Design and Operating Requirements

(1) Except as provided in 310 CMR 30.613(4), each surface impoundment shall be underlain by two liners which are designed and constructed in a manner that prevents the migration of liquids into or out of the space between the liners. The liners shall be designed, constructed, and installed to prevent anymigration of wastes out of the impoundment to the adjacent groundwater, surface water, or subsurface soil at any time during the active life and during the closure period of the impoundment. The liners may be constructed of materials (e.g., clays and admixes) that allow waste to migrate into the liners themselves, but not into the space between the liners or into the adjacent groundwater, surface water, or subsurface soil during the active life of the facility provided that the impoundment is closed in compliance with 310 CMR 30.617(1). Each liner shall be: (a) of a hydraulic conductivity not to exceed 1 x 10-7 cm/sec; (b) constructed of materials that have appropriate chemical properties and sufficient strength and thickness to prevent failure due to pressure gradients, including static head and external hydrogeologic forces, physical contact with the waste or leachate to which they are exposed, climatic conditions, exposure to ultraviolet light, ozone, microbes, the stress of installation, and the stress of daily operation, including the use of machinery and equipment upon the liner after installation; (c) placed upon a foundation or base capable of providing support to the liner and resistance to pressure gradients above and below the liner due to settlement, compression or uplift; rocks, boulders, irregularities with sharp edges, and all material that may damage the liner shall be removed from the subgrade prior to installation of the liner; and (d) installed to cover all surrounding earth likely to be in contact with the waste or leachate. (2) The bottom liner shall be at least four feet above the probable high groundwater level as determined pursuant to 310 CMR 30.675. This shall not prohibit the owner or operator from carrying out design and operating procedures which artificially lower the groundwater table throughout the operating life of the facility, provided that the facility's license specifically authorizes this. (3) A leak detection, collection, and removal system shall be designed, constructed, maintained and operated between the liners to detect, collect, and remove any discharge of liquid into the space between the liners. The detection, collection and removal system shall be designed, constructed, operated and maintained so that leakage flows freelyfrom the collection system and is removed either as it accumulates or with sufficient frequency to prevent backwater within the collection system. If liquid leaks into the leak detection, collection, and removal system, the owner or operator shall: (a) Notify the Department of the leak immediately by the quickest available means and also notify the Department in writing within seven days; and (b) Within a period of time which shall be specified by the Department, remove accumulated liquid, repair or replace the liner which is leaking to prevent the migration of liquids through the liner, and obtain a certification from an independent Massachusetts registered professional engineer that, to the best of his knowledge and opinion, the leak has been stopped. If the leakage which is collected is identified as hazardous waste pursuant to 310 CMR 30.100, it shall be managed as hazardous waste in compliance with 310 CMR 30.000. (4) The direct discharge onto a liner of hazardous waste or other material shall not be allowed to occur without adequate provision having been made for energy dissipation. (5) Each surface impoundment shall be designed, constructed, maintained and operated to prevent overtopping resulting from normal or abnormal operation, overfilling, wind and wave action, precipitation, run-on, malfunction of level controllers, alarms or other equipment, or human error. (6) Each surface impoundment shall be designed, constructed, operated and maintained to provide at least 60 centimeters (two feet) of freeboard. The design shall reflect a consideration of the difference between the precipitation and evaporation anticipated for the area. (7) Each surface impoundment shall be designed, constructed and maintained so that any flow of waste into the impoundment can be immediately shut off in the event of overtopping or liner failure. (8) Run-on shall be diverted away from a surface impoundment. Diversion systems shall have the capacity to handle the run-on during peak discharge from 24-hour, 100-year storm. (9) Each surface impoundment shall have dikes that are designed, located, constructed and maintained with sufficient structural integrity to prevent failure of the dikes. In ensuring structural integrity, the owner or operator shall not presume that the liner system will function without leakage during the active life of the impoundment. Each earthen dike shall be kept free of perennial woody plants with root systems which could displace the earthen material upon which the structural integrity of the dike is dependent and free of burrowing animals which could remove earthen material upon which the structural integrity of the dike is dependent. Each earthen dike shall have a protective cover, such as grass, shale or rock, to minimize wind or water erosion and to preserve the structural integrity of the dike. (10) Completely surrounding each impoundment shall be a barrier (e.g., a fence in good repair) designed to prevent accidental contact between persons at the facility site and hazardous waste in the surface impoundment. This barrier shall be in addition to the barrier required by 310 CMR 30.514(2)(b)3. Posted on or near such barrier shall be at least one sign, the lettering of which shall be legible from a distance of at least 25 feet. The sign shall: (a) Identify the contents of the surface impoundment as "Hazardous Waste"; (b) Identify, in words, the contents of the surface impoundment; and (c) Identify, in words, the hazard(s) associated with the hazardous waste.