CalEJ - California Environmental Justice Mapper

Live Demo: [Coming Soon]
GitHub: https://github.com/psadigh91/CalEJ
License: MIT

🗺️ What is CalEJ?

CalEJ is an interactive web platform that maps environmental hazards and demographic data across California communities. It combines CalEnviroScreen scores, EPA Superfund sites, toxic release facilities, and census demographics to help Californians understand environmental justice issues in their neighborhoods.

Key Features

🗺️ Interactive Map - Explore 8,000+ California census tracts
📊 Pollution Burden Scores - CalEnviroScreen 4.0 comprehensive ratings
🏭 Facility Tracking - EPA Superfund sites and TRI facilities
👥 Demographics - Income, race/ethnicity, language, education
🔍 Address Search - Find your neighborhood in seconds
📱 Mobile Responsive - Works on any device
🆓 Free & Open Source - No ads, no tracking, community-driven

🎯 Why CalEJ?

The Problem: Environmental hazards (contaminated sites, industrial pollution, toxic waste) disproportionately impact low-income communities and communities of color. Data exists but is scattered across multiple government sources and hard to access.

The Solution: CalEJ brings together multiple data sources into one interactive map, making it easy for:

Residents to understand environmental issues in their community
Advocates to identify and organize around environmental justice concerns
Researchers to analyze patterns across California
Journalists to investigate environmental inequities
Policymakers to make data-driven decisions

📊 Data Sources

CalEJ integrates data from trusted government sources:

CalEnviroScreen 4.0 (California EPA)
- Pollution burden scores for all CA census tracts
- 20 environmental and health indicators
- Updated October 2021
EPA Superfund Sites (CERCLIS)
- Contaminated land requiring cleanup
- National Priorities List (NPL) status
- Real-time API updates
EPA Toxics Release Inventory (TRI)
- Industrial facilities releasing toxic chemicals
- Annual pollution quantities by chemical
- Historical data (1987-present)
U.S. Census Bureau (American Community Survey)
- Demographic data at census tract level
- Income, race/ethnicity, language, education
- Updated annually

All data is public domain and freely accessible.

🚀 Quick Start

For Users

Visit the live site and:

Search for your address or click on the map
View your census tract's pollution burden score
See nearby Superfund sites and TRI facilities
Compare your area to the California average

For Developers

# Clone the repository
git clone https://github.com/psadigh91/CalEJ.git
cd calej

# Backend setup (AWS CDK)
cd backend
npm install
cdk bootstrap
cdk deploy --all

# Seed data
npm run seed

# Frontend setup
cd ../frontend
npm install
cp .env.example .env.local
# Edit .env.local with API URL from CDK output
npm run dev

# Visit http://localhost:3000

Detailed deployment instructions: DEPLOYMENT.md

🏗️ Architecture

Technology Stack

Frontend:

Next.js 14 (React 18, App Router)
TypeScript
Tailwind CSS
Mapbox GL JS (interactive mapping)
Recharts (data visualization)
React Query (data fetching)

Backend:

AWS Lambda (serverless functions)
Amazon API Gateway (REST API)
PostgreSQL + PostGIS (spatial database)
Amazon RDS (managed database)
AWS CDK (infrastructure as code)

Data Pipeline:

CalEnviroScreen 4.0 CSV import
EPA Envirofacts API integration
Census Bureau API integration
GeoJSON processing for tract boundaries

System Architecture

┌─────────────┐
│   Browser   │
│  (Next.js)  │
└──────┬──────┘
       │
       ▼
┌─────────────────────┐
│   AWS Amplify       │
│  (Static Hosting)   │
└──────┬──────────────┘
       │
       ▼
┌─────────────────────┐
│   API Gateway       │
│  (REST Endpoints)   │
└──────┬──────────────┘
       │
       ▼
┌──────────────────────────────────────┐
│          AWS Lambda                   │
│  ┌──────────┬──────────┬───────────┐ │
│  │ Tracts   │ Search   │ Facilities│ │
│  └──────────┴──────────┴───────────┘ │
└──────┬───────────────────────────────┘
       │
       ▼
┌─────────────────────┐      ┌──────────────┐
│  PostgreSQL + PostGIS│◄────►│  EPA APIs    │
│   (RDS Database)     │      │  (External)  │
└──────────────────────┘      └──────────────┘

