Erection of a Three Bedroomed Dwelling, Northampton
Case Study Reference: 15-11-02
Planning Authority: Northampton Borough Council
Planning Reference: N/2013/1144
Due to the sensitive nature of the development and the site being located in an area of naturally occurring elevated levels of contamination a contaminated land planning condition was attached to the decision notice for the erection of a dwelling.
Demeter Environmental were commissioned to prepare the desk study report for the site, the review of the environmental data revealed that the site was in an area where full radon protection measures were required and the historical review identified that the site formed part of an allotment gardens as well as a number of excavations within 250m and an industrial estate to the south of the site.
Made ground was identified on the site and photographs in the public domain indicated that the site was occupied by a residential garage. The site had been cleared prior to the walkover survey and the site soils were exposed. Given the made ground identified on site and the past use of the site as allotment gardens, samples of the soils were taken and analysed to a broad range suite.
The assessment of the soil contamination data identified elevated levels of lead in site soils as well as a slight exceedance of dibenz(ah)anthracene. The exceedance of dibenz(ah)anthracene was discounted as posing a risk to human health and bioaccessibility testing was undertaken to determine the risks posed by the elevated lead in the site soils, and the risk from lead was discounted.
Whilst a number of potential sources of ground gas were present within 250m of the site, the risk was assessed and it was concluded that the full radon protection measures would be sufficient to break the pollution linkages associated with ground gases.
The report was accepted and the remedial measures proposed int he report will need to be incorporated into the building design.
The desk study report can be accessed via the Northampton Planning Portal.