Former Petrol Station
Former Petrol Station Leicester
Former Petrol StationClient: National House Builder Location: Former Petrol Station in Bristol Project: Complete Site Clearance, Remedial Works & Site Management Duration: 12 weeks Value: £160,000 T&P Regeneration were appointed to undertake the remedial design and were awarded the contract for the demolition and remediation of the site. Upon completion of the works T&P undertook the site management of the installation of steel piles followed by the construction of the new houses to dpc level and service roads including all the sewer works. The scope of the works included: production of a suitable Remedial Strategy, using third party investigation data, to obtain approval from the Regulatory Authorities; demolition of the existing buildings, including the removal of the asbestos based materials for a fixed lump sum price; removal of the chemically unacceptable material, validation of the excavations and backfilling, in a controlled manner, with suitable fill material; supervise the setting out and driving of tubular steel piles, construction of reinforced concrete ring beams and under build to damp proof course level; oversee the construction of all foul and surface water sewers including liaison with the local water board inspector; manage the construction of adoptable service roads to base course level; obtain Regulatory “sign off” for the remedial works.
Former Petrol Station LeicesterClient: National House Builder Location: Former Petrol Station and garage in Leicester Project: Site Clearance, hotspot removal and groundwater in-situ treatment. Duration: 16 weeks site works followed by 3 months groundwater monitoring. Value: £345,000 contracting costs The scope of the works included: Removal of the identified notifiable asbestos within the buildings; Demolition of the buildings and removal of foundations to a depth of 1.5m; Removal of the underground storage tanks and associated hydrocarbon impacted soils; Undertake in-situ groundwater treatment; Obtain Regulatory “sign off” for the works Following the demolition and removal of the tanks the grossly impacted soils were excavated and removed from site to suitably licensed landfill. In addition to the pumping the groundwater from the excavations groundwater abstraction points were installed in the unexcavated area down gradient of the tank farm from which the impacted groundwater was pumped in order to improve the general groundwater quality ahead of the second phase of in-situ treatment. All the groundwater removed was passed through a treatment system prior to discharge to foul sewer. Tanks and contaminated water The in-situ groundwater treatment was undertaken using modified fenton’s reagent, which was injected into the groundwater along the identified plume of impacted groundwater to cause a reaction with the hydrocarbon to breakdown the bonds to produce carbon dioxide and water. Over a six week period two injection rounds were undertaken with the subsequent groundwater monitoring confirming that the agreed target levels had been achieved.
International Pension Fund
Former Haulage Depot
International Pension FundClient: International Pension Fund Location: West Midlands Project: Fuel leak from an above ground fuel tank Duration: 1½ years Value: £32,000 The Environment Agency had tracked the source of hydrocarbons within a water course to a leaking underground diesel feed pipe between the above ground tank and the boiler room on a large warehouse site in the West Midlands.T&P were appointed by the site owner to liaise with the Regulators to agree appropriate remedial measures, supervise the tender process, oversee the works, produce the verification reports and obtain regulatory confirmation that the site was no longer considered to represent an ongoing risk. The initial phase of the works was to agree with the Environment Agency the scope of further investigations, which included excavation of trial pits in the vicinity of the tank and drilling a network of boreholes across the site to permit 3 months of monitoring and in-situ permeability testing; Upon completion of the investigations T&P designed a remedial strategy based upon site specific P20 risk assessments involving excavation and removal of the grossly impacted soils followed by a two phase groundwater treatment comprising vacuum abstraction to remove any residual hydrocarbons that was then augmented by the use of ORC to assist in the in-situ bioremediation of the dissolved phase hydrocarbons; On behalf of the client T&P produced the tender documents and managed the assessment and interview phase to enable a specialist contractor to be appointed; T&P oversaw all the operations which due to the need to reinstate the yard area so it could be trafficked by high point load fork lift trucks and lorries required the excavations to be undertaken in sections with the construction of reinforced concrete walls to support the spanning slabs and dewatering points. When the six months post remediation groundwater monitoring was completed T&P produced the Completion Report detailing all the works undertaken and verification testing and obtained regulatory approval.
