Got a Water Service Line Letter From the City of Houston? What 'Unknown,' 'Galvanized,' and 'Lead' Mean, and How to Check Your Pipe in 10 Minutes

Since late 2024, more than 429,000 Houston Water customers have been getting a letter in or alongside the water bill titled “Notice of Unknown Water Service Line Material,” and under federal rules it will keep arriving every year until somebody confirms what the pipe between the meter and the house is made of. The letter mentions lead, which is why we get calls about it. Here is what it actually means, how to find out in ten minutes what your line is, what “galvanized requiring replacement” means for the thousands of older Houston homes that have it, and what replacement involves and costs if it comes to that.

Why Houston Is Sending These Letters

The EPA’s Lead and Copper Rule Revisions required every public water system in the country to build an inventory of the material of every service line, the small pipe that runs from the water main in the street to each building. The inventory has to cover both halves of the line: the stretch the city owns, from the main to the meter, and the stretch the property owner owns, from the meter into the house. Any customer whose line is lead, galvanized requiring replacement, or unknown gets a written notice, and the notice repeats annually until the line is replaced or verified as non-lead.

Houston Public Works runs six water systems, and when it compiled the inventory in 2024 it had records for only a small share of private-side lines. It mailed notices to 429,662 customers with unknown material by November 15, 2024, and it said at the time it had not found any lead pipes in the city-owned service lines. The follow-on federal rule, the Lead and Copper Rule Improvements, sets a compliance date of November 1, 2027 and gives utilities ten years from that date to replace lead and galvanized-requiring-replacement lines under their control; that rule was still being litigated as of October 2026, so the dates could move, but the inventory and notice requirements are already in effect.

The city’s resources for all of this live at houstonpublicworks.org/lead-and-copper-rule-revisions, including the address-searchable inventory map, the self-report form, and copies of each letter in English, Spanish, Vietnamese, Mandarin, Arabic, French, and Urdu. The 311 line is (713) 837-0311.

The Three Letters and What Each One Means

Lead solder in copper joints (common before 1986) and brass fixtures are a separate, interior issue the letter does not cover.

Who Owns Which Part of the Line

• The City of Houston owns and maintains the service line from the water main in the street to the meter, which is normally in a box at the curb or the edge of the property.
• The property owner owns everything from the meter to the house: the buried run across the yard, the riser where it comes up at the wall, the main shutoff, and the interior plumbing.

Replacing the city’s half is the city’s job and cost. Replacing your half is yours. As of October 2026 the city has not announced a funding or reimbursement program for private-side replacement; if that changes it will be on the Public Works page or available through 311.

What Houston Service Lines Are Usually Made Of

Houston was built in waves, and the service line under your yard almost always matches the wave:

• Before the mid-1960s: galvanized steel is the norm. Threaded gray pipe, typically 3/4 inch, now 60 to 90 years old and heavily rusted inside. This is the group most likely to get a “galvanized” letter eventually. Lead service lines were used in some American cities in this era, but Houston’s inventory has not turned them up.
• Mid-1960s to late 1970s: copper, usually soft Type K or L. Long-lived, though Houston’s clay soil and stray electrical currents pit it from the outside, which is why these lines leak in the yard rather than fail from lead.
• Late 1970s to mid-1990s: polybutylene (gray or blue plastic, sometimes black) in a huge share of subdivisions. No lead concern at all, but a well-documented failure record; our main water line guide covers it.
• Mid-1990s to today: copper, PEX, CPVC, or HDPE. Homes built after 1989 should not have a lead service line, period, because federal law banned them in the late 1980s.

Lead in Houston is more likely to turn up in short “gooseneck” connectors at the main (the city’s side) or in a line that was patched decades ago than as a full lead run. Still, the only way to close the file is to look.

How to Check Your Pipe in 10 Minutes

You need a strong magnet (a refrigerator magnet works), a coin or a key, a flashlight, and your phone for photos.

