2.3.2    Site preparation

The detailed design of the remediation activities should always start with the site preparations. Table 8.1 is an example of information that has to be part of a detailed design of the site preparation. This part of the detailed design addresses the site organization with a focus on Health, Safety and Environmental (HSE) aspects of the site remediation campaign. The basic site information has already been presented in Phase 1, 2 and 3 reports and has to be used as a reference. HSE aspects should be added. An example of such HSE aspect is an unpaved site road: improvement of accessibility during the rainy season and combating dust forming during the dry season should be addressed in this section of the detailed design. The detailed design of the site preparation elaborates on all preparatory activities so that they can be carried out in a safe, healthy, sustainable, and environmentally friendly manner.

 

 

Table 8.1: An example of a limitive summary of site preparation topics to be addressed in a detailed design

Topics Remark
General information
Site address Include a site location and description of at least: ‘The site is situated in the middle of the village behind the house of Mr Xxx with the spatial coordinates
Site contacts Could be the site owner, the caretaker, the responsible person in the local administration, etc.
Site location Regional map with site location indicated
Site accessibility Site layout map indicating all site components and a description of the condition of the site path(s)/ road(s)
Permission/permits Include where to obtain and explain procedure and the time needed to obtain permission and/or permits to carry out the remediation activities
Site layout and zoning
Zoning Site layout map with the contaminated, the decontamination and the clean zone. The specification of the temporary site fencing and zone demarcation are also part of the description
Site layout Site layout map with all site components and facilities to be installed such as parking place, shelter, canteen etc.
Tools, equipment, material and Personal Protective Equipment (PPE)
PPE The type and numbers of for instance coveralls and half-face mask including cartridges for a staff working in the contaminated zone, the clean zone etc.
Safety equipment and materials This includes for instance the number of fire extinguishers, the set-up of the contaminated zone, the decontamination zone, with the sluice between these zones, the location of the first aid kits, spill control kit and the emergency shower etc.
Tools and materials This includes for instance the big bag filing station, the crane, forklift, wheel loader, truck and hand tools etc.

 

2.3.2    Remediation measures

Information to be used for the detailed design of the remediation measures is provided in the site investigation reports (see Module 3) and the report on the remediation assessment, the Site Remediation Plan (see Module 6). Table 8.2 is an example of information that has to be part of a detailed design of the remediation measures. The example has the following site components.

Hazardous waste

If hazardous waste has to be collected and packed, the Phase 2 report provides the information on the location, the amount, types and conditions of the hazardous substances. The collection and packaging plan of Phase 3 describes the general approach of the collection and packaging. This part of the detailed design elaborates on all activities to carry out to remove, pack, transport and temporarily store all hazardous substances in a safe and environment friendly manner, while awaiting final destruction. The design contains also the information needed by the destruction company to destruct safely the hazardous substances and waste. It is proposed to split this part of the detailed design into collection, packaging, transportation, temporary storage and destruction. The detailed design provides sufficient information to calculate the cost.

Buried hazardous waste

If a pit with buried hazardous waste has to be cleaned, the Phase 2 report gives information on the location and dimensions of the pit, the amount buried, types, and condition(s) of the buried hazardous substances. Phase 2 also gives information the depth to the groundwater, the soil type and the conditions of the bottom and sides and cover of the pit. The excavation plan of Phase 3 describes the general approach for the removal of the buried hazardous substances and the packaging. The detailed design elaborates on all activities to remove, pack, transport and temporarily store and dispose of all hazardous substances in a safe and environment friendly manner. With this information the cost involved can be calculated. This part of the design is split-up into the pit excavation, the pit backfilling, the packaging of the contaminated material, i.e., the hazardous substances but also the remediation of the contaminated soil of sides and bottom of the excavated pit, the transportation, the temporary storage and the destruction of the hazardous substances and in or ex-situ soil and groundwater remediation measures.

Contaminated building

If a contaminated building such as for instance a storage building, a bunker or a simple shed has to be cleaned, the Phase 2 report provides the location and the details of the building, such as its dimensions, building materials and the parts where and the degree to which the building is contaminated (floor, walls, etc.). The decontamination and/or the demolishing and/or renovation plan of Phase 3 describes the general approach of the decontamination, the renovation or demolition, including respectively the removal of the clean and the decontaminated and/or disposal of contaminated rubble and other building materials. The detailed design describes the same, but gives far more details on type and quantities so that all costs can be calculated and all activities can be carried out in a safe and environmentally sound manner. The detailed design clearly explains the demolition of the subsoil part of the building to avoid cross contamination of the surrounding soil and/or the subsurface structures. If the building is connected to facilities like water and electricity, a special section in the detail design is devoted to disconnection and protection/removal of such facilities. This section lists the different cables and lines with the name and contact details of the owners/providers. The locations of these facilities are provided on separate site location maps with a legend clearly giving the different types.

