WCS WPL VSF04 User manual

VSF04 WPL SANDFILTER
OPERATION AND MAINTENANCE MANUAL
Site name:
Reference number:

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Contents
Contents ............................................................................................................................................................1
1. SAFETY........................................................................................................................................................3
1.1 Health and safety at work act 1974:......................................................................................................3
1.2 General health and safety: ...................................................................................................................3
1.3 Leptospirosis: ......................................................................................................................................3
1.4 Sensible precautions:...........................................................................................................................3
1.5 Vaccinations:.......................................................................................................................................4
2. Risk Assessment Notes....................................................................................................................................4
3. INTRODUCTION...........................................................................................................................................6
4. DELIVERY....................................................................................................................................................6
4.1 Off-Loading...............................................................................................................................................6
4.2 Extent of Supply........................................................................................................................................7
4.3 Electrical Equipment..................................................................................................................................7
4.4 Bolts and Bolt Strips ..................................................................................................................................7
4.5 Lifting .......................................................................................................................................................8
5. TANK INSTALLATION - IN GROUND...............................................................................................................9
5.1 Introduction..............................................................................................................................................9
5.2 Installation of Unit.....................................................................................................................................9
5.3 Local Ground Conditions.......................................................................................................................... 11
5.4 Installation of Kiosk ................................................................................................................................. 12
5.5 Connections to kiosk................................................................................................................................ 12
6. PIPEWORK, DUCTS AND SAMPLE CHAMBERS.............................................................................................. 13
6.1 Pipework ................................................................................................................................................ 13
6.2 Sample Chamber..................................................................................................................................... 13
7. ELECTRICAL INSTALLATION......................................................................................................................... 14
8. PLANT DESCRIPTION.................................................................................................................................. 15
8.1 Plant Description..................................................................................................................................... 15
9. Operation and Maintenance...................................................................................................................... 16
9.1 SAND FILTER COMMISSIONING AND OPERATING INSTRUCTIONS ............................................................... 16
........................................................................................................................................................................ 19
APPENDIX 1...................................................................................................................................................... 20
KIOSKS AND BASE SLABS............................................................................................................................ 20
Medium Kiosk............................................................................................................................................... 20
Large Kiosk................................................................................................................................................... 20
Extra Large Kiosk........................................................................................................................................... 20

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APPENDIX 2...................................................................................................................................................... 21
LIFTING..................................................................................................................................................... 21
APPENDIX 3...................................................................................................................................................... 22
APPENDIX 4...................................................................................................................................................... 23
Revision History:
Date
Change description
Owner
Checked
Revision
09/07/2015
First issue
TGH
KM
A
13/01/2021
Revised Layout
RT
TC
B
07/07/2021
New front and pack page
RT
C

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SITE NAME
1. SAFETY
It is extremely important that maintenance procedures in this document are followed. Any deviation from
this could cause serious injury or have a detrimental effect on the filter and its operation.
1.1 Health and safety at work act 1974:
Section 6a of this act requires manufacturers to advise their customers on safety and handling
precautions to be observed when operating, maintaining and servicing their products.
The user’s attention should be drawn to the following:
•All sections of this manual should be read before undertaking work on the equipment.
•Suitably trained personnel must carry out the installation.
•Normal safety precautions must be taken and appropriate procedures observed to avoid
accidents.
•Refer to WPL Ltd for further technical advice or product information.
1.2 General health and safety:
The layout of the Croesgoch plant has been laid out to ensure that health and safety on site is optimised.
It will be vital that the routes to all of the equipment are laid out in a proper manner and they a re
followed implicitly. Lone working in the plant should be prohibited.
1.3 Leptospirosis:
The following is extracted from a health warning card issued to WPL Ltd’s staff. It is the client’s
responsibility to ensure that the relevant Personal Protective Equipment (PPE) is available and used.
There are two types of Leptospirosis that effect people in the UK and they are as follows:
1. Weil’s disease, which is a serious infection transmitted to humans by contact with soil, water or
sewage that has become contaminated with urine from infected rats.
2. Hardjo-type Leptospirosis, which is transmitted from cattle to humans.
The typical symptoms for both diseases start with a flu like illness, with a persistent and severe headache,
muscle pains and vomiting. Jaundice generally appears on the fourth day of the illness.
The bacteria can enter your body through cuts and scratches or through the lining of the mouth, throat
and eyes.
1.4 Sensible precautions:
After working with contaminated fluid or other materials it is important that hands and forearms are
washed thoroughly with soap and water. If your clothing or boots become contaminated then they
should also be washed immediately after use.
Immediate action should be taken, so that any cuts scratches or abrasions are washed thoroughly with
clean water, prior to applying any protective covering (plaster or bandage).

