REMEDIATION METHOD STATEMENT 10-1024.03
RIVERSIDE, BOSTON
FOR CHESTNUT HOMES LTD
Preliminaries
This remediation method statement (RMS) has been written in order to assist the developer of new housing at the
Site to make the finished construction suitable for use by addressing risks in respect of human health posed by
ground contaminants and ground gas.
Introduction
This RMS has been derived using information from Delta-Simons’ Phase I and Phase II reports (Reference 053100.01 and 10-1024.01) dated September 2006 and June 2010. The RMS is required to comply with the precommencement planning conditions from Boston Borough Council and the requirements of National House
Building Council (NHBC) Standards 4.1 Managing Land Condition.
The data obtained from the report identified shallow soils at the Site which are considered to be physically
unsuitable for use in a residential end-sue scenario. In addition, isolated and low levels of soil contamination was
identified with respect to a residential end-use scenario.
An RMS is required to develop the following principles to be adopted by the developer and make the completed
development suitable for use. The contamination recommendations are as follows:
1. Remediation by soil screening to remove coarse debris within the Made Ground and re-use of topsoil and
subsoil.
2. Validation of the topsoil following screening.
3. Removal and off-Site disposal of fly tipped waste and burnt out car at the Site.
4. Liaison with the local water supply authority with regard to specifying suitable fresh water pipe
specification in accordance with the ground conditions.
5. Use of suspended floor slabs with ventilated void and suitable damp proof membrane.
Objectives of the Remediation
Primary:
1.0 Protect human health in the long term (chronic) from total concentrations of soil contaminants and ground
gas.
Secondary:
1.0 Protect human health in the short term (acute) from total concentrations of soil contaminants and ground gas.
2.0 Maintain the Duty of Care in wastes and materials management.
Design Considerations for Objectives
The Site was formally occupied by a caravan park. The shallow depth Made Ground soil has been found to be
chemical suitable for use in a residential end-use scenario, however, coarse debris making the soil physically
unsuitable was identified. As such, a soil screening exercise to improve the quality of the Made Ground soil has
been recommended. Following completion of the soil screening, further chemical testing to confirm the quality of
the soil will be completed.
Riverside, Boston 10-1024.03 13/07/10 Page 2 of 3
A potential source of ground gas has not been identified at any stage of the risk assessment for the Site. Further,
elevated concentrations of ground gas have not been identified during ground gas monitoring undertaken at the
Site. However, in order to maintain a conservative and precautionary approach, a sub-floor void with a 1200
gauge DPM are to be included within the development.
Protocol for Addressing Previously Unidentified ‘Hotspots’ of Contamination
Should an area of contamination be identified by visual or olfactory means (in these two areas or anywhere across
the Site) the following procedure will be followed:

Immediately stop all works in the area where contamination is suspected;

Immediately inform the Site Manager who should then contact Delta-Simons;

Delta-Simons will judge each occurrence on merit and should it be deemed necessary Delta-Simons will
attend Site to oversee the removal of the ‘hotspot’ and collect validation samples;

Any excavated material should be isolated from all other material at the Site and be disposed of to a
suitably licensed facility. Delta-Simons should be supplied with consignment notes for all off-Site disposal;

The excavation should remain open until the validation has been completed;

Any identified hot spot would need to be appropriately classified prior to disposal to landfill (or transferred
to a treatment centre). If material is identified as hazardous then the Site needs to be registered with the
Environment Agency as a producer of hazardous waste. This can be done online and requires the
company's registration code and a code that relates to the industry type; and

Delta-Simons will notify the Local Planning Officer in line with the requirements under the planning
process.
Re-use of Uncontaminated Site Won Soil
Delta-Simons has shown that the natural soils, including the topsoil at the Site, to be uncontaminated and
therefore potentially suitable for re-use in garden areas. It is likely that in order to comply with the requirements of
both the Local Authority and the NHBC, additional laboratory testing will be required. Generally a testing ration of
one sample per 1,000 tonnes re-used should be sufficient to validate the soil’s suitability for use. This ratio is
based upon the low levels of soil contaminants identified to date and on the basis that Site won soil is to be reused in the development.
Mitigation of Risks to Groundworkers During Development
As with any brownfield development there is the potential for further previously unidentified hotspots of
contamination to be present at the Site. As such, it is recommended that the contractor provides appropriate
inductions to all groundworkers who are required to perform sub-surface work at the Site in order to ensure they
are made aware of the possibility of encountering contamination at the Site. In addition, good standards of
personal hygiene should be observed and appropriate levels of personal protective equipment (PPE) and
respiratory protective equipment (RPE), where applicable, provided and utilised in order to mitigate the potential
for direct contact.
Upgrading of potable water supply pipes
The Statutory providers should be contacted and provided with copies of Delta-Simons’ reports with respect to
their requirements for fresh water pipe provision.
Validation Report
In order to demonstrate that the RMS requirements have been complied with, a Validation Report will be
produced. The following list states the actions and items required:
1. Chemical test data for topsoil/subsoil intended for re-use following completion of screening (To be
supplied by Delta-Simons).
2. The soil validation sampling will take place from stockpiles of Site won soils at the Site. Delta-Simons will
provide photographs and estimates of the stockpile quantity and a record all validation sampling
undertaken. The sampling will be carried out after screening but before emplacement of both subsoil and
topsoil. The sampling will include a suite of testing in accordance with the site investigation comprising:
metals and speciated PAH (Photographs to be supplied by Delta-Simons).
Delta-Simons Environmental Consultants Limited
The Lawn, Union Road, Lincoln LN1 3BL. Switchboard: 0870 0400 012
Riverside, Boston 10-1024.03 13/07/10 Page 3 of 3
3. Statement on fresh water supply pipe specification (To be supplied by Chestnut Homes Ltd).
4. Presentation of consignment notes for any soil disposal off-Site (e.g. Hazardous Waste transfer notes), if
required (To be supplied by Chestnut Homes Ltd).
5. Report containing the above (To be supplied by Delta-Simons).
Delta-Simons Environmental Consultants Limited
The Lawn, Union Road, Lincoln LN1 3BL. Switchboard: 0870 0400 012