This part of the detailed design is divided in the activities to be carried out to protect and/or remove the subsurface facilities, the decontamination of the building, the renovation and/or demolition of the building, the off-site removal and transportation, and the landfilling/treatment of the decontaminated rubble and/or building materials.

Contaminated soil and groundwater

If contaminated soil including a hotspot and contaminated groundwater has to be remediated, the Phase 2 gives the location and the details of the soil and groundwater contamination, such as the location, the soil profiles, the volumes, the dimensions and the degree of contamination in the hotspot, soil and groundwater. The Site Remediation Plan of Phase 3 describes the general approach of the hotspot, soil and groundwater remediation. The detailed design describes the same, but gives far more details, so that all remediation measures can be cost calculated and carried out in a safe and environmentally sound manner. The part of the detailed design is divided in site-specific information and the short-, mid- and long-term soil and groundwater remediation measures.

Table 8.2: An example of a limitive summary of remediation measures to be addressed in a detailed design

Topic Remarks
Packaging of hazardous substances
Hazardous substances Conveniently listed types, quantities and conditions of solids, liquids and other hazardous substances including photos of the stock(s) and if possible, photos of the labels
Packaging material The types, quantities and specifications of for instance the needed big bags, overhead drums, boxes and PE drums
Needed staff to pack in a safe and healthy manner Packing cannot be done without constant supervision. An aspect that should be considered is that working in coverall and using respiratory mask during warm weather should be limited in time, dehydration being a constant threat
Transportation of hazardous substances
Legal Applicable laws and regulations on transportation of hazardous waste. Reference to legal documents and the procedure to obtain a hazardous waste transportation permit should be included
Road condition Maximum permitted load of road to the destination including dimensions, conditions and photos of the road to destination (temporary storage, destruction facility or for instance a seaport if hazardous substances and its waste are exported for destruction)
Destination Regional map with site location and destination indicated
Address of destination Site layout map and description of the destination
Contact Name and contact details of the destination. Could be site owner, caretaker, the responsible person in the local administration, etc.
Temporary storage of hazardous substances
Storage access condition A site layout map indicating the temporary storage
Site storage condition If there is no temporary storage site available, the preconditions for such storage should be given
Site storage facilities The facilities at the temporary storage site needed are for instance loading platform, forklift safety equipment, spill kit, etc., and should be described when the temporary storage is part of the contract
Destruction of hazardous substances
Hazardous substances to be destructed Analytical results, the number of different packages, and the total tonnage of each distinguished batch are the information needed by a destruction company
Destruction technology There are several companies using different kinds of techniques to destruct the hazardous substances. A detailed design only presents the detailed information and the preconditions. The companies assess themselves if they can destruct the hazardous substances and meet the preconditions
Packaging type, maximum volume and weight of a single parcel accepted by destruction company This information is essential but can only be given if the destruction company is already known
Excavion of buried hazardous substances
Condition of the pit Detailed site layout map with the buried hazardous waste including photos of the pit, dimensions and cover
Excavation Detailed cross section of the pit including the groundwater level, the boundaries of the pit to be excavated with safe slopes
Groundwater drainage If groundwater drainage is needed yes or no. If yes, the needed permits to drain and discharge and the treatment of the drained water
Material and quantities to be excavated

The different batches present should be described (volumes, type, specific weight and form) such as:

·       Clean soil (texture) from the cover and slopes xx m3

·       Contaminated soil (texture) from cover, slopes and bottom xx m3

·       The different types of packaging of the hazardous substances (bags with xx, drum with xx)

·       Unknown hazardous substances (bags with xx, drum with xx)

·       The different types of unpacked hazardous substances xx m3

·       Unknown unpacked hazardous substances xx m3
Pit backfilling
The backfilling The specifications of the backfill such as the type/texture, demanded environmental quality, the backfill height and the compacting demands of the backfill
Packaging, Temporary storage, Transportation and Destruction
Excavated hazardous waste The same information as above has to be provided for the excavated waste
Decontamination of the building
Condition of contaminated building

Detailed site layout map with the contaminated building with photos and specifications of the contaminated part of the building such as:

·       ‘The concrete floor of storage is 20 cm thick and the first 10 cm is impregnated by spilled liquid hazardous substances’

·       ‘The plastered walls of the storage show up to 1.5-meter-high staining by spilled liquid hazardous substances’

·       ‘Also, the iron entrance door is stained by spillage’
Decontamination

Details on the techniques to be used to decontaminate the building such as:

·       ‘The concrete floor has to be removed and kept separate for packaging’

·       ‘The wall of the storage should be cleaned by removing the plaster up to 1.5-meter height, the plaster is kept separate for subsequent packaging’