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Do not handle food, drink or smoking material without first washing your hands. If you display any of the
symptoms described after coming in to contact with sewage; report to your doctor immediately advising
them of the circumstances.
1.5 Vaccinations:
To avoid the possibility of illness it is recommended that all site personnel have the following
vaccinations. WPL Ltd also recommends that you that you consult your doctor for any additional
vaccinations that you may require. The general vaccinations WPL use for all personnel are as follows:
•Hepatitis A
•Hepatitis B
•Polio
•Tetanus
•Typhoid/cholera –probably carried out as a child.
2. Risk Assessment Notes
This section of the manual is intended as a guide and as such does not cater for every situation that may
be experienced on site. WPL Ltd assumes that the installer/end user has ensured that all necessary
permissions have been sought and granted and that the installation procedures will be carried out
observing the requirements of the Health & Safety at Work Act and will involve good building and sound
civil engineering practice. Please ensure that due consideration has been given to and appropriate action
taken with regard to the following:
➢Planning permissions & Building Regulations and other regulating or interested parties.
➢Environment Agency consent to discharge.
➢The legal responsibility for the plant as far as operation and maintenance and ongoing discharge is
concerned.
➢Note –failure to comply with any regulation may result in pollution, odour and nuisance and health
hazards, which may lead to legal action.
➢The size of the plant relevant to the number and type of people that will be using it, e.g. domestic,
light industrial, etc. Consideration should be given to any unusual conditions such as B & B
accommodation, special laundry requirements and frequent entertaining.
➢Costs, legal implications and siting in consideration to shared systems.
➢The whereabouts of wells, bore holes and springs used as sources of potable water; existing non-
mains sewerage systems and soakaways; water courses, ponds and lakes and designated protected
areas.
➢The whereabouts of other services, pipes, cables, ducts, etc.
➢Local ground conditions. Is specialist knowledge of civil engineering required to cater for unusual soil
conditions such as underground rivers, running sand, chemicals in the soil, etc?
➢The water table at the time of installation. Specialist knowledge is required when installing in an
excavation that allows water to enter.

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The water table in winter. Special consideration should be given to installations that will be subject to
high water table pressure or flood conditions. The treatment plant will need to be installed so that it
cannot “float” out of the ground and provision made for continued discharge of treated effluent, should
the discharge pipework/soakaway be under water.
Note –failure to maintain the ability to discharge may result in pollution, odour and nuisance and
health hazards, which may lead to legal action. WPL can not be held responsible for failure to
discharge due to poorly designed, constructed or positioned soakaways and discharge pipework
systems.
Siting. The plant must be sited within 30m of heavy vehicle access for de-sludging. The plant should,
where possible, be sited above the high water table mark and above or beyond the flood plain. See items
above and accompanying note. The plant should be sited as far from the habitable parts of the dwelling
as possible. Many local authorities recommend 10m as a minimum, but easements are possible for
smaller sites.
Gas & odour ventilation. WPL recommend that the plant be vented. This can be via the vent pipe,
normally attached to the building, or by additional venting (high or low level) off of the inlet or outlet
pipework or the sample chamber.
Sample point. A safe and adequate sampling point is usually a requirement of the Environment Agency.
This can be an off the shelf item or constructed using standard drainage components. Open pipe
discharges to ditches, watercourses, etc, through pipework of less than 5m in length, do not require a
sampling point if the effluent can be sampled from the end of the pipe.
Electrical supply. A qualified electrician (see Electrical Installation section) should only undertake
electrical installation. A safe and reliable power supply is required at all times, as the air blower is
required to run continuously. Adequate means of air or power failure indication should be provided. This
can be an audible or visual alarm or by regular manual checks.
Due to the health risks associated with raw sewage, WPL recommend that the sewage treatment plant is
not used until the system is complete, commissioned and handed over.
Before carrying out any maintenance or installation work, the equipment must be electrically isolated.
Do not leave covers open for any longer than necessary. Temporary barriers and warning signs should
be erected around any open covers or manholes as appropriate, in particular warning of deep water in
the tanks.
Any visiting personnel must report to site office on arrival and fully acquaint themselves with safety
regulations applicable.

