Lorton splits almost down the middle. Of the roughly 7,319 homes in the census area, 38% went up in the 1980s and 1990s and 46% have gone up since 2000, so the single most useful thing a homeowner here can do is work out which half their house is in.
We are closer to Lorton than to anywhere else in Fairfax County, and that split is the first thing we think about when 22079 comes up on the phone. Two houses a mile apart can need entirely different conversations. One was plumbed while polybutylene was going into new construction. The other went up after it left the market.
Only 5% of homes here predate 1970, tied for one of the lower shares among the 26 areas we cover. The galvanized supply lines closing up after sixty years, the work that fills our week in Annandale and Springfield, is mostly not a Lorton problem. Three of the 26 areas we cover have a higher share built since 2000. Lorton is fourth.
Which Half Your House Is In
Build era is not material. A 1988 house may have gone in with copper, or been repiped since, and nobody reads your walls off your address. Era tells us what was standard the year the plumber ran the pipe, which is enough to know what to load on the truck.
40% built in the 2000s. The overlap years of copper, CPVC and PEX arriving. PVC drains throughout.
23% built in the 1980s. Copper, and polybutylene from 1978 onward.
15% built in the 1990s. Polybutylene until about 1995, then copper and CPVC.
Go and look. Under a vanity, or at the connections on top of the water heater, the pipe is right there. Grey plastic, often stamped PB2110, is polybutylene. Cream rigid plastic is CPVC. Flexible tubing with crimp rings is PEX. Copper looks like copper.
What matters is the failure mode rather than the odds. Polybutylene gives no warning drip. Chlorinated water attacks the resin from the inside and the acetal fittings go brittle, so the pipe holds and holds and then opens, usually at a fitting, often while the house is empty. Early CPVC splits at fittings instead. Find grey and the question is no longer whether to repipe, only whether you pick the date or it does.
What A 2004 Lorton House Actually Needs
In the newer half the buried work is still young, so the calls move to the short-life parts. A builder-grade water heater fitted at handover is roughly a ten-year item, which puts a subdivision finished in 2004 into its second round about now. What makes those expensive is where they sit: closets and upstairs utility spaces over finished ceilings. So on a water heater replacement we care about the parts nobody photographs, a pan with a drain that goes somewhere and an expansion tank still holding its charge, because on a closed system thermal expansion goes into that tank or into the relief valve.
Two Different HVAC Conversations On The Same Street
Equipment follows the build era as reliably as pipe does. In the 2000s half, builder-grade systems fitted at handover reach the end of a first life cycle at roughly twelve to fifteen years, and a neighbourhood that went up inside a couple of years of itself arrives there together. It rarely shows up as a decline you could budget for. It shows up as a no-cool call in the first genuinely hot week.
The 1980s and 1990s half is second generation by now. Original equipment has been replaced once already, often by whoever was cheapest that month, and the finding we write up most is a system sized for a different house than the one it sits in. Where an R-22 condenser is still limping along, topping it up every summer is money that does not come back. Heat pumps are the usual replacement, and a maintenance plan at this age buys the leak found in April rather than July.
Hard Water, And The Plant Down The Road
Fairfax Water's Griffith treatment plant physically sits in Lorton and draws from the Occoquan Reservoir. That is geography, and we will not stretch it into a claim about your tap, because the utility publishes its service-area boundaries only as maps and says those borders may change. Hosting a plant is not the same as being served by it.
Hardness is published. Fairfax Water's own FAQ describes the water as "moderately hard to hard (5 - 10 grains per gallon, or 84 - 170 mg/l)", and monthly lab results in 2025 landed outside that in both directions, so treat it as a range rather than a constant. At that level you get scale in a tank and fewer years out of a heater than the label promised. A softener here is an equipment-life decision rather than a necessity.
Permits, And Who Chases The Inspector
Water service, new or replacement or repair. Plumbing permit required. The Appendix Q line item is $77.70 and the base permit minimum is $141.75. The schedule does not say how those combine, so we will not invent a total.
