Check your own address

Your water bill and your real estate tax bill settle it better than a mailing address or this map: the bill names your water utility, and the tax bill names the government that taxes the property.

Start with two pieces of paper

• The water bill names the company or government that sends your water. In some places the biller and the operator differ: Fairfax Water handles wastewater billing for the City of Fairfax, for example, and the sewer is still the city's.
• The real estate tax bill names the county or city that taxes the house. That is usually the first clue to which permit office you need. In the District, Arlington and Alexandria it settles the place straight away.

Why the mailing address can mislead

Post office names cross government lines. Plenty of Fairfax County homes have an Alexandria or Falls Church mailing address, and McLean and Great Falls are mailing names rather than governments. Water lines cross lines too. The Town of Vienna says about one-third of its water customers are outside town limits, and Arlington buys water from Fairfax Water for its Willston area.

Then ask the office that would know

• In DC: look up your address on DC Water's lead map, and take historic-district questions to the Historic Preservation Office.
• In Fairfax County: the county publishes wastewater guidance, including online tools showing whether a lateral may lie in a state road right of way. Its permit office page lists what needs a permit.
• In a town or small city: phone the town or city before you book work. We could not confirm from their own pages who issues plumbing permits in Herndon or the City of Fairfax.

Before anyone digs

Have the contractor contact 811 first. Virginia 811 asks for three days' notice, and Miss Utility covers the District. The marks are approximate and don't show private lines such as your own lateral. See digging and 811.

Now turn to your sheet

Use the list of places, or start from who owns which pipe.