PFAS Results

How to read my results

or read below

Sample Results – START HERE
Analyte = name of the specific PFAS tested

Your water was tested for 25 different substances. Pay special attention to the number in the Result column for those with established Maximum Contaminant Levels (MCLs): HFPO-DA, PFBS, PFHxS, PFNA, PFOA, PFOS.
Result = the concentration of the compound detected in your water

Each result should be compared against the federal MCLs and Maximum Contaminant Level Goals (MCLGs), if established.
ND = Non-Detect

The compound was not detected at or above the method reporting limit (MRL). A value of zero is used in calculating the Hazard Index.
MDL = Method Detection Limit

The lowest concentration the equipment can detect a contaminant.
MRL = Method Reporting Limit

The lowest concentration the lab can reliably report with confidence. Also called the Limit of Quantitation (LOQ).
Units

ng/L = nanograms per liter = parts per trillion (ppt)
Qualifier

If there is something in this column, check the “Notes and Definitions” page for additional information.
Surrogate(s) – STOP HERE

What do these numbers mean?

On April 10, 2024, the U.S. EPA finalized the National Primary Drinking Water Regulation (NPDWR) for six PFAS, and Nevada has adopted the federal regulation. These enforceable Maximum Contaminant Levels (MCLs) apply only to public water systems; for a private well they are the recommended health-based benchmarks to compare your results against. The EPA has also established separate Maximum Contaminant Level Goals (MCLGs), which represent the level of contaminant in drinking water below which there is no known or expected risk to health. The MCLs are set as close to MCLGs as feasible using the best available treatment technology and taking cost into consideration. The MCLG for PFOA and PFOS is 0 ppt, meaning that no amount of these compounds in your water is considered safe.

Table 2: Enforceable and Health-Based Limits for Select PFAS

Compound	Maximum Contaminant Level (MCL)	Maximum Contaminant Level Goal (MCLG)
PFOA	4.0 ppt	0 ppt
PFOS	4.0 ppt	0 ppt
PFNA	10 ppt	10 ppt
PFHxS	10 ppt	10 ppt
HFPO-DA (GenX)	10 ppt	10 ppt
Mixtures of two or more of PFHxS, PFNA, HFPO-DA, and PFBS	Hazard Index = 1.0 (unitless)	Hazard Index = 1.0 (unitless)

Important note on the changing rule: On May 14, 2025, EPA announced it would keep the PFOA and PFOS MCLs of 4.0 ppt, but that it intends to rescind and reconsider the determinations for PFHxS, PFNA, HFPO-DA, and the Hazard Index mixture. Those four standards may change, but for now private well users should use the levels in the table above as guidance.

Comparing the attached report to the health-based standards

Comparing the WELL 01 results in Table 1 against the MCLs in Table 2:

PFOA = 10 ppt – exceeds the 4.0 ppt MCL.
PFOS = 5 ppt – exceeds the 4.0 ppt MCL.
PFHxS = 160 ppt – exceeds the 10 ppt MCL.
PFNA = ND – below the MRL of 2.0 ppt.

How is the Hazard Index calculated?

The Hazard Index (HI) is calculated for mixtures of PFHxS, PFNA, HFPO-DA, and PFBS. For each compound you divide the measured result by its health-based value, then add the ratios. Non-detect (ND) results count as zero. If the total is greater than 1.0, the mixture exceeds the standard. Using the attached WELL 01 results:

Table 3: Example Hazard Index Calculation

Compound	Result (ppt)	Health-Based Value (ppt)	Ratio (Result ÷ Value)
PFHxS	160	10	16.0
PFNA	ND (0)	10	0
HFPO-DA (GenX)	ND (0)	10	0
PFBS	81	2,000	0.04
Hazard Index (sum of ratios)	16.04

Because 16.04 is above 1.0, this sample would exceed the Hazard Index standard — driven almost entirely by PFHxS. PFOA and PFOS are evaluated separately against their own 4.0 ppt MCLs and are not part of the Hazard Index.

How do I remove PFAS, and is help available?

If there are PFAS in your drinking water, then you may consider installing a home filter. A home filter could be an effective way to reduce PFAS levels. If PFAS have been measured but are below federal limits, a filter may not be useful to you. There are many water filters on the market, but not all filters address PFAS.

Several treatment technologies are effective at reducing PFAS in drinking water, including granular activated carbon (GAC), ion-exchange resins, and reverse osmosis (commonly used as point-of-use treatments in homes). When selecting a home treatment system, use the National Sanitation Foundation (NSF) database to find products certified to reduce PFOA, PFOS, or Total PFAS under applicable NSF/ANSI standards.

Funding is currently not available to help private well owners install or purchase PFAS treatment systems. If funding opportunities become available through the Health District, eligible participants will be notified.

The table below lists products certified under NSF/ANSI Standard 53 to reduce PFAS, as of June 22, 2026.

Table 4: NSF/ANSI Standard 53 Certified Filters

Manufacturer	Filter Brand/Type	Approximate Cost
Amway	eSpring™ Under Counter Unit	Initial Equipment w/Filter: $1,300 Filter Replacements: $280 per filter (12 months or 1,320 gallons)
Amway	eSpring™ Countertop Unit Connected to Faucet	Initial Equipment w/Filter: $1,300 Filter Replacements: $280 per filter (12 months or 1,320 gallons)
Brio Water Technology	All-in-One 3-Stage Under Sink	Initial Equipment w/Filter: $150 Filter Replacements: $70 per filter (6-month use)
Brio Water Technology	Multi-Stage 3-in-1 Amphora Under Sink	Initial Equipment w/Filter: $500 Filter Replacements: $130 per filter (12-month use)
Culligan	Pitchers/Dispensers	Initial System: $100 Filter Replacements: $20 per filter (20 gallons use)
LARQ	Under Sink	Initial Equipment w/Filter: $200 Filter Replacements: $80 per filter (6-months use)
4Patriots	Countertop System	Initial Equipment w/Filter: $250 Filter Replacements: $80 per filter (200 gallons use)

Contact Information

privatewells@snhd.org
(702) 759-0660

Nevada Relay “Dial 711” (TTY)
After Hours & Public Health Emergencies
(702) 759-1000