Package Plants Arrive on Site Virtually Ready to Operate and Built to Minimize the Day-To-Day Attention Required to Operate the Equipment

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Influent water

Package Plant Advantages Package Package plants arrive on site virtually ready to operate and built to minimize the day-to-day attention required to operate the equipment. How To Select a Package Plant a Package Select How To Package plant systems are most appropriate for plant sizes that treat 25,000 to 6,000,000 from cubic gallons per day (GPD) (94.6 to 22,710 meters per day). and Design Description System Considerations Package plants can differ widely with regard to design criteria, and operating and maintenance considerations. most important consideration in determining the suitability of a package plant application. Complete influent water quality records need levels, to be examined to establish turbidity and color fluctuations, seasonal temperature and color level expectations. Both high turbidity may require beyond many coagulant dosages Pilot tests package plants design specifications. (tests that evaluate treatment processes and operations on a small scale to obtain performance criteria) may be necessary to select a package plant for more innovative designs using high flow rates and shorter detention time unit processes. Package treatment equipment manufacturers often perform these tests.

○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ ○○○○○○○○○○ A NATIONAL DRINKING WATER CLEARINGHOUSE FACT SHEET FACT CLEARINGHOUSE WATER DRINKING A NATIONAL

violet radiation), filtration including reverse osmosis or ultra filtration, slow sand filtration, pressure filtration, diatomaceous earth filtration), or granular activated carbon), and . disinfection (chlorination, ozonation, ultra- . filtration (bag and cartridge filters, membrane . aeration, . ion exchange, . activated carbon adsorption (using powdered . softening. NATIONAL DRINKING WATER CLEARINGHOUSE DRINKING WATER NATIONAL Package Plants: Alternative to Conventional Treatment Package Plants: Alternative plant? is a package What Package technology offers an alternative to in-ground conventional treatment technology. not altogether differentThey are from other processes several package although treatment plant models contain innovative treatment The elements, such as adsorptive clarifiers. between package primary distinction, however, is that plants and custom-designed plants package plants are units assembled treatment in a factory, skid mounted, and transported to the site. widely used to treat most These units are surface water supplies for removal of turbidity, organisms and coliform with filtration color, treatment many other processes. However, technologies are as available to small systems package plants. These technologies or a combi- nation of them can be incorporated into a comprehensivepackage plant to provide water including: treatment, Small water treatment systems often find it difficult systems often Small water treatment to comply with the U.S. Environmental face financial problems Small communities often in purchas- (EPA)Protection Agency regulations. systems. Their problem complicated if they is further conventional treatment ing and maintaining Treatment The Surface Rule Water of a full-time, trained operator. do not have the services (SWTR) requirements have greatly increasedin in the possible use of package plants interest Package plants can also be applied to treat of the country. many areas contaminants such as iron via oxidation and filtration. and manganese in groundwater Summary Package Plants Package two

PAGE OF FOUR Package Plants Figure 1:Tube-TypeClarifierPackage Plant multiple typesofcontaminants. possible inabilityofpackageplantstotreat package capability.Challengesincludethe Act anditsamendmentsmightchallenge oftheSafeDrinkingWaterThe requirements endorse themcompletely. reluctantto plants inuse,manystatesare numberofpackage Despite therelatively large advantages oflowcostandautomation. and thattendstonegatethepackageplant a highlevelofoperationalskillandattention, Highly variableinfluentwaterqualityrequires Package PlantLimitations chlorine toformdisinfectionby-products). materials insource waterthatcanreact with trihalomethane precursors organic (whichare substances and water, includingcolor-causing to removedissolvedsubstancesfromtheraw tained. Packageplantsalsocanbedesigned main- competent operatorsandareproperly thattheyare runby tent quality,provided wateroffairlyconsis- and bacteriafrom surface removeturbidity Package plantscaneffectively operate onatightbudget. plants attractivetocommunitiesthatmust and maintenance.Thesefeatures makepackage design andinstallationcosts,operation savingsinengineering, finished systemare The mainadvantagesofapackagedfactory- operation, anddesignforunattendedoperation. relativeeaseof compact size,costeffectiveness, Other majoradvantagesofpackageplantsare Connection Influent Polyelectrolyte Chemical Feed Chlorine Alum System Chamber Flash Mix Flocculation

Waste ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ Settling Tube standards fortheseunitsare: sedimentation, andfiltration.Typicaldesign tional processes ofcoagulation,flocculation, their nameindicates,theycontaintheconven- toavarietyofspecifications.As by severalfirms manufacturedConventional packageplantsare Conventional PackagePlant Systems Types of Package Plant Filtration plant is illustrated in Figure 1.Thistypeof plant isillustratedinFigure A flowdiagramofatube-typeclarifierpackage tank orchamber). average lengthoftimewaterremainsinthe settlers toreduce settlingdetentiontime(the Tube-type clarifierpackageplantsusetube Tube-Type ClarifierPackagePlant package plants. isnonationalverificationprocess for there Presently, the potentialforsuccessorfailure. basis, withonlytheirownexperiencetojudge review eachpotentialplanonacase-by-case for theinstallationofpackagesystemsmust plans State agenciesresponsibleforreviewing andoperationsofthesesystems. performance has beencollectedtodemonstratelong-term watersupplies,butlittledata plants totreat currentlyusingpackage Many communitiesare rapidsandfiltersratedat2gallons per • 2hoursedimentationdetentiontime, and • 20to30minuteflocculationdetention time, • Chamber second/square meter). second/square foot(1.34liter/ minute (gpm)persquare Source: U.S.Environmental Protection Agency, 1989 Connection Effluent Media Mixed Filter SIX•November 1997 Connection Backwash Backwash Storage Clear Waterand To Service PAGE three OF FOUR Pump Backwash Filter Underdrain ® Control Panel Surface Wash Valve Aquaritrol Mixed Media Filter Adsorption Clarifier While passing through the adsorption media, the coagulant and water are mixed, contact intensity, flocculated, and clarified. The mixing as measured by the mean velocity or gradient, ranges from 150 to 300 feet per second. Floccu- lation is accomplished through turbulence as water passes through the adsorption media. In addition, flocculation is enhanced by contact between the flocculated materials and the floc- is reducedcoated media. Turbidity through adsorption of the coagulated and flocculated solids onto the adsorption media and the previously adsorbed materials. The adsorption or greaterclarifier can achieve 95 percent removal foot (6.8 liters/ at 10 gpm/square second/square meter). This highly efficient clarification method results in extremely compact designs. Adsorption clarifiers are cleaned by a combina- tion of air scouring followed by water flushing. for The air scouring starts the cleaning process Adsorption the plastic media used in the clarifier. Adsorption Clarifier Package Plant Package Clarifier Adsorption plants use an clarifier package Adsorption media plastic bead with low density upflow filter to replace adsorption clarifier) (called the the basin, thereby and sedimentation flocculation into one. A mixed these two steps combining treatment. completes the media filter Figure 2 shows a typical example.

○○○○○○○○ ○○○○○○○○○ ○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ Waste and Waste Overflow Trough Influent Overflow and Waste Source: U.S. Environmental Protection Agency, 1989 Agency, Protection U.S. Environmental Source: Figure 2: Adsorption Clarifier Package Plant Clarifier Package Figure 2: Adsorption NATIONAL DRINKING WATER CLEARINGHOUSE DRINKING WATER NATIONAL plant has two versions with different versions has two plant capacity version can treatranges; one 10 to 100 from and the other, to 6.3 liters/second), gpm ( 0.63 200 to can treat from with dual units, equipped (12.6 to 88.3 liters/second). 1,400 gpm the disinfectant, package systems, In these and polymer coagulant aid primary coagulant, added beforeare enters the flash the influent mixer; then the water enters the flocculation chamber where mechanical mixers gently agitate the water for 10 to 20 minutes depend- ing on the flow. The flocculated water then enters the tube settlers, which consist of many 1 inch (2.5 centimeters [cm]) deep, 39 inches (99 cm) long split hexagonal shaped passage- ways. The large surface area of the many 1 inch (2.5 cm) deep tube settlers achieves an effective clarification overflow rate (6.1 cubic of less than 150 GPD/square foot meters). Adequate clarifica- meters/day/square minute tion is attained with less than 15 detention times. The clarifier water then enters a gravity flow mixed-media filter (a filter with a coarse-to-fine gradation of filter media or several types of filter media). A constant filtration rate is maintained pump discharging by a low-head filter effluent through a float-operated, level control valve. After a preset headloss is reached, backwashing of the filter is initiated automatically. (Headloss is pressure or energy loss as a result of turbulence caused by the velocity of water flowing and the roughness of the channel walls.) A manual backwash cycle can be initiated any time (if desired). Settled sludge from the tube settlers is flushed during the backwashing cycle. Combining backwashing and tube settler flushing simplifies operations and reduces operator skill requirements. four

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the automationfails, operator needstoturn rawwaterqualityvaries. When situations where success ofanypackageplant, particularlyin Operators are thecriticalfactorinoverall Subsequently, annualvisitsshouldbesufficient. the nextshouldfollowinanothersixmonths. more thansixmonthsafterinitialoperation; recommended. Thefirst visitshouldbeno are equipment operationandperformance adjustments totheplantandinspect Periodic visitsbythemanufacturer tomake shootingguides. instructions, andtrouble chemicaldosages,operating lishing proper contain operatingprinciples,methodsofestab- Typical plantoperatorandmaintenancemanuals characteristics. time operatorsorwithhighlyvariableinfluent especially appropriate forplantswithoutfull- levels. Automatedchemicalfeedsystemsare finished waterdoesnotexceedsetturbidity are thatthe builtintomanyplantstoensure turbidimetersandfail-safecontrolsThe effluent hensive trainingsession. manual, andshouldhaveattendedacompre- with watertreatmentprinciplesandtheplant However, theoperatorneedstobewellacquainted welldocumentedinmanuals. are requirements variable influentcharacteristics.Maintenance for plantswithoutfull-timeoperatorsorwith Chemical feedcontrols are especiallyimportant operating parameters,suchasbackwashing. connected tochemicalfeedcontrolsandother turbidimeters mated featuressuchaseffluent Package plantoperationissimplifiedbyauto- Operation andMaintenance solids. mance isenhancedbysomeresidual becauseperfor-adsorption mediaisnotdesired and eighthhour. Completecleaningofthe is generallytimedtooccurbetweeneveryfourth away bytheflowofincomingwater. Flushing bing actiondislodgessolids,whicharewashed causes avigorous scrubbingaction.Thescrub- The airintroduced undertheadsorptionmedia monitors headlossacross theadsorptionmedia. switchthatcontinuously timer orapressure process isautomaticallyinitiatedeitherbya removed bytheclarifier. The clarifiercleaning than filterbackwashingbecausemore solidsare clarifier cleaningisinitiatedmore frequently

○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○○ at BriefsfromourWebmay downloadTech site are availableattheabovenumbers oryou Additional free copiesofTechBrieffactsheets the abovenumbers. calltheNDWCatoneof further information, thecountry.For at smallwatersystemsaround abouttechnologiesinuse contains information isapublicreference databasethat (RESULTS) forSmallSystems Technologies ers ofTreatment Also, theNDWC’sRegistryofEquipmentSuppli- to orders. ndwc.wvu.edu viae-mailat be ordered alsomay item #DWBKDM04.NDWCproducts (800) 624-8301or(304)293-4191andrequest order,book, costs$30.05.To calltheNDWCat Facilities Drinking Water Treatment nologies forUpgradingExistingorDesigningNew photocopyingexpenses. to helprecover thisdocument also,butatacost (NDWC) offers The NationalDrinkingWater Clearinghouse Development at(513)569-7562. and ofResearch Protection AgencyOffice theU.S.Environmental from free ordered Facilities New DrinkingWater Treatment forUpgradingExistingorDesigning Technologies primarily from twosources: inthisfactsheetwasobtained Information information? Where more canIfind operate theplantmanually. theautomaticcontrols/instrumentationand off 2 “Package PlantsforSmallSystems:AField (2) (1) http://www.ndwc.wvu.edu. pages 39–47. Lay. and Trudie Jr.,Lykins JamesGoodrich,DallasPost, Study” bySusanCampbell,BenjaminW. Facilities, Designing NewDrinkingWater Treatment Technologies forUpgradingExistingor EPA/625/4-89/023; and . Postal charges are added . Postalchargesare AWWA Journal SIX•November 1997 ndwc_orders@ , a209-page , Nov.1995 Tech- can be