Title 18 . Environmental Conservation

Chapter 72 . Administrative Enforcement

Section 255. Stabilization ponds

18 AAC 72.255. Stabilization ponds

(a) The department will approve plans for construction of a stabilization pond if

(1) the submittal requirements of 18 AAC 72.205(a) are met;

(2) the submittal requirements of 18 AAC 72.205(c) for a nonpercolating stabilization pond, or of 18 AAC 72.205(c) and (d) for a percolating stabilization pond, are met;

(3) the design or design criteria for the following parameters meet the requirements of 18 AAC 72.220:

(A) design flows and waste loads;

(B) treatment capacities;

(C) siting with respect to potential for health hazards, nuisances, flooding, and effect on groundwater;

(D) dike design, materials, construction, and safety;

(E) permeability of impoundment seal;

(F) methods to control operational variables;

(G) methods and location of sludge or septage disposal;

(H) thermal protection considerations;

(4) the provisions of 18 AAC 72.245(3) - (9) are met;

(5) soil test holes, soil analysis, and the soil report meet the criteria of 18 AAC 72.265(2) - (5), and (10);

(6) soil borings and analysis show that the vertical separation between the lowest part of the system and

(A) the seasonal high water table is at least four feet; and

(B) bedrock, clay, or other impermeable strata with an expected percolation rate greater than 120 minutes per inch is at least six feet;

(7) test holes are located, and tests are conducted, to yield data representative of the area planned for the system;

(8) the number of test holes is that number necessary to adequately evaluate subsurface characteristics of the area planned for the system;

(9) for nonpercolating stabilization ponds, the coefficient of permeability of the seal does not exceed an equivalent percolation rate of 500 gpd per acre at a water depth of six feet; and

(10) for percolating stabilization ponds

(A) a wastewater discharge permit has been issued, and mixing calculations for any required mixing zone demonstrate compliance with

(i) permit conditions under AS 46.03 and this chapter; and

(ii) water quality standards at 18 AAC 70; and

(B) hydrologic data demonstrate that permit conditions will be met and that use of the stabilization pond will not interfere with existing public and private drinking water sources.

(b) As necessary to protect public health, public and private water systems, and the environment, the department will require periodic groundwater monitoring as a wastewater discharge permit condition.

History: Eff. 4/1/99, Register 149

Authority: AS 44.46.020

AS 46.03.010

AS 46.03.020

AS 46.03.050

AS 46.03.090

AS 46.03.720