1. T/13CCO/N11/ZIN/AMM/24-05-2015/001
Technical specifications for Phase 1 Wastewater Network tank
interceptors
1.1.1 Sewage tank interceptors
The scope of work under this tender is to design, procure and install sewage interceptor tanks
to control safe disposal of wastewater by allowing discharge of generated sewage from
households. This tank will separate and capture the solids and let them settle and allow only
liquid part of the wastewater to flow to the main sewer system which will be installed at later
stage and will be solid-free. The plan is to connect an average of 10 households to each tank
through pipe connections.
At the onset of the camp, communal WASH blocks were constructed to provide access to
water and sanitation services to the refugees, these WASH blocks are connected to steel tanks
of large holding capacity to discharge wastewater. Interceptor tanks shall be connected to
these steel tanks to streamline desludging process.
Interceptor tanks should be water tight (completely sealed). In addition the contractor MUST
consider in the design sewage corrosiveness and gas emissions in addition to the location and
traffic load. The tanks will be placed at shallow depth to maintain required slope to connect
to the main sewerlines.
Scope of work
The work is to design, supply and install interceptor tanks in Za’atari camp. The contractor
must quote for two types of material tank (Reinforced concrete and HDPE). Interceptor tanks
will be in circular (cylindrical) form.
The estimated total number of tanks required is 1110 installed in districts 1,2,3,4,5,7,10,11 &
12 (see Zaatari map). This number is subject to ± 10% based on actual requirements in the
field.

2. T/13CCO/N11/ZIN/AMM/24-05-2015/001
The camp is relatively flat but has different soil formation across the whole surface area.
Thick sand/clay formation on the West side and rocky (Basalt) on the East side of the camp.
The contractor must provide appropriate equipment and machinery to perform and complete
excavation according to the schedule.
(a) Construction materials
The material for construction of the interceptor tanks is limited to reinforced concrete and
HDPE,
(b) Design parameters
The contractor is responsible to prepare and submit detailed design of the sewer tanks
according to the given design parameters and will be reviewed and approved by the client
group (ACTED, OXFAM, JEN). The septic tanks should be of multiple chambers with
baffle inside all pre-cast (see figure AA) and this will be for the two tanks size ( 4 and 8) m3
effective volume. 8m3 tanks is approximately (15-35)% of the total number of the tanks and
will be ONLY used when connection to steel tanks is not feasible. The normal situation is to
have 4m3 interceptor tanks connected to existing steel tanks.
The interceptor tanks along with the baffle will capture and enable solids settling and only
solid free liquid component will be allowed to flow to the main sewer.
The preferred geometry of the tank should be cylindrical, few design guidelines are listed
below;

3. T/13CCO/N11/ZIN/AMM/24-05-2015/001
Effective tank
capacity
Diameter in mm Height in mm
(bottom to top)
4m3 2000 1400
8 m3 3000 1200
Figure AA
 Distance between crown inlet to tank top is 20 cm
 Difference between invert inlet and invert outlet is 5 cm
 Max. backfill Height over the tank=55cm
 Max distance between nearest HH and tank should be 25 m
HDPE 10 cm T- fitting should be fitted and embedded from inside the tank, again the
variance between inlet invert and invert outlet should be 5 cm
A pipe fitting should be fitted and built in the concrete at both outlet and inlet. From outside
inlets and outlets should be made from HDPE PE80 SDR11, min. 30 cm long to enable easy
connections of HDPE sewer lines. Inlet and outlets of the tank should be fitted with a 10 cm
diameter T-shaped fitting suitably sized to prevent scum and solids from escaping with the
effluent and easily replaced or repaired if required. The top section of the T should extend
10cm above the liquid level and down to approximately 40% of the liquid level. freeboard of
20cm should be provided to accommodate the storage of scum and to provide ventilation.