1. Find where the line enters the house. Houston homes sit on slabs, so there is no basement pipe to look at. The service line comes up out of the ground at an exterior wall, usually the front or a side wall, right where you find the main shutoff valve and often a hose bib. Our how to shut off your water main guide shows what that spot looks like. On some homes the riser is inside the garage wall or a utility closet.
2. Look at the pipe below the first valve, between the ground and the shutoff. That is the service line material. Anything above the valve may have been replaced during a repair and does not count.
3. Clean a spot. If it is painted, caked in dirt, or corroded, use sandpaper to get to bare material.
4. Check the color first. White, blue, gray, or black plastic: you are done, no test needed. Note PVC, CPVC, PEX, or polybutylene if you can read the print.
5. Try the magnet. It sticks only to galvanized steel. It will not stick to copper, lead, or plastic.
6. Scratch it. Copper scratches to a bright penny color. Galvanized steel is hard to scratch and stays dull gray. Lead is soft, scratches easily to a shiny silver, and dents under a thumbnail.
7. Tap it with the coin. Copper rings; lead thuds. Galvanized rings too, but the magnet already settled that.
8. Photograph the scratched spot, the pipe where it enters the ground, and the shutoff, then upload them through the city’s self-report form so your address moves from “unknown” to verified and the letters stop.

One honest caveat. The scratch test tells you what the pipe is at the house end. A service line can change material halfway across the yard if a section was replaced after a leak, and the meter end is the city’s side. If the riser is copper or plastic on a 1950s house, the buried run is probably the same, but the city’s test-hole program at the meter is how an “unknown” on a very old home gets closed with certainty.

If the Pipe Is Galvanized

Galvanized steel is the realistic finding for most pre-1965 Houston homes, and the lead question is only one of its problems. Over 60 or more years, the zinc coating is gone and the inside is a tube of rust that narrows the flow and sheds color. If you have a galvanized service line, you have probably also noticed:

• Weak pressure at every fixture, worse when two things run at once. Our low water pressure guide puts the galvanized service line near the top of the list for older homes.
• Brown or yellow water after the water has been off or after the city works on the main nearby; see brown, yellow, or cloudy water.
• Pinhole leaks in the yard that show up as a wet spot or a high water bill.

The EPA’s “requiring replacement” label applies when the galvanized line is or ever was downstream of lead. In practice, a plumber will tell you the same thing for pressure and water-quality reasons regardless of lead: a 70-year-old galvanized service line is at the end of its life. A galvanized service line also usually means galvanized pipe inside the walls; our signs you need to repipe guide covers how to tell whether the interior is due too.

Reducing Exposure While You Sort It Out

These are the EPA and City of Houston recommendations for any home with an unknown, galvanized, or lead line:

• Flush before you drink. Run the cold tap 30 seconds to 2 minutes if water has been sitting in the pipes for several hours, longer if the line is lead. A shower or a toilet flush counts as flushing the service line.
• Cold water only for drinking, cooking, and infant formula. Hot water dissolves more lead.
• Do not boil to remove lead. Boiling concentrates it.
• Clean faucet aerators every few months; particles collect there.
• Use a filter certified to NSF/ANSI 53 for lead reduction if you want certainty: a pitcher, a faucet-mount, or an under-sink unit. Whole-house softeners and sediment filters do not remove lead; our water softener vs. whole-house filter guide explains the difference. Replace cartridges on schedule.
• Test the water if you are concerned. Certified labs test for lead, and the city’s Public Works page lists sampling resources; children under six and pregnant women are the priority. Ask your pediatrician about a blood lead test if a lead line is confirmed.

What Replacing a Service Line Involves

Replacing the private side of a water service line is a one-day job for most Houston homes:

1. Locate and mark the existing line and call in utility locates for the yard.
2. Run a new line from the meter to the house in PEX or Type K copper, by open trench along the old route or by directional boring under driveways, sidewalks, and landscaping. Repiping crews do this daily.
3. Set a new main shutoff valve, and a pressure reducing valve and expansion tank if the pressure test calls for them.
4. Pressure test, backfill, and restore the yard.
5. Permit and inspection through the City of Houston, which also updates the city’s inventory so the annual letter stops.

