Environmental Modeling - contaminated soil volume estimates

[Kaitlin S]

Hi there,

 

I work for an Environmental Consulting company and have been asked to 1) model sediment data, and 2) provide the volume of how much of that sediment has a Total PCB contaminant concentration greater than 0.023 mg/kg (NJDEP's Saline Water Criteria, Effects Range Low).

 

Here is a quick overview of how I set up the project in RockWorks17: A total of 45 borings were advanced, and several samples were collected from each boring.  Using the Borehole Manager, I have entered the Total PCB concentration results (mg/kg) for each sample under the I-Data tab. The Location, Lithology, and Stratigraphy tabs have also been populated.

 

My question is this, please: The extent of the PCB contamination has not yet been horizontally or vertically delineated. Is there a way to have the model predict when delineation would occur, and then provide a total volume?

Is running the I-Data model the best approach for what my company is asking? I have attached a screen shot of what I have been able to create for reference.

 

I am still fairly new to the world of RockWorks and would appreciate any feedback you could provide. Thank you!!

 

[Alison]

Kaitlin,

 

Thanks for posting the image and detailed explanation!  RockWorks really relies on data (non-detects or low measured concentrations) to delineate contamination.  The program does not include any tools for predicting where contamination might end.  Here are a few additional thoughts on this:

 

1.  Vertically, contamination is often delineated by geology - either by a bedrock surface or perhaps a confining layer.  If a geologic feature limits contamination vertically, you could use a stratigraphy surface as a lower "Subface" surface during modeling.

 

2.  If you don't have sufficient data to delineate contamination laterally, you might consider using a distance filter or a polygon during modeling.  Some users may also add additional "professional judgement" boreholes to help control the shape modeled contamination.

 

If you continue to have questions, feel free to send an email to tech@rockware.com, along with your dataset.

 

Best Regards,

Alison

[Kaitlin S]

Hi Alison,

Thank for you getting back to me so quickly; you have answered my question!!

 

Take care,

Kaitlin