Waste-Water Device

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Overview Researchers in the Environmental Engineering Group, Trinity College Dublin have developed a novel device for providing even distribution of on-site wastewater effluent across a subsoil percolation area by gravity flow. In rural areas not served by sewer networks, wastewater effluent must be treated and disposed of on-site. These systems can take the form of a septic tank or a package treatment plant, where the wastewater is partially treated before it is discharged to the subsoil, through which it percolates and receives further natural degradation before reaching the water table. The even distribution of effluent across a percolation area is therefore a critical design factor for such gravity systems as emphasised in the soon to be released EPA Code of Practice for Wastewater Treatment for Single Houses. However, experience and research shows that most systems discharging effluent by gravity fail to work consistently under the sporadic and very low flows which typifies on-site treatment systems and makes them particularly sensitive to solids, biofilm growth and grease which inevitably accumulate after a period of time. This device has been proved in on-site trials to provide a consistently even split of on-site effluent flowing by gravity with no pumping or regular maintenance required. Furthermore the device has been especially devised to minimise the drop in hydraulic head across it, thus leaving as greater depth of unsaturated soil as possible downstream of the device for the effluent to percolate through. This device provides a sustainable solution for the even distribution of effluent which is essential in order to prevent the overloading of a small section of the percolation area which could lead to groundwater and / or the surface water pollution as a result of the effluent ponding on the surface. Advantages Simple mechanical construction utilizing a basic pivot system ensuring unity and equal distribution of discharge. No power required. Minimal hydraulic head required. Development Stage Prototypes developed and testing on-going in the field. Principal Inventor Mr. Laurence Gill from the School of Engineering, Trinity College Dublin, Ireland. Patent A preliminary patent application has been filed. Trinity College Ref LG01-142-01.