Operations andMaintenanceManual

17

AJR STRIPPING FACILITY

Eau Claire Municipal Well FieldEau Claire, Wisconsin

CKMHIIL October, 1987

CONTENTS

SectionIntroduction 1-1

Facility Overview 1-1Manual Organization 1-4

Process Description 2-1Process Summary 2-1

Treatment System Overview 2-1Air Stripping Process 2-3

Control Concept 2-7Facility Description 3-1

Packed Towers 3-1Inlet Distribution Header and 3-2

Weir-Trough DistributorPacking Media 3-2Sump and Plenum 3-3Mist Eliminator and Stack 3-3Differential Pressure Gauges 3-4

Packed Tower Fans 3-4Effluent Pumps 3-5Booster Pump 3-6Chlorine System 3-7Acid Wash/Hypochlorite Wash System 3-9Sump Pumps 3-10Equipment Summary 3-11

Control Systems 4-1Local Control Panel 4-1Remote Plant Control Panel 4-2Control Loops 4-3

Packed Towers 4-3Tower Effluent Pumps 4-7Building Sump Level 4- 10Well Field Booster Pump Control 4-11Chlorine System 4- 13Remote System Alarms 4- 16Annunciator 4 - 18Existing Well Pumps ShutdownInterlock 4- 18

Programmable Controller Failure 4- 19System Shutdown 4-20

Process Equipment Operation 5-1General Considerations 5-1Packed Tower Fans 5-2

Startup 5-2Normal Operation 5-3Shutdown 5-3

CONTENTS (Continued)

SectionPacked Towers 5-4

Startup 5-4Normal Operation 5-4Shutdown 5-5

Effluent Pumps 5-5Startup 5-5Normal Operation 5-7Shutdown 5-8

Booster Pump 5-8Startup 5-8Normal Operation 5-9Shutdown 5- 10

Chlorine System 5- 10Startup 5- 10Normal Operation 5-11Shutdown 5- 12

Acid Wash System 5- 12Startup 5- 13Wash Cycle 5- 14Discharge Cycle 5- 16Flush Cycle 5- 17Shutdown 5- 18

Hypochlorite Wash System 5- 19Startup 5-19Wash Cycle 5- 19Discharge Cycle 5-20Flush Cycle 5-20Shutdown 5-20

Valving Arrangements for NormalOperating Modes 5-20

Monitoring 6-1Pressure Loss Through Towers 6-1VOC Removal Efficiency 6-2Fluctuations in Contaminant

Concentrations 6-2Recordkeeping 7-1Maintenance 8-1

Tower Sump and Plenum 8-1Tower Internals 8-1Air Vents and Overflows 8-2Blower Drive Belts 8-2Silencers and Blowers 8-3

11

CONTENTS (Continued)

Section

10

Utility SystemsHVAC

Main Equipment RoomChlorine Room

Electrical SystemSafety

Potential Hazardous AreasSafety Equipment

Paae9-19-19-19-29-3

10-110- 110-4

Appendix A.Appendix B.Appendix C.

TroubleshootingQuality Assurance Project PlanProgrammable Controller SoftwareDocumentation

GLT590/34

ill

Introduction

Section 1INTRODUCTION

This manual provides the information necessary for the oper-ation of the air stripping facility located in the Eau ClaireMunicipal Well Field. The manual describes the overall treat-ment system, the equipment used in air stripping process/ andthe instrumentation and controls for the process equipment.Procedures for startup, normal operation, and shutdown of theprocess equipment are also described.

This manual is intended to be used in conjunction with theoperation and maintenance (O&M) manuals provided by the manu-facturers of the process equipment, and as such will notfocus on routine maintenance of standard equipment items( i . e . , pumps, motors, valves, e tc . ) . Reference to the manu-facturer's O&M manuals will be made throughout this manualand it is, therefore, imperative that the operators becomefamiliar with those documents as well.

FACILITY OVERVIEW

The air stripping facility consists of two packed towers com-plete with internals and media, two fan units, two effluentpumps, a booster pump, a continuous chlorination system, andan acid hypochlorite wash system. Except for the packed

1-1

towers and fan units, all equipment and controls are locatedin the Mechanical Building as shown in Figure 1-1 . The tow-ers and fans are located on a concrete slab just east of thebuilding.

The primary function of the air stripping facility is toremove volatile organic compounds (VOCs) from the ground-water supplying the municipal wells. As their name implies,VOCs will volatilize or transfer from the water to the airat the air/water interface. In the air stripping process,the contaminated water is pumped to the top of the towers anddistributed over a bed of loosely packed media. As the watercascades down through the packing media, it breaks up intosmall droplets that provide a large surface area and, there-fore, a large air/water interface for the transfer of VOCs.Air is forced through the packing from the tower base toenhance the transfer of VOCs from the water to the air. Thetreated water then collects in a sump in the tower base andis pumped to the existing water treatment plant for furthertreatment prior to distribution.

The air stripping facility was designed to handle a totalflow of 1 1 . 2 million gallons per day (mgd) from Well Nos. 11,14, 15, 16, and 17. Modifications have also been made toallow flow from Well No. 10 to be diverted to the air strip-ping facility; however, it is not recommended that flow fromall six wells be directed to the towers at the same time.

1-2

c cVARIABLEFREQUENCYDRIVES

LOCAL CONTROLPANEL WITHPROGRAMMABLECONTROLLER

FROMCONTAMINATEDWELLS

CHLORINEROOM

BOOSTERPUMPMCC ANDSUBSTATION

EXISTING 24WATER MAIN

EFFLUENTPUMPS24 POLYETHYLENE

WASTE LINEMECHANICALBUILDING

TO SLUDGELAGOONS

PACKEDTOWER FANS

PACKEDTOWERS

WASHRECIRCULATIONPUMP

TO EXISTINGWATERTREATMENTPLANT

FIGURE 1-1AIR STRIPPING FACILITYGENERAL LAYOUTCITY OF EAU CLAIRE

This could result in operational problems and inadequateremoval efficiencies in the packed towers. (This is dis-cussed in more detail in Section 5 — Process Equipment Oper-ation. )

The five VOCs detected in the groundwater are:

o 1, 1-dichloroethene ( 1 , 1 -DCE)o Trichloroethene (TCE)o Tetrachloroethene (PCE)

, , o 1 ,1-dichloroethane ( 1 , 1-DCA)o 1,1 , 1-trichloroethane ( 1 , 1 , 1-TCA)

The air stripping system was designed to achieve 9 9 . 3 percent\.^S removal of 1 , 1 -DCE at a design concentration of 20 ppb and a

flowrate of 1 1 .2 mgd. 1 ,1-DCE was selected as the criticalcontaminant for design since it requires the most completeremoval. Achieving the design removal efficiency for 1 , 1 -DCEresults in removal efficiencies which exceed those requiredfor each of the other VOCs listed above.

Since the potential for contaminants to migrate further intothe well field exists, the air stripping facility wasdesigned so a third packed tower could be retrofit, if neces-sary.

1-3

MANUAL ORGANIZATION

A brief summary of the sections in this manual follows:

o Section 2—Process Description. Describes the pro-cess function, its relationship to other processes,operational goals, and the control considerationsto achieve them.

o Section 3—Facility Description. Describes thelayout, functions, and operational characteristicsof the system components.

o Section 4—Control Systems. Describes the compon-ents of the instrumentation and controls system andpresents the function and logic of the controlloops and the associated alarms.

o Section 5—Process Equipment Operation. Presentsstep-by-step procedures to start up, operate, andshut down the air stripping process equipment.

o Section 6—Monitoring. Describes sampling and ana-lysis procedures to monitor the effectiveness ofthe air stripping system and suggested procedures

1-4

in the event that VOC concentrations in the wellwater increase above the design concentrations.

Section 7—Recordkeeping. Describes the record-keeping requirements for the air strippingprocess.

Section 8—Maintenance. Describes routine mainten-ance and inspection of specific system componentswhich are not covered in the manufacturer's O&Mmanuals.

Section 9—Utility Systems. Briefly describes theutilities serving the air stripping facility.

Section 10—Safety. Discusses the safety equip-ment provided with the air stripping facility.

Appendix A—Troubleshooting. Identifies the more————————————————————common operating problems, causes, and correctiveactions associated with the process and processequipment.

Appendix B—Quality Assurance Project Plan.

1-5

o Appendix C—Programmable Controller Software Docu-mentation

GLT590/26

1-6

Process Descripton

Section 2I , PROCESS DESCRIPTION

This section provides an overview of the entire air strip-ping treatment system and then presents a more focused dis-cussion of the air stripping process. The control consider-ations to achieve operational goals are also discussed.

PROCESS SUMMARY

TREATMENT SYSTEM OVERVIEW

The air stripping system acts as an intermediate treatmentstep between the existing well field pumps and the watertreatment plant (Figure 2-1 ) . The well field piping has beenmodified so that flow from the existing contaminated wells(Well Nos. llf 15, 16, and 17) is pumped directly to the airstripping facility. Isolation valves have also beeninstalled so that Well Nos. 10 and 14 can be routed eitherdirectly to the existing water treatment plant or through theair stripping system if they become contaminated. The exist-ing pumps in the four contaminated wells are capable of deliv-ering flows up to 6.2 mgd to the air stripping towers withoutthe use of the booster pump. With the addition of Well No.14, approximately 7.1 mgd can be delivered to the air strip-ping towers. The approximate incremental flowrates that can

2-1

, . . . .-- 38" MAiM FROM NOH1 H

NEW VALVE

FIGURE 2-1MODIFICATIONS TOEXISTING WELL FIELDCITY OF EAU CLAIRE

be delivered to the stripping system from the existing well\J field pumps are shown in Table 2-1 . Due to the increased

static head of the packed towers, the existing pumps are notable to achieve the desired flowrate. The booster pump sup-plies the additional head to increase the flowrate of thetowers to a maximum of 1 1 .2 mgd.

Treated water from the stripping towers is pumped by thetower effluent pumps into the north well field raw water pipeand then flows to the water treatment plant. The tower dis-charge piping is manifolded in such a way to allow the oper-ation of either tower while the remaining tower is out-of-service.

A continuous chlorination system is provided in the airstripping facility to maintain a sufficient chlorine concen-tration to prevent any biological growth in the towers.Although several of the existing wells have the capabilityof adding chlorine at the well head, a controllable systemcapable of treating all the flow that could be routed to thetowers is required. Continuous disinfection of the towerprovides more reliable protection from bacterial growth andis therefore recommended instead of shock treatment of thetower and packing. However, a hypochlorite wash system hasbeen provided to allow for shock chlorination if necessary.

