Acid Rain and Un-surveyed streams

[Chaz]

Rain is naturally acidic, but it is only marginally acid. A water sample would tell them right away if it was acid rain causing the issue, they can tell by the chemistry. Many stream in the ANF are naturally acidic according the AFM for that area, I spoke to him on the phone after being up there one time.
But acid rain would exacerbate the problem of natural acidity. As I remember Ltl. Salmon starts on the same ridge as the Spring Creek tribs. If the buffering is depleted by acid rain it would be a very long time before long term improvement of water quality would happen without intervention.

 

[FarmerDave]

Chaz wrote:
Rain is naturally acidic, but it is only marginally acid. A water sample would tell them right away if it was acid rain causing the issue, they can tell by the chemistry. Many stream in the ANF are naturally acidic according the AFM for that area, I spoke to him on the phone after being up there one time.
But acid rain would exacerbate the problem of natural acidity. As I remember Ltl. Salmon starts on the same ridge as the Spring Creek tribs. If the buffering is depleted by acid rain it would be a very long time before long term improvement of water quality would happen without intervention.

Salmon and Bluejay are opposite of Millstone and Spring Creeks on the same ridge. The first two flow to Tionesta Creek, and the latter flow into the Clarion. I know of only one trib of the 4 main streams that surveys better than Class D and it is only a C.

The geology sucks in that area, and buffering is minimal at best. Acid is a problem, but in the case of Millstone, I believe the soil and geology are actually the larger contributor of acidity.

Let me put it this way. It is pretty hard to ignore when the PH of a stream is CONSIDERABLY lower than the average PH of precipitation in the area. Well, hard for me to ignore at least, but then, this is my only PHD.

 

[MHanes]

Chaz the rain is acid in the region and has been documented as one of the worst areas in the state for acid rain. Stick with what you know something about.

 

[troutbert]

FarmerDave wrote:

It is pretty hard to ignore when the PH of a stream is CONSIDERABLY lower than the average PH of precipitation in the area.

I noticed that too. He says the pH of the rainfall in the area is about 5.0 and the ph of those streams is 4.7-4.8.

That is something that requires explanation.

I think he is simply wrong on his data about the pH of the rainfall.

http://www.dep.state.pa.us/dep/deputate/airwaste/aq/acidrain/report/tab12.pdf

According to the DEP info for 2005, the state mean was pH 4.46, and for Kane, the closest monitoring site to these streams, the pH was 4.4.

So the rainfall is coming down at around pH 4.4. Because the geology is very infertile, it gets just a little buffering, which brings the stream water up to pH 4.7-4.8.

On other acid precipitation affected streams in the state, pH 4.7 - 4.8 is not unusual. And this includes areas with no history of coal mining or natural gas production.

 

[FarmerDave]

troutbert wrote:

FarmerDave wrote:

It is pretty hard to ignore when the PH of a stream is CONSIDERABLY lower than the average PH of precipitation in the area.

I noticed that too. He says the pH of the rainfall in the area is about 5.0 and the ph of those streams is 4.7-4.8.

That is something that requires explanation.

I think he is simply wrong on his data about the pH of the rainfall.

http://www.dep.state.pa.us/dep/deputate/airwaste/aq/acidrain/report/tab12.pdf

According to the DEP info for 2005, the state mean was pH 4.46, and for Kane, the closest monitoring site to these streams, the pH was 4.4.

So the rainfall is coming down at around pH 4.4. Because the geology is very infertile, it gets just a little buffering, which brings the stream water up to pH 4.7-4.8.

On other acid precipitation affected streams in the state, pH 4.7 - 4.8 is not unusual. And this includes areas with no history of coal mining or natural gas production.

Good points there Dwight, and you may be correct.

The authors assessment of the two tribs of Spring Creek are likely spot on and frankly his assessment of SE ANF is what I have been saying for years as well only I have been saying it about a much broader area. I would have at least expanded it to include Salmon Creek drainage and maybe Bluejay and Maple Creeks as well.

I'm not sure how we got off on the Millstone tangent, but all I am saying is that I believe Millstone (which he also mentioned) has additional issues besides low buffering. It is clearly worse than all streams around it and even has the appearance of other issues. I bet the mineral content on some of the Millstone tribs is not so low based only on the appearance.

 

[pcray1231]

What is interesting is that some of the shorter streams off that ridge aren't bad at all. Logan, for instance, runs into the Tionesta from the south between Salmon and BlueJay. Class A. Other short ones like that are all decent. I would assume they get the same rain pH. Is there more buffering? Or is there a natural rock formation further south that leads to the acidity, and the short streams are too short to reach it?

