Dredging Up the Past

For Spring Brook Country Club in Morristown, N.J., removing sediment from water through hydro-dredging was the ideal way to transform an eyesore into a clean, wildlife-friendly irrigation source.

Armstrong Pond at Spring Brook CC is prominently with pride after a hydro-dredging left it clean.

Armstrong Pond, the irrigation source at Spring Brook Country Club in Morristown, N.J., is also a focal point of the property. But years of sediment buildup and algae growth had turned it into an unhealthy eyesore.

Two years ago, the staff realized that something had to be done about its deteriorating condition, and not only because of its aesthetic appeal, which dwindled as the water was drawn down for irrigation. Every summer, Golf Course Superintendent Bob Carey worried that the property would not have enough water to get through the season, and in 2010, the property almost ran out of water after an extremely dry July and August.

As a result, Carey turned to the Internet to research pond dredging. He considered conventional dredging, but it would have drawn down the pond and displaced wildlife. Then he came across two companies that offered hydro-dredging, or hydraulic dredging, services. He also made site visits to two locations—one in Wisconsin and one in Puerto Rico—that were hydro-dredging in November and December 2010.

Spring Brook Country Club in Morristown, N.J. THE GOAL: Spring Brook Country Club needed to capture more water to use for irrigation and to return Armstrong Pond to its state of 30 to 40 years ago, to provide greater aesthetic appeal and enjoyment for its members. THE PLAN: Hydro-dredging was performed on the pond to remove sediment accumulation and algae growth. The slurry was pumped through a high-density polyethylene (HDPE) piping system into geo-textile bags that were filled with a 5:1 ratio of water to sediment. The heavier sediment fell to the bottom of the bag with the aid of a polymer that had been injected along the piping system. The sediment stayed in the bags, which included a filtration system, while clean water was released back to the pond through pipes. THE PAYOFF: Hydro-dredging has improved the water quality and quantity by removing sediment buildup and algae growth from the pond while also increasing its water storage capacity by 4.1 million gallons. The process has also provided more enjoyment for the members by improving the health and aesthetics of the pond, which is visible from the clubhouse, six holes on the golf course and an adjacent road. In addition, the pond now provides habitat for wildlife, including ducks, turtles and a variety of fish.

Hydro-dredging is a high-tech means of removing sediment from bodies of water. The dredge, which basically includes pumps and a collection system that acts like a vacuum cleaner, floats on the surface to excavate and pump material through a temporary pipeline to an off-site location, which can be up to several thousand feet away.

Carey, however, has a much more personal definition of the process.

“For our club, it was a safe, economical, effective way of removing 9,000 cubic yards of sediment material from the pond to a lay-down area, without disrupting golf or roadways,” he says.

The 7.5-acre Armstrong Pond was named after a 19th-century owner of the land that Spring Brook CC, established in 1921 and the site of numerous professional and amateur tournaments, now occupies. In addition, the now defunct Armstrong Brick Factory once pulled water and clay from the pond to make bricks.

“That’s what sat atop our golf course,” notes Carey.

Because of its significance, the need to restore the pond—visible from the clubhouse, six golf holes and a road alongside the golf course—to its natural beauty and function was vital to the property.

The project took two months from start to finish. The company that performed the work started setting up for the project on Feb. 20, 2011. The dredging took place from March 1 until April 15, 2011, and the company pulled out of the site five days later.

The hydro-dredging process cost $385,000, which, according to Carey, was comparable to conventional dredging. However, the entire project—including permitting, water and silt-control structures, additional drainage of other smaller waterways, creeks and drainage swales on the property, and cleanup of water that runs off the property—totaled about $740,000.

The timing of the project was an important factor as well. “We could not have done our pond in-season, because there were so many dissolved solids in the water column that would clog heads and keep us from running our irrigation system properly,” notes Carey.

Spring Brook personnel also decided to undertake the project during the off-season because there are no hatching or nesting areas at the pond in the winter. Although the pond was covered in six inches of ice when the process started, the equipment could break the ice. The hydro-dredging company used an Amphibex, a large floating barge with two high-velocity pumps and a shovelhead that had a rotating wheel of teeth on the end of the arm, to churn up the sediment.

Hydro-dredging of Armstrong Pond was done during the off-season to avoid dissolved solids and any disruption of hatching and nesting periods for resident fish and wildlife.

