BIOCHLOR A Screening Level Natural Attenuation Model and Database for Solvents C.E. Aziz C. J. Newell A.P. Smith Groundwater Services, Inc. J.R. Gonzales P.E. Haas Air Force Center for Environmental Excellence Y. Sun T.P. Clement Battelle Pacific Northwest National Laboratory

BIOCHLOR Model Domenico Solution for Groundwater Transport Reductive Dechlorination/ Sequential First Order Rxns Reductive Dechlorination/ Sequential First Order Rxns

Why Use BIOCHLOR? Method for Estimating Plume Lengths System to Organize Site Data Tool to Help Understand Site Processes Screening Tool for Applicability of NA Supporting Line of Evidence for NA Method for Estimating Plume Lengths System to Organize Site Data Tool to Help Understand Site Processes Screening Tool for Applicability of NA Supporting Line of Evidence for NA

BIOSCREEN vs. BIOCHLOR: Similarities Domenico Analytical Model Microsoft Excel Platform User-Friendly Interface Based on Site Database Free Over the Internet Domenico Analytical Model Microsoft Excel Platform User-Friendly Interface Based on Site Database Free Over the Internet

BIOSCREEN vs. BIOCHLOR: Differences Petroleum Hydrocarbon Sites – BTEX Biodegradation: Petroleum Hydrocarbon Sites – BTEX Biodegradation: BIOSCREEN BIOCHLOR Solvent Sites More Complex Biodegradation: Solvent Sites More Complex Biodegradation: -1st Order Decay or -Electron Acceptor Limited -1st Order Decay or -Electron Acceptor Limited - Sequential Reactions - Different Zones - Sequential Reactions - Different Zones

BIOCHLOR: Key Processes Advection (1-D) Dispersion (3-D) Sorption Biodegradation: -Reductive dechlorination -Sequential reactions (parents to daughters) -Limited hydrolysis Different biodegradation zones Advection (1-D) Dispersion (3-D) Sorption Biodegradation: -Reductive dechlorination -Sequential reactions (parents to daughters) -Limited hydrolysis Different biodegradation zones

BIOCHLOR Model Domenico Solution for Groundwater Transport Reductive Dechlorination/ Sequential First Order Rxns Reductive Dechlorination/ Sequential First Order Rxns

Sequential Reactions PCETCEDCE VC ETH Rate PCE = –  1 C PCE Rate TCE =  1 y 1 C PCE –  2 C TCE

Reactive Transport Equations A-D Equation (1-D advection, 3-D dispersion) etc.... Rate PCE = d C PCE d t = L ( C PCE ) -  1 C PCE Rate TCE = d C TCE d t = L ( C PCE ) +  1 y 1 C PCE -  2 C TCE Rate TCE = d C TCE d t = L ( C PCE ) +  2 y 2 C TCE -  3 C DCE L ( C 1 ) = – v d C 1 d x + D x d 2 C 1 d x 2 + D y d 2 C 1 d y 2 + D z d 2 C 1 d z 2

BIOCHLOR Model Domenico Solution for Groundwater Transport Y. Sun / T.P. Clement Transformation

Distance from Source TCE DCE VC Results in BIOCHLOR

BIOCHLOR Model: Other Features Two Reaction Zones for Mixed Sites Zone 1: High Decay Rates (Carbon Present) Zone 2: Low Decay Rates (No Carbon) Source PCE TCE DCE VC ETH PCE TCE DCE VC ETH PCE TCE DCE VC ETH PCE TCE DCE VC ETH Zone 1 Zone 2

BIOCHLOR Model: Other Features Single Vertical Plane Source Single Vertical Plane Source Superimposed Sources (Connor et al., 1995) Superimposed Sources (Connor et al., 1995) Source 1 Source 2 Source 3

Predicts Parent, Daughter Compound Concentrations BIOCHLOR Model: Summary Provides Analytical Solution to Transport Equations with Sequential Reactions Simulates Two Biodegradation Zones for Mixed Sites Zone 1 Zone 2

BIOCHLOR Version 2.0 Rate Constant Decision Support System Source Decay Option Animation Feature Rate Constant Decision Support System Source Decay Option Animation Feature

Version 1.0: Available on CD OR Download free Currently: Jan. 2000: ( CsMOS Web Page ) How To Get BIOCHLOR... Version 2.0: Available: Fall 2000

BIOCHLOR Demonstration Case Study: Cape Canaveral AS, Fire Training Area Release: Solvents, degreasers, JP fuels ( ) Site Hydrogeology : Avg. Depth to Groundwater Hydraulic Conductivity Hydraulic Gradient Typical Groundwater Seepage Velocity 1.8 x cm/sec ft/ft 112 ft/yr 5 ft BGS

BIOCHLOR Interface – Input Parameters

BIOCHLOR Output

Individual Chlorinated Solvent Output

Array Output