about a lack of water for central Illinois?

- You know, not for central Illinois, I'd say, but certain parts of the state where water's being overused there could be an issue, like in the Chicago area.

As far as drought related?

You know, groundwater, especially, is more drought resistant because aquifers are buried.

They're not so susceptible to the fluctuations like a river or a lake are.

And so it's usually, they're more dependable over a period of a drought.

- We know that water in central Illinois can come from rivers, it can come from lakes, but a lot of it comes from aquifers.

What is the definition of an aquifer?

- So an aquifer is a saturated geologic unit of material.

So typically, that's sand and gravel that's buried underground and it's completely saturated and we draw water from that.

Or it's bedrock, where, obviously, water doesn't come from the rock itself, it comes from all the fractures and fissures that are in the rock and so we draw wells into those to tap into that source.

- Is there a historical reason why we have aquifers in central Illinois?

- As far as, you know, just the way the glaciers formed, you know, most of Illinois's glaciated, we're fortunate in that respect, and all the material that was deposited when those glaciers melted, it's just like the river beds today.

You have sandbars along rivers, small streams, especially that sand and gravel was deposited in the bottom of these bedrock valleys that were once flowing through Illinois.

So as far as a bedrock valley goes, you can think of it like the Grand Canyon.

It's a bedrock valley that a river formed.

The Colorado River runs through it.

When the glaciers came, they filled all that up.

And as the water's running, the largest materials fall out first and so the bottom of those valleys are full of gravel and sands before you have finer material that doesn't store water.

- I wanna talk at length about aquifers, but one question about rivers.

Is there a relationship between rivers and aquifers?

- Oh, totally.

Most rivers are either a discharge point or a recharge point for an aquifer.

So typically, it's part of the hydrologic cycle.

Water infiltrates into the ground, it gets into groundwater, that groundwater is always moving towards a discharge point and that typically is a river or a stream.

And so, yeah, they're very connected.

- So, and we'll talk a little bit about rivers later, but aquifers, there's two aquifers in central Illinois, the Sankoty and the Mahomet.

And they actually connect to one another?

- Yeah, so there were two bedrock valleys.

One came from West Virginia, the Mahomet Teays.

It runs through Indiana and Illinois, and it meets just south of here in Mason County.

And the ancient Mississippi bedrock valley, the glaciers basically changed the direction of the Mississippi River to what it is today.

Before there were glaciers, it actually ran through Peoria.

And so where those two meet, is where we're at basically.

And so we have both Sankoty and Mahomet Aquifer on the east side of the Illinois River.

- But those are different types of aquifers?

- They just have different sources.

So again, when the glaciers melted, both of those bedrock valleys filled with sand.

The Sankoty, which came from the north, the DePue is where the ancient Mississippi valley comes south.

And so all that's full of sand and all the Mahomet, which I live in Champaign, everything from the east coming this way is all Mahomet sand.

And because they had different source grains that formed all of that, it's ground up rock that makes sand, or some of it.

They're different in like texture, color, but they act as the same type of unit.

I mean, they're both sand, so they both hold water and provide water source.

- And you grew up in Logan county.

- [Steve] Yeah.

- And you had well water when you were growing up?

- We did.

So growing up, we bought my grandpa's 40 acre farm, our homestead.

And we had an old dug well that he hand dug in 1933.

So it was only 14 feet deep.

It was in a ravine, so it could catch more water, which he didn't understand and neither of my dad, that that was a risk because it's collecting surface water, and it was a pasture, we had livestock, all those things.

- We'll talk about the risk of wells in just a moment.

But in terms of, there are three types of wells.

- Right.

- And can you explain what those three different wells are?

- Sure, sure.

So you either have a drilled well that's usually a four to six inch casing, or you have a large diameter well, where there is no real aquifer available.

So the three types of wells, two of those are drilled and it's either in sand and gravel.

We'll use a 200 foot well for an example for both of these.

If you have a 200 foot sand and gravel well, it's finished at the bottom in sand and gravel, it usually has a four or five foot screen.

All of the water is coming from that four or five feet at 200 to 195 feet.

If you have a bedrock well, once you hit bedrock as you're drilling, you drill through the rock and you're trying to find fractures and fissures in the rock, because the rock itself, solid rock, doesn't have water in it per se, that's usable.

It's the fractures and the fissures which act like pipe flow.

So when you drill a bedrock well, you'll only put the casing 10 feet into the rock, or maybe 20 feet into the rock and the rest of your hole is open so those fractures can actually be usable.

And the hole you've cut through the rock acts as the casing.

And so, as an example, if bedrock's at 30 feet below land surface, you might only have 50 feet of casing for that 200 foot well.

