TE_5.pdf

Operation and Maintenance Guide for

Tactical Vehicle Wash Facility East Range, Oahu, Hawaii

Prepared For:

U.S. Army Corps of Engineers

Honolulu District

Prepared By:

Parsons Brinckerhoff Quade & Douglas Inc. &

Hawaii Pacific Engineers, Inc.

October 12, 2005

O&M Guide for Tactical Vehicle Wash Facility, East Range

October 2005 i

OPERATION AND MAINTENANCE GUIDE FOR

TACTICAL VEHICLE WASH FACILITY, EAST RANGE

TABLE OF CONTENTS

A. Overview of this Manual

B. General Description of Facility

C. Individual Process Components

1. Wash Area and Trench Drain

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

2. Sedimentation Basin and Sump Pumps

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

3. Pressure Filters and Filter Backwash Pumps

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

4. Disinfection System

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

5. Finished Water Storage Tank

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

6. Hose Stream Booster Pumps

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

7. Pressure Washer Units

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

October 2005 ii

TABLE OF CONTENTS (CONT.)

8. Process Piping

a. Description

b. Typical Operating Sequence and Procedures

c. Typical Maintenance

9. Process Equipment Alarms

D. Standard Operating Instructions for Military Personnel

October 2005 iii

LIST OF TABLES

Table 1 Wash Area Fixtures

Table 2 Sources of Sedimentation Sump Inflow

Table 3 Sedimentation Sump Pump Characteristics

Table 4 Sedimentation Sump Pump Activation Levels

Table 5 Pressure Filter Characteristics

Table 6 Filter Backwash Pump Characteristics

Table 7 Finished Water Storage Tank Piping Connections

Table 8 Hose Stream Booster Pump Characteristics

Table 9 Pressure Washer Characteristics

Table 10 Process Piping Characteristics

Table 11 Civil Sitework Piping

Table 12 Process Equipment Alarm Events

Table 13 Wash Procedures for Military Personnel

Table 14 Maintenance Tasks for Military Personnel

Table 15 General Rules for Military Personnel

October 2005 iv

LIST OF FIGURES

Figure 1 Simplified Process Flow Diagram

Figure 2 Process Flow Diagram

Figure 3 Process Piping Plan

Figure 4 Wash Area Plot Plan

Figure 5 Sedimentation Basin Plan and Section

Figure 6 Sedimentation Basin Outlet Structure

Figure 7 Sedimentation Basin Sump

Figure 8 Sedimentation Basin Sump Pumps Schematic Control Diagram

Figure 9 Mechanical Building – Plan

Figure 10 Mechanical Building - Pressure Filtration and Backwash Sys tem

Figure 11 Pressure Filters and Backwash Pumps Schematic Control Diagram –

Filtration

Figure 12 Pressure Filters and Backwash Pumps Schematic Control Diagram –

Backwash

Figure 13 Mechanical Building - Booster Pump, Pressure Washers, and Disinfection

System

Figure 14 Disinfection System Schematic Control Diagram

Figure 15 Storage Tank Plot Plan

Figure 16 Finished Water Storage Tank Plan and Section

Figure 17 Hose Stream Booster Pumps Schematic Control Diagram

October 2005 v

APPENDIX

Appendix A Inspection and Maintenance Forms

October 2005 1

OPERATION AND MAINTENANCE GUIDE FOR

TACTICAL VEHICLE WASH FACILITY, EAST RANGE

A. OVERVIEW OF THIS MANUAL

This Operations and Maintenance (O&M) Guide is provided to give the O&M Contractor a generalized overview of typical operational procedures and maintenance work required for keeping the Tactical Vehicle Wash Facility in proper operating condition.

The manual is written assuming that the process and equipment selected for the project are consistent with the originally specified processes and equipment. This O&M Guide is not intended to replace equipment manufacturers O&M manuals that are provided with the purchased equipment. In the event of conflict with the equipment manufacturer supplied O&M Manual, the equipment manual shall govern.

This O&M Guide is structured as follows:

a. Overview of This Manual

b. General Description of the Facility

c. Individual Process Components

i. Description

ii. Typical Operating Sequence/Procedures

ii. Typical Maintenance

d. Standard Operating Instructions for Military Personnel

B. GENERAL DESCRIPTION OF THE FACILITY

The Tactical Vehicle Wash Facility, East Range, is used as a field wash for vehicles utilizing the Schofield Barracks East Range Training Area. The primary purpose of the facility is to reduce the potential migration of mud and native plant seeds to areas outside of the East Range Training Area.

The Tactical Vehicle Wash Facility recycles spent vehicle washwater for reuse to minimize consumption of potable water. A simplified process flow diagram showing the main process components for the facility is shown in Figure 1. The facility utilizes sedimentation (settling), pressure filtration, disinfection (chlorination), finished water storage, and recycling of the finished water.

The facility was designed to wash 80 vehicles per day, with each vehicle being washed for 30 minutes. However, the facility is capable of washing more vehicles per day. A higher level of maintenance and operator attention would be required to keep the facility in good operating condition.

• Vehicle Loading = 80 vehicles/day

• Wash bays provided = 6

• Design wash time/vehicle = 30 minutes/vehicle

October 2005 2

• Design time to wash 80 vehicles = 6.67 hours

• 68 wash events per year = facility used 5 days/week, 12 times a year including 4 weekends (Saturday and Sunday) throughout the year.

