China
Africa
Explore chapters and articles related to this topic
Selection of Site and System
Published in Richard J. Perkins, Onsite Wastewater Disposal, 1989
There is one phenomenon which must be considered when using the percolation rate measured in sandy soils to size a drain field. Initial percolation through coarse sand is quite rapid. In fact, doses of sewage effluent are able to move down through the sand as clouds of saturation, and receive little treatment. However, over a period of several months, the bacterial slime layer that accumulates at the bottom of the disposal trench slows the percolation of wastewater so that it seeps through over a longer period of time, allowing unsaturated conditions below the drain field and more efficient cleansing. This slower percolation rate requires a larger drain field than would be indicated by the percolation test. The specific loading rates allowable for various sands are discussed in the chapter on sand filters, and it is sufficient to mention here that a loading rate of 1.2 gallons of effluent per square foot of trench bottom surface per day should not be exceeded with subsurface absorption systems.
Sewage Disposal Systems
Published in Herman Koren, Best Practices for Environmental Health, 2017
The three basic types of tests used to determine whether or not soil is suitable for a septic tank system are: the percolation test (perc test), soil core analysis, and backhoe cuts to a maximum depth of 12 feet. The percolation test consists of digging a series of holes in the area of the effluent distribution field, prewetting the inside of the holes, adding a measured amount of new water to the holes, and then measuring how fast the water flows out. (See endnote 1 for total details of an acceptable procedure.) Core sample analysis consists of digging a hole to remove a core sample of the various soil layers and taking it back to a laboratory for analysis or digging a deep hole with a machine typically 7–10 feet deep or more and looking at the sides of the hole for variations in color and types of soils. This will indicate the drainage characteristics of that particular piece of land at the hole. The backhoe cut is made into good holes 25 feet apart. It is necessary in order to get a permit to demonstrate at least 4 feet of sand, sandy loam, or loam which is 4 feet above the seasonally high water table as determined by soil conditions. Where clay is encountered first and then sand still 4 feet above the seasonally high water table, 50% of the clay could be removed and replaced with clean sand which creates a conduit to the virgin sand below. In this type of test especially it is very important for the individuals conducting the tests, whether it be the local environmental health practitioner or others who are certified, to wear hard hats and special boots, and stay away from the perimeter of the hole to prevent a cave in and significant damage or death to the individual.
MSWI BA treated with Advanced Dry Recovery: a field scale study on materials’ leaching properties
Published in International Journal of Sustainable Engineering, 2018
Laura Annika Sormunen, Tommi Kaartinen, Riina Rantsi
Table 3 summarises the L S−1 ratios (L kg−1) and concentrations of the analysed substances at the beginning and at the end of the laboratory and both field tests. At the end of the sampling period, the achieved L S−1 ratios (L kg−1) were 1.6 and 0.13 for the lysimeter and interim storage field site, respectively (Table 3). In the laboratory percolation test, an L S−1 (L kg−1) of up to 1.5 was taken for comparison even though the test was continued up to an L S−1 (L kg−1) of 10. This was because such an L S−1 (L kg−1) was too high to be compared with the L S−1 (L kg−1) obtained in the field studies within the given sampling period. As mentioned in chapter 2.3, the lysimeter study is still ongoing, and more data will be collected in order to make comparisons between laboratory and lysimeter studies with higher L S−1 (L kg−1) in the future.
Communicating environmental information: rethinking options for construction products
Published in Building Research & Information, 2019
Benjamin Ströbele, Thomas Lützkendorf
In this context, a standardization initiative within the Technical Committee CEN TC 351: Construction Products – Assessment of Release of Dangerous Substances (CEN, 2018) was dedicated to the development of horizontal standardized assessment procedures for the release (and/or the content, if applicable or required by law) of regulated hazardous substances in accordance with the Construction Products Directive, taking into account the intended use of the product. This applies to emissions into indoor air as well as releases to the soil, surface water and groundwater. A comprehensive group of standards is now available (CEN, 2018), for example: CEN/TR 17105: Construction Products – Assessment of Release of Dangerous Substances – Guidance on the Use of Ecotoxicity Tests Applied to Construction Product (CEN, 2017)CEN/TS 16637-1: Construction Products – Assessment of Release of Dangerous Substances – Part 1: Guidance for the Determination of Leaching Tests and Additional Testing Steps (CEN, 2014a)CEN/TS 16637-2: Construction Products – Assessment of Release of Dangerous Substances – Part 2: Horizontal Dynamic Surface Leaching Test (CEN, 2014b)CEN/TS 16637-3: Construction Products – Assessment of Release of Dangerous Substances – Part 3: Horizontal Up-Flow Percolation Test (CEN, 2016)EN 16516: Construction Products: Assessment of Release of Dangerous Substances – Determination of Emissions into Indoor Air (EN, 2017)