Bioreactor Foaming

1      Types of foam

There are two basic types of foam:

1.1      Chemical foams

Chemical foams are typically

·         Light in texture - the bubble size may range from “bath like” bubbles to dense 1 – 2 mm bubbles.

·         Easy to break down with water or by leaving to stand.

·         Range in colour from pale brown to dark brown.

Chemical foaming events typically

·         Are of short duration.

·         Sudden to start and stop.

·         May be regular in occurrence (at a certain time of the day).

·         Are due to ship operations involving cleaning chemicals.

1.2      Biological foams

Biological foams are typically

·         Dense.

·         Stable when subjected to mechanical or physical abuse.

·         Range in colour from black brown though to mid brown

Biological foaming events typically

·         Are persistent – may take days to stop.

·         Occur as a result of longer term environmental problems with the bacteria.

2      Sources/locations of foam

Foaming is caused by the application of energy to the body of the biomass or to a liquid surface. Typically this energy may be in the form of:

·         air passing through the liquid body as in the main bioreactor tanks, or

·         free flow of liquid coming into contact with a free liquid surface as in the bioreactor first stage.

Thus typical areas where foam may develop are:

1.         Main bioreactor first stage – from aeration and raw water falling onto the liquid surface.

2.    Main bioreactor second stage – from aeration.

3.    Screenings tank from free falling liquid out of ISF.

4.    Filtrate tank – from free falling liquid out of ISF.

Of these, 2, foaming from the main bioreactor tanks and 3, foaming from the screenings tank are the most common but all may be experienced from time to time.

3      Preventing foam

3.1      By design

Certain design precautions will have been taken to prevent foaming occurring. These will typically be in place on any MBR installation. Standard design considerations may be:

·         Baffling free falling flows to direct the liquid energy onto a wall and away from free surfaces or pump suctions.

·         Minimising the amount of air used at any given time to reduce aeration energy in reactors.

3.2      By operation

The operator may use any or all of the following strategies to reduce the risk of foaming.

·         Using low foaming characteristic chemicals for cleaning and other applications which pass the chemical into the grey or black water system.

·         Ensuring that chemicals enter the system from cleaning applications in a controlled way and are not allowed to form high concentration sin the grey water tanks.

·         Management of the grey water so that flows with typical high foaming qualities such as the laundry waste are passed into the grey water system over as long a period of time as can be managed.

·         Maintaining the biological environment within the recommended design limits set out in the O&M manual.

·         Ensuring the loading onto the system is maintained as much as possible within the design limits set out in the O&M manual.

·         Maintaining log sheets to monitor long term changes in the operating parameters on the system.

Each of these will act either to reduce the chance of a foaming event or enable monitoring of the system to predict a change in the biological environment that may promote foaming.

4      Controlling foam

Foaming may be controlled by:

·         Reducing the energy available to create the foam.

·         Adding antifoam to the system to control the foam as it is created.

MEASURES TO BE TAKEN IN THE EVENT OF FOAMING.

Design measures will have been taken to automatically control foaming events and to ensure that any foam produced is retained within the system, however at times these may not be enough and the operator may have to intervene. In these instances the following action should be taken:

1.    Remove the source of energy creating the foam by:

·         Switching of the interstage filter and ISF feed pump[1].

·         Switching off the process blowers.

Note: Either of these actions will put the unit into fault mode and close the inlet valves The operator may wish to monitor levels in the black and grey water storage to ensure the operation of the vessels waste water system is not compromised.

2.    Contain foam if necessary by replacing access hatches on tanks – access hatches on the screenings or filtrate tanks will often be where foam will emerge.

3.    Use any pumps operating in manual to reduce the level in tanks affected by the foaming – this applies particularly to foaming occurring in the screenings or filtrate tank.

4.    Switch on the antifoam pumps if these are not already running.

5.    Wait for foaming to subside

6.    Once the unit has stabilised and the foaming has stopped run one small blower in hand and start ISF and pumps - note adding a cap full of antifoam to the screenings and filtrate tank will help to prevent further foaming.

