Klargester Enviroceptors forecourt separators

CONTENTS

Page

Health & Safety

1. Introduction

2. Handling & Storage

3. Site Planning

4. Installation - General

5. Concrete Specification

6. Enviroceptor Granular Installations

7. Enviroceptor Concrete Installations

8. Alarm Installation

9. Operation

10. Maintenance

11. Emergencies

Appendices

Dimensioned unit drawings CLASS 1 GRANULAR BACKFILL 800812

CLASS 2 GRANULAR BACKFILL 800813

CLASS 1 CONCRETE BACKFILL 800792

Oil probe fitting details All units PD0323

Enviroceptor Maintenance Log

1.0 Introduction

These Guidelines represent Best Practice for the installation of the above Klargester Separator Units. Many years of specialist experience has led to the successful installation of thousands of separator units. It must be noted, however, that these Guidelines are necessarily of a general nature. It is the responsibility of others to verify that they are appropriate for the specific ground conditions and in-service loads of each installation. Similarly, a qualified specialist (e.g. Civil engineering consultant) must verify any information or advice given by employees or agents of Klargester regarding the design of an installation.

For guidance of Separator selection and application, please refer to the most recent issue of Environment

Agency Guidelines pollution prevention guideline No. 3 (PPG3) and EN-858.

2.0 Handling & Storage

2.1. Care must be taken to ensure that units are not damaged during delivery and handling on site.

2.2. The design requirements of Klargester products will frequently mean that the centre of gravity of the unit is “offset”. Care must therefore be taken to ensure that the unit is stable when lifting. Rainwater may also collect inside units, particularly if they have been stored on site prior to installation, adding weight and increasing instability. Check units before lifting and pump out any excess water.

2.3. When lifting units, use webbing slings of a suitable specification. DO NOT USE CHAINS.

2.4. A suitable spreader bar should be used to ensure that units are stable and that loads are evenly distributed during lifting. When lifting separators, a spreader bar should be used where the slings would otherwise be at an angle > 30 degrees to the vertical.

2.5. Lifting equipment should be selected by taking into account the unit weight, length and the distance of lift required on site.

2.6. Klargester Environmental accepts no responsibility for the selection of lifting equipment.

2.7. Whenever Klargester units are stored or moved on site, ensure that the storage location is free of rock, debris and any sharp objects, which may damage the unit. The units must be placed on ground, which is flat and level to evenly support the base of the unit. Do not roll separators.

3.0 Site Planning

The following points should be considered before installation of the equipment:

3.1. The discharge must have the consent of the relevant Environmental Regulator.

3.2. The installation should have Planning and Building Control approval.

3.3. Consider installing flow cut-off valves to isolate the separator in an emergency or during site cleaning operations. See Environment Agency Guidelines PPG3.

3.4. Consider installation of a sampling point downstream of the separator. There is no suitable facility to effectively sample the waste water from inside the unit. EN 858 Pt 1.

3.5. Consider venting of the unit. Comply with local regulations. In the UK, comply with the following regulations. For Petrol Stations: Health and Safety Guidance Note 41 (HS(G)41). For other applications: BS8301: 1985 (obsolescent) BS EN 752 Building Drainage. Adequate ventilation should be provided to the separator. The ventilation pipe should be as short as is practicable and be terminated not less than 2.5m above paving nor less than 1m above the head of an openable window or other opening into a building within a horizontal distance of 3m.

3.6. Uncontaminated run off such as roof water should be excluded from separators. (EA Guidelines PPG3.)

3.7. Our units are provided as being suitable for installation with a granular backfill, or for installation with a concrete backfill. DO NOT USE THE GRANULAR BACKFILL METHOD WITH UNITS

PROVIDED FOR CONCRETE INSTALLATION

4.0 Installation – General

4.1. When units are installed in unstable ground conditions where movement of the surrounding material and/or unit may occur, the connecting pipework should be designed to minimise the risk of damage from differential movement of the unit(s) and/or surrounding material.

4.2. For separators with burial depths greater than 1000mm from cover level to the top of the unit, specific site conditions should be taken into consideration and the backfill designed to bear any loads which may be applied during and after installation to prevent the tank being subjected to these loads.