2-2

Table 2-1i ^ WELL WATER DELIVERED TO AIR STRIPPING TOWERS

Flow_____Operating Pump(s)_____ (gpm) (mgd)Wells No. 15 and 17 2 , 5 0 0 3 . 5 6Wells No. 15, 17, and 16 3 , 6 0 0 5 . 2 0Wells No . 15, 17, 16, and 1 1 4 , 3 0 0 6 . 1 8Wells No. 15, 17, 16, 1 1 , and 14 4 , 9 0 0 7 . 0 7Wells No. 11 , 15, 16, 17, 14and Well Field Booster Pump 7 , 8 0 0 1 1 .2

Note: Flowrates are based on the capacity of the wellswhen the well screens are clean. Actual flowratesdelivered to the facility vary under normal operation

GLT590/31

The air stripping process and the continuous disinfection ofthe raw water with chlorine may cause oxidation of some ironand manganese compounds, resulting in the formation of aninsoluble precipitate on the tower media. The packing mediamay require occasional cleaning and flushing to remove theprecipitate and prevent plugging. The acid wash system isprovided to remove any metal precipitates. The system con-sists of a fiberglass recirculation pump to circulate a mildacid solution (about 1 to 5 percent hydrochloric (HC1) acid)through each tower for a period of time sufficient to loosenthe precipitates. All piping and valves exposed to the acidwash solution are constructed of acid resistant fiberglassmaterials. The spent cleaning solution is pumped to wasteusing the circulation pump. After flushing, the towers and

\^s sumps should be manually inspected and put back on-line.Discharge of the spent acid wash and the flushing water isrouted to the existing lime sludge lagoon through a 24-inchpolyethylene waste line.

AIR STRIPPING PROCESS

The following discussion is intended to provide some insightinto the design of the air stripping system so the operatoris better prepared to make process decisions and detect poten-tial operational problems.

2-3

The critical parameters in the design of the air stripping\J towers were water flowrate, the air to water ratio, water

temperature, contaminant concentration, and the desiredremoval efficiency. Table 2-2 lists the parameters used inthe design of the air stripping towers for Eau Claire.

Water Flowrate

The towers were designed to handle a maximum flowrate of 1 1 .2mgd ( 7 , 8 0 0 gpm) which corresponds to a maximum hydraulic load-ing rate of 3 4 . 4 gpm/fta. The hydraulic loading rate is cal-culated as follows:

QHydraulic loading rate(N x A)

where:Q * Total water flowrate (gpm)N = Number of towers in serviceA « Cross-sectional area of towers(for 12-foot-diameter, A « 1 13 . 1 fta)

Operation at hydraulic loading rates above 34 gpm/ft2 is notrecommended since it may cause operational problems such asflooding or channeling and may result in decreased removalefficiencies. Figure 2-2 illustrates the recommended rangesof liquid flowrate for single-tower and two-tower operations.

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Table 2-2SUMMARY OF DESIGN PARAMETERS

Water Flowrate 1 1 .2 mgd ( 7 , 8 0 0 gpm)Water Temperature 50° F ( 10° C)1,1-DCE Concentration 20 ppbDesired Removal Efficiency 9 9 . 3 %Air/Water Ratio (by volume) 50 : 1Tower Diameter 12 feetPacking Depth 26 feet

GLT590/32

SWITCH TOSINGLE-TOWER TWO-TOWER

OPERATION OPERATIONTWO-TOWEROPERATION

OPERATION ATHYDRAULIC LOADINGRATES ABOVE34 gpm/ft2 ISNOT RECOMMENDED

0 1,000 2,000 3,000 4.000 5,000 6.000 7,000 8,000 9.000 10,000

WATER FLOW RATE(gpm)

FIGURE 2-2HYDRAULIC LOADING VSWATER PLOW RATECITY OF EAU CLAIRE

Air/Water Ratio

The air/water ratio is simply the volume 6f air (cfm) sup-plied to the tower divided by the volume of water (cfm)being delivered to the tower. By varying the air/waterratio, the operator is able to increase or decrease theremoval efficiency of the tower. For example, if the waterflow was held constant and the air flow was increased, theair/water ratio would increase and the removal efficiencywould also increase. If the air flow was decreased, theair/water ratio would decrease and the removal efficiencywould also decrease. In the same manner, the water flowcould be adjusted to either increase or decrease the removalefficiency.

However, there are practical limitations on the extent towhich the air and water flows can be adjusted. At high waterflows (liquid loading rates above 34 gpm/ft a), the inlet dis-tributor may flood causing flow channelization, increasedheadloss, and poor removal efficiencies. High water flowscan also cause a condition known as "flooding" of the packingin which the volume of water passing through the packingdecreases the area through Which the air must flow. Theresult is that an increasing quantity of water is held up inthe packing and the pressure drop increases significantly.Flooding can also occur at low water flows and high air flows.

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Water Temperature

The performance of the air stripping tower is very sensitiveto the temperature at which it operates. The system wasdesigned to operate at a temperature of 50 °F and this valueis expected to remain relatively constant. However, a temper-ature drop of about 5 degrees may occur during extremely coldmonths. As the temperature within the tower drops, theremoval efficiency also drops. If necessary, the air/waterratio can be increased (as described earlier) to compensatefor the efficiency loss during these periods.

Contaminant Concentration and Desired Removal Efficiency

The air stripping towers were designed to achieve 9 9 . 3 per-cent removal of 1 , 1-DCE at an influent concentration of20 ppb and an air/water ratio of 50. This removal efficiencywill result in an effluent concentration which meets the

41 j appropriate regulations. If the influent concentrationexceeds the design value of 20 ppb, the system will stillachieve 9 9 . 3 percent removal; however, the effluent concen-tration will be higher and may exceed the regulatory limits.In this situation, the air/water ratio will need to beincreased (as discussed previously) to achieve a higher per-cent removal.

2-6

If the influent concentration is below the design concentra-t J tion, the system will easily achieve 9 9 . 3 percent removal.

In this situation, the air/water ratio could be decreased toreduce the power consumption of the tower fans. It is alsonoteworthy that at very low concentrations (less than1 ppb), it becomes more difficult to achieve the9 9 . 3 percent removal. However, at this low of an influentconcentration, the effluent will be well within theregulatory limits.

CONTROL CONCEPT

Primary control of the air stripping facility is slaved tothe contaminated well field pumps which are in line with thefacility. When one or more of the contaminated wells isturned on, the stripping system will self-start as the con-taminated water begins to flow to the system. All logic forthe control of the system is handled through a programmable

* , controller. The tower fans and the chlorination system startautomatically on a flow indication signal from the towerinfluent flowmeters. The tower effluent pumps start automat-ically when the water level in the tower sumps reaches aspecified set point. The tower effluent pumps are equippedwith adjustable speed, variable frequency drives controlledby level sensing in the tower sumps. The programmable con-troller also provides the interface between the air stripping

2-7

facility and the telemetry system. System on/off, system\J trouble, and system fail status are sent to the main control

area at the existing treatment plant. The well field boosterpump has the provision for starting and stopping from aremote telemetry signal from the main plant control system.The booster pump effectively operates as another well fieldpump.

Valving arrangements to configure the system with one or twotowers in operation is handled manually at the strippingfacility. The chlorination system requires manual settingat a specific concentration which is maintained automaticallyby flow pacing. The wash recirculation pump and the cleaning/flushing cycle are manually controlled.

GLT590/28

2-8

Facility Description

Section 3FACILITY DESCRIPTION

This section describes the general layout, functions, andoperating characteristics of the specific components of thefacility.

PACKED TOWERS

The air stripping facility has two packed towers (PT-1A andPT-1B) each 12 feet in diameter and 60 feet high includingthe stack. The towers are constructed of fiberglass rein-forced plastic (FRP) with an outer protective coating to pre-vent damage from ultraviolet light. Each tower has five man-holes to provide access to the tower internals and media.

A cross-sectional view of a tower is illustrated in Fig-ure 3-1 . Well water enters the side of the tower through aflanged inlet approximately 41 feet above the tower bottom.The water discharges, by means of an inlet distributionheader, into two parting boxes on the weir-trough distributorThe water then flows from the parting boxes into 12 lateralboxes that evenly distribute the water over the media. Asthe water cascades down through the media, it comes in con-tact with air that is forced through the air inlet openinglocated just below the packing support. Within this section

3-1

LIFTING LUG -

STACK SAMPLING PORT

ACID/HYPOCHLORITEWASH FEED INLET

RAW WATER INLETT. ' . . ' . ' . . '/.my.. ' . . ' . ' . '. . . . . . . . . . . . . n .v . .- . .- . .- ,r

\v H

DIFFERENTIAL PRESSUREGAUGE

ACID/HYPOCHLORITEADDITION INLET

TOWER EFFLUENT PIPEVESSEL I .D.

MIST ELIMINATOR

INLET DISTRIBUTION HEADER

WEIR-TROUGH DISTRIBUTOR

BED LIMITER

PACKING SUPPORT

48" WIDE X 36" HIGH AIR INLET

HIGH LEVEL SWITCH

PRESSURE TRANSDUCER

FIGURE 3-1CROSS SECTION OF PACKED TOWERSCITY OF EAU CLAIRE

of the tower, the VOCs transfer from the water to the air and^ J the exhaust air then passes through a mist eliminator and

exits through the top of the tower. The treated water col-lects in the tower sump and is pumped to the existing treat-ment plan.

INLET DISTRIBUTION HEADER AND WEIR-TROUGH DISTRIBUTOR

The inlet distribution header and weir-trough distributor areshown in more detail in Figure 3 -2 . Both the header and thedistributor are constructed of FRP. (Figure 3-2 also illus-trates how the acid/hypochlorite wash inlet connects into themain distribution header.)

The inlet distribution system was designed to evenly distri-bute water over the entire cross-sectional area of the towerwhile providing sufficient open area for the passage of theair flow. Even distribution of the water flow is criticalto proper operation of the air stripping towers. If the dis-tributor is not level or becomes clogged in one portion,uneven distribution and channelization could occur and wouldresult in decreased removal efficiencies.

PACKING MEDIA

The packing media in the towers is polypropylene Jaeger Tri-packs No. 2 (3- 1/2 inches in diameter) . The bed of packing

3-2

c c C c C

ACID/H YPOCH LORITEWASH FEED INLET

RAW WATER INLET

PARTING BOXES

3/4" 0 HOLES

LATERAL BOXES

FIGURE 3-2INLET DISTRIBUTION HEADERAND WEIR-TROUGH DISTRIBUTORI-ITV np FAI I n AIRE

in each tower is 26 feet dee|> and is held in place with a bedlimiter at the top and a packing support at the bottom. Thebed limiter is a FRP grating which prevents the media frombeing blown up into the distributor. The packing support isa gas-injection type support plate also of PRP construction.The support plate is designed to support the bed of mediawhile providing even distribution of the air and allowing thepassage of treated water into the tower sump.

SUMP AND PLENUM

The bottom section of each tower serves as both a plenum foreven distribution of the air and as a sump for collection ofthe treated water. An underflow baffle is located over theeffluent port in each of the tower sumps to provide a quies-cent zone for the release of entrained air prior to dischargeof the treated water. An acid/hypochlorite addition inletis also provided for addition of the chemicals necessary to

* , perform the acid wash or shock chlorination.

MIST ELIMINATOR AND EXHAUST STACK

As the air passes through the packed tower, it picks up notonly VOCs, but also a considerable amount of moisture. Amist eliminator (a polypropylene mat) is located just abovethe inlet header to remove water droplets entrained in theair. The air then exits the tower through a 4-foot-diameter

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exhaust stack. A gas sampling port is located on the sideof the stack for monitoring emissions if it should becomenecessary in the future.

