CORRESPONDENCE_1982-1983 - Laserfiche WebLink

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Forward, Inc. -7- 23 April 1982 production are important factors in the context of Group 2 liquids and refuse, then such factors are all the more critical in the context of "borderline" Group 1 wastes in a Class !I site. As a rule, leachate will not be produced if the waste in place has a moisture content which is less than field capacity. Field capa- city (or specific retention) is the quantity of water retained by a material against the pull of gravity, expressed as volume of water per volume of dry solids. Field capacities for typical soils may range from 4% for sand to 28% for clay. A soil with an "average" texture - i .e. , a loam - would have a field capacity of approximately 24%. Without convincing evidence to the contrary, we believe that the moisture of waste in place should not exceed expected field capacity. Lacking data on actual field capacities at the site, the selection of a Value of 24% as an interim criterion appears — , reasonable and sufficiently conservative. _fIiTs criterion should not be construed as prohibiting disposal of wastes with moisture capacities in excess of 24% ; for example , dewatered sludges typically have a moisture content of approximately 805 yet are not prohibited. Only the total material in place in the trench - for example, the combination of contaminated soil and dewatered sludge - must meet the 24% criterion, assuming uniform distribution.] 11. The following materials are prohibited by the Executive Officer for discharge at the Forward, Inc. , Class H-1 waste disposal site. A. Group 1 wastes riot authorized above. B. Bulk liquids , containerized liquids , or containerized materials containing free liquids in the landfill portion of the site. [The intention is to prevent leachate formation . Containerized liquids are conditionally banned from landfills by the US EPA. Bulk liquids are not prohibited from discharge to solar evaporation ponds.] C. Wastes which could impair the integrity of liner materials.