Avoiding Stormwater Runoff Pollutants

Technically speaking, storm water runoff is defined as any precipitation pouring into a body of water. It’s not necessarily harmful on its own.

But add toxins, excess nutrients, sediments and bacteria into the mix, and runoff is suddenly a recipe for pollution.

With more and more impervious surfaces—such as parking lots and buildings—popping up in the Hamptons, some precipitation can’t filtrate back into the ground and, instead, runs off, picking up pollutants along the way before washing down a storm drain and winding up in the local bays and oceans, according to Group for the East End Environmental Advocate Jennifer Skilbred.

To spread awareness, Springs School recently teamed up with Project Most for a stormwater drain stenciling project, Ms. Skilbred said. The stencils, which were spray-painted next to storm drains, read, “No dumping. Drains to bay.”

“Storm water runoff is something we’re hearing a lot about these days, but not everyone might be up to speed on it,” Ms. Skilbred said during an interview at the organization’s Bridgehampton office earlier this month. “And part of the reason you’re hearing a lot about it is that it’s a national issue for surface water quality.”

And it’s an issue that is being taken seriously not only in the Hamptons, but across the country. In 2003, New York State adopted Municipal Separate Storm Sewer System, or MS4, regulations that have required municipalities to strengthen efforts in reducing the amount of polluted storm water that reaches tidal and freshwater bodies—an expenditure that comes with a hefty price tag.

“But in order for that to really succeed, private homeowners and property owners need to take some steps, as well, to complement that work,” Ms. Skilbred said. “Every little bit makes a difference, even if you just pick a little part of this to attempt at home. You’re making a difference.”

Step one is eliminating fertilizer, pesticide and herbicide use on lawns and gardens—or even just minimizing it. The chemicals found in them are toxic to ocean and bay ecosystems, she said.

“Herbicides that are made to kill plants can also damage eel grass, which are underwater plants that provide habitat for shellfish like scallops,” she said. “So there’s all these negative impacts that people might not be thinking about when you’re just trying to make your lawn greener.”

If there’s no negotiating on fertilizer use, consider amount and timing before applying, Ms. Skilbred suggested.

“Nitrogen issues come from fertilizer,” she said. “When there’s excessive fertilizer put on the lawn and the plants don’t take it all up, or you put it on right before it rains, that can run off into the bay. Excessive nutrients in the bay is what can trigger harmful algal blooms, like red tide. The impact of that can lead to fish kills and low and dissolved oxygen. Fish won’t have enough oxygen in the water.”

The key to reducing fertilizer is planting native vegetation that is accustomed to growing in Long Island soil and weathering the Long Island climate, Ms. Skilbred continued. Also, she said, set the lawn mower blade higher—at least 3 inches high—as taller grass has deeper roots, allowing for a healthier plant.

Step two is to avoid using leaf blowers. They often push soil and sand, along with the leaves, off the property, into the street and down the storm drains. The excess sediment can choke out the shellfish living in the bays.

“It buries them, essentially,” she said. “They can’t survive because they’re filter feeders and if they filter in too much of that, they’re not going to survive.”

Step three is to limit lawn size. Larger swaths of grass attract geese, and with more geese comes more animal waste—which contains fecal coliform, a bacteria that, if picked up by storm water runoff, can cause shellfish closure, Ms. Skilbred said.

“You’re attracting more waterfowl into a concentrated area, so then there’s more of that waste that becomes concentrated, so it can actually complicate the problem,” she explained, adding, “Also, manage pet waste. It’s good to pick it up because no one wants to step in it, but if you’re not picking it up, it’s eventually going to make its way into the bay, and there’s often pathogens in there that can cause beach closures and shellfish contamination.”

Other than reducing pollutant levels, property owners should strive to contain as much precipitation on their land as possible.

During or after a rainstorm, walk around the yard and see where the water is pooling. That may be a great area to plant a rain garden, Ms. Skilbred said. The idea is to fill it with plants that can handle periods of completely saturated soil and wet weather. They’ll soak up the water and reduce runoff.

In general, gardens are also a place to redirect rain gutters, Ms. Skilbred said.

“Many times, the rain gutters will just hit the driveway,” she said. “Engineering-wise, it makes sense. People are like, ‘Okay, get the rain off the roof, onto the road, away from my house.’ Unfortunately, then it becomes runoff and picks up these pollutants. So redirect it to a plant bed where the plants will use it. You can buy relatively cheap gutter extensions and aim them wherever you want.”

Extensions can run anywhere from $10 to $25. Rain barrels, which can cost up to $200, are a more expensive option. The system collects storm water runoff from the roof gutter and saves it for later use, Ms. Skilbred explained. Many are hooked up to a gardening hose, she said, and emphasized using a mosquito net over the top of the container.

Additionally, reduce impermeable surfaces wherever possible, she said.

“If you happen to be redoing your driveway, it’s great to think about that and how much pavement is being used,” she pointed out. “There are alternatives now, like these little paver stones. The water can go through and around, back into the ground.”

And while it’s an extreme measure, think about installing a green, or living, roof, which is partially or completely covered with vegetation.

“I don’t know of any in Southampton Town. It’s kind of neat, but it’s certainly more effort than using less fertilizer,” Ms. Skilbred said.

She laughed, and continued, “You know, it’s easier for people who are waterfront to think about these connections, but all of us are within a watershed. About half of us in Southampton Town are Peconics and half of us are on the ocean side. But the impacts are the same.”