Boston
MA

Is Boston, MA Tap Water Safe to Drink?

Boston's tap water is generally safe to drink and meets federal drinking-water standards. Recent EPA testing detected trace levels of PFAS compounds and lithium, but none of these exceeded EPA limits or health benchmarks. There are no regulatory violations in the data, though a PFAS-rated filter is a reasonable precaution for sensitive households.

1Water system
49ZIP codes
0%ZIPs above EPA guideline
Metro areaBoston-Cambridge-Newton, MA-NH
Latest data2024-10-22

Where Does Boston Get Its Water?

Boston, MA gets its drinking water through the Boston Water and Sewer Commission, which draws from the Massachusetts Water Resources Authority (MWRA) regional water supply. The MWRA system relies primarily on surface water from large reservoir systems west of the city, delivering treated water through a regional network.

The MWRA connection serves all 49 ZIP codes included in this dataset. There is one primary water system supplying Boston's tap water, so water quality is consistent across the service area.

How Is Boston Tap Water Treated?

Boston's water goes through a multi-step treatment process before it reaches your tap. The MWRA system uses ozone treatment as a key disinfection step, which breaks down organic compounds and pathogens without leaving as many byproducts as older methods alone would. Ultraviolet light treatment is also applied, adding a second barrier against microbial contamination.

Chloramine or chlorine-based disinfection is used to maintain water quality as it travels through the distribution system to your home. This residual disinfectant prevents bacterial regrowth in the pipes between the treatment plant and your faucet.

The treatment train also includes other processes to manage taste, odor, and particulates. This layered approach is why Boston's water consistently meets federal standards even before it arrives at the tap.

What's in Boston Tap Water?

The most widely detected substance in Boston's tap water is lithium, found in all 49 ZIP codes at a peak level of 9 micrograms per liter. This is at the reporting threshold rather than a measured concentration above it, and no ZIP code exceeded EPA's non-regulatory health reference level. There is no federal enforceable maximum for lithium in drinking water.

Several PFAS compounds were also detected across all 49 ZIP codes. These include PFTrDA at up to 0.007 micrograms per liter, and 8:2 FTS, 11Cl-PF3OUdS, and PFBA each at up to 0.005 micrograms per liter. None of these values exceeded EPA guidelines. These detections represent at or near the minimum reporting threshold for each compound.

PFAS are a broad class of synthetic chemicals used in industrial and consumer products for decades. They can enter water supplies through industrial discharge, firefighting foam, and runoff. Low-level detections like those found in Boston are not uncommon in large surface-water systems, and the levels here fall below current EPA benchmarks.

ContaminantPeak detectedEPA guidelineZIPs detectedStatus
lithium 9 µg/L — 0 ZIPs Within guideline
PFTrDA 0.007 µg/L — 0 ZIPs Within guideline
8:2 FTS 0.005 µg/L — 0 ZIPs Within guideline
11Cl-PF3OUdS 0.005 µg/L — 0 ZIPs Within guideline
PFBA 0.005 µg/L — 0 ZIPs Within guideline

Health Risk Profile for Boston

None of the contaminants detected in Boston's water exceeded an EPA limit or health benchmark. The PFAS compounds found are present at or near the minimum detection threshold. Lithium was detected at 9 micrograms per liter, which is at the reporting limit; there is no federal enforceable maximum for lithium in drinking water, and EPA's reference level was not exceeded in any ZIP code.

Sensitive groups, including infants, pregnant individuals, and people with compromised immune systems, may want to take extra precautions even when levels are within guidelines. PFAS compounds at any detectable level are a topic of ongoing scientific review, and some health agencies recommend minimizing exposure where practical.

If you want additional peace of mind, a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI P473 is effective against PFAS. NSF/ANSI is an independent third-party certification program, so look for those labels on the filter box to confirm it has been tested for the specific contaminants you care about. These filter types will also reduce lithium and most other trace compounds.

EPA's PFAS standards are still evolving, and the science on low-level long-term exposure continues to develop. The detections in Boston are at the floor of what current instruments can reliably measure, which means the actual concentrations may be at or below the reported values.

Best Filters for PFAS Water Profile

PFAS compounds are detected in this water supply. A reverse osmosis (RO) system or an activated-carbon filter specifically certified under NSF/ANSI P473 is required for reliable PFAS reduction. Standard pitcher and faucet filters without P473 certification do not remove PFAS.

Waterdrop G3P600 Reverse Osmosis System
Under-sink RO system

8-stage tankless RO system certified to NSF/ANSI 58, reduces 1,000+ contaminants including PFAS, lead, arsenic, fluoride, and nitrates.

Epic Pure XP Water Filter Pitcher
Pitcher filter

NSF-certified dual-layer filtration reduces 70+ contaminants including PFAS, lead, chlorine, microplastics, and bacteria.

See recommendations matched to your exact address: choose your ZIP code below.

Frequently Asked Questions about Boston Tap Water

Is Boston tap water safe to drink?

Yes, Boston's tap water meets federal drinking-water standards. Recent EPA testing found trace levels of PFAS compounds and lithium, but none exceeded regulatory limits or EPA health benchmarks. The water is safe for most people as delivered. Households with infants, pregnant individuals, or immunocompromised members may want to consider a PFAS-rated filter as an added precaution.

What contaminants are in Boston tap water?

EPA testing through October 2024 detected lithium at up to 9 micrograms per liter and four PFAS compounds: PFTrDA at up to 0.007 micrograms per liter, and 8:2 FTS, 11Cl-PF3OUdS, and PFBA each at up to 0.005 micrograms per liter. All values were at or near the minimum detection threshold and below EPA health benchmarks.

Where does Boston get its drinking water?

Boston's tap water comes from the Massachusetts Water Resources Authority regional system, which draws from surface water reservoirs west of the city. The Boston Water and Sewer Commission distributes that treated water locally. A single regional treatment system serves all ZIP codes included in this data.

Do I need a water filter in Boston?

Boston's water is within EPA limits, so a filter is not required. However, if you want to reduce trace PFAS compounds, look for a filter certified to NSF/ANSI 58 (reverse osmosis) or NSF/ANSI P473. NSF/ANSI is an independent certification that confirms a filter has been tested for specific contaminants. These will also reduce lithium and other trace substances.

How often is Boston tap water tested?

The EPA requires regular monitoring of public water systems, and the most recent samples in this dataset were collected in October 2024. Boston's water is tested continuously for regulated contaminants under federal rules, and the MWRA publishes an annual Consumer Confidence Report with detailed results. The PFAS and lithium data here come from a targeted EPA national monitoring effort.

What is the best water filter for Boston?

Given that PFAS compounds are the primary detected substances, the most effective options are filters certified to NSF/ANSI 58 (reverse osmosis systems) or NSF/ANSI P473 (pitcher or under-sink filters verified to reduce PFAS). Both will also reduce lithium. Check the filter's packaging for the NSF/ANSI certification mark to confirm it covers the contaminants you want to address.

Tap water reports by ZIP in Boston

Water utilities serving Boston, MA

Service area boundaries are approximate and based on state filings or modeled estimates. Contact your utility to confirm exact service at a specific address.

Modeled boundaries are shown with a dashed outline.

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