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Subchapter 1 |
Regulations: Title 27, Environmental Protection--Division 2, Solid Waste Chapter 3. Criteria for All Waste Management Units, Facilities, and Disposal Sites |
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Subchapter 2. Siting and DesignArticle 4. SWRCB - Waste Management Unit Construction Standards
(a) Class II waste management units (Class II "Units") shall be designed and constructed to prevent migration of wastes from the Units to adjacent geologic materials, ground water, or surface water, during disposal operations, closure, and the post closure maintenance period. Class II and Class III MSW landfills are also subject to any applicable waste containment system design requirements of SWRCB Resolution No. 93-62 to the extent that such requirements are more stringent than those applicable to a non-MSW Class II or Class III landfill under this subdivision. (b) Each Class II Unit shall be designed and constructed for the containment of the specific wastes which will be discharged. (c) Class III landfills shall have containment structures which are capable of preventing degradation of waters of the state as a result of waste discharges to the landfills if site characteristics are inadequate. (d) For the purposes of this paragraph, the words "new" and "existing" have the same meaning as described in section 20080(d). New landfills, waste piles, and surface impoundments shall comply with the requirements of this article. Existing waste piles and surface impoundments shall be fitted with liners and leachate collection and removal systems as described in section 20330 and section 20340 as feasible. Existing landfills and waste piles shall have interim cover as described in section 20705. Existing landfills, waste piles, and surface impoundments shall be fitted with subsurface barriers as described in section 20360 as needed and feasible, and shall have precipitation and drainage control facilities as described in section 20365. Existing surface impoundments shall comply with section 20375. New and existing land treatment units shall comply with section 20377. All existing Units shall comply with the seismic design criteria in section 20370. (e) Containment structures shall be designed by, and construction shall be supervised and certified by, a registered civil engineer or a certified engineering geologist. Units shall receive a final inspection and approval of the construction by RWQCB or SWRCB staff before use of the Unit commences. (f) The discharger shall maintain the integrity of containment structures in spite of normal excavation or fire control work; nevertheless, for fire control work, the discharger can damage containment structures to the extent necessary to control the fire, so long as the discharger promptly repairs such damage after extinguishing the fire. Excavations made as part of discharge operations shall not result in removal of any portion of a containment structure. (g) Stability Analysis For any portions of the Units containment system installed after July 18, 1997, for which the RWQCB has not approved a slope and foundation stability report on or before that date, the discharger shall meet the requirements of section 21750(f)(5). Note:
(a) Material Properties Materials used in containment structures shall have appropriate chemical and physical properties to ensure that such structures do not fail to contain waste because of pressure gradients (including hydraulic head and external hydrogeologic forces), physical contact with the waste or leachate, chemical reactions with soil and rock, climatic conditions, the stress of installation, or because of the stress of daily operation. (b) Applicable Permeants Hydraulic conductivities specified for containment structures other than cover shall be relative to the fluids, including waste and leachate, to be contained. Hydraulic conductivities specified for final cover shall be relative to water. (c) Determining Hydraulic Conductivity Hydraulic conductivities shall be determined primarily by appropriate field test methods in accordance with accepted civil engineering practice. The results of laboratory tests with both water and leachate, and field tests with water (e.g., on the test pad), shall be compared to evaluate how the field permeabilities will be affected by leachate. It is acceptable for the discharger to use appropriate compaction tests in conjunction with laboratory hydraulic conductivity tests to determine field permeabilities as long as a reasonable number of field hydraulic conductivity tests are also conducted (e.g., a sealed double-ring infiltrometer test on the test pad). (d) Soils Used in Containment Structures Earthen materials used in containment structures other than cutoff walls and grout curtains shall consist of a mixture of clay and other suitable fine grained soils which have the following characteristics, and which, in combination, can be compacted to attain the required hydraulic conductivity when installed. Liners made of such materials are referred to as "clay liners" in this subchapter.
(e) Synopses Construction standards for waste management units other than land treatment are given on Table 4.1 and in Figure 4.1. Note:
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After July 18, 1997, the RWQCB shall require construction for all liner systems and final cover systems to be carried out in accordance with a CQA plan certified by an appropriately registered professional to satisfy the requirements of section 20324. If the RWQCB finds that any construction of the liner system or final cover system was undertaken in the absence of a CQA plan that satisfies the requirements of section 20324, the RWQCB shall require the discharger to undertake any corrective construction needed to achieve such compliance. Note:
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(a) Performance Standard The construction quality assurance (CQA) program, including all relevant aspects of construction quality control (CQC), shall provide evidence that materials and procedures utilized in the placement of the any containment feature at a waste management unit (Unit) will be tested and monitored to assure the structure is constructed in accordance with the design specifications approved by the RWQCB. (b) Professional Qualifications.
(c) Reports.
(d) Documentation Construction quality assurance documentation requirements shall include, at the minimum: reports bearing unique identifying sheet numbers for cross referencing and document control, the date, project name, location, descriptive remarks, the data sheets, inspection activities, and signature of the designated authorities with concurrence of the CQA officer.
