Onsite Wastewater Treatment System Site Evaluation
This guidance document is advisory in nature but is binding on an agency until amended by such agency. A guidance document does not include internal procedural documents that only affect the internal operations of the agency and does not impose additional requirements or penalties on regulated parties or include confidential information or rules and regulations made in accordance with the Administrative Procedure Act. If you believe that this guidance document imposes additional requirements or penalties on regulated parties, you may request a review of the document.

Form #: 12-034 Guidance Documents Revised: 12/4/23
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165 KB 12-034 OWTS Site Evaluation.pdf

Each proposed site for the location of an onsite wastewater treatment system must be evaluated by a professional engineer, registered environmental health specialist, Journeyman Installer, or Master Installer. The following information must be recorded and provided to the Nebraska Department of Environment and Energy (NDEE) on request:
· The type, size, location and elevation of the proposed system clearly identified on a scaled drawing of sufficient size that includes the following information:

o The legal description and a survey of the lot and immediate vicinity;

o Property lines;

o Buildings;

o Water supply wells;

o Buried water pipes and utility lines;

o The ordinary high water mark of lakes, rivers, streams; and

o The location and the type of water supply wells within 1000 feet of the proposed onsite wastewater treatment system.

· Depth to the seasonal highest measured or estimated groundwater table and to the bedrock or other barrier layer surface, if this depth is less than the depth of the seasonal high groundwater table, along with a detailed description of the method used to determine depth. The seasonal high water elevation of the groundwater table must be at least four feet below the bottom of the infiltrative surface of the soil absorption system in order to provide adequate filtration through the soil and avoid pollution of the groundwater. One or more of the following sources or types of information can be used to determine the seasonal high water elevation of the groundwater:

o U.S. Department of Agriculture Natural Resources Conservation Service soils maps and soil interpretation records;

o Evaluation of soil color and the presence or absence of mottling;

o Evaluation of impermeable or semi-permeable soil layers; and

o Measured water levels from nearby test holes, observation wells or water wells.

If the depth to seasonal high groundwater or to the bedrock or other barrier layer is less than 10 feet, soil borings or other site specific methods are required to be used.
· Direction of groundwater flow; and

· Soil conditions, properties and soil percolation test locations, data and results.

Additional information may be required as part of the application process for a permit or subdivision approval.