Operations where more than 80 vehicles/day occur will require the following additional maintenance:

• More frequent make-up water filling of reservoir (due to additional water losses)

• More frequent backwashing of filters

• More frequent filling of calcium hypochlorite tablets on disinfection system

• More frequent cleaning of accumulated sediment in basin

The increased maintenance requirements due to the increase in vehicles washed are discussed in the specific process sections. Specific process units covered in this document include:

1. Wash Area and Trench Drain

2. Sedimentation Basin and Sump Pumps

3. Pressure Filter and Filter Backwash Pumps

4. Disinfection System

5. Finished Water Storage Tank

6. Hose Stream Booster Pumps

7. Pressure Washers

8. Process Piping

9. Process Equipment Alarms

A more detailed process drawing is shown in Figure 2 and includes design data for individual processes. Figure 3 depicts the physical layout of the facility. Specific process units are described in detail in the following sections.

C. INDIVIDUAL PROCESS COMPONENTS

1. Wash Area and Trench Drain

a. Description

The wash area was designed to wash WHEELED VEHICLES ONLY. If tracked vehicles need to be washed at the facility, the tracked vehicle must be loaded onto a low-boy trailer first. The wash area concrete slab was not designed to accommodate tracked vehicles. DO NOT RUN TRACKED VEHICLES over the wash area.

Do not wash any vehicle that is NOT PARKED ENTIRELY on the concrete wash area because the spent washwater will not properly drain to the sedimentation basin.

October 2005 3

The wash area consists of a reinforced concrete pad with curbing to accommodate the vehicles during a wash event (Figure 4). A total of 6 wash area bays (WA) are provided, with one tandem stall (WA-01 and WA-02) to accommodate trucks with trailers, and the remaining four bays (WA-03 to WA-06) as individual stalls. Each of the 6 wash bays are equipped with the following fixtures (Table 1):

Table 1

Wash Area Fixtures

Fixture/Drawing Designation Number per bay Design Flow, lpm (gpm) Pressure, kPa (psi) at delivery point Low-pressure hose connection/HC 2 95 (25) 517 (75)

High-pressure connection /E 2 11 (2.8) 6410 (930)

Water to the low-pressure hose connections (HC) is supplied by the hose stream booster pumps at the mechanical building. Water to the high-pressure washer connections (E) is supplied by individual pressure washer units at the mechanical building. The maximum flowrate anticipated from the wash process is 212 lpm (56 gpm) per wash bay, or a total flowrate of 1273 lpm (336 gpm) when all 6 wash bays are in use.

As vehicles are washed on the concrete wash pads, spent washwater will be conveyed through a concrete trench drain to the adjacent sedimentation basin. No underground piping is used to convey spent washwater from the wash area to the sedimentation basin. Each wash bay is sloped to a center trench drain (Trench Drain A) running perpendicular to the wash pads. The trench drain has a U-shaped invert sloped at 2 percent to maximize hydraulic efficiency and to minimize accumulation of settled solids.

The trench drain is overlaid with a removable traffic-rated, heavy-duty metal grating.

As shown on Figure 3, Trench Drain A makes a 90-degree bend into the sedimentation basin. To facilitate hydraulics and prevent deposition of solids in the trench, the bend consists of a 90-degree curve with a 1 m (3.28 ft) radius. Thus, in the event of the trench drain becoming clogged, the low-pressure hoses (HC) can be used to flush the blockage through the trench. In addition, the metal grating can be removed by hand to facilitate removal of the blockage.

In addition to the trench design minimizing deposition of solids, a trench flush nozzle is connected at the upstream end of the trench (Figure 4) to provide a continuous flow of water into the trench. The trench flush nozzle is connected to the pipe supplying the low-pressure hoses (Hose Stream Process Line “D”) and is actuated by a pressure-sustaining flow control valve. When pressure in Process Line “D” upstream of the sustaining valve exceeds the preset value of 606 kPa (88 psi), the valve will open and release water into the trench. This would typically occur when only one or two of the wash pad fixtures are in use. As more wash area hoses activate, the system pressure upstream of the valve will either close the valve completely or decrease the flow through the trench flush nozzle. Thus, when only one or two wash areas are used, more water

October 2005 4 will discharge from the trench flush nozzle as compared to when all 6 wash areas are in use. When all 6 wash areas are in use, little or no flow will discharge from the trench flush nozzle.

Two dual hose bibs are also included separate from the Wash Area. The dual hose bibs are connected to Hose Stream Process Line “D” and are located along the approach pavement to the Wash Area. One set of hose bibs is adjacent to the trash container and the other set of hose bibs is located in front of the Mechanical Building and Finished Water Storage Tank (Figure 3). The dual hose bibs are intended for use by the soldiers after a wash event to clean the approach pavement Note that in order for the dual hose bibs to operate, the hose stream booster pump in the Mechanical Building must be operating. Refer to Section C6 for Hose Stream Booster Pump operation.

b. Typical Operating Sequence and Procedures

Before Wash Event

1) Remove low pressure wash hoses/nozzles from storage area in Mechanical Building and connect to individual hose connections at wash area. There are a total of 12 hoses (hose connections HC-01 through HC-

12) to be connected at the wash area. Ensure that ball valves at the hose connections are opened after connecting hoses. Do not lay hose nozzles on the Wash Area pavement where vehicles can run over nozzles.

2) Remove pressure washer hoses/wands from storage area in Mechanical Building and connect to individual quick connect couplers at the wash area. There are a total of 12 hoses to be connected (Pressure Washer connections E-01 through E-12) at the wash area. Ensure that ball valves at the hose connections are opened after connecting hoses. Do not lay pressure washer wands on Wash Area pavement where vehicles can run over wands.

3) Activate Hose Stream Booster Pumps inside Mechanical Building. Refer to Section C6 for Hose Stream Booster Pump operation.

4) Activate Pressure Washer units inside Mechanical Building. Refer to Section C7 for Pressure Washer operation.

During Wash Event

1) Check for leaking fixtures/hoses/nozzles/wands at Wash Area.

