The Resource Management Act in New Zealand places an obligation on companies and others to take every precaution to ensure that effluent discharged from their premises is not contaminated above certain levels.
In order to comply with the above, it is important to ensure that wherever it is proposed to dispense motor spirits, suitable equipment is installed to catch possible petrol or diesel spills within a defined catchment area. The API Separator is a device that will carry out this function efficiently and be cost effective.
It is a proven product having been tested under stringent conditions and found to comply with the requirements of the Environmental Guidelines for Water Discharges from Petroleum Industry Sites in New Zealand dated August 1997. These specify that such devices shall have a spill retention provision of 2500 litres at Service Stations and Truckstops, that the discharged effluent shall not have more than 15 parts per million of total petroleum hydrocarbons (TPH) when averaged over the design storm event and that the horizontal velocity through the unit shall not exceed 25 metres per hour.
The design is largely based on the rainfall and stormflow characteristics of a particular district and the size of the catchment. Because these vary from area to area, and country to country, each unit is designed individually and is site specific.
Inbuilt safety features include (1) an emergency shut off valve (2) telescopic valve operating handle and (3) water level indicator.
The units are also provided with a colour coded ID system so that, in the event of an emergency, it is clear what action should be taken.
Moving parts are kept to a minimum greatly reducing the possibility of any mechanical breakdown. It is however recommended that the units are regularly maintained and operated in accordance with the instructions detailed later. Staff training should be carried out before the start up of each site.
REDCAR NZ will ensure that the unit is built to design, constructed within strictly controlled parameters and supplied on time.
As well as satisfying Statutory requirements, companies have to satisfy themselves that the installation of the equipment needed is carried out efficiently and quickly with a minimum of disruption to normal everyday business.
Units built insitu can, and usually do especially on sites already in operation, result in excavations having to be carried out over a considerable number of days. On Service Stations and similar locations this can cause major problems including lane closures, traffic congestion, danger to the public and loss of profits.
Precast concrete units, such as those produced by REDCAR NZ, can largely eliminate these problems. Provided the siteworks are organised correctly and the associated drainage system is complete, a unit can be installed and connected to the relevant public utility on one day and be ready for use, certainly the next day, but, sometimes later on the day of installation.
In New Zealand, REDCAR NZ try and arrange delivery so that the unit can be placed in its final location at the same time. Cranage is arranged to suit by the site contractor and if it can be organised so that both operations are carried out simultaneously, financial savings can be made.
Structurally, they are designed to carry the maximum legal wheel loading in New Zealand and whilst it may be better if they are positioned away from heavy traffic areas, they can be installed in any suitable position. If required, advice can be supplied regarding the best location for the unit. This can be important as they have been standardised as much as possible and should be installed to suit and within certain parameters.
Date of Test: 20th May 1998
Carried out by: Redcar
Associates Ltd, previous owners, testing facility.
Witnessing: All tests were witnessed indepentently.
Calculations were prepared for a site in the Auckland Area requiring an API Separator with the minimum internal length. A standard unit of this size unit was then set up on a level base and filled with clean water to its operating level. At the start of the test more water was introduced at a rate equivalent to the design rainfall intensity to simulate stormflow conditions. 2500 litres of diesel was then introduced via a 100 NB hose running from a nearby road tanker located at a slightly higher level to create a gravity flow into the Separator.
The length of the test was one hour and the water and diesel was introduced at the following times within that period :
0 - 10 minutes simulated stormflow water only introduced.
After 10 minutes 2500 litres of diesel was added over about 6 minutes.
Simulated stormflow water continued to be introduced for the full 60 minutes.
After 60 minutes the water was turned off and the liquid levels within the unit allowed to equalise.
Refer to Test Samples Analyses. (Available upon request)
The samples were supplied for analysis in 500 ml. sealed jars sent by Courier to the Laboratory in a chilli-bin packed with frozen slicka pads.
Before the test started a sample of the water inside the Separator was taken.
After 15, 30, 45 and 60 minutes further samples were taken.
After equalisation a further sample was taken.
During the introduction of the water and diesel a test was made to ascertain the horizontal velocity through the unit.
All units are
constructed in a steel mould using:
After construction the units are fitted out using:
or 100 NB galvanised
pipe and fittings with nitrile seals and SS bolts
150 NB or 100 NB couplings are supplied for connection to the public utility.
To ensure there can be no confusion regarding the shut off valve, the recessed toby lid which accomodates the telescopic valve operating handle, is powdercoated blue and clearly marked showing how to open/close the valve.
