In relation to drilling of soil borings at contaminated sites, it is necessary to consider the disposal of extracted material (detritus). Since disposing of contaminated soil during drilling activities might be expensive, it is convenient to separate uncontaminated soil from potentially contaminated soil. If there is any doubt whether soil is contaminated or not, it should be considered contaminated and treated accordingly. Consequently, final decisions regarding solid waste disposal will depend on previous soil analyses results.
Non-hazardous media (drill cuttings/soil/sediment):
- can be deposited in a landfill
- can be returned to the site of original removal
- must not be allowed to be used as fill on other areas of the site or off site, unless the media is not mixed with other solid waste and does not have the potential to cause contamination that may threaten human health or the environment.
Hazardous waste can be:
- deposited in an in situ security cell, if present
- containerized when generated and treated accordingly in a processing plant
Drill core samples are normally kept in boxes until the investigation phase has finished in case revision is necessary. During this time, the boxes have to be stored properly in a covered place and separated from sampling equipment. Once these core samples are not required anymore they have to be managed following the procedure mentioned before. Hermetic and waterproof containers (metal barrels, cisterns) with hazardous waste (contaminated drill cuttings/soil/sediments) can be temporarily stored on site where generated on designated area. The selection of containers will be based on local regulations (appropriate Department of Transportation requirements should be checked). Immediately following containerization, each waste container will be labeled by waste classification, identification number and date of generation. Transportation of the containers from the site to the place of waste disposal or treatment will be performed by an authorized/ licensed company. The procedure of transporting, loading-unloading of waste has to be arranged avoiding accidental spillages that could cause environmental contamination and following regulations accepted along the whole planned trip, including intermodal transportation. If no specific regulation is applicable the European Agreement concerning International Carriage of Dangerous Goods by Roads or the corresponding railway and maritime agreement, which is based on UNO recommendations, can be of guidance. This Agreement establishes the rules regarding packing, transport, documentation and all other aspects regarding hazardous waste transport, including loading, unloading and storage of waste. It also establishes the responsibilities of every stakeholder during transport operation in order to avoid damage to humans, animals or the environment.
Regarding sampling activities, the samples that are not sent to the laboratory will be managed according to their predictable attributes, which can be estimated based on the organoleptic characteristics annotated during sample taking and on the measurements obtained with portable devices as FID (Flame Ionization Detector), PID (Photoionization Detector), etc..
Moreover, samples will be taken with one-use bailers, which will be disposed off together with contaminated drill cuttings, soil, sediment, etc. in an in situ security cell or it will be double bagged and placed in a refuse dumpster.
Finally, other kind of waste as for example paper used for cleaning buckets, probes, etc. (see “taking care of equipment”) will be disposed off in a hermetic rubbish bin together with used and dirty PPE.