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A septic drain field, a septic tank, and associated piping compose a septic system. The drain field typically consists of an arrangement of trenches containing perforated pipes and porous material (often gravel) covered by a layer of soil to prevent animals (and surface runoff) from reaching the wastewater distributed within those trenches. [1]
Unlike the traditional septic system, the aerobic treatment system produces a high quality secondary effluent, which can be sterilized and used for surface irrigation. This allows much greater flexibility in the placement of the leach field, as well as cutting the required size of the leach field by as much as half. [1]
If there is a suitable septic tank in place, pumping the effluent from the tank is the lowest cost option for initial costs. Whether the septic tank is the lowest cost option over time depends on the cost of electricity in the area, how often the tank must be emptied and how much it costs to have the solids pumped out of the tank.
A Allocation of costs is the transfer of costs from one cost item to one or more other cost items. Allowance - a value in an estimate to cover the cost of known but not yet fully defined work. As-sold estimate - the estimate which matches the agreed items and price for the project scope. B Basis of estimate (BOE) - a document which describes the scope basis, pricing basis, methods ...
Orangeburg was a low cost alternative to metal for sewer lines in particular. Lack of strength causes pipes made of Orangeburg to fail more frequently than pipes made with other materials. The useful life for an Orangeburg pipe is about 50 years under ideal conditions, but has been known to fail in as little as 10 years.
In 2011 leaching, both heap leaching and in-situ leaching, produced 3.4 million metric tons of copper, 22 percent of world production. [8] The largest copper heap leach operations are in Chile, Peru, and the southwestern United States. Although heap leaching is a low cost-process, it normally has recovery rates of 60-70%.
A good example of the autoclave leach process can also be found in the metallurgy of zinc. It is best described by the following chemical reaction: [citation needed] 2 ZnS + O 2 + 2 H 2 SO 4 → 2 ZnSO 4 + 2 H 2 O + 2 S. This reaction proceeds at temperatures above the boiling point of water, thus creating a vapour pressure inside the vessel.
Well construction depends on the injection fluid injected and depth of the injection zone. Deep wells that are designed to inject hazardous wastes or carbon dioxide deep below the Earth's surface have multiple layers of protective casing and cement, whereas shallow wells injecting non-hazardous fluids into or above drinking water sources are ...