American Water Quality Map 2026: What You Need to Know

Every day in the United States, millions of families depend on community water systems for their daily supply of water. From morning coffee to kids' baths, it's the lifeline for households everywhere. Yet, water quality varies widely across regions. What flows from a tap in California might differ greatly from one in Michigan, due to factors like local geology, farming practices, industrial activity, and aging pipes.

To better inform you on what’s in your water, Waterdrop analyzed the current water quality data from authoritative sources such as the EPA , CDC, WQA, and the USGS. By analyzing the data together, we gain comprehensive insight into the local problem. This can help you on how to protect the daily drinking water within your family.

The region of the Northeast that goes from New England into New York, New Jersey, and Pennsylvania is the oldest extensively urbanized area in the U.S.

Joya Banerjee, a water specialiast at US Water Alliance , hightlighted that “the Northeast states also face a wide array of water quality issues”. Issues concerning the water resources in the region are mostly due to the historical industrialization of the region.

The region where the industrial revolution began in the United States was the Northeast. Thus, the region suffered from the consequences of industrial activities for many years. Among the rivers that suffered from the following pollutants in the past are the Hudson River, Passaic River, Schuylkill River, among

• heavy metals (lead, mercury, chromium)
• persistent organic pollutants
• volatile organic compounds (VOCs)
• petrochemical residues

Despite the dramatic improvements achieved since the Clean Water Act was passed, the sediments in some waterways contain toxic levels that could come back out during the process of dredging, storm events, or floods.

Urban areas in the Northeast tend to maintain water pipe infrastructures dating back more than 70-100 years. Neighborhoods in older areas tend to maintain service line pipes made from lead. New Jersey and Pennsylvania contain some of the largest numbers of the older population’s lead piping in the United States.

The Northeast region is one of the areas where PFAS detection is most common due to the reasons outlined below:

• Dense population
• many airports & military bases
• ong-established chemical production

States like New York and New Jersey have enacted some of the toughest PFAS regulations in the nation in response.

Older cities like New York and Philadelphia also maintain some infrastructure consisting of combined sewers where stormwater runoff combines with sewage. This process occasionally results in overflow into water sources through the entry of microorganisms.

Starting from the Midwest region that includes Illinois, Indiana, Ohio, Wisconsin, Michigan, Iowa, and Minnesota, the region faces some the toughest water-related challenges in the whole of the United States. This is mainly because the region is dominated by contemporary agricultural business.

Since the heart of the U.S. commodity crops sector—is corn, soybeans, and livestock—the Midwest region witnesses widespread usage of:

• nitrogen & phosphorus fertilizers
• herbicides (for instance, atrazine,
• manure from large-scale farming operations.

Compared to industrial pollutants, the problem of nonpoint source pollution cannot be controlled by specific boundaries. It spills over thousands of square miles. The effect is considerable because:

• high levels of nitrates in groundwater (primarily in Iowa and Illinois)
• Algal blooms in lakes & rivers
• Hypoxia in the Gulf of Mexico fueled by the runoff of nutrients from the Mississippi Basin

Contamination from nitrates is especially problematic for rural wells owned by individuals because it is not regulated by federal drinking water regulations .

The Great Lakes contain 90% of the surface freshwater in the North American region and are the primary water supply for 30 million people. However, the lakes face constant threats in the form of:

• Nutrient-fed algal blooms in Lake Erie
• Legacy PCBs & mercury in sediments
• invasive plant species concerning ecological stability
• Stormwater flows from growing cities

Lake Erie’s toxic algae blooms have contributed to various instances of drinking water crises in the region, including the 2014 Toledo event .

Urban areas such as Detroit, Gary, and Cleveland formerly had major steel production, automobile assembly plants, and chemical works. Pollutants from such activities continue to impact the surrounding riverside sedimentation and groundwater. Also common in these regions are the brownfield sites and Superfunds.

Regions where farming is extensively irrigated witness the depletion of groundwater levels. This limits the supply of water. Also, the concentration of pollutants rises because the groundwater reservoir gets depleted.

The South, ranging from the Carolinas through Georgia to Alabama, Mississippi, Arkansas, Tennessee, Louisiana, Texas, etc. is one of the regions in the United States that fares poorly in terms of water quality.

These regions also rely heavily on small, rural, or resource-deprived water systems that do not contain the following:

• qualified operators
• consistent monitoring
• funding for improvements
• adequate corrosion control

As a result, the South experiences a disproportionate number of violations of drinking water standards. Communities of color, particularly in rural areas, are especially vulnerable, as limited budgets further constrain their ability to address these water quality challenges.

The South region of the United States is home to extensive corridors of chemical manufacturing, with Louisiana’s notorious “ Cancer Alley ” serving as a prominent example.

Communities in these areas face exposure to a variety of hazardous substances, including petrochemical solvents, heavy metals, PFAS, industrial surfactants, refinery discharges, and chemical residues.

In addition to industrial sites, many military bases and airports contribute to local PFAS contamination, further compounding the environmental and health risks for nearby populations.

The South faces more intense thunderstorms, hurricanes, and flooding than the rest of the United States. Such incidents usually result in the following:

• wastewater overflows
• pathogen spikes
• chemical spills
• saltwater intrusion (particularly in Louisiana and Florida)

Following hurricanes, whole water supply systems must occasionally be reconstructed.

Areas in Texas and Alabama are known to contain high levels of natural components such as calcium and magnesium (hardness), iron and manganese, and arsenic. Such constituents may not pose health threats but affect the aesthetic value of the water.

