From the lake to your tank
Hard Water Damage to Water Heaters in Milwaukee
Moderately hard lake water, treated with ozone and chloramine. Here is what it does inside a tank.
People who move here from places with very hard well water are often surprised at how mild Milwaukee's water is. People who move from soft-water cities notice the white crust on faucets.
Both reactions make sense. Milwaukee's water sits in the middle, and that middle ground still shapes how long a water heater lasts.
The short version
- Milwaukee Water Works draws from Lake Michigan and treats it at the Linnwood and Howard Avenue plants.
- Average hardness is about 137 milligrams per liter, roughly 8 grains per gallon, with a reported range of 112 to 142.
- That is moderately hard. It builds sediment slowly, so yearly flushing keeps up with it.
- The water is disinfected with chloramine and treated with a phosphorus compound to limit lead and copper leaching.
- Several suburbs get lake water from other plants. Brookfield uses groundwater, which is harder.
Where the water comes from
Milwaukee Water Works pulls water from Lake Michigan through two intakes. The Linnwood plant, finished in 1939, draws from about a mile and a quarter offshore. The Howard Avenue plant, finished in 1962, draws from more than two miles out.
Treatment includes ozone, which kills microorganisms and removes taste and odor compounds, then coagulation, settling and filtration through coal and sand. Chlorine goes in after filtering, and ammonia is added as the water leaves the plant, turning that chlorine into chloramine. A phosphorus compound limits lead and copper from dissolving off old pipes.
The utility serves the city and sells water to many nearby communities, including Wauwatosa, West Allis, Shorewood and Brown Deer, and serves Greenfield and St. Francis directly.
Hardness and what it does
Hardness is mostly calcium and magnesium. The utility reports an average of about 137 milligrams per liter, or 8 grains per gallon. That is moderately hard.
When water heats, some of that mineral comes out of solution. In a tank it settles to the bottom as sediment. On electric elements it forms a hard shell. In a tankless unit it coats the narrow passages of the heat exchanger.
- Gas tanks: the sediment blanket over the burner stretches each heating cycle and cooks the bottom steel.
- On an electric tank, scale makes the lower element work harder and fail sooner.
- On a tankless unit, scale triggers overheating and flow errors.
At 8 grains, the buildup is gradual. A yearly flush on a tank, and a descale every year or two on a tankless unit, keeps up with it in most homes.
Chloramine and rubber parts
Chloramine stays in the water longer than chlorine, which is why utilities use it. It can also be harder on some rubber parts over time, like washers, gaskets and the seals in some valves.
Around a water heater, that can show up as a drip at a connector, a relief valve that weeps, or a drain valve that will not seal. These are small repairs. Asking for chloramine-resistant parts when they are replaced is reasonable.
Corrosion control and old pipes
The phosphorus compound the utility adds forms a thin coating inside pipes that limits how much lead and copper dissolve. It is one reason the city can manage old lead service lines while it replaces them with copper.
When a lead line is replaced, the water may run cloudy or gritty for a while as the new connection settles. Some of that grit ends up in the water heater. A flush a few weeks later clears it.
Taste, smell and color at the hot tap
If the hot water looks or smells different from the cold, the water heater is usually the reason.
- Rust-colored hot water. The anode may be spent and the tank corroding, or old galvanized pipe may be shedding rust.
- A rotten egg smell from hot water only. Often a reaction between the anode rod and bacteria in the tank.
- Cloudy hot water that clears in a glass. Usually tiny air bubbles, which are harmless.
- White flakes in aerators. Scale or bits of a broken dip tube. A plumber can tell which.
If the cold water also looks or tastes off, the source is upstream of the heater, and Milwaukee Water Works or your local utility is the right call.
Suburbs with different water
- Glendale, Whitefish Bay and Fox Point share the North Shore Water Commission plant in Glendale, which treats Lake Michigan water.
- Oak Creek treats its own lake water and sells it to Franklin.
- Cudahy and South Milwaukee each run their own lake water plants.
- Brookfield pumps groundwater from wells, and some homes there are on private wells. Groundwater in the area tends to be harder than lake water, so tanks there need more attention.
Do you need a softener?
For homes on lake water, a softener is a choice, not a requirement. Many tanks do fine with yearly flushing and an anode check. A softener helps tankless units and makes sense if you dislike spots on dishes and fixtures.
If you add one, check the anode rod more often. Softened water can wear it faster.
A flush is one of the cheaper visits, well under the repair prices posted for Milwaukee water heater repair, and it pairs well with an anode check.
Milwaukee water: what Milwaukee readers ask
Is Milwaukee water hard?
Moderately. Milwaukee Water Works reports about 137 milligrams per liter, roughly 8 grains per gallon.
Does Milwaukee use chlorine or chloramine?
Chloramine. The utility adds chlorine after filtration and then ammonia as the water leaves the plant, forming chloramine.
Should I flush my water heater after a lead line replacement?
It is a reasonable step. Grit loosened during the work can settle in the tank. A flush a few weeks later clears it.
Is water harder in the suburbs?
Suburbs on lake water are similar to the city. Brookfield and homes on private wells usually have harder groundwater.