2) Check the trench flush nozzle – a stream of water should be flowing from the nozzle into the trench drain. If only one hose is being used, the flow from the flush nozzle should be high. Likewise, as more low-pressure hoses are turned on, the flow from the flush nozzle should decrease correspondingly.

October 2005 5

3) Check that soldiers leave hose nozzles on the concrete islands whenever vehicles enter/exit wash area bay to prevent vehicles from running over nozzles.

4) Check that soldiers leave Pressure Washer wands on the concrete islands whenever vehicles enter/exit wash area bay to prevent vehicles from running over Pressure Washer wands.

After Wash Event

1) Go to the Mechanical Building to deactivate individual Pressure Washer units. Refer to Section C7 for Pressure Washer operation.

2) Keep Hose Stream Booster Pumps activated for post-wash cleaning of facility asphalt and concrete pavements by soldiers.

3) Upon completion of post wash pavement cleaning, verify that Trench Drain A is clear of debris/ obstructions, and concrete Wash Area and AC paved approach are clear of debris/mud. Cleanup of these areas are the responsibility of military personnel using the facility. Refer to Section D for military personnel cleanup responsibilities.

4) Verify that trench flush nozzle is clear of debris.

5) Shutdown Hose Stream Booster Pumps. Refer to Section C6 for Hose Stream Booster Pump operation.

6) Close all wash hose connection (HC) valves; disconnect all wash hoses/nozzles at wash area and return to Mechanical Building storage.

7) Close all pressure washer quick connect coupling (E) valves; disconnect all pressure washer hoses/wands and return to Mechanical Building storage.

8) Verify no water is discharging from any of the wash hose connections (HC), Pressure Washers (E) connections, or trench flush nozzle in Trench Drain A.

c. Typical Maintenance

Typical maintenance procedures are recommended below (refer to Wash Area and Trench Drain Inspection and Maintenance Data Sheet in Appendix A). Note that some typical maintenance procedures are included as part of the typical operating sequence and procedures. Tasks listed with daily maintenance refer to maintenance done on the day of the wash event.

October 2005 6

Wash Area

1) (Daily) Verify concrete wash area and asphalt approach areas are clear of mud/silt, pebbles, rocks, and other debris. Military personnel are responsible for cleanup of Wash Area and pavement.

2) (Daily) Check condition of hose connection (HC) ball valves and threaded connections.

3) (Daily) Check condition of Pressure Washer (E) ball valves and quick connect couplings.

4) (Daily) Check for debris clogging the nozzle entrance.

5) (Daily) Conduct general housekeeping around area.

6) (Daily) Check working level lighting fixtures (4 per wash bay) and overhead pole mounted lights for burnt out bulbs.

Trench Drain A

1) (Daily) Verify trench drain is clear of mud/silt, pebbles, rocks, and other debris. Military personnel are responsible for cleanup of Trench Drain A.

2) (Daily) Check for debris blockage at spent filter backwash connection to Trench Drain A at the 90-degree bend in trench. Remove any blockage.

3) (Daily) Ensure that all metal grates are in place over trench.

4) (Daily) Check condition of metal trench grates. Replace/repair as needed.

Trench Flush Control Valve

1) (Daily) Check for leakage around piping/valve joints.

2) (Daily) Conduct general housekeeping around area.

3) (Annually) Check/lubricate flow control valve per manufacturer requirements.

4) (Annually) Clean and re-lubricate isolation valve stems on Trench Flush Control Valve assembly.

5) (Annually) Clean and wire brush corroded areas. Spot paint as needed.

October 2005 7

2. Sedimentation Basin and Sump Pumps

The sedimentation basin is a large concrete tank used to settle out larger clumps of mud, small rocks and pebbles, and other heavy particles washed off of the vehicles.

The total depth of the basin is approximately 1.829m (6 ft). The bottom 0.450 m (1.5 ft) depth of the basin is used for sediment storage, while the upper 0.450 m (1.5 ft) of the basin is used for freeboard.

Design characteristics of the sedimentation basin are as follows:

• Maximum flowrate into basin:

- 12 low-pressure hoses at 95 lpm (25 gpm) = 1140 lpm (300 gpm)

- 12 high-pressure wands at 11 lpm (3 gpm) = 132 lpm (36 gpm)

- Total maximum inflow = 1272 lpm (336 gpm)

• Detention time at maximum inflow = 4.6 hours

• Basin water storage required = 305,500 liters (80,600 gallons)

• Basin water volume provided = 352,800 (93,100 gallons)

• Sediment storage required = 93.52 m3 (3,300 ft3)

• Sediment storage provided = 102.22 m3 (3,607 ft3)

Most of the basin is below grade and is rectangular-shaped in plan view. As shown on Figure 5 – Sedimentation Basin - Plan, Trench Drain A discharges into a junction box inside the sedimentation basin. Two openings in the junction box direct flows to basin compartments A and B. Fiberglass reinforced plastic (FRP) slide gates mounted within the junction box allows either compartment to be isolated for maintenance.

Washwater enters the basin through the inlet junction box, flows through the basin passing under a floating oil boom and a geomembrane baffle, then to the opposite end and into the outlet trench. Oil and grease are NOT ALLOWED to be discharged to the Sedimentation Basin. To capture floating oil and/or grease, absorbant floating oil booms are located at the outlet end of the basin compartments (Figure 5, Sedimentation Basin – Plan). Additionally, a geomembrane outlet baffle is located between the floating oil booms and outlet trench to prevent floatables such as leaves from entering the outlet trench and basin sump (Figure 6, Section A).

The outlet trench is a U-shaped concrete trench covered by removable metal grating to preclude larger floating objects from getting into the trench (Section A on Figure 6). The outlet trench is connected to the basin sump through a short 8-in PVC pipe connection as shown on Figure 6, Plan – Basin Outlet Structure. Each basin compartment has its own overflow trench and connection into the basin sump.

