Florida Water Resources Journal - October 2014

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Editor’s Office and Advertiser Information:

Florida Water Resources Journal 1402 Emerald Lakes Drive Clermont, FL 34711 Phone: 352-241-6006 • Fax: 352-241-6007 Email: Editorial, editor@fwrj.com Display and Classified Advertising, ads@fwrj.com

Business Office: P.O. Box 745, Windermere, FL 34786-0745 Web: http://www.fwrj.com General Manager:

Michael Delaney

Editor:

Rick Harmon

Graphic Design Manager:

Patrick Delaney

Mailing Coordinator:

Buena Vista Publishing

Published by BUENA VISTA PUBLISHING for Florida Water Resources Journal, Inc. President: Richard Anderson (FSAWWA) Peace River/Manasota Regional Water Supply Authority Vice President: Greg Chomic (FWEA) Heyward Incorporated

News and Features 4

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Reclaimed Water Systems in Marion County: Wastewater Treatment Facility Expansions and Upgrades to Provide a Practical Alternative Water Source for Irrigation with Joint Funding From Regulatory Agencies—Douglas R. Andrews, Christopher C. Baggett, and Dennis A. Davis FWPCOA Awards FSAWWA Water Conservation Awards Call for Entries Internalizing Lift Station Rehabilitation at Toho Water Authority: A Cost Reduction Endeavor— Robert F. Pelham Bigger is Definitely Better: One Florida Utility’s Transition Into the 21st Century—Brad Macek and Richard M. Schoenborn Florida Water Festival

Treasurer: Rim Bishop (FWPCOA) Seacoast Utility Authority Secretary: Holly Hanson (At Large) ILEX Services Inc., Orlando

Technical Articles 10

Moving? The Post Office will not forward your magazine. Do not count on getting the Journal unless you notify us directly of address changes by the 15th of the month preceding the month of issue. Please do not telephone address changes. Email changes to changes@fwrj.com, fax to 352-241-6007, or mail to Florida Water Resources Journal, 1402 Emerald Lakes Drive, Clermont, FL 34711

Membership Questions FSAWWA: Casey Cumiskey – 407-957-8447 or fsawwa.casey@gmail.com FWEA: Karen Wallace, Executive Manager – 407-574-3318 FWPCOA: Darin Bishop – 561-840-0340

Training Questions FSAWWA: Donna Metherall – 407-957-8443 or fsawwa.donna@gmail.com FWPCOA: Shirley Reaves – 321-383-9690

For Other Information DEP Operator Certification: Ron McCulley – 850-245-7500 FSAWWA: Peggy Guingona – 407-957-8448 Florida Water Resources Conference: 888-328-8448 FWPCOA Operators Helping Operators: John Lang – 772-559-0722, e-mail – oho@fwpcoa.org FWEA: Karen Wallace, Executive Manager – 407-574-3318

Websites Florida Water Resources Journal: www.fwrj.com FWPCOA: www.fwpcoa.org FSAWWA: www.fsawwa.org FWEA: www.fwea.org and www.fweauc.org Florida Water Resources Conference: www.fwrc.org Throughout this issue trademark names are used. Rather than place a trademark symbol in every occurrence of a trademarked name, we state we are using the names only in an editorial fashion, and to the benefit of the trademark owner, with no intention of infringement of the trademark. None of the material in this publication necessarily reflects the opinions of the sponsoring organizations. All correspondence received is the property of the Florida Water Resources Journal and is subject to editing. Names are withheld in published letters only for extraordinary reasons. Authors agree to indemnify, defend and hold harmless the Florida Water Resources Journal Inc. (FWRJ), its officers, affiliates, directors, advisors, members, representatives, and agents from any and all losses, expenses, third-party claims, liability, damages and costs (including, but not limited to, attorneys’ fees) arising from authors’ infringement of any intellectual property, copyright or trademark, or other right of any person, as applicable under the laws of the State of Florida.

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Phased Control Allows Lake Wales to Achieve Outstanding Effluent Quality and Nitrate Removal from an Existing Oxidation Ditch Basin—John E. Olson, Ted Long, and Lewis Bryant Sustainable Aeration Design: Right-Sizing Aeration Systems and Other Methods to Facilitate Energy Efficient Operation of Wastewater Treatment Plants—Eric Stanley, Chuck Flynn, Vin Morello, Alonso Griborio, Joe Rohrbacher, and Patricia Carney

Education and Training 4 13 14 25 31 34 41 45

FWEA Collection Systems Committee Training AWWA Water Infrastructure Conference FSAWWA Conference CEU Challenge Florida Water Resources Conference Call for Papers TREEO Center Training FWPCOA Training Calendar FWPCOA Online Training Institute

Columns 17 26 30 32 34 43 44

FSAWWA Speaking Out—Carl R. Larrabee Jr. FWEA Chapter Corner—Kristi Fries and Chuck Olson Spotlight on Safety—Doug Prentiss Sr. Reader Profile—Joseph Cheatham C Factor—Jeff Poteet FWEA Focus—Kart Vaith and Amber Batson Certification Boulevard—Roy Pelletier

Departments 46 49 51

Service Directories Classifieds Display Advertiser Index

Volume 66

ON THE COVER: The redesign of the Lake Wales wastewater treatment system utilizes dissolved oxygen and oxidation reduction potential measurements to operate the aerators to meet incoming oxygen demand. Learn more beginning on page 10. (photo: Steve Eckstein)

October 2014

Number 10

Florida Water Resources Journal, USPS 069-770, ISSN 0896-1794, is published monthly by Florida Water Resources Journal, Inc., 1402 Emerald Lakes Drive, Clermont, FL 34711, on behalf of the Florida Water & Pollution Control Operator’s Association, Inc.; Florida Section, American Water Works Association; and the Florida Water Environment Association. Members of all three associations receive the publication as a service of their association; $6 of membership dues support the Journal. Subscriptions are otherwise available within the U.S. for $24 per year. Periodicals postage paid at Clermont, FL and additional offices.

POSTMASTER: send address changes to Florida Water Resources Journal, 1402 Emerald Lakes Drive, Clermont, FL 34711

Florida Water Resources Journal • October 2014

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Reclaimed Water Systems in Marion County: Wastewater Treatment Facility Expansions and Upgrades to Provide a Practical Alternative Water Source for Irrigation with Joint Funding From Regulatory Agencies Douglas R. Andrews, Christopher C. Baggett, and Dennis A. Davis

systems in the area help to further increase efficiency and reduce maintenance and operational costs.

Facility expansions are often conducted to accommodate projected future growth. With tight budgets and concerns about water shortages, several utilities are taking full advantage of expansion and upgrades to assess their systems, make their operations more efficient, and find ways to incorporate alternative water sources into their systems. Incorporating an alternative water source into a system can help to not only reduce consumption of potable water for nonpotable uses, it can also provide valuable leverage to help support funding expansions and upgrades that are often costly. The use of reclaimed water as an alternative water source continues to increase as communities seek to take advantage of its beneficial reuse and work to sustain their natural resources. Reclaimed water for public-access irrigation allows a utility to replace or augment valuable yet strained potable water supplies; therefore, improving and expanding reclaimed water systems is more important than ever. Centralizing system operations by rerouting flows from older, smaller wastewater

Marion County’s Story

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October 2014 • Florida Water Resources Journal

In 2001, Marion County Utilities Department (MCUD) acquired the Oak Run Wastewater Treatment Facility (WWTF) from DECCA, a private utility operator. At that time, the facility had already undergone one expansion—from 0.5 mil gal per day (mgd) to 0.8 mgd—to accommodate treatment and disposal needs for the area. In 2009, MCUD decided to expand this facility to a capacity of 1.6 mgd to accommodate projected future growth and to provide for rerouting of flows from other small wastewater facilities in the area so that those small plants could be removed from service or unloaded to facilitate modification. The expansion is the latest installment in MCUD's larger regionalization effort in southwestern Marion County with the goals of increasing cost-efficiency, protecting water resources, and supporting economic development. By expanding the Oak Run facility and extending the pipeline, three other smaller and less-efficient plants were shut down and the wastewater redirected to Oak Run. Because the Oak Run facility produces treated water that meets or exceeds advanced wastewater treatment standards, the quality of the water returning to the aquifer has improved, and MCUD has realized cost savings from operating one plant instead of four. Jones Edmunds provided design, permitting, agency coordination, and construction-phase services for this project, which included a 1.6-milgal (MG) reclaimed water ground storage tank, two transfer pumps, a 15,000-gal hydropneumatic tank, 3.14 mi of reclaimed water transmission main, and wastewater treatment plant (WWTP) control modifications. Construction on the Oak Run WWTP expansion was completed in May 2014. The newly expanded facility will deliver public-access reclaimed water to two golf courses in the Oak Run development, one at Spruce Creek Preserve, and multiple common areas, and will also have provisions for expanding the system in the future. This reduces or eliminates pumping of groundwater for irrigation, and further purifies the treated water as it soaks into the ground. The expansion reduces potable water use and supports regional water conservation efforts. Continued on page 6


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Continued from page 4

Reducing Expansion Costs Business expansion requires water and sewer, and MCUD’s expanded facility and pipelines have made it less expensive for new businesses to connect to necessary utilities. The total regionalization efforts in the southwestern region have cost about $27 million and included a partnership with the Florida Department of

Environmental Protection in the form of a lowinterest State Revolving Fund loan, as well as cooperative funding from developers. The reclaimed portion of the project cost approximately $4.7 million, with the Southwest Florida Water Management District providing 50 percent of the funding. The District’s regional water supply plan sets a district-wide reclaimed water long-term use goal of 75 percent of all wastewater treatment plant flows and 75 percent offset efficiency of all reclaimed water used.

A Detailed Look at the Treatment System The Oak Run Wastewater Treatment Plant consists of a 1.6-mgd advanced nutrient removal treatment facility using a four-stage bioreactor process. The bioreactor includes a primary anoxic zone, an extended aeration zone, a secondary anoxic zone, and a reaeration zone before the solids settling component. This advanced process includes complete biological treatment, as well as nitrogen removal. Tertiary filtration is used for removing dissolved nitrogen and phosphorous compounds. This process provides superior nitrogen removal and control, as well as biological treatment. These treatment components are followed by chlorine contact chambers for high-level disinfection before the effluent enters the reuse water pumping facilities.

Reuse Water Goals The reuse water replaced potable water demands used for nonpotable purposes, which included: Golf courses irrigation Residential irrigation Homeowner association (HOA) green areas and property owner association (POA) green area irrigation These golfing communities include the Oak Run Executive Golf Course, the Royal Oaks Golf Course, and the Spruce Creek Preserve Golf Course. In addition, MCUD secured a reuse agreement with the JB Ranch Subdivision for residential and common area irrigation. Reuse demands for these irrigation areas are listed in Table 1.

Integrating Rapid Infiltration Basins and Ponds for Reuse Storage Reuse storage facilities for the effluent disposal system include a combination of 16 rapid infiltration basins (RIBs) and three storage ponds. The RIBs are located at the plant site and the storage ponds are located within the golf course communities mentioned previously. A fourth storage pond serving the JB Ranch subdivision is to be located in later design phases. Reuse storage facilities are listed in Table 2 and Table 3 shows the design and construction phases. Douglas R. Andrews, P.E., is deputy director with Marion County Utilities in Ocala, Christopher C. Baggett, P.E., is a senior engineer with Jones Edmunds & Associates Inc. in Tampa, and Dennis A. Davis, P.E., is vice president with Jones Edmunds & Associates Inc. in Gainesville.

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October 2014 • Florida Water Resources Journal



FWPCOA AWARDS

Awardees Honored at Fall State Short School The Florida Water & Pollution Control Operators Association recognized several outstanding water/wastewater professionals, utilities, and facilities for operational excellence, outstanding safety records, and service to the Association during its Fall State Short School. The school was held in August at the Indian River State College in Fort Pierce.

Dr. A.P. Black Award— Water Plant Operator Award of Excellence Mike Darrow, City of Temple Terrace

Robert Hellman Award— Industrial Pretreatment Award of Excellence Paul Salerno, City of Port-Orange

Dr. A.P. Black Award— Wastewater Plant Operator Award of Excellence Glen Siler, Brevard County

Senior Systems Operators Award of Excellence, Water Distribution Jose Perez

Joseph V. Towry Award— Reclaimed Water Service Award of Excellence Jeff Collins

Senior Systems Operators Award of Excellence, Wastewater Collection Robert Kenner

Outstanding Website Award Hillsborough County Public Utilities Accepted by Eugene Merritt and Mark Grant.

SHORT SCHOOL ACTIVITIES

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October 2014 • Florida Water Resources Journal

Emory Dawkins Award— Regional Newsletter Award of Excellence Region XII— Mark Harris, editor

Utility Maintenance Award David Pachucki


SAFETY AWARDS

Bonita Springs Utilities Accepted by Sean McPartlin.

Murphree Water Treatment Plant Accepted by Tom Mikell.

Three Oaks Wastewater Treatment Facility High Point Wastewater Treatment Facility Accepted by Barry Rickoski.

Woodward & Curran Inverness Wastewater Treatment Facility Accepted by John Soula.