4. T/13CCO/N11/ZIN/AMM/24-05-2015/001
Figure 1 – Sewer tanks inlet and outlet details (UNHCR/IRD design)
the tank should be fitted with a bolted access hatch suitably sized to allow accessibility
during regular operation and maintenance of the chamber.
Galvanized steel vented pipe of 3 inch should be embedded in tank concrete cover. The tanks
should be vented for controlled release of odorous and potentially harmful gases.
The tanks design should consider hooks and /or any other properly designed means for lifting
, transporting and installation of the tanks safely
Concrete tank cover should be equipped for two hooks and/or any other properly designed
means for lifting if maintenance is required.
(c) Structural considerations
The structural design of the tanks should ensure sufficient strength to bear the dead loads,
lateral soil loads, local imposed loads, hydrostatic loads and buoyancy considerations,.
Note: If the tanks have to be set in soil that may be saturated at any time, flotation collars
should be used to prevent flotation when the tank is desludged
The structural design calculation documentation should be submitted
(d) Location and installation
The depth of installation will be determined on site but should under all conditions not
exceed 55 cm from the top of the tank to the (Over Ground Level)OGL. Installation depth
will be governed by the prevailing depth of the main sewerline level to which the tanks will
discharge into. This depth be determined so as to ensure no backflow conditions in the inlet
condominial sewers upstream of the tank.

5. T/13CCO/N11/ZIN/AMM/24-05-2015/001
The tanks should be located where they can be reached easily and preferably 20m from
lateral roads to allow for routine removal of solids Tanks cover/ slab should be adequately
reinforced to withstand live traffic loads.
The tanks should not be installed in waterlogged ground or in places with a high water table
or places prone to flooding.
The tank must be set level on undisturbed soil at an elevation that allows at least a 1% slope
in the building sewer. If over-excavation occurs or the natural soil is soft or yielding, The
contractor must bring and use single grade course material selected as bedding material.
Otherwise the contractor may use same excavation material (clean soil) backfill should be
free of large stones, rubbish, waterlogged or other unsuitable materials. Bedding under the
tank should be according to Ministry of Public Works and Housing standards and codes. A
layer of 10cm lean concrete should be made beneath. Once the tank is installed, the soil
around the tank will be compacted (95%)
Finally the tank will be coated from inside with two bitumen layers.
In the vicinity of the inlet and outlet piping, the backfill should be placed manually and
tamped.
1.1.2 Geotechnical assessment of the site condition
10 trial pits will be dug at the proposed site. The depth of the pits will be at least 1m greater
than the envisaged depths. The maximum height of the groundwater table will be determined.
Undisturbed soil samples will be taken from the depths of the ponds for the following tests:
· Particle size distribution;
· Maximum Dry Density;
· Atterburg limits;
· Organic contents;
· Coefficient of permeability (the ponds will be lined if the permeability exceeds the
permissible values.
The contractor shall also responsible to carry out soil testing according to Jordanian
standards.
The contractor is responsible to mark each tank with batch number and date of production
and undertake concrete cube cast test from each batch of the concrete mix. Each cube will
recorded in terms of batch number and production date. Tests must be in according to
Ministry of Public works and housing standards and in certified and authenticated
laboratories.
RC Qty Design
cost in JD
Procurement
to site cost
in JD
Installation
cost in JD
4m3 944

6. T/13CCO/N11/ZIN/AMM/24-05-2015/001
8m3 166
HDPE
4m3 944
8m3 166
1.1.3 Production and construction capacity and Delay fine
Production capacity should be not less than 20 tanks per day. The contractor is also
responsible to harmonize the installation capacity to maintain the set production daily rate.
Otherwise a penalty of 500 JD shall be applied for each tank delayed per day.
1.1.4 Tanks inspection and testing
1. Immediate water drop test
Once tanks are in the ground and before backfilling works, all tanks shall be tested to
determine water tightness. The tank shall be filled with water to the maximum level and
observed for a period of 24 hours during which no drop or leakages shall be accepted. If
water level dropped or leakages are observed corrective procedure shall be immediately
conducted by the Supplier.
2. Medium water drop test
Water level will be tracked for an additional 72 hours. In case of water level drop exceeds the
allowable leakage rate of 0.1 percent of the water volume in any 24 hour period of time,
corrective procedures shall be immediately undertaken by the Supplier.
In case of failure to pass any of the quality assurance tests listed above, the Supplier is
responsible to undertake necessary corrective procedures and/or replace the tank.
Quality Assurance
The supplier will be responsible of 30 years guarantee of the Pre cast tanks