Chapter 3. Criteria for All Waste Management Units, Facilities, and Disposal Sites
Subchapter 2. Siting and Design
Article 3. Waste Management Unit, Facility, or Disposal Site Classification and Siting
Section 20240. SWRCB - Classification and Siting Criteria. (C15: section 2530)
(a) Units and Facilities Waste management units (Units) shall be classified according to their ability to contain wastes. Containment shall be determined by geology, hydrology, topography, climatology, and other factors relating to the ability of the Unit to protect water quality. A waste management facility can consist of several Units each with a different classification. Classification of Units shall be based on the criteria contained in this article, on field inspections by RWQCB and SWRCB staffs, and on other pertinent information. Information used to classify Units shall be submitted according to the provisions of Article 4, Subchapter 3, Chapter 4 of this subdivision (section 21710 et seq.). Owners or operators of classified Units shall comply with waste discharge requirements (WDRs) adopted by the RWQCB.
(b) ReclassificationExisting Units shall be reclassified according to applicable criteria in this article, provided that such Units:
(1) comply with siting criteria for each category of existing Units in section 20250 and section 20260, and summarized in table 3.1 of this article; and
(2) are operating in compliance with section 20080(d).
(c) Five-Foot Separation All new landfills, waste piles, and surface impoundments shall be sited, designed, constructed, and operated to ensure that wastes will be a minimum of five feet (5 ft.) above the highest anticipated elevation of underlying ground water. Existing landfills, waste piles, and surface impoundments shall be operated to ensure that wastes will be a minimum of five feet (5 ft.) above the highest anticipated elevation of underlying ground water. For new and existing land treatment units, the base of the treatment zone shall be a minimum of five feet (5 ft.) above the highest anticipated elevation of underlying ground water and dischargers shall not be entitled to exemption under section 20080(b).
(d) Unit Foundation All engineered structures (including, but not limited to, containment structures) constituting any portion of a Unit shall have a foundation or base capable of providing support for the structures, and capable of withstanding hydraulic pressure gradients to prevent failure due to settlement, compression, or uplift and all effects of ground motions resulting from at least the maximum probable earthquake [for Class III Units (see section 20370)] or the maximum credible earthquake [for Class II Units (see section 20370)], as certified by a registered civil engineer or certified engineering geologist. [Note: see also section 21750(f)(5).]
Section 20250. SWRCB - Class II: Waste Management Units for Designated Waste. (C15: Section 2532)
(a) General Class II waste management units (Class II Units) shall be located where site characteristics and containment structures isolate waste from waters of the state. The classification criteria in this section shall be used for reclassification of existing Units at disposal sites approved as Class II 1 under previous versions of these SWRCB regulations, and for existing Units used for treatment or for storage, whether or not classified, provided that no hazardous wastes other than those which DTSC has determined need not be discharged as a hazardous waste) have been discharged at such Units (including discharge at any expansion of such Units).
(b) Geologic Setting.
(1) New and existing Class II landfills or waste piles shall be immediately underlain by natural geologic materials which have a hydraulic conductivity of not more than 1x10-6 cm/sec (i.e., 1 foot/year) and which are of sufficient thickness to prevent vertical movement of fluid, including waste and leachate, from Units to waters of the state for as long as wastes in such units pose a threat to water quality. Class II units shall not be located where areas of primary (porous) or secondary (rock opening) hydraulic conductivity greater than 1x10-6 cm/sec (i.e., 1 foot/year) could impair the competence of natural geologic materials to act as a barrier to vertical fluid movement.
(2) Natural or artificial barriers shall be used to prevent lateral movement of fluid, including waste and leachate.
(3) A liner system which conforms to the requirements of Article 4 of this subchapter with a hydraulic conductivity of not more than 1x10-6 cm/sec (i.e., 1 foot/year) shall be used for landfills and waste piles when natural geologic materials do not satisfy the requirements in (b)(1).
(4) Class II surface impoundments are not required to comply with the requirements of (b)(1), but shall have a liner system designed in accordance with the applicable SWRCB-promulgated provisions of Article 4 of this subchapter (Section 20310 et seq.). The RWQCB can allow Class II surface impoundments which are designed and constructed with a double liner system in accordance with that article to use natural geologic materials which comply with (b)(1) for the outer liner.
(5) Land treatment units (LTUs) are not required to comply with the requirements of (b). Dischargers who treat or dispose of wastes in LTUs shall demonstrate, prior to application of the waste, that waste can be completely degraded, transformed, or immobilized in the treatment zone. To demonstrate this, prior to the application of waste, the discharger shall operate a test plot for a sufficient period to give the RWQCB a reasonable indication that degradation, transformation, or immobilization will take place in the treatment zone. During the full scale operation of the LTU, soil and soil pore liquid samples shall be taken within the treatment zone to verify that complete degradation, transformation, or immobilization is taking place. The RWQCB shall specify in WDRs the elements of the land treatment program including the dimensions of the treatment zone. The maximum depth of the treatment zone shall not exceed 5 feet from the initial soil surface.