7.    Bring the plant back up by running additional blowers in hand until the desired number of blowers is running.

8.    Once the plant is operating in a stable way put the blowers into automatic operation.

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[1] Foaming from the ISF is a clear indication of chemical foam. In this instance hotel services should be contacted to identify potential chemical management measures to reduce future risk of foaming occurring.

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Membran Bio Reactror Cleaning

MEMBRANE BACKFLUSHING.

Frequency:

Each membrane bank must be back flushed weekly.

Method:

1.    Fill cleaning tank with technical water or permeate.

2.    Switch off crossflow pump.

3.    Isolate membrane bank from feed and bleed system.

4.    Open membrane bank to cleaning system.

5.    Direct the cleaning system return to pump to the reactor first stage.

6.    Operate the cleaning pump to discharge the tank contents.

7.    Fill the cleaning tank with technical water or permeate.

8.    Operate the cleaning pump to discharge the tank contents.

9.    Isolate the membrane bank from the cleaning system.

10.  Open the membrane bank to the feed and bleed system.

11.  Start crossflow pump.

12.  Check crossflow loop pressure in stable and within normal operating levels.

13.  Check bleed flow is stable and within normal operating levels.

MEMBRANE CLEANING.

Frequency:

Each membrane bank should be cleaned every 4 – 6 weeks (Monthly).

Method:

Part 1 – Setting up the bank

1.    Switch of crossflow pump.

2.    Isolate membrane bank from feed and bleed system.

3.    Open membrane bank to cleaning system.

4.    Direct the cleaning system return to pump to the reactor first stage.

5.    Direct the permeate via the three way valve on the permeate manifold from the bank to be cleaned to discharge to the cleaning tank.

Part 2 – Flushing

6.    Fill cleaning tank with technical water or permeate

7.    Operate the cleaning pump to discharge the tank contents.

8.    Fill the cleaning tank with technical water or permeate.

9.    Operate the cleaning pump to discharge the tank contents.

10.  Direct the cleaning system return to the cleaning tank.

Part 3 – Bio 40 cleaning

11.  Fill the cleaning tank with technical water or permeate. During the fill add 1 litre of part 1 chemical per membrane module in the bank to be cleaned.

12.  Run the cleaning pump for four hours.

13.  Direct the flow from the cleaning pump to the sludge tank.

14.  Allow the cleaning tank to be pumped to the sludge tank until the cleaning pump stops

15.  Direct the flow from the cleaning pump to the membrane bank.

Part 4 – Flushing

16.  Direct the cleaning system return to pump to the reactor first stage.

17.  Fill the cleaning tank with technical water or permeate.

18.  Operate the cleaning pump to discharge the tank contents.

19.  Fill the cleaning tank with technical water or permeate.

20.  Operate the cleaning pump to discharge the tank contents.

21.  Direct the cleaning system return to pump to the cleaning tank.

Part 5 – Clipclean cleaning

22.  Fill the cleaning tank with technical water or permeate, during the fill add 1 litre of the part 2 chemical to the cleaning tank.

23.  Run the cleaning pump for four hours.

24.  Direct the flow from the cleaning pump to the sludge tank.

25.  Allow the cleaning tank to be pumped to the sludge tank until the cleaning pump stops

Part 6 - Flushing

26.  Direct the flow from the cleaning pump to the membrane bank.

27.  Direct the cleaning system return to pump to the reactor first stage.

28.  Fill the cleaning tank with technical water or permeate.

29.  Operate the cleaning pump to discharge the tank contents.

30.  Direct the cleaning system return to run to the cleaning tank.

Part 7 - Disinfection

This part of the cleaning process is optional and may be excluded. However regular disinfection of the membrane banks and permeate system will help with control of the effluent quality in terms of faecal coliforms.

31.  Fill the cleaning tank with technical water, during the fill add 2-4 litres of Sodium Hypochlorite to the cleaning tank.

32.  Direct the permeate flow from the bank being cleaned to the permeate tank using the three way valve on the permeate manifold.

33.  Run the cleaning pump for half an hour.

34.  At the end of the half hour period the operator may choose to sample the circulating flow and analyse for chlorine content. If this is less than 1 mg/l increase the quantity of chlorine in step 31 during subsequent cleaning cycles. If the residual is very high the reduce the amount of Hypochlorite added.

