Multi-Source Water Intelligence
County-level water data, written in plain language.
WaterByCounty is independently published data journalism. We present the water-quality statistics that the federal government already collects — drinking water compliance, watershed health, monitoring records, and streamflow snapshots — for every one of America's 3,144 counties.
What WaterByCounty Is
WaterByCounty is a data-journalism site, not an engineering or hydrogeology consultancy. Our purpose is to take county-level water statistics published by the federal government and present them in a form a regular person can actually compare and act on. If you are deciding where to move, evaluating drinking water quality in a region you're considering, or just want to know how your county stacks up nationally, this site is built for you.
Every page on the site is built from primary-source datasets: EPA SDWIS (Safe Drinking Water Information System), EPA ATTAINS (Clean Water Act assessments), EPA Water Quality Portal (monitoring records), and USGS NWIS (streamflow gauges). Each statistic is attributed to its source, and the underlying methodology is published on the methodology page.
What We Do
WaterByCounty makes federal water data accessible to homeowners, renters, journalists, researchers, and families. Most water tools pick one signal — drinking-water compliance, or watershed health, or streamflow — and stop there. We surface all four side-by-side, so the picture is honest: tap-water compliance can be clean while the watershed is impaired, and streamflow can be normal while monitoring is sparse.
We never pretend a county has data when it doesn't. Every per-county zone is conditional. If your county doesn't have an §303(d) assessment yet, you won't see a Watershed Health panel with invented numbers — you'll see no panel.
Four Data Sources
Drinking Water Compliance
The Safe Drinking Water Information System tracks every public water system that serves at least 25 people or has 15 service connections. We aggregate health-based and reporting violations from the past 5 years to compute the water quality grade (A–F) and score (0–100) shown on each county page.
Watershed Health
ATTAINS records state §303(d) assessments under the Clean Water Act — which water bodies fail state-defined quality standards, and why. We show what share of a county's assessed water bodies are impaired, the top impairment causes (mercury, E. coli, sediment, nutrients, etc.), and the reporting cycle. Where a state attributes assessments only by HUC-8 watershed, we use a USGS-derived crosswalk to map back to counties.
Monitoring Records
The WQP is the federal data warehouse for water-quality monitoring records, aggregating samples from EPA STORET, USGS NWIS, and tribal/state programs. We summarize the past 5 years per county: how many monitoring sites are active, how many measurements were recorded, and what characteristic groups (microbiological, inorganics, etc.) are measured most frequently.
Streamflow Snapshot
The USGS streamgage network publishes river and stream discharge readings across the country. We select one representative gauge per county (the one with the largest drainage area) and compare the latest pipeline snapshot against its full-record long-term mean. Counties without an NWIS gauge are honestly noted, not filled in.
Who Runs WaterByCounty
WaterByCounty is published and edited by Evan Brooks, Data Editor of the ByCounty Network. The site uses automated pipelines to ingest public datasets from the EPA, U.S. Census Bureau, USGS, and other federal agencies, then transforms them into plain-language reporting that anyone can use.
The data editor documents the methodology for composite scores and rankings across all 13 sites in the network, spot-checks AI-generated narratives for accuracy, and signs off on every published page. The data editor is the named editorial owner of this site: published statistics either match the source data or they are corrected.
The data editor is not a hydrogeologist, water-quality engineer, or licensed environmental consultant, and WaterByCounty does not present itself as an engineering resource. We do not design water-treatment systems, certify water safety, or provide remediation advice. Our role is the data-editor role — verify the numbers, respect the underlying measurement limitations, and decline to publish anything that strays beyond what the source data supports.
Long-form features and reported pieces, when published, carry a visible byline and — for topics that benefit from subject-matter expertise — a named reviewer credit at the top of the article.
Why I Built WaterByCounty
I started WaterByCounty after trying to understand drinking water quality and watershed health while evaluating where to move. The EPA publishes extraordinary data through SDWIS, ATTAINS, and the Water Quality Portal, but it is buried in databases and technical reports. I wanted a site where a regular person could see, in 30 seconds, how their county compares on drinking water compliance, watershed health, and monitoring coverage — with the sources right there on the page. No paywall, no gatekeeping, just public data presented honestly.
That same need shows up in every vertical we cover: property taxes, cost of living, crime, schools, environmental risk, health. The government already collects this data. Our job is to clean it, verify it, and make it comparable.
What We Don't Do
- We don't test water ourselves. All numbers come from federal databases.
- We don't fill in missing data with estimates. If something is N/A in the source, it's N/A on our site.
- We don't cover private wells. SDWIS only tracks public systems serving 25+ people. About 13% of US households on private wells need their own testing.
- We don't speak to taste, hardness, or non-regulated contaminants. A passing SDWIS grade means the water systems met federal standards — not that the water is perfect.
How We Decide What to Publish
Two documents govern this site's editorial decisions:
- Editorial Standards — our mission, source policy, AI-usage policy, corrections process, funding disclosure, and update cadence.
- Methodology — the exact data sources, composite-score formula, limitations, and update cadence behind every page.
Both documents carry a "Last reviewed" date and are regenerated when our methodology changes.
Our Relationship to the Data
WaterByCounty is independent. We are not affiliated with the U.S. Environmental Protection Agency, the U.S. Geological Survey, or any government agency. We use their public datasets under the licenses they publish — for federal works, that is public-domain release. Each county page credits the data source that drives it.
When we link out — for example, to a state environmental agency or to EPA ECHO for detailed violation reports — we link to primary sources, not aggregators.
AI in Our Workflow
Per-county pages include a short narrative summary generated with the assistance of Claude (Anthropic) from the same statistics shown on the page. This is a tool for turning a row of numbers into a readable paragraph; it is not the source of any data on the site. The narrative prompt is constrained to forbid causation claims, treatment recommendations, and unsourced inference. The Data Editor reviews the prompt and spot-checks output before publication. When source data is refreshed, narratives are regenerated.
We disclose this clearly because honesty is the right policy — and because Google's policies treat undisclosed AI authorship as a separate problem from AI authorship itself. The fix for AI prose on a YMYL site is not to hide it; the fix is to pair it with a named human editor, a clear methodology, and source-grounded constraints. That is what we do.
Part of the ByCounty Network
WaterByCounty is one site in the ByCounty Network — a family of independent data sites covering property taxes, cost of living, income, crime, schools, environmental risk, health, weather, and more. Visit CountyScore.com for the network's flagship hub, which combines every vertical's data into a single composite county report.
Contact
For data corrections, source attributions, partnership questions, or press inquiries, write to editorial@waterbycounty.com. See our editorial standards for the corrections process and timelines.
This page was last reviewed on by Evan Brooks, Data Editor.
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