Water Contaminants Explained: PFAS, Legionella, E. coli, Lead & More

Water Contaminants Explained:

PFAS, Legionella, E. coli, Lead & More

Expert Answers from US Environmental Testing (USENVI)

When people search questions like “What are PFAS?” or “What is the action level for lead in water?” they are usually looking for a clear answer—not a chemistry lecture. At US Environmental Testing (USENVI), we specialize in translating complex environmental science into actionable insight for homeowners, commercial operators, industrial sites, and Government/Federal developments.

We operate across Illinois (Chicago metro), EPA Region 5 (Midwest), Region 4 (Southeast), and Region 9 (Western U.S.), delivering certified, defensible water testing aligned with EPA, ANSI, OSHA, VHA Directive 1061/ASHRAE 188, and DOD Standards

Below are straightforward answers to the most commonly asked water safety questions—written the way people actually search and speak.

What are PFAS?

PFAS stands for Per- and Polyfluoroalkyl Substances. These are a large group of man-made chemicals used in products like firefighting foam, non-stick cookware, waterproof fabrics, and food packaging.

They’re often called “forever chemicals” because they don’t break down easily in the environment or the human body.

In water systems, PFAS contamination is most commonly found near:

• Military bases and training sites (AFFF firefighting foam use)

• Airports

• Industrial manufacturing facilities

• Landfills and wastewater plants

From a scientific standpoint, PFAS compounds are highly stable due to their carbon-fluorine bonds—one of the strongest in chemistry. That’s why they persist.

From a regulatory standpoint, the EPA has set extremely low advisory levels (parts per trillion), meaning even trace amounts matter.

Why it matters: Long-term exposure has been linked to cancer, immune suppression, thyroid disruption, and developmental effects.

Why USENVI: We perform ultra-trace PFAS analysis using EPA-approved methods (like EPA 537.1 and 533), with strict chain-of-custody procedures required for government compliance.

What are PFCAs?

PFCAs are Perfluorocarboxylic Acids, a subgroup of PFAS.

The most well-known example is PFOA (Perfluorooctanoic Acid).

These compounds:

• Are highly mobile in groundwater

• Do not degrade naturally

• Bioaccumulate in humans and wildlife

In plain terms: PFCAs are one of the main reasons PFAS contamination spreads so far and lasts so long.

For procurement and compliance teams, PFCAs are often part of:

• CERCLA investigations

• DoD environmental restoration programs

• State-level PFAS monitoring mandates

  
  

What are PFSSs?

PFSSs refers to Perfluoroalkyl Sulfonate Substances, commonly including compounds like PFOS.

These chemicals were widely used in:

• Firefighting foams (AFFF)

• Industrial degreasers

• Stain repellents

They are:

• More bioaccumulative than many other PFAS

• Strongly linked to human health risks

Key distinction:PFSS compounds tend to bind more strongly to proteins in the human body, making them particularly concerning in long-term exposure scenarios.

What are PFSAs?

PFSAs are Perfluoroalkyl Sulfonic Acids, a chemical class within PFAS that includes PFOS.

They are:

• Extremely persistent

• Resistant to heat, water, and oil

• Common in legacy contamination sites

For government and military facilities, PFSAs are a primary target analyte group in environmental investigations due to their historic use in fire suppression systems.

What are n:2 FTSAs?

n:2 FTSAs (Fluorotelomer Sulfonic Acids) are replacement PFAS chemicals used after older compounds like PFOS were phased out.

They are often described as “next-generation PFAS,” but that doesn’t mean they’re safe.

Examples include:

• 6:2 FTSA

• 8:2 FTSA

These compounds:

• Break down into other PFAS over time

• Still persist in the environment

• Are increasingly included in advanced testing panels

Bottom line:Even newer PFAS chemicals still create long-term contamination concerns.

USENVI includes these in expanded PFAS analytical suites required for modern compliance.

What is E. coli?

E. coli (Escherichia coli) is a type of bacteria found in the intestines of humans and animals.

In water testing, it’s used as an indicator organism.

If E. coli is present, it means:

• Fecal contamination has occurred

• Other harmful pathogens may also be present

Common sources include:

• Failing septic systems

• Agricultural runoff

• Stormwater infiltration

Health risks:

• Gastrointestinal illness

• Severe infection (in certain strains)

Regulatory standard:E. coli should not be present at all in drinking water.

USENVI performs rapid microbial analysis and confirmatory lab testing, critical for public water systems, schools, and federal facilities.

What is Legionella?

Legionella is a bacteria that causes Legionnaires’ disease, a severe form of pneumonia.

It thrives in:

• Warm, stagnant water

• Cooling towers

• Hot water systems

• Plumbing in large buildings

This makes it a major concern in:

• Hospitals

• Hotels

• Government buildings

• Military housing and barracks

Key fact: Legionella is not typically ingested—it’s inhaled through water droplets (like showers or HVAC mist).

Why it matters for procurement: Legionella control programs are often required under OSHA and VA/DoD facility guidelines.

USENVI provides:

• VHA Directive 1061/ASHRAE 188 protocols and compliant reporting

• Legionella risk assessments

• Water management program validation

• Routine sampling and compliance reporting

  
  

What are nanoparticles?

Nanoparticles are extremely small particles (1–100 nanometers in size).

They can come from:

• Industrial processes

• Advanced materials

• Natural sources

In water systems, they matter because:

• Their small size allows them to bypass filtration

• They can carry other contaminants

• Their health effects are still being studied

For advanced facilities (including defense and research sites), nanoparticle monitoring is part of emerging contaminant surveillance.

What is the action level for lead in water?

The EPA action level for lead in drinking water is:

15 parts per billion (ppb)

This is not a “safe” level—it’s the point where:

• Utilities must take corrective action

• Public notification is required

• Corrosion control measures must be evaluated

Important: There is no safe level of lead exposure, especially for children.

Common sources:

• Old plumbing

• Lead service lines

• Brass fixtures

USENVI conducts:

• First-draw and flushed sampling

• School and childcare compliance testing

• Full lead and copper rule (LCR) support

  
  

Why US Environmental Testing (USENVI)?

For government agencies, municipalities, and military procurement officers, selecting a testing partner isn’t just about capability—it’s about defensibility, compliance, and reliability.

USENVI delivers:

• EPA-compliant laboratory methods

• Multi-state licensed operations (IL, IN, WI, OH, SC, ND, HI)

• Experience across residential, commercial, and federal facilities

• Strict chain-of-custody and QA/QC protocols

• Rapid turnaround times for mission-critical environments

We understand the requirements of:

• DoD and federal procurement standards

• Public health compliance mandates

• Environmental liability management

  
  

Serving Chicago, Illinois & EPA Regions 4, 5, and 9

Whether you are in:

• Chicago, Naperville, DuPage County, Cook County (EPA Region 5)

• The Southeast (Region 4)

• The Western U.S. including California, Arizona, Nevada (Region 9)

USENVI provides scalable testing solutions for:

• Drinking water systems

• Industrial and municipal facilities

• Military bases and federal properties

• Real estate and development projects

  
  

Need Water Testing You Can Trust?

If you’re asking these questions, you’re already on the right track.

US Environmental Testing (USENVI) is ready to help you:

• Identify contaminants

• Stay compliant

• Protect human health

Contact us to schedule certified water testing or to discuss federal and commercial project requirements.