(e) Laboratory Testing Requirements. [Note: the following (ASTM) standards are available from the American Society of Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2929, phone: 610-832-9585.]
(f) Field Testing Requirements The following minimum field test procedure shall be performed for each layer in the containment system: ASTM Designation: D 2488 93 [9/93], Standard Practice for Description and Identification of Soils (Visual Manual Procedure), which is incorporated by reference. (g) Test Fill Pad Requirements Before installing the compacted soil barrier layer component of a final cover system, or the compacted soil component of a liner system, the operator shall accurately establish the correlation between the design hydraulic conductivity and the density at which that conductivity is achieved. To accomplish this the operator shall:
(h) Earthen Material Requirements.
(i) Geosynthetic Membrane Requirements.
Note:
(a) Performance Standard Liners shall be designed and constructed to contain the fluid, including landfill gas, waste, and leachate, as required by Article 3 of this subchapter (Section 20240 et seq., and section 20310). (b) Clay Liners Clay liners for a Class II Unit shall be a minimum of 2 feet thick and shall be installed at a relative compaction of at least 90 percent. For a Class III landfill, a clay liner, if required, shall be a minimum of 1 foot thick and shall be installed at a relative compaction of at least 90 percent. For MSW landfills subject to the liner requirements in the federal MSW regulations of 40CFR258, after the Federal Deadline for liners at that Unit, the requirements of this paragraph are superseded by those of SWRCB Resolution No. 93-62 for all portions of the Unit outside the Existing Footprint. (c) FMLs Flexible membrane liners ("FMLs," or synthetic liners) shall have a minimum thickness of 40 mils (i.e., 0.040"). For an MSW landfill subject to the liner requirements in the federal MSW regulations (40CFR258), after the Federal Deadline for liners at that Unit, the requirements of this paragraph are superseded by those of SWRCB Resolution No. 93-62 for all portions of the Unit outside the Existing Footprint. (d) Lined Area Liners shall be installed to cover all natural geologic materials (at the Unit) that are likely to be in contact with waste (including landfill gas or leachate). (e) S.I. With Replaceable Liner A Class II surface impoundment may have a single clay liner with a hydraulic conductivity of 1x10-6 cm/sec (i.e., 1 foot/year) or less if the liner is removed or replaced before the last 25 percent (minimum 1 foot thickness) of the liner is penetrated by fluid, including waste or leachate. The method used to determine seepage velocity shall be included with the calculations of liner penetration. Note:
(a) Basic LCRS Design Leachate collection and removal systems (LCRS) are required for Class II landfills and surface impoundments, and for Class III landfills which have a liner or which accept sewage or water treatment sludge. The LCRS shall be installed directly above underlying containment features for landfills and waste piles, and installed between the liners for surface impoundments. LCRS requirements are summarized on table 4.1. Class II landfills and waste piles which contain only dry wastes (not including nonhazardous solid waste and decomposable waste) may be allowed to operate without an LCRS if the discharger demonstrates, based on climatic and hydrogeologic conditions, that leachate will not be formed in, or migrate from, the Unit; nevertheless, for a Class II or Class III MSW landfill, after the Federal Deadline for installing liners at that Unit, the LCRS requirements of SWRCB Resolution No. 93-62 apply to all portions outside of the Units Existing Footprint. (b) Placement Except as otherwise provided in (e or f), where an LCRS is used, it shall be installed immediately above the liner (except in the case of a surface impoundment), and between the inner and outer liner of a double liner system, and shall be designed, constructed, maintained, and operated to collect and remove twice the maximum anticipated daily volume of leachate from the Unit. (c) Head Buildup The RWQCB shall specify design and operating conditions in WDRs to ensure that there is no buildup of hydraulic head on the liner. The depth of fluid in the collection sump shall be kept at the minimum needed to ensure efficient pump operation. (d) Clogging LCRSs shall be designed and operated to function without clogging through the scheduled closure of the Unit and during the post closure maintenance period. The systems shall be tested at least annually to demonstrate proper operation. The results of the tests shall be compared with earlier tests made under comparable conditions. (e) Standard LCRS LCRSs shall consist of a permeable subdrain layer which covers the bottom of the Unit and extends as far up the sides as possible, (i.e., blanket type) except as provided in (f). The LCRS shall be of sufficient strength and thickness to prevent collapse under the pressures exerted by overlying wastes, waste cover materials, and by any equipment used at the Unit. (f) Alternative LCRS Except as otherwise required for MSW landfills, under SWRCB Resolution No. 93-62, if a Class III landfill is required to have an artificial liner and receives only permeable waste that allows free drainage of percolating fluid, the RWQCB can allow the use of a dendritic LCRS which underlies less than 100 percent of the waste; in this type of LCRS system, only wastes which have an hydraulic conductivity which approximates that of subdrain material, and which will remain permeable throughout the active life and post closure maintenance period of the landfill, shall be placed adjacent to the liner. Furthermore, to prevent ponding, when using this type of LCRS, all portions of the liner not overlain by a portion of the subdrain system shall be sloped towards the subdrain so that ponding is minimized and leachate is removed as quickly as possible from the base of the landfill. (g) Leachate Handling Except as otherwise provided under SWRCB Resolution No. 93-62 (for MSW landfills subject to 40CFR258.28), collected leachate shall be returned to the Unit(s) from which it came or discharged in another manner approved by the RWQCB. Collected leachate can be discharged to a different Unit only if:
(h) Leachate Production Rate After July 18, 1997, for a landfill equipped with an LCRS, the discharger shall note, as a part of each regularly scheduled monitoring report [under Article 1, Subchapter 3, Chapter 3 of this division (section 20380 et seq.)], the total volume of leachate collected each month since the previous monitoring report. Note:
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(a) Subsurface barriers are cutoff walls or grout curtains which are used in conjunction with natural geologic materials to assure that lateral hydraulic conductivity standards specified in Article 3 of this subchapter are satisfied. Paragraphs (b) and (c) specify conditions under which cutoff walls and grout curtains, respectively, are used. (b) Cutoff walls.
