Project 5: TCR Violations Across 5 States

Client: UMass Amherst Water Research Team
Analyst: Aminasahra Warsame Date: April 2026

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Overview

This project analyzes Total Coliform Rule (TCR) violations across five U.S. states using data from the Safe Drinking Water Information System (SDWIS) database. The five states — Maine, Georgia, Texas, Nebraska, and California — were selected to represent five different EPA regions, providing a geographically representative sample of TCR violations across the United States.

A key focus of the analysis is whether small water systems (serving 10,000 or fewer people) experience disproportionately higher violation rates compared to large systems.

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Repository Contents

File	Description
Project5_TCR_Violations.ipynb	Main Python notebook with all analysis and figures
Maine.csv	SDWIS Water System Summary — Maine (EPA Region 1)
Georgia.csv	SDWIS Water System Summary — Georgia (EPA Region 4)
Texas.csv	SDWIS Water System Summary — Texas (EPA Region 6)
Nebraska.csv	SDWIS Water System Summary — Nebraska (EPA Region 7)
California.csv	SDWIS Water System Summary — California (EPA Region 9)
Project5_SOW.docx	Scope of Work
Project5_Gantt.xlsx	Project Gantt Chart
Project5_Timesheet.xlsx	Project Timesheet
Project5_written report.docx	Project report
Project5_technical summary.docx	Project technical summary
Project5_non technical summary.docx	Project non technical summary

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Data Source

Data was downloaded from the SDWIS Federal Reports Public Dashboard:
https://sdwis.epa.gov/ords/sfdw_pub/r/sfdw/sdwis_fed_reports_public/1

• Report Type: Water System Summary
• Submission Year: 2026, Quarter 1
• Owner Type: State-owned systems
• Activity Status: Active

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How to Run

Requirements

Install the required Python packages:

pip install pandas numpy matplotlib geopandas

Steps

1. Clone or download this repository
2. Place all 5 CSV files in the same folder as the notebook
3. Open Project5_TCR_Violations.ipynb in Jupyter
4. Click Kernel → Restart & Run All

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Analysis Summary

Figures Produced

• Figure 1: Total and average violations per system by state
• Figure 2: Small vs. large system violation comparison by state
• Figure 3: Choropleth map of violations across the 5 study states

Key Findings

• California had the highest total number of violations due to its large number of state-owned facilities
• Small water systems (≤10,000 population served) made up the majority of systems in all five states
• Small systems consistently showed higher average violations per system compared to large systems, consistent with national trends reported in peer-reviewed literature
• Differences across states are likely driven by infrastructure age, system size distribution, and regulatory capacity

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Python Packages Used

Package	Purpose
pandas	Data loading, cleaning, and analysis
numpy	Numerical operations
matplotlib	Data visualization
geopandas	Choropleth map creation (new package)

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References

• Allaire, M., Wu, H., & Lall, U. (2018). National trends in drinking water quality violations. PNAS, 115(9), 2078–2083.
• U.S. EPA. (2017). Drinking Water and Wastewater Utility Small Systems. EPA 816-F-17-003.
• U.S. EPA. (2023). Total Coliform Rule. https://www.epa.gov/dwreginfo/total-coliform-rule
• SDWIS Federal Reports. (2026). Water System Summary. https://sdwis.epa.gov