Re-using drilling mud for multiple bore holes

[theoak]

Hi everyone. I had a question about whether or not drilling mud is re-used when multiple boreholes are drilled. The site that I am thinking of is a smaller site where all of the boreholes are within a few hundred feet of each other, and the drilling mud is kept in a portable container. So moving the mud from one hole to the next would not be a problem.
The site is an environmental inspection where I suspect there is groundwater and soil contamination from TCE. I am mainly asking because I need to get a rough idea of how many containers of waste we will have after drilling. If mud can be re-used for multiple holes then it will cut that number big time. My only concern is that with re-using mud, there is a chance of cross-contaminating other boreholes.
I appreciate any thoughts that people may have. Thanks.

 

[Erdbau]

You are correct. Drum up the fluid and cuttings after each boring. You should also be decontaminating the tooling. You also need to consider the potential from cross-contamination within an individual borehole. You don't want to contaminate a lower aquifer if there is one.

 

[theoak]

Thanks a bunch Erdbau. I had looked everywhere and couldn't find anything about this.

 

[fattdad]

the EPA has plenty of guidance for these sorts of studies.

I prefer hollow stem augers, when ground conditions allow. If you are installing wells and have any desire to do a well test for permeability, drilling mud can affect results.

f-d

¡papá gordo ain’t no madre flaca!