(c) Grout Curtains.
Note: Reference:
(a) General Units and their respective containment structures shall be designed and constructed to limit, to the greatest extent possible, ponding, infiltration, inundation, erosion, slope failure, washout, and overtopping under the precipitation conditions specified in table 4.1 (of this article) for each class of waste management unit (Unit). [Note: see also section 21090(b)(1).] (b) Undiverted Precipitation Precipitation on landfills or waste piles which is not diverted by covers or drainage control systems shall be collected and managed through the leachate collection and removal system, which shall be designed and constructed to accommodate precipitation conditions specified in table 4.1 of this article or each class Unit. (c) Performance Standards Diversion and drainage facilities shall be designed, constructed, and maintained:
(d) Maintain Capacity Collection and holding facilities associated with precipitation and drainage control systems shall be emptied immediately following each storm or otherwise managed to maintain the design capacity of the system. (e) Divert Drainage Surface and subsurface drainage from outside of a Unit shall be diverted from the Unit. (f) Resist Erosion from Design Storm Cover materials shall be graded to divert precipitation from the Unit, to prevent ponding of surface water over wastes, and to resist erosion as a result of precipitation with the return frequency specified in table 4.1 (of this article) for each class of Unit, unless, for a landfill, the CIWMB/EA requires (for protection of public health and safety) that the design be capable of resisting erosion resulting from a longer return interval storm [see Section 21150(b)]. Any drainage layer in the final cover shall be designed and constructed to intersect with the final drainage system for the Unit in a manner promoting free drainage from all portions of the drainage layer. Note: Reference:
(a) Class II Units shall be designed to withstand the maximum credible earthquake (MCE) without damage to the foundation or to the structures which control leachate, surface drainage, or erosion, or gas. Class III Units shall be designed to withstand the maximum probable earthquake (MPE) without damage to the foundation or to the structures which control leachate, surface drainage, or erosion, or gas. [Note: see also submittal requirements under section 21750(f)(5)] Note:
(a) Freeboard Surface impoundments shall have sufficient freeboard to accommodate seasonal precipitation and the design storm specified in table 4.1 of this article, but in no case less than 2 feet (measured vertically, from the water surface up to the point on the surrounding lined berm, or dike, having the lowest elevation), and shall be designed and constructed to prevent overtopping as a result of wind conditions likely to accompany such precipitation conditions. The RWQCB can allow a freeboard of less than 2 feet at surface impoundments located on the interior portions of a waste management facility where:
(b) Operation Plan An operation plan shall be submitted to the RWQCB which will provide operation levels and waste input quantities permitted each month based on anticipated precipitation and on past precipitation conditions for the year. (c) Fail-Safe Direct pipeline discharge to surface impoundments shall be either equipped with devices or shall have fail safe operating procedures to prevent overfilling. Discharges shall be stopped in the event of any containment system failure which causes a threat to water quality. (d) Unauthorized Discharges There shall be no discharge from a surface impoundment except as authorized by WDRs. (e) Scour Protection Surface impoundments shall be designed and constructed to prevent scouring of containment structures at points of discharge into the impoundments and by wave action at the waterline. (f) Liner Inspections All visible portions of synthetic liners shall be inspected weekly until all free liquid is removed from the surface impoundment as part of closure pursuant to section 21400(a). If, during the active life of the impoundment, the wastes are removed and the bottom of the impoundment is cleaned down to the liner, an inspection shall be made of the bottom of the liner prior to refilling of the impoundment. Note:
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(a) General Dischargers operating LTUs shall comply with the general criteria specified in Section 20320(a & d), with the precipitation and drainage controls specified in Section 20365, and with the seismic design criteria in Section 20370. (b) Performance Standard Dischargers shall design, construct, operate, and maintain LTUs to maximize the degradation, transformation, and immobilization of waste constituents in the treatment zone. Dischargers shall design, construct, operate, and maintain units in accord with all design and operating conditions that were used in treatment demonstrations under Section 20250. Note: Reference: |
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Last updated: March 21, 2008 Regulations http://www.ciwmb.ca.gov/Regulations/ Legal Office: dsturges@ciwmb.ca.gov (916) 341-6066 |