Woodward & Curran Water Conserv II Accepted by Steve Schwab.

Palm Coast Wastewater Treatment Plant No. 1 Accepted by Patrick Henderson.

SERVICE AWARDS

Marco Island Reverse Osmosis Water Treatment Plant Accepted by Scott Edson and Jack Green.

Northeast Regional Wastewater Treatment Facility Accepted by Chuck Nichols and Mark Lowenstine.

City of Oakland Park Stormwater System Accepted by Art Saey.

Northeast Water Reclamation Facility Accepted by Bob Case.

Lake Park Water Treatment Plant Accepted by David Hauser, Paul Kavanagh, Luis Ortega, and John Appenzeller.

Lake Worth Sewer Collection Systems Accepted by Robert Gordon.

Seacoast Utility Distribution System Accepted by Elliott Minns.

In Appreciation of Hard Work and Dedication

50+ Years of Membership, Dedication, and Support Richard Harden

Katherine Kinloch

Thomas J. King

William Allman

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Phased Control Allows Lake Wales to Achieve Outstanding Effluent Quality and Nitrate Removal from an Existing Oxidation Ditch Basin John E. Olson, Ted Long, and Lewis Bryant he City of Lake Wales is situated in the headwaters of the Everglades. Near the geographic center of the Florida peninsula along Highway 27, the Lake Wales community is located on what is known as the Lake Wales Ridge, a sandy upland area running roughly parallel to both coasts in the center of the Florida peninsula. All waters channel through this deposit in a southerly direction toward the Everglades National Park. The Everglades is an extremely delicate ecosystem that is susceptible to eutrophication caused by excessive nutrient discharges. Excessive nutrients in surface waters can lead to a large amount of algal growth, so discharges into these types of ecosystems must be of exceptional quality. The City discharges its treated effluent to groundwater through two different types of outfalls: R-001, which is a rapid rate land application system consisting of a seven-cell rapid infiltration basin system (RIB); and R002, designated as a slow-rate public access reuse system consisting of designated irrigation uses listed within the City’s permit. Treated effluent travels through the soil media of these outfalls and enters the groundwater flowing toward the Everglades. Major compounds that contribute to a wastewater’s readily available nutrient quantity are nitrate-nitrogen and phosphorus. The City’s current discharge permit limits nitrate-nitrogen (NO3) discharges to 12 mg/L and requires a quantitative study of its phosphorus discharges. This is consistent with known groundwater discharge guidelines based on the capability of the soil to remove phosphorus by absorption via its Cation Exchange Capacity (CEC), leaving nitrate-nitrogen as the major pollutant of concern for these systems. The focus of the retrofit for the existing wastewater treatment system by Lakeside Equipment Corp. (Lakeside) was to implement a design that would remove nitrate-nitrogen now and be easily upgraded in the future for biological phosphorus removal should the City’s discharge permit require phosphorus discharge control.

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Existing System In 2010, the existing treatment plant was 25 years old. The plant was in need of repairs and updating due to deferred maintenance that was not performed. This issue was identified by the City’s newly elected commissioners, who realized that work needed to be done to bring the treatment facility back to standard condition. The commission quickly approved the expenditures needed to accomplish a plant upgrade. Kimley-Horn and Associates Inc. was contracted to perform the design and make recommendations for rehabilitation and process improvements. The design approach was to listen to plant operators to fully understand the issues and include their recommendations in the process design and equipment selection. This ability to see the issues from the operator’s point of view provided an insight that is often overlooked in the wastewater treatment engineering field. Prior to project implementation, the existing treatment system consisted of headworks with mechanical screening and grit removal systems. Secondary treatment was provided by a 1.83-mil-gal (MG) oxidation ditch with rotary brush aerators, which was followed by two 65-ft diameter clarifiers. The return activated sludge (RAS) was returned from the clarifiers to the aeration basin. Tertiary filtration was provided by an automatic traveling bridge sand filtration system; the effluent was then chlorinated for disinfection prior to discharge. Waste sludge was digested in one aerobic digester with a capacity of 176,300 gal before being dewatered in a rotary drum thickener and screw press. The plant was manually operated and did not include an automated control system. The aerators were operated solely to maintain aerobic conditions, with limited focus on maintaining proper anoxic conditions for denitrification. Prior to the plant modification, nitrate levels in the effluent as high as 20 mg/L were common. A plant redesign would be required to meet the new total nitrogen discharge requirements issued in the 2012 permit.

October 2014 • Florida Water Resources Journal

John E. Olson, P.E., is regional sales manager with Lakeside Equipment Corporation in Chicago. Ted Long is an operator with City of Lake Wales. Lewis Bryant, P.E., is a project manager with Kimley-Horn and Associates in Ocala.

Process Design Considerations The engineering team carefully considered the technical aspects of the project and interviewed several manufacturers. Lakeside had extensive experience in designing phasecontrolled reactors for nutrient removal in many applications. In this specific application, the basin could be redesigned with an organic load of up to 20 lb/1000 gal to provide the additional capacity required to meet a 2.19-milgal-per-day (mgd) design flow. This higher loading would also promote the driving force required for a well operating nutrient removal system. One of the challenges that had to be met on this project was that the state of Florida required this single-basin oxidation ditch to remain in service treating wastewater throughout the construction phase; the existing limits would still be enforced throughout this time period. Because the mixed liquor suspended solids (MLSS) are mixed by the rotors as they add oxygen, the basin’s MLSS level could not even be lowered. To accomplish this tricky startup, Kimley-Horn and Lakeside’s engineering department collaborated to create a precise rotor aerator design. The aerator’s framework would have to be manufactured to exactly match the existing concrete structure. This required coordination of field measurements taken by the engineering team with Lakeside’s manufacturing team. The teamwork was successful and allowed the installation of the rotor aerators to be accomplished one at a time while the tank was in full service actively treating wastewater.


New Treatment System Redesign One of the goals of the new treatment plant redesign was to increase the design flow rate while incorporating a new Sharp™ biological control system that could meet the new permit requirement of 12 mg/L NO3–N in a cost-effective manner. The redesign started with a new fine screen to replace the existing mechanical bar screen. The fine screen was then followed by the existing grit chamber and grit removal equipment. Wastewater flow is then directed to the existing 1.83-MG oxidation ditch. The existing oxidation ditch was redesigned to include high-performance Magna-Rotor aerators to handle the increased load. Additionally, the existing rotors were retrofitted with variable frequency drives (VFDs) to allow for more precise oxygenation rates and conservation of energy use. Therefore, the ditch now has five efficiently operating Magna-Rotors, all operating on VFDs. The new biological nutrient reduction (BNR) control system was designed to monitor the basin’s oxidation reduction potential (ORP) and dissolved oxygen (DO) conditions. Flow from the ditch then travels to the two clarifiers. These were retrofitted with new sludge collection systems for optimum solids removal efficiencies. New telescoping valves were also provided to improve RAS return and waste activated sludge (WAS) control. Because of space limitations, the existing traveling bridge sand filters were retrofitted with disc filters. This resulted in increased filtration capacity within the same footprint as the existing filtration system. Also, a new 176,300-gal digester was added to the system to double the plant’s sludge stabilization process capacity. The WAS portion of the flow now initially goes to the primary digester where treatment and thickening occurs. The sludge is then transferred on to the secondary digester for further stabilization. Both of the digesters have now been upgraded to include new blowers, mixers, and controllers to allow for precise treatment of residual solids. Waste solids are processed by the aerobic digestion process, dewatered by a screw press, and loaded onto trailers for transfer for final disposal by land application. The effluent from the clarifiers is directed to two disc filters for final filtration, chlorinated for disinfection, and then discharged to either the RIBs or the public access reuse system for final disposal. The operational concept of the BNR system was to continuously monitor DO levels and adjust the rotor speed to maintain a preset DO concentration. This concept included flex-

Lakeside’s rotor as seen from the bridge of an operating rotor upstream in the channel.

Figure 1. Operational Data After Project Execution

ibility by providing a choice of two methods of operation for plant personnel: cyclic aerobic/anoxic operation and simultaneous aerobic/anoxic operation. Cyclic aerobic/anoxic operation occurs when aerobic conditions are maintained throughout the entire ditch, and biochemical oxygen demand (BOD) oxidation and nitrification occur throughout this time period. This is then followed by a period of time where anoxic conditions are maintained, allowing denitrification to occur. Simultaneous aerobic/anoxic operation occurs when both aerobic and anoxic conditions are maintained at the same time in different zones of the ditch. The location and extent of the aerobic and anoxic zones are controlled by varying the speed and duration of rotor operation, which is known as phased isolation measurement and control. The placement of the probes measuring DO and ORP is critical in allowing the programmable control system to reliably operate in this mode, allow-

ing suitable aerobic and anoxic conditions to occur within the appropriate zones of the ditch to produce maximum nitrogen removal. The BNR system configuration incorporates two DO probes and one ORP probe. The DO probe located nearest to the discharge of the oxidation ditch is the primary controller for aerobic settings. The current set point for this aerobic zone is 1.5 mg/L of DO. The ORP is measured for informational purposes, but the anoxic zone is controlled by time sequencing of the rotor and mixer operation. At the present influent flow rates (approximately 50 percent of rated capacity), the rotors are operated to maintain the 1.5-mg/L DO for approximately 60 minutes for the nitrification phase. Mixers are used during the denitrification phase to maintain proper ditch mixing velocities during this low-flow and loading condition. Continued on page 12


Continued from page 10

Results The BNR control system has proven to be very beneficial for controlling the nitrificationdenitrification processes within the single basin. Figure 1 is a tabular excerpt of data showing the plant’s BOD and total suspended solids (TSS) data since the plant retrofit was completed. The

results indicate that a very stable operation has been achieved. The discharge to the tertiary filter is consistent and stable, containing low levels of solids. Since startup, BOD and TSS removal efficiencies have averaged greater than 99.54 and 99.37 percent, respectively. Figure 2 is a graph of effluent nitratenitrogen results that have been measured since the plant was modified. The average discharge of NO3-N has been 1.99 mg/L,

Figure 2. Monthly Effluent Nitrate-Nitrogen Since Startup

with a maximum of 6.26 mg/L occurring in February 2014. The nitrate-nitrogen effluent limit of 12 mg/L has not been approached. Reduction of nitrate is possible because of the higher organic loading allowed to flow into the basin. When BOD is present but free oxygen isn’t, the microbes utilize combined oxygen, such as that found in nitrate to metabolize the food; the microbes utilize the oxygen and discharge nitrogen gas when in this condition. By manipulating the control system to maximize nitrification of ammonia in the aerobic phase of the cycle, followed by an anoxic denitrification phase, the nitrates formed can be quickly denitrified and removed from the system and a very low level of effluent NO3 can be achieved. This is a notable accomplishment for phased control in a treatment system consisting of a single aeration basin when zone separation is not physically possible. The plant’s staff has experimented with different time settings to control the amount of aerobic/anoxic staging in the ditch. The current seasonal flows have been studied and it was found that the maximum removal rate of nitrate-nitrogen was achieved when the timer was set to produce 110 minutes of aerobic treatment, followed by 60 minutes of anoxic denitrification time. This has resulted in an excellent reduction of nitrogen levels. In one of the operator’s experiments, manipulation of the cycle times also resulted in a reduction of the effluent phosphorus levels by 80 percent in April and May of 2013. However, long-term operation in this mode was not possible because of decreased effluent quality and increased nitrate levels. Since the focus of this redesign has been on nitrate reduction, the phosphorus removal mode of operation was quickly abandoned.

Conclusion

Lakeside’s biological nutrient reduction control system utilizes dissolved oxygen and oxidation reduction potential measurements to operate the aerators as needed to meet the incoming oxygen demand.

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October 2014 • Florida Water Resources Journal

The redesign of the Lake Wales wastewater treatment system has been a great success, with sorely needed maintenance and equipment replacement achieved. New equipment has been installed allowing the expected life of the treatment system to be expanded to 2030 and beyond. The design flow of the activated sludge system was successfully increased to 2.19 mgd. The flexible aeration control system has allowed the operators to discover the most effective phase control set points, allowing the system to produce an effluent that consistently meets the new discharge permit requirements, with room to spare. Most importantly, nitrate discharge levels to the environment from the City of Lake Wales are no longer a concern.


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FSAWWA SPEAKING OUT Carl R. Larrabee Jr. Chair, FSAWWA re you an inspired person? Where and to whom do you look for inspiration? Are you a source of inspiration for others? What are your aspirations? Have you been able to achieve what you’ve aspired to do? I would contend that all of these are questions we should be asking ourselves— throughout our lives. Inspiration and aspirations go together; they both drive our motivations. Motivations move us to do things. Having interesting, challenging, and beneficial things to do and then accomplishing what we set out to do make for an enriched life. And who doesn’t aspire to that! So where does one go for inspiration? You might look to others who recognize and develop good ideas, have wisdom and good judgment, and have an established record of accomplishments. You might look for recurring problems that cause loss of life, property damage, or lost productivity. If something can be done at lower

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What Inspires YOU? cost, easier, quicker, or more reliably, discover and develop a solution! Here’s one issue to get you thinking, for practice. In Florida, it rains more than 50 inches a year, on average. During the rainy season, many areas that had collected standing water now drain the water downgradient from swales, ditches, canals, and rivers into lower elevation water bodies: lakes, estuaries, and the ocean. The normal solution would be to get that water to drain downgradient quicker. What if, instead, areas upgradient were found to store and/or percolate the water before it drained downhill? This very concept was used by the City of Cocoa to alleviate flooding episodes on both a state and a local road. Runoff from upgradient roadways and developed properties built prior to current stormwater rules overloaded the capacity of drainpipes. Frequent summer storms caused traffic backups and stalled vehicles. The cost of replacing the pipes, some located in downtown areas under the state road, was astronomical.