4.3. The excavation must be deep enough to provide bedding and cover depth as determined by the type of surface pavement and loading. Asphalt and concrete pads should extend a minimum of 300mm horizontally beyond the unit in all directions.

4.4. In situations where the excavation will not maintain a vertical wall, it will be necessary to shore up the side walls of the excavation with suitable trench sheets and bracing systems to maintain a vertical wall from the bottom to the top of the excavation. DO NOT completely remove the shoring system until the backfilling is complete, but before the concrete fully hardens.

4.5. In areas where the water table is above the bottom of the excavation and/or the excavation is liable to flood, the excavation should be dewatered using suitable pumping equipment and this should continue until the installation is complete.

4.6. During installation care must be taken to ensure that the body of any unit is uniformly supported so that point loads through the unit are avoided.

4.7. Concrete Specification SK296 is a general specification. It is not a site-specific installation design.

5.0 CONCRETE SPECIFICATION (SK296)

CONCRETE SPECIFICATION SK296 IN ACCORDANCE WITH BS 5328 PARTS 1,2,3 AND 4

TYPE OF MIX DESIGN

PERMITTED TYPE OF CEMENT BS 12 (OPC): BS 12 (RHPC): BS 4027 (SRPC)

PERMITTED TYPE OF AGGREGATE (coarse & fine)

BS 882

NOMINAL MAXIMUM SIZE OF AGGREGATE 20 mm

GRADES: C30 (30 N/mm2)

C30 (30 N/mm2)

C20 (20 N/mm2)

REINFORCED & ABOVE GROUND WITH HOLDING

DOWN BOLTS

REINFORCED (EG. FOR HIGH WATER TABLE)

UNREINFORCED (NORMAL CONDITIONS)

MINIMUM CEMENT

CONTENT

C30

C20

270 – 280 Kg/m3

220 – 230 Kg/m3

SLUMP (NOT IN ACCORDANCE WITH BS 5328) 25mm

RATE OF SAMPLING READY MIX CONCRETE SHOULD BE SUPPLIED

COMPLETE WITH APPROPRIATE DELIVERY

TICKET IN ACCORDANCE WITH BS 5328 PART 3

NOTE: STANDARD MIXES SHOULD NOT BE USED WHERE SULPHATES OR OTHER AGGRESSIVE CHEMICALS EXIST IN GROUND WATER

6.0 ENVIROCEPTOR INSTALLATIONS - GRANULAR BACKFILL

6.1 To install the tank proceed as follows:

6.2 Lay the tank webbing securing straps across the base of the excavation in the positions shown on the relevant installation drawings supplied with the tank 800812 class1 / 800813 Class 2, paying particular attention to the dimensions across the base and the spacing between the straps. Refer also to manufacturer's brochure supplied with webbing straps for detailed assembly.

6.3 Construct a suitable level concrete base over the straps to suit site conditions. Refer to unit dimensions. Ensure straps extend vertically upwards from the base slab and tie the straps into position using twine supplied with straps (refer to manufacturer's instructions). Ensure that straps are aligned with the positions marked 'HOLD DOWN' on the drawings (800812 / 800813).

6.4 When the concrete base has set, lay a level 300mm pea shingle or fine stone crushings bed on top of the concrete base. See paragraph 6.7 for backfill and bedding material specification.

6.5 With suitable slings positioned around the tank inside the guides on the top of the tank, (refer to drawings 800812 / 800813), lower the tank on to the pea shingle bed and set to level after removing pockets where the feet will land. Ensure that the straps are aligned with the positions marked 'HOLD DOWN' on drawings.

Make sure that there are no voids under the tank body and around the stabilising feet.

6.6 Anchor the tank using the webbing straps secured at the positions marked 'HOLD DOWN' on the drawing. The straps must be tightened evenly and should be snug on the tank. DO NOT over tighten the straps.

Granular Backfill and Bedding Material Specification

6.7 Klargester Enviroceptors must be installed using either gravel or stone/gravel crushings, which meet the following specifications.

6.8 Gravel - Use pea gravel (rounded particles) washed and free flowing with a minimum diameter of 3mm and maximum diameter of 18mm.

