There are now about 250,000 cesspools in place in Suffolk County, and another 100,000 Suffolk properties deploy septic systems.
“That’s not a good thing,” said Frank Russo, associate director for wastewater initiatives at the Stony Brook Center for Clean Water Technology. “We’re dumping sewage into the ground, and that eventually makes its way to the groundwater.”
It’s an urgent problem that Stony Brook scientists are helping to fix.
“Long Island relies on groundwater as our only option for drinking water,” said Christopher J. Gobler, professor in the School of Marine and Atmospheric Sciences and director of the Center for Clean Water Technology.
“Given trends in surface and groundwater quality since the late twentieth century, it is clear changes are needed to ensure the long-term sustainability of clean water for Long Island,” Gobler said. “The Center for Clean Water Technology will continue to partner with state and local governments and industry to being these changes via innovative solutions.”
Chemically speaking, the culprit is nitrate, an inorganic compound that occurs under a variety of conditions in the environment, both naturally and synthetically. Nitrate is one of the most common groundwater contaminants in suburban areas, and is regulated in drinking water primarily because excess levels can cause methemoglobinemia, or “blue baby” disease.
Nitrate in groundwater originates primarily from septic systems, and from items commonly found in any household – soaps, shampoos, cleaners, pharmaceuticals, and many other products. Though these wastes are deposited deep in the ground, they eventually seep up. On Long Island, that means the nitrate ends up in places like Great South Bay, Peconic Bay, and the Long Island Sound, which feed the Island’s drinking water supply.
That decades-long legacy of nitrogen-rich waste moving from homes to the ecosystem has contributed to the creation of harmful algal blooms, a decrease in the shellfish population, and lower oxygen levels in Long Island’s surface waters, including its bays, rivers and the Sound.
“Do you remember the problems Florida had with its water?” asks Russo, referring to the harmful and well-documented algal blooms the state experienced in 2018. “Long Island is not too far away from that.”
To help combat the problem, Stony Brook is working to develop technology that will remove nitrogen before it can reach the groundwater. The initiative, dubbed “10/10/30,” aims to develop technology that can get the nitrate levels down to 10 mg/liter in a system that costs no more than $10,000 and has a lifespan of at least 30 years.
“We are pilot testing a version of this system, but the current version is too land-intensive for Long Island, which has many plots of ¼-acre or less,” explained Russo. “We need to understand the process, apply existing theories and combine it with our research to get it to a point where it’s viable.”
To facilitate the necessary research, the Center for Clean Water Technology operates a state-of-the-art Wastewater Research & Innovation Facility (WRIF) for the purpose of developing an affordable onsite wastewater treatment system that reduces total nitrogen to less than 10 mg/L prior to groundwater discharge. The facility is a working laboratory that utilizes domestic sewage collected at the Suffolk County Sewer District No. 10 pumping station for actual use within the facility. These systems are intended eventually to replace archaic cesspools that provide virtually no treatment for nitrogen.
Unfortunately, nitrates present just one challenge. Another contaminant becoming more common in Long Island’s groundwater is a compound called 1,4-dioxane, which is a waste product resulting from the manufacturing processes that were pervasive during Long Island’s industrial heyday. Stony Brook is currently providing grant support to test an advanced oxidation process to combat this challenge.
“If regulation kicks in, public water supplies will need to meet the new standards,” warns Arjun Venkatesan, associate director for drinking water at the Stony Brook Center for Clean Water Technology. “If that happens, that means that more than 200 water treatment facilities on Long Island will need to be upgraded at a cost of more than $1 million per system.”
Venkatesan’s cost estimate is significantly more conservative than the roughly $300 million cost estimated by New York’s Department of Health (NYDOH) in 2018. And to illustrate the extent of how unknown the cost of such regulation might be, the NYDOH’s number is less than half of the astounding $840 million the Long Island Conference, a group of water professionals that focus on keeping Long Island’s water supply safe and plentiful, says it would cost to add treatment systems to the 185 drinking water wells contaminated by 1,4-dioxane, according to a Newsday report in February 2019.
Though drinking water cleanliness is an important driver in this research, there’s another potentially catastrophic danger that’s growing; Long Island’s wetlands are disappearing. The wetlands absorb tidal surges, serving as an important barrier during hurricanes. The devastating effects of this erosion were realized in 2012 when Hurricane Sandy ravaged the East Coast and caused an estimated $19 billion of damage to New York City and the surrounding areas, including Long Island.
With the damages of Sandy still being felt by many seven years later, efforts are moving ahead in earnest. There is currently one pilot system running full-scale in Suffolk County, though any wide-scale solution is still years away.
“There are important questions that need to be answered,” said Venkatesan. “We’re trying to attach emerging contaminants and others that are not currently regulated. We need to develop a fundamental understand of the chemical transformation and any potential by-products and figure out the best way to move forward.”
— Rob Emproto