"This report provides technical background for use by permittees, designers, specifiers, quality assurance engineers, and permit writers for hazardous waste disposal facilities. The document addresses the quality control aspects of construction, operation, and closure of a hazardous waste disposal facility. (It is assumed that the quality control aspects of site selection, characterization, and design have already been dealt with.) The permittee's responsibilities during construction, operation, and closure of a hazardous waste disposal facility are discussed with regard to four topics: (1) geotechnical parameters that should be tested or observed, (2) selection of sampling plans and sample sizes for the geotechnical parameters, (3) laboratory and field testing methods for investigating geotechnical parameters, and (4) a quality assurance program suited to the unique responsibilities of the permittee. Types of facilities covered by the report include landfills (burial sites), surface impoundments, waste piles, and land treatment units. Land farms, injection wells, and seepage facilities are not included."