DESIGN EXPERIENCE EE&T's water treatment design experience ranges from designing new state-of-the-art water treatment facilities to rehabilitating or expanding existing processes and facilities. Many of our designs offer flexibility for potential future regulations, while keeping unit processes easy to operate and cost effective. Our water treatment design experience includes the following: Rapid Mix, Flocculation, Sedimentation We have extensive experience in optimizing these processes. Our design for the City of Richmond, VA included 8 rapid mix units and 32 flocculators for a 140 mgd water treatment plant. Similar designs were performed for the City of Durham, NC and Camden, SC. We have experience with various types of impeller designs, multiple impeller arrangements, and VFD speed controllers to maximize mixing and chemical efficiency. Our experience includes designs of new efficient sedimentation basins and rehabilitation of existing basins. We have incorporated tube settlers and plate settlers in our designs. Our engineers pay particular attention to equal flow distribution throughout all basins via computer models to avoid maldistribution and short circuiting. Continuous Sludge Collection Systems EE&T has designed continuous sludge collection systems in new and existing facilitiesfor the Charlotte-Mecklenburg Utility Department; the City of Durham, NC; Camden, SC; and several utilities in Virginia. Regardless of the project complexity, we have experienced personnel to develop a cost effective sludge collection system. Filtration Our design team has designed filter upgrades for the City of Durham including new media, underdrains, controls, and air scour backwash. For the City of Camden, SC, our design includes deep bed filters for future GAC, air scour backwash, and filter controls communication with a central SCADA system. Recently, we completed an extensive filter improvement study for the City of Henderson, NC which resulted in the highest approved filtration rate in North Carolina. Typically our filter designs include special features such as influent control weirs, constant level controls, effluent particle counters, and hydraulic constraints to prevent filters from draining. Aqua Ammonia Feed EE&T has been designing ammonia feed facilities for water utilities since 1986. For the City of Chesapeake, VA we designed a facility for 9-mgd production. For a 46-mgd water treatment plant in Virginia, we just completed an ammonia storage facility consisting of two 8,000-gal storage tanks, four feed pumps, multiple chemical diffusor and mixing points, instrumentation, and SCADA screens for various operational modes. We have also designed an ammonia storage and feed system for a 6-mgd water treatment plant in Camden, SC and performed preliminary design for a 150- and 240-mgd water plant in Washington, DC operated by the Corps of Engineers. Chlorine Storage and Feed Our staff has designed several chlorine feed facilities operating in conjunction with ammonia feed systems. For the Appomattox River Water and Sewer Authority in Petersburg, VA we designed a new chlorine gas system with four 2,000-lb/d chlorinators. For the City of Camden, SC we designed a 1,000- lb/d chlorine storage and feed system. Currently we are designing a chlorine scrubber system for the City of Durham, NC at a 30-mgd water treatment plant. Sodium Hypochlorite Our staff is experienced with the design considerations associated with sodium hypochlorite. Our staff has completed six sodium hypochlorite designs. We have visited numerous facilities and collected extensive operational data from other utilities that have had good and bad experiences with this chemical. Currently we are in the final design stage of a sodium hypochlorite storage and feed system for a 22-mgd plant operated by the City of Durham, NC. Miscellaneous Chemical Feed EE&T has designed every type of chemical feed system employed by water treatment plants. Our staff is experienced with pumping difficult chemicals such as powdered activated carbon, hydrated lime slurries, polymers, and corrosion inhibitors. We have used all types of pumps for chemical feed including diaphragm, peristaltic, progressive cavity, rotary lobe, centrifugal, and plunger. We have also used eductors and carrier water for slurry feed systems. All our designs focus on safety, ease of operation, low maintenance, and reliability. High Service Pumping EE&T personnel have completed numerous pump station designs including the use of vertical turbine and split case centrifugal pumps, with and without variable frequency drives. These projects have included related appurtenances including piping, valves, controls, power, and integration with existing SCADA systems. EE&T personnel have often employed the use of skid-mounted pump systems and modular, prefabricated buildings to minimize construction and start-up time. In addition to new facilities, EE&T personnel have been responsible for the modifications to existing structures, pump well cleaning and rehabilitation, intake evaluations, chemical feed systems, and pump troubleshooting. Clearwells EE&T staff has experience with conventional cast-in-place concrete tanks and prestressed concrete tanks. In Camden, SC we designed a 1.3-MG prestressed clearwell and 300,000-gal chlorine contact tank. In Fayetteville, NC we completed a major rehabilitation project for a 12-MG clearwell. For the City of