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AbTech and Smart Sponge in Erosion Control Magazine Feb 2015

EPA estimates that between 1988 and 1994, there were over 12,000 instances where people could not swim safely in US coastal beaches because of high pollution and bacteria levels. Population increases and development along coastal areas will put additional pressures on water quality in these regions, forcing communities to develop more stringent water quality management plans.

Sag Harbor is an incorporated ­village on Long Island in Suffolk County, NY. The 2010 census put the population of the village at a little over 2,000. Sag Harbor has historical roots that date back to the American Revolution and the War of 1812. Even further back, it was declared an international port by 1789 and soon became a major whaling port. The whaling industry peaked around the 1840s but collapsed in 1847 with the discovery of kerosene and coal oils.

About 100 years later, in 1947, a giant drainage “ditch” was cut through Havens Beach in Sag Harbor. The ditch was 900 feet long and 25 feet wide, and 137 acres drained into it, explains Dee Yardley, superintendent of public works for Sag Harbor Village. “It had to have some way to go out. And back then, that’s just the way it was done.

“It was a trench that went all the way out to the beach,” he continues. “All the water just flowed to the lowest area. It was stormwater runoff and in some areas, the water just sat there.”

As the Suffolk County Department of Health monitored beach water quality in recent years, it found that the bacteria counts increased in the ditch. Stormwater runoff from the village was accumulating in the old ditch area, Yardley says. And while the situation had been under study for a number of years, in 2012 it got a welcome supporter. The mayor of Sag Harbor, Brian Gilbride, was very active in his support stormwater improvements at Havens Beach. Upon his re-election as mayor, he took on the project, commenting that he was looking forward to “tackling the stormwater runoff pollution at Havens Beach, as well as erosion at the West Water Street.”

Nancy Pierson, senior public health sanitarian with the Suffolk County Department of Health Services’ Office of Ecology, explains, “In an effort to protect public health, the Suffolk County Department of Health Services’ Office of Ecology conducts a comprehensive bathing beach water-quality-monitoring program from mid-May through mid-September at approximately 191 beaches. The frequency of sampling is determined using a tiered, risk-based approach, with more testing conducted at beaches that have historically demonstrated periods of poor water quality or are potentially at risk because of their proximity to pollution sources. Sampling at these beaches is typically performed at least twice per week.”

To evaluate beach water quality, levels of indicator organisms are used as an estimate of fecal contamination. Although the organisms are usually considered to be harmless, they may indicate that fecal contamination is present, along with other disease-causing organisms. Per recommendations from EPA under the BEACH (Beaches Environmental Assessment and Coastal Health) Act and the requirements of the New York State Sanitary Code for Bathing Beaches, Suffolk County uses Enterococci as the indicator organism for its marine beaches.

Pierson says that obtaining grant funding through the BEACH Act has allowed Suffolk County to expand its beach monitoring program significantly in recent years. Where it collected approximately 520 samples in 2002-03, it increased its collections to more than 4,000 in 2013. In 2003 only the beach was being sampled. But in 2008 resident complaints and concerns about possible bacterial contamination led Suffolk County to start sampling the end point of the long trench.

“Decisions regarding beach closures are based on sample results as well as various beach-specific factors, including knowledge of potential sources of contamination in the beach watershed, historic water quality data, past criteria exceedances, weather, and area flushing characteristics,” she notes. “Under certain conditions, such as during or in anticipation of unusually heavy rainfall, or other events or situations that can pose a risk to public health, advisories recommending against bathing are issued. Precautionary advisories are typically issued for a 24-hour period to allow for sufficient tidal exchange to dilute any contamination that may be present. And although beaches may close in response to these advisories, they are not an indication that unacceptable bacterial levels exist, but rather are a precaution against potential contamination.”

However, while the bacteria counts at the Havens Beach outfall continued to rise, potentially threatening beach water quality, officials searched for a source or sources and for alternatives to solve the problem. The Village of Sag Harbor, together with Inter-Science Research Associates Inc. as its environmental and planning consultant, approached the ­Suffolk County Department of Health Services’ Office of Ecology to get input, data, and expertise in this area. Richard Warren, AICP, president of Inter-Science Research Associates, and Mike Schiano, environmental planner with the company, became involved with Havens Beach as site designers, planners, and coordinators, together with S.L. Maresca Associates, a local consulting engineering firm.

“On Long Island, most septic systems are subsurface systems and could potentially be a problem,” explains Schiano. “All the testing came up inconclusive.” He says the Suffolk County Department of Health Services conducted dye testing of some nearby septic systems to see if any of them were contributing to the ditch’s bacteria levels, but they came back negative. But, because the bacteria levels were high, officials wanted a solution: “Fix the problem!”

“At marine and coastal beaches in Suffolk County, stormwater runoff is the predominant source of bacteria-laden water,” says Pierson. “The effects of the runoff on water quality are site specific, and are influenced by a number of factors, including the type of land use, area topography, and the degree of tidal flushing. Both Enterococci andEscherichia coli bacteria can be introduced to recreational waters from a variety of sources, including stormwater runoff, resident waterfowl populations, failing or poorly operating septic systems, sewage spills, boats and marinas, floatable debris, and from bathers themselves.”

“We knew we would need more than just one technique to ensure the highest removal efficiency,” says Schiano. “The ditch area needed to be dredged to remove the material that had been building up in it since it was created in 1947. Once the ditch was dredged, it was filled with clean sand to provide a stable bottom for planting material. We also included a settling basin that extended about 200 feet from the inlet pipe, a check dam at the end of the basin, and an area about 700 feet by 20 feet for a wetland with aquatic plants that helped to remove nitrogen and other typical stormwater pollutants.”

In planting the bioswale, Schiano explains, all of the plants were planted in clean sand with no soil amendments. The mix of native plants included duck potato (Sagitaria latifolia), pickerelweed (Pontederia cordata), soft rush(Juncus effusus), tussock sedge (Carex stricta) and narrow-leaved cattail (Typha angustifolia). All plant plugs were planted 1-foot on-center. Plant populations were installed, alternating dense and open, to allow water to flow and seep.

By the time the bioremediation portion of the Havens Beach project was designed, he says, planners had already decided on AbTech Industries to supply its Smart Sponge Plus for bacteria removal on the site. AbTech Industries is a stormwater management firm located in Scottsdale, AZ. Smart Sponge Plus can be used anywhere there is a need to remove excessive bacteria. These locations vary but are often near beaches, rivers, and lakes.

The Smart Sponge Plus structure is porous and elastic, giving it excellent hydraulic properties, along with its chemical properties that make it chemically selective towards hydrocarbons. Smart Sponge is hydrophobic, so it repels water, while being oleophilic to attract oil and grease. The oil and grease are permanently bound to the Smart Sponge and will not leach back into the environment. Saturated Smart Sponge has passed EPA Toxicity Characteristic Leaching Procedure (TCLP) testing as a “non-leaching” product, and therefore can be disposed of in any nonhazardous (Class D) landfill, waste-to-energy facility, or cement kiln.

The Smart Sponge Plus contains an antimicrobial agent that is chemically bound to the polymer surface. The permanent bond allows the agent to be active without leaching out downstream, thereby avoiding toxicity issues at other locations. The organosilane derivative that is used in the Smart Sponge Plus is used in a variety of products including medical and dental products, consumables, pool equipment, and other consumer goods. Using no electricity, chlorine, or heavy metals, the mechanism works to inactivate microorganisms at the cellular level. Using flow rates and bacteria concentration, AbTech engineers the Smart Sponge Plus to meet the desired performance requirements of each individual customer.

After determining a number of factors such as flow rate, bacteria levels, sediment loading, desired bacteria reduction, and various others, AbTech recommends using a specific size Smart Sponge Plus Smart Pak bed depth. This Smart Pak bed depth will reflect the proper empty bed retention time to meet the customer’s desired bacteria reduction through the biostatic charge of the media.

Smart Sponge Plus is typically used in a vault system. Once installed, the system requires minimal routine maintenance and replacement of the antimicrobial Smart Paks to keep it operating at peak efficiency. When the Smart Paks become saturated with sediment, oil, and grease, they need to be replaced. Typically, 10–15% of the antimicrobial Smart Paks will need to be replaced each year.

Superintendent Dee Yardley described the AbTech vault installation at Havens Beach. “All the material in the ditch was dredged. There was about 5,000 to 10,000 tons dredged from there. Then they put the new sand back in. That’s the biofiltration area before it gets to the Smart Sponge Plus vault.” He continues, “It was installed in 2013, and using a crane they literally dug a large hole to install the precast vault. It’s a giant concrete vault with stainless steel compartments for the antimicrobial Smart Sponge Plus ‘pillows,’ or Smart Paks. You can’t tell it’s even there.”

The 10-foot by 10-foot vault that houses the Smart Paks is inconspicuous to beachgoers, but there is a manhole cover on the cement top so that he, or AbTech service technicians, can go inside to service the filters.

The bacteria levels that had previously reached as high as 12,500 in October of 2009 have remained below 1,000, a greater than 92% reduction, since the Smart Sponge Plus installation in August 2013, as determined by a data chart supplied by Nancy Pierson. Also noted in the data, of 16 effluent samples taken since August 2013, 11 had bacteria levels below 300. The bioswale area is doing its part to filter the stormwater runoff as well. The data for samples taken before and after the bioswale show that 8 out of 12 samples were remarkable after passing through the bioswale. When using the data chart supplied by Pierson, even though numbers seem erratic, there is an overall downward trend since the Smart Sponge Plus was installed.

Yardley concludes that since the Smart Sponge Plus was installed in 2013, there has been no instance of bacteria exceeding the acceptable levels at Havens Beach.

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