Site Investigation on Old Opencast Ironstone Quarries in Northampton

We have recently undertaken a ground investigation on a proposed residential site in Northamptonshire, conducting a Phase I and Phase II Investigation. The Phase I Desk Study indicated that the site was underlain by Northampton Sands Ironstone, deposited in the Jurassic Period between 170.3 million and 174.1 million years ago. The Northampton Sands Ironstone is present across the country, spreading from The Cotswolds, across The Midlands and to North Lincolnshire, and has historically been worked for iron ore.


Due to the site being located near to a historic Ironworks which was active from the late 1800s to early 1900s, and in an area of possible quarrying, there was a requirement for a Phase II soil investigation. Continuous tube boreholes were undertaken to identify any potential Made Ground/Fill from where the area could have historically been worked for iron ore, TRL DCP testing was conducted in areas proposed to become pavements/roads in order to give an equivalent CBR, and hand augers were carried out to take shallow soil samples for contamination testing. Due to Northampton Sands Ironstone having a high naturally occurring Arsenic content, shallow soil samples were also tested for their Arsenic Bioavailability to identify any risk to Human Health receptors. This is important to help clear any contaminated land planning conditions, which are often placed on developments where brownfield land is being developed.  Ongoing groundwater and gas monitoring is also being conducted due to the site being in an area of possible quarrying and the potential risk of ground gas (carbon dioxide).



If you need a Phase 1 Desk Study for planning purposes or a Phase 2 site investigation, give us a call on 01280 8164019 or drop us an email.

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