Gaithersburg, MD Water Quality Report
Is Gaithersburg tap water safe? See PFAS and lead contamination levels for Gaithersburg, Maryland. Compare to EPA limits and get filter recommendations.
Quick Answers
Is Gaithersburg, MD tap water safe to drink? Gaithersburg, MD tap water meets most federal EPA limits, but PFAS compounds have been detected at an average of 4.74 ppt across 2 compounds. A certified pitcher filter or reverse osmosis system is recommended for sensitive populations.
What contaminants are in Gaithersburg, MD water? Top PFAS compounds detected in Gaithersburg water: PFPeA (6.7 ppt), PFHxA (4.8 ppt). See the full table for all monitored contaminants and comparison to EPA limits.
What filter should I use in Gaithersburg, MD? An NSF/ANSI 58 reverse osmosis system is the strongest option, removing 90%+ of PFAS along with lead and arsenic. For renters or smaller households in Gaithersburg, a pitcher certified to NSF-53 for PFAS (ZeroWater, PUR PLUS) is a practical alternative. Ordinary Brita cartridges are not certified for PFAS.
Gaithersburg, MD Water Quality Summary
EPA testing has detected PFAS "forever chemicals" in Gaithersburg, MD drinking water. Recent monitoring found a peak level of 6.7 ppt across 1 water system, representing an average of 4.74 ppt across 2 detected compounds. These levels come from individual EPA UCMR 5 water samples (2023-2025). The EPA's 4 ppt limit for PFOA and PFOS is enforced on a running annual average, so a sample above it shows real exposure but is not by itself a violation.
Contamination Level: LOW – Low contamination – PFAS detected but at lower levels; monitoring continues.
Top Detected Compounds
- PFPeA: 6.7 ppt (exceeds EPA 4 ppt limit for PFOA/PFOS)
- PFHxA: 4.8 ppt (exceeds EPA 4 ppt limit for PFOA/PFOS)
Lead in Gaithersburg, MD Water
EPA Lead and Copper Rule testing has recorded 13 lead samples for Gaithersburg water systems, with a 90th-percentile high of 0.0062 mg/L (within the EPA 0.015 mg/L action level). There is no safe level of lead for children; if your home was built before 1986, a certified NSF/ANSI 53 lead-removal filter is recommended.
EPA Violations in Gaithersburg, MD
Gaithersburg public water systems have 5 health-based EPA Safe Drinking Water Act violations on record, including Di(2-ethylhexyl) phthalate (DEHP), Lead and Copper Rule Revisions, Stage 1 Disinfectants and Disinfection Byproducts Rule. Health-based violations mean a contaminant exceeded its federal limit or required treatment was not applied.
About the Data
The numbers on this page are drawn from EPA UCMR5 monitoring (2023-2025), which covers about 10,000 public water systems nationwide, including those serving Gaithersburg, MD's approximately 69,099 residents.
ZIP Codes Served
What Gaithersburg, Maryland Residents Should Do
- Enter your exact ZIP code at knowyourexposure.com for address-level data
- Install an NSF/ANSI 58 reverse osmosis filter (removes 94-99% of PFAS)
- If you're in a high-exposure group (pregnant, young children), consider a PFAS home test kit
- Review the Consumer Confidence Report (CCR) your Maryland utility publishes annually