DC
Washington, DC
25 verified firms · spring band $2,500–$6,000
Water treatment service in Washington →Washington permit officeWater treatment service in DC
25 verified water firmsacross 1 city. This page carries the state licence lookup and the permit offices; each city page carries the firm records and local cost band.
Verified listings25 verified listings1 citySpring band $2,500–$6,000
Information last verified: 8 November 2026.Dataset compiled 8 November 2026.
What qualifies as a listing
DC licence and permit rules
Check the licence with the state board before work starts. The state lookup is theDC contractor licensing.
Permits are local. Washington: Ask whether the job needs a permit and who pulls it.Each city page links its own permit office.
Sewer line costs across DC
The national band is from the site’s cost guide, checked 2026-11-08. The state range applies the metro factors in the dataset; it is an illustrative planning band, not a local price survey.
| Job | National range | DC planning range | 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 |
Water treatment service by city in DC
Water treatment service in DC: common questions
How many water firms are listed in DC?
25 verified water firms are listed across 1 city in DC. Each city page shows the date its records were last verified.
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.
Do I need a permit for a water in DC?
Permit rules are set by the city or county, not by the state. Washington: Ask whether the job needs a permit and who pulls it. The office for each city is linked on its city page.
Browse the directory.