DIFFERENTIAL PRESSURE GAUGE

A diaphragm-actuated pressure gauge is provided on each towerto measure the pressure differential across the packed bed.The gauge provides the operator with a means to detect prob-lems (such as plugging from bacteria or scale) within thetower .

A summary of the packed tower components is presented inTable 3-1 .

PACKED TOWER FANS

Air is supplied to each packed tower by a forced draft fanunit. A separate fan is provided for each tower as shown inFigure 3-3 (TSF-1A and TSF-1B) . Both fans have the samecapacity and are manually controlled to maintain a specificair to water ratio as described in Section 2. Control of theair flow is accomplished by manually adjusting the inletdampers.

The two fans are Class II, centrifugal fans with backwardinclined airfoil blades. The fans have a rated capacity of

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Table 3-1SUMMARY OF PACKED TOWER COMPONENTS

ComponentMist Eliminator

Inlet HeaderWeir-TroughDistributor

Bed LimiterMedia

Packing SupportBaffleAcid InletPressure Gauges

Quantity(per tower)

1

11

12,941 ft3

1

1

1

1

ManufacturerKoch

DeltaKoch3(Delta)Delta

JaegerTri-packs

DeltaDeltaDeltaDwyer

Model Number2414

(polypropylene)—

302 (FRP)

D-FRP-141

2( po 1 yp ropy 1 ene )

RD-FRP-1209

——

2004-LT

Distributor design by Koch Engineering Company butmanufactured by Delta Reinforced Plastic Structures

GLT590/33

PLANT NORTH

BOOSTED PUMPIJECTOR

I l/Z" FVlS TO 24'MOUMT

, OVER

TOWER F;CTVPI —

tHLORIMATOKUP TO EF-Ie'.B'CuCT DOWN! TO I'-O ABOVE FLOOR

1 7 , 5 0 0 cfm at 4.3 inches of static pressure, 70 °F , andI j 1 , 0 5 0 rpm. The fans are belt driven using constant speed,

20-hp, 460-vol t , three-phase, 60 -Hz, 1 ,800-rpm, drip-proofelectric motors. A bird screen and inlet silencer areincluded with each fan unit.

EFFLUENT PUMPS

Treated water is pumped from the tower sumps to the existingwater treatment facility by two effluent pumps (P-2A andP-2B) located in the mechanical building. Each pump has suf-ficient capacity to pump the maximum design flow, so thesecond pump is included as a standby. As shown in Figure 3-3 ,the tower effluent piping is manifolded so that either pumpcan be used as the lead pump while the second pump is placedon standby or taken out of service for maintenance.

The two effluent pumps are horizontal split case, single-i stage, double suction, centrifugal pumps with 100-hp

variable-speed drives. Each pump has a rated capacity of8 , 5 0 0 gpm at 30 feet of head and 880 rpm.

The pumps operate automatically based on the water level inthe tower sumps. Control signals from the pressure trans-ducers in the sumps are sent to the programmable controllerwhich automatically adjusts the speed of the effluent pumps.A low inlet water pressure switch is provided on the suction

3-5

side of each pump to prevent damage from cavitation or lowflow conditions.

BOOSTER PUMP

During normal operation, the existing well field pumps haveadequate capacity to meet the water supply requirements ofthe City. However, in periods of high water demand, thedynamic pressure losses through the well field piping limitthe flow that the well field pumps can achieve with theincreased static head of the packed towers. The booster pumpis used to provide the additional energy necessary to meetthe desired flow at the increased head. The booster pump islocated in the mechanical building (Figure 3-3) and must beturned on manually at the local control panel or by a remoteswitch located in the existing treatment plant.

The booster pump is a horizontal split case, single stage,i , double suction, centrifugal pump with a 100 hp constant-speed

drive. The pump has a rated capacity of 7 , 8 0 0 gpm at 35 feetof total head and 880 rpm. A low inlet water pressure switchis provided to prevent damage from cavitation or overheatingduring low flow conditions.

3-6

CHLORINE SYSTEM

The continuous chlorination system is provided in the airstripping facility to maintain a sufficient chlorine concen-tration in the water to prevent any biological growth on themedia and tower internals. The system is located in asealed room in the northwest corner of the mechanicalbuilding (Figure 3 -3 ) . The major components of the systeminclude two direct cylinder mounted chlorinators, anautomatic switchover module, a flow proportioning gascontrol valve, an ejector, a chlorine feed pump, atwo-cylinder scale, and a chlorine detector.

Two 150-pound cylinders of chlorine gas are connected to thesystem during normal operation. When one cylinder becomesempty, the chlorinator will automatically switch over to theother cylinder. Ample space has also been provided for stor-age of four additional cylinders in the chlorine room.

The chlorinators are vacuum operated, solution feed unitswith a maximum capacity of 100 pounds of chlorine gas per24 hours ( 100 ppd). The chlorinators have a visual indicatorto signal exhausted or interrupted gas supply and a pressurerelief valve to vent excessive pressure within the chlorin-ator.

3-7

The flow proportioning gas control valve is a wall-mountedunit located between the automatic switchover module and theejector. As the influent water flow varies, the controlvalve automatically adjusts the gas feed rate to maintain apre-selected dosage. A dosage control knob is provided tomanually set or adjust the desired dosage. A Manual/Autoswitch and a manual rate adjustment knob are also providedto manually operate the valve in the event of a power failure,loss of input signal, or manual override. (Under normal oper-ating conditions, a dosing rate between 0 . 2 5 and 0 . 5 0 ppm isrecommended to control biological growth in the tower.)

Solution feed water for the chlorine system is piped in fromthe booster pump influent line, through a chlorine feed pump(to increase pressure) , and then into the ejector. Thechlorine feed pump (P-6) is a 1- 1/2 hp, self-priming centri-fugal pump. A low pressure switch is provided to trigger aremote alarm when the pressure in the discharge line from thechlorine feed pump is below a pre-set pressure. The set pres-sure varies depending on the chlorine requirement.

The chlorine solution from the ejector is transported througha 1-1/2-inch PVC line to the tower influent header (Fig-ure 3-3) . A 1-1/2-inch check valve prevents backflow ofwater and a 1-1/2-inch ball valve is provided to allow shut-down of the chlorine system if necessary.

3-8

A chlorine leak detector is provided in the chlorine room to\J detect 1 ppm of chlorine in the air. The detector has a

warning light which will flash at 1 ppm and an alarm lightand audible horn which will activate at 5 ppm of chlorine.(The set points are adjustable.) A control signal from thedetector will automatically cause the emergency exhaust fanto start and the louvers on the vent to open when chlorineis detected at 1 ppm.

ACID WASH/HYPOCHLORITE WASH SYSTEM

Air stripping of the well water may cause the oxidation ofsome iron and manganese resulting in the formation of a pre-cipitate on the packing media. A buildup of precipitatecould cause plugging and result in increased headloss andpoor removal of VOCs. The acid wash system provides a meansto clean the media without removing it from the tower. Thewash system is also designed to be used for shock chlorin-ation of the packing media if continuous chlorination is notsufficient to prevent biological growth or if a tower hasbeen out of service for a period of time.

The system consists of a fiberglass recirculation pump(located in the southeast corner of the mechanical building)and the associated piping network as shown on Figure 3-3.The recirculation pump (P-3) is a horizontal, end suction,

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centrifugal pump with a 25-hp constant-speed drive. The pump\J has a rated capacity of 1 , 0 0 0 gpm at 50 feet of total head

and 1 , 7 5 0 rpm. More detail on the actual operation of thewash system is provided in Section 5, Process EquipmentOperation.

SUMP PUMPS

Two sump pumps (P-4A and P-4B) are located in the sump in thenortheast corner of the mechanical building. The sump isprovided to collect floor drainage and to allow the towersumps and effluent piping to be drained if necessary. Bothpumps discharge into a common pipe which connects to the24-inch polyethylene waste line (Figure 3 -3 ) . The pumpsoperate based on the liquid level in the sump:

o Level Switch Low — Pumps turn offo Level Switch Medium — Lead pump turns ono Level Switch High — Lag pump turns ono Level Switch High-High — Alarm is actuated

The pumps alternate between the lead and lag position eachtime they are used. The two pumps are 1- 1/2 hp, verticalwet-pit centrifugal pumps with a rated capacity of 100 gpmat 24 feet of head and 1 , 150 rpm. The motors arethree-phase and 460 volts.

3-10

EQUIPMENT SUMMARY

Table 3-2 summarizes the pertinent information on the majorprocess equipment for the air stripping facility.

GLT590/30

3-11

c c C c CTable 3-2

EQUIPMENT SUMMARY

Quantity Item

2 Packed lowerFans

2 Effluent Punps

1 Booster Pu»p

2 Sump Punps

1 HashRecirculationPump

1 ChlorineFeed Puap

Manu f ac tur er Equipment& Model No. Tag No.

New York Blower TSF-1A#363, Class II, 6P TSF-1B

Inger soil-Rand P-2A, P-2B14 x 18 x 19 SL

Inger soil-Rand P-514 x 18 x 19 SL-A

PACO P-4A, P-4BType SL- 2095-0

Ingersol 1-Rand P- 36 x 4 x 10 GRP

Sta-Rite P-6DHF3-3

Unit Sizeor Capacity

17,500 cfm @ 4.3 in s.p.,1,050 rpm, Local20 Hp motor

8,500 gpm @ 30 f t TDH,880 rpm,100 Hp variable-

speed drive

7,800 gpm 0 35 ft TDH,880 rpm,100 Hp motor

100 gpm @ 24 ft TDH,1,150 rpm,1-1/2 Hp motor

1,000 gpm @ 50 f t TDK,1,750 rpm,25 Hp motor

7.5 gpm @ 50 psi,3,450 rpm,

Type of Control

1. HAND/OFF/AUTO

2. Programmablecontroller

1. HAND/OFF/AUTOLocal

2. Programmablecontroller

1. START/STOPLocal

2. START/STOPTreatment Plant

1. HAND/OFF/AUTOLocal

2. Float Switches

1. START/STOPLocal

1. ON/OFF/AUTOLocal

Shutdown& Alarms

None

Low inletpressure

Low inletpressure

High levelalarm

None

Low dischargepressure— t • — — - I— J

1-1/2 Hp motor 2. Programmablecontroller

GLT590/40

Control Systems

0 0

_J I.__I

F^^NEL. CP ELEVATIONSI'-O"_J

ITEMNO.i2345678910

II

TAGNO.

HS-8 (ACKlHS-8 [TEST] _ _ns-a IRESETIFI - 1ALI- 'AFI- 1BLI-IBHS-I[A-B-BOTH]

PANEL SCHEDULENAMEPLATE INSCRIPTION

nRST UNE / SECOND LINE / THIRD UNECONTROL PANEL / CP120 POINT ANNUNCIATOR LIGHT CABINET)

—————————————————————————————————————————————————————

p r.Kcn TnwFB A / INFLUENT FLOWP CKEO TOWER A / SUMP LEVELP CKED TOWER B / IMFLUEMT FLOWP CKED TOWER B / SUMP LEVELP CKED TOWER / SELECT

TOWER EFFLUENT / LEAD PU«P / SELECT

D

FIGURE 4-1LOCAL CONTROL PANEL

WINDOWHOW-COL

ANNUNCIATOR SCHEDULEWINDOW INSCRIPTION

FIRST UNE / SECOND UNE / THIRD UNE;PACKEC)_TOWER_ / KOT SELECTED

_ _ [PACKED IQ1KER / FIN i ^ FA\J^E_ _ 'PAC«EE> TOWER / A HIGH-H IGH ^E.L,.

. T O W E R EJTLUEtlT / Pl,UP A LCA / \-'.J,~ = i?I P*CK.E.D_TOWi;R_/. EFfl'JENJ_PyW.P /' A -~i'.L

_ "jTTOWE.R..EFFLUENT /LEAD PUWP / NO" Si-ECPACKED 70WTR / FSN 0 / F AILUT

, PACKED TOWER. / 8 H,G't-HIW , lEvL _] IOWER EFFLUENT / pyup B LO* / I N L E T C=; PACKED. TOWER / EFFLUENT PUMP-/ B F A ' I U|BylLplNG.SUMP / hlCH-HICM^Lr.'E.LIBOOSTER_PUMP_/ LOW INLET /_PRESSURE

_TBOOSIER .PUMP_/..FAILJJHE_ ___ _ . _ . _ __ _

[BLANk) . _ _ . _ . . "CHLOflJNE FEED / PUUP FAILURECHLORINE FEED / LOW PRESSURECHLORltJAlOfi / HIGH/LOW / PWESSLIBFCHLOfilNl /J..EAKPSOGR4MUABLE y CONTROLLER / TAILUHf

To Rac> WITH

ki Tni_.__L

COKTKDL f^XHEL MOUNTlHa DETAIL

j$ _ THINK VALUE ENGINEERING — «

COWS OF ENGMEEFBOUHA. NEBRASKA

EMJ CUUM NUHCIPM. WELL FIELDAIR STOWING FACILITY

PANEL ELEUMTKMS,WlfflHG D4AGRAM, AND DETAILS

&*C

yntttnumbvr

1-3

)

FIGURE 4-2PROCESS AND

INSTRUMENTATION DIAGRAM_ THINK VALUE ENGINEERING — $5

wncoNwiEAUCLAHKMUMCIMIWEU. FIELD

AIR STRIPPING FACILITYPROCESS AND INSTRUMENTOIN DIAGRAM

D

5

D

C

B

A

4

INSTRUMENT IDENTIFICATIONEXAMPLE pYMBOlS

_F RST LETTEB 1 S )/^-SUCCEEDING LETTERS

/ / THE TOTAL NUMBER OF UN ITS/ / / 11 V A R I E S FROM t TO A)

\ UN T NUMBER (USED "HEN THERE ARE MULTIPLE\ UN TS B ITH THE SAME X DESIGNAT ON I

LOOP NUMBER

f } F ELD MOUNTED INSTRUMENT

/^S/P

PANEL «

—— •v.00( Qk_i1 j MOTOR C

SPECIAL CASESx— -X00(Q*-\

f ——— j OPENED INC

/7s^C1 1 OPENED ANC

. _ . 00/TTV ON-OFF HAhf H5 \ ICONTHOLLE\~ "7 POKER AfTE

/'H?N STOP-STARTi -•) SH ITCHES\ J ON RETURN

OUNTED INSTRUMENT

3NTROL CENTER MOUNTED NSTRUMtNT

EVENT L IGHTS

CLOSED POS IT ION L IGHTS

CLOSED P O S I T I O N SW ITCHES

O SH TCH. MA INTA INED CONTACT S H I T C HD DEVICE * 1LL RESTART ON RETURN OFR POKER FAILURE).

HAND SK1TCH MOMENTARY CONTACTCONTROLLED DEVICE H ILL MOT RESTARTOF POWER AFTER POWER FA I LURE ) .

A ANALOG

D D I G I T A LE VOLTAGEF FRFQIItr^v E/AHPLE^ S^j\I'P CURRENT TO PNEUMAT 1 C

I CURRENTP PNEUMATICPF PULSE FREQUENCYPD PULSS DURATION

1 NST RU ME NT SF IRST LETTER(S)

PltJCESS 01

tiumisit)IUHE> El HEmoucimn«HTl«tut IME HID,1UCE

: IB RENTDIER CU

KIEL10 TIW

ISIRS CHOICfm•SHSmf lOR I1CUIN)QIUNT1 1 1 I t [ V E M T i M INTE tR

If lffHTUWWITIVHI l l lE lM

KitHi ot tana

t 7 PANEL , IN A FLOB LOOP)

O C l E T V OF A M E R I C A TA B L ESUCCEEDING LETTERS

READMIT 01IE) fWSHt IUHCIW* WIfllt EWCTIWl HOIEI I IILIRIISEK tW)l«(n USERS CHqtCEIt l BERS OBIC i ( l )

II1UI ILiMHl

»IU

COHTROl ST IT IMttm ifiioii .EII

IIMU

1I I I IC1

IE IKIECUl iIECMO 01 HI«I

11U.HH•UTI IUKCTIOIKt )

-. _ mct i s s iF iEDin _ *c >ss i innni unn.tiiiniintini ( 1CTII1TI OR

H> (HEN II 51 0 II'LIIIIION IS UON (OllCtlll 10USTRIHEUT sum SEE tnn«iinoiis UDL i l l EU StMOIS

5

LINE LEGEND

_ _ i —— — ANALOG S IGNAL(4 TO 20 MADC ETC )

——— _ _ _ ,OISCBETE S IGNAL(ON/OFF ETC )——— — ——— B U I L D ING OB F t C I L I TV

BOUNDARY

3 2 1

*1JLJ*. >-MH CONNECTING L INES1 I

11— ; — — — NON-CONNECTING L I N E S

INTERFACE SYMBOLS\LLVf IMTtt f lCE K 0» ISO PBOt ISS ' ^L/^' EITiKHll 10 MOI1ET •'

SELF CONTAINED VALVE &EQUIPMENT TAG NUMBERS

D P

————— GS

ARV

= TANK= MECHAN ICAL EQUIPMENT• GATE* EJECTCR• S ILENCER• » IH RELEASE VALVE" AIR AN3 VACUUM RELEASE VALVE

PCV * PRESSURE CONTROL VALVEPT = P A C K E D TOUER

TSF ' IO»Efi STR IPP ING FIN

X = LOOP SUM8EHY = U N I T WM3EB

VALVE SYMBOLS— OO— GATE Jh PHESSUBE REL I E F— — KN IFE GATE ^ AIR AND/OR VACUUM RELEASE-Hti — BUTTERFLY , REGULATED S IDE— C«J— GLOBE —£%- PRESSURE CONTROL— C«>— BALL — (8>- P INCH

V— 1«0— VEE -BALL -H?!~ NEEDLE-=*>£$ . t .T ——————

-d- O . . P M B A G M @___

PRIMARY ELEMENT— «M-»- PROPELLER OH TURBINE

IQj HETER

1 I ROTAMETEH

SAMPLE

SYMBOLSA LEVEL ( F L O A T )

PUMP & COMPRESSOR SYMBOLSXX AS ADJUSTABLE SPEEDC S - I CONSTANT SPEED (S INGLE SPEED)

C S - ? CONSTANT SPEED UHO SPEED)

—— tf-3f**^ ?OflYRpm*L PUMP &* * SUBMERSIBLE SUMP PUMP

GENERAL NOTES1 CO-P^NENTS *NO PANELS SHCHN HUM t OOUSLE ASTERISK

I " ) ARE TO BE PROV IDED AS PART DF » PACKAGE S Y S T E M1 T H I S IS t STANDARD LEGEND THEREFORE . NCT ALL OF

T H I S I N FORMAT ION MAY BE USED ON T H I S PROJECT

4

MISCELLANEOUS SYMBOLSt20V~- 120 VOLT, 60 HZ POUEH 1- — ^.•^ SUPPLY POINT Jl

t-H 1 I-*-——

Logic

Tower (s) in Service. The PC receives a signal from thePACKED TOWER SELECT switch on the LCP indicating which tow-er (s) are in service — A/B/BOTH. This information is thenused in other process control functions.

Influent Water Flow to Each Tower. The PC receives a flowsignal from each of the influent water flow meters. The PCthen transmits a signal to each of the PACKED TOWER INFLUENTFLOW gauges on the LCP. The PC also uses this informationin other process control functions.

Tower Fan(s ) Run Status. The PC receives a signal from eachof the tower fans indicating the current run status — ON orOFF. The PC also transmits a signal to each of the fan motorstarters. Each fan starts when flow into its respectivetower exceeds 650 gpm. Each fan stops when flow into itsrespective tower falls below 450 gpm.

Water Level in Each Tower Sump. The PC receives a signalfrom the level sensors in each of the tower sumps indicatingthe water level. The PC then transmits a signal to each ofthe PACKED TOWER SUMP LEVEL gauges on the LCP. The PC alsouses this information for control of the effluent pumps (seeControl Loop 2) . If both towers are selected to operate, thePC uses the highest sump level to control the effluent pump

4-4

speed. If only one tower is selected, the PC uses only theselected tower's sump level.

Inlet Pressure on Tower Effluent Pump(s ) . The PC receives asignal from each of the inlet pressure gauges on the effluentpumps. When the pump inlet pressure falls below 12 inchesof water, the PC sends a signal to trigger the TOWER EFFLUENTPUMP LOW INLET PRESSURE alarm on the LCP and initiates a SYS-TEM FAIL at the RPCP. Only the pressure on the selected leadtower effluent pump is used for this control function.

Alarms or Indicator Lights

The following alarms or indicator lights associated with Con-trol Loop 1 are provided on the LCP or RPCP:

LCP

o Tower fan failureo Tower effluent pump low inlet pressureo Tower sump high-high levelo Tower not selected

RPCP

o System A ONo System A OFF

4-5

o System B ONo System B OFFo System Troubleo System Fail

Tower Fan Failure. The tower fan failure alarm is initiatedon the following conditions:

o Failure of the tower fan to start 10 seconds afterit is called to start

o Fan shutdown while system flow still exceeds650 gpm

Tower Effluent Pump Low Inlet Pressure. This alarm is ini-tiated when the pump inlet pressure falls below 12 inches ofwater.

Tower Sump High -High Level. This alarm is initiated when thesump level rises above 5 feet.

Tower Not Selected. This alarm is initiated if the PACKEDTOWER SELECT switch does not provide an input signal to thePC. A 2-second time delay is provided on the alarm to allowfor switching towers.

4-6

System A ON/OFF and System B ON/OFF. These status lights arelocated at the RPCP. A system is ON if the water flow to thetower exceeds 650 gpm, the tower fan is ON, and either efflu-ent pump is operating. A system is OFF if neither effluentpump is running and the system fan is OFF.

System Trouble and System Fail. These alarms are discussedlater in this section.

LOOP 2; TOWER EFFLUENT PUMPS

Function

Control Loop 2 controls all process functions for the towereffluent pumps:

o Lead pump selectiono Pump run status—ON/OFFo Pump, speed control

Logic

Lead Pump Selection. The PC receives a signal from the TOWEREFFLUENT LEAD PUMP SELECT switch on the LCP indicating whichpump is selected. The PC uses this information for otherprocess control.