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3. INTRODUCTION
The WPL range of sand filters has been designed to treat the treated effluent from sites with population
equivalents in the range of 1 up to 600 persons
Use of the sand filter can achieve BDO and TSS standards better than 10mg/l.
The plant is designed for either above or in ground installation. This installation manual deals only with in
ground installation. Blowers and controls to provide air to the unit are housed in a kiosk adjacent to the
plant. All tanks, covers and kiosk are manufactured in GRP for corrosion resistance and long life.
4. DELIVERY
4.1 Off-Loading
The purchaser may be responsible for off-loading at the nearest roadway to site that is suitable for heavy
goods vehicles. A minimum height clearance to 16’ 6” (5m) is required. If there are electrical cables
overhead, ensure that there is a means of turning the power off. For off-loading from a lorry mounted
HIAB, there needs to be a firm area for the stabilisers, the total width being a minimum of 15 feet (4.6m).
If the nearest road access for a heavy goods vehicle is not adjacent to the site, it is the responsibility of
the purchaser to arrange transport from the road to the site. If in doubt, contact WPL as soon as possible
with any queries.
Inspect the unit for any damage to the base before placing on the ground and then inspect the sides. The
unit should only be placed on level ground with no sharp stones, bricks etc as they may damage the base
of the unit.
The control panel and blowers should be stored in suitable conditions i.e. dry and condensation free.

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4.2 Extent of Supply
See the delivery note for full details. The standard unit comes with the following:
A GRP tank, incorporating the two sections
A blower kiosk with blower and control panel fitted.
Items supplied loose will be found either inside the filter section or on a separate pallet.
4.3 Electrical Equipment
All electrical equipment, including blowers, must be stored in clean dry conditions until required for use.
If the electrical equipment is fitted into the kiosk, some form of anti-condensation heater will be required
if the unit is not to run immediately. (Data Sheets for electrical components can be found in appendix 3).
4.4 Bolts and Bolt Strips
Due to the settling of the joints during transportation of the unit, the bolts may become loose and need
tightening. It is important that the bolt strips are not overtightened as this can cause leaks.
Tighten all bolts in the metal strips to 50Nm to ensure all the foam is compressed then tighten up to a
final value of 60Nm. Silo Bolts (with no metal strips) around the top of the unit should only be tightened
to 30Nm.
Closed Cell
Foam Strip
50 then 60 NM
(35 then 44 lb.ft)
Pinched Foam Strip
Can Cause Leaks
CAUTION Do Not Over Tighten

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4.5 Lifting
See Appendix II for lifting points.
DO NOT walk on top of the units with muddy boots, as this will scratch the surface.
NOTE: Units with extensions, for inverts greater than 0.5m, turrets with covers are supplied separately
and therefore the unit may collect rainwater.
When moving across rough ground, great care should be taken to avoid increased loads due to sudden
movement of the unit.

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5. TANK INSTALLATION - IN GROUND
5.1 Introduction
All installation procedures should be carried out observing the requirements of the Health and Safety at
Work Act and involve good building practice.
During the course of installation the following will be required:
-Normal construction equipment and plant
-Concrete for base. This MUST be designed to support the unit for normal operation.
-Calculate the amount of backfill required. THIS IS VERY IMPORTANT. Lean mix or dry mix
concrete must be used to backfill the excavation. However, prevailing local ground condition
may override this requirement. If wet mix concrete is to be used, a qualified civil engineer
must be consulted and the pour cannot take place in a single operation. Contact WPL for
further information
-Adequate supply of water to fill unit
-Pumping equipment where necessary.
N.B. Installing in an excavation that allows water to enter (i.e. is not dry) requires special advice.
Water table and flood conditions are typical examples that will cause problems during
installation. It may also affect the operation of the plant. Again, specialist advice must be taken
in these conditions.
5.2 Installation of Unit
Step 1 Excavate to tank dimensions (see GA Drawings) with minimum of 150mm clearance all
round and under base of unit. Allow adequate clearance for all pipes and any other connectors
to the unit.
Backwash
Effluent Influent
Orientation of Sand Filter

