Recycle treated effluent to meet looi of the facility's non-potable water needs. nutrient removal and activated carbon adsorption.

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Griffin Ramsey
8 years ago
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1 INNOVATIVE ADVANCED T R. U m SY- ACHIEVES "ZERO DISCBARGE" Dal6 E. Chaudhary, P.E., Vice President Robert E. Hagadorn, P.E., Senior Vice President Bazen and Savyer Environmental Engineers C Scientist, Hew York When PepsiCo, Inc. chose the shore6 of the Xuscoot Reservoir in somers, New York a6 the site for it6 new World Beverage Headquarters, it vasn't hoping for an award for innovative engineering design. Proxbaity to the re"roir, a New York City water supply, however, demanded that PepsiCo build a "zero isc charge" sanitary wastevater treatment system capable of supporting a corporate facility that will ultimately ~ 1 6, ~ people. Following environmental and treatment system design considerations were established as part of overall project planning guideline.. Zero discharge due to proximity to the usc coot Reservoir,. Resenre site aesthetics and conserve space, Recycle treated effluent to meet looi of the facility's non-potable water needs.. Remaining treated effluent to recharge bed6 located under the parking lot.. High quality effluent requirement including dual nutrient removal and activated carbon adsorption.. Separate RO treatment of cooling tower blowdown to conserve water, Flexibility to expand in phases. Since effluent is reused and a portion is discharged to a subsurface leaching System, very stringent effluent levels were established as given in Table 1: 153

Proxbaity to the re"roir, a New York City water supply, however, demanded that PepsiCo build a "zero isc charge" sanitary wastevater treatment system capable of supporting a corporate facility that

2 BOD5 - mg/1-1 TSS - mg/l - 1 TKH Yng/l 3 Ammonia Nitrogen Nitrates as N - - mg/l 2 w/l - 1 PhOSphorUS a6 P - mg/l - 3 Wastewater treatment facilitier are sized for the Phase f population 2, flow of 4, gpd, with provision for expansion to the ultimate population 6, flow of 116, gpd. Design influent wastewater characteristics are as given in Table-2: i office Population - 2, Wastewater Flow - GPD BOD5 w /l TSS mg/l TIDS - mg/l Ammonia Nitrogen - mg/l Nitrates as N mg/l Phosphorus as P - mg/l - 4, The complex on-site sanitary waste treatment processes employed treat the wastewater to required levels and recycle up to 7% of the treated effluent to provide 1% of the facility's nonpotable water needs. Remaining 38 of the treated effluent is discharged to groundwater recharge beds of 38, square feet concrete chambers located under the office complex parking lot. This effectively preserves space and site aesthetics. Recycling both reduces Pepsico's water requirements and lessens the amount of groundwater recharge to the poorly permeable soils. Prelainary trea-ent processes include screening, flov equalization, primary settling, and alum addition for phosphorus removal. Next, activated sludge with single stage extended aeration substantially reduces BOD and TSS levels and provides nitrification. Denitrification is achieved in packed bed, fixed film anaerobic reactors with methanol addition and is followed by multimedia filtration and hypochlorite disinfection prior to groundwater

Design influent wastewater characteristics are as given in Table-2: i office Population - 2, Wastewater Flow - GPD BOD5 w /l TSS mg/l TIDS - mg/l Ammonia Nitrogen - mg/l Nitrates as N mg/l Phosphorus

3 di&~arge. The treated effluent targeted for recycle receives carbon adsorption for color and odor control and is re&dorinated for disinfection to create an acceptable non-potable -tur supply as illustrated in the schenratic (Figure-1). Shown on right side of the schematic is the cooling tower blovdown, reverse oslposis trea-ent system vhich also provide6 for vater recycle. Process parameters monitored include BODS, TSS, TRN, ammonia nitrogen, nitrates and phosphorus. In addition, activated sludge mhcd liquor solids, ph and temperature levels arc recorded for process control. Alum addition for phosphorus removal tends to lover the ph level requiring Caustic addition to adjust PH and restore alkalinity for nitrification. Final effluent BOD is very oensitive to methanol feed in the denitrification column and close attention i6 required to prevent overdosing. Primary sludge and vamte activated sludge is discharged to on-rite sludge holding tanks and then trucked for disposal off-site. After initial start-up adjustment in process parameters, treatment system performance continues to be in compliance with all effluent parameterb. Plant performance for the calendar year 1989 is given in Table-3. Influent Parametex merll BODS 224 TSS 335 TKN 5 Anna-N 27 Nitrate-N 9 Phosp-P 9 Effluent mcr/l Percent Removal % 94% 95. 6% % Hazen and Sawyer's design of this advanced treatment System received first prize in the 1989 New York American Consulting mgineers ~ouncil~s Engineering Excellence Competition for its ability to meet a complex set of environmental requirements. Theee included minimizing space usage and preserving the site aesthetics of the naturally wooded area, creating an effluent recycling system to accommodate limited well vater supplies, poor soil permeability, and lack of a nearby public 6ewer system; and achieving a high quality of effluent to protect the reservoir and meet the "zero discharge" requirements of a planning agreement with the City of New York. 155

the schenratic (Figure-1). Shown on right side of the schematic is the cooling tower blovdown, reverse oslposis trea-ent system vhich also provide6 for vater recycle.

4 Due to the stringent environmental requirements of the project rite, Bazen and Sawyer provided assistance b treatment process and effluent requirement negotiations vith Nev York City and Weotcheeter county officials; liasion activities to secure necessary project approvals and permits; and intensive post startup merives including operator training, operations and maintenance manual preparation, and on-going system consultation, The application of state-of-the-art technologies beyond their nom1 uses satisfied the aesthetic and environmental concerns that were the focus of this project. For Pepsico, these innovative engineering solutions vere tailored to help them continue their grovth in M environmentally responsible manner. For the engineering profession, they provide demonstration for practical application elsewhere to alleviate 6bilar environmental problems associated with growing land developen+.

and on-going system consultation, The application of state-of-the-art technologies beyond their nom1 uses satisfied the aesthetic and environmental concerns that were the focus of this project.

5 t t FIGURE 1 157

6 Case Studies

OPTIMIZING BIOLOGICAL PHOSPHORUS REMOVAL FROM AN SBR SYSTEM MIDDLEBURY, VT. Paul Klebs, Senior Applications Engineer Aqua-Aerobic Systems, Inc.

OPTIMIZING BIOLOGICAL PHOSPHORUS REMOVAL FROM AN SBR SYSTEM ABSTRACT MIDDLEBURY, VT Paul Klebs, Senior Applications Engineer Aqua-Aerobic Systems, Inc. The Middlebury Wastwater Treatment Plant, located