Research & Innovation

Dibs Sarkar is Protecting New Jersey’s Water Resources with a Collaborative Grant of $778K from NJDEP

Civil, environmental and ocean engineering professor is combating pollution and harmful algal blooms as part of a collaborative research group with NJIT and Rutgers

Addressing New Jersey’s water quality issues — and the environmental damage and social inequalities that they cause — requires better management of stormwater and runoff. As a coastal state, water is one of New Jersey’s primary resources; but while the Atlantic Ocean looms large in this picture, the lakes and rivers of the state also play an important role in the health of its land and its people. 

The rain that falls from the sky can wash phosphorus and other nutrients into lakes, promoting the growth of harmful algal blooms. Decay of this algae consumes dissolved oxygen, which ultimately depletes the water of oxygen and proves deadly for the fish and other organisms that call these lakes home. Stormwater can also wash excess nutrients from lawns, roadways and parking lots into rivers and groundwater.

Although these issues exist everywhere in the state, they create the biggest harm in marginalized and disadvantaged communities, making them key environmental justice issues in need of attention.

Portrait photo of Dibs SarkarDibs Sarkar, professor, Department of Civil, Environmental, and Ocean Engineering

Pollution and climate change threaten the health of these waters, and addressing the issue will require innovation and teamwork on a statewide level. To develop cost-effective solutions to the problem, the New Jersey Department of Environmental Protection (NJDEP) awarded a $778,000 grant to Stevens Institute of Technology civil, environmental and ocean engineering Professor Dibs Sarkar and an interdisciplinary team of researchers from across New Jersey. The grant is part of a larger $10 million fund earmarked by Governor Phil Murphy to improve water quality across New Jersey.

“This is such a big problem that three top research universities are joining hands to come up with a plan and begin to implement it,” Sarkar said.

‘Creating a playbook’

Managing issues such as harmful algal blooms isn’t a one-time fix. To address the problem, environmental managers need to reduce or eliminate the excess nitrogen and phosphorus that is entering lakes and rivers. Doing so requires knowing where and how these compounds are entering the water. 

Identifying these nutrient transport routes is the foundation of the project developed by Sarkar and the other scientists on the grant — Michel Boufadel, an environmental engineering professor at New Jersey Institute of Technology and Christopher Obropta, a professor of environmental engineering at Rutgers University. The team is starting small, with just a handful of lakes in Essex, Sussex and Middlesex Counties. But Sarkar hopes that these relatively small-scale projects will have a much larger impact on the communities, many of which are overburdened and under-resourced.

Most watershed management projects are massive in scope and contain a multitude of bottlenecks and bureaucratic issues, which can limit their efficacy. Many times, smaller lakes, particularly those in overburdened communities, are overlooked when it comes to remediating harmful algal blooms. 

“Developing watershed restoration and protection plans are equally critical for smaller lakes as they are for the larger ones.” Sarkar said.

Sarkar and his fellow scientists intend to do just this. These projects that are local in nature can be conducted on a much smaller scale in terms of staffing, budget and scope that would make them more accessible to smaller and under-resourced communities. Sarkar hopes this approach and the project’s impact will stretch far beyond the communities in New Jersey where their pilot program takes place.

“We want to create a playbook for other people to follow,” Sarkar said.

‘Testing the impact’

Exactly how the team will address the pollution will depend on what they find and where they find it. Sarkar said that he expects some sources of phosphorus, nitrogen and other contaminants will be obvious, such as a septic field next to a lake or river. Their single source and identifiable locale make the task of removing the contamination more straightforward.

Sometimes, however, the chemical pollutants in a lake arise from a range of sources, not all of which can be readily pinpointed. In this case, Sarkar and his colleagues hope to begin testing the impact of various green infrastructure projects like bioswales and rain gardens. By providing a place for rain- and groundwater to seep through the soil and other soft surfaces, these projects can reduce the effects of flooding and help filter out some of the water’s contaminants before it reaches the river.

At Stevens, Sarkar’s lab has helped develop what he calls green engineered mulch, an inexpensive and environmentally beneficial substrate that he hopes homeowners and municipalities can use in rain gardens and bioswales to provide extra water filtration to remove pollutants. Many of the harmful chemicals in water have electrically charged functional groups, which gives engineers a way to filter them out.

Using the aluminum-rich residuals generated in drinking water treatment plants as the source material and an organic compound called alginate (a gel-like polymer derived from brown algae and seaweed which forms cross-links with itself), Sarkar converted regular wood mulch into a potent filtration device that is capable of removing pollutants from water. This mulch doesn’t just help to remove phosphorus and ammonium nitrogen, but it also filters out other contaminants such as heavy metals.

The advantage of these types of green infrastructure approaches isn’t just their environmental impacts, but also their financial ones. Algal blooms negatively impact the coastal economy of the lakes in New Jersey. These lakes are not only used for recreation but also as a source of drinking water. Treating this water, however, can be expensive unless the root cause — the source of nutrient overloading — is properly identified and “nipped in the bud,” Sarkar said, “with the implementation of innovative best management plans.” 

Sarkar ​​— who has spent his entire career working under the umbrella of sustainability and environmental engineering — hopes that the work he and other New Jersey scientists complete on this grant will provide a financially sustainable, cost-effective way to improve water quality for everyone in the state.

“It’s basically science for the benefit of society,” Sarkar said.

Learn more about academic programs and research in the Department of Civil, Environmental and Ocean Engineering: