Coming Clean with the Environment
Long Island is a long, slender island located directly east of Manhattan in the southern tip of New York State. In the 20th century, the north shore of Long Island earned the nickname of “Gold Coast” and attracted large private estates of the likes of the Vanderbilts, Roosevelts, Whitneys, Charles Pratt, J. P. Morgan, F. W. Woolworth, and others. The western end of the island includes Brooklyn and Queens, while the eastern tip includes the famous Hamptons.
Long Island has always been the getaway place for the rich and famous of New York. The beautiful vistas of the north shore, white sandy beaches of the outer barrier islands and world class fishing attract people from all over the state. As more and more people take on a longer commute in exchange for a home outside the congested cities, the population continues to increase. Long Island has moved up to be the most-populated island in the US and the 17th most populous island in the world.
With the explosion of the population, public utilities needed to be upgraded and/or replaced. Many of the more obvious utilities were improved to support the growth. However, with any increases in population, the waste load that a given environment can absorb may be tested and, in many cases, overloaded. In an effort to protect the public, beaches, local aquatic life and the groundwater of Long Island, the local Environmental Agencies and Suffolk County worked together to develop new discharge standards for local wastewater treatment plants.
Due to the growing population in the region, resources were being consumed at an ever-increasing rate. The price of electricity, in particular, climbed significantly – its demand growing faster than its supply. In an effort to find new technologies to help in the conservation of resources and energy, the state of New York implemented the New York State Energy Research and Development Authority (NYSERDA). The role of NYSERDA was to provide support to groups through grant funding for the purpose of testing, as well as the full-scale implementation of new energy-saving technologies. NYSERDA joined forces with the New York State Environmental Facilities Corporation (EFC) to help upgrade local wastewater treatment plants with energy-efficient technologies that could meet the more stringent effluent limits.
In early 2002, a local Long Island newspaper company was in need of a wastewater treatment technology that could efficiently and cost-effectively treat their waste stream to the levels required for subsurface discharge. Their existing activated sludge system, followed by denitrification filters, was struggling to meet the required effluent. The waste stream was made up of a combination of sewage, biodegradable inks, solvents and cleaners from the printing process. In 2003, the company, in conjunction with NYSERDA, entered into the testing phase of a combined fixed film and activated sludge process from WesTech Engineering. This technology – the STM-Aerotor™ – could be easily retrofitted into the existing aeration basins with minimal modifications to the structures. Following a 6-month pilot program, the technology was deemed feasible for saving energy and providing complete nitrification and denitrification for this difficult waste stream. Today, the completed plant includes an anoxic zone, STM-Aerotors and membranes as its STM/MBR.
Even before the above treatment plant was beginning its testing phase, the Village of Greenport on the northeast tip of Long Island was evaluating technologies to prepare for the upcoming total nitrogen limit of 5 mg/L that it would be required to meet. Greenport is a tourist town with high fluctuations in population based upon the season.
For many years, Greenport utilized aerated lagoons followed by secondary clarification. Knowing that money was an issue, the Village of Greenport was able to secure NYSERDA funding for the pilot testing of the STM-Aerotor. Following a successful pilot, a full-scale plant was installed in 2010. Today, the plant is achieving high-quality effluent with a total nitrogen averaging around 3 mg/L. Moreover, the STM-Aerotor is using 30% less energy than a comparable conventional activated sludge or sequencing batch reactor (SBR) system.
While the above plants were in the midst of the testing and design work for their STM-Aerotor facilities, the Village of Patchogue, New York, was in a similar predicament regarding upcoming effluent limits and the need to find a cost-effective solution. The Mayor of the Village of Patchogue was a big driver in pushing for improvements to the effluent quality of the sewage treatment plant in an effort to protect the Patchogue River and Great South Bay. Knowing that the Village of Patchogue’s RBC treatment system would not achieve the required effluent, the Village worked to find a suitable treatment process that would be simple to operate, would achieve the required level of quality and would not have a high operating expense over the life of the system. Following their evaluation of various technologies, the STM-Aerotor was selected based on its simplicity, treatment capabilities and cost effectiveness. Moreover, the existing site was fairly tight, and the compactness of the STM-Aerotor process allowed for the construction of the system into a tight footprint, allowing the reuse of other unit processes of the existing facility. The STM-Aerotors were put into service in May, 2011. Through the care and effort of the operations staff, the Patchogue wastewater treatment plant achieves BOD and TSS levels of less than 10 mg/L and an effluent total nitrogen around 3 mg/L.