Durham, NC, construction is currently underway for rehabilitating and baffling two 1.0-MG clearwells. Clearwell rehabilitation projects have included HDPE membrane liners, urethane coatings, expansion joint repairs, crack repairs, and baffling improvements. SCADA We have successfully designed several state-of-the-art SCADA systems in the last three years utilizing the latest software available for water utilities. Our designs include design of field devices, PLC's, development of SCADA screens, and computer logic for chemical feed control. Our staff works extensively with the utility's engineering and operational staffs to develop computer screens that are operator friendly. Many of our designs include capabilities to view the SCADA screens and plant performance remotely from the utility's main offices. SCADA systems designed by EE&T include: Erie County Water Authority, NY City of Camden, SC Rivanna Water and Sewer Authority, VA Roosevelt Roads Water Treatment Plant, Puerto Rico Distribution System Analysis EE&T personnel have completed analysis of numerous water distribution systems to increase system capacities, provide fire flow to residential, commercial and institutional facilities, and to size and locate booster pump stations and water storage tanks. Employing pre-engineered software including EPA Net, Micro-Hardy Cross, Cybernet, and KYPIPE, augmented with on-site flow testing where feasible, EE&T engineers have assembled over 15 hydraulic models to simulate existing distribution systems and model proposed system improvements. Analyses included difficult to model features such as multiple water sources, booster stations, and multi-pressure zones, as well as large daily and seasonal variations in water demand. EE&T engineers also analyzed and made recommendations for the reconstruction of the effluent header system of a 200 MGD water treatment plant to improve overall energy efficiency of the pumping system. Pipeline Rehabilitation EE&T engineers have performed engineering services for the cleaning and cement lining of cast iron water mains up to 60 inches in diameter, including over 50,000 linear feet of small diameter (up to 12-inches) and 10,000 linear feet of large diameter (up to 60-inches) piping for the City of Buffalo, New York. We have also completed design and construction administration services for the cleaning of 18,000 linear feet of concrete transmission main, increasing the C-factor of the pipeline from less than 70 to over 120. Cleaning experience also includes steel wastewater force mains, as well as a combined 11,000 linear feet of 60 and 72-inch raw water intake piping for the City of Erie, Pennsylvania and numerous small diameter piping systems. New Transmission Systems EE&T engineers successfully completed design and construction administration services for several hundred miles of water transmission and distribution piping, and wastewater force mains. Materials of construction include pipes of PVC, ductile iron, concrete, HDPE, steel, and asbestos cement. One project in particular involved the design and construction administration services for 13.2 miles of treated water transmission main and appurtenances involving a water authority, Indian nation, and five municipalities. EE&T personnel have completed engineering services for a 90-inch filtered water conduit, including wet-connection to existing operating clearwell and tunnels, and 5000 linear feet of 66-inch pile-supported, above ground sanitary force main. Subaqueous Piping EE&T personnel  conducted analysis, design, and construction administration for subaqueous pipeline installations ranging from 16 to 66-inches in diameter, involving lakes, creeks, rivers, and ocean installations. Projects include the crossing of the Niagara River with 2,500 linear feet of 36-inch piping, and 12,500 linear feet of 66-inch diameter ocean outfall for the Hampton Roads Sewer District. EE&T personnel designed and administered construction of raw water intakes featuring multiple port inlets, air backwash, and biofouling control. Additionally, EE&T personnel have successfully engineered the installation of nearly 100,000 linear feet of HDPE piping to protect the raw water intakes of over 30 North American utilities from biofouling. Water Quality Laboratories Laboratories for water treatment plants have evolved from basic wet chemistry to advanced microbiological analytical facilities. EE&T has remained at the forefront of laboratory design during this evolution process. We have designed several water quality laboratories ranging in size from 1,000 ft2 to over        6,000 ft2.  Advanced water quality laboratories designed by EE&T include gas chromatographs, TOC analyzers, wet chemistry, nutrients analyses, and analyses for Giardia and Cryptosporidium. Water Master Planning An integral part of water treatment design to develop an effective and realistic long range master plan. EE&T has developed several comprehensive long range water master plans for utilities. Typical components of a water master plan include: Population projections Industrial and residential water demand Raw water supply Watershed protection Water quality and treatability infrastructure condition/improvements Distribution system impacts and improvements Schedule of improvements Cost of improvements EE&T has successfully completed water master plans for utilities in Virginia, North Carolina, and internationally.