Arlington sits right between Dallas and Fort Worth, home to roughly 400,000 people in one of the fastest-growing metro areas in the country. The city gets its water from surface reservoirs — primarily Lake Arlington and the Tarrant Regional Water District’s system — fed by the Trinity River watershed.
The water works. It meets federal standards. But the combination of rapid growth, warm-weather algal blooms, aging distribution pipes, and upstream pressures means Arlington residents have legitimate reasons to pay attention to what comes out of their taps.
The Source Water
Arlington’s water supply comes from surface reservoirs rather than groundwater. The Tarrant Regional Water District (TRWD) supplies the bulk of the city’s water through a network of reservoirs, including Lake Arlington, Cedar Creek Reservoir, and Richland-Chambers Reservoir.
Surface water in Texas faces a different set of challenges than groundwater:
- Agricultural and urban runoff carries fertilizers, pesticides, and sediment into the watersheds that feed these reservoirs
- Wastewater effluent from upstream cities enters the Trinity River and its tributaries, contributing nutrients and trace contaminants
- Algal blooms — fueled by nutrient loading and warm Texas temperatures — can produce taste and odor compounds and, in rare cases, toxins
The Trinity River watershed spans a massive area of North Texas, collecting runoff from millions of acres of farmland, suburban development, and urban centers. By the time it reaches Arlington’s water treatment plants, it’s picked up whatever was on the land.
Disinfection Byproducts
Arlington’s biggest water quality challenge is one that’s common across Texas and the Sun Belt: disinfection byproducts (DBPs).
When chlorine or chloramine is used to disinfect water — which every public water system does — it reacts with organic matter in the source water to form byproducts. The two regulated categories are total trihalomethanes (TTHMs) and haloacetic acids (HAA5).
Texas reservoirs tend to have higher organic matter loads than many other source waters, particularly during warm months when algae are active. This means treatment plants have to use more disinfectant, which generates more byproducts.
Arlington’s water quality reports show the city manages TTHMs and HAA5 within federal limits, but some monitoring locations have measured levels that approach the maximums — particularly in the hotter months. Long-term exposure to elevated DBPs has been associated with increased cancer risk, though the science is still evolving.
Taste and Odor Issues
If you’ve lived in Arlington (or anywhere in DFW) during late summer, you’ve probably noticed the water tastes or smells different. That’s almost always caused by geosmin and 2-methylisoborneol (MIB), compounds produced by blue-green algae in the reservoirs.
These compounds are not harmful at the levels found in treated water, but they create an earthy, musty taste that’s genuinely unpleasant. Treatment plants use activated carbon and other methods to reduce them, but during major algal events the taste can persist for days or weeks.
It’s not dangerous, but it’s the number one complaint Arlington water customers have during summer and early fall.
Lead and Aging Infrastructure
Arlington’s rapid growth happened in waves. Much of the city’s housing stock dates from the 1960s through 1990s, with older sections going back further. Homes built before 1986 may have lead solder in their plumbing, and some older service connections may contain lead.
The city treats its water with corrosion control chemicals to minimize lead leaching, and Arlington has generally tested well within EPA limits for lead at the tap. But individual homes — particularly those with original plumbing — can have higher levels than what shows up in citywide sampling.
The city is currently working through the EPA’s revised Lead and Copper Rule requirements, which include inventorying all service line materials and developing a replacement plan for any lead lines identified.
PFAS on the Horizon
North Texas has multiple military installations and industrial facilities that used AFFF firefighting foam. While Arlington itself doesn’t host a major military base, the DFW metroplex includes several — and PFAS contamination doesn’t respect city limits.
Texas has been slower than coastal states to set enforceable PFAS standards, but the state is increasing monitoring requirements. As more data becomes available, residents across the DFW area — including Arlington — will get a clearer picture of PFAS levels in their water supply.
What Arlington Residents Should Do
- Read the annual report. The City of Arlington publishes a water quality report every year. Focus on TTHMs, HAA5, and lead levels.
- Flush your tap in the morning. If you’re in an older home, let the water run for a minute or two before drinking. This clears water that’s been sitting in contact with your plumbing overnight.
- Filter if you’re sensitive. A quality carbon filter handles taste and odor issues plus reduces DBPs. Reverse osmosis goes further and handles PFAS and lead as well.
- Report taste or odor problems. The city tracks complaints and adjusts treatment accordingly. Your report helps them respond faster during algal events.
If you’re concerned about your water quality, a certified water treatment professional can test your tap water and recommend the right system for your home. DFW’s surface water challenges — DBPs, seasonal taste issues, and emerging contaminants — are all manageable with the right filtration.
Sources
- City of Arlington annual water quality reports
- Tarrant Regional Water District source water assessments
- Texas Commission on Environmental Quality drinking water monitoring data
- EPA Lead and Copper Rule requirements
- Trinity River Authority watershed assessments