WAVIN-LABKO LTD Labkotie 1 FIN KANGASALA Tel: Fax:

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1 WAVIN-LABKO LTD Labkotie 1 FIN KANGASALA Tel: Fax: tanks@wavin-labko.fi 08/04 Labko MökkiSAKO-1 Instructions for Installation, Operation and Maintenance

2 Contents 1 GENERAL PLANNING THE GROUND INFILTRATION SYSTEM GENERAL LABKO MÖKKISAKO-1 INFILTRATION SYSTEM STRUCTURE OPERATING PRINCIPLE INSTALLATION OF THE LABKO MÖKKISAKO-1 INFILTRATION SYSTEM TRANSPORT AND HANDLING OF THE TANK INSTALLATION OF THE SEPTIC TANK General Installation CONSTRUCTING THE INFILTRATION DITCHES MAINTENANCE SEPTIC TANK INFILTRATION FIELD MALFUNCTIONS WAVIN-LABKO OY 2(10)

3 1 GENERAL This Instruction Manual contains a description of the Labko MökkiSAKO-1 infiltration system, as well as installation, operation and maintenance instructions. When infiltrating dish and washing waters into the ground, soil in the infiltration area should represent water penetrating sand or mineral soil. Additionally, the distance from infiltration pipes to the closest ground water level must be at least 1 metre. If the soil is unsuitable for infiltration, as e.g. silt, clay or too tight moraine, a sand filter or similar system should be used. MökkiSAKO-1 infiltration system is intended exclusively for treatment of small amounts of dish and washing waters from summer residences. The wastewaters are led from the building along the drain pipes to a septic tank and from the tank through the infiltration pipes into the ground. 150 l of dish and washing waters can be processed during one day. 2 PLANNING THE GROUND INFILTRATION SYSTEM 2.1 General The wastewaters processed in the ground must be ordinary domestic sewage waters. The planning of the ground infiltration system must be done properly. When planning, some vital points must be considered: soil quality, ground water conditions, shape of terrain, safety distances, municipal directives and maintenance. Place for the ground treatment area of sewage waters should be carefully chosen in order to ensure good functioning of the system and to prevent contamination of ground waters. You should choose the location in cooperation with municipal specialists. Proper planning and installing guarantees a high performance and a long-time operation of the infiltration system. The septic tank should be placed so that the emptying vehicle has a free access to it. NOTE! The emptying lorry should not be driven nearer than 1.5 m from the septic tank. Length of the emptying hose is ca m. Any vehicle traffic is prohibited on the tank and the infiltration area. The system should be installed in frost-free depth or provided with adequate thermoinsulation. The ground infiltration field should always be located in an area were snow removal is not necessary. When choosing location for the infiltration system, you should observe the following safety distances: 1. Distance from a water intake at least 30 m 2. Distance from a waterway at least 30 m 3. Distance from the site boundary at least 5 m 4. Distance from a ditch at least 10 m 5. Distance to the neighbour water intakes should be known within a radius of 150 m 6. Vertical distance between the infiltration layer and the ground water level should be at least 1 m WAVIN-LABKO OY 3(10)

4 7. Distance from the septic tank to a residential house or the site boundary should be at least 10 m In Labko MökkiSAKO-1 infiltration system the infiltration is carried out by a ditchlike excavation (Figure 3), due to the fact that the infiltration pipe line is only ca. 7 metres in length. On hilly terrain the infiltration system must be placed on the ridge of the hill or at the central point. Infiltration pipes must be aligned with the altitude contours. Water well 1 Soil survey should be made on this area. SAKO system Road Ditch Figure 1. Distances to be observed when choosing the infiltration system location This installation instruction serves only general purposes; each application must be separately planned with the local authorities and analysts. 3 LABKO MÖKKISAKO-1 INFILTRATION SYSTEM 3.1 Structure Labko MökkiSAKO-1 infiltration system consists of a 250 l spherical septic tank and of the infiltration pipes (Figure 2). 3.2 Operating principle In Labko MökkiSAKO-1 infiltration system the settling and floating matters remain in the septic tank, and only sewage, free from suspended matter, is led into the ground infiltration. The ground infiltration system works as a combined mechanical-biologicalchemical wastewater treatment plant. When the wastewater is absorbed into the ground, the organic matter will degrade as a result of microbe activity in the so called bio layer on surface of the infiltration area. WAVIN-LABKO OY 4(10)