35.  Direct the flow from the cleaning pump to the sludge tank.

36.  Allow the contents of the cleaning tank to empty.

Part 8 – Restarting the system

37.  Isolate the cleaned bank from the cleaning system.

38.  Open the cleaned bank to the feed and bleed system.

39.  Start the crossflow pump.

40.  Check crossflow loop pressure in stable and within normal operating levels.

41.  Check bleed flow is stable and within normal operating levels.

MEMBRANE DISINFECTION.

Frequency:

Each membrane bank should be disinfected as required by the system. In the event of a Idexx monitoring sample on the plant starting to show higher faecal coliform values a disinfection cycle will ensure that the system is cleaned and the effluent quality is maintained.

Note: This operation will increase the effluent chlorine concentration to greater than the permitted discharge level in some waters, for this reason it is preferable to carry this out outside 12 miles.

Method:

Note: The disinfection process is carried out with the permeate valve directed to the permeate tank.

Part 1 – Setting up and flushing the first bank

1.    Switch of crossflow pump on the bank.

2.    Isolate membrane bank from feed and bleed system.

3.    Open membrane bank to cleaning system.

4.    Direct the cleaning system return to pump to the reactor first stage.

5.    Fill cleaning tank with technical water or permeate

6.    Operate the cleaning pump to discharge the CIP tank contents.

7.    Fill the cleaning tank with technical water or permeate.

8.    Operate the cleaning pump to discharge the CIP tank contents.

9.    Direct the cleaning system return to the CIP tank.

Part 3 – Disinfecting the first bank

10.  Fill the cleaning tank with technical water or permeate during the fill add 2 – 4 litres of Sodium Hypochlorite.

11.  Run the cleaning pump to empty the CIP tank to low level.

12.  Isolate the disinfected bank from the cleaning system.

Note: A minimum contact time of 30 minutes must be allowed for each bank to ensure disinfection is complete. Thus the last bank to be disinfected must be held for a minimum of 30 minutes to ensure complete disinfection prior to returning the system to service.

Part 4 – Setting up and flushing subsequent banks

Repeat sections 1 – 9 for the second and subsequent banks

Part 5 – Disinfecting subsequent banks

Repeat sections 10 – 12 for the second and subsequent banks until all banks are off line and charged with disinfecting solution.

Part 6 – Flushing and returning first bank into service

13.  Allow the last unit charged to stand for 30 minutes.

14.  Open the first membrane bank to cleaning system.

15.  Direct the cleaning system return to pump to the reactor sludge tank.

16.  Fill the cleaning tank with technical water.

17.  Operate the cleaning pump to discharge the tank contents.

18.  Isolate the disinfected bank from the cleaning system.

19.  Open the disinfected bank to the feed and bleed system.

20.  Start the crossflow pump.

21.  Check crossflow loop pressure in stable and within normal operating levels.

22.  Check bleed flow is stable and within normal operating levels.

Part 7 – Flushing and returning subsequent banks into service

Repeat sections 13 - 22  until all banks are back in service.

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MR 750 Potable Water Treatment

1      Potable Water

1.1    Source

1.1.1     Bunkering Water From Shore Side

Drinking water bunkered from shore supplies shall be potable.

Attempt to get the most recent copy of the microbiological report from the port where you intend to bunker through the agent at least 48 hours before arrival.  If a microbiological report is not available, collect a water sample from the shore source supply and run a coli-alert E. coli test on the sample.  Log test results in Bunker Water Logbook.  Maintain shore side microbiological report in Bunker Water Logbook.  Retain the records for 12 months

1.1.2     Water Production

The distillation plant or RO unit shall not be operated in port or harbor areas.

1.2    Bunker and Production Halogenation

1.2.1     Residual Halogen

Potable water shall be continuously halogenated to at least 2.0 mg / l (ppm) free residual halogen at the time of bunkering or production with an automatic halogenation device.

