The design in this document has a vault size 80 x 80 x 80 centimetres, which is approximately 500 litres (0. For more complex designs, soakaways can take up to two days to install and therefore are likely to cost around £2,500. Soak-away pit Design - Free download as Excel Spreadsheet (. 2. Full Drainage Design Suite. uk. Ignoring the influence of spatial effect, the foundation pit support is regarded as a plane problem only, and the traditional Rankine or Coulomb earth pressure theory can be used for analysis and design, which certainly will result in conservative results. THE SOAKAWAY SYSTEM. The wall separating the two is about two-thirds the length away from the inlet. with base area A. Small domestic soakaways are usually backfilled with rubble or hardcore which will have a porosity of around 30%. DESIGN MANUAL: SEWAGE DISPOSAL SYSTEMS IN PRINCE GEORGE’S COUNTY . This pit acts as a replica of the intended soakaway. Testing to BRE365 standards involves the following: First, a trial pit is excavated. Digest. Percolation testing for leach lines and horizontal seepage pits. Pedro gonzalez ramirez. A drainage field is a specifically designed arrangement of perforated pipework, laid in trenches to allow the effluent to filter into the ground. 2 Filling the pit several times in quick succession whilst monitoring the rate of seepage, to represent soil moisture conditions typical of the site when the soakaway becomes operative. The pit should be covered by a slab with manhole. This is achieved by: 1 Excavating a trial pit of sufficient size to represent a section of the design soakaway. 2 Filling the pit several times in quick succession whilst monitoring the rate of seepage, to represent soil moisture conditions typical of the site when the soakaway becomes operative. Small bore solid-free sewer As for the septic tank and soakaway except that the liquid effluent is conveyed by a system of small-diameter. Pea gravel could block the sump pump. Purpose: To facilitate sedimentation and decomposition of small solid particles. Septic tank and absorption pit. For your soakaway to be as efficient as possible, you’ll need to pick the right area for it. l f. Box 1923, 41185 Dodoma Drawing title 24 APRIL 2018 DCNM STANDARD DESIGN FOR COUNCIL LEVEL HOSPITALS IN TANZANIA JCR STP A/101 PRESIDENT'S OFFICE, REGIONAL ADMINISTRATION AND LOCAL GOVERNMENTS, MKAPA BUILDING, P. 2 Filling the pit several times in quick succession whilst monitoring the rate of seepage, to represent soil moisture conditions typical of the site when the soakaway becomes operative. Calculates the capacity utilisation and time to empty to 50% for a selected soakaway size, using impervious and pervious drained area, soil infiltration rate (f), rainfall intensity (r value), climate change, and selected rainfall event return periods. 1 A 100 HECTARE CATCHMENTBackfill the soakaway and drainage channels with the free draining gravel. Water supply = 200 lits/day. Function. This is useful for absorbing small amounts of clean water such as the runoff from an outdoor shower or a swimming pool. Soakaway pits can be used where soils have a percolation rate ;;. We would like to show you a description here but the site won’t allow us. site of the soakaway. I found a ground assessment from a property built reasonably. Fill your pit; Fill the bottom of your pit with about 15cm of compacted sand or shingle. 2. Dig the pit to full depth, squaring off all edges. A soak pit, also known as a soakaway or septic tank soakaway, is a simple and effective way to manage wastewater from a household or small-scale development. Known as fusion landscape design, this landscape design will be designed with effective rainfall management in mind and will combine. Low Impact Development Design Guidance Manual Prepared for: Watershed Management Services Municipality of Anchorage Project Management and Engineering Department Technology and Program Design 6 Legislation and Standards for Urban Sanitation 11. In sloping areas, water points should not be sited within. includes: plants and sections. See full list on diydoctor. pvc pipe. 6. 12 Unofficial Translation ANNEX (D) Holding Tanks Design and Measurements Criteria 1. 15 There shall be no physical connection between a public or private potable water supply system and a sewer. A soakaway is especially useful in built-up areas that have been built from impermeable materials, as it allows water that would usually pool and flood to naturally ‘soak away’. Soakaway Trench Soakaway Pit The general components of a soakaway system are described below: i) Dung Channel . 5 and 4 m deep, and as a rule of thumb, never less than 2 m above the highest groundwater table. This effluent is disposed of to a soakaway (also called a soak pit or seepage pit, Figure 6. 8 m2. 38 × 30 m 3 = 11. 