If the city’s half is also galvanized or lead, coordinate so both halves are replaced close together. The EPA warns that replacing only part of a lead line can temporarily increase lead levels as the disturbed pipe sheds scale. Flush heavily for a few days after any service line work and use a filter in the meantime.

What It Costs

Length, what the line runs under, and whether the interior pipe is replaced at the same time move the number more than the pipe material does. Our main water line replacement cost guide breaks the pricing down further, and the repipe cost guide covers doing the inside at the same time, which is the economical moment to do it.

How Hugo Plumbing Helps

If you got the letter and would rather not crawl around the riser with a magnet, we will identify the service line material during a free visit, photograph it in the format the city’s self-report form wants, and check pressure and the interior pipe while we are there. If the line is galvanized or lead, the replacement is one flat written price before any digging starts, with permit and city inspection included so the inventory gets updated. Financing is available on larger jobs, the $300 repipe coupon applies when the interior is done at the same time, and customers 55 and older or military receive 10% off. Licensed master plumbers (MPL 41319) are available across the Houston area at (713) 409-7176, call or text, with Spanish-speaking technicians and CSRs.

Frequently Asked Questions

Why did I get a letter from the City of Houston about my water service line?

Under the EPA’s Lead and Copper Rule Revisions, every water utility had to inventory the material of the service line to each customer, both the city-owned stretch from the main to the meter and the privately owned stretch from the meter to the house, and notify anyone whose line is lead, galvanized requiring replacement, or unknown. Houston Public Works had no record for about 429,662 customers when the first notices went out in late 2024, and the rule requires the notice to repeat every year until the material is verified. An ‘unknown’ letter is a records gap, not a test result. As of the city’s 2024 inventory it had found no lead in its own service lines.

Does an unknown service line letter mean I have lead pipes?

No. It means the city has no record of what your line is made of. Houston homes built after 1989 should not have a lead service line, because federal law banned them in the late 1980s, and most older Houston homes have galvanized steel, copper, or polybutylene service lines rather than lead. The letter exists because the EPA treats an unverified line as a possible lead line until someone looks at it. Checking takes ten minutes with a magnet and a coin, and the city asks you to report what you find.

How do I tell if my water service line is lead, galvanized, copper, or plastic?

Find where the line comes out of the ground and enters the house, usually at the front or side wall near the main shutoff and a hose bib, and look at the pipe before the first valve. Plastic is white, blue, gray, or black and needs no test. On metal, scrape a spot with a coin or key: a bright penny color is copper. A dull gray that stays dull, is hard to scratch, and holds a magnet is galvanized steel. A soft gray pipe that scratches to a shiny silver, does not hold a magnet, and gives a dull thud when tapped is lead. Photograph the result for the city’s self-report form, and remember the test only tells you the material at the house end of the buried run.

Who pays to replace a lead or galvanized water service line in Houston?

The City of Houston owns and replaces the segment from the water main to the meter. The property owner owns the segment from the meter to the house, and replacing that stretch is the owner’s cost. As of October 2026 the city has not announced a funding program for private-side replacement; call 311 for the current status. As a general Houston-area market range as of October 2026, a full private-side water service replacement runs about $2,000 to $8,000 depending on length, whether it is trenched or bored, and what sits on top of it. Hugo Plumbing quotes it in one flat written number after a free visit.

What should I do while my service line is unknown or galvanized?

Use the same precautions the EPA and the city recommend for any possible lead exposure: run the cold tap 30 seconds to 2 minutes before drinking or cooking after water has sat for several hours, use only cold water for drinking, cooking, and infant formula, clean faucet aerators every few months, and if you want certainty use a pitcher or faucet filter certified to NSF/ANSI 53 for lead reduction. Boiling does not remove lead. Then verify the pipe, report it to the city, and if it is galvanized or lead, plan the replacement.

If your service line is a question mark, call Hugo.