Tap & Air

Aurora, CO · Aurora City of · data through December 2025

Is Aurora tap water safe to drink?

Aurora's tap water comes from Aurora City of, which serves about 533,407 people. The federal data worth knowing about: chloramine as its disinfectant. Arapahoe County is EPA Radon Zone 1, the highest-risk tier, so a radon test is worth doing.

Chlorine or chloramine?

Worth knowing

Aurora City of disinfects with chloramine, according to its own water quality reporting. Chloramine is chlorine bonded with ammonia. It lasts longer in the pipes, which is why utilities use it, but it is much harder to remove at home than plain chlorine.

Most cheap shower filters use KDF and standard carbon, which barely affect chloramine. Look for vitamin C or catalytic carbon media, and for drinking water, a filter that lists chloramine reduction specifically. If you keep fish, chloramine must be neutralized before it reaches the tank.

How hard is the water?

Looks fine

Aurora's water measures about 5.8 grains per gallon (100 mg/L as calcium carbonate), which is moderately hard on the US Geological Survey scale: soft below 60 mg/L, moderately hard 60-120, hard 120-180, very hard above 180.

At this level a water softener is usually not worth the cost. Spend on filtration for taste or specific contaminants instead.

Hardness data: TapWaterData Water Hardness Dataset (tapwaterdata.com), licensed CC BY 4.0. Underlying source: Utility-reported water quality data — DENVER WATER BOARD (PWSID CO0116001), 2025-10-07.

Lead and copper

Looks fine

In Aurora City of's most recent lead sampling, for the period ending December 2025, 90% of tested homes came in at or below 2.5 ppb of lead. That is low on any of the federal yardsticks.

This is a system-wide statistic, not a reading of your tap. Lead comes from lead service lines, old solder and some brass fixtures inside homes, so two houses on the same street can differ. Testing your own tap costs $15-40, and many utilities test free on request.

EPA's lead action level is 15 parts per billion (ppb) today and drops to 10 ppb in November 2027 under the Lead and Copper Rule Improvements. FDA's limit for bottled water is 5 ppb. EPA's health goal for lead is zero.

PFAS ("forever chemicals")

Worth knowing

In EPA's 2023-2025 sampling of Aurora City of, these PFAS were detected: PFBS up to 3.3 ppt (no federal limit). All results were below the 2024 limits. These are the highest single results; utilities are judged on running annual averages, so a high sample is not by itself a violation.

Reverse osmosis is the most reliable home treatment for PFAS. Some carbon filters are certified for PFOA and PFOS reduction under NSF/ANSI 53; check the product listing for that claim, not just the word PFAS on the box.

CompoundHighest resultAvg. of detectionsDetections2024 EPA limit
PFBS3.3 ppt3.3 ppt1none

In April 2024 EPA set enforceable limits of 4 parts per trillion (ppt) for PFOA and PFOS, and 10 ppt for PFHxS, PFNA and HFPO-DA (GenX). In May 2025 EPA said it intends to keep the PFOA and PFOS limits, extend the compliance deadline to 2031, and rescind the other three. We compare results to the 2024 limits and label which ones may change.

Health-based violations since 2016

Looks fine

Aurora City of has no health-based violations on file with EPA since 2016.

Radon

Take action

Aurora is in Arapahoe County, which EPA places in Radon Zone 1: the predicted average indoor level is above 4 pCi/L, EPA's action level.

In Zone 1, testing is the single highest-value home health check you can do. A $15-25 charcoal kit gives an answer in a few days; a digital monitor shows how levels move with the seasons. If you measure 4 pCi/L or more, a mitigation system (typically $800-2,500) brings it down permanently.

EPA radon zones describe counties, not houses. Zone 1 counties have a predicted average indoor level above 4 picocuries per liter (pCi/L), Zone 2 between 2 and 4, Zone 3 below 2. Homes with high levels are found in every zone, which is why EPA recommends that every home be tested, and fixed at 4 pCi/L or above. See every Colorado county's radon zone.

What to do in Aurora

Matched to the findings above, most important first.

We may earn a commission from links below, at no cost to you. Recommendations come from the data above, not from who pays. How we make money.

If you rent

No plumbing changes, takes it with you

Radon test kit

Arapahoe County is EPA Radon Zone 1.

A short-term charcoal kit costs about $15-25 and tells you whether you need to go further.

Chloramine shower filter

Your water is disinfected with chloramine.

Vitamin C or catalytic carbon media actually reduce chloramine; standard KDF shower filters barely touch it.

Countertop reverse osmosis

PFAS were detected, below EPA limits.

Reverse osmosis removes PFAS, lead, nitrate and arsenic. Countertop units need no plumbing, so renters can use them.

Home water test kit

See what is in your own tap, beyond the utility's averages.

Checks your own tap, which can differ from the utility's system-wide numbers.

If you own

Whole-home fixes that protect the house

Digital radon detector

Arapahoe County is EPA Radon Zone 1.

Shows a running average so you see how levels change with seasons and ventilation.

Chloramine shower filter

Your water is disinfected with chloramine.

Vitamin C or catalytic carbon media actually reduce chloramine; standard KDF shower filters barely touch it.

Under-sink reverse osmosis

PFAS were detected, below EPA limits.

The most thorough option for drinking water: PFAS, lead, nitrate, arsenic and more. Look for NSF/ANSI 58.

Home water test kit

See what is in your own tap, beyond the utility's averages.

Checks your own tap, which can differ from the utility's system-wide numbers.

Questions people ask about Aurora water

Is Aurora tap water safe to drink?+

Aurora's tap water comes from Aurora City of, which serves about 533,407 people. The federal data worth knowing about: chloramine as its disinfectant. Arapahoe County is EPA Radon Zone 1, the highest-risk tier, so a radon test is worth doing. For your own home, a tap test is the only reading that reflects your pipes.

Does Aurora use chlorine or chloramine?+

Aurora City of disinfects with chloramine, according to its own water quality reporting. Chloramine is chlorine bonded with ammonia. It lasts longer in the pipes, which is why utilities use it, but it is much harder to remove at home than plain chlorine.

How hard is Aurora water?+

Aurora's water measures about 5.8 grains per gallon (100 mg/L as calcium carbonate), which is moderately hard on the US Geological Survey scale: soft below 60 mg/L, moderately hard 60-120, hard 120-180, very hard above 180.

Is there lead in Aurora water?+

In Aurora City of's most recent lead sampling, for the period ending December 2025, 90% of tested homes came in at or below 2.5 ppb of lead. That is low on any of the federal yardsticks.

Is radon a problem in Aurora?+

Aurora is in Arapahoe County, which EPA places in Radon Zone 1: the predicted average indoor level is above 4 pCi/L, EPA's action level. Testing is strongly recommended.

Sources

  • Utility: Aurora City of, EPA public water system ID CO0103005, serving about 533,407 people. Look it up at EPA.
  • Disinfectant: utility water quality reporting.
  • Lead, copper, violations and treatment: EPA Safe Drinking Water Information System (SDWIS), via EPA ECHO, 2026 Q2 export.
  • PFAS: EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), sampling 2023-2025, results released through August 2026.
  • Radon: EPA Map of Radon Zones. County: US Census geocoder.
  • Hardness data: TapWaterData Water Hardness Dataset (tapwaterdata.com), licensed CC BY 4.0.
  • Population: US Census Bureau 2024 population estimates and 2024 Gazetteer (403,130 residents).

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