By Avanti Nambiar
Boston University News Service
If there is one thing cities never stop producing, it is sewage. The question is, what to do with it? In the 1980s, Boston’s answer was dumping raw sewage into bodies of water. With pollution threatening both humans and ecology, the Boston harbor became known as “the dirtiest harbor in America.”
Much of the fault lay with the administration of the Deer Island Treatment Plant, which had fallen into disrepair. For years, the city left the plant to languish, allowing untreated sewage to seep into the harbor. Due to mounting public pressure, the plant finally underwent revitalization in 1995, restoring the purity of Boston’s rivers.
Nowadays, this plant doesn’t just clean the city’s water; it turns waste into fertilizer, converts methane into energy and runs tests to track the health of communities. In fact, sewage testing has been a powerful tool to measure the spread of COVID-19. Thanks to the renewable design, Boston’s sewage went from being harmful, to helpful.
Yet, Boston’s system is still far from perfect. Due to climate change, New England’s outdated infrastructure faces increasingly extreme weather.
Hydraulics engineer Ellen Douglas explained that many sewers in the greater Boston area were built to combine stormwater and wastewater. During heavy rains, stormwater can overwhelm Boston’s pipelines, causing rivers to flood with raw sewage. Rivers with smaller water basins, such as the Muddy River and the Neponset, have particularly struggled with this contamination. This can spread waterborne gastrointestinal diseases, including Enterococcal infections.
Douglas also said that in recent years, there has been a population explosion in Massachusetts’s cities. Despite being the seventh smallest state, Massachusetts is currently the third most densely populated area in America.
“Even without any kind of climate change, we have wastewater systems and storm drain systems that are undersized,” Douglas said.
What is more, traditional construction styles have worsened water runoff and stripped away natural areas which could soak up excess rain. All this careless design may overburden Boston’s aging and leaking sewer pipes.
To make matters worse, there is also the issue of illegal dumping. Pipelines from large buildings or residential homes can funnel sewage straight into New England’s waters. This waste can be difficult for authorities to detect and even harder to trace.
Fortunately, Boston’s Water and Sewer Commission has been working to do just that. On top of stopping illicit dumping and repairing faulty pipes, the Commission works to update Boston’s infrastructure. Commission Director Charlie Jewell said the city has been gradually separating the flow of stormwater and wastewater.
Jewell said that Boston’s sewers, which used to be “60% separate, 40% combined,” are now at an “80:20” ratio. Jewell also said that all new construction in Boston needs to meet certain standards, in terms of handling stormwater.
Sure, there is still a sizable number of sewage pipes combining stormwater and wastewater in Boston. And, sure, illicit dumping still happens. And, sure, many of Boston’s older buildings fail to meet the new “green” standards of construction. Still, it is encouraging to hear that the city is working to address old problems.
But what about the new problems? Climate change is causing rising sea levels and more extreme rainfall and storms. For now, the sewage system is ill-equipped to cope with this looming threat.
“Storms are occurring more intensely, and they’re happening more frequently,” Douglas said, adding that this process may end in “havoc.”
Sea level rise could result in the flooding of hospitals, MBTA stations and evacuation routes. Thunderstorms, Nor’easters, frontal storms and even tropical storms could take place in greater numbers. These extreme climate events could cause leaks in Boston’s old sewage pipes and create combined sewer overflows.
To predict the effects of this climate change, the Water and Sewer Commission made an inundation modeling map, which has its own website. Based on the data, the commission recommends building barriers, pump stations, storage tanks and storm drains. The problem, in Jewell’s words, is “who’s gonna pay for all this stuff?”
Though engineers can find ways to fortify Boston’s sewage system, it is unclear how the city can secure the funds to undertake such a massive project. Jewell said that “the ratepayers of Boston cannot pay for this stuff, this stuff is expensive.” Yet, the price of doing nothing–of leaving Boston exposed to sewage overflow–may be far greater, to industry, public health, and our ecosystem.
Sewage can pollute rivers and spread disease. It can also be a valuable resource, allowing authorities to monitor community health before turning it into fuel and fertilizer. Design makes all the difference. Let us hope that the city of Boston will be able to design infrastructure that adapts to the changing times, just as it did in 1995.
“Even though we haven’t solved the problem, we still have to keep trying,” Douglas said. “We have to keep hoping.”