1.2.2     Monitoring

A halogen demand test and pH shall be conducted on the shore-side water supply before starting the bunkering process to establish the correct halogen dosage and to determine if pH adjustment is necessary.  Use the Hach test kit for chlorine and pH to get this determination.  Log results in Bunker Water Logbook

PH adjustment is necessary when the pH is above 8 or below 7.

Halogen analyzer-chart recorders are used in lieu of manual tests.  The recorders shall be calibrated at the beginning of bunkering or production and when the charts are changed and the calibration shall be recorded on the chart or in a logbook.  If automatic analyzer/recorder is not operational, test free halogen residual hourly for bunkered water and every 4 hours for production of water.  Log in Bunker Water Logbook.  The analyzer charts shall be 24-hour charts.  The charts shall be signed and dated when changed.  Note any unusual events ion chart or in logbook.

Water samples for halogen testing shall be obtained from a sample cock located on the bunker or production water line at least 3 m (10 ft) after the halogen injection point and before the storage tank.

Maintain all records for 12 months onboard.

1.3    Shore Supplied Water Bunkering Procedures

• Shore supplied water must be potable.  Obtain recent microbiological report through the port agent. 
• Test shore supply for free halogen and pH.  Obtain water sample for E coli testing.
• Lay out potable water hoses on the pier.  Do not drag ends on the ground, pier, or deck surfaces.  Do not drop the hoses into the harbor.
• Potable water connections shall be above ground on stands on each side of the connection and periodically on hose.  The end caps from each connection shall be connected to each other during bunkering operations.  Before connecting the hoses to the ship’s potable water manifold, flush the hose for one minute.
• When bunkering operations are complete, turn off shore water supply, disconnect all connections and roll hoses up.  Sanitize hose caps in sanitizing bucket at 100 ppm for 10 seconds and reconnect hose cap on hoses .
• Store hoses, in the hose locker.  Insure hose locker is clean. Only hoses, bleach, and sanitizing bucket can be stored in hose locker.        

1.4    Potable Water System

1.4.1     Potable Water Tanks

Interior coating on potable water tanks shall be approved for potable water contact.  When tanks are recoated, record in Amos D.  Include the name of coating and manufacturer.

Potable water tanks shall be identified with a number and the words “Potable Water” in letters 13 mm high, have sample valves that point down and vent lines shall be protected.

1.4.2     Potable Water Piping

Potable water piping shall be painted light blue or striped with 15 cm light blue bands or a light blue stripe at fittings on each side of partitions, decks, and bulkheads and at intervals not to exceed 5 m in all spaces, except where the décor would be marred by such markings.

The potable water bunker filling line shall have a screw cap or plug fastened by a non-corroding chain to an adjacent bulkhead or surface in such a manner that the cap or plug shall not touch the deck when hanging free.

Each potable water filling line shall be painted light blue and clearly marked “POTABLE WATER FILLING” in letters at least 13 mm high, stamped on a non-corrosive label plate or the equivalent and located at or near the point of hose connection.

Non-potable freshwater, if used on the vessel shall be bunkered through separate piping using fittings non-compatible for potable water bunkering

Non- potable freshwater shall flow through a completely different piping system and be identified with a different color.

1.4.3     Potable water Hoses

1.4.3.1    Construction

Potable water hoses shall have unique fittings from all other hose fittings on the vessel.

Potable water hoses shall be identified for use with potable water.

Potable water hoses and fittings shall be constructed of safe easily cleanable materials and shall be maintained in good repair.

Potable waster hose lockers shall be constructed of easily cleanable material and maintained in good repair.

Potable water hose lockers shall be marked “POTABLE WATER HOSE AND FITTING STORAGE” in letters at least 13 mm high.

The potable water hose lockers shall be mounted at least 45 cm above the deck and shall be clean and self-draining.

The locker shall not be used for any other purpose than storing potable water hoses, fittings, sanitizing buckets, and other associated equipment.;

1.4.3.2    Handling

Potable water hoses shall not be used for any other purpose.  All hoses, fittings and associated fittings shall be stored in a sanitary manner.

Potable water hoses shall be handled with care to prevent contamination by dragging ends on the ground, pier, pr deck surfaces, or by dropping the hose into the harbor.

