The shifting sands of the Essex stormwater management plan
Construction of a gravel wetland near the intersection of Mansfield Avenue and Brickyard Road. Photo by Shanti Boyle.
ESSEX -- Ann Costandi will have a job forever, according to Essex public works director Dennis Lutz.
Costandi is the stormwater engineer for the Town of Essex. And Lutz is right: the business of stormwater management in Essex is, as he puts it, “a shifting sand business,” and Costandi will likely never find solid ground as long as she remains the stormwater engineer. This was true before the pandemic, and the recent crisis has Lutz, Costandi, and others working on stormwater management wondering just how much COVID-19 has affected their future work.
“We don’t really know the implications yet,” Costandi explained. The engineer has been working on the Town’s stormwater management plan for seven and a half years. “As far as the current projects that we have, our timelines have been shifted and that’s the only real major impact. But we don’t know what the funding is going to look like for our future. When another grant program comes out, how much money are they going to have available? It's probably going to be less than what they've offered in the past.”
The stormwater management plan almost entirely depends on state and federal grants. Right now, Lutz and Costandi are working with about $3 million in grants. The capital budget--which is what Essex property owners pay--by comparison is $150,000. The capital budget contains most of the construction funds for the management plan and does not include salaries.
Vermont is delegated by the federal government to enforce the Clean Water Act, and has designated Essex a small Municipal Separate Storm Sewer System (MS4) in an attempt to comply with the law. The Town of Essex and the Village of Essex Junction both operate under a General Permit (3-9014) that requires stormwater management and programs to improve water quality in Indian and Sunderland Brooks and ultimately Lake Champlain.
Stormwater staff mainly focus on flow restoration and phosphorus reduction of the two impaired watersheds, Indian Brook and Sunderland Brook. When a waterbody does not meet water quality standards, it is considered “impaired.” In this case, both brooks are listed as impaired due to the health of aquatic biota.
The projects implemented this summer bundle both flow restoration and phosphorus reduction. Unchecked flow causes erosion of the streambank, adding sediment into the water that, in turn, negatively impacts water quality and the health of fish and macroinvertebrates. The sediment also contains phosphorous, the nutrient which encourages blooms of cyanobacteria, better known as blue-green algae.
The first project is being overseen by the Village. The project is a conversion of a storm drainage ditch into a gravel wetland near the intersection of Mansfield Avenue and Brickyard Road. It involves installing a catch basin and a stormwater gravel wetland, which will help capture stormwater, reducing flow into the brook. Gravel wetland construction is expected to conclude by October 2020.
The second project is headed by the Town, and takes place on Sydney Drive in Lang Farm. The Town is converting an existing retention pond into an underground storage and infiltration system. Infiltration is essentially water absorption into soil, and it’s crucial for flow restoration. Right now, infiltration is limited because the soil consists of a sand layer and a clay layer.
“You can't get infiltration with clay, so we added a sand layer underneath the storm chambers with water treatment residuals from Champlain Water District. These water treatment residuals have been shown to remove phosphorus. You don't need a lot, you just need to mix it with a sand layer and you get better phosphorus treatment,” Costandi described.
Lutz expects that the Town’s project will be completed by next spring at the latest, and after that, the completion of one more final project will conclude the flow restoration component of the stormwater management plan.
But Lutz and Costandi are expecting some hiccups come colder weather. Aging infrastructure and increased chloride levels in streams disrupt the efforts of stormwater management, and unyielding Vermont winters directly enhance their power.
“We have pipes in the ground that are between 60 and 70 years old. Any time we have a sinkhole, we have to televise the stormwater line to determine if it’s an isolated area or the entire condition of the pipe. And do we need to replace that pipe or can we just fix it in that particular location? That can be quite expensive when you start thinking about how many linear feet of pipe we have throughout both communities,” Costandi said.
Luckily, Essex has another grant to televise all of the stormwater lines in the Town and in the Village. Costandi says that plans are in place for a subcontractor to come in, examine the lines with a camera and do a condition assessment on all of the pipes to create an overall infrastructure rehabilitation blueprint. But the issue of chloride is not so easily mitigated.
Said Costandi, “We're seeing an increase in chloride in streams from ... plow trucks putting down salt. We've reduced our salt application quite significantly over the years, and we have that data, but it's just that there isn't a good way to remove chloride from streams. There's not a system that you can construct--like the gravel wetland--that will take the chloride out of the stormwater as it's going back into the stream.”
Problems like chloride levels and further phosphorus reduction strategies do make for a working environment that is “like being on the sands of Arabia and you can’t get your feet settled in a place without the sand shifting underneath,” as Lutz poetically illustrated. Without the concrete knowledge of which grants the state and federal government will be offering, this leaves the stormwater staff with hope and not much else; weather won’t wait for funding.
