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NoVA & DC Plumbing Map

Sheet 18 of 18 · Fairfax County

Mount Vernon and Route 1: which Alexandria?

Full map

Along Mount Vernon and Route 1, county rules apply to many addresses that say Alexandria, so check whether yours sits in Fairfax County before you rely on any city rule.

Sheet revised November 3, 2026 · who makes this map

Modern glass-walled house among trees at Hollin Hills
A Charles Goodman-designed house in Hollin Hills, Fairfax County.
Who does what here
WaterIn the county, Fairfax Water's pipe ends at the meter. Inside the City of Alexandria, Virginia American Water owns the main to the curb stop instead. source
SewerFor a county address the whole lateral is the owner's. Main backups and overflows go to the county's round-the-clock line, 703-323-1211. source
PermitsFor county addresses, the county's Land Development Services handles permits online. The City of Alexandria's Permit Center handles addresses inside the city. source
LicensingWhich state contractor class a job needs depends on its value; the office you apply to explains its checks. source
Lead pipesAsk Fairfax Water for its records on your service line, or Virginia American Water if your bill carries its name. source

The mailing-name trap

Fairfax County has addresses with Alexandria mailing names, and the same is true of Falls Church. The post office name does not tell you which government you live under. Along Route 1 the line between city and county is easy to cross without noticing, and this map is schematic, so we draw no boundary. Treat the matter as a thing to check, not a thing to assume. Compare the Old Town sheet and the West End sheet, which are for addresses inside the city.

Single-story house behind trees and utility wires in Woodlawn
A house in Woodlawn, near Route 1.

How to tell which side you are on

Three records settle it. First, your real-estate tax bill names the locality that taxes the parcel. Second, your water bill names the supplier: Fairfax Water suggests the county, and Virginia American Water suggests the city. Third, the county's PLUS portal lets you search property information, so an address that returns a result there is a county address. If the records disagree, ask the county assessor or the city, in writing.

County rules once you know

For a county address, the owner is responsible for the entire sewer lateral, including under public easements and roads. A county plumbing permit is required for repairs, and a VDOT permit where the work lies in a state right of way. Route 1 itself is a major road, so ask which agency controls the road before trenching near it. The county does not locate private laterals. For the rest, turn to sewer lateral repair or who owns which pipe.

Reporting a sewer problem

The county's Customer Communications Center answers at 703-323-1211 day and night. Use it for backups you think come from the main, overflows from manholes, a missing manhole cover, or sewer odor outside your house. Signs of an overflow include water flowing from manholes and toilet paper on the ground. Keep children away from any overflow.

Older areas

The county lists historic overlay districts under its Architectural Review Board. We did not confirm whether any lies on your street. Ask before you alter the outside of an older building; see historic district limits.

What the map can't tell you

  • Which locality governs your Alexandria-labeled address. Only the tax record answers that.
  • Whether a historic overlay applies to your street.
  • Where a private lateral crosses a state road's right of way.
  • Whether your sewer is gravity-fed or served by a low-pressure system.

Check your own address

  1. Take your latest real-estate tax bill and read the name of the locality on it.
  2. Read the water bill for the supplier's name; Fairfax Water and Virginia American Water point to different governments.
  3. Search the address in the county's PLUS portal; no result suggests you should ask the city.
  4. Call 703-323-1211 about a suspected main problem before booking a plumber.
  5. Confirm with the county whether a VDOT permit applies before any trench near Route 1.

More on checking an address

Survey notes: sources for this page