4-7

Pump Run Status. The PC receives a signal from each variablefrequency drive indicating the current run status for eachpump—ON/OFF--and the status for each drive—LOCAL (manual)/OFF/REMOTE (automatic). The PC also transmits a signal toeach of the variable frequency drives to start the lead pumpwhen the water level in the sump(s) reaches 2 feet. When thewater level in the sump(s) drops below 1.7 feet, the PC sendsa signal to the variable frequency drives to shutdown thepumps.

Pump Speed Control. As the level in the tower sump(s)changes, the PC sends a signal to the variable frequencydrives to increase or decrease the speed in proportion to thelevel. The PC adjusts the effluent pump speed based on thehighest sump level if both towers are selected. If only onetower is selected, then the effluent pump speed is adjustedbased on that tower's sump level.

Alarms or Indicator Lights

The following alarms or indicator lights associated with Con-trol Loop 2 are provided on the LCP or RPCP.

LCP

o Lead pump not selectedo Pump failure

4-8

RPCP

o System A ONo System B OFFo System B ONo System B OFFo System Troubleo System Fail

Lead Pump Not Selected. This alarm is initiated if the TOWEREFFLUENT PUMP SELECT switch does not provide an input signalto the PC. A 2-second time delay is provided on the alarmto allow switching the lead pumps.

Pump Failure. This alarm is initiated on the following con-ditions:

o Failure of the effluent pump to start 10 secondsafter it is called to start

o Failure of a pump to keep the level in the towersump(s) below 4 feet

o Variable frequency drive failure

o Selected lead pump's variable frequency drive notin Remote (AUTO)

4-9

If a pump failure occurs, the PC shuts down the lead pump andstarts the standby pump. If the standby pump does not startor bring the level in the tower sump(s) below 4 feet within60 seconds, the PC shuts down the standby pump and initiatesa System Failure (discussed later in this section).

System A ON/OFF and System B ON/OFF. These alarms were pre-viously described.

System Trouble and System Fail. These alarms are discussedlater in this section.

LOOP 4: BUILDING SUMP LEVEL

Function

Control Loop 4 monitors the water level in the building sump.

The PC receives a signal from the level sensing device in thesump indicating the water level. When the level exceeds apreset value, the PC triggers the BUILDING SUMP HIGH-HIGHLEVEL alarm at the LCP and initiates a SYSTEM TROUBLE at theRPCP.

4-10

Alarms or Indicator Lights

The following alarms or indicator lights associated withControl Loop 4 are provided on the LCP or the RPCP:

LCP

o Building sump high-high level

RPCP

o System Trouble

Building Sump High-High Level. This alarm is initiated whenthe water level in the building sump exceeds a preset level.

System Trouble. This alarm is discussed later in this sec-tion.

LOOP 5: WELL FIELD BOOSTER PUMP CONTROL

Function

Control Loop 5 controls all process functions for the boosterpump:

4-11

o Remote START/STOPo Remote pump run status — ON/OFFo Pump low inlet pressure

Logic

Remote START/ STOP. The PC receives signals via the telemetrysystem for remote START/STOP from the RPCP.

Remote Pump Run Status — ON/OFF. The PC transmits signals viathe telemetry system for remote ON/OFF status at the RPCP.

Pump Low Inlet Pressure. The PC receives a signal from theinlet pressure gauge on the booster pump. When the pumpinlet pressure falls below 15 psig, the PC sends a signal totrigger the BOOSTER PUMP LOW INLET PRESSURE alarm on the LCPand initiates the SYSTEM TROUBLE alarm at the RPCP.

Alarms or Indicator Lights

The following alarms or indicator lights associated with Con-trol Loop 5 are provided on the LCP or the RPCP.

LCP

o Booster pump low inlet pressureo Booster pump failure

4-12

RPCP

o System Trouble

Booster Pump Low Inlet Pressure. This alarm is initiatedwhen the pump inlet pressure falls below 15 psig.

Booster Pump Failure. This alarm is initiated on the follow-ing conditions:

o Failure of pump to start 10 seconds after it iscalled to start

o Pump shutdown on low inlet pressure or any othercondition other than manual stop

System Trouble. This alarm is discussed later in this sec-tion.

LOOP 6; CHLORINE SYSTEM

Function

Control Loop 6 controls the following process functions ofthe chlorine system:

4-13

o Chlorine leak detectiono Low chlorine ejector pressureo High/low chlorinator pressureo Chlorine feed pump run status—ON/OFFo Flow pacing of chlorine feed solution

Logic

Chlorine Leak Detection. The PC receives a signal from thechlorine leak detector when the probe detects chlorine abovea preset level (1 ppm) . The PC then triggers the CHLORINELEAK alarm on the LCP and initiates a SYSTEM TROUBLE at theRPCP .

Low Chlorine Ejector Pressure. The PC receives a signal fromthe pressure switch on the ejector when there is low pressurein the ejector feed line. The PC then triggers the CHLORINEFEED LOW PRESSURE alarm on the LCP and initiates a SYSTEMTROUBLE at the RPCP.

High/Low Chlorinator Pressure. The PC receives a signal fromthe pressure switch on the inlet of the flow proportioninggas control valve. The switch sends a signal to the PC whenthe gas pressure on the chlorinator discharge is above orbelow a preset range. The PC then triggers the CHLORINE GASHIGH/LOW PRESSURE alarm on the LCP and initiates a SYSTEMTROUBLE at the RPCP.

4-14

Chlorine Feed Pump Run Status — ON/OFF. The PC receives asignal indicating the chlorine feed pump's current status —ON/OFF. The PC also transmits a signal to the feed pump tostart when the sum of the tower flows reaches 650 gpm.

Flow Pacing of Chlorine Feed Solution. The PC transmits aflow signal to the flow proportioning gas control valve.The control valve uses the signal to maintain a constantchlorine concentration as the water flow varies.

Alarms or Indicator Lights

The following alarms or indicator lights associated with Con-trol Loop 6 are provided on the LCP or the RPCP:

LCP

o Chlorine leaki ; o Low chlorinator pressure

o High/ low chlorinator pressureo Chlorine feed pump failure

RPCP

System Trouble

4-15

Chlorine Leak, Low Chlorinator Pressure, and High/Low Chlor-inator Pressure. These alarms are initiated as describedpreviously under the heading LOGIC.

Chlorine Feed Pump Failure. This alarm is initiated underthe following conditions:

o Failure of the chlorine feed pump to start 10 sec-onds after it is called to start

o Pump shutdown while system flow exceeds 650 gpm

System Trouble. This alarm is discussed in the followingsection.

LOOP 7: REMOTE SYSTEM ALARMS

Function

Control Loop 7 controls the alarms at the RPCP.

Logic

The PC receives signals from the various process sensingdevices and then transmits signals to the RPCP via the tele-metry system for certain alarm conditions.

4-16

Alarms or Indicator Lights

System Trouble. This alarm is initiated under the followingconditions:

o Building sump high-high levelo Chlorine leak detectiono Chlorine gas high/low pressureo Chlorine feed low pressureo Chlorine system failureo Booster pump low inlet pressureo Booster pump failureo One tower effluent pump failure

System Fail. This alarm is initiated under the followingconditions:

o Tower fan(s) failureo Tower sump(s) high-high levelo Two tower effluent pumps failureo No tower selectedo No tower effluent pump selectedo Programmable controller failureo Selected tower effluent pump low inlet pressure

The conditions which initiate a SYSTEM FAIL will cause a sys-tem shutdown (see Loop 11) .

4-17

LOOP 8: ANNUNCIATOR

Function

Control Loop 8 provides the sequencing for alarming to allthe annunciator indicators on the LCP and for the horn.

Logic

At the occurrence of any fault, the respective indicator onthe annunciator panel flashes on and off. When the ACKNOW-LEDGE pushbutton is depressed, the indicator changes tosteady-on. When the fault condition is corrected, the indi-cator will not go out until the RESET pushbutton is depressedA TEST pushbutton is provided to illuminate all visual indi-cators to ensure they are working properly.

LOOP 9; EXISTING WELL PUMPS SHUTDOWN INTERLOCK

Function

Control Loop 9 provides the shutdown interlock circuit forexisting well pumps 10, 11, 14, 15, 16, and 17 at the exist-ing treatment plant control panel.

4-18

Logic

When the PC initiates a SYSTEM FAIL, a signal is sent via thetelemetry system to shut down all the well pumps feeding theair stripping facility. The well pumps can be started againwhen the alarm is cleared.

LOOP 10: PROGRAMMABLE CONTROLLER FAILURE

Function

Control Loop 10 provides a system shutdown if the program-mable controller fails.

Logic

The circuit uses a continuously energized output and relay.When the PC fails, the output contacts are no longer ener-

i i gized and the relay trips the system failure interlock at theRPCP via the telemetry system.

Alarms or Indicator Lights

The alarms associated with Control Loop 10 are the PROGRAM-MABLE CONTROLLER FAILURE indicator at the LCP and the SYSTEMFAIL at the RPCP.

4-19

LOOP 11; SYSTEM SHUTDOWN

Function

Control Loop 11 shuts down the system on any of the followingconditions:

o Tower fan failureo Tower sump(s) high-high levelo Two tower effluent pumps failureo PC failureo No tower selectedo No tower effluent pump selectedo Selected tower effluent pump low inlet pressure

Logic

Tower Fan Failure. If a tower fan does not start within thei i time period specified or fails while operating, the PC shuts

down the well pumps through the system fail interlock. Whenflow through the system stops, the booster pump fails on lowinlet pressure and the PC shuts down the chlorine feed pump.The tower effluent pump will continue to operate until thelevel in the tower sump(s) reaches the programmed pump shut-down level.

4-20

Tower Sump(s) High-High Level. If a high-high level is\J detected in a tower sump, the PC shuts down the well pumps

through the system fail interlock. When flow through thesystem stops, the booster pump fails on low inlet pressureand the PC shuts down the chlorine feed pump and tower fan(s)The tower effluent pumps are shut down by the PC.

Two Tower Effluent Pumps Failure. If both tower effluentpumps fail, the PC shuts down the well pumps through the sys-tem fail interlock. When flow through the system stops, thebooster pump fails on low inlet pressure and the PC shutsdown the chlorine feed pump and tower fan ( s ) .

Programmable Controller Fail. If the PC fails, the wellpumps shut down through the system fail interlock. When flowthrough the system stops, the booster pump fails on low inletpressure. The rest of the system shuts down automaticallydue to the failure of the PC.

No Tower Selected. If the PC senses that there is no towerselected, the following sequences occur:

o If the system is not running, the PC won't allowthe well pumps to start until the condition is cor-rected.

4-21

o If the system is running, the PC shuts down thewell pumps through the system fail interlock. Whenflow through the system stops, the booster pumpfails on low inlet pressure and the PC shuts downthe chlorine feed pump and the tower fan ( s ) . Thetower effluent pump will continue to operate untilthe level in the tower sump(s) reaches the pro-grammed pump shutdown level.