Potable water connections shall be above ground on stands on each side of the connection and at intervals that insure the hose is kept off the ground.  The end caps from each connection shall be connected to each other during bunkering operations.

Potable water hoses shall be flushed before being used and shall be drained and fittings sanitized in a white bucket with 100 ppm free residual chlorine after each use. Test papers shall be available.

Potable water hoses shall be stowed with the ends capped, on reels, or racks in potable water hose lockers.

1.5    Potable Water System Contamination

1.5.1     Cleaning and disinfection

Potable water tanks and any parts of the potable water distribution system shall be cleaned, disinfected, and flushed with potable water:

• Before being placed in service and
• Before returning to operation after repair
• Being subjected to any contamination, including entry into a potable water tank.

Potable water tanks shall be inspected, cleaned and disinfected during dry/wet docks or every 2 years whichever is less.  Document the cleaning in Amos-D and maintain record for 12 months.

Disinfection following potential contamination shall be accomplished by increasing free residual halogen to at least 50 mg/l (ppm) throughout the affected area and maintaining this concentration for 4 hours or 100 mg/l (ppm for 1 hour.

The disinfected parts of the system shall be flushed with potable water until the free residual halogen is Less than 5.0 mg/l 9ppm).

1.6    Potable Water System Halogenation

1.6.1     Operation

The halogenation device shall provide continuous halogenation of the potable water distribution system and shall maintain a free residual halogen of 0.2 mg/l (ppm) to 5.0 mg/l (ppm) throughout the distribution system.

A flow meter or a free halogen analyzer shall control the amount of halogen injected into the potable water system.

At least one backup halogen pump shall be connected to the system with automatic switchover to maintain the free residual halogen in the event that the primary pump fails.

1.6.2     Potable Water System Halogen Monitoring

1.6.2.1    Halogen Analyzer-Chart Recorder

The halogen analyzer-chart recorder shall be properly maintained, operated, and calibration checked daily in accordance with the manufacturer’s instructions.;

The calibration shall be recorded on the chart or in a logbook.

The free residual halogen measured by the halogen analyzer shall be +- 0.2 mg/l (ppm) of the free residual halogen measured by the manual test.

The test kit used to calibrate the halogen analyzer shall be graduated in increments no greater than 0.2 mg/l (ppm) in the range of free residual halogen normally maintained in the potable water system

1.6.2.2    Halogen Analyzer Charts

Halogen analyzer-chart recorder charts shall have a range of 0.0 to 5.0 mg/l (ppm) and have a recording period of 24 hours.

Halogen analyzer-chart shall be changed, initialed, and dated daily by the engineer in charge of the potable water distribution system.  Charts shall contain notations of any unusual water events in the potable water system.

Halogen analyzer-chart recorder charts shall be retained for at least 12 months and shall be available to the VSP for review during inspections.

Records from the halogen analyzer-chart recorder shall verify the free residual halogen of 0.2 mg/l (ppm) to 5.0 mg/l (ppm) in the water distribution system for at least 16 hours in each 24-hour period since the last inspection of the vessel.

1.6.3     Manual Halogen Monitoring

1.6.3.1    Equipment Failure

Free residual halogen shall be measured by a manual test kit at the halogen analyzer at least every 4 hours in the event of equipment failure.

Manual readings shall be recorded on a chart or log, and shall be retained at least 12 months, and shall be available to the VSP for review during inspections.

Repairs on malfunctioning halogen analyzer-chart recorders shall be completed within 10 days of equipment failure.

1.7    Microbiological Monitoring

1.7.1     Sampling and Analysis

A minimum of four potable water samples per month shall be collected and analyzed for the presence of E. coli.  Samples shall be collected randomly from locations forward, aft, upper and lower decks of the vessel.

Samples are tested with the Coli-Alert Test Kit.  The kit is to be in control of the Chief Engineer or his designee.  Supplies for testing can be ordered in Amos-D.  .

The kit consists of the following.  An incubator, and sample bottle holder, sample bottles including extra bottles, and sample growing media pillows including extra pillows. Also included is one black light.