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Note: Dimensions are detailed on the GA Drawing for each individual plant which is sent to the
customer with confirmation of order. If this has been lost, please contact WPL for another copy.
Step 2 Cast the concrete base; ensure that the slab is designed to support the unit in its normal
operation (i.e. full of water). The base must be level and to the correct height to suit the invert
level of the sand filter. Allow for initial set before positioning the unit.
Step 3 Excavation must be kept dry during the installation and until the concrete has cured.
Step 4 Ensure the surface of the concrete base is free of water, stones etc. and lower the unit
into correct position to suit pipe connections. Check the levels.
Step 5 Stabilise unit in excavation, taking care not to cause distortion of the unit. Fit temporary
covers over all pipe connections.
Step 6 Commence filling unit with water into all sections to a level of 500mm.
Step 7 Commence back filling with lean mix. The back fill must be evenly placed around the unit
at all times and worked by hand up to a maximum level of 400mm above the base.
DO NOT USE VIBRATING POKERS
The water level in all sections must be increased and be kept at a level of 300mm above the top
of the backfill, until final pour after step 8.
Step 8 When the backfill is approximately 0.5m below the lowest underground connections, pipe
connections should be made. Remove lifting eye nuts and bolts and replace with green silo bolts
supplied. Also provide for hose draw chamber, servicing ducts for the air lines and future cable
connections to the unit via bulkhead connectors. Fit bulkhead connections through tank top or
extensions with the orientation to suit the site.

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Step 9 Continue to fill with water and backfill to the rim of the tank.
Step 10 Leave unit full of water
N.B. See G A Drawing for kiosk slab dimensions and type of kiosk supplied (See Appendix I for
descriptions).
5.3 Local Ground Conditions
The local ground conditions must be taken into account when installing the unit. The amount of concrete
backfill used must be sufficient to overcome the effects from the up-thrust of ground water.
The unit is designed for a maximum water table of 1.0m from the base of the tank unless specified
otherwise. If the water table is higher than this maximum, damage may occur during backwash or
emptying of the tank. The concrete backfill must be designed to stop the water table pressure damaging
the tank. A qualified engineer must be consulted to determine the civil design.
FAILURE TO DO THIS MAY RESULT IN DAMAGE TO THE TANK
THE WATER TABLE MAY BE SUBJECT TO SEASONAL VARIATION and THE MAXIMUM WATER
TABLE ABOVE BASE = 1.0m.

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UPTHRUST FROM
WATER TABLE
Tank
Base
5.4 Installation of Kiosk
-Step 1 Lay a concrete slab to suit the kiosk, above the adjacent surface water level (and the
flood plain) to avoid surface water ingress. Provision for servicing ducts for air lines, cables
and mains power should be made.
-Step 2 Lay the ducting from the kiosk to the unit, mains supply and any pumping chambers or
sand filter.
-Step 3 A mains electricity supply is required into the kiosk.
-Step 4 Secure kiosk to the slab through the unistrut and seal to the concrete with mastic. Do
not secure until the concrete slab has fully cured.
5.5 Connections to kiosk
-Step 1 The air hoses will have been delivered lying on top of the filter section of the unit.
Feed the hoses down the duct and connect to the bulk head connectors on the top of the
unit (or turret if fitted). Jubilee clips are either secured to a blower or in the delivery
envelope. Ensure there are no kinks in the lines. Then cut the air lines to length to allow
connection to the blower in the kiosk without any sharp bends. It should be noted that the
pipe becomes warm during operation, softens and may deform at sharp bends.
-Step 2 Electrical connections –See Section 7, Page 14.

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6. PIPEWORK, DUCTS AND SAMPLE CHAMBERS
6.1 Pipework
Gradient. It must be ensured that there is sufficient fall (gradient) from the dwelling to the invert level of
the inlet pipe, normally 0.5m below the top lip of the unit. A fall of between 1:50 and 1:100 is usually
required to give a self-scouring velocity that prevents blockages in the pipes.
6.2 Sample Chamber
Positioning. This should be close to the outlet from the plant to provide a point at which the Environment
Agency can take a sample.
Dimensions. The sample chamber should incorporate a large enough drop to allow a sample chamber to
be filled with the treated discharge. The following drawings give an indication of dimensions.
100 mm
200 mm
FROM
HIPAF
OUTLET
SIDE
PLAN
END

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7. ELECTRICAL INSTALLATION
It is not feasible to state a specific installation arrangement due to the variance of sites and installation
configurations. Therefore it is important that the electrical installation be performed by a qualified
electrician in accordance with 17th, or later, edition of the Institute of Electrical Engineers (I.E.E.)
regulations, with appropriate current protection devices for the site configuration.
The supply to the sand filter should have a dedicated circuit incorporating isolation and protection
devices to the regulation requirements of the I.E.E. An earth leakage circuit breaker is recommended and
should be incorporated into the supply to the sand filter. A device with a 30mA maximum trip current is
recommended.
N.B. The wiring diagram is a separate sheet in the envelope containing all the other documents. If it is
missing or lost, please contact WPL for another copy.
Three Phase Connection
When the 3-phase supply is switched on, check the rotation of the blowers is correct. Incorrect rotation
will cause damage if run for more than a brief check. This observation must be done with all the air-
lines disconnected from the blowers.
IMPORTANT NOTE
IF THE THREE PHASE IS NOT CORRECTLY CONNECTED, SERIOUS DAMAGE CAN OCCUR. SHOULD A
POWER FAILURE OCCUR, ISOLATE THE SUPPLY TO THE UNIT. WHEN POWER IS RECONNECTED, ENSURE
THE PHASES AND ROTATION ARE CORRECT.

