Does anyone know if it’s viable to raise a trout streams PH?

[tomgamber]

The specific one I'm remembering is not a mining reclamation. It's an acid rain problem. Rock run that runs into Linn run. All I can find are articles saying they'll announce their findings that are over a year ago. I'm sure someone can find it.

 

[Cebe]

The lime dosing I saw was addressing acid mine drainage, which is probably a different issue than just a naturally low pH stream.
Low pH usually means less invertebrates such as insects because less calcium is available for their exoskeletons, thus less insects as a food source for trout.

Acid mine drainage affects that also, but has the addition of solubilizing heavy metals which become toxic to fish and probably insects. Lime dosing is as much targeting tying up toxic metals making them less soluble.

I am not sure of the harmful effects of lower pH on fish or differences of tolerance across species.

Dumping limestone in just about any form will eventually be dissolved by low pH water just that the finer it is the faster it dissolves. I wasn’t aware that it could actually seal off from dissolution in certain situations, but I suppose anything is possible.

 

[Oregon_OwlII]

Another factor in your situation may be the riparian vegetation. There are trees that produce leaf litter that are very favorable for aquatic insect production, and others that are less so, and that most likely depends upon the underlying geology and soil types in your region. This situation may be "unfixable" in the big picture of things. Water chemistry may not be the only limiting factor in your area.

 

[lestrout]

Another factor in your situation may be the riparian vegetation. There are trees that produce leaf litter that are very favorable for aquatic insect production, and others that are less so, and that most likely depends upon the underlying geology and soil types in your region. This situation may be "unfixable" in the big picture of things. Water chemistry may not be the only limiting factor in your area.

Enlarging on this useful thought, I heard the great Stroud Water Research Center discussing the effect of native trees on stream macroinvertebrates. For instance, tan caddis (Hydropsyche) around here, which are native, greatly prefer eating the fallen leaves from native trees like oak. Not so much the exotic trees homeowners plant, like ginkhos, etc. Kinda like pandas eating only bamboo shoots. The caddis pops of a local stream exhibit this effect a lot. So maybe more midges or whatever, but definitely fewer caddis.

Also certain tree leaves like oak are very tannic, which is low pH. Dunno if the tree roots moderate the soil pH,

 

[HoboWithAFlyRod]

Enlarging on this useful thought, I heard the great Stroud Water Research Center discussing the effect of native trees on stream macroinvertebrates. For instance, tan caddis (Hydropsyche) around here, which are native, greatly prefer eating the fallen leaves from native trees like oak. Not so much the exotic trees homeowners plant, like ginkhos, etc. Kinda like pandas eating only bamboo shoots. The caddis pops of a local stream exhibit this effect a lot. So maybe more midges or whatever, but definitely fewer caddis.

Also certain tree leaves like oak are very tannic, which is low pH. Dunno if the tree roots moderate the soil pH,

Gonna dump a truckload of oak leaves from my yard into spring creek this fall, got it.

 

[tomgamber]

Leaves would be rather acidic.

 

[Paul Barci]

I didn't hear anyone mention what was done on Pine Creek at one of the tribs dumping mine acid in just above Slate Run to improve the hatches.
It did seem to do the trick.
This was many years ago, but as far as I know, the pits are still in operation.

 

[lycoflyfisher]

There are two very different topics being discussed on this post.
1. Abandoned or acid mine drainage remediation.
2. Low stream pH due to atmoshperic deposition (acid rain) in watersheds with bedrock material that has little to no alkaline material.

It sounds like the OP is interested in 2, but we do not have enough information. Nor does it sound like he has enough imformation to know what is causing the perceived issues in his watershed of interest in North Carolina.

 

[Oregon_OwlII]

Enlarging on this useful thought, I heard the great Stroud Water Research Center discussing the effect of native trees on stream macroinvertebrates. For instance, tan caddis (Hydropsyche) around here, which are native, greatly prefer eating the fallen leaves from native trees like oak. Not so much the exotic trees homeowners plant, like ginkhos, etc. Kinda like pandas eating only bamboo shoots. The caddis pops of a local stream exhibit this effect a lot. So maybe more midges or whatever, but definitely fewer caddis.