Virtually all of the streams that run into the Tionesta from the north are at least decent, and some are very good. Again, I'd assume same rain. What's the difference?

 

[troutbert]

pcray1231 wrote:
What is interesting is that some of the shorter streams off that ridge aren't bad at all. Logan, for instance, runs into the Tionesta from the south between Salmon and BlueJay. Class A. Other short ones like that are all decent. I would assume they get the same rain pH. Is there more buffering? Or is there a natural rock formation further south that leads to the acidity, and the short streams are too short to reach it?

Virtually all of the streams that run into the Tionesta from the north are at least decent, and some are very good. Again, I'd assume same rain. What's the difference?

The difference is geology. In some places the bedrock and the soils derived from it supply a decent amount of buffering. In other places they don't.

 

[FarmerDave]

troutbert wrote:

pcray1231 wrote:
What is interesting is that some of the shorter streams off that ridge aren't bad at all. Logan, for instance, runs into the Tionesta from the south between Salmon and BlueJay. Class A. Other short ones like that are all decent. I would assume they get the same rain pH. Is there more buffering? Or is there a natural rock formation further south that leads to the acidity, and the short streams are too short to reach it?

Virtually all of the streams that run into the Tionesta from the north are at least decent, and some are very good. Again, I'd assume same rain. What's the difference?

The difference is geology. In some places the bedrock and the soils derived from it supply a decent amount of buffering. In other places they don't.

And in some places the geology actually contributes to the acidity.

Here is my attempt to address Pat's question.

Pat, it isn't really a ridge. It's a plateau. I chose to just stick with Chaz's choice or words, but now I need to correct that.

Also I never fished Logan, and frankly I don't like to talk about the tiny streams specifically but since you brought it up...

Logan likely drains a different geological layer compared to the tribs in question. As you move NW in that area, the surface rocks get older. Plus Logan drains a deeper gorge I think meaning it cuts into even deeper layers compared to the small tribs in question. I'm also going by geological maps available on the innertubes.

The Spring Creek and Millstone tribs in question are mostly on the plateau with relatively shallow gorges and drain more recent rock formations from the Carboniferous period.

It is still all sandstone, but different formations does mean different buffering.

Also, speaking of Salmon, I looked at a sat view, and didn't realize there are that many old wells there. It was likely wise for the author to exclude that, and I apologize for bring it and bluejay into the discussion.

 

[troutbert]

FarmerDave wrote:

And in some places the geology actually contributes to the acidity.

Are there examples of this?

I don't think it's the case that the geology is adding to the acidity.

But rather a case of the geology not providing enough buffering to raise the pH of the precipitation to a level that supports fish, or very much other aquatic life.

 

[pcray1231]

troutbert,

I do not know whether it is the case in that area that geology is adding to the acidity. But yes, there are indeed examples of it.

Pyrite and marcasite. When in contact with water, it forms sulfuric acid.

It's really much the same phenomena as AMD. Cept in mines it's exposed in much more massive amounts.

It does affect streams, in lesser degrees, quite naturally. Of course, we don't call this "affected", because it's not human induced. And streams don't suddenly die, rather, they were never that great to begin with. But when you read articles about AMD, sulfate levels and such, there is the "background level", which varies from drainage to drainage. This is the affects of natural AMD, so to say. And yes, if it weren't for humans, it is a source of natural variation between stream qualities.

We do expose increased levels in activities other than mining and drilling. For instance, at Mountaintop just north of State College, I'm sure you are aware that the I-99 construction exposed a massive pyrite vein, leading to a well publicized abatement effort (the gravelly slopes you see today). That vein did reach the surface naturally. It did drain a small, very acidic feeder into Buffalo Run. Thankfully, Buffalo Run is a limestoner and was not all that affected by it. But when they built the road, they exposed much more of it, leading to danger of worse, and hence abatement.

 

[FarmerDave]

troutbert wrote:

FarmerDave wrote:

And in some places the geology actually contributes to the acidity.

Are there examples of this?

I don't think it's the case that the geology is adding to the acidity.

But rather a case of the geology not providing enough buffering to raise the pH of the precipitation to a level that supports fish, or very much other aquatic life.

Do you honestly think i would have said it if there were not examples of this?

Look, when some minerals are dissolved in water, they form an acidic solution, right? Minerals come from the ground, right? Why would you think it can't occur without a human digging a hole first?

