WorldWide Drilling Resource

21 WorldWide Drilling Resource ® SEPTEMBER 2013 Environmental Monitoring by Thomas Kwader, Ph.D., P.G. Selecting the Optimum Pumping Rate for Groundwater Plume Capture There are many groundwater reme- diation systems operating for the purpose of recovering contaminated groundwater. The goal is usually to reduce the size of the contaminated plume and/or contain the plume and prevent it from moving further down gradient. For the purpose of this discussion, we will keep it simple and assume the plume is oval in shape and from a single source originating as a spill on top of the ground. To properly design a groundwater recovery well, we need to quantify a num- ber of hydrologic parameters, namely: 1. Extent of the plume, shape, gradient (i), and flow direction. 2. Transmissivity (T) of the water- bearing zone in which the plume i s t r a v e l i n g . T i s u s u a l l y determined by conduc t i ng a pumping test in the water-bearing zone, expressed in units of feet s q u a r e d p e r day (ft 2 /day). A groundwater recovery well should be located at the leading edge of the plume with a mini- mum of a four-inch wel l, screened, or open to at least the bottom half of the aqu i f e r. Cap t u r e width (W), in feet, of a pumping wel l is determined by the equation: W=Q/(T(i)) Q is gallons pumped per day. If we assume a pumping rate of 1 gallon per minute (1440 gallons per day), a trans- missivity of 1000 ft 2 /d and a gradient of 0.01, then: W (feet) = 1440 gallons 1000 ft 2 /d (0.01) W = 144 feet The shape of the plume would look like “U” with the well being in the center of the U and the width being the dis- tance across the top of the U. Note the capture width is very sensitive to the gradient - a “flat” gradient will have a very wide capture area. Also, the ability of the well to pull back the plume (from down gradient) is very limited and is only about 1/6th the length of the width, or in this case about 24 feet. Increasing the pumping rate does not generally speed up the cleanup pro- cess, because the increase in pumping is mainly from additional clean water coming from increasing the width of the capture area. Tom admin@ worldwidedrillingresource.com The ORIGINAL Recycled Ground Protection Mats Adapted from Information by AlturnaMATS, Inc. AlturnaMats was established in 1993 by Jim and Janet Aaron of Franklin, Pennsylvania. Jim was working for a local utility company which used fiberglass mats to access off-road jobsites in the field. These mats were expensive and didn’t hold up to the harsh conditions they faced. Jim believed there had to be a bet- ter way to provide ground stabilization, and he found it! Made from recycled HDPE (high-den- sity polyethylene), A l t u r naMATS are a durable, environmentally- friendly product. In addition to pro- tecting the ground surface fromdam- age, they also prevent rigs from getting stuck, pro- viding practical and safe access to just about any jobsite. Available outrigger pads provide further stabilization. The company was awarded a grant from the Ben Frankl in Technology Partnership based on their innovation and use of recycled plastic. By 1994, the company was awarded a patent for the AlturnaMATS cleat design. Other awards include: % 2003 Governor’s Award - New to Export % 2013 Governor’s Award - Export Impact Award These mats have been tested in record cold and heat and are designed to bend, not break. In addition to locations in the U.S., you will find AlturnaMATS products in Australia, Belgium, Chile, China, Ecuador, France, Germany, Guatemala, Indonesia, Japan, Malaysia, and the UK. The company continually strives to be the best recycled plastic ground protection mat in the market. AlturnaMATS are covered by a limited lifetime warranty!