340-095-0030 Design Criteria (1) Except as otherwise provided in OAR 340, division 95, any person who designs, constructs, expands or modifies any non-municipal land disposal site must do so in conformance with the design requirements of this rule. (2) Plan Design Requirements. Unless an exemption has been granted under OAR 340-093-0070(4), in addition to the requirements of OAR 340-093-0070, detailed plans and specifications for non-municipal land disposal sites shall include but not be limited to: (a) Topographic maps which show natural features of the site; the location and design of all pertinent existing and proposed structures, such as berms, dikes, surface drainage control devices, access and on-site roads, water and waste water facilities, gas control devices, monitoring wells, fences, utilities, maintenance facilities, shelter and buildings; legal boundaries and property lines, and existing contours and projected finish grades. Unless otherwise approved by the Department, the scale of the plan drawings shall be no greater than one inch equals 200 feet, with contour intervals not to exceed five feet. Horizontal and vertical controls shall be established and tied to an established bench mark located on or near the site. Where the Department deems it essential to ensure compliance with OAR 340, divisions 93 and 95, the bench mark shall be referenced to the Oregon State Plane Coordinate System, Lambert Projection; (b) If a landfill, a minimum of two perpendicular cross section drawings through the non-municipal land disposal site. Each cross section shall illustrate existing grade, excavation grade, proposed final grade, any additions for groundwater protection, water table profile and soil profile. Additional cross sections shall be provided as necessary to adequately depict underlying soils, geology and landfill contours, and to display the design of environmental protection devices or structures; (c) A description of the design assumptions and methods used to forecast flows and to determine the sizing of pumps, pipes, ditches, culverts and other hydraulic equipment used for the collection, treatment and disposal of leachate and for the control of surface drainage; (d) A detailed operations plan pursuant to OAR 340-095-0020(3) and timetable which describes the proposed method of operation and progressive development of the non-municipal land disposal site, such as trenches and/or landfill lifts or cells. (3) Leachate. Any person designing or constructing a non-municipal land disposal site shall ensure that leachate production is minimized. Where required by the Department, leachate shall be collected and treated or otherwise controlled in a manner approved by the Department. Leachate storage treatment impoundments shall be located, designed, constructed and monitored, at a minimum, to the same level of environmental protection as the land disposal site. (4) Gas Control. No person shall establish, expand or modify a non-municipal land disposal site such that: (a) The concentration of methane (CH4) gas at the landfill exceeds 25 percent of its lower explosive limit in facility structures (excluding gas control or gas recovery system components) or its lower explosive limit at the property boundary; (b) Malodorous decomposition gases become a public nuisance. (5) Surface Drainage Control. Each permittee shall ensure that the non-municipal land disposal site is designed and constructed so that drainage will be diverted around or away from active and completed operational areas. Statutory/Other Authority: ORS 459.045, 459A.100 - 459A.120 & 468.020 Statutes/Other Implemented: ORS 459.015 & 459.045 History: DEQ 10-1994, f. & cert. ef. 5-4-94 DEQ 5-1993, f. & cert. ef. 3-10-93, Renumbered from 340-061-0040 DEQ 2-1984, f. & ef. 1-16-84 DEQ 26-1981, f. & ef. 9-8-81 DEQ 41, f. 4-5-72, ef. 4-15-72