6.9 Stone Crushings - Stone crushings should be washed and free flowing. Angular size should be between 3mm and 12mm.

6.10 No more than 3% of backfill material shall pass through a number 8 sieve (2.38mm sieve opening).

These specifications should be certified by the supplier. DO NOT use other backfill materials.

6.11 Note: Using other than approved bedding or backfill materials will invalidate the tank warranty.

Dry Hole Backfilling

6.12 The excavation should be backfilled with the same material used for bedding the tank, see previous paragraphs from 6.7 – 6.11 for material specification. In freezing conditions, ensure the material is dry and free of ice and snow.

6.13 Partially fill the tank with clean ballast water until it settles firmly on the prepared bed. The ballast level in a tank must never exceed the backfill material level in the hole during installation by more than 200mm.

6.14 Place a 300mm lift of backfill evenly around the tank, working the material completely beneath the tank body and ends by hand in order the provide full support. A board or tamping bar should be used to force the materials in place.

6.15 After the first 450 to 600mm of backfill is in place, use the tamping bar to work the backfill into the voids under the edges of the tank. DO NOT strike the tank with steel tamping bars.

6.16 When the backfill has reached the outlet drain invert level and safe access can be gained, connect drainage pipework to tank.

6.17 Raise backfill above the crown of the tank.

6.18 The tank should be ballasted with water at the same rate as the backfill. At no time should the water level inside the tank be more than 200mm higher than the level of either the backfill or the excavation water level, whichever is greater.

Wet Hole Installation

6.19 Pump water from the excavation to maintain minimum water level. Add a minimum of 300mm of backfill material to the hole and level the bed to provide support to the underside of the tank. Position the tank in the hole.

6.20 Partially fill the tank with clean ballast water until it settles firmly on the prepared bed. The ballast level in a tank must never exceed the external water or backfill material level in the hole during installation by more than 200mm.

6.21 After levelling tank, dry hole backfilling procedures should be followed as detailed in paragraph 9.

6.22 Use only enough water to ballast the tank until backfill material is even with the crown of the tank.

6.23 The tank should be ballasted with water at the same rate as the backfill. At no time should the water level inside the tank be more than 200mm higher than the level of either the backfill or the excavation water level, whichever is greater.

Over Site Finish

6.24 Continue backfill to the underside of the top slab level.

6.25 Design of over site slab should be such that all loads are transmitted to the backfill surround and care should be taken to ensure that the tank shaft is protected from such loads being transmitted to the tank body by separation with a suitable compressible material.

6.26 The tank will have been charged with clean water to outlet level during the installation and will, therefore, be ready for use.

7.0 ENVIROCEPTOR INSTALLATIONS – CONCRETE BACKFILL

7.1 Excavate a hole of sufficient length and width to accommodate the tank and a minimum 225mm concrete surround and to a depth that allows for the burial depth of the unit plus concrete base slab.

7.2 Construct a suitable concrete base slab appropriate to site conditions. Ensure that the slab is flat and level.

7.3 When the concrete base slab has set enough to support the installed load, add a concrete haunch so as to provide even support under the unit. Lower the unit onto the haunch using suitable webbing slings and lifting equipment.

7.4 Pour no more than 300mm depth of clean water into the unit, avoiding shock loads. Add water through the overflow as well as the inlet. DO NOT OVERFILL,

the unit is not designed to hold water whilst unsupported.

7.5 Place concrete backfill to approximately 300mm depth under and to the sides of the tank ensuring good compaction to remove voids. DO NOT use vibrating pokers.

7.6 Continue adding concrete backfill, simultaneously keeping the internal water level no more than 200mm above the backfill level at all times, until the backfill is just below the underside of the outlet drain, giving sufficient room to connect the inlet and outlet pipework.