The bottom of the basin was sized to provide sediment storage for approximately one year. If wash activity exceeds the design criteria, sediment is expected to accumulate more rapidly and will require cleaning more frequently. To facilitate basin draining

October 2005 8 during times of sediment removal, a double valve system will allow water levels to be drawn down. A telescoping valve installed in each compartment (150mm Telescoping Valves A and B) allows water to be decanted from a normal operating depth of approximately 1.372 m (4.5 ft) down to a depth of approximately 0.450 m (1.5 ft), which is the estimated yearly sediment accumulation depth (Figure 6 – Section A). The telescoping valve allows the operator to manually draw down the water in the basin and maintain control over the amount of silt-laden water discharging to the sump. Once the water level is lowered to a depth of approximately 0.450 m (1.5 ft), the accumulated sediment should be left for several days in the basin to facilitate additional dewatering via evaporation. The second valve in each compartment, Knife Gate Valves A and B, are intended for use in conjunction with filter fabric or straw bales to provide additional dewatering (Figure 6). The knife gate valves are set at the invert of the basin, which is sloped at 0.50 percent to facilitate drainage along the basin bottom (Figure 7, Section A).

Sedimentation Basin Sump and Pumps

The basin sump is a rectangular concrete structure and functions similarly to a pump station wet well (Figure 7). Washwater from the overflow trenches discharge into the sump and is pumped through the pressure filters and into the finished water storage tank. The sump will receive water from several sources indicated in the following Table 2 and depicted on Figure 7:

Table 2 Sources of Sedimentation Sump Inflow

Source Pipe size, mm

(in) Frequency of discharge Compartments A and B outlet trenches

200 (8) During wash operations or rainfall event

Telescoping Valves A and B 150 (6) During drawdown of water level for sediment removal

Knife Gate Valves A and B 150 (6) During drawdown of water level for sediment removal

Recirculation Line 75 (3) During recirculation of storage tank water

Chlorine Residual Sampling Line 13 (0.5) Constant

As shown on Figure 7, the sump contains a total of 4 valved connections to the sedimentation basin. As indicated previously, each basin compartment has a knife gate valve and a telescoping valve. The te lescoping valve is installed along the floor of the outlet end of the basin and can be used to decant water to a depth of 0.45 m (18 inches) during maintenance events. The knife gate valve is installed at the invert of the basin floor and can be used in conjunction with straw bales or fabric wrapped gravel to prevent drawing excessive silt into the sump.

October 2005 9

The basin sump is equipped with two submersible non-clog pumps, normally operated with one pump in duty mode and the other in standby mode. The pumps are equipped with an auto-alternator to automatically alternate duty and standby modes between the two pumps. Sump pump characteristics are shown in Table 3:

Table 3 Sedimentation Sump Pump Characteristics

Number 2 – 1 duty/1 standby Type Submersible, centrifugal, non-clog Design Operating Points 1,288 lpm @16.165m (340 gpm @ 53 ft)

1,364 lpm @ 14.024 m (360 gpm @ 46 ft) Electrical Characteristics 15 Hp, 460 VAC, 3 phase, 60 Hz

The pumps are normally always activated and will operate during a storm event if water levels in the sump rise. Pump operation is activated by level switches at the following water levels in the sump (Table 4):

Table 4

Sedimentation Sump Pump Activation Levels

Water elevation (m)

Water depth above sump bottom (m) Action Notes

264.659 1.772 High water level alarm

(LAH)

Pump control panel red light and horn activated

264.509 1.622 Lag pump on

264.359 1.472 Lead pump on

263.597 1.150 Pump off

263.447 0.560 Low water level alarm

(LAL)

Pump control panel red light and horn activated

262.887 --- Bottom of sump

Figure 8 shows a schematic control diagram for the sump pumps. The pumps are wired for 5 alarm conditions: Level alarm high, Level alarm low, emergency shutdown, pump motor trip, and power failure. Each of the alarm conditions will trigger a red light and audible horn on the sump pump control panel mounted in the Mechanical Building Electrical Room. The control panel alarm signals are also transmitted to the Emergency Shutdown/Alarm Cabinet mounted on the outside face of the Mechanical Building (Figure 9). The sump pumps are also connected to the Emergency Shutdown/Alarm Cabinet. The disconnect switch at the Emergency Shutdown/Alarm Cabinet can be used to shut down all processes automatically in the event of an emergency.

The sedimentation basin sump pumps are interlocked with the pressure filter backwash pumps to prevent both units from operating at the same time. Refer to Section C3 for Filter Backwash Pump operations.

October 2005 10

1) Verify Trench Drain A leading into sedimentation basin has no blockage.

Remove or flush out any observed blockage. DO NOT ALLOW WATER

TO FLOW INTO SEDIMENTATION BASIN WITH BLOCKAGE TO ITS

INLET/ OUTLET.

2) Verify sedimentation basin junction box has no accumulated material or blockages. Remove or flush out any observed blockage.

3) If one of the basin compartments is out of service, verify that the slide gate at the junction box is in place and completely closed.

4) Verify sedimentation basin outlet trench and trench drains into sump have no blockages. Remove or flush out any observed blockage.

5) Skim leaves, and other floating debris from water surface, especially along the water surface between the geomembrane outlet baffle and outlet trench.

1) If sump pump is running, open manual air release valve at top of piping header assembly to vent discharge line (Figure 7 – Section A).

2) If an alarm event is triggered, the red light and annunciator at the Emergency Shutdown/Alarm Cabinet at the Mechanical Building will activate. If alarm conditions have been triggered, go to Emergency Shutdown/Alarm Cabinet and shut down process. Check source of alarm trigger and resolve before re-setting alarm.

