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GO Contaminated Land Solutions
Remediation for commercial and residential use.
Case study: Freeport designer outlet, Alcochete.
The UK regulatory framework is based upon:
Risk assessment
and
Suitability for use
commercial
parkland
residential
It can therefore be adapted and applied to other settings
A site walk over was undertaken;
including a climb to the top of
the water tower
The first step was to visit the
site of the former tyre factory
A Desk Top Study
was undertaken
Orange
grove
Factory
Scrub
Past land usage, geology and
hydrogeology were investigated
Design of site investigation
and testing regime
Considerations for testing regime
-Likely contaminants identified in DTS
Hydrocarbons
Asbestos
Heavy metals
PCB’s
-Relevant Environmental Quality Standards
Portuguese & UK
- How many samples on what pattern?
Culvert
Tejo estuary
environmental
(pathway)
Freeport
Considerationzone
of site
specific items
(receptor)
designer
outlet
Wells (pathway)
underground
tanks (source)
Pollution linkage example
SOURCE
PATHWAY
Transformer
Asbestos
sheets
Groundwater
Soil
Leaking
tanks
Air
Fly tipping
Culvert
Alluvial
deposits
RECEPTOR
Human &
fauna by:
Ingestion,
Inhalation,
Skin absorption
River Tejo
Flora - by
root take up
Property
source
contaminated
leaching
Potential
groundwater
pollution linkage
soil
unsaturated zone
ground water flow
saturated zone
(aquifer)
Tejo estuary
potential receptor
Computer modelling is undertaken
by specialists if required
Assessment of site investigation results
The results for each contaminant are analysed
statistically to obtain:
- A picture of the whole site
- 95% certainty of compliance
The Remediation Strategy addressed
- Contaminants identified
- Remediation proposals
- Areas requiring further investigation
- Protection of receptors during construction
- Monitoring of groundwater
- Validation testing
- Records to be kept
Frequent monitoring visits were made as
demolition and site clearance progressed
The soil contaminated with hydrocarbons
Leakage
had
occurred
was placed in windrows on polythene
from some
sheeting
underground tanks
Validation sampling after removal
of extent of assumed contamination
Location Ref.
Description
VS 1
Weigh bridge
The Validation Report
was completed
Comments
This location was found to be free from contamination.
Above-ground fuel
oil tank
The discovery of high concentrations of TPH at a nearby location (VS 5) meant that the area as a whole had to be
excavated extensively, making sampling at this particular location impossible . However, as this location is found
within an area that was sampled extensively on previous occasions (specifically, at sampling locations VS 3, VS 4,
RL 6 and RL 7), it is considered that samples taken at these locations are representative of conditions at this
particular location (see comments for these locations).
VS 3
Below-ground fuel oil
tank
Concentrations exceeding the ICRCL guideline levels for boron, for land uses where plants are grown, were found
at this location. However, as boron is considered to be a contaminant which is phytotoxic but not normally
hazardous to human health, and this area is to be predominantly hard surfaced, this is not considered to be a
problem.
VS 4
Gravel catchment pit
area
This location was found to be free from contamination.
VS 5
Below-ground water
tank
When this tank was being demolished it became evident that the surrounding soils were contaminated, and a spot
sample taken at the time confirmed the presence of high concentrations of TPH (see results from City Analytical
Services in Appendix D.1) (omitted). Subsequently the area was excavated until no visual evidence of
contamination was apparent and the excavated material was placed on impermeable pvc sheeting in order to
undergo a process of bio-remediation until deemed to be fit for appropriate disposal. Windrowing material taken to
CITRI, Setubal (ref. Appendix K).
VS 6a
Concrete tank
VS 2
Including the post remediation testing
And documentation to demonstrate
With the exception of benzo(ghi)perylene and fluoranthene, the analytical laboratory reported concentrations of
appropriate disposal of potentially
arsenic, cadmium, chromium, PCB, benzene, ethylbenzene, xylene, dichlorobenzene, 1,2,4,5-tetrachlorobenzene,
and 1,2,4-trichlorobenzene as being below the limit of detection of the analytical instrument, for a water sample
hazardous
materials
taken from
water that was found within
this tank. Faecal streptococci, e-coli and other (total) coliforms were also
This location was found to be free from contamination.
VS 6b (water
and soils)
Water holding tank
(ETAR)
found to be present. However, the results showed that the quality of the water was acceptable for disposal into the
environment, in accordance with current Portuguese legislation (see Descrição das Actividades 30 de Março de
2001, and Descrição das Actividades 6 de April de 2001) (omitted). Soil samples taken subsequently from the
excavation were found to be free of contamination.
VS 7
Below-ground fuel
tank
This location was found to be free from contamination.
VS 8
Gravel catchment pit
area
VS 9
Below-ground fuel
tank
VS 10
Pigment tank
Slightly elevated levels of boron were found at this location. However, as boron is considered to be a contaminant
which is phytotoxic but not normally hazardous to human health, it is believed that this is not of concern within the
context of the proposed development (see comments for VS 3). Other than the above, the location was found to be
free from contamination.
Elevated levels of TPH (mineral oils) were detected. The location will be excavated further to remove the
contaminated soils; following this, it will be re-tested for validation. Contaminated material deposited at CITRI,
Setubal (ref. Appendix K).
This location was found to be free from contamination.
Demonstrating the site’s suitability
as a 75,000m2 retail and leisure
development
We have:
- Considerable breadth of experience
GO Contaminated Land Solutions
- Some 15 years of working on projects
involving contaminated land
We provide:
- A client focused environmental consultancy
- A project specific cost effective service
Experience includes
the following:
- Gas works
- Petrol filling stations
- Sewage works
- Scrap yards
- Hospitals
- Industrial sites
- Water treatment works
- Potential unexploded ordnance
Services include:
-Desk top studies
-Ecological surveys
-Remediation strategies
-Environmental impact assessments
This old water works required surveys of flora
and fauna as well as a contaminated land
remediation strategy.
And a variety
of end uses:
- Retail
- Industrial
- Leisure
- Residential,
both with and without private gardens
GO
Contaminated Land Solutions