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The fifth and last of the Flushing Bay pollution control meetings sponsored by the New York City Department of Environmental Protection was held last week at the Olmstead Center in Flushing Meadows-Corona Park. At the meeting, the recommended water body/watershed plan for both Flushing Bay and Flushing Creek, the narrow channel that extends southward from the lower part of the bay, was revealed. It was no surprise that an industrial engineering or "end of pipe" plan was chosen, since it and all alternative plans constituted the DEP's presentation in previous meetings. But attendees at the meeting also heard a DEP official speak of and illustrate pollution entrapment measures. The source control plans he described are being applied to Jamaica Bay, at the south shore of Queens and Brooklyn. His description left attendees to infer that source control might eventually be applied on the north shore, in Flushing Bay.
The DEP's choice for the lower part of Flushing Bay (which has a volume of pollution nearly 40 times as great as the upper bay) is to install a 25-million-gallon collection tunnel there. The plan would also include bending weirs on key regulators and netting systems at two points of outfall on the shore of the lower bay. The tunnel would be 26 feet in diameter, set in a loop about 7,000 feet long and laid 150 feet below grade in the lower bay. Its 25-million-gallon combined sewage overflow (CSO) could be transferred to the weir installation running to the bay from an initial point at 43rd Avenue and 105th Street; and from there to the Bowery Bay water pollution control plant (WPCP) on Berrian Boulevard in Astoria. Another part of the plan is a dredging operation which would be conducted to a level five feet below mean lower low water (MLLW), and the bottom then capped with a two-foot layer of clean sand. Dredging would remove CSO-related sediments that are exposed at low tide.
The Flushing Creek project has long since been undertaken (at a cost thus far of $332 million), and the CSO tank was, in fact, in operation as of the end of May, as reported at the meeting. A total of 43 million gallons of CSO can be stored: 28 million in the tank, 15 million inline. It is conveyed in a northeast direction to the Tallman Island WPCP on Powell's Cove Boulevard. Yet to come is the dredging operation, to be conducted to a level five feet below MLLW and capped with a two-foot level of clean sand.
It was not surprising that the DEP's Flushing Bay/Creek plan drew unfavorable commentary from skeptics, who may have had to resign themselves to it but didn't have to like it or believe it would succeed in its purpose. The bay and creek plans were related to the audience by Philip Hwang of the engineering firm O'Brien & Gere. On hand with him to handle the inevitable criticism were Stephen Whitehouse of Starr Whitehouse, a landscape architectural firm, and Chris Villari of DEP. Among the critics was the head of Community Board 7's environmental committee, who said that dredging could have unseen consequences; Villari could only agree. Tim Eaton of Queens College said the tunnel and weirs are subject to groundwater invasion that could dilute the volume of CSOs and simply increase the pumping burden. Hwang tried to tell him of the technical proficiency of these container systems but Eaton wasn't impressed, saying that nature would foil the plans of engineers. He cited a pipe system in Milwaukee that was opened with high hopes in 1986 but never worked well and recently had to be relined. Thomas Campagna, a consulting engineer in the Queens borough president's office, warned that the water table level is rising, which would affect the system. The example he cited was York College in Jamaica, also built in the 1980s. At the time it was built, he said, the water table was seven feet below the basement. Now, it is two feet above, and the impact on the York College buildings is acute.
In the early part of the evening, John McLaughlin, DEP ecological services director, talked about storm water management pilot projects within the Jamaica Bay watershed. He explained how existing roadways might allow for increased street-side tree planting, which could be modified to capture a portion of storm water runoff. Modification would "peel" water from the centralized combined sewer system and start a decentralization process. He showed an illustration of a hypothetical "Design Avenue, somewhere in the Jamaica Bay watershed" that had streetside swales for capturing storm water, saying that up to 25 gallons of it could be drained from each linear foot of roadway. Also, streetside infiltration swales could be planted in the understory of tree pits. He said the largest practical street tree sidewalk openings should be tried, and methods should be studied for storing water during rainstorms for later reuse by the trees through employment of soil moisture sensors and solar-activated pumps. Wherever possible, porous pavement should be used. (On playgrounds, it has the additional advantage of noise abatement; basketballs bounced on it don't make as loud a report as on standard blacktop or concrete.) "Typical urban runoff should be more than well treated by these methods," he said.
McLaughlin also spoke of constructed urban wetlands, which have been attempted at some places beside the Long Island Expressway but not yet in the Jamaica Bay area. He said that green roofs are more practical on commercial than residential buildings, but at least 20 such roofs exist in the city at present; an example is the Silvercup building in Long Island City, beneath the Queensborough Bridge. Restoration of oysters to Jamaica Bay will promote nitrogen removal, if not fishing for them, which hasn't been done in the bay since 1920; rib mussels, inedible to begin with, should be useful in the bay for pathogen uptake. But he warned that the rate of wetlands disappearance, 44 acres per year on the shoreline, would guarantee its elimination by 2025. Wave attenuators are a means of staving off wetlands deterioration. Tom Lowenhaupt asked McLaughlin when the pilot program starts in Jamaica Bay and McLaughlin said by the end of this summer. And when in Flushing Bay? McLaughlin had no sure answer.
