Airport projects sensitive to environment, yet no answer to pond algae bloom

Mimicking Mother Nature

John Howell
Posted 8/27/15

Jay Brolin has a word for it – “sinuosity.”

The manager of environmental programs at the Rhode Island Airport Corporation (RIAC) said sinuosity is going to improve the quality of water …

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Airport projects sensitive to environment, yet no answer to pond algae bloom

Mimicking Mother Nature

Posted

Jay Brolin has a word for it – “sinuosity.”

The manager of environmental programs at the Rhode Island Airport Corporation (RIAC) said sinuosity is going to improve the quality of water flowing into Warwick Pond and Buckeye Brook.

“Nature doesn’t like straight lines,” Brolin said Friday morning during a tour of airport projects relating to the extension of Runway 5-23 and extension of the safety overrun zone at the end of the shorter crosswind runway.

Of course, pilots like straight lines when it comes to runways and taxiways. When Brolin talks about sinuosity, he’s talking about streams and streams that don’t flow in straight lines. In reclaiming about 30 acres of wooded wetlands north of Warwick Pond, to offset about seven acres of Buckeye Brook wetlands lost to the extended runway safety zone, a straight ditch from Spring Green Pond is being transformed into a meandering creek.

And it’s not just happenstance.

Brolin is looking to mimic Mother Nature right down to a stream’s gravel bed, undercut embankments and rivulets that introduce oxygen as they flow over rocks and around tree stumps. The rocks, even the tree stump, have been introduced to the scene as if Brolin is the master of a giant diorama, only this isn’t being environmentally controlled at an aquarium or nature center. It’s the real thing.

That should be good news for environmentalists and those looking to ensure the water quality of Warwick Pond and Buckeye Brook.

But conditions would appear to say otherwise.

For the only time in the memories of those living on the pond, the pond is experiencing a blue-green algae bloom that has turned the waters a muddy green and promoted the department of environmental management (DEM) and the Health Department (HEALTH) to issue an advisory for people and their pets not to have contact or ingest the water. The toxins associated with the algae can produce nausea, vomiting and skin rashes. The advisory is in effect until Nov. 1, or until the water is tested and found free of the algae, which DEM is not going to do because of budget constraints.

The algae, which DEM has found in six other ponds in the state, develops during prolonged warm periods and when the water is rich in nutrients – nitrogen and phosphorous.

Pond resident Philip D’Erole believes airport projects, especially the softball and soccer fields at the new Winslow Park, have introduced nutrients to the pond, causing the algae bloom and loss of the use of the waterway to 80 homeowners on its shores. D’Erole believes field fertilizers have run off into the pond in heavy downpours associated with this summer’s series of thunderstorms. D’Erole has invited DEM, HEALTH and city officials, as well as area residents, environmental groups and league officials, to a meeting Sept. 1 at 6 p.m. at the Warwick Public Library. His objective is to hopefully identify the source of the problem and initiate corrective action so the bloom doesn’t reoccur in years to come.

Brolin doesn’t have a source for the bloom, but he doesn’t see it as a byproduct of either Winslow Park or other RIAC projects.

“There’s no reason to believe anything bad over there [is] getting over here,” Brolin says of chemicals, including fertilizers used at the airport.

Brolin said the $7.5 million Winslow Park project – which replaces fields now lost to the relocation of Main Avenue – is designed to retain water runoff through in-ground percolation. The soccer fields are gently rolling so that during heavy rains, water collects in pools. Parking lots and walkways are of crushed stone so that rainwater and snow melt will naturally filtrate into the soil, and there are retention areas that include vegetation aimed at holding water during big rain events.

Park catch basins go to dry wells, not the airport system that feeds into the brook or brook wetlands.

The park project includes the Airport Road intersection with the service road that will continue to access the maintenance garage and Winslow Park. Airport Road is being widened to provide a left turning lane in the westbound lane. It will be signalized and part of an “adaptive light” program the Department of Transportation has planned for Airport Road, Brolin said. Using computers, the program is designed to allow for improved traffic flow through signal coordination and timing. Brolin said the final coat of asphalt is scheduled for this week.

As for the fields, Brolin said there has already been some league play and that they should be ready to turn over to the city by the end of the month. The city will lease the park from RIAC for $1, and in turn the city has an agreement with the Apponaug Girls Softball and Warwick Firefighters Soccer Leagues. The leagues assume responsibility for maintenance of the grounds.

The wetlands restoration project includes the replacement of the Lakeshore Drive culvert. The new culvert is wider and has elevated openings at both sides of the main channel to provide increased capacity when there is stream flooding. During installation, water from upstream is pumped over a dam through a filtration system to reduce turbidity to the pond side, affording the construction crew relatively dry conditions in which to work. The culvert and extended wetlands should be finished next month, with two-way traffic on Lakeshore Drive restored by Sept. 15.

Could recreation of the wetlands and the removal of the old culvert have introduced nutrients to the pond by the disturbance of nitrogen-rich top soil and decayed organic material? Brolin thinks not.

“This project,” Brolin said of the culvert and wetlands, “should not have an impact unless we did it really poorly, which we didn’t.”

Of the airport projects affecting Buckeye Brook and the pond, the extension of the runway safety overrun is the most extensive and costly. Overall, work on the shorter runway to bring it in compliance with Federal Aviation Administration safety standards by the end of this year is costing $43.5 million. At the pond end of the runway, the work has involved the removal of 87,500 cubic yards of peat from the wetlands; the installation of giant concrete subterranean detention ditches; steel sheathing where the safety zone joins the wetlands; and the introduction of 181,000 cubic yards of clean fill to elevate the roll-off zone to that of the runway. As a means of comparison, Brolin said, that’s equivalent to 85 feet on top of a football field.

Last week, a crane lifted a giant slab of steel and then dropped it to compact the base material for the safety zone, while a second machine vibrated the ground for the compaction of fine material.

Last October, RIAC completed the $33 million glycol recovery system to capture deicing fluid before it reaches Buckeye Brook. Brolin said the system, along with collection trucks, captured 67 percent of the glycol used. Recapturing all of it is impossible, since it remains on the aircraft and dissipates in the air.

Throughout the construction process – including the relocation of Main Avenue, which will allow for the extension of the main runway – Brolin said RIAC recognizes that construction can be disruptive.

“We try to keep it down to a level where it constitutes an annoyance, not a hardship,” he said.

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