Idaho § 39-7410 - Standards for design

§ 39-7410. Standards for design

(1) These standards apply to new MSWLF units and lateral expansions of existing facilities as provided in 40 CFR 258.40.

(2) An application shall indicate the liner design that will be used in each phase of construction. All MSWLF units shall use one (1) or more of the following designs, in combination or alone:

(a) A composite liner design, as provided under 40 CFR 258.40(b) that includes a leachate collection system as provided under 40 CFR 258.40(a)(2);

(b) A site-specific alternate liner 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);

(c) A site-specific arid 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 only applies if:

(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;

(iii) No potential for migration is demonstrated; and

(iv) The location has less than twenty-five (25) inches of precipitation annually, net evaporative losses greater than thirty (30) inches annually, and a holding capacity in native soils greater than annual absorbance.

(3) 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), 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).