1.7.1.1    Testing Procedure

The test procedure is as follows:

• Allow potable water to run for about one minute.
• Remove cap from sample bottle.
• Fill sample bottle to 100 ml level.
• Open media pillow of powered growing sugar and add to sample.
• Replace cap

·         Shake sample to mix.

• Place in rack in the incubator.
• Turn on the incubator.
• Read results in 24 hours.

1.7.1.2    Results

Results are read as follows:

• No change in water color is negative for coliform bacteria.
• A yellow color sample is positive for coliform bacteria
• If the sample color turned yellow it must be viewed under a black light to determine if E coli is present. If color changes from yellow to blue under the black light, E. coli bacteria is present.

1.7.1.3    Records

This procedure is EPA approved for the testing of water for coliform.  The results of the test must be logged and kept with the halogen analyzer charts onboard for 12 months.

1.8    Water Distribution System Protection Cross-Connection Control

1.8.1     Definitions:

Air-gap - The unobstructed, vertical distance through the free atmosphere, between the lowest opening from any pipe or faucet supplying water into a tank, plumbing fixture, or other device, and the flood-level rim of the receptacle, or receiving fixture. The air gap must be at least twice the diameter of the supply pipe or faucet.

Backflow preventer - An approved backflow prevention plumbing device that is necessary on a potable water outlet.  Some are designed for continuous pressure, but some are non-pressure types. Caution must be used to ensure the proper application for protection of the water supply. The following types are available.

• Atmospheric vacuum breaker - An approved backflow plumbing device, that is necessary on a potable water outlet designed for an attachment, which does not have a shutoff downstream from the attachment to preclude the possibility of backflow. Example - Bell type unit on dish washing fill lines.
• Hose connection vacuum breaker - An approved backflow device that attaches directly to a hose bib. It has a single check with an atmospheric vacuum breaker vent. It is not designed for continuous pressure. Example - The screw on faucet type NLF 9 - No shutoff is allowed downstream.
• Specialty backflow preventer with intermediate atmospheric vents - An approved backflow device that has two independent check valves with an intermediate vacuum breaker and a relief valve. It is used in low hazard situations and is effective under constant pressure. Example - RPZs Watts N9 and 9D

These are only examples. When ordering, the catalog must be checked for exact use.

RPZ Backflow Preventer

An RPZ backflow preventer must be tested with an approved testing kit at least once a year. The test shall be recorded, results should show the pressure differences on both sides of the valves and kept up to date, in the engine room log book. Include the type of test kit needed to test the RPZ units.

1.8.2     Program

The potable water distribution system shall be maintained free of cross-connections with non-potable piping systems and tanks. When potable water is supplied under pressure, the system must be protected against backflow or other contamination by:

• Vacuum breakers,
• Backflow preventers, or
• Air gaps between the delivery point of the water and the overflow rim on the unit.

The vessel’s comprehensive cross-connection control program provides safe connections to the potable water system through air gaps or appropriate backflow devices at the following locations, if present:

• Potable water supply lines to swimming pools, whirlpool spas, hot tubs, bathtubs, showers, and similar facilities.
• Photographic laboratory developing machines and utility sinks
• Beauty and barber shop spray rinse hoses
• Potable water faucets where hoses are connected or can be connected by threaded or quick-connect outlets such as those serving tanks containing chlorine and other chemicals, and deck taps.
• Garbage grinders and pulpers
• Mechanical ware washing machines
• Hospital and laundry equipment
• Air conditioning expansion tanks
• Boiler feed water tanks
• Fire systems
• Toilets Potable water, bilge, and sanitary pumps that require priming
• Freshwater or saltwater ballast systems
• Bilge or other waste water locations
• International shore connection and
• Any other connection between potable and non-potable water systems.

1.8.3     Device Installation

Backflow preventers shall be installed when air gaps are impractical or when water under pressure is required.

Air gaps shall be at least twice the diameter of the delivery fixture opening and a minimum of 3 cm (1 inch).

An atmospheric vacuum breaker shall be installed at least 15 cm (6 inches) above the flood-level rim of the fixtures.

An atmospheric vacuum breaker shall be installed only in the supply line on the discharge side of the last control valve.