The solution chosen was to find areas located within the drainage basin and convert them to dry retention/percolation ponds. A number of city properties were identified, including a portion of a fire station site. Stormwater inlets were constructed to divert runoff into these excavated and sodded areas. Once completed, the roadways no longer flooded, the surficial aquifer received more water from rainfall events, and the volume of freshwater and nutrients going into the Indian River Lagoon diminished. The main ingredient needed to accomplish this particular challenge is inspired water professionals. If this is something you aspire to do, start looking around for opportunities. If this isn’t it, that’s fine. Recognize that the possibilities for improvements around you are endless and the satisfaction for making them is enormous. Constantly look for places to apply your knowledge and abilities. Seek out people to inspire you to do great things. While you’re at it, look for opportunities to inspire others along the way!

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Sustainable Aeration Design: Right-Sizing Aeration Systems and Other Methods to Facilitate Energy Efficient Operation of Wastewater Treatment Plants Eric Stanley, Chuck Flynn, Vin Morello, Alonso Griborio, Joe Rohrbacher, and Patricia Carney lectricity comprises a significant portion of operating costs for the water industry in the United States, with approximately 3 percent of energy consumed by water and wastewater treatment plants (Krause et al., 2010). It is well known that the aeration treatment process is typically the largest consumer of energy at conventional wastewater treatment plants; 70 percent of plants exceeding 2.5 mil gal per day (mgd) utilize activated sludge secondary treatment, and 45 to 75 percent of electricity use is consumed for aeration treatment (Rosso and Stenstrom, 2006). Improving the efficiency of aeration can result in significant cost and energy savings to utilities in Florida—and beyond. The sizing of aeration systems is often based on maximum flow and load in worstcase scenarios, whereas actual conditions are typically far below design conditions. Aeration blowers are often oversized and cannot efficiently operate under low loading conditions. Aeration basins are also often oversized, with excessive diffusers installed, and aeration system operation can be driven by mixing requirements rather than process aeration demands. Sustainable aeration system design requires that the full range of flow, load, and ambient temperature conditions be considered.

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Changes in aeration efficiency over time due to diffuser fouling and wear also need to be considered. Key elements of sustainable aeration system design include: Providing flexible aeration basin designs to match volumetric capacity to influent flows throughout the life of the system Providing multiple sizes of blowers to ensure adequate turndown and optimal efficiency throughout the range of operation Providing an effective control system to match blower operation to process aeration and mixing requirements Most of the sustainable design methods discussed in this article, including anoxic zones and activated sludge foul air diffusion, were installed at the Broward County North Regional Wastewater Treatment Plant (WWTP) Module C in 2004. Based on the successful track record of operation of this WWTP, the nearby Plantation Regional WWTP decided to implement a similar sustainable system and has recently completed the design phase for conversion from mechanical aeration to fine bubble diffused aeration. The Plantation Regional WWTP system, which incorporates the recommendations discussed in this article, is illustrated in Figure 1.

Figure 1. Plantation Regional Wastewater Treatment Plant Right-Sized Aeration System

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Eric Stanley, P.E., is a senior principal engineer with Hazen and Sawyer in Boca Raton. Chuck Flynn is director of utilities with City of Plantation Utilities Department. Vin Morello, P.E., is project manager with Broward County Water and Wastewater Services. Alonso Griborio, Ph.D., P.E., is an associate, and Patricia Carney, P.E., is a senior associate, with Hazen and Sawyer in Hollywood. Joe Rohrbacher, P.E., is a senior associate with Hazen and Sawyer in Charleston, S.C.

Fine Bubble Diffusers Fine bubble diffused air systems are typically more efficient at oxygen transfer than mechanical aeration or coarse bubble diffused air technology. The reason for this is that the smaller bubble size produced by fine bubble diffusers has a higher surface-area-to-volume ratio, which allows much higher oxygen transfer per unit volume of air than other technologies. Design considerations for right-sizing fine bubble diffuser systems include: Diffuser Tapering - Each zone/cell in an aeration basin has a specific air demand as the oxygen demand varies due to changes in organic load down a plug flow biological reactor. Alpha, or the ratio of oxygen transfer between dirty and clean water, will also typically vary along the reactor length. A tapered aeration diffuser layout configures the diffusers to follow the oxygen demand profile in the reactor. Thus, more diffusers should be located at the influent end (i.e., highest load and oxygen demand) and be tapered or reduced towards the effluent end of the reactor. Process simulation software, such as BioWin™, can be used to simulate oxygen uptake rates for each cell to determine the oxygen demand among the zones/cells of the aeration basin.


Diffuser Density - Because diffuser systems are often created for a design flow that will not occur until 20 or more years in the future, they can sometimes be oversized. In general, the lower the airflow per diffuser, the greater the standard oxygen transfer efficiency (SOTE). A higher diffuser coverage on the basin floor, also known as diffuser density, also results in a greater SOTE. This may lead some designers to provide too many diffusers in current conditions, which may result in uneven air distribution, especially during nighttime and early morning low-flow conditions as the airflow struggles to overcome the head loss across the diffuser membrane. In the case of 9-in. membrane disc diffusers, uneven air distribution occurs below approximately 0.5 cu ft per minute (cfm) per diffuser. This condition is worsened with fouling. To remedy this, diffuser grids should be designed with spare saddles to add diffusers for future loadings. Existing diffuser systems that are determined to currently have too many diffusers can have surplus diffusers plugged. Avoid Minimum Mixing Limitations - It is required to maintain a minimum level of aeration at all times to maintain minimum mixing requirements. For a full-floor grid, 0.1 cfm/sf of basin floor area is a typical value for providing adequate mixing (Mueller et al., 2002; Krause et al., 2010). During low-flow and loading conditions, the air demand can often drop below the minimum mixing level. At this point, it is necessary to provide air beyond that demanded for adequate wastewater treatment, which results in wasted energy. If the same wastewater loading could be achieved in a lower aeration basin volume/floor area, the minimum mixing airflow requirement would be reduced and the aeration demand of the wastewater would be controlled. Sustainable aeration system design consideration should balance the “more and smaller” basin approach with the “less and larger” basin approach to prevent the need to operate in minimum mixing mode as best as possible. Note 1 in Figure 2 demonstrates the minimum mixing requirements of an aeration system with six basins online, versus an aeration system with four basins online. In this example, it is apparent that if four basins are operated, the system can operate at a substantially lower-flow rate during low air demand periods, resulting in substantial energy savings. Reduce Fouling - Diffuser fouling can significantly reduce oxygen transfer by affecting bubble geometry and increasing the pressure loss in the system, resulting in decreased diffuser efficiency. Fine bubble membrane diffuser manufacturers typically recommend that aeration basins be taken out of service annually to have the diffusers hosed down and any

Notes: 1. “More and smaller” instead of “less and larger” basins are provided, allowing basins to be brought offline to meet current or low-season design loadings and preventing wasted energy to provide minimum mixing of 0.1 cfm/sf 2. Fouled, nonmaintained diffusers can raise the pressure requirement of the system, resulting in wasted energy 3. With both “small” and “large” blowers, a gap in airflow is avoided and a more efficient operation results 4. Maximum-month average daily loading is met with one unit out of service, and maximum-day loading with all units in service 5. The system is designed to only provide 0.5 to 1.0 milligrams per liter (mg/L) dissolved oxygen (DO) concentration during maximum-day loadings

Figure 2. Typical Sustainable Aeration System Blower Curve Plot for Multistage Centrifugal Blowers

biofilm brushed off. Studies have shown that the cost and energy savings achieved by a biannual or annual regular diffuser cleaning routine more than compensate for the time and material investment by plant owners. Note 2 in Figure 2 shows the effect of a nonmaintained diffuser system. Note that the amount of pressure required to meet the same flow rate can be increased by as much as 0.5 pounds per sq in. (psi) according to diffuser manufacturers, resulting in wasted energy.

Blower Systems Traditional blower technologies used for aeration in biological treatment processes include positive displacement, multistage centrifugal, and single-stage integrally geared centrifugal blowers. Hybrid rotary lobe-screw positive displacement blowers and high-speed single-stage centrifugal

blowers have been introduced into the municipal wastewater market as more energy efficient alternatives to traditional rotary-lobe positive displacement and multistage centrifugal blowers. The appropriate blower technology for each facility depends on multiple factors, and is best determined on a case-by-case basis. Hazen and Sawyer has conducted several studies evaluating performance and capital/operation and maintenance (O&M) costs for multistage centrifugal blowers, turbo blowers, and single-stage integrally geared blowers. These studies have resulted in the following general conclusions: Turbo blowers are generally more efficient than multistage centrifugal blowers, although the advantage is not nearly as pronounced when multistage blowers are allowed to run near their design capacity for maximum efficiency. Continued on page 20

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Continued from page 19 Turbo blowers are typically not as efficient as single-stage integrally geared blowers. Turbo blowers, multistage blowers, and integrally geared blowers are generally competitive against one another in terms of total net present-worth costs, depending on specific project conditions and capacity requirements. Replacement of existing blowers with new, more efficient blowers, just for the sake of improving efficiency, generally does not have a favorable payback period due to the high capital cost involved. Once a blower is at the end of its service life, it makes sense to consider replacement with a more efficient technology available at that time. Considerations for sustainably designing blower systems include: Blower Configuration to Avoid Performance Gaps - The ratio of minimum-to-maximum oxygen demand within a typical activated sludge process varies from approximately 3:1 to 5:1 between the peak and off-peak hours. For smaller plants the ratio can be as much as 16:1 (Tchobanoglous et al., 2003). As wastewater flow and strength fluctuate, there is a corresponding fluctuation in the amount of oxygen required to provide treatment over the course of the day. As a result, aeration blowers that are sized to meet average and maximum daily loads may not efficiently operate under low loading conditions. A sustainable blower system should be capable of providing the entire range of required airflows with minimal gaps in coverage, from maximum-day to minimum-day design flow. Multistage centrifugal and high-speed direct drive blowers often cannot be turned down lower than 50 percent of their design flow rate, which results in gaps in the blower system’s air flow rate capacity. A solution to this is to install two separate size blowers when using multistage centrifugal or a high-speed direct

drive blower, with the smaller blower having 50 to 80 percent capacity of the larger blowers. At least two blowers of each size should be provided for redundancy and to maintain full coverage. Turndown to minimum mixing should also be considered, as this often controls during low overnight flows. Note 3 in Figure 2 demonstrates that with only large 300 hp blowers installed, an operational gap of 1,200 cfm is encountered between the one- and two-blower operating condition. If the system is frequently operating within this lower airflow range, anytime the airflow demand falls within this range, energy is wasted. With both small and large blowers, the gap in airflow is avoided, and a more efficient operation results. Defer Installation of Equipment - Blower systems are often created for a design flow that will not occur until 20 years, or more, in the future. This can result in a blower system with multiple idle blowers, incurring unnecessary capital and maintenance costs. Sometimes regulations require adequate blower capacity to be installed, even if this results in idle equipment. If permit conditions allow, it is good practice to provide enough blower capacity to meet intermediate flow and loading rates, while leaving room on the blower pad or blower building for installation of future blowers. Figure 3 demonstrates a blower system at the City of Plantation Regional WWTP, with planned room for a future fifth blower; it also shows the typical layout of two large 350 horsepower (hp) and two small 200 hp blowers at the plant. Avoid Oversizing the System by Setting Appropriate Key Design Criteria - The blower system should be sized so that with the largest unit out of service, it can still satisfy the oxygen requirement of the system under most conditions. To reduce capital costs and the need for extraneous blower capacity, it may be permissible to allow the system to satisfy maximum-

Figure 3. Typical Sustainable Blower System Layout at Plantation Regional Wastewater Treatment Plant

