Is Denver, CO tap water safe to drink in 2026?

Denver tap water earns a B- grade on CleanWaterGrade. While it meets baseline utility standards, testing shows 2.9 ppt combined PFOA/PFOS (vs the 4.0 ppt EPA limit), 6.8 ppb 90th-percentile lead, and 5.2 gpg (89 mg/L) hardness.

How hard is the water in Denver, CO?

Denver water hardness averages 5.2 grains per gallon (89 mg/L), classified by the USGS as Moderately Hard.

What is the best water filter for Denver, CO?

For drinking and cooking in Denver, an NSF-58 under-sink reverse osmosis system like the Waterdrop G3P800 removes 99.4% of PFAS and lead. For whole-home scale and disinfectant protection, the Aquasana Rhino EQ-1000 is matched to Denver water chemistry.

Denver, CO EPA UCMR5 & USGS Water Report • PWSID CO0116001

Denver, CO Tap Water Quality Report (2026): Grade B-

Direct Answer: Denver, CO tap water (served by Denver Water) earns an overall B- Safety Grade (78/100). Public testing records 2.9 ppt combined PFOA/PFOS (approaches the 4.0 ppt EPA federal limit), 6.8 ppb 90th-percentile lead, and 5.2 gpg (89 mg/L — Moderately Hard) mineral hardness.

Official Municipal Water System Filing • Population Served: 1,500,000

Denver Water

Primary Water Source: South Platte River, Blue River, Williams Fork & Fraser River Rocky Mountain Snowmelt

Covered ZIP Codes: 80202, 80203, 80204, 80205, 80206, 80207, 80209, 80210, 80211, 80212, 80218, 80220+

B- Score 78/100

PFAS (PFOA + PFOS)

2.9 ppt

PFOA: 1.6 ppt • PFOS: 1.3 ppt (EPA Limit: 4.0 ppt)

Near 4.0 ppt EPA MCL

Lead (90th Percentile)

6.8 ppb

EPA Action Level: 10.0 ppb • Goal: 0 ppb

Point-of-Use RO Advised

Disinfection Byproducts

38.1 ppb TTHM

HAA5: 22.4 ppb • Chloramine Active

Catalytic Carbon Target

USGS Water Hardness

5.2 gpg

89 mg/L CaCO3 (Moderately Hard)

Moderately Hard

Best Filter Match for Denver Homeowners: Waterdrop G3P800 under the kitchen sink for 99.4% PFAS/lead removal + Aquasana Rhino EQ-1000 for whole-house chloramine & scale control.

See Waterdrop G3P800 ($0.32/day) → See Aquasana Rhino EQ-1000 →

Homeowner 5-Year Water Math (Family of 4)

Why Bottled Water & Pitchers Lose to NSF-58 Reverse Osmosis

Verified against NSF/ANSI 53, 58 & 372 Lab Standards

Bottled Cases

$1,460/yr

$4.00/day • $7,300 over 5 years

240,000+ nanoplastic particles per liter in PET bottles
Unregulated under EPA Safe Drinking Water Act
Heavy weekly hauling & plastic waste

PFAS Lock: Unverified / Variable

Standard Carbon Pitcher

$180/yr

$0.49/day • Taste & Chlorine Only

0% removal of dissolved hardness minerals (TDS)
Standard granular carbon misses short-chain PFAS & fluoride
40-gallon media saturates every 4–6 weeks

PFAS Lock: Partial / Clogs Fast

NSF-58 Tankless Under-Sink RO

$0.32/day

$450–$599 Year 1, then $58 every 6 mos

99.4% PFOA/PFOS, lead, chromium-6, arsenic & TDS removal
800 GPD tankless direct-flow (fills 8 oz glass in 5 sec)
2-second twist-and-lock cartridge swap twice a year

Compare NSF-58 Tankless RO →

What This Means for Your Home

How Denver’s Water Impacts Drinking, Skin & Appliances

1. Drinking & Cooking Water

PFAS (2.9 ppt) & Lead (6.8 ppb)

Denver tap water scores a B- with clean Rocky Mountain snowmelt sources, but pre-1951 homes face elevated lead risk (6.8 ppb 90th percentile under Denver Water's active lead-pipe replacement program) plus chloramine disinfection. Boiling tap water concentrates PFAS and lead rather than removing them. Installing an NSF/ANSI 58 tankless reverse osmosis system under your kitchen sink strips 99.4% of PFOA, PFOS, lead, chromium-6, and dissolved solids right at the tap.

Fix Kitchen Tap: Waterdrop G3P800 →

2. Water Heater, Dishwasher & Fixtures

5.2 gpg (89 mg/L) Moderately Hard Water

At 5.2 grains per gallon, calcium and magnesium carbonate crust inside tank and tankless water heaters, cutting heating efficiency by up to 24% and leaving white chalky spots on glass shower doors and faucets.

Fix Scale: SpringWell Whole-House →

3. Shower Steam, Skin & Hair

Chloramine & 38.1 ppb TTHMs

Denver Water uses chloramine (chlorine bound with ammonia) to disinfect distribution mains, producing 38.1 ppb Total Trihalomethanes (TTHMs) and 22.4 ppb Haloacetic Acids that volatilize in hot showers and dry out sensitive skin.

Compare Aquasana Rhino EQ-1000 →

Engine 2 • 6-Month Cartridge Continuity

Free 6-Month Replacement Filter Reminder

Saturated carbon pre-filters allow PFAS and chlorine breakthrough after 6 months (causing membrane fouling). Pick your system below and we will email your exact OEM cartridge match when it is time to swap.

Engine 3 • Local Licensed Water Pros

Claim the Exclusive City Water Specialist Slot ($149/mo)

Are you a state-licensed C-36 / Master Plumber or WQA-certified water treatment installer? Lock in the single Featured Local Installer spot on your city's tap water report page for $149/month flat—zero per-lead bidding wars.