WorldWide Drilling Resource

23 WorldWide Drilling Resource ® DECEMBER 2013 Outsmarting the Dirt ~ Remediation Part 2 by Thomas D. Dalzell, CWD Director of Environmental Research AMS, Inc. Remedial Investigations/ Remediation, and Site Closure Once a site has been properly char- acterized, a precise and strategic reme- dial investigation can be conducted. For complex lithology above or below the groundwater table, it may be necessary to conduct a detailed and precise reme- dial investigation to collect data a reme- dial engineer can use to develop the RAP (remedial action plan). Depending on the contaminant type, subsurface lithology, and applicable regulatory re- quirements, sometimes a RAP can be developed based on the data collected during an initial EI (environmental drilling investigation). As part of a detailed reme- dial investigation, a pilot study is conduct- ed to determine the radius of influence and the time it takes to affect (remedi- ate) a certain area. The RAP will include, at a minimum, the appropriate course of action for the successful remediation of the site, com- pliance with all applicable regulatory requirements, timeline for completion, verification/confirmation requirements for completion, and a cost-effective de- sign and implementation. This article describes some of the general advantages and basic capabil- ities of direct push for remedial activities. It does not describe the many important details and regulatory requirements need- ed to be taken into account prior to begin- ning any field activities of environmental drilling. The main types of remedial activi- ties are as follows: (1) Pilot studies and remedial injec- tions can be conducted with direct push technology. For remedial injections, the follow- ing are the minimum considera- tions: (a) The proper remedial solu- tion for a specific contaminant and lithology must be selected. (b) Moving/pushing the contam- ination beyond the character- ized extent must be avoided. (c) The remedial injection solu- tion must be injected where it will neutralize or significantly reduce the contamination, so as to not just indiscriminately pump a volume of remedial solution into the ground/subsurface. The following remedial actions are components of conventional remedi- al systems: (2) Installation and use of biologi- cal or chemical treatment injection wells; (3) Vapor extraction wells; (4) Pump and treat wells; and (5) Air-sparge wells. Remedial injections do not require the installation of relatively expensive conventional remediation systems that require ongoing operation and mainte- nance and the associated costs. In addition, there is little or no derived wastes generated with remedial injec- tions. Not every site or subsurface contam- ination can be properly remediated with remedial injections. It is the experience of the remedial engineer, characteristics of the subsurface lithology, requirements of the property owner, and all applicable regulations which should be taken into consideration to determine if remedial injections are appropriate for the site. We will conclude this series next month. Tom Thomas D. Dalzell may be contacted via e-mail at admin@ worldwidedrillingresource.com *0 -4 - $+* .&*+ -'.1&((" +2"- +- /-&0) %+/"( -++). (( *! -"#"- /+ **0 ( +*#"-"* " 0." +!" ")&* -. 3%& &/. ,,4 %+0- ,-&)" -& !&**"- *! 0".! 4 *&$%/ "#+-" /%" +*1"*/&+* +0&.& * -+0*! /"- ..+ & /&+* +*1"*/&+* - !" %+2