Land-farming

Land farming has been used extensively to treat soils contaminated with petroleum hydrocarbons, pentachlorophenol (PCP), and polycyclic aromatic hydrocarbons (PAHs), and potentially could be used to treat low to medium concentrations of explosives as well. In land farming, soils are excavated to treatment plots and periodically rototilled to mix in nutrients, 

Another alternative option in the pollution prevention hierarchy is the ultimate disposal. This method mainly consists of land-farming, land-filling, deep-well injection, and ocean-dumping. 

The oldest, simplest, easiest, and safest waste disposal method is landfarming. The wastes are dumped on a land to be stabilized by natural environmental processes. The wastes, mainly containing organics especially from food and petroleum industries, are dumped by this method. 

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When available land space is insufficient for land farming, soil treatment can be carried out in piles or pits. Typical biopile and biopit constructions are presented in Figure 14.8 and Figure 14.9, respectively. When the soil has relatively low permeability, the pile can be constructed with sequential lifts of soil, approximately 60 cm in thickness, separated by permeable sand layers. These layers are connected with a vacuum pump or blower that is used to produce airflow though the soil pile. Water and nutrients are sprinkled on the top of the pile. 

Land farming. This is a solid-phase treatment system for contaminated soils it may be carried out in situ or ex situ. 

Landau-Fermi liquid, 23 840 Landau quasiparticle model, 23 840 Land cost, 9 527 Landering, 8 438-439 Land-farming, 3 768 defined, 3 759t Landfill gas, 25 880 Landfill leachate treatment, reverse osmosis in, 21 646-647 Landfill liners, 25 877-878... 

Land disposal. Land disposal Is the most widely used, least expensive, most often available disposal system at the present time. The term land disposal Includes sanitary landfills, surface Impoundments, evaporation ponds and land farming. Land disposal In a sanitary landfill, specially permitted to accept such wastes, can be expected to be the method of choice for the majority of the label statements proposed. Empty containers, waste pesticides and other wastes are commonly disposed of In a sanitary landfill or burled at the site of use. 

Drilling muds are fluids that are pumped into the bore holes to aid in the drilling process. Most are water based and contain barite, hgnite, chrome lignosulfate, and sodium hydroxide [11], but oil-based drilling muds are still used for economic and safety reasons [12]. Used muds can be removed by vacuum trucks, pumped down the well annulus, or allowed to dewater in pits, which are then covered with soil or disposed of by land farming. 

Bates, M.H. Land farming of reserve pit fluids and sludges Fates of selected contaminants. Wat. Res. 

The composting system effectively remediates soils that are heavily contaminated and cannot be treated by in situ methods as well as wastes containing hazardous volatile constituents untreatable by land farming methods. 

The process of drilling for crude oil and natural gas generates waste drilling fluids or muds, which are often disposed of by land farming. Most of these fluids are water based and contain barite and other metal salts. Thus barium may be introduced into soils as the result of land farming these slurried reserve pit wastes (Bates 1988). 

Barium added to soils (e.g., from the land farming of waste drilling muds) may either be taken up by vegetation or transported through soil with precipitation (Bates 1988). Relative to the amount of barium found in soils, little is bioconcentrated by plants (Schroeder 1970). However, this transport pathway has not been comprehensively studied. 

Disposals The final placement or destruction of toxic, radioactive, or other wastes surplus or banned pesticides or other chemicals polluted soils and drums containing hazardous materials from removal actions or accidental releases. Disposal may be accomplished through use of approved secure landfills, surface impoundments, land farming, deep-well injection, ocean dumping, or incineration... 

On the other hand, other hydrocarbon-rich materials (e.g., sediment contaminated with PCP, creosote, and bunker oil) are not readily destroyed by land farming. 

To identify air emission sources, the study team utilized a variety of measurement techniques. Table III summarizes the different techniques used to define the airborne emissions. Emissions from sewer vents, water ponds, the inactive land-farm, and oil/water separator were measured directly (Amoco/EPA, 1991c). In general, mass balance techniques are not sufficiently accurate for most inventory calculations (NRC, 1990). However, since their flow rates were small, easily measurable, and reasonably constant over time, mass balances and inlet/outlet water analyses were used to determine emissions from the cooling tower and wastewater tanks. 

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