Microproduct Data GuideIntermediate

EPA Community Water Service Areas Version 2.1

EPA's pinned community-water-system boundaries and census-block allocations for local drinking-water coverage analysis.

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At a Glance

Difficulty
Intermediate — some data preparation helps
Size
Medium · 0.4–1.1 GB
Formats
GeoPackage, CSV
Access
Download
API Key
Not Required
Provider
U.S. Environmental Protection Agency
Updates
Occasional
Last Verified
Sep 28, 2026
Source Type
Government Source
Data Terms
EPA-produced data are public domain unless otherwise specified; check source metadata for state-supplied boundary limitations and cite EPA. Modeled areas are estimates.
  • Python Syntax Checked

From Source to Product Signal

Test a Product Idea in Four Steps

HouseHunter pins EPA's version 2.1 GeoPackage and matching 2020 Census block allocation table from the EPA model's version history. Read only a few allocation rows with an HTTP byte range. Version 3 is now current, so do not silently mix it with the pinned version 2.1 or interpret modeled boundaries as exact household service.

1

Check the Setup

  • Python 3.10 or newer
  • An internet connection
  • The requests Python package
2

Access the Data

  1. 1.Read the EPA service-area documentation and public-domain notice.
  2. 2.Fetch the beginning of the exact version 2.1 block allocation CSV.
  3. 3.Keep the version 2.1 GeoPackage and block table together for full analysis.
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3

Run the Python Example

Install the packages, then run the notebook cell.

python -m pip install requests

import csv
import io
import requests

url = ("https://media.githubusercontent.com/media/USEPA/ORD_SAB_Model/"
       "main/Version_History/2_1/Census_Tables/Blocks_V_2_1.csv")
response = requests.get(url, headers={"Range": "bytes=0-8191"}, timeout=30)
response.raise_for_status()
assert response.status_code == 206, "Server did not honor bounded byte range"
rows = csv.DictReader(io.StringIO(response.content.decode("utf-8", errors="ignore")))
for row in list(rows)[:3]:
    print(row["GEOID20"], row["PWSID"], row["Pop20_AW"])
4

Test a Useful Signal

Inspect One Water Service Allocation

Identify the population allocation attached to a water system and census block.

  1. 01Read a few pinned version 2.1 block rows and retain their PWSIDs.
  2. 02Compare the matching boundary provenance before using the allocation.
  3. 03Explain why modeled service areas do not establish an exact household provider.

Related Datasets

Dataset Details

U.S. Environmental Protection Agency is a government source. Last verified 2026-09-28. Temporal coverage: version 2.1 pinned by HouseHunter, released November 2025.

Geography

United States

Provider

U.S. Environmental Protection Agency

Data Terms

EPA-produced data are public domain unless otherwise specified; check source metadata for state-supplied boundary limitations and cite EPA. Modeled areas are estimates.

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