01The verdict: is Hornsby water safe?
Hornsby's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (89.3/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 892 residents using groundwater (wells).
3 unresolved violations on record
EPA records show open compliance items for this system. Most are administrative, but unresolved items are worth watching.
See what was cited ↓Lead is well under the limit
90th-percentile lead is 1.4 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓Check back after the next refresh
EPA data updates on a rolling basis; we fold in new samples and violations every month.
Get alerts ↓Hornsby's drinking water received a grade of A- (89.3 out of 100), indicating good water quality. The city's 1 water system serves approximately 892 residents using purchased ground water.
Lead levels were measured at 1.4 ppb (90th percentile), well within EPA limits. This system has not yet been tested for PFAS under the EPA UCMR 5 program. The system has 5 violations on record, including 1 health-based violation. 3 remain unresolved.
Hornsby ranks #94 out of 299 cities in Tennessee for water quality, placing it mid-range in the state. Hornsby purchases its water from a regional wholesaler, meaning quality depends on both the supplier's treatment and the local distribution system's condition. As a small community water system, Hornsby may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Hornsby's water
Every contaminant flagged in Hornsby, on one shared scale: distance to its own legal limit. The red line is the limit — anything past it is out of compliance, and the closer a bar gets, the less headroom the system has.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 1.4 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Tennessee
Cities ranked by compounds detected Cu Copper in Tennessee
Cities ranked by 90th-percentile copper
03Hornsby's ten-year track record
Each box is one year. A green check means no EPA violations; a numbered badge counts that year's violations — red if any were health-based, amber if they were monitoring or paperwork issues. The system has 5 violations on record, including 1 health-based violation. 3 remain unresolved.
All ten of the last ten years were clean — no EPA violations recorded for Hornsby.
▼ Down 2.6 ppb since 1993. Latest reading: 1.4 ppb (2025) — 9% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Hornsby's water comes from
Hornsby purchases its water supply from a regional wholesale provider rather than treating raw water directly.
Purchased Groundwater
Water is bought from a regional wholesaler; quality starts at the supplier's intake and treatment.
Wholesale supplier
Primary treatment happens at the wholesaler; the local utility maintains disinfectant residual in its pipes.
1 system
1 water system, operated under local government ownership.
892 people
Residents served across Hornsby's service area.
Water quality depends on both the wholesaler's treatment standards and the condition of Hornsby's local distribution pipes and storage facilities. Purchased water systems are common in suburban areas and smaller communities that lack the infrastructure for independent treatment. The system is operated by local government ownership and serves approximately 892 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| HORNSBY WATER DEPT | TN0000312 | 892 | Purchased Groundwater |
Water bodies near Hornsby
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Hornsby's watershed
Outside forces that shape what reaches the treatment plant. None of these is a verdict on the tap by itself — but each adds pressure worth knowing about.
Flood & storm history
2 federal disaster declarations on record for Hardeman County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
06How Hornsby compares
Scores for nearby Tennessee cities on one line, with the average marked.
dashed line = Tennessee average (73/100)
Hornsby scores 89.3/100 — above the Tennessee average of 73/100. It outscores 9 of 10 nearby cities. Full Tennessee rankings →
69 / 100CMemphis, TN
66.2 / 100CKnoxville, TN
55 / 100BMurfreesboro, TN
80.6 / 100BClarksville, TN
75.5 / 100CChattanooga, TN
65.5 / 100
Compare all cities in the county — grades, violations, and contaminant data side by side.→
07What to do at home
Steps matched to what testing actually found in Hornsby's water — not generic advice.
A basic carbon filter still helps
Hornsby's water meets federal standards, but a simple carbon filter improves taste and adds a margin of safety against short-term issues.
Compare tested filters →Read your utility's annual report
Every utility must publish a yearly Consumer Confidence Report with its own testing results. It pairs well with the independent data on this page.
How to read a CCR →Watch for Hornsby alerts
We refresh EPA data monthly and surface new violations, advisories, and boil-water notices for your county on this page.
All water alerts →Frequently asked questions
Is Hornsby, TN tap water safe to drink?
Hornsby's water quality earned a grade of A- (89.3/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #94 out of 299 cities tested in Tennessee.
What contaminants are in Hornsby's water?
Lead was measured at 1.4 ppb (90th percentile). 5 violations are on record.
How is Hornsby's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Hornsby?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Hornsby's water come from?
Hornsby's water is sourced from Purchased ground water. The city has 1 water system serving approximately 892 residents.
What health violations has Hornsby's water system had?
Hornsby has 1 health-based violation on record. The most recent violation was recorded in July 2009. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 3 violations remain unresolved.
Is Hornsby's groundwater at risk of contamination?
Hornsby uses groundwater, which can be affected by naturally occurring contaminants like arsenic, radon, and nitrate, as well as agricultural runoff and industrial activity. The system has 5 violations on record that may relate to groundwater quality. Groundwater systems are generally less susceptible to surface contamination but should be monitored for emerging contaminants like PFAS.
How does Hornsby's water compare to other cities?
Hornsby ranks #94 out of 299 cities in Tennessee (better than 69% of state cities) and #2907 out of 15382 cities nationally (81th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Hornsby's small water system affect quality?
Hornsby's system serves approximately 892 residents. Small community water systems (under 3,300 people) may have fewer financial resources for infrastructure upgrades and advanced treatment technologies. However, they are held to the same EPA drinking water standards as larger systems. This system has 5 violations on record.