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month or maximum-week average daily loading with one unit out of service, and maximum-day loading with all units in service. As an additional way to reduce the size of the aeration system, it is typical to allow the system to provide 0.5 to 1.0 mg/L of oxygen concentration in the aeration basins during design maximum-day loadings, as opposed to the typical 2 mg/L DO for lesser loadings (Mueller et al., 2002). The example in Figure 2, Note 4 demonstrates that maximum-month loading is met with the largest unit out of service, while maximum day is met with the largest unit in service. Note 5 in Figure 2 indicates that the maximum-day aeration capacity calculated is based on 0.5 mg/L. Note that increasing the DO requirement at maximum-day loading would result in the need for an additional blower. Determine Appropriate Design Weather Conditions - The maximum-day design flow and associated head loss through the piping and diffuser system define the design point for the blowers. Because hotter air is less dense and has less oxygen per unit volume, the blower system must provide a high enough flow rate to supply adequate oxygen for the hottest summer day. Because colder air contracts, but blowers intake a constant volume of air, the blower motors should also be sized to handle denser winter air so that they are nonoverloading over the entire range of operation. Also affecting oxygen transfer is humidity, because moisture contained in a unit volume of air displaces oxygen. If a blower is sized for correct inlet temperature and pressure, but does not consider humidity, the blower will deliver the correct maximum volume of air but will be undersized to deliver the design maximum oxygen flow rate. However, incorrectly using relative humidity can also result in oversized blowers. A common mistake when sizing blowers is to use a high or maximum relative humidity, such as in the range of 90 to 100 percent, in combination with a maximum design temperature. Relative humidity in this range is possible, but only at temperatures much lower than the maximum design temperature. A psychrometric chart should be used with the design dry bulb temperature and wet bulb temperature to determine design relative humidity. Design wet bulb data for representative cities of a geographical location are available from the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE). The design dry bulb temperature should be the design maximum temperature for the system, which in this case is also taken from the ASHRAE charts. Based on the preceding discussion, typical design


weather conditions for a blower system in south Florida are provided in Table 1. An existing blower system was recently evaluated at a large WWTP in Florida. The existing blower system was installed in the 1980s, and upgraded in the 1990s. The ceramic fine bubble diffusers are located in basins that require dewatering of the shallow underlying aquifer (approximately 5 ft below grade) to prevent flotation of the thin concrete floors of the basins. Because of the difficulty in dewatering, the diffusers are generally not cleaned or maintained, which increases the head loss due to fouling. Upon examination of the blower curves, it was apparent that the existing blowers were both pressure-limited at hot weather conditions and the motors were undersized for cold weather conditions. Indeed, the plant staff reported that, in the summertime, surge conditions occasionally occurred during hot weather, making it necessary to shut down the blowers. Furthermore, plant staff reported that, during cold weather, the horsepower limitation of blowers is reached due to the increased air density, making it necessary to limit blower flow rate by inlet throttling to prevent the blower motors from overloading. The evaluation resulted in a recommendation to right-size the system by installing new blowers, or to potentially modify the existing blowers with new impellers and/or motors.

Table 1. National Oceanic and Atmospheric Administration (NOAA) and ASHRAE Weather Design Conditions for West Palm Beach

Table 2. WEFTEC Paper Survey of Energy Savings Available Through Implementing Automatic Dissolved Oxygen Control

Controls As wastewater flow and strength fluctuate, there is a corresponding fluctuation in the amount of oxygen required to provide treatment. It is common to maintain a DO level of 1 to 3 mg/L in aeration basins to ensure that adequate oxygen is supplied to sustain the microorganisms in the wastewater. The most simple DO control strategy is manual control, where operators take periodic manual readings of DO or other related parameters, then manually adjust valve or blower settings to meet the required oxygen level. However, because operators typically conservatively set the airflow to the maximum worst-case airflow demand incurred during peak flow and wastewater strength, the result is that, during many times of the day, DO levels higher than 1 to 3 mg/L are supplied, resulting in wasted energy. A typical automatic DO control strategy utilizes DO sensors to continuously take readings and feedback signals to a controller that automatically adjusts airflow to maintain a predetermined set point (typically 1 to 3 mg/L) by continuously adjusting the blowers and/or air distribution control valves to each basin. As such, implementing automated DO control can greatly reduce electricity costs, operator work-

load, and help to maintain consistent effluent quality. A literature review of DO control implementation papers presented at the Water Environment Federation Technical Exhibition and Conference (WEFTEC) was recently compiled. A summary of the various strategies implemented are presented in Table 2 to demonstrate various methods of implementing aeration controls and the energy savings achieved.

Anoxic Zones/Denitrification Incorporation of anoxic zones upstream of aerated zones can provide substantial benefits to conventional nitrification facilities that are not yet required to meet nutrient limits. Since many facilities in Florida that are not required to nitrify do so anyway, due to the yearround high temperatures and resulting increased microbial kinetics, why not reap the

benefits of subsequent denitrification? These benefits include decreased aeration requirements, improved solids settleability, and alkalinity recovery as described: Denitrification in an Anoxic Zone Reduces the Aeration Requirements of the System - Implementing and/or improving the denitrification capability of the secondary process will result in a reduction in process aeration demands. Conversion of ammonia to nitrate-nitrogen (NO3N) requires 4.57 lbs oxygen per lb ammonia-nitrogen (NO3-N) oxidized to NO3N. Denitrification of nitrate to nitrogen gas under anoxic conditions reduces oxygen requirements through consumption of influent readily biodegradable carbon as an electron donor. This reduction in organic carbon loading decreases the amount of oxygen required in the aerobic zone by 2.86 lb of oxygen per lb Continued on page 22

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Continued from page 21 NO3-N reduced to nitrogen gas (N2). Significant savings in aeration can be achieved by providing an anoxic zone upfront of an aerobic zone for denitrification of the return activated sludge. Denitrification in an Anoxic Zone Reduces the Overall Consumption of Alkalinity (and Subsequent pH Suppression) - The nitrification process consumes 7.1 grams of alkalinity (as CaCO3) per gram of NH3-N oxidized to NO3N. This alkalinity is partially recovered through denitrification at a rate of 3.6 grams of alkalinity (as CaCO3) per gram of NO3-N reduced to N2, resulting in a net loss of 3.5 grams of alkalinity (as CaCO3) per gram of

nitrogen removed through the nitrification/denitrification process. Nitrification without subsequent denitrification will decrease alkalinity almost twice as much as nitrification, followed by denitrification. A reduction in alkalinity results in a decrease in the wastewater pH, which may decrease the nitrification capacity of the process, in addition to potential effluent quality violations. Denitrification in an Anoxic Zone can Increase the Settleability of the Mixed Liquor - Implementation of an initial unaerated zone can also improve secondary solids settleability by providing an anoxic selector to preclude the growth of filamentous bacteria and select for

Figure 4. Broward County North Regional Wastewater Treatment Plant Sludge Volume Index Before and After Anoxic Zones Table 3. Broward County North Regional Wastewater Treatment Plant Estimated Savings Due To Reduction in Oxygen Demand

Table 4. Plantation Regional Wastewater Treatment Plant Activated Sludge Foul Air Diffusion Savings

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bacteria that form tight, dense flocs with good settling properties. Filamentous bacteria can form bridges between flocs, keeping them in suspension and decreasing secondary clarifier performance. Many filamentous bacteria use readily biodegradable carbon very efficiently, but cannot utilize these substances under anoxic conditions where nitrate (and not oxygen) is an electron acceptor (Grady et al., 1999). The anoxic selector allows for the removal of readily biodegradable organic matter under conditions where filamentous organism growth is restricted. Aerated zones with membrane fine bubble diffusers can be converted to an anoxic zone with relatively little capital investment. A motor-operated modulating valve can be installed on the aeration piping drop leg to the anoxic zone, and the valve can be programmed to periodically open and bump the anoxic zone for a short period of time to maintain mixing. Valves in the anoxic zones for each basin can be programmed to operate sequentially to avoid sudden destabilizing increases in aeration demand. Ceramic diffusers may be more prone to fouling in this situation. Anoxic Zones at Broward County North Regional Wastewater Treatment Plant The Broward County North Regional WWTP is rated to treat an average flow of 100 mgd and is composed of five individual activated sludge modules (20 mgd/module), each comprising four aeration trains. A pilot program was conducted from February through July of 2009 to evaluate the ability of the facility to operate with an anoxic zone with no physical improvements and only process modifications. The pilot study also tested the effectiveness of the anoxic selector to improve the settleability of the activated sludge. As a part of this study, air was turned off to the first grid of membrane fine bubble diffusers to create an anoxic selector at the front of Module C. Operations staff turned on the first diffuser grid for 10 minutes every two hours to bump the basin and keep the solids in suspension. The upstream cell of trains 2 and 3 of the four trains in Module C were operated in the unaerated mode for six weeks, with trains 1 and 4 operated in fully aerated mode, and the performance of Module C was monitored for nitrogen removal. Sludge volume index (SVI) values were monitored during the pilot operation. The SVI trend presented in Figure 4 confirms that the anoxic selector zone considerably improved the settleability of the activated sludge in Module C. Further details of this evaluation and pilot study are available (Griborio et al., 2009). The results of the nitrogen removal in the trains with the anoxic zones, compared to the


fully aerated trains, was significant, as demonstrated in Table 3. Assuming an average multistage centrifugal blower efficiency of 62 percent operating 10 minutes every two hours it is anticipated that this level of denitrification would account for a reduction in airflow and power, resulting in over $25,000 per year of annual savings for Module C alone.

Activated Sludge Foul Air Diffusion for Odor Control Activated sludge foul air diffusion is a rarely used, but viable, option for odor control in lieu of conventional odor control, such as chemical scrubbers or bioscrubbers. Utilization of activated sludge foul air diffusion can result in significant savings in capital, operation, and maintenance costs by avoiding the need for odor control vessels and chemicals and has been implemented successfully at many locations throughout the country. The diffusion involves conveying foul air to the suction of aeration blowers and diffusing it through the fine bubble diffuser system into the mixed liquor. The odors are removed by a combination of mechanisms including absorption, adsorption, condensation, and biological oxidation in the basins. Typical odor removal efficiencies are reported in the 80–99 percent range for moderate- to high-strength odors. Odorous contaminants are absorbed into the activated sludge mixture due to the fine bubble diffusion and microorganisms present in the activated sludge, converting the hydrogen sulfide (H2S) into the sulfate (SO42-) form. This process is limited by the efficiency of the absorption of the gases from the vapor phase into the liquid phase and pH. Under the activated sludge diffusion scenario, there are several design considerations to keep in mind: A fan should be provided near the source of odor to convey air to the blower system through the suction piping. Aeration blowers and any equipment located within 3 ft of foul air may be required to be explosion-proof-rated (subject to interpretation and local code requirements) since they may be handling odorous foul air from a classified area. Grease filter/mist eliminators should be provided upstream of the blowers to protect the blower components. Aeration blowers should be constructed of materials or provided with coatings (such as heresite) on internal surfaces to prevent corrosion. Additionally, aeration piping should be made of 316 stainless steel to help prevent corrosion. Continued on page 24 Florida Water Resources Journal • October 2014

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Continued from page 23 Activated Sludge Foul Air Diffusion at Plantation Regional Wastewater Treatment Plant Based on the successful operation of an activated sludge foul air diffusion system at the Broward County North Regional WWTP Module C in 2004, the nearby Plantation Regional WWTP decided to investigate the benefits of installing a similar system. A capital cost analysis presented in Table 4 predicted that the City of Plantation will realize a net present worth savings of over $1.4 million by implementing an activated sludge foul air diffusion system instead of chemical scrubbers.

References • Brogdon, Jennifer et al., 2008. Enhancing the Energy Efficiency of Wastewater Aeration. WEFTEC 08 Conference Proceedings, Alexandria, Va., WEF Press. • Grady, C. P. L., Daigger, G. T., Lim, H. C., (1999) Biological Wastewater Treatment, 2nd ed. New York: Marcel Dekker Inc. • Griborio, A., Harris, R., Vinci, P., Pitt, P., Aliseo, R., Field Testing and Cost-Benefit Analysis of Anoxic/Anaerobic Selectors. 2009 Water Environment Federation Technical Education Conference (WEFTEC), Orlando, Fla., October 13, 2009. • Krause, Terry L. et al., 2010. Design of Muncipal Wastewater Treatment Plants: WEF Manual of Practice. • Liu. W. et al., 2005. Side-by-Side Comparison Demonstrated a 36 Percent Increase of Nitrogen Removal and 19 Percent Reduction of Aeration Requirements Using a Feed Forward Online Optimization System. WEFTEC 2005 Conference Proceedings, Alexandria,Va., WEF Press. • Moise, Mark and Morris, Mark, 2005. Process Optimization and Automation Improves Reliability and Cost Efficiency of Oxnard WWTP. WEFTEC 2005 Conference Proceedings, Alexandria, Va., WEF Press. • Mueller, James A. et al., 2002. Aeration: Principles and Practice. Boca Raton: CRC Press. • Rosso, Diego and Stenstrom, Michael K. 2006. Economic Implications of Fine-Pore Diffuser Aging. Water Environment Research, Volume 78, No. 8 (August): 810-815. • Tchobanoglous, George et al., 2003. Wastewater Engineering: Treatment and Reuse, Fourth Edition, New York: McGraw Hill. • Walz, Thomas et al., 2009. Energy Savings at Phoenix 23rd Avenue Wastewater Treatment Plant Using Feed-Forward Process Control, WEFTEC 2009 Conference Proceedings, Alexandria, Va., WEF Press.