A continuous pressure-type backflow preventer shall be installed when a valve is located downstream from the backflow preventer.

Backflow preventers shall be provided on all fixtures using potable water and which have submerged inlets.

A vacuum breaker shall be installed on a potable water supply that is connected to a vacuum toilet system.  An atmospheric vacuum breaker shall be located on the discharge side of the last control valve (flushing device)

Lines to divert potable water to other systems by valves or interchangeable pipe fittings shall have an air gap following the valve.

Backflow preventers shall be located so they may be serviced and maintained.,

1.8.4     Air Supply Connections

The air supply to a compressed air system that supplies pressure to both non-potable and potable water pneumatic tanks shall be through a press-on (manual) type of air valve or hose.

A fixed connection of this valve may be used when the air supply is from a separate compressor used exclusively for pressure to potable water pneumatic tanks.

1.9    Backflow Preventer Inspection and Testing

1.9.1     Vessel Log of Backflow Preventers

All Day Service Engineers must complete a log of all the backflow preventers, including type, located throughout the vessel.

The following examples are the type of identification needed for all backflow prevention locations.

• Beauty salon - Three wash sinks each equipped with a Watts inline 9-D backflow preventer.
• Post mix beverage dispensers - Nine total, equipped with a Chudnow stainless steel double check valve.
• Hot tubs - Two hot tubs filled through a Watts inline RPZ 909.
• Swimming pools - Filled through an air gap.

1.9.2     Maintenance

Backflow preventers shall be maintained in good repair.  All backflow prevention devices should be periodically inspected and any failed units shall be replaced.

Backflow prevention devices requiring testing, for example reduced pressure backflow preventer and double check valves with test cocks shall be scheduled for inspection in Amos D and inspected and tested with a test kit at least annually.  Test results showing the pressure differences on both sides of the valves shall be maintained for each device.

1.9.3     Testing

The inspection and test results for backflow preventers shall be retained for at least 12 months and shall be available to the VSP for review during inspections.

1.10Water Filters

USPHS allows for the use of approved type water filters in certain locations, provided the following conditions are met.  The water filters must be Class 3 NSF approved type. They must be changeable without touching the filter media. 

1.10.1.1 Installation

The following types of installations are approved:

Vitality juice dispensing systems,

Post mix soda-dispensing systems,

Coffee fill lines, and

Potable water fill stations and ice machines.

1.10.1.2 Filter Location Log

All filter locations must be logged, with dates entered as to when they were, and when they will be, changed.  The Day Service Engineer will be responsible for this log.

1.10.1.3 Procedure for Changing Water Filters.

Proper procedures for the changing of filters are as follows:

• With colored ring in lowered position (turned all the way to the left) orient lug on cartridge filter, with cutout under label on ring.
• Insert cartridge straight up into ring, just enough to allow lugs on cartridge to rest on the ledge inside the ring when cartridge is rotated to the right.
• When cartridge lugs are resting on inside ledge of the ring, turn colored ring as far to the right as possible to drive cartridge filter up into head.
• Move valve handle down to lock ring into place and turn on water. Be sure handle leg engages ring locking lugs.
• Check for leaks using the following sequence:
• Rotate valve handles to the “off” position. Pressurize and check for inlet piping leaks.
• Then, move valve handle to the “on” position. Check for leaks at the cartridge filter seals and outlet plumbing connection.
• Finally, activate the filter. Cartridges must be activated one at a time for five minutes each. Failure to do this reduces the life of the filter by half. For maximum life, the filters must be activated before use. The water flowing through the cartridge at full force deposits the all-important Micro-pure filtering media on the septum. This process is called pre-coating the filter. Filter cartridges must be activated after each cartridge change. Activate the filter by following the prescribed procedures:
• Install an Everpure gauge/activation kit P/N 3013-26
• Turn off water to all filters by placing valve handles in full counter clockwise position.
• Open activation kit valve, and then turn on water to cartridge no.1. Let water run at full flow for five minutes.
• Repeat for other cartridges in the series. 
• Finally, close activation kit valve and turn on water to all cartridges.
• Update filter log to note replacement of filter.

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