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8. PLANT DESCRIPTION
This description is only supplied for interest and is not essential reading for plant installation, operation or
maintenance.
8.1 Plant Description
The sand filter will be supplied as a one-piece unit, the function and operation is as follows: -
The WPL sand filter has been designed to physically filter an effluent that has already undergone primary
settlement and biological treatment. The sand filter is composed of two chambers; the inner filter
chamber contains a graded granular material referred to as sand. The sand sits on a perforated steel
plate, which is installed approximately 450mm above the floor of the inner chamber.
Effluent flows into the inner chamber, where the head differential between the water level in the inner
and outer chambers forces it through the sand and the perforated steel plate, into the outer holding
chamber and ultimately out of the outlet.
As the filtering sand becomes blocked by contaminants, the passage of effluent is restricted and causes a
backup in the filter chamber. This back up is monitored by a sensing device and at a pre-determined level
the device activates a relay in the control panel to open one part of the “back-wash cycle” circuitry. The
other part of the back-wash cycle circuitry is activated by a timer. Both the relay and the timer must be
activated to initiate a back-wash cycle. During a back-wash cycle, a pump in the inner chamber pumps
the effluent back to the beginning of the entire treatment system. This lowers the level in the filter
chamber causing a reversal of flow through the sand. In conjunction with this, air is introduced under the
steel plate, which bubbles through the sand and “scours” the contaminates off of the sand and puts them
back into suspension in the effluent, which in turn is removed by the pump.
The timer should be set to come on during the periods of a low flow entering the beginning of the entire
treatment system. This is to prevent a combination of new effluent and back-wash water overloading the
system.
WPL sand filters are immediately effective once they are commissioned.

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9. Operation and Maintenance
9.1 SAND FILTER COMMISSIONING AND OPERATING INSTRUCTIONS
These instructions form part of commissioning and MUST be performed to allow the sand filter to work.
All settings are at the start point and should be verified by further trials after commissioning
The sand filter in this unit will function without attention when the timers are set correctly. It is designed
to backwash automatically at times of low flow. The backwash is by a combination of reverse water flow
and air scour. The times to initiate the backwash sequence are selected by a 7-day time clock. We would
advise that the backwash cycle be initiated during periods of low flow.
For a plant with a minimum of flow during the evening, the time clock should initially be set to start at
04.00 hours and off at 04.04 hours. The time clock is provided with battery backup to retain the settings
during normal short power failures. These times were set at the factory but they should be checked
during commissioning. The time clock selector switch must be in the auto position for the backwash cycle
to work.
The delay timer begins the backwash cycle by operating a solenoid valve to allow the air to flow through
the sand. After the air scour the backwash pump operates until the timer expires.
Ensure that the unit is full, with flow discharging from the sand filter outlet, before starting trials. The
backwash flow rate should be set by adjusting the butterfly valve on the return line.
The correct operation on backwash start-up is as follows:
-Pump draws down the waste level
-The air scour initiates
-The backwash water is drawn from the holding tank around the sand filter body
-The air scour ends
-The pump continues to run until the delay timer switches off or the level sensor on the pump
operates.

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SAND FILTER MAINTENANCE
The sand filter requires no special routine maintenance but its correct operation should be checked every
three months. In doing so, the level of the sand in the centre tube needs to be kept topped up. On
experience this should be topped up every year, although the amount of sand required varies from site.
The sand should be kept at level of 450mm from the steel plate. 2mm-4mm Dry Quartz sand should be
used and can be purchased from WPL directly.
Sand Filter Pump 1315 (Appendix 3)
The condition of the Sand Filter Pump should be checked as per the manufacturer’s instructions. Please
see the Lowara O&M (attached with this document).
Blower 2BH1610 (Appendix 4)
The condition of the Sand Filter Blower should be checked as per the manufacturer’s instructions. Please
see the Elmo Rietschle O&M (attached with this document).
Below on page 18,19 are the servicing manuals for the blowers. Please read through these carefully.

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