Also certain tree leaves like oak are very tannic, which is low pH. Dunno if the tree roots moderate the soil pH,

I didn't get detailed, but Stroud is the source of my info. I know in SE PA, Sycamore, silver maple and river birch produce some of the best leaf litter nutrition for the aquatic insects in that region. Those very trees may not succeed in the part of North Carolina being referenced in the OP, again for the very reasons of soil characteristics and underlying geology. Also, the trees I mentioned grow best in a flood plain situation.

 

[Old Town]

I got involved with liming low PH streams in the mid 70s. Then about 20 plus years ago I spearheaded a liming project on a small brook trout stream in South Central Pa do to it having very limited if any natural buffering. We used high PH lime and shoveled it into the stream at two branches multiple times each year. We keep readings including PH and it did help. However the main problem was from high water conditions from heavy rain storms and winter -spring snow melts. Biologists noticed a absence of certain year classes that was do to low PH spikes and the eggs not hatching. Several year later there was no evidence of the absence of year classes after the project was complete. However the project did NOT increase the normal day to day PH other then right after we reapplied fresh lime. We did notice a slight PH increase after many years and was do to western states no longer burning high sulfur coal to generate power. ( this is what we were told).
A final note : Between buying the lime. transportation and site prep it can run into a fairly large expense and can be difficult to convince those in power that this will help the environment. Many trees and flowers require a low PH to survive.

 

[Dave_W]

I got involved with liming low PH streams in the mid 70s. Then about 20 plus years ago I spearheaded a liming project on a small brook trout stream in South Central Pa do to it having very limited if any natural buffering. We used high PH lime and shoveled it into the stream at two branches multiple times each year. We keep readings including PH and it did help. However the main problem was from high water conditions from heavy rain storms and winter -spring snow melts. Biologists noticed a absence of certain year classes that was do to low PH spikes and the eggs not hatching. Several year later there was no evidence of the absence of year classes after the project was complete. However the project did NOT increase the normal day to day PH other then right after we reapplied fresh lime. We did notice a slight PH increase after many years and was do to western states no longer burning high sulfur coal to generate power. ( this is what we were told).
A final note : Between buying the lime. transportation and site prep it can run into a fairly large expense and can be difficult to convince those in power that this will help the environment. Many trees and flowers require a low PH to survive.

Thanks for mentioning this.

This was a good plan and I helped many times with the shovel work. Between 2006 and (I think) 2012 I did some macro surveys above and below both sites and these revealed better results below the liming sites. It should be pointed out that the results were not striking, but noticeable and consistent (more macros, greater size, diversity, etc.).

 

[chief17]

I've been involved with treating acid mine drainage for a good 12 or 13 years now. There are several success stories in PA where a mine discharge was treated and the stream rebounded and now house plentiful trout populations. These are all mainly treated at the source of the problem.

What the OP has described sounds like the low pH conditions could be caused by the granite bed running under the entire length of streambed? Basically you need to figure out if the low pH water is coming from a certain point, be it a trib, seep, or maybe a section of stream that passes over some sort of geologic formation that drops the pH. If it's a single point, treating is pretty easy like an AMD site. If the whole stream is low, then that would be a different animal I think.

You could add lime to it, but would have obviously do so continuously (paced off of the flow) and then see how far downstream the pH stays elevated. If it drops at some point back down to baseline, you'd need another treatment point, etc. Lime really isn't all that soluble, so immediately downstream of the treatment point, you might end up with a section that's coated with calcite and possibly devoid of aquatic life (I don't know how well bugs do in an area where the stream bed is covered in lime/calcite).

I thought there was a PA DEP website that had all info on their AMD treatment systems and success stories but can't find it at the moment. The Office of Surface Mining Reclamation and Enforcement might have some resources or advice. While your application isn't mining specific, they deal with this sort of thing on the mining side all of the time.