There is a lot of iron around there, and there is likely high sulfur coal is very close to the surface there too. the surface Geology is from Carboniferous (the coal age).

link

See Pat's response.

That said, I do not know if that is the case on Millstone or Spring Creek watersheds, but I suspect it in Millstone. Either that or there are a few old abandoned gas wells...

 

[troutbert]

Do you know the water chemistry of that small tributary before the recent road construction? And before the road cuts were made for the original Route 322 construction?

Where can you find that information?

 

[FarmerDave]

What kind of argument is that? Do you not agree that it can happen in nature without man's help?

 

[troutbert]

If "natural AMD" is a widespread thing, there should be many examples of streams that have not been mined or affected by similar types of land disturbances, that have a water chemistry similar to that of AMD affected streams.

So, what are some examples of these streams?

I don't think the evidence supports it. Even in "coal country" the streams in undisturbed watersheds run clean and support a lot of trout. In Clearfield County, in the whole headwaters of the West Branch Susquehanna up above Clearfield, that's what you see.

The streams in undisturbed watersheds are not suffering from "natural AMD." Their water chemistry is not similar to that of the AMD streams. The unaffected streams have very low amounts of dissolved materials, and the AMD impacted streams have very high levels.

Here's a chart comparing water chemistry of streams affected by AMD, and affected by acid precip.

http://www.cotf.edu/ete/modules/waterq/acidtable.html

 

[pcray1231]

Before the original route 322, no, I'm not that old, and environmental data from those days is scarce. Before I-99, I don't have it on me, but yeah, I've seen it. It was very acidic. It was a very small volume.

As far as the best proof of it. Read some scientific articles about measuring AMD levels. Any one worth it's salt will include readings for "background levels" of say, sulfates, which are usually taken in nearby "non-affected" drainages. They typically can't get the original value for the stream in question, so they take it from several nearby ones to get an idea of how much it is elevated by AMD. Not perfect, but the best that can be done.

Note that the background levels on those non-affected streams are not zero. And they do vary somewhat, which is why they get several from the area.

In the age of the dinosaurs, those levels were not zero either. If there are sulfates in the stream, sulfuric acid was formed. As FD says, pyrite is a natural rock. When it meets natural water, it forms acid. Are you trying to say pyrite has never been naturally introduced to water?

I doubt there's ANY streams in PA which aren't affected at all by natural acidification. There are plenty where other factors vastly overshadow or more than counteract it. But pyrite forming acid which flows into streams likely happens, at least on a small scale, in every single waterway.

 

[FarmerDave]

troutbert wrote:
If "natural AMD" is a widespread thing, there should be many examples of streams that have not been mined or affected by similar types of land disturbances, that have a water chemistry similar to that of AMD affected streams.

First of all, the first part of that is a strawman. I never said it was widespread, but saying it is non existent is extremely closed minded. Minerals dissolve in water, right? Some minerals raise PH, some lower it, right? What's the problem?

As Pat said, these acid forming minerals are indeed widespread. but fortunately in most places there are also minerals that neutralize acid. Mothernature is grand. Hell, you can even see fairly large deposits of pyrite inside of Penns cave (I was just there). Are you going to claim that this was man made? Fortunately the dominate mineral is limestone. Now, are you going to claim that there is always enough limestone around to neutralize these naturally forming acid forming minerals?

The surface geology in the area talked about in the article and we can expand on that to most of NWPA is dominated by sandstone and coal, and both of those are acidic in that area. Just look at the exposed sandstone. You will very often see raised brown ridges that do not erode as quickly as the rest of the rock. That is iron. The area was dotted with iron furnaces in the 19th century and it is fact that the ore was not hauled in.

The only significant buffering in that region was drug here by glaciers, and the area the author was talking about was never glaciated. Look it up.

There is a vast amount of records from the coal industry as well. NWPA is high sulfur coal and it is very close to the surface. IN FACT, there are natural outcroppings that were thee even before Europeans settled it. Since there is no limestone, why wouldn't groundwater running off of that coal be acidic?

So, what are some examples of these streams?

Here is the problem. I cannot prove that a stream is acidic just from natural sources anymore than you can prove that global warming is caused exclusively by human activity. Neither is 100% true. Furthermore, we (at least Pat and I) are talking about very small streams. Basically acidic mineral springs.

I don't think the evidence supports it. Even in "coal country" the streams in undisturbed watersheds run clean and support a lot of trout. In Clearfield County, in the whole headwaters of the West Branch Susquehanna up above Clearfield, that's what you see.

