About South Whittier’s drain & sewer lines
South Whittier sits just south of the City of Whittier and is not part of it: it’s an unincorporated, census-designated community governed by Los Angeles County. The 2020 Census counted 56,415 residents across about 5.3 square miles, which makes it considerably denser than the city to its north. Neighborhoods are mostly single-family tract homes built in the postwar decades, with a growing number of garage conversions and accessory dwelling units.
That density shows up in the plumbing. More people per home means more water, more grease and more paper moving through laterals that were sized and installed for a smaller household 60-plus years ago. When an ADU or a second bathroom is tied into an original clay or cast-iron line, small weaknesses — a slight sag, a root-infiltrated joint — start causing real backups.
Common drain problems in South Whittier
Backups after an ADU or added bathroom
New fixtures send more volume through an original lateral that may already have a sag or root issue.
Grease from busy household kitchens
Larger households cook more, and grease coats long kitchen runs faster.
Wipes and paper in the main
“Flushable” wipes don’t break down, and they snag on rough clay joints.
Root intrusion near parkway trees
Street and yard trees planted in the 1950s and 60s are now fully grown.
Call and describe what’s happening — we’ll explain the likely cause and the right next step.
Hydro jetting services available in South Whittier
Every service below is available to South Whittier homes and businesses in ZIPs 90602, 90604, 90605. Tap any service for details.
- Residential Hydro JettingFull-diameter cleaning for tract homes, duplexes and homes with added units.
- Commercial Hydro JettingService for restaurants, markets and retail along South Whittier’s commercial corridors.
- Sewer Line Hydro JettingLateral jetting to the County main — the pipe you’re responsible for under LA County rules.
- Main Sewer Line CleaningHelp when the main backs up into a shower or floor drain, including after an ADU tie-in.
- Drain Line Hydro JettingKitchen, laundry and bathroom branch lines cleaned with controlled pressure.
- Grease & Sludge RemovalRemoves heavy grease buildup in high-use household and food-service kitchen lines.
- Tree Root Intrusion CleaningRoot cutting where mature parkway and yard trees have reached old clay joints.
- Recurring Drain Clog RepairPinpoints whether a repeat clog is buildup, roots or a sag that needs repair.
- Preventive Drain MaintenanceScheduled cleaning for rental properties and multi-unit lots.
LA County rules: you own the whole lateral
Because South Whittier is unincorporated, the public sewer mains are maintained by Los Angeles County Public Works through its sewer maintenance district. The County is explicit that house laterals are owned entirely by the property owner they serve — including the portion under the street and parkway — and that owners must keep them flowing and free of roots and grease. If several homes on your street back up at the same time, call the County; if it’s just your home, it’s almost always the lateral.
Adding an ADU? Check the line first
If you’re planning a garage conversion or backyard unit that will connect to the existing sewer, a camera inspection of the lateral before construction can save you from discovering a root-choked or sagging line the week your tenant moves in. Cleaning and inspecting first gives your contractor real information to plan with.
Rentals and multi-unit lots
A growing share of South Whittier lots carry a rental unit, a converted garage or a duplex. For owners, a backup affects tenants’ health and your obligations as a landlord, not just your own plumbing. Two habits help: give tenants simple written guidance on what not to put down drains (grease, wipes), and keep a record of each cleaning with any camera footage. If backups keep happening, the records make it clear whether the cause is use or the pipe itself.
South Whittier ZIP codes we serve
South Whittier addresses commonly use ZIPs 90602, 90604 and 90605. Neighborhood names and ZIP boundaries don’t line up perfectly in Whittier, so if you’re nearby, just call with your address. See all Whittier ZIP codes →
South Whittier hydro jetting FAQs
Is South Whittier part of the City of Whittier?
No. South Whittier is an unincorporated community of Los Angeles County. The County maintains public sewer mains there, and property owners maintain their laterals.
Who pays to fix a sewer lateral in South Whittier?
Under LA County rules, the property owner owns and maintains the entire lateral, including the part under the street.
Should I jet my sewer line before adding an ADU?
It’s a smart step. Cleaning and a camera inspection show whether the existing lateral can handle the added load or needs repair first.