That also makes it a little more risky because you could have water coming in from as high as 50 feet versus 195 from the surface.

- And then the one that your grandfather dug is... - The third type, yeah.

And so typically, you have a large diameter well is meant almost like a cistern.

It's meant to be a storage vessel for water to seep in slowly.

So we're fortunate in Illinois that our water table is typically pretty low, or pretty high.

I know in Champaign County, it's between seven and 15 feet, I think.

And this is for heavier soils where there's no sand and gravel.

And so you put in a bored well today, which it usually uses concrete tile, four foot sections of tile that you just set on top of each other.

They're not cemented together.

So each of those four foot rings, water can seep in.

And so you might bore a well that's 40 or 50 feet deep.

It's all more clay, silty type material, but the water table's there so it can slowly seep in.

And by having it three or four foot diameter, you've created storage.

So when you use the water during the day or in the morning or in the evening, then overnight, it can kind of fill back up and it's taking advantage of the water table.

- The water table is at different heights, depending on where you are in the aquifers.

So Mason County, it's pretty high.

- So the water table isn't necessarily an aquifer.

That's the one distinction.

So in Champaign County, say we have a 30 foot bored well.

It's taking water that's all consolidated material, I mean, all clay and silt, its not an aquifer.

But the water table is what infiltrates into the ground.

And once you get so deep it's saturated from there on down, even if it's not aquifer material per se.

So in Mason County, the water table is the water level in the aquifer because it's all just sand from the surface.

But in Champaign County, we have a water table that's seven to 15 feet.

But if we drill a wall into the Mahomet, which is about 200 feet below land surface or more, the water level in the Mahomet over there is about 60 feet.

So they're completely separate.

And in some places like in Champaign County, we have two or three aquifers as you go down because there's more than one glaciation that left sand.

- So, we have a water table and we have an aquifer.

- [Steve] Correct.

- They may or may not be- - [Steve] The same.

- The same.

- [Steve] Right.

- And Mason County is rather unique because its water table and the aquifer are so high that the irrigation systems down there, they can pump water.

- They're very fortunate there as far as water availability.

And it's because we get so much rainfall in Illinois, you know, 36 inches or so, depending on what part of the state you're in, that Mason County, because it's sand at the surface, there's a lot more infiltration.

11 to 14 inches of rainfall actually is infiltration and replenish the aquifer.

Champaign County, on the other hand, where it's tighter, a glacial till at the surface, most of it runs off.

The estimated recharge to the Mahomet in Champaign County is about a half to a quarter of an inch.

And so yeah, Mason County is very lucky because like during the drought in 2012, we only saw water levels in Mason County drop seven to 10 feet, where in Champaign County, they dropped almost 40 or 50 feet.

They did drop 40 or 50 feet during the drought because of pumpage.

- And in Mason County, the water table can actually be above ground level.

- Yeah and it's a unique feature there because the Illinois River is the discharge.

And it's not just the Illinois, but Crane Creek, the Mackinaw, the Sangamon, it's all sand.

And so the elevation of the water is higher further east.

So in Champaign County, our water may be at 600 feet mean sea level and at the Illinois River it's 440.

And so because of that difference, water's being pushed east to west and it discharges into those rivers.

And so what happened during the flooding in '93 is the Illinois River was high for so long, that the water that was trying to go into the Illinois River had nowhere to go and so it just kept filling up the bathtub, so to speak.

And eventually, I think around July or August of '93, we had about 1,000 lakes form in Mason County because the natural water level was above the land surface.

- I wanna talk about those pivots, as they're called, the irrigation systems.

- [Steve] Sure.

- Many of you may be familiar with the Ogalalla Aquifer.

It's a huge aquifer.

It may have some replenishing difficulties in the future, but Ogalalla is in Nebraska, in Texas, Oklahoma.

How many pivots are out there?

How many pivots are in Mason County?

How many pivots are in Champaign County?

To give people an idea of agricultural use of water.

- Well, on a big scale, we have about 8,000 pivots in Illinois, in the state, versus Nebraska has 93,000.

And the reason they have so many more is because we get so much more rainfall and we have pretty good soil.

So a lot of our areas don't need irrigation.

It's just the sandy areas or if they're trying to guarantee a crop, or for some other financial reason, like seed corn.

These days, most seed corn guys have irrigation so they can guarantee they're gonna get a crop.

Nebraska, on the other hand, gets 11 to 15 inches of rain.

And so that's why there's so much more going on and they have real problems because of that.

Not only with the water quantity in the Ogalalla but they're cycling that water and it's causing salinity problems and other things related to water quality there too.

As far as the largest area in the state of Illinois is in Mason County.

