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City water profile

Water hardness in Washington

Find official utility reports, understand hardness, and check the water system serving your home in Washington, District of Columbia.

Utility-reported hardness

Not yet available

Check your provider and source →
State comparison
At state median
Evidence comparison rank
#1 of 1
Matched utilities
1
Active health records
0

Your tap water

What does the utility report?

Match the utility name to your water bill. These results describe the utility’s water, not a test at your home. A ZIP can include several water systems.

Utility hardness unavailable in this index

Nearby river or groundwater samples cannot tell us the hardness coming out of your tap. Ask your water provider for total hardness as CaCO₃, or test it at home.

Find an official utility report →

Match the name on your water bill

Your utility’s measurements and compliance records

These are possible serving systems. A record for one system does not apply to every home in this ZIP. Confirm your provider before interpreting a measurement or notice. Federal records can lag current utility notices.

EPA snapshot: 2026Q2. Historical window begins Jan 1, 2021.

D.c. Water And Sewer Authority

DC0000002 · Surface water · 632,323 people served system-wide

A municipal system, in-state city, and served county all agree with this Census ZCTA.

No active health-based record in this imported snapshot

Find this utility’s official report →
Measurements (1)

An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.

Lead (90th percentile)

EPA SDWIS Lead and Copper Rule samples

Below action level
Reported level
0.002 mg/L
Action level
0.015 mg/L

13% of the listed benchmark

Monitoring period: Jul 1, 2025 to Dec 31, 2025

Violation history (4)
Imported violation history for D.c. Water And Sewer Authority
RuleStatusPeriod
Revised Total Coliform RuleResolvedJan 1, 2023 to Jan 31, 2023
Surface Water Treatment RuleResolvedJan 1, 2023 to Jan 31, 2023
Revised Total Coliform RuleResolvedDec 1, 2022 to Dec 31, 2022
Surface Water Treatment RuleResolvedDec 1, 2022 to Dec 31, 2022

City summary

What the indexed records say

Washington has 57 published ZIP profiles across District Of Columbia County. The regional-evidence median is 73 PPM. Its comparison-eligible median is 73 PPM versus 73 PPM statewide.

Among the 1 District of Columbiacities meeting the comparison standard, Washington ranks #1from highest to lowest. Across all 57 state ZIP profiles, available estimates run from 70.6to 73.3 PPM.

The 70.6–73.3 PPM range shows how much the available ZIP estimates vary within the city label.

Hardness distribution

How local ZIP estimates compare

Soft0 ZIPs
Moderately hard57 ZIPs
Hard0 ZIPs
Very hard0 ZIPs

57 of 57 ZIP profiles have a hardness estimate. Bars count ZIP profiles, not households or laboratory samples.

Evidence quality

Distance, dates, and confidence

Median nearest distance
5.4 miles
Profiles with evidence
57/57

Confidence labels

High: 57Moderate: 0Low: 0

Observation window: Jun 8, 2016 to Jun 17, 2026.

ZIP directory

Water reports in Washington

Open a ZIP for site-level provenance and measurements.