9k Views. Mini-diggers like CAT or JCB are commonly used to excavate the pit, although manual excavation is also possible. 15m from any building, and sufficiently distant from any other soakaway, including roof water. The inflow will discharge through a porous feeder pipe originating from a collection chamber to which. While digging the hole, look out for changes in soil characteristics. Roof leaders (pipes installed to drain water from roof gutters) can directly connect to the Dry Well, which may be a gravel-filled pit (most cost-effective), a prefabricated storage chamber made from plastic or. A sewage septic tank is a water tight tank, typically underground, in which sewage is collected and allowed to decompose through bacterial activity before draining by means of a soak away. In areas where the ground water level below 4m a soak pit can be used. 250 min, 500 recommended, 1000 max, to suit site conditions. 2 metres from a boundary. The two determining factors for soakaway success are the size of the area (or volume of water) to be drained and the percolation rate of the soil/sub-soil (or, in some sites, the depth to the water table). For deeper excavations please seek specialist advice. This is achieved by: 1 Excavating a trial pit of sufficient size to represent a section of the design soakaway. g. Such a soakaway would normally be one of three types: a porous chamber, a stonefilled pit or a layout of irrigation drains. Septic Tank Reinforcement Detail. Soakaway design. The pit is usually filled with a layer of loose stones, brick bats and brick ballast. The soakaway pit and soil would be clogged very easily if solids were allowed to be carried into the soakaway pit; this would happen if sludge were allowed to build up to within 30 cm (1 ft. For small soakaways serving 25m2 or less, a design rainfall of 10mm in 5 minutes is quoted in the Building Regulation Approved Document H as being an appropriate worst case. 150x150mm DIA LONS 210 980 210. This means the top of the drainage cube should be at least 300mm under the ground level. Mech - elect - plumb. With any rain garden or soakaway pit, be sure that the overflow drains safely away from all properties. Digest 365 is one of the most widely used BRE A traditional way of disposing of surface water from buildings. Technology and Program Design 6 Legislation and Standards for Urban Sanitation 11. 6. Overview: Placenta pits allow pathological waste to degrade naturally. There are the following considerations for the design of a soak-pit such as; It should be between 1. This Standard gives design guidance on how soakaways shall be incorporated into systems used to treat and store road runoff prior to discharging to ground. The soak pit shall comprise either a rock filled hole or a lined chamber both of these options shall be enclosedThis video is about Soakaway DeignSoakaway pit: A soakaway pit, also known as a soakaway, leach pit or absorption pit, is a covered, porous-walled chamber that allows water to slowly soak into the ground. The trial pit should be 0. Capacity testing and policy applicable to vertical seepage pits. In these conditions a long shallow trench soakaway will achieve greater. Soak Pit Design. Fill the hole with water and come back and check it the next morning. For an easy-to-access garden, you can expect a small soakaway to cost around £1,000. Fill with crushed stone or rubble (no fines) and put a sheet of poly over the top (250mm from the surface) finish off with whatever the topping will be. In this guide, we will look at what a soakaway is and how it relates to a septic tank. In some cases for small soakaways it may be possible to dig the pit close to vertical and install the geotextile and fill before the pit walls collapse. Each Brett Martin crate measures 1200mm long, 600mm wide and. So if you want to: Know the rules and standards; See how to undertake a soakaway test; Design a soakaway; Construct and maintain a soakaway; Then you’ll love this new guide. Step- One. 4 – Time divided by 4 = 120min/4 = 30mins. First published in 1991 as a replacement for the old BRE 151, BRE 365 has become the standard. Enter the observations for the soakage trial pits 6 BRESOAK Soakaway design software Enter the data for the area to be drained When trial data has been entered the program calculates the minimum design soil infiltration rate. Thus, soak pits are best suited for soil with good absorp-tive properties; clay, hard packed or rocky soil is not appropriate. The groundwater level should be monitored daily over a minimum one week period between mid-. It is a hole completely filled with irregularly sized and shaped rocks. Provided in fully editable AutoCAD . The soak pit may be of any suitable shape preferably circular. 7KB. File Type: DWG. Pit/well of this type is to first store immediate stormwater run-off and then slowly dissipate it through infiltration into surrounding soil. To calculate the size/volume of a rubble filled soakaway, the same calculation can be used but the result divided by 0. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Pit privies shall preferably be located on the leeward side of a building and shall be ventilated. O. SLAUGHTER HOUSE. 10 m and 1 m depth below the inverted level of the inlet tube. £1500 - £2000. a suitable design in upvc is illustrated. Suppose we have to Design a Septic Tank & Soak Pit for 10 Residential Buildings. Design Guidance Manual December 2008 Page iv ACRONYMS AND ABBREVIATIONS AAC. CONSERVANCY TANKS. It has been specified in a number of British Standards. (AutoCAD 2015. 5m and 7. Soakaways are used to manage surface water at its source, and serve as an alternative option to draining off surface water via a stream or sewer system. 250 min, 500 recommended, 1000 max, to suit site conditions. Includes 14 different detailed soakaway construction drawings including traditional pit soakaways, infiltration trenches and geocellular soakaways. size 50mm from septic depth to be fixed on site tank outlet 200mm thick blockwork wall f. Purpose : To collect and convey wastewater to the inlet of the catch-pit. Allow the concrete to set for a minimum of 24 hours and then remove the frame or leave it in place. Standard regulations states that for any house up to and including 3 bedrooms, the minimum size sewage system that can be installed is for 5 persons, with one extra person added for each extra bedroom. Catch pits need regular maintenance to ensure optimum functionality. The design of a typical soak pit generally consists of a pit of approximately 1 cubic meter with a depth of 1. . T his update follow ed the D ecem ber 1992 issue of the N ational R ivers A uthority A quifer P rotection P olicy which superseded the. Viewer. It allows the effluent to percolate into the surrounding soil, where it is treated naturally through biological processes. Septic Tank is deeper than Soakaway, unlike Soakaway, the body plastered and the floor, floored. · With a disposal hole of about 30 x 40 cm. A catch pit is designed to collect silt and debris before it enters any drainage system. Soakaway: Valence, France: 98-54 - 88--- Infiltration trench: Various: 70 - 90: 70 - 90. The general cost for constructing septic and soakaway tank is between N250,000 to N300,000. Soak Pit Design. So if you want to: Know the rules and standards; See how to undertake a soakaway test; Design a soakaway;. 588m3 Outflow from soakaway O O = as50 x f x D = Internal surface area of soakaway pit to 50%. The frame will eventually rot away and be easier to pull out of the sump. Includes 14 different detailed soakaway construction drawings including traditional pit soakaways, infiltration trenches and geocellular soakaways. Author: Abdul Hayyi bin Awang. Smaller crates, like 0. If a soakaway isn't far enough from the home, or isn't draining correctly, this could cause issues for the home's foundations. 040) Example 1. Refer any discrepancies to the Architects. Septic tanks are a minimum of 2700 litres (650 gallons) for a 2 bedroom house. txt) or read online for free. The solids being heavier than the waste liquids, settles down at the bottom of the septic. Fit the sump cover. Rainwater soakaways are usually made from gravel or stone or even plastic soakaway crates. The soaking pit should be raised above ground level and the surface water should not enter into the soak pit. 5 and 4 metres deep, but never less than 2 metres above the groundwater table as a thumb rule. section through proposed catch pit manhole and soakaway (based on highway sa4) cover level bend to suit top crate level stormbloc modules (800w x 800d x 660h each) laid in 2 layers 1320 base levelHi, I know what you mean logic dictates that it would be fine, show it away from the house Building control are asking for a soakaway design that works, certified by the structural engineer involved. # Description Unit Quantity. The soakaway should be covered by at least 100mm of gravel. Infiltration Testing and Design. 1–3 At present, more and more scholars and engineers pay attention to the research on. The soak pit may be filled with stone aggregates or may be kept empty. Granite (4 ton), 6" solid blocks (300), sharp sand (full tipper), cement and water supply. Day 5: Block work starts. 12 no. Pre-settled effluent from a water-based collection and storage/treatment or a (semi-) centralised treatment technology is discharged to the underground chamber from which it infiltrates into the. 0 below the invert level of the inlet pipe. These documents were first produced by FHI 360 and HCWH under funding provided by the CDC to support and inform proper management of health care waste. The pit will then be filled several times in quick succession while monitoring the rate of seepage. Herringbone. Anti-burglar Grating for Culvert Outfall. O. Submit Search . 