1) With hose stream booster pumps still active, water will continue to flow into sedimentation basin from cleaning operations conducted by soldiers along the wash area.

2) Upon completion of cleaning operations, verify that Trench Drain A leading into sedimentation basin has no blockages. Remove or flush out any observed blockage.

3) Verify sedimentation basin junction box has no accumulated material or

4) Verify sedimentation basin outlet trench and drains into sump have no

October 2005 11

5) Skim leaves, and other floating debris from water surface, especially along the water surface between the geomembrane outlet baffle and outlet trench.

6) Check condition of outlet baffles.

7) Check condition of floating oil booms. If oil booms are saturated with oil, replace with new booms.

Typical maintenance procedures are recommended as follows (refer to Sedimentation Basin and Sump Pumps Inspection and Maintenance Data Sheet in Appendix A). Note that some typical maintenance procedures are included as part of the typical operating sequence and procedures. Tasks listed with daily maintenance refer to maintenance done on day of wash event.

Basin

1) (Daily) Check Trench Drain A and Basin Junction Box are clear of debris.

Military personnel are responsible for cleaning of Junction Box and Trench Drain A.

2) (Daily) Skim and remove floating material such as leaves and other dead vegetation on basin water surface/edges .

3) (Daily) Check floating absorbent oil boom and connectors to basin walls.

If boom is saturated with oil, replace with new boom. NO DISCHARGES of oil and/or grease are allowed to sedimentation basin).

4) (Daily) Check outlet trench metal grating for accumulated floatables.

Remove any debris covering grating.

5) (Daily) Check outlet trench drains from Compartments A and B into sump for blockages. Remove any blockages.

6) (Daily) Check condition of geomembrane outlet baffle and connection to basin walls. Repair any rips, tears, or faulty connections to basin walls.

7) (Daily) General housekeeping around basin area.

8) (Monthly) Check condition of removable fiberglass reinforced plastic slide gates A and B for Basin Junction Box. Slide gates are normally stored inside Mechanical Building when not in use.

9) (Monthly) Check condition of slide gate guides at Basin Junction Box.

Slide gates are normally stored inside Mechanical Building when not in use.

10) (Monthly) Check Basin curbing and exposed concrete surfaces for cracks or other signs of concrete distress. Repair as needed.

October 2005 12

11) (Annually) Drain basin and remove accumulated silt. Refer to separate Basin Draining and Cleaning Procedures below for this task.

Sump and Pumps

1) (Daily) Check for unusual sounds from sump pumps

2) (Daily) Check for oil/grease accumulation in sump. If oil/grease is visible, remove.

3) (Daily) Vent manual air release valve at top of sump pump piping discharge header. Pump must be operating to properly vent air from piping header .

4) (Daily) Check sump pump control panel and indicator lights (inside Mechanical Building Electrical Room).

5) (Daily) Check for float switch entanglement in sump.

6) (Daily) Check for excessive movement of check valve arm on pump discharge header piping.

7) (Daily) General housekeeping around area.

8) (Monthly) Check inside sump and look for leakage around pipe connection flanges/joints and valves.

9) (Semi-Annually) Clean and re-lubricate telescoping and knife gate valve stems per manufacturer’s recommendations.

10) (Annually) Remove pumps from sump and check motor bearings and seals per manufacturers recommendations.

11) (Annually) Check/lube pump and motor per manufacturer requirements.

12) (Annually) Check bearing temperature.

13) (Annually) Check shaft coupling.

14) (Annually) Check shaft sleeve and oil seal.

15) (Annually) Clean, wire brush corroded areas and spot paint as needed.

Procedures for Removal of Accumulated Sediment

Note: Removal of accumulated sediment will likely be more effective during the summer months due to higher evaporation rates and drier weather. Based on the facility design parameters, it is estimated that accumulated sediment would require removal once per year. Procedures for draining and cleaning Compartment A are described below. Procedures for draining and cleaning Compartment B are similar.

louis.kalani Highlight

October 2005 13

1) Insert stop gate A into slotted holder at the sedimentation basin Junction Box. This will divert all water from a wash or rainfall event into Basin Compartment B.

2) Prior to sediment removal, the basin compartment should be left unused for at least 24 hours to facilitate settling and allow quiescent conditions to develop. This will aid in decanting of liquid from the basin compartment.

3) Begin by slowly lowering Telescoping Valve A to decant the water level in Compartment A. The telescoping valve is capable of drawing down approximately 1.04 m (3.4 ft) of water, leaving a water depth of approximately 0.450 m (18 in) in the basin.

4) During draining, the operator shall carefully note the clarity of decanted water. If silty slurry is observed overflowing the telescoping valve weir, the sediment depth may be deeper than the design 0.450 m (18 in) depth. If this is the case, drainage filter fabric can be draped over the telescoping valve inlet to prevent excessive silt from being drained into the sump. Water should be drained down to a depth of 0.450 m (18 in) if possible. However, if the water is too silty, stop draining of the compartment with the telescoping valve.

5) Place filtration media (i.e., a gravel pack wrapped with filter fabric, or a straw bale) in front of the 150 mm (6 in) knife gate opening. Ensure that the filtration media fits snugly up against the sump outer wall. If using straw bales, use sandbags to keep the bale in place.

6) Slowly open knife gate valve to begin draining the remaining liquid in the basin. Carefully monitor the amount of silty material entering the sump. If excessive, use a second gravel pack/straw bale in front of knife gate valve.

Also, do not fully open the knife gate valve. Valve can be partially opened to control the rate of flow through the valve.

7) After draining the basin, the remaining sediment slurry should be left in place for several days to dry, longer if possible.

