What contaminants are in Washington's water?

Washington's water utility tests for 130 different contaminants. Currently, 6 contaminants are above EPA MCLGs. You can view detailed information about each contaminant, including test results, health effects, and comparisons to EPA MCLGs in the sections above.

Do I need a water filter in Washington?

Yes, we recommend using a water filter in Washington. With 6 contaminants above EPA MCLGs, a certified water filter can reduce your exposure to these substances. Look for filters certified for NSF-53 (health effects) or NSF-58 (reverse osmosis) that specifically remove the contaminants found in your water.

Does Washington have any water quality violations?

D.C. WATER AND SEWER AUTHORITY currently has no reported Maximum Contaminant Level (MCL) violations, meaning the water meets all federal legal limits. However, health-based guidelines are often more protective than legal limits, which is why we compare test results to EPA MCLG Levels on this page.

Why does Washington's water taste like chlorine?

D.C. WATER AND SEWER AUTHORITY uses chloramines, filtration, hypochlorite to disinfect the water and kill harmful bacteria and viruses. While chlorine is essential for public health, it can affect the taste and smell of your water. A simple activated carbon filter (like a pitcher filter or faucet mount) can effectively remove chlorine and improve taste.

Is Washington's water hard or soft?

Washington's water has 117 PPM average hardness. Soft water is generally easier on plumbing and appliances, and requires less soap for cleaning.

What are the main contaminants in Washington tap water?

The main contaminants of concern in Washington's tap water include Bromodichloromethane, Dichloroacetic Acid (DCA), Gross Alpha Activity. These substances were found above EPA health-based guidelines. You can view detailed information about each contaminant, including health effects and recommended filters, in the contaminants section above.

Can you drink tap water in Washington?

While you can technically drink tap water in Washington as it meets legal requirements, 6 contaminants are above EPA health guidelines. We recommend using a certified water filter for optimal protection, especially for vulnerable individuals.

How often is Washington's water tested?

D.C. WATER AND SEWER AUTHORITY is required by federal law to test water quality regularly. The frequency depends on the contaminant - some are tested daily (like bacteria), while others are tested monthly, quarterly, or annually. The test results shown on this page are from the most recent testing period reported to the EPA.

Where does Washington's tap water come from?

Washington's drinking water comes from surface water purchased. Surface water sources include rivers, lakes, and reservoirs, which require more extensive treatment to remove sediments and potential contaminants. The utility treats this water using conventional before distribution.

What is the overall water quality in Washington?

Washington has 6 contaminants above EPA health guidelines (MCLGs) out of 130+ tested. While meeting federal legal limits (MCLs), the presence of contaminants above health-based guidelines suggests that using a certified water filter could provide additional protection, especially for sensitive populations.

What are the most common contaminants detected in Washington water?

The most commonly detected contaminants in Washington water include: Bromodichloromethane, Dichloroacetic Acid (DCA), Total HPC, Bromochloroacetic acid, Gross Alpha Activity. Of these, 6 exceed EPA health guidelines. These contaminants are regularly monitored by D.C. WATER AND SEWER AUTHORITY and reported to the EPA. View the detailed contaminant section above for specific levels and health information.

Washington Tap Water Quality Report

Washington's water has 6 contaminants above EPA MCLGs. We recommend using a certified water filter.

Utilities

4 Utilities

People Served

665,214

MCL Violations

Last Updated

2025-10-10

Is Washington Tap Water Safe to Drink?

Washington's water has 6 contaminants above EPA health-based guidelines. We strongly recommend using a certified water filter to reduce exposure to these contaminants. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Washington's water.

The data below shows test results from 4 water utilities serving 665,214 people in the Washington area. Water quality testing is conducted regularly and reported to the EPA. This report was last updated 2025-10-10.

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Washington Water Service Areas

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Recommended Water Filters for Washington

Based on Washington's water quality data, these NSF-certified filters are recommended to remove contaminants above EPA MCLGs.

Our Pick

BEST LEAD REMOVAL

Solventum Purification Inc.

3MRO401

(35 reviews)

679.95

NSF Certified:

NSF-58

Daily Production

11.48 gpd

Removes 15 contaminants:

Arsenic, Barium, Cadmium, Chromium (Total), Chromium (VI) +10 more

View Details

BEST LEAD REMOVAL

Solventum Purification Inc.

3MRO301

(13 reviews)

586.95

NSF Certified:

NSF-58

Daily Production

11.48 gpd

Removes 15 contaminants:

Arsenic, Barium, Cadmium, Chromium (Total), Chromium (VI) +10 more

View Details

Best Value

EDITOR'S CHOICE

BEST BUDGET

Culligan

ZeroWater

24.99

NSF Certified:

NSF-42

NSF-53

NSF-401

NSF-372

Flow Rate

1.9 gpm

Daily Production

1 gpd

Removes 19 contaminants:

Nitrate, Copper, Zinc, Barium, Sulfate +14 more

View Details

Best Value

EDITOR'S CHOICE

BEST BUDGET

Santevia

19.99

NSF Certified:

NSF-42

NSF-53

Flow Rate

0.36 gpm

Removes 1 contaminants:

Chlorine

View Details

Browse All Water Filter Types

Verify Your Water Quality with Independent Testing

With 6 contaminants above EPA health guidelines, independent laboratory testing provides a second opinion and can track changes over time.

RECOMMENDED

SimpleLab

Advanced Home Water Test

$369

Most comprehensive home water test including all standard tests plus additional parameters for ultimate peace of mind.

(19 reviews)

7-10 days

300+ tested

EPA Certified

Tests 300+ parameters

Most thorough analysis available

EPA-certified laboratory

Order Test Kit

SimpleLab

Standard Home Water Test

$232

Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.

(209 reviews)

7-10 days

200+ tested

EPA Certified

Tests 200+ contaminants

EPA-certified laboratory

Easy mail-in sample collection

Order Test Kit

Tap Score

Haloacetic Acids (HAA9) Test

$275

Tests for disinfection byproducts formed when chlorine reacts with organic matter in water treatment.

7-10 days

9+ tested

EPA Certified

Tests 9 HAA compounds

Identifies chlorination byproducts

Important for chlorinated water

Order Test Kit

EPA-Certified Labs

7-10 Day Results

Easy Mail-In Collection

Browse All Test Kits

Frequently Asked Questions About Washington Tap Water

Washington's water has 6 contaminants above EPA MCLGs. We strongly recommend using a certified water filter to reduce exposure to these contaminants. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Washington's water.

Washington Tap Water Quality Report

Is Washington Tap Water Safe to Drink?

Washington Water Service Areas

Recommended Water Filters for Washington

3MRO401

3MRO301

ZeroWater

Browse All Water Filter Types

Verify Your Water Quality with Independent Testing

Advanced Home Water Test

Standard Home Water Test

Haloacetic Acids (HAA9) Test

Frequently Asked Questions About Washington Tap Water

Is Washington tap water safe to drink?

What contaminants are in Washington's water?

Do I need a water filter in Washington?

Does Washington have any water quality violations?

Why does Washington's water taste like chlorine?

Is Washington's water hard or soft?

What are the main contaminants in Washington tap water?

Can you drink tap water in Washington?

How often is Washington's water tested?

Where does Washington's tap water come from?

What is the overall water quality in Washington?

What are the most common contaminants detected in Washington water?

Stay Informed About Your Water Quality