Section 18.60.330. Design standards.

	(a)  The design standards in this section supplement 18 AAC 60.220 - 18 AAC 60.230 and apply to a new Class I MSWLF or lateral expansion of an existing Class I MSWLF or a landfill that accepts polluted soil.  These design standards apply to a Class II MSWLF and, if the department so decides, to a Class III MSWLF, only if the department  
		(1) has evidence that leachate from the site is polluting an aquifer of resource value; or  
		(2) finds that a liner and leachate collection system of appropriate design is necessary to protect public health or the environment.  
	(b)  The owner or operator of a MSWLF subject to this section shall ensure that the MSWLF is constructed  
		(1) in accordance with a design approved by the department; the design must ensure that the maximum contaminant levels listed in 40 C.F.R. 258.40, Table 1, as amended through December 6, 1995, adopted by reference in this chapter, will not be exceeded in the uppermost aquifer at the relevant point of compliance, established in accordance with 18 AAC 60.825(c); or  
		(2) with a composite liner, described in (c) of this section, and a leachate collection system designed and constructed to maintain less than a 12-inch head of leachate over the liner.  
	(c)  For purposes of (b)(2) of this section, a composite liner consists of a flexible membrane liner (FML) installed on top of, and in direct and uniform contact with a compacted soil layer.  The FML must be at least 30 mils thick unless it is made of high density polyethylene (HDPE), which must be at least 60 mils thick.  The compacted soil component layer must be at least two feet thick and must have a hydraulic conductivity of no more than 1 x 10-7 centimeters per second.  
	(d)  In approving a design under (b)(1) of this section, the department will consider at least the following factors:  
		(1) the hydrogeologic characteristics of the facility and surrounding land;    
		(2) the climatic factors of the area; and    
		(3) the volume and physical and chemical characteristics of the leachate.  

Authorities

44.46.020;46.03.010;46.03.020;46.03.100;46.03.110;46.03.800;46.03.810;46.06.080

Notes

Reference

18 AAC 60.213
18 AAC 60.300
18 AAC 60.360
18 AAC 60.397
18 AAC 60.485

Authority

AS 44.46.020 AS 46.03.010 AS 46.03.020 AS 46.03.100 AS 46.03.110 AS 46.03.800 AS 46.03.810 AS 46.06.080

History

Eff. 1/28/96, Register 137; am 10/29/98, Register 148