5 Septic tank, 1-section, 250 l 8 Extension D110 mm, 2 pcs 2 Maintenance shaft and lid, D400 mm 9 Angular connection D Inlet pipe D75 or D110 mm 10 Ventilation pipe D110 mm 4 Outlet pipe with T-branch D110 mm 11 Cap of the ventilation pipe D110 mm 5 Distribution pipe D110 mm, non-punched 12 Vent holes 4 x Ø8 mm (to be drilled) 6 Angular connection D110 mm, flexible 13 Inlet sewer (accessory) 7 Infiltration pipe D110 mm, 3 x 1,78 m = 5,3 m Figure 2. Structure of the Mökkisako-1 infiltration system. 14 Distance to the ground water surface, min. 1m 4 INSTALLATION OF THE LABKO MÖKKISAKO-1 INFILTRATION SYSTEM 4.1 Transport and Handling of the Tank Tank of the Labko MökkiSAKO-1 infiltration system should be handled with care. It should not be rolled or dropped. During transportation the tank should be tied and protected from damage. Lift the tank using the fork truck by its maintenance shaft. Before installation check the tank for possible damage during transportation. The infiltration pipes are placed inside the septic tank to make transportation and storage easier. Remove them before installation. 4.2 Installation of the Septic Tank General The septic tank should be placed so that an emptying vehicle has a free access to it. However, the emptying lorry should not drive over the tank or nearer than 1.5 m from the tank. Use a specialist contractor for installing the tank Installation Dig a mounting pit for the septic tank. Depth of the pit may vary according to the installation depth of the incoming sewage pipe, from 1.3 to 2 m. The minimum installation depth of the tank is 400 mm, and maximum 1000 mm as measured from the lower edge of the tank inlet pipe to the ground surface. On each side there should be at least 20 cm of free space and cm on the bottom. Bottom of the pit should be smooth, firmly bearing and non-settling. Compact a cm thick horizontal layer of stone-free sand on bottom of the mounting pit. Lift the Labko MökkiSAKO-1 septic tank with care into the pit. Place the tank in a direct position. If the there is a risk that water may flow into the pit, the WAVIN-LABKO OY 5(10)

6 tank should be anchored against lifting forces. Use non-stretching belts for anchoring (optional accessory: polyester belt, width 25 mm, length 6 m, weight capacity 2000 kg, 4 pcs), which are tied around the tank and the maintenance shaft, and fixed to impregnated wooden logs (50x100x1000 mm) Flexible inlet pipe (2x15 o 5 Impregnated logs, 5x10x100 cm, angles), accessory accessory 2 Distribution pipe, green, D110 6 Sand or gravel 2-8 mm mm 3 Infiltration pipe, blue, type 5, 7 Distribution layer, washed breakstone D110 mm mm 4 Anchoring belt, accessory 8 Filling soil Figure 3. MökkiSAKO-1 installation and anchoring. Start filling the pit with stone-free sand. Alternatively, you can use also sieved gravel with 2-8 mm grain size. Compact and fill the sand layer by the bottom and the skids with care, without damaging the tank. Continue filling in 30 cm layers, which must be well compacted. When the filling almost reaches the upper edge of the tank, the incoming sewer pipe is connected to the inlet, and the distribution pipe to the outlet. Incoming household sewage should be led into the tank by a D75 or D110 mm pipe, which is connected to the tank with a socket connector. In addition to that, also 2 x 15 o angular connectors may be used, for example, one after the other for making a flexible inlet connection. The incoming sewage pipe should be installed at a downward angle of at least 20 per mille (20 mm/m). The outgoing distributing pipe should be installed at 5-10 per mille (5-10 mm/m) angle of slope. In case the mounting depth of the septic tank is less than 1100 mm from the lower edge of the inlet pipe to the ground surface, the maintenance shafts should be cut at right height e.g. with an angular grinder or saw. However, you may cut the shafts only when you exactly know the final height of the ground surface. If you cut the shaft, you should drill new holes (φ 8 mm) in the skirt of the shaft for fixing the lid. Set the lids on their places. This is the proper moment for making thermal insulation of the septic tank e.g. using insulating plates. You may add insulation in any case. Thickness of the insulation WAVIN-LABKO OY 6(10)