(c) Flooding New and existing Class II Units shall be designed, constructed, operated, and maintained to prevent inundation or washout due to floods with a 100 year return period. MSW landfills are also subject to any more-stringent flood plain and wetland siting requirements referenced in SWRCB Resolution No. 93-62 (i.e., see Section 258.11 and Section 258.12 of 40CFR258).
(d) Ground Rupture New Class II Units, other than LTUs and expansions of existing Class II units, shall have a 200 foot setback from any known Holocene fault. Other units (that are subject to this section)can be located within 200 feet of a known Holocene fault, provided the RWQCB finds that the Units containment structures are capable of withstanding ground accelerations associated with the maximum credible earthquake.
(e) Rapid Geologic Change New and existing Class II Units can be located within areas of potential rapid geologic change only if the RWQCB finds that the Units containment structures are designed, constructed, and maintained to preclude containment failure. MSW landfills are also subject to any more-stringent unstable area siting requirements referenced in SWRCB Resolution No. 93-62 (i.e., see Section 258.15 and Section 258.16 of 40CFR258).
(f) Tidal Waves New and existing Class II Units may be located in areas subject to tsunamis, seiches, and surges. Other Units may be located within these areas if designed, constructed, and maintained to preclude failure due to such events.
Section 20260. SWRCB - Class III: Landfills for Nonhazardous Solid Waste. (C15: Section 2533)
a) General Class III landfills shall be located where site characteristics provide adequate separation between nonhazardous solid waste and waters of the state. The classification criteria in this section shall be used for reclassification of existing landfills at disposal sites approved as Class II-1 or II-2 (under previous versions of these SWRCB regulations) and any expansions of such landfills.
(b) Geologic Setting.
(1) MSW landfills are subject to the SWRCB-promulgated waste containment requirements of this subdivision and of SWRCB Resolution No. 93-62. New Class III and existing Class II-2 landfills shall be sited where soil characteristics, distance from waste to ground water, and of water beneath or adjacent to the landfill. Factors that shall be evaluated include:
factors will ensure no impairment of beneficial uses of surface water or of ground
(A) size of the landfill:
(B) hydraulic conductivity and transmissivity of underlying soils;
(C) depth to ground water and variations in depth to ground water;
(D) background quality of ground water;
(E) current and anticipated use of the ground water; and
(F) annual precipitation.
(2) Where consideration of the factors in (b)(1) indicates that site characteristics alone do not ensure protection of the quality of ground water or surface water, Class III landfills shall be required to have a single clay liner with hydraulic conductivity of 1x10-6 cm/sec or less.
(c) Flooding New Class III and existing Class II-2 landfills shall be designed, constructed, operated, and maintained to prevent inundation or washout due to floods with a 100 year return period. MSW landfills are also subject to any more-stringent flood plain and wetland siting requirements referenced in SWRCB Resolution No.93-62 (i.e., see Sections 258.11, 258.12, and 258.16 of 40CFR258).
(d) Ground Rupture New Class III and expansions of existing Class II-2 landfills shall not be located on a known Holocene fault. However, existing landfills assigned a Class II-2 designation under previous versions of the SWRCB regulations may be located on a known Holocene fault, provided that the Units containment structures are capable of withstanding ground accelerations associated with the maximum probable earthquake (see Section 20370).
(e) Rapid Geologic Change New Class III and unreclassified existing Class II-2 landfills can be located within areas of potential rapid geologic change only if the RWQCB finds that the Units containment structures are designed, constructed, and maintained to preclude failure. MSW landfills are also subject to any more-stringent unstable area siting requirements referenced in SWRCB Resolution No. 93-62 (see section 258.15 and Section 258.16 of 40CFR258).
Section 20270. CIWMB - Location Restrictions: Airport Safety. (T14:Section 17258.10)
(a) Owners or operators of new Municipal Solid Waste Landfill units (MSWLF), existing MSWLF units, and lateral expansions of MSWLF units that are located within 10,000 feet (3,048 meters) of any airport runway end used by turbojet aircraft or within 5,000 feet (1,524 meters) of any airport runway end used by only piston-type aircraft must demonstrate that the units are designed and operated so that the MSWLF unit does not pose a bird hazard to aircraft.
(b) Owners or operators proposing to site new MSWLF units and lateral expansions located within a five-mile radius of any airport runway end used by turbojet or piston-type aircraft must notify the affected airport and the Federal Aviation Administration (FAA).
(c) The owner or operator must place the demonstration made pursuant to paragraph (a) of this section in the operating record and notify the EA that it has been placed in the operating record.
(d) Existing MSWLF units that cannot make the demonstration specified in section 20270(a) pertaining to airports must:
(1) close by October 9, 1996, in accordance with section 21110 of this article;
(2) conduct postclosure activities in accordance with section 21110 of this article; and
(3) conduct closure and postclosure activities in accordance with applicable sections of Chapter 4, and Chapter 6, of this Division.
(e) The deadline for closure required by paragraph (a) of this section may be extended up to two years if the owner or operator demonstrates to the CIWMB that:
(1) There is no available alternative disposal capacity; and
(2) There is no immediate threat to human health and the environment.