GO Contaminated Land Solutions

Remediation for commercial and residential use.

Case study: Freeport designer outlet, Alcochete.

It can therefore be adapted and applied to other settings

The UK regulatory framework is based upon:Risk assessment and Suitability for use

parkland

commercial

residential

The first step was to visit the site of the former tyre factory

A site walk over was undertaken;

including a climb to the top of the water tower

A Desk Top Study was undertaken

Orangegrove

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 DTSHydrocarbonsAsbestosHeavy metalsPCB’s

-Relevant Environmental Quality Standards

Portuguese & UK

- How many samples on what pattern?

Consideration of site specific itemsFreeport designer outlet

Wells (pathway)underground tanks (source)

Culvert

(pathway)

Tejo estuary environmental zone (receptor)

SOURCE PATHWAY RECEPTOR

Transformer

Asbestos sheets

Leaking tanks

Fly tipping

Alluvial deposits

Groundwater

Soil

Air

Culvert

Human &fauna by:

Ingestion,

Inhalation,

Skin absorption

River Tejo

Flora - by

root take up

Property

Pollution linkage example

source

Tejo estuary potential receptor

contaminated soil

unsaturated zone

saturated zone (aquifer)

ground water flow

leaching

Potential groundwater pollution linkage

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

Leakage had occurred from some underground tanks

The soil contaminated with hydrocarbons was placed in windrows on polythene sheeting

Validation sampling after removal of extent of assumed contamination

Location Ref. Description Comments

VS 1 Weigh bridge This location was found to be free from contamination.

VS 2Above-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 3Below-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 4Gravel catchment pit

area This location was found to be free from contamination.

VS 5Below-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 This location was found to be free from contamination.

VS 6b (water and soils)

Water holding tank (ETAR)

With the exception of benzo(ghi)perylene and fluoranthene, the analytical laboratory reported concentrations of 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 taken from water that was found within this tank. Faecal streptococci, e-coli and other (total) coliforms were also 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 7Below-ground fuel

tank This location was found to be free from contamination.

VS 8Gravel catchment pit

area

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.

VS 9Below-ground fuel

tank

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).

VS 10 Pigment tank This location was found to be free from contamination.

VS 11 Settlement tank This location was found to be free from contamination.

Including the post remediation testing

The Validation Report was completed

And documentation to demonstrate appropriate disposal of potentially hazardous materials

Demonstrating the site’s suitability as a 75,000m2 retail and leisure development

GO Contaminated Land Solutions

We provide:

- A client focused environmental consultancy

- A project specific cost effective service

We have:- Considerable breadth of experience

- Some 15 years of working on projects involving contaminated land

- Gas works

- Petrol filling stations

- Sewage works

- Scrap yards

- Hospitals

- Industrial sites

- Water treatment works

- Potential unexploded ordnance

Experience includes the following:

This old water works required surveys of flora and fauna as well as a contaminated land remediation strategy.

Services include:

-Desk top studies

-Ecological surveys

-Remediation strategies

-Environmental impact assessments

- Retail

- Industrial

- Leisure

- Residential,

both with and without private gardens

And a variety of end uses:

GO Contaminated Land Solutions