8) The remaining sediment should be tested for hazardous waste classification. A Toxicity Characteristic Leaching Procedure (TCLP) test should be conducted to verify that the sediment is not classified as hazardous and is suitable for disposal in a landfill.

9) A front-end loader should be used for sediment removal. If the accumulated material is still in slurry form, a vactor truck can be used to pump out the slurry. If using a front-end loader, do not drag bucket on the bottom of the basin as this may damage the basin slab.

10) After the accumulated debris is removed from the basin, inspect the interior surfaces of the basin, noting any cracks in the concrete or other signs of distress. Any cracks noted in basin should be repaired prior to placing the compartment back into service.

October 2005 14

3. Pressure Filters and Filter Backwash Pumps

Three skid-mounted pressure filters are provided to filter the settled washwater. The filters are located inside the Mechanical Building (Figures 9 and 10) and are sized to run concurrently during a wash event. If one of the filters is out of service, flow will be routed through the remaining two filters. Each pressure filter is 1.520 m (5 ft) in diameter and is classified as a deep bed sand filter. This type of filter contains separate layers of sand and gravel. The three filter units are controlled by electric motor actuated butterfly control valves to operate under normal filtration mode and during the backwashing sequence. Figure 11 depicts the flow routing for the filters during normal filtration operations. The filters have the following design characteristics (Table 5):

Table 5 Pressure Filter Characteristics

Filter diameter 1.52 m (5 ft) Filter loading rate 204 lpm/m2 (5 gpm/ft2) Design flowrate 428 lpm (113 gpm)

The filter backwash sequence can be operated in one of three modes: (1) manual, (2) time delay, or (3) pressure differential. Under normal operations, the filters would be operated on manual activation mode, which allows the operator to manually start the backwash process after completion of a wash event. The time delay mode allows the backwash sequence to start after a preset time delay, such as 30 minutes after completion of the wash event. The pressure differential setting allows the operator to preset a differential pressure. An instrument measures the difference between the pressures at the inlet and outlet of the filters. When the preset pressure differential is reached, the backwash sequence is automatically initiated. The desired backwash sequence is set at the pressure filter control panel.

The filter control system is configured to take all three filter vessels out of service during backwash and to backwash only one filter vessel at a time (due to capacity of backwash pump). Thus, during backwash events all three filters will need to be backwashed, one at a time, before re-starting the filtration process. Figure 12 depicts the flow routing for the filters during backwashing operations. The estimated time of backwashing per vessel is approximately 10 minutes, or a total time of about 30 minutes to backwash all three filters. Washing activity can continue during filter backwashing. At a maximum flowrate of 336 gpm over the 30-minute backwashing period, the water level in the sedimentation basin would rise an estimated 75 mm (3 inches).

The filter control panel contains the filter backwash sequence mode selector, and has an alarm condition for a failed backwash sequence. The alarm condition is conveyed to the emergency/shutdown alarm cabinet.

October 2005 15

Filter Backwash Pumps

The skid-mounted filter backwash pumps flush out material accumulated on the filter media. The filter backwash pumps are configured in duty/standby operating mode and are located inside the Mechanical Building (Figure 9). Backwash water will be pumped back into Trench Drain A as shown on Figure 5. The filter backwash pumps have the following design characteristics (Table 6):

Table 6 Filter Backwash Pump Characteristics

Type End suction, centrifugal Design Operating Points 1,137 lpm @10.061m (300 gpm @ 33 ft) Electrical Characteristics 5 Hp, 460 VAC, 3 phase, 60 Hz

The filter backwash pumps are normally kept in active mode in the event that the preset pressure differential develops across the filter and triggers a backwash event. The pumps have the following alarm conditions: motor overload, low suction pressure, and high system pressure. These alarm conditions are indicated at the pressure filter control panel, which activates an alarm condition at the Emergency Shutdown/Alarm Cabinet at the Mechanical Building.

1) Check sump pump control panel inside Mechanical Building Electrical Room.

Verify that no alarm conditions are triggered. If alarm conditions have been triggered, do not start up wash sequence. Resolve alarm condition before starting wash sequence.

2) Check control panels at pressure filter and filter backwash pumps. Verify that no alarm conditions are triggered. If alarm conditions have been triggered, do not start up wash sequence. Resolve alarm condition before starting wash sequence.

1) Verify that no alarms have been triggered at pressure filter backwash pumps.

Normally, if an alarm event is triggered, the red light and annunciator at the Emergency Shutdown/Alarm Cabinet at the Mechanical Building will activate.

If alarm conditions have been triggered, go to Emergency Shutdown/Alarm Cabinet and shut down process by pressing Emergency Shutdown button.

Check source of alarm trigger and resolve before re-setting alarm.

2) Monitor pressure on influent/effluent header. Differential pressure between influent/effluent lines should not be greater than 4 psi. In the event that the

October 2005 16 differential pressure is greater than 4 psi, the pressure filters should be shut down and backwashed.

1) Commence backwash sequence – interlock on backwash pumps and sump pumps will prevent both systems from operating at the same time.

2) After backwash sequence is completed (approximately 30 minutes), verify that no alarms have been triggered at the filter control panel. If an alarm condition has been triggered, resolve problem before securing facility.

Typical maintenance procedures are recommended below (refer to Pressure Filters and Filter Backwash Pumps Inspection and Maintenance Data Sheets in Appendix A). Note that some typical maintenance procedures are included as part of the typical operating sequence and procedures. Tasks listed with daily maintenance refer to maintenance

Pressure Filters

1) (Daily) Check electric actuator system for proper operation.

2) (Daily) Check for leakage around flanges and joints.

3) (Daily) Check for unusual sounds.

4) (Daily) Check valve positions at influent/effluent piping.

5) (Daily) General housekeeping around area.

6) (Daily) Read and record differential pressure before backwash.

