Risk-Based Prioritization for Investigating Illicit Discharges Elizabeth Garcia - Project Manager Max Higgins - Assistant Manager George Sanchez - GIS Analyst Jacqueline Lara- Environmental Consultant Austin Holman- Chief Technology Officer

Overview Introduction and Problem Statement Data Methods Introduction and Problem Statement Data Methods Results and Discussion Conclusions References

INTRODUCTION AND PROBLEM STATEMENT 1 TxDOT is required to regulate Census urbanized areas in compliance with Municipal Separate Storm Sewer Systems(MS4’S) To keep in compliance, TxDOT needs to regulate the new urbanized area of San Marcos, Texas.

GIS IMPORTANCE 1 The use of GIS and GIScience helps reduce the hours in checking low risk outfalls. GIS also helps categorize zoning areas and buildings Slope helped calculate direction of flow of illicit discharge

2 Data Source Edwards Aquifer Texas Water Development Board Neighborhood and Sectors San Marcos GIS Website Floodplain Contours-Atlas Zoning-Atlas City Limit and ETJ City Streets Outfall Locations MS4 Urbanized Area TxDOT 2

STUDY AREA 2

2 FLOW CHART

METHODS 3 Based on our research, high population concentration and commercial areas are more likely to pollute than residential areas. Buffers on Outfalls near ROW Zoning Individual Buildings 303D layer

We needed to have an Idea where our study area was and the things around the outfalls. 4

Next we set threat levels of different buildings Next we set threat levels of different buildings. To understand what buildings are of a potential threat to the outfalls. 4

We also wanted an Idea of the water bodies that may be affected. 4

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RESULTS AND DISCUSSION 4 Finishing prioritization zoning Analyzing slope layers Creating elevation model

5 CONCLUSIONS Reduced pollution to surrounding environment Less hours used in monitoring lower probability outfalls Nation-wide DOT use

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