Fourteen days curing time is ideally required before the units are ready for delivery. Provided the weather is suitable, it maybe possible to reduce this to twelve days. Any deliveries requested earlier than 14 days will only be arranged if the purchaser accepts full responsibilty for any damage that may occur.
Units can be required longer than REDCAR NZ can currently build. Material kitsets can be supplied for longer units to be built insitu, or, alternatively, units can be installed and operated in parallel.
Certification / Operating / Maintenance
A producer statement for structural integrity is avialable if required.
Lifting and Transportation
It is important that the units are lifted and transported in the correct manner.
Upon collection, the unit will be loaded on to the truck by REDCAR NZ in two pieces (body and lid) as follows :
a) If the truck has a flat timber deck the body will be directly loaded.
It will be placed on appropriate dunnage located under the Swiftlift lifting eyes which are cast into the floor of the unit.
b) The lid will then be placed on to the body and appropriate dunnage running the length of the body located between the body and the lid. The loaded unit will then be strapped down ready for transportation to site.
IF FOR ANY REASON THERE IS A NEED TO OFFLOAD THE UNIT AND RELOAD LATER, THE ABOVE PROCEDURE SHALL BE USED.
IMPORTANT : RHS STRUT/S ( IF FITTED ) SITUATED AT THE TOP OF THE BODY MUST NOT BE USED FOR LIFTING PURPOSES. ONLY LIFT USING THE SWIFTLIFT EYES CAST INTO THE BODY AND LID.
Upon arrival at site the unit can be offloaded and either :
c) Placed immediately into position.
d) Placed in a suitable position for installation later.
IN THIS CASE THE UNIT MUST BE PLACED ON APPROPRIATE DUNNAGE LOCATED AS DESCRIBED IN a) AND b) ABOVE.
If the unit is to be stored for any length of time before lifting again for any reason, a check MUST be made to see if rainwater has accumulated within the body. If so, it MUST be removed before lifting.
Please note that when installing the unit, the same lifting procedures as described above MUST be used - refer to Installation details later in this catalogue.
To ensure the efficiency of the Separator it is vitally important that it be installed in the prescribed way, namely :
a) A hole must be dug large enough to accept the unit and gain access to the inlet and outlet couplings. The depth of this excavation would normally be about 2200 and, as such, all applicable Regulations regarding safety MUST be observed.
All soft spots must be removed and backfilled with appropriate material.
If the water table is high, the ground conditions are poor or if any other potential technical problem is experienced, the advice of a Consulting Engineer, preferably having local knowledge, should be sought.
b) Backfill shall then be placed, compacted to a minimum thickness of 200 and levelled.
c ) Then place and compact 50 sand.
IMPORTANT : THE BODY OF THE UNIT MUST BE INSTALLED LEVEL. IDEALLY, THE LID SHOULD ALSO BE LEVEL, BUT, IT CAN BE ALLOWED TO SLOPE TO SUIT THE ADJOINING GROUND PROVIDED THE GAP FORMED IS FILLED COMPLETELY WITH LOAD BEARING GROUT.
Once the excavation has been completed the unit can be placed, connections made and the adjoining area backfilled and compacted ready to accept the selected surface finish. Units can be installed lower than the surface finish if required, providing REDCAR NZ are advised at the time of ordering.
The lid should be placed on to load bearing grout so that it is sealed to the body.
IMPORTANT : AT THIS STAGE, THE SEPARATOR MUST BE FILLED WITH CLEAN WATER TO ITS OPERATING DEPTH. THIS IS NOT TO ACT AS BALLAST TO COUNTERACT ANY UPLIFT THAT MAY BE EXPERIENCED, BUT, IS TO MAKE SURE THAT THE INTEGRITY OF THE UNIT IS NOT AFFECTED BY ANY CONTAMINATED MATERIAL THAT MAY ENTER BEFORE IT IS IN OPERATIONAL USE.
These are obviously dependent on site conditions, but, as a guide:
If the invert level at the collection sump is no more than 400 below the finished grate level and the ground is level, the Separator may be installed up to 40 metres away from the sump. This is allowing for the pipe from sump to unit to have a gradient of 1 : 100.
It also assumes the unit is a standard model ie. having its inlet pipe 800 below finished ground level. This dimension can be adjusted slightly, provided, REDCAR NZ are advised before starting construction and any design implications are taken into account.
If the ground rises from the sump to the Separator, the distance between the two will need to be reduced. Conversely, it may be increased if there is a fall from the sump to the Separator.
Installation of Valve Operating Handle
Note: the unit leaves the Works with the valve in the 'open' position and the telescopic valve handle and blue toby lid are sent loose in the unit - remove before fitting concrete lid.
Fitting instructions are provided.