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Operators: Take the CEU Challenge! Members of the Florida Water & Pollution Control Association (FWPCOA) may earn continuing education units through the CEU Challenge! Answer the questions published on this page, based on the technical articles in this month’s issue. Circle the letter of each correct answer. There is only one correct answer to each question! Answer 80 percent of the questions on any article correctly to earn 0.1 CEU for your license. Retests are available. This month’s editorial theme is New

Facilities, Expansions, and Upgrades. Look above each set of questions to see if it is for water operators (DW), distribution system operators (DS), or wastewater operators (WW). Mail the completed page (or a photocopy) to: Florida Environmental Professionals Training, P.O. Box 33119, Palm Beach Gardens, FL 33420-3119. Enclose $15 for each set of questions you choose to answer (make checks payable to FWPCOA). You MUST be an FWPCOA member before you can submit your answers!

___________________________________________ SUBSCRIBER NAME (please print)

Article 1 ________________________________________ LICENSE NUMBER for Which CEUs Should Be Awarded

Article 2 ________________________________________ LICENSE NUMBER for Which CEUs Should Be Awarded

If paying by credit card, fax to (561) 625-4858 providing the following information:

Earn CEUs by answering questions from previous Journal issues!

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Contact FWPCOA at membership@fwpcoa.org or at 561-840-0340. Articles from past issues can be viewed on the Journal website, www.fwrj.com.

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Phased Control Allows Lake Wales to Achieve Outstanding Effluent Quality and Nitrate Removal from an Existing Oxidation Ditch Basin John E. Olson, Ted Long, and Lewis Bryant

(Credit Card Number)

(Expiration Date)

Sustainable Aeration Design: Right-Sizing Aeration Systems and Other Methods to Facilitate Energy Efficient Operation of Wastewater Treatment Plants

(Article 1: CEU = 0.1 WW)

Eric Stanley, Chuck Flynn, Vin Morello, Joe Rohrbacher, Alonso Griborio, and Patricia Carney

1. The permitted nitrate nitrogen concentration limit for this facility is ___ mg/l. a. 2 b. 5 c. 12 d. 20

(Article 2: CEU = 0.1 WW)

2. In this specific application, the oxidation ditch basin could be redesigned for an organic loading rate of _________ lb. /1,000 gal. a. 20 b. 40 c. 60 d. 80 3. Which of the following probes is the primary controller for aerobic settings in the redesigned oxidation ditch? a. Dissolved oxygen b. Oxidation/reduction potential c. pH d. Channel velocity 4. In which treatment phase are the bulk of nitrates removed? a. Aerobic b. Anoxic c. Primary sedimentation d. Secondary clarifier 5. The primary environmental concern requiring a reduction in this facility’s effluent nitrate concentration is a. impaired surface waters to which effluent was directly discharged. b. a threat to the city’s drinking water supply. c. potential nutrient contribution to Everglades National Park. d. nuisance weed control in rapid infiltration basins and receiving waters.

1. Studies have revealed which of the following type blowers to be most efficient? a. Turbo b. Multistage centrifugal c. Single-stage integrally geared d. Rotary lobe positive displacement 2. Many filamentous bacteria cannot use readily biodegradable carbon under ___________ conditions where nitrate is an electron acceptor. a. low pH b. high pH c. oxygen rich d. anoxic 3. Fine bubble diffuser manufacturers typically recommend _______________ hosing and brushing of diffusers. a. annual b. semi-annual c. quarterly d. biennial 4. Typical aeration system design provides for a dissolved oxygen concentration of _____ mg/l at maximum daily load. a. 0.5 b. 1.0 c. 1.5 d. 2.0 5. A ______________ aeration diffuser layout is one in which the diffusers follow the reactor oxygen demand. a. symmetrical b. uniform c. tapered d. proportional Florida Water Resources Journal • October 2014

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FWEA CHAPTER CORNER Welcome to the FWEA Chapter Corner! Each month, the Public Relations Committee of the Florida Water Environment Association hosts this article to celebrate the success of recent association chapter activities and inform members of upcoming events. To have information included for your chapter, send the details via email to Suzanne Mechler at MechlerSE@cdm.com.

Suzanne Mechler

Central Florida Chapter 15th Annual Scholarship Golf Tournament is a Great Success Kristi Fries and Chuck Olson

Kim Krutski and two of her teammates from the Atkins team celebrate on the course just after she won the women’s longest drive competition. Pictured in photo from left to right are Ken Poole, Kim Krutski, and Chester Wendrzyk.

he Central Florida Chapter of FWEA held its 15th Annual Scholarship Golf Tournament on August 22 at Falcon’s Fire Golf Club. The proceeds from the tournament benefit the Gabe Delneky Scholarship Fund and the Norm Casey Scholarship Fund, which are both for local students pursuing engineering degrees at the University of Central Florida. The tournament is funded by donations from both sponsors and competitors. This year’s event was highly successful as 94 golfers participated in the event and $4,500 was raised for the fund. It was a fierce competition throughout the day, but the following teams came away victorious: The first-place team, from URS Corporation, included Craig Fuller, Dave Wilcox, Tim Todd, and Kevin Goolsby. The Tetra Tech team, consisting of Gary ReVoir, Chris Fasnacht, Brett Messner, and Tommy Howes, secured second place.

T

The URS Corporation team, consisting of (from left to right) Tim Todd, Dave Wilcox, Craig Fuller, and Kevin Goolsby, secured first place.

The second-place team, from Tetra Tech, included (from left to right) Gary ReVoir, Chris Fasnacht, Tommy Howes, and Brett Messner.

Tommy Howes (from the Tetra Tech team) won the closest-to-the-pin competition.

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Craig Fuller (from the URS Corporation team) won the men’s longest drive competition.

October 2014 • Florida Water Resources Journal

The individual contest winners were: Craig Fuller (URS Corporation team) for men’s longest drive Kim Krutski (Atkins team) for women’s longest drive Tommy Howes (Tetra Tech team) for closest to the pin Keith Morrison (National Water Main Cleaning Co. team) and Kenny Blanton (Black & Veatch team) took home a cash prize for being the putting contest winners, each having a hole-in-one.

The Central Florida Chapter would like to gratefully thank all of the sponsors and participants involved in the event. We are very proud of our success and it is due to the support of our sponsors and participants in the tournament. The Platinum sponsors were: Atkins BFA Environmental Consultants Black and Veatch CPH Inc. Garney Companies Hydra Service Inc. Moss-Kelley National Water Main Cleaning Company R.C. Beach & Associates Tetra Tech URS Corporation USSI The Gold sponsors were: Hanson Pressure Pipe Reiss Engineering The Silver sponsors were: Barney’s Pumps Carollo Engineers EnviroSales of Florida The Bronze sponsors were: HDR MTS Environmental Electrical Design Associates Thanks also to the Central Florida Chapter Golf Tournament Committee consisting of Kristi Fries (chair), Greg Kolb (FWEA Central Florida Chapter chair), Kenny Blanton, Nicole Quinby, Angel Martin, Alyssa Filippi, Danielle Sikes, Elizabeth Seitz, Christie Hesse, Sandra Kiser, Chuck Olson, Tony Bray, and Da Yu.


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Internalizing Lift Station Rehabilitation at Toho Water Authority: A Cost Reduction Endeavor Robert F. Pelham Toho Water Authority (TWA) is a water, wastewater, and reuse utility located in Osceola County, with service extending into Polk County and Orange County. Lift station rehabilitation projects for TWA have historically been designed by engineering consulting firms and competitively bid to construction contractors. The Authority has added customer value to its wastewater lift station rehabilitation program by annually internalizing the design and construction of eight rehabilitation projects. This article discusses the development of a pilot lift station rehabilitation program—designed and constructed by staff— and the transition to a permanent program.

Pilot Program The lift station rehabilitation pilot program team included representatives from TWA’s engineering, purchasing, finance, field services, and maintenance divisions. Specifically, two professional engineers, an engineering manager, and an engineering technician designed three pilot program lift stations. Electrical, structural, and surveying services, when required, were provided by consulting firms. The pilot program construction team consisted of two temporarily assigned employees, one each from TWA’s maintenance and field services divisions. The Authority did not have an experienced lift station construction manager; subsequently a contract employee was retained to lead the construction effort. The contract em-

ployee agreement included two lift station rehabilitation projects and one lift station upgrade project. The contract employee provided necessary tools and equipment, excluding lift station bypass pumping, which was provided by TWA, and management of the following construction disciplines that were competitively bid: Wet well wall rehabilitation High-density polyethylene pipe (HDPE) pipe fusion Electrical Site fencing The contract employee preconstruction services included material quantity takeoffs and constructability reviews; TWA staff provided bidding services, including issuance of purchase orders. The pilot program rehabilitation project was completed, averaging 11 weeks per lift station. The stations were similar in size and complexity to a consultant-designed and competitively bid lift station project of six lift stations. The pilot program resulted in an average savings of $15,419 in nonconstruction costs and $26,277 in construction costs, totaling $41,396 per pump station. Nonconstruction costs for TWA include personnel costs, with labor burden covering engineering, purchasing, and finance staff, and the design consultant’s cost. Engineering staff and design consultant construction administration services are included in construction costs. The Authority elected to extend the pilot program to include three additional pump stations. The temporarily assigned TWA con-

* The cost of the pilot program design incorporates development of documents that are reused on subsequent projects.

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struction staff was replaced with full-time, nonpermanent employees, and the contract employee agreement was extended to include the lift stations. Additionally, a HDPE fusion machine was purchased, eliminating the need for this subcontracted discipline. Amortization cost of the TWA-supplied lift station bypass and HDPE fusion equipment is included in the analysis. The preconstruction process was streamlined by bidding continuing contracts for the following items, awarded to low bidders: Pipes and valves Fencing Wet well wall coating (nonstructural) Additionally, electrical subcontractors were prequalified to bid electrical improvements. Experience gained by engineering and lift station rehabilitation staff, the streamlined process, and a reduced construction time of 10 weeks per lift station further lowered TWA costs for the three additional lift stations. Specifically, the extended pilot program resulted in an average savings of $57,704 per pump station, $21,601 in nonconstruction costs, and $36,103 in construction costs. The design and construction cost savings are detailed in the table. In addition to efficiency and process improvements, the following items also factor into the savings: Complete bid documents are not required; construction drawings, equipment and material specifications, and associated bid documents are sufficient to construct projects. No performance and payment bonds are required. The Authority is not taxed and avoids state sales tax on purchase materials. The Authority does not have a profit motive; all work, including construction changes, is “at cost.” Subcontract work is performed without a general contractor’s markup. Project administrative costs are minimized; for example, projects do not require evaluation and processing of monthly pay requests. Mobilization and demobilization costs are minimal; crews move from site to site within TWA’s service area. Based on the success of the pilot, TWA has transitioned the program to a permanent status and the contract employee has elected to be-


come an employee of TWA. Moving forward, the Authority is in the process of adding a second lift station crew and modifying the two-person crew format from two utility workers to a lift station construction technician and a utility worker. The lift station foreman (formally the contract employee) will supervise both crews. The Authority anticipates completing eight lift station projects annually with two crews. To date, a total of 16 lift stations have been designed and eight constructed by TWA staff. The staff designs are completed a minimum of two months prior to construction. Equipment, material, and subcontract bids are completed with sufficient time to have items available for

construction as the lift station crews transition from a completed project to a new lift station rehabilitation site. Presently, lift station designs have been completed for rehabilitation projects extending through 2014 into mid-2015.

Lessons Learned Getting volunteers from staff to transfer, on temporary assignment, to the lift station pilot construction crew did not materialize and the staff assigned was not motivated. Hiring staff for the pilot program initially would have provided a better working environment and higher efficiency.

Bidding to vendors is not the same as bidding to contractors. In the future, vendors will be informed in the bidding solicitation that they are bidding to an owner and not a general contractor. Not making this clear led to confusion and limited bid submittals. Vendors require more information than generally provided to general contractors; bid documents must be detailed to the point of identifying bolts, gaskets, uniflanges, etc., for pipe installation. A written scope of work is a necessary component of the bid documents. Robert F. Pelham, P.E., is director of engineering for Toho Water Authority in Kissimmee.

