State licence
DC contractor licensing
Check the licence with the state board before work starts.
Open the official lookup →Water treatment service near me
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Water treatment service in Washington, DC
There are 25 verified water firms listed in Washington, DC. Listings are compiled from public business records and checked against the DC contractor licensing; each record shows the date it was last verified.
Verified listings25 verified listingsSpring band $2,500–$6,000DC licence + Washington permit links
Information last verified: 8 November 2026. Dataset compiled 8 November 2026.
What qualifies as a listing
Sewer lines in Washington
Water treatment service work in Washington follows the same pattern as the rest of DC: the failure mode decides the method, not the other way round.
Permit rules in Washington are set locally. Ask the city whether your job needs a permit and who pulls it.
What water work costs in Washington
The national range is from the site’s cost guide, checked 2026-11-08. The local column applies the 1.00× metro factor and rounds to $5. It is a planning band, not a quote.
| Job | National range | Washington planning band | What it includes |
|---|---|---|---|
| Whole-house softener, installed | $2,500–$6,000 | $2,500–$6,000 | Typical US range |
| Whole-house filtration | $3,500–$9,000 | $3,500–$9,000 | Typical US range |
| Well tank replacement | $1,200–$2,800 | $1,200–$2,800 | Typical US range |
| Well pump replacement | $900–$2,200 | $900–$2,200 | Typical US range |
| Reverse osmosis, installed | $3,500–$8,000 | $3,500–$8,000 | Typical US range |
| Annual service, no salt | $150–$400 | $150–$400 | Typical US range |
Editorial metro factor, not a measured price index. The factor is not a measured local price index; it estimates labour and permit overhead. A quote that is far below the band usually has a smaller scope, not a better price.
Licence and permit checks for Washington
Local permit
Washington permit office
Ask whether the job needs a permit and who pulls it.
Open the permit office →These links go to the official state or city page. The directory does not file permits and does not verify a contractor’s current insurance for you.
Sewer line firms in Washington, DC
25 verified records. The order is the dataset order, not a ranking. Each card shows the date its record was last verified.
Verified
Mid Atlantic Water Services
Water treatment service contractor
- Address
- 14 Hudson St
Washington, DC - Phone
- (410) 573-1020
- Website
- Not published
- Rating
- 4.9 / 5 · 1206 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
National Water Service
Water treatment service contractor
- Address
- 2878 Daisy Rd
Washington, DC - Phone
- (301) 854-1333
- Website
- Not published
- Rating
- 4.9 / 5 · 605 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Capital Water Treatment
Water treatment service contractor
- Address
Washington, DC- Phone
- 506-261-3369
- Website
- Not published
- Rating
- 5.0 / 5 · 30 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Blue Plains Advanced Wastewater Treatment Plant
Water treatment service contractor
- Address
- 5000 Overlook Ave
Washington, DC - Phone
- (202) 870-9789
- Website
- Not published
- Rating
- 4.4 / 5 · 27 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Water Doctor
Water treatment service contractor
- Address
- 10983 Guilford Rd
Washington, DC - Phone
- (410) 792-0327
- Website
- Not published
- Rating
- 5.0 / 5 · 53 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Clear Wave Water Solutions
Water treatment service contractor
- Address
- 3613 Prince Andrew Ln
Washington, DC - Phone
- (757) 828-8594
- Website
- Not published
- Rating
- 4.9 / 5 · 35 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
District of Columbia Water and Sewer Authority
Water treatment service contractor
- Address
- 1385 Canal St
Washington, DC - Phone
- (202) 787-2000
- Website
- Not published
- Rating
- 2.7 / 5 · 37 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Wellness Water Filtration Systems
Water treatment service contractor
- Address
- 1000 Wisconsin Ave
Washington, DC - Phone
- (771) 213-5813
- Website
- Not published
- Rating
- Not published
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
DC Water
Water treatment service contractor
- Address
- 301 Bryant St
Washington, DC - Phone
- (202) 787-2000
- Website
- Not published
- Rating
- 3.5 / 5 · 8 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Roto-Rooter Plumbing & Water Cleanup
Water treatment service contractor
- Address
- 5125 MacArthur Blvd
Washington, DC - Phone
- (202) 921-9873
- Website
- Not published
- Rating
- 4.7 / 5 · 2991 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
PureSpring Water Softeners & Filters
Water treatment service contractor
- Address
- 34 Sheridan St
Washington, DC - Phone
- (771) 717-6034
- Website
- Not published
- Rating
- Not published
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Northwest Water Treatment, Inc.