7) (Daily) Read and record differential pressure after backwash.

8) (Monthly) Check control panels and lights.

9) (Monthly) Check filter backwashing operations and cycle.

10) (Monthly) Check mechanical equipment for lubrication requirements.

11) (Semi-Annually) Check differential pressure gage.

12) (Semi-Annually) Check and flush differential pressure gage strainer.

13) (Semi-Annually) Shut down one filter at a time and check filter media elevation. Also check media for unevenness, grease/oil, mud balls or slime.

14) (Semi-Annually) Check condition of electric actuator valves.

15) (Annually) Check control panels for proper operation and deficiencies.

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16) (Annually) Thoroughly check electric actuator valve system.

17) (Annually) Check air relief valve on top of filter.

18) (Annually) Open filter and inspect condition of filter media with assistance of filter manufacturer representative. Remove and clean as needed.

Follow manufacturer’s instructions.

19) (Annually) Check inflow nozzles and underdrain system for deterioration, damage or clogging.

20) (Annually) Check and note condition of the filter interior wall protective coating.

21) (Annually) Inspect exterior of tanks and spot paint if needed.

Pressure Filter Backwash Pumps

1) (Daily) Check and record if pump operational or not.

2) (Daily) Read and record pump running time.

3) (Daily) Read and record pump amperage.

4) (Daily) Read and record pump discharge pressure.

5) (Daily) Check for leakage around flanges and joints.

6) (Daily) Check for unusual sounds from pump.

7) (Daily) General housekeeping around area.

8) (Monthly) Exercise spare pump.

9) (Semi-Annually) Check pump and motor bearings and seals.

10) (Annually) Check/lube pump and motor per manufacturer requirements.

11) (Annually) Check bearing temperature.

12) (Annually) Check shaft coupling.

13) (Annually) Check shaft sleeve and oil seal.

14) (Annually) Clean and re-lubricate valve stems.

15) (Annually) Clean, wire brush corroded areas and spot paint as needed.

4. Disinfection System

A disinfection mixing and feed system in the mechanical building chlorinates the filtered washwater prior to storage (Figure 9). The skid mounted disinfection system utilizes solid calcium hypochlorite tablets that are stacked in a storage canister above a mixing chamber. A 25 mm (1 in) water line feeds the mixing chamber, causing the tablets to louis.kalani Highlight

October 2005 18 dissolve and release hypochlorite. The hypochlorite converts to hypochlorite acid, which is the primary disinfecting agent. A feed pump on the chlorination skid injects the hypochlorite solution into the pressure filter washwater manifold as shown on Figure 13

– Disinfection System.

The control system for the tablet chlorinator consists of a compound loop process controller and chlorine residual analyzer (Figure 14). A sample is drawn from Process Line “C1” (Backwash Pump feed line) and is conveyed to a wall mounted chlorine residual analyzer via a 13 mm (0.5 in) PVC tube. The residual analyzer sends a 4 to 20 mA signal that varies in proportion to the chlorine concentration to the process controller to control the variable speed injection feed pumps. The pump speed is controlled to increase or decrease the hypochlorite solution feed rate to maintain a typical chlorine residual of 1.0 mg/L.

A standard 80 vehicle/day wash event would consume approximately 6.8 kg (15 lbs) of tablets, while a 24-hour wash event would consume approximately 16.3 kg (36 lbs).

The storage canister has a capacity of 36.4 kg (80 lbs), which would require re-filling every 5 standard wash events

A flow switch on the pressure filter discharge manifold prevents the disinfection system from feeding chlorine solution under no flow conditions. A 75 mm (3 in) recirculation line from Process Line “C1” (Figure 15) allows the operator to recirculate water from the storage tank to the sedimentation basin sump. As water drains into the sump and water levels rise, the sump pump will start and pump water through pressure filters, activating the flow switch. This enables the chlorination system to begin feeding chlorine into the system.

The disinfection system has the following alarm conditions: low tablet supply, low residual chlorine, and high residual chlorine. These alarm conditions will be relayed to the Emergency Shutdown/Alarm Cabinet at the Mechanical Building.

1) Check calcium hypochlorite storage canister – if storage is low, fill with tablets.

Recirculation of water

1) If facility has not been in use for over a week, it is likely that residual chlorine levels will be low and the water in the storage tank should be recirculated to re-start the chlorination process. To recirculate water, fully open the buried 75 mm (3 in) plug valve located between the Mechanical Building and the Finished Water Storage Tank (Figure 15).

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2) As water fills the sump, the sump pumps will operate. As water is pumped through the filters, the flow switch on the filter discharge header will enable the chlorinator, feeding chlorine into the system.

3) To provide sufficient residual, the recirculation valve should be opened at least 24 hours prior to commencement of wash operations. It is estimated approximately 65 percent of the Finished Water Storage Tank capacity will be recirculated over a 24-hour period.

1) Check storage canister to see if refilling is needed.

2) Check pipe connections and hoses for leaks.

1) Check calcium hypochlorite storage canister – if storage is low, fill with tablets.

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Typical maintenance procedures are recommended below (refer to Disinfection System Inspection and Maintenance Data Sheet in Appendix A). Note that some typical maintenance procedures are included as part of the typical operating sequence and procedures. Tasks listed with daily maintenance refer to maintenance done on day of wash event.

1) (Daily) Read and record pump running time.

2) (Daily) Check and record if standby pump operational or not.

3) (Daily) Check for leakage around flanges and joints.

4) (Daily) Check for unusual sounds from pump.

5) (Daily) Check that pump is sequencing properly.

6) (Daily) Check chemical level in storage tank.

7) (Daily) Check supply of calcium hypochlorite tablets. Order more if needed.

8) (Daily) General housekeeping around disinfection equipment skid area.

9) (Monthly) Exercise spare pump.