Former Haulage DepotClient: National House Builder Location: Former Haulage Depot in Northampton Project: Pump and treat in-situ groundwater remediation system. Duration: Groundwater treatment over a 10 week period followed by a 6 month monitoring period. Value: £35,000 contracting costs The site was located adjacent to a river and the groundwater had been shown to be grossly impacted with hydrocarbons (diesel). T&P Regeneration were appointed to provide a “turn key” service whereby we investigated to plume, designed the remedial solution, undertook the works and obtained Regulatory “sign off”. The development was already underway on the site so the remedial design had to be tailored so as not to interfere with the on going works and to be robust enough to be flexible to adjust to the build programme whilst still providing sufficient comfort to the Regulators that the identified pollution was successfully treated.Therefore the remedial design proposed by T&P and agreed all parties was to install 25No. 300mm dia. abstraction points across the site in locations that would not impact the build (e.g. in driveways or public open spaces) along the identified plume of contaminated water. As it was not possible to install a network of permanent pipes between the abstraction points due to the movement of heavy plant around the site a low technology system was adopted whereby a bowser was towed around the site to each abstraction point. A standard 2" pump, which was also transported around the site, was then used to pump the groundwater into the bowser.The filled bowser was then towed across the site to the treatment plant where the water was passed through a water/petrol interceptor fitted with carbon filters. As it was not possible to obtain a consent to discharge to treated water to foul sewer the water was placed in a storage tank from which samples were collected to ensure the target levels had been achieved prior to being discharged back into the ground via a soakaway. After 10 weeks of pumping the hydrocarbon concentrations within the groundwater were shown to be below the agreed target levels so the pumping operations ceased and 6 months of monitoring commenced, which confirmed there was no “rebound” so the works were approved by the Environment Agency.
Former Factory and Residential Property at Wotton-Under-Edge: Site Clearance and landscaping
Historic Demolished Factory: Asbestos Hotspot Removal
Historic Allotments and Open Field at Milborne Port: Site Clearance and reprofiling
Earthworks operations and aerial surveying and 3D modelling
Former Factory and Residential Property at Wotton-Under-Edge: Site Clearance and landscapingClient : National House Builder Value : £94,000.00 Duration : 4 weeks site works followed verification testing of garden capping. The scope of the works included: Excavation of soils contaminated with lead; Placement of soils unsuitable for residential gardens in a landscaped bund located in an area of public open space on site; Carry out levelling works on site with the bulk of materials being placed in the area of public open space to reduce volumes of material required to be taken off site; Validate private soft landscaped gardens on a plot by plot basis; Obtain Regulatory “sign off” for the works. Following a desk study and ground investigation carried out on the proposed development site a number of contaminants were shown to be present within the soils onsite which would pose a risk to human health. If these soils needed to be removed from site as waste then a small portion of it would be classified as had the potential to be classified as hazardous which would have incurred a much higher disposal cost. T&P undertook liaison with the local authority and the environment agency on behalf of the developers in order to provide a solution that would allow for reuse of the material unsuitable for residential gardens in a proposed area of public open space on site in order to reduce the final remedial costs. T&P attended site prior to the groundworkers, who would be undertaking the main build works on site, in order to carry out vegetation clearance and then strip the proposed garden areas of the contaminated material with the majority being placed within an embankment created on site in the POS area and a small portion being removed from site to a suitably licensed tip. The site was then handed over to the groundworkers for them to start build works without needing to deal with any excavation work of the contaminated land. T&P provided advice throughout the build works and then carried out final verification testing in the garden areas in order to demonstrate the suitability of imported material that had been used by the groundworkers to raise levels in gardens and provide a growth medium for planting. Upon completion of all of the works T&P produced verification reports which were submitted to the NHBC and local authority and allowed for the clearance of planning conditions associated with the site and the sale of the new residential properties.
Historic Demolished Factory: Asbestos Hotspot RemovalClient : National House Builder Value : £104,250.00 Duration : 3 weeks site works. The scope of the works included: Excavation of contaminant hotspots including hazardous asbestos; Management of H&S aspects involving works with asbestos containing material; Verification testing of hotspots; Obtain Regulatory “sign off” for the works. Following a desk study and ground investigation carried out on the proposed development site a number of contaminants hotspots were noted on site. These mainly consisted of asbestos fibres noted within the made ground, probably associated with the former buildings on site. Due to the human health risk posed by these contaminants T&P were asked to undertake works to remove these hotspots from site. This involved managing the risk posed by the asbestos fibres during the excavation works in the form of air monitoring, additional specialist PPE, fencing off the working area from the rest of the site and providing equipment to keep the excavated material damped down to prevent fibre release. T&P attended site prior to the groundworkers, who would be undertaking the main build works on site and excavated the contaminant hotspots with the material being loaded onto road going lorries for disposal at an appropriately licensed tip. In order to manage costs more affectively for our client T&P were able to divide the asbestos containing waste into both hazardous and non hazardous classification based upon the percentage of asbestos encountered within the soil matrix. Following the excavation works verification samples were collected by T&P from the side walls and bases of the hotspots to demonstrate that the contaminants had been removed. The site was then handed over to the groundworkers for them to start build works without the requirement .for specialist health and safety procedures to deal with asbestos risk. T&P provided advice throughout the build works and then carried out final verification testing in the garden areas in order to demonstrate the suitability of imported material that had been used by the groundworkers as a capping layer in the appropriate plots. Upon completion of all of the works T&P produced verification reports which were submitted to the NHBC and local authority and allowed for the clearance of planning conditions associated with the site and the sale of the new residential properties.