2. This is achieved by: 1 Excavating a trial pit of sufficient size to represent a section of the design soakaway. More complex soakaway construction with additional depth, pipework, size or reinforcement. 5m deep. It is important that Infiltration Rates are tested before a Soakaway design is completed. a %%ustandard soakaway. Pedro gonzalez ramirez. SOAK AWAY PIT DIMENSION. Assuming the trial pit dimensions were 2. 100. Location of a water point at a safe distance from potential sources of pollution drainage channel above the ground so that the wastewater can drain away. 8m x 1. area A. The soak pit should be between 1. Getting it emptied pronto might just prevent any permanent damage. It must not be constructed nearby a drinking water source as it can pose contamination of the drinking water source. A soakaway is the name for a pit filled with rubble or hard core that helps water drain slowly into the soil around it. That's the bones of soakaway design. The soakaway system has to be capable of dealing with all the waste water produced by the household, which can often be in the region of 40 gallons per day per person. 9201 Basil Court, Suite 318 . grade src 40 concrete. 33 9 100. A drainage field (or soakaway system) is made up of a series of perforated/slotted. Download also: Rainwater Drainage Design Calculation Excel Sheets XLS. The wastewater generated in the house from the kitchen and bathrooms has to be disposed of. 5 m for permeable areas up to 100m2draining to the soakaway. 0m in each direction is appropriate for buildability. A soakaway pit, also called a dry well, is an underground pit filled with stones and lined and covered with landscaping fabric. 5 External links. Previous Post. Pre-settled effluent. l pp %$56 at 200mm c/c. This page includes describes some important construction details for soakaway pits, soakaway trenches and soakaway crate systems. clear stone or plastic soakaway crate) Filter fabric must be placed on all sides and top (or choker course of 5-10cm of 5mm clear stone for top) of the stone reservoir to prevent sediment entering the void spaceSpread the love. This pit is then filled with water repeatedly, and in a short space of time. This paper demonstrates a stepwise approach to design an optimal open pit to exploit the deposit by using Surpac and Whittle software. Initial Depth = Soakaway Pit Initial Water Level; Storage Curve = Functional; Storage Functional Curve Coefficient = 0; Constant = Soakaway Pit Width x Length x Porosity; Other parameters keep as default as in VOSWMM. Connect the trenches to flow into the hole. 3 Pit sizing procedure 3. Let’s get started. 3. The septic tank section is responsible for treating the wastewater naturally by separating the solid waste from the liquids. Health Review Section. ALL GLAZED OR EMBEDED IN CEMENT OPENING VERTICAL JOIST. Does not cover the design of soak pits with overflows discharging to outfalls. 9B. The first is to soak the septic tank liquid away. 8m deep) Excavated Dimensions For Septic Tank = 3m x 3m x 3. Fig. The proposed soakaway design must also ensure that: a suitable form of oil interception device would be fitted to the inflow pipe from the proposed paved areas; would. 0127 = 1. The basic functions and the need for a soak pit. A design rainfall of 10mm over 5 minutes has been assumed to give the worst case all as Building Regulation Approved Document H. Make a lid for the hole. This pit acts as a sortof replica of the intended soakaway. The water storage cistern shall be preferably reinforced concrete and provided with. Sewage generation = 85 % of water supply. 3. Summary A soak pit, also known as a soakaway or leach pit, is a covered, porous-walled chamber that allows water to slowly soak into the ground. pit(s) / borehole(s), ideally in the approximate location of the proposed soakaway. A trench soakaway may be preferred to a conventional soakaway pit in the following conditions; Where there are restrictions on the depth of the soakaway, for example where there are layers of contaminated soils or impermeable strata. Soakaway Trench Soakaway Pit The general components of a soakaway system are described below: i) Dung Channel . 4 m long x 2. The pit may be lined with stone, brick or concentrated blocks with dry and open joints. Determine a suitable size and number of pits. Environmental Engineering/Policy Program Largo Government Center . 3 = 2. 588m3 Outflow from soakaway O O = as50 x f x D = Internal surface area of soakaway pit to 50%. Domestic Wastewater:- Means the effluent, including settleable materials (sludge) and scum discharged from water closets, ablutions, kitchens…etc, of houses and institutions. Where an existing soakaway shows signs of instability it is recommended that after the remedial measures have been completed the bottom two metres of the chamber be sealed with a bituthene coating protected by a 150mm thick dwarf wall formed from Class ST4 concrete. 