Mason and the southern part of Tazewell, there's about 2,400 pivots of the 8,000 are there.

So 30% are in that one and a half counties, versus Champaign County might have, between Champaign, Ford and Vermilion, maybe 120 pivots or so.

But it's because of the way the aquifer is, they draw down a lot more water in Champaign County than the 2,400 do in Mason County.

And it's just a matter of the amount of water available.

- You mentioned quality of water.

So let's turn the conversation to issues that may exist.

And you mentioned the southern half of Tazewell County.

I know Tazewell County, on occasion, some wells have an issue with arsenic.

- [Steve] Yeah.

- How serious of a problem is that?

How do we monitor that?

- Well, communities have to monitor for arsenic by law, through the Safe Drinking Water Act, but for private well owners, we recommend that everyone tests that's on the Mahomet, but especially in Tazewell County, we've done a lot of research through the Illinois State Water Survey and there's a lot of data available that there's just a lot of arsenic that naturally occurs in the aquifer, the Mahomet and the Sankoty.

And so everyone should test their well, just to know if they have arsenic or not.

It's kind of complicated as far as why it's there, but basically, it's in the source grains and the arsenic is attached to some pyrite that's in the aquifer.

And so depending on the chemistry, how reducing the conditions are, that arsenic may be released into the water versus staying bound to the material.

And so you can have a well that has 200 parts per billion of arsenic, which the health standard is 10 for community water supply, and a well half a mile away could be less than three.

And it's really a very local phenomenon.

So we've even had drillers over here call us and say, which depth should I drill to, to reduce the chance of arsenic?

And we can't tell them because there's no rhyme or reason.

You have to test every well.

- And it just depends on the geologic arrangement and what elements are... - That close to the well, right.

And the chemistry is, yeah.

And what we've learned is when you take a water sample, if there's sulfate, typically you don't see the arsenic being released.

But if there's no sulfate, then we typically see higher arsenic.

And there's a lot of research that's been done to look at that.

And that's why we recommend everyone tests and then you'll know.

- And because many wells are in rural areas, there could be an issue with nitrates.

How serious of a problem is that?

- Well, there hasn't been a real comprehensive nitrate study done for many years, since the '80s.

But we do know that especially areas like Mason County, where it's more sandy soil and there's more infiltration that there's likely in agricultural areas or near livestock facilities, you may have more nitrate.

And there's work going on currently to look at that.

I know there's groups that are looking at sampling statewide to do a nitrate study.

And so, just again, it's really about testing your well if you're a private well owner.

And again, communities, even the small rural communities all have to test by law.

- More recently, we've heard the term PFAS, polyfluoroalkyl substances.

- [Steve] Mm-hm.

- Can that be in groundwater?

- Oh, it is.

Actually, you know, it's everywhere.

It's a real problem.

It's in the air, it's in our bodies, it's in groundwater, it's in surface water, it's in plants.

We've used it for so many things for so many years that it's gonna be a real tenuous thing to do anything about.

Luckily, there's ways to treat for PFAS, even for private well owners.

And so there's existing treatment techniques at work, which I probably couldn't tell you what they are today, but I mean, regular types of treatment that are being used for years that work on PFAS chemicals.

- With all these issues with arsenic, with nitrates and many other issues with private wells, you have a class that you conduct.

- [Steve] Yeah.

- It's called privatewellclass.org.

- Yeah.

So we're funded through the U.S. EPA and RCAP, which is the Rural Community Assistance Partnership.

They're a technical assistance provider that work nationwide.

They have 200 some staff around the country.

They fund us to manage a program called the Private Well Class.

It's a 10 lesson class that anyone can sign up for for free.

It's basically a well owner 101.

It's sent to you as a PDF once a week through your email.

And then in support of that, we also answer people's questions and do webinars every month.

- That's for private well owners.

- [Steve] Yes.

- What about the small communities, communities that are 10,000 or less population?

Because we have the Safe Drinking Water Act of '72, it's been amended several times.

- [Steve] Right.

- It becomes more and more strict.

- [Steve] Yep.

- Small communities, do they have an issue keeping up with these kinds of changes in the law?

- They certainly do.

So they lack the economies of scale, that like a Peoria water company or anybody else has.

So mostly small communities tend to be the ones that are out of compliance, or have compliance issues, or are able to be sustainable.

And so the EPA funds a lot of work through technical assistance providers like RCAP.

And we're part of that.

So we developed this website, wateroperator.org, that provides free resources and helps small community operators find information.

We can refer them to people.

We also have a calendar that lists all the continued education credit training that's in the country as a service to provide for those small systems.

- Do we have to worry about pesticides?

- On the private well side?