No Tower Effluent Pump Selected. If the PC senses thatthere is no tower effluent pump selected, the followingsequences occur:

o If the system is not running, the PC won't allowthe well pumps to start until the condition is cor-rected.

o If the system is running, the PC shuts down thet j well pumps through the system fail interlock. When

flow through the system stops, the booster pumpfails on low inlet pressure, and the PC shuts downthe chlorine feed pump and tower fan ( s ) . The sel-ected tower effluent pump fails when the conditionoccurs. When the selected tower effluent pumpfails, the backup pump starts and runs until thelevel in the tower sump(s) reaches the programmedpump shutdown level.

4-22

Selected Tower Effluent Pump Low Inlet Pressure. If a towereffluent pump low inlet pressure is detected, the well pumpsshut down through the system fail interlock. When flowthrough the system stops, the booster pump fails on low inletpressure and the PC shuts down the chlorine feed pump, towerfan ( s ) , and tower effluent pump(s) .

GLT590/35

4-23

Process Equipment Operation 5

TO-JULY-37 EC-BASE1

NUMBER

CD©GD®CDCD©(DCD©©©©©©dD©©©©@>©©

©©©

W4LWE" FUNCTION SCHEDULEVALVE FUNCTIONMAIH INFLUENTBYPASSP-5 INFLUENTP-5 EFFLUENTPT-1A INFLUENTPT-1BINFLUENTPT-1A EFFLUENTPr-IH EFFLUENTP-2A INFLUENTP-2B INFLUENTP-2A EFFLUENTP-2B EFFLUENTPT-1A WASH UNE EFFLUENTPT-1B WASH UNE EFFLUENTPT-1A WASH LINE INFL.UENTPf-TB WASH LINE INFLUENTWASH L/Wr DISCHARGEWASH LINE DISCHARGEWASH UNE" DISCHARGETREATED EFFLUENTTREATED EFFLUENTWASTE UNE DISCHARGEWASTE UNE DISCHARGEP-6 INFLUENTCHLORINE SYSTEM ISOLATIONP-6 EFFLUENTWASH LINE DRAIN

CHLORINESOLUTION UNE

• FROMCONTAMINATEDWELLS ^fcs.

&LEGEND

BUTTERFLY VALVE

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE VALVE

BALL VALVE

PROPELLER TYPE FLOWMETER

VALVE SCHEDULE NUMBER

WASH RECIRC-ULATION PUMP

c C c CTable 5-2

VALVING ARRANGEMENTS FOR NORMAL OPERATING MODES

ValveNumber

123456789

1011121314IS1617IB192021222324252627

NormalOperationusing

Both Towers

OpenClosedOpenOpenOpenOpenOpenOpenOpenOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedOpenOpen

ClosedClosedOpenOpenOpen

Closed

NormalOperationusing PT-1A

OpenClosedOpenOpenOpen

ClosedOpen

ClosedOpenOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedOpenOpen

ClosedClosedOpenOpenOpen

Closed

NormalOperationusing PT-1B

OpenClosedOpenOpen

ClosedOpen

ClosedOpenOpenOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedOpenOpen

ClosedClosedOpenOpenOpen

Closed

Sump Discharge

(Valves on dis-charge line tosump pumpsshould alwaysbe open andvalve Nos. 18and 19 sbouldalways beclosed. Statusof all othervalves In thefacility willnot affect thesump discharge.)

ClosedClosed

Hash Cycleon PT-1A

ClosedOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedClosedOpen

ClosedOpen

ClosedClosedClosedClosedClosedClosedClosedClosedOpenOpenOpen

Closed

DischargeCycle

on PT-1A

ClosedOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedClosedOpen

ClosedClosedClosedOpenOpenOpen

ClosedClosedClosedClosedOpenOpenOpen

Closed

Flush Cycleon PT-1A

OpenClosedOpenOpenOpen

ClosedOpen

ClosedOpenOpenOpenOpenOpen

ClosedOpen

ClosedClosed-- >0pen

OpenOpen

ClosedClosedOpenOpenOpenOpenOpen

Closed

Nash Cycleon PT-1B

ClosedOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedClosedClosedOpen

ClosedOpen

ClosedClosedClosedClosedClosedClosedClosedOpenOpenOpen

Closed

DischargeCycle

on PT-1B

ClosedOpenOpenOpen

ClosedClosedClosedClosedClosedClosedClosedClosedClosedOpen

ClosedClosedOpenOpenOpen

ClosedClosedClosedClosedOpenOpenOpen

Closed

Flush Cycleon PT-1B

OpenClosedOpenOpen

ClosedOpen

ClosedOpenOpenOpenOpenOpen

ClosedOpen

ClosedOpen

Closed™ >OpenOpenOpen

ClosedClosedOpenOpenOpenOpenOpen

Closed

SystemShutdown

ClosedOpenOpenOpenOpenOpen

ClosedClosedClosedClosedClosedClosed

Open~X:iosedOpen — XTlosedOpen — >ClosedOpen — XTlosed

ClosedClosedClosedClosedClosedClosedClosedOpenOpenOpen

Open — >Closed

CorrespondingFigure Ho. 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-10 5-11

For system shutdown, valve Nos. 13, 14, 15, 16, and 27 should be opened to allow the wash recirculation line to drainto the building sump. After the line has drained, the valves should be closed.

GLT590/43

Section 5PROCESS EQUIPMENT OPERATION

This section provides detailed procedures for startup, normaloperation, and shutdown of the process equipment in the airstripping facility.

GENERAL CONSIDERATIONS

The primary objectives of the air stripping facility are toremove volatile organic contaminants from the groundwater andto supply treated drinking water to the City of Eau Claire.With these objectives in mind, the facility was designed tooperate continuously with groundwater being supplied fromsome combination of at least two of Well Nos. 11, 15, 16, 17,and 14. Modifications were also made to allow water fromWell No. 10 to be pumped to the air stripping facility if itbecomes contaminated. As mentioned previously, operating theair stripping facility with all six wells and the boosterpump is not recommended since the total flow will exceed thehydraulic design capacity of the system.

The objectives of the facility provide the basis for makingthe following operational decisions:

o How many packed towers should be in service?

5-1

o What is the appropriate fan setting?

Table 5-1 provides guidelines for making these operationaldecisions. The values listed under Recommended Fan Settingrefer to the positions shown in Figure 5-1 which is an illus-tration of the inlet guide vane adjustment on the fans.Since actual flowrate, contaminant concentrations, andremoval efficiencies will vary, it is essential that the oper-ator uses his experience with the facility to modify theseguidelines.

PACKED TOWER FANS

STARTUP

The fans can be controlled manually at the motor control cen-ter or automatically by the programmable controller. Thepanel at the motor control center contains a HAND/OFF/AUTOselector switch, ON and OFF indicator lights, and a resetbutton. In the HAND position, the fans operate continuouslyregardless of the water flow to the towers. In the AUTOposition, the fans start and stop automatically based on thewater flow to the towers. When the flowrate to a towerreaches 650 gpm, the programmable controller sends a signalto start the fan. (If only one tower is selected, then thefan for only that tower starts.) If a fan fails to start

5-2

Table 5-1GUIDELINES FOR AIR STRIPPING FACILITY OPERATION

No. of WellsPumping to

Air StrippingFacility

EstimatedaFlowrate(gpra)

800

1,900 to 2,500

3,100 to 3,600

RecommendedNo. of Towersin Service^

None

1

1or

Desired tAir Flowrate(cfm)

12 ,700 to 16,700

20,700 to 24,000

10,400 to 12,000

RecommendedFan Setting(position)

4

1 to 2

4 to 5

Comments

Operation with only one well on isnot recommended.

With the first option, the operatormust manually adjust fan setting.With second option, the operatormust manually open the valves forthe second tower. If desiredflowrate is expected to increase,the second option is the betterchoice.

5 plusbooster pump

4,300

4,900 to 5,000

14,400

16,400 to 16,700

7,800 26,000

4

3 to 4 Fan setting can be left at position 4if the influent concentrations areless than the design values. Asinfluent concentrations approachdesign, the lower setting {position 3)may be necessary.

Estimated water flowrate is based on capacity of wells when well screens are clean.under normal operation is likely to be less than shown.Desired air flowrate is based on A/W = 50:1 .

Actual water flowrate delivered to the facility

GLT590/42

HANDLE FORADJUSTINGINLET GUIDEVANES

LEGENDINDICATES POSITION NO. 1

FIGURE 5-1POSITION INDICATIONS FORADJUSTMENT OF INLETGUIDE VANES ON PACKEDTOWER FANSCITY OF EAU CLAIRE

within 10 seconds, the programmable controller initiates aSYSTEM FAIL and shuts down the well pumps.

After startup of the fans, the operator must manually adjustthe inlet guide vanes to attain the desired air/water ratioas shown in Table 5-1 .

NORMAL OPERATION

During normal operation, the selector switch is in the AUTOposition and the fans are controlled through the programmablecontroller. When water flow to the towers is 650 gpm, thefans start automatically. As the water flowrate increases,the operator must manually adjust the inlet guide vanesaccording to the guidelines outlined in Table 5-1 . Whenwater flow drops below 450 gpm, the fans will automaticallyshut down.

If a fan fails during operation, the programmable controllerinitiates a SYSTEM FAIL and shuts down the well pumps.

SHUTDOWN

Fan shutdown occurs in the AUTO position when water flow tothe tower drops below 450 gpm. Fan shutdown can be accomp-lished manually by turning the selector switch to the OFFposition.

5-3

A lockout-stop switch is provided at the base of each fan ifit is to be taken out of service for maintenance.

PACKED TOWERS

STARTUP

The packed towers do not have any controls directly relatedto their operation. Startup is accomplished by manuallyopening the influent and effluent valves to each tower (valveNos. 5 and 7 for PT-1A and valve Nos. 6 and 8 for PT-1B) asshown in Figure 5-2. Since both packed towers may not beoperating continuously, tower rotation should be practicedto allow for more even wear of the fans and other processequipment .

NORMAL OPERATION

The packed towers require very little operator attention dur-ing normal operation. Periodic readings should be taken fromthe pressure gauges as outlined later in Section 6 —Monitoring. The lines on each gauge should be drained beforethe readings are taken. The water flowrate, water temper-ature, and fan setting should also be noted. Periodicinspection of the tower internals and air vents on the over-flows are discussed in Section 8 — Maintenance.

5-4

SHUTDOWN

Shutdown of both packed towers is accomplished by opening theby-pass valve and closing the main valve (valves Nos. 2 and1 on Figure 5-2) or by shutting down the well pumps directedto the air stripping facility and closing the tower influentand effluent valves.

Shutdown of one tower while the second is in operation isaccomplished by first closing that tower's influent valve andthen closing the effluent valve (valve Nos. 5 and 7 for PT-1Aand valve Nos. 6 and 8 for PT-1B) . The tower sump can thenbe drained by opening valve No. 13 for PT-1A or valve No. 14for PT-1B and valve No. 27. Water in the tower sumps thendrains to the building sump.

EFFLUENT PUMPS

STARTUP

The effluent pumps are normally controlled from the VFD con-trol panel. This panel contains a LOCAL/OFF/REMOTE selectorswitch and a manual speed adjustment. In the REMOTE position,the lead effluent pump starts automatically when the waterlevel in the tower sumps reaches 2.0 feet. If this pumpfails to start within 10 seconds, the programmable controllerautomatically shuts it down and starts the standby pump.