100x100x400mm OR. Soak pit construction procedure. Typical Soakaway Construction Drawings. The material used for the pit wall is sometimes perforated to allow wastewater to seep in from the sides. 450 pcs of 9" block @N140 = 63,000. For soakaways serving larger areas reference should be made to BS EN 752-4, or BRE Digest 365 Soakaway design. Size: 10. Larger capacities are the best fit for a two-compartment tank. DETENTION PERIOD:- 12 to 36 hrs (adopted 24hrs) LENGTH TO WIDTH RATIO:- Length is 2 to3 times of width. Earth Sciences. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting. Septic tank section, plan, soak away system and plumbing details that includes a detailed view of method of fixing water gauge meter for domestic aise withing the cavity of boundary wall, septic tank plan. The pit is then filled with water repeatedly and in a short. A software. 5. Farms which can achieve very high levels of dry removal ofsolidwaste,andlowlevelsofwateruse(ie. Today I'm going to show you Exactly how to build a strong Soakaway pit or leachpit or soakpitIs a flooding Bathroom dangerous?Yes If the Bathroom over floods. This new edition describes the design and construction procedures for soakaways, and explains how to calculate rainfall design values and soil infiltration rates. Unlike water wells that Dry wells (also known as soakaway pits, soakwell, or soak pit), is one of the earliest models of a water runoff management system. 13. 74. . 4 References. SEPTIC & SOAKAWAY PIT President's Office, Regional Administration and Local Governments. Difficult, unusual or larger project with complex pipework, difficult access, deep excavation through hardened materials (concrete, garden walls etc), disposal of waste material and reinforced materials. One of the firs. . Jan 27, 2021 - Explore Iheks's board "SOAKAWAY" on Pinterest. This is achieved by: 1 Excavating a trial pit of sufficient size to represent a section of the design soakaway. Fill with water to depth of 300mm. The tables were calculated assuming that the pits will be lined and not filled with rocks. These trial pits can be dug by hand, but tend to be excavated by mini-diggers ( CAT or JCB ). Rubble pits only work if the soil drains well and you have a low volume of water. It, therefore, perform better than the single compartment tank. These modular water storage cells have a high void ratio and are used for either attenuation or infiltration of stormwater in residential, commercial, industrial and agricultural applications. A Soak Pit, also known as a Soakage Pit or Leach Pit, is an underground structure designed to collect and absorb excess water or wastewater into the surrounding soil. 5 m and 4 m deep. 5 KG/CM for Manholes/Inspection chambers TABLE 1 SEPTIC TANK SIZES No. Looking for our range of soakaway crates to buy - shop soakaway crates here > Soakaway Crates - A New Era. The performance of any soakaway system is dependent on the soakaway construction details being designed and installed correctly. The soakaway must not be in an area of unstable ground or where the lowest point of the soakaway meets the water table at any point of the year. txt) or read online for free. Provided in fully editable AutoCAD . Soak Pit Design What is a Soak Pit? : A soak pit which is also called a soakaway is a closed porous wall chamber that is primary design to allows water to. C. Use M-15 grade of P. 3. 67 8 83. A soak pit or a soakaway is a closed porous chamber that is directly connected to a primary treatment unit of residential or commercial building. g. The area of the soak pit does not include the base. Location and Number of test holes The test shall be conducted at points where the disposal unit(s) (soakaway pit or absorption trenches) are to be located. However, you as the applicant are responsible for the application of the Manual to your site and making the decision regarding which soakage system is adopted as required. It should be locatedBy combining the design of a soakaway and an attenuation tank, we can utilize the “soaking away” nature of the under-ground soil, and use the attenuation tank to provide adequate hydraulic. Report DMCA. Design Considerations The soak pit should be between 1. The appropriate bottom area of each. Placenta Pit Design. to soakaway pits outlet to soakaway pits section a-a manhole 600x500mm with c. Soak pits are a water sensitive urban design (WSUD) mechanism that relies on the stormwater principles of retention and infiltration. Published by National Roads Authority, Dublin 2015 Before you start digging a soakaway pit or rain garden on your property, Contact Ontario One Call to check where utility lines are buried. Concrete soakaway rings used in a surface