Why Costa Mesa Tap Water Can Look Amber, and When It Is Your Pipes

The redwood water under Costa Mesa

Deep below Costa Mesa is an aquifer whose water carries an amber tint from buried redwood forests that grew along the Orange County coast tens of thousands of years ago. Mesa Water taps it through two deep wells, roughly 1,000 feet down, at the Mesa Water Reliability Facility.

Mesa Water describes that raw water as naturally soft and meeting drinking water standards even before treatment. The facility uses sand separators, cartridge filters and nanofiltration membranes to remove the color, so it reaches customers clear. The district has nicknamed it redwood tea.

It is a real part of the supply. Mesa Water reports that the deep amber water accounts for about 15% of its total supply, with the other 85% coming from shallower wells in the Orange County Groundwater Basin. Together they let the district serve customers with 100% local groundwater.

Supply problem or pipe problem?

Where the color shows up is the best clue.

If the whole street is affected, especially after nearby main repairs or a hydrant flush, call your utility first. Most Costa Mesa homes are Mesa Water customers, and some are served by IRWD. Your bill tells you which.

Rust from inside the house

Many Costa Mesa homes date to the 1950s and 1960s, and some still have original galvanized steel supply lines. Galvanized pipe rusts from the inside. The rust flakes off, especially when water has been sitting or when flow changes suddenly, and turns the first water out of the tap brown or orange.

The same corrosion narrows the pipe, which is why rusty water and falling water pressure often show up together. When both are happening, replacing the supply lines is usually the lasting fix rather than chasing individual sections.

The water heater clue

If only your hot water looks rusty, the water heater is the prime suspect. Tank water heaters have a glass lining and a sacrificial anode rod. When the anode is used up and the lining starts to fail, the steel tank rusts, and that rust comes out of every hot tap.

Sediment can also discolor hot water, particularly in a tank that has never been flushed. A flush sometimes clears it. Rusty hot water from a tank past about ten years old is often the first sign it is near the end, and a replacement is worth pricing before it leaks.

A rotten egg smell from hot water only is a different issue, usually a reaction at the anode rod. It is often fixed by changing the anode type.

A simple test you can do at home

1. Run cold water from the kitchen. Let it run for a minute or two and watch whether the color clears.
2. Run hot water separately. Compare the color with the cold side.
3. Check another fixture. Try a bathroom sink and an outdoor hose bib.
4. Ask a neighbor. If they see it too, the cause is likely in the supply, not your house.

Write down what you found. It tells a plumber or the utility exactly where to start.

Other things that tint or cloud tap water

Not every odd color is rust. Milky or cloudy water that clears from the bottom of the glass up is usually tiny air bubbles, common after plumbing work or when pressure changes. It is harmless and settles in a minute.

A blue or green stain on sinks and tubs points to copper pipe reacting with the water, often where there is a small leak or a lot of standing water. Black specks can come from a degrading rubber washer or supply hose, which chloramine in the water can speed up.

Each of these has a different fix, which is why the location test below matters more than the color alone. Note the time of day as well. Color that appears only first thing in the morning points to water sitting in the pipes overnight, while color at every draw points to a steady source.

What to do next

If the color points to your plumbing, a leak test and pipe check can tell you how far the corrosion has gone. If you want better-tasting water for other reasons, such as chloramine taste, see a carbon filtration system.

Amber water questions