5-5

(The lead pump selection switch is located on the local con-trol panel.) Failure of one tower effluent pump causes theSYSTEM TROUBLE indicator at the remote plant control panelto go on. If both effluent pumps fail, the SYSTEM FAILindicator comes on and the programmable controller shuts downthe well field pumps.

To manually start the effluent pumps from the VFD panel, usethe following procedure.

1. Verify that each pump and drive is operational. Referto the manufacturer's manuals for startup procedures.

2. Set the LOCAL/OFF/REMOTE selector switch to the OFFposition.

3. Set the variable frequency drive speed control dial tothe slowest speed.

4. Check the pressure gauge at the pump inlets and verifythat the pressure is at least 1 psig.

5. Verify that the valves at the inlet and discharge ofeach pump are open.

5-6

6. Start the pump by setting the selector switch to LOCAL.Verify that the pump runs and the speed increases as themanual speed adjustment knob is turned clockwise.

NORMAL OPERATION

During normal operation, the selector switch is set in theREMOTE position and the effluent pumps are controlled throughthe programmable controller. As the level in the tower sumpsrises or falls, the speed of the effluent pump is increasedor decreased to maintain a constant level in the sump. Ifboth towers are selected, the programmable controller adjuststhe speed based on the highest level. If the lead pump failsor the water level in the sump(s) reaches 4 feet, the con-troller shuts down the lead pump and starts the standby pump.If the standby pump does not start or if the water level inthe sump(s) is above 4 feet for 60 seconds, the programmablecontroller shuts down the second pump and initiates a systemfailure.

If the water level in the sump(s) drops below 1.7 feet, theprogrammable controller automatically shuts down the effluentpump until the level rises to 2 feet.

5-7

SHUTDOWN

As mentioned previously, the effluent pumps automaticallyshut down when the water level drops to 1.7 feet. If aneffluent pump is to be shut down for maintenance, use thefollowing procedure:

1. At the motor control center locate the circuit breakerfor the pump and lock out the pump. Sign the lockouttag. The person who locks out the drive is responsiblefor removing the tag when the drive is returned to ser-vice.

2. Isolate the pump by closing the manual suction and dis-charge valves. Drain and flush the pump casing and pip-ing.

3. Service the pump as directed by the manufacturer's man-ual.

BOOSTER PUMP

STARTUP

The booster pump can be controlled locally at the motor con-trol center in the air stripping facility or remotely fromthe water treatment plant. The panel on the motor control

5-8

center contains ON/OFF/MOTOR TEMP HI/REMOTE status lights, a\J LOCAL/REMOTE selector switch, a reset button, and START and

STOP buttons. To control the pump locally, the selectormust be set to the LOCAL position. Before starting thebooster pump, verify that the inlet and discharge valves areopen and that the pump inlet pressure gauge reads at least2 psig.

If the booster pump fails to start within 10 seconds, the pro-grammable controller signals a SYSTEM TROUBLE at the treat-ment plant.

NORMAL OPERATION

Based on the City's historical water demand, the booster pumpis estimated to be used only a few days a year. The boosterpump is manually started (from either the local or remotelocation) during the periods of high water demand and is thenmanually stopped when the additional flow is no longer neededFailure of the booster pump energizes the SYSTEM TROUBLE indi-cator at the treatment plant. Since the booster pump hashigher energy consumption than the existing well pumps, themost cost-effective pumping strategy is to use the boosterpump only when operation of all the existing well pumps can-not supply the desired water flow.

5-9

SHUTDOWN

Shutdown of the booster pump is accomplished by pushing theSTOP button at the REMOTE or LOCAL location.

Caution:Operation of the booster pump for periods of more thanone hour at a flowrate less than 3 , 1 0 0 gpm may resultin increased vibration, noise, and mechanical damage tothe pump.

CHLORINE SYSTEM

STARTUP

The chlorine system is set up to operate automatically whenthe chlorine feed pump starts. (Startup and operatinginstructions for each component of the chlorine system arefound in the manufacturer's O&M manual.) The chlorine feedpump can be operated manually or automatically through theprogrammable controller. The panel at the motor control cen-ter contains a HAND/OFF/AUTO selector switch, ON and OFF indi-cator lights, and a reset button. The chlorine feed pump isstarted manually by turning the selector switch to the HANDposition. In the AUTO position, the chlorine feed pumpstarts automatically based on the water flow to the towers.

5-10

When the total flowrate reaches 650 gpm, the programmablecontroller sends a signal to start the chlorine feed pump.If the chlorine feed pump fails to start within 10 seconds,the programmable controller signals a SYSTEM TROUBLE at thewater treatment plant.

NORMAL OPERATION

During normal operation, the selector switch is in the AUTOposition and the chlorine system is controlled by the pro-grammable controller. When the total water flow reaches650 gpm, the chlorine feed pump starts automatically. Duringoperation, the programmable controller sends a flow signalto the flow proportioning gas control valve. This componentof the chlorine system adjusts the chlorine gas feed rate tomaintain a preselected concentration in the influent waterline. (For adjustment of the flow proportioning gas controlvalve refer to the manufacturer's O&M manual.)

The programmable controller signals a SYSTEM TROUBLE alarmfor the following conditions:

o Failure of the chlorine feed pumpo High/ low chlorinator pressureo Low chlorine ejector pressureo Chlorine leak

5-11

SHUTDOWN

Shutdown of the chlorine system occurs in the AUTO positionwhen the water flow drops below 650 gpm. Shutdown can alsobe accomplished by manually turning the selection switch tothe OFF position.

ACID WASH SYSTEM

Operation of the acid wash system involves the followingsteps:

o Startup — Describes procedures for filling the towersump with water and starting the wash recircul-

X^X ation pump.

Wash cycle — Describes procedures for adding acidto make the wash solution and for adding causticto neutralize the solution when the wash cycle iscomplete .

Discharge cycle — Describes procedures for dis-charging the waste wash-water.

Flush cycle — Describes procedures for flushing thetower and wash lines.

5-12

o Shutdown — Describes shutdown of the acid wash sys-tern.

STARTUP

1. While water is being pumped to the towers close the rawwater influent valve to the tower that is to be washed(valve No. 5 for PT-1A or valve No. 6 for PT-1B) .Leave the effluent valves to each tower open.

2. Switch the tower effluent pumps to manual operation asdescribed previously in this section under EFFLUENTPUMPS. Manually reduce the pump speed to allow thelevel in the tower sumps to rise to about 3.5 feet asindicated by the level gauges on the local controlpanel.

3. When the level reaches 3.5 feet, close the effluentvalve to the tower that is to be washed.

4. Shut down the wells to the air stripping facility.

5. Verify that valve No. 27 is closed.

6. Open the wash line influent and effluent valves for thetower to be washed and close the wash line influent and

5-13

effluent valves for the tower on standby (valve Nos. 13and 15 for PT-1A and valve Nos. 14 and 16 for PT-1B) .Verify that valve Nos. 17, 18, and 19 are closed.

7. Start up the wash recirculation pump. The pump is con-trolled manually at the motor control center. The panelcontains ON and OFF indicator lights, a START button, aSTOP button, and a RESET button. To start the pump,verify that the pressure gauge on the pump inlet readsat least 1 psig, and then press the START button.

8. Allow the water to circulate in the system for about15 minutes to verify that there is an adequate volumeof water to prevent the pump from running dry. If not,stop the recirculation pump and add more water to thetower sump by repeating steps 1 through 4 .

WASH CYCLE

1. With water circulating through the system, remove thecap to the acid addition inlet and add the hydrochloricacid to tower sump.

Concentrated commercial grade hydrochloric acid (about3 1 . 5 percent) can be purchased in 55 gallon drums fromvarious chemical suppliers. The acid can be added to

5-14

the sump using a drum pump. The actual volume of acidV J required depends on numerous factors and should be

determined based on operator experience. A concentra-tion of 1 to 5 percent is recommended for initial washes(For a 2 percent solution, approximately 200 gallons ofconcentrated hydrochloric acid should be added to thewash water; for a 3 percent solution, approximately 300gallons of HC1; and for a 5 percent solution, about500 gallons of HC1) .

Caution:To prevent injury from contact or inhalation of vapors,proper safety precautions should be used when handlingacid (see Section 10 — SAFETY) . The emergency eyewash/bodyspray should be operational and nearby at all timesIf any acid spills onto the outside of the tower vesselor onto the anchor lugs, it should be flushed immedi-ately with water.

2. Once the appropriate amount of acid is added, allow thewash solution to circulate through the system forapproximately 1/2-hour.

3. Stop the wash recirculation pump by pushing the STOPbutton .

5-15

4. Neutralize the acid wash solution by adding causticthrough the acid addition inlet until the pH is about 4or 5. Sodium hydroxide (NaOH) can be purchased in55-gallon drums of 50-percent solution. The actualquantity of NaOH required will be determined from oper-ator experience. (Approximately 200 gallons will beneeded for the 5-percent wash solution; 120 gallons forthe 3-percent solution; and 80 gallons for the2-percent solution.)

DISCHARGE CYCLE

1. Close the influent valve for the wash line in operation(valve No. 15 for PT-1A or valve No. 16 for PT-1B) .

2. Open the wash line discharge valves—valve Nos. 17, 18,and 19.

3. Start the wash recirculation pump to discharge the neu-tralized wash solution to the waste lagoon.

4. When the water level in the tower sump drops below0.5 feet, stop the wash recirculation pump.

5-16

FLUSH CYCLE

1. Verify that valve Nos. 20 and 21 are closed. THE SPOOLPIECE BETWEEN THE TWO VALVES SHOULD BE REMOVED TO ASSURETHAT CROSS-CONTAMINATION DOES NOT OCCUR. (The portableadjustable gantry can be used to remove the spool piece.)

2. Open the waste line discharge valve Nos. 22 and 23.

Note: Improper operation of valve Nos. 20, 21, 22, and23 during the acid wash or chlorine wash cyclescould result in discharge of wastewater to thewater supply distribution system.

3. Open valve Nos. 9, 10, 11, and 12.

4. Open the raw water influent and treated water effluentvalves to the tower which is being washed (valve Nos. 5and 7 for PT-1A or valve Nos. 6 and 9 for PT-1B) . Ver-ify that the influent and effluent valves on the standbytower are closed.

5. Verify that the main influent valve (valve No. 1) isopen and that the by-pass valve (valve No. 2) is closed.

6. Switch the tower effluent pumps to the REMOTE or auto-matic position.

5-17

7. Start up two of the well pumps that pump to the airstripping facility.

8. When the water level in the tower sump reaches about2 feet, start the wash recirculation pump.

9 . Open the wash line influent valve to the tower in oper-ation (valve No. 15 for PT-1A or valve No. 16 for PT-1B) ,and close valve No. 17. This ensures that the washline influent piping is flushed adequately. Allow thesystem to circulate for about 15 minutes, then openvalve No. 17.

SHUTDOWN

1. After 30 minutes of flushing, shut down the wash recir-culation pump.

2. Shut down the well pumps. (When the sump level reaches1.7 feet the effluent pumps will shut down automatic-ally.)

3. Close valve Nos. 17, 18, 19, 22, and 23.

4. Open valve No. 27 to drain the wash recirculation line.

5-18

5. Remove the lowest manway cover on the tower and inspectthe sump for accumulation of scale or debris and cleanthe sump if necessary. Replace the manway cover.