·       ‘The iron entrance door can be cleaned using cotton waste. The cotton waste is kept separate for subsequent packaging’
Renovation and/or demolition
Renovation If only part of the building needs decontamination and the building is to be used again, the decontaminated part should be renovated. If this renovation is part of the remediation campaign the specifications of the renovation activities should be given
Demolition

If parts or the whole building are not to be used anymore and demolition is part of the campaign the demolition activities should be divided into:

·       Parts higher than man’s height

·       Parts lower than man’s height, but above ground level

·       Parts lower than ground level
Removal of facilities

If the building is connected to facilities and they have to be removed the following has to be provided:

·       Different types, installation depth and location

·       A description of a connection to the public water supply is given below:

–      PE water main has a diameter of 25 mm

–      The piping is installed in a trench of 0.5 meter deep

–      The trench is filled with coarse sand

–      The sand in the trench is contaminated (see Phase 2 report)

–      The removal of the water main will be carried under strict enforcement of the HSE rules of the contaminated zone

–      The water main entrances the building under the main entrance

–      The main tape is installed in a cupboard direct left of the main entrance

–      The water company is xxx and the contact person is Mr yy

–      The company has to be asked two weeks in advance to disconnect the building from the water

·       The location of the water piping is given on the site location map of Appendix cc
Packaging, Temporary storage, Transportation and Destruction and/or landfilling
Contaminated building material The same information as above has to be provided for the excavated waste
Landfilling decontaminated building materials The acceptance criteria of the non-hazardous waste (moisture content, leaching characteristics) set by the landfill site management should be given. Based on the waste characteristics the pre-treatment for landfilling has to be described
Soil and groundwater remediation
CSM The updated CSM should be part of the detailed design. The site layout maps with the soil and groundwater contamination including cross sections should have such a scale that the layout of the remediation measures can be added. Definitions, dimensions and quantities of the distinguished batches of soil (source area, strongly, moderately and slightly contaminated) should be listed and illustrated with detailed maps and photos
Installation and implementation of short-term remediation measures
Source area/hotspot The source area has to be treated in the same way as buried hazardous waste and the design of the remediation of the source area has the same set-up as the remediation of buried hazardous substance (see above)
Strongly contaminated soil Strongly contaminated soil is hard to remediate with the currently available bio- and phytoremediation technologies. The short-term remediation measures therefore are often restricted to excavation and transportation to a soil treatment facility. In a detailed design, preconditions such as remediation target values are given and bidders assess whether or not they are able to meet these preconditions
Moderately contaminated soil Moderately contaminated soil can be remediated with the currently available bioremediation technologies. If the volumes are not too large, the short-term remediation measures are often excavation and transportation to a soil treatment facility. If the volumes are large and bio-, on-site and/or in-situ remediation is possible, the short-term remediation measures are the installation of the bio-, on‑site and/or in-situ remediation equipment. Phytoremediation could be possible, but will take a very long time and when the site is located in an intensively used urban area, this is not a preferable option. In a detailed design, preconditions such as remediation target values are given and designers assess whether or not they are able to meet these preconditions
Slightly contaminated soil Slightly contaminated soil can be remediated with the currently available bio- and phytoremediation technologies. If the volumes are small, the short-term remediation measures are often excavation and transportation to soil treatment facility or remediated in the same way as the moderate contaminated soil. However, if the volumes are large, remediation is only economically feasible when phytoremediation, containment measures and land use restrictions are implemented. The short-term remediation measures are the installation of containment (erosion control) measures and planting of vegetation for the phytoremediation. In a detailed design, preconditions such as remediation target values are given and designers assess whether or not they are able to meet these preconditions
Contaminated groundwater Hazardous substances contaminated groundwater is often remediated by pump and treat methods. The short-term remediation measures are the installation of the system to remediate. In a detailed design preconditions such as remediation target values are given and designers assess whether or not they are able to meet these preconditions
Installation of the mid-term remediation measures
Moderately and slightly contaminated soil The equipment to remediate the contaminated soil are installed as short-term measures. The mid-term measures are aftercare of the remediation installation and monitoring of the remediation progress (designed in a Monitoring and Aftercare Plan)
Contaminated groundwater The equipment to remediate the contaminated groundwater are installed as a short-term measure. The mid-term measures are aftercare of the remediation installation and monitoring of the remediation progress (designed in a Monitoring and Aftercare Plan)
Installation of the long-term remediation measures
Slightly contaminated soil The long-term measures are aftercare of the remediation installation and monitoring of the remediation progress (designed in a Monitoring and Aftercare Plan)
Contaminated groundwater The long-term measures are aftercare of the remediation installation and monitoring of the remediation progress. If the groundwater contamination allows a long-term remediation, technique is natural attenuation. The US Environmental Protection Agency (EPA) defines natural attenuation as ‘a variety of physical, chemical, or biological processes that, under favourable conditions, act without human intervention to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater’. The long-term measure is monitoring of the natural attenuation progress (designed in a Monitoring and Aftercare Plan)