ZIP code

20001

Moderately Hard

73.2 PPM

Nearest site
5.5 mi
Confidence
High

View full ZIP evidence →

ZIP code

20002

Moderately Hard

71.9 PPM

Nearest site
7.4 mi
Confidence
High

View full ZIP evidence →

ZIP code

20003

Moderately Hard

71 PPM

Nearest site
6.8 mi
Confidence
High

View full ZIP evidence →

ZIP code

20004

Moderately Hard

73.1 PPM

Nearest site
5.4 mi
Confidence
High

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ZIP code

20005

Moderately Hard

73.1 PPM

Nearest site
4.9 mi
Confidence
High

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ZIP code

20006

Moderately Hard

73.1 PPM

Nearest site
4.6 mi
Confidence
High

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ZIP code

20007

Moderately Hard

73.2 PPM

Nearest site
1.6 mi
Confidence
High

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ZIP code

20008

Moderately Hard

73.3 PPM

Nearest site
3.1 mi
Confidence
High

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ZIP code

20009

Moderately Hard

73.2 PPM

Nearest site
4.3 mi
Confidence
High

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ZIP code

20010

Moderately Hard

73.2 PPM

Nearest site
4.6 mi
Confidence
High

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ZIP code

20011

Moderately Hard

73.1 PPM

Nearest site
5.3 mi
Confidence
High

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ZIP code

20012

Moderately Hard

73 PPM

Nearest site
5.8 mi
Confidence
High

View full ZIP evidence →

ZIP code

20015

Moderately Hard

73.3 PPM

Nearest site
4.1 mi
Confidence
High

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ZIP code

20016

Moderately Hard

73.2 PPM

Nearest site
1.5 mi
Confidence
High

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ZIP code

20017

Moderately Hard

73 PPM

Nearest site
6.7 mi
Confidence
High

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ZIP code

20018

Moderately Hard

71.9 PPM

Nearest site
7.7 mi
Confidence
High

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ZIP code

20019

Moderately Hard

70.6 PPM

Nearest site
5.2 mi
Confidence
High

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ZIP code

20020

Moderately Hard

71 PPM

Nearest site
5.6 mi
Confidence
High

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ZIP code

20024

Moderately Hard

73 PPM

Nearest site
6.3 mi
Confidence
High

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ZIP code

20032

Moderately Hard

72 PPM

Nearest site
7.2 mi
Confidence
High

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ZIP code

20036

Moderately Hard

73.1 PPM

Nearest site
4.3 mi
Confidence
High

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ZIP code

20037

Moderately Hard

73.1 PPM

Nearest site
4.3 mi
Confidence
High

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ZIP code

20045

Moderately Hard

73.1 PPM

Nearest site
5.2 mi
Confidence
High

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ZIP code

20052

Moderately Hard

73.1 PPM

Nearest site
4.3 mi
Confidence
High

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ZIP code

20057

Moderately Hard

73.2 PPM

Nearest site
2.7 mi
Confidence
High

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ZIP code

20059

Moderately Hard

73.1 PPM

Nearest site
5.2 mi
Confidence
High

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ZIP code

20064

Moderately Hard

73 PPM

Nearest site
6.3 mi
Confidence
High

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ZIP code

20204

Moderately Hard

72 PPM

Nearest site
6.3 mi
Confidence
High

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ZIP code

20220

Moderately Hard

73.1 PPM

Nearest site
5 mi
Confidence
High

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ZIP code

20230

Moderately Hard

73.1 PPM

Nearest site
5 mi
Confidence
High

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ZIP code

20240

Moderately Hard

73.1 PPM

Nearest site
4.7 mi
Confidence
High

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ZIP code

20245

Moderately Hard

73.1 PPM

Nearest site
4.6 mi
Confidence
High

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ZIP code

20250

Moderately Hard

73 PPM

Nearest site
5.4 mi
Confidence
High

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ZIP code

20260

Moderately Hard

73 PPM

Nearest site
5.9 mi
Confidence
High

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ZIP code

20317

Moderately Hard

73.1 PPM

Nearest site
5.5 mi
Confidence
High

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ZIP code

20319

Moderately Hard

72 PPM

Nearest site
6.9 mi
Confidence
High

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ZIP code

20373

Moderately Hard

72 PPM

Nearest site
7.2 mi
Confidence
High

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ZIP code

20388

Moderately Hard

71 PPM

Nearest site
6.6 mi
Confidence
High

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ZIP code

20390

Moderately Hard

71 PPM

Nearest site
6.8 mi
Confidence
High

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ZIP code

20408

Moderately Hard

73.1 PPM

Nearest site
5.7 mi
Confidence
High

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ZIP code

20415

Moderately Hard

73.1 PPM

Nearest site
4.6 mi
Confidence
High

View full ZIP evidence →

ZIP code

20418

Moderately Hard

73.1 PPM

Nearest site
4.5 mi
Confidence
High

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ZIP code

20422

Moderately Hard

73.1 PPM

Nearest site
5.7 mi
Confidence
High

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ZIP code

20427

Moderately Hard

73.1 PPM

Nearest site
4.2 mi
Confidence
High

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ZIP code

20431

Moderately Hard

73.1 PPM

Nearest site
4.4 mi
Confidence
High

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ZIP code

20510

Moderately Hard

72 PPM

Nearest site
6.4 mi
Confidence
High

View full ZIP evidence →

ZIP code

20515

Moderately Hard

72 PPM

Nearest site
6.5 mi
Confidence
High

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ZIP code

20520

Moderately Hard

73.1 PPM

Nearest site
4.4 mi
Confidence
High

View full ZIP evidence →

ZIP code

20530

Moderately Hard

73.1 PPM

Nearest site
5.5 mi
Confidence
High

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ZIP code

20535

Moderately Hard

73.1 PPM

Nearest site
5.5 mi
Confidence
High

View full ZIP evidence →

ZIP code

20540

Moderately Hard

71 PPM

Nearest site
6.7 mi
Confidence
High

View full ZIP evidence →

ZIP code

20542

Moderately Hard

73.1 PPM

Nearest site
4.8 mi
Confidence
High

View full ZIP evidence →

ZIP code

20551

Moderately Hard

73.1 PPM

Nearest site
4.6 mi
Confidence
High

View full ZIP evidence →

ZIP code

20560

Moderately Hard

73.1 PPM

Nearest site
5.5 mi
Confidence
High

View full ZIP evidence →

ZIP code

20565

Moderately Hard

73.1 PPM

Nearest site
5.9 mi
Confidence
High

View full ZIP evidence →

ZIP code

20566

Moderately Hard

73.1 PPM

Nearest site
4 mi
Confidence
High

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ZIP code

20591

Moderately Hard

73 PPM

Nearest site
5.8 mi
Confidence
High

View full ZIP evidence →

Practical next steps

Move from index to evidence

  1. 1. Open your ZIP. Check distance, dates, confidence, and the associated utility.
  2. 2. Read the current CCR. Confirm source water, detections, limits, ranges, and notices.
  3. 3. Use a measured hardness result. Confirm health concerns or treatment sizing with the right method.

Questions people ask

About water in Washington

Is the water hard?

Check the utility-reported result above when available. Nearby environmental samples cannot establish tap-water hardness. Ask your provider or test your tap.

Is the tap water safe?

Compliance history is utility-wide and cannot guarantee conditions at every tap. Check current notices and test when address-specific evidence is needed.

Do I need treatment?

Choose treatment only after confirming the problem at the property. A softener targets hardness; contaminant treatment requires a matching, verified performance claim.