New Infrastructure Helps Clean Up Nursery’s Polluted Runoff, EcoRI, February 25, 2021

By GRACE KELLY/ecoRI News staff
MIDDLETOWN, R.I. — Hoogendoorn Nurseries on Turner Road had a runoff problem.

Founded in 1986, the wholesale nursery is on a hill abutting Berkeley Avenue and come rain or storm, water would sluice down to the roadway, bringing soil and fertilizer with it.

“There’s a tremendous amount of supplementation to the soils to support their business and the growth of plants, and this can lead to some issues with stormwater runoff,” said Allison McNally, program director at the Aquidneck Island Planning Commission, during a Feb. 23 virtual presentation hosted by the Middletown-based nonprofit Clean Ocean Access. “For instance, fertilizer runoff will come down off the property and eventually make its way into the Maidford River … which supplies the Nelson and Gardiner ponds, which are part of the surface drinking water supply managed by the Newport Water Division.”

Aquidneck Island has a surface-based water supply that serves three different municipalities and, as McNally noted, the island’s soils are notoriously incompatible with proper drainage and a good portion of the island has impervious pavement. The ponds that supply the Newport Water System and its nearly 15,000 service connections with drinking water are impaired — pretreament — and don’t meet the federal requirements of the Clean Water Act.

“This creates a tremendous amount of stormwater runoff, which does compromise our water quality, as well as our coastal water,” McNally said.

Hoogendoorn Nurseries, while a valuable member of a close-knit agricultural community, was contributing to the problems that Aquidneck Island’s fragile watershed faces.

In 2015, Hoogendoorn was in discussion with the Rhode Island Department of Environmental Management (DEM), which told the nursery that it needed to do something about the stormwater runoff washing down from its property.

“The issue, however, was that this was going to be a huge, expensive undertaking,” said Sarah Churgin, district manager for the Eastern Rhode Island Conservation District.

A maze of infrastructure on the Hoogendoorn Nurseries property helps filter stormwater runoff before it’s discharged into a sensitive watershed. (AIPC)
A maze of infrastructure on the Hoogendoorn Nurseries property helps filter stormwater runoff before it’s discharged into a sensitive watershed. (AIPC)

Five years later, in May 2020, the nursery broke ground on the installation of extensive green infrastructure project with the financial help of the U.S. Department of Agriculture, DEM, the Aquidneck Island Planning Commission, and the town of Middletown.

The infrastructure installations are comprised of a variety of stormwater mitigation tactics, including erosion control wattles, inlet/outlet protection, an underground outlet, and water collection basins.

One of the biggest undertakings was the creation of what is called “Basin D.”

“Probably the one basin to rule them all is in the bottom left-hand corner of this diagram,” said McNally, showing a map of the various projects installed on the property. “This is the one basin that takes any remaining runoff. If you look at the other types of structures, what they’re designed to do is slow down the water … and trap stormwater flow to give it time to filter. It’s almost like a pinball game for the sheathing water that is running off the slope, and eventually everything will wind up in Basin D.”

Basin D has an outflow installed that connects to a Middletown right of way and a series of conduits that direct the significantly filtered water to the Maidford River.

McNally showed a photo of some of the stormwater runoff prior to the infrastructure installation and described it as looking like “chocolate milk.”

Then, she shared a photo of Basin D filled with runoff before it was connected to the Middletown right of way. The difference in water quality from a purely visual perspective is stark.

“I mentioned earlier on that … before the project commenced … the water that was running down into the Maidford River actually looked like chocolate milk,” McNally said. “But you’ll notice that the water in these photos is already looking cleaner.”

This spring DEM will take water samples to concretely measure the effectiveness of the changes made at Hoogendoorn Nurseries. McNally and Churgin hope that pending positive results, this project could inspire other landowners to undertaking similar water mitigation projects on their properties.

“We hope that people from the farming community will come away seeing … all of these people came together to help improve something that was going to be a potentially very serious problem,” Churgin said.

Editor’s note: This article was updated March 3.