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Los Altos, CA · Water Hardness, Sewer Laterals and Permits · ZIPs 94022, 94023 and 94024
Emergency Plumber in Los Altos, CA: Hard Water, Old Laterals and Who Handles What
Two Los Altos neighbors can have very different water, because the supply is a blend of local groundwater and purchased surface water. They also share a sewer rule that splits the lateral at the first joint past the property line, not at the cleanout. This page explains both, what the Building Division's form covers, and what happens when a call arrives from outside our verified list.
Why water hardness in Los Altos depends on your address
California Water Service's Los Altos Suburban district supplies the town. Its 2024 report shows two sources with very different water: local groundwater with hardness from 155 to 440 mg/L, averaging 309, and purchased Valley Water supply from 93 to 133 mg/L, averaging 111.
By that report's own scale, 309 mg/L is very hard, while 111 is moderately hard. Which one reaches your tap depends on where your street sits in the blend, and we could not find a public map of it.
| Source | Hardness range | Average hardness | Average pH |
|---|---|---|---|
| Local groundwater | 155 to 440 mg/L | 309 mg/L | 7.6 |
| Valley Water supply | 93 to 133 mg/L | 111 mg/L | 7.7 |
Test at the tap before spending on a softener, and look at the heating element or the tankless exchanger for scale. A tankless unit is the appliance that suffers most on the harder blend. The disinfectant is chloramine, and the district's customer line is (650) 917-0152.
Los Altos splits the sewer lateral at the first joint, not the cleanout
The City's rule is specific. The owner pays for reconstruction from the first joint after the property line to the house, and the City handles reconstruction from that first joint to the main.
The City's FAQ adds two details. The City repairs a defect only when it is beyond the first full section of pipe past the cleanout. And City crews may clear a blockage between the property-line cleanout and the main as a courtesy.
- Find the cleanout. It is typically about nine inches across, with a concrete cover over a plastic cap, near the property line.
- Call Maintenance on a backup. The line is (650) 947-2785, and after hours Los Altos Police dispatch maintenance at (650) 947-2770.
- Ask where the first joint is. Engineering Services, at (650) 947-2780, can say where a lateral runs if you do not know.
- Get a camera look before agreeing to a repair. Whether the defect sits before or after the first joint decides who pays.
If there is no cleanout, the City's FAQ suggests installing one, which also gives a camera a way in.
Backed up in Los Altos? Call now and stop running water while we talk.
Call (833) 840-2034What the Building Division's permit form lists for plumbing
The Building Division at City Hall, One North San Antonio Road, answers at (650) 947-2752. Its residential permit application has plumbing checkboxes for sewer line replacement, water heater replacement, tankless water heaters, new electric water heaters, new heat pump water heaters and new gas appliances, which need a gas line diagram.
The form notes a backwater valve requirement for a sewer line replacement. It does not list repiping, and the pages we read do not say whether each item is legally a permit item, so confirm with the Division before work starts.
- Ask whether a backwater valve is required before a lateral replacement is priced.
- A switch to a heat pump unit has its own checkbox, so say so at the start.
- Excavation in a public street needs a separate permit under the municipal code text we read.
Pool and spa water: where it may and may not go
A Los Altos pool or spa is a common source of a sewer question. The City's FAQ allows pool or spa water into the private sewer at no more than 100 gallons per minute, or onto private landscaping. It never goes to the street or the storm drain, and violations may be cited.
That matters at draining time. Run the pump to a cleanout or a landscaped area and keep the rate low, rather than pointing a hose at the curb.
Sluggish drains and scaled fixtures in Los Altos: where to read next
| What you see | Page to open |
|---|---|
| Several drains sluggish at once | Drain cleaning for slow drains |
| Roots or a cracked lateral under the lawn | Sewer lateral repair |
| Wet patches, or a bill that jumped | Tracing a concealed leak |
| A tank that runs out fast or leaks | Water heater service |
| Scale on fixtures from hard water | Water softener options |
What happens with a Los Altos call
The ZIP codes for Los Altos, 94022, 94023 and 94024, are missing from the verified list, and for that reason the town is not described as covered here.
Phone with the street address. If a plumber can come, we say so; if not, the answer comes first and you can try someone closer to home.
Not sure we reach your street in Los Altos? Call and ask.
Call (833) 840-2034Hard water, lateral costs and pool drainage in Los Altos
Do you serve Los Altos?
Los Altos's ZIP codes, 94022, 94023 and 94024, are left out of the verified list, so Los Altos is not called covered. Phone with an address and we say whether someone can come.
Is the water in Los Altos hard?
It depends on the address. Cal Water's 2024 report shows groundwater averaging 309 mg/L, which is very hard, and Valley Water supply averaging 111 mg/L, which is moderately hard. Test at your own tap.
Who pays for a sewer lateral repair in Los Altos?
The owner pays from the first joint past the property line to the house, and the City from that first joint to the main. The City repairs a defect only beyond the first full section of pipe past the cleanout.
Who do I call about a sewer backup in Los Altos?
Maintenance Services at (650) 947-2785. After hours, Los Altos Police at (650) 947-2770 dispatch maintenance.
Where can pool water be drained in Los Altos?
Into the private sewer at no more than 100 gallons per minute, or onto private landscaping. Never to the street or the storm drain.
Is a visit possible at your Los Altos address?
Phone with the street address. The answer on a visit comes first, and a written range comes before any work.