7 should be ca cm, depending of the usage season, geographical location and installation depth. For usage in winter, the septic tank should always be insulated. After connecting the inlet and distribution pipes and adding possible insulation, continue filling around the tank with a 30 cm sand layer. Note! Do not fill yet the outletpipe side of the pit (heading to the ground infiltration). Instead, construct the infiltration ditch first. For final filling you can use also surface soil, on condition that it does not contain large stones. We recommend that you shape the ground surface on top of the infiltration field a little raised in order to lead rainwaters away from it. After installing, fill the septic tank with clean water. 4.3 Constructing the infiltration ditches When a suitable place for the infiltration field has been chosen and the septic tank is installed and filled up to the level of the outlet pipe, you should dig ditches for the infiltration pipes. The exact structure of the infiltration pipework depends on each case and the given dimensions are only guideline values. The infiltration ditch can be skew when seen from the level of the inlet sewer. The infiltration pipes can also be deviated from a direct line, in case of which the necessary angular connections must be self acquired. If the infiltration pipes are not installed in a direct line, special attention must be paid on the correct angles (Figure 4) Usually the ditch depth is m, length ca. 7 m and width at least 0.7 m. The ditch bottom should be horizontal and, when necessary, smoothed with a 3-5 cm coarse sand layer. The sand layer also prevents the filler sand and the ground soil from mixing with each other. If the soil structure is very coarse, the sand layer slows down the water transfer into the ground, thus furthering the cleaning process. In a compact ground the smoothing sand layer evens the load of the filler layer as the infiltration of water into the ground is rather slow. 1 Distribution layer, washed ballast (breakstone), granular size mm 2 Infiltration pipework 3 Filtration fabric/ thermal insulation 4 Filling soil 5 Highest ground water level Figure 4. Profile of the infiltration ditches WAVIN-LABKO OY 7(10)

8 Use for the filler layer washed ballast with (12-24) mm granular size. At first, spread on the bottom of the ditch a 20 cm ballast layer. Connect the pipe without holes (green pipes) straight to the outlet pipe of the septic tank with a double socket tilting 5-10 per mille downwards (5-10 mm/m). The double socket is fastened straight to the outlet pipe of the septic tank. Install the blue pipes in their numerical order (type 1 to the side of the septic tank, and type 8 last of all) at proper tilt of 5-10 mm/m on the ballast layer. Also in the end part of the infiltration drains there should be at least a 10 cm ballast layer under the pipes. The infiltration pipe of type 5 is attached to the distribution pipe by a flexible angular connection (stored in the septic tank). Note! Turn the pipes so that the marking on the pipe (painted line) comes upward, so the infiltration holes are directed downwards. Place rubber sealings in the first grooves of the pipes before connecting them. The sealings (5 pcs) of the drain pipes are delivered in the same package with the filtration fabrics (stored in the tank), and other 3 pcs are already installed at the ends of the extensions and pipes. The infiltration pipes should be supported by their whole length at the same downward angle. After installing and supporting the pipes, the ventilation pipes should be connected to the infiltration pipes. The ventilation pipes are connected vertically to the end of both infiltration pipes using an angular connector of D After this, continue ballast filling until the layer reaches at least 5 cm over the infiltration pipe also at the tank end of the pipe. Total thickness of the filler layer should be cm (Figure 4). Distance of the infiltration pipes from the ground surface depends on the mounting depth of the septic tank, and it may vary from 40 to 120 cm. Before adding the surface soil, the ballast layer should be covered with filtration fabric, which prevents the surface soil from mixing with the filler ballast. If the infiltration pipes are installed above the frost level, thermal insulation plates of 50 mm or 100 mm should be placed above them in order to prevent damages by frost heaving, and to improve the filtering effect of the drain system. If you use insulation plates the filtration fabric is not necessary. After installing the filtration fabric and the insulation, fill up the pit with filler soil. Shape the infiltration area in a mound form to lead the rain and flood waters away from it. Spread earth on the area and sow grass. In wintertime snow should not be removed from the infiltration area. After installing, do not forget to drill 8 mm ventilation holes in the upper end of the ventilation pipes (Figure 5). WAVIN-LABKO OY 8(10)

