VA's Artificial Wetland is the Real Deal in Slowing Stormwater Pollution

Waynesboro installation uses ponds to filter runoff from 330 acres of a residential neighborhood.

But Waynesboro, VA is bringing stormwater treatment to the forefront. Recently, the city of 21,000 installed a 10-acre “constructed wetland” in its center.

Mimicking nature as best as it can, it filters runoff from its natural drainage basin — 330 acres of mostly residential neighborhood. The beneficiary is a mile or so to the east: the South River, which flows through the city and eventually to the Shenandoah’s South Fork 15 miles away.

This constructed wetland works by forcing runoff to cascade gradually downhill through an array of three ponds — four, if you count the highest elevation, the “sediment forebay,” which captures mud from the runoff before it enters the vegetated ponds. According to Waynesboro’s stormwater manager, Trafford McRae, the city will likely have to dredge the forebay every two to three years.

By the time the water reaches the bottom pond and is piped to the river, it has spent enough time in the wetland to allow natural processes — chiefly absorption in the underlying soil and mud, uptake by plants and microbial processes — to remove most of the polluting nutrients.

Built on what had been a grassy “detention basin,” or large stormwater collection pond, in the city’s Jefferson Park neighborhood, the new wetland is expected to remove around 300 pounds of phosphorus and 1,700 bounds of nitrogen annually from the runoff that passes through it. That’s a very small fraction of Waynesboro’s total nutrient contribution to the river, but it’s moving the city in the right direction, according to McRae.

The $1.6 million project was funded by a grant from the Virginia Department of Environmental Quality’s Stormwater Local Assistance Fund and a low-interest loan from the DEQ’s Virginia Clean Water Revolving Loan Fund.

Waynesboro is the first city in the valley to take on a stormwater project of this kind, though it might be the last to do so with help from the state, at least for the time being. Virginia legislators earlier this year, looking for places to tighten the state’s budget, chose not to renew stormwater local-assistance funding.

Read more: Bay Journal

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Taxonomy

• Water Pollution
• Treatment
• Stormwater Management
• Pollution
• Wetlands
• Sustainability
• Stormwater
• Constructed Wetlands
• Storm Water Management