The following photos show before and after examples of the rehabilitation projects:

Preconstruction

Postconstruction

Postconstruction

Florida Water Resources Journal • October 2014

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SPOTLIGHT ON SAFETY

Partners for Safety and Training: Still in the Game Doug Prentiss Sr. ollowing my last article, where I introduced Judd Mooso as the new FWEA Safety Committee chair, I received several nice emails congratulating me on my retirement, but also asking about what will happen to the training classes I have done around our state for the last few decades. The short answer is simple: I plan to work with individuals and organizations that will carry on the training that I have done for years. When I retired from Gainesville Regional Utilities (GRU) I had a replacement in mind who I knew would continue the training programs I had struggled to create. I knew that is some ways my replacement would improve on what I had invested so many years in developing. Today, GRU continues to have one of the best training programs in the state. At the last Florida Water Resources Conference, Greg Chromic presented me with a FWEA Service Award for being the FWEA Safety Committee chair from 1984 to 2014. I was very pleased to accept the award and hand over the responsibility to Judd Mooso. I had been working on getting Judd to accept the position for over two years. We waited until he completed a military assignment, and the general manager of Destin Water Users Inc. (DWU) encouraged him in every way he could. The entire management team at Destin supports him and knows that Judd will do a great a job for FWEA—just like he has for DWU and the U.S. Army. So yes, I am confident FWEA has a replacement that will do as

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well, or better, than I did. Some of you may be aware that at one point my plans for future training classes were to have my son pick up where I was leaving off. Many of you who are reading this have met Doug Jr. during training sessions over the last few years as he served his apprenticeship with me. Unfortunately, being on the road performing training was not a good fit for his young family and before long an offer he couldn’t refuse came his way. He now gets to sleep in his own bed and only travel when the U.S. Air Force Reserves (or his wife) tells him he has to. When I retired as the FWEA Safety Committee chair I did not quit training but I am now slowing down. I still enjoy the training I do and my new plan is to travel less but continue to train. My last class was at Poe Springs Lodge on the Santa Fe River just outside High Springs near where I live. Two separate organizations attended two days of permit-required confined space training for entrants, attendants, and entry supervisors. In both cases the training coordinator for each organization was present and I worked closely with them to develop future training classes that they could present, as well as providing basic certification for their workers. My co-instructor for this class was a young man who has worked with me as an emergency response team member and will be retiring from his regular job in just a few years. Like me, he has “walked the walk” and his training is first-hand and meaningful. About two years ago I presented a series of safety supervisor classes for FWEA around Florida because I identified what I would describe as a gap between the responsibilities

Two Destin Water users training on a ton simulator.

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October 2014 • Florida Water Resources Journal

given to front-line supervisors related to safety/training and the actual preparation, tools, and training given them prior to receiving their new assignments. That FWEA safety supervisor program provided an overview for supervisors of the wide-ranging methods that can be used for the most common Occupational Safety and Health Administration (OSHA) safety requirements. The classes focused on those requirements that were supported by industry standards and clearly apply to those of us in the water and wastewater industry. A wide range of options were provided and individual students went away with plans, ideas, and strategies on how to implement programs or training clearly required by industry and safety standards. Many of my former students are now managers, administrators, and chief operators, and at this point, are passing on the training that I provided to them. The FWPCOA classes always include safety training and have been the foundation of safety/training for water distribution and wastewater collection operations, in addition to operator training. Over 20 years ago, Jeff Poteet, the current FWPCOA president, and I were both creating safety videos for workers and promoting safe work procedures, and those efforts still continue to be made by many of the professionals and leaders in our industry. Over the next few years I plan on continuing the training of supervisors by going back to my roots at the University of Florida Training, Research, and Education for Environmental Occupations (TREEO) Center. The Center is the perfect venue for the training outreach I have in mind. Class offerings ini-

Spring at Poe Springs Lodge where Prentiss held the training session for confined spaces. This picture is from the Springs website.


Clermont Wastewater Treatment Plant (photo: Bob Reed)

tially will be limited, but the ability to present classes close to home will extend the time I can continue to teach with the energy level required to train water professionals. Discussions so far have focused on bringing back a chlorine gas class early in 2015 at the Center and requests from any of you will identify what other training is needed. Contact chinton@treeo.ufl.edu at TREEO if you have interest in setting up a class. Any training listed on my website at www.dougprentiss.com can be held at TREEO if enough interest supports it. I will also be continuing to work with the City of Clermont to provide monthly training programs during all of 2015 on the third Thursday of every month. We will finalize the 2015 schedule before the end of 2014 so that other organizations can plan and schedule their workers for the classes they need. Outside participants are welcome, but reservations should be made in advance. Many of the smaller utilities in the Clermont area have participated in this training over the last several years. You can go to hwooding@clermontfl.org if you would like to be copied with the schedule when it’s complete. I will continue to work with DWU each year, scheduling a full week of safety seminars, including: trench competent person, confined space, and hazardous chemical handling. These programs are open to outside agencies and Judd Moose will coordinate the dates and schedule if you have interest in attending. Last year, the seminar was held on the third week of April, but the 2015 schedule is not out yet. You can contact jmooso@dwuinc.com if you would like to be copied with the date when it is available. Only one seminar will be held during 2015. I am also working with two talented artists to revise and update many of my safety videos and training modules and plan on making them available in spring 2015, online or on DVD. In addition, the forms and information on my website can be downloaded for free and I am always available for questions. So yes, my corporation has closed and I am not bidding on any new jobs, but I will be here for several more years for my existing customers and friends and available through TREEO for programs that you request. Doug Prentiss Sr. is president of DPI, providing a wide range of safety services throughout Florida.

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FWRJ READER PROFILE strategic planning, customer focus, knowledge management, employee engagement, operations focus, and business results.

Joseph Cheatham City of Tallahassee Underground Utilities

Work title and years of service. I have been the wastewater operations manager for the past nine years. Prior to coming to Tallahassee I worked for Collier County Public Utilities as its wastewater director for six years. I retired from Gainesville Regional Utilities (GRU) in 1999 after serving 29 years in various positions, including water reclamation facilities manager. This month will start my 45th year in the wastewater treatment industry. What does your job entail? I presently am responsible for the operations and maintenance of the awardwinning Thomas P. Smith Advanced Wastewater Treatment Facility (AWT). The plant is completing a $227 million plant upgrade to meet AWT standards, along with improvements to the biosolids section that produces 100-percent AA biosolids using thermal drying. In addition, I am responsible for a 4,000-acre sprayfield, a 1.2-mgd public access reuse facility, and 107 wastewater pumping stations. I have five direct reports and 65 indirect reports, with an operations and maintenance budget of $10 million.

What do you like best about your job? I am sold on being the “best in class” in all that you do within your job. I liked the opportunity I had at GRU, Collier County, and the City of Tallahassee to be involved with leading-edge planning in setting the workplace climate to one of continuous improvement. This keeps me engaged and motivated to not be satisfied with the status quo, and I’m always looking for the latest technology and business practices that make you a leader in the state and the nation. What organizations do you belong to? I belong to FWPCOA, FWEA, and WEF. How have the organizations helped your career? The FWPCOA provided me the cornerstone of my training when I first started in 1970 as a wastewater plant operator trainee. In those early days, the industry leaders volunteered their time to train the new operators coming into the field. That was their way of giving back to the industry all they had learned from those preceding them, and is the way FWPCOA continues to be the leader in operator training today. The FSAWWA gave me the opportunity to serve as a peer reviewer for the Qualserve program, where I became a subject matter expert in wastewater operations and served as a peer reviewer for the City of Tallahassee (2000), City of Clarksville, Tenn. (2003), and the City of Henderson, Nev. (2005). With FWEA, I had the opportunity to serve as the chair of the Utility Management Committee and the Operations Challenge Committee, and

What training have you taken? The majority of my training has been in wastewater operations, management, and leadership development. Over my 44 years of experience, the training provided by FWPCOA, FSAWWA, FWEA, the Water Environment Federation (WEF), and the University of Florida Training, Research, and Education for Environmental Occupations (TREEO) Center has been the most beneficial to my career. Recently I have focused on continuous improvement training through the Florida Sterling Council, which includes leadership,

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October 2014 • Florida Water Resources Journal

serve on its board of directors and Executive Committee. My WEF service included membership on the National Operations Challenge Committee, Name Change Committee (Water Pollution Control Federation to WEF), Plant Operations Committee, Environmental Management Systems Committee, and Utility Management Committee; director on the Professional Wastewater Operations Division (PWOD); and in 1990, I served on the WEF executive board representing all of PWOD. What do you like best about the industry? I like the quality of training that we receive in the state through all of our professional associations. I like the ability to network with wastewater professionals in all walks of life, both here in Florida and across the country. I especially like the lasting friendships that I have made over my years of service to the water environment industry. What do you do when you’re not working? I enjoy volunteering at the Mission San Luis, which is a replica of an early Spanish mission in Florida dating from 1656-1704. I serve as a reenactment member of the Spanish militia responsible for guarding the fort from English forces and the Creek Indians. I also serve as a docent at the Pebblehill Plantation, which is an historic plantation in Thomasville, Ga., dating from 1860-1978. The plantation has over 4,000 acres and was used as an upscale hunting lodge from 1904-1978. The main house has over 27,000 sq ft and is loaded with antiques and very expensive art work. Today, it is the only plantation in the area open to the public as a historic museum. I also enjoy classes in yoga and am a choir member at the Trinity United Methodist Church where I sing Tenor II.


Florida Water Resources Journal • October 2014

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C FACTOR

Awards Recognize Contributions to the Industry Jeff Poteet President, FWPCOA

ur annual fall awards banquet was simply outstanding! The awards ceremony is a special time to give thanks to those who have given back to our industry, and especially our association. Shirley Reaves did an outstanding job in putting together the banquet and Renee Moticker handed out so many awards her voice is probably still hoarse! I would also like to thank past presidents Bill Allman and Phil Donovan for their contributions to the banquet—Bill for giving the benediction and Phil for presenting information about Water and Wastewater Professionals Month. I was able to give out four special awards to people who have given far more than their

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time; they have given a piece of their heart to our industry and this association. Past president and honorary life member Jim Smith has served in almost every capacity in our association. Jim currently is the state’s short school chair and continues to support in any way possible. Katherine Kinloch has been active in Region X and has been the cornerstone for many years that keeps that region moving forward. Past president and honorary life member Tom King continues to contribute to both his region and the state, and he has been selected by the Nominating Committee to serve once again as president for 2015. Lastly, Bill Allman, who has dedicated his life to the operators of this great state and to this association, was recognized for his contributions. I realize that many other people in our association are worthy of recognition; both you and your colleges know who you are. If you know of someone who should be recognized

for his or her efforts and contributions, please nominate them for an award; a list of them can be found at our website at www.fwpcoa.org. There will be several awards handed out at the Florida Water Resource Conference in April next year, which means you need to start to thinking about those nominations now.

New Technology is Everywhere The October issue you are reading is dedicated to new facilities, expansions, and upgrades, which plays right into the hands of the association. There is nowhere better to learn about new technologies, new tweaks to old technologies, and facilities that have been recently built than with FWPCOA. Most of our regional meetings are held at treatment plants. Operators with new facilities love to share the things that they’re doing with the rest of the industry, so this makes a perfect match. Nothing is more exciting that checking out new technology in action!

License Renewal Deadline If you have attained the continuing educational units needed for your license renewal, you need to know that it is crunch time! There are only about six months left for you to get the CEUs you need to renew you license. The association has great training opportunities between now and the end of April. Our online training program is an excellent choice for those who would like to get training from the convenience of their home. Whether it is through live instruction or online training, FWPCOA will meet your educational needs. Please keep in mind that this is your association. Become engaged in your industry by getting involved with FWPCOA. I am confident that your involvement will directly benefit you and your professional endeavors. For regional contact information, please go to our website, look for the region that you belong to, and you’ll find the information you need.

Birthday Board Meeting The November board of directors meeting will actually be held in October! Rim Bishop, our secretary-treasurer, has invited the board to participate in his birthday ritual and we accommodated the meeting date and location so that all could attend. The meeting will be held at the Jupiter Beach Resort and Spa on Sunday, October 26, at 9:30 a.m. I hope to see you there!

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Florida Water Resources Journal • October 2014

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Bigger is Definitely Better: One Florida Utility’s Transition Into the 21st Century Brad Macek and Richard M. Schoenborn

Figure 1. City of Port St. Lucie, 2014

The City of Port St. Lucie is an urban area located in southeast Florida with a rapidly expanding population and utilities service area. The city was initially created by a developer as a retirement community, but today is home to more than 167,000 people. Water and wastewater utility services started out as individual homes with wells and septic tanks and evolved into three distinct areas serviced by small regional package plants. Members of the city council had a vision for expanding the city’s urban boundaries. Water and wastewater utility services would form the foundation for this plan of growth, and the very heart of this plan would be a modern streamlined utility system. The streamlining of the utility means consolidation of the different service areas into one large service area. What this means for the city is: A larger service area allows the economic burden for new and upgraded facilities to be shared by a larger service population. The larger facilities mean better economies of scale. Cost per treated gal drops so the cost to the service population is less. Better treatment facilities can be constructed. Regulatory compliance becomes easier.

