Kentucky Water Quality Rankings 2026: Best & Worst Cities

This page ranks the 23 Kentucky cities whose water systems we have matched to EPA records. Every city starts at 100 points and loses points for health-based EPA violations in the last five years (SDWIS 2026Q2), its most recent Lead and Copper Rule 90th-percentile result, PFAS detected in EPA's 2023–2026 UCMR5 monitoring, and 2012–2019 compliance samples that averaged near or above a limit. Letters follow fixed bands (A ≥90, B ≥80, C ≥70, D ≥60, F below 60). Cities run from the highest score (Bowling Green) down to the lowest (Georgetown); ties are ordered by population served. See the full scoring methodology for every deduction and the data vintages. 7 further Kentucky cities are listed at the bottom without a grade because we have not yet matched them to an EPA water system.

What your city's grade means

An A or B grade points to water that consistently tests within federal safety limits, while a C suggests moderate issues worth watching and a D or F flags contaminants or compliance problems serious enough to act on. These grades describe system-level water leaving the treatment plant — they can't account for your home's own plumbing, so older houses with lead service lines or fixtures can add contaminants after the water arrives. For a contaminant-by-contaminant view, see the Kentucky contaminant breakdown or drill into the county-level rankings.

What Kentucky residents should do

• Find your city in the ranking below and open its full report for its violation history, lead results and PFAS table.
• See how Kentucky compares against the best-rated and worst-rated cities nationwide.
• Test your home's water if you have concerns — the most common issues involve lead, PFAS, and arsenic.
• Check whether your utility still has lead service lines in Kentucky — EPA's inventory counts lead pipes by water system, a risk that plant-level grades cannot capture. Read the lead guide for testing and filter options.
• If treatment makes sense for your situation, compare certified water filters matched to the contaminants found in your area.

This ranking covers 30 Kentucky cities. 23 of them are matched to an active EPA-registered community water system (PWSID). Those 23 systems report serving 2,544,635 people in EPA's Safe Drinking Water Information System (SDWIS).

Of 23 cities of the 30 Kentucky cities we can grade from EPA records, 20 cities (87%) grade B or better, 3 sit in the C range and 0 grade D or F. The average score is 93/100. 7 cities are not graded because they have not been matched to an EPA system yet.

EPA records 1 health-based violation in the last five years across 1 city. Monitoring and reporting violations (3 in the same window) are paperwork lapses and cost far fewer points.

23 cities have a Lead and Copper Rule 90th-percentile result from 2020 or later: 3 cities at 5 ppb or more.

EPA's UCMR5 PFAS monitoring (2023–2026) covers 23 cities: PFAS were detected in 12 cities, and PFOA or PFOS reached EPA's 4 ppt limit in 5 cities.

Bowling Green scores highest (100) and Georgetown lowest (71), a 29-point spread.

The clearest hard data for Kentucky is EPA's service line inventory, updated 2026-08-18 (Q2 2026). 388 Kentucky systems inventoried 1,907,254 service lines: 5,248 confirmed lead plus 22,810 galvanized lines requiring replacement, spread across 26 systems. Another 424,074 lines (22%) are still of unknown material, which EPA counts as possible lead until verified.

Of the 23 city-linked Kentucky utilities with an inventory on file, 14 report at least one lead or galvanized-requiring-replacement line, 3 report none but still have a quarter or more of their lines unverified, and 6 report no lead with most lines verified. LOUISVILLE WATER COMPANY, which serves Louisville and 806,997 people, is the biggest and reports 483 lead lines and 2,064 galvanized requiring replacement. The most lead lines among city-linked systems belong to NORTHERN KENTUCKY WATER DISTRICT (Fort Thomas): 4,047.

Our Kentucky water guide flags disinfection byproducts, lead, nitrates, and PFAS as the contaminants of regional concern. Disinfection byproducts (regulated as TTHM (80 ppb) and HAA5 (60 ppb)) are associated with increased cancer risk over long exposure; Lead (EPA action level 0.015 mg/L (15 ppb); health goal 0) harms brain development in children and raises blood pressure and kidney risk in adults; Nitrate (EPA MCL 10 mg/L (as nitrogen)) can cause methemoglobinemia ("blue baby syndrome") in infants under six months; PFAS (EPA 2024 MCLs of 4.0 ppt for PFOA and PFOS) are linked to immune, developmental, liver and some cancer effects.

Source water explains a lot of the pattern in Kentucky. Disinfection byproducts are a surface-water signature: chlorine reacts with organic matter in rivers and reservoirs, so byproducts tend to run higher where systems chlorinate surface water. Nitrate follows fertilizer, manure and septic loading, so it is most often a concern for systems drawing shallow groundwater in farm regions. PFAS are tied to specific sites — industrial discharges, firefighting-foam use at airports and bases — rather than to geology, so contamination is local and can affect either source type. Lead is different again: it enters after treatment from service lines and household plumbing, which is why the inventory figures above matter more than plant-level results. Your utility's Consumer Confidence Report names your source.

The best water quality in Kentucky is found in Bowling Green with a score of 100/100 and a grade of A. This puts Bowling Green among the top-performing cities in the country for drinking water safety.

The most concerning water quality is in Georgetown scoring 71/100 with a grade of C. Residents may want to consider home water testing and filtration options.

The statewide average score is 93/100, which is 5 points above the national average of 88/100. A strong majority (78%) of Kentucky cities exceed the national average, indicating generally good water infrastructure across the state.