Water treatment service contractor
- Address
- 19312 Patterson Rd
Washington, DC - Phone
- (253) 630-7177
- Website
- Not published
- Rating
- 5.0 / 5 · 10 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Water Mold Fire Restoration of Washington DC
Water treatment service contractor
- Address
Washington, DC- Phone
- (202) 650-0299
- Website
- Not published
- Rating
- 3.6 / 5 · 9 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Sharp Water Culligan (Salisbury, MD)
Water treatment service contractor
- Address
- 129 Columbia Dr
Washington, DC - Phone
- (410) 742-3333
- Website
- Not published
- Rating
- 4.6 / 5 · 322 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
WG Basement Waterproofing Washington DC
Water treatment service contractor
- Address
- 1428 U St
Washington, DC - Phone
- (771) 220-7445
- Website
- Not published
- Rating
- 5.0 / 5 · 17 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Crawl Space Brothers
Water treatment service contractor
- Address
- 700 12th St
Washington, DC - Phone
- (571) 582-3591
- Website
- Not published
- Rating
- 4.8 / 5 · 96 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
DC AIR CONDITIONING &Heating
Water treatment service contractor
- Address
- 2015 14th St
Washington, DC - Phone
- (202) 985-8885
- Website
- Not published
- Rating
- 4.9 / 5 · 466 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
The DRIPBaR D.C. - Georgetown
Water treatment service contractor
- Address
- 1720 Wisconsin Ave
Washington, DC - Phone
- (202) 998-8242
- Website
- Not published
- Rating
- 5.0 / 5 · 52 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
The Tox DC Georgetown
Water treatment service contractor
- Address
- 1202 30th St
Washington, DC - Phone
- (202) 322-5620
- Website
- Not published
- Rating
- 4.9 / 5 · 251 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Stantec
Water treatment service contractor
- Address
- 2101 L St
Washington, DC - Phone
- (202) 822-8227
- Website
- Not published
- Rating
- 5.0 / 5 · 4 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
LimnoTech
Water treatment service contractor
- Address
- 1015 18th St
Washington, DC - Phone
- (202) 833-9140
- Website
- Not published
- Rating
- Not published
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Tim Whistler Plumbing, Gas Fitting, HVAC, and Electrical
Water treatment service contractor
- Address
- 2345 Distribution Cir
Washington, DC - Phone
- (833) 907-6190
- Website
- Not published
- Rating
- 4.7 / 5 · 330 reviews
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Weston Solutions
Water treatment service contractor
- Address
- 1101 14th St
Washington, DC - Phone
- (202) 741-4800
- Website
- Not published
- Rating
- Not published
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Verified
Access Medical Books
Water treatment service contractor
- Address
- 1473 Massachusetts Ave
Washington, DC - Phone
- (202) 801-2031
- Website
- Not published
- Rating
- Not published
- Place ID
- Not recorded
- Record
- Information last verified: 8 November 2026
Firms in Washington, DC are shown in the order supplied by the dataset, not by rating or payment. No placement is sold. Each name opens that firm’s own profile page.
How this list was built
The directory starts from public business records: the firm’s own website, its published address and phone number, and the state or city licence register named above. A record is marked verified only when a person has checked the name, address, phone and licence against those sources and recorded the date. The place_id field is kept so a future rebuild can match the same entity without guessing.
The national cost band comes from the site’s cost guide. The metro factor is an editorial estimate, not a survey. No rating, review text, price or availability is invented for a verified page; where a public rating is shown it is attributed and dated.
If a record is wrong, the firm can ask for a correction or removal.Corrections: contact@watertreatmentpro.com. Read the fulllisting verification method.
Water treatment service in Washington: common questions
How many water firms are listed in Washington?
25 verified water firms are listed in Washington, DC. 0 publish a website, and 24 records have been verified. The city page is generated only because the dataset contains at least one genuine listing record; a city with no record has no page.
What does water treatment service cost in Washington?
The directory’s planning band for a torsion spring replacement is $2,500–$6,000. It is the national range ($2,500–$6,000, checked 2026-11-08) multiplied by an editorial metro factor of 1.00 and rounded to $5. It is an estimate, not a local price survey, and not a quote. Get three written quotes for the same scope.
Does DC license water contractors?
Check the licence with the state board before work starts. The official lookup is the DC contractor licensing, linked on this page. A licence or registration number is a starting point, not a substitute for checking insurance and the scope of the work.
Do I need a permit for a water in Washington?
Ask whether the job needs a permit and who pulls it. The permit office is the Washington permit office, linked on this page. If the contractor says no permit is needed, ask them to put the reason in writing.
Water treatment service near Washington
The closest metros in this directory, by straight-line distance. Each link opens that city’s own cost, licence and permit page.
Guides for Washington homeowners
What water treatment service costs
Installed ranges by job, and the five lines every quote should show.
Read the guide →Diagnose the problem first
Symptom to cause, what proves it, and what not to do first.
Read the guide →How to choose a contractor
Licence, insurance, warranty and the questions that expose a thin scope.
Read the guide →Compare the options
Repair, replace or change the opening — decided on scope and five-year cost.
Read the guide →Browse the whole directory.
All service areas ·All DC service areas ·Cost guides ·Methodology