9 Cap of the vent pipe Vent hole Ventilation pipe Figure 5. Vent holes in the end of the ventilation pipe. 5 MAINTENANCE To ensure a reliable and proper function of the Labko MökkiSAKO-1 infiltration system, certain inspection and maintenance should be made regularly. Regular service guarantees also the best cleaning result. A Service Journal should be kept of all maintenance works and malfunctions, and also of measures taken in disturbance situations. 5.1 Septic Tank Observe the sludge accumulating in the septic tank. The sludge should be removed from the tank at least once a year or when the sludge layer reaches the interconnection pipe. The emptying vehicle should take the sludge to a waste disposal centre to be properly processed. When emptying the tank, you should also clean the T-branch e.g. with a water hose. By emptying the sludge often enough you can prevent suspended matters from getting into the infiltration pipes, which makes the service life of the infiltration system longer. Immediately after emptying fill the septic tank with clean water to prevent the floating suspended matters from moving from the first compartment to the next or even to the infiltration pipes. If the system is not used during the winter, the desludging should be done in the autumn. In this case, to prevent freezing, the filling with water can be excluded from the cleaning operation. However, the filling with water should be done in the spring, before starting the operational season. You should check the condition and proper function of the septic tank at least every ten years. You should ensure that the constructions are not damaged or the walls depressed in. Check the constructions always when emptying the tank. 5.2 Infiltration Field Service life of a ground infiltration field varies from several years to several decades. It depends on how the system was built, how the septic tank is serviced, how dirty is the sewage led into the system, and what is the ability of the soil to receive sewage waters. Emptying the sludge from the septic tank often enough makes the service life of the infiltration field longer. WAVIN-LABKO OY 9(10)

10 It is recommended monthly to observe the function and condition of the infiltration system through ventilation pipes. In case a strong backwater is noticed in the ventilation pipes, it means that the infiltration pipework may be blocked or the penetration ability of the infiltration field has decreased. The infiltration pipework should be cleaned when required, and at least once in ten years. 6 MALFUNCTIONS The house sewer does not drain, or the infiltration field does not drain. Immediately check the surface level in the septic tank. If the water level is normal in the septic tank, there is a blockage in the sewage pipes between the house and the septic tank. Open the blockage(s). If the water level is high in the tank, there is a blockage in the outlet or in the infiltration field. Check through the ventilation pipes of the infiltration system if there is any water up in them. If there is no water in the ventilation pipes, the blockage is in the outlet. Remove the blockage. If water is high in the ventilation pipes, the infiltration pipework may be blocked or the penetration ability of the infiltration field has weakened. In this case you should empty the septic tanks with a gullet emptying vehicle and wash the infiltration pipework completely. WAVIN-LABKO OY 10(10)