Is Boston’s water safe?

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It’s a brisk and sunny day in early March at the Quabbin Reservoir, located about 65 miles west of downtown Boston, where protected woods surround the quite oasis of crystal clear water.

The 200 million gallons of drinking water that comes into homes each day in Boston and the surrounding area originates in the Quabbin Reservoir, which is about 530 feet above sea level, along with diverted water from the Wachusett Reservoir, at an elevation of 395 feet, and the Ware River. The water travels miles eastward by gravity until it pours out of the faucets in homes in the Boston metropolitan area.

“As long as all the people live down by sea level, the system works great,” said Dave Coppes, director of waterworks at the Massachusetts Water Resource Authority, or MWRA, which serves as the wholesaler that sells the water to about 50 communities in the Boston area.

Outside the Caroll Treatment Center where water used to be diverted from the old Wachusett Aqueduct

Outside the Caroll Treatment Center where water used to be diverted from the old Wachusett Aqueduct

It all travels downhill, and as it does, it undergoes a number of treatments before it gets to taps in Hub homes and businesses. That includes ozone and ultraviolet light treatment to ensure that the water is free of contaminants and safe.

In addition, sodium carbonate is added to make the water less acidic and  minimize lead and copper leaching from home plumbing.

“It reduces the corrosivity on any metallic pipes that we might have, any metallic pipes that communities’ distribution system might have and the pipes in the customer’s home,” Coppes said.

Lead can leach into drinking water when it comes into contact with materials that contain lead. This can include a lead service line that connects a home or an apartment building to the water main in the street, or leaded solder used in some older brass fixtures. If the water is corrosive and is left in contact with lead-bearing material, lead can leach into the water.

In Boston alone there are more than 3,500 buildings that get their water from lead service lines, according to a recent report in the Boston Globe.

The water the MWRA sends into the system does not contain lead, and all the pipes carrying that water are made of concrete, iron, or steel, agency officials say.

Concerns about lead in tapwater rose nationwide when Flint, Michigan, discovered increased lead levels in drinking water. The source was determined to be lead that leached into the system after a change in the source and treatment of supplies from the city of Detroit to the Flint River’s more acidic water and a different treatment plant. Flint did not install corrosion control treatments when the switch was made, however, and the more acidic supplies began corroding pipes..

In addition, the initial reports of poor water quality, including bad taste and odor, were ignored. Local and state officials at first dismissed the initial data suggesting that the lead levels in the water – and in Flint children’s blood – were elevated.

In Boston, a 2014 MWRA report found that out of 450 houses tested in member communities, seven had lead above the Lead Action Level. None had copper above that level. The federal Environmental Protection Agency’s Lead and Copper Rule requires samples to be taken in some homes that are most likely to have lead service lines, to determine whether corrosion controls are effective.

When elevated lead levels are found, the local community follows up with the homeowners, but the MWRA does not track whether or not the homeowners replaced their lead service pipes. The MWRA also tracks customer complaints on a daily, weekly and monthly basis and investigates each complaint.

In Flint, almost half the homes had lead service lines. In Massachusetts, MWRA communities have been working to eliminate lead piping. Only 5 percent of the 430,000 connections have lead lines, typically connecting older buildings. Lead service lines often were installed up until just after World War II ended.

Homeowners who opt to replace a lead service line can take advantage of a  zero-interest loan program through the MWRA.

Bostonians who want to learn whether their house or building has lead service pipes can consult the Boston Water and Sewer Commission’s Lead Service Map. There you can also learn how to test for lead in your water and find incentive programs for those who want to replace lead piping. In those programs, typically, the Boston Water and Sewer Commission funds the first $1,000 and lends the remainder over a 24-month period at no interest.

For those with lead pipes and corrosive water, “lead leaks out when it is sitting there overnight,” said Ria Convery, an MWRA spokeswoman . “The longer the water sits in the pipe, the more likely the lead will leak out, so the answer is to let it run. If you’re coming home from work or just getting up in the morning let it run for thirty or sixty seconds.”

As for the treatment of the water that travels east from the Quabbin Reservoir and other water sources in central Massachusetts, the water is first processed in giant tanks underneath the Carroll Water Treatment Plant and Storage Facility Center in Marlborough.

In a process that began in 2005, the water is first treated with ozone, as electrically charged oxygen, or O3, a really strong chemical that reacts with organic matter, bubbles up through the water, purifying it and killing any bacteria in its in path.

“The stuff is really strong oxygen, so if you inhale ozone it will attack the mucus membranes in your sinus cavities or your lungs,” said Coppes. “It’s a really nasty, nasty chemical.”

The ozone is then brought back up through a fan and goes through a catalyst that converts it back to pure oxygen, or O2, before releasing it back into the air. Sodium bisulfite is then used to remove the remaining ozone from the water.

After the water travels downstream into a second building at the facility, it undergoes ultraviolet light treatment. This procedure began in April 2014 because of federal regulations requiring filtered water be disinfected twice. The water passes through a stainless steel device with tubes that shoot ultraviolet, or UV light, through the liquid.

The UV light damages the reproductive systems of any organism that might have survived the ozone treatment, rendering them unable to reproduce and sicken someone drinking the water.

The machines that shoot UV light through the water “look like tanning booths – there are tubes with bulbs in them and the water passes through them and it emits this light and basically just zaps everything, which is really cool,” Convery said.

During pre-treatment, fluoride for dental health and aqueous ammonia that combines with chlorine to create residual disinfectant is added to the water to keep bacteria from re-entering as it travels through the system.

Overlooking the Quabbin Reservoir (New Boston Post photo by Beth Treffeisen)

Overlooking the Quabbin Reservoir (New Boston Post photo by Beth Treffeisen)

Before the Quabbin Reservoir was built, Bostonians got their water from more local sources, such as Spot Pond, north of the city in Medford, Jamaica Pond in Roxbury and Lake Cochituate, west of the city near Natick. But it eventually became clear that those sources wouldn’t be able to meet the demands of the growing region.

Boston’s population had been steadily rising since the early 1800s. From 1817 to 1920, the population increased from 40,000 to 748,000, according to Friends of the Quabbin.

To meet the thirsty region’s needs, the Legislature passed the Swift River Act in 1927, which authorized Quabbin construction. To this day, Boston residents get their water from reservoirs in protected lands miles west of downtown Boston.

Along with the MWRA upgrades to treatment processes with ozone and ultraviolet light, the authority also has built underground holding facilities to replace outdoor units. Before construction of the subterranean facilities, water that was treated would sit in open ponds where it could be contaminated by geese and other birds and animals, pollen and other pollutants.

A final water storage facility, the Spot Pond Tank in Stoneham, is slated to open later this year.

“Was it as safe? Heck no,” Coppes said of the old open-water holding method. “There was an opportunity for it to get re-contaminated.” He said the authority would get complaints about the taste or smell of the water in the summer as a result of the algae growth in the open facilities. The complaints have disappeared with the advent of ozone treatment and underwater facilities.

“Now, once the water gets here it doesn’t see the light of day until it reaches your tap, which is really good,” Convery said.

Map courtesy of the MWRA

Map courtesy of the MWRA

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