7.7 Connect inlet and outlet drains and vent pipes when safe access to the backfill can be gained.

PIPEWORK CONNECTION

In all cases, ensure that the outlet pipework level is maintained for correct operation. (Unless specified on the order, the fall across the unit will be as per the data sheet and unit drawing) small units are generally fitted with PVCu spigots to both the outlet and the inlet. Connect using the same size PVCu socket or a suitable reducer. Larger units are generally fitted with Klargester GRP manufactured sockets. The connecting pipework should be pushed into the socket and a joint made to fill in the gap using rope/hemp with a cement mortar or bonding mix. Ensure that the seal is secure and watertight before backfilling the pipe.

Alternatively, proprietary flex seal couplings can be obtained to fit over the outside of the site pipework and the outside of the GRP socket. When using this connection method, please be aware that the outside GRP laminate is not perfectly regular and that you may need to use a sealant on the outside diameter of the GRP. Take care not to over tighten the coupling when connecting to the GRP and ensure that the seal is secure before backfilling the pipe.

Drawing DS 0185 (available on request) provides the ID of our GRP sockets. The OD is variable, as the wall thickness can be up to 15-20 mm. If purchasing a flexseal coupling for connection to clay or concrete, we suggest that a size 110 mm larger than the ID is selected. 

7.8 Lift all coalescer assemblies as they include a closure device If the unit has not been filled from the outlet the closure devices may have activated. If you have purchased Extension necks so as to place the unit at a deeper invert, remove the assemblies before fitting the necks. Fit the extension lifting handle to the coalescer/core tube and replace. This is necessary so as to allow removal of the assembly to either replace the media, or to lift the closure device at a later date. When refitting, ensure that the assembly is correctly positioned into the base fitting. Drill appropriate holes in the neck to refit brackets.

7.9 Extension necks for Access shafts. Temporarily strut the extension neck(s) to avoid distortion during the concrete installation and back filling. Flanged extension necks are supplied with mastic and bolts. Line up the nicks. Ensure good & even compression of the mastic so as to provide a watertight seal. Consider sealing by GRP lamination (if skilled operatives are available).

Where more than one neck section is required to suit a deep invert, back-fill section by section. If the extension neck is too long, it can be trimmed using a fine-toothed saw. Ensure that the vent socket if cut out, is replaced elsewhere.

7.10 The maximum recommended inlet invert is 2000mm (using up to a maximum of 1500mm extension necks). If you are installing a unit deeper than this then you must make your own arrangements for removing and replacing the coalescer/core tube assembly. Consideration must be given to the depth of lift involved and silted weight of the assembly.

7.11 Oil level Alarm Probe tube. When requested at the time of purchase, Klargester will fit a tube to receive the alarm probe. This tube provides protection and ensures that the probe is positioned at the correct level to sense the oil build up. The tube design and probe level setting assumes the use of Klargester standard oil alarm system and may not be suitable for other alarm suppliers equipment.

The probe tube may be fitted either within the neck or within the body of the unit. It should be extended to ground level when fitted in the body of the tank and you should make provision to extend the tube to the required height before backfilling. Consult the alarm suppliers instructions for their detailed fitting installation instructions.

7.12 Ensure that the probe is placed within the tube and can be accessed from ground level. For Mains fed equipment, lay an appropriate or 82mm diameter PVCu underground ducting between the alarm panel location and the alarm probe position. The ducting should be 500mm below ground level and fitted with a drawstring for later cable insertion. Any changes of direction should be by long radius bend.

If necessary, drill a suitable hole in the access shaft adjacent to the alarm probe terminal box, to accept the ducting. Seal.

7.13 Continue backfilling with concrete over the tank body to the required level. Build up a shell of concrete, minimum 225mm thick, around the access shaft(s). extension neck and alarm probe tube (as applicable).

7.14 In traffic areas a suitable top slab must be constructed. The top slab should bear on a suitable foundation to prevent superimposed loads being transmitted to the unit and access shafts. Loads applied to covers and frames must bear on the top slab, not the access shaft.

7.15 The unit should be filled with clean water up to the invert level of the outlet pipe. Check that there is a discharge. Occasionally, on installation, the float does not rise and a vacuum develops on the outlet.  The vacuum must be broken, this can be done by lifting the coalescers /core tubes to break the seal.  (This vacuum can be caused when there is a downstream chamber which is pumped out, the pump may be strong enough under certain conditions to pull the float(s) down onto its seating. This situation must be avoided.)