Early History

Figure 2. City of Port St. Lucie, 1980

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October 2014 • Florida Water Resources Journal

The city started off in the early 1960s as a dream of the General Development Corporation (GDC), which marketed the city as a retirement location to workers in the Northeast and Midwest. With an easy payment of 10 dollars a month, a buyer could, according to GDC, own “a slice of paradise.” By 1980, the city population was estimated by the federal government to be 14,000; however, in 1983, that estimate was revised to 26,591. Figure 1 presents the city boundary and utility service area of the early 1980s. Like many cities in Florida, several distinct service areas had begun to evolve based on manmade limits and some natural geographic limits. In 1980, the manmade limits were chiefly the end of development, county boundaries, and the almost ever present Florida Turnpike; the natural limits included the North Fork of the St. Lucie River. At that time, the majority of the city’s population was on septic tanks. Approximately one-third to one-half of the residents were connected to city water and wastewater services, and for them, the treatment needs were easily met by three pairs of package plants: three plants for water and three for wastewater. The early boundaries of the utility service areas were established as Southport, Northport, and Westport. In 1980, no interconnection among the three service areas existed. In the early 1990s, the population had grown to about 62,400 and the majority of citizens were still on wells and septic tanks. In 1990, GDC went bankrupt, and in 1994, the city decided to incorporate. The bankruptcy left the city with unfinished roads and unfinished water and wastewater utilities. Continued on page 38


Florida Water Resources Journal • October 2014

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Continued from page 36 In 1996, a recently hired city manager guided the city into a plan to extend water and wastewater service to almost everyone in the city, and the potential for real growth began in earnest. A graph of the city’s population is presented in Figure 4. The impact of the decision to extend water and wastewater services to as much of the city as practical was significant and almost immediate. Between 1993 and 2000, the population grew by 42 percent, and between 2000 and 2013, the population had dramatically risen by 78 percent. The majority of that growth was occurring in the newly annexed areas west of the city. With the new growth, the city began to think about expanding into adjacent areas, annexing them into the city limits, and providing them with water and wastewater service. The utility service area was also growing, but the three, distinct service areas remained separate and unconnected. By 2003, the population had expanded to 111,000. The city’s boundaries and areas of water and sewer installation are presented in Figure 5. The city council and the city manager were thinking of ways to attract businesses and families; the utility systems would be the tool they would use to attract them.

On the potable water side, the package plants were gone. The city’s Prineville Lime Softening Plant was upgraded with construction of a new on-site reverse osmosis treatment plant. A new reverse osmosis water treatment plant was also being built to better serve the western portion of the city and the areas that were about to be annexed. The city’s service areas, regarding potable water, had already been consolidated. On the wastewater side, however, the three separate, unconnected service areas remained. Two new state-of-the-art treatment plants were being planned, but the Glades Wastewater Treatment Facility (WWTF), which was meant to serve the city’s newest arrivals, was being located farther and farther from to the west of the city because of the “Not In My Back Yard” sentiment of many county and city residents. In fact, they had successfully pushed its location out of the city’s limits. But that was about to change.

The Consolidation of Utility Service Areas A study in the late 1990s by an engineering firm, which was a local consultant hired by the city, indicated that consolidation of the Southport and Westport service areas would substantially reduce the costs to the city for wastewater treatment. Furthermore, in 2003, developers were begin-

Figure 3. City of Port St. Lucie, 1994 Figure 4. Port St. Lucie Population, 1993 to 2013

Figure 5. City of Port St. Lucie, 2003

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October 2014 • Florida Water Resources Journal

Figure 6. City of Port St. Lucie, 2011


ning to request annexation of a substantial area of unincorporated county land west of I-95 into the city. A win-win situation was taking shape. Between 2004 and 2009, the developer’s annexation requests were granted and the city’s land area grew overnight by 60 percent. Just as important, however, the consolidation of service areas had begun. A new 24-in. diameter force main connecting the Southport service area to the new Westport treatment plant was completed in 2005. The same year, the Westport WWTF changed from a complete mix package plant to a new cast-in-place concrete plant featuring the modified Ludtz-Enteger process for nutrient reduction. The consolidation of the Southport and Westport service areas was underway. In 2007, the Glades WWTF was completed and a new Northport Wastewater Booster Pumping Station (WWBPS) and 24-in. force main were simultaneously placed into service. The residents living near the old Northport plant were ecstatic as odors were eliminated completely by the in-line regional wastewater booster pumping station. Later that year, the original Northport WWTF was demolished. The consolidation of the Northport and Glades service areas was complete. In 2009, construction of the Southport WWBPS was completed and the station was placed into service. The 24-in. force main that had been constructed in 2005 between the Southport and Westport plants was now placed into service. The Southport plant was eventually retired in 2011 following completion of the Westport WWTF expansion. By 2012, the consolidation of the wastewater service areas was also complete.

Figure 7. Annual Operations and Maintenance Costs Versus Year

The Cost-Benefit of Consolidation The utility expansion and service area consolidation has been an unqualified success for the city. The benefits include: Lower total annual treatment plant operating costs Lower operating cost per gal of treated wastewater The city doing its fair share of protecting the environment It has helped the city bring water and wastewater services to most residents, while lowering the total annual operating and overall cost per mil gal per day (mgd) of treated wastewater. Figure 7 presents a graph of total annual operating costs for treatment in millions of dollars; a graph of annual flows in mgd is also shown. Since 2007, when the Northport and Glades service areas were combined, annual costs have steadily declined. More importantly, the cost per mgd of treated wastewater has dropped dramatically to less than 2004 levels. Figure 8 presents a comparison of annual treatment costs, with annual average daily flows for 2004 through 2012. With each new facility entering into full service, the cost per gal of treated effluent has dropped. The new Glades and Westport treatment facilities both use reuse water and deep injection wells for disposal of effluent and both plants have access to other wells for emergency disposal in the event the primary well is incapacitated. The possibility of discharge of partially treated sewage into nearby surface waters of the state is extremely limited. Figure 9 presents a comparison of annual treatment costs with the citywide population. Today, with a population of over 167,000, the city, through economies of scale, has substantially lowered its unit cost of wastewater treatment operations from $4.96 million annually in 2006 down to $3.78 million in 2012. A larger and streamlined utility is definitely better for everyone. Today, growth in the area is reawakening, and Port St. Lucie’s utility infrastructure is ready for it. Brad Macek is the assistant director, and Richard M. Schoenborn, P.E., is a senior civil engineer, utility engineering division, with the Utility Systems Department in Port St. Lucie.

Figure 8. Annual Operations and Maintenance Costs/mgd Versus Year

Figure 9. Annual Operation and Maintenance Costs and Population Versus Year Florida Water Resources Journal • October 2014

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FWEA Announces 4th Annual Florida Water Festival An individual can survive several weeks without food, but only a few days without water. Celebrate this vital resource at the fourth annual Florida Water Festival to be held on October 25, from 10 a.m. to 2 p.m., at Cranes Roost Park at Uptown Altamonte in Altamonte Springs. Sponsored by FWEA and the City of Orlando, the festival is designed to educate the public about the importance of protecting the state’s water resources and offers fun and educational events for those in the water industry and their families and friends. Last year’s festival had over 200 visitors and there is no cost to attend! See what it’s like to carry water for a long distance—as many in the developing world still must do every day—by participating in the one-mile Walk for Water. Participants will also learn facts about water around the world as they walk. Enjoy music, interactive demonstrations on water quality sampling and testing, and learn how water reclamation systems work. Children will enjoy the poster contest, water animal face painting, and a water filtration test. There will be exhibits from area companies and agencies, and hourly raffle drawings. For more information, contact Stacey Smich at Stacey.Smich@ch2m.com or (407) 375.0761. You can also visit www.fwea.org/water_festival.php and Like the Facebook page at www.facebook.com/FloridaWaterFestival.

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Student Water Design Competition

Face Painting Booth

October 2014 • Florida Water Resources Journal

The Walk for Water attracts all ages.

Walk for Water Event


FWPCOA TRAINING CALENDAR SCHEDULE YOUR CLASS TODAY!

OCTOBER 6-8 ........Backflow Repair ............................................Deltona ..................$275/305 20-23 ........Backflow Tester ..............................................Pensacola ..............$375/405 24 ........Backflow Tester Recert*** ..........................Deltona ..................$85/115

NOVEMBER 3-6 ........Backflow Tester ..............................................St. Petersburg..........$375/405 3-6 ........Backflow Tester ..............................................Deltona ..................$375/405 17-21 ........Reclaimed Water Field Site Inspector....Deltona ..................$350/380 21 ........Backflow Tester Recert*** ..........................Deltona ..................$85/115

DECEMBER 1-3 ........Backflow Repair ............................................Deltona ..................$275/305

Course registration forms are available at http://www.fwpcoa.org/forms.asp. For additional information on these courses or other training programs offered by the FWPCOA, please contact the FW&PCOA Training Office at (321) 383-9690 or training@fwpcoa.org.

* Backflow recertification is also available the last day of Backflow Tester or Backflow Repair Classes with the exception of Deltona ** Evening classes

You are required to have your own calculator at state short schools and most other courses.

*** any retest given also Florida Water Resources Journal • October 2014

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FWEA FOCUS Kart Vaith President , FWEA

Amber Batson, Treasurer, FWEA have asked our treasurer, Amber Batson, to co-author this column with me. We have just wrapped up the accounting for our 2013-2014 fiscal year and the numbers are remarkable! In 2013-2014, FWEA conducted: 23 chapter meetings 7 scholarship golf tournaments 7 seminars/workshops 3 water festivals 9 other networking and volunteer activities

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These 49 events do not include the numerous other activities in which our members gathered together in the spirit of fellowship and networking. The current fiscal year is shaping up to be equally robust, with about 50 activities already scheduled to occur. We have also continued our outreach to the next generation of water industry professionals by having many universities across Florida participate in our student design competition,

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FWEA Advances Its Goals and Remains Fiscally Strong with over $43,000 in scholarship support given directly to students, as well as to the programs at our state’s colleges and universities. As a result, we are able to advance our core objectives of increasing participation from a broader cross section of our industry. Another goal that we have set for ourselves is to operate FWEA more efficiently while achieving our financial goals. On the financial front, we closed the year fiscally strong, with a healthy 50 percent of our planned expenses in reserve to support our ongoing activities. As FWEA grows, we believe that lessening the burden on our volunteers in planning and executing events is the key to allowing more of our members to volunteer. To that end, we have advanced the use of online marketing for events, streamlined online registration, and developed tools to process payments efficiently during our events—all with the goal of reducing the paperwork burden on volunteers. In addition, we are looking at alternatives to further reduce the burden on our volunteer mem-

October 2014 • Florida Water Resources Journal

bers by using FWEA staff to assist them. All of these improvements will likely exert a greater financial burden on FWEA and we are working to find ways to provide these added services while preserving our fiscal health. In addition to the goal of broadening our membership, we want to operate FWEA with a clear vision and mission through 2020. To achieve this last goal, the FWEA board of directors, member committees, and local chapters will meet in the coming two months to craft a new vision/mission statement with clear goals, objectives, and metrics. This initiative, called Strategy 2020, is under development and we will keep you abreast of our progress in the coming months. As we formulate our new strategy, I invite you to provide your thoughts and comments to me by email at kvaith@tcgeng.com. Once Strategy 2020 is implemented, we believe that our key objectives of broadening our membership, while organizing and conducting our events without overworking our volunteers, will be successfully achieved.



Certification Boulevard

Roy Pelletier 1. Which type of solid is typically the highest percentage in the total solids profile of raw wastewater? a. Suspended c. Colloidal

b. Dissolved d. Settleable

2. Given the following data, what is the solids loading rate on the secondary clarifiers? • Plant influent flow is 14.0 mgd • The return activated sludge (RAS) rate is 55 percent of Q • There are two 120-ft diameter secondary clarifiers • The aeration mixed liquor suspended solids (MLSS) is 3,450 mg/L a. 27.6 lbs/day/ft2 b. 8.6 lbs/day/ft2 c. 18.9 lbs/day/ft2 d. 35.5 lbs/day/ft2 3. Which is the lowest life form in the activated sludge process: a free swimming ciliate, a stalked ciliate, or a rotifer? a. Free swimming ciliate b. Stalked ciliate c. Rotifer d. They are all the same. 4. Which condition may produce the best denitrification efficiency in an aeration tank? a. High air supply b. High aeration dissolved oxygen (DO) c. Low aeration DO d. Low MLSS 5. Which activated sludge growth phase is considered to have the highest food-tomicroorganisms (F/M) ratio, the lowest solids retention time (SRT), the highest sludge yield, and the best oxygen utilization efficiency?

Test Your Knowledge of Various Wastewater Treatment Topics 6. What is the term when ammonia-N and organic-N are added together? a. b. c. d.

Total Kjeldahl Nitrogen (TKN) Soluble organic nitrogen (SON) Total nitrogen (TN) Combination of NO2 and NO3 (nitrite and nitrate): NOx

7. Which two age parameters are most similar to each other? a. Gould Sludge Age (GSA) and F/M ratio b. SRT and mean cell residence time (MCRT) c. SRT and GSA d. GSA and MCRT 8. Which group of bacteria is most responsible for removal of phosphorus in the biological nutrient removal (BNR) activated sludge process? a. Sludge volume index (SVI) b. GSA c. Autotrophic d. Phosphorus-accumulating organisms (PAO) 9. How much alkalinity is required to convert 1 lb of ammonia-nitrogen during the nitrification process? a. 7.2 lbs b. 8.34 lbs c. 7.48 lbs d. 4.6 lbs 10. What will organic material do in a muffle furnace? a. It will burn. b. It will not burn. c. It will change to inorganic material. d. It will convert to dissolved solids.

a. High-rate aeration b. Extended aeration c. Conventional aeration d. Declining growth

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October 2014 • Florida Water Resources Journal

Answers on page 51

LOOKING FOR ANSWERS?

Check the Archives Are you new to the water and wastewater field? Want to boost your knowledge about topics youʼll face each day as a water/waste-water professional? All past editions of Certification Boulevard through the year 2000 are available on the Florida Water Environment Associationʼs website at www.fwea.org. Click the “Site Map” button on the home page, then scroll down to the Certification Boulevard Archives, located below the Operations Research Committee.