I mean, they test on the drinking water, the small community side, but on private well side, you know, it comes down to what I tell well owners is, it really depends on your well and your geology.

You can have a well that's right next to a field where pesticides applied and have no issues.

If you're in Champaign County where you're getting your water from 300 feet below land surface, if you're well's properly constructed and properly grouted, which is the clay material that goes around your casing to keep stuff from flowing down in the borehole you've made, then you shouldn't have any issues with pesticides.

But if you have a well like the one I grew up on, that's an old dug well, we find Wells without a cap, or with a Folgers can on top of it, (Wayne laughing) or all kinds of things, and it's an older well where you don't have a log and you don't know the construction, then you need to be more concerned.

Or if you're in a sandier area where there's a lot more infiltration, then you're more likely to have some pesticide issues.

- With regard to depletion of groundwater, and that's going to vary depending on where you are, obviously, less water is one of the issues, but do we need to be concerned about the degradation of the quality of the water as the aquifer is depleted?

- Not so much in Illinois do we see that per se.

- Not necessarily in Mason County or Tazewell County.

- [Steve] Okay.

- But, you know, there's parts of Illinois that still have issues with wells and the quality of the water as you get less and less water available in the groundwater.

- So when a well lowers, the water level lowers, you're exposing rock, or usually a lot of times it's bedrock, to air.

And that changes the chemistry, it oxidizes materials.

So if there's metals in the rock or other things, and then when the water level rises again, that can get into the water system.

And so certainly lowering water levels, you know, like the drought in California, they've lowered things several hundred feet.

I mean, new wells that have to go in three or 400 feet deeper than old ones on the same property in order to get water.

So there's exposed to a lot more rock that could have metals and things like that in it.

And so there's always a risk when you oxidize materials that are normally saturated and don't ever have air, that you're gonna change the chemistry of the water, too.

- I wanna go back to the structure of an aquifer.

And we'll talk about the sand and gravel primarily in this area.

How much of it is actually water?

And how much is actually sand and gravel?

- So that's why Mason County has so much water.

You know, it's 100 feet thick and the porosity of that sand, if it were completely dry, if I've had a jar of sand, about 30% of that jar is air, so the porosity is 30%.

So in an aquifer, that 30% is all water in between the grains.

So if in Mason County, for example, if I took all the sand away, there'd still be 30 feet of water available if it's 100 feet thick and 100 feet saturated.

And that's just an amazing amount of water.

And the Mahomet, which stretches all the way back to Champaign and covers over 11 counties, is in some places as much as 200 feet thick and it's mostly confined and so it's completely saturated.

And so there's just a lot of water available.

And so the differences again, are the amount of recharge you get on a short term, why Mason County can pump so much water than Champaign County can.

- I know you're a hydrologist, not a geologist.

- [Steve] Sure.

- But I'm gonna ask this question anyway.

- [Steve] That's all right.

- If we deplete the water enough in a aquifer, is there any possibility of subsidence?

We talk a lot in central Illinois about mine subsidence.

All of a sudden we get sink holes, we commonly call them.

- [Steve] Mm-hm.

- Because the sand and gravel has 30% air, is there any possibility that when the water is removed, that collapses a little bit?

- It can, we don't usually see that here, but there are other parts of the world where that's been an issue, where they've mined enough water out of a unit that it's caused some subsidence.

And there's also other issues like in southern Illinois, karst, Pike County, where it's all karst, which is soft rock basically, so that water, it's what forms all the caves and caverns and all those things, is what?

Moving water.

And so you see sinkholes develop where the rock has eventually been worn away.

And that's a real water quality of concern.

- And there's an organization called the Central Region Groundwater Protection Committee.

- Mm-hm.

- You consult that organization?

- So I'm kind of their advisor, or one of their advisors, as a member of the Water Survey.

So I participate in their meetings and it's really meant to be a local stakeholder group.

They've been around for a long time and they do a lot of good in the area.

They're made up of County Health Department folks, water operators, drillers, other water stakeholders in the tri-county region here in Peoria.

And so I think it's those three counties, but it's because we have a vulnerable aquifer here where sand is the surface, that that's why they're formed.

And they do a lot of good.

- And with that, our conversation on air has to conclude.

We hope to continue it later on at those websites that we showed you, if you have a well, or if you're living in a small community and operating a small water system.

Say thank you to Steve Wilson, who is with the Illinois State Water Survey as a groundwater hydrologist.

Thank you for being with us on "That Issue."

- Thanks for inviting me.

- And we'll be back next time with another edition of "That Issue."

This time we're going to be talking about copi.

Yes, Asian carp.

It's a new name.

We're gonna see if copi is going to have an impact on the acceptability of Asian carp in your diet, on the next "That Issue."

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