Where does rainwater go, and what does it carry with it as it rushes across a parking lot? What about all that melted snow each spring, flowing from the mountains toward the Seacoast?
The University of New Hampshire Stormwater Center (UNHSC) has for years tackled these and other questions, tracking how polluted runoff from parking lots, roofs, gutters, driveways and streets can carry pet waste, lawn fertilizer, motor oil, chemicals, litter and more into local streams, rivers and bays.
“Anybody who has swam in a river should want to know where that water is coming from,” said Alison Watts, a research assistant and professor of civil and environmental engineering at UNH. “You don’t want your dog swimming in it, you don’t want to drink it.”
The UNHSC is a dynamic research, testing and educational facility that serves as a technical resource in New England. The research done here is crucial to the fundamental goal of clearing up stormwater pollution and how this can be managed.
Currently, UNHSC is undergoing a renovation. They are removing the 13 previous systems studied and replacing them with six new systems. The demand for new research and new solutions is what drives this rebuild. The systems are studied to find the best treatment methods for the pollution in the stormwater, and researchers work to enhance these systems.
“There are three classes of treatment systems. Conventional, ponds and swales, green stormwater infrastructure, modern and grey, manufactured systems. We are re-tooling the site to focus on manufactured systems,” said Thomas Ballestero, an associate professor of civil and environmental engineering and principal investigator of the UNH Stormwater Center.
According to Ballestero, each system is meant to manage stormwater. This includes stormwater’s quantity and quality. The same stormwater is tested in each system and then is studied and assessed on the performance in removing pollutants.
“We had the site at the West Edge lot for two decades. And those systems, you know, we’ve studied to death. And what we’re doing is rebuilding it so that we can test manufactured systems,” Ballestero said. “This is a billion-dollar-a-year market, it’s a big market for stormwater devices.”
Maintenance of the systems is one of the big focuses because without maintenance, the systems would fail over time which makes the rebuild even more essential.
“It’s like buying a brand-new Ferrari, never changing the oil and expecting it to last forever,” said Daniel Macadam, an environmental and stormwater researcher.
The UNHSC has spots all over the campus where stormwater is regulated. For example, rain gardens behind Hamilton Smith and systems being studied near Williamson residential hall. A lot of these spots are meant to make sure College Brook isn’t negatively affected by stormwater pollution.
“Another major thrust is outreach. And that outreach is for all the public to professionals and everything in between,” Ballestero said.
Stormwater collects nitrogen compounds and other pollutants as it flows over farmlands, paved surfaces, and lawns treated with chemical fertilizers. When stormwater collects nitrogen, The Great Bay and local waterways are at risk.
“Because we have a coast, we impact our coast,” Watts said.
According to the U.S. Environmental Protection Agency, water quality can be affected when polluted water makes its way to the oceans. Stormwater can also carry disease-causing bacteria and viruses. Swimming in polluted waters can make you sick. This is why local beaches close their swimming areas due to the poor water conditions.
“Nutrients are a big issue for the Great Bay. So, nutrients are phosphorus and nitrogen,” said Ballestero. “Less light gets into the bed of the Great Bay. And so, all the seagrass dies. That’s the big issue right now.”
Nitrogen in stormwater runoff is especially dangerous because it will cause overgrowth to aquatic plants and algae. This will clog water intakes and block light going towards deeper waters. Nitrogen water pollution will feed algal blooms. Fish and other marine organisms can suffocate under severe conditions if all their necessary oxygen has suddenly been used up.
“If you have too many nutrients, the algae want to grow and grow. Dead algae use oxygen to break down and will use up too much oxygen.” Watts says.
The Great Bay is one of the biggest concerns that researchers in New Hampshire focus on because streams and rivers from Southeastern New Hampshire flow into it. The Great Bay is also a reserve where land and other animal species are protected. It’s a big contributor to the economy in New Hampshire. Being able to protect this body of water has become increasingly important.
“Nitrogen is actually one of our emphases because Great Bay is nitrogen impaired. That’s the water body that is kind of negatively affected by too much nitrogen,” said Wilfred Wollheim, a professor of natural resources and environment at UNH. “The solutions are to better understand when and where that nitrogen is coming into the rivers and then be able to prioritize where to reduce the nitrogen, so it doesn’t get to the Great Bay.”
UNH is collaborating with other local communities all over New England, with researchers like Ballestero traveling all over the world, on an innovative approach to dealing with “non-point source” nitrogen pollution.
Non-point source is the term used to describe stormwater coming from all directions, and not one single point. The goal is to implement a nitrogen reduction plan.
“The good news is this problem is solvable,” Watts says.
At the UNHSC, researchers work to develop effective stormwater treatment systems and provide resources to campus and surrounding communities and states.
Humans make a big impact on stormwater pollution. The use of sealants on driveways, fertilizers in yards, and pavements used for roads are some of the biggest human contributors to pollution.
“Science needs better communication to the public,” Macadam said.
Stormwater pollution is a valuable issue because pollution impacts everybody. This sort of pollution is what is responsible for events that set rivers on fire or make people sick swimming in unregulated bodies of water.
“The other problem is that cyanobacteria create the cyanotoxins, these are the algae that are potentially harmful to pets if they swim in it or potentially even people living nearby. There’s been some suggestions of linkages with ALS.” Wollheim said.
Individuals can take steps to help solve the problem. Rain gardens, which are depressed areas in a yard that collect stormwater runoff and allow it to soak into the ground, are inexpensive ways to reduce runoff from properties. Rain barrels in yards can capture water from a roof that can then be saved for gardens, lawns, or indoor plants. It’s free water and a great way to reduce runoff.
“I have a rain barrel at my house, which helps a little bit,” Wollheim said. “You actually save it and then you use it for your garden.”
The good news is that researchers are working constantly to find new and better ways to filter pollutants in stormwater and to keep rivers and other bodies of water clear. The damage done has been a culmination of centuries of urbanization, but beginning to reverse the effects now is the goal.
“We’re not going to fix the problems we created over the last 400 years in one lifetime. So, we have to be in it for the long haul,” said Ballestero.