The soils analysis and report must meet the following criteria:

1. (1) the number of test holes, minimum test hole depth, and percolation tests must be sufficient to adequately evaluate subsurface characteristics of the area for the type of system proposed;

2. (2) soils in the usable wastewater disposal area must be shown by percolation test to have an acceptable percolation rate for the type of system proposed; percolation tests must be

   1. (A) performed by a registered engineer, or a person under the responsible charge of a registered engineer;
   2. (B) be performed in accordance with standard sanitary engineering principles and practices;
   3. (C) taken in each soil stratum to be included in an infiltrative surface area; and
   4. (D) confirmed to be accurate by a correlation of the observed soil texture in the test hole with the range of soil texture types associated with percolation rates in 18 AAC 72.530(f)(3);
3. (3) soil borings and soil analysis must show the location and elevation of seasonal high water table and impermeable strata in relation to the wastewater system;

4. (4) seasonal high water table must be determined by

   1. (A) monitoring test holes or soil borings taken between June 1 and September 30;
   2. (B) soil mottling analysis;
   3. (C) interpretation of levels of standing open water;
   4. (D) the knowledge and experience of the engineer, based on past subsurface investigative work in the vicinity of the project; or
   5. (E) a combination of these methods;
5. (5) the depth to seeps, if any, must be recorded; the department may require subsequent monitoring;

6. (6) in areas known or suspected to contain permafrost,

   1. (A) a soil moisture content profile analysis derived from laboratory testing methods must show the soils are adequately drained throughout the usable wastewater disposal area; and
   2. (B) the results of a geotechnical study must show that the area can successfully be used for the system proposed and will remain stable under the proposed design; and
7. (7) the report must be sealed by a registered engineer.

(Eff. 4/1/99, Register 149; am 5/12/2016, Register 218; am 10/1/2023, Register 247)

Authority: AS 44.46.020, AS 46.03.020, AS 46.03.100, AS 46.03.010, AS 46.03.050, AS 46.03.110