📱 Features

Interactive Map

Color-Coded Tracts: Census tracts colored by CalEnviroScreen percentile
Facility Markers: Superfund sites (red pins), TRI facilities (orange pins)
Zoom & Pan: Explore anywhere in California
Click for Details: Tap any tract to see full breakdown
Layer Toggles: Show/hide environmental layers

Tract Detail View

Each census tract shows:

Overall CalEnviroScreen score and percentile
Pollution burden breakdown (air quality, water, hazardous waste)
Population characteristics breakdown (age, income, education, race/ethnicity, health)
Nearby facilities (Superfund sites within 5 miles, TRI facilities)
Comparison to California average
Designated as "disadvantaged community" (SB 535)

Search & Discovery

Address Search: Enter any California address
City Search: Find all tracts in a city
ZIP Code Search: Explore by postal code
Filter by Score: Show only high-pollution areas
Disadvantaged Communities: Filter for SB 535 designated areas

📖 Understanding the Scores

CalEnviroScreen Scores

CalEnviroScreen ranks census tracts on a scale of 1-100:

1-25: Lower pollution burden
26-50: Moderate pollution burden
51-75: Higher pollution burden (watch zones)
76-100: Highest pollution burden (priority areas)

Tracts scoring 75+ are designated as "disadvantaged communities" under California SB 535.

Components

Pollution Burden (50% of score):

Ozone and PM2.5 air pollution
Diesel particulate matter
Drinking water contaminants
Pesticide use
Toxic releases from facilities
Traffic density
Cleanup sites (Superfund, etc.)
Groundwater threats
Hazardous waste
Impaired water bodies
Solid waste sites

Population Characteristics (50% of score):

Asthma rates
Low birth weight
Cardiovascular disease
Educational attainment
Housing burden
Linguistic isolation
Poverty
Unemployment

🤝 Contributing

CalEJ is open source and welcomes contributions!

How to Contribute

Report Issues: Found a bug or have a feature request? Open an issue
Submit PRs: Fix bugs, add features, improve documentation
Share Data: Know of additional data sources? Let us know
Spread the Word: Share CalEJ with your community

Development Setup

See CONTRIBUTING.md for detailed development guidelines.

💰 Cost Estimate

Development (Free Tier)

Lambda: Free (1M requests/month)
RDS PostgreSQL: ~$15/month (db.t3.micro)
API Gateway: Free (1M requests/month)
S3: <$1/month
Amplify Hosting: Free tier or ~$5/month

Total: ~$20/month for California-only deployment

Production (10K monthly users)

Lambda: $5/month
RDS PostgreSQL: $30/month (db.t3.small)
API Gateway: $3.50/month
Data Transfer: $5/month
Amplify Hosting: $15/month

Total: ~$60/month

🔒 Privacy & Security

No User Tracking: We don't collect personal data
No Cookies: Session-free browsing
Open Source: All code is auditable
Public Data Only: We display government data, no private information
Secure Infrastructure: AWS best practices (encryption, IAM policies)

📄 License

MIT License - see LICENSE for details.

This project displays public government data. Data sources retain their original licenses:

CalEnviroScreen 4.0: Public domain (California EPA)
EPA Data: Public domain (U.S. Government)
Census Data: Public domain (U.S. Census Bureau)

🙏 Acknowledgments

Built with:

CalEnviroScreen 4.0 by California Office of Environmental Health Hazard Assessment (OEHHA)
EPA Envirofacts APIs
U.S. Census Bureau American Community Survey
Mapbox for mapping platform
Next.js and the React ecosystem
Claude Code (Anthropic) for development assistance

Inspired by:

EPA EJScreen
CalEnviroScreen website
Environmental justice organizations across California

📧 Contact

Issues: GitHub Issues
Email: [Your contact email]
Portfolio: https://github.com/psadigh91

🗺️ Roadmap

Phase 1: MVP (Current)

Phase 2: Enhanced Features

Historical trend analysis (pollution over time)
County and city aggregations
Downloadable reports (PDF export)
Comparison tool (compare two tracts)
Mobile app (iOS/Android)

Phase 3: Community Features

Community incident reporting
User accounts and saved locations
Email alerts for nearby facility changes
Advocacy toolkit (template letters, meeting resources)
Spanish language support

Phase 4: Expansion

Additional states (starting with Oregon, Washington)
National coverage using EPA EJScreen
Climate resilience data (flooding, heat, wildfires)
Air quality real-time monitoring

Last Updated: July 21, 2026
Version: 1.0.0 MVP
Status: In Development 🚧

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README.md		README.md

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