Coal Country is too broad of a term. Would you agree that the geology in the area you are talking about is different from what is in SE ANF? See the map that I linked. Not only is it a different drainage, it is also different terrain and geology.

The streams in undisturbed watersheds are not suffering from "natural AMD."

Prove it.

This is getting silly and detracts from the OP. The real problem is too much acid and lack of buffering and acidic rain is a significant problem.

But you know, precip on average has always been somewhat acidic, and to claim that man made acid rain over the past century or so depleted more buffering than 300 million years (youngest exposed rocks in that area) of less acidic rain is kind of silly as well don't you think?

But yea, acid rain is a serious problem.

 

[pcray1231]

The unaffected streams have very low amounts of dissolved materials, and the AMD impacted streams have very high levels.

I don't disagree, but you inadvertantly proved my point. Very low amounts does not mean zero! The unaffected streams do indeed have SOME. And, while I can't say that hundreds of years of human activity hasn't changed that at all, I can say that it was still NOT ZERO throughout geologic history.

What's more, is that those unaffected streams are not all the same. Some, quite naturally, have more than others.

I do agree with you that, even in streams barely large enough to carry trout, it is likely extremely rare for such effects to severely impact a stream. Tiny little mineral seeps near a vein, yeah, but on a small enough scale that most true "streams" can handle it with even minimal buffering, combined with dilution.

Still, water chemistry is full of tipping points. Buffering is funny like that. Take a jar of water with good buffering, and you can add a significant amount of acid without really changing the pH. But once you use it up, the next drop starts to have real effects! I'm not claiming that many major streams are naturally beyond a "tipping point", and "degraded", so to say. But I am saying that natural seeps like that can bring you a bit closer to such a point, lowering the ability of the stream to handle more. It's part of the equation.

Acidity of rainfall

buffering characteristics (based on geology)

natural sources of acid (based on geology)

unnatural sources of acid (roadbuilding, mining, etc. which expose acid rocks)

drainage characteristics (maybe there's plenty of pyrite, but the water shoots through that and then sits in a limestone deposit, whereas in the neighboring stream it discharges immediately to the surface stream).

It's complicated. I'm interested in such things, and have a basic scientific mind who can understand complex issues. But I am not a geologist, and have not had the time to study all of PA's rock layers and such.

 

[Chaz]

FarmerDave wrote:

troutbert wrote:

pcray1231 wrote:


Pat, it isn't really a ridge. It's a plateau. I chose to just stick with Chaz's choice or words, but now I need to correct that.

Dave thanks for correcting me, I know it is a plateau, but on a flat map on a computer screen it looks like a ridge. And anyway not all of the top of the plateau is flat.
I cannot attest for pyrite causing a similar effect as AMD though I would think some streams run across pyrite and are affected.
There are plenty of streams that because of geology are naturally acidic, and I can cite a few not far from me, Northkill is one, ALK near 0 according to Mike.
In boundary of Berks and Schuylkill counties quite a few streams start out infertile similar to that. Most of the streams south of the ridge cross into the limestone valley and become much more ferilte in that valley. And it happens pretty fast, because the limestone valley is very close to the base of the ridge. On the north side of the ridge very few of the streams get any better as far as alk and ph go. Go too far north and the AMD kicks in.
Very different from the glaciated Poconos, which is part of the Allegheny Plateau in the East for those that don't know. There are also streams in NEPA where it wasn't glaciated that the streams are very infertile, places like Mehoopany, Bowman, Rickettes Glen area.

 

[FarmerDave]

Chaz, Just so you know, I wasn't being critical of your choice of words. You know your stuff when it comes to this subject. It absolutely looks like a ridge on a flat map. I only felt a need to explain that after Pat compared a specific stream.

Your comment about being able to tell from a water sample was spot on.

The article was also likely spot on where it applies to the two tribs that were tested and I apologize that this side discussion has detracted from that.

I think the big confusion is that Dwight was looking at this from a general rule perspective. A macro point of view (larger drainage) and I was looking at it from a micro point of view (small tributaries). Kind of like if Dwight was going to write a book about it covering the entire state.;-)

 

[pcray1231]

If "natural AMD" is a widespread thing, there should be many examples of streams that have not been mined or affected by similar types of land disturbances, that have a water chemistry similar to that of AMD affected streams.

My point was that nearly all of them have constituents in the water chemistry similar to that of AMD affected streams. Just not to anywhere near as great of a degree. But the same minerals which cause AMD are present everywhere in much smaller, and varying amounts.