10) (Monthly) Clean and check pumps, mixers and solution tank.

11) (Monthly) Check/lube pump and motor per manufacturer requirements.

12) (Semi-Annually) Check pump and motor bearings and seals.

13) (Annually) Clean and re-lubricate valve stems

14) (Annually) Clean, wire brush corroded areas and spot paint as needed.

Additional Maintenance

1) (Annually) Comprehensive inspection including calibration of the disinfection feed pumps and chlorine residual analyzer by equipment manufacturer’s representative or supplier.

louis.kalani Highlight

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5. Finished Water Storage Tank

The 625,300 liter (165,000 gallon) aboveground steel tank provides storage for the finished water (Figures 15 and 16). The tank has a diameter of 9.1 m (29.7 ft) and has a height of 9.8 m (32.2 ft). The tank is sized to provide stand-alone storage for the design 80 vehicles/day wash event, accounting for water usage during the wash event and water losses due to evaporation and vehicle carry-off. The tank has the following piping connections (Table 7):

Table 7 Finished Water Storage Tank Piping Connections

Type Size, mm (in) Inlet from Filtered Washwater Process Line “B” 150 (6) Inlet from potable water fill line 100 (4) Discharge to Process Line “C” 150 (6) Discharge to sanitary sewer 150 (6) Discharge to overflow drain 150 (6)

The interior of the tank is fitted with an overflow weir box that is connected to an exterior 150 mm (6 in) pipe that drains to grade. The overflow pipe is located along the east side of the tank and daylights at a concrete splash block. The tank has an exterior gage board mounted on its north face, adjacent to the 150 mm (6 in) potable water connection. The gage is connected to a float inside the tank and indicates the water level in the tank. Water lost during a wash event will lower the water elevation in the tank by an estimated 1.52 m (5 ft). Under normal operating conditions, the tank operating levels would range between 9.146 m (30 ft - full) and 6.098 m (20 ft). This would enable two consecutive 80 vehicle/day wash events to occur without having to replenish the water tank levels with potable water.

1) Check water level in tank by observing exterior gage board indicator on the north side of the tank.

2) If indicator is below 7.62 m (25 ft), fill the tank with potable water to the 9.1 (30 ft) mark. Refer to section on Make-Up Water Filling. If the number of vehicles is not significant (i.e. 5 or fewer lightly soiled vehicles), it is possible to run the wash facility first, then refill the tank with potable water after the wash event is completed.

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1) Check water level in tank by observing gage board indicator – if excessive carry-off or water waste (i.e. hoses being directed off of the wash area and not discharging to Trench Drain A) is occurring, water levels in tank will fall more rapidly. Do not let water level in tank drop below 6.1 m (20 ft). If water level is below 6.1 m (20 ft) level, initiate make-up water filling operations.

1) Check water level in tank by observing gage board indicator.

2) If indicator is below 7.62 m (25 ft), fill the tank with potable water to the 9.1 (30 ft) mark. Refer to section on Make-Up Water Filling. Ensure that potable water fill line valve is closed completely upon completion of filling operation.

3) Check overflow line on east side of tank – no water should be seen discharging from tank.

Make-up water filling

1) To fill water tank with potable make-up water, first verify the water level in the tank by observing the gage board indicator.

2) To commence filling, open the 100 mm (4 in) valve on the potable water connection line (Figure 15 – Detail 1). This above grade valve is located on the north side of the tank.

3) Observe the rising water level as it corresponds to the gage board indicator. When indictor reaches a level of 9.1 m (30 ft), turn off 100 mm (4 in) potable water supply gate valve. DO NOT EXCEED 9.1 (30 ft). The overflow weir is set for a maximum tank water level of 9.1 m (30 ft), so excess water will begin to discharge through the overflow piping along the east side of the tank.

Typical maintenance procedures are recommended below (refer to Finished Water Storage Tank Inspection and Maintenance Data Sheet in Appendix A). Note that some typical maintenance procedures are included as part of the typical operating sequence and procedures. Tasks listed with daily maintenance refer to maintenance done on day of wash event.

1) (Daily) Check condition of water level indicating gage.

2) (Daily) Check condition of tank steel roof.

3) (Daily) Check condition of access hatch on tank roof.

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4) (Daily) Check condition of pressure/vacuum relief valve atop tank roof.

5) (Daily) Check insect screen at air vent and overflow drain.

6) (Daily) Check for damp spots along concrete base ring (dampness could be indication of leaking tank).

7) (Monthly) Check and exercise Process Line “B” gate valve.

8) (Monthly) Check and exercise Potable Water Fill gate valve.

9) (Monthly) Check and exercise Process Line “C” gate valve.

10) (Monthly) Check and exercise Tank Drain gate valve.

11) (Monthly) Check concrete ring foundation for cracks, spalling, other signs of concrete distress.

12) (Monthly) Check exterior of steel tank walls for corrosion, touch up as necessary.

13) (Monthly) Cut back tree branches from tank wall and vegetation from concrete ring base.

14) (Annual) Drain tank and flush out any accumulated silt/debris (refer to the following instructions for Finished Water Storage Tank Draining).

Finished Water Storage Tank Draining

Note: DO NOT schedule Finished Water Storage Tank draining and cleaning during:

(1) inclement weather, and (2) at the same time as a vehicle wash event. Water should not be draining into the Sedimentation Basin sump during Water Storage tank draining and cleaning operations. Water draining to the sump may activate the sump pumps, causing water to be pumped into the Finished Water Storage Tank.

1) Manually shut off sump pumps at control panel located in Mechanical

Building Electrical Room. This will prevent sump pumps from pumping water into the Storage Tank during cleaning operations.

2) Close above grade gate valve on Process Line “B” feed line into tank

3)…