The tap water in Boston is safe to drink. However, many buildings with lead piping systems are exposed to lead contamination as the water is distributed to the buildings.
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 on a monthly basis. The data below was gathered from the MWRA’s Monthly Water Quality Report for February 2022 and details multiple factors that determine the overall quality of water in Boston.
| Contaminant | Boston levels | EPA action limit | EPA’s public health goal |
|---|---|---|---|
| Lead | 0.072 to 120 ppb | 15 ppb | Zero |
| Copper | 3 to 222 ppb | 1,300 pbb | 300 ppb |
| Fluoride | 0.24 to 0.81 ppm | 2 ppm | 1 ppm |
| Chloramines | 0 to 4 ppm | 4 ppm | 4 ppm |
| Total trihalomethanes | 6 to 34.8 ppb | 80 ppb | Zero |
| Arsenic | Zero | 10 ppb | 0.004 ppb |
As seen by the data, the only contaminant that goes above the legal limits in Boston’s tap water is lead. You should consider a lead water test kit to keep an eye on the lead levels of your water.
Lead
22 of 448 water samples taken from Boston tap water show lead presence above the action limit set by the Environmental Protection Agency (15 parts per billion). The lead levels range between 0.072 ppb to, alarmingly, 120 ppb. The average lead presence of all water samples is 8.56 ppb.
Although the Environmental Protection Agency (EPA) sets its lead action limit at 15 ppb, it deems no amount of lead in drinking water as safe due to the exposure to several health risks such as hindering the neurological development of children and causing various types of cancer.
Boston residents suffering from lead contamination are advised to purchase and install a whole house lead water filter system.
Microbial Results
28 samples of unfiltered water was taken from the Quabbin Reservoir’s water and tested for fecal coliform. These would indicate potential fecal contamination.
From the results, “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.”
Indeed, seven of the 28 samples tested positive for fecal coliform. However, none of the samples exceeded the requisite 20 fecal coliforms per 100mL.
Likewise, six of 28 samples taken from the Wachusett Reservoir also tested positive, and none exceeded 20 fecal coliforms per 100mL. 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 0.026 A/cm, and Wachusset’s had absorbance levels that averaged 0.083 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 found to be within safe parameters.
Algae Levels
Drinking water with high algae levels is not dangerous to consume. However, they may result in off-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 February.
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 of 68 mg/L, which is a moderate level of hardness.
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 material as it flows into the reservoirs. That is the first step in the cleaning process.
The MWRA has detailed how natural, undeveloped watersheds are a key part of keeping all water sources that are under the organization’s authority clean and clear. In addition, the Massachusetts Department of Conservation and Recreation organization undertakes daily patrols of the streams and reservoirs to ensure complete safety. As well, they conduct frequent testing of the waters.
Watersheds are land areas that channel precipitation like rainwater and melted snow to larger bodies of water. The Massachusetts Water Resources Authority takes advantage of 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 gets 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 United States city with the cleanest tap water is somewhat difficult to pinpoint. Nevertheless, cities in Southern states like Tennessee and North Carolina outrank the others in most 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. In particular, installing a point-of-use water filter is often recommended.