“The machine was designed to help dredge the Red River in Canada, one of the few rivers that runs from south to north,” adds Carey.

The slurry was pumped at a rate of 1,800 gallons a minute through a 1,600-ft. high-density polyethylene (HDPE) piping system into geo-textile bags in a fallow field, which had been engineered into a flat lay-down area, to prevent the bags from rolling.

Sand bags secured a plastic liner on top of the soil of the lay-down field, and the plastic helped to minimize erosion under the bags as dewatering occurred. The sandbags were removed once the geo-textile bags were ready to be placed in the lay-down area.

The geo-textile bags, made of a heavy woven fabric, measured 28 feet by 200 feet, and expanded to 6 or 7 feet high when they were filled with a 5:1 ratio of water-to-sediment slurry. The heavier sediment fell to the bottom of the bag, with the aid of a polymer that had been injected along the piping system. The sediment stayed in the bags, which included a filtration system, while the water released out back to the pond through pipes.

“The drainage system was set up to capture 95 percent, if not all, of the water, and return it to the pond in a clean state,” explains Carey.

Contractors cut open the geo-textile bags in July, then dozed and shaped the sediment into a sloping meadow. The meadow requires little maintenance other than mowing, with herbicide applied once in the spring and once in the fall, reports Carey.

“The bags were disposed of in our local landfill and will decompose in a short time,” he adds. Although not the case at Spring Brook CC, the bags have been reused for slope stabilization during grow-in projects that involved steep inclines.

Slurry was pumped out of the pond through piping and into geo-textile bags in a fallow field.

During the project, the Spring Brook course-and-grounds staff had several duties that included: helping to install the plastic liner and unroll geo-textile bags on the lay-down field; helping to ensure that the bags were dewatering properly; walking across them to make sure a sediment crust did not form and impede the dewatering process; seeding the field after final grading; and removing silt fencing that was used for erosion control.

Carey believes the work was well worth the effort. The hydro-dredging process increased water storage by 4.1 million gallons, which equals the property’s state Department of Environmental Protection allocation per month and provides an extra month of watering.

In addition, Carey reveals, “It did not affect one single golfer. We ran the pipes so they weren’t in the way of play. We built ramps over cart paths and used an existing sewer line to run pipe across roadways.”

The hydro-dredging also got rid of a lot of sediment material that harbored aquatic reed seeds. The plants that grew out of these seeds flourished before they died and decomposed, leading to the formation of algae.

Sediment stayed in the bags while over 95 percent of the water was cleaned and returned to the pond, yielding a water-storage gain of 4.1 million gallons. The bags were then cut open in the summer, and the sediment was used to create a new meadow on the property.

During the process, Carey kept in close contact with the New Jersey DEP, apprising the agency of the project logistics and explaining how the process worked, how the property would be restored back to normal, and the safety precautions that were followed. “There’s no need to be afraid of the DEP, as long as you keep the agency engaged,” he says.

The dredging of the pond has resulted in a number of environmental benefits as well. Natural enzymes are now used to help deter the algae, and the property has reduced chemical inputs into the pond by 50 percent.

“We could almost walk across the pond before we dredged it,” notes Carey. “Now our wildlife is much healthier, and the pond is teeming with animal life.”

Resident wildlife includes ducks, turtles, blue and white herring, sunfish, bass, and blue gill. Courtesy of a relationship that Spring Brook CC has built with The Raptor Trust of Millington, N.J., Armstrong Pond can also take in swans that need a safe place to rehabilitate.

In addition, notes Carey, “If we’re stuck in a hot, dry summer, we can prolong watering deeper into the summer.”

He also says that no algae formed on the pond last summer, even though the golf course experienced 19 days when the temperature topped 102 degrees.

Two fountains in the pond are thriving as well. In the past, Carey reports, the water level in the pond got so low that the water features could not even function.

While Armstrong Pond will not have to be dredged again during his lifetime, Carey says, Spring Brook CC has plans to hydro-dredge its five-acre Hipson Pond in the next two or three years. “It’s dying quickly, by no one’s fault,” he explains. “It’s just the life cycle of the pond—but this will take it back 40 or 50 years.”

And sometimes, a step back is the best way to move forward.

Tags: Armstrong Pond Bob Carey Hipson Pond hydro-dredging issue Morristown N.J. Red River Spring Brook Country Club