7.16 Check that the product identification is marked in the neck. The unit It is now ready for use.

However please note that the site installation activities may have caused excessive amounts of silt, you may wish to avoid connecting the separator to the drains until the installation is complete so as to protect the coalescer media.

8.0 Alarm Installation

8.1 Install the oil alarm probe and control panel, as per the Suppliers Alarm Installation Guidelines.

Ensure that the probe is positioned correctly for the required storage of oil. Units provided with a protective tube have a float locating device suitable for Klargester standard equipment supply so that the probe is positioned at the correct level. The table below indicates the recommended maximum volume of oil stored and the depth of floating oil expected in the separation chamber.

8.2

9.0 Operation

The unit is designed for use in petrol stations. It is sized so that in the case of a spillage, the contents of one compartment of a road tanker (7600 litres) may be contained
Contaminated water enters the unit. The unit’s internal design and configuration ensures that quiescent conditions are promoted and that any oil which enters is able to separate from the liquid. Lighter than water pollutants, i.e. oil and petrol & diesel rises to the surface of the water within the separator. Separated liquid is discharged through the core tube/coalescer assembly.

9.1 Class 1 units include a core tube with replaceable media. Separated Liquid passes through the media to the outlet. A closure device is located within the core tube. The coalescer media requires maintenance and replacement at intervals.

9.2 Class 2 units include a core tube and a closure device, but does not include any media.

9.3 Both Class I and Class 2 units include a closure device which is in the form of a float. As the level of oil accumulates and forms a floating layer, so the float moves downwards. The plate seals on the base and prevents oily water being passed to the outlet. The unit MUST be emptied of oil after the float has operated. The coalsecer media (Class 1 units only) should be inspected and changed if fouled. See section 8

9.4 An oil probe should be positioned to detect the build up of oil in no or low flow conditions so that the alarm operates when the oil has accumulated to 90% of the maximum recommended oil storage volume. The above table indicates the depth of 100 % of the max. recommended oil storage. When the alarm operates, the oil MUST be removed. Accumulated silt should also be removed.

9.5 These Separators are not effective for the removal of soluble or emulsified pollutants such as oil/detergent mixes found in vehicle wash effluents. With permission, such discharges may be drained to the foul sewer. Contact Klargester Technical Sales Department for details of Separators to meet these applications.

10. Maintenance

Separated light liquid/oil MUST be removed from separator when 90% of the oil capacity has been reached.

10.1 Separators should be inspected at least every six months or more frequently if experience dictates. A log should be maintained detailing the depth of oil found, any volume removed and any silt removal or cleaning carried out. A specimen maintenance log is included in the appendices.

10.2 Every site is different, in respect to the amount and type of silt generated by the drain design and installation. Frequently, the site construction programme itself generates large and perhaps unusual quantities of silt and grit. We recommend that following the initial installation, an inspection of the separator contents be made to check that building rubble has not entered the unit. Further inspections at 3 and 6 months should be made so as to be able to assess the volumes of silt and oil accumulated.

An inspection and emptying programme can then be defined following the first 6 months site experience. We recommend a maximum inspection interval of 6 months.

10.3 The Coalescer media system is a replaceable item and available as spares.

10.4 Alarm probes where fitted, should be removed and inspected to ensure that they are clean and working. Inspection frequency as a minimum should take place whenever the waste material is removed from the separator. Please note the alarm may alert until the liquid level is replaced.

Consult the alarm suppliers literature.

10.5 If the unit has been emptied, the closure device should be raised, checked and replaced. See section

5.15 This should be checked after the unit has been refilled as under certain circumstances, the valve may self seat. Consider filling from the outlet where possible

10.6 Separator waste is a “special waste” under the terms of The Waste Management Code of Practice.

The Code imposes a duty of care on the waste producer to ensure that the Cleansing contractor is registered with the Environment Agency and that the final disposal of the waste is to a licensed facility.

10.7 You should consider the purchase of a maintenance service, from a competent installer or service provider which includes bi-annual inspections, removal of oil and silt, cleaning of the alarm probe and cleaning or replacement of the coalescer media (if appropriate/required).

