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The Stuff Paradise is Made Of Like clockwork, every few minutes another 20-ton, 10-wheel Mack dump truck lumbers along the athletic field access road and veers off into the cracked, dusty bed of the drained Paradise Pond. The truck stops just long enough for a front-end loader to scoop a ton of mucky sludge and dirt (called sediment) from the pond's floor and dump it in the truck bed. Then it moves out and another truck moves in.
After the dredging of Paradise Pond this summer, Smith's
Physical Plant had hoped to refill the pond with water by early September.
But extended drought conditions during August made that impossible. It
took a substantial rainfall to give the crew team enough water to row
in again. It's early August. The trucks belong to Warner Bros. trucking company, of Sunderland, Massachusetts. Paradise Pond is being dredged. That is, all the excess sediment built up over the years is being scooped up and hauled away. It's a procedure that needs to be done every eight years or so, reports project manager Gary Hartwell. He has records of dredgings in the summers of 1974, '82 and '90, "and we'll probably have to do it again in 2006," he says. Eight Warner Bros. trucks in rotation haul the sediment out to West Street and up Route 66 to the Northampton landfill off Glendale Road, some five miles away. The dredgers work in eight-hour shifts for two weeks straight. By the time they finish they will have hauled about 17,000 tons or 1,000 truckloads of the stuff to the landfill, where it'll be used for cover. Northampton health agent Peter McErlain, who oversees the operation of the landfill, says the nutrient-rich Paradise Pond sediment is particularly useful for fertilizing grass on the landfill's exterior slopes. "This is special stuff," he says. "It's high-quality. We don't just use it to cover trash every day. It's too good for that." This is a new use for the sediment. Local homeowners and gardeners used to buy truckloads of the silt and soil to use as fertilizer. The state Department of Environmental Protection allowed such use as long as the sediment's hydrocarbon contamination level did not exceed the DEP's mandated limit. This year, however, the DEP lowered that limit, rendering the sediment unfit for upland disposal and illegal for use on lawns and gardens. Depth Warrant Not much can be done to avoid sediment buildup in Paradise Pond, says Hartwell. Over the years, the Mill River washes excess silt, sand, leaf matter and dirt downstream into the pond bed. The sediment builds up layer upon layer. Various plans have been discussed for alternative ways to dredge the pond or to avoid the need to do so, Hartwell says. More frequent dredgings, for example, would allow less buildup. Hydraulic dredging could be done without draining the pond. But each of those plans poses its own problems, he says. Another option would be to do nothing, to simply let sediment accumulate on the pond bottom. But the problem with sediment buildup is that it reduces the depth of the pond-an important matter, Hartwell points out, in a facility used for canoeing, kayaking and team rowing sports. If the pond were not dredged, the sediment would eventually poke above the surface, forming little swampy islands with weed overgrowth, he says. And when crew team members and boat rowers come along, aggressively dipping their oars in the water, which ideally runs between six and 16 feet deep, they would jam them into the muddy bottom, abruptly ending the race. "It wouldn't be suitable for boating," Hartwell says. "Unfortunately, there really is no good solution," Hartwell notes, adding that the pond is likely to continue being dredged every eight years. To drain the pond, a sluice gate at the side of the dam downstream is opened to allow water to pass through at a controlled flow. Within two weeks, the pond dwindles to a narrow channel. This drawdown has to be monitored closely, says Hartwell, to mitigate the release of suspended sediment in the river and protect a rare species of mussel further downstream. The weather can cause trouble at any stage of the dredging, Hartwell says. A good rain (one that dumps one or two inches in a six-hour span, say) can cause the pond to rapidly rise, delaying the project. This summer's operation began about three weeks late, for example, because of heavy rain in June. Once the pond was drained, the bed was left to dry. Then the trucks came in. By late August, the dredging was complete. But Paradise Pond remained dry. It would take a substantial rain to counter the effects of a summer drought, refill the pond and allow physical plant to close the sluice gate-which had been opened to drain the pond-to capture the water. The entire process was not considered complete until water was again spilling over the dam. |
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