The Western regions of California, Arizona, Nevada, New Mexico, and parts of Utah and Colorado faces the challenge of water shortage in the region. Issues pertaining to the quality of water used in the region are directly related to the region’s water shortage.

In regions where the water levels are low, the pollutants in the water increase in concentration. Additionally, drought results in:

• higher salinity in rivers & reservoirs
• reliance on deeper, poorer-quality groundwater
• Higher levels of arsenic, uranium, and selenium
• stress on treatment plants

Since the condition of scarcity forces the utility companies to mix different sources of water together, the issue of chemical stability in water becomes complicated.

California’s Central Valley is one of the world’s most productive agricultural regions—and also one of the most seriously nitrate-contaminated groundwater basins in the United States. How did one of the world’s most successful agricultural regions also become one of the most seriously groundwater-contaminated in the United States?

Climate-related wildfires that affect California and the Western region pose its own risks to the water quality:

• ash & sediment flow into reservoirs
• Turbidity spikes
• Introduction of toxic organic compounds
• Post-fire destruction of plastic water pipes (those that contain the toxin benzene in their plastic composition)

Areas hit by large forest fires may also encounter long-term water contamination. According to a survey by the California Wildfire & Forest Resilience , “Top priorities were ecosystem restoration to protect watershed, as well as secure water supply for residential use and addressing water pollution impacts to ecosystems.”

Even if the West is less industrialized than the Northeast, it faces rising PFAS contamination threats from airports, military bases, and some factories.

Regions like the Mountain West (states including Colorado, Wyoming, Montana, Idaho), along with the Pacific Northwest (states including Washington and Oregon), contain some of the top-quality raw sources in the nation. Much of their supply comes from the forests in the mountains.

Many of the world’s largest cities, in Seattle and Portland being two examples. They are supplied from very conservatively managed forested basins. Such water sources tend to require very little processing in terms of dissolved minerals and very low levels of organics. Thus, consumers often enjoy the best possible taste.

Rivers, streams, and snowmelt may contain microorganisms like Giardia, Cryptosporidium, E. coli. The Centers for Disease Control and Prevention (CDC) notes that “Infection with Shiga toxin-producing E. coli (STEC) can lead to a serious health condition called hemolytic uremic syndrome (HUS). It can lead to kidney failure, permanent health problems, and even death”.

Despite being normally protected sources of water, they may develop higher levels of microorganisms due to natural disasters like floods.

Like in the Western region in the USA, the Mountain region continues to encounter threats from wildfires. Additionally, the burned areas might generate ample erosion from rainfall in order to produce higher levels of nutrients, sedimentation, and heavy metals. Localities surrounding the areas might require the installation of new treatment works.

The hard rock mines (gold, silver, copper) in the region of the Rocky Mountains result in acid mine drainage and contamination by arsenic, cadmium, and lead. There are also abandoned mines with tunnels that drain into streams. While some of them are localized in nature, they also impact water resources.

While US water quality reports offer broad trends, don't overlook the neighborhood-level threats that can affect the water your family drinks and uses every day.

As EPA 2024 researchers have found, “ reverse osmosis (RO) system can potentially remove water contaminants such as lead, volatile organic compounds (VOCs), PFAS, arsenic, bacteria, and viruses, and improve water quality effectively.”

To protect your family from localized water contamination, choosing the right filtration system is essential. The Waterdrop RO system provides highly purified drinking water, using multi-stage filtration including sediment pre-filters, activated carbon, and a precision RO membrane.

It effectively removes heavy metals, PFAS, nitrates, and other contaminants, improving taste and odor. This system is ideal for households in urban or industrial areas, such as the Northeast and Midwest, where legacy pollutants are common.

For whole-house protection, the Waterdrop WHR01 water softener removes chlorine, iron, manganese, and sediment from your taps. It is especially suited for regions with hard water or high sediment, such as the South, Southwest, and Western states like California and Arizona, protecting plumbing, appliances, and providing clean water throughout the home.

Water quality varies widely across the United States, with each region facing its own set of challenges, from industrial pollutants in the Northeast to hard water and sediment in the South and West. Understanding these local conditions is key for families who want safe and reliable drinking water.

High-quality home filtration systems can provide an effective solution. The Waterdrop RO system delivers purified drinking water by removing contaminants like heavy metals, nitrates, and PFAS, making it ideal for your family's everyday use.

1. Environmental Protection Agency, “About EPA,” https://www.epa.gov/ .

2. Environmental Protection Agency, “Summary of the Clean Water Act,” https://www.epa.gov/laws-regulations/summary-clean-water-act .

3. New Jersey Department of Environmental Protection, “PFAS Standards,” https://dep.nj.gov/pfas/standards/ .

4. Johns Hopkins Bloomberg School of Public Health, “The Shocking Hazards of Louisiana’s Cancer Alley,” August 4, 2025, https://publichealth.jhu.edu/2025/the-shocking-hazards-of-louisianas-cancer-alley .

5. National Weather Service, “Notable Weather Events of 2014,” https://www.weather.gov/cle/event_notable_2014 .

6. Environmental Protection Agency, “National Primary Drinking Water Regulations,” https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations .

7. Environmental Protection Agency. “Treating Water With Less Waste: Reverse Osmosis Systems.” November 2024. https://www.epa.gov/system/files/documents/2024-11/ws-products-ro-systems-mini-report.pdf

8. Centers for Disease Control and Prevention, “About E. coli (Escherichia coli).” May 14, 2024, https://www.cdc.gov/ecoli/about/index.html .

9. California Wildfire & Forest Resilience. n.d. “Water Security — Southern California Regional Profile.” https://wildfiretaskforce.org/southern-california-regional-profile/water-security/ .