Waste Removal Procedure – Oil & Silt

Oil should only be removed when there is no flow entering the unit. Isolate the unit and prevent flow from entering. Always remove the oil before attempting to remove the coalescer.

If this is not done, when the coalescer is withdrawn, any excess oil may coat the media surface and when replaced, this oil could later be drawn through the media causing contamination of the effluent.

10.8 Remove the access cover and lower the desludging hose into the separation chamber. Draw off the surface oil.

10.9 Lower the desludging hose to the base of the tank and withdraw any grit or sludge that may be present. It is not necessary to remove all the liquid unless you need to ensure the unit has been fully emptied.

10.10 Remove the alarm probe, if fitted, inspect, clean and replace. Ensure that it is working correctly after the unit has been refilled.

10.11 Consider the period of time that the coalescer has been installed and consider removing and inspecting (cleaning or replacing) the coalescer media. If removed, ensure that it is correctly replaced and secured into position and that the closure device operates.

10.12 Re-fill the separator with clean water up to the outlet level. If an alarm is fitted, it may display an alarm condition until the separator is re-filled. Check alarm operation when unit full.

10.13 Check the float valve and raise it, if it has self seated. Check discharge

Checking the Coalescer Assembly

Class 1 units only. Coalescers should be checked following a major incident and replaced.

Please contact Klargester if you wish to purchase a replacement coalescer media. Identify the type and size of separator (shown on labels inside the access neck). It is best to lower the water level to aid refitting the coalescer.

10.14 Any lifting device used to lift the coalescer assembly must be capable of :

·  Lifting in excess of the maximum assembly weight.

·  Lifting the assembly completely out of the access shaft.

·  Giving a smooth and controlled lift.

·  Swinging the assembly to one side clear of the access shaft.

10.16 Ensure that the area around the access shaft is clear and that there is space to place the coalescer core tube assembly once removed. If space is not available it will be necessary to support the assembly over the access shaft. e.g. by scaffold poles and platform. Do not leave the access shaft uncovered and unattended.

10.17 Use appropriate lifting equipment for the expected weight. Consider that the coalescer media may be silted.

Removing the coalescer assembly.

10.18 Undo and remove the nut and washer, which secures the lifting handle to the access shaft.

10.19 Lift the assembly with a smooth and steady motion. Class 1 coalescers will become lighter as water drains from the exposed media. Allow the water to drain completely. Assemblies blocked with fine silt may be very heavy.

10.20 Fully extract the assembly and set it down adjacent to the access shaft.

Cleaning the coalescer assembly/ Media Replacement.

10.21 Hose down the assembly using clean water at normal pressure. (You may be able to return the cleaning water into the separator, if there is sufficient capacity.) If the media is heavily contaminated with oil and silt it may not be possible to clean effectively by hosing. Do not allow untreated cleaning water to pass out of the unit. Continue hosing until the water runs clear.

10.15 Undo the banding. Slide media onto core tube. Ensure apertures are covered by the media. Resecure or replace banding. Consider replacing media every two years.

Replacing the coalescer assembly.

10.22 Position it over the access shaft. Remove any safety coverings.

10.23 Lower the assembly steadily into the access shaft until it is nearly submerged.

10.24 Rotate and position the assembly so that the bracket on the handle is aligned with the bolt protruding from the access shaft. and approximately 250mm above it. Lower the assembly until the bracket hole is lined up with the bolt, and the base of the coalescer is positively located. Secure the handle to the access shaft. Note, new base seals absorb water and should be compressed into position.

10.25 Replace the access cover.

11.0 Emergencies

11.1 At sites where there is a high risk of spillage, spill kits containing drain seals, absorbent materials, disposal containers and other appropriate equipment should be held. In the event of a spillage on site, the material should be contained, (if a spill kit is not available, sand or soil may be used) and the Environment Agency notified immediately using the appropriate emergency hotline number listed in the Agency Guideline PPG3. Year 2001 phone number is 0800 80 70 60

ENVIROCEPTOR MAINTENANCE LOG

Site address/location

Separator location

Type of separator

Nominal Size

3P Volume Filter VF 1 P106