City Water: Treated Before It Reaches Your Home

If your home receives water from a municipal or public water system, that water is treated and routinely monitored before it reaches your house.

Public water systems must comply with federal and state drinking-water requirements. Depending on the source and treatment facility, the process may include filtration, disinfection, chemical treatment, and other processes designed to make the water safe for public consumption.

The utility also routinely tests for regulated contaminants and reports water-quality information to its customers.

That's an important advantage of municipal water.

But there's an important distinction I like homeowners to understand:

Safe drinking water and ideal water for your home aren't necessarily the same thing.

A municipal water supply can meet drinking-water standards while still having characteristics you may want to improve.

What Do Homeowners Commonly Notice About City Water?

The concerns I hear from municipal-water customers are often different from those I hear from private-well owners.

Hardness is a common example.

Hard water contains dissolved calcium and magnesium. While hardness generally isn't considered a health concern, it can create scale on faucets and shower doors, spotting on dishes, buildup inside water heaters and appliances, and other problems throughout the home.

Municipal customers may also notice the taste or smell of chlorine or other disinfectants used during water treatment.

Some homeowners are interested in additional treatment for particular substances that may be present at regulated levels, while others simply want their drinking water to taste better.

That's why treating city water isn't necessarily about correcting unsafe water.

Often, it's about improving the water after the utility has done its job.

Well Water Is Different

With a private well, the homeowner has a much different responsibility.

There isn't a municipal treatment plant continuously treating and monitoring the water before it reaches your home.

Your well is essentially your own private water supply.

The chemistry of that water depends heavily on the groundwater beneath your property, the depth and construction of the well, surrounding geology, land use, and environmental conditions.

That's why two private wells—even relatively close together—can produce surprisingly different water.

What Can Be Found in Well Water?

Private-well water can contain naturally occurring minerals as well as contaminants introduced through activities at or near the surface.

Depending on the location and aquifer, Iowa well owners may encounter issues such as:

Hardness — Calcium and magnesium that can cause scale and buildup.

Iron — Often responsible for orange or reddish staining on fixtures and laundry.

Manganese — Can contribute to dark staining and other water-quality problems.

Sulfur-related odors — The familiar “rotten egg” smell some well owners experience.

Nitrate — Particularly important in agricultural areas and something private-well owners should routinely test for.

Bacteria — Another important reason regular private-well testing matters.

Other contaminants may also be present depending on the location, geology, nearby land use, and history of the property.

This is why I don't like making assumptions about well water.

You need to test it.

Who Is Responsible for Testing?

This is one of the biggest differences between city water and private wells.

If you're connected to a public water system, the utility is responsible for regulatory monitoring and providing information about the quality of the water it supplies.

If you own a private well, that responsibility largely falls on you.

Private-well owners should have their water tested regularly for appropriate contaminants, including nitrate and bacteria. Additional testing may be warranted based on the location of the well, surrounding land use, flooding, changes in taste or odor, or other concerns.

Clear water isn't necessarily contaminant-free water.

Some of the most important things we test for can't be seen, smelled, or tasted.

City Water Treatment and Well Water Treatment Aren't the Same

This is where understanding the water source becomes especially important.

A homeowner on city water may primarily want to address hardness, chlorine, taste, odor, or additional treatment of their drinking water.

A homeowner on a private well might need to address hardness, iron, manganese, nitrate, bacteria, odor, sediment, or some combination of those issues.

That can require completely different equipment.

A water softener is excellent at doing the job it was designed to do—primarily addressing hardness minerals.

But a softener isn't automatically an iron-removal system, nitrate-removal system, drinking-water purifier, or solution for every contaminant that might be present in a private well.

Likewise, installing a drinking-water filter doesn't necessarily solve the water-quality problems affecting the rest of the home.

The treatment has to match the water.

Water for the Home. Water for the Body.

I like to separate residential water treatment into two conversations.

Water for the home is the water running through your plumbing, water heater, dishwasher, washing machine, showers, faucets, and fixtures.

Problems such as hardness, iron, staining, scale, and certain odors can affect the entire house. Whole-home treatment is generally designed around those concerns.

Then there's water for the body—the water your family actually drinks and uses for cooking, coffee, ice, and food preparation.

That's where drinking-water treatment such as reverse osmosis may come into the conversation.

Depending on the particular system and its certifications, reverse osmosis can reduce a wide range of dissolved substances and contaminants, potentially including nitrate, lead, arsenic, certain PFAS compounds, salts, minerals, and other substances.

These are two different jobs.

A well-designed water-treatment plan considers both.

Don't Choose Equipment Based on Your Neighbor's Water

This is particularly important with private wells.

I've seen homeowners purchase equipment because a neighbor has the same system or because someone told them, “Everybody around here has iron.”

That isn't enough information.

Even neighboring wells can differ in depth, construction, mineral content, contaminant levels, and overall water chemistry.

The system that works perfectly next door may not be the right system for your house.

The same principle applies when shopping online.

Buying water-treatment equipment before understanding your water is a little like buying medication before knowing what you're treating.

Start with the water.

What About Buying a Home?

Water source is something I think more homebuyers should consider before purchasing a property.

If the home is on municipal water, ask which utility serves the property and review its annual Consumer Confidence Report.

If the property has a private well, ask about the well's age, depth, construction, maintenance history, previous water tests, and existing treatment equipment.

And whenever appropriate, have the water independently tested as part of your evaluation of the property.

A beautiful house can still have challenging water.

Knowing about it before you buy gives you the opportunity to understand the problem and the cost of properly treating it.

So Which Is Better: City Water or Well Water?

I don't think that's the right question.

I've seen excellent city water and challenging city water. I've seen private wells produce beautiful water, and I've seen wells that require significant treatment.

Neither source automatically tells you everything you need to know about the water coming from your faucet.

The better question is:

What is in my water, and what do I want my water to be?

Once you can answer those questions, choosing treatment becomes much easier.

The Bottom Line for Iowa Homeowners

Whether your water comes from a municipal utility or a private well, good water treatment begins in the same place:

Understand your source. Understand your water. Then treat the actual problem.

If you're on city water, start with your utility's annual water-quality report and identify the things about your home's water you'd like to improve.

If you're on a private well, regular testing becomes even more important because you're responsible for understanding the quality of your own water supply.

Don't buy equipment simply because someone says you need it.

Don't assume your neighbor's water is the same as yours.

And don't assume that one piece of equipment solves every water problem.

Start with the water—not the water treatment system.

About Brook Haas

Brook Haas is the owner of BrightWater Kinetico in Central Iowa and has more than 16 years of experience in the water-treatment industry. He works with homeowners, businesses, builders, and community organizations to better understand local water-quality challenges and identify appropriate treatment solutions.

Suggested website resources:
Iowa Department of Natural Resources — Drinking Water
Iowa DNR — Private Well Program
U.S. Environmental Protection Agency — Private Drinking Water Wells
U.S. EPA — Consumer Confidence Reports