SEND US YOUR QUESTIONS Readers are welcome to submit questions or exercises on water or wastewater treatment plant operations for publication in Certification Boulevard. Send your question (with the answer) or your exercise (with the solution) by email to roy.pelletier@cityoforlando.net, or by mail to: Roy Pelletier Wastewater Project Consultant City of Orlando Public Works Department Environmental Services Wastewater Division 5100 L.B. McLeod Road Orlando, FL 32811 407-716-2971



ENGINEERING DIRECTORY

Tank Engineering And Management Consultants, Inc.

Engineering • Inspection Aboveground Storage Tank Specialists Mulberry, Florida • Since 1983

863-354-9010 www.tankteam.com

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October 2014 • Florida Water Resources Journal


ENGINEERING DIRECTORY

Fort Lauderdale 954.351.9256

Jacksonville 904.733.9119

Miami 305.443.6401

Orlando 407.423.0030

Gainseville 352.335.7991

Key West 305.294.1645

Navarro 850.939.8300

Tampa 813.874.0777 813.386.1990

West Palm Beach 561.904.7400

Naples 239.596.1715

Showcase Your Company in the Engineering or Equipment & Services Directory Contact Mike Delaney at 352-241-6006 ads@fwrj.com

EQUIPMENT & SERVICES DIRECTORY

Florida Water Resources Journal • October 2014

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EQUIPMENT & SERVICES DIRECTORY

Motor & Utility Services, LLC

Instrumentation,Controls Specialists Instrumentation Calibration Troubleshooting and Repair Services On-Site Water Meter Calibrations Preventive Maintenance Contracts Emergency and On Call Services Installation and System Start-up Lift Station Controls Service and Repair

Central Florida Controls,Inc. Florida Certified in water meter testing and repair P.O. Box 6121 • Ocala, FL 34432 Phone: 352-347-6075 • Fax: 352-347-0933

w w w. c e nt r a l f l or i d a c ont rol s . c om

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October 2014 • Florida Water Resources Journal

CEC Motor & Utility Services, LLC 1751 12th Street East Palmetto, FL. 34221 Phone - 941-845-1030 Fax – 941-845-1049 prademaker@cecmotoru.com • Motor & Pump Services Test Loaded up to 4000HP, 4160-Volts • Premier Distributor for Worldwide Hyundai Motors up to 35,000HP • Specialists in rebuilding motors, pumps, blowers, & drives • UL 508A Panel Shop, engineer/design/build/install/commission • Lift Station Rehabilitation Services, GC License # CGC1520078 • Predictive Maintenance Services, vibration, IR, oil sampling • Authorized Sales & Service for Aurora Vertical Hollow Shaft Motors


EQUIPMENT & SERVICES DIRECTORY

CLASSIFIEDS Positions Av ailable Purchase Private Utilities and Operating Routes Florida Corporation is interested in expanding it’s market in Florida. We would like you and your company to join us. We will buy or partner for your utility or operations business. Call Carl Smith at 727-8359522. E-mail: csmith@uswatercorp.com

We are currently accepting employment applications for the following positions: Water & Wastewater Licensed Operator’s – positions are available in the following counties: Pasco, Polk, Highlands, Lee, Marathon Maintenance Technicians – positions are available in the following locations: Jacksonville, New Port Richey, Fort Myers, Lake, Marion, Ocala, Pembroke Pines Construction Manager – Hillsborough Customer Service Manager - Pasco

Utilities Storm Water Supervisor $53,039-$74,630/yr. Plans/directs the maintenance, construction, repair/tracking of stormwater infrastructure. AS in Management, Environmental studies, or related req. Min. five years’ exp. in stormwater operations or systems. FWPCOA “A” Cert. preferred.

Employment is available for F/T, P/T and Subcontract opportunities Please visit our website at www.uswatercorp.com (Employment application is available in our website) 4939 Cross Bayou Blvd. New Port Richey, FL 34652 Toll Free: 1-866-753-8292 Fax: (727) 848-7701 E-Mail: hr@uswatercorp.com

Utilities Treatment Plant Operator I $41,138-$57,885/yr plus $50/biweekly for “B” lic.; 100/biweekly for “A” lic. Class “C” FL DW Operator Lic. & membrane experience required.

Utilities Treatment Plant Will Call Operator $17.93-$27.82/hour. Part time. Must have passed the C drinking water exam. Apply: 100 W. Atlantic Blvd., Pompano Beach, FL 33060. Open until filled. E/O/E. http://pompanobeachfl.gov for details.

City of Vero Beach Electronics Technician Services, maintains, installs and performs preventative maintenance of electronic and electrical equipment throughout the water and sewer system. Must have thorough working knowledge of configuring, programming and maintenance of Modicon Programmable Logic Controllers and GE IFix HMI software version 5.5 and later. Visit website for complete job description, qualifications needed, and instruction to apply. $28.04 p/hr www.covb.org City of Vero Beach EOE/DFWP 772 978-4909

Water and Wastewater Utility Operations, Maintenance, Engineering, Management

Booth, Ern, Straughan & Hiott, Inc. Utility Design Engineer BESH Engineering seeks experienced utility design engineer for all aspects of water and wastewater design, including treatment plants, pump stations, and collection/transmission/distribution systems. Applicant must have water and wastewater treatment plant design and permitting experience. Experience with hydraulic modeling, specification writing, Autocad drafting, project bidding, construction oversight and project funding preferred. Applicant must possess State of Florida E.I. with minimum 4 years experience. Florida P.E. a plus. Salary commensurate with experience. Come join a great team! Drug Free Workplace and an Equal Opportunity Employer. Please email resume to: info@besandh.com Florida Water Resources Journal • October 2014

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Engineer II Bachelor's degree in the civil engineering field from an accredited college or university and 4 to 7 years of experience in civil and/or environmental engineering, planning design and construction, including experience of an administrative nature required. Computer aided drafting/design knowledge and experience as well as familiarization with G.I.S. and floodplain management and knowledge of water and/or wastewater modeling is desirable. Training in six sigma statistical process improvement methods also desirable. Knowledge of Microsoft Office is required. Must possess a valid Driver’s License and have an acceptable driving record and maintain an acceptable driving record. SPECIAL REQUIREMENTS: Must be registered as a Professional Engineer in the State of Florida. May be eligible for a trainee position providing Professional Engineer license is obtained within 2 years of hire date. Starting salary for trainee position is $49,247. Please apply online at www.palmbayflorida.org.

CREW LEADER II - $12.87/Hour High school graduate or equivalent plus 3 years' experience in construction, concrete work, or gravity sewer maintenance/construction. Florida Class DEP Level III Distribution License and FWPCOA Wastewater “C” Certificate desired. See website www.titusville.com for application. - EOE

Positions Wanted EDWARD T. URBANEK – Holds a Florida Dual “C” level Water & Wastewater license with eight years experience; five in route work and a clean drivers license and strong maintenance skills. Seeking a permanent position anywhere in Region 8. Contact at 15750 NE 46th St., Williston, Fl. 32696. eddieurb58@gmail.com 352-528-0281 JUAN McELROY - Seeking a Wastewater Trainee position. Passed test and needs hours in plant to obtain license. Prefers central Florida within an hours drive. Contact at 4518 Almark Dr. Orlando, Fl 32839. 407-850-9683 or 407-376-0088 PHILIP O’DRISCOLL – Seeking a Wastewater Trainee position and has completed course and needs plant hours to obtain license. Prefers the west coast, Port Charlotte, Ft. Myers, Sarasota area – Will consider Gainesville area. Contact at 23232 Macellan Ave, Port Charlotte, Fl. 32980. 941-286-9896

Training Specialist, Sr. UF/TREEO is seeking a Water/Wastewater Trainer. This is a full-time position located in Gainesville, Florida. Requirements include five years’ experience training adults, A, B or C level State of Florida Water or Wastewater Operator license, and a CET designation or ability to obtain CET within one year. Apply at https://jobs.ufl.edu/postings/56661 by 10/19/2014. Position number - 00018229.

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October 2014 • Florida Water Resources Journal

SHARIFF THOMAS – Has passed his C Wastewater test and needs additional hours to obtain his license. Prefers Sanford to the Kissimmee area. Contact at 844 Grand Regency Point, Altamonte Springs, Fl. 32714. 321-460-3164

Looking For a Job? T he FWPCOA Job Placement Committee Can Help! Contact Joan E. Stokes at 407-293-9465 or fax 407-293-9943 for more information.


Certification Boulevard Answer Key From page 44 1. B) Dissolved Typically, the dissolved solids fraction is about 80 percent of the overall total solids concentration.

2. A) 27.6 lbs/day/ft2 Formula Total lbs/day entering the secondary clarifier ÷ total clarifier surface area 624,374 lbs/day ÷ 22,608 ft2 = 27.6 lbs/day/ft2 Total lbs/day entering the secondary clarifier = (14.0 mgd + 7.7 mgd) x 3,450 mg/L x 8.34 lbs/gal = 624,374 lbs/day Clarifier surface area = 3.14 x (60 ft x 60 ft) = 11,304 ft2 x 2 clarifiers = 22,608 ft2

3. A) Free swimming ciliate Beginning with the lowest life form, the microorganism indicators are amoebas, small flagellates, large flagellates, free swimming ciliates, stalk ciliates, rotifers, nematodes (worms), and water bears. So, of the three indicators listed in the question, the free swimming ciliate is the lowest life form in the activated sludge process.

4. C) Low aeration DO Because denitrification is an anoxic reaction, low dissolved oxygen levels in the aeration tank will typically improve denitrification efficiency.

8. D) PAO

10. A) It will burn.

PAO, or phosphorus-accumulating organisms, are responsible for the uptake and removal of phosphorus from the wastewater in a BNR activated sludge process.

9. A) 7.2 lbs Nitrification consumes alkalinity at the rate of about 7.2 lbs of alkalinity for each lb of ammonia oxidized. Because this action causes the mixed liquor pH to drop, biological denitrification is desirable, which replenishes the alkalinity at a rate of about 3.6 lbs of alkalinity for each lb of nitrate that is consumed as a source of oxygen. The action of denitrification helps to stabilize the MLSS pH in a range acceptable to the nitrifying bacteria.

Organic material, and other volatile matter, will typically burn in a muffle furnace at temperatures of about 550oC. However, just because something burns in a muffle furnace does not necessarily mean that it is biological in nature. For example, a PVC pipe shaved into a sample will burn in a muffle furnace; the PVC, however, is neither biology, nor food for the biology.

Editorial Calendar January . . . . . .Wastewater Treatment February . . . . .Water Supply; Alternative Sources March . . . . . . .Energy Efficiency; Environmental Stewardship April . . . . . . . .Conservation and Reuse; Florida Water Resources Conference May . . . . . . . . .Operations and Utilities Management June . . . . . . . .Biosolids Management and Bioenergy Production; FWRC Review July . . . . . . . . .Stormwater Management; Emerging Technologies August . . . . . .Disinfection; Water Quality September . . .Emerging Issues; Water Resources Management October . . . . . .New Facilities, Expansions, and Upgrades November . . . .Water Treatment December . . . .Distribution and Collection

5. A) High-rate aeration In regard to the growth curve of microorganisms, the far left side of the curve has high food availability, fast bug growth, high yield of new cells, low solids inventory, and excellent oxygen utilization transfer efficiency. This translates to high F/M ratio, low SRT, high sludge yield, and lowest pounds of oxygen required per pound of CBOD5 destroyed. This high rate aeration growth rate is also called “log growth.”

6. A) TKN TKN (Total Kjeldahl Nitrogen) is the combination of ammonia-nitrogen and organic-nitrogen. Typically, the majority of TKN of domestic raw wastewater is in the ammonia form.

7. B) SRT and MCRT The SRT and MCRT have similar concepts: pounds of solids in the activated sludge system divided by the pounds per day of solids LEAVING the process. Typically, SRT is based on total solids, and MCRT is based on volatile solids. Gould Sludge Age (GSA), however, is the pounds of solids in the activated sludge process divided by the pounds per day of solids ENTERING the aeration system.

Technical articles are usually scheduled several months in advance and are due 60 days before the issue month (for example, January 1 for the March issue). The closing date for display ad and directory card reservations, notices, announcements, upcoming events, and everything else including classified ads, is 30 days before the issue month (for example, September 1 for the October issue). For further information on submittal requirements, guidelines for writers, advertising rates and conditions, and ad dimensions, as well as the most recent notices, announcements, and classified advertisements, go to www.fwrj.com or call 352-241-6006.

Display Advertiser Index Aqua Aerobics......................................37 CEU Challenge ....................................25 Crom ..................................................23 Data Flow ............................................27 FSAWWA Conference......................14-17 FWEA Collection Systems Committee Training ............................4 FWPCOA Online Training ......................45 FWPCOA Training ................................41 FWRC Call for Papers ..........................31

Garney .................................................5 GML Coating ..................................29, 50 Hudson Pump ......................................35 Polston Technology ..............................33 Professional Piping ..............................43 Reiss Engineering ..................................7 Stacon ...................................................2 TREEO ................................................34 US Water .............................................24 Xylem .................................................52

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