water. The outlet of the septic tank should be compulsorily connected to a soak pit. com. 2. Check the drainage tubing with a 4-ft. So basically the difference between Septic Tank and Soak Away is that a Septic Tank is deeper and plastered then floored, while Soakaway is not given such treatment as the floor is left like that, it is. The purpose of these innovative crates is to allow excess rainwater to be released back into the ground. Uploaded by HRK65. A stone-filled dry well is the simplest of all seepage pits. It helps manage and disperse the effluent (wastewater. Kapiti's first choice for soak pit installation. Soakaway chamber. The only function of a surface water soak away is to disperse the water into the ground, but a sewage effluent soak away has two functions. A test pit was excavated to the invert level of the proposed infiltration structure. The Construction Information Service brings together a comprehensive collection of essential technical documents from a wide range of publishers in one online package. Soakaway Design Spreadsheet. Sub Category: Bathroom and toilet CAD Blocks & CAD Model. Upload. xls), PDF File (. Part B. 0 m (width of each soakaway pit) n = 0. Download Soak-away Pit Design. A worked example is as follows; 1 – Hole pre-soaked overnight. BoQ Septic Tank & Soakage Pit for Public Toilets (2 Stalls) Sr. See more ideas about septic tank design, septic tank, sewage system. Library. Calculate the design width of the soakaway: Volume equation I –. ¾ in. Soakaway Crates are quick & simple. Average time to seep away from 75% to 25% =. Soakaway crate sizes can vary, but a common size for residential use is around 1m x 1m x 1m. A. Rubble filled pitThe most common size of soakaway for residential use is 1 Cubic Metre (1m³), as this is what most Local Authorities seem to specify. And I hope this will help you out. ) Filling the pit three times in quick succession whilst monitoring the rate of seepage, to represent soil moisture conditions typical of the site when the soakaway becomes operative. Download pdf PREMIUM - 194. INLET AND OUTLET TEES. Materials and labour fees. , 2014; Yadouléton, 2015). Information on design and functional aspects, and environmental effects. A drain field is made of solid perforated. 10C. site of the soakaway. Provided in fully editable. Periodic effluent is added to the septic tank to avoid the smell. Wrap the fabric over the top and. 3. Carrying out a soakaway test In order to carry out the test you need to excavate a trial pit to an adequate depth beneath the. 100. and perimeter P. Soakaways is a method for disposing rainwater, it is a hole or a pit in the ground into which you run the rainwater drainage. Sokoine Building, P. Stephen L Garvin. In St Jean, the maximum depth to water table is observed at 1. O. Calculate how large your soakage trench needs to be. A soak pit, also known as a soakaway or leach pit, is a covered, porous-walled chamber that allows water to slowly soak into the ground. The soakaway should not be located within 10m of potable water supplies in order to avoid possible cross-contamination. 15cm main bars and 18cm distribution bars c/c. Wrap your soakaway crate in the geotextile membrane, making sure the membrane covers any outward-facing surfaces, including the pipe entry point. A unique design graph is produced which allows the professional designer to optimize a BRE 365 compliant soakaway design in minutes. Privies shall not be used in areas where the water table is within 2 feet of the surface since they will not function well. 0 below the invert level of the inlet pipe. He's categorically ruling out normal soakaway based on current percolation results. 3. This totally depends on the size of the soakaway pit and the bar spacing. Steps: To build a basic stand-alone soakaway, dig a pit in your soft turf no less than 1m2 and 1. 3 Examining site data to ensure. 71 KB. 90 m and a minimum depth of 1. 1 load of gravel = 20,000. Purpose : Percolation of wastewater to surrounding subsoil. Wasa guidelines for design of water and wastewater systems - Download as a PDF or view online for free. Start in the center by pointing the head of your shovel into the well. £3000+. SEPTIC & SOAKAWAY PIT President's Office, Regional Administration and Local Governments. Dig a 4 by 4 ft (1. . The absorption area of the soak. The fill should be single sized gravel or similar material and the void ratio affects the storage volume of the soakaway so design values must be carefully chosen. 04 886 2059. 5 and 4 m deep, but as a rule of thumb, never less than 2 m above the groundwater table. Soakaway design to BRE Digest 365 2016. It serves the function of letting the wastewater coming from the septic tank to slowly soak into the underlying ground. The groundwater level should be monitored daily over a minimum one week period between mid-.