6. Replace the spool piece between valve Nos. 20 and 21,and open the valves.

7. When the lines have drained, close valve No. 27.

8. Close the wash line influent and effluent valves (valveNos. 13 and 15 for PT-1A and valve Nos. 14 and 16 forPT-1B) .

HYPOCHLORITE WASH SYSTEM

The hypochlorite wash is identical to the acid wash exceptchlorine is added instead of acid.

STARTUP

See ACID WASH SYSTEM — STARTUP.

WASH CYCLE

See ACID WASH SYSTEM — WASH CYCLE.

5-19

Instead of adding HC1, add approximately 6 gallons of house-hold bleach solution (5- 1/4 percent chlorine) through theacid/chlorine addition inlet. This will give a chlorine washsolution of about 100 mg/1 when the water level in the sumpis at 3.5 feet. The appropriate safety precautions shouldbe used when working with the chlorine solution to avoidinjury (see Section 10—SAFETY).

DISCHARGE CYCLE

See ACID WASH SYSTEM—DISCHARGE CYCLE.

FLUSH CYCLE

See ACID WASH SYSTEM—FLUSH CYCLE.

SHUTDOWN

See ACID WASH SYSTEM—SHUTDOWN.

VALVING ARRANGEMENTS FOR NORMAL OPERATING MODES

The recommended valving arrangements for normal operatingmodes are shown in Table 5-2 for a majority of the valves inthe air stripping facility. Corresponding Figures 5-3through 5-11 show the valve locations and the process flowstreams in use during each operating mode.GLT590/41

5-20

10- JULY-87 n

VALVE FUNCTION SCHEDULENUMBER

CDCDCDCDCD©cz>CDCD©cs>©©

©OD©©

©©©©©>©

WLVT FUNCTIONMAIN INFLUENTBYPASSP-5 INFLUENTP-5 EFFLUENTPT-1A INFLUENTPT-1B INFLUENTPT-1A EFFLUENTPT-1B EFFLUENTP-2A INFLUENTP-23 INFLUENTP-2A EFFLUENTP-2B EFFLUENTPT-1A WASH LINE EFFLUENTPT-1B WASH LINE EFFLUENTPT-1A WASH LINE INFLUENTPT-1B WASH LINE INFLUENTWASH LINE DISCHARGEWASH LINE DISCHARGEWASH LINE DISCHARGETREATED EFFLUENTTREATED EFFLUENTWASTE LINE DISCHARGEWASTE UNE DISCHARGEP-6 INFLUENTCHLORINE SYSTEM ISOLATIONP-6 EFFLUENTWASH LINE DRAIN

LEGEND

BUTTERFLY VALVE

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE VALVE

BALL VALVE

PROPELLER TYPE FLOWUETER

VALVE SCHEDULE NUMBER

CHLORINESOLUTION LINE

•FROM ^«CONTAMINATEDWELLS

WELL FIELDBOOSTER PUMP

WASH RECIRC-ULATION PUMP

ACtD/HYPOCHLORnEADDITION INLET (TYP)

WASH REdRCULATION LINESUMP DISCHARGE LINE

TREATED EFFLUENT LINE

TO EXISTING WATERTREATMENT PLANT

FIGURE 5-3PROCESS FLOW STREAM

FOR NORMAL OPERATION

10- JULY-87 F2

VALVE FUNCTION SCHEDULENUMBER

CD©©©©©©®®

, ©/ »̂.

WLVE FUNCTIDW*WJN INFLUENTBYPASS \P-5 INFLUENTP-5 EFFLUENTPT-1A INFLUENTPT-1B INFLUENTPT-1A EFFLUENTPT-JB EFFLUENTP~2* INFLUENTp-2B INFLUENTP-2A EFFLUENTP-2B EFFLUENTPT-TA WASH UNE EFFLUENTPT-18 WASH LINE EFFLUENTPT-1,4 WASH L/NE INFLUENTPT-1B WASH UNE INFLUENTWASH UNE DISCHARGEWASH LINE DISCHARGEWASH UNE DISCHARGETREATED EFFLUENTTREATED EFFLUENT

CHLORINESOLUTION UNE

WAST-: LINE DISCHARGEP-6 INFLUENTCHLORINE SYSTEM ISOLATIONP-6 EFFLUENTWASH LINE DRAIN

LEGEND

BUTTERFLY VALVE

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE VALVE

BALL VALVE

PROPELLER TYPE FLOWUETER

VALVE SCHEDULE NUMBER

HELL HELDBOOSTER PUUP

WASH RECIRC-ULATJON PUUP

A CSD/H YPOCHLORiTEADDITION INLET (TYP)

WASH REClRCVLATION LINESUMP DISCHARGE: UNE

•FROMCONTAMINATEDWELLS

TREATED EFFLUENT UNE

TO EXISTING WATERTREATMENT PLANT

F IGURE 5-4PROCESS FLOW STREAM

FOR SUMP DISCHARGE

10-JULY-87

\

NUMBER

VALVE FUNCTION SCHEDULEVALVE FUNCTIONMAW INFLUENTBYPASSP-5 INFLUENTP-5 EFFLUENTPT-1A INFLUENTPT-7B INFLUENTPT-1A EFFLUENTPt-JB EFFLUENTP-2A INFLUENTP-2B INFLUENTP-2A EFFLUENTP-20 EFFLUENTPT-7A WASH UWE EFFLUENTPT-1B WASH LINE EFFLUENTPT-1A WASH LINE INFLUENTPT-1B WASH UNE INFLUENTWASH LINE DISCHARGEWASH UNE DISCHARGEWASH UNE DISCHARGETREATED EFFLUENTTREATED EFFLUENTWASTE LINE DISCHARGE

LEGEND

BUTTERFLY VALVE

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE VALVE

BALL VALVE

PROPELLER TYPE FLOWMETER

VALVE SCHEDULE NUMBER

SAMPLE LINES—•

CHLORINESOLUTION LINE

L__®

ID-JULr-87 F5

VALVE FUNCTION SCHEDULENUM3ER VALVE FUNCTION

MAIN INFLUENTBYPASSP-5 INFLUENT

®CDCD©r-^-CDU———®___©

(g)©(3)©-©©©©©©̂̂

P-5 EFFLUENTPT-1A INFLUENTPT-JS INFLUENTPr-M EFFLUENTP7-1S EFFLUENTP-2A INFLUENTP-2B INFLUENTP-2A EFFLUENTP-2B EFFLUENTPT-1A WASH LINE EFFLUENTPT-1B WASH LINE EFFLUENTPT-^A WASH LINE INFLUENTPT-1B WASH LINE INFLUENTWASH LINE DISCHARGEWASH LINE DISCHARGE.WASH LINE DISCHARGETREATED EFFLUENTTREATED EFFLUENTWASTE LINE DISCHARGE

P-B INFLUENTCHLORINE SYSTEM ISOLATIONP-G EFFLUENTWASH LINE DRAIN

LEGEND

*

^•"•x

BUTTERFLY VALVE

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE WALVC:

BALL VALVE

PROPELLER TYPE FLOWUETER

VALVE SCHEDULE NUMBERTO EXISTING WATERTREATMENT

A CiD/H YPOCHL ORtTEADDITION INLET (TYP)

WASH RECtRCULATlON UNESUUP DISCHARGE LINE

'FROMCONTAMINATEDWELLS

TREATED EFFLUENT LINE

TO WASTELAGOONS

F IGURE 5-6PROCESS FLOW STREAM

FOR PT-1A DISCHARGE CYCLE

1O-JULY-87 F7

NUMBER

CDCDd>©CD©

— — - —CDd§>dD©©(3)(g)

1O- JULY-87

VALVE FUNCTION SCHEDULENUMBEH

—————————CDCDC±)(5)©CDCl)CDCg)©Cg)@>(Q>

©©©

P~6 INFLUENTCHLORINE SYSTEM ISOLATIONP-6 EFFLUENTWASH LINE DRAIN

LEGEND

BUTTERFLr VALVF

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE VALVE

BALL VALVE

PROPELLER TYPE FLOWMETER

VALVE SCHEDULE NUMBER

WASH KECIRG-ULATJON PUMP

-ACtD/HYPOCHLORITEADDITION INLET (TYP)

WASH REORCULATION UNESUUP DISCHARGE UNE

FROMCONTAMINATEDWELLS

TREATED EFFLUENT UNE

TO EXISTING WATERTREATMENT PLANT

FIGURE 5-8PROCESS FLOW STREAMFOR PT-1BWASH CYCLE

ID-JULY-87

NUMBER

CDCDCD

dD(3>©©cgi©©>©©@iC§)©

1/4LVE FUNCTION SCHEDULEVALVE FUNCTION«A/N INFLUENTBYPASSP-5 INFLUENTP-5 EFFLUENTPT-1A INFLUENTPT-18 INFLUENTPT-1A EFFLUENTPr-IS EFFLUENTP~2A INFLUENTP-2B INFLUENTP-2A EFFLUENTP-2B EFFLUENTPT-1A WASH LINE EFFLUENTPT-lB WASH LINE EFFLUENTPT-1A WASH LINE INFLUENTPT-W WASH LINE INFLUENTWASH LINE D/SCHAffGEWASH LINE DISCHARGEWASH LINE DISCHARGETREATED EFFLUENTTREATED EFFLUENTWASTE LINE DISCHARGEI 09: ©

1 — —~ —\ ~

f=3

FUNCTION SCHEDULENUMBER VALVE FUNCTION

MAIN INFLUENT

CD

BYPASSP-5 INFLUENTP~5 EFFLUENTPT-1A INFLUENTPT-19 INFLUENTPT-1A EFFLUENTPT-10 EFFLUENTP~2A INFLUENTP-2B INFLUENTP-2A EFFLUENTP-2B EFFLUENTPT-1A WASH UNE EFFLUENTPT-18 WASH UNE EFFLUENTPT-1A WASH UNE INFLUENT CHLORINESOLUTION UNEPT-W WASH UNE INFLUENTWASH UNE DISCHARGEWASH LINE DISCHARGEWASH UNE DISCHARGETREATED EFFLUENTTREATED EFFLUENTWASTE UNE DISCHARGEWASTE: LINE DISCHARGEP~6 INFLUENTCHLORINE SYSTEU ISOLATIONP-6 EFFLUENTWASH LINE DRAIN

LEGEND

BUTTERFLY VALVE

DOUBLE DOOR CHECK VALVE

SWING CHECK VALVE

GLOBE VALVE

BALL VALVE

PROPELLER TYPE FLOWUETER

VALVE SCHEDULE NUMBER

*SX^® J

WEU. FIELDBOOSTER PUMP

A CtD/H YPOCHLORITEADDITION INLET (TYP)

WASH REdRCULATtON UNESUUP DISCHARGE:

'FROMCOWT-AM/WATTDMO.LS

TREATED EFFLUENT UNE

TO EXISTING WATERTREATMENT PLANT

FIGURE 5-10PROCESS FLOW STREAMFOR PT-1B FLUSH