Fall Sewer Checklist for San Jose Homes, Before the Rains
Other parts of the country winterize their sewer lines before the ground freezes. San Jose's ground doesn't freeze, and the thing to get ahead of isn't cold — it's water. The rainy season starts in November, the first big storms raise groundwater and flood old clay laterals through their open joints, and the city mains run full. A lateral that's marginal in September fails in December. Here's what to check in the next few weeks, in order of how little it costs.
The checklist
- Find the cleanout. A capped 4-inch pipe near the foundation, usually on the side facing the street, sometimes in a small box in the lawn. Know where it is before you need it at 10 p.m. Houses built before about 1950 in Naglee Park, Rose Garden and the older parts of Willow Glen often don't have one.
- Take the cap off. If it's stuck, a wrench and some care. If it's cracked or missing, replace it; an open cleanout is a route for rainwater into the sewer and for sewer gas into the yard.
- Run every drain and listen. Fill the tub and let it go while you stand by the hall toilet. Gurgling means air is being forced through a partial blockage. Run the washing machine and check the shower. Anything slow now will be stopped in December.
- Sniff the yard on a warm afternoon. Sewer smell near the foundation, the cleanout or along the line's path means sewage is reaching soil.
- Look at the lawn before the rains green it up. A stripe that stayed green all summer along the lateral's path is a leak. Once the rain comes everything's green and the evidence is gone until next August.
- Walk the driveway and sidewalk. A depression, a new crack line or a soft spot over the pipe's path means soil is washing into a broken pipe.
- Check what's over the line. If you're planning a patio, a new driveway or a pool this winter, get the lateral located and inspected first. Lining it under a new $30,000 patio is easy now and painful later.
- Clear the roof gutters and check where downspouts go. Downspouts connected to the sanitary sewer are illegal and, on some older houses, still connected. Every gallon of roof water they send down your lateral in a storm is a gallon the pipe and the city main have to handle. Redirect them to the yard or the storm drain.
- Get the line jetted and cameraed if any of the above turned something up. $600–$1,300 for hydro jetting plus a recorded camera inspection, with the fault marked on the surface. For a clay lateral under a redwood, this is an annual item in any case.
- Decide before December. If the camera shows roots at several joints, an offset, or Orangeburg, book the repair while the ground is dry and the schedule has room. The repair page and the trenchless page cover the options.
Why rain breaks sewer lines here
It doesn't, quite. What it does is expose them. Clay joints that roots have opened admit groundwater once the water table rises; the surge in flow carries debris into the root mat; and a main taking that infiltration from hundreds of houses runs surcharged, so any lateral with a low spot backs up sooner. On the valley floor near the Guadalupe River and Coyote Creek, where groundwater sits closest to the surface, a wet January can keep a lateral half-full of infiltration for weeks.
Storm water also finds its way in through cracked cleanout caps, unsealed roof-drain connections and yard drains someone tied into the sewer decades ago. All of that is water your lateral was never sized for.
Things not to do
- Don't pour drain cleaner into a main line. It doesn't reach a root mass 40 feet away and it makes the line dangerous for whoever opens it next.
- Don't wait for the second backup. The first one is information. The second one is the same information, plus a ruined weekend.
- Don't let anyone quote a replacement from the driveway. The camera first, every time.
After the first big storm
If the whole street backs up at once in the first November deluge, that's the main, not you — call San Jose 311. If it's just your house, the checklist above tells you where to look, and the signs post tells you what each symptom means. Rain is coming either way; the only question is whether you've looked inside the pipe before it arrives.
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