Inspections. Booked in PLUS, and a request filed before 11:59 p.m. gets the next business day with a two-hour window emailed that morning. Combination inspections bundle on one day or a $141.75 reinspection fee can apply.
Fairfax County maintains roughly 3,300 miles of sewer main and 63 pumping stations, but the lateral from the house to the main is yours under County Code 65-6-1 and Virginia Property Maintenance Code 504.1, and the county will not locate or mark it. Lorton Station, the Route 1 corridor and the rest of 22079 are regular ground for us, same day on emergencies at any hour, on Class A licence #2705131990.
Common Questions
How old are most houses in Lorton?
About 38% were built in the 1980s and 1990s and 46% since 2000, with only 5% predating 1970 and the 2000s the most common decade. That comes from Census table B25034 for Lorton CDP. The near-even split is why we ask the age of the house before anything else, because here it genuinely changes the answer.
Does my Lorton house have polybutylene?
We cannot tell from your address and neither can anyone else. What we can say is that 38% of homes here went up in the 1980s and 1990s, and polybutylene was installed from 1978 until roughly 1995. Look under a vanity or at the water heater connections for grey plastic pipe, often stamped PB2110. If your house is a 2000s build you are almost certainly clear of it.
Do I need a permit to replace a gas water heater in Lorton?
Yes, even for a like-for-like swap. Fairfax County requires a permit for gas or oil-fired water heater replacement under VRC 108.2 and its Household Appliance permit page. The fee is $78.75 for one appliance, $96.60 for two, $116.55 for three and $135.45 for four, plus a 10% technology surcharge per transaction. We pull the permit and schedule the inspection as part of the job rather than leaving it with you.
How hard is the water in Lorton, and do I need a softener?
Fairfax Water's FAQ describes its water as "moderately hard to hard (5 - 10 grains per gallon, or 84 - 170 mg/l)", and 2025 monthly lab results fell outside that in both directions, so it is a range and not a fixed figure. At that hardness a softener is an equipment-life and comfort choice rather than a requirement. If you skip it, flush the water heater annually and keep the aerators clean.
Lorton has a water treatment plant in it. Does that mean my water comes from the Occoquan?
Not necessarily, and we will not claim otherwise. The Griffith plant is in Lorton and draws from the Occoquan Reservoir, but Fairfax Water also runs the Corbalis plant on the Potomac and purchases Washington Aqueduct water, moving all of it through more than 4,000 miles of main to about 2.2 million people. Service-area boundaries are published only as maps and the utility says they may change, so hosting the plant does not settle where any particular street's water is treated.
Should I worry about a lead service line in Lorton?
No. As of November 2025 Fairfax Water reported 15 utility-owned lead service lines, one customer-owned lead line, two galvanized lines requiring replacement and 116 unknowns out of more than 290,000 lines. All of them are in Belle Haven except the single customer-owned line in the City of Fairfax, and the unknowns were resolved through VDH-approved predictive modelling. In housing this new it is close to a non-question.
Who owns the sewer pipe between my house and the street?
You do. Fairfax County maintains around 3,300 miles of sewer main and 63 pumping stations, but the house lateral is the property owner's responsibility under County Code 65-6-1 and Virginia Property Maintenance Code 504.1, and the county does not locate or mark private laterals. Repair or replacement on private property needs a plumbing permit at the $77.70 line item, with a state permit as well if the work reaches VDOT right of way. More on sewer line repair and replacement.
Can you test my backflow preventer in Fairfax County?
Not in Fairfax County, and here is the rule so you can check anyone who says they can. A testable assembly has to be tested annually by someone who is both DPOR-certified as a Backflow Prevention Device Worker and listed on the Fairfax County Authorized Vendor List. We are not on that list, so the annual test is not ours to do here. Installing or replacing an assembly is a different matter, needs a plumbing permit even like-for-like, and is work we do. See backflow preventers.
