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41414: 41- Marion County Building Inspection Division Onsite Septic Review OREGON PUBLIC WORKS Activity Number: 08-03243 Date: April 3,2009 Project Address: Abiqua Ridge Estates Lot#15 Completed By: Jessica L. Joye, REHS, Onsite Wastewater Specialist ONSITE WASTEWATER TREATMENT SYSTEM SITE EVALUATION ALTERNATIVE TREATMENT SYSTEM APPROVAL General Description of Site Evaluations Sewage contains disease-causing organisms and other pollutants that can cause adverse impacts to human health and the environment. An onsite sewage disposal system must treat and dispose of sewage in a way that will not cause a public health hazard,contaminate drinking water supplies,or pollute public waters. Proper treatment in an onsite system begins with primary treatment in the septic tank. The septic tank separates the solid particles in sewage from the liquid. The liquid that comes out of the septic tank is called effluent. The effluent may then be dispersed in the soil for further treatment or discharged into a secondary treatment device such as a sand or gravel filter or other alternative treatment unit prior to dispersal in the soil. For proper treatment, the effluent must slowly infiltrate into the underlying soil. Dissolved wastes and bacteria in the effluent are trapped or adsorbed to soil particles or decomposed by microorganisms. This process removes disease-causing organisms,organic matter,and most nutrients. Effluent that comes to the ground surface(through poor soils or other problems with the system)can be a possible health hazard because it may still contain some disease-causing organisms. Soil that drains too quickly may not give the effluent enough treatment and may result in groundwater contamination. The purpose of the evaluation is to locate suitable soils in an area that is large enough for both the initial drainfield area and the replacement drainfield area. The criteria used for this site evaluation can be found in Oregon Administrative Rules (OAR)340-071. In the site inspection, the following features are evaluated: • Soil types - how well they drain and other indicators of good soil structure for treatment • Depth to evidence of groundwater • Wells located on the site or adjacent sites • Slopes, escarpments, ground surface variations,topography • Creeks or springs on the site or adjacent properties • Whether the soils have been disturbed • Setbacks from property lines, buildings, water lines, and other utilities • Other site features that could affect the placement of your onsite system. 555 Court St NE - P O.Box 14500-Salem.Oregon 97309-5036-Phone(503)588-5147-Fax(503)588-7948 Page I of4