Stone cutting /slurry

[jvoisin]

Anybody have experience treating water used for cutting granite stone. It is a small operation. I was thinking pretreatment with septic tanks and discharging to a pond. There is no municipal sanitary sewer on the site.

 

[dhengr]

Jvoisin:
I don’t know what a septic tank would do, but a couple solid bottom conc. tanks in parallel might be a good idea. You could switch from one to the other, while you were treating/neutralizing and removing the solid contents of one of the tanks. Maybe these tanks should be wide enough to run a small skid steer front bucket machine into. I would take some of the water and fine solids to a testing lab and ask them to tell you what of the contents might get you in trouble with the EPA and the like. Then run the water into a settling basin for evaporation and settling into the soil and ground water system. I’m also not sure how you collect this sawing slurry, won’t it just end up down in the bottom of the pit, to settle out the fines and pump out the water? The rock is already there, the question is, when you turn it to dust and slurry by sawing, do you transform it to a more lethal form, that you have to clean up before release?

 

[Ron]

If the only residue is rock dust and water, septic tanks won't help...nothing organic to digest.

You probably only need a stilling basin and decanting system to pull clear water from the top. Concentrated sludge from the rock dust can then be spread on the ground to complete the drying and mixed with soil for stabilization.

 

[bimr]

Septic tanks are used to remove dissolved organic material which is not present in the stone cutting operation.

Treatment of this type of wastewater would normally be handled by running the water through several tanks where the solids are allowed to settle out. Most of the solids will settle in the first tank. Make this tank large enough so that you can excavate the material out with a clamshell bucket.

The overflow water can be recycled back to the saw so that water discharge is minimized.

 

[jvoisin]

Thanks. A series of tanks is essentially a septic tank. The principal is the same. A series of tanks could also be used to treat organic matter.

I am thinking to use a shallow tailing pond with turfs stone bottom that an excavator could feel when removing sediment. Overflow would be discharged through a weir to an enhanced swale containing check dams.

 

[dicksewerrat]

Test the slurry. If it is alkali, it could be used on sod fields to reduce acid in the soil.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[Canuck67]

No specific knowledge, however, I did tour a building last year where stone cutting took place. All the cutting equipment utilized water in the process which was collected as a slurry in pits by the equipment. In one location of the building, the pit was drained of water and an backhoe was used to scoop the material out into a disposal bin. At another location, the slurry drained to a large sump pit in the corner of the building. The slurry was pumped up to roof level to some form of specialty equipment that had large filter bags that retained the solids. The large filter bags full of the solids were then presumably disposed of somehow. "Pristine" appeared to be the manufacturer's name on the equipment.

 

[jvoisin]

Thanks Canuck67. I will be onsite tomorrow to have a look at the equipment and will update.

 

[LittleInch]

Have you considered using geobags? If you have a lot of space out can just pump slurry into them, let them drain out with clean water then as the fill up with sediment either transport the bags whole or cut them open and remove with excavators etc. you can get these things in hundreds of metres length as a tube.

something like this but I think there are many suppliers

http://www.uat.com.au/geobags.html

or

http://www.dewateringsolutions.net/geotubes.htm

Or you could use a cyclone to reduce your water content that you need to store and allow 90% to be discharged straight away. They are very effective with sand and gravel.

My motto: Learn something new every day

Also: There's usually a good reason why everyone does it that way

 

[SteveWag]

Check this list to determine, if in USA, who has jurisdiction:

http://water.epa.gov/type/groundwater/uic/class5/permittingauthorities.cfm

If EPA is the agency, then consider a Class V Well. This is just a pond with a permeable bottom and maybe sides. The area/soils must “perc”, so the wetted area is based on GPM/sq. ft. of perc. rate, same as a septic system. It is a one page letter application with no testing requirement because there is no surface discharge. If you discharge directly to the well it would be hard to recover/reuse the water. You said “small”, I have done a well for a local (PA) one man operation.
Just for info, I have done quite a few for disposal of Fe/Mn waste generated by treating mining contaminated well water. Sort of nice to send in a plant permit application, with all the specs and drawings to the State permitting people, with an EPA attached letter that effectively removes the liquid/solids disposal system from the State purview.
Steve