Purpose

A risk assessment of the Saltings allotment
site recommended that a ground investigation, comprising hand-dug
pits and boreholes, be carried out to investigate the presence,
nature and extent of the potential sources of contaminations to the
groundwater aquifer in order to update the Conceptual Site Model
and risk assessment. It was recommended that
this work be carried out in two phases as follows.
Phase 1
¦ Vegetation clearance to enable access to proposed hand-pit
locations and ensure access to the proposed borehole location for
the drilling rig in Phase 2.
¦ Following the completion of the vegetation clearance,
excavation of up to 45 No. handdug pits to depths of 1.0 metres
below ground level (m bgl) across the Salting Allotments
area.
¦ Chemical testing of soil and soil-leachate samples. Phase
2
¦ Drilling of 11 No. boreholes to an absolute maximum depth
of 10m bgl across the Salting Allotments area.
¦ Installation of 11 No. groundwater monitoring standpipes
in the boreholes;
¦ Continuous groundwater elevation readings over a set time
period;
¦ Groundwater sampling from standpipes. It is proposed to
carry out three fortnightly monitoring visits;
¦ Surface water sampling from two locations to obtain
parameters to determine EQS values for the GQRA; and
¦ Chemical laboratory testing of soil, soil-leachate,
groundwater and surface water samples.

Decision

To approve the award of contract to WSP to
fully manage and deliver the flood relief investigation works
within South Saltings Allotments area of the site to alleviate the
regular groundwater flooding of this area and providing protection
to neighbouring residential properties.
The full cost of this works is £233,000.