01The verdict: is Big Wells water safe?
Big Wells's drinking water has significant quality concerns based on EPA testing data. With a grade of A- (88/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 1 water system serves approximately 870 residents using groundwater (wells).
12 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 2.7 ppb — beneath the 15 ppb federal action level and under the 5 ppb watch threshold.
See the trend ↓A flood-prone service area
3 federal disaster declarations on record. After severe weather, watch for boil-water advisories.
See the risk factors ↓Big Wells's drinking water received a grade of A- (88 out of 100), indicating good water quality. The city's 1 water system serves approximately 870 residents using groundwater.
Lead levels were measured at 2.7 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 20 violations on record, including 0 health-based violations. 12 remain unresolved.
Big Wells ranks #96 out of 1067 cities in Texas for water quality, placing it one of the best in the state. Big Wells relies on groundwater, which is generally less vulnerable to surface contamination but can be affected by naturally occurring minerals like arsenic and nitrate, as well as agricultural and industrial runoff. As a small community water system, Big Wells may have fewer resources for advanced treatment technologies and infrastructure upgrades compared to larger utilities.
02What's in Big Wells's water
Every contaminant flagged in Big Wells, 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. | 2.7 | 15 | ppb | Inorganic | Safe |
Cities ranked by 90th-percentile lead PF PFAS in Texas
Cities ranked by compounds detected Cu Copper in Texas
Cities ranked by 90th-percentile copper
03Big Wells'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 20 violations on record, including 0 health-based violations. 12 remain unresolved.
All ten of the last ten years were clean — no EPA violations recorded for Big Wells.
▼ Down 0.60 ppb since 1993. Latest reading: 2.7 ppb (2024) — 18% of the action level. Sampled at higher-risk homes (90th percentile).
04Where Big Wells's water comes from
Big Wells's drinking water is drawn from underground aquifers through wells.
Groundwater
Underground aquifers reached by wells — naturally filtered, but can carry minerals like arsenic and nitrate.
Local treatment
Groundwater generally needs less treatment — typically disinfection and, where needed, mineral removal.
1 system
1 water system, operated under local government ownership.
870 people
Residents served across Big Wells's service area.
Groundwater is naturally filtered through rock and soil layers, generally requiring less treatment than surface water. However, it can contain naturally occurring contaminants like arsenic, radon, and minerals. Agricultural activity, septic systems, and industrial operations near well fields can introduce nitrates, pesticides, and volatile organic compounds. The system is operated by local government ownership and serves approximately 870 people through 1 water system.
| System name | PWSID | Population | Source |
|---|---|---|---|
| CITY OF BIG WELLS | TX0640012 | 870 | Groundwater |
Water bodies near Big Wells
These water bodies shape the regional watershed and can indirectly affect groundwater quality.
05Pressure on Big Wells'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
3 federal disaster declarations on record for Dimmit County. Flooding and severe storms can overwhelm treatment plants, cause sewage overflows, and push runoff into supplies.
Drought
Dimmit County is in D1 (moderate drought) per the U.S. Drought Monitor (week of Jul 2026). Drought can raise disinfection-byproduct levels and taste/odor issues as utilities draw from lower reservoirs.
06How Big Wells compares
Scores for nearby Texas cities on one line, with the average marked.
dashed line = Texas average (46/100)
Big Wells scores 88/100 — above the Texas average of 46/100. It outscores 10 of 10 nearby cities. Full Texas rankings →
27.8 / 100FSan Antonio, TX
33.1 / 100FAustin, TX
31.2 / 100FDallas, TX
36.2 / 100FFort Worth, TX
34.5 / 100FEl Paso, TX
35.8 / 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 Big Wells's water — not generic advice.
A basic carbon filter still helps
Big Wells'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 Big Wells alerts
This area has a history of flood declarations — after severe weather, watch for boil-water advisories from the utility, and check the live alerts on this page.
All water alerts →Frequently asked questions
Is Big Wells, TX tap water safe to drink?
Big Wells's water quality earned a grade of A- (88/100). The water generally meets EPA standards and is considered safe for consumption. The city ranks #96 out of 1067 cities tested in Texas.
What contaminants are in Big Wells's water?
Lead was measured at 2.7 ppb (90th percentile). 20 violations are on record.
How is Big Wells'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 Big Wells?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Big Wells's water come from?
Big Wells's water is sourced from Groundwater. The city has 1 water system serving approximately 870 residents.
Is Big Wells's groundwater at risk of contamination?
Big Wells 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 20 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 Big Wells's water compare to other cities?
Big Wells ranks #96 out of 1067 cities in Texas (better than 91% of state cities) and #3705 out of 15382 cities nationally (76th percentile). The grade of A- reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.
Does Big Wells's small water system affect quality?
Big Wells's system serves approximately 870 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 20 violations on record.