NAC445A.961. Letter of approval to construct, alter or expand system: Engineering report.

     1. The engineering report required pursuant to NAC 445A.9608 must include, without limitation, a soils analysis performed by a qualified person approved by the Division or other administrative authority, including, without limitation, a design engineer, a soils scientist or a geologist. The soils analysis must include, without limitation:

     (a) Data from a percolation test pursuant to NAC 445A.9668, from a minimum of two test holes in the area of the proposed effluent absorption system, unless an alternative investigation of soil characteristics pursuant to NAC 445A.967 is used. If an alternative investigation of soil characteristics is performed, the results of that investigation must be included in the soils analysis.

     (b) Soil logs from at least one test pit excavated to a minimum depth of 5 feet below the bottom of the proposed absorption system. The soil logs must describe the soil in accordance with sections 28 through 30, Figure 29-1, Table 29-1 and Appendix A of Design Manual: On-site Wastewater Treatment and Disposal Systems, as adopted by reference in NAC 445A.9592. The soil logs must include notations relating to impervious barriers, bedrock, fractures, areas of open solution, clay, caliche or other limiting factors. The depth to the seasonal high groundwater, as observed as the surface of free water or as indicated by mottling or historical documentation, must also be included in the soil logs.

     (c) Verification by the design engineer, soils scientist or geologist of the depth of the high groundwater and bedrock, areas susceptible to flooding, the ground slope and the results of percolation tests, including, without limitation, a morphological study of soil conditions with particular reference to soil color and sequence of horizons. In addition:

          (1) If the natural soil condition has been altered by filling or other attempts to improve wet areas, the Division or other administrative authority may require the verification by the design engineer, soils scientist or geologist to include observation of high groundwater levels under saturated soil conditions.

          (2) If the natural soil condition has been altered by filling or other attempts to improve the percolation rate of the soil, the Division or other administrative authority may require the verification by the design engineer, soils scientist or geologist to include a determination of whether the fill material is suitable for an on-site sewage disposal system.

     (d) The long-term acceptance rate of the soil, as referenced in the table set forth in NAC 445A.9674.

     (e) If required by the Division or other administrative authority pursuant to paragraph (b) of subsection 3 of NAC 445A.9602, a groundwater mounding analysis.

     2. The Division or other administrative authority may require the design engineer to include in the engineering report a nitrogen balance to demonstrate that the effluent will not cause any waters of the State to exceed the maximum contaminant level of nitrate, and groundwater samples from the installed monitoring wells must be obtained before initiation of operation of the on-site sewage disposal system.

     3. The engineering report may include any other data determined by the design engineer to be relevant to the design specifications of the proposed on-site sewage disposal system.

     (Added to NAC by Environmental Comm’n by R194-07, eff. 8-26-2008)