- Laredo's water is legal. It met every federal standard in the latest EPA compliance quarter on record (April to June 2024).
- EWG, which uses stricter health-based guidelines, lists 31 contaminants detected and 13 above its guideline, from 2021 to 2023 utility testing.
- Almost all of the 13 are byproducts of chlorine disinfection. The highest is haloacetic acids (HAA9) at 715 times the EWG guideline.
- Separately, the water is very hard. Homes I test read 30 to 42 grains per gallon. The Water Quality Association calls anything over 10.5 “very hard.”
Legal limit vs health guideline
Two different yardsticks get mixed up in every conversation about Laredo water. The EPA sets legal limits, and the City of Laredo meets them. The Environmental Working Group (EWG) publishes health guidelines that are much stricter, based on state and federal public-health research, and it compares the utility's own test results against those. A contaminant can be far above the EWG guideline and still be completely legal. Both statements are true at the same time, and I say both at every water test.
EWG's note on the Laredo page says it plainly: legal limits for many contaminants have not been updated in almost 20 years, and a passing federal grade does not mean the water meets the latest health guidelines.
The 13 contaminants above the EWG guideline
From the EWG Tap Water Database record for the City of Laredo (PWS ID TX2400001), utility test data 2021 to 2023, checked October 7, 2026. “This utility” is the annual average the city reported. The multiple is how many times over the EWG health guideline that average sits.
| Contaminant | This utility | EWG guideline | Times over | Legal limit |
|---|---|---|---|---|
| Haloacetic acids (HAA9) | 42.9 ppb | 0.06 ppb | 715× | none |
| Bromochloroacetic acid | 9.93 ppb | 0.02 ppb | 496× | none |
| Total trihalomethanes (TTHMs) | 60.2 ppb | 0.15 ppb | 402× | 80 ppb |
| Bromodichloromethane | 21.3 ppb | 0.06 ppb | 355× | none |
| Haloacetic acids (HAA5) | 30.7 ppb | 0.1 ppb | 307× | 60 ppb |
| Dibromoacetic acid | 5.14 ppb | 0.03 ppb | 171× | none |
| Dibromochloromethane | 16.2 ppb | 0.1 ppb | 162× | none |
| Trichloroacetic acid | 9.62 ppb | 0.1 ppb | 96× | none |
| Dichloroacetic acid | 15.0 ppb | 0.2 ppb | 75× | none |
| Chloroform | 17.6 ppb | 0.4 ppb | 44× | none |
| Bromoform | 3.80 ppb | 0.5 ppb | 7.6× | none |
| Nitrate | 0.489 ppm | 0.14 ppm | 3.5× | 10 ppm |
| Uranium | 1.45 pCi/L | 0.43 pCi/L | 3.4× | 20 pCi/L |
ppb = parts per billion, ppm = parts per million, pCi/L = picocuries per liter. “None” means the EPA has no legal limit for that individual compound; TTHMs and HAA5 are regulated as groups. Another 18 contaminants were detected below the EWG guideline, including fluoride, manganese, aluminum, barium and selenium.
Why it's mostly chlorine byproducts
Laredo draws its water from the Rio Grande, a surface source with organic material in it. The city disinfects with chlorine, which is what keeps bacteria out of the pipes and is the reason boil notices are rare. When chlorine reacts with that organic material it forms trihalomethanes and haloacetic acids. Eleven of the thirteen items in the table are those byproducts. This is normal for river-fed systems in Texas; it is not a sign the city is doing something wrong.
It does mean the water that reaches your tap still carries chlorine and its byproducts, which is what you smell in the shower and taste in a glass. Carbon filtration is the treatment that adsorbs them.
The number EWG doesn't show: hardness
Hardness is not a contaminant, so it is not on the EWG list, but it is the thing most Laredo families notice first. Calcium and magnesium from the river and the limestone it runs through leave white spots on dishes, scale inside water heaters, and the dry skin and stiff laundry everyone here knows. At kitchen sinks across Laredo my titration kit reads between 30 and 42 grains per gallon. The Water Quality Association's scale calls 10.5 and up “very hard,” so Laredo sits at three to four times that threshold. Hardness is what a softener removes; it is a separate job from filtering chlorine byproducts.
Which treatment handles which number
| What's in the water | What handles it | Where |
|---|---|---|
| Hardness (30–42 GPG) | Ion-exchange softener (Azul Essentials or Azul+) | Whole house, at the main line |
| Chlorine, TTHMs, haloacetic acids, taste and smell | Carbon stages (Azul+ for the whole house, A550 pre-filters for the drinking tap) | Every tap, or the kitchen faucet |
| Nitrate, uranium, dissolved solids (TDS) | Reverse osmosis membrane (A550, NSF/ANSI 58) | Drinking and cooking tap, fridge line |
| Bacteria during a boil notice, well water | UV disinfection after the filters | Whole house |
I don't make health claims about water, and I won't tell you the city's water will hurt you. What I will do is test your tap in person, show you the numbers next to the ones above, and tell you honestly whether a system is worth it for your house. If your numbers are fine, I'll say so.
Questions people ask about Laredo water
Is Laredo tap water safe to drink?
By the legal standard, yes: the city was in compliance with federal drinking water standards in the latest EPA quarter on record. By EWG's stricter health guidelines, 13 contaminants were above the guideline. Which standard matters to you is a personal decision. Many Laredo families add a reverse osmosis tap for drinking and cooking and leave the rest of the house as is.
Does boiling water fix any of this?
Boiling kills bacteria, which is why the city issues boil notices after a main break. It does not remove hardness, nitrate, uranium or disinfection byproducts, and it concentrates dissolved solids slightly as water evaporates. For the items in the table above you need filtration or reverse osmosis.
Do pitcher filters or fridge filters help?
They are small carbon filters, so they improve taste and reduce chlorine while the cartridge is fresh. They do nothing for hardness and little for nitrate or uranium, and in Laredo's water they clog quickly. A reverse osmosis system under the sink does the same job with a membrane and lasts years between membrane changes.
How often does this data change?
EWG updates its database when it receives new utility test data from the Texas Commission on Environmental Quality, usually once a year. I re-check the Laredo record every quarter and update this page and the home page when the numbers move. The date at the top tells you when it was last checked.
Sources
- EWG Tap Water Database, City of Laredo (PWS ID TX2400001), utility data 2021–2023, accessed October 7, 2026
- EPA Enforcement and Compliance History (ECHO) compliance status as reported on the EWG record, quarter April–June 2024
- Water Quality Association hardness scale (10.5+ GPG = very hard)
- Azul Water Co in-home test readings, Laredo, 2024–2026 (hardness 30–42 GPG range)