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Septic Site Evaluation 555-19-000864-EVAL r� Page 3 of 5 wmom .- 0tta�� . s �$ 0 * , A6s 1-04 � s s0011 * fRAt-O�r SI %0ve 400, a of444 � 1 t €odescr ptpS ,431 Ot lam .x ' A;isA y ,mt r .......... 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: •❑0000❑❑❑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 •❑❑❑❑❑000 Slopes, escarpments,ground surface variations,topography •❑❑❑❑❑❑❑❑Creeks or springs on the site or adjacent properties •❑❑❑❑noon Whether the soils have been disturbed •❑❑❑❑onoo Setbacks from property lines, buildings,water lines, and other utilities •0000000❑Other site features that could affect the placement of your onsite system Approved Area&System Type Soil test pits and other site features were evaluated during a site visit on March 25,2019. The conditions observed during the evaluation indicate that the area around the test pits is not suitable for a STANDARD system due to the following limitations: Temporary groundwater level is too close to the ground surface DEQ Rule requirement: Temporary groundwater level cannot come within 24"of ground surface for a Standard system, within 18"for an Alternative system with a Standard equal distribution drainfield,and within 12"for an Alternative system(on a slope of 12%or less with a Capping Fill drainfield). "Temporary groundwater"refers to a water table that completely dries up during certain times of the year. OAR 340-071-0220(1)(b)(B). Evidence of a temporary water table was observed at around 18 inches below the surface in the test pits. Description: Treatment of sewage occurs in the soils around the drainfield area. If groundwater comes in contact with the sewage before it has been adequately treated in the soils,there are two concerns: 1)very little treatment occurs in saturated soils—the presence of air is required for good treatment; and 2)sewage may be"forced"to the surface where it poses a potential public health hazard. Site/Soil adversely modified:DEQ Rule requirement: The site has not been filled or the soil has not been modified in a way that would adversely affect the functioning of the system. OAR 340-071-0220(1)(f) Description: Soils provide an important part of the treatment and"sanitizing"process for sewage. However,this treatment by the soils requires good structure. The problems caused by fill material: poor treatment of the sewage due to discontinuity of soil texture in layers. Sewage can flow through loose soils and potentially surface,causing a public health hazard. The area around the observed test pits has been heavily tilled. Further disturbance may result in an outright denial of the site. CALL BEFORE YOU DIG...ITS THE LAW ATTENTION:Oregon law requires you to follow rules adopted by the Oregon Utility Notification Center. Those rules are set forth by Oregon Administration Rules. You may obtain copies of the rules by calling the center.(Note:The telephone number for the Oregon Utility Notification Center is 1-800-332-2344.) 3/26/19:3:53:20PM Page 3 of 5 ONS_OnsiteEvaluation_pr