Plumbing Service Area in Union City, CA and Nearby
Union City is home base. We also take calls from Fremont, Hayward, Newark and Castro Valley, and the utilities differ from town to town.
This page shows where we work, which agency owns which pipe, and how ZIP codes relate to city lines.
- Union City, CA 94587
- ACWD water and USD sewer
- 24/7 phone line
- 94587
- 94552
- 94544
Where we send plumbers
Our address is 32040 Union Landing Dr, Union City, CA 94587, and the core of our service area is Union City itself. We also take calls from Fremont, Hayward, Newark and Castro Valley. Tell the dispatcher your street and the nearest cross street, and say which city your water bill comes from.
Fremont gets its own page because it shares both the water and the sewer agency with Union City. The emergency plumber in Fremont page covers its historic districts, hills and ZIP codes. Hayward, Newark and Castro Valley are covered here on this page.
Union City neighborhoods and what each one needs
Union City formed in 1959 from Alvarado, Decoto and New Haven. The modern map has more pieces, but these are the names callers use.
Alvarado
Alvarado has a historic district and a California Historical Landmark marking the site of Alameda County's first courthouse at 30977 Union City Blvd. On older streets, ask the plumber to run a camera through the sewer before replacing fixtures, since age often shows up underground.
Decoto
Decoto was one of the communities that merged into Union City. If your home was built before 1960, ACWD says a galvanized service line is likely, so a pressure drop deserves a look at the line from the meter.
Union Landing area
Our address is here, near the theaters, restaurants and Sugar Mill Landing Park with its Flight 93 Memorial at Smith and Dyer Streets. Restaurant owners should ask about grease interceptors and floor drains, covered on the commercial plumbing page.
Station District and BART
The Station District is the transit-oriented area around Union City BART at 10 Union Square. In apartment and other multi-unit buildings, a leak may involve a shared shutoff, so find out whether the building has a master valve before calling.
Mission Blvd corridor
Mission Blvd runs toward Fremont and passes the Masonic Home at 34400 Mission Blvd. Properties on or near it use the same ACWD water and USD sewer as the rest of the city.
ZIP codes around Union City and what they mean
ZIP codes do not follow city limits, so a mailing address can be misleading about which utility serves you.
| ZIP code | What it covers | What it means for your call |
|---|---|---|
| 94587 | The Union City ZIP that appears on addresses for City Hall, Union City BART, the Kaiser medical offices, the Masonic Home and our own address | Most callers are here. Give the cross street so we can place you. |
| 94552 | A large mixed ZIP. Census files show Castro Valley, Union City, Hayward and a sliver of Fremont inside it | Check your water bill. It will say whether ACWD, a city or EBMUD serves you. |
| 94544, 94545, 94542 | Mostly Hayward ZIP codes. Small slivers of Union City fall inside them | A Hayward mailing address does not rule out Union City limits, so confirm the city. |
| 94536, 94538, 94539, 94555 | Fremont ZIP codes | Read the Fremont page for the district names and hills. |
ZIP data comes from Census Bureau place and ZIP boundary files. USPS preferred city names can differ from the Census geography.
Utilities by town: who owns which pipe
Our private-side plumbing work is the same everywhere. The agency you call for a main line problem is not.
| Town | Water | Sewer |
|---|---|---|
| Union City | Alameda County Water District | Union Sanitary District |
| Fremont | Alameda County Water District | Union Sanitary District |
| Newark | Alameda County Water District | Union Sanitary District |
| Hayward | City of Hayward Utilities Division | City of Hayward Utilities Division |
| Castro Valley | EBMUD | Castro Valley Sanitary District |
Utility assignments are from agency websites. Confirm with your latest bill.
Who owns the problem? A short walk-through
Find the water meter
ACWD maintains pipe on the street side of the meter. If the leak is upstream of it, call ACWD Operations at (510) 668-6500.
Look at the meter side
The owner maintains everything from the meter into the property. This includes the water line to the house, which is where our water line repair page picks up.
Check the sewer cleanout
Union Sanitary District says the owner maintains the full lateral to the main. A cleanout outside the house or just behind the sidewalk is the usual access point, and older homes may not have one.
Ask USD to check the main
USD's 24 hour line is (510) 477-7500, and it inspects the public main for free. If the main is clear, the problem is on your side and you need a plumber.
Not sure which side of the line you are on?
Describe where the water or sewage is showing up. The dispatcher can tell you who owns it.
Hayward Fault and Alameda Creek: two local facts that affect plumbing
The Union City Station District sits west of the Hayward Fault, with the nearest trace about 680 feet to the northeast, according to the city's environmental review. California requires water heaters to be braced or strapped against earthquake movement, so a heater with no straps is both a code issue and a risk for a gas leak. After any strong shake, check for water and gas leaks and shut off both at the main if you find one.
The Alameda Creek Flood Control Channel runs through Union City and Fremont, and the Alameda Creek Regional Trail has entrances here. Water showing up in a yard or crawl space after rain may be drainage rather than plumbing, so check roof gutters and grading before assuming a pipe has broken.
Source type: City of Union City environmental review, California Seismic Safety Commission, Alameda County Flood Control District
Hayward, Newark and Castro Valley: what to expect
We take calls from Hayward, Newark and Castro Valley as well as Union City and Fremont. Distances are rough estimates by road. Central Fremont is about 4 to 5 miles from Union City, Newark's city hall is about the same, and downtown Hayward is about 8 miles. Castro Valley lies a couple of miles north of the city line, past the Fairview area.
In Hayward and Castro Valley the main line owner is a different agency, so a sewer backup goes to the city of Hayward or the Castro Valley Sanitary District rather than USD. Our work on the private side of the meter and lateral is the same. For a quick start, begin with drain cleaning or leak detection, depending on what you see.
Not sure whose pipe it is?
Call and give us the street and the nearest cross street. We will tell you whether it sits on the utility side or the property side, and arrange a plumber if it is yours.
What to do first when water or sewage shows up
The right first step depends on where the water appears, and it takes a minute to check.
- Water on the street side of the meter. Call ACWD Operations at (510) 668-6500, because that side of the meter is the utility's.
- Water inside the house. Turn the house valve clockwise, then call the 24/7 line.
- Sewage backing up. Stop using water and call USD at (510) 477-7500, since USD checks its own main for free. If the main is clear, the blockage is in your lateral.
Service area questions
Union City is our base. We also take calls from Fremont, Hayward, Newark and Castro Valley. If you are not sure whether your address falls inside the area, call and ask.
No. ZIP codes are mail routes that cross city lines. Your water bill names your water provider, and that is the reliable source.
In Union City, Alameda County Water District maintains the pipe on the street side of the meter. You maintain everything from the meter to the house.
Hayward's sewer system is run by the city utilities division, not Union Sanitary District. Call the city to check the public main, then call us for the private side.
The utilities are the same, so the ownership rules match. The Fremont page covers its historic districts and hill areas, where USD notes a sewer backflow device may be prudent.
Call from anywhere in the Tri-City area
Tell us the city and cross street, and we will sort out the utility and send a plumber.
Call (510) 544-1962