Yes, Boston’s tap water is definitely safe to drink. In fact, tap water in Massachusetts is widely regarded as among the cleanest and safest in the US.
This guide breaks down the key details from the MWRA’s Monthly Water Quality Report for April 2024, focusing specifically on the Boston area. We cover the levels of lead, copper, turbidity, fecal coliform, and much more. So, you’ll be able to see just how safe Boston’s tap water is.
Boston Water Quality Report: What is in the Water?
The Massachusetts Water Resources Authority (MWRA) publishes the Greater Boston area’s water quality test results monthly. The data below was gathered from the MWRA’s Monthly Water Quality Report for April 2024 and details multiple factors that determine the overall quality of Boston’s water.
| Contaminant | Boston levels | EPA action limit | EPA’s public health goal |
| Lead | Below the method testing limit (0.05 ug/l) | 15 ppb | Zero |
| Copper | Below the method testing limit (3.0 ug/l) | 1,300 ppb | 300 ppb |
| Fluoride | 0.68 mg/l | 2 ppm | 1 ppm |
| Arsenic | Below the method testing limit (1.0 ug/l) | 10 ppb | 0.004 ppb |
Lead
You may have read some of the alarming reports about high lead levels in Boston’s drinking water. However, the MWRA’s report for April 2024 states that the levels of lead in the tested water samples were too low to be reliably measured, as they were below the method reporting limit of 0.05 ug/l.
This is good news for Boston residents as it suggests the lead levels in the treated water are incredibly low. Yet, this doesn’t mean the levels are as low when the water reaches people’s faucets.
The report clearly states that: “Lead results will vary at your home dependent on household plumbing.” So, if your home has old lead piping, the lead levels in your tap water could be much higher than in the samples taken by the MWRA. You should consider a lead water test kit to keep an eye on the levels in your water.
Although the Environmental Protection Agency (EPA) sets its lead action limit at 15 ppb, it deems no amount of lead in drinking water safe due to several health risks, including:
- Stunted neurological development in children
- Various types of cancer
- Cardiovascular issues
- Kidney damage
- Reduced sperm counts
- Memory issues
Boston residents suffering from lead contamination are advised to purchase and install a whole-house lead water filter system.
Microbial Results
As stated in the report, “The Surface Water Treatment Rule for unfiltered water supplies allows for no more than 10% of source water samples prior to disinfection over any 6-month period to have more than 20 fecal coliforms per 100mL.”
30 samples of unfiltered water were taken from the Quabbin Reservoir and tested for fecal coliform, which would indicate potential fecal contamination.
Four of the 28 samples tested positive for fecal coliform. However, none of the samples exceeded the requisite 20 fecal coliforms per 100 mL.
Likewise, four of the 30 samples taken from the Wachusett Reservoir also tested positive, and none exceeded 20 fecal coliforms per 100 mL. These samples were taken before the water was disinfected and filtered.
UV Absorbance
High levels of UV absorbance indicate the need for higher doses of disinfectant over the course of the treatment process. Quabbin’s water had UV absorbance levels that averaged 0.027 A/cm, and Wachusset’s had absorbance levels that averaged 0.092 A/cm.
Turbidity
Turbidity measures the levels of various types of particles suspended in the water. These particles can include clay, silt, organic and inorganic matter, algae, and microorganisms.
Before the disinfection process began, both Quabbin and Wachusset’s maximum turbidity results were within safe parameters during April 2024.
Algae Levels
Drinking water with high algae levels is not dangerous to consume. However, it can result in unpleasant tastes and odors.
High algae levels can also degrade replaceable water filters more quickly. There were no algae-related complaints from Boston’s local water departments recorded in April 2024.
Is Boston Tap Water Hard or Soft?
According to the United States Geological Survey (USGS), water hardness runs on a scale of 0-180 mg/L (milligrams per liter). Boston has water hardness levels of 15 to 20 mg/L, which means the city’s water is considered to be soft.
Water hardness refers to the amount of dissolved calcium and magnesium in the water. High water hardness can result in slimy residue appearing on your skin after washing. What’s more, you might notice spots of soap scum on your sinks, tubs, and dishes.
High water hardness is not dangerous. However, many homeowners and renters find it unpleasant.
Where Does Boston Get Its Water?
The MWRA provides wholesale drinking water in the Greater Boston area. They source the water from central and western Massachusetts.
Specifically, the protected Quabbin and Wachusett Reservoirs and the Ware River. These reservoirs are filled naturally by rain and snowfall. The city’s water is stored on Deer Island and in the Chestnut Hill Reservoir.
Along with the Massachusetts Department of Conservation and Recreation (DCR), the Massachusetts Water Resources Authority owns and operates the collection, treatment, distribution, and storage facilities that supply the majority of Boston’s drinking water.
How is Tap Water Treated in Boston?
According to the MWRA’s website, Boston’s drinking water comes into contact with soil, rock, plants, and other materials as it flows into the reservoirs. That is the first step in the cleaning process.
The MWRA has detailed how the natural, undeveloped watersheds are a key part of keeping all water sources under the organization’s authority clean and clear. In addition, the Massachusetts Department of Conservation and Recreation undertakes daily patrols of the streams and reservoirs to ensure complete safety.
Watersheds are land areas that channel precipitation, such as rainwater and melted snow, to larger bodies of water. The Massachusetts Water Resources Authority uses naturally occurring watersheds to gather, clean, and store Boston’s drinking water.
In the MetroWest and Metropolitan Boston area, the Massachusetts Water Resources Authority tests its water on a near-constant basis, taking more than 1,600 water samples per month.
The water then undergoes a thorough treatment process involving:
- Ozone (primary disinfectant)
- Sodium bisulfite (to remove the ozone)
- Ultraviolet light (second primary disinfectant)
- Chlorine (residual disinfectant)
- Fluorite (to promote dental health)
- Aqueous ammonia (residual disinfectant)
- Sodium carbonate (to raise alkalinity)
- Carbon dioxide (to adjust the pH levels)
After being treated, the Massachusetts Water Resources Authority’s water is supplied to 53 consumer communities across the state, including Boston. Boston’s water is then sent through the MetroWest Water Supply Tunnel and the Hultman Aqueduct, where it is stored in covered tanks.
The water is then drawn into distribution mains where it pours into Boston’s community pipes.
Does Boston Have the Cleanest Tap Water?
No. The city in the United States with the cleanest tap water is somewhat difficult to pinpoint. Nevertheless, cities in Southern states like Tennessee and North Carolina outrank most others in water cleanliness competitions.
However, on a state level, Massachusetts water is considered to be among the cleanest in the country.
Do People Drink Tap Water in Boston?
Yes, people can and do drink Boston tap water all the time. It is both safe to drink and high quality. In 2014, Boston’s tap water won the American Water Works Association (AWWA) national taste test.
However, it’s best to take precautionary steps to avoid the potential consumption of lead, chlorine byproducts, and/or microplastics. The best way to do that is to install a point-of-use water filter.
