Making Better Decisions: Real-Time Data Collection and Interpretation

Transcription

1 Making Better Decisions: Real-Time Data Collection and Interpretation Designing the Investigation and Interpreting the Data March 22-25, 2016 Presented by: Jason C. Ruf S 2 C 2 Inc., Raritan, New Jersey The Problem with Traditional Site Characterization Approaches Poor Characterization Traditional Site Characterization Results in Poor takes Descisions too long, and is often incomplete Regarding Exposure Risks and Remedial Design Extrapolating information from small data sets of high quality data to reflect large site-wide conditions is almost ALWAYS inaccurate & misleading Site needs to be Re-characterized Remedy fails 1

2 Objectives and Advantages of High Resolution Site Characterization (HRSC) Rapid and Complete Site Characterization REDUCES UNCERTAINTY when implementing remediation strategies Cost Effective on a program-wide perspective Allows for more targeted/appropriate remedial technique Designing the Investigation Evaluate Past Data Sets Analytical Data Geological Data Aerial Photographs San Born Fire Insurance Maps Previous Reports 2

3 Designing the Investigation Conceptual Site Model The conceptual site model is a critical tool that should be used to identify sources, receptors and pathways associated with the area of concern and/or site. The conceptual site model should support scientific and technical decisions for the site. The conceptual site model can also assist the investigator to communicate effectively with interested parties about the critical issues, and/or processes identified at the site, and support the remedial decision making process. Development and refinement of the conceptual site model will help identify data gaps in the characterization process and can ultimately support remedial decision making. Designing the Investigation Determine the BEST tool for the job: Maximize data density at the lowest cost per data point with data quality that satisfies data quality objectives. The selected tool(s) must also be feasible to advance based on known site conditions! 3

4 Designing the Investigation Best Tool For the Job Overburden Membrane Interface Probe (MIP) BTEX : Dissolved phase CVOCs: Source Area & Dissolved Laser Induced Fluorescence Hydrocarbons: Residual and Free Product Not Dissolved phase Electrical Conductivity (EC), Hydraulic Profiling Tool (HPT) & Cone Penetrometer (CPT) Soil Lithology Historic Fill Preferential Pathways/Targeting sample Intervals Bedrock Mobile Laboratory Rock Coring w/ packer testing Matrix Core Analysis Flute Liners Downhole Geophysical Mobile Laboratory SVOC PAHs, Pesticides, PCBs VOCs Below MIP detection limits and Speciation Metals XRF Test Kits Numerous available (PCBs, Pesticides, TPH, metals) Pre-Investigation Site Preparation A HRSC daily cost is typically more expensive than traditional sampling programs You know more about your site then your contractor! Getting a site ready prior to the contractor arriving can save time and money Call in you own public utility locate and/or have a professional locate done prior to contractor mobilization. Site access understand access to site and access to potential locations. Inform the property owner/tenants in advance. Don t stop with Direct-Sensing to collect soil/groundwater samples unless absolutely necessary. 4

5 Dynamic Work Strategies Experienced field team implements an Adaptive Sampling Program In-Field Decision-Making directs subsequent data collection activities as the Conceptual Site Model is refined Iterative process continues In The Field until sufficient characterization is achieved Direct-sensing data provides incredibly dense vertical data sets. However, it does nothing for horizontal data density! Interpreting HRSC Data HRSC programs generate a tremendous amount of data. It is critical to have a way to visualize the data Basemap and plotting of results in the field Computer based visualization in the field or off-site Good survey information is critical (GPS, auto-leveling, traditional surveying) Geoprobe provides free software for viewing their Direct-Sensing Logs -image-viewer-20 5

6 PID Response (uv) New Membrane New Membrane New Membrane 3/21/2016 Interpreting HRSC Data Geologic Data Making Picks Looking for patterns EC data shows changes in electrical conductivity typically related to grain-size changes HPT data shows pressure response in the subsurface to the injection of water CPT data shows tip and sleeve pressure Direct Sensing Detector Data Evaluating Response Direct-Sensing data provides an electrical response from a detector not a concentration. Must understand limitations of detectors FID, PID, XSD, UVOST/FFD. Must understand response tests! Figure 2: Pre and Post-Test Response Test Histogram 5 ppm Benzene - PID Detector Pre-Test Response (uv) Post-Test Response (uv) :59:00 10:50:00 12:25:00 PM 02:00:00 PM 08:10:00 09:40:00 11:10:00 08:00:00 09:40:00 11:15:00 09:05:00 09:00:00 11:00:00 02:00:00 PM 08:14:00 10:20:00 12:19:00 PM 01/06/1501/06/1501/06/1501/06/1501/07/1501/07/1501/07/1501/07/1601/08/1601/08/1601/08/1601/20/1601/21/1601/21/1601/21/1601/22/1601/22/1601/22/16 GP-20 GP-21 GP-22 GP-26 GP-23 GP-24 GP-25 GP-27 GP-28 GP-29 GP-30 GP-35 GP-34 GP-36 GP-32 GP-38 GP-37 GP-31 MIP Location 6

7 Detector Response (uv) 3/21/2016 Membrane Interface Probe HTL - TCE Response Test - XSD 7.00E E E+06 Notes: This graph shows XSD Response over a range of TCE standards with respect to time. Actual XSD response in the field will differ from the laboratory test due to the nature of the formation (i.e., matrix composition, saturation, etc.), actual chemical constituents present, as well as the phase of the chemical constituents (i.e., vapor, dissolved, solid). 100 ppm 200 ppm 400 ppm 4.00E E+06 MIP configuration: Heated Trunkline; PID and XSD detector in-line. XSD detector set to medium sensitivity. Test completed 12/10/ ppm 25 ppm 2.00E+06 XSD (uv) 10 ppm 1.00E+06 5 ppm 500 ppb 1 ppm ECD Detector Saturation 150 ppb 0.00E ,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000 Time (Seconds) Example MIP Logs 7

8 Collaborative Data Sets MIP detections found in low permeability soil. Groundwater sample from this interval had 11.3ppm total cvocs What are Collaborative Data Sets Very powerful in 3D- Visualization THIS IS IMPORTANT!!! All data points must be located in space correctly or nothing works. How do we incorporate sound interpretations into 3D visualization software? 3D Data visualization is increasingly becoming more common in data evaluation. Overall, this is a good trend; however, it is important that these interpretations be accurate! 3D Data Visualization is only as good as the data! If the density of data collected is sufficient to manage the uncertainties inherent in a heterogeneous subsurface an accurate interpretation is possible. Key to good 3D interpretations is good data and experienced professionals interpreting the data! 3D HRSC Animation CVOC Site 3D HRSC Animation - Arsenic & CVOCs 8

9 HRSC Data/3D Visualizations and Remediation Use 3D Visualization to Evaluate Remedial Options Injection design Volume and Mass of source zones Vertical and Horizontal Contaminant Distribution Use 3D analysis to evaluate performance as well 9