Help...My Bunkers Smell!

[Brian Marion]

Anyone here have a solution for algae buildup in bunkers with silica based "sand" and porous concrete liners?


We have two, less than three year old bunkers that consistently get algae on the top layer. Our HGS has turned them over several times, they get regular hand raking, etc. The "high" side of the bunkers are clean, it's the lowest areas that build up. I suspect due to water draining to that area but would think it's not that wet due to the liners.


I've thought of a bleach solution?


Advice anyone? And let's not say "change sand" at least not yet. 

[Tom_Doak]

Baltusrol had this same problem after the previous renovation.  The water is not releasing through the profile.  The solution is either different sand, deeper sand, or better drainage (which is difficult to fix because of the liners).

[Randy Thompson]

Bleach will probably work but your only attacking the symptom not the problem. There is an apparent drainage problem that needs to be addressed. Solutions will take time and there are several credited laboratories that specialize in these physical analysis.

[John Emerson]

I agree.  The sand particle size and shape may be inhibiting water infiltration or the liner has some sort of issue. If the sand is too  round and uniform then it can pack together easily and, in turn, inhibit drainage creating a constantly wet surface. Here is a little educational material from the usga https://www.usga.org/content/usga/home-page/course-care/green-section-record/58/11/a-guide-to-selecting-the-right-bunker-sand-for-your-course-.html

[Adam Lawrence]

The latest innovation from Capillary Concrete is designed to deal with this and other sorts of sand contamination.


The Wash Box enables you to pressure wash your sand and remove impurities. It has been trialled in Florida and removed algae from bunker sand very effectively. But obviously you have to have their liner installed.


https://capillarybunkers.com/capillary-wash-box/

[Anthony_Nysse]

Anyone here have a solution for algae buildup in bunkers with silica based "sand" and porous concrete liners?


We have two, less than three year old bunkers that consistently get algae on the top layer. Our HGS has turned them over several times, they get regular hand raking, etc. The "high" side of the bunkers are clean, it's the lowest areas that build up. I suspect due to water draining to that area but would think it's not that wet due to the liners.


I've thought of a bleach solution?



Advice anyone? And let's not say "change sand" at least not yet. 

Just break the surface tension. Rake deeper than you normally do to loosen up the sand. Yes, it will be soft for a day, but will allow the the sand to finally dry down. Or spray Daconil on the sand. Seriously.

[Bruce Hospes]

Add sand.  With the fractured sands and permanent liners you need enough head pressure to flush the water through the profile.  In most instances, 6" of sand is enough but I would have your sand tested as others have suggested to find out what the release curve is.

[Alan FitzGerald CGCS MG]

Bruce is correct. Algae means the sand isn't releasing the water. All the other solutions are band aids and not fixing the underlying problem.


All the porous liners act like a USGA spec green by creating a perched water table at the interface between the sand and liner - a finer material over a coarser material will not drain until there is enough hydraulic head to push it through. The only permanent fix is to add more sand which will provide room for the hydraulic head to build and then let the water drain through the perched water table. The sand depth required will vary depending on the liner and the sand, so each specific combo should be tested for it's release curve. It can also be done by trial and error  - just keep adding an inch of sand until the algae goes away. On the flip side, you can add too much sand, which can make the top too droughty and lead to fried eggs.

[Randy Thompson]

Bruce is correct. Algae means the sand isn't releasing the water. All the other solutions are band aids and not fixing the underlying problem.


All the porous liners act like a USGA spec green by creating a perched water table at the interface between the sand and liner - a finer material over a coarser material will not drain until there is enough hydraulic head to push it through. The only permanent fix is to add more sand which will provide room for the hydraulic head to build and then let the water drain through the perched water table. The sand depth required will vary depending on the liner and the sand, so each specific combo should be tested for it's release curve. It can also be done by trial and error  - just keep adding an inch of sand until the algae goes away. On the flip side, you can add too much sand, which can make the top too droughty and lead to fried eggs.


I agree and usually in renovations of this type, the sand was probably tested and installed according to the results of the labortory. I still have to ask, if all the bunkers were constructed in the same manner, why have these three failed?

[Brian Marion]

From reading above, I would surmise that the two have failed due to not enough sand/pressure to push the water through. Time to add sand!


The practice bunker and 15th hole were renovated to show the membership what renovated bunkers would look and play like. Unfortunately, our course was reworked in the late '80's. Shall I say more?



We just completed a reno of our 18th hole with Mike Young doing the work. It's gone so well that we are now in the planning stages of the rest of the course and planning on ground breaking in spring '22.

[Alan FitzGerald CGCS MG]

Bruce is correct. Algae means the sand isn't releasing the water. All the other solutions are band aids and not fixing the underlying problem.


All the porous liners act like a USGA spec green by creating a perched water table at the interface between the sand and liner - a finer material over a coarser material will not drain until there is enough hydraulic head to push it through. The only permanent fix is to add more sand which will provide room for the hydraulic head to build and then let the water drain through the perched water table. The sand depth required will vary depending on the liner and the sand, so each specific combo should be tested for it's release curve. It can also be done by trial and error  - just keep adding an inch of sand until the algae goes away. On the flip side, you can add too much sand, which can make the top too droughty and lead to fried eggs.


I agree and usually in renovations of this type, the sand was probably tested and installed according to the results of the labortory. I still have to ask, if all the bunkers were constructed in the same manner, why have these three failed?

Randy,


In this case, it sounds like they were some trial bunkers and the other weren't done.


Failed is a strong word - Algae usually just means the sand is damp. The drainage still works and water will leave the system, but capillary action will hold the moisture until there is enough hydraulic head to push it through. The only issue is the sand is staying damper than it would if all the water properly evacuated. If there is standing water, that takes a long time to drain, then there may be more serious issues of a blocked liner or drain.


Saying that, sand moves so there can be variability in the moisture content of the sand even one bunker. I've seen bunkers where the sand was put in to the correct depth and compacted, but over time it settled some more, to where there was not enough sand to provide the hydraulic head to drain all the water from the sand. I've seen in some bunkers where the lower (flat) side is wetter/firmer and needs more sand but the face is fine, with less sand depth as the angle of the face is adding depth (as the sand is stacked at an angle) so it fully drains. That last bit is difficult to explain properly in writing so hopefully it makes sense.

[Randy Thompson]

Alan,
I agree with everything your saying if they are dealing with a temporarily surfaces algae problem. The title of the thread leads me to believe that the problem is more severe because surface algae usually deosnīt have a strong ordor. Strong ordor however are associated with black layer and more complex drainage problems.

[Brian Marion]

Alan,
I agree with everything your saying if they are dealing with a temporarily surfaces algae problem. The title of the thread leads me to believe that the problem is more severe because surface algae usually deosnīt have a strong ordor. Strong ordor however are associated with black layer and more complex drainage problems.

Randy,


I've already talked with our HGS and he's going to take it one step at a time based on the feedback given here. Start with simpler solutions and work our way toward solving the issue.


I do notice that under the algae layer, there is good white sand. So we will turn it over and add more as needed, first.