Historic Allotments and Open Field at Milborne Port: Site Clearance and reprofilingClient : National House Builder Value : £100,366.00 Duration : 6 weeks site works followed verification testing of garden capping. The scope of the works included: Excavation of topsoil contaminated with arsenic; Carrying out levelling works to allow a 600mm capping layer to be placed in soft landscaped areas across the eastern half of the site; Stockpiling excavated sub soil material on site for reuse; Validate private soft landscaped gardens on a plot by plot basis; Obtain Regulatory “sign off” for the works Following a desk study and ground investigation carried out on the proposed development site a number of contaminants were shown to be present within the soils onsite which would pose a risk to human health. Due to the intended final build levels on site the volume of material that would require removal as Non-hazardous waste prevented the project from being commercially viable. T&P carried out site specific risk assessment works which resulted in an increase in the allowable concentrations of the contaminants in the soil than the standard soil guideline values. Following this site specific risk assessment it was possible for T&P to create a three dimensional picture of the contaminant spread across the site. Based upon this model it was then possible to reduce the volume of material requiring removal from site as non-hazardous waste, with the bulk of the sub soil material excavated being shown to be suitable either under areas of hardstanding or in areas of soft landscaping dependent upon its chemical composition. T&P attended site prior to the groundworkers, who would be undertaking the main build works on site, in order to strip the topsoil from the site with approximately ¾ of it being removed as non-hazardous waste while ¼ was retained for reuse on site. T&P then undertook levels digs on a plot by plot basis in order to ensure that where contaminants had been noted at deeper depths a 600mm capping of clean material chemically suitable material could be placed in the garden areas. All materials excavated from these locations were retained on site for placement under areas of hardstanding to reduce disposal costs. The site was then handed over to the groundworkers for them to start build works without needing to deal with any excavation work of the contaminated land. T&P provided advice throughout the build works and then carried out final verification testing in the garden areas in order to demonstrate the suitability of imported material that had been used by the groundworkers as a capping layer in the appropriate plots. Upon completion of all of the works T&P produced verification reports which were submitted to the NHBC and local authority and allowed for the clearance of planning conditions associated with the site and the sale of the new residential properties.
Earthworks operations and aerial surveying and 3D modelling
Project: Earthworks Operations
Client: National House Builder
Duration: 8 weeks
Former sand quarry: Earthworks operations to use predominately site won material to backfill an existing former sand quarry.
Summary T&P Regeneration was approached by a national house building client who needed to find a cost-effective method of filling an approximate 30,000 m3 void present on site to a standard that would be suitable for the constructions of residential properties.
SCOPE OF WORKS The Scope of remedial contracting work included: Assessment of on-site material from a geotechnical and environmental perspective to determine its suitability for reuse on site.
Production of a site-specific Earthworks Specification considering the potential for reuse of site won material through a Materials Management Plan (MMP). This enabled T&P Regeneration to provide a cost-effective method of reducing the volume of material that would need to be imported onto site to fill the void by 75%.
Groundworks including excavation of site won material and placement and compaction following the T&P Specification.
Geotechnical testing of the compacted layers throughout the works to demonstrate compliance. Environmental sampling was also undertaken to demonstrate that the material being used on-site would not pose a future risk to human health or the environment.
The scope of the aerial surveying and subsurface modelling work included:
Numerous aerial surveys throughout the project lifecycle to track site progress and allow accurate survey surfaces for live tracking of material volumes to be generated.
Gathering of site imagery for use within marketing material and eventual show home video reels.
Subsurface modelling of placed material, demonstrating placement thickness, geotechnical characteristics and testing locations/ results.
The full work package provided a streamlined audit trail to demonstrate the ongoing progress and success of the engineering infill operations. The use of aerial surveying allowed rapid computation of volumetric computation of volumetric soil movements and aided in faster decision making between site personnel, the client and regulators.
Soil Removal Verification
Former FarmClient: National House Builder Location: Former Farm near Bristol Project: Complete Site Clearance and Remedial Works Duration: 2 weeks Value: £25,000 Fixed lump sum contract for the demolition of the existing farm buildings plus adjacent semi-detached bungalows followed by the remediation of the site so as to make it suitable for a mixed residential and commercial/leisure development.Based on a third party site investigation report T&P obtained agreement from the Regulators for a remedial strategy for the site; Asbestos removal and demolition of the out building and single storey extensions structures to the main farm house plus two unsafe semi-detached bungalows that had been damaged by fire Excavation and removal to a suitably licensed tip of metal impacted soils followed by validation sampling to confirm the site was suitable for a residential development. “Sign off” by the Regulators
College SiteClient: National House Builder Location: College Site in Bristol Project: Asbestos Removal and Demolition followed by the supervision and validation of the approved remedial works. Duration: 16 weeks Value: £200,000 The project required the demolition of a 1960’s college building within an active further education establishment with T&P being responsible for liaison with the college authorities regarding accesses and safety. A number of the trees within the site were listed and special precautions had to be employed to protect them during the works. Due to the requirements of the Local Authority no brick would be accepted within 6F2 crushed material therefore unsuitable hard demolition arisings were removed from site to a recycling facility. Upon completion of the demolition works T&P undertook a detailed site investigation and designed a suitable remedial strategy that the Regulators approved. T&P then oversaw the remedial works and produced a validation report.
National House Builder
WatfordSample Project Two - Watford Client : National House Building Company Volume of Soil : 1,000m3 Following the successful bioremediation of hydrocarbon impacted soils the use of the Code of Practice by T&P permitted the treated soils to be re-used on site within a soft landscaped area. The use of the Code of Practice not only negated the need to apply for an exemption under the Waste Management Licensing Regulations it also created a substantial saving by avoiding both the disposal costs for the contaminated soils and subsequent import costs for chemically suitable replacement fill.
National House BuilderClient: National House Builder Location: Former Quarry and Haulage Yard in Northampton Project: Bioremediation of soils followed by treatment of hydrocarbon impacted groundwater Duration: Soil treatment 12 weeks Groundwater treatment & monitoring 6 months Value: £250,000 contracting costs T&P Regeneration were appointed to provide the initial design, liaise with the regulators to obtain all necessary approvals, manage the tender process and oversee/validate the subsequent remedial works. The site, which was adjacent to a river, was shown to contain in the region of 13,000m³ of hydrocarbon impacted soils and this had also resulted in groundwater contamination beneath the site. Based on an economic evaluation it was shown that bioremediation of the soils was the most cost effective solution. The general scope of the works undertaken by T&P included: Review of the existing third party site investigation data followed by an intrusive supplementary investigation to provide necessary information to model the site conditions; Liaison with the Local Authority and Environment Agency to agree the most suitable remedial strategy; Production of tender documents and management of the tendering process and assessment of submissions; Supervision and management of the remedial works; Production of Validation Reports to obtain regulatory “sign off” for the works
Residential Development Company
WatfordSample Project Two - Watford Client : National House Building Company Volume of Soil : 1,000m3. Following the successful bioremediation of hydrocarbon impacted soils the use of the Code of Practice by T&P permitted the treated soils to be re-used on site within a soft landscaped area. The use of the Code of Practice not only negated the need to apply for an exemption under the Waste Management Licensing Regulations it also created a substantial saving by avoiding both the disposal costs for the contaminated soils and subsequent import costs for chemically suitable replacement
QuedgleySample Project One - Quedgely Client : National House Building Company Volume of Soil : 15,000m3 Following a review of the third party information and discussions with the designing consultant T&P were able to produce a design that permitted to re-use of site won material with marginally elevated arsenic concentrations within the backfilling operation on a housing development site.
Residential Development CompanyValue : £18,000 Duration : 4 weeks T&P Regeneration were commissioned to organise and orchestrate the necessary approvals with the Environment Agency(EA) and Local Authority(LA) under the Code of Practice “Definition of Waste” to allow the infilling of an existing gravel pit to facilitate the construction of a series of new residential plots. The scope of the works included: Full geotechnical and geo-environmental investigation of the site area to characterise the soils from a chemical and geotechnical standpoint including gas monitoring. Liaison and agreement of the proposed infilling/redevelopment strategy with the NHBC, EA and LA under the Code of Practice “Definition of Waste” Act as “Qualified Person” under the terms of the Code of Practice. Prior to commencement of the filling the superficial reworked made ground at the base of the quarry was excavated and removed. Infilling of the quarry area was completed using engineered compaction of a mixture of site won and imported granular material. The works were completed over a four week period. On completion reinforced foundations were constructed across the infilled area.