The Septic Guide 如何根據州牌照名冊建立化糞池服務承辦商牌照數據集

The Septic Guide (https://thesepticguide.com/) runs a directory of septic service providers. We released the aggregate numbers behind it as an open dataset: septic providers by state and county, how many match an official state license or certification list, the agencies and license types behind those matches, and each state's licensing rules. CC BY 4.0, DOI 10.5281/zenodo.23550642 (v1.0.1: 10.5281/zenodo.23643824). This post covers how it was built and what it can't tell you.

What's in it

File	Rows
septic-providers-by-state.csv	45 (44 states + DC)
septic-providers-by-county.csv	1,828
license-types-by-issuer.csv	421
state-licensing-rules.csv	51 (50 states + DC)
summary.json	national totals

No row-level records: no business names, phones, addresses, websites or license numbers. Snapshot as of Oct 21, 2026.

How it was built

The directory. Most listings came from official state license and certification rosters: 26,329 providers have services attributed via a state roster, 2,571 via provider websites, and 194 via the Pennsylvania Septage Management Association member directory. One record per business.
License match. A provider counts as license-matched when it holds at least one credential from an official list issued by its own state, or a certification. That's the same rule the live site uses. Only active credentials held by in-state businesses were kept.
Aggregation. A small Python script counts providers by state, county, issuer and license label. Records outside the 50 states + DC are dropped. Providers with no county count in state totals only.
Licensing rules. Researched Oct 16–20, 2026 from official agency sites, and coded as licensing_level (state / local / partial) and public_roster (list / lookup / none).

Nothing is estimated or imputed. A blank means not available.

Headline numbers

28,546 providers listed; 27,065 (94.8%) matched to lists from 26 state agencies; 22,183 have a phone number.
26 states publish a downloadable roster of septic license holders, 9 offer only one-at-a-time lookup, and for 15 we found no public list.
32 states license septic installers at the state level, 12 leave it to counties or towns, and 6 credential only some septic trades.
Most license-matched providers: North Carolina 4,522, Georgia 1,983, Connecticut 1,903.
Largest single license type: NC Certified Onsite Wastewater Installer (Level II), 2,956 providers.

The caveat that matters most

The match rate is not a compliance rate. Most listings were sourced from license rosters, so a match rate near 100% mostly reflects that sourcing. It doesn't measure the share of septic businesses that are licensed. The 15 jurisdictions with listed providers but zero matches (CO, DC, IN, IA, KS, KY, MA, MO, NV, NJ, NM, PA, UT, WA, WI) are places where no statewide roster exists or none was loaded. They aren't places with unlicensed contractors. Pennsylvania, for example, has 232 listed providers and 0 matches.

Other limits:

These are directory counts, not official state totals. A state's own roster may be larger.
Coverage is 44 states + DC. There are no providers for AK, HI, ME, MT, VT or WY.
One business can hold several license types, so license-type rows don't add up to provider totals.

A quick look with the standard library:

import csv
rows = list(csv.DictReader(open("septic-providers-by-state.csv", encoding="utf-8")))
zero = [r["state"] for r in rows if r["providers_license_matched"] == "0"]
print(len(rows), len(zero))  # 45 15

Where to get it

Data page: https://thesepticguide.com/septic-data/
Dataset (Zenodo): https://doi.org/10.5281/zenodo.23550642 (v1.0.1: https://doi.org/10.5281/zenodo.23643824)
Hugging Face: https://huggingface.co/datasets/chimneyrepairguide/thesepticguide-septic-licensing-statistics
SourceForge: https://sourceforge.net/projects/us-septic-licensing-stats/

Disclosure: this post is published by The Septic Guide. It was drafted with AI assistance and reviewed by the site owner. All figures come from the dataset files and its documentation.