Plumbers in San Jose, CA

Find out which water you have before you buy anything

San Jose is supplied from more than one source, and the difference between them is large enough to change what breaks in your house.

San Jose Water publishes the numbers by source type. Groundwater runs 11 to 26 grains per gallon. Imported surface water runs 4 to 9. Mountain surface water runs 5 to 12. The utility also publishes a supply map so you can find which one predominantly serves your address, and that is the first thing to check before spending money on treatment.

Twenty-six grains is a serious number. It is harder than the water in most desert cities, and it puts a substantial part of the valley floor into the category where scale is a first-order plumbing problem rather than a cosmetic complaint. Four grains, at the other end, is water you can more or less ignore.

That spread is why generic advice about San Jose water is close to useless, and why a plumber here should be asking where you are before recommending anything.

What 26 grains does to a water heater

The water heater is where hard water does its most expensive work, and the mechanism is worth understanding because it explains why the fix is so cheap relative to the damage.

Water carrying dissolved calcium and magnesium drops them out of solution as it heats. Those minerals settle in the bottom of the tank as sediment. In a gas heater, that layer sits directly between the burner and the water, so the burner has to drive heat through an insulating crust, which overheats the tank bottom and wastes fuel. In an electric heater the deposit forms on the element itself with the same result. The heater runs longer for the same amount of hot water, starts making the popping and rumbling noises that come from steam escaping through sediment, and reaches the end of its life years before it should.

Draining and flushing the tank annually clears the sediment before it builds into that layer. On valley groundwater it is the single highest-return piece of plumbing maintenance available, and it is the reason the same appliance lasts noticeably longer in some parts of this city than others.

Scale does the same thing in slower motion everywhere else the water goes: inside supply pipe, in valves, in shower heads and aerators. If flow has dropped at one fixture, the fixture is usually the problem. If it has dropped throughout the house, the pipe is.

Building on flat ground, over an aquifer that moved

The Santa Clara Valley has a history that is unusual even by California standards. Pumping groundwater from the early 1900s through the late 1960s pulled water levels down by more than 200 feet, and the ground came with it: downtown San Jose permanently sank about 13 feet between 1915 and 1969, with roughly 14 feet at the worst point in the centre of the valley.

Valley Water was founded in 1929 in response to exactly this, and the fix was recharge. Surface reservoirs from the 1930s captured stormwater, and percolation ponds were built where natural gravel lets water soak back down into the aquifers. Permanent subsidence was essentially halted by around 1970.

The useful consequence for a homeowner is narrower than the history suggests, and worth stating plainly rather than overselling. Sewer laterals are gravity systems: they depend on fall, and on a valley floor this flat there is not much fall to spare. A line with a slight sag, a settled section or a partial obstruction misbehaves here in ways it would not on a slope. Given the ground history, slope on an old buried line is not something to take on trust.

So in the older flatland neighbourhoods, recurring drainage problems deserve a camera rather than another round of cabling. That tells you whether you are looking at roots, a bellied section holding water, or a collapse, which are three different bills. Housing built since 1970 has none of this behind it.

Slab housing, and why locating the leak matters more than fixing it

Most of San Jose is post-war tract housing built slab-on-grade, which means the supply lines run in or under the concrete floor.

That single fact sets the economics of nearly every supply-side repair in this city. The leak may be a pinhole in a short run of copper. The cost is in reaching it: locating it, cutting the slab, doing a repair that would take minutes if it were exposed, then putting the floor back.

Which is why precise leak detection earns its money here. Acoustic and pressure testing that narrows a leak to a small area turns a large opening into a small one. An approximate guess does the opposite. And where an older system has already had two or three slab repairs, rerouting the line overhead is often cheaper over any reasonable horizon than continuing to open the floor. That is a judgment call worth asking a plumber to make explicitly rather than defaulting to another patch.

The older neighbourhoods, Naglee Park, Willow Glen and the streets near downtown, are the exception in age but bring the other problem: mature trees standing over sewer laterals that were laid when those trees were small. Roots find open joints and return to the same spot after every cleaning, which is why a line that blocks once usually blocks again.

Every plumber we dispatch in San Jose holds the California state licence and pulls city permits for the work that requires them.