TITLE 39

HEALTH AND SAFETY

CHAPTER 74

IDAHO SOLID WASTE FACILITIES ACT

39-7409.  Standards for design. (1) Applicability. These standards apply to new MSWLF units and lateral expansions of existing facilities as provided in 40 CFR 258.40.

(2)  Liner designs. All owners or operators of MSWLF units shall use one (1) of the following designs:

(a)  Composite liner design. A liner as provided under 40 CFR 258.40(b) and shall include a leachate collection system as provided under 40 CFR 258.40(a)(2); or

(b)  Alternate liner design. A site-specific design based upon environmental performance, as allowed under 40 CFR 258.40(a)(1) which will ensure that the concentration values listed in table 1, 40 CFR 258.40, or as amended, will not be exceeded in the uppermost aquifer at the relevant point of compliance. This design shall demonstrate consideration of site specific factors as provided in 40 CFR 258.40(c) and shall include a leachate collection system as provided under 40 CFR 258.40(a)(2); or

(c)  Arid design. A site-specific design based upon environmental performance, as allowed under 40 CFR 258.40(a)(1) which will ensure that the concentration values listed in table 1, 40 CFR 258.40, or as amended, will not be exceeded in the uppermost aquifer at the relevant point of compliance. This design shall use both field collected data and predictions that maximize contaminant migration for demonstrating no potential for migration. This design will apply to locations having less than twenty-five (25) inches of precipitation annually, net evaporative losses greater than thirty (30) inches annually, and holding capacity in native soils greater than annual absorbance; and

(i)   solid waste is deposited no less than fifty (50) feet above the seasonal high level of ground water in the uppermost aquifer;

(ii)  the geologic formation beneath the site and above the uppermost aquifer must have capillary capacities greater than the projected maximum volume of leachate generated during the active life of the MSWLF unit; and

(iii) "no potential for migration" is demonstrated when the geologic formation beneath the site and above the uppermost aquifer has sufficient hydrogeological characteristics and holding capacity adequate to contain all hazardous constituents generated during the active life, closure and post-closure care periods.

(3)  Point of compliance. For each MSWLF unit, the relevant point of compliance shall be set by a qualified professional by criteria contained in 40 CFR 258.40(d)(1) through (d)(8), inclusive, subject to approval by the director.

(4)  Leachate discharge shall comply with permitted discharge requirements under the federal clean water act (PL 95-217) and federal storm water discharge regulations (40 CFR part 122).

History:

[39-7409, added 1992, ch. 331, sec. 1, p. 982; am. 1993, ch. 139, sec. 9, p. 355.]