API 4734 : 2005

Executive Summary
Technical Highlights
1.0 Introduction
1.1 Project Overview
     1.1.1 Research Objective
     1.1.2 Project Organization
     1.1.3 Scope of Modeling
1.2 Background
     1.2.1 Fulfilling an Industry Need
     1.2.2 Potential Impacts of a Release
     1.2.3 Common Soil Restoration Programs
     1.2.4 Restoration of Chloride in Ground Water
2.0 Factors Influencing the Migration of Chloride
2.1 Vadose Zone Factors
     2.1.1 Vadose Zone Texture
     2.1.2 Water Content in the Vadose Zone
     2.1.3 Dispersion Length of Chloride in the Vadose Zone
     2.1.4 Depth to Ground Water or Vadose Zone Thickness
2.2 Climate
2.3 Brine Release Factors
     2.3.1 Chloride Concentration of Release
     2.3.2 Release Volume and Total Mass
     2.3.3 Height of Spill
2.4 Groundwater Characteristics
     2.4.1 Ground Water Flux
     2.4.2 Aquifer Thickness
     2.4.3 Aquifer Ambient Chloride Concentration
2.5 Heterogeneity
2.6 Repeated Releases
3.0 Modeling Approach
3.1 Vadose Zone Model: HYDRUS-1D
     3.1.1 Model Overview
     3.1.2 Applicability of HYDRUS-1D for Produced Water Releases
3.2 Saturated Zone Model: Mixing Model and MODFLOW
3.3 Data Sources
     3.3.1 Soil Data
     3.3.2 Climate Data
4.0 Sensitivity Analysis of Factors Determining Brine Fate
4.1 Purpose
4.2 Modeling Specifics
     4.2.1 Vadose Zone Factors
     4.2.2 Aquifer Factors
     4.2.3 Brine Release Factors
4.3 Simulation Responses
4.4 Statistical Analysis of the Responses at a Monitoring Well
     4.4.1 Maximum Chloride Concentration
     4.4.2 Arrival Time of Maximum Chloride Concentration
5.0 Initial Vertical Distribution of Chloride (First Year)
5.1 Purpose
5.2 Modeling Methodology
5.3 Analysis and Data Presentation
6.0 Heterogeneity
6.1 Purpose
6.2 Modeling Methodology and Input
6.3 Analysis and Data Representation
7.0 Vertical Chloride Distribution Over Thirty Years
7.1 Purpose
7.2 Modeling Methodology
7.3 Analysis and Data Presentation
8.0 Repeated Releases
8.1 Purpose
8.2 Modeling Methodology and Input
8.3 Analysis and Data Presentation
9.0 Soil Restoration
9.1 Purpose
9.2 Modeling Methodology and Input
9.3 Data Analysis and Presentation
10.0 Effects of Vegetation
10.1 Purpose
10.2 Modeling Methodology and Input
10.3 Data Analysis and Presentation
11.0 Understanding the Role of Each Factor
11.1 Produced Water Release Characteristics
11.2 Vadose Zone Characteristics
11.3 Climate
11.4 Vegetation
12.0 Verification of Model HYDRUS 1D for Prediction of Chloride Fate
12.1 Purpose
12.2 Approach
12.3 Description of Sites and Boundary Locations
12.4 HYDRUS 1D Simulations
     12.4.1 Anode Beds (Sites L-21 and M-33)
     12.4.2 Junction Boxes (Sites EME P36-2 19S 3E and
            EME M-3-1A 21S 36E)
12.5 Data Analysis and Presentation
References
Appendix A Results of homogenous and heterogeneous profiles
Figures
Tables

Describes a scientific basis for